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Sample records for boric acids

  1. Chronic boric acid poisoning in infants.

    OpenAIRE

    O`Sullivan, K.; Taylor, M.

    1983-01-01

    We report 7 infants suffering from seizures induced by chronic boric acid ingestion. The boric acid was given by dipping a soother in a proprietary borax and honey mixture. The babies have remained well since the mixture was withheld.

  2. Chronic boric acid poisoning in infants.

    Science.gov (United States)

    O'Sullivan, K; Taylor, M

    1983-09-01

    We report 7 infants suffering from seizures induced by chronic boric acid ingestion. The boric acid was given by dipping a soother in a proprietary borax and honey mixture. The babies have remained well since the mixture was withheld.

  3. Boric Acid in Kjeldahl Analysis

    Science.gov (United States)

    Cruz, Gregorio

    2013-01-01

    The use of boric acid in the Kjeldahl determination of nitrogen is a variant of the original method widely applied in many laboratories all over the world. Its use is recommended by control organizations such as ISO, IDF, and EPA because it yields reliable and accurate results. However, the chemical principles the method is based on are not…

  4. Nanoscale Properties of Boric Acid

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Nanoscale properties of boric acid were studied by using atomic force microscopy (AFM) and nanome-chanical testing system. XPS was used to research on the transform behaviors of H3BO3 at different temperatures.The crystal structure, surface morphology, and mechanical properties of H3BO3 were described. The results showthat H3BO3 has layered structure, and can be transformed to boron oxide at high temperature. In addition there area lot of defects in H3BO3 crystal.

  5. Boric acid and boronic acids inhibition of pigeonpea urease.

    Science.gov (United States)

    Reddy, K Ravi Charan; Kayastha, Arvind M

    2006-08-01

    Urease from the seeds of pigeonpea was competitively inhibited by boric acid, butylboronic acid, phenylboronic acid, and 4-bromophenylboronic acid; 4-bromophenylboronic acid being the strongest inhibitor, followed by boric acid > butylboronic acid > phenylboronic acid, respectively. Urease inhibition by boric acid is maximal at acidic pH (5.0) and minimal at alkaline pH (10.0), i.e., the trigonal planar B(OH)3 form is a more effective inhibitor than the tetrahedral B(OH)4 -anionic form. Similarly, the anionic form of phenylboronic acid was least inhibiting in nature.

  6. Lubrication from mixture of boric acid with oils and greases

    Science.gov (United States)

    Erdemir, Ali

    1995-01-01

    Lubricating compositions including crystalline boric acid and a base lubricant selected from oils, greases and the like. The lubricity of conventional oils and greases can also be improved by adding concentrates of boric acid.

  7. Boric acid ovicidal trap for the management of Aedes species

    Directory of Open Access Journals (Sweden)

    L Charlet Bhami

    2015-01-01

    Interpretation & conclusion: Boric acid is less toxic compared to different pesticides, and in low concentrations, it attracts the ovipositing female Aedes sp as well as fertile males. Dilute boric acid solution is an effective ovitrap since the eggs laid by mosquitoes either die or the larvae that hatch out from them do not survive in boric acid. Boric acid kills the males that come in contact with the solution, which are attracted to the trap by the females hovering around.

  8. Thermal properties of epoxy composites filled with boric acid

    Science.gov (United States)

    Visakh, P. M.; Nazarenko, O. B.; Amelkovich, Yu A.; Melnikova, T. V.

    2015-04-01

    The thermal properties of epoxy composites filled with boric acid fine powder at different percentage were studied. Epoxy composites were prepared using epoxy resin ED-20, boric acid as flame-retardant filler, hexamethylenediamine as a curing agent. The prepared samples and starting materials were examined using methods of thermal analysis, scanning electron microscopy and infrared spectroscopy. It was found that the incorporation of boric acid fine powder enhances the thermal stability of epoxy composites.

  9. Thermal properties of epoxy composites filled with boric acid

    OpenAIRE

    Visakh, P. M.; Nazarenko, Olga Bronislavovna; Amelkovich, Yuliya Alexandrovna; Melnikova, T. V.

    2015-01-01

    The thermal properties of epoxy composites filled with boric acid fine powder at different percentage were studied. Epoxy composites were prepared using epoxy resin ED-20, boric acid as flame-retardant filler, hexamethylenediamine as a curing agent. The prepared samples and starting materials were examined using methods of thermal analysis, scanning electron microscopy and infrared spectroscopy. It was found that the incorporation of boric acid fine powder enhances the thermal stability of ep...

  10. Chemical Reaction between Boric Acid and Phosphine Indicates Boric Acid as an Antidote for Aluminium Phosphide Poisoning

    Directory of Open Access Journals (Sweden)

    Motahareh Soltani

    2016-08-01

    Full Text Available Objectives: Aluminium phosphide (AlP is a fumigant pesticide which protects stored grains from insects and rodents. When it comes into contact with moisture, AlP releases phosphine (PH3, a highly toxic gas. No efficient antidote has been found for AlP poisoning so far and most people who are poisoned do not survive. Boric acid is a Lewis acid with an empty p orbital which accepts electrons. This study aimed to investigate the neutralisation of PH3 gas with boric acid. Methods: This study was carried out at the Baharlou Hospital, Tehran University of Medical Sciences, Tehran, Iran, between December 2013 and February 2014. The volume of released gas, rate of gas evolution and changes in pH were measured during reactions of AlP tablets with water, acidified water, saturated boric acid solution, acidified saturated boric acid solution, activated charcoal and acidified activated charcoal. Infrared spectroscopy was used to study the resulting probable adduct between PH3 and boric acid. Results: Activated charcoal significantly reduced the volume of released gas (P <0.01. Although boric acid did not significantly reduce the volume of released gas, it significantly reduced the rate of gas evolution (P <0.01. A gaseous adduct was formed in the reaction between pure AlP and boric acid. Conclusion: These findings indicate that boric acid may be an efficient and non-toxic antidote for PH3 poisoning.

  11. Chemical Reaction between Boric Acid and Phosphine Indicates Boric Acid as an Antidote for Aluminium Phosphide Poisoning

    Science.gov (United States)

    Soltani, Motahareh; Shetab-Boushehri, Seyed F.; Shetab-Boushehri, Seyed V.

    2016-01-01

    Objectives: Aluminium phosphide (AlP) is a fumigant pesticide which protects stored grains from insects and rodents. When it comes into contact with moisture, AlP releases phosphine (PH3), a highly toxic gas. No efficient antidote has been found for AlP poisoning so far and most people who are poisoned do not survive. Boric acid is a Lewis acid with an empty p orbital which accepts electrons. This study aimed to investigate the neutralisation of PH3 gas with boric acid. Methods: This study was carried out at the Baharlou Hospital, Tehran University of Medical Sciences, Tehran, Iran, between December 2013 and February 2014. The volume of released gas, rate of gas evolution and changes in pH were measured during reactions of AlP tablets with water, acidified water, saturated boric acid solution, acidified saturated boric acid solution, activated charcoal and acidified activated charcoal. Infrared spectroscopy was used to study the resulting probable adduct between PH3 and boric acid. Results: Activated charcoal significantly reduced the volume of released gas (P <0.01). Although boric acid did not significantly reduce the volume of released gas, it significantly reduced the rate of gas evolution (P <0.01). A gaseous adduct was formed in the reaction between pure AlP and boric acid. Conclusion: These findings indicate that boric acid may be an efficient and non-toxic antidote for PH3 poisoning. PMID:27606109

  12. Influence of boric acid additive size on green lubricant performance.

    Science.gov (United States)

    Lovell, Michael R; Kabir, M A; Menezes, Pradeep L; Higgs, C Fred

    2010-10-28

    As the industrial community moves towards green manufacturing processes, there is an increased demand for multi-functional, environmentally friendly lubricants with enhanced tribological performance. In the present investigation, green (environmentally benign) lubricant combinations were prepared by homogeneously mixing nano- (20 nm), sub-micrometre- (600 nm average size) and micrometre-scale (4 μm average size) boric acid powder additives with canola oil in a vortex generator. As a basis for comparison, lubricants of base canola oil and canola oil mixed with MoS(2) powder (ranging from 0.5 to 10 μm) were also prepared. Friction and wear experiments were carried out on the prepared lubricants using a pin-on-disc apparatus under ambient conditions. Based on the experiments, the nanoscale (20 nm) particle boric acid additive lubricants significantly outperformed all of the other lubricants with respect to frictional and wear performance. In fact, the nanoscale boric acid powder-based lubricants exhibited a wear rate more than an order of magnitude lower than the MoS(2) and larger sized boric acid additive-based lubricants. It was also discovered that the oil mixed with a combination of sub-micrometre- and micrometre-scale boric acid powder additives exhibited better friction and wear performance than the canola oil mixed with sub-micrometre- or micrometre-scale boric acid additives alone.

  13. The Acid-Base Titration of a Very Weak Acid: Boric Acid

    Science.gov (United States)

    Celeste, M.; Azevedo, C.; Cavaleiro, Ana M. V.

    2012-01-01

    A laboratory experiment based on the titration of boric acid with strong base in the presence of d-mannitol is described. Boric acid is a very weak acid and direct titration with NaOH is not possible. An auxiliary reagent that contributes to the release of protons in a known stoichiometry facilitates the acid-base titration. Students obtain the…

  14. Surface interactions of cesium and boric acid with stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Grossman-Canfield, N.

    1995-08-01

    In this report, the effects of cesium hydroxide and boric acid on oxidized stainless steel surfaces at high temperatures and near one atmosphere of pressure are investigated. This is the first experimental investigation of this chemical system. The experimental investigations were performed using a mass spectrometer and a mass electrobalance. Surfaces from the different experiments were examined using a scanning electron microscope to identify the presence of deposited species, and electron spectroscopy for chemical analysis to identify the species deposited on the surface. A better understanding of the equilibrium thermodynamics, the kinetics of the steam-accelerated volatilizations, and the release kinetics are gained by these experiments. The release rate is characterized by bulk vaporization/gas-phase mass transfer data. The analysis couples vaporization, deposition, and desorption of the compounds formed by cesium hydroxide and boric acid under conditions similar to what is expected during certain nuclear reactor accidents. This study shows that cesium deposits on an oxidized stainless steel surface at temperatures between 1000 and 1200 Kelvin. Cesium also deposits on stainless steel surfaces coated with boric oxide in the same temperature ranges. The mechanism for cesium deposition onto the oxide layer was found to involve the chemical reaction between cesium and chromate. Some revaporization in the cesium hydroxide-boric acid system was observed. It has been found that under the conditions given, boric acid will react with cesium hydroxide to form cesium metaborate. A model is proposed for this chemical reaction.

  15. 40 CFR 721.3032 - Boric acid (H3BO2), zinc salt.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid (H3BO2), zinc salt. 721... Substances § 721.3032 Boric acid (H3BO2), zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO2), zinc salt (PMN...

  16. Influence of boric acid on electrospray ionization efficiency.

    Science.gov (United States)

    Rebane, Riin; Herodes, Koit

    2012-01-01

    Liquid chromatography electrospray ionization mass-spectrometry (LC-ESI-MS) was used to analyze 9-fluorenylmethylmethoxycarbonyl chloride (Fmoc-Cl) and diethyl ethoxymethylenemalonate (Deemm) derivatives of three amino acids and five other compounds. Influence of boric acid on their ionization was investigated and dramatic impact on the signal was observed. The strongest signal suppression (6% of signal remains) was observed for the Deemm derivative of beta-Alanine (with ammonium acetate in eluent). With only formic acid as the eluent pH modifier, signal enhancement was observed, being largest for Fmoc-Cl derivative of Phenylalanine, 267%. Investigation of the influence of boric acid shows that it is a possible signal enhancer for LC-ESI-MS analysis.

  17. Synthesis of Enriched 10B Boric Acid of Nuclear Grade

    Institute of Scientific and Technical Information of China (English)

    张雷; 张卫江; 徐姣; 任新

    2014-01-01

    An economic and effective method of preparing enriched 10B boric acid was established by chemical reac-tion of enriched 10BF3 and CaCO3. A process of boron trifluoride reacting with water was investigated under certain conditions. Calcium carbonate was selected to counteract hydrofluoric acid followed on. Some key operation factors were investigated, such as temperature, reaction time and the ratio of CaCO3 to 10BF3. The results showed that the yield of enriched 10B boric acid could reach 97. 2%and the purity was up to 94. 1%under the following conditions:the tem-perature was 50—60,℃, the reaction time was 28 h and the ratio of CaCO3 to 10BF3 was 4. In addition, after recrystal-lization and titration analysis, the purity of the product could reach over 99. 2%from 94.1%.

  18. Zinc-Nickel Codeposition in Sulfate Solution Combined Effect of Cadmium and Boric Acid

    Directory of Open Access Journals (Sweden)

    Y. Addi

    2011-01-01

    Full Text Available The combined effect of cadmium and boric acid on the electrodeposition of zinc-nickel from a sulfate has been investigated. The presence of cadmium ion decreases zinc in the deposit. In solution, cadmium inhibits the zinc ion deposition and suppresses it when deposition potential value is more negative than −1.2 V. Low concentration of CdSO4 reduces the anomalous nature of Zn-Ni deposit. Boric acid decreases current density and shifts potential discharge of nickel and hydrogen to more negative potential. The combination of boric acid and cadmium increases the percentage of nickel in the deposit. Boric acid and cadmium.

  19. Effect of boric acid supplementation of ostrich water on the expression of Foxn1 in thymus.

    Science.gov (United States)

    Xiao, Ke; Ansari, Abdur Rahman; Rehman, Zia Ur; Khaliq, Haseeb; Song, Hui; Tang, Juan; Wang, Jing; Wang, Wei; Sun, Peng-Peng; Zhong, Juming; Peng, Ke-Mei

    2015-11-01

    Foxn1 is essential for thymus development. The relationship between boric acid and thymus development, optimal dose of boric acid in ostrich diets, and the effects of boric acid on the expression of Foxn1 were investigated in the present study. Thirty healthy ostriches were randomly divided into six groups: Group I, II, III, IV, V, VI, and supplemented with boric acid at the concentration of 0 mg/L, 40 mg/L, 80 mg/L, 160 mg/L, 320 mg/L, 640 mg/L, respectively. The histological changes in thymus were observed by HE staining, and the expression of Foxn1 analyzed by immunohistochemistry and western blot. TUNEL method was used to label the apoptotic cells. Ostrich Foxn1 was sequenced by Race method. The results were as following: Apoptosis in ostrich thymus was closely related with boric acid concentrations. Low boric acid concentration inhibited apoptosis in thymus, but high boric acid concentration promoted apoptosis. Foxn1-positive cells were mainly distributed in thymic medulla and rarely in cortex. Foxn1 is closely related to thymus growth and development. The nucleotide sequence and the encoded protein of Foxn1 were 2736 bases and 654 amino acids in length. It is highly conserved as compared with other species. These results demonstrated that the appropriate boric acid supplementation in water would produce positive effects on the growth development of ostrich thymus by promoting Foxn1 expression, especially at 80 mg/L, and the microstructure of the thymus of ostrich fed 80 mg/L boric acid was well developed. The supplementation of high dose boron (>320 mg/L) damaged the microstructure of thymus and inhibited the immune function by inhibiting Foxn1 expression, particularly at 640 mg/L. The optimal dose of boric acid supplementation in ostrich diets is 80 mg/L boric acid. The genomic full-length of African ostrich Foxn1 was cloned for the first time in the study.

  20. PERIODS OF VERTEBRAL COLUMN SENSITIVITY TO BORIC ACID TREATMENT IN CD-1 MICE IN UTERO

    Science.gov (United States)

    Periods of vertebral column sensitivity to boric acid treatment in CD-1 mice in utero.Cherrington JW, Chernoff N.Department of Toxicology, North Carolina State University, Raleigh, NC 27695, USA. jana_cherrington@hotmail.comBoric acid (BA) has many uses as...

  1. Boric acid equilibria in near-critical and supercritical water

    Energy Technology Data Exchange (ETDEWEB)

    Wofford, W.T.; Gloyna, E.F.; Johnston, K.P. [Univ. of Texas, Austin, TX (United States)

    1998-05-01

    Greater knowledge of acid-base equilibria is crucial to understanding the chemistry of hydrothermal processes including oxidation of organics, corrosion, catalysis, hydrolysis reactions, crystal growth and formation, precipitation of metal complexes and steam power cycles. The pH values of aqueous solutions of boric acid and KOH were measured with the optical indicator 2-naphthol at temperatures from 300 to 380 C. The equilibrium constant K{sub b}{sup {minus}1} for the reaction B(OH){sub 3} + OH{sup {minus}} = B(OH){sub 4}{sup {minus}} was determined from the pH measurements and correlated with a modified Born model. The titration curve for the addition of HCl to sodium borate exhibits strong acid-strong base behavior even at 350 C and 24.1 MPa. At these conditions, aqueous solutions of sodium borate buffer the pH at 9.6 {+-} 0.25.

  2. Radiolysis of Boric Acid Solutions under Mixed Thermal and Fast Neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Im, Heejung; Choi, Ke Chon; Yeon, Jeiwon; Song, Kyuseok; Jung Hoansung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    The thermal neutron irradiation of water samples containing neutron absorbers has not been published except for a paper reporting the experimental data obtained at high temperatures. However, irradiation or simulations of water and voluminous liquid samples with fast neutrons and gamma rays are frequently discussed in several published papers. Several water samples containing {sup 10}B-enriched boric acid, and natural and {sup 10}B-enriched mixed boric acids in the range of 0 to 2000 μg/mL for the function of {sup 10}B concentration, were irradiated to study the radiolysis of the cooling water containing boric acid. The concentration of natural boron in the primary coolant of pressurized water reactors (PWRs) is known to start at 1500 μg/mL, and boric acid is used for the purpose of nuclear reaction control.

  3. An efficient synthesis of 1,5-benzodiazepine derivatives catalyzed by boric acid

    Institute of Scientific and Technical Information of China (English)

    Xin Zhou; Mei Yue Zhang; Shu Tao Gao; Jing Jun Ma; Chun Wang; Chao Liu

    2009-01-01

    1,5-Benzodiazepine derivatives have been synthesized by the condensation of o-phenylenediamines and ketones in the presence of boric acid as catalyst under mild conditions. This method is simple, environmentally benign and high yielding.

  4. Preparation and characterization of (10)B boric acid with high purity for nuclear industry.

    Science.gov (United States)

    Zhang, Weijiang; Liu, Tianyu; Xu, Jiao

    2016-01-01

    Boric acid is often added into coolant as neutron capture agent for pressurized water reactor, whose amount is influenced by its abundance and purity. Therefore, the preparation of enriched (10)B boric acid with high purity is beneficial to nuclear industry. (10)B is also used in developing tumor-specific boronated drugs in boron neutron capture therapy. The boronated drug can be administered to patient intravenously, intratumorally, or deposited at tumor site in surgical excision. Thus, enriched (10)B boric acid is of practical significance in the field of medicine. Self-made boron trifluoride-methanol-complex solution was selected as one of the experimental reagents, and the preparation of (10)B acid was realized by one-step reaction for the complexes with water and calcium chloride. The determination of electrical conductivity in reaction process proves that the optimum reaction time was 16-20 h. Furthermore, the effect of reaction time, ratio of calcium chloride to complex as well as the amount of water on the purity and yield of boric acid was investigated. Finally, the optimum reaction time was 20 h, the optimal solid-liquid ratio (molar ratio) was 3:1, and the amount of water was 1 L of deionized water for each mol of the complex. H2O2 was added in the reaction process to remove Fe(2+). After recrystallization, IR spectra of (10)B boric acid was measured and compared with standard to verify the product of boric acid. The feasibility of the preparation method was determined by the detection of XRD of boric acid. To observe the morphology by polarizing microscope, crystal structure was obtained. The purity of the final product is 99.95 %, and the yield is 96.47 %. The ion concentration of boric acid accords with the national standard of high purity, which was determined by ICP.

  5. Rapid accurate isotopic measurements on boron in boric acid and boron carbide.

    Science.gov (United States)

    Duchateau, N L; Verbruggen, A; Hendrickx, F; De Bièvre, P

    1986-04-01

    A procedure is described whereby rapid and accurate isotopic measurements can be performed on boron in boric acid and boron carbide after fusion of these compounds with calcium carbonate. It allows the determination of the isotopic composition of boron in boric acid and boron carbide and the direct assay of boron or the (10)B isotope in boron carbide by isotope-dilution mass spectrometry.

  6. Preparation and Characterization of High Purity Enriched10B Boric Acid via Anti-Solvent Recrystallization

    Institute of Scientific and Technical Information of China (English)

    张卫江; 刘天雨; 徐姣

    2016-01-01

    Self-made enriched10B boric acid as raw material was purified by recrystallization. The effects of final crystallization temperature, crystallization time, stirring speed, crystallization frequency and other factors on the purity were investigated. The appropriate operating condition was that the final crystallization temperature and time were 5,℃and 10 h respectively under a low-speed stirring for crystallizing twice, which would make the purity and yield of boric acid reach 99.94% and 95.36%, respectively. Taking this as foundation, recrystallization process was optimized with acetone as anti-solvent, whose amount was the most important index. The boric acid solution was added into acetone and recrystallized under the same condition, and the purity and yield of boric acid would reach 99.98% and 99.61%, respectively. The product detected by XRD was confirmed as boric acid crystal. Main ion concentration in the product was detected by ICP, which basically met the national standard of high purity. Crystal morphology of boric acid was observed by SEM.

  7. Removal of Aqueous Boron by Using Complexation of Boric Acid with Polyols: A Raman Spectroscopic Study

    Energy Technology Data Exchange (ETDEWEB)

    Eom, Ki Heon; Jeong, Hui Cheol; An, Hye Young; Lim, Jun-Heok; Lee, Jea-Keun; Won, Yong Sun [Pukyong National University, Busan (Korea, Republic of)

    2015-12-15

    Boron is difficult to be removed from seawater by simple RO (reverse osmosis) membrane process, because the size of boric acid (B(OH){sub 3}), the major form of aqueous boron, is as small as the nominal pore size of RO membrane. Thus, the complexation of boric acid with polyols was suggested as an alternative way to increase the size of aqueous boron compounds and the complexation behavior was investigated with Raman spectroscopy. As a reference, the Raman peak for symmetric B-O stretching vibrational mode both in boric acid and borate ion (B(OH){sub 4}{sup -}) was selected. A Raman peak shift (877 cm{sup -1} →730 cm{sup -1}) was observed to confirm that boric acid in water is converted to borate ion as the pH increases, which is also correctly predicted by frequency calculation. Meanwhile, the Raman peak of borate ion (730 cm{sup -1}) did not appear as the pH increased when polyols were applied into aqueous solution of boric acid, suggesting that the boric acid forms complexing compounds by combining with polyols.

  8. Boric acid as reference substance: pros, cons and standardization.

    Science.gov (United States)

    Amorim, M J B; Natal-da-Luz, T; Sousa, J P; Loureiro, S; Becker, L; Römbke, J; Soares, A M V M

    2012-04-01

    Boric acid (BA) has been successfully used as reference substance in some standard test guidelines. Due to the fact that previously selected reference substances present a significant risk to human health and/or are banned for environmental reasons, BA is being discussed for broader adoption in OECD or ISO guidelines. To provide input on BA data and contribute to the discussion on its suitability as a reference substance, in the present study BA was tested with two standard soil organisms, Enchytraeus albidus and Folsomia candida, in terms of survival, reproduction and avoidance. Additionally, published data on other organisms was analysed to derive the most sensitive soil dwelling invertebrate (hazard concentration-HC5). Results showed that BA affected the tested organisms, being two times more toxic for collembolans (LC50 = 96; EC50 = 54 mg/kg) than for enchytraeids (LC50 = 325; EC50 = 104 mg/kg). No avoidance behaviour occurred despite the fact that BA affects earthworms. Actually, it is the recommended reference substance for the earthworm avoidance test. Clearly, the suitable performance of BA in one species should not be generalized to other species. Absolute toxicity is not an important criterion for the selection of a reference substance, but it has been proposed that effects should occur within a reasonable range, i.e. <1,000 mg/kg. We could confirm, compiling previous data that for most soil invertebrates, the EC50 is expected to be below 1,000 mg/kg. From these data it could be derived that the most sensitive soil dwelling invertebrate (HC5, 50%) is likely to be affected (EC10) at 28 (8-53) mg H(3)BO(3)/Kg, equivalent to 4.6 (1.4-8.7) mg boron/kg.

  9. Effect of Boric Acid on Properties of Calcined Flint Clay-Bauxite Castables

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; DAI Wenyong

    2010-01-01

    In order to prolong the working time of calcined flint clay-bauxite castables during construction at high temperature,boric acid was added into the castables.The effect of boric acid on working time and curing cold crushing strength of the castables at 25 ℃ and 35 ℃were investigated.After 24 h curing in mould and another 24 h curing at 110 ℃ after demoulding,the specimens were heat treated at 1 000 ℃,1 300 ℃,and1 500 ℃ for 3 h,respectively.The permanent linear change,bulk density,modulus of rupture,and cold crushing strength were determined.The result shows that there is no need to add boric acid when calcined flint clay-bauxite ca.stables works at 25 ℃ ; when calcined flint clay-bauxite castables works at 35 ℃,boric acid can increase the working time of the castables,but decrease the curing cold crushing strength a little.Adding boric acid into calcined flint clay-bauxite castables doesn' t worsen performance of the castablcs.

  10. Chloride stress corrosion cracking of Alloy 600 in boric acid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Berge, Ph. [Electricite de France, 92 - Paris la Defense (France); Noel, D.; Gras, J.M.; Prieux, B. [Electricite de France, 77 - Moret-sur-Loing (France). Direction des Etudes et Recherches

    1997-10-01

    The high nickel austenitic alloys are generally considered to have good resistance to chloride stress corrosion cracking. In the standard boiling magnesium chloride solution tests, alloys with more than 40% nickel are immune. Nevertheless, more recent data show that cracking can occur in both Alloys 600 and 690 if the solution is acidified. In other low pH media, such as boric acid solution at 100 deg C, transgranular and intergranular cracking are observed in Alloy 600 in the presence of minor concentrations of sodium chloride (2g/I). In concentrated boric acid at higher temperatures (250 and 290 deg C), intergranular cracking also occurs, either when the chloride concentration is high, or at low chloride contents and high oxygen levels. The role of pH and a possible specific action of boric acid are discussed, together with the influence of electrochemical potential. (author) 21 refs.

  11. CEC mechanism in electrochemical oxidation of nitrocatechol-boric acid complexes

    Energy Technology Data Exchange (ETDEWEB)

    Rafiee, Mohammad, E-mail: rafiee@iasbs.ac.ir [Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan (Iran, Islamic Republic of); Nematollahi, Davood; Salehzadeh, Hamid [Faculty of Chemistry, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of)

    2011-11-30

    Graphical abstract: Display Omitted Highlights: > Nitrochetechol and its anionic form undergo complex reaction with boric acid. > The electron transfer of complex is coupled with both proceeding and following chemical reactions. > Electrochemical behavior of complex is resolved by diagnostic criteria and digital simulation. - Abstract: The electrochemical behavior of nitrocatechols-boric acid complexes in aqueous solution has been studied using cyclic voltammetry. The results indicate that nitrocatechol-boric acid complex derivatives are involved in the CEC mechanism. In this work, the impact of empirical parameters on the shape of the voltammograms is examined based on a CEC mechanism. In addition, homogeneous rate constants of both the preceding and the following reactions were estimated by comparing the experimental cyclic voltammograms with the digitally simulated results. The calculated dissociation constants for the complexes (K{sub d}) and for ring cleavage of nitroquinone (k{sub f2}) were found to vary in the following order: 4-nitrocatechol > 3-methylnitrocatechol > 3-metoxynitrocatechol.

  12. Boric Acid Toxicity Trials on the Wood Borer Heterobostrychus aequalis Waterhouse (Coleoptera: Bostrychidae

    Directory of Open Access Journals (Sweden)

    Daljit K. Singh

    2011-01-01

    Full Text Available Problem statement: The Heterobostrychus aequalis Waterhouse was a serious pest lumber of timber heveawood. The H. aequalis infest and tunnel along the wood grain, depositing eggs, which concomitantly turn into larvae and reduces the wood starch to a soft powder. The objectives of the study were to establish a suitable method for preservative trials on the wood borer and access the toxicity levels of boric acid for controlling the H. aequalis infestation. Approach: The voracious H. aequalis was collected from infested heveawood, mated and cultured on cassava. The adult beetles were exposed to boric acid treated cassava blocks as pilot trials. The boric acid concentration used was 1-5% including a control. Each treatment consists of five replicates. The voracious of H. aequalis generation was cultured for obtaining its freshly new emerged adult by exposing a number of H. aequalis directly from infested heveawood into artificial diet block and cassava. The mortality, weight loss of the test blocks, frass discharge duration and numbers of holes caused by H. aequalis were observed. Results: The results showed that the H. aequalis infested tended to penetrate the film after wrapping the heveawood with a layer of transparent cling film for 24 h experiment. The H. aequalis larvae stock cultured collected from infested heveawood exhibited differences in colour, activeness and aggression among males and females. The suitable test block size used was (2.0×5.0×1.5 cm3. The freshly emerged voracious of H. aequalis adults was more suitable than the larvae for boric acid toxicity trials. The 2% concentration was sufficiently killed the 4% boric acid treated test blocks. There was no hole observed on 5% boric acid treated test block and hence these concentrations were not infested by H. aequalis due to absence of frass in exposed blocks. Conclusion/Recommendations: There are noticeable physical and behavioural differences between voracious

  13. Genotoxic effects of boric acid and borax in zebrafish, Danio rerio using alkaline comet assay

    OpenAIRE

    Gülsoy, Nagihan; Yavaş, Cüneyd; Mutlu, Özal

    2015-01-01

    The present study is conducted to determine the potential mechanisms of Boron compounds, boric acid (BA) and borax (BX), on genotoxicity of zebrafish Danio rerio for 24, 48, 72 and 96-hours acute exposure (level:1, 4, 16, 64 mg/l BA and BX) in semi-static bioassay experiment. For that purpose, peripheral erythrocytes were drawn from caudal vein and Comet assay was applied to assess genotoxicity. Acute (96 hours) exposure and high concentrations of boric acid and borax increases % tail DNA and...

  14. Decay resistance of wood treated with boric acid and tall oil derivates.

    Science.gov (United States)

    Temiz, Ali; Alfredsen, Gry; Eikenes, Morten; Terziev, Nasko

    2008-05-01

    In this study, the effect of two boric acid concentrations (1% and 2%) and four derivates of tall oil with varying chemical composition were tested separately and in combination. The tall oil derivates were chosen in a way that they consist of different amounts of free fatty, resin acids and neutral compounds. Decay tests using two brown rot fungi (Postia placenta and Coniophora puteana) were performed on both unleached and leached test samples. Boric acid showed a low weight loss in test samples when exposed to fungal decay before leaching, but no effect after leaching. The tall oil derivates gave better efficacy against decay fungi compared to control, but are not within the range of the efficacy needed for a wood preservative. Double impregnation with boric acid and tall oil derivates gave synergistic effects for several of the double treatments both in unleached and leached samples. In the unleached samples the double treatment gave a better efficacy against decay fungi than tall oil alone. In leached samples a better efficacy against brown rot fungi were achieved than in samples with boron alone and a nearly similar or better efficacy than for tall oil alone. Boric acid at 2% concentration combined with the tall oil derivate consisting of 90% free resin acids (TO-III) showed the best performance against the two decay fungi with a weight loss less than 3% after a modified pure culture test.

  15. Production of fired construction brick from high sulfate-containing fly ash with boric acid addition.

    Science.gov (United States)

    Başpinar, M Serhat; Kahraman, Erhan; Görhan, Gökhan; Demir, Ismail

    2010-01-01

    The increase of power plant capacity has led to the production of an increasing amount of fly ash that causes high environmental impact in Turkey. Some of the fly ash is utilized within the fired brick industry but high sulfate-containing fly ash creates severe problems during sintering of the fired brick. This study attempted to investigate the potential for converting high sulfate-containing fly ash into useful material for the construction industry by the addition of boric acid. The chemical and mineralogical composition of fly ash and clay were investigated. Boric acid (H(3)BO(3)) was added to fly ash-clay mixtures with up to 5 wt.%. Six different series of test samples were produced by uniaxial pressing. The samples were fired at the industrial clay-brick firing temperatures of 800, 900 and 1000 degrees C. The microstructures of the fired samples were investigated by scanning electron microscopy and some physical and mechanical properties were measured. It was concluded that the firing at conventional brick firing temperature of high sulfate fly ash without any addition of boric acid resulted in very weak strength bricks. The addition of boric acid and clay simultaneously to the high sulfate- containing fly ash brick dramatically increased the compressive strength of the samples at a firing temperature of 1000 degrees C by modifying the sintering behaviour of high sulfate fly ash.

  16. 40 CFR 721.1875 - Boric acid, alkyl and substituted alkyl esters (generic name).

    Science.gov (United States)

    2010-07-01

    ... alkyl esters (generic name). 721.1875 Section 721.1875 Protection of Environment ENVIRONMENTAL... esters (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance boric acid, alkyl and substituted alkyl esters (PMN P-86-1252) is subject to...

  17. Boric acid reduces axonal and myelin damage in experimental sciatic nerve injury

    Institute of Scientific and Technical Information of China (English)

    Zahir Kzlay; Haydar Ali Erken; Nesibe Kahraman etin; Serdar Akta; Burin rem Abas; Ali Ylmaz

    2016-01-01

    hTe aim of this study was to investigate the effects of boric acid in experimental acute sciatic nerve injury. Twenty-eight adult male rats were randomly divided into four equal groups (n = 7): control (C), boric acid (BA), sciatic nerve injury (I) , and sciatic nerve injury + boric acid treatment (BAI). Sciatic nerve injury was generated using a Yasargil aneurysm clip in the groups I and BAI. Boric acid was given four times at 100 mg/kg to rats in the groups BA and BAI atfer injury (by gavage at 0, 24, 48 and 72 hours) but no injury was made in the group BA.In vivo electrophysiological tests were performed at the end of the day 4 and sciatic nerve tissue samples were taken for histopathological examination. The amplitude of compound action potential, the nerve conduction velocity and the number of axons were signiifcantly lower and the myelin structure was found to be broken in group I compared with those in groups C and BA. However, the amplitude of the compound action potential, the nerve conduction velocity and the number of axons were signiifcantly greater in group BAI than in group I. Moreover, myelin injury was signiifcantly milder and the intensity of nuclear factor kappa B immunostaining was signiifcantly weaker in group BAI than in group I. hTe results of this study show that administration of boric acid at 100 mg/kg atfer sciatic nerve injury in rats markedly reduces myelin and axonal injury and improves the electrophysiological function of injured sciatic nerve possibly through alleviating oxidative stress reactions.

  18. Boric acid reduces axonal and myelin damage in experimental sciatic nerve injury

    Science.gov (United States)

    Kızılay, Zahir; Erken, Haydar Ali; Çetin, Nesibe Kahraman; Aktaş, Serdar; Abas, Burçin İrem; Yılmaz, Ali

    2016-01-01

    The aim of this study was to investigate the effects of boric acid in experimental acute sciatic nerve injury. Twenty-eight adult male rats were randomly divided into four equal groups (n = 7): control (C), boric acid (BA), sciatic nerve injury (I), and sciatic nerve injury + boric acid treatment (BAI). Sciatic nerve injury was generated using a Yasargil aneurysm clip in the groups I and BAI. Boric acid was given four times at 100 mg/kg to rats in the groups BA and BAI after injury (by gavage at 0, 24, 48 and 72 hours) but no injury was made in the group BA. In vivo electrophysiological tests were performed at the end of the day 4 and sciatic nerve tissue samples were taken for histopathological examination. The amplitude of compound action potential, the nerve conduction velocity and the number of axons were significantly lower and the myelin structure was found to be broken in group I compared with those in groups C and BA. However, the amplitude of the compound action potential, the nerve conduction velocity and the number of axons were significantly greater in group BAI than in group I. Moreover, myelin injury was significantly milder and the intensity of nuclear factor kappa B immunostaining was significantly weaker in group BAI than in group I. The results of this study show that administration of boric acid at 100 mg/kg after sciatic nerve injury in rats markedly reduces myelin and axonal injury and improves the electrophysiological function of injured sciatic nerve possibly through alleviating oxidative stress reactions. PMID:27904499

  19. Proposing Boric Acid as an Antidote for Aluminium Phosphide Poisoning by Investigation of the Chemical Reaction Between Boric Acid and Phosphine

    Directory of Open Access Journals (Sweden)

    Motahareh Soltani

    2013-01-01

    Full Text Available Aluminium phosphide (AlP is a storage fumigant pesticide, which is used to protect stored grains especially from insects and rodents. It releases phosphine (PH3 gas, a highly toxic mitochondrial poison, in contact with moisture, particularly if acidic. Although the exact mechanism of action is unknown so far, the major mechanism of PH3 toxicity seems to be the inhibition of cytochrome-c oxidase and oxidative phosphorylation which eventually results in adenosine triphosphate (ATP depletion and cell death. Death due to AlP poisoning seems to be as a result of myocardial damage. No efficient antidote has been found for AlP poisoning so far, and unfortunately, most of the poisoned human cases die. PH3, like ammonia (NH3, is a Lewis base with a lone-pair electron. However, boric acid (B(OH3 is a Lewis acid with an empty p orbital. It is predicted that lone-pair electron from PH3 is shared with the empty p orbital from B(OH3 and a compound forms in which boron attains its octet. In other words, PH3 is trapped and neutralised by B(OH3. The resulting polar reaction product seems to be excretable by the body due to hydrogen bonding with water molecules. The present article proposes boric acid as a non-toxic and efficient trapping agent and an antidote for PH3 poisoning by investigating the chemical reaction between them.

  20. Evaluation on degradation of cable in nuclear power plant by boric acid

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Munhwan; Song, Geundong; Kim, Yeonku; Maeng, Wanyoung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    Exposures to these conditions for long periods of times can cause a degradation of cable. Borated water is used in the primary systems of PWR plants to control the reactivity during normal plant operation and refueling, and under potential accident conditions. If borated water leaks from primary and secondary systems, significant corrosion problems can develop. However, little research has been carried out on the effects of cable degradation by borated water. In this experiment, TGA, indenting test, and FT-IR were performed to evaluate the degradation of cable by borated water. An evaluation of cable degradation by borated water was carried out. A TGA analysis, the measurement of cable microhardness and an FT-IR analysis before and after spraying with boric acid (B:170,000ppm). It is considered that there is no significant degradation of cables due to spraying with boric acid. More studies on long-term experiments for severe conditions are now progressing.

  1. Effect of boric acid sintering aid on densification of barium ferrite

    Indian Academy of Sciences (India)

    S S Vidyawathi; R Amaresh; L N Satapathy

    2002-11-01

    Boric acid has been added in 0.1–0.6% range for studying the densification characteristics of solid state sintered barium hexaferrite. Sintering studies have been carried out at three different temperatures. Physical properties like density and porosity have been studied for all compositions. The phase identification and microstructural investigation on the fractured surface have been carried out to understand the effect of sintering aid on the densification characteristics.

  2. General corrosion of metallic materials in boric acid environments; La corrosion generalisee des materiaux metalliques en milieu acide borique

    Energy Technology Data Exchange (ETDEWEB)

    Gras, J.M.

    1994-05-01

    Certain low-alloy steel components in PWR primary circuit were corroded by leaking water containing boric acid. A number of studies have been performed by manufacturers in the USA and by EDF in France to determine the rate of general corrosion for low-alloy steels in media containing varying concentrations of boric acid. The first part of this paper summarizes the studies performed and indicates how far work has advanced to date in establishing the resistance of stainless steels to general corrosion in concentrated boric acid solutions. The second part of the paper discusses the mechanism of corrosion and proposes a model. Carbon steels and low-alloy steels - carbon steels and low-alloy steels in deaerated diluted boric acid solutions (pH > 4) corrode very slowly (<20{mu}m/year). The corrosion rate is approximately 1 {mu}m/year in the nominal primary water in static conditions; - in non-deaerated solutions, the corrosion rate is determined by the solubility of iron. Important factors are the pH, the temperature and the operating conditions, which determine the iron solubility in the medium: the rate of renewal of the medium or the S/V ratio of the metal surface exposed to the volume of solution. The steel composition is not a determinant factor. Stainless steels. General corrosion of stainless steels in concentrated boric acid solutions depends primarily on their chromium content. Steels containing less than 15% chromium offer excellent resistance to corrosion regardless of their structure or nickel content. The corrosion rate is less than 10 {mu}m/year at 250 deg C and approximately 40 {mu}m/year at 300 deg C. Steels containing 13% chromium corrode in hot concentrated media. The apparent activation energy of general corrosion is approximately 25 kJ.mol{sup -1}. (author). 31 refs., 12 figs., 13 tabs.

  3. Inhibition studies of soybean (Glycine max) urease with heavy metals, sodium salts of mineral acids, boric acid, and boronic acids.

    Science.gov (United States)

    Kumar, Sandeep; Kayastha, Arvind M

    2010-10-01

    Various inhibitors were tested for their inhibitory effects on soybean urease. The K(i) values for boric acid, 4-bromophenylboronic acid, butylboronic acid, and phenylboronic acid were 0.20 +/- 0.05 mM, 0.22 +/- 0.04 mM, 1.50 +/- 0.10 mM, and 2.00 +/- 0.11 mM, respectively. The inhibition was competitive type with boric acid and boronic acids. Heavy metal ions including Ag(+), Hg(2+), and Cu(2+) showed strong inhibition on soybean urease, with the silver ion being a potent inhibitor (IC(50) = 2.3 x 10(-8) mM). Time-dependent inhibition studies exhibited biphasic kinetics with all heavy metal ions. Furthermore, inhibition studies with sodium salts of mineral acids (NaF, NaCl, NaNO(3), and Na(2)SO(4)) showed that only F(-) inhibited soybean urease significantly (IC(50) = 2.9 mM). Competitive type of inhibition was observed for this anion with a K(i) value of 1.30 mM.

  4. Extreme Activity of Drug Nanocrystals Coated with A Layer of Non-Covalent Polymers from Self-Assembled Boric Acid

    Science.gov (United States)

    Zhan, Honglei; Liang, Jun F.

    2016-12-01

    Non-covalent polymers have remarkable advantages over synthetic polymers for wide biomedical applications. In this study, non-covalent polymers from self-assembled boric acid were used as the capping reagent to replace synthetic polymers in drug crystallization. Under acidic pH, boric acid self-assembled on the surface of drug nanocrystals to form polymers with network-like structures held together by hydrogen bonds. Coating driven by boric acid self-assembly had negligible effects on drug crystallinity and structure but resulted in drug nanocrystals with excellent dispersion properties that aided in the formation of a more stable suspension. Boric acid coating improved drug stability dramatically by preventing drug molecules from undergoing water hydrolysis in a neutral environment. More importantly, the specific reactivity of orthoboric groups to diols in cell glycocalyx facilitated a rapid cross-membrane translocation of drug nanocrystals, leading to efficient intracellular drug delivery, especially on cancer cells with highly expressed sialic acids. Boric acid coated nanocrystals of camptothecin, an anticancer drug with poor aqueous solubility and stability, demonstrated extreme cytotoxic activity (IC50 drug delivery field.

  5. Evaluation of commercial boric acid containing vials for urine culture: Low risk of contamination and cost effectiveness considerations

    Directory of Open Access Journals (Sweden)

    Suma B Appannanavar

    2013-01-01

    Full Text Available Background: Urine culture is a gold standard in the diagnosis of urinary tract infection. Clean catch midstream urine collection and prompt transportation is essential for appropriate diagnosis. Improper collection and delay in transportation leads to diagnostic dilemma. In developing countries, higher ambient temperatures further complicate the scenario. Here, we have evaluated the role of boric acid as a preservative for urine samples prior to culture in female patients attending outpatient department at our center. Materials and Method: Consecutive 104 urine samples were cultured simultaneously in plain uricol (Control-C and boric acid containing tubes from Becton Dickinson urine culture kit (Boric acid group-BA. Results: In the real-time evaluation, we found that in almost 57% (59/104 of the urine samples tested, it was more effective in maintaining the number of the organisms as compared to samples in the container without any preservative. Our in vitro study of simulated urine cultures revealed that urine samples could be kept up to 12 h before culture in the preservative without any inhibitory effect of boric acid. Though the use of boric acid kit may marginally increase the initial cost but has indirect effects like preventing delays in treatment and avoidance of false prescription of antibiotics. If the man-hours spent on repeat investigations are also taken into consideration, then the economic cost borne by the laboratory would also decrease manifold with the use of these containers.

  6. Effect of Silica Sol on Boric-sulfuric Acid Anodic Oxidation of LY12CZ Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    LIU Hui-cong

    2016-07-01

    Full Text Available Aluminum alloy anodizing coatings were prepared for LY12CZ in the boric-sulfuric acid solution (45g/L sulfuric acid,8g/L boric acid with the addition of 10%,20%,30% (volume fractionsilica sol,with the gradient voltage of 15V. The current and voltage transients of the anodizing process were collected by data collection instrument. The surface morphologies,microstructure and chemical composition of the anodic coatings were characterized by scanning electron microscopy (SEM. The corrosion resistance was examined by neutral salt spray,electrochemical impedance spectroscopy (EIS test and titrating test. The results show that the different concentration of silica sol addition can influence the forming and dissolution of anodizing coatings,improve the compactness smoothness and corrosion resistance during the anodizing process in the boric-sulfuric acid solution.

  7. Boric acid as a mobile phase additive for high performance liquid chromatography separation of ribose, arabinose and ribulose.

    Science.gov (United States)

    De Muynck, Cassandra; Beauprez, Joeri; Soetaert, Wim; Vandamme, Erick J

    2006-01-01

    A new high performance liquid chromatographic (HPLC) method is described for the analysis of ribose, arabinose and ribulose mixtures obtained from (bio)chemical isomerization processes. These processes gain importance since the molecules can be used for the synthesis of antiviral therapeutics. The HPLC method uses boric acid as a mobile phase additive to enhance the separation on an Aminex HPX-87K column. By complexing with boric acid, the carbohydrates become negatively charged, thus elute faster from the column by means of ion exlusion and are separated because the complexation capacity with boric acid differs from one carbohydrate to another. Excellent separation between ribose, ribulose and arabinose was achieved with concentrations between 0.1 and 10 gL(-1) of discrete sugar.

  8. Is Boric Acid Toxic to Reproduction in Humans? Assessment of the Animal Reproductive Toxicity Data and Epidemiological Study Results.

    Science.gov (United States)

    Duydu, Yalçın; Başaran, Nurşen; Ustündağ, Aylin; Aydın, Sevtap; Undeğer, Ulkü; Ataman, Osman Yavuz; Aydos, Kaan; Düker, Yalçın; Ickstadt, Katja; Waltrup, Brita Schulze; Golka, Klaus; Bolt, Hermann Maximilian

    2016-01-01

    Boric acid and sodium borates are classified as toxic to reproduction in the CLP Regulation under "Category 1B" with the hazard statement of "H360FD". This classification is based on the reprotoxic effects of boric acid and sodium borates in animal experiments at high doses. However, boron mediated reprotoxic effects have not been proven in epidemiological studies so far. The epidemiological study performed in Bandırma boric acid production plant is the most comprehensive published study in this field with 204 voluntarily participated male workers. Sperm quality parameters (sperm morphology, concentration and motility parameters), FSH, LH and testosterone levels were determined in all participated employees as the reproductive toxicity biomarkers of males. However, boron mediated unfavorable effects on reproduction in male workers have not been determined even in the workers under very high daily boron exposure (0.21 mg B/kg-bw/day) conditions. The NOAEL for rat reproductive toxicity is equivalent to a blood boron level of 2020 ng/g. This level is higher than the mean blood boron concentration (223.89 ± 69.49 ng/g) of the high exposure group workers in Bandırma boric acid production plant (Turkey) by a factor of 9. Accordingly, classifying boric acid and sodium borates under "Category 1B" as "presumed reproductive human toxicant in the CLP regulation seems scientifically not reasonable. The results of the epidemiological studies (including the study performed in China) support for a down-classification of boric acid from the category 1B, H360FD to category 2, H361d, (suspected of damaging the unborn child).

  9. 40 CFR 721.1730 - Poly(oxy-1,2-ethanediyl), α-butyl-ω-hydroxy, ester with boric acid (H3BO3).

    Science.gov (United States)

    2010-07-01

    ...-hydroxy, ester with boric acid (H3BO3). 721.1730 Section 721.1730 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-butyl-ω-hydroxy, ester with...

  10. 40 CFR 721.1731 - Poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with boric acid (H3BO3).

    Science.gov (United States)

    2010-07-01

    ...-hydroxy, ester with boric acid (H3BO3). 721.1731 Section 721.1731 Protection of Environment ENVIRONMENTAL..., ester with boric acid (H3BO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as poly(oxy-1,2-ethanediyl), α-methyl-ω-hydroxy, ester with...

  11. Ecotoxicity of boric acid in standard laboratory tests with plants and soil organisms.

    Science.gov (United States)

    Princz, Juliska; Becker, Leonie; Scheffczyk, Adam; Stephenson, Gladys; Scroggins, Rick; Moser, Thomas; Römbke, Jörg

    2017-03-17

    To verify the continuous sensitivity of ecotoxicological tests (mainly the test organisms), reference substances with known toxicity are regularly tested. Ideally, this substance(s) would lack specificity in its mode action, be bioavailable and readily attainable with cost-effective means of chemical characterization. Boric acid has satisfied these criteria, but has most recently been characterized as a substance of very high concern, due to reproductive effects in humans, thus limiting its recommendation as an ideal reference toxicant. However, there is probably no other chemical for which ecotoxicity in soil has been so intensively studied; an extensive literature review yielded lethal (including avoidance) and sublethal data for 38 taxa. The ecotoxicity data were evaluated using species sensitivity distributions, collectively across all taxa, and separately according to species type, endpoints, soil type and duration. The lack of specificity in the mode of action yielded broad toxicity among soil taxa and soil types, and provided a collective approach to assessing species sensitivity, while taking into consideration differences in test methodologies and exposure durations. Toxicity was species-specific with Folsomia candida and enchytraied species demonstrating the most sensitivity; among plants, the following trend occurred: dicotyledonous (more sensitive) ≫ monocotyledonous ≫ gymnosperm species. Sensitivity was also time and endpoint specific, with endpoints such as lethality and avoidance being less sensitive than reproduction effects. Furthermore, given the breadth of data and toxicity demonstrated by boric acid, lessons learned from its evaluation are discussed to recommend the properties required by an ideal reference substance for the soil compartment.

  12. Equilibrium studies of cellulase aggregates in presence of ascorbic and boric acid.

    Science.gov (United States)

    Iram, Afshin; Amani, Samreen; Furkan, Mohammad; Naeem, Aabgeena

    2013-01-01

    The aggregate formation of cellulase was detected at 300 and 10 mM ascorbic and boric acid respectively. These aggregates showed reduced enzyme activity, loss in near-UV signal, decrease tryptophan and ANS fluorescence. They possess increase in non-native β-sheet structure as evident from far-UV CD and FTIR spectra, large hydrodynamic radii, increase thioflavin T fluorescence and shift in Congo red. Cellulase at 90 mM ascorbic acid exists as molten globule with retention of secondary structure, altered tryptophan environment, high ANS binding and loss in tertiary structure. Ascorbic acid acts as an antioxidant up to 90 mM and beyond this as a pro-oxidant.

  13. Nonclinical safety evaluation of boric acid and a novel borate-buffered contact lens multi-purpose solution, Biotrue™ multi-purpose solution.

    Science.gov (United States)

    Lehmann, David M; Cavet, Megan E; Richardson, Mary E

    2010-12-01

    Multipurpose solutions (MPS) often contain low concentrations of boric acid as a buffering agent. Limited published literature has suggested that boric acid and borate-buffered MPS may alter the corneal epithelium; an effect attributed to cytotoxicity induced by boric acid. However, this claim has not been substantiated. We investigated the effect of treating cells with relevant concentrations of boric acid using two cytotoxicity assays, and also assessed the impact of boric acid on corneal epithelial barrier function by measuring TEER and immunostaining for tight junction protein ZO-1 in human corneal epithelial cells. Boric acid was also assessed in an in vivo ocular model when administered for 28 days. Additionally, we evaluated Biotrue multi-purpose solution, a novel borate-buffered MPS, alone and with contact lenses for ocular compatibility in vitro and in vivo. Boric acid passed both cytotoxicity assays and did not alter ZO-1 distribution or corneal TEER. Furthermore, boric acid was well-tolerated on-eye following repeated administration in a rabbit model. Finally, Biotrue multi-purpose solution demonstrated good ocular biocompatibility both in vitro and in vivo. This MPS was not cytotoxic and was compatible with the eye when administered alone and when evaluated with contact lenses. We demonstrate that boric acid and a borate-buffered MPS is compatible with the ocular environment. Our findings provide evidence that ocular effects reported for some borate-buffered MPS may be incorrectly attributed to boric acid and are more likely a function of the unique combination of ingredients in the MPS formulation tested.

  14. Molecular complexes of alprazolam with carboxylic acids, boric acid, boronic acids, and phenols. Evaluation of supramolecular heterosynthons mediated by a triazole ring.

    Science.gov (United States)

    Varughese, Sunil; Azim, Yasser; Desiraju, Gautam R

    2010-09-01

    A series of molecular complexes, both co-crystals and salts, of a triazole drug-alprazolam-with carboxylic acids, boric acid, boronic acids, and phenols have been analyzed with respect to heterosynthons present in the crystal structures. In all cases, the triazole ring behaves as an efficient hydrogen bond acceptor with the acidic coformers. The hydrogen bond patterns exhibited with aromatic carboxylic acids were found to depend on the nature and position of the substituents. Being a strong acid, 2,6-dihydroxybenzoic acid forms a salt with alprazolam. With aliphatic dicarboxylic acids alprazolam forms hydrates and the water molecules play a central role in synthon formation and crystal packing. The triazole ring makes two distinct heterosynthons in the molecular complex with boric acid. Boronic acids and phenols form consistent hydrogen bond patterns, and these are seemingly independent of the substitutional effects. Boronic acids form noncentrosymmetric cyclic synthons, while phenols form O--H...N hydrogen bonds with the triazole ring.

  15. Boric Acid as an Accelerator of Cerium Surface Treatment on Aluminum

    Directory of Open Access Journals (Sweden)

    K. Cruz-Hernández

    2014-01-01

    Full Text Available Aluminum pieces are often used in various industrial processes like automotive and aerospace manufacturing, as well as in ornamental applications, so it is necessary to develop processes to protect these materials, processes that can be industrialized to protect the aluminum as well or better than chromate treatments. The purpose of this research is to evaluate boric acid as an accelerator by optimizing its concentration in cerium conversion coatings (CeCC with 10-minute immersion time with a concentration of 0.1 g L−1 over aluminum to protect it. The evaluation will be carried out by measuring anticorrosion properties with electrochemical techniques (polarization resistance, Rp, polarization curves, PC, and electrochemical impedance spectroscopy, EIS in NaCl 3.5% wt. aqueous solution and surface characterization with scanning electron microscopy (SEM.

  16. Synthesis of boron carbide nano particles using polyvinyl alcohol and boric acid

    Directory of Open Access Journals (Sweden)

    Amir Fathi

    2012-03-01

    Full Text Available In this study boron carbide nano particles were synthesized using polyvinyl alcohol and boric acid. First, initial samples with molar ratio of PVA : H3BO3 = 2.7:2.2 were prepared. Next, samples were pyrolyzed at 600, 700 and 800°C followed by heat treatment at 1400, 1500 and 1600°C. FTIR analysis was implemented before and after pyrolysis in order to study the reaction pathway. XRD technique was used to study the composition of produced specimens of boron carbide. Moreover, SEM and PSA analysis were also carried out to study the particle size and morphology of synthesized boron carbide. Finally, according to implemented tests and analyses, carbon-free boron carbide nano particles with an average size of 81 nm and mainly spherical morphology were successfully produced via this method.

  17. Evaluation of ultrasonic technique to characterize the concentration of boric acid in liquid medium; Avaliacao de tecnica ultrassonica para medida de concentracao de acido borico em meio liquido

    Energy Technology Data Exchange (ETDEWEB)

    Kohara, Richard Yuzo Ramida

    2015-06-01

    This dissertation is to analyze the viability of using ultrasonic technique to characterize the concentration of boric acid in liquid medium non-invasively, therefore, ultrasonic tests were performed relating different boric acid concentrations with the travel time of the ultrasonic wave, also were evaluated factors able to mask the characterization of these concentrations by ultrasonic technique. The results showed that the ultrasonic technique allows the characterization of boric acid concentrations in liquid medium in very simple terms by the ultrasonic wave travel time, requiring further studies in complex conditions. (author)

  18. One-pot Synthesis of Bis(dihydropyrimidinone-4-yl)benzene Using Boric Acid as a Catalyst

    Institute of Scientific and Technical Information of China (English)

    TU Shu-Jiang; ZHU Xiao-Tong; FANG Fang; ZHANG Xiao-Jing; ZHU Song-Lei; LI Tuan-Jie; SHI Da-Qing; WANG Xiang-Shan; JI Shun-Jun

    2005-01-01

    A simple effective synthesis of bis(dihydropyrimidinone-4-yl)benzene derivatives, using boric acid as catalyst,from isophthalic aldehyde or terephthalic aldehyde, 1,3-dicarbonyl compounds and urea or thiourea in glacial acetic acid was described. As the expansion of the classical Biginelli reaction, this method has the advantage of excellent yields 83%-94% and short reaction time 0.5-1.5 h.

  19. Boric acid as cost-effective and recyclable catalyst for trimethylsilyl protection and deprotection of alcohols and phenols

    Energy Technology Data Exchange (ETDEWEB)

    Rostami, Amin; Akradi, Jamal; Ahmad-Jangi, Firoz, E-mail: a_rostami372@yahoo.co [University of Kurdistan, Sanandaj (Iran, Islamic Republic of). Faculty of Science. Dept. of Chemistry

    2010-07-01

    Boric acid has been used as a green, selective and recyclable catalyst for trimethysilylation of alcohols and phenols using hexamethyldisilazane in acetonitrile. Deprotection of trimethylsilyl ethers to their parent alcohols and phenols was also achieved using this catalyst in water at room temperature. The salient features of this methodology are cheap processing, mild acidity conditions, excellent yields of products and easy availability of the catalyst. (author)

  20. Experimental study on effects of boric acid on aerosol revaporization in wind project

    Energy Technology Data Exchange (ETDEWEB)

    Shibazaki, Hiroaki; Maruyama, Yu; Kudo, Tamotsu; Yuchi, Yoko; Chino, Eiichi; Nakamura, Hideo; Hidaka, Akihide; Hashimoto, Kazuichiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2000-11-01

    The revaporization of the once-deposited FPs onto surfaces of reactor coolant piping is being investigated in WIND (Wide Range Piping Integrity Demonstration) project at JAERI. The objectives of the present study are to characterize the aerosol revaporization from piping surfaces under various thermal-hydraulic conditions and to investigate the effects of boric acid on aerosol revaporization. Cesium iodide was introduced into the test section on which metaboric acid was/was not placed in advance. After quantifying the deposited mass of cesium and iodine, the test section was heated to realize the revaporization. The revaporized materials were deposited onto another test section with an axial temperature gradient located in downstream. In the cases that metaboric acid was placed on the test sections, it was found that the mole ratio of iodine to cesium deposited onto wall became gradually small as the wall temperature increased up to 500degC. Chemical analyses with XPS suggested that chemical reaction of deposited cesium iodide with metaboric acid would result in formation of borate, cesium oxide and molecular iodine. In the revaporization phase, the experiments showed that the once-deposited cesium and iodine compounds were mostly revaporized when the temperature exceeded 500degC. (author)

  1. Alternative method for thermal neutron flux measurements based on common boric acid as converter and Lr-15 detectors

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, D.; Greaves, E. D.; Sajo B, L.; Barros, H. [Universidad Simon Bolivar, Laboratorio de Fisica Nuclear, Apdo. Postal 89000, Caracas (Venezuela, Bolivarian Republic of); Ingles, R. [Universidad Nacional de San Antonio Abad del Cusco, Av. de la Cultura No. 733, Cusco (Peru)

    2010-02-15

    A method to determine the flux and angular distribution of thermal neutrons with the use of Lr-115 detectors was developed. The use of the Lr-115 detector involves the exposure of a pressed boric acid sample (tablet) as a target, in tight contact with the track detector, to a flux of thermalized neutrons. The self-absorption effects in thin films or foil type thermal neutron detectors can be neglected by using the Lr-115 detector and boric acid tablet setup to operate via backside irradiation. The energy window and the critical angle-residual energy curve were determined by comparisons between the experimental and simulated track parameters. A computer program was developed to calculate the detector registration efficiency, so that the thermal neutron flux can be calculated from the track densities induced in the Lr-115 detector using the derived empirical formula. The proposed setup can serves as directional detector of thermal neutrons. (Author)

  2. Limitations when use chloramphenicol-bcyclodextrins complexes in ophtalmic solutions buffered with boric acid/borax system

    Directory of Open Access Journals (Sweden)

    Todoran Nicoleta

    2014-12-01

    Full Text Available Chloramphenicol eye drops are commonly prescribed in concentrations of 0.5-1% in the treatment of infectious conjunctivitis. In terms of ophthalmic solution preparation, the major disadvantage of chloramphenicol consists in its low solubility in water. The solubility is increased by substances that form chloramphenicol-complexes, for example: boric acid/borax or cyclodextrins. Objective: Experimental studies aimed to evaluate the potential advantages of enhancing the solubility and stability of chloramphenicol (API by molecular encapsulation in b-cyclodextrin (CD, in formulation of ophthalmic solutions buffered with boric acid/borax system. Methods and Results: We prepared four APIb- CD complexes, using two methods (kneading and co-precipitation and two molar ratio of API/b-cyclodextrin (1:1 and 1:2. The formation of complexes was proved by differential scanning calorimetry (DSC and the in vitro dissolution tests. Using these compounds, we prepared eight ophthalmic solutions, formulated in two variants of chloramphenicol concentrations (0.4% and 0.5%. Each solution was analyzed, by the official methods, at preparation and periodically during three months of storing in different temperature conditions (4°C, 20°C and 30°C. Conclusions: Inclusion of chloramphenicol in b-cyclodextrin only partially solves the difficulties due to the low solubility of chloramphenicol. The protection of chloramphenicol molecules is not completely ensured when the ophthalmic solutions are buffered with the boric acid/borax system.

  3. Potential of using boric acid as a boron drug for boron neutron capture therapy for osteosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, C.F.; Lin, S.Y. [Institute of Nuclear Engineering and Science, National Tsing Hua University, Taiwan (China); Peir, J.J. [Nuclear Science and Technology Development Center, National Tsing Hua University, Taiwan (China); Liao, J.W. [Graduate Institute of Veterinary Pathobiology, National Chung Hsing University, Taiwan (China); Lin, Y.C. [Department of Veterinary Medicine, National Chung Hsing University, Taiwan (China); Chou, F.I., E-mail: fichou@mx.nthu.edu.tw [Institute of Nuclear Engineering and Science, National Tsing Hua University, Taiwan (China)] [Nuclear Science and Technology Development Center, National Tsing Hua University, Taiwan (China)

    2011-12-15

    Osteosarcoma is a malignant tumor commonly found in human and animals. The ability of boric acid (BA) to accumulate in osteosarcoma due to the mechanism of the bone formation of cancer cells would make boron neutron capture therapy (BNCT) an alternative therapy for osteosarcoma. This study evaluated the feasibility of using BA as the boron drug for BNCT of bone cancer. The cytotoxicity of BA to L929 cells exceeded that of UMR-106 cells. With 25 {mu}g {sup 10}B/mL medium of BA treatment, the boron concentration in UMR-106 cells was higher than that in L929 cells. The biodistribution and pharmacokinetics of BA in Sprague-Dawley (SD) rats were studied by administrating 25 mg {sup 10}B/kg body weight to SD rats. Blood boron level decreased rapidly within one hour after BA injection. Boron concentration in the long bone was 4-6 time higher than that of blood. Results of this study suggest that BA may be a potential drug for BNCT for osteosarcoma.

  4. Experiments and Modeling of Boric Acid Permeation through Double-Skinned Forward Osmosis Membranes.

    Science.gov (United States)

    Luo, Lin; Zhou, Zhengzhong; Chung, Tai-Shung; Weber, Martin; Staudt, Claudia; Maletzko, Christian

    2016-07-19

    Boron removal is one of the great challenges in modern wastewater treatment, owing to the unique small size and fast diffusion rate of neutral boric acid molecules. As forward osmosis (FO) membranes with a single selective layer are insufficient to reject boron, double-skinned FO membranes with boron rejection up to 83.9% were specially designed for boron permeation studies. The superior boron rejection properties of double-skinned FO membranes were demonstrated by theoretical calculations, and verified by experiments. The double-skinned FO membrane was fabricated using a sulfonated polyphenylenesulfone (sPPSU) polymer as the hydrophilic substrate and polyamide as the selective layer material via interfacial polymerization on top and bottom surfaces. A strong agreement between experimental data and modeling results validates the membrane design and confirms the success of model prediction. The effects of key parameters on boron rejection, such as boron permeability of both selective layers and structure parameter, were also investigated in-depth with the mathematical modeling. This study may provide insights not only for boron removal from wastewater, but also open up the design of next generation FO membranes to eliminate low-rejection molecules in wider applications.

  5. Hierarchical porous photoanode based on acid boric catalyzed sol for dye sensitized solar cells

    Science.gov (United States)

    Maleki, Khatereh; Abdizadeh, Hossein; Golobostanfard, Mohammad Reza; Adelfar, Razieh

    2017-02-01

    The hierarchical porous photoanode of the dye sensitized solar cell (DSSC) is synthesized through non-aqueous sol-gel method based on H3BO3 as an acid catalyst and the efficiencies of the fabricated DSSC based on these photoanodes are compared. The sol parameters of 0.17 M, water mole ratio of 4.5, acid mole ratio of 0.45, and solvent type of ethanol are introduced as optimum parameters for photoanode formation without any detectable cracks. The optimized hierarchical photoanode mainly contains anatase phase with slight shift toward higher angles, confirming the doping of boron into titania structure. Moreover, the porous structure involves two ranges of average pore sizes of 20 and 635 nm. The diffuse reflectance spectroscopy (DRS) shows the proper scattering and blueshift in band gap. The paste parameters of solid:liquid, TiO2:ethyl cellulose, and terpineol:ethanol equal to 11:89, 3.5:7.5, and 25:64, respectively, are assigned as optimized parameters for this novel paste. The photovoltaic properties of short circuit current density, open circuit voltage, fill factor, and efficiency of 5.89 mA/cm2, 703 mV, 0.7, and 2.91% are obtained for the optimized sample, respectively. The relatively higher short circuit current of the main sample compared to other samples is mainly due to higher dye adsorption in this sample corresponding to its higher surface area and presumably higher charge transfer confirmed by low RS and Rct in electrochemical impedance spectroscopy data. Boric acid as a catalyst in titania sol not only forms hierarchical porous structure, but also dopes the titania lattice, which results in appreciated performance in this device.

  6. Reverse osmosis for the recovery of boric acid from the primary coolant at nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Bártová, Šárka, E-mail: sarka.bartova@cvrez.cz [Research Centre Řež Ltd., Husinec-Řež 130, 250 68 Řež (Czech Republic); Kůs, Pavel [Research Centre Řež Ltd., Husinec-Řež 130, 250 68 Řež (Czech Republic); Skala, Martin [Research Centre Řež Ltd., Husinec-Řež 130, 250 68 Řež (Czech Republic); University of Chemical Technology, Prague, Department of Chemical Engineering, Technická 5, Prague 166 28 (Czech Republic); Vonková, Kateřina [Research Centre Řež Ltd., Husinec-Řež 130, 250 68 Řež (Czech Republic)

    2016-04-15

    Highlights: • RO membranes tested for boric acid recovery from primary coolant of nuclear power plants. • Scanning electron microscopy was used for the characterization of the membranes. • Lab scale experiments performed under various operation conditions. • We proposed configuration of and operation conditions for RO unit in nuclear power plant. - Abstract: At nuclear power plants (NPP), evaporators are used for the treatment of primary coolant and other liquid radioactive waste containing H{sub 3}BO{sub 3}. Because the operation of evaporators is expensive, a number of more cost-effective alternatives has been considered, one of which is reverse osmosis. We tested reverse osmosis modules from several manufactures on a batch laboratory apparatus. SEM images of the tested membranes were taken to distinguish the differences between the membranes. Water permeability through membranes was evaluated from the experiments with pure water. The experiments were performed with feed solutions containing various concentrations of H{sub 3}BO{sub 3} in a range commonly occurring in radioactive waste. The pH of the feed solutions ranged from 5.2 to 11.2. Our results confirmed that the pH of the feed solution plays the most important role in membrane separation efficiency of H{sub 3}BO{sub 3}. Certain modifications to the pH of the feed solution were needed to enable the tested membranes to concentrate the H{sub 3}BO{sub 3} in the retentate stream, separate from the pure water in the permeate stream. On this basis, we propose the configuration of and operational conditions for a reverse osmosis unit at NPP.

  7. Spatial self-phase modulation in the H2TPP(OH)4 doped in Boric Acid Glass

    CERN Document Server

    Allam, Srinivasa Rao; Venkatramaiah, N; Venkatesan, R; Sharan, Alok

    2015-01-01

    Self-diffraction rings or spatial self-phase modulation (SSPM) was observed in tetra-phenyl porphyrin derivative 5,10,15,20 - meso-tetrakis (4-hydroxyphenyl) porphyrin (H2TPP(OH)4) doped in boric acid glass (BAG) at 671 nm excitation wave-length lying within the absorption band of sample with TEM00 mode profile. Intensity modulated Z-scan was performed on these systems to study the thermal diffusion and to estimate the thermo-optic coefficients. The results obtained from self-diffraction rings experiment and modulated Z-scan are compared and analyzed for different concentration.

  8. Metal‐Free Dehydration of Glucose to 5‐(Hydroxymethyl)furfural in Ionic Liquids with Boric Acid as a Promoter

    DEFF Research Database (Denmark)

    Ståhlberg, Tim; Rodriguez, Sergio; Fristrup, Peter;

    2011-01-01

    The dehydration of glucose and other hexose carbohydrates to 5‐(hydroxymethyl)furfural (HMF) was investigated in imidazolium‐based ionic liquids with boric acid as a promoter. A yield of up to 42 % from glucose and as much as 66 % from sucrose was obtained. The yield of HMF decreased...... as the concentration of boric acid exceeded one equivalent, most likely as a consequence of stronger fructose–borate chelate complexes being formed. Computational modeling with DFT calculations confirmed that the formation of 1:1 glucose–borate complexes facilitated the conversion pathway from glucose to fructose....... Deuterium‐labeling studies elucidated that the isomerization proceeded via an ene–diol mechanism, which is different to that of the enzyme‐catalyzed isomerization of glucose to fructose. The introduced non‐metal system containing boric acid provides a new direction in the search for catalyst systems...

  9. Cover Picture: Metal‐Free Dehydration of Glucose to 5‐(Hydroxymethyl)furfural in Ionic Liquids with Boric Acid as a Promoter (Chem. Eur. J. 5/2011)

    DEFF Research Database (Denmark)

    Ståhlberg, Tim Johannes Bjarki; Rodriguez, Sergio; Fristrup, Peter;

    2011-01-01

    Boric acid promotes the dehydration of glucose to 5-(hydroxy)methylfurfural in ionic liquids. Computational analyses by DFT calculations show a significant decrease in energy for the isomerization of glucose to fructose when the sugars are bound to boric acid and isotopic labeling NMR studies con...

  10. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Science.gov (United States)

    2010-07-01

    ... polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section 721.1729 Protection... acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and......

  11. Reprint of The improvement of the energy resolution in epi-thermal neutron region of Bonner sphere using boric acid water solution moderator.

    Science.gov (United States)

    Ueda, H; Tanaka, H; Sakurai, Y

    2015-12-01

    Bonner sphere is useful to evaluate the neutron spectrum in detail. We are improving the energy resolution in epi-thermal neutron region of Bonner sphere, using boric acid water solution as a moderator. Its response function peak is narrower than that for polyethylene moderator and the improvement of the resolution is expected. The resolutions between polyethylene moderator and boric acid water solution moderator were compared by simulation calculation. Also the influence in the uncertainty of Bonner sphere configuration to spectrum estimation was simulated.

  12. The improvement of the energy resolution in epi-thermal neutron region of Bonner sphere using boric acid water solution moderator.

    Science.gov (United States)

    Ueda, H; Tanaka, H; Sakurai, Y

    2015-10-01

    Bonner sphere is useful to evaluate the neutron spectrum in detail. We are improving the energy resolution in epi-thermal neutron region of Bonner sphere, using boric acid water solution as a moderator. Its response function peak is narrower than that for polyethylene moderator and the improvement of the resolution is expected. The resolutions between polyethylene moderator and boric acid water solution moderator were compared by simulation calculation. Also the influence in the uncertainty of Bonner sphere configuration to spectrum estimation was simulated.

  13. Fabrication and study on tribological characteristics of cast copper-TiO{sub 2}-boric acid hybrid composites

    Energy Technology Data Exchange (ETDEWEB)

    Ramesh, C.S. [Department of Mechanical Engineering, PESIT, Bangalore (India); Noor Ahmed, R. [Department of Mechanical Engineering, Anjuman Engineering College, Bhatkal (India); Mujeebu, M.A. [Department of Mechanical Engineering, Anjuman Engineering College, Bhatkal (India); School of Mechanical Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)], E-mail: mamujeeb5@yahoo.com; Abdullah, M.Z. [School of Mechanical Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2009-05-15

    Copper based composites having hard reinforcements such as silicon carbide, alumina and cerium oxide do possess higher strength, better wear resistance and higher coefficient of friction when compared to copper. However, they pose several challenges in machining such as higher tool wear and inferior surface finish. On the other hand, copper based composites having soft reinforcements such as graphite, molybdenum disulphide and calcium fluoride do possess lower coefficient of friction and better machinability characteristics. Against this background, an attempt is made to develop a new class of copper composite materials by dispersing both the hard and soft reinforcements in appropriate proportions to ensure optimization of mechanical properties and machinability characteristics. In this paper the development and testing of copper-TiO{sub 2}-boric acid composites by liquid metallurgy method is presented. Metallographic study, micro hardness, tensile strength, friction and wear tests on these hybrid composites have been carried out. The results show that copper-TiO{sub 2}-boric acid composites possess higher hardness, higher tensile strength, higher coefficient of friction and better wear resistance when compared with pure copper00.

  14. Simultaneous pollutant removal and electricity generation in denitrifying microbial fuel cell with boric acid-borate buffer solution.

    Science.gov (United States)

    Chen, Gang; Zhang, Shaohui; Li, Meng; Wei, Yan

    2015-01-01

    A double-chamber denitrifying microbial fuel cell (MFC), using boric acid-borate buffer solution as an alternative to phosphate buffer solution, was set up to investigate the influence of buffer solution concentration, temperature and external resistance on electricity generation and pollutant removal efficiency. The result revealed that the denitrifying MFC with boric acid-borate buffer solution was successfully started up in 51 days, with a stable cell voltage of 205.1 ± 1.96 mV at an external resistance of 50 Ω. Higher concentration of buffer solution favored nitrogen removal and electricity generation. The maximum power density of 8.27 W/m(3) net cathodic chamber was obtained at a buffer solution concentration of 100 mmol/L. An increase in temperature benefitted electricity generation and nitrogen removal. A suitable temperature for this denitrifying MFC was suggested to be 25 °C. Decreasing the external resistance favored nitrogen removal and organic matter consumption by exoelectrogens.

  15. Boric acid as a mild and efficient catalyst for one-pot synthesis of 1-amidoalkyl-2-naphthols under solvent-free conditions

    Indian Academy of Sciences (India)

    Aziz Shahrisa; Somayeh Esmati; Mahdi Gholamhosseini Nazari

    2012-07-01

    An efficient green chemistry method has been developed for the synthesis of 1-amidoalkyl-2-naphthol derivatives via a one-pot three-component condensation of 2-naphthol, aldehydes and amide in the presence of boric acid as a mild catalyst.

  16. Some features of the effect the pH value and the physicochemical properties of boric acid have on mass transfer in a VVER reactor's core

    Science.gov (United States)

    Gavrilov, A. V.; Kritskii, V. G.; Rodionov, Yu. A.; Berezina, I. G.

    2013-07-01

    Certain features of the effect of boric acid in the reactor coolant of nuclear power installations equipped with a VVER-440 reactor on mass transfer in the reactor core are considered. It is determined that formation of boric acid polyborate complexes begins under field conditions at a temperature of 300°C when the boric acid concentration is equal to around 0.065 mol/L (4 g/L). Operations for decontaminating the reactor coolant system entail a growth of corrosion product concentration in the coolant, which gives rise to formation of iron borates in the zones where subcooled boiling of coolant takes place and to the effect of axial offset anomalies. A model for simulating variation of pressure drop in a VVER-440 reactor's core that has invariable parameters during the entire fuel campaign is developed by additionally taking into account the concentrations of boric acid polyborate complexes and the quantity of corrosion products (Fe, Ni) represented by the ratio of their solubilities.

  17. The Simultaneous Determination of Silicic, Boric and Carbonic Acids in Natural Water via Ion-Exclusion Chromatography with a Charged Aerosol Detector

    Directory of Open Access Journals (Sweden)

    Yu Otsuka

    2016-03-01

    Full Text Available The simple and simultaneous determination of silicic, boric and carbonic acids was made using ion-exclusion chromatography (IEC and a Corona™ charged aerosol detector (C-CAD. Silicic and boric acids were separated by the column packed with a weakly acidic cation-exchange resin in H+-form and ultra-pure water eluent, and the detector responses were improved by the addition of acetonitrile to eluent. Under the optimized conditions, the simultaneous determination of weak inorganic acids, except for carbonic acid, was successfully performed. When the conversion column packed with a strong acidic cation-exchange resin in Na+- or K+-form was inserted between the separation column and the detector, weak inorganic acids including carbonic acid could be detected by the C-CAD. The calibration curves were linear in the range of 0.5–10 mg·L−1 as Si for silicic acid (r2 = 0.996, 10–100 mg·L−1 as B for boric acid (r2 = 0.998 and 1.3–21 mg·L−1 as C for carbonic acid (r2 = 0.993. The detection limits based on three times the standard deviation were 0.03 mg·L−1 as Si for silicic acid, 0.40 mg·L−1 as B for boric acid and 0.08 mg·L−1 as C for carbonic acid. This method was applicable to river, hot spring and drinking water.

  18. Cellular responses in the Malpighian tubules of Scaptotrigona postica (Latreille, 1807) exposed to low doses of fipronil and boric acid.

    Science.gov (United States)

    Ferreira, Rafael Alexandre Costa; Silva Zacarin, Elaine Cristina Mathias; Malaspina, Osmar; Bueno, Odair Correa; Tomotake, Maria Eliza Miyoko; Pereira, Andrigo Monroe

    2013-03-01

    Studies of sub-lethal effects of pesticide residues on stingless bees are scarce and morphological analysis of organs would add information to toxicological analysis in order to clarify the continuous exposure of Scaptotrigona postica to insecticides. The aim of this study was to evaluate the morphology and histochemistry of the Malpighian tubules (excretory organ) of S. postica exposed to fipronil or boric acid to detect cellular responses that indicate toxicity or adaptative mechanisms to stress induced by exposure of worker bees to low doses of these chemical compounds. Newly emerged bees were submitted to toxicological bioassays and morphological analyses by optical microscopy and Transmission Electron Microscopy, as well as histochemical methods, were performed to detect proteins and glycoconjugates. Additionally, immunohistochemical detection of DNA fragmentation and HSP70 (70-kDa Heat shock protein) were performed to detect cell death and stress response, respectively. Statistical analysis, for the bioassays conducted with ingestion of contaminated diet with boric acid at 0.75% (w/w) or with fipronil at 0.1μg/kg of food, showed that the survival of bees that ingested the contaminated diets were significantly different to the survival rate presented by the control group (P<0.0001). Although some characteristics indicative of initiation of cell death were observed, the cells remained metabolically active in the processes of excretion and inactivation of chemical compounds. The data from this study reinforce the importance of research on sublethal effects of low doses of pesticides on bees in an attempt to assess a possible realistic dose and evaluate the risk assessment of stingless bee S. postica foraging in the vicinity of cultivated fields and/or in green urban areas.

  19. Influence of Polyethylene and Oxidized Polyethylene Wax Emulsions on Leaching Dynamics of Boric Acid from Impregnated Spruce Wood

    Directory of Open Access Journals (Sweden)

    Boštjan Lesar

    2010-12-01

    Full Text Available Boron biocides belong to the most frequently used ingredients of commercial wood preservatives. They are very effective fungicides and insecticides, but they do not react with wood and thus leach from it in wet applications. This fact signifi cantly limits use of boron compounds in the field of wood preservation. In order to reduce leaching of boric acid, the emulsion of polyethylene (WE1 and an emulsion of oxidized polyethylene (WE6 wax were combined with boric acid (cB = 0.1 % or 0.5 % of boron. Spruce wood specimens were vacuum impregnated and afterwards leached according to the prCEN/TS 15119-1, EN 1250-2 and EN 84 procedures. The results showed that the boron leaching is predominantly infl uenced by moisture content of wood during leaching, and furthermore by the concentration gradient (frequency of water replacement. The fact that the prCEN/TS 15119-1 leaching procedure is less severe than other two methods is also refl ected in the results. The results of the EN 84 and ENV 1250 test are comparable, while the results of the prCEN/TS 15119-1 testing are not in line with the other two methods. Considerable portions of boron are leached from wood in the first leaching cycles, already. WE6 wax emulsion (oxidized polyethylene wax emulsion in combination with heat treatment reduces boron leaching to a certain extent. On the other hand, impregnation of wood with WE1 (polyethylene wax emulsion does not reduce it and it even enhances it.

  20. Proposing Boric Acid as an Antidote for Aluminium Phosphide Poisoning by Investigation of the Chemical Reaction Between Boric Acid and Phosphine

    OpenAIRE

    Motahareh Soltani; Seyed Farid Shetab-Boushehri; Hamidreza Mohammadi; Seyed Vahid Shetab-Boushehri

    2013-01-01

    Aluminium phosphide (AlP) is a storage fumigant pesticide, which is used to protect stored grains especially from insects and rodents. It releases phosphine (PH3) gas, a highly toxic mitochondrial poison, in contact with moisture, particularly if acidic. Although the exact mechanism of action is unknown so far, the major mechanism of PH3 toxicity seems to be the inhibition of cytochrome-c oxidase and oxidative phosphorylation which eventually results in adenosine triphosphate (ATP) depletion ...

  1. Equilibrium study on the reactions of boric acid with some cis-diaqua CrIII-complexes

    Indian Academy of Sciences (India)

    G N Mukherjee; Ansuman Das

    2003-08-01

    Substitution inert cis-diaqua CrIII complexes: cis-[(L-)CrIII(H2O)2](3-)+ derived from N-donor ligands (L-) viz., bipyridine and 1,10-phenanthroline ( = 0) and N,O-donor ligands viz., nitrilotriacetate and anthranilate N,N-diacetate ( = 3) titrate as diprotic acids in aqueous solution and enhance the acidity of otherwise weakly acidic boric acid (H3BO3) producing mononuclear and binuclear mixed ligand CrIII-borate complexes: [(L)Cr(H2BO4)]- and [(L)Cr(BO4)Cr(L)](1-2)+ respectively through coordination of the H2O and/or OH- ligands, cis-coordinated in the CrIII-complexes on the electron deficient BIII-atom in H3BO3 with release of protons. Deprotonation of the parent CrIII-complexes and their reactions with H3BO3 have been investigated by potentiometric method in aqueous solution, = 0.1 mol dm-3 (NaNO3) at 25 ± 0.1° C. The equilibrium constants have been evaluated by computerized methods and the tentative stoichiometry of the reactions have been worked out on the basis of the speciation curves.

  2. Effect of addition of tartaric acid on synthesis of boron carbide powder from condensed boric acid–glycerin product

    Energy Technology Data Exchange (ETDEWEB)

    Tahara, Naoki; Kakiage, Masaki, E-mail: kakiage@apc.saitama-u.ac.jp; Yanase, Ikuo; Kobayashi, Hidehiko

    2013-10-05

    Highlights: •B{sub 4}C powder was synthesized from a condensed H{sub 3}BO{sub 3}-glycerin product with tartaric acid added. •A precursor consisting of B{sub 2}O{sub 3} and carbon was prepared by the thermal decomposition in air. •The precursors had a three-dimensional bicontinuous B{sub 2}O{sub 3}/carbon network structure. •The dispersion state became more homogeneous and finer with the addition of tartaric acid. •The complete formation of B{sub 4}C powder was achieved at 1250 °C within a shorter heat treatment time. -- Abstract: The effect of the addition of tartaric acid on the synthesis of boron carbide (B{sub 4}C) powder from a condensed boric acid (H{sub 3}BO{sub 3})–glycerin product was investigated in this study. The condensed product was prepared by dehydration condensation after directly mixing equimolar amounts of H{sub 3}BO{sub 3} and glycerin with the addition of 0–50 mol% tartaric acid (based on glycerin), which was followed by thermal decomposition in air to obtain a precursor powder from which excess carbon had been eliminated. The dispersion state of the boron oxide (B{sub 2}O{sub 3}) and carbon components in the precursor prepared from the condensed product with 25 mol% tartaric acid added was finer than that without tartaric acid added, in which both precursors had a three-dimensional bicontinuous B{sub 2}O{sub 3}/carbon network structure. The complete formation of crystalline B{sub 4}C powder was achieved at 1250 °C within a shorter heat treatment time for the precursor with a fine dispersion state. The synthesized B{sub 4}C powders became fine owing to the increased number of nucleation sites.

  3. Solubility study of nickel ferrite in boric acid using a flow-through autoclave system under high temperature and high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yong Joon; Choi, Ke Chon; Ha, Yeong Keong [Nuclear Chemistry Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-04-15

    The solubility of nickel ferrite in an aqueous solution of boric acid was studied by varying the pH at the temperatures ranging from 25 .deg. C to 320 .deg. C. A flow-through autoclave system was specially designed and fabricated to measure the solubility of Fe in hydrothermal solutions under high temperature and pressure. The performance of this flow-through system was directly compared with the conventional static state technique using a batch-type autoclave system. The stability of fluid velocity for the flow-through autoclave system was verified prior to the solubility measurement. The influence of chemical additives, such as boric acid and H2, on the solubility of nickel ferrite was also evaluated.

  4. FOLIAR APPLICATION OF CALCIUM AND BORON-BASED CALCIUM CHLORIDE AND BORIC ACID MIXED ON INCOME TANK FOR THE EVALUATION OF SOYBEAN SEED.

    OpenAIRE

    Arantes, Rafael Pereira; Faculdade Dr. Francisco Maeda; Cury, Tadeu Nascimento; Faculdade Dr. Francisco Maeda; Leão, Fabiana De Paula; Universidade Federal de Viçosa; Maciel Junior,Vinicius Antonio

    2009-01-01

    The experiment was conducted in the municipality of Ituverava, in the Estiva farm in the agricultural year of 07/08. The work used the soybean cultivar BRS Valiosa RR to evaluate the performace of the soybean with application of calcium chloride to 26% and boric acid to 17% in different stages of development of culture. The treatments consisted of applications in eight steps, as follows: pre-bloom, pre-bloom + flowering, pre-bloom + flowering + pod, pre - bloom + pod, bloomed, flowering ...

  5. 基于有机硼酸的糖传感器研究进展%Progress in Boric Acid-Based Saccharide Sensors

    Institute of Scientific and Technical Information of China (English)

    狄玲; 王苍; 吴健; 万灵书; 徐志康

    2011-01-01

    有机硼酸能与二羟基化合物高亲和性地可逆结合,是一类新型的糖传感器材料.根据检测手段的不同可将基于有机硼酸的糖传感器分为光谱传感器、pH指示型传感器、电化学传感器等几类.本文详细评述了各种传感器的检测原理、制备方法和应用,并系统总结了最新研究进展,展望了今后的研究方向.%Because of strong interaction with diol moieties, boric acid group often plays a critical role in the design of saccharide sensors. We presents an overview about the recent development of saccharide sensors based on various mechanisms, including spectroscopies, pH-indicators and electrochemistry. The chemistry involved in the binding between boric acid and saccharides are described also.Furthermore, potential directions of future research for these boric acid-based saccharide sensors arediscussed.

  6. The effects of temperature and aeration on the corrosion of A508III low alloy steel in boric acid solutions at 25-95 °C

    Science.gov (United States)

    Xiao, Qian; Lu, Zhanpeng; Chen, Junjie; Yao, Meiyi; Chen, Zhen; Ejaz, Ahsan

    2016-11-01

    The effects of temperature, solution composition and dissolved oxygen on the corrosion rate and electrochemical behavior of an A508III low alloy steel in boric acid solution with lithium hydroxide at 25-95 °C are investigated. In aerated solutions, increasing the boric acid concentration increases the corrosion rate and the anodic current density. The corrosion rate in deaerated solutions increases with increasing temperature. A corrosion rate peak value is found at approximately 75 °C in aerated solutions. Increasing temperature increases the oxygen diffusion coefficient, decreases the dissolved oxygen concentration, accelerates the hydrogen evolution reaction, and accelerates both the active dissolution and the film forming reactions. Increasing dissolved oxygen concentration does not significantly affect the corrosion rate at 50 and 60 °C, increases the corrosion rate at 70 and 80 °C, and decreases the corrosion rate at 87.5 and 95 °C in a high concentration boric acid solution with lithium hydroxide.

  7. Electrochemical properties and stress corrosion cracking of alloys 600, 690, and 800 in solutions containing boric acid and chloride

    Energy Technology Data Exchange (ETDEWEB)

    Bae, J. H.; Won, C. H. [Chungnam Nation Univ., Taejon (Korea, Republic of); Lee, E. H.; Kim, H. P.; Kim, W. C. [KAERI, Taejon (Korea, Republic of)

    2000-10-01

    Electrochemical characteristics and stress corrosion cracking(SCC)of Alloy 600, Alloy 690 and Alloy 800 have been studied in boric acid solution with chloride. Electrochemical characteristics were measured in mixed solution of 3% H{sub 3}BO{sub 3} and 0.2g/l Cl{sup -} at 320 .deg. C. SCC resistance was predicted with Parameter(P{sub SCC}) including current density ratio obtained at two different scan rates. P{sub SCC} increased with a following sequence: Alloy 600MA, 600TT, 690TT and Alloy 800. SCC test was carried out with C-ring specimens and reverse U-bend(RUB) specimens at 320 .deg. C and 350 .deg. C. Test solutions were mixture of 3% H{sub 3}BO{sub 3} and 0.2g/l Cl{sup -} at 320 .deg. C and mixture of 27% H{sub 3}BO{sub 3} and 2g/l Cl{sup -} at 350 .deg. C. C-ring specimens test in the solution of 3% H{sub 3}BO{sub 3} and 0.2g/l Cl{sup -} at 320 .deg. C for 2400hrs did not show SCC. RUB specimen of Alloy600MA and 600TT showed SCC after 1920 hours exposure to the solution of 27% H{sub 3}BO{sub 3} and 0.2g/l Clat 350 .deg. C.

  8. Mixed ligand complex formation of FeIII with boric acid and typical N-donor multidentate ligands

    Indian Academy of Sciences (India)

    G N Mukherjee; Ansuman Das

    2002-06-01

    Equilibrium study of the mixed ligand complex formation of FeIII with boric acid in the absence and in the presence of 2,2'-bipyridine, 1,10-phenanthroline, diethylenetriamine and triethylenetetramine (L) in different molar ratios provides evidence of formation of Fe(OH)2+, Fe(OH)$^{+}_{2}$, Fe(L)3+, Fe(H2BO4), Fe(OH)(H2BO4)-, Fe(OH)2(H2BO4)2-, Fe(L)(H2BO4) and Fe2(L)2(BO4)+ complexes. Fe(L)$^{3+}_{2}$, Fe(L)2(H2BO4) and Fe2(L)4(BO4)+ complexes are also indicated with 2,2'-bipyridine and 1,10-phenanthroline. Complex formation equilibria and stability constants of the complexes at 25 ± 0 × 1° C in aqueous solution at a fixed ionic strength, = 0.1 mol -3 (NaNO3) have been determined by potentiometric method.

  9. OsNIP3;1, a rice boric acid channel, regulates boron distribution and is essential for growth under boron-deficient conditions.

    Science.gov (United States)

    Hanaoka, Hideki; Uraguchi, Shimpei; Takano, Junpei; Tanaka, Mayuki; Fujiwara, Toru

    2014-06-01

    Boron is an essential micronutrient for higher plants. Boron deficiency is an important agricultural issue because it results in loss of yield quality and/or quantity in cereals and other crops. To understand boron transport mechanisms in cereals, we characterized OsNIP3;1, a member of the major intrinsic protein family in rice (Oryza sativa L.), because OsNIP3;1 is the most similar rice gene to the Arabidopsis thaliana boric acid channel genes AtNIP5;1 and AtNIP6;1. Yeast cells expressing OsNIP3;1 imported more boric acid than control cells. GFP-tagged OsNIP3;1 expressed in tobacco BY2 cells was localized to the plasma membrane. The accumulation of OsNIP3;1 transcript increased fivefold in roots within 6 h of the onset of boron starvation, but not in shoots. Promoter-GUS analysis suggested that OsNIP3;1 is expressed mainly in exodermal cells and steles in roots, as well as in cells around the vascular bundles in leaf sheaths and pericycle cells around the xylem in leaf blades. The growth of OsNIP3;1 RNAi plants was impaired under boron limitation. These results indicate that OsNIP3;1 functions as a boric acid channel, and is required for acclimation to boron limitation. Boron distribution among shoot tissues was altered in OsNIP3;1 knockdown plants, especially under boron-deficient conditions. This result demonstrates that OsNIP3;1 regulates boron distribution among shoot tissues, and that the correct boron distribution is crucial for plant growth.

  10. Enhanced photoelectrochemical-response in highly ordered TiO{sub 2} nanotube-arrays anodized in boric acid containing electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Ruan, Chuanmin; Paulose, Maggie; Varghese, Oomman K.; Grimes, Craig A. [Department of Electrical Engineering, & amp; Department of Materials Science and Engineering, 217 Materials Research Laboratory, The Pennsylvania State University, University Park, PA 16802 (United States)

    2006-05-23

    We examine the photoelectrochemical properties of highly ordered titanium dioxide nanotube-array photoanodes, fabricated by anodization of titanium in a nitric acid/hydrofluoric acid electrolyte, with and without the addition of boric acid. Under UV-Vis illumination the photocurrent densities achieved with TiO{sub 2} nanotube-arrays fabricated in the H{sub 3}BO{sub 3}-HNO{sub 3}-HF electrolyte are a factor of seven greater than the TiO{sub 2} nanotube-array samples obtained in the commonly used HNO{sub 3}-HF electrolyte, indicating the ability to control the photoelectrochemical response of the highly ordered nanotube arrays by tailoring the electrolyte composition. For 560nm long boric-acid fabricated nanotube arrays, a photoconversion efficiency of 7.9% is achieved upon a 320-400nm illumination at an intensity of 98mW/cm{sup 2}, with hydrogen generated by water photoelectrolysis at the power-time normalized rate of 1708-{mu}mol/hW (42ml/hW). The resulting nanotube-arrays demonstrate excellent photocorrosion stability, with no detectable degradation in photoconversion properties over 6 months of testing. While the titania bandgap is not suitable for high visible spectrum efficiencies, the high photoconversion efficiency achieved under UV illumination indicates the suitability of the highly ordered nanotube-array architecture for hydrogen generation by water photoelectrolysis. (author)

  11. Study of Application of Boric Acid in High Temperature Coatings%硼酸应用在耐高温涂层中的研究

    Institute of Scientific and Technical Information of China (English)

    闫实; 刘朝辉; 成声月; 刘强; 阮峥; 邓智平

    2015-01-01

    选取硼酸高温脱水后的混合物作为填料,与高岭土、滑石粉、铝粉等填料制备了以有机硅树脂为基料,可以耐受800℃的耐高温防护涂层并测试了涂层的各项性能。为研究硼酸混合物在涂层高温灼烧过程中的作用机理,对涂层在经200℃固化、500℃高温灼烧和700℃高温灼烧后的表层形貌、元素和涂层物质变化情况进行分析。阐明了涂层中有机硅树脂上的有机基团会在500℃时大量分解。硼酸混合物在高温下,会以熔融态填充有机硅树脂分解挥发产生的空隙,并粘接其他颜填料,但是涂层表面会有硼酸混合物脱水造成的少量凹陷存在。%Using silicone resin as base stock, using dehydrated boric acid mixture,kaolin,talcum powder and aluminum powder as fillers, a high temperature coating which can resist 800 ℃ was prepared. And every performance of the coating was tested. In order to research the action mechanism of boric acid mixture in high temperature calcination process of the coating, changes of the surface morphology and composing elements of the coating during solidifying under 200 ℃ and calcining under 500 ℃ and 700 ℃ were analyzed. The results show that, lots of organic groups on the organosilicon resin can be decomposed at 500 ℃;under high temperature, boric acid mixture in the molten state can fill the voids of the organosilicon resin produced by decomposition of organic groups, but a small amount of pits on surface of the coat will be formed by dehydration of boric acid mixture.

  12. 多羟基化合物对硼酸络合效果的实验研究%Experimental Research on the Complexation Effect Between Polyol Compounds and Boric Acid

    Institute of Scientific and Technical Information of China (English)

    袁佳佳; 贾铭椿; 王晓伟

    2013-01-01

    通过将D-山梨醇、D-果糖、甘露醇、木糖醇与硼酸进行络合,在酸性和碱性条件下分别通过溶液电导率和pH值的变化情况来确定多羟基化合物与硼酸的最佳络合比,结果表明在酸性条件下,最佳络合比均为2∶1,当溶液呈碱性时,部分络合剂与硼酸反应会产生1∶1的化合物.只有当溶液中络合剂的物质的量过量达到硼酸的10倍以上的时候,硼酸才能够完全被络合成硼酸酯.%The boric acid is complexed with the D-sorbitol,D-fructose,mannitol and xylitol.Under the acidic and alkaline conditions it can fix on the best ratio of the polyol compounds and boric acid through the electrical conductivity and pH of the solution.The result indicates the best ratio is 2 ∶ 1 under the acidic condition.When in alkaline solution,some complexing agent and boric acid can generate the product that the ratio is 1 ∶ 1.Only when the amount of the complexing agent in the solution is excess of the 10 times of the boric acid,the boric acid can completely turn into boric acid ester.

  13. Separate vaporisation of boric acid and inorganic boron from tungsten sample cuvette-tungsten boat furnace followed by the detection of boron species by inductively coupled plasma mass spectrometry and atomic emission spectrometry (ICP-MS and ICP-AES).

    Science.gov (United States)

    Kataoka, Hiroko; Okamoto, Yasuaki; Tsukahara, Satoshi; Fujiwara, Terufumi; Ito, Kazuaki

    2008-03-10

    Utilising extremely different vaporisation properties of boron compounds, the determination procedures of volatile boric acid and total boron using tungsten boat furnace (TBF) ICP-MS and TBF-ICP-AES have been investigated. For the determination of volatile boric acid by TBF-ICP-MS, tetramethylammonium hydroxide (TMAH, Me(4)NOH) was used as a chemical modifier to retain it during drying and ashing stages. As for the total boron, not only non-volatile inorganic boron such as boron nitride (BN), boron carbide (B(4)C), etc. but also boric acid (B(OH)(3)) was decomposed by a furnace-fusion digestion with NaOH to produce sodium salt of boron, a suitable species for the electrothermal vaporisation (ETV) procedure. The proposed method was applied to the analysis of various standard reference materials. The analytical results for various biological and steel samples are described.

  14. Protective Effect of Boric Acid on Oxidative DNA Damage In Chinese Hamster Lung Fibroblast V79 Cell Lines

    Directory of Open Access Journals (Sweden)

    SezenYılmaz

    2016-02-01

    Full Text Available Objective: Many studies have been published on the antioxidative effects of boric acid (BA and sodium borates in in vitro studies. However, the boron (B concentrations tested in these in vitro studies have not been selected by taking into account the realistic blood B concentrations in humans due to the lack of comprehensive epidemiological studies. The recently published epidemiological studies on B exposure conducted in China and Turkey provided blood B concentrations for both humans in daily life and workers under extreme exposure conditions in occupational setting. The results of these studies have made it possible to test antioxidative effects of BA in in vitro studies within the concentration range relevant to humans. The aim of this study was to investigate the protective effects of BA against oxidative DNA damage in V79 (Chinese hamster lung fibroblast cells. The concentrations of BA tested for its protective effect was selected by taking the blood B concentrations into account reported in previously published epidemiological studies. Therefore, the concentrations of BA tested in this study represent the exposure levels for humans in both daily life and occupational settings. Materials and Methods: In this experimental study, comet assay and neutral red uptake (NRU assay methods were used to determinacy to toxicity and genotoxicity of BA and hydrogen peroxide (H2O2. Results: The results of the NRU assay showed that BA was not cytotoxic within the tested concentrations (3, 10, 30, 100 and 200 μM. These non-cytotoxic concentrations were used for comet assay. BA pre-treatment significantly reduced (P<0.05, one-way ANOVA the DNA damaging capacity of H2O2 at each tested BA concentrations in V79 cells. Conclusion: Consequently, pre-incubation of V79 cells with BA has significantly reduced the H2O2-induced oxidative DNA damage in V79 cells. The protective effect of BA against oxidative DNA damage in V79 cells at 5, 10, 50, 100 and 200 μM (54

  15. Quantity of non condensing gases (Such as hydrogen and oxygen) produced from the Irradiation of boric acid solutions in a research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Im, Hee Jung; Choi, Ke Chon; Yeon, Jei Won; Kim, Hung Woo; Cho, Man Soon; Jang, Kyung Duk; Park, Ul Jae; Hong, Sung Tack; Han, Jae Sam; Park, Sang Jun; Jung, Hoan Sung; Song, Kyu Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-10-15

    Several pipeline rupture accidents as a result of the detonation of a hydrogen-oxygen mixture accumulated due to radiolysis have been reported. However, non-condensing gases (such as oxygen and hydrogen molecules) are usually not detected in cooling systems of pressurized water reactors (PWRs) under high temperature, or research reactors even under room temperature irradiation conditions. In the meantime, it was observed that the presence of certain amounts of boric acid, which is known as a water soluble thermal neutron absorber, produces an evolution of gases in significant quantity in the reactor at room temperature. Nuclear reactions of neutron absorbers such as B-10 or Li-6 in solid materials with thermal neutrons have been widely studied, and the applications are quite broad. Nevertheless, the irradiation of water samples containing neutron absorbers has not been published except for theoretical calculations using computer codes or a paper reporting experimental data obtained at high temperatures, written by B. Pas tina et al. To study the radiolysis of the cooling water and calculate the amount of gases that could have been produced in this manner, we irradiated several water samples containing natural, {sup 10}B-enriched, and mixed boric acid in the ranges of 0 to 2000 {mu}g/m L for the function of {sup 10}B concentration.

  16. Fabrication of Li{sub 2}TiO{sub 3} pebbles using PVA–boric acid reaction for solid breeding materials

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yi-Hyun, E-mail: yhpark@nfri.re.kr; Cho, Seungyon; Ahn, Mu-Young

    2014-12-15

    Highlights: • Li{sub 2}TiO{sub 3} pebbles were successfully fabricated by the slurry droplet wetting method. • Boron was used as hardening agent of PVA and completely removed during sintering. • Microstructure of fabricated Li{sub 2}TiO{sub 3} pebble was exceptionally homogeneous. • Suitable process conditions for high-quality Li{sub 2}TiO{sub 3} pebble were summarized. - Abstract: Lithium metatitanate (Li{sub 2}TiO{sub 3}) is a candidate breeding material of the Helium Cooled Ceramic Reflector (HCCR) Test Blanket Module (TBM). The breeding material is used in pebble-bed form to reduce the uncertainty of the interface thermal conductance. In this study, Li{sub 2}TiO{sub 3} pebbles were successfully fabricated by the slurry droplet wetting method using the cross-linking reaction between polyvinyl alcohol (PVA) and boric acid. The effects of fabrication parameters on the shaping of Li{sub 2}TiO{sub 3} green body were investigated. In addition, the basic characteristics of the sintered pebble were also evaluated. The shape of Li{sub 2}TiO{sub 3} green bodies was affected by slurry viscosity, PVA content and boric acid content. The grain size and average crush load of sintered Li{sub 2}TiO{sub 3} pebble were controlled by the sintering time. The boron was completely removed during the final sintering process.

  17. Boric acid poisoning

    Science.gov (United States)

    ... for any reason, 24 hours a day, 7 days a week. Take the container with you to the hospital, if possible. ... Transfer to a hospital that specializes in burn care Washing of the ... to a hospital for more treatment. Surgery may be needed if ...

  18. Determination of Iron in Layered Crystal Sodium Disilicate and Sodium Silicate by Flame Atomic Absorption Spectrometry with Boric Acid as a Matrix Modifier

    Institute of Scientific and Technical Information of China (English)

    Zhi Hua WANG; Min CAI; Shu Jun WANG

    2006-01-01

    The effects of matrix silicate and experimental conditions on the determination of iron in flame atomic absorption spectrometry (FAAS) were investigated. It was found that boric acid as a matrix modifier obviously eliminated silicate interference. Under the optimum operating conditions, the determination results of iron in layered crystal sodium disilicate and sodium silicate samples by FAAS were satisfactory. The linear range of calibration curve is 0-10.5 μg.mL-1, the relative standard deviation of method is 1.2%-2.2%, the recovery of added iron is 96.0%-101%, the of iron of the standard curve method, standard addition calibration and colorimetry method was the same, but the first has the merits of rapid sample preparation, reduced contamination risks and fast analysis.

  19. Effect of Addition of Boric Acid and Borax on Fire-Retardant and Mechanical Properties of Urea Formaldehyde Saw Dust Composites

    Directory of Open Access Journals (Sweden)

    Zenat A. Nagieb

    2011-01-01

    Full Text Available Properties of the flame retardant urea formaldehyde (UF board made from saw dust fibers were investigated. Flame retardant chemicals that were evaluated include boric acid (BA and borax (BX which were incorporated with saw dust fibers to manufacture experimental panels. Three concentration levels, (0.5, 1, and 5% of fire retardants and 10% urea formaldehyde resin based on oven dry fiber weight were used to manufacture experimental panels. Physical and mechanical properties including water absorption, modulus of rupture (MOR, and modulus of elasticity (MOE were determined. The results showed that water absorption and bending strength decreased as the flame retardant increased. The highest concentration of (BA + BX enhanced the fire retardant more than the lower ones. Scanning electron microscope and FTIR of composite panels were studied.

  20. The Efficacy of Boric Acid Used to Treat Experimental Osteomyelitis Caused by Methicillin-Resistant Staphylococcus aureus: an In Vivo Study.

    Science.gov (United States)

    Güzel, Yunus; Golge, Umut H; Goksel, Ferdi; Vural, Ahmet; Akcay, Muruvvet; Elmas, Sait; Turkon, Hakan; Unver, Ahmet

    2016-10-01

    We explored the ability of local and systemic applications of boric acid (BA) to reduce the numbers of methicillin-resistant Staphylococcus aureus (MRSA) in a rat model of tibial osteomyelitis (OM), and compared boric acid with vancomycin (V). Implant-associated osteomyelitis was established in 35 rats. After 4 weeks, at which time OM was evident both radiologically and serologically in all animals, the rats were divided into five groups of equal number: group 1, control group (no local application of BA or other medication); group 2, V group; group 3, local BA + V group; group 4, local BA group; and group 5, local + systemic BA group. Serum total antioxidant status, and the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6, were measured. Pathological changes attributable to bone OM were evaluated using a grading system. Bacterial colony-forming units (CFUs) per gram of bone were counted. The lowest bacterial numbers were evident in group 3, and the bacterial numbers were significantly lower than that of the control group in all four test groups (p < 0.001). Group 3 also had the least severe bone infection (OM score 1.7 ± 1.1, p < 0.05). Upon histological and microbiological evaluation, no significant difference was evident between groups 2 and 3. Total antioxidant levels were significantly different in all treatment groups compared to the control group. Microbiological and histopathological evaluation showed that systemic or local application of BA was effective to treat OM, although supplementary V increased the effectiveness of BA.

  1. Effect of boric acid composition on the properties of ZnO thin film nanotubes and the performance of dye-sensitized solar cell (DSSC)

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, M.Y.A., E-mail: mohd.yusri@ukm.edu.my; Roza, L.; Umar, A.A., E-mail: akrajas@ukm.edu.my; Salleh, M.M.

    2015-11-05

    The effect of boric acid (H{sub 3}BO{sub 3}) composition at constant concentration of hexamethylenetetramine (HMT) and zinc nitrate (Zn(NO{sub 3}){sub 2}) on the morphology, thickness, elemental composition, optical absorption, structure, photoluminescence of ZnO nanotubes has been investigated. The performance of the DSSC utilizing the ZnO samples has also been studied. It was found that the structure, thickness, elemental composition, optical absorption and morphology of ZnO nanostructure are significantly affected by the concentration of H{sub 3}BO{sub 3}. The diameter and thickness of ZnO nanotubes decreases as the composition of H{sub 3}BO{sub 3} increases. The DSSC utilizing ZnO nanotubes synthesized at 2 wt. % H{sub 3}BO{sub 3} performs the highest J{sub SC} and η of 2.67 mA cm{sup −2} and 0.29%, respectively. The highest performance of the device is due to the highest optical absorption of ZnO nanotubes sample and lowest charge interfacial resistance. - Graphical abstract: Nyquist plots of the DSSCs utilizing ZnO nanotubes prepared at various boric acid compositions. - Highlights: • Boron was doped into ZnO films by adding H{sub 3}BO{sub 3} into the growth solution. • Diameter and thickness of ZnO nanotubes decreases with the composition of H{sub 3}BO{sub 3}. • The DSSC performs the highest J{sub SC} and η of 2.67 mA cm{sup −2} and 0.29%, respectively. • This is due to high specific surface area and low charge interfacial resistance.

  2. GEMAS: prediction of solid-solution phase partitioning coefficients (Kd) for oxoanions and boric acid in soils using mid-infrared diffuse reflectance spectroscopy.

    Science.gov (United States)

    Janik, Leslie J; Forrester, Sean T; Soriano-Disla, José M; Kirby, Jason K; McLaughlin, Michael J; Reimann, Clemens

    2015-02-01

    The authors' aim was to develop rapid and inexpensive regression models for the prediction of partitioning coefficients (Kd), defined as the ratio of the total or surface-bound metal/metalloid concentration of the solid phase to the total concentration in the solution phase. Values of Kd were measured for boric acid (B[OH]3(0)) and selected added soluble oxoanions: molybdate (MoO4(2-)), antimonate (Sb[OH](6-)), selenate (SeO4(2-)), tellurate (TeO4(2-)) and vanadate (VO4(3-)). Models were developed using approximately 500 spectrally representative soils of the Geochemical Mapping of Agricultural Soils of Europe (GEMAS) program. These calibration soils represented the major properties of the entire 4813 soils of the GEMAS project. Multiple linear regression (MLR) from soil properties, partial least-squares regression (PLSR) using mid-infrared diffuse reflectance Fourier-transformed (DRIFT) spectra, and models using DRIFT spectra plus analytical pH values (DRIFT + pH), were compared with predicted log K(d + 1) values. Apart from selenate (R(2)  = 0.43), the DRIFT + pH calibrations resulted in marginally better models to predict log K(d + 1) values (R(2)  = 0.62-0.79), compared with those from PSLR-DRIFT (R(2)  = 0.61-0.72) and MLR (R(2)  = 0.54-0.79). The DRIFT + pH calibrations were applied to the prediction of log K(d + 1) values in the remaining 4313 soils. An example map of predicted log K(d + 1) values for added soluble MoO4(2-) in soils across Europe is presented. The DRIFT + pH PLSR models provided a rapid and inexpensive tool to assess the risk of mobility and potential availability of boric acid and selected oxoanions in European soils. For these models to be used in the prediction of log K(d + 1) values in soils globally, additional research will be needed to determine if soil variability is accounted on the calibration.

  3. Application study of boric acid glycerin polyester in electrolytic capacitors%硼酸丙三醇聚酯在铝电解电容器工作电解液中的应用研究

    Institute of Scientific and Technical Information of China (English)

    周攀登; 刘仁其; 龙立平

    2013-01-01

    采用正交实验法配制了一种耐高压电容器工作电解液配方,在该配方中添加自己合成的硼酸丙三醇聚酯.研究表明,随着硼酸丙三醇聚酯的添加,电解液的电导率较未加的高,而闪火电压没有明显的变化.即硼酸丙三醇聚酯能提高该工作电解液的电导率,而对闪火电压的影响较小.%Use the orthogonal experiment method to the preparation of a high voltage capacitor work electrolyte formula, Boric acid glycerin polyester have been added to this work electrolyte. The studies showed that the conductivity of the electrolyte had improved greatly, with the addition of boric acid glycerol polyester, while no significant change in the voltage of the flash fire. It means that, boric acid glycerol polyester can improve the conductivity of the electrolyte of the working, and less impact on the voltage of the flash fire.

  4. 非抑制离子色谱法测定膨化食品中硼砂(硼酸)%Determination of Borax( Boric Acid) in Puffing Foods by Non-suppressed Ion Chromatography

    Institute of Scientific and Technical Information of China (English)

    吴凌涛; 余欣达; 潘灿盛; 陈军; 钟新林

    2011-01-01

    A new method was developed for the determination of borax (boric acid) in puffing foods using non-suppressed ion chromatography. The samples were extracted with methanesulfonie acid by ultra-sound. The solution was made passed through OnGuard II RP, Ag column, Na column and filter membrane after centrifugation and filtration. The separation of boric acid was performed on an anion exchange column of Dionex Ionpac AG16(50 mm x4 mm) + AS16(250 mm x4 mm) with 5 mmol/L sodium hydroxide by isocratic elution at a column temperature of 30 °C. The optimum chromatography conditions were investigated. Under the optimal conditions, the calibration curve for boric acid showed a good linearity in the range of 0. 3 - 3. 0 mg/g with correlation coefficient of 0. 999 5. The spiked recoveries for boric acid were in the range of 78% - 105% with RSDs of 1. 5% -4. 6% . The detection limit was 0. 06 mg/g. This method was applicable for the determination of borax (boric acid) in puffing foods.%建立了非抑制离子色谱法测定膨化食品中硼砂(硼酸)的分析方法,优化了色谱分离条件.样品在甲基磺酸溶液中超声提取后,经离心、过滤,依次过RP固相萃取柱、银柱、钠柱、滤膜后,进样分析.采用5 mmol/L氢氧化钠作为淋洗液,硼酸根经Dionex Ionpac AG16(50 mm ×4 mm)+ AS16(250 mm×4 mm)阴离子交换柱等度分离,柱温30℃,电导检测器检测.在优化实验条件下,硼酸的线性范围为0.3~3.0 mg/g,相关系数(r)为0.999 5,回收率为78% ~ 105%,相对标准偏差为1.5% ~4.6%,检出限为0.06 mg/g.该方法适用于膨化食品中硼砂(硼酸)含量的测定.

  5. AN EFFICIENT SYNTHESIS OF 1,3-DIOXANE-4,6-DIONES CATALYZED BY BORIC ACID. Eine effiziente Synthese von 1,3-Dioxan-4 ,6-dione BY BORSÄURE katalysierten

    Directory of Open Access Journals (Sweden)

    Zhao hui XU*,Chun hua Lin ,Jian hui Xia

    2013-07-01

    Full Text Available Several kinds of 1,3-dioxane-4,6-diones have been synthesized from malonic acid and ketones using boric acid as catalyst, acetic anhydride as condensing regent at room temperature. The present method does not involve any hazardous organic solvents, it gives some notable advantages such as mild reaction conditions, short reaction time,less catalyst dosage and high yields.Further study showed that H3BO3 was reused for four times without any noticeable decrease in the catalytic activity.

  6. 复方硼酸含漱液的药理毒理学研究%Pharmacological and toxicological research of compound boric acid gargle

    Institute of Scientific and Technical Information of China (English)

    吴静

    2016-01-01

    ObjectiveTo investigate pharmacology and toxicology of compound boric acid gargle. MethodsA total of 60 rats as study subjects were randomly divided into normal saline group, aspirin group, low, moderate and high compound borax solution groups, with 12 cases in each group. Another 12 rats were taken in acute toxicity test of compound borax solution. Anti-inflammatory, analgesic and bacteriostatic effects by compound borax solution were observed by hot plate test, writhing test and antibacterial experiment in vitro in xylene-induced rat auricle edema and carrageenin-induced rat toe inflammation models. Experimental findings were observed.Results Compound borax solution showed remarkable inhibiting effect on xylene-induced rat auricle edema, and its difference with the normal saline had statistical significance (P<0.05). The difference of improved pain threshold proportion in various compound borax solution dosage groups had statistical significance with the normal saline group (P<0.05). Compound borax solution showed good inhibiting and bactericidal effect on staphylococcus aureus and group A streptococcus, along with high safety and low toxicity.ConclusionCompound boric acid gargle provides remarkable anti-inflammatory, analgesic, and bactericidal effects. It can accelerate early rehabilitation in patients, with precise curative effect and low toxicity.%目的:探讨复方硼酸含漱液的药理毒理学。方法60只小鼠为实验对象,随机分为生理盐水组、阿司匹林组、复方硼酸含漱液低、中、高组,各12只。另选取12只大鼠进行复方硼酸含漱液急性毒性试验。采用二甲苯所致的小鼠耳廓肿胀和角叉菜胶所致大鼠足趾炎症模型、热板法、扭体法以及体外抑菌试验,观察复方硼酸含漱液的抗炎、镇痛以及抑菌作用。观察实验结果。结果复方硼酸含漱液对二甲苯所致的小鼠耳廓肿胀有显著的抑制作用,与生理盐水组比较

  7. Efficient boron abstraction using honeycomb-like porous magnetic hybrids: Assessment of techno-economic recovery of boric acid.

    Science.gov (United States)

    Oladipo, Akeem Adeyemi; Gazi, Mustafa

    2016-12-01

    Porous magnetic hybrids were synthesized and functionalized with glycidol to produce boron-selective adsorbent. The magnetic hybrid (MH) comparatively out-performed the existing expensive adsorbents. MH had a saturation magnetisation of 63.48 emu/g and average pore diameter ranging from meso to macropores. The magnetic hybrids showed excellent selectivity towards boron and resulted in 79-93% boron removal even in the presence of competing metal ions (Na(+) and Cr(2+)). Experiments were performed in a column system, and breakthrough time was observed to increase with bed depths and decreased with flow rates. The batch experiments revealed that 60 min was enough to achieve equilibrium, and the level of boron sorption was 108.5 mg/g from a synthetic solution. Several adsorption-desorption cycles were performed using a simple acid-water treatment and evaluated using various kinetic models. The spent adsorbents could be separated easily from the mixture by an external magnetic field. The cost-benefit analysis was performed for the treatment of 72 m(3)/year boron effluent, including five years straight line depreciation charges of equipment. The net profit and standard percentage confirmed that the recovery process is economically feasible.

  8. Retention of ionisable compounds on high-performance liquid chromatography XVIII: pH variation in mobile phases containing formic acid, piperazine, tris, boric acid or carbonate as buffering systems and acetonitrile as organic modifier.

    Science.gov (United States)

    Subirats, Xavier; Bosch, Elisabeth; Rosés, Martí

    2009-03-20

    In the present work dissociation constants of commonly used buffering species, formic acid, piperazine, tris(hydroxymethyl)-aminomethane, boric acid and carbonate, have been determined for several acetonitrile-water mixtures. From these pK(a) values a previous model has been successfully evaluated to estimate pH values in acetonitrile-aqueous buffer mobile phases from the aqueous pH and concentration of the above mentioned buffers up to 60% of acetonitrile, and aqueous buffer concentrations between 0.005 (0.001 mol L(-1) for formic acid-formate) and 0.1 mol L(-1). The relationships derived for the presently studied buffers, together with those established for previously considered buffering systems, allow a general prediction of the pH variation of the most commonly used HPLC buffers when the composition of the acetonitrile-water mobile phase changes during the chromatographic process, such as in gradient elution. Thus, they are an interesting tool that can be easily implemented in general retention models to predict retention of acid-base analytes and optimize chromatographic separations.

  9. Quantitative Analysis of Borax, Boric Acid and Total Boron in Zhengshiming Diyanye%珍视明滴眼液中硼砂、硼酸及总硼的含量测定

    Institute of Scientific and Technical Information of China (English)

    周平; 张倩; 赵翠; 王伯涛

    2011-01-01

    Objective;To establish the quantitative analysis method for borax, boric acid and total boron in Zhengshiming diyanye. Method; Borax, boric acid and total boron in Zhengshiming Diyanye were determined by micro-titration and constant titration. Result; The linear range of borax was from 8-16 mg, and the regression equation was Y = 504. 52X - 0. 14 ( r = 0. 998 8 ) with the average recovery rate 98. 29% ( n = 6, RSD 1. 37% ). The linear range of boric acid was from 50-70 mg, and the regression equation was Y = 141. 74.X+0. 07, r =0. 999 7 with the average recovery rate 97. 02% (n = 6, RSD 0. 78% ). The linear range of total boron was from 0. 8-1. 2 mmol, and the regression equation was Y = 9. 51 X -0. 05 , r =0. 999 7 with the average recovery rate 95. 29% (n = 6, RSD 0. 75 % ). Conclusion; This method is simple with high accuracy and easy to popularize, can provide foundation for the quality control of Zhengshiming diyanye.%目的:建立珍视明滴眼液中硼砂、硼酸及总硼的含量测定方法.方法:结合微量滴定法与常量滴定法测定珍视明滴眼液中硼砂、硼酸及总硼的含量.结果:硼砂的线性范围为8 ~16 mg,线性方程Y=504.52X -0.14(r=0.998 8),加样回收率为98.29% (n =6,RSD 1.37%).硼酸的线性范围为50 ~ 70 mg,线性方程y=141.74X +0.07,(r=0.999 7),加样回收率为97.02%(n=6,RSD 0.78%).总硼的线性范围在0.8 ~1.2 mmol,线性方程Y=9.51X -0.05 (r=0.999 7),加样回收率为95.29%(n =6,RSD 0.75%).结论:该方法简单、准确度高、易于推广,可用于珍视明滴眼液的质量评价.

  10. Research on the Antirust Performance of Eco-friendly Nitrogen Organic Boric Acid Ester%环境友好型含氮硼酸酯的防锈性能研究

    Institute of Scientific and Technical Information of China (English)

    张佳; 杨红刚; 陈琛; 曹居正; 毕玉岩

    2011-01-01

    Nitrogen organic boric acid ester was synthesized by hydroxymethylation BTA and oleic acid polyacrylamide boric acid ester two ethanol. The corrosion inhibition performance in the aqueous solution was evaluated by the weight-loss and antirust experiment. The lubricity was evaluated by four ball test machine test, and cleaning performance was e-valuated through ring method. Discuss the influence on the antirust performance such as volume, temperature and time. Results showed that all of the capabilities were good when the synthesis of product's additive quantity was 0. 25%, and antirust properties kept well under a little higher temperatures and longer working-time. The product could be used as anti-rust and lubricating additives for water-based cutting fluid.%合成出一种有机硼酸酯,含有羟甲基化苯并三氮唑和油酸二乙醇酰胺硼酸酯的特征基团.采用失重法、防锈试验方法测定了其防腐蚀及防锈性能.并采用四球摩擦磨损试验法、圆环法测定其润滑性与清洗性.在改变添加剂添加量、实验温度、实验时间的条件下探讨这些因素对切削液性能的影响.结果表明,在合成产物的质量分数添加量为0.25%时,各项性能测试情况良好,在较高温度及较长时间的连续工作情况下仍保持优良的防锈性能,可用作水基切削液中常用的防锈润滑添加剂.

  11. 柱前衍生-高效液相色谱法测定香精香料中硼酸和硼砂%HPLC Determination of Boric Acid and Borax in Essence and Perfume with Precolumn Derivatization

    Institute of Scientific and Technical Information of China (English)

    周示玉; 蒋健; 周国俊; 胡宝祥; 李祖光

    2012-01-01

    香精香料样品中的硼酸经姜黄素的乙酸溶液在室温下进行衍生化,所得硼的衍生物用高效液相色谱法分析。选用Hypersil ODS2色谱柱(4.6mm×250mm,5μm)为固定相,以甲醇与0.012m01.L^-1四丁基溴化铵(TBABr)溶液按体积比80比20混合所得溶液为流动相进行淋洗,于波长550nm处进行检测。根据硼砂在硫酸环境下定量转化成硼酸的原理间接测定硼砂。硼的色谱峰面积与其质量浓度在0.004-0.2mg·L叫范围内呈线性关系,检出限(3s)为4.0×10^-4mg·L^-1。在3个浓度水平下做加标回收试验,所得硼酸和硼砂的平均回收率分别在92.1%-106.6%和92.9%-107.1%之间。%Boric acid in samples of essence and perfume was derivatized with curcumin (dissolved in acetic acid) at room temperature. The derivatized product of boron was used for HPLC analysis, using Hypersil ODS2 chromatographic column (4.6 mm×250 mm, 5 μm) as stationary phase and mixtures of methanol and 0. 012 mol · L^-1 TBABr (802-20) as mobile phase. Based on the quantitative conversion of borax into boric acid in sulfuric acid medium, borax was determined by indirect determination of boric acid. I.inear relationship was found between values of peak area determined at wavelength of 550 ran and mass concentration of boron in the range of 0. 004-0. 2 mg· L^-1, with detection limit (3s) of 4. 0 × 10-4 mg· L^- 1. Tests for recovery were performed by standard addition method at 3 concentration levels; results of recovery of boric acid and borax found were in the ranges of 92. 1%- 106.6% and 92.9%-107. 1% respectively.

  12. 芳基硼酸聚合作用下高分子防火材料制备技术%Preparation Technology of Polymer Fire Retardant Materials Under Action of Aromatic Boric Acid Polymerization

    Institute of Scientific and Technical Information of China (English)

    谭瑶

    2016-01-01

    The preparation of polymer materials with high polymer materials under the action of boric acid polymerization was proposed. First memory aryl boric acid polymer molecular characteristics analysis, polymer of fire resistance and flame retardant characteristics analysis, experiment, hafnium chloride (I. g, 4.0 mmol) and APTES (AR) AIDRICH- thiol acrylate (1.32 g, 8.0 mmol) was dissolved in DMF, aryl boric acid polymer nanometer TiO2 powder (30%) with Tween-208- crown 6 content increased with increasing. Under temperature programmed synthesized screw [4,4]-1,6- Ren dimethyl- 3- phenyl propylene, high pressure dense phase processing, in the hyperbaric chamber with 10 DEG C- min-1 speed heated from room temperature to 240 DEG C, join for thermionic coating and improve the fireproof material of thermal stability, chemical stability and mechanical stability in the expansion and contraction of the state, the completion of aryl boric acid polymerization under the action of macromolecule fire-proof material preparation. The experimental results show that the method has good thermal stability, high heat absorption peak and flame retardant layer with high thermal stability, high temperature resistance and fire resistance.%提出采用基硼酸聚合作用下高分子防火材料制备技术.首先根据芳基硼酸聚合物的分子特性分析,进行聚合物的防火性和阻燃性特征分析,实验中,将氯化铪(1.281 g,4.0 mmol)和APTES(AR AIDRICH)3-巯丙(1.32 g,8.0 mmol)溶于DMF中,芳基硼酸聚合物TiO2纳米粉体(30%))随着Tween-208-冠-6含量的增加而增加.在程序控温下,合成了螺[4,4]-1,6-壬二甲基-3-苯基丙烯,进行高压密相处理,在高压舱中以10℃·min-1的速度从室温加热到240℃,加入换热离子涂层,在热胀冷缩状态下提高防火材料的热稳定性、化学稳定性和力学稳定性,完成芳基硼酸聚合作用下高分子防火材料制备.实验结果表明,采用该方法制

  13. 含氮硼酸酯在聚醚水溶液中的成膜性能%Film-forming Property of Polyether Aqueous Solutions with Nitrogenous Boric Acid Ester

    Institute of Scientific and Technical Information of China (English)

    耿明; 张朝辉; 刘思思; 孙跃涛; 明尔扬

    2013-01-01

    含氮硼酸酯和聚醚添加剂都是性能良好的水基润滑添加剂,两种添加剂的混合水基润滑液的成膜性能尚未研究.将月桂酸无规共聚醚(Lauric acid random copoly-ether,LPE)和硼酸三乙醇胺(Boric acid triethanolamine,BN)按质量比为1∶1混合后得到无色透明的水基润滑液,选取半浸泡的润滑方式,利用纳米级润滑膜厚度测量仪(NGY-6型)进行膜厚测量并做机理分析,分别从浓度、载荷和线速度三方面研究水基润滑液的成膜性能.结果表明该水基润滑液(浓度5%,载荷100N)膜厚度基本稳定在5.5 nm,承受0.86 GPa的载荷;水基润滑液的成膜性能受浓度、载荷和线速度综合影响,随着载荷的增大,线速度对成膜性能的影响越小.经分析该水基润滑液在试验中形成化学吸附膜.纳米级厚度润滑薄膜的成膜性能研究将在精密仪器领域有很大的应用.%Nitrogen contained boric acid ester and polyether additive are all well-performed water-based lubricant additives. The film forming properties of the two additives mixed water-based lubricating fluid is not studied. The transparent aqueous solution is the 1:1 (m/m) mixture of lauric acid random copoly-ether (LPE) and boric acid triethanolamine (BN). The effect of concentration, load and linear speed on the film-forming property of the mixed polyether aqueous solution are analyzed by the nanometer scale lubrication film thickness gauge (NGY-6). Results of the tests show that film thickness of the water-based lubricant (5%, v/v, load 100 N) is 5.5 nm, and it can bear the load of 0.86 GPa. The film-forming property of water-based lubricants is affected by the concentration, load and linear speed. With the increase in the load, the effect of linear speed on film-forming property decreases. Meanwhile, in the experiments, the chemical adsorption film is formed on the friction pair surfaces. The nanoscale film-forming properties of the lubricating film can be widely

  14. Development of Twelve Acid Diethanolamide Boric Acid Ester and Its Application in Semi-synthetic Cutting Fluid%十二酸二乙醇酰胺硼酸酯的制备及其在半合成切削液中的应用

    Institute of Scientific and Technical Information of China (English)

    袁博; 衣守志; 杜天源

    2015-01-01

    Twelve acid diethanolamide boric acid ester was prepared by using twelve acid and diethanolamine and boric acid as raw materials,and its structure was analyzed by using Fourier Transform Infrared Spectrometer. A semi⁃synthetic cutting fluid was prepared by adding a certain amount of boric acid ester into the base oil,the corrosion performance and anti⁃rust property were analyzed,and the extreme pressure and anti⁃wear properties were tested by four ball friction testing machine. The results show that the prepared borate ester has good extreme pressure and anti⁃wear properties in semi⁃syn⁃thetic cutting fluid,when the mass fraction of boric acid ester is 11�3%,the friction coefficient of 5% diluent of the cutting fluid reaches 0�056 and maximum non⁃seizure load reaches 392 N.The performance indicators of the semi synthetic cutting fluid with the borate ester as additive meet the national standard of GB/T 6144⁃2010.%采用十二酸、二乙醇胺和硼酸为原料制备十二酸二乙醇酰胺硼酸酯,采用傅里叶变换红外光谱仪分析其结构。将一定量的该硼酸酯加入基础油中制备一种半合成切削液,分析其腐蚀性能和防锈性能,并通过四球摩擦试验机测试其极压抗磨性能。结果表明;制备的硼酸酯在半合成切削液中具有良好的极压抗磨性能,当硼酸酯的质量分数为11�3%时,5%切削液稀释液的摩擦因数达到0�056,最大无卡咬负荷达到392 N。采用该硼酸酯制备的半合成切削液的各性能指标达到GB/T 6144⁃2010标准。

  15. Enraizamento de estacas de Ginkgo biloba tratadas com ácido indolbutírico e ácido bórico Rooting of Ginkgo biloba cuttings treated with indolbutyric and boric acids

    Directory of Open Access Journals (Sweden)

    Janice Valmorbida

    2008-04-01

    Full Text Available Objetivou-se neste trabalho estudar o efeito do ácido indolbutírico (AIB e do ácido bórico (B no enraizamento de estacas de Ginkgo biloba. Em estacas com duas folhas, medindo 15 cm de comprimento foram provocadas duas lesões na base de aproximadamente 2 cm, expondo o câmbio e procedeu-se à imersão por 10 segundos no tratamento correspondente, AIB (0, 1000, 2000 e 3000 mg L-1 na ausência ou presença de B (0 e 150 mg L-1. Em seguida foram colocadas para enraizar em bandejas de polipropileno contendo areia lavada. O delineamento foi em blocos casualizados num fatorial 4X2, com seis repetições. Foram avaliadas porcentagem de estacas enraizadas, estacas não enraizadas e mortas, diâmetro e comprimento das raízes, aos 70 dias do tratamento. Os dados foram submetidos à análise de variância sendo previamente testados para normalidade pelo Teste de Shapiro-Wilk. As médias foram comparadas pelo Teste de Tukey. Os tratamentos com 2000 mg L-1 de AIB foram superiores à ausência de AIB (80,55% vs. 55,56%, respectivamente, não diferindo dos demais tratamentos. A utilização de B não afetou a taxa de enraizamento, de estacas não enraizadas e mortas, não havendo interação entre a concentração de AIB e a utilização ou não de B. O diâmetro e o comprimento das raízes não foram afetados pela utilização de AIB e B.The aim of the work was to study the effect of indolbutyric (IBA and boric (B acids to root Ginkgo biloba cuttings. At the base of cuttings, with two leaves and 15 cm of length, were made two lesions with 2 cm to expose the cambium. Cuttings were treated for a period of 10 seconds with four concentrations of IBA (0, 1000, 2000 and 3000 mg L-1 combined with two concentration of B (0 and 150 mg L-1. After that, cuttings were taken in polypropylene trays filled with washed sand. The experimental design was of randomized blocks in the factorial arrangement (4x2, with six replications. After 70 days, evaluations were done

  16. 不同浓度配比硼酸溶液比定压热容的实验测量%Experimental measurement of isobaric heat capacity of boric acid solution

    Institute of Scientific and Technical Information of China (English)

    宋星佑; 苏超; 刘向阳; 何茂刚

    2015-01-01

    采用高精度的流动型量热法测量了温度在303~396 K、压力在0.1~0.5 MPa时,质量摩尔浓度分别为0.648、3.700(无杂质)和3.700(含杂质)mol/kg 三种配比硼酸溶液的比定压热容。实验系统的温度、压力、比定压热容的测量不确定度分别小于0.05 K、18 kPa、0.28%。为了验证实验系统的测量精度和可靠性,测量了温度为296~396 K、压力为0.1~6.0 MPa内纯水的比定压热容,与 NIST 值相比的相对偏差绝对平均值为0.41%。%Isobaric heat capacities of boric acid solution at the concentrations of 0.648,3.700 (no impurities)and 3.700 mol/kg (containing impurities) were measured using high accuracy flow calorimeter at temperatures of 303-396 K and pressures of 0.1-0.5 MPa.The uncertainties of temperature,pressure,and isobaric haet capacity were less than ±0.05 K,±18 kPa and ±0.28 %, respectively.In order to evaluate the reliability of the experimental system,isobaric heat capacities of pure water at temperatures of 296-396 K and pressures from atmosphere to 6.0 MPa were measured, and the measured average relative deviation from the NIST literature values is within 0.41%.

  17. 硼酸及硼酸酯类过氧化氢荧光探针的最新研究进展%Recent advances in the boric acid/boronate-based fluorescent probes for detection of hydrogen peroxide

    Institute of Scientific and Technical Information of China (English)

    李震宇; 李静; 杜吕佩; 李敏勇; 沈月毛

    2012-01-01

    生物新陈代谢过程中产生的过氧化氢(H2O2)是生命活动所必需的,但是过量过氧化氢的存在可以引发多种疾病,因此对体内过氧化氢的检测具有重要意义.采用荧光探针法,借助激光共聚焦成像技术能够实现对活细胞和组织内的过氧化氢“实时、可见、定量”的检测,为深入阐明过氧化氢在生理和病理过程中所起的作用提供了一个重要手段.本文按荧光探针的结构分类,对近几年来以硼酸及硼酸酯基团作为荧光开关的具有高选择性和灵敏度的过氧化氢荧光探针进行了综述,主要探讨其设计思想、作用机制及应用,为过氧化氢探针的设计提供了新思路.%The physiological level of hydrogen peroxide (H2O2) is believed to be indispensable in regulating diverse cellular processes. However, excessive hydrogen peroxide generation is involved in the pathogenesis of many diseases, including cardiovascular disease, cancer, and neurological disorders. Thus, it is of significance to detect hydrogen peroxide in vivo. Fluorescent probe method, combined with confocal laser scanning microscopy (CLSM) can be used in real-time, visible and quantitative detection of hydrogen peroxide in living cells and tissues, which provides powerful tools for the understanding of hydrogen peroxide in physiological and pathological processes. This critical review highlights recent advances of design, mechanisms and applications of boric acid/boronate-based fluorescent probes employed to monitor hydrogen peroxide.

  18. 硼酸木材防虫剂预防建筑物白蚁药效研究%Efficacy of boric acid wood preservative against termite in buildings

    Institute of Scientific and Technical Information of China (English)

    尹红; 隋晓斐

    2011-01-01

    Objective To measure the efficacy of boric acid wood preservatives in the prevention of Coptotermes formosanus (Shiraki) and Reticulitermes speratus (Kolbe) in buildings. Methods A cohort of C. formosanus or R. speratus were subject to timbers or wood blocks treated with 5% or 10% borate preservative by painting or dipping to determine the respective toxicity and residual effect. Results Borate treated wood demonstrated a good resistance effect against C. formosanus and R. speratus, which were dead at both concentrations with either wood treatment approach. C. formosanus were more susceptible to the agent as the subjects demonstrated shorter survival duration. All subjects of C. formosanus died in ( 12.6 ± 2.4) days and all R. speratus in (16.8 ± 1.7)days as exposed to wood without ageing, both shorter than the time for death of the groups exposed to wood after ageing, (19.1 ±2.7) days for C. formosanus and (21.8±5.0) days for R. speratus, respectively. The death rate of the control group was lower than 0.1%. C. formosanus was more susceptible to boric acid in view of the resistance effect, as the intactness index of each piece of borate treated wood in that group was higher than 90. The intactness index of wood treated in 5% by painting or 10% agent by either painting or dipping, with or without ageing, remained above 90. In contrast, wood in the control group was seriously damaged with the intactness index as low as 60 and 40, respectively. It was suggested that borate treated wood had satisfyingly stable and long-last toxicity against termites, which was not compromised by ageing. Conclusion Borate wood preservative can be used for wood treatment for effective termite prevention in buildings.%目的 研究硼酸木材防护剂对危害建筑物的台湾乳白蚁和栖北散白蚁的预防效果.方法 用涂刷法和浸泡法处理木材,然后采用群体法测定5%和10%浓度的药液对台湾乳白蚁和栖北散白蚁的毒效

  19. 铈盐对铝合金硼酸-硫酸阳极氧化膜的封闭效应%Sealing effect of cerium salt on boric-sulfuric acid anodic film of aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    王帅星; 赵晴; 杜楠; 邵志松; 舒伟发; 陈庆龙

    2012-01-01

    The boric-sulfuric acid anodic (BSAA) film on aluminum alloy was sealed by cerium salt conversion solution. The effects of sealing parameters on the corrosion resistance of BSAA film were researched through electrochemical impedance spectroscopy (EIS), while the corrosion resistance of anodic films sealed by different methods was studied. It is found that the resistance of porous layer increases significantly, the corrosion resistance is improved greatly and the corrosion current density is reduced by about 1 order of magnitude when the BSAA film was immersed in the cerium conversion solution (5 g/L Ce(NO3)3+0.5% H2O2) at 30 ℃ for 30 min. Besides, the corrosion resistance of BSAA film sealed by this method is much better than that by boiling water sealing, and also slightly superior to that of the dilute CrO3 solution sealing. Combined with EDS analysis results, it is indicated that a intact, compact cerium conversion film forms on the outside surface of BSAA film, and the porous layer is also filled with sealing products when the BSAA film is sealed by cerium salt conversion solution. The synergism of the two actions almost completely sealed the pores of BSAA film, thereby effectively improving the corrosion resistance of anodic film.%将铝合金硼酸-硫酸阳极氧化膜浸入铈盐转化液中进行封闭.采用交流阻抗谱技术研究各封闭参数对氧化膜耐蚀性的影响,比较了不同方法封闭的氧化膜的耐蚀性差异.结果表明:将硼酸-硫酸阳极氧化试样浸入30℃的铈盐转化液(5 g/L Ce(NO3)3+0.5% H2O2)中处理30min后,多孔层电阻Rp大幅增加,且腐蚀电流密度降低1个数量级,耐蚀性明显优于沸水封闭氧化膜的,也稍优于稀铬酸封闭氧化膜的耐蚀性.结合EDS分析表明:铈盐转化封闭后硼酸-硫酸阳极氧化膜的外表面形成了一层完整致密的铈盐转化膜,多孔层内也充满了铈的封闭产物,二者的协同作用几乎完全封住了硼酸-硫酸阳极氧

  20. 星点设计-效应面法优化硼酸乳膏基质配方及质量控制%Optimization of the Base Formula of Boric Acid Cream by Central Composite Design-response Surface Methodology and Its Quality Control

    Institute of Scientific and Technical Information of China (English)

    侯晓军; 唐菱; 周芃; 张小琼

    2016-01-01

    Objective:To optimize the base formula of boric acid cream,and investigate its quality. Methods:Using central composite design-response surface methodology,with the viscosity of cream as the index,the amounts of Cremophor A6,Cremophor A25,cetyl alcohol,stearyl alcohol,isooctadecyl isooctadecanoate,jojoba oil and light liquid paraffin were optimized. The appearance characteristics,particle size,viscosity and stability of the preparation and the content of boric acid were studied. Results:The optimal conditions were as follows:50 g Cremophor A6-Cremophor A25(3 ∶2),65 g cetyl alcohol-stearyl alcohol(3∶7),and 125 g isooctadecyl isooctadecanoate-jojoba oil- light liquid paraffin(5 ∶3 ∶2). According to the optimal formula,the cream showed the property of semi-fluid cream,the content of boric acid was 98. 5% of the labeling amount,and the viscosity was about 1. 64 × 104 mPa·s. The predicted value was equivalent to the measured one,and the stability of the preparation was promising. Conclusion:The central composite design-response surface methodology used in the base optimization of boric acid cream is simple with high precision and good predictability,and the quality of the preparation is stable and controllable.%目的:优化硼酸乳膏基质配方,考察制剂成品质量。方法:采用星点设计效应面法,以乳膏黏度为评价指标,优化脂肪醇醚-6(和)硬脂醇、鲸蜡硬脂醇聚醚-25、十六醇、十八醇、异硬脂醇异硬脂酸酯、霍霍巴油、轻质液状石蜡的用量;考察优化后制剂的外观性状、粒度、黏度、稳定性及硼酸的含量。结果:配方中含脂肪醇醚-6-鲸蜡硬脂醇聚醚-25(3∶2)50 g、十六醇-十八醇(3∶7)65 g、异硬脂醇异硬脂酸酯-霍霍巴油-轻质液状石蜡(5∶3∶2)125 g 时,制得的成品为白色半流体乳膏,硼酸含量为标示量的98.50%,粘度为1.64×104 mPa·s,预测值与实测值相当,制剂稳定性较好

  1. 氦氖激光照射联合硼酸湿敷治疗老年患者压疮的效果%Effect of helium neon laser irradiation combined with boric acid wet packing on elder patients with pressure ulcers

    Institute of Scientific and Technical Information of China (English)

    黄萍; 王怡; 张宇; 周翠柳; 潘切; 丁桂凤

    2011-01-01

    Objective To investigate the clinical effect of helium neon laser irradiation combined with boric acid wet packing on elder patients with pressure ulcers.Methods 52 cases of elderly patients with pressure ulcer were randomly divided into treatment group and control group.The control group was treated with boric acid wet packing after the wound debridement.The treatment group was treated with the helium neon laser irradiation on the pressure ulcer surface 20 minutes after the wound debridement and then boric acid wet packing once a day.Both groups received comprehensive treatment and nursing measures of pressure ulcers.Pressure ulcer healing was observed for 30 days.Results The effective rate of the treatment group was 96.2% and that of the control group was 69.2%.Clinical effect of the treatment group was better than that of the control group,and the difference was statistically significant( x2 =4.837,P <0.05 ).The effect initiating time of the treatment group was lower than the control group [ ( 12.19 ± 6.40) d vs ( 19.36 ± 9.30) d],and the difference was statistically significant ( t =- 2.425,P < 0.05 ).Conclusions Helium neon laser irradiation combined with boric acid wet packing can promote wound healing of pressure ulcers in elder patients,shorten course of disease.%目的 探讨氦氖激光照射联合硼酸湿敷治疗老年患者压疮的效果.方法 将52例住院带有压疮的老年患者随机分成对照组和治疗组,对照组常规清洁疮面后用硼酸纱布湿敷;治疗组同样清创后给予氦氖激光照射压疮表面20 min,再用硼酸纱布湿敷,每天1次.两组患者治疗期间均采用压疮综合治疗护理措施.观察30 d压疮愈合情况.结果 治疗组有效率为96.2%,对照组有效率为69.2%.两组比较差异有统计学意义(x2=4.837,P<0.05);治疗组显效时间也明显较对照组缩短[(12.19 ±6.40)d比(19.36±9.30)d],差异有统计学意义(t=-2.425,P<0.05).结论 氦氖激光照射联合

  2. Solid Phase Extraction by Boric Acid-Functionalized Silica for Determination of Dopamine with High Performance Liquid Chromatography%基于新型硼酸固相萃取柱的多巴胺色谱分析方法

    Institute of Scientific and Technical Information of China (English)

    段语晖; 卫引茂

    2013-01-01

    用“点击化学”方法,将炔基化3-氨基苯硼酸与叠氮化硅胶反应,制备了新型硼酸固相萃取吸附剂.采用固相萃取(SPE)对样品进行前处理,反相高效液相色谱分离,紫外检测,建立了一种快速、高效、灵敏的多巴胺分析方法.固相萃取的最优条件为:对200 mg吸附剂装填的萃取柱,用甲醇活化,磷酸盐缓冲溶液(pH 8.0)平衡,再分别用1mL水和2 mL 20%甲醇淋洗,3 mL 1 mol/L醋酸甲醇溶液洗脱.采用C18反相色谱柱,50 mmol/L磷酸二氢钠-乙腈-甲醇流动相(7∶2∶1,V/V)和检测波长280nm的色谱条件,对洗脱液进行色谱分析.结果表明,该吸附剂对顺式邻羟基化合物有良好的识别能力.在最优萃取条件下,多巴胺的回收率达90%以上.多巴胺分析的线性范围为0.1 ~ 100 mg/L,检出限为0.0001 mg/L,相对标准偏差(RSD)<10.6%.在实际样品分析中,大鼠空白血加标液的回收率均高于97%,相对标准偏差为4.30%.%A new boronic acid-functionalized solid phase extraction ( SPE) sorbent was prepared by the reaction of 3-aminophenyl boronic acid with azide-functionalized silica through "click chemistry". A SPE-HPLC-UV method was developed for the determination of dopamine. The solid-phase extraction conditions were optimized as following: the extraction column packed with 200 mg of sorbent was activated by methanol and equilibrated with phosphate buffer (pH 8.0), and then the loaded sample was washed with 1.0 mL of water followed by 2. 0 mL of 20% methanol aqueous solution to remove interferences and finally the dopamine was eluted with 3 mL of 1. 0 mol/L acetic acid in methanol solution. Using C18 reversed phase chromatographic column, dihydrogen phosphate buffer (50 mmol/L; sodium salt)-acetonitrile-methanol (7:2:1, V/V) as the mobile phase, the eluent was analyzed by HPLC at wavelength of 280 nm. The results showed that the sorbent had excellent recognition ability toward cis-diols compounds. Under the

  3. EFFCTS OF pH AND Cl- CONCENTRATION ON THE CORROSION BEHAVIOR OF COPPER IN BORIC ACID BUFFER SOLUTION%硼酸缓冲溶液中pH值和Cl-浓度对Cu腐蚀行为的影响

    Institute of Scientific and Technical Information of China (English)

    王长罡; 董俊华; 柯伟; 陈楠

    2011-01-01

    The strategy for disposal of high-level radioactive waste in china is to enclose the spent nuclear fuel in sealed metal canisters which are embedded in bentonite clay hundreds meters deep in the bed-rock. The choice of container material depends largely on the redox conditions and the aqueous environment of the repository. One of the choices for the fabrication of waste canisters is copper, for it is thermodynamically stable under the saline, anoxic conditions over the large majority of the container lifetime. For this advantage, some other countries (Canada, Sweden) have selected copper as the material of nuclear waste container. However, in the early aerobic phase of the geological disposal the corrosion of copper could take place, and the corrosion behavior of copper would be influenced by the complex chemical conditions of groundwater markedly. Regularly, in atmosphere environment the semiconductor passive film which is constructed by Cu2O would generate on the surface of copper. On the one hand, the Cu2O film could protect copper from corrosion. On the other hand, the formation of Cu2O film is necessary to maintain the propagation of crack during the stress corrosion cracking. Therefore, the study of the effect of water chemistry conditions on the stability of Cu2O passive film makes great sense for the general corrosion and stress corrosion cracking of copper. For copper and copper alloy, Cl- is a highly aggressive ion. Lots of cases of failure and corrosion behavior of copper and copper alloy in Cl- environment have been studied. The immersion of Cl- would affect the semiconductor properties of Cu2O, therefore, we focused on the effect of pH and Cl- concentration on the corrosion behavior and semiconductor properties of Cu2O in this paper. The polarization behavior of Cu electrodes and the stability of passive film Cu2O in boric acid buffer solution have been investigated respectively by potentiodynamic polarization, electrochemical impedance spectroscopy

  4. Efeito da época de estaquia, fitorreguladores e ácido bórico no enraizamento de estacas de porta-enxertos de videira Effect of pruning time, growth regulators and boric acid on rooting of grape rootstock cuttings

    Directory of Open Access Journals (Sweden)

    S. Leonel

    1993-05-01

    Full Text Available Estudaram-se as interações entre os ácidos indol-butírico, alfa-naftaleno-acético e bórico no desenvolvimento de raízes em estacas de porta-enxertos de videira (Vitis vinifera L.. As estacas tinham aproximadamente 25 cm de comprimento e, necessariamente, 2 gemas, sendo obtidas em três épocas distintas (janeiro, abril e julho e colocadas para enraizar em bandejas de isopor, tendo vermiculita como substrato, e mantidas sob nebulização. O tratamento constou da imersão de 2,5 cm da base das estacas em soluções, por um tempo de imersão de 1 minuto. Os tratamentos utilizados corresponderam a: 1 .000; 2.000 e 5.000 ppm de IBA; 1.500 e 3.000 ppm de NAA; 150 microgramas/ml de H3BO3; IBA 1.000; 2.000 e 5.000 + H3BO3 150 microgramas/ml e H2O. Avaliaram-se a porcentagem de enraizamento, o número médio de raízes formadas por estaca e o comprimento médio das raízes (mm aos 90 dias após a instalação, no mês de julho. O IBA 2.000 ppm propiciou o enraizamento em 88,87% das estacas, contudo não diferiu estatisticamente da testemunha (H2O-61,10%. A melhor época de coleta de estaca para o enraizamento foi o mês de julho (inverno.The effects of indolebutyric, naphtalen acetic and boric acids were studied on rooting of grape rootstock cuttings. The cuttings were 25 cm long with two buds and were taken in three different times (January, April and July. Rooting was carried out in styrofoam trays with vermiculite as substratum and under intermittent mist. Cuttings were imersed up to 2.5 cm from the base in solutions for one minute. The treatments were: 1,000; 2,000 and 5,000 ppm of IBA; 1,500 and 3,000 ppm of NAA; 150 micrograms/ml H3BO3; IBA 1,000; 2,000 and 5,000 ppm plus H3BO(3150 niicrograins/ml and H2O. Rooting percentage, average number of roots per cutting and average length of roots (mm were evaluated 90 days after planting, in July. IBA at 2,000 ppm was the best treatment with 88.8% of rooted cuttings. The best time for rooting was

  5. Photocatalytic Degradation of Dicofol and Pyrethrum with Boric and Cerous Co-doped TiO2 under Light Irradiation

    Institute of Scientific and Technical Information of China (English)

    GONG Lifen; ZOU Jing; ZENG Jinbin; CHEN Wenfeng; CHEN Xi; WANG Xiaoru

    2009-01-01

    Boric and cerous co-doped nano titanium dioxide (B/Ce co-doped TiO2) was synthesized using a sol-gel tech-nique, which involved the hydrolyzation of tetrabutyl titanate with the addition of boric acid and cerous nitrate. The B/Ce co-doped TiO2 was employed for the photocatalytic degradation of dicofol, cyfluthrin and fenvalerate under light irradiation. XRD, TEM, Fr-IR and UV-Vis DRS methods were used to characterize the crystalline structure. Experimental results showed that only the anatase signal phase was found for B/Ce co-doped TiO2, but multiplicate phases, including anatase, rutile and less brookite phases, were identified both in the pure TiO2 nanoparticles and Ce-doped TiO2 nanoparticles. The band gap value of B/Ce co-doped nano TiO2 was narrower than that of undoped nano TiO2. Compared to undoped TiO2, a stronger absorption in the range of 420 to 850 nm was found for B/Ce co-doped nano TiO2, which presented a higher photocatalytic activity in the degradation of dicofol, cyfluthrin and fenvalerate than both Ce doped nano TiO2 and pure nano TiO2 under the same light irradiation.

  6. Determination of organic acids evolution during apple cider fermentation using an improved HPLC analysis method

    NARCIS (Netherlands)

    Zhang, H.; Zhou, F.; Ji, B.; Nout, M.J.R.; Fang, Q.; Zhang, Z.

    2008-01-01

    An efficient method for analyzing ten organic acids in food, namely citric, pyruvic, malic, lactic, succinic, formic, acetic, adipic, propionic and butyric acids, using HPLC was developed. Boric acid was added into the mobile phase to separate lactic and succinic acids, and a post-column buffer solu

  7. Cementation of wastes with boric acid; Cimentacao de rejeitos contendo acido borico

    Energy Technology Data Exchange (ETDEWEB)

    Tello, Cledola C.O.; Haucz, Maria Judite A. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil); Alves, Lilian J.L.; Oliveira, Arno H. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2000-07-01

    In nuclear power plants (PWR) are generated wastes, such as concentrate, which comes from the evaporation of liquid radioactive wastes, and spent resins. Both have boron in their composition. The cementation process is one of the options to solidify these wastes, but the boron has a negative effect on the setting of the cement mixture. In this paper are presented the experiments that are being carried out in order to overcome this problem and also to improve the efficiency of the process. Simulated wastes were cemented using additives (clays, admixtures etc.). In the process and product is being evaluated the effect of the amount, type and addition order of the materials. The mixtures were selected in accordance with their workability and incorporated waste. The solidified products are monolithic without free water with a good mechanical resistance. (author)

  8. Low-temperature sintering of silica-boric acid-doped willemite and microwave dielectric properties

    Science.gov (United States)

    Ando, Minato; Ohsato, Hitoshi; Igimi, Daisuke; Higashida, Yutaka; Kan, Akinori; Suzuki, Sadahiko; Yasufuku, Yoshitoyo; Kagomiya, Isao

    2015-10-01

    Millimeter-wave wireless communications in a high-level information society have been expanding in terms of high-density data transfer and radar for pre-crash safety systems. For these communications, millimeter-wave dielectrics have been expected for the development of substrates with high quality factor (Qf), low dielectric constant (ɛr), and near-zero temperature coefficient of resonance frequency (TCf). We have been studying several silicates such as forsterite, willemite, diopside, wollastonite, and cordierite/indialite glass ceramics. In this study, the synthesis of willemite and low-temperature-sintered willemite for low temperature co-fired ceramics (LTCC) is examined. The raw materials used for preparing slurries in doctor blade tape casting are also analyzed.

  9. EFFECT OF BORIC ACID ON THE EXTRACTION OF BASTNASITE LEACHING LIQUOR BY CYANEX 923

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    IntroductionIt is known that bastnasite is one of the mainsources of cerium. Bac it is still a problem forhydrometallurgy of bastnasite because of large amountof fluorine in the ore. Fltiorine in the bastnasiteleaching liquor forms precipitation with trivalent rareearths and leads to emulsion. So several roastingprocesses of bastnasite with alkali have been putforward and chelants have been added tO eliminate theinfluence of fluorinell-4]. The general chelant is boricacid. One new process with Cyanex 923151...

  10. Role of boric acid in nickel nanotube electrodeposition: a surface-directed growth mechanism.

    Science.gov (United States)

    Graham, Lauren M; Cho, Seungil; Kim, Sung Kyoung; Noked, Malachi; Lee, Sang Bok

    2014-01-18

    Nickel nanotubes have been synthesized by the popular and versatile method of template-assisted electrodeposition, and a surface-directed growth mechanism based on the adsorption of the nickel-borate complex has been proposed.

  11. Boric acid permeation in forward osmosis membrane processes: modeling, experiments, and implications.

    Science.gov (United States)

    Jin, Xue; Tang, Chuyang Y; Gu, Yangshuo; She, Qianhong; Qi, Saren

    2011-03-15

    Forward osmosis (FO) is attracting increasing interest for its potential applications in desalination. In FO, permeation of contaminants from feed solution into draw solution through the semipermeable membrane can take place simultaneously with water diffusion. Understanding the contaminants transport through and rejection by FO membrane has significant technical implications in the way to separate clean water from the diluted draw solution. In this study, a model was developed to predict boron flux in FO operation. A strong agreement between modeling results and experimental data indicates that the model developed in this study can accurately predict the boron transport through FO membranes. Furthermore, the model can guide the fabrication of improved FO membranes with decreased boron permeability and structural parameter to minimize boron flux. Both theoretical model and experimental results demonstrated that when membrane active layer was facing draw solution, boron flux was substantially greater compared to the other membrane orientation due to more severe internal concentration polarization. In this investigation, for the first time, rejection of contaminants was defined in FO processes. This is critical to compare the membrane performance between different membranes and experimental conditions.

  12. Improvement of Vegetative and Reproductive Growth of ‘Camarosa’ Strawberry: Role of Humic Acid, Zn, and B

    Directory of Open Access Journals (Sweden)

    Somaye Rafeii

    2015-03-01

    Full Text Available This experiment was conducted with the aim to improve vegetative and reproductive growth of strawberry (Fragaria × ananassa Duch. cv. ‘Camarosa’ using humic acid, zinc sulfate (ZnSO4, and boric acid. We evaluated applications of humic acid at 0, 20 and 40 mg·L-1, ZnSO4 at 0, 50 and 100 mg·L-1, and boric acid at 0, 50 and 100 mg·L-1 at 30 days after planting and blooming stage on growth of strawberry cv. ‘Camarosa’. Results indicated that humic acid, ZnSo4, and boric acid application improved reproductive and vegetative characteristics compared to control treatment. The results showed, that plants treated with humic acid, ZnSO4, and boric acid at higher their concentrations exhibited generally higher dry weight of roots and shoots, number of flowers and inflorescences, leaf area, length of roots and shoots, length of flowering period, yield, weight of primary and secondary fruits and number of their achenes. Total yield was significantly increased by all treatments compared to control treatment at both stages of application, especially at blooming stage. Moreover, conclusion showed that the mentioned materials could have impact on vegetative and reproductive growth of strawberry generally. In this study humic acid at 40 mg L-1 at blooming stage resulted in best effects on development of strawberry cv. ‘Camarosa’.

  13. Complexion of Boric Acid with 2-Deoxy-D-glucose (DG) as a novel boron carrier for BNCT

    OpenAIRE

    Akan, Zafer; Demiroglu, Hasan; Avcibasi, Ugur; Oto, Gokhan; Ozdemir, Hulya; Deniz, Sabahattin; Basak, Ali Sadi

    2014-01-01

    Objective: Boron neutron capture therapy (BNCT) is an intensive research area for cancer researchers. Especially the side effects and inabilities of conventional therapies in some cases, directs researchers to find out a new cancer therapy methods such as BNCT. One of three important problem of BNCT is targeting of boron to tumor tissue. Borono Phenyl Alanine (BPA) and Borono Sodium Borocaptate (BSH) are already using in clinical studies as boron carriers. New boron carriers are searching fo...

  14. Enhanced Control of PWR Primary Coolant Water Chemistry Using Selective Separation Systems for Recovery and Recycle of Enriched Boric Acid

    Energy Technology Data Exchange (ETDEWEB)

    Ken Czerwinski; Charels Yeamans; Don Olander; Kenneth Raymond; Norman Schroeder; Thomas Robison; Bryan Carlson; Barbara Smit; Pat Robinson

    2006-02-28

    The objective of this project is to develop systems that will allow for increased nuclear energy production through the use of enriched fuels. The developed systems will allow for the efficient and selective recover of selected isotopes that are additives to power water reactors' primary coolant chemistry for suppression of corrosion attack on reactor materials.

  15. THE KINETICS OF SAPONIFICATION OF IODOACETIC ACID BY SODIUM HYDROXIDE AND BY CERTAIN ALKALINE BUFFER SOLUTIONS.

    Science.gov (United States)

    Brdicka, R

    1936-07-20

    1. The rate of the saponification of iodoacetic acid in sodium hydroxide and alkaline buffer solutions yielding glycollic acid was measured by means of Heyrovský's polarographic method. 2. From the bimolecular velocity constants, increasing with the ionic strength of the solution, the Brönsted factor, F, which characterizes the primary salt effect, was calculated. 3. In the borate buffer solutions the monomolecular constants of the saponification were determined which, at values above the pH of neutralization of boric acid, show a proportionality to the concentration of hydroxyl anions. Below the pH of neutralization of boric acid, they are proportional to the concentration of borate anions.

  16. Direct solid surface fluorescence spectroscopy of standard chemicals and humic acid in ternary system

    Science.gov (United States)

    Mounier, S.; Nicolodelli, G.; Redon, R.; Milori, D. M. B. P.

    2017-04-01

    The front face fluorescence spectroscopy is often used to quantify chemicals in well-known matrices as it is a rapid and powerful technique, with no sample preparation. However it was not used to investigate extracted organic matter like humic substances. This work aims to fully investigate for the first time front face fluorescence spectroscopy response of a ternary system including boric acid, tryptophan and humic substances, and two binaries system containing quinine sulfate or humic substance in boric acid. Pure chemicals, boric acid, tryptophan, quinine sulfate and humic acid were mixed together in solid pellet at different contents from 0 to 100% in mass. The measurement of excitation emission matrix of fluorescence (3D fluorescence) and laser induced fluorescence were then done in the front face mode. Fluorescence matrices were decomposed using the CP/PARAFAC tools after scattering treatments. Results show that for 3D fluorescence there is no specific component for tryptophan and quinine sulfate, and that humic substances lead to a strong extinction effect for mixture containing quinine sulfate. Laser induced fluorescence gives a very good but non-specific related response for both quinine sulfate and tryptophan. No humic substances fluorescence response was found, but extinction effect is observed as for 3D fluorescence. This effect is stronger for quinine sulfate than for tryptophan. These responses were modeled using a simple absorbance versus emission model.

  17. Direct solid surface fluorescence spectroscopy of standard chemicals and humic acid in ternary system.

    Science.gov (United States)

    Mounier, S; Nicolodelli, G; Redon, R; Milori, D M B P

    2017-04-15

    The front face fluorescence spectroscopy is often used to quantify chemicals in well-known matrices as it is a rapid and powerful technique, with no sample preparation. However it was not used to investigate extracted organic matter like humic substances. This work aims to fully investigate for the first time front face fluorescence spectroscopy response of a ternary system including boric acid, tryptophan and humic substances, and two binaries system containing quinine sulfate or humic substance in boric acid. Pure chemicals, boric acid, tryptophan, quinine sulfate and humic acid were mixed together in solid pellet at different contents from 0 to 100% in mass. The measurement of excitation emission matrix of fluorescence (3D fluorescence) and laser induced fluorescence were then done in the front face mode. Fluorescence matrices were decomposed using the CP/PARAFAC tools after scattering treatments. Results show that for 3D fluorescence there is no specific component for tryptophan and quinine sulfate, and that humic substances lead to a strong extinction effect for mixture containing quinine sulfate. Laser induced fluorescence gives a very good but non-specific related response for both quinine sulfate and tryptophan. No humic substances fluorescence response was found, but extinction effect is observed as for 3D fluorescence. This effect is stronger for quinine sulfate than for tryptophan. These responses were modeled using a simple absorbance versus emission model.

  18. Development and Production of Boric-Magnesium-Zinc Nitro-Compound Fertilizer with 100 kt/a Compound Fertilizer Production Unit%采用100 kt/a 复合肥生产装置开发生产硼镁锌硝基复合肥

    Institute of Scientific and Technical Information of China (English)

    念吉红

    2015-01-01

    Using phosphoric acid, ammonium nitrate solution, gaseous ammonia, sulfuric acid, solid potassium sulfate, borax, magnesium sulfate and zinc sulfate as raw materials, the new type of functional boric-magnesium-zinc nitro-compound fertilizer is produced with revamped 100 kt /a compound fertilizer production unit.The production conditions and technical features of the new functional compound fertilizer are introduced, and matters needing attention in production are summarized.%采用磷酸、硝酸铵溶液、气氨、硫酸、固体硫酸钾、硼砂、硫酸镁、硫酸锌为原料,在100 kt/a 复合肥生产装置上改造生产新型功能型硼镁锌硝基复合肥。介绍了该新型功能型复合肥料的生产情况、技术特点,并对生产中应注意的问题进行总结。

  19. 柠檬酸对腐蚀铝箔高压阳极氧化膜微观结构与电化学性能的影响%Effect of citric acid on microstructure and electrochemical characteristics of high voltage anodized alumina film formed on etched Al Foils

    Institute of Scientific and Technical Information of China (English)

    班朝磊; 何业东; 邵鑫

    2011-01-01

    将高压铝电解电容器用腐蚀铝箔与沸水反应,然后再在硼酸溶液或硼酸-柠檬酸混合酸溶液中进行530 V高压阳极氧化制得耐压薄膜,应用透射电镜(TEM)、X射线衍射(XRD)研究不同电解液所形成的高压阳极氧化膜的微观结构与结晶程度,利用电化学交流阻抗(EIS)、LCR数字电桥与小电流充电测试阳极氧化膜的电化学性能.结果表明:高压阳极氧化膜具有明显层状结构,内层结晶程度较高、外层结晶程度较低;与单纯硼酸溶液所形成的氧化膜相比,混合酸液所形成的阳极氧化膜的外层结晶程度与晶粒平均尺寸较大,抗电场强度与比电容均比较高,但相变使得氧化膜外层微观缺陷密度增多,氧化膜比电阻与耐电压值有所降低.%Aluminum capacitor foils with a tunnel etch structure were reacted with boiling water and then anodized at 530 V in boric acid solution or boric acid+citric acid mixed solution. The microstructure and crystallinity of the resulting anodized film were examined by TEM and XRD. The special capacitance, resistance and withstanding voltage of the film were explored with electrochemical impedance spectroscopy (EIS), LCR meter and small-current charging. The results show that the high voltage anodized oxide film consists of an inner layer with high crystallinity and an outer layer with low crystallinity. However, the crystallinity of the film formed in boric acid+citric acid mixed solution is higher than that of the film formed in only boric acid solution, leading to an increase in film's field strength and special capacitance. Meanwhile, there are more defects from phase transformation in the out layer of the film formed in boric acid+citric acid mixed solution than in that of film formed in only boric acid solution, leading to a decrease in film's resistance and withstanding voltage.

  20. Utilization of Negative Ion ESI-MS and Tandem Mass Spectrometry to Detect and Confirm the NADH-Boric Acid Complex

    Science.gov (United States)

    Kim, Danny H.; Eckhert, Curtis D.; Faull, Kym F.

    2011-01-01

    Mass spectrometry (MS) is a powerful analytical technique that is now widely used in the chemical, physical, engineering, and life sciences, with rapidly growing applications in many areas including clinical, forensic, pharmaceutical, and environmental fields. The increase in use of MS in both academic and industrial settings for research and…

  1. 硼酸双甘油酯硬脂酸酯的合成研究%Synthetic Study of Boric Diglyceride Stearic Acid Ester Surfactant

    Institute of Scientific and Technical Information of China (English)

    洪哲; 黄凤远; 姜云鹏

    2010-01-01

    以硼酸、甘油为原料,在氮气保护下合成硼酸双甘油酯,然后在强酸性阳离子交换树脂催化下与硬脂酸反应合成出具有半极性键的有机硼酸酯表面活性剂,并用红外光谱确定了产物结构.实验结果表明:硼酸与甘油的摩尔比为1∶2.0、反应温度为180℃、反应时间为4h时,硼酸双甘油酯的收率为96.0%;硼酸双甘油酯与硬脂酸的摩尔比为1∶0.9、反应温度为200℃、反应时间为3.5h、催化剂用量(相对于硬脂酸的质量)为2.0%时,硬脂酸转化率为96.4%.该合成工艺具有酸转化率高、后处理简单等优点.

  2. 硼酸二甘油酯脂肪酸酯的合成研究%Study of synthesis of boric diglyceride fatty acid ester surfactant

    Institute of Scientific and Technical Information of China (English)

    杜春霖; 刘波; 洪哲

    2010-01-01

    以硼酸、甘油为原料,在氮气保护下合成硼酸二甘油酯,然后在强酸性阳离子交换树脂催化下分别与月桂酸、肉豆蔻酸、硬脂酸反应合成出3种具有半极性键的有机硼酸酯表面活性剂.用红外光谱确定了产物的结构.研究了硼酸二甘油酯月桂酸酯的合成工艺,得到了优化的工艺条件,结果表明:硼酸与甘油的摩尔比为1∶2.0,反应温度为180 ℃,反应时间为4 h时,硼酸二甘油酯的收率为96.0%;硼酸二甘油酯与月桂酸的摩尔比为1∶0.9,反应温度为200 ℃,反应时间为3.5 h,催化剂用量(相对于月桂酸的质量)为2.0%时,月桂酸转化率为97.5%.硼酸二甘油酯肉豆蔻酸酯和硼酸二甘油酯硬脂酸酯在相同的工艺条件下合成时酸转化率分别为97.0%和96.4%.该工艺具有酸转化率高,后处理工艺简单的优点.

  3. Effect of time period after boric acid injection on {sup 10}B absorption in different regions of adult male rat's brain

    Energy Technology Data Exchange (ETDEWEB)

    Baghban Khojasteh, Nasrin, E-mail: khojasteh.nasrin@gmail.com [Nuclear Engineering Department, Science and Research Branch, Islamic Azad University, Poonak Sq. PO Box 14515-775, Tehran (Iran, Islamic Republic of); Pazirandeh, Ali [Nuclear Engineering Department, Science and Research Branch, Islamic Azad University, Poonak Sq. PO Box 14515-775, Tehran (Iran, Islamic Republic of); Jameie, Behnam [Nuclear Engineering Department, Science and Research Branch, Islamic Azad University, Poonak Sq. PO Box 14515-775, Tehran (Iran, Islamic Republic of); Laboratory of Basic Science and Neuroscience, Basic Science Dept, Faculty of Allied Medicine, Cellular and Molecular Research Center, Tehran University of Medical Science, Pardis-e-Hemmat,Tehran (Iran, Islamic Republic of); Goodarzi, Samereh [Nuclear Engineering Department, Science and Research Branch, Islamic Azad University, Poonak Sq. PO Box 14515-775, Tehran (Iran, Islamic Republic of)

    2012-06-15

    Distribution of {sup 10}B in different regions of rat normal brain was studied. Two groups were chosen as control and trial. Trial group received 2 ml of neutral boron compound. 2, 4 and 6 h after the injection brain removed, coronal sections of forebrain, midbrain and hindbrain were sandwiched between two pieces of polycarbonate. Autoradiography plots of {sup 10}B distribution showed significant differences in three regions with the highest {sup 10}B concentration in the forebrain during 4 h after injection. - Highlights: Black-Right-Pointing-Pointer Normal tissue tolerance is very important in BNCT. Black-Right-Pointing-Pointer This study has been done to determine {sup 10}B distribution in three anatomical regions of rat normal brain. Black-Right-Pointing-Pointer These specific regions of brain have not been studied in previous BNCT projects. Black-Right-Pointing-Pointer We found significant differences in {sup 10}B distribution between these three regions. Black-Right-Pointing-Pointer In different time periods after neutral boron compound injection, there has been a significant difference in boron absorption.

  4. Boron

    Science.gov (United States)

    ... an eye wash. Boron was used as a food preservative between 1870 and 1920, and during World Wars ... chemical symbol), B (symbole chimique), Borate, Borate de Sodium, Borates, Bore, Boric Acid, Boric Anhydride, Boric Tartrate, ...

  5. 水杨酸二甘酯的合成及工艺优化%The Synthesize and Craftsmanship Optimization of Salicylic Acid Diglyceride

    Institute of Scientific and Technical Information of China (English)

    刘艳梅

    2009-01-01

    Salicylic acid diglyceride, as an important chemical raw material, is an organic solvent and synthetic perfume. The article researches the compound of salieylic acid diglyeefide from salicylic acid and diglyceride and finds a better result of the eatalyst of a mixture of boric acid, paratoluenesulfonic acid, sulphurie acid and oxalic acid.%水杨酸二甘酯是一种重要的化工原料,也是很好的有机溶荆和合成香料.文章研究由水杨酸和二甘醇合成水杨酸二甘酯,发现硼酸、对甲苯磺酸、硫酸及草酸的混合酸作催化荆效果较好.

  6. Aspartic acid

    Science.gov (United States)

    Aspartic acid is a nonessential amino acids . Amino acids are building blocks of proteins. "Nonessential" means that our ... this amino acid from the food we eat. Aspartic acid is also called asparaginic acid. Aspartic acid helps ...

  7. Analysis of Glutamic Acid in Cerebrospinal Fluid by Capillary Electrophoresis with High Frequency Conductivity Detection

    Institute of Scientific and Technical Information of China (English)

    Hai Yun ZHAI; Jun Mei WANG; Xiao Li YAO; Xue Cai TAN; Pei Xiang CAI; Zuan Guang CHEN

    2005-01-01

    A rapid method to determine glutamic acid (Glu) in cerebrospinal fluid (CSF) by capillary electrophoresis with high frequency conductivity detection (contactless conductivity detection) was described. The CSF sample was pretreated with silver cation resin to remove high concentration of Cl- ions in CSF. The separation was achieved in the buffer solution of 10 mmol/L Tris and 8 mmol/L boric acid at the separation voltage of 20.0 kV. Glu showed linear response in the range of 5.0×10-6 to 6.0×10-3 mol/L, the limit of detection was 1.0×10-6 mol/L. The method was used for analysis Glu in CSF satisfactorily with a recovery of 97.8-98.8%.

  8. Separation of glycols from dilute aqueous solutions via complexation with boronic acids

    Energy Technology Data Exchange (ETDEWEB)

    Randel, L.A.; King, C.J.

    1991-07-01

    This work examines methods of separating low molecular weight glycols from dilute aqueous solution. Extraction into conventional solvents is generally not economical, since, in the literature reviewed, distribution ratios for the two- to four-carbon glycols are all less than one. Distribution ratios can be increased, however, by incorporating into the organic phase an extracting agent that will complex with the solute of interest. The extracting agent investigated in this work is 3-nitrophenylboronic acid (NPBA). NPBA, a boric acid derivative, reversibly complexes with many glycols. The literature on complexation of borate and related compounds with glycols, including mechanistic data, measurement techniques, and applications to separation processes, provides information valuable for designing experiments with NPBA and is reviewed herein. 88 refs., 15 figs., 24 tabs.

  9. Electrodeposition of nickel powder from nickel sulphate solution in presence of glycerol and sulphuric acid

    Directory of Open Access Journals (Sweden)

    S.G. Viswanath

    2013-09-01

    Full Text Available Nickel powder was obtained by electrodeposition of nickel from boric acid, glycerol and sulphuric acid. The morphology and particle size of these powders were studied. Spongy, irregular, flaky, fibrous and aggregate particles were obtained. Size of more than 85% particles was smaller than 384µm. From XRD graphs, it was found that the smaller particles are in the range of 106 and 373 nm. The apparent density of nickel powder decreased with increase in concentration of glycerol. The stability of the powder and current efficiency were also studied. In absence of nickel sulphate there was some nickel deposition on the cathode. The effect was discussed in present work. New definition for electrodeposition was suggested.

  10. An Optical Test Strip for the Detection of Benzoic Acid in Food

    Directory of Open Access Journals (Sweden)

    Fatimah Abu Bakar

    2011-07-01

    Full Text Available Fabrication of a test strip for detection of benzoic acid was successfully implemented by immobilizing tyrosinase, phenol and 3-methyl-2-benzothiazolinone hydrazone (MBTH onto filter paper using polystyrene as polymeric support. The sensing scheme was based on the decreasing intensity of the maroon colour of the test strip when introduced into benzoic acid solution. The test strip was characterized using optical fiber reflectance and has maximum reflectance at 375 nm. It has shown a highly reproducible measurement of benzoic acid with a calculated RSD of 0.47% (n = 10. The detection was optimized at pH 7. A linear response of the biosensor was obtained in 100 to 700 ppm of benzoic acid with a detection limit (LOD of 73.6 ppm. At 1:1 ratio of benzoic acid to interfering substances, the main interfering substance is boric acid. The kinetic analyses show that, the inhibition of benzoic is competitive inhibitor and the inhibition constant (Ki is 52.9 ppm. The activity of immobilized tyrosinase, phenol, and MBTH in the test strip was fairly sustained during 20 days when stored at 3 °C. The developed test strip was used for detection of benzoic acid in food samples and was observed to have comparable results to the HPLC method, hence the developed test strip can be used as an alternative to HPLC in detecting benzoic acid in food products.

  11. Ultrasonic Strengthening Low Grade Boric Magnesium Ore Acidolysis Reaction%超声强化低品位硼镁矿石酸解反应过程研究

    Institute of Scientific and Technical Information of China (English)

    王国胜; 杨鹤南; 齐广

    2016-01-01

    以辽宁花园沟低品位硼镁矿为原料,在搅拌和硫酸酸解过程基础上,引入超声辅助强化酸解过程,考察了超声功率与温度的影响,对比搅拌与超声辅助酸解过程得到,超声辅助可以降低反应温度,缩短反应时间,其产品收率增加,质量提高,硼酸晶体颗粒均匀且晶粒大。%Used low grade boric magnesium ore from Liaoning garden ditch as raw material, based on the condition of stirring, introduction of ultrasonic auxiliary have strengthened acidolysis process, the effect of ultrasonic power and temperature were investigated, and compared to stir and ultrasonic assisted acidolysis process, ultrasound assisted can reduce the reaction temperature, reaction time, the product yield increased, quality improved, borate crystals was uniform grain and grain size was big.

  12. Study on stabilities and electrochemical behavior of V(V) electrolyte with acid additives for vanadium redox flow battery

    Institute of Scientific and Technical Information of China (English)

    Gang; Wang; Jinwei; Chen; Xueqin; Wang; Jing; Tian; Hong; Kang; Xuejing; Zhu; Yu; Zhang; Xiaojiang; Liu; Ruilin; Wang

    2014-01-01

    Several acid compounds have been employed as additives of the V(V) electrolyte for vanadium redox flow battery(VRB) to improve its stability and electrochemical activity. Stability of the V(V) electrolyte with and without additives was investigated with ex-situ heating/cooling treatment at a wide temperature range of-5 ?C to 60 ?C. It was observed that methanesulfonic acid, boric acid, hydrochloric acid, trifluoroacetic acid,polyacrylic acid, oxalic acid, methacrylic acid and phosphotungstic acid could improve the stability of the V(V) electrolyte at a certain range of temperature. Their electrochemical behaviors in the V(V) electrolyte were further studied by cyclic voltammetry(CV), steady state polarization and electrochemical impedance spectroscopy(EIS). The results showed that the electrochemical activity, including the reversibility of electrode reaction, the diffusivity of V(V) species, the polarization resistance and the flexibility of charge transfer for the V(V) electrolyte with these additives were all improved compared with the pristine solution.

  13. Experiment on the Application of Ionic Liquid as Green Medium for Extraction of Boric Acid from Salt Lake Brine%离子液体作为绿色介质从盐湖卤水中萃取硼酸

    Institute of Scientific and Technical Information of China (English)

    宋贤菊; 李在均

    2011-01-01

    Ionic liquid is a green solvent for extraction of boron from salt lake beine as extraction medium, 1-octyl-3-methylimidazolium hexafluorophosphate ionic liquid was prepared and the ionic liquid, isooctyl alcohol and kerosene were used as extraction medium, synergic reagent and diluent respectively. The influence of ionic liquid dosage and extraction conditions on the boron extraction were investigated. The optimal experimental parameters were obtained as follows: ionic liquid dosage 10% ,the extractant 50% ,the ratio of organic phase to brine 1:1, the extraction time 10 min, and pH 2.4. The concentration of Mg2+ 4.268 mollL. Under optimal conditions, the boron can be fully extracted to the organic phase with three step extractions and a recovey of 99.54% was obtained.%制备了1-辛烷基-3-甲基咪唑六氟磷酸盐离子液体,再以离子液体(IL)为萃取介质、异辛醇为萃取剂及煤油为稀释剂建立盐湖卤水硼萃取研究模型,考察了离子液体用量和萃取条件对硼萃取的影响.异辛醇从卤水中萃取提硼的最佳实验条件:离子液体体积分数为10%,萃取剂体积分数为50%,相比(O/A)为1:1,萃取时间10 min,pH 2.4,Mg2+浓度为4.268 mol/L.在此条件下,当萃取级数为3级时,萃取率为99.54%,卤水中的硼可被完全萃取到有机相中.

  14. Un nuevo Método para Mejorar el Proceso de Producción de Acido Bórico A New Method to Improve the Production Process of Boric Acid

    OpenAIRE

    Orlando J Domínguez; Emilio M Serrano; Jorge E Flores; Raquel L Michel

    2011-01-01

    En este trabajo se propone una modificación al proceso tradicional para obtener ácido bórico, con el agregado fraccionado del ácido lixiviante, para lograr un producto altamente soluble, como el pentaborato de sodio. Con esto se consigue la disolución del mineral en frío con menor cantidad de reactivo lixiviante, ahorrando así energía. Al líquido clarificado se le disminuye el pH logrando así la precipitación del ácido bórico. La ganga se agota con diferentes etapas de precipitación y filtrac...

  15. 硼酸对顺铂致体外人胚肾细胞毒性保护作用%Preventive effects of boric acid on cisplatin-induced nephrotoxicity in 293 cells

    Institute of Scientific and Technical Information of China (English)

    曹军; 姜丽平; 耿成燕; 姚晓峰; 薛向欣; 仲来福

    2008-01-01

    目的 体外研究硼酸对顺铂所致肾毒性的保护作用,并探讨其可能机制.方法 体外培养人胚肾293(HEK293)细胞,四甲基偶氮噻唑蓝(MTT)法观察硼酸对顺铂细胞毒性的保护作用,硫代巴比妥酸反应产物测定法观察硼酸对顺铂引起的脂质过氧化的影响,荧光比色法观察硼酸对顺铂诱导的谷胱甘肽耗竭的影响.结果 硼酸能明显抑制顺铂对HEK293细胞的细胞毒性作用,24h半数抑制浓度(IC50)值由(0.38±0.04)mmol.L升高为(0.87±0.10)mmol.L,2者之间差异有统计学意义(P<0.05);硼酸能明显抑制顺铂所致脂质过氧化产物的形成.并能提升顺铂引起的还原型谷胱苷肽(GSH)含量的下降.结论 硼酸能抑制顺铂所致HEK293细胞的细胞毒性,其机制可能与其抗氧化作用和清除自由基活性有密切关系.

  16. 用硼酸作为显色剂光度法测定阿昔洛韦%Spectrophotometric determination of acyclovir with boric acid as a chromogenic agent

    Institute of Scientific and Technical Information of China (English)

    李晶; 汪瑾; 魏献军; 李全民

    2010-01-01

    在pH 12.00的缓冲溶液中,阿昔洛韦(ACV)与H_3BO_3形成组成比为1∶1的反应产物,其最大吸收波长λ_max=289 nm,ACV的质量浓度在0.48~57.6 mg/L范围内与吸光度成良好关系,线性回归方程A=-0.01796+0.01624ρ,相关系数r=0.9990,表观摩尔吸光系数ε=3.7×10~3 L·mol~(-1)·cm~(-1),回收率为99.9%~101.6%. 据此建立了测定ACV的新方法,能够直接用于药物样品中ACV的测定.

  17. Folic acid

    Science.gov (United States)

    ... taking folic acid by itself, or with L-carnitine a compound similar to an amino acid from ... levels. It is not clear if folic acid supplementation reduces hearing loss in people with normal folate ...

  18. Valproic Acid

    Science.gov (United States)

    ... acid is in a class of medications called anticonvulsants. It works by increasing the amount of a ... older (about 1 in 500 people) who took anticonvulsants such as valproic acid to treat various conditions ...

  19. Ascorbic Acid

    Science.gov (United States)

    Ascorbic acid is used to prevent and treat scurvy, a disease caused by a lack of vitamin C ... Ascorbic acid comes in extended-release (long-acting) capsules and tablets, lozenges, syrup, chewable tablets, and liquid drops ...

  20. Amino acids

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002222.htm Amino acids To use the sharing features on this page, please enable JavaScript. Amino acids are organic compounds that combine to form proteins . ...

  1. Fatty acids - trans fatty acids

    Science.gov (United States)

    The data supporting a negative effect of dietary trans fatty acids on cardiovascular disease risk is consistent. The primary dietary sources of trans fatty acids include partially hydrogenated fat and rudiment fat. The adverse effect of trans fatty acids on plasma lipoprotein profiles is consisten...

  2. Ibotenic acid and thioibotenic acid

    DEFF Research Database (Denmark)

    Hermit, Mette B; Greenwood, Jeremy R; Nielsen, Birgitte

    2004-01-01

    In this study, we have determined and compared the pharmacological profiles of ibotenic acid and its isothiazole analogue thioibotenic acid at native rat ionotropic glutamate (iGlu) receptors and at recombinant rat metabotropic glutamate (mGlu) receptors expressed in mammalian cell lines....... Thioibotenic acid has a distinct pharmacological profile at group III mGlu receptors compared with the closely structurally related ibotenic acid; the former is a potent (low microm) agonist, whereas the latter is inactive. By comparing the conformational energy profiles of ibotenic and thioibotenic acid...... with the conformations preferred by the ligands upon docking to mGlu1 and models of the other mGlu subtypes, we propose that unlike other subtypes, group III mGlu receptor binding sites require a ligand conformation at an energy level which is prohibitively expensive for ibotenic acid, but not for thioibotenic acid...

  3. Okadaic acid

    DEFF Research Database (Denmark)

    Danielsen, E Michael; Hansen, Gert H; Severinsen, Mai C K

    2014-01-01

    Okadaic acid (OA) is a polyether fatty acid produced by marine dinoflagellates and the causative agent of diarrhetic shellfish poisoning. The effect of OA on apical endocytosis in the small intestine was studied in organ cultured porcine mucosal explants. Within 0.5-1 h of culture, the toxin caused...... in acidic organelles, implying a different toxic mechanism of action. We propose that rapid induction of LBs, an indicator of phospholipidosis, should be included in the future toxicity profile of OA....

  4. Folic Acid

    Science.gov (United States)

    ... damage. 10 Do I need folic acid after menopause? Yes. Women who have gone through menopause still need 400 micrograms of folic acid every ... United States: 2003–2006 . American Journal of Clinical Nutrition; 91(1): 231–237. Hamner, H.C., Cogswell, ...

  5. Mefenamic Acid

    Science.gov (United States)

    ... any of the inactive ingredients in mefenamic acid capsules. Ask your pharmacist for a list of the inactive ingredients.tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking ...

  6. Acid Rain

    Science.gov (United States)

    Bricker, Owen P.; Rice, Karen C.; Dietrich, W.E.; Sposito, Garrison

    1997-01-01

    Acid deposition, or acid rain as it is more commonly referred to, has become a widely publicized environmental issue in the U.S. over the past decade. The term usually conjures up images of fish kills, dying forests, "dead" lakes, and damage to monuments and other historic artifacts. The primary cause of acid deposition is emission of S02 and NOx to the atmosphere during the combustion of fossil fuels. Oxidation of these compounds in the atmosphere forms strong acids - H2SO4 and HNO3 - which are returned to the Earth in rain, snow, fog, cloud water, and as dry deposition.Although acid deposition has only recently been recognized as an environmental problem in the U.S., it is not a new phenomenon (Cogbill & Likens 1974). As early as the middle of the 17th century in England, the deleterious effects of industrial emissions on plants, animals, and humans, and the atmospheric transport of pollutants between England and France had become issues of concern (Evelyn 1661, Graunt 1662). It is interesting that well over three hundred years ago in England, recommendations were made to move industry outside of towns and build higher chimneys to spread the pollution into "distant parts." Increasing the height of smokestacks has helped alleviate local problems, but has exacerbated others. In the U.S. the height of the tallest smokestack has more than doubled, and the average height of smokestacks has tripled since the 1950s (Patrick et al 1981). This trend occurred in most industrialized nations during the 20th century and has had the effect of transforming acid rain from a local urban problem into a problem of global scale.

  7. Doping Polypyrrole Films with 4-N-Pentylphenylboronic Acid to Enhance Affinity towards Bacteria and Dopamine.

    Science.gov (United States)

    Golabi, Mohsen; Padiolleau, Laurence; Chen, Xi; Jafari, Mohammad Javad; Sheikhzadeh, Elham; Turner, Anthony P F; Jager, Edwin W H; Beni, Valerio

    2016-01-01

    Here we demonstrate the use of a functional dopant as a fast and simple way to tune the chemical affinity and selectivity of polypyrrole films. More specifically, a boronic-functionalised dopant, 4-N-Pentylphenylboronic Acid (PBA), was used to provide to polypyrrole films with enhanced affinity towards diols. In order to prove the proposed concept, two model systems were explored: (i) the capture and the electrochemical detection of dopamine and (ii) the adhesion of bacteria onto surfaces. The chemisensor, based on overoxidised polypyrrole boronic doped film, was shown to have the ability to capture and retain dopamine, thus improving its detection; furthermore the chemisensor showed better sensitivity in comparison with overoxidised perchlorate doped films. The adhesion of bacteria, Deinococcus proteolyticus, Escherichia coli, Streptococcus pneumoniae and Klebsiella pneumoniae, onto the boric doped polypyrrole film was also tested. The presence of the boronic group in the polypyrrole film was shown to favour the adhesion of sugar-rich bacterial cells when compared with a control film (Dodecyl benzenesulfonate (DBS) doped film) with similar morphological and physical properties. The presented single step synthesis approach is simple and fast, does not require the development and synthesis of functional monomers, and can be easily expanded to the electrochemical, and possibly chemical, fabrication of novel functional surfaces and interfaces with inherent pre-defined sensing and chemical properties.

  8. Separation and quantitation of phycobiliproteins using phytic acid in capillary electrophoresis with laser-induced fluorescence detection.

    Science.gov (United States)

    Viskari, Pertti J; Colyer, Christa L

    2002-10-01

    The similar electrophoretic mobilities and sizes of several of the phycobiliproteins, which are derived from the photosynthetic apparatus of cyanobacteria and eukaryotic algae, render their separation and quantitation a challenging problem. However, we have developed a suitable capillary electrophoresis (CE) method that employs a phytic acid-boric acid buffer and laser-induced fluorescence (LIF) detection with a single 594 nm He-Ne laser. This method takes advantage of the remarkably high quantum yields of these naturally fluorescent proteins, which can be attributed to their linear tetrapyrrole chromophores covalently bound to cysteinyl residues. As such, limits of detection of 1.18 x 10(-14), 5.26 x 10(-15), and 2.38 x 10(-15) mol/l were obtained for R-phycoerythrin, C-phycocyanin, and allophycocyanin proteins, respectively, with a linear dynamic range of eight orders of magnitude in each case. Unlike previously published CE-LIF methods, this work describes the separation of all three major classes of phycobiliproteins in under 5 min. Very good recoveries, ranging from 93.2 to 105.5%, were obtained for a standard mixture of the phycobiliproteins, based on seven-point calibration curves for both peak height and peak area. It is believed that this development will prove useful for the determination of phycobiliprotein content in naturally occurring cyanobacteria populations, thus providing a useful tool for understanding biological and chemical oceanographic processes.

  9. Hydroxycarboxylic acids and salts

    Energy Technology Data Exchange (ETDEWEB)

    Kiely, Donald E; Hash, Kirk R; Kramer-Presta, Kylie; Smith, Tyler N

    2015-02-24

    Compositions which inhibit corrosion and alter the physical properties of concrete (admixtures) are prepared from salt mixtures of hydroxycarboxylic acids, carboxylic acids, and nitric acid. The salt mixtures are prepared by neutralizing acid product mixtures from the oxidation of polyols using nitric acid and oxygen as the oxidizing agents. Nitric acid is removed from the hydroxycarboxylic acids by evaporation and diffusion dialysis.

  10. Hydrofluoric acid poisoning

    Science.gov (United States)

    Fluorhydric acid ... stomach, or intestine have holes (perforations) from the acid. ... Hydrofluoric acid is especially dangerous. The most common accidents involving hydrofluoric acid cause severe burns on the skin ...

  11. Photographic fixative poisoning

    Science.gov (United States)

    Photographic developer poisoning; Hydroquinone poisoning; Quinone poisoning; Sulfite poisoning ... Quinones Sodium thiosulfate Sodium sulfite/bisulfite Boric acid Photographic fixative can also break down (decompose) to form ...

  12. Dehydroabietic acid

    Directory of Open Access Journals (Sweden)

    Xiao-Ping Rao

    2009-10-01

    Full Text Available The title compound [systematic name: (1R,4aS,10aR-7-isopropyl-1,4a-dimethyl-1,2,3,4,4a,9,10,10a-octahydrophenanthrene-1-carboxylic acid], C20H28O2, has been isolated from disproportionated rosin which is obtained by isomerizing gum rosin with a Pd-C catalyst.. Two crystallographically independent molecules exist in the asymmetric unit. In each molecule, there are three six-membered rings, which adopt planar, half-chair and chair conformations. The two cyclohexane rings form a trans ring junction with the two methyl groups in axial positions. The crystal structure is stabilized by intermolecular O—H...O hydrogen bonds.

  13. [Teichoic acids from lactic acid bacteria].

    Science.gov (United States)

    Livins'ka, O P; Harmasheva, I L; Kovalenko, N K

    2012-01-01

    The current view of the structural diversity of teichoic acids and their involvement in the biological activity of lactobacilli has been reviewed. The mechanisms of effects of probiotic lactic acid bacteria, in particular adhesive and immunostimulating functions have been described. The prospects of the use of structure data of teichoic acid in the assessment of intraspecific diversity of lactic acid bacteria have been also reflected.

  14. Plasma amino acids

    Science.gov (United States)

    Amino acids blood test ... types of methods used to determine the individual amino acid levels in the blood. ... test is done to measure the level of amino acids in the blood. An increased level of a ...

  15. POLYELEOSTEARIC ACID VESICLES

    Institute of Scientific and Technical Information of China (English)

    LI Zichen; XIE Ximng; FAN Qinghua; FANG Yifei

    1992-01-01

    α-Eleostearic acid and β-eleostearic acid formed vesicles in aqueous medium when an ethanol solutionofeleostearic acid was injected rapidly into a vigorously vortexed aqueous phase. Formation of the vesicles was demonstrated by electron microscopic observation and bromothymol blue encapsulation experiments. Polymerizations of the eleostearic acids in the formed vesicles carried out by UV irradiation produced poly-α-eleostearic acid and poly-β-eleostearic acid vesicles.

  16. Acid distribution in phosphoric acid fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Okae, I.; Seya, A.; Umemoto, M. [Fuji Electric Co., Ltd., Chiba (Japan)

    1996-12-31

    Electrolyte acid distribution among each component of a cell is determined by capillary force when the cell is not in operation, but the distribution under the current load conditions had not been clear so far. Since the loss of electrolyte acid during operation is inevitable, it is necessary to store enough amount of acid in every cell. But it must be under the level of which the acid disturbs the diffusion of reactive gases. Accordingly to know the actual acid distribution during operation in a cell is very important. In this report, we carried out experiments to clarify the distribution using small single cells.

  17. Gas-phase Acidities of Aspartic Acid, Glutamic Acid, and their Amino Acid Amides.

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhong; Matus, Myrna H; Velazquez, Hector A; Dixon, David A; Cassady, Carolyn J

    2007-02-14

    Gas-phase acidities (GA or ΔGacid) for the two most acidic common amino acids, aspartic acid and glutamic acid, have been determined for the first time. Because of the amide linkage’s importance in peptides and as an aid in studying side chain versus main chain deprotonation, aspartic acid amide and glutamic acid amide were also studied. Experimental GA values were measured by proton transfer reactions in an electrospray ionization/Fourier transform ion cyclotron resonance mass spectrometer. Calculated GAs were obtained by density functional and molecular orbital theory approaches. The best agreement with experiment was found at the G3MP2 level; the MP2/CBS and B3LYP/aug-cc-pVDZ results are 3–4 kcal/mol more acidic than the G3MP2 results. Experiment shows that aspartic acid is more acidic than glutamic acid by ca. 3 kcal/mol whereas the G3MP2 results show a smaller acidity difference of 0.2 kcal/mol. Similarly, aspartic acid amide is experimentally observed to be ca. 2 kcal/mol more acidic than glutamic acid amide whereas the G3MP2 results show a correspondingly smaller energy difference of 0.7 kcal/mol. The computational results clearly show that the anions are all ring-like structures with strong hydrogen bonds between the OH or NH2 groups and the CO2- group from which the proton is removed. The two amino acids are main-chain deprotonated. In addition, use of the COSMO model for the prediction of the free energy differences in aqueous solution gave values in excellent agreement with the most recent experimental values for pKa. Glutamic acid is predicted to be more acidic than aspartic acid in aqueous solution due to differential solvation effects.

  18. Gas-phase acidities of aspartic acid, glutamic acid, and their amino acid amides

    Science.gov (United States)

    Li, Zhong; Matus, Myrna H.; Velazquez, Hector Adam; Dixon, David A.; Cassady, Carolyn J.

    2007-09-01

    Gas-phase acidities (GA or [Delta]Gacid) for the two most acidic common amino acids, aspartic acid and glutamic acid, have been determined for the first time. Because of the amide linkage's importance in peptides and as an aid in studying side chain versus main chain deprotonation, aspartic acid amide and glutamic acid amide were also studied. Experimental GA values were measured by proton transfer reactions in an electrospray ionization/Fourier transform ion cyclotron resonance mass spectrometer. Calculated GAs were obtained by density functional and molecular orbital theory approaches. The best agreement with experiment was found at the G3MP2 level; the MP2/CBS and B3LYP/aug-cc-pVDZ results are 3-4 kcal/mol more acidic than the G3MP2 results. Experiment shows that aspartic acid is more acidic than glutamic acid by ca. 3 kcal/mol whereas the G3MP2 results show a smaller acidity difference of 0.2 kcal/mol. Similarly, aspartic acid amide is experimentally observed to be ca. 2 kcal/mol more acidic than glutamic acid amide whereas the G3MP2 results show a correspondingly smaller energy difference of 0.7 kcal/mol. The computational results clearly show that the anions are all ring-like structures with strong hydrogen bonds between the OH or NH2 groups and the CO2- group from which the proton is removed. The two amino acids are main-chain deprotonated. In addition, use of the COSMO model for the prediction of the free energy differences in aqueous solution gave values in excellent agreement with the most recent experimental values for pKa. Glutamic acid is predicted to be more acidic than aspartic acid in aqueous solution due to differential solvation effects.

  19. Clean and cost-effective dry boundary lubricants for aluminum forming.

    Energy Technology Data Exchange (ETDEWEB)

    Erdemir, A.; Fenske, G. R.

    1997-12-05

    Preliminary research in our laboratory has demonstrated that boric acid is an effective lubricant with an unusual capacity to reduce sliding fiction (providing friction coefficients as low as 0.02) and wear of metallic and ceramic materials. More recent studies have revealed that water or methanol solutions of boric acid can be used to prepare strongly bonded layers of boric acid on aluminum surfaces. It appears that boric acid molecules have a strong tendency to bond chemically to the naturally oxidized surfaces of aluminum and its alloys and to make these surfaces very slippery. Recent metal formability tests indicated that the boric acid films formed on aluminum surfaces by spraying or dipping worked quite well; improving draw scale performance by 58 to 75%. These findings have increased the prospect that boric acid can be formulated and optimized as an effective boundary lubricant and used to solve the friction, galling, and severe wear problems currently encountered in cold-forming of aluminum products. Accordingly, the major goal of this paper is to demonstrate the usefulness and lubrication capacity of thin boric acid films formed on aluminum surfaces by simple dipping or spraying processes and to describe the lubrication mechanisms under typical metal forming conditions. We will also examine the nature of chemical bonding between boric acid and aluminum surfaces and develop new ways to optimize its performance as an effective boundary lubricant.

  20. Acid Thunder: Acid Rain and Ancient Mesoamerica

    Science.gov (United States)

    Kahl, Jonathan D. W.; Berg, Craig A.

    2006-01-01

    Much of Mesoamerica's rich cultural heritage is slowly eroding because of acid rain. Just as water dissolves an Alka-Seltzer tablet, acid rain erodes the limestone surfaces of Mexican archaeological sites at a rate of about one-half millimeter per century (Bravo et al. 2003). A half-millimeter may not seem like much, but at this pace, a few…

  1. Effects of boric acid and plant growth regulating substances on pollen germination and tube growth in pistachio%硼及植物生长调节物质对阿月浑子花粉萌发和花粉管生长的影响

    Institute of Scientific and Technical Information of China (English)

    李旭新; 张艳青; 周如久; 白志英; 路丙社

    2009-01-01

    以阿月浑子(Pistacia vera L.)为试材,研究了硼及植物生长调节物质对花粉萌发和花粉管生长的影响.结果表明:低浓度的硼酸、赤霉素、萘乙酸、吲哚乙酸和2,4-D均能促进花粉萌发和花粉管生长,而高浓度时却不利于花粉萌发和花粉管生长;适宜阿月浑子花粉萌发和花粉管生长的硼酸浓度为100 mg/L,赤霉素浓度为25 mg/L,萘乙酸浓度为0.5 mg/L,吲哚乙酸和2,4-D浓度均为15 mg/L.

  2. Effect of Boric Diglyceride Palmitic Acid Ester on Properties of PVC-rice Hull Powder Wood-plastic Composite%硼酸二甘油酯棕榈酸酯对PVC-稻壳粉木塑性能的影响

    Institute of Scientific and Technical Information of China (English)

    杜春霖

    2013-01-01

    以硼酸二甘油酯棕榈酸酯作为PVC-稻壳粉木塑润滑加工助剂应用于木塑的加工研究,考察了稻壳粉在木塑复合材料中加入量分别为30%、40%、50%、60%时产品的性能.结果表明:当加入比例增大时,产品的挤出速度、冲击强度、拉伸强度和弯曲强度都有不同程度的提高.当硼酸二甘油酯棕榈酸酯的加入量完全替代原有润滑剂使用时,PVC-稻壳粉木塑的挤出速度平均提高了3.98%.冲击强度平均增加了2.36%,拉伸强度平均增加了0.82%,弯曲强度平均增加了0.55%.同时吸水率最大增加了0.21%.

  3. 硼酸二甘油酯月桂酸酯对PVC-稻壳粉木塑性能的影响研究%Research on Properties of PVC-rice Hull Powder WPC With Boric Diglyceride Lauric Acid ester

    Institute of Scientific and Technical Information of China (English)

    洪哲; 杜春霖

    2013-01-01

    以硼酸二甘油酯月桂酸酯作为PVC-稻壳粉木塑润滑加工助剂应用于木塑复合材料的研究,考察了稻壳粉在木塑复合材料中加入量分别为30%,40%,50%,60%时产品的性能.结果表明:当硼酸酯加入比例增大时,产品的挤出速度,冲击强度,拉伸强度和弯曲强度都有不同程度的提高.当硼酸酯的加入量完全替代原有润滑剂使用时,PVC-稻壳粉木塑的挤出速度平均提高了4.07%.冲击强度平均增加了3.63%,拉伸强度平均增加了0.72%,弯曲强度平均增加了0.85%.同时吸水率最大增加了0.35%.

  4. Resposta à adubação com uréia, cloreto de potássio e ácido bórico em mudas abacaxizeiro'Smooth Cayenne' Response to fertilization with urea, potassium chloride and boric acid in the 'Smooth Cayenne' pineapple plants

    Directory of Open Access Journals (Sweden)

    Ruimário Inácio Coelho

    2007-04-01

    Full Text Available Mudas do abacaxizeiro (Ananas comosus L., cultivar Smooth Cayenne, obtidas por seccionamento de caule, foram submetidas à adubação foliar com soluções em diferentes concentrações de uréia, KCl e H3BO3. O delineamento utilizado foi fatorial fracionado do tipo (1/55³, com três tipos de adubo e cinco concentrações, num total de 25 tratamentos, que consistiram de combinações de concentrações de 0; 2,5; 5,0; 7,5 e 10 g L-1 de uréia e KCl, e 0; 0,5; 1,0; 1,5 e 2,0 g L-1 de H3BO3. Os tratamentos foram iniciados nove semanas após o plantio das seções do caule, com 26 pulverizações semanais para a uréia e KCl e 4 pulverizações mensais para o H3BO3. Verificou-se crescimento linear positivo para as características: altura das brotações, número de folhas, área foliar, massa seca e fresca das mudas, em resposta a níveis crescentes de uréia. Não foi observado efeito do KCl e H3BO3 para nenhuma das características de crescimento avaliadas. As mudas adubadas com 10 g L-1 de uréia atingiram altura de 40 cm e massa fresca de 242 g no 9º mês após o plantio das seções.Suckers of the pineapple plant (Ananas comosus L., Smooth Cayenne cv., obtained by stem sectioning, were submitted to leaf fertilization with solutions at different concentrations of urea, KCl and H3BO3. The fractionated factorial design of the type (1/55³ was used, with three fertilizer types and five concentrations, totalizing 25 treatments that consisted of combination of concentrations (0; 2.5; 5.0; 7.5 and 10 g L-1 of urea and KCl, as well as 0; 0.5; 1.0; 1.5 and 2.0 g L-1 of H3BO3. The treatments began nine weeks after planting the stem sections. Twenty six sprays of urea and KCl were weekly applied as well as four monthly sprays of H3BO3. Positive linear growth was verified for the following characteristics: sprouting heights, leaf numbers, leaf area, dry and fresh matter of the suckers in response to increasing urea levels. No effect of KCl and H3BO3 were observed for the growth characteristics under evaluation. The suckers fertilized with 10 g L-1 urea reached 40 cm height and 242 g fresh matter at the 9th month after planting the sections.

  5. Amino Acid Metabolism Disorders

    Science.gov (United States)

    ... this process. One group of these disorders is amino acid metabolism disorders. They include phenylketonuria (PKU) and maple syrup urine disease. Amino acids are "building blocks" that join together to form ...

  6. Catalytic Synthesis Lactobionic Acid

    Directory of Open Access Journals (Sweden)

    V.G. Borodina

    2014-07-01

    Full Text Available Gold nanoparticles are obtained, characterized and deposited on the carrier. Conducted catalytic synthesis of lactobionic acid from lactose. Received lactobionic acid identify on the IR spectrum.

  7. Omega-3 Fatty Acids

    Science.gov (United States)

    Omega-3 fatty acids are used together with lifestyle changes (diet, weight-loss, exercise) to reduce the ... the blood in people with very high triglycerides. Omega-3 fatty acids are in a class of ...

  8. Omega-6 Fatty Acids

    Science.gov (United States)

    Omega-6 fatty acids are types of fats. Some types are found in vegetable oils, including corn, evening primrose seed, safflower, and soybean oils. Other types of omega-6 fatty acids are found in black currant ...

  9. Lactic acid test

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003507.htm Lactic acid test To use the sharing features on this page, please enable JavaScript. Lactic acid is mainly produced in muscle cells and red ...

  10. Folic Acid Quiz

    Science.gov (United States)

    ... folic acid 9. A woman should be taking folic acid if she: A is planning a pregnancy B is capable of becoming pregnant, even if ... Answer: D CORRECT: A woman should be taking folic acid if she is planning a pregnancy, is capable of becoming pregnant (even if she ...

  11. Immunoglobulin and fatty acids

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to a composition comprising 0.1-10 w/w % immunoglobulin (Ig), 4-14 w/w % saturated fatty acids, 4-14 w/w % mono-unsaturated fatty acids and 0-5 w/w % poly-unsaturated fatty acids, wherein the weight percentages are based on the content of dry matter in the composition...

  12. Acid Rain Study Guide.

    Science.gov (United States)

    Hunger, Carolyn; And Others

    Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid…

  13. The Acid Rain Reader.

    Science.gov (United States)

    Stubbs, Harriett S.; And Others

    A topic which is often not sufficiently dealt with in elementary school textbooks is acid rain. This student text is designed to supplement classroom materials on the topic. Discussed are: (1) "Rain"; (2) "Water Cycle"; (3) "Fossil Fuels"; (4) "Air Pollution"; (5) "Superstacks"; (6) "Acid/Neutral/Bases"; (7) "pH Scale"; (8) "Acid Rain"; (9)…

  14. Production of structured lipids by acidolysis of an EPA-enriched fish oil and caprylic acid in a packed bed reactor: analysis of three different operation modes.

    Science.gov (United States)

    González Moreno, P A; Robles Medina, A; Camacho Rubio, F; Camacho Páez, B; Molina Grima, E

    2004-01-01

    Structured triacylglycerols (ST) enriched in eicosapentaenoic acid (EPA) in position 2 of the triacylglycerol (TAG) backbone were synthesized by acidolysis of a commercially available EPA-rich oil (EPAX4510, 40% EPA) and caprylic acid (CA), catalyzed by the 1,3-specific immobilized lipase Lipozyme IM. The reaction was carried out in a packed bed reactor (PBR) operating in two ways: (1) by recirculating the reaction mixture from the exit of the bed to the substrate reservoir (discontinuous mode) and (2) in continuous mode, directing the product mixture leaving the PBR to a product reservoir. By operating in these two ways and using a simple kinetic model, representative values for the apparent kinetic constants (kX) for each fatty acid (native, Li or odd, M) were obtained. The kinetic model assumes that the rate of incorporation of a fatty acid into TAG per amount of enzyme, rX (mole/(h g lipase)) is proportional to the extent of the deviation from the equilibrium for each fatty acid (i.e., the difference of concentration between the fatty acid in the triacylglycerol and the concentration of the same fatty acid in the triacylglycerol once the equilibrium of the acidolysis reaction is reached). The model allows comparing the two operating modes through the processing intensity, defined as mLt/(V[TG]0) and mL/(q[TG]0), for the discontinuous and continuous operation modes, respectively. In discontinuous mode, ST with 59.5% CA and 9.6% EPA were obtained. In contrast, a ST with 51% CA and 19.6% EPA were obtained when using the continuous operation mode. To enhance the CA incorporation when operating in continuous mode, a two-step acidolysis reaction was performed (third operation mode). This continuous two-step process yields a ST with a 64% CA and a 15% EPA. Finally, after purifying the above ST in a preparative silica gel column, impregnated with boric acid, a ST with 66.9% CA and 19.6% EPA was obtained. The analysis by reverse phase and Ag+ liquid chromatography of

  15. Acidic Ionic Liquids.

    Science.gov (United States)

    Amarasekara, Ananda S

    2016-05-25

    Ionic liquid with acidic properties is an important branch in the wide ionic liquid field and the aim of this article is to cover all aspects of these acidic ionic liquids, especially focusing on the developments in the last four years. The structural diversity and synthesis of acidic ionic liquids are discussed in the introduction sections of this review. In addition, an unambiguous classification system for various types of acidic ionic liquids is presented in the introduction. The physical properties including acidity, thermo-physical properties, ionic conductivity, spectroscopy, and computational studies on acidic ionic liquids are covered in the next sections. The final section provides a comprehensive review on applications of acidic ionic liquids in a wide array of fields including catalysis, CO2 fixation, ionogel, electrolyte, fuel-cell, membrane, biomass processing, biodiesel synthesis, desulfurization of gasoline/diesel, metal processing, and metal electrodeposition.

  16. [Biosynthesis of adipic acid].

    Science.gov (United States)

    Han, Li; Chen, Wujiu; Yuan, Fei; Zhang, Yuanyuan; Wang, Qinhong; Ma, Yanhe

    2013-10-01

    Adipic acid is a six-carbon dicarboxylic acid, mainly for the production of polymers such as nylon, chemical fiber and engineering plastics. Its annual demand is close to 3 million tons worldwide. Currently, the industrial production of adipic acid is based on the oxidation of aromatics from non-renewable petroleum resources by chemo-catalytic processes. It is heavily polluted and unsustainable, and the possible alternative method for adipic acid production should be developed. In the past years, with the development of synthetic biology and metabolic engineering, green and clean biotechnological methods for adipic acid production attracted more attention. In this study, the research advances of adipic acid and its precursor production are reviewed, followed by addressing the perspective of the possible new pathways for adipic acid production.

  17. Demospongic Acids Revisited

    Directory of Open Access Journals (Sweden)

    Gilles Barnathan

    2010-10-01

    Full Text Available The well-known fatty acids with a D5,9 unsaturation system were designated for a long period as demospongic acids, taking into account that they originally occurred in marine Demospongia sponges. However, such acids have also been observed in various marine sources with a large range of chain-lengths (C16–C32 and from some terrestrial plants with short acyl chains (C18–C19. Finally, the D5,9 fatty acids appear to be a particular type of non-methylene-interrupted fatty acids (NMA FAs. This article reviews the occurrence of these particular fatty acids in marine and terrestrial organisms and shows the biosynthetic connections between D5,9 fatty acids and other NMI FAs.

  18. Acid-Base Homeostasis.

    Science.gov (United States)

    Hamm, L Lee; Nakhoul, Nazih; Hering-Smith, Kathleen S

    2015-12-07

    Acid-base homeostasis and pH regulation are critical for both normal physiology and cell metabolism and function. The importance of this regulation is evidenced by a variety of physiologic derangements that occur when plasma pH is either high or low. The kidneys have the predominant role in regulating the systemic bicarbonate concentration and hence, the metabolic component of acid-base balance. This function of the kidneys has two components: reabsorption of virtually all of the filtered HCO3(-) and production of new bicarbonate to replace that consumed by normal or pathologic acids. This production or generation of new HCO3(-) is done by net acid excretion. Under normal conditions, approximately one-third to one-half of net acid excretion by the kidneys is in the form of titratable acid. The other one-half to two-thirds is the excretion of ammonium. The capacity to excrete ammonium under conditions of acid loads is quantitatively much greater than the capacity to increase titratable acid. Multiple, often redundant pathways and processes exist to regulate these renal functions. Derangements in acid-base homeostasis, however, are common in clinical medicine and can often be related to the systems involved in acid-base transport in the kidneys.

  19. Jack bean (Canavalia ensiformis) urease. Probing acid-base groups of the active site by pH variation.

    Science.gov (United States)

    Krajewska, Barbara; Ciurli, Stefano

    2005-07-01

    A pH-variation study of jack bean (Canavalia ensiformis) urease steady-state kinetic parameters and of the inhibition constant of boric acid, a urease competitive inhibitor, was performed using both noninhibitory organic (MES, HEPES and CHES) and inhibitory inorganic (phosphate) buffers, in an effort to elucidate the functions exercised in the catalysis by the ionizable groups of the enzyme active site. The results obtained are consistent with the requirement for three groups utilized by urease with pK(a)s equal to 5.3+/-0.2, 6.6+/-0.2 and 9.1+/-0.4. Based on the appearance of the ionization step with pK(a)=5.3 in v(max)-pH, K(M)-pH and K(i)-pH profiles, we assigned this group as participating both in the substrate binding and catalytic reaction. As shown by its presence in v(max)-pH and K(M)-pH curves, the obvious role of the group with pK(a)=9.1 is the participation in the catalytic reaction. One function of the group featuring pK(a)=6.6, which was derived from a two-maxima v(max)-pH profile obtained upon increasing phosphate buffer concentration, an effect the first time observed for urease-phosphate systems, is the substrate binding, another possible function being modulation of the active site structure controlled by the ionic strength. It is also possible that the pK(a)=6.6 is a merger of two pK(a)s close in value. The study establishes that regular bell-shaped activity-pH profiles, commonly reported for urease, entail more complex pH-dependent behavior of the urease active site ionizable groups, which could be experimentally derived using species interacting with the enzyme, in addition to changing solution pH and ionic strength.

  20. Bile acid sequestrants

    DEFF Research Database (Denmark)

    Hansen, Morten; Sonne, David P; Knop, Filip K

    2014-01-01

    Bile acids are synthesized in the liver from cholesterol and have traditionally been recognized for their role in absorption of lipids and in cholesterol homeostasis. In recent years, however, bile acids have emerged as metabolic signaling molecules that are involved in the regulation of lipid...... and glucose metabolism, and possibly energy homeostasis, through activation of the bile acid receptors farnesoid X receptor (FXR) and TGR5. Bile acid sequestrants (BASs) constitute a class of drugs that bind bile acids in the intestine to form a nonabsorbable complex resulting in interruption...... of the enterohepatic circulation. This increases bile acid synthesis and consequently reduces serum low-density lipoprotein cholesterol. Also, BASs improve glycemic control in patients with type 2 diabetes. Despite a growing understanding of the impact of BASs on glucose metabolism, the mechanisms behind their glucose...

  1. Citric Acid Alternative to Nitric Acid Passivation

    Science.gov (United States)

    Lewis, Pattie L. (Compiler)

    2013-01-01

    The Ground Systems Development and Operations GSDO) Program at NASA John F. Kennedy Space Center (KSC) has the primary objective of modernizing and transforming the launch and range complex at KSC to benefit current and future NASA programs along with other emerging users. Described as the launch support and infrastructure modernization program in the NASA Authorization Act of 2010, the GSDO Program will develop and implement shared infrastructure and process improvements to provide more flexible, affordable, and responsive capabilities to a multi-user community. In support of the GSDO Program, the purpose of this project is to demonstratevalidate citric acid as a passivation agent for stainless steel. Successful completion of this project will result in citric acid being qualified for use as an environmentally preferable alternative to nitric acid for passivation of stainless steel alloys in NASA and DoD applications.

  2. Parenteral Nutrition: Amino Acids

    Science.gov (United States)

    Hoffer, Leonard John

    2017-01-01

    There is growing interest in nutrition therapies that deliver a generous amount of protein, but not a toxic amount of energy, to protein-catabolic critically ill patients. Parenteral amino acids can achieve this goal. This article summarizes the biochemical and nutritional principles that guide parenteral amino acid therapy, explains how parenteral amino acid solutions are formulated, and compares the advantages and disadvantages of different parenteral amino acid products with enterally-delivered whole protein products in the context of protein-catabolic critical illness. PMID:28287411

  3. Parenteral Nutrition: Amino Acids.

    Science.gov (United States)

    Hoffer, Leonard John

    2017-03-10

    There is growing interest in nutrition therapies that deliver a generous amount of protein, but not a toxic amount of energy, to protein-catabolic critically ill patients. Parenteral amino acids can achieve this goal. This article summarizes the biochemical and nutritional principles that guide parenteral amino acid therapy, explains how parenteral amino acid solutions are formulated, and compares the advantages and disadvantages of different parenteral amino acid products with enterally-delivered whole protein products in the context of protein-catabolic critical illness.

  4. Diterpenoid acids from Grindelia nana.

    Science.gov (United States)

    Mahmoud, A A; Ahmed, A A; Tanaka, T; Iinuma, M

    2000-03-01

    Two new norditerpenoid acids of the labdane-type (norgrindelic acids), 4,5-dehydro-6-oxo-18-norgrindelic acid (1) and 4beta-hydroxy-6-oxo-19-norgrindelic acid (2), as well as a new grindelic acid derivative, 18-hydroxy-6-oxogrindelic acid (3), were isolated from the aerial parts of Grindelia nana. In addition, the known compounds, 6-oxogrindelic acid, grindelic acid, methyl grindeloate, 7alpha,8alpha-epoxygrindelic acid, and 4alpha-carboxygrindelic acid were also isolated. The structures of the new compounds were characterized on the basis of spectroscopic analysis.

  5. Amino Acid Crossword Puzzle

    Science.gov (United States)

    Sims, Paul A.

    2011-01-01

    Learning the 20 standard amino acids is an essential component of an introductory course in biochemistry. Later in the course, the students study metabolism and learn about various catabolic and anabolic pathways involving amino acids. Learning new material or concepts often is easier if one can connect the new material to what one already knows;…

  6. Peptide Nucleic Acids (PNA)

    DEFF Research Database (Denmark)

    2002-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  7. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  8. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2003-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  9. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds known as peptide nucleic acids, bind complementary DNA and RNA strands, and generally do so more strongly than the corresponding DNA or RNA strands while exhibiting increased sequence specificity and solubility. The peptide nucleic acids comprise ligands selected from...

  10. Carbolic acid poisoning

    Science.gov (United States)

    ... you to. If the person swallowed the carbolic acid, give them water or milk right away, if a provider tells ... well someone does depends on how much carbolic acid they swallowed and how quickly they receive treatment. The faster medical help is given, the better ...

  11. Fats and fatty acids

    Science.gov (United States)

    The absolute fat requirement of the human species is the amount of essential fatty acids needed to maintain optimal fatty acid composition of all tissues and normal eicosanoid synthesis. At most, this requirement is no more than about 5% of an adequate energy intake. However, fat accounts for appro...

  12. Locked nucleic acid

    DEFF Research Database (Denmark)

    Jepsen, Jan Stenvang; Sørensen, Mads D; Wengel, Jesper

    2004-01-01

    Locked nucleic acid (LNA) is a class of nucleic acid analogs possessing very high affinity and excellent specificity toward complementary DNA and RNA, and LNA oligonucleotides have been applied as antisense molecules both in vitro and in vivo. In this review, we briefly describe the basic...

  13. Peptide Nucleic Acid Synthons

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  14. Chlorogenic acid and caffeic acid are absorbed in humans

    OpenAIRE

    2001-01-01

    Chlorogenic acid, an ester of caffeic acid and quinic acid, is a major phenolic compound in coffee; daily intake in coffee drinkers is 0.5-1 g. Chlorogenic acid and caffeic acid are antioxidants in vitro and might therefore contribute to the prevention of cardiovascular disease. However, data on the absorption of chlorogenic acid and caffeic acid in humans are lacking. We determined the absorption of chlorogenic acid and caffeic acid in a cross-over study with 4 female and 3 male healthy ileo...

  15. Chlorogenic acid and caffeic acid are absorbed in humans

    NARCIS (Netherlands)

    Olthof, M.R.; Hollman, P.C.H.; Katan, M.B.

    2001-01-01

    Chlorogenic acid, an ester of caffeic acid and quinic acid, is a major phenolic compound in coffee; daily intake in coffee drinkers is 0.5-1 g. Chlorogenic acid and caffeic acid are antioxidants in vitro and might therefore contribute to the prevention of cardiovascular disease. However, data on the

  16. 2-Methylaspartic acid monohydrate

    Directory of Open Access Journals (Sweden)

    Ray J. Butcher

    2013-12-01

    Full Text Available The title compound, C5H9NO4·H2O, is an isomer of the α-amino acid glutamic acid that crystallizes from water in its zwitterionic form as a monohydrate. It is not one of the 20 proteinogenic α-amino acids that are used in living systems and differs from the natural amino acids in that it has an α-methyl group rather than an α-H atom. In the crystal, an O—H...O hydrogen bond is present between the acid and water molecules while extensive N—H...O and O—H...O hydrogen bonds link the components into a three-dimensional array.

  17. Halogenated fatty acids

    DEFF Research Database (Denmark)

    Mu, Huiling; Wesén, Clas; Sundin, Peter

    1997-01-01

    Chlorinated fatty acids have been found to be major contributors to organohalogen compounds in fish, bivalves, jellyfish, and lobster, and they have been indicated to contribute considerably to organohalogens in marine mammals. Brominated fatty acids have been found in marine sponges. Also......, chlorinated lipids have been found in meat exposed to hypochlorite disinfected water, and in chlorine-treated flour and in products made from such flour. Following exposure to chlorine bleached pulp mill effluents, aquatic organisms may have elevated concentrations of chlorinated fatty acids in their lipids....... However, a natural production of halogenated fatty acids is also possible. In this paper we summarize the present knowledge of the occurrence of halogenated fatty acids in lipids and suggested ways of their formation. In Part II (Trends Anal. Chem. 16 (1997) 274) we deal with methods...

  18. Fusidic acid in dermatology

    DEFF Research Database (Denmark)

    Schöfer, Helmut; Simonsen, Lene

    1995-01-01

    Studies on the clinical efficacy of fusidic acid in skin and soft-tissue infections (SSTIs), notably those due to Staphylococcus aureus, are reviewed. Oral fusidic acid (tablets dosed at 250 mg twice daily, or a suspension for paediatric use at 20 mg/kg/day given as two daily doses) has shown good...... efficacy and tolerability. Similarly, plain fusidic acid cream or ointment used two or three times daily in SSTIs such as impetigo are clinically and bacteriologically effective, with minimal adverse events. Combination formulations of fusidic acid with 1% hydrocortisone or 0.1% betamethasone achieve...... excellent results in infected eczema by addressing both inflammation and infection. A new lipid-rich combination formulation provides an extra moisturizing effect. Development of resistance to fusidic acid has remained generally low or short-lived and can be minimized by restricting therapy to no more than...

  19. 21 CFR 172.860 - Fatty acids.

    Science.gov (United States)

    2010-04-01

    ... acid, caprylic acid, lauric acid, myristic acid, oleic acid, palmitic acid, and stearic acid. (b) The... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Fatty acids. 172.860 Section 172.860 Food and Drugs... Multipurpose Additives § 172.860 Fatty acids. The food additive fatty acids may be safely used in food and...

  20. Gluconic acid production.

    Science.gov (United States)

    Anastassiadis, Savas; Morgunov, Igor G

    2007-01-01

    Gluconic acid, the oxidation product of glucose, is a mild neither caustic nor corrosive, non toxic and readily biodegradable organic acid of great interest for many applications. As a multifunctional carbonic acid belonging to the bulk chemicals and due to its physiological and chemical characteristics, gluconic acid itself, its salts (e.g. alkali metal salts, in especially sodium gluconate) and the gluconolactone form have found extensively versatile uses in the chemical, pharmaceutical, food, construction and other industries. Present review article presents the comprehensive information of patent bibliography for the production of gluconic acid and compares the advantages and disadvantages of known processes. Numerous manufacturing processes are described in the international bibliography and patent literature of the last 100 years for the production of gluconic acid from glucose, including chemical and electrochemical catalysis, enzymatic biocatalysis by free or immobilized enzymes in specialized enzyme bioreactors as well as discontinuous and continuous fermentation processes using free growing or immobilized cells of various microorganisms, including bacteria, yeast-like fungi and fungi. Alternatively, new superior fermentation processes have been developed and extensively described for the continuous and discontinuous production of gluconic acid by isolated strains of yeast-like mold Aureobasidium pullulans, offering numerous advantages over the traditional discontinuous fungi processes.

  1. Trans Fatty Acids

    Science.gov (United States)

    Doyle, Ellin

    1997-09-01

    Fats and their various fatty acid components seem to be a perennial concern of nutritionists and persons concerned with healthful diets. Advice on the consumption of saturated, polyunsaturated, monounsaturated, and total fat bombards us from magazines and newspapers. One of the newer players in this field is the group of trans fatty acids found predominantly in partially hydrogenated fats such as margarines and cooking fats. The controversy concerning dietary trans fatty acids was recently addressed in an American Heart Association (AHA) science advisory (1) and in a position paper from the American Society of Clinical Nutrition/American Institute of Nutrition (ASCN/AIN) (2). Both reports emphasize that the best preventive strategy for reducing risk for cardiovascular disease and some types of cancer is a reduction in total and saturated fats in the diet, but a reduction in the intake of trans fatty acids was also recommended. Although the actual health effects of trans fatty acids remain uncertain, experimental evidence indicates that consumption of trans fatty acids adversely affects serum lipid levels. Since elevated levels of serum cholesterol and triacylglycerols are associated with increased risk of cardiovascular disease, it follows that intake of trans fatty acids should be minimized.

  2. Amino acid racemisation dating

    Energy Technology Data Exchange (ETDEWEB)

    Murray-Wallace, C.V. [University of Wollongong, Wollongong, NSW (Australia). School of Geosciences

    1999-11-01

    The potential of the time-dependent amino acid racemisation reaction as a method of age assessment was first reported by Hare and Abelson (1968). They noted that in specimens of the bivalve mollusc Mercenaria sp., greater concentrations of amino acids in the D-configuration with increasing fossil age. Hare and Abelson (1968) also reported negligible racemisation in a modern specimen of Mecanaria sp. On this basis they suggested that the extent of amino acid racemisation (epimerisation in the case of isoleucine) may be used to assess the age of materials within and beyond the range of radiocarbon dating. For the past thirty years amino acid racemisation has been extensively applied in Quaternary research as a method of relative and numeric dating, and a particularly large literature has emerged on the subject 12 refs.

  3. [Hydrofluoric acid burns].

    Science.gov (United States)

    Holla, Robin; Gorter, Ramon R; Tenhagen, Mark; Vloemans, A F P M Jos; Breederveld, Roelf S

    2016-01-01

    Hydrofluoric acid is increasingly used as a rust remover and detergent. Dermal contact with hydrofluoric acid results in a chemical burn characterized by severe pain and deep tissue necrosis. It may cause electrolyte imbalances with lethal consequences. It is important to identify high-risk patients. 'High risk' is defined as a total affected body area > 3% or exposure to hydrofluoric acid in a concentration > 50%. We present the cases of three male patients (26, 31, and 39 years old) with hydrofluoric acid burns of varying severity and describe the subsequent treatments. The application of calcium gluconate 2.5% gel to the skin is the cornerstone of the treatment, reducing pain as well as improving wound healing. Nails should be thoroughly inspected and possibly removed if the nail is involved, to ensure proper healing. In high-risk patients, plasma calcium levels should be evaluated and cardiac monitoring is indicated.

  4. Acid rain: An overview

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Summary of the effects of acid rain and related processes, sources, issues, corrective actions, research, current law, potential solutions, political solutions,...

  5. Folic acid - test

    Science.gov (United States)

    ... folic acid before and during pregnancy helps prevent neural tube defects, such as spina bifida. Women who are ... take more if they have a history of neural tube defects in earlier pregnancies. Ask your provider how ...

  6. Stomach acid test

    Science.gov (United States)

    Gastric acid secretion test ... The test is done after you have not eaten for a while so fluid is all that remains in ... injected into your body. This is done to test the ability of the cells in the stomach ...

  7. Fatty Acid Oxidation Disorders

    Science.gov (United States)

    ... acid oxidation disorders are tested for in newborn screening? The March of Dimes recommends that all babies ... in behavior Diarrhea, nausea (feeling sick to your stomach) and throwing up Drowsiness Fever Fussiness Little appetite ...

  8. Amino Acids and Chirality

    Science.gov (United States)

    Cook, Jamie E.

    2012-01-01

    Amino acids are among the most heavily studied organic compound class in carbonaceous chondrites. The abundance, distributions, enantiomeric compositions, and stable isotopic ratios of amino acids have been determined in carbonaceous chondrites fi'om a range of classes and petrographic types, with interesting correlations observed between these properties and the class and typc of the chondritcs. In particular, isomeric distributions appear to correlate with parent bodies (chondrite class). In addition, certain chiral amino acids are found in enantiomeric excess in some chondrites. The delivery of these enantiomeric excesses to the early Earth may have contributed to the origin of the homochirality that is central to life on Earth today. This talk will explore the amino acids in carbonaceous chondritcs and their relevance to the origin of life.

  9. Ethylenediaminetetraacetic acid in endodontics

    OpenAIRE

    Mohammadi, Zahed; Shalavi, Sousan; Jafarzadeh, Hamid

    2013-01-01

    Ethylenediaminetetraacetic acid (EDTA) is a chelating agent can bind to metals via four carboxylate and two amine groups. It is a polyamino carboxylic acid and a colorless, water-soluble solid, which is widely used to dissolve lime scale. It is produced as several salts, notably disodium EDTA and calcium disodium EDTA. EDTA reacts with the calcium ions in dentine and forms soluble calcium chelates. A review of the literature and a discussion of the different indications and considerations for...

  10. Neutron Nucleic Acid Crystallography.

    Science.gov (United States)

    Chatake, Toshiyuki

    2016-01-01

    The hydration shells surrounding nucleic acids and hydrogen-bonding networks involving water molecules and nucleic acids are essential interactions for the structural stability and function of nucleic acids. Water molecules in the hydration shells influence various conformations of DNA and RNA by specific hydrogen-bonding networks, which often contribute to the chemical reactivity and molecular recognition of nucleic acids. However, X-ray crystallography could not provide a complete description of structural information with respect to hydrogen bonds. Indeed, X-ray crystallography is a powerful tool for determining the locations of water molecules, i.e., the location of the oxygen atom of H2O; however, it is very difficult to determine the orientation of the water molecules, i.e., the orientation of the two hydrogen atoms of H2O, because X-ray scattering from the hydrogen atom is very small.Neutron crystallography is a specialized tool for determining the positions of hydrogen atoms. Neutrons are not diffracted by electrons, but are diffracted by atomic nuclei; accordingly, neutron scattering lengths of hydrogen and its isotopes are comparable to those of non-hydrogen atoms. Therefore, neutron crystallography can determine both of the locations and orientations of water molecules. This chapter describes the current status of neutron nucleic acid crystallographic research as well as the basic principles of neutron diffraction experiments performed on nucleic acid crystals: materials, crystallization, diffraction experiments, and structure determination.

  11. Fatty Acid Biosynthesis IX

    DEFF Research Database (Denmark)

    Carey, E. M.; Hansen, Heinz Johs. Max; Dils, R.

    1972-01-01

    # 1. I. [I-14C]Acetate was covalently bound to rabbit mammary gland fatty acid synthetase by enzymic transacylation from [I-14C]acetyl-CoA. Per mole of enzyme 2 moles of acetate were bound to thiol groups and up to I mole of acetate was bound to non-thiol groups. # 2. 2. The acetyl-fatty acid...... synthetase complex was isolated free from acetyl-CoA. It was rapidly hydrolysed at 30°C, but hydrolysis was greatly diminished at o°C and triacetic lactone synthesis occurred. In the presence of malonyl-CoA and NADPH, all the acetate bound to fatty acid synthetase was incorporated into long-chain fatty acids....... Hydrolysis of bound acetate and incorporation of bound acetate into fatty acids were inhibited to the same extent by guanidine hydrochloride. # 3. 3. Acetate was also covalently bound to fatty acid synthetase by chemical acetylation with [I-14C]acetic anhydride in the absence of CoASH. A total of 60 moles...

  12. Performance Comparison of New Combinations of Acids with Mud Acid in Sandstone Acidizing

    Directory of Open Access Journals (Sweden)

    Mian Umer Shafiq

    2014-01-01

    Full Text Available The aim of this research is to find the best suitable acid to acidize undamaged low permeable sandstone formation Stimulation of sandstone formations is a challenging task, which involves several chemicals and physical interactions of the acid with the formation. Mud acid has been successfully used to stimulate sandstone reservoirs for a number of years. Matrix acidizing may also be used to increase formation permeability in undamaged wells. The change may be up to 50 to 100% with the mud acid. For any acidizing process, the selection of acid (Formulation and Concentration and the design (Pre-flush, Main Acid, After-flush is very important. Different researchers are using different combinations of acids with different concentrations to get the best results for acidization. Mainly the common practice is combination of Hydrochloric Acid- Hydrofluoric with Concentration (3% HF-12% HCl. This study presents the results of a laboratory investigation of Orthophosphoric acid instead of hydrochloric acid in one combination and the second combination is Fluoboric and formic acid and the third one is formic and hydrofluoric acid. The results are compared with the mud acid and the results analyzed are porosity, permeability, strength, color change and FESEM Analysis. All of these new combinations shows that these have the potential to be used as acidizing acids on sandstone formations.

  13. Inhibitory effect of ethanol, acetic acid, propionic acid and butyric acid on fermentative hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bo; Wan, Wei; Wang, Jianlong [Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084 (China)

    2008-12-15

    The inhibitory effect of added ethanol, acetic acid, propionic acid and butyric acid on fermentative hydrogen production by mixed cultures was investigated in batch tests using glucose as substrate. The experimental results showed that, at 35 C and initial pH 7.0, during the fermentative hydrogen production, the substrate degradation efficiency, hydrogen production potential, hydrogen yield and hydrogen production rate all trended to decrease with increasing added ethanol, acetic acid, propionic acid and butyric acid concentration from 0 to 300 mmol/L. The inhibitory effect of added ethanol on fermentative hydrogen production was smaller than those of added acetic acid, propionic acid and butyric acid. The modified Han-Levenspiel model could describe the inhibitory effects of added ethanol, acetic acid, propionic acid and butyric acid on fermentative hydrogen production rate in this study successfully. The modified Logistic model could describe the progress of cumulative hydrogen production. (author)

  14. Effect of acidity and hydrogenation ability on the hydrodenitrogenation performance of NiW/Al2 O3 catalyst%NiW/Al2 O3催化剂酸性与加氢活性的调变及对重油加氢脱氮性能的影响

    Institute of Scientific and Technical Information of China (English)

    韩璐; 周亚松; 魏强; 罗怡; 王靖宇

    2014-01-01

    以 Ni、W 为催化剂的活性金属组分,采用等体积浸渍法制备了 NiW/ Al2 O3加氢脱氮催化剂,考察了 Al2 O3载体表面经硼酸修饰后对催化剂酸性的影响,以及活性金属与柠檬酸络合后对催化剂加氢反应性能的影响。 NH3-TPD、HRTEM、H2-TPR、XPS 等表征结果表明,Al2 O3载体表面硼酸修饰增加了催化剂表面的中强酸量,减少了强酸量,且削弱了金属与载体之间的强相互作用,但活性中心数目减少。金属与柠檬酸络合可以减小活性相晶粒长度、提高活性相分散性及硫化程度。催化剂的反应评价结果表明,硼酸修饰与柠檬酸络合共同作用可以增强催化剂的重油加氢处理能力,促进芳环与胶质的加氢饱和;具有适宜的氢解与加氢活性,兼顾碱性氮与非碱性氮的脱除,体现了催化剂良好的重油加氢脱氮性能。%NiW / Al2 O3 catalysts for the hydrodenitrogenation of heavy oil were prepared by nickel-tungstateactive metals located on Al 2 O 3 with wetness impregnation. The effect of boric acid on the acidity and the effect of citric acid on the hydrogenation ability were studied. The results of NH 3-TPD, HRTEM, H2-TPR and XPS showed that the addition of boric acid increased the proportion of strong and medium acid. The strong interaction between the support and metal has been weakened. Citric acid achieved moderate length of Ni-W-S active phases, increased the dispersion and the sulfidation degree of the metal on catalysts surface. NiW catalystmodified with boron acid and citric acid had outstanding HDN performance for Venezuela deasphalted oil , promoted the hydrogenation of aromatics and resin. It also had strong HDN abilities to basic and non-basic nitrogen compounds. The catalyst showed outstanding HDN performance of heavy oil.

  15. Amino acids in the sedimentary humic and fulvic acids

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.

    Humic and fulvic acids isolated from a few sediment samples from Arabian Sea and Bay of Bengal were analysed for total hydrolysable amino acids concentration and their composition. The amono acids content of fulvic acids was higher than in the humic...

  16. Synthesis and anticonvulsant activity of novel bicyclic acidic amino acids

    DEFF Research Database (Denmark)

    Conti, Paola; De Amici, Marco; Joppolo Di Ventimiglia, Samuele

    2003-01-01

    Bicyclic acidic amino acids (+/-)-6 and (+/-)-7, which are conformationally constrained homologues of glutamic acid, were prepared via a strategy based on a 1,3-dipolar cycloaddition. The new amino acids were tested toward ionotropic and metabotropic glutamate receptor subtypes; both of them...

  17. Diffusion-Limited Aggregation in Potato Starch and Hydrogen Borate Electrolyte System

    Directory of Open Access Journals (Sweden)

    Tuhina Tiwari

    2013-01-01

    Full Text Available Natural growth of diffusion-limited aggregate (DLA, without any external stimuli, in boric acid doped starch system is reported here. Fractals grown were confirmed to be of diffusion-limited aggregate (DLA pattern having fractal dimension ~1.49. Effect of substrate and humidity on growth pattern has also been discussed. The existence of a different vibration band of H3BO3 in FTIR confirmed that growth structures are related to boric acid. XRD pattern has shown broad peak along with some sharp peaks. Broad peak is related to starch’s amorphous nature, as where intense sharp peaks are due to boric acid.

  18. EFFECT OF ACIDITY ON ACID-SENSITIVE UV CURING SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Qi-dao Chen; Bing Wu; Xiao-yin Hong

    1999-01-01

    By using diphenyliodonium salts with different counterions as photo acid generators (PAGs), the effect of acidity on ring-opening polymerization of epoxy monomers and polycondensation of polyol with hexamethoxymethyl melamine (HMMM) was studied. The result shows that the rate of ring-opening polymerization is evidently dependent on the acidity of the acid and strong photo-generated acid is required.However, there is a leveling effect in the polycondensation system; if the photo-generated acid is stronger than protonated HMMM, the acidity does not obviously affect the polycondensation rate.

  19. Determination of Sialic Acids by Acidic Ninhydrin Reaction

    Directory of Open Access Journals (Sweden)

    Yao,Kenzabroh

    1987-12-01

    Full Text Available A new acidic ninhydrin method for determining free sialic acids is described. The method is based on the reaction of sialic acids with Gaitonde's acid ninhydrin reagent 2 which yields a stable color with an absorption maximum at 470 nm. The standard curve is linear in the range of 5 to 500 nmol of N-acetylneuraminic acid per 0.9 ml of reaction mixture. The reaction was specific only for sialic acids among the various sugars and sugar derivatives examined. Some interference of this method by cysteine, cystine and tryptophan was noted, although their absorption maxima differed from that of sialic acids. The interference by these amino acids was eliminated with the use of a small column of cation-exchange resin. The acidic ninhydrin method provides a simple and rapid method for the determination of free sialic acids in biological materials.

  20. Domoic Acid Epileptic Disease

    Directory of Open Access Journals (Sweden)

    John S. Ramsdell

    2014-03-01

    Full Text Available Domoic acid epileptic disease is characterized by spontaneous recurrent seizures weeks to months after domoic acid exposure. The potential for this disease was first recognized in a human case study of temporal lobe epilepsy after the 1987 amnesic shellfish-poisoning event in Quebec, and was characterized as a chronic epileptic syndrome in California sea lions through investigation of a series of domoic acid poisoning cases between 1998 and 2006. The sea lion study provided a breadth of insight into clinical presentations, unusual behaviors, brain pathology, and epidemiology. A rat model that replicates key observations of the chronic epileptic syndrome in sea lions has been applied to identify the progression of the epileptic disease state, its relationship to behavioral manifestations, and to define the neural systems involved in these behavioral disorders. Here, we present the concept of domoic acid epileptic disease as a delayed manifestation of domoic acid poisoning and review the state of knowledge for this disease state in affected humans and sea lions. We discuss causative mechanisms and neural underpinnings of disease maturation revealed by the rat model to present the concept for olfactory origin of an epileptic disease; triggered in dendodendritic synapases of the olfactory bulb and maturing in the olfactory cortex. We conclude with updated information on populations at risk, medical diagnosis, treatment, and prognosis.

  1. Hydrogen production by fermentation using acetic acid and lactic acid.

    Science.gov (United States)

    Matsumoto, Mitsufumi; Nishimura, Yasuhiko

    2007-03-01

    Microbial hydrogen production from sho-chu post-distillation slurry solution (slurry solution) containing large amounts of organic acids was investigated. The highest hydrogen producer, Clostridium diolis JPCC H-3, was isolated from natural environment and produced hydrogen at 6.03+/-0.15 ml from 5 ml slurry solution in 30 h. Interestingly, the concentration of acetic acid and lactic acid in the slurry solution decreased during hydrogen production. The substrates for hydrogen production by C. diolis JPCC H-3, in particular organic acids, were investigated in an artificial medium. No hydrogen was produced from acetic acid, propionic acid, succinic acid, or citric acid on their own. Hydrogen and butyric acid were produced from a mixture of acetic acid and lactic acid, showing that C. diolis. JPCC H-3 could produce hydrogen from acetic acid and lactic acid. Furthermore, calculation of the Gibbs free energy strongly suggests that this reaction would proceed. In this paper, we describe for the first time microbial hydrogen production from acetic acid and lactic acid by fermentation.

  2. Halogenated fatty acids

    DEFF Research Database (Denmark)

    Mu, Huiling; Sundin, Peter; Wesén, Clas

    1997-01-01

    Halogenated fatty acids are the major contributors to organohalogen compounds in lipids of marine mammals, fish, and bivalves. For the initial characterization of these recently noticed compounds, a determination of the halogen concentration has usually been combined with some lipid isolation...... and separation method. This review covers separation by solid phase chromatography, gel permeation chromatography, and liquid-liquid extraction, followed by halogen determination. All studies performed according to this outline have indicated that the major organohalogen compounds are chlorinated fatty acids...... bound in different lipids. For the detection and identification of individual, halogenated fatty acid methyl esters (FAMEs) liberated from the lipids, gas chromatography (GC) has been employed together with detection methods such as electron capture detection, electrolytic conductivity detection (ELCD...

  3. Calorimetry of Nucleic Acids.

    Science.gov (United States)

    Rozners, Eriks; Pilch, Daniel S; Egli, Martin

    2015-12-01

    This unit describes the application of calorimetry to characterize the thermodynamics of nucleic acids, specifically, the two major calorimetric methodologies that are currently employed: differential scanning (DSC) and isothermal titration calorimetry (ITC). DSC is used to study thermally induced order-disorder transitions in nucleic acids. A DSC instrument measures, as a function of temperature (T), the excess heat capacity (C(p)(ex)) of a nucleic acid solution relative to the same amount of buffer solution. From a single curve of C(p)(ex) versus T, one can derive the following information: the transition enthalpy (ΔH), entropy (ΔS), free energy (ΔG), and heat capacity (ΔCp); the state of the transition (two-state versus multistate); and the average size of the molecule that melts as a single thermodynamic entity (e.g., the duplex). ITC is used to study the hybridization of nucleic acid molecules at constant temperature. In an ITC experiment, small aliquots of a titrant nucleic acid solution (strand 1) are added to an analyte nucleic acid solution (strand 2), and the released heat is monitored. ITC yields the stoichiometry of the association reaction (n), the enthalpy of association (ΔH), the equilibrium association constant (K), and thus the free energy of association (ΔG). Once ΔH and ΔG are known, ΔS can also be derived. Repetition of the ITC experiment at a number of different temperatures yields the ΔCp for the association reaction from the temperature dependence of ΔH.

  4. Ethylenediaminetetraacetic acid in endodontics.

    Science.gov (United States)

    Mohammadi, Zahed; Shalavi, Sousan; Jafarzadeh, Hamid

    2013-09-01

    Ethylenediaminetetraacetic acid (EDTA) is a chelating agent can bind to metals via four carboxylate and two amine groups. It is a polyamino carboxylic acid and a colorless, water-soluble solid, which is widely used to dissolve lime scale. It is produced as several salts, notably disodium EDTA and calcium disodium EDTA. EDTA reacts with the calcium ions in dentine and forms soluble calcium chelates. A review of the literature and a discussion of the different indications and considerations for its usage are presented.

  5. Whither Acid Rain?

    Directory of Open Access Journals (Sweden)

    Peter Brimblecombe

    2000-01-01

    Full Text Available Acid rain, the environmental cause célèbre of the 1980s seems to have vanished from popular conscience. By contrast, scientific research, despite funding difficulties, has continued to produce hundreds of research papers each year. Studies of acid rain taught much about precipitation chemistry, the behaviour of snow packs, long-range transport of pollutants and new issues in the biology of fish and forested ecosystems. There is now evidence of a shift away from research in precipitation and sulfur chemistry, but an impressive theoretical base remains as a legacy.

  6. Fatty acids of Thiobacillus thiooxidans.

    Science.gov (United States)

    Levin, R A

    1971-12-01

    Fatty acid spectra were made on Thiobacillus thiooxidans cultures both in the presence and absence of organic compounds. Small additions of glucose or acetate had no significant effect either on growth or fatty acid content. The addition of biotin had no stimulatory effect but did result in slight quantitative changes in the fatty acid spectrum. The predominant fatty acid was a C(19) cyclopropane acid.

  7. Lactic acid bacterial cell factories for gamma-aminobutyric acid.

    Science.gov (United States)

    Li, Haixing; Cao, Yusheng

    2010-11-01

    Gamma-aminobutyric acid is a non-protein amino acid that is widely present in organisms. Several important physiological functions of gamma-aminobutyric acid have been characterized, such as neurotransmission, induction of hypotension, diuretic effects, and tranquilizer effects. Many microorganisms can produce gamma-aminobutyric acid including bacteria, fungi and yeasts. Among them, gamma-aminobutyric acid-producing lactic acid bacteria have been a focus of research in recent years, because lactic acid bacteria possess special physiological activities and are generally regarded as safe. They have been extensively used in food industry. The production of lactic acid bacterial gamma-aminobutyric acid is safe and eco-friendly, and this provides the possibility of production of new naturally fermented health-oriented products enriched in gamma-aminobutyric acid. The gamma-aminobutyric acid-producing species of lactic acid bacteria and their isolation sources, the methods for screening of the strains and increasing their production, the enzymatic properties of glutamate decarboxylases and the relative fundamental research are reviewed in this article. And the potential applications of gamma-aminobutyric acid-producing lactic acid bacteria were also referred to.

  8. Effect of domoic acid on brain amino acid levels.

    Science.gov (United States)

    Durán, R; Arufe, M C; Arias, B; Alfonso, M

    1995-03-01

    The administration of Domoic Acid (Dom) in a 0.2 mg/kg i.p. dose induces changes in the levels of amino acids of neurochemical interest (Asp, Glu, Gly, Tau, Ala, GABA) in different rat brain regions (hypothalamus, hippocampus, amygdala, striatum, cortex and midbrain). The most affected amino acid is the GABA, the main inhibitory amino acid neurotransmitter, whereas glutamate, the main excitatory amino acid, is not affected. The rat brain regions that seem to be the main target of the Dom action belong to the limbic system (hippocampus, amygdala). The possible implication of the amino acids in the actions of Dom is also discussed.

  9. Koetjapic acid chloroform hemisolvate

    Directory of Open Access Journals (Sweden)

    Z. D. Nassar

    2010-06-01

    Full Text Available The asymmetric unit of the title compound, C30H46O4·0.5CHCl3, consists of one koetjapic acid [systematic name: (3R,4aR,4bS,7S,8S,10bS,12aS-7-(2-carboxyethyl-3,4b,7,10b,12a-pentamethyl-8-(prop-1-en-2-yl-1,2,3,4,4a,4b,5,6,7,8,9,10,10b,11,12,12a-hexadecahydrochrysene-3-carboxylic acid] molecule and one half-molecule of chloroform solvent, which is disordered about a twofold rotation axis. The symmetry-independent component is further disordered over two sites, with occupancies of 0.30 and 0.20. The koetjapic acid contains a fused four-ring system, A/B/C/D. The A/B, B/C and C/D junctions adopt E/trans/cis configurations, respectively. The conformation of ring A is intermediate between envelope and half-chair and ring B adopts an envelope conformation whereas rings C and D adopt chair conformations. A weak intramolecular C—H...O hydrogen bond is observed. The koetjapic acid molecules are linked into dimers by two pairs of intermolecular O—H...O hydrogen bonds. The dimers are stacked along the c axis.

  10. Phenylpyruvic acid in urine

    NARCIS (Netherlands)

    Meulemans, O.; Vergeer, E.G.

    1960-01-01

    The method of The, Fleury And Vink for the determination of phenylpyruvic acid (PPA) in urine is modified by measuring the extinction after the green colour with ferric chloride has faded, and subtracting this extinction from that found initially. More accurate values are obtained and low PPA values

  11. Accidents with sulfuric acid

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2006-01-01

    Full Text Available Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eighteen years (from 1988 till the beginning of 2006 are analyzed in this paper. It is very alarming data that, according to all the recorded accidents, over 1.6 million tons of sulfuric acid were exuded. Although water transport is the safest (only 16.38% of the total amount of accidents in that way 98.88% of the total amount of sulfuric acid was exuded into the environment. Human factor was the common factor in all the accidents, whether there was enough control of the production process, of reservoirs or transportation tanks or the transport was done by inadequate (old tanks, or the accidents arose from human factor (inadequate speed, lock of caution etc. The fact is that huge energy, sacrifice and courage were involved in the recovery from accidents where rescue teams and fire brigades showed great courage to prevent real environmental catastrophes and very often they lost their lives during the events. So, the phrase that sulfuric acid is a real "environmental bomb" has become clearer.

  12. Azetidinic amino acids

    DEFF Research Database (Denmark)

    Bräuner-Osborne, Hans; Bunch, Lennart; Chopin, Nathalie

    2005-01-01

    of two diastereoisomers that were easily separated and converted in two steps into azetidinic amino acids. Azetidines 35-44 were characterized in binding studies on native ionotropic Glu receptors and in functional assays at cloned metabotropic receptors mGluR1, 2 and 4, representing group I, II and III...

  13. Hyaluronic Acid Assays

    DEFF Research Database (Denmark)

    Itenov, Theis S; Kirkby, Nikolai S; Bestle, Morten H

    2015-01-01

    BACKGROUD: Hyaluronic acid (HA) is proposed as a marker of functional liver capacity. The aim of the present study was to compare a new turbidimetric assay for measuring HA with the current standard method. METHODS: HA was measured by a particle-enhanced turbidimetric immunoassay (PETIA) and enzyme...

  14. Lactic acid and lactates

    NARCIS (Netherlands)

    Schreurs, V.V.A.M.

    2010-01-01

    This review aims to integrate the present state of knowledge on lactate metabolism in human and mammalian physiology as far as it could be subject to nutritional interventions. An integrated view on the nutritional, metabolic and physiological aspects of lactic acid and lactates might open a perspec

  15. Acid Rain Investigations.

    Science.gov (United States)

    Hugo, John C.

    1992-01-01

    Presents an activity in which students investigate the formation of solid ammonium chloride aerosol particles to help students better understand the concept of acid rain. Provides activity objectives, procedures, sample data, clean-up instructions, and questions and answers to help interpret the data. (MDH)

  16. The Acid Rain Game.

    Science.gov (United States)

    Rakow, Steven J.; Glenn, Allen

    1982-01-01

    Provides rationale for and description of an acid rain game (designed for two players), a problem-solving model for elementary students. Although complete instructions are provided, including a copy of the game board, the game is also available for Apple II microcomputers. Information for the computer program is available from the author.…

  17. Acid Rain Classroom Projects.

    Science.gov (United States)

    Demchik, Michael J.

    2000-01-01

    Describes a curriculum plan in which students learn about acid rain through instructional media, research and class presentations, lab activities, simulations, design, and design implementation. Describes the simulation activity in detail and includes materials, procedures, instructions, examples, results, and discussion sections. (SAH)

  18. A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid

    Energy Technology Data Exchange (ETDEWEB)

    Arceo, Elena; Ellman, Jonathan; Bergman, Robert

    2010-05-03

    An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.

  19. Potentiometric determination of peroxodisulfuric acid during electrolysis sulfuric acid

    Directory of Open Access Journals (Sweden)

    Fedor Malchik

    2013-09-01

    Full Text Available Was proposed two potentiometric methods for determining peroxodisulfuric acid during electrolysis of sulfuric acid (potentiometric titration method and direct potentiometry, based on its interaction with a known excess of a solution Fe2+.

  20. Progress in engineering acid stress resistance of lactic acid bacteria.

    Science.gov (United States)

    Wu, Chongde; Huang, Jun; Zhou, Rongqing

    2014-02-01

    Lactic acid bacteria (LAB) are widely used for the production of a variety of fermented foods, and are considered as probiotic due to their health-promoting effect. However, LAB encounter various environmental stresses both in industrial fermentation and application, among which acid stress is one of the most important survival challenges. Improving the acid stress resistance may contribute to the application and function of probiotic action to the host. Recently, the advent of genomics, functional genomics and high-throughput technologies have allowed for the understanding of acid tolerance mechanisms at a systems level, and many method to improve acid tolerance have been developed. This review describes the current progress in engineering acid stress resistance of LAB. Special emphasis is placed on engineering cellular microenvironment (engineering amino acid metabolism, introduction of exogenous biosynthetic capacity, and overproduction of stress response proteins) and maintaining cell membrane functionality. Moreover, strategies to improve acid tolerance and the related physiological mechanisms are also discussed.

  1. Effect of phenolic acids on glucose and organic acid metabolism by lactic acid bacteria from wine.

    Science.gov (United States)

    Campos, Francisco M; Figueiredo, Ana R; Hogg, Tim A; Couto, José A

    2009-06-01

    The influence of phenolic (p-coumaric, caffeic, ferulic, gallic and protocatechuic) acids on glucose and organic acid metabolism by two strains of wine lactic acid bacteria (Oenococcus oeni VF and Lactobacillus hilgardii 5) was investigated. Cultures were grown in modified MRS medium supplemented with different phenolic acids. Cellular growth was monitored and metabolite concentrations were determined by HPLC-RI. Despite the strong inhibitory effect of most tested phenolic acids on the growth of O. oeni VF, the malolactic activity of this strain was not considerably affected by these compounds. While less affected in its growth, the capacity of L. hilgardii 5 to degrade malic acid was clearly diminished. Except for gallic acid, the addition of phenolic acids delayed the metabolism of glucose and citric acid in both strains tested. It was also found that the presence of hydroxycinnamic acids (p-coumaric, caffeic and ferulic) increased the yield of lactic and acetic acid production from glucose by O. oeni VF and not by L. hilgardii 5. The results show that important oenological characteristics of wine lactic acid bacteria, such as the malolactic activity and the production of volatile organic acids, may be differently affected by the presence of phenolic acids, depending on the bacterial species or strain.

  2. Circulating folic acid in plasma: relation to folic acid fortification

    Science.gov (United States)

    The implementation of folic acid fortification in the United States has resulted in unprecedented amounts of this synthetic form of folate in the American diet. Folic acid in circulation may be a useful measure of physiologic exposure to synthetic folic acid, and there is a potential for elevated co...

  3. Usnic acid controls the acidity tolerance of lichens.

    Science.gov (United States)

    Hauck, Markus; Jürgens, Sascha-René

    2008-11-01

    The hypotheses were tested that, firstly, lichens producing the dibenzofuran usnic acid colonize substrates characterized by specific pH ranges, secondly, this preferred pH is in a range where soluble usnic acid and its corresponding anion occur in similar concentrations, and thirdly, usnic acid makes lichens vulnerable to acidity. Lichens with usnic acid prefer an ambient pH range between 3.5 and 5.5 with an optimum between 4.0 and 4.5. This optimum is close to the pK(a1) value of usnic acid of 4.4. Below this optimum pH, dissolved SO(2) reduces the chlorophyll fluorescence yield more in lichens with than without their natural content of usnic acid. This suggests that usnic acid influences the acidity tolerance of lichens. The putative mechanism of the limited acidity tolerance of usnic acid-containing lichens is the acidification of the cytosol by molecules of protonated usnic acid shuttling protons through the plasma membrane at an apoplastic pH

  4. Acetic acid extraction from aqueous solutions using fatty acids

    NARCIS (Netherlands)

    IJmker, H.M.; Gramblicka, M.; Kersten, S.R.A.; Ham, van der A.G.J.; Schuur, B.

    2014-01-01

    A major challenge for production of acetic acid via bio-based routes is cost-effective concentration and purification of the acetic acid from the aqueous solutions, for which liquid–liquid extraction is a possible method. A main challenge in extraction of acetic acid from dilute aqueous solutions is

  5. Acid hydrolysis of cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, H.

    1980-12-01

    One of the alternatives to increase world production of etha nol is by the hydrolysis of cellulose content of agricultural residues. Studies have been made on the types of hydrolysis: enzimatic and acid. Data obtained from the sulphuric acid hydrolysis of cellulose showed that this process proceed in two steps, with a yield of approximately 95% glucose. Because of increases in cost of alternatives resources, the high demand of the product and the more economic production of ethanol from cellulose materials, it is certain that this technology will be implemented in the future. At the same time further studies on the disposal and reuse of the by-products of this production must be undertaken.

  6. Autohydrolysis of phytic acid.

    Science.gov (United States)

    Hull, S R; Gray, J S; Montgomery, R

    1999-09-10

    The autohydrolysis of phytic acid at 120 degrees C resulted in the formation of most of the phosphate esters of myo-inositol in varying amounts depending upon the reaction time. Eighteen of the 39 chromatographically distinct myo-inositol mono-, bis-, tris-, tetrakis-, pentakis-, and hexakisphosphates have been characterized using two different HPLC systems. These myo-inositol phosphates were partially purified by preparative anion-exchange chromatography under acidic and alkaline elution conditions. The combination of these two methods provides a two-tiered chromatographic approach to the rapid and sensitive identification of inositol phosphates in complex mixtures. Identification of the products was confirmed by 1D and 2D (1)H NMR analysis. The analytical procedure was applied to the autohydrolysis of the mixture of inositol phosphates from corn steep water.

  7. N-(3-Methylphenylsuccinamic acid

    Directory of Open Access Journals (Sweden)

    B. Thimme Gowda

    2010-02-01

    Full Text Available In the crystal structure of the title compound, C11H13NO3, the conformations of the N—H and C=O bonds in the amide segment are anti to each other, and that of the amide H atom is anti to the meta-methyl group in the benzene ring. Furthermore, the conformations of the amide oxygen and the carbonyl O atom of the acid segment are also anti to the adjacent –CH2 groups. The C=O and O—H bonds of the acid group are syn to each other. In the crystal, the molecules are packed into infinite chains through intermolecular N—H...O and O—H...O hydrogen bonds.

  8. N-(3-Chlorophenylmaleamic acid

    Directory of Open Access Journals (Sweden)

    B. Thimme Gowda

    2010-07-01

    Full Text Available In the title compound, C10H8ClNO3, the molecular conformation is stabilized by two intramolecular hydrogen bonds. The first is a short O—H...O hydrogen bond within the maleamic acid unit and the second is a C—H...O hydrogen bond which connects the amide group with the phenyl ring. The maleamic acid unit is essentially planar, with an r.m.s. deviation of 0.044 Å, and makes a dihedral angle of 15.2 (1° with the phenyl ring. In the crystal, intermolecular N—H...O hydrogen bonds link the molecules into C(7 chains running [010].

  9. Accidents with sulfuric acid

    OpenAIRE

    Rajković Miloš B.

    2006-01-01

    Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eigh...

  10. Phenolic acids bioavailability

    OpenAIRE

    2011-01-01

    The daily intake of phenolic compounds does not necessarily reflect the dose at which they reach the physiological targets in the organisms. The biological activity of phenolic compounds metabolites found in blood, organs and target tissues, as a result of digestive and hepatic activity, may differ from those of the native forms of the substances. This review discusses the absorption and metabolism of phenolic acids, a class of phenolic compounds abundant in food, and the methodologies used f...

  11. Omega-3 fatty acids (image)

    Science.gov (United States)

    Omega-3 fatty acids are a form of polyunsaturated fat that the body derives from food. Omega-3s (and omega-6s) are known as essential fatty acids (EFAs) because they are important for good health. ...

  12. Bile acids for viral hepatitis

    DEFF Research Database (Denmark)

    Chen, Weikeng; Liu, J; Gluud, C

    2007-01-01

    Trials have assessed bile acids for patients with viral hepatitis, but no consensus has been reached regarding their usefulness.......Trials have assessed bile acids for patients with viral hepatitis, but no consensus has been reached regarding their usefulness....

  13. LACTIC ACID BACTERIA: PROBIOTIC APPLICATIONS

    OpenAIRE

    NEENA GARG

    2015-01-01

    Lactic acid bacteria (LAB) is a heterotrophic Gram-positive bacteria which under goes lactic acid fermentations and leads to production of lactic acid as an end product. LAB includes Lactobacillus, Leuconostoc, Pediococcus, Lactococcus and Streptococcus which are grouped together in the family lactobacillaceae. LAB shows numerous antimicrobial activities due to production of antibacterial and antifungal compounds such as organic acids, bacteriocins, diacetyl, hydrogen peroxide and reutrin. LA...

  14. Biological properties of lipoic acid

    Directory of Open Access Journals (Sweden)

    Anna Bilska

    2002-06-01

    Full Text Available Lipoic acid is a prostetic group of H-protein of the glycine cleavage system and the dihydrolipoamide acyltransferases (E2 of the pyruvate, alpha-ketoglutarate and branched-chain alpha-keto acid dehydrogenase complexes. Lipoic acid and its reduced form, dihydrolipoic acid, reacts with oxygen reactive species. This paper reviews the beneficial effects in oxidative stress models or clinical conditions.

  15. Acids and bases solvent effects on acid-base strenght

    CERN Document Server

    Cox, Brian G

    2013-01-01

    Acids and bases are ubiquitous in chemistry. Our understanding of them, however, is dominated by their behaviour in water. Transfer to non-aqueous solvents leads to profound changes in acid-base strengths and to the rates and equilibria of many processes: for example, synthetic reactions involving acids, bases and nucleophiles; isolation of pharmaceutical actives through salt formation; formation of zwitter- ions in amino acids; and chromatographic separation of substrates. This book seeks to enhance our understanding of acids and bases by reviewing and analysing their behaviour in non-aqueous solvents. The behaviour is related where possible to that in water, but correlations and contrasts between solvents are also presented.

  16. East Europe Report

    Science.gov (United States)

    2007-11-02

    from China paraffins, red phosphorus, boric and chrome acids, aluminium chloride , and other inorganic chemical products. China is currently...metallurgical es- tablishments, electric power plants, coking batteries , and chemical enter- prises; 7. devote increased attention to supplying water

  17. Drug: D04113 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D04113 Mixture, Drug Boric acid - Inorganic salt mixt; Artificial tear mytear (TN) ...PHTHALMOLOGICALS S01X OTHER OPHTHALMOLOGICALS S01XA Other ophthalmologicals S01XA20 Artificial

  18. 75 FR 17716 - Notice of Receipt of Requests to Voluntarily Cancel Certain Pesticide Registrations

    Science.gov (United States)

    2010-04-07

    ...-20202 Green Light Boric acid Roach Powder 000875-00097 Accord II Iodine Iodine Detergent- Sanitizer and... Flower Pyrethrins Spray Piperonyl butoxide 067517-00042 Tomato and Piperonyl butoxide Vegetable...

  19. Folic Acid: Data and Statistics

    Science.gov (United States)

    ... can prevent birth defects, or take vitamins containing folic acid before pregnancy. [ Read article ] Use of Supplements Containing Folic Acid ... Report has published a new study looking at folic acid use before pregnancy in women who have had a previous pregnancy ...

  20. Pantothenic acid biosynthesis in zymomonas

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Luan; Tomb, Jean-Francois; Viitanen, Paul V.

    2014-07-01

    Zymomonas is unable to synthesize pantothenic acid and requires this essential vitamin in growth medium. Zymomonas strains transformed with an operon for expression of 2-dehydropantoate reductase and aspartate 1-decarboxylase were able to grow in medium lacking pantothenic acid. These strains may be used for ethanol production without pantothenic acid supplementation in seed culture and fermentation media.

  1. Acid Rain Limits Global Warming

    Institute of Scientific and Technical Information of China (English)

    Will Knight; 张林玲

    2004-01-01

    @@ Acid rain restricts global warming by reducing methane① emissions from natural wetland areas, suggests a global climate study. Acid rain is the result of industrial pollution,which causes rainwater to carry small quantities of acidic compoumds② such as sulphuric and nitric acid③. Contaminated rainwater can upset rivers and lakes, killing fish and other organisms and also damage plants, trees and buildings.

  2. Fumaric acid production by fermentation

    NARCIS (Netherlands)

    Roa Engel, C.A.; Straathof, A.J.J.; Zijlmans, T.W.; Van Gulik, W.M.; Van der Wielen, L.A.M.

    2008-01-01

    Abstract The potential of fumaric acid as a raw material in the polymer industry and the increment of cost of petroleum-based fumaric acid raises interest in fermentation processes for production of this compound from renewable resources. Although the chemical process yields 112% w/w fumaric acid fr

  3. Heterogeneous uptake of amines by citric acid and humic acid.

    Science.gov (United States)

    Liu, Yongchun; Ma, Qingxin; He, Hong

    2012-10-16

    Heterogeneous uptake of methylamine (MA), dimethylamine (DMA), and trimethylamine (TMA) onto citric acid and humic acid was investigated using a Knudsen cell reactor coupled to a quadrupole mass spectrometer at 298 K. Acid-base reactions between amines and carboxylic acids were confirmed. The observed uptake coefficients of MA, DMA, and TMA on citric acid at 298 K were measured to be 7.31 ± 1.13 × 10(-3), 6.65 ± 0.49 × 10(-3), and 5.82 ± 0.68 × 10(-3), respectively, and showed independence of sample mass. The observed uptake coefficients of MA, DMA, and TMA on humic acid at 298 K increased linearly with sample mass, and the true uptake coefficients of MA, DMA, and TMA were measured to be 1.26 ± 0.07 × 10(-5), 7.33 ± 0.40 × 10(-6), and 4.75 ± 0.15 × 10(-6), respectively. Citric acid, having stronger acidity, showed a higher reactivity than humic acid for a given amine; while the steric effect of amines was found to govern the reactivity between amines and citric acid or humic acid.

  4. Microbial degradation of poly(amino acid)s.

    Science.gov (United States)

    Obst, Martin; Steinbüchel, Alexander

    2004-01-01

    Natural poly(amino acid)s are a group of poly(ionic) molecules (ionomers) with various biological functions and putative technical applications and play, therefore, an important role both in nature and in human life. Because of their biocompatibility and their synthesis from renewable resources, poly(amino acid)s may be employed for many different purposes covering a broad spectrum of medical, pharmaceutical, and personal care applications as well as the domains of agriculture and of environmental applications. Biodegradability is one important advantage of naturally occurring poly(amino acid)s over many synthetic polymers. The intention of this review is to give an overview about the enzyme systems catalyzing the initial steps in poly(amino acid) degradation. The focus is on the naturally occurring poly(amino acid)s cyanophycin, poly(epsilon-L-lysine) and poly(gamma-glutamic acid); but biodegradation of structurally related synthetic polyamides such as poly(aspartic acid) and nylons, which are known from various technical applications, is also included.

  5. Molecular Interaction of Pinic Acid with Sulfuric Acid

    DEFF Research Database (Denmark)

    Elm, Jonas; Kurten, Theo; Bilde, Merete

    2014-01-01

    We investigate the molecular interactions between the semivolatile α-pinene oxidation product pinic acid and sulfuric acid using computational methods. The stepwise Gibbs free energies of formation have been calculated utilizing the M06-2X functional, and the stability of the clusters is evaluated...... from the corresponding ΔG values. The first two additions of sulfuric acid to pinic acid are found to be favorable with ΔG values of -9.06 and -10.41 kcal/mol. Addition of a third sulfuric acid molecule is less favorable and leads to a structural rearrangement forming a bridged sulfuric acid-pinic acid...... cluster. The involvement of more than one pinic acid molecule in a single cluster is observed to lead to the formation of favorable (pinic acid)2(H2SO4) and (pinic acid)2(H2SO4)2 clusters. The identified most favorable growth paths starting from a single pinic acid molecule lead to closed structures...

  6. Microbial transformations of isocupressic acid.

    Science.gov (United States)

    Lin, S J; Rosazza, J P

    1998-07-01

    Microbial transformations of the labdane-diterpene isocupressic acid (1) with different microorganisms yielded several oxygenated metabolites that were isolated and characterized by MS and NMR spectroscopic analyses. Nocardia aurantia (ATCC 12674) catalyzed the cleavage of the 13,14-double bond to yield a new nor-labdane metabolite, 2. Cunninghamella elegans (-) (NRRL 1393) gave 7beta-hydroxyisocupressic acid (3) and labda-7,13(E)-diene-6beta,15, 17-triol-19-oic acid (4), and Mucor mucedo (ATCC 20094) gave 2alpha-hydroxyisocupressic acid (5) and labda-8(17),14-diene-2alpha, 13-diol-19-oic acid (6).

  7. Acidic aerosol in urban air

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, M.; Yamaoka, S.; Miyazaki, T.; Oka, M.

    1982-01-01

    The distribution and chemical composition of acidic aerosol in Osaka City were investigated. Samples were collected at five sites in the city from June to September, 1979. Acidic aerosol was determined by the acid-base titration method, sulfate ion by barium chloride turbidimetry, nitrate ion by the xylenol method, and chloride ion by the mercury thiocyanate method. The concentration of acidic aerosol at five sites ranged from 7.7 micrograms per cubic meter to 10.0 micrograms per cubic meter, but mean concentrations in the residential area were slightly higher than those in the industrial area. When acidic aerosol concentrations were compared with concentrations of sulfate, nitrate, and chloride ions, a significant correlation was found between acidic aerosol and sulfate ion. The sum of the ion equivalents of the three types showed good correlation with the acidic aerosol equivalent during the whole period.

  8. Amino Acid Catabolism in Plants.

    Science.gov (United States)

    Hildebrandt, Tatjana M; Nunes Nesi, Adriano; Araújo, Wagner L; Braun, Hans-Peter

    2015-11-02

    Amino acids have various prominent functions in plants. Besides their usage during protein biosynthesis, they also represent building blocks for several other biosynthesis pathways and play pivotal roles during signaling processes as well as in plant stress response. In general, pool sizes of the 20 amino acids differ strongly and change dynamically depending on the developmental and physiological state of the plant cell. Besides amino acid biosynthesis, which has already been investigated in great detail, the catabolism of amino acids is of central importance for adjusting their pool sizes but so far has drawn much less attention. The degradation of amino acids can also contribute substantially to the energy state of plant cells under certain physiological conditions, e.g. carbon starvation. In this review, we discuss the biological role of amino acid catabolism and summarize current knowledge on amino acid degradation pathways and their regulation in the context of plant cell physiology.

  9. Metalworking and machining fluids

    Science.gov (United States)

    Erdemir, Ali; Sykora, Frank; Dorbeck, Mark

    2010-10-12

    Improved boron-based metal working and machining fluids. Boric acid and boron-based additives that, when mixed with certain carrier fluids, such as water, cellulose and/or cellulose derivatives, polyhydric alcohol, polyalkylene glycol, polyvinyl alcohol, starch, dextrin, in solid and/or solvated forms result in improved metalworking and machining of metallic work pieces. Fluids manufactured with boric acid or boron-based additives effectively reduce friction, prevent galling and severe wear problems on cutting and forming tools.

  10. Handbook of Thermal Insulation Applications.

    Science.gov (United States)

    1983-01-01

    According to industry experts, 3 billion pounds of insulation were produced in 1980 and this figure may more than double by 1990 (see Goutte , * . 1981...by shredding and pulling recycled paper or wood pulp into a fluffy, low density miaterial. Boric acid , borax 5 mol, or a mixture of these two materials...on two cellulosic fiber samples, one without a fire retardant and one with 25 percent by weight boric acid . Both produced severe surface corrosion

  11. Nucleic Acid Vaccines

    Institute of Scientific and Technical Information of China (English)

    LU Shan

    2004-01-01

    @@ Anew method of immunization was discovered in the early 1990s. Several research groups independently demonstrated that direct inoculation of DNA plasmids coding for a specific protein antigen could elicit immune responses against that antigen[1-4].Since in theory the mRNA molecules also have the potential to be translated into the protein antigen, this vaccination approach was officially named by WHO as the nucleic acid vaccination even though the term DNA vaccine has been used more commonly in the literature. This novel approach is considered the fourth generation of vaccines after live attenuated vaccines, killed or inactivated vaccines and recombinant protein based subunit vaccines.

  12. Mycophenolic Acid in Silage

    Science.gov (United States)

    Schneweis, Isabell; Meyer, Karsten; Hörmansdorfer, Stefan; Bauer, Johann

    2000-01-01

    We examined 233 silage samples and found that molds were present in 206 samples with counts between 1 × 103 and 8.9 × 107 (mean, 4.7 × 106) CFU/g. Mycophenolic acid, a metabolite of Penicillium roqueforti, was detected by liquid chromatography-mass spectrometry in 74 (32%) of these samples at levels ranging from 20 to 35,000 (mean, 1,400) μg/kg. This compound has well-known immunosuppressive properties, so feeding with contaminated silage may promote the development of infectious diseases in livestock. PMID:10919834

  13. Kinetics of wet oxidation of formic acid and acetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shende, R.V.; Mahajani, V.V. [Univ. of Mumbai (India). Dept. of Chemical Technology

    1997-11-01

    Oxidation of lower molecular weight carboxylic acids such as formic, acetic, glyoxalic, and oxalic acids is often the rate-controlling step during wet oxidation (WO) of an aqueous waste stream exhibiting very high chemical oxygen demand (COD). The kinetics of WO of formic acid was studied in the absence and presence of a cupric sulfate as catalyst in the temperature range 150--240 C and oxygen partial pressure range 0.345--1.380 MPa. Wet oxidation of acetic acid was carried out in the presence of cupric sulfate in the temperature range 215--235 C. Homogeneous copper sulfate was found to be a very good catalyst for oxidation of formic acid and acetic acid.

  14. Solid acid catalysis from fundamentals to applications

    CERN Document Server

    Hattori, Hideshi

    2014-01-01

    IntroductionTypes of solid acid catalystsAdvantages of solid acid catalysts Historical overviews of solid acid catalystsFuture outlookSolid Acids CatalysisDefinition of acid and base -Brnsted acid and Lewis acid-Acid sites on surfacesAcid strengthRole of acid sites in catalysisBifunctional catalysisPore size effect on catalysis -shape selectivity-Characterization of Solid Acid Catalysts Indicator methodTemperature programmed desorption (TPD) of ammoniaCalorimetry of adsorption of basic moleculesInfrare

  15. Electrolytic nature of aqueous sulfuric acid. 2. Acidity.

    Science.gov (United States)

    Fraenkel, Dan

    2012-09-27

    In part 1 of this study, I reported that the Debye-Hückel limiting law and the smaller-ion shell (SiS) model of strong electrolyte solutions fit nicely with the experimental mean ionic activity coefficient (γ(±)) of aqueous sulfuric acid as a function of concentration and of temperature when the acid is assumed to be a strong 1-3 electrolyte. Here, I report that the SiS-derived activity coefficient of H(+), γ(H(+)), of the 1-3 acid is comparable to that of aqueous HCl. This agrees with titration curves showing, as well-known, that sulfuric acid in water is parallel in strength to aqueous HCl. The calculated pH is in good accord with the Hammett acidity function, H(0), of aqueous sulfuric acid at low concentration, and differences between the two functions at high concentration are discussed and explained. This pH-H(0) relation is consistent with the literature showing that the H(0) of sulfuric acid (in the 1-9 M range) is similar to those of HCl and the other strong mineral monoprotic acids. The titration of aqueous sulfuric acid with NaOH does not agree with the known second dissociation constant of 0.010 23; rather, the constant is found to be ~0.32 and the acid behaves upon neutralization as a strong diprotic acid practically dissociating in one step. A plausible reaction pathway is offered to explain how the acid may transform, upon base neutralization, from a dissociated H(4)SO(5) (as 3H(+) and HSO(5)(3-)) to a dissociated H(2)SO(4) even though the equilibrium constant of the reaction H(+) + HSO(5)(3-) ↔ SO(4)(2-) + H(2)O, at 25 °C, is 10(-37) (part 1).

  16. Japodic Acid, A Novel Aliphatic Acid from Jatropha podagrica Hook

    OpenAIRE

    Aiyelaagbe, Olapeju O.; Gloer, James B.

    2008-01-01

    A new aliphatic acid named japodic acid (1) with a gem-dimethyl cyclopropane ring has been isolated from the roots of Jatropha podagrica. Its structure was established by 1D and 2D NMR and mass spectrometric data. Two other known compounds, erythrinasinate (2) and fraxidin (3) were also isolated from this plant for the first time. Japodic acid showed mild insect growth inhibition activity against Helicoverpa zea (37% growth reduction at 100 ppm). Fraxidin and erythrinasinate exhibited antibac...

  17. Bile acid interactions with cholangiocytes

    Institute of Scientific and Technical Information of China (English)

    Xuefeng Xia; Heather Francis; Shannon Glaser; Gianfranco Alpini; Gene LeSage

    2006-01-01

    Cholangiocytes are exposed to high concentrations of bile acids at their apical membrane. A selective transporter for bile acids, the Apical Sodium Bile Acid Cotransporter (ASBT) (also referred to as Ibat; gene name Slc10a2)is localized on the cholangiocyte apical membrane. On the basolateral membrane, four transport systems have been identified (t-ASBT, multidrug resistance (MDR)3,an unidentified anion exchanger system and organic solute transporter (Ost) heteromeric transporter, OstαOstβ. Together, these transporters unidirectionally move bile acids from ductal bile to the circulation. Bile acids absorbed by cholangiocytes recycle via the peribiliaryplexus back to hepatocytes for re-secretion into bile.This recycling of bile acids between hepatocytes and cholangiocytes is referred to as the cholehepatic shunt pathway. Recent studies suggest that the cholehepatic shunt pathway may contribute in overall hepatobiliary transport of bile acids and to the adaptation to chronic cholestasis due to extrahepatic obstruction. ASBT is acutely regulated by an adenosine 3', 5'-monophosphate (cAMP)-dependent translocation to the apical membrane and by phosphorylation-dependent ubiquitination and proteasome degradation. ASBT is chronically regulated by changes in gene expression in response to biliary bile acid concentration and inflammatory cytokines.Another potential function of cholangiocyte ASBT is to allow cholangiocytes to sample biliary bile acids in order to activate intracellular signaling pathways. Bile acids trigger changes in intracellular calcium, protein kinase C (PKC), phosphoinositide 3-kinase (PI3K), mitogenactivated protein (MAP) kinase and extracellular signalregulated protein kinase (ERK) intracellular signals.Bile acids significantly alter cholangiocyte secretion,proliferation and survival. Different bile acids have differential effects on cholangiocyte intracellular signals,and in some instances trigger opposing effects on cholangiocyte secretion

  18. Rotational study of the bimolecule acetic acid-fluoroacetic acid

    Science.gov (United States)

    Feng, Gang; Gou, Qian; Evangelisti, Luca; Caminati, Walther

    2017-01-01

    The rotational spectrum of the acetic acid-fluoroacetic acid bimolecule was measured by using a pulsed jet Fourier transform microwave spectrometer. One conformer, in which fluoroacetic acid is in trans form, has been observed. The rotational transitions are split into two component lines, due to the internal rotation of the methyl group of acetic acid. From these splittings, the corresponding V3 barrier has been determined. The dissociation energy of this complex has been estimated to 66 kJ/mol. An increase of the distance between the two monomers upon the OH → OD substitution (Ubbelohde effect) has been observed.

  19. Esterification by the Plasma Acidic Water: Novel Application of Plasma Acid

    Science.gov (United States)

    Gu, Ling

    2014-03-01

    This work explores the possibility of plasma acid as acid catalyst in organic reactions. Plasma acidic water was prepared by dielectric barrier discharge and used to catalyze esterification of n-heptanioc acid with ethanol. It is found that the plasma acidic water has a stable and better performance than sulfuric acid, meaning that it is an excellent acid catalyst. The plasma acidic water would be a promising alternative for classic mineral acid as a more environment friendly acid.

  20. Determination of acetylsalicylic acid and salicylic acid in foods, using HPLC with fluorescence detection.

    OpenAIRE

    Venema, D.P.; Hollman, P.C.H.; Janssen, P.L.T.M.K.; Katan, M B

    1996-01-01

    We developed a specific and sensitive HPLC method with fluorescence detection for the determination of free acetylsalicylic acid, free salicylic acid, and free salicylic acid plus salicylic acid after alkaline hydrolysis (free-plus-bound) in foods. Acetylsalicylic acid was detected after postcolumn hydrolysis to salicylic acid. With the method for free acetylsalicylic acid and salicylic acid, recovery was 95-98␏or acetylsalicylic acid added to foods and 92-102␏or salicylic acid. Recovery of a...

  1. Molecular Simulation of Naphthenic Acid Removal on Acidic Catalyst Ⅱ. Experimental results of catalytic decarboxylation over acidic catalysts

    Institute of Scientific and Technical Information of China (English)

    Fu Xiaoqin; Tian Songbai; Hou Shuandi; Longjun; Wang Xieqing

    2008-01-01

    The energy barriers of thermal decarboxylation reactions of petroleum acids and catalytic decarboxylation reactions of Br(o)nsted acid and Lewis acid were analyzed using molecular simulation technology.Compared with thermal decarboxylation reactions of petroleum acids, the decarboxylation reactions by acid catalysts were easier to occur. The decarboxylaton effect by Lewis acid was better than Br(o)nsted acid. The mechanisms of catalytic decarboxylation over acid catalyst were also verified by experiments on a fixed bed and a fluidized bed, the experimental results showed that the rate of acid removal could reach up to 97% over the acidic catalyst at a temperature above 400℃.

  2. Synthesis of aminoaldonic acids

    DEFF Research Database (Denmark)

    Jørgensen, Christel Thea

    With the aim of synthesising aminoaldonic acids, two 2-acetamido-2-deoxyaldonolactones with D-galacto (6) and D-arabino (11) configuration were prepared from acetylated sugar formazans in analogy with a known procedure. Empolying the same procedure to acetylated sugar phenylhydrazones gave mixtures...... and 82, respectively. The aminolactone 84 was converted into the corresponding amino sugar 89.With the aim of synthesising substrates for the Pictet-Spengler reaction three 4-aldehydo acetamidodideoxytetronolactones 92, 97 and 103 were prepared by periodate cleavage of the corresponding hexonolactones......,4-lactone, respectively. A 2,3-aziridino-2,3-dideoxypentonamide 70 was also prepared from D-glucono-1,5-lactone. The lactones were converted into methyl 3,4-O-isopropylidene-2-O-sulfonyl esters 42, 50, 62 and 68, which upon treatment with concentrated aqueous ammonia yielded the aziridino compounds...

  3. Acid mine drainage

    Science.gov (United States)

    Bigham, Jerry M.; Cravotta, Charles A.

    2016-01-01

    Acid mine drainage (AMD) consists of metal-laden solutions produced by the oxidative dissolution of iron sulfide minerals exposed to air, moisture, and acidophilic microbes during the mining of coal and metal deposits. The pH of AMD is usually in the range of 2–6, but mine-impacted waters at circumneutral pH (5–8) are also common. Mine drainage usually contains elevated concentrations of sulfate, iron, aluminum, and other potentially toxic metals leached from rock that hydrolyze and coprecipitate to form rust-colored encrustations or sediments. When AMD is discharged into surface waters or groundwaters, degradation of water quality, injury to aquatic life, and corrosion or encrustation of engineered structures can occur for substantial distances. Prevention and remediation strategies should consider the biogeochemical complexity of the system, the longevity of AMD pollution, the predictive power of geochemical modeling, and the full range of available field technologies for problem mitigation.

  4. Enzymatic tRNA acylation by acid and alpha-hydroxy acid analogues of amino acids.

    Science.gov (United States)

    Owczarek, Alina; Safro, Mark; Wolfson, Alexey D

    2008-01-08

    Incorporation of unnatural amino acids with unique chemical functionalities has proven to be a valuable tool for expansion of the functional repertoire and properties of proteins as well as for structure-function analysis. Incorporation of alpha-hydroxy acids (primary amino group is substituted with hydroxyl) leads to the synthesis of proteins with peptide bonds being substituted by ester bonds. Practical application of this modification is limited by the necessity to prepare corresponding acylated tRNA by chemical synthesis. We investigated the possibility of enzymatic incorporation of alpha-hydroxy acid and acid analogues (lacking amino group) of amino acids into tRNA using aminoacyl-tRNA synthetases (aaRSs). We studied direct acylation of tRNAs by alpha-hydroxy acid and acid analogues of amino acids and corresponding chemically synthesized analogues of aminoacyl-adenylates. Using adenylate analogues we were able to enzymatically acylate tRNA with amino acid analogues which were otherwise completely inactive in direct aminoacylation reaction, thus bypassing the natural mechanisms ensuring the selectivity of tRNA aminoacylation. Our results are the first demonstration that the use of synthetic aminoacyl-adenylates as substrates in tRNA aminoacylation reaction may provide a way for incorporation of unnatural amino acids into tRNA, and consequently into proteins.

  5. Ghrelin and gastric acid secretion.

    Science.gov (United States)

    Yakabi, Koji; Kawashima, Junichi; Kato, Shingo

    2008-11-07

    Ghrelin, a novel growth hormone-releasing peptide, was originally isolated from rat and human stomach. Ghrelin has been known to increase the secretion of growth hormone (GH), food intake, and body weight gain when administered peripherally or centrally. Ghrelin is also known to stimulate the gastric motility and the secretion of gastric acid. In the previous studies, the action of ghrelin on acid secretion was shown to be as strong as that of histamine and gastrin in in-vivo experiment. In the studies, the mechanism for the action of ghrelin was also investigated. It was shown that vagotomy completely inhibited the action of ghrelin on the secretion of gastric acid suggesting that vagal nerve is involved in the mechanism for the action of ghrelin on acid secretion. As famotidine did not inhibit ghrelin-induced acid secretion in the study by Masuda et al, they concluded that histamine was not involved in the action of ghrelin on acid secretion. However, we have shown that famotidine completely inhibited ghrelin-induced acid secretion and histidine decarboxylase (HDC) mRNA was increased in gastric mucosa by ghrelin injection which is inhibited by vagotomy Our results indicate that histamine is involved in the action of ghrelin on acid secretion. Furthermore synergistic action of gastrin and ghrelin on gastric acid secretion was shown. Although gastrin has important roles in postprandial secretion of gastric acid, ghrelin may be related to acid secretion during fasting period or at night. However, further studies are needed to elucidate the physiological role of ghrelin in acid secretion.

  6. Racemization of Meteoritic Amino Acids

    Science.gov (United States)

    Cohen, Barbara A.; Chyba, Christopher F.

    2000-05-01

    Meteorites may have contributed amino acids to the prebiotic Earth, affecting the global ratio of right-handed to left-handed (D/L) molecules. We calculate D/L ratios for seven biological, α-hydrogen, protein amino acids over a variety of plausible parent body thermal histories, based on meteorite evidence and asteroid modeling. We show that amino acids in meteorites do not necessarily undergo complete racemization by the time they are recovered on Earth. If the mechanism of amino acid formation imposes some enantiomeric preference on the amino acids, a chiral signature can be retained through the entire history of the meteorite. Original enantiomeric excesses in meteorites such as Murchison, which have undergone apparently short and cool alteration scenarios, should have persisted to the present time. Of the seven amino acids for which relevant data are available, we expect glutamic acid, isoleucine, and valine, respectively, to be the most likely to retain an initial enantiomeric excess, and phenylalanine, aspartic acid, and alanine the least. Were the D/L ratio initially identical in each amino acid, final D/L ratios could be used to constrain the initial ratio and the thermal history experienced by the whole suite.

  7. [Hydrofluoric acid poisoning: case report].

    Science.gov (United States)

    Cortina, Tatiana Judith; Ferrero, Hilario Andrés

    2013-01-01

    Hydrofluoric acid is a highly dangerous substance with industrial and domestically appliances. Clinical manifestations of poisoning depend on exposure mechanism, acid concentration and exposed tissue penetrability. Gastrointestinal tract symptoms do not correlate with injury severity. Patients with history of hydrofluoric acid ingestion should undergo an endoscopy of the upper gastrointestinal tract. Intoxication requires immediate intervention because systemic toxicity can take place. We present a 5 year old girl who accidentally swallowed 5 ml of 20% hydrofluoric acid. We performed gastrointestinal tract endoscopy post ingestion, which revealed erythematous esophagus and stomach with erosive lesions. Two months later, same study was performed and revealed esophagus and stomach normal mucous membrane.

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

    Science.gov (United States)

    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.

  9. Antibiofilm Properties of Acetic Acid

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Alhede, Morten; Jensen, Peter Østrup;

    2014-01-01

    of the infected implant, tissue, or organ and thereby the biofilm. Acetic acid is known for its antimicrobial effect on bacteria in general, but has never been thoroughly tested for its efficacy against bacterial biofilms. In this article, we describe complete eradication of both Gram-positive and Gram......-negative biofilms using acetic acid both as a liquid and as a dry salt. In addition, we present our clinical experience of acetic acid treatment of chronic wounds. In conclusion, we here present the first comprehensive in vitro and in vivo testing of acetic acid against bacterial biofilms....

  10. ACETIC ACID AND A BUFFER

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent.......The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent....

  11. MCNP在计算硼酸质量分数影响反应堆有效增值系数Kνeff如值中的应用%MCNP in the Application of the Affect in Simulate the Value of Boron Acid Acts on the Critical Factor Kνeff

    Institute of Scientific and Technical Information of China (English)

    赵梦云; 杨波; 刘义保; 曾磊

    2011-01-01

    In this paper, Monte Carlo method were used in the MCNP procedures for the establishment of Qinshan nuclear power station simulation model, construct the reactor pressure vessel and vessel core component composition and arrangement, KCODE card were used to calculate the effect of the effective value-added factor Kνeff by the boron acid .The calculation results show that, without considering the control rods and the burnable poison on the reactor effective value-added factor Keff, with the increasing of the boric acid concentration, Keff linear dropped from 1.330 47 to 1.024 84, the results consistent with the actual value.%运用蒙特卡罗方法中的MCNP程序建立秦山某核电站模拟计算模型,构建出反应堆压力容器及压力容器内堆芯组件成分及排布,利用KCODE卡计算反应堆中硼酸质量分数对有效增值系数Kνeff值的影响。计算结果表明:在不考虑控制棒和可燃毒物对反应堆有效增值系数Kνeff值影响的情况下,随着硼酸质量分数的增大,有效增值系数Kνeff值线性从1.33047降到1.02484,计算结果与实际值一致。

  12. Peptide Nucleic Acids Having Amino Acid Side Chains

    DEFF Research Database (Denmark)

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary DNA and RNA strands more strongly than the corresponding DNA or RNA strands, and exhibit increased sequence specificity and solubility. The peptide nucleic acids comprise ligands selected from a group consisting...

  13. Fatty Acid Desaturases, Polyunsaturated Fatty Acid Regulation, and Biotechnological Advances

    Directory of Open Access Journals (Sweden)

    Je Min Lee

    2016-01-01

    Full Text Available Polyunsaturated fatty acids (PUFAs are considered to be critical nutrients to regulate human health and development, and numerous fatty acid desaturases play key roles in synthesizing PUFAs. Given the lack of delta-12 and -15 desaturases and the low levels of conversion to PUFAs, humans must consume some omega-3 and omega-6 fatty acids in their diet. Many studies on fatty acid desaturases as well as PUFAs have shown that fatty acid desaturase genes are closely related to different human physiological conditions. Since the first front-end desaturases from cyanobacteria were cloned, numerous desaturase genes have been identified and animals and plants have been genetically engineered to produce PUFAs such as eicosapentaenoic acid and docosahexaenoic acid. Recently, a biotechnological approach has been used to develop clinical treatments for human physiological conditions, including cancers and neurogenetic disorders. Thus, understanding the functions and regulation of PUFAs associated with human health and development by using biotechnology may facilitate the engineering of more advanced PUFA production and provide new insights into the complexity of fatty acid metabolism.

  14. Fatty Acid Desaturases, Polyunsaturated Fatty Acid Regulation, and Biotechnological Advances.

    Science.gov (United States)

    Lee, Je Min; Lee, Hyungjae; Kang, SeokBeom; Park, Woo Jung

    2016-01-04

    Polyunsaturated fatty acids (PUFAs) are considered to be critical nutrients to regulate human health and development, and numerous fatty acid desaturases play key roles in synthesizing PUFAs. Given the lack of delta-12 and -15 desaturases and the low levels of conversion to PUFAs, humans must consume some omega-3 and omega-6 fatty acids in their diet. Many studies on fatty acid desaturases as well as PUFAs have shown that fatty acid desaturase genes are closely related to different human physiological conditions. Since the first front-end desaturases from cyanobacteria were cloned, numerous desaturase genes have been identified and animals and plants have been genetically engineered to produce PUFAs such as eicosapentaenoic acid and docosahexaenoic acid. Recently, a biotechnological approach has been used to develop clinical treatments for human physiological conditions, including cancers and neurogenetic disorders. Thus, understanding the functions and regulation of PUFAs associated with human health and development by using biotechnology may facilitate the engineering of more advanced PUFA production and provide new insights into the complexity of fatty acid metabolism.

  15. Carbonic Acid Pretreatment of Biomass

    Energy Technology Data Exchange (ETDEWEB)

    G. Peter van Walsum; Kemantha Jayawardhana; Damon Yourchisin; Robert McWilliams; Vanessa Castleberry

    2003-05-31

    This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. 1) Solidify the theoretical understanding of the binary CO2/H2O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. 2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. 3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. 4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. 5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for the use of carbonic

  16. Carbonic Acid Retreatment of Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Baylor university

    2003-06-01

    This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. (1) Solidify the theoretical understanding of the binary CO{sub 2}/H{sub 2}O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. (2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. (3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. (4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. (5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for

  17. Ghrelin and gastric acid secretion

    Institute of Scientific and Technical Information of China (English)

    Koji Yakabi; Junichi Kawashima; Shingo Kato

    2008-01-01

    Ghrelin, a novel growth hormone-releasing peptide, was originally isolated from rat and human stomach. Ghrelin has been known to increase the secretion of growth hormone (GH), food intake, and body weight gain when administered peripherally or centrally. Ghrelin is also known to stimulate the gastric motility and the secretion of gastric acid. In the previous studies, the action of ghrelin on acid secretion was shown to be as strong as that of histamine and gastrin in-vivo experiment. In the studies, the mechanism for the action of ghrelin was also investigated. It was shown that vagotomy completely inhibited the action of ghrelin on the secretion of gastric acid suggesting that vagal nerve is involved in the mechanism for the action of ghrelin on acid secretion. As famotidine did not inhibit ghrelin-in-duced acid secretion in the study by Masuda et al, they concluded that histamine was not involved in the action of ghrelin on acid secretion. However, we have shown that famotidine completely inhibited ghrelin-induced acid secretion and histidine decarboxylase (HDC) mRNA was increased in gastric mucosa by ghrelin injection which is inhibited by vagotomy Our results indicate that histamine is involved in the action of ghrelin on acid secretion. Furthermore synergistic action of gastrin and ghrelin on gastric add secretion was shown. Although gastrin has important roles in postprandial secretion of gastric acid, ghrelin may be related to acid secretion during fasting period or at night. However, further studies are needed to elucidate the physiological role of ghrelin in acid secretion.

  18. Amino acids in Arctic aerosols

    Directory of Open Access Journals (Sweden)

    E. Scalabrin

    2012-07-01

    Full Text Available Amino acids are significant components of atmospheric aerosols, affecting organic nitrogen input to marine ecosystems, atmospheric radiation balance, and the global water cycle. The wide range of amino acid reactivities suggest that amino acids may serve as markers of atmospheric transport and deposition of particles. Despite this potential, few measurements have been conducted in remote areas to assess amino acid concentrations and potential sources. Polar regions offer a unique opportunity to investigate atmospheric processes and to conduct source apportionment studies of such compounds. In order to better understand the importance of amino acid compounds in the global atmosphere, we determined free amino acids (FAAs in seventeen size-segregated aerosol samples collected in a polar station in the Svalbard Islands from 19 April until 14 September 2010. We used an HPLC coupled with a tandem mass spectrometer (ESI-MS/MS to analyze 20 amino acids to quantify compounds at fmol m−3 levels. Mean total FAA concentration was 1070 fmol m−3 where serine and glycine were the most abundant compounds in almost all samples and accounted for 45–60% of the total amino acid relative abundance. The other eighteen compounds had average concentrations between 0.3 and 98 fmol m−3. The higher amino acid concentrations were present in the ultrafine aerosol fraction (<0.49 μm and accounted for the majority of the total amino acid content. Local marine sources dominate the boreal summer amino acid concentrations, with the exception of the regional input from Icelandic volcanics.

  19. Infrared spectra of hydrogen-bonded salicylic acid and its derivatives : Salicylic acid and acetylsalicylic acid

    Science.gov (United States)

    Wójcik, Marek J.

    1981-11-01

    Infrared spectra of hydrogen-bonded salicylic acid, O-deutero-salicylic acid and acetylsalicylic acid crystals have been studied experimentally and theoretically. Interpretation of these spectra was based on the Witkowski-Maréchal model. Semi-quantitative agreement between experimental and theoretical spectra can be achieved with the simplest form of this model, with values of interaction parameters transferable for equivalent intermolecular hydrogen bonds.

  20. Production of succinic Acid from citric Acid and related acids by lactobacillus strains.

    Science.gov (United States)

    Kaneuchi, C; Seki, M; Komagata, K

    1988-12-01

    A number of Lactobacillus strains produced succinic acid in de Man-Rogosa-Sharpe broth to various extents. Among 86 fresh isolates from fermented cane molasses in Thailand, 30 strains (35%) produced succinic acid; namely, 23 of 39 Lactobacillus reuteri strains, 6 of 18 L. cellobiosus strains, and 1 of 6 unidentified strains. All of 10 L. casei subsp. casei strains, 5 L. casei subsp. rhamnosus strains, 6 L. mali strains, and 2 L. buchneri strains did not produce succinic acid. Among 58 known strains including 48 type strains of different Lactobacillus species, the strains of L. acidophilus, L. crispatus, L. jensenii, and L. parvus produced succinic acid to the same extent as the most active fresh isolates, and those of L. alimentarius, L. collinoides, L. farciminis, L. fructivorans (1 of 2 strains tested), L. malefermentans, and L. reuteri were also positive, to lesser extents. Diammonium citrate in de Man-Rogosa-Sharpe broth was determined as a precursor of the succinic acid produced. Production rates were about 70% on a molar basis with two fresh strains tested. Succinic acid was also produced from fumaric and malic acids but not from dl-isocitric, alpha-ketoglutaric, and pyruvic acids. The present study is considered to provide the first evidence on the production of succinic acid, an important flavoring substance in dairy products and fermented beverages, from citrate by lactobacilli.

  1. Bile acids for viral hepatitis

    DEFF Research Database (Denmark)

    Chen, Weikeng; Liu, J; Gluud, C

    2003-01-01

    The viral hepatitides are common causes of liver diseases globally. Trials have assessed bile acids for patients with viral hepatitis, but no consensus was reached regarding their usefulness.......The viral hepatitides are common causes of liver diseases globally. Trials have assessed bile acids for patients with viral hepatitis, but no consensus was reached regarding their usefulness....

  2. Protein and amino acid nutrition

    Science.gov (United States)

    Dairy cow protein and amino acid nutrition have a significant role in sustainable dairying. Protein, amino acids, and nitrogen are inextricably linked through effects in the rumen, metabolism of the cow, and environmental nutrient management. Feeding systems have been making progress toward emphasiz...

  3. Phosphorus derivatives of salicylic acid

    Science.gov (United States)

    Chvertkina, L. V.; Khoklov, P. S.; Mironov, Vladimir F.

    1992-10-01

    The present state of work on the methods of synthesis, chemical properties, and practical applications of phosphorus-containing derivatives of salicylic acid has been reviewed. The characteristics of the chemical transformations of cyclic and acyclic phosphorus derivatives of salicylic acid related to the coordination state of the phosphorus atom have been examined. The bibliography includes 158 references.

  4. Pantothenic acid (Vitamin B5)

    Science.gov (United States)

    ... vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B12 (cyanocobalamin), and folic acid. However, some products do ... Pantothenas, Calcium D-Pantothenate, Calcium Pantothenate, Complexe de Vitamines B, D-Calcium Pantothenate, D-Panthenol, D-Panthénol, ...

  5. Acid Rain: The Scientific Challenge.

    Science.gov (United States)

    Godfrey, Paul J.

    1991-01-01

    Documents the workings and findings of the Massachusetts Acid Rain Monitoring Project, which has pooled the volunteer efforts of more than 1,000 amateur and professional scientists since 1983. Reports on the origins of air pollution, the prediction of acid rain, and its effects on both water life and land resources. (JJK)

  6. Acid Rain: What's the Forecast?

    Science.gov (United States)

    Bybee, Rodger

    1984-01-01

    Discusses various types of acid rain, considered to be a century-old problem. Topics include: wet and dry deposition, effects on a variety of environments, ecosystems subject to detrimental effects, and possible solutions to the problem. A list of recommended resources on acid rain is provided. (BC)

  7. Kinetics and Mechanism of Oxidation of Phenyl Acetic Acid and Dl-Mandelic Acid by Permanganate in Acid Medium

    Directory of Open Access Journals (Sweden)

    B.Syama Sundar

    2014-06-01

    Full Text Available Kinetics of oxidation of phenyl acetic acid and DL- Mandelic acid by potassium permanganate in aqueous acetic acid and perchloric acid mixture reveals that the kinetic orders are first order in oxidant, first order in H+ and zero order in substrate for phenyl acetic acid. DL-Mandelic acid exhibits first order in oxidant and zero order in substrate. The results are rationalised by a mechanism involving intermediate formation of mandelic acid in case of Phenyl acetic acid and ester formation with Mn (VII in case of DL-Mandelic acid. The following order of reactivity is observed: DL-Mandelic acid > Phenyl acetic acid. The high reactivity of DL-Mandelic acid over phenyl acetic acid may be due to different mechanisms operating with the two substrates and benzaldehyde is the final product in both the cases.

  8. N-(3-Nitrophenylmaleamic acid

    Directory of Open Access Journals (Sweden)

    B. Thimme Gowda

    2010-07-01

    Full Text Available In the title compound, C10H8N2O5, the molecule is slightly distorted from planarity. The molecular structure is stabilized by two intramolecular hydrogen bonds. The first is a short O—H...O hydrogen bond (H...O distance = 1.57 Å within the maleamic acid unit and the second is a C—H...O hydrogen bond (H...O distance = 2.24 Å which connects the amide group with the benzene ring. The nitro group is twisted by 6.2 (2° out of the plane of the benzene ring. The crystal structure manifests a variety of hydrogen bonding. The packing is dominated by a strong intermolecular N—H...O interaction which links the molecules into chains running along the b axis. The chains within a plane are further assembled by three additional types of intermolecular C—H...O hydrogen bonds to form a sheet parallel to the (overline{1}01 plane.

  9. Molten fatty acid based microemulsions.

    Science.gov (United States)

    Noirjean, Cecile; Testard, Fabienne; Dejugnat, Christophe; Jestin, Jacques; Carriere, David

    2016-06-21

    We show that ternary mixtures of water (polar phase), myristic acid (MA, apolar phase) and cetyltrimethylammonium bromide (CTAB, cationic surfactant) studied above the melting point of myristic acid allow the preparation of microemulsions without adding a salt or a co-surfactant. The combination of SANS, SAXS/WAXS, DSC, and phase diagram determination allows a complete characterization of the structures and interactions between components in the molten fatty acid based microemulsions. For the different structures characterized (microemulsion, lamellar or hexagonal phases), a similar thermal behaviour is observed for all ternary MA/CTAB/water monophasic samples and for binary MA/CTAB mixtures without water: crystalline myristic acid melts at 52 °C, and a thermal transition at 70 °C is assigned to the breaking of hydrogen bounds inside the mixed myristic acid/CTAB complex (being the surfactant film in the ternary system). Water determines the film curvature, hence the structures observed at high temperature, but does not influence the thermal behaviour of the ternary system. Myristic acid is partitioned in two "species" that behave independently: pure myristic acid and myristic acid associated with CTAB to form an equimolar complex that plays the role of the surfactant film. We therefore show that myristic acid plays the role of a solvent (oil) and a co-surfactant allowing the fine tuning of the structure of oil and water mixtures. This solvosurfactant behaviour of long chain fatty acid opens the way for new formulations with a complex structure without the addition of any extra compound.

  10. Pentadecanoic and Heptadecanoic Acids: Multifaceted Odd-Chain Fatty Acids.

    Science.gov (United States)

    Pfeuffer, Maria; Jaudszus, Anke

    2016-07-01

    The odd-chain fatty acids (OCFAs) pentadecanoic acid (15:0) and heptadecanoic acid (17:0), which account for only a small proportion of total saturated fatty acids in milk fat and ruminant meat, are accepted biomarkers of dairy fat intake. However, they can also be synthesized endogenously, for example, from gut-derived propionic acid (3:0). A number of studies have shown an inverse association between OCFA concentrations in human plasma phospholipids or RBCs and risk of type 2 diabetes and cardiovascular disease. We propose a possible involvement in metabolic regulation from the assumption that there is a link between 15:0 and 17:0 and the metabolism of other short-chain, medium-chain, and longer-chain OCFAs. The OCFAs 15:0 and 17:0 can be elongated to very-long-chain FAs (VLCFAs) such as tricosanoic acid (23:0) and pentacosanoic acid (25:0) in glycosphingolipids, particularly found in brain tissue, or can be derived from these VLCFAs. Their chains can be shortened, yielding propionyl-coenzyme A (CoA). Propionyl-CoA, by succinyl-CoA, can replenish the citric acid cycle (CAC) with anaplerotic intermediates and, thus, improve mitochondrial energy metabolism. Mitochondrial function is compromised in a number of disorders and may be impaired with increasing age. Optimizing anaplerotic intermediate availability for the CAC may help to cope with demands in times of increased metabolic stress and with aging. OCFAs may serve as substrates for synthesis of both odd-numbered VLCFAs and propionyl-CoA or store away excess propionic acid.

  11. Fatty acid composition of selected prosthecate bacteria.

    Science.gov (United States)

    Carter, R N; Schmidt, J M

    1976-10-11

    The cellular fatty acid composition of 14 strains of Caulobacter speices and types, two species of Prosthecomicrobium, and two species of Asticcacaulis was determined by gas-liquid chromatography. In most of these bacteria, the major fatty acids were octadecenoic acid (C18:1), hexadecenoic acid (C16:1) and hexadecanoic acid (C16:0). Some cyclopropane and branched chain fatty acids were detected in addition to the straight chained acids. Hydroxytetradecanoic acid was an important component of P.enhydrum but significant amounts of hydroxy acids were not detected in other prosthecate bacteria examined.

  12. The Property and Application of Arachidonic Acid

    Institute of Scientific and Technical Information of China (English)

    王相勤; 姚建铭; 袁成凌; 王纪; 余增亮

    2002-01-01

    Arachidonic acid (AA) is one of the most important PUFAs (polyunsaturated fatty acids) in human body. A high-yield arachidonic acid-producing strain (mortierella alpina) was selected by ion implantation (the relative content of arachidonic acid is 70.2% among all fatty acids). This paper mainly introduced the structure, distribution, source, physiologic healthcare function and application of AA.

  13. Phytic acid in green leaves.

    Science.gov (United States)

    Hadi Alkarawi, H; Zotz, G

    2014-07-01

    Phytic acid or phytate, the free-acid form of myo-inositolhexakiphosphate, is abundant in many seeds and fruits, where it represents the major storage form of phosphorus. Although also known from other plant tissues, available reports on the occurrence of phytic acid, e.g. in leaves, have never been compiled, nor have they been critically reviewed. We found 45 published studies with information on phytic acid content in leaves. Phytic acid was almost always detected when studies specifically tried to detect it, and accounted for up to 98% of total P. However, we argue that such extreme values, which rival findings from storage organs, are dubious and probably result from measurement errors. Excluding these high values from further quantitative analysis, foliar phytic acid-P averaged 2.3 mg·g(-1) , and represented, on average, 7.6% of total P. Remarkably, the ratio of phytic acid-P to total P did not increase with total P, we even detected a negative correlation of the two variables within one species, Manihot esculenta. This enigmatic finding warrants further attention.

  14. Terahertz spectrum of gallic acid

    Science.gov (United States)

    Wu, Meng; Zhao, Guozhong; Wang, Haiyan; Liang, Chengshen

    2009-11-01

    Gallic acid is natural polyphenol compound found in many green plants. More and more experiments have demonstrated that the gallic acid has comprehensive applications. In the field of medicine, the gallic acid plays an important role in antianaphylaxis, antineoplastic, antimycotic, anti-inflammatory, antivirotic, antiasthmatic and inhibiting the degradation of insulin. It also has a lot of applications in chemical industry, food industry and light industry. So it is important to study the terahertz time-domain spectroscopy of gallic acid. Terahertz time-domain spectroscopy (THz-TDS) is a new coherent spectral technology based on the femtosecond laser. In this work, the spectral characteristics of gallic acid in the range of 0.4 THz to 2.6 THz have been measured by THz-TDS. We obtained its absorption and refraction spectra at room temperature. The vibration absorption spectrum of the single molecule between 0.4 THz and 2.6 THz is simulated based on the Density Functional Theory (DFT). It is found that the gallic acid has the spectral response to THz wave in this frequency range. The results show the abnormal dispersion at 1.51 THz and 2.05 THz. These results can be used in the qualitative analysis of gallic acid and the medicine and food inspection.

  15. Determination of polyfluoroalkyl phosphoric acid diesters, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, perfluoroalkyl carboxylic acids, and perfluoroalkane sulfonic acids in lake trout from the Great Lakes region.

    Science.gov (United States)

    Guo, Rui; Reiner, Eric J; Bhavsar, Satyendra P; Helm, Paul A; Mabury, Scott A; Braekevelt, Eric; Tittlemier, Sheryl A

    2012-11-01

    A comprehensive method to extract perfluoroalkyl carboxylic acids, perfluoroalkane sulfonic acids, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, and polyfluoroalkyl phosphoric acid diesters simultaneously from fish samples has been developed. The recoveries of target compounds ranged from 78 % to 121 %. The new method was used to analyze lake trout (Salvelinus namaycush) from the Great Lakes region. The results showed that the total perfluoroalkane sulfonate concentrations ranged from 0.1 to 145 ng/g (wet weight) with perfluorooctane sulfonate (PFOS) as the dominant contaminant. Concentrations in fish between lakes were in the order of Lakes Ontario ≈ Erie > Huron > Superior ≈ Nipigon. The total perfluoroalkyl carboxylic acid concentrations ranged from 0.2 to 18.2 ng/g wet weight. The aggregate mean perfluorooctanoic acid (PFOA) concentration in fish across all lakes was 0.045 ± 0.023 ng/g. Mean concentrations of PFOA were not significantly different (p > 0.1) among the five lakes. Perfluoroalkyl phosphinic acids were detected in lake trout from Lake Ontario, Lake Erie, and Lake Huron with concentration ranging from non-detect (ND) to 0.032 ng/g. Polyfluoroalkyl phosphoric acid diesters were detected only in lake trout from Lake Huron, at levels similar to perfluorooctanoic acid.

  16. Pyroligneous acid-the smoky acidic liquid from plant biomass.

    Science.gov (United States)

    Mathew, Sindhu; Zakaria, Zainul Akmar

    2015-01-01

    Pyroligneous acid (PA) is a complex highly oxygenated aqueous liquid fraction obtained by the condensation of pyrolysis vapors, which result from the thermochemical breakdown or pyrolysis of plant biomass components such as cellulose, hemicellulose, and lignin. PA produced by the slow pyrolysis of plant biomass is a yellowish brown or dark brown liquid with acidic pH and usually comprises a complex mixture of guaiacols, catechols, syringols, phenols, vanillins, furans, pyrans, carboxaldehydes, hydroxyketones, sugars, alkyl aryl ethers, nitrogenated derivatives, alcohols, acetic acid, and other carboxylic acids. The phenolic components, namely guaiacol, alkyl guaiacols, syringol, and alkyl syringols, contribute to the smoky odor of PA. PA finds application in diverse areas, as antioxidant, antimicrobial, antiinflammatory, plant growth stimulator, coagulant for natural rubber, and termiticidal and pesticidal agent; is a source for valuable chemicals; and imparts a smoky flavor for food.

  17. ELECTRODIALYTIC PRODUCTION OF HYPOPHOSPHOROUS ACID

    Institute of Scientific and Technical Information of China (English)

    CHENG Jianzhong; ZHANG Yingzhe; ZHANG Baogui; ZHANG Zhengpu

    2001-01-01

    Disclosed is a method of preparing hypophosphorous acid comprising contacting an insoluble anode with an aqueous solution of hypophosphite anions and applying a direct current through the insoluble anode to a cathode in electrical contact with the aqueous solution to generate H+ ions in the aqueous solution thereby forming a hypophosphorous acid solution. The process is simple,low cost and high efficient, which can be tied into an existing process for producing sodium hypophosphite wherein the product of sodium hypophosphite process is used as a starting material in the hypophosphorous acid process.

  18. Amino Acids from a Comet

    Science.gov (United States)

    Cook, Jamie Elisla

    2009-01-01

    NASA's Stardust spacecraft returned samples from comet 81P/Wild 2 to Earth in January 2006. Examinations of the organic compounds in cometary samples can reveal information about the prebiotic organic inventory present on the early Earth and within the early Solar System, which may have contributed to the origin of life. Preliminary studies of Stardust material revealed the presence of a suite of organic compounds including several amines and amino acids, but the origin of these compounds (cometary- vs. terrestrial contamination) could not be identified. We have recently measured the carbon isotopic ratios of these amino acids to determine their origin, leading to the first detection of a coetary amino acid.

  19. Enhanced acid tolerance of Rhizopus oryzae during fumaric acid production.

    Science.gov (United States)

    Liu, Ying; Lv, Chunwei; Xu, Qing; Li, Shuang; Huang, He; Ouyang, Pingkai

    2015-02-01

    Ensuring a suitable pH in the culture broth is a major problem in microorganism-assisted industrial fermentation of organic acids. To address this issue, we investigated the physiological changes in Rhizopus oryzae at different extracellular pH levels and attempted to solve the issue of cell shortage under low pH conditions. We compared various parameters, such as membrane fatty acids' composition, intracellular pH, and adenosine triphosphate (ATP) concentration. It was found that the shortage of intracellular ATP might be the main reason for the low rate of fumaric acid production by R. oryzae under low pH conditions. When 1 g/l citrate was added to the culture medium at pH 3.0, the intracellular ATP concentration increased from 0.4 to 0.7 µmol/mg, and the fumaric acid titer was enhanced by 63% compared with the control (pH 3.0 without citrate addition). The final fumaric acid concentration at pH 3.0 reached 21.9 g/l after 96 h of fermentation. This strategy is simple and feasible for industrial fumaric acid production under low pH conditions.

  20. Molar extinction coefficients of some fatty acids

    Science.gov (United States)

    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.

  1. Omega-3 Fatty Acids during Pregnancy

    Science.gov (United States)

    OMEGA-3 FATTY ACIDS DURING PREGNANCY S HARE W ITH W OMEN OMEGA-3 FATTY ACIDS DURING PREGNANCY During pregnancy, your ... the foods you eat and vitamins you take. Omega-3 fatty acids (omega-3s) are an important ...

  2. Folic Acid: MedlinePlus Health Topic

    Science.gov (United States)

    ... Article: Folic Acid Supplementation for the Prevention of Neural Tube Defects:... Article: Folic Acid Supplementation for the Prevention of Neural Tube Defects:... Article: Folic Acid Supplementation for Prevention of ...

  3. Low acid producing solid propellants

    Science.gov (United States)

    Bennett, Robert R.

    1995-01-01

    The potential environmental effects of the exhaust products of conventional rocket propellants have been assessed by various groups. Areas of concern have included stratospheric ozone, acid rain, toxicity, air quality and global warming. Some of the studies which have been performed on this subject have concluded that while the impacts of rocket use are extremely small, there are propellant development options which have the potential to reduce those impacts even further. This paper discusses the various solid propellant options which have been proposed as being more environmentally benign than current systems by reducing HCI emissions. These options include acid neutralized, acid scavenged, and nonchlorine propellants. An assessment of the acid reducing potential and the viability of each of these options is made, based on current information. Such an assessment is needed in order to judge whether the potential improvements justify the expenditures of developing the new propellant systems.

  4. Bile acid sequestrants for cholesterol

    Science.gov (United States)

    ... ency/patientinstructions/000787.htm Bile acid sequestrants for cholesterol To use the sharing features on this page, ... are medicines that help lower your LDL (bad) cholesterol . Too much cholesterol in your blood can stick ...

  5. PHYSIOLOGY OF ACID BASE BALANCE

    Directory of Open Access Journals (Sweden)

    Awati

    2014-12-01

    Full Text Available Acid-base, electrolyte, and metabolic disturbances are common in the intensive care unit. Almost all critically ill patients often suffer from compound acid-base and electrolyte disorders. Successful evaluation and management of such patients requires recognition of common patterns (e.g., metabolic acidosis and the ability to dissect one disorder from another. The intensivists needs to identify and correct these condition with the easiest available tools as they are the associated with multiorgan failure. Understanding the elements of normal physiology in these areas is very important so as to diagnose the pathological condition and take adequate measures as early as possible. Arterial blood gas analysis is one such tool for early detection of acid base disorder. Physiology of acid base is complex and here is the attempt to simplify it in our day to day application for the benefit of critically ill patients.

  6. Compact oleic acid in HAMLET.

    Science.gov (United States)

    Fast, Jonas; Mossberg, Ann-Kristin; Nilsson, Hanna; Svanborg, Catharina; Akke, Mikael; Linse, Sara

    2005-11-07

    HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a complex between alpha-lactalbumin and oleic acid that induces apoptosis in tumor cells, but not in healthy cells. Heteronuclear nuclear magnetic resonance (NMR) spectroscopy was used to determine the structure of 13C-oleic acid in HAMLET, and to study the 15N-labeled protein. Nuclear Overhauser enhancement spectroscopy shows that the two ends of the fatty acid are in close proximity and close to the double bond, indicating that the oleic acid is bound to HAMLET in a compact conformation. The data further show that HAMLET is a partly unfolded/molten globule-like complex under physiological conditions.

  7. LACTIC ACID BACTERIA: PROBIOTIC APPLICATIONS

    Directory of Open Access Journals (Sweden)

    NEENA GARG

    2015-10-01

    Full Text Available Lactic acid bacteria (LAB is a heterotrophic Gram-positive bacteria which under goes lactic acid fermentations and leads to production of lactic acid as an end product. LAB includes Lactobacillus, Leuconostoc, Pediococcus, Lactococcus and Streptococcus which are grouped together in the family lactobacillaceae. LAB shows numerous antimicrobial activities due to production of antibacterial and antifungal compounds such as organic acids, bacteriocins, diacetyl, hydrogen peroxide and reutrin. LAB are used as starter culture, consortium members and bioprotective agents in food industry that improve food quality, safety and shelf life. A variety of probiotic LAB species are available including Lactobacillus acidophilus, L. bulgaricus, L. lactis, L. plantarum, L. rhamnosus, L. reuteri, L. fermentum, Bifidobacterium longum, B. breve, B. bifidum, B. esselnsis, B. lactis, B. infantis that are currently recommended for development of functional food products with health-promoting capacities.

  8. Biotechnological production of citric acid

    Directory of Open Access Journals (Sweden)

    Belén Max

    2010-12-01

    Full Text Available This work provides a review about the biotechnological production of citric acid starting from the physicochemical properties and industrial applications, mainly in the food and pharmaceutical sectors. Several factors affecting citric acid fermentation are discussed, including carbon source, nitrogen and phosphate limitations, pH of culture medium, aeration, trace elements and morphology of the fungus. Special attention is paid to the fundamentals of biochemistry and accumulation of citric acid. Technologies employed at industrial scale such as surface or submerged cultures, mainly employing Aspergillus niger, and processes carried out with Yarrowia lipolytica, as well as the technology for recovering the product are also described. Finally, this review summarizes the use of orange peels and other by-products as feedstocks for the bioproduction of citric acid.

  9. Anthranilic acid derivatives from Inula japonica

    Institute of Scientific and Technical Information of China (English)

    Jiang Jiang Qin; Hui Zi Jin; Jian Jun Fu; Xiao Jia Hu; Yan Zhu; Yun Heng Shen; Shi Kai Yan; Wei Dong Zhang

    2008-01-01

    Three new anthranilic acid derivatives, N-heneicosanoylanthranilic acid (1b), N-tricosanoylanthranilic acid (1d), N-tetra-cosanoylanthranilic acid (1e), and two known N-arachidylanthranilic acid (1a) and N-docosanoylanthranilic acid (1c) were isolatedfrom the aerial parts of Inula japonica Thunb. Their structures were established by spectroscopic and chemical methods.2008 Hui Zi Jin. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

  10. 21 CFR 172.862 - Oleic acid derived from tall oil fatty acids.

    Science.gov (United States)

    2010-04-01

    ... FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.862 Oleic acid derived from tall oil fatty acids. The food additive oleic acid derived from tall oil fatty acids may be safely used in food and as... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Oleic acid derived from tall oil fatty acids....

  11. Simultaneous analysis of small organic acids and humic acids using high performance size exclusion chromatography

    NARCIS (Netherlands)

    Qin, X.P.; Liu, F.; Wang, G.C.; Weng, L.P.

    2012-01-01

    An accurate and fast method for simultaneous determination of small organic acids and much larger humic acids was developed using high performance size exclusion chromatography. Two small organic acids, i.e. salicylic acid and 2,3-dihydroxybenzoic acid, and one purified humic acid material were used

  12. Alternative to Nitric Acid Passivation

    Science.gov (United States)

    Kessel, Kurt R.

    2016-01-01

    Corrosion is an extensive problem that affects the National Aeronautics and Space Administration (NASA) and European Space Agency (ESA). The deleterious effects of corrosion result in steep costs, asset downtime affecting mission readiness, and safety risks to personnel. It is vital to reduce corrosion costs and risks in a sustainable manner. The primary objective of this effort is to qualify citric acid as an environmentally-preferable alternative to nitric acid for passivation of stainless steel alloys.

  13. Nucleic Acid Aptamers Against Proteases

    DEFF Research Database (Denmark)

    Dupont, D M; Andersen, L M; Bøtkjær, Kenneth Alrø

    2011-01-01

    Proteases are potential or realized therapeutic targets in a wide variety of pathological conditions. Moreover, proteases are classical subjects for studies of enzymatic and regulatory mechanisms. We here review the literature on nucleic acid aptamers selected with proteases as targets. Designing...... strategies and of new principles for regulating the activity of the inhibitory action of aptamers of general interest to researchers working with nucleic acid aptamers...

  14. Cyanuric acid-epichlorohydrin prepolymers

    OpenAIRE

    Pedroso, L. M.; Simões, P; Portugal, A.

    2006-01-01

    In this study, we investigated the reaction of cyanuric acid and epichlorohydrin (ECH). SnCl4 was used as a catalyst. Several reaction conditions were tested, and the products were analyzed by means of Fourier transform infrared and 1H-NMR spectroscopy, hydroxyl group content, molar mass, elemental and thermal analysis, viscosity, and density. ECH reacted with the amine groups of the cyanuric acid ring to form lateral chains that contained chloroalkyl and hydroxyl end groups. Full substitutio...

  15. Biocatalytic reduction of carboxylic acids.

    Science.gov (United States)

    Napora-Wijata, Kamila; Strohmeier, Gernot A; Winkler, Margit

    2014-06-01

    An increasing demand for non-petroleum-based products is envisaged in the near future. Carboxylic acids such as citric acid, succinic acid, fatty acids, and many others are available in abundance from renewable resources and they could serve as economic precursors for bio-based products such as polymers, aldehyde building blocks, and alcohols. However, we are confronted with the problem that carboxylic acid reduction requires a high level of energy for activation due to the carboxylate's thermodynamic stability. Catalytic processes are scarce and often their chemoselectivity is insufficient. This review points at bio-alternatives: currently known enzyme classes and organisms that catalyze the reduction of carboxylic acids are summarized. Two totally distinct biocatalyst lines have evolved to catalyze the same reaction: aldehyde oxidoreductases from anaerobic bacteria and archea, and carboxylate reductases from aerobic sources such as bacteria, fungi, and plants. The majority of these enzymes remain to be identified and isolated from their natural background in order to evaluate their potential as industrial biocatalysts.

  16. SATURATED PICRIC ACID PREVENTS AUTOPHAGIA

    Directory of Open Access Journals (Sweden)

    V Rahimi-Movaghar

    2008-08-01

    Full Text Available "nThe dysesthesia and paresthesia that occurs in laboratory rats after spinal cord injury (SCI results in autophagia. This self-destructive behavior interferes with functional assessments in designed studies and jeopardizes the health of the injured rat. In this study, we evaluated role of saturated picric acid in the prevention of autophagia and self-mutilation. All rats were anesthetized with an intraperitoneal injection of a mixture of ketamine (100 mg/kg and xylazine (10 mg/kg for the SCI procedures. In the first 39 rats, no solution applied to the hind limbs, but in the next 26 cases, we smeared the saturated picric acid on the tail, lower extremities, pelvic, and abdomen of the rats immediately after SCI. In the rats without picric acid, 23 rats died following autophagia, but in the 26 rats with picric acid, there was no autophagia (P < 0.001. Picric acid side effects in skin and gastrointestinal signs such as irritation, redness and diarrhea were not seen in any rat. Saturated picric acid is a topical solution that if used appropriately and carefully, might be safe and effectively prevents autophagia and self-mutilation. When the solution is applied to the lower abdomen and limbs, we presume that its bitterness effectively prevents the rat from licking and biting the limb.

  17. Excitatory amino acid receptor antagonists

    DEFF Research Database (Denmark)

    Johansen, T N; Frydenvang, Karla Andrea; Ebert, B

    1997-01-01

    We have previously shown that (RS)-2-amino-2-(5-tert-butyl-3-hydroxyisoxazol-4-yl)acetic acid (ATAA) is an antagonist at N-methyl-D-aspartic acid (NMDA) and (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors. We have now resolved ATAA via diastereomeric salt formation......)-phenylethylamine salt of N-BOC-(R)-ATAA. Like ATAA, neither (R)- nor (S)-ATAA significantly affected (IC50 > 100 microM) the receptor binding of tritiated AMPA, kainic acid, or (RS)-3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid, the latter being a competitive NMDA antagonist. Electrophysiological experiments......, using the rat cortical wedge preparation, showed the NMDA antagonist effect as well as the AMPA antagonist effect of ATAA to reside exclusively in the (R)-enantiomer (Ki = 75 +/- 5 microM and 57 +/- 1 microM, respectively). Neither (R)- nor (S)-ATAA significantly reduced kainic acid-induced excitation...

  18. Performance of Different Acids on Sandstone Formations

    Directory of Open Access Journals (Sweden)

    M. A. Zaman

    2013-12-01

    Full Text Available Stimulation of sandstone formations is a challenging task, which involves several chemicals and physical interactions of the acid with the formation. Some of these reactions may result in formation damage. Mud acid has been successfully used to stimulate sandstone reservoirs for a number of years. It is a mixture of hydrofluoric (HF and hydrochloric (HCl acids designed to dissolve clays and siliceous fines accumulated in the near-wellbore region. Matrix acidizing may also be used to increase formation permeability in undamaged wells. The change may be up to 50% to 100% with the mud acid. For any acidizing process, the selection of acid (Formulation and Concentration and the design (Pre-flush, Main Acid, After-flush is very important. Different researchers are using different combinations of acids with different concentrations to get the best results for acidization. Mainly the common practice is combination of Hydrochloric Acid – Hydrofluoric with Concentration (3% HF – 12% HCl. This paper presents the results of a laboratory investigation of Orthophosphoric acid instead of hydrochloric acid in one combination and the second combination is Fluoboric and formic acid and the third one is formic and hydrofluoric acid. The results are compared with the mud acid and the results calculated are porosity, permeability, and FESEM Analysis and Strength tests. All of these new combinations shows that these have the potential to be used as acidizing acids on sandstone formations.

  19. Vanadocene reactions with hydroxy acids. [Hydroxy acids: acetylsalicylic, gallic, lactic, salicyclic, orotic,. gamma. -hydroxybutyric acids

    Energy Technology Data Exchange (ETDEWEB)

    Latyaeva, V.N.; Lineva, A.N.; Zimina, S.V.; Ehllert, O.G.; Arsen' eva, T.I. (Gor' kovskij Meditsinskij Inst. (USSR))

    1984-03-01

    To prepare a series of vanadium cyclopentadienylcarboxylates soluble in water, the vanadocene reactions with lactic, ..gamma..-oxybutyric-, salicylic,- gallic-, orotic-, and acetylsalicylic acids have been studied. To determine the influence of cyclopentadienyl groups, bound with a vanadium atom, on the physiological activity of the complexes formed, vanadium halides are made to react with lactic acid. Only the vanadocene reaction with orotic acid was conducted in an aqueous medium, other interactions were realized in the diethyl ether, toluene, T, H, P medium. The interaction of vanadocene and vanadium halides with lactic-, salicylic-, acetylsalicylic- and gallic acids was found to lead to the formation of water-soluble vanadium complexes of Cp/sub 2/, VOCOR or CpV (OCOR)/sub 2/ type. The data on the produced compounds yield, their IR spectra, decomposition temperatures, solubility, effective magnetic moments are presented.

  20. An Efficient Procedure for Esterification of Aryloxyacetic Acid and Arylthioacetic Acid Catalyzed by Silica Sulfuric Acid

    Institute of Scientific and Technical Information of China (English)

    LI,Hong-Ya; LI,Ji-Tai; LI,Hui-Zhang

    2004-01-01

    @@ Aryloxyacetate and arylthioacetate are wildly used in herbicides, plant regulator and insecticides. Recently, Wille et al. have reported that methyl aryloxyacetate is an efficient agent to prevent and treat allergic contact dermatitis.[1] The most popular synthesis is by heating sodium phenoxide (mercaptide) with ethyl chloroacetate in DMF,[2] or by the esterification of acid with alcohol using concentrated H2SO4 as catalyst.[3] In this paper, synthesis of aryloxyacetate and aryl thioacetate from aryloxyacetic acid and arylthioacetic acid respectively in ether catalyzed by silica sulfuric acid in 83%~94% yields is described. The catalyst is reused for 3 times without significant loss of activity (Entry 4). Compared with common procedures, the present procedure possesses the advantages of the operational simplicity, short reaction time,less-corrosion, high yield and reusable catalyst.

  1. Molecular screening of wine lactic acid bacteria degrading hydroxycinnamic acids.

    Science.gov (United States)

    de las Rivas, Blanca; Rodríguez, Héctor; Curiel, José Antonio; Landete, José María; Muñoz, Rosario

    2009-01-28

    The potential to produce volatile phenols from hydroxycinnamic acids was investigated for lactic acid bacteria (LAB) isolated from Spanish grape must and wine. A PCR assay was developed for the detection of LAB that potentially produce volatile phenols. Synthetic degenerate oligonucleotides for the specific detection of the pdc gene encoding a phenolic acid decarboxylase were designed. The pdc PCR assay amplifies a 321 bp DNA fragment from phenolic acid decarboxylase. The pdc PCR method was applied to 85 strains belonging to the 6 main wine LAB species. Lactobacillus plantarum, Lactobacillus brevis, and Pediococcus pentosaceus strains produce a positive response in the pdc PCR assay, whereas Oenococcus oeni, Lactobacillus hilgardii, and Leuconostoc mesenteroides strains did not produce the expected PCR product. The production of vinyl and ethyl derivatives from hydroxycinnamic acids in culture media was determined by high-performance liquid chromatography. A relationship was found between pdc PCR amplification and volatile phenol production, so that the LAB strains that gave a positive pdc PCR response produce volatile phenols, whereas strains that did not produce a PCR amplicon did not produce volatile phenols. The proposed method could be useful for a preliminary identification of LAB strains able to produce volatile phenols in wine.

  2. [Regulating acid stress resistance of lactic acid bacteria--a review].

    Science.gov (United States)

    Wu, Chongde; Huang, Jun; Zhou, Rongqing

    2014-07-04

    As cell factories, lactic acid bacteria are widely used in food, agriculture, pharmaceutical and other industries. Acid stress is one the important survival challenges encountered by lactic acid bacteria both in fermentation process and in the gastrointestinal tract. Recently, the development of systems biology and metabolic engineering brings unprecedented opportunity for further elucidating the acid tolerance mechanisms and improving the acid stress resistance of lactic acid bacteria. This review addresses physiological mechanisms of lactic acid bacteria during acid stress. Moreover, strategies to improve the acid stress resistance of lactic acid were proposed.

  3. Extractive fermentation of acetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Busche, R.M. [Bio En-Gene-Er Associates, Inc., Wilmington, DE (United States)

    1991-12-31

    In this technoeconomic evaluation of the manufacture of acetic acid by fermentation, the use of the bacterium: Acetobacter suboxydans from the old vinegar process was compared with expected performance of the newer Clostridium thermoaceticum bacterium. Both systems were projected to operate as immobilized cells in a continuous, fluidized bed bioreactor, using solvent extraction to recover the product. Acetobacter metabolizes ethanol aerobically to produce acid at 100 g/L in a low pH medium. This ensures that the product is in the form of a concentrated extractable free acid, rather than as an unextractable salt. Unfortunately, yields from glucose by way of the ethanol fermentation are poor, but near the biological limits of the organisms involved. Conversely, C. thermoaceticum is a thermophilic anaerobe that operates at high fermentation rates on glucose at neutral pH to produce acetate salts directly in substantially quantitative yields. However, it is severely inhibited by product, which restricts concentration to a dilute 20 g/L. An improved Acetobacter system operating with recycled cells at 50 g/L appears capable of producing acid at $0.38/lb, as compared with a $0.29/lb price for synthetic acid. However, this system has only a limited margin for process improvement. The present Clostridium system cannot compete, since the required selling price would be $0.42/lb. However, if the organism could be adapted to tolerate higher product concentrations at acid pH, selling price could be reduced to $0.22/lb, or about 80% of the price of synthetic acid.

  4. Anaerobic biotransformation of organoarsenical pesticides monomethylarsonic acid and dimethylarsinic acid

    Science.gov (United States)

    Sierra-Alvarez, R.; Yenal, U.; Feld, J.A.; Kopplin, M.; Gandolfi, A.J.; Garbarino, J.R.

    2006-01-01

    Monomethylarsonic acid (MMAV) and dimethylarsinic acid (DMAV) are extensively utilized as pesticides, introducing large quantities of arsenic into the environment. Once released into the environment, these organoarsenicals are subject to microbial reactions. Aerobic biodegradation of MMAV and DMAV has been evaluated, but little is known about their fate in anaerobic environments. The objective of this study was to evaluate the biotransformation of MMAV and DMAV in anaerobic sludge. Biologically mediated conversion occurred under methanogenic or sulfate-reducing conditions but not in the presence of nitrate. Monomethylarsonous acid (MMAIII) was consistently observed as an important metabolite of MMAV degradation, and it was recovered in molar yields ranging from 5 to 47%. The main biotransformation product identified from DMAV metabolism was MMAV, which was recovered in molar yields ranging from 8 to 65%. The metabolites indicate that reduction and demethylation are important steps in the anaerobic bioconversion of MMAV and DMAV, respectively. ?? 2006 American Chemical Society.

  5. Gallic Acid, Ellagic Acid and Pyrogallol Reaction with Metallic Iron

    Science.gov (United States)

    Jaén, J. A.; González, L.; Vargas, A.; Olave, G.

    2003-06-01

    The reaction between gallic acid, ellagic acid and pyrogallol with metallic iron was studied using infrared and Mössbauer spectroscopy. Most hydrolysable tannins with interesting anticorrosive or inhibition properties are structurally related to these compounds, thus they may be used as models for the study of hydrolysable tannins and related polyphenols. The interaction was followed up to 3 months. Results indicated two different behaviors. At polyphenol concentrations higher than 1% iron converts to sparingly soluble and amorphous ferric (and ferrous) polyphenolate complexes. At lower concentrations (0.1%), the hydrolysis reactions are dominant, resulting in the formation of oxyhydroxides, which can be further reduced to compounds like magnetite by the polyphenols.

  6. Boronic acid-based autoligation of nucleic acids

    DEFF Research Database (Denmark)

    Barbeyron, R.; Vasseur, J.-J.; Smietana, M.;

    2013-01-01

    Abstract: The development of synthetic systems displaying dynamic and adaptive characteristics is a formidable challenge with wide applications from biotechnology to therapeutics. Recently, we described a dynamic and programmable nucleic acid-based system relying on the formation of reversible...... boronate internucleosidic linkages. The DNA- or RNA-templated system comprises a 5′-ended boronic acid probe connecting a 3′-ended ribonucleosidic oligonucleotide partner. To explore the dominant factors that control the reversible linkage, we synthesized a series of 3′-end modified ribonucleotidic strands...

  7. Isothermal Amplification of Nucleic Acids.

    Science.gov (United States)

    Zhao, Yongxi; Chen, Feng; Li, Qian; Wang, Lihua; Fan, Chunhai

    2015-11-25

    Isothermal amplification of nucleic acids is a simple process that rapidly and efficiently accumulates nucleic acid sequences at constant temperature. Since the early 1990s, various isothermal amplification techniques have been developed as alternatives to polymerase chain reaction (PCR). These isothermal amplification methods have been used for biosensing targets such as DNA, RNA, cells, proteins, small molecules, and ions. The applications of these techniques for in situ or intracellular bioimaging and sequencing have been amply demonstrated. Amplicons produced by isothermal amplification methods have also been utilized to construct versatile nucleic acid nanomaterials for promising applications in biomedicine, bioimaging, and biosensing. The integration of isothermal amplification into microsystems or portable devices improves nucleic acid-based on-site assays and confers high sensitivity. Single-cell and single-molecule analyses have also been implemented based on integrated microfluidic systems. In this review, we provide a comprehensive overview of the isothermal amplification of nucleic acids encompassing work published in the past two decades. First, different isothermal amplification techniques are classified into three types based on reaction kinetics. Then, we summarize the applications of isothermal amplification in bioanalysis, diagnostics, nanotechnology, materials science, and device integration. Finally, several challenges and perspectives in the field are discussed.

  8. 21 CFR 184.1097 - Tannic acid.

    Science.gov (United States)

    2010-04-01

    ... Substances Affirmed as GRAS § 184.1097 Tannic acid. (a) Tannic acid (CAS Reg. No. 1401-55-4), or hydrolyzable gallotannin, is a complex polyphenolic organic structure that yields gallic acid and either glucose or quinic... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Tannic acid. 184.1097 Section 184.1097 Food...

  9. 21 CFR 582.5013 - Ascorbic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ascorbic acid. 582.5013 Section 582.5013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5013 Ascorbic acid. (a) Product. Ascorbic acid. 1 Amino acids listed in this subpart may...

  10. Microbial production of amino acids in Japan.

    Science.gov (United States)

    Kumagai, H

    2000-01-01

    The microbial biotechnology of amino acids production which was developed and industrialized in Japan have been summarized. The amino acids include L-glutamic acid, L-lysine, L-threonine, L-aspartic acid, L-alanine, L-cysteine, L-dihydroxyphenylalanine, D-p-hydroxyphenyl-glycine, and hydroxy-L-proline.

  11. 21 CFR 184.1061 - Lactic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Lactic acid. 184.1061 Section 184.1061 Food and... Substances Affirmed as GRAS § 184.1061 Lactic acid. (a) Lactic acid (C3H6O3, CAS Reg. Nos.: dl mixture, 598... hydrogen cyanide and subsequent hydrolysis to lactic acid. (b) The ingredient meets the specifications...

  12. Effect of propionic acid on citric acid fermentation in an integrated citric acid-methane fermentation process.

    Science.gov (United States)

    Xu, Jian; Bao, Jia-Wei; Su, Xian-Feng; Zhang, Hong-Jian; Zeng, Xin; Tang, Lei; Wang, Ke; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

    2016-03-01

    In this study, an integrated citric acid-methane fermentation process was established to solve the problem of wastewater treatment in citric acid production. Citric acid wastewater was treated through anaerobic digestion and then the anaerobic digestion effluent (ADE) was further treated and recycled for the next batch citric acid fermentation. This process could eliminate wastewater discharge and reduce water resource consumption. Propionic acid was found in the ADE and its concentration continually increased in recycling. Effect of propionic acid on citric acid fermentation was investigated, and results indicated that influence of propionic acid on citric acid fermentation was contributed to the undissociated form. Citric acid fermentation was inhibited when the concentration of propionic acid was above 2, 4, and 6 mM in initial pH 4.0, 4.5 and, 5.0, respectively. However, low concentration of propionic acid could promote isomaltase activity which converted more isomaltose to available sugar, thereby increasing citric acid production. High concentration of propionic acid could influence the vitality of cell and prolong the lag phase, causing large amount of glucose still remaining in medium at the end of fermentation and decreasing citric acid production.

  13. Toxicologic Study of Monochloroacetic Acid

    Institute of Scientific and Technical Information of China (English)

    Lu Bo; Zhan Ping

    2006-01-01

    @@ Monochloroacetic Acid (MCA) is a chlorinated analog of acetic acids. MCA and its sodium salt (SMCA) are widely used as a chemical intermediate (primarily in the manufacture of chlorophenoxy herbicides,carboxymethylcelluose, glycine and indigoid dyes).Moreover, MCA has been found as a common by-product of the chlorination of drinking water. Chloroacetates are ubiquitous in the environment, and MCA is the most abundant among chloroacetates. A background level of 0.1 - 1μg/L is expected to occur in precipitation[1]. Total world wide annual production of MCA reported was about 400 000 tons[2]. Many studies have showed that MCA not only caused acute or chronic damage to the skin , liver, kidney, heart, brain and other organs, but also caused acute death systemically under high concentration[2,3]. So this article will discuss the toxic effect of Monochloroacetic Acid in Toxicology.

  14. Anions in Nucleic Acid Crystallography.

    Science.gov (United States)

    D'Ascenzo, Luigi; Auffinger, Pascal

    2016-01-01

    Nucleic acid crystallization buffers contain a large variety of chemicals fitting specific needs. Among them, anions are often solely considered for pH-regulating purposes and as cationic co-salts while their ability to directly bind to nucleic acid structures is rarely taken into account. Here we review current knowledge related to the use of anions in crystallization buffers along with data on their biological prevalence. Chloride ions are frequently identified in crystal structures but display low cytosolic concentrations. Hence, they are thought to be distant from nucleic acid structures in the cell. Sulfate ions are also frequently identified in crystal structures but their localization in the cell remains elusive. Nevertheless, the characterization of the binding properties of these ions is essential for better interpreting the solvent structure in crystals and consequently, avoiding mislabeling of electron densities. Furthermore, understanding the binding properties of these anions should help to get clues related to their potential effects in crowded cellular environments.

  15. Fauna of an acid stream

    Energy Technology Data Exchange (ETDEWEB)

    Jewell, M.E.

    1922-01-01

    The hydrogen-ion concentration of the water of the big muddy river was found to vary between pH 5.8 and pH 6.8 to 7.2, the higher acidity occurring during the winter. The bottom fauna was characterized by the abundance of clams and shrimp, and by the absence of branchiate snails and ephemerid nymphs. Fish fry and fingerlings were found in large numbers during the summer in weakly acid water, pH 6.8. Observations on our acid streams, continued over a considerable period of time, would tell us much concerning the adaptability of various species to different hydrogen-ion concentrations and are greatly needed in the interpretation of experimental data.

  16. Tumor Acidity as Evolutionary Spite

    Directory of Open Access Journals (Sweden)

    Mohammed E. A. Shayoub

    2011-01-01

    Full Text Available Most cancer cells shift their metabolic pathway from a metabolism reflecting the Pasteur-effect into one reflecting the Warburg-effect. This shift creates an acidic microenvironment around the tumor and becomes the driving force for a positive carcinogenesis feedback loop. As a consequence of tumor acidity, the tumor microenvironment encourages a selection of certain cell phenotypes that are able to survive in this caustic environment to the detriment of other cell types. This selection can be described by a process which can be modeled upon spite: the tumor cells reduce their own fitness by making an acidic environment, but this reduces the fitness of their competitors to an even greater extent. Moreover, the environment is an important dimension that further drives this spite process. Thus, diminishing the selective environment most probably interferes with the spite process. Such interference has been recently utilized in cancer treatment.

  17. Tumor Acidity as Evolutionary Spite

    Energy Technology Data Exchange (ETDEWEB)

    Alfarouk, Khalid O., E-mail: khalid.alfarouk@act.sd [Department of Biotechnology, Africa City of Technology, Khartoum (Sudan); Department of Pharmaceutics, Faculty of Pharmacy, University of Khartoum, Khartoum (Sudan); Muddathir, Abdel Khalig [Department of Pharmacognosy, Faculty of Pharmacy, University of Khartoum, Khartoum (Sudan); Shayoub, Mohammed E. A. [Department of Pharmaceutics, Faculty of Pharmacy, University of Khartoum, Khartoum (Sudan)

    2011-01-20

    Most cancer cells shift their metabolic pathway from a metabolism reflecting the Pasteur-effect into one reflecting the Warburg-effect. This shift creates an acidic microenvironment around the tumor and becomes the driving force for a positive carcinogenesis feedback loop. As a consequence of tumor acidity, the tumor microenvironment encourages a selection of certain cell phenotypes that are able to survive in this caustic environment to the detriment of other cell types. This selection can be described by a process which can be modeled upon spite: the tumor cells reduce their own fitness by making an acidic environment, but this reduces the fitness of their competitors to an even greater extent. Moreover, the environment is an important dimension that further drives this spite process. Thus, diminishing the selective environment most probably interferes with the spite process. Such interference has been recently utilized in cancer treatment.

  18. Solubilities of Isophthalic Acid in Acetic Acid + Water Solvent Mixtures

    Institute of Scientific and Technical Information of China (English)

    CHENG Youwei; HUO Lei; LI Xi

    2013-01-01

    The solubilities of isophthalic acid (1) in binary acetic acid (2) + water (3) solvent mixtures were determined in a pressurized vessel.The temperature range was from 373.2 to 473.2K and the range of the mole fraction of acetic acid in the solvent mixtures was from x2 =0 to 1.A new method to measure the solubility was developed,which solved the problem of sampling at high temperature.The experimental results indicated that within the temperature range studied,the solubilities of isophthalic acid in all mixtures showed an increasing trend with increasing temperature.The experimental solubilities were correlated by the Buchowski equation,and the calculate results showed good agreement with the experimental solubilities.Furthermore,the mixed solvent systems were found to exhibit a maximum solubility effect on the solubility,which may be attributed to the intermolecular association between the solute and the solvent mixture.The maximum solubility effect was well modeled by the modified Wilson equation.

  19. Ghrelin and gastric acid secretion

    OpenAIRE

    Yakabi, Koji; Kawashima, Junichi; Kato, Shingo

    2008-01-01

    Ghrelin, a novel growth hormone-releasing peptide, was originally isolated from rat and human stomach. Ghrelin has been known to increase the secretion of growth hormone (GH), food intake, and body weight gain when administered peripherally or centrally. Ghrelin is also known to stimulate the gastric motility and the secretion of gastric acid. In the previous studies, the action of ghrelin on acid secretion was shown to be as strong as that of histamine and gastrin in in-vivo experiment. In t...

  20. Spherical agglomeration of acetylsalicylic acid

    Directory of Open Access Journals (Sweden)

    Polowczyk Izabela

    2016-01-01

    Full Text Available In this paper spherical agglomeration of acetylsalicylic acid was described. In the first step, the system of good and poor solvents as well as bridging liquid was selected. As a result of a preliminary study, ethyl alcohol, water and carbon tetrachloride were used as the good solvent, poor one, and bridging liquid, respectively. Then, the amount of acetylsalicylic acid and the ratio of the solvents as well as the volume of the bridging liquid were examined. In the last step, the agglomeration conditions, such as mixing intensity and time, were investigated. The spherical agglomerates obtained under optimum conditions could be subjected to a tableting process afterwards.

  1. General consideration on sialic acid chemistry.

    Science.gov (United States)

    Cao, Hongzhi; Chen, Xi

    2012-01-01

    Sialic acids, also known as neuraminic acids, are a family of negatively charged α-keto acids with a nine-carbon backbone. These unique sugars have been found at the termini of many glycan chains of vertebrate cell surface, which play pivotal roles in mediating or modulating a variety of physiological and pathological processes. This brief review covers general approaches for synthesizing sialic acid containing structures. Recently developed synthetic methods along with structural diversities and biological functions of sialic acid are discussed.

  2. Salicylic acid-independent plant defence pathways

    OpenAIRE

    Pieterse, C.M.J.; Loon, L. C. Van

    1999-01-01

    Salicylic acid is an important signalling molecule involved in both locally and systemically induced disease resistance responses. Recent advances in our understanding of plant defence signalling have revealed that plants employ a network of signal transduction pathways, some of which are independent of salicylic acid. Evidence is emerging that jasmonic acid and ethylene play key roles in these salicylic acid-independent pathways. Cross-talk between the salicylic acid-dependent and the salicy...

  3. Modulating the electronic structure of amino acids: interaction of model lewis acids with anthranilic acid

    Directory of Open Access Journals (Sweden)

    Tareq Irshaidat

    2014-01-01

    Full Text Available On the basis of theoretical B3LYP calculations, Yáñez and co-workers (J. Chem. Theory Comput. 2012, 8, 2293 illustrated that beryllium ions are capable of significantly modulating (changing the electronic structures of imidazole. In this computational organic chemistry study, the interaction of this β-amino acid and five model Lewis acids (BeF1+, Be2+, AlF2(1+, AlF2+, and Al3+ were investigated. Several aspects were addressed: natural bond orbitals, including second order perturbation analysis of intra-molecular charge delocalization and the natural population analysis atomic charges; molecular geometries; selected infrared stretching frequencies (C-N, C-O, and N-H, and selected ¹H-NMR chemical shifts. The data illustrate that this interaction can weaken the H-O bond and goes beyond strengthening the intra-molecular hydrogen bond (N...H-O to cause a spontaneous transfer of the proton to the nitrogen atom in five cases generating zwitterion structures. Many new features are observed. Most importantly, the zwitterion structures include a stabilizing hydrogen bond (N-H...O that varies in relative strength according to the Lewis acid. These findings explain the experimental observations of α-amino acids (for example: J. Am. Chem. Soc. 2001, 123, 3577 and are the first reported fundamental electronic structure characterization of β-amino acids in zwitterion form.

  4. Acid-functionalized polyolefin materials and their use in acid-promoted chemical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Oyola, Yatsandra; Tian, Chengcheng; Bauer, John Christopher; Dai, Sheng

    2016-06-07

    An acid-functionalized polyolefin material that can be used as an acid catalyst in a wide range of acid-promoted chemical reactions, wherein the acid-functionalized polyolefin material includes a polyolefin backbone on which acid groups are appended. Also described is a method for the preparation of the acid catalyst in which a precursor polyolefin is subjected to ionizing radiation (e.g., electron beam irradiation) of sufficient power and the irradiated precursor polyolefin reacted with at least one vinyl monomer having an acid group thereon. Further described is a method for conducting an acid-promoted chemical reaction, wherein an acid-reactive organic precursor is contacted in liquid form with a solid heterogeneous acid catalyst comprising a polyolefin backbone of at least 1 micron in one dimension and having carboxylic acid groups and either sulfonic acid or phosphoric acid groups appended thereto.

  5. Amino Acid Analyses of Acid Hydrolysates in Desert Varnish

    Science.gov (United States)

    Perry, Randall S.; Staley, James T.; Dworkin, Jason P.; Engel, Mike

    2001-01-01

    There has long been a debate as to whether rock varnish deposits are microbially mediated or are deposited by inorganic processes. Varnished rocks are found throughout the world primarily in arid and semi-arid regions. The varnish coats are typically up to 200 microns thick and are composed of clays and alternating layers enriched in manganese and iron oxides. The individual layers range in thickness from 1 micron to greater than 10 microns and may continue laterally for more than a 100 microns. Overlapping botryoidal structures are visible in thin section and scanning electron micrographs. The coatings also include small amounts of organic mater and detrital grains. Amino-acid hydrolysates offer a means of assessing the organic composition of rock varnish collected from the Sonoran Desert, near Phoenix, AZ. Chromatographic analyses of hydrolysates from powdered samples of rock varnish suggest that the interior of rock varnish is relatively enriched in amino acids and specifically in d-alanine and glutamic acid. Peptidoglycan (murein) is the main structural component of gram-positive bacterial cell walls. The d-enantiomer of alanine and glutamic acid are specific to peptidoglycan and are consequently an indicator for the presence of bacteria. D-alanine is also found in teichoic acid which is only found in gram-positive bacteria. Several researchers have cultured bacteria from the surface of rock varnish and most have been gram-positive, suggesting that gram-positive bacteria are intimately associated with varnish coatings and may play a role in the formation of varnish coatings.

  6. Kinetics of wet air oxidation of glyoxalic acid and oxalic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shende, R.V.; Mahajani, V.V. (Univ. of Bombay (India). Dept. of Chemical Technology)

    1994-12-01

    Oxidation of lower molecular weight monobasic and dibasic acids such as formic acid, acetic acid, glyoxalic acid, and oxalic acid is often the rate-controlling step during wet air oxidation (WAO) of an aqueous waste stream exhibiting very high chemical oxygen demand (COD). The kinetics of WAO of glyoxalic acid and oxalic acid was studied in absence and presence of a cupric sulfate catalyst in the temperature range of 120--245 C and oxygen partial pressure of 0.345--1.380 MPa. The wet oxidation of oxalic acid was found to require more severe conditions as compared to glyoxalic acid. The reaction mechanism and kinetic model have been discussed.

  7. Citric Acid Passivation of Stainless Steel

    Science.gov (United States)

    Yasensky, David; Reali, John; Larson, Chris; Carl, Chad

    2009-01-01

    Passivation is a process for cleaning and providing corrosion protection for stainless steel. Currently, on Kennedy Space Center (KSC), only parts passivated with nitric acid are acceptable for use. KSC disposes of approximately 125gal of concentrated nitric acid per year, and receives many parts from vendors who must also dispose of used nitric acid. Unfortunately, nitric acid presents health and environmental hazards. As a result, several recent industry studies have examined citric acid as an alternative. Implementing a citric acid-based passivation procedure would improve the health and environmental safety aspects of passivation process. However although there is a lack of published studies that conclusively prove citric acid is a technically sound passivation agent. In 2007, NASA's KSC Materials Advisory Working Group requested the evaluation of citric acid in place of nitric acid for passivation of parts at KSC. United Space Alliance Materials & Processes engineers have developed a three-phase test plan to evaluate citric acid as an alternative to nitric acid on three stainless steels commonly used at KSC: UNS S30400, S41000, and S17400. Phases 1 and 2 will produce an optimized citric acid treatment based on results from atmospheric exposure at NASA's Beach Corrosion Facility. Phase 3 will compare the optimized solution(s) with nitric acid treatments. If the results indicate that citric acid passivates as well or better than nitric acid, NASA intends to approve this method for parts used at the Kennedy Space Center.

  8. Acid Rain: What It Is -- How You Can Help!

    Science.gov (United States)

    National Wildlife Federation, Washington, DC.

    This publication discusses the nature and consequences of acid precipitation (commonly called acid rain). Topic areas include: (1) the chemical nature of acid rain; (2) sources of acid rain; (3) geographic areas where acid rain is a problem; (4) effects of acid rain on lakes; (5) effect of acid rain on vegetation; (6) possible effects of acid rain…

  9. Fatty acid profile of Albizia lebbeck and Albizia saman seed oils: Presence of coronaric acid

    Science.gov (United States)

    In this work, the fatty acid profiles of the seed oils of Albizia lebbeck and Albizia saman (Samanea saman) are reported. The oils were analyzed by GC, GC-MS, and NMR. The most prominent fatty acid in both oils is linoleic acid (30-40%), followed by palmitic acid and oleic acid for A. lebbeck and ol...

  10. 5-Caffeoylquinic acid and caffeic acid orally administered suppresses P-selectin expression on mouse platelets

    Science.gov (United States)

    Caffeic acid and 5-caffeoylquinic acid are a naturally occurring phenolic acid and its ester found in human diets. In this paper, potential effects of caffeic acid and 5-caffeoylquinic acid found in coffee and other plant sources on platelet activation were studied via investigating P-selectin expre...

  11. Determination of acetylsalicylic acid and salicylic acid in foods, using HPLC with fluorescence detection.

    NARCIS (Netherlands)

    Venema, D.P.; Hollman, P.C.H.; Janssen, P.L.T.M.K.; Katan, M.B.

    1996-01-01

    We developed a specific and sensitive HPLC method with fluorescence detection for the determination of free acetylsalicylic acid, free salicylic acid, and free salicylic acid plus salicylic acid after alkaline hydrolysis (free-plus-bound) in foods. Acetylsalicylic acid was detected after postcolumn

  12. Analysis of proteins responsive to acetic acid in Acetobacter: molecular mechanisms conferring acetic acid resistance in acetic acid bacteria.

    Science.gov (United States)

    Nakano, Shigeru; Fukaya, Masahiro

    2008-06-30

    Acetic acid bacteria are used for industrial vinegar production because of their remarkable ability to oxidize ethanol and high resistance to acetic acid. Although several molecular machineries responsible for acetic acid resistance in acetic acid bacteria have been reported, the entire mechanism that confers acetic acid resistance has not been completely understood. One of the promising methods to elucidate the entire mechanism is global analysis of proteins responsive to acetic acid by two-dimensional gel electrophoresis. Recently, two proteins whose production was greatly enhanced by acetic acid in Acetobacter aceti were identified to be aconitase and a putative ABC-transporter, respectively; furthermore, overexpression or disruption of the genes encoding these proteins affected acetic acid resistance in A. aceti, indicating that these proteins are involved in acetic acid resistance. Overexpression of each gene increased acetic acid resistance in Acetobacter, which resulted in an improvement in the productivity of acetic acid fermentation. Taken together, the results of the proteomic analysis and those of previous studies indicate that acetic acid resistance in acetic acid bacteria is conferred by several mechanisms. These findings also provide a clue to breed a strain having high resistance to acetic acid for vinegar fermentation.

  13. Simultaneous liquid-chromatographic determination of urinary vanillylmandelic acid, homovanillic acid, and 5-hydroxyindoleacetic acid.

    Science.gov (United States)

    Gironi, A; Seghieri, G; Niccolai, M; Mammini, P

    1988-12-01

    We describe a liquid-chromatographic method for quantifying, simultaneously by a single procedure, vanillylmandelic acid (VMA), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) in urine. After solvent extraction of acidified urine, the analytes were chromatographed on a C8 column, with use of a mobile phase of phosphate buffer (20 mmol/L, pH 4.0) and methanol with a variable gradient elution, and detected fluorometrically. We report the analytical recovery, sensitivity, precision, working linear range, and potential for interference from similar molecules or drugs. The results of such tests demonstrate that the proposed method is sensitive and reproducible. It is, furthermore, easy to perform, and thus is suitable for use in the clinical laboratory.

  14. Alternative to Nitric Acid Passivation

    Science.gov (United States)

    Kessel, Kurt R.

    2015-01-01

    The Ground Systems Development and Operations (GSDO) Program at NASA John F. Kennedy Space Center (KSC), Florida, has the primary objective of modernizing and transforming the launch and range complex at KSC to benefit current and future NASA programs along with other emerging users. Described as the launch support and infrastructure modernization program in the NASA Authorization Act of 2010, the GSDO Program will develop and implement shared infrastructure and process improvements to provide more flexible, affordable, and responsive capabilities to a multi-user community. In support of NASA and the GSDO Program, the objective of this project is to qualify citric acid as an environmentally-preferable alternative to nitric acid for passivation of stainless steel alloys. This project is a direct follow-on to United Space Alliance (USA) work at KSC to optimize the parameters for the use of citric acid and verify effectiveness. This project will build off of the USA study to further evaluate citric acids effectiveness and suitability for corrosion protection of a number of stainless steels alloys used by NASA, the Department of Defense (DoD), and the European Space Agency (ESA).

  15. Liquid chromatography of organophosphorus acids

    NARCIS (Netherlands)

    Verweij, A.; Kientz, C.E.; Berg, J. van den

    1988-01-01

    The applicability of different liquid chromatographic systems such as ion-exchange, ion-exclusion, reversed phase and ion-pair partition was studied for the analysis of a number of simple structurally related organophosphorus acids which lack a chromophoric group. Preliminary experiments based on th

  16. 2-(3-Hydroxybenzylaminoacetic acid

    Directory of Open Access Journals (Sweden)

    Li-Hua Zhi

    2011-07-01

    Full Text Available There are two independent 2-(3-hydroxybenzylaminoacetic acid molecules, C9H11NO3, in the asymmetric unit of the title compound. The dihedral angle between the benzene rings of the two independent molecules is 58.12 (4°. The crystal packing is stablized by intermolecular O—H...O and N—H...O hydrogen bonds.

  17. Adipic Acid: Vigorous Import Growth

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Adipic acid is mainly used to manufacture nylon 6,6, plasticizers, grease, polyurethane etc. There are three major commercial production processes: cyclohexane process, cyclohexanol process, butadiene carbonylation process, and the air oxidation of cyclohexane process constitute 93% of the total.

  18. Getting folic acid nutrition right

    Science.gov (United States)

    The two articles in this issue of the journal provide some definitive answers to questions relating to folic acid exposure and folate nutritional status of the US population in the post-fortification era, and, by implication, pose other questions. Most convincingly, these reports, which are based la...

  19. Acid resistance of starch granules

    Energy Technology Data Exchange (ETDEWEB)

    Nara, S.; Sakakura, M.; Komiya, T.

    1983-08-01

    When potato starch was hydrolyzed to form Naegeli amylodextrin by 16% sulfuric acid at 30/sup 0/C, only the amorphous portion of the starch granules was deteriorated. The crystallinity of Naegeli amylodextrin showing the hydrolysis ratio of 0.22 was 1.28 times as large as that of original starch. The hydrolysis process at above 45/sup 0/C was given by two exponential equations. The value of acid resistance portion (C/sub 0/) at 30 and 38/sup 0/C was 100%, while the values at 45, 50 and 55/sup 0/C were 67, 38 and 18%, respectively. The high value of C/sub 0/ generally showed the high acid resistance in the various starches. Sweet potato and waxy rice starches were more easily hydrolysed than other starches, although they gave the relatively high value of C/sub 0/. Thus, it was slightly more difficult for low acid resistance portion of potato starch to be hydrolyzed than for that of other starches. Moreover, that of waxy rice was easily hydrolyzed.

  20. Engineering robust lactic acid bacteria

    NARCIS (Netherlands)

    Bron, P.A.; Bokhorst-van de Veen, van H.; Wels, M.; Kleerebezem, M.

    2011-01-01

    For centuries, lactic acid bacteria (LAB) have been industrially exploited as starter cultures in the fermentation of foods and feeds for their spoilage-preventing and flavor-enhancing characteristics. More recently, the health-promoting effects of LAB on the consumer have been widely acknowledged,

  1. Combinatorics of aliphatic amino acids.

    Science.gov (United States)

    Grützmann, Konrad; Böcker, Sebastian; Schuster, Stefan

    2011-01-01

    This study combines biology and mathematics, showing that a relatively simple question from molecular biology can lead to complicated mathematics. The question is how to calculate the number of theoretically possible aliphatic amino acids as a function of the number of carbon atoms in the side chain. The presented calculation is based on earlier results from theoretical chemistry concerning alkyl compounds. Mathematical properties of this number series are highlighted. We discuss which of the theoretically possible structures really occur in living organisms, such as leucine and isoleucine with a chain length of four. This is done both for a strict definition of aliphatic amino acids only involving carbon and hydrogen atoms in their side chain and for a less strict definition allowing sulphur, nitrogen and oxygen atoms. While the main focus is on proteinogenic amino acids, we also give several examples of non-proteinogenic aliphatic amino acids, playing a role, for instance, in signalling. The results are in agreement with a general phenomenon found in biology: Usually, only a small number of molecules are chosen as building blocks to assemble an inconceivable number of different macromolecules as proteins. Thus, natural biological complexity arises from the multifarious combination of building blocks.

  2. Benzylidene Acetal Protecting Group as Carboxylic Acid Surrogate: Synthesis of Functionalized Uronic Acids and Sugar Amino Acids.

    Science.gov (United States)

    Banerjee, Amit; Senthilkumar, Soundararasu; Baskaran, Sundarababu

    2016-01-18

    Direct oxidation of the 4,6-O-benzylidene acetal protecting group to C-6 carboxylic acid has been developed that provides an easy access to a wide range of biologically important and synthetically challenging uronic acid and sugar amino acid derivatives in good yields. The RuCl3 -NaIO4 -mediated oxidative cleavage method eliminates protection and deprotection steps and the reaction takes place under mild conditions. The dual role of the benzylidene acetal, as a protecting group and source of carboxylic acid, was exploited in the efficient synthesis of six-carbon sialic acid analogues and disaccharides bearing uronic acids, including glycosaminoglycan analogues.

  3. Omega-3 Fatty Acids and Inflammatory Processes

    Directory of Open Access Journals (Sweden)

    Philip C. Calder

    2010-03-01

    Full Text Available Long chain fatty acids influence inflammation through a variety of mechanisms; many of these are mediated by, or at least associated with, changes in fatty acid composition of cell membranes. Changes in these compositions can modify membrane fluidity, cell signaling leading to altered gene expression, and the pattern of lipid mediator production. Cell involved in the inflammatory response are typically rich in the n-6 fatty acid arachidonic acid, but the contents of arachidonic acid and of the n-3 fatty acids eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA can be altered through oral administration of EPA and DHA. Eicosanoids produced from arachidonic acid have roles in inflammation. EPA also gives rise to eicosanoids and these often have differing properties from those of arachidonic acid-derived eicosanoids. EPA and DHA give rise to newly discovered resolvins which are anti-inflammatory and inflammation resolving. Increased membrane content of EPA and DHA (and decreased arachidonic acid content results in a changed pattern of production of eicosanoids and resolvins. Changing the fatty acid composition of cells involved in the inflammatory response also affects production of peptide mediators of inflammation (adhesion molecules, cytokines etc.. Thus, the fatty acid composition of cells involved in the inflammatory response influences their function; the contents of arachidonic acid, EPA and DHA appear to be especially important. The anti-inflammatory effects of marine n-3 PUFAs suggest that they may be useful as therapeutic agents in disorders with an inflammatory component.

  4. Eskimo plasma constituents, dihomo-gamma-linolenic acid, eicosapentaenoic acid and docosahexaenoic acid inhibit the release of atherogenic mitogens.

    Science.gov (United States)

    Smith, D L; Willis, A L; Nguyen, N; Conner, D; Zahedi, S; Fulks, J

    1989-01-01

    Studies in man and laboratory animals suggest that omega 3 polyunsaturated fatty acid constituents of fish oils have antiatherosclerotic properties. We have studied the effects of several such polyunsaturated fatty acids for ability to modify the in vitro release of mitogens from human platelets. Such mitogens may produce the fibro-proliferative component of atherosclerotic plaques. Both 5,8,11,14,17-eicosapentaenoic acid (20:5 omega 3) and 4,7,10,13,16,19-docosahexaenoic acid (22:6 omega 3), major constituents of fish oils, inhibited adenosine diphosphate-induced aggregation of platelets and the accompanying release of mitogens. These effects are dose dependent. Linolenic acid (18:3 omega 3), the biosynthetic precursor of eicosapentaenoic acid, also inhibited platelet aggregation and mitogen release. Eicosapentaenoic acid also inhibited mitogen release from human monocyte-derived macrophages, which, in vivo, are an additional source of mitogens during atherogenesis. Potent inhibition of human platelet aggregation and mitogen release was also seen with dihomo-gamma-linolenic acid (8,11,14-eicosatrienoic acid 20:3 omega 6), whose levels are reportedly elevated in Eskimos subsisting on marine diets. We conclude that diets that elevate plasma and/or tissue levels of eicosapentaenoic acid, docosahexaenoic acid and dihomo-gamma-linolenic acid precursor gamma-linolenic acid (18:3 omega 6) may exert antiatherosclerotic effects by inhibiting the release of mitogens from platelets and other cells.

  5. Effect of acetic acid on citric acid fermentation in an integrated citric acid-methane fermentation process.

    Science.gov (United States)

    Xu, Jian; Chen, Yang-Qiu; Zhang, Hong-Jian; Tang, Lei; Wang, Ke; Zhang, Jian-Hua; Chen, Xu-Sheng; Mao, Zhong-Gui

    2014-09-01

    An integrated citric acid-methane fermentation process was proposed to solve the problem of extraction wastewater in citric acid fermentation process. Extraction wastewater was treated by anaerobic digestion and then recycled for the next batch of citric acid fermentation to eliminate wastewater discharge and reduce water resource consumption. Acetic acid as an intermediate product of methane fermentation was present in anaerobic digestion effluent. In this study, the effect of acetic acid on citric acid fermentation was investigated and results showed that lower concentration of acetic acid could promote Aspergillus niger growth and citric acid production. 5-Cyano-2,3-ditolyl tetrazolium chloride (CTC) staining was used to quantify the activity of A. niger cells, and the results suggested that when acetic acid concentration was above 8 mM at initial pH 4.5, the morphology of A. niger became uneven and the part of the cells' activity was significantly reduced, thereby resulting in deceasing of citric acid production. Effects of acetic acid on citric acid fermentation, as influenced by initial pH and cell number in inocula, were also examined. The result indicated that inhibition by acetic acid increased as initial pH declined and was rarely influenced by cell number in inocula.

  6. Incorporation and distribution of dihomo-gamma-linolenic acid, arachidonic acid, and eicosapentaenoic acid in cultured human keratinocytes

    Energy Technology Data Exchange (ETDEWEB)

    Punnonen, K.; Puustinen, T.; Jansen, C.T.

    1986-02-01

    Human keratinocytes in culture were labelled with /sup 14/C-dihomo-gamma-linolenic acid, /sup 14/C-arachidonic acid or /sup 14/C-eicosapentaenoic acid. All three eicosanoid precursor fatty acids were effectively incorporated into the cells. In phospholipids most of the radioactivity was recovered, in neutral lipids a substantial amount, and as free unesterified fatty acids only a minor amount. Most of the radioactivity was found in phosphatidylethanolamine which was also the major phospholipid as measured by phosphorous assay. The incorporation of dihomo-gamma-linolenic acid and arachidonic acid into lipid subfractions was essentially similar. Eicosapentaenoic acid was, however, much less effectively incorporated into phosphatidylinositol + phosphatidylserine and, correspondingly, more effectively into triacylglycerols as compared to the two other precursor fatty acids. Once incorporated, the distribution of all three precursor fatty acids was relatively stable, and only minor amounts of fatty acids were released into the culture medium during short term culture (two days). Our study demonstrates that eicosanoid precursor fatty acids are avidly taken up by human keratinocytes and esterified into membrane lipids. The clinical implication of this finding is that dietary manipulations might be employed to cause changes in the fatty acid composition of keratinocytes.

  7. Synthesis of Stereoisomers of 3-Aminocyclohexanecarboxylic Acid and cis-3-Aminocyclohexene-5-carboxylic Acid

    Institute of Scientific and Technical Information of China (English)

    HU Yu; YU Sheng-Liang; YANG Yu-Jin; ZHU Jin; DENG Jin-Gen

    2006-01-01

    A practical synthesis of stereoisomers of 3-aminocyclohexanecarboxylic acid and cis-3-aminocyclohexene-5-carboxylic acid was achieved from cyclohexene-4-carboxylic acid via a key resolving approach with chiral 1-phenylethylamine.

  8. Chemical peeling - Glycolic acid versus trichloroacetic acid in melasma

    Directory of Open Access Journals (Sweden)

    Kalla G

    2001-01-01

    Full Text Available Melasma continues to be a therapeutic challenge. 100 patients of melasma not responding to conventional depigmenting agents were divided into 2 groups, one treated with 55 - 75% glycolic acid (68 patients and the other with 10-15% trichloroacetic acid (32 patients. Applications were made after every 15 days and response assessed clinically along with relapse or hyperpigmentation after 3 month follow up period. More than 75% improvement was seen in 30%, and 50-75% improvement in 24% patients. Response with TCA was more rapid as compared to GA. Chronic pigmentation responded more favourably to TCA. Relapse and hyperpigmentation was more-25% in TCA as compared to 5.9% GA. Sun exposure was the most important precipitating factor followed by pregnancy and drugs.

  9. Biophysical properties of phenyl succinic acid derivatised hyaluronic acid

    DEFF Research Database (Denmark)

    Neves-Petersen, Maria Teresa; Klitgaard, Søren; Skovsen, Esben

    2010-01-01

    acid has been derivatised with the anhydride form of phenyl succinic acid (PheSA). The fluorescence of PheSA was efficiently quenched by the HA matrix. HA also acted as a singlet oxygen scavenger. Fluorescence lifetime(s) of PheSA in solution and when attached to the HA matrix has been monitored...... capacity of scavenging singlet oxygen and of quenching PheSA fluorescence. These studies revealed that HA-PheSA is a strong quencher of electronic excited state PheSA and acts as a scavenger of singlet oxygen, thus medical applications of this derivatised form of HA may protect tissues and organs...... with ps resolved streak camera technology. Structural and fluorescence properties changes induced on HA-PheSA due to the presence of singlet oxygen were monitored using static light scattering (SLS), steady state fluorescence and ps time resolved fluorescence studies. SLS studies provided insight...

  10. Endocrine and paracrine role of bile acids

    Institute of Scientific and Technical Information of China (English)

    Verena Keitel; Ralf Kubitz; Dieter H(a)ussinger

    2008-01-01

    Bile acids are not only important for the absorption of dietary lipids and fat soluble vitamins but are signalling molecules with diverse endocrine and paracrine functions.Bile acids regulate bile acid,lipid and glucose metabolism and modulate temperature and energy homeostasis.Furthermore,bile acids can not only promote cell proliferation and liver regeneration but can also induce programmed cell death.Bile acid functions are mediated through different pathways which comprise the activation of nuclear hormone receptors,of intracellular kinases and of the plasma membranebound,G-protein coupled bile acid receptor TGR5/Gpbar-1.

  11. Accidental intoxication with hydrochloric acid and hydrofluoric acid mixture.

    Science.gov (United States)

    Smędra-Kaźmirska, A; Kędzierski, M; Barzdo, M; Jurczyk, Ap; Szram, S; Berent, J

    2014-01-01

    The paper describes a fatal case of accidental ingestion of a mixture of hydrochloric acid and hydrofluoric acid. The man was admitted to hospital, where appropriate treatment, adequate to his condition, was instituted. Numerous ventricular fibrillation episodes, for which the patient was defibrillated repeatedly, were observed during the period of hospitalization. The patient was in a critical condition, with progressive symptoms of hypovolemic shock and multiorgan failure. On the next day after admission, signs of electromechanical dissociation progressing to asystole were noted. The instituted resuscitation procedure proved ineffective and the patient died. Autopsy revealed brownish discoloration of the esophageal, gastric, and small intestinal mucous membranes. Numerous ulcerations without signs of perforation were found both in the esophagus and in the stomach. The mucous membrane of the small intestine demonstrated focal rubefactions, whereas no focal lesions of the large intestinal mucosa were seen. Microscopic investigation of the biopsy specimens collected from the stomach, duodenum and small intestine revealed mucous membrane necrosis foci, reaching the deeper layers of the wall of these organs. The mucous membrane of the large intestine was congested. Bioptates obtained from the lungs indicated the presence of hemorrhagic infarcts and focal extravasations. Poisoning with the aforementioned acids with consequent necrosis of the esophageal, gastric, duodenal and small intestinal walls with hemorrhages to the gastrointestinal tract, as well as extravasations and hemorrhagic infarcts in the lungs was considered to be the cause of death.

  12. Accidental intoxication with hydrochloric acid and hydrofluoric acid mixture

    Directory of Open Access Journals (Sweden)

    Anna Smędra-Kaźmirska

    2014-08-01

    Full Text Available The paper describes a fatal case of accidental ingestion of a mixture of hydrochloric acid and hydrofluoric acid. The man was admitted to hospital, where appropriate treatment, adequate to his condition, was instituted. Numerous ventricular fibrillation episodes, for which the patient was defibrillated repeatedly, were observed during the period of hospitalization. The patient was in a critical condition, with progressive symptoms of hypovolemic shock and multiorgan failure. On the next day after admission, signs of electromechanical dissociation progressing to asystole were noted. The instituted resuscitation procedure proved ineffective and the patient died. Autopsy revealed brownish discoloration of the esophageal, gastric, and small intestinal mucous membranes. Numerous ulcerations without signs of perforation were found both in the esophagus and in the stomach. The mucous membrane of the small intestine demonstrated focal rubefactions, whereas no focal lesions of the large intestinal mucosa were seen. Microscopic investigation of the biopsy specimens collected from the stomach, duodenum and small intestine revealed mucous membrane necrosis foci, reaching the deeper layers of the wall of these organs. The mucous membrane of the large intestine was congested. Bioptates obtained from the lungs indicated the presence of hemorrhagic infarcts and focal extravasations. Poisoning with the aforementioned acids with consequent necrosis of the esophageal, gastric, duodenal and small intestinal walls with hemorrhages to the gastrointestinal tract, as well as extravasations and hemorrhagic infarcts in the lungs was considered to be the cause of death.

  13. Interference effects from coexisting fatty acids on elaidic acid separation by fractionating crystallization: A model study

    DEFF Research Database (Denmark)

    Jala, Ram Chandra Reddy; Guo, Zheng; Bjerring, Thomas;

    2010-01-01

    A multi-stage temperature-programmed fractionating crystallization process was carried out to examine the effects of the presence of stearic acid (SA), oleic acid (OA), and linoleic acid (LA) on the separation of elaidic acid (EA). The results showed that the efficiency of fractionating crystalli......A multi-stage temperature-programmed fractionating crystallization process was carried out to examine the effects of the presence of stearic acid (SA), oleic acid (OA), and linoleic acid (LA) on the separation of elaidic acid (EA). The results showed that the efficiency of fractionating...

  14. Ursodeoxycholic acid in the Ursidae: biliary bile acids of bears, pandas, and related carnivores.

    Science.gov (United States)

    Hagey, L R; Crombie, D L; Espinosa, E; Carey, M C; Igimi, H; Hofmann, A F

    1993-11-01

    The biliary bile acid composition of gallbladder bile obtained from six species of bears (Ursidae), the Giant panda, the Red panda, and 11 related carnivores were determined by reversed phase liquid chromatography and gas chromatography-mass spectrometry. Bile acids were conjugated solely with taurine (in N-acyl linkage) in all species. Ursodeoxycholic acid (3 alpha, 7 beta-dihydroxy-5 beta-cholan-24-oic acid) was present in all Ursidae, averaging 1-39% of biliary bile acids depending on the species; it was not detected or present as a trace constituent (bears, and its proportion averaged 34% (range 0-62%). Ursodeoxycholic acid averaged 17% of biliary bile acids in the Polar bear (n = 4) and 18% in the Brown bear (n = 6). Lower proportions (1-8%) were present in the Sun bear (n = 2), Ceylon Sloth bear (n = 1), and the Spectacled bear (n = 1). Bile of all species contained taurine-conjugated chenodeoxycholic acid and cholic acid. In some related carnivores, deoxycholic acid, the 7-dehydroxylation product of cholic acid, was also present. To determine whether the 7 beta hydroxy group of ursodeoxycholic acid was formed by hepatic or bacterial enzymes, bile acids were determined in hepatic bile obtained from bears with chronic biliary fistulae. Fistula bile samples contained ursodeoxycholic acid, chenodeoxycholic acid, and a trace amount of cholic acid, all as taurine conjugates, indicating that ursodeoxycholic acid is a primary bile acid formed in the liver in Ursidae.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Linoleic acid: between doubts and certainties.

    Science.gov (United States)

    Choque, Benjamin; Catheline, Daniel; Rioux, Vincent; Legrand, Philippe

    2014-01-01

    Linoleic acid is the most abundant polyunsaturated fatty acid in human nutrition and represents about 14 g per day in the US diet. Following the discovery of its essential functions in animals and humans in the early 1920's, studies are currently questioning the real requirement of linoleic acid. It seems now overestimated and creates controversy: how much linoleic acid should be consumed in a healthy diet? Beyond the necessity to redefine the dietary requirement of linoleic acid, many questions concerning the consequences of its excessive consumption on human health arise. Linoleic acid is a direct precursor of the bioactive oxidized linoleic acid metabolites. It is also a precursor of arachidonic acid, which produces pro-inflammatory eicosanoids and endocannabinoids. A majority of the studies on linoleic acid and its derivatives show a direct/indirect link with inflammation and metabolic diseases. Many authors claim that a high linoleic acid intake may promote inflammation in humans. This review tries to (i) highlight the importance of reconsidering the actual requirement of linoleic acid (ii) point out the lack of knowledge between dietary levels of linoleic acid and the molecular mechanisms explaining its physiological roles (iii) demonstrate the relevance of carrying out further human studies on the single variable linoleic acid.

  16. Apoptosis induced by boric anhydrite (B2O3) after partial hepatectomy in rat liver.

    Science.gov (United States)

    Ozen, A; Canbek, M

    2016-01-01

    Boron is one of the important elements that have a cell-growth suppressing effect. The apoptotic effects of B(2)O(3) that were investigated in rats on liver regeneration following 70 % partial hepatectomy (PH). Wistar albino male rats were used and divided into 4 groups (n = 7). The Saline control groups were given only a single dose of saline; the B(2)O(3)-treated groups that were only given a single dose of 1800 mg.kg(-1) B(2)O(3) by means of intraperitoneal injections following hepatectomy. Three and 6 hours after surgical procedures, all the groups were dissected and liver tissue samples were taken from the groups for NF-κB for caspase-3 gene and protein levels investigation by RT-PCR and TaqMan Protein Assay and histological analyses by TUNEL assay. B(2)O(3)-treated animals were examined and it was observed that NF-κB levels were decreased; however, caspase-3 gene expression and protein levels were increased significantly. This study demonstrated that B(2)O(3) induces caspase-3 and inhibits NF-κB at the early stage of liver regeneration (Fig. 4, Ref. 26).

  17. Effect of supplementation of arachidonic acid (AA) or a combination of AA plus docosahexaenoic acid on breastmilk fatty acid composition

    NARCIS (Netherlands)

    Smit, EN; Koopmann, M; Boersma, ER; Muskiet, FAJ

    2000-01-01

    We investigated whether supplementation with arachidonic acid (20:4 omega 6; AA), ora combination of AA and docosahexaenoic acid (22:6 omega 3; DHA) would affect human milk polyunsaturated fatty acid (PUFA) composition. Ten women were daily supplemented with 300 mg AA, eight with 300 mg AA, 110 mg e

  18. Prenatal long-chain polyunsaturated fatty acid status : the importance of a balanced intake of docosahexaenoic acid and arachidonic acid

    NARCIS (Netherlands)

    Hadders-Algra, Mijna

    2008-01-01

    This review addresses the effect of prenatal long-chain polyunsaturated fatty acid (LCPUFA) status on neuro-developmental outcome. It focuses on the major LPCUFA doxosahexaenoic acid (DNA; 22:6 omega 3) and arachidonic acid (AA; 20:4 omega 6). Due to enzymatic competition high DHA intake results in

  19. Lower fetal status of docosahexaenoic acid, arachidonic acid and essential fatty acids is associated with less favorable neonatal neurological condition

    NARCIS (Netherlands)

    Dijck-Brouwer, DAJ; Hadders-Algra, M; Bouwstra, H; Decsi, T; Boehm, G; Martini, IA; Boersma, ER; Muskiet, FAJ

    2005-01-01

    Long-chain polyunsaturated fatty acids, notably arachidonic (AA) and docosahexaenoic (DHA) acids are abundant in brain and may be conditionally essential in fetal life. We investigated umbilical artery (UA) and vein (UV) fatty acid compositions and early neonatal neurological condition in 317 term i

  20. Pollen germination of the walnut cultivar ‛Geisenheim 286’ on different culture media

    Directory of Open Access Journals (Sweden)

    Janković Dragan M.

    2014-01-01

    Full Text Available Pollen of the walnut cultivar ‛Geisenheim 286(27.8% when the germination medium contained 0.8% of agar, 15% of sucrose, 600 ppm of ’ was cultured on germination media containing all possible combinations of sucrose (10, 15 and 20%; agar (0.6 and 0.8%; boric acid (0, 300 and 600 ppm and calcium chloride (0, 50 and 100 ppm. A total of 54 different combinations of germination media were tested in an attempt to establish a suitable culture in vitro pollen germinability The interactions of the concentrations of agar and calcium chloride, boric acid and sucrose, calcium chloride and sucrose, as well as those of boric acid, calcium chloride and sucrose were significant. Pollen germination was maximized media for studying of the walnut. Significant differences in pollen germination were observed in response to changing concentrations of sucrose, boric acid and calcium chloride, but germination was not affected by changes in agar concentration. boric acid and 50 ppm of calcium chloride.

  1. Tuz Stresi Altında Çimlendirilen Arpa Tohumlarında Borik Asit Uygulamasının Sitogenetik Etkisi

    Directory of Open Access Journals (Sweden)

    Dilek ÇAVUŞOĞLU

    2015-09-01

    Full Text Available The effect of exogenous boric acid on the mitotic activity and chromosomal aberrations in root tip meristems of barley (Hordeum vulgare L. cv. ‘Bülbül 89’ seeds germinated under salt stress was investigated. The inhibitory effect of salinity on mitotic index increased with increasing salt concentrations (0.00- control, 0.25, 0.275 and 0.30 M, molar NaCl as compared to control group. The mitotic index greatly reduced at the highest salt level (0.30 M NaCl. At the same time, the frequency of chromosomal aberrations increased significantly in parallel with the salt concentration rise. It was determined that application of alone boric acid (0,005 µM was not a prohibitive effect on mitotic index as compared with the barley seeds germinated in distilled water (C, control. Also, the frequency of chromosomal aberrations in application of boric acid increased approximately three-fold according to the control group. Boric acid+different NaCl concentrations simultaneously application remarkably increased the negative effects of salinity on the mitotic activity. However, boric acid application, particularly at high salt concentrations showed a perfect successful in alleviating of the detrimental effect of salinity on the chromosomal aberrations

  2. Ecofriendly Fire Retardant and Rot Resistance Finishing of Jute Fabric Using Tin and Boron Based Compound

    Science.gov (United States)

    Samanta, Ashis Kumar; Bagchi, Arindam

    2017-02-01

    Treatment with sodium stannate followed by treatment with boric acid imparts jute fabric wash fast fire resistance property as indicated by its Limiting Oxygen Index (LOI) value and 45° inclined flammability test results. The treatment was carried out by impregnation of sodium stannate followed by impregnation with an aqueous solution of boric acid and drying. Application of sodium stannate (20%) and boric acid (20%) treatment on jute fabric showed balanced flame retardancy property (LOI value 34) with some loss in fabric tenacity (loss of tenacity is 14.5%). Treated fabric retained good fire retardant property after three consecutive washing. Treated fabric also possessed good rot resistance property as indicated by soil burial test and strength retention after 21 days soil burial was found to be 65%. It is found that of sodium stannate and boric acid combination by double bath process form a synergistic durable fire-retardant as well as rot resistant when impregnated on jute material, which is considerably greater than the use of either sodium stannate or boric acid alone. TGA, FTIR and SEM analysis are also reported to support the results and reaction mechanism.

  3. Nucleic acid based logical systems.

    Science.gov (United States)

    Han, Da; Kang, Huaizhi; Zhang, Tao; Wu, Cuichen; Zhou, Cuisong; You, Mingxu; Chen, Zhuo; Zhang, Xiaobing; Tan, Weihong

    2014-05-12

    Researchers increasingly visualize a significant role for artificial biochemical logical systems in biological engineering, much like digital logic circuits in electrical engineering. Those logical systems could be utilized as a type of servomechanism to control nanodevices in vitro, monitor chemical reactions in situ, or regulate gene expression in vivo. Nucleic acids (NA), as carriers of genetic information with well-regulated and predictable structures, are promising materials for the design and engineering of biochemical circuits. A number of logical devices based on nucleic acids (NA) have been designed to handle various processes for technological or biotechnological purposes. This article focuses on the most recent and important developments in NA-based logical devices and their evolution from in vitro, through cellular, even towards in vivo biological applications.

  4. Prostatic acid phosphatase by radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Lindholm, G.R.; Stirton, M.S.; Liedtke, R.J.; Batjer, J.D.

    1980-11-07

    Prostatic acid phosphatase values in 98 patients with prostatic carcinoma were measured by a commmercial radioimmunoassay (RIA) and by enzymatic assay. Forty-three carcinomas were staged by rigorous pathological criteria. Patients (N = 129) with benign prostatic hyperplasia were the control group. At 94% specificity, sensitivities of the RIA vs the enzymatic assay for clinically staged patients were as follows: stage A, 22% vs 6%; B, 29% vs 10%; C, 52% vs 38%; and D, 87% vs 80%. However, none of the seven patients with pathological stage A and B disease had a positive test result, and we suggest that variability in staging criteria accounts for the discrepant sensitivity claims reported. Prostatic acid phosphatase RIA should not be used for screening but as an adjunct for staging known prostatic carcinoma.

  5. Palmitic Acid and Health: Introduction.

    Science.gov (United States)

    Agostoni, Carlo; Moreno, Luis; Shamir, Raanan

    2016-09-09

    Interest in the dietary role and metabolic effect of saturated fatty acids has been recently renewed on the basis of epidemiologic observations and economical approach to health and well-being. Saturated fats may favorably increase blood HDL-Cholesterol levels without significant changes of the total cholesterol/HDL-Cholesterol ratio. Also, the negative effect of saturated fat on cardiovascular diseases risk has recently been challenged. Palmitic acid, among all, may have special structural and functional roles in utero and in infancy, and indeed is it is being delivered in a unique form in human milk. Future research should include objective cost-benefit analyses when disentangling the role of saturated fats in dietary recommendations.

  6. Polyunsaturated fatty acids and epilepsy.

    Science.gov (United States)

    Taha, Ameer Y; Burnham, W McIntyre; Auvin, Stéphane

    2010-08-01

    Omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) are dietary fatty acids that are involved in a myriad of physiologic processes in the brain. There is some evidence suggesting that PUFAs-and particularly omega-3 PUFAs-may have anticonvulsant effects, both in humans and in animals. In the present review, we assess the evidence related to the antiseizure properties of the n-3 PUFAs, discuss their possible mechanism(s) of action, and make recommendations for future clinical trials. In general, the available data from cell cultures and whole animal studies support the idea that the n-3 PUFAs have antiseizure properties. Future clinical trials involving the n-3 PUFAs should involve higher doses and longer periods of administration in order to definitively assess their possible antiseizure effects.

  7. Ursodeoxycholic acid and superoxide anion

    Institute of Scientific and Technical Information of China (English)

    Predrag Ljubuncic; Omar Abu-Salach; Arieh Bomzon

    2005-01-01

    AIM: To investigate the ability of ursodeoxycholic acid (UDCA) to scavenge superoxide anion (O2-).METHODS: We assessed the ability of UDCA to scavenge (O2-) generated by xanthine-xanthine oxidase (X-XO) in a cell-free system and its effect on the rate of O2--induced ascorbic acid (AA) oxidation in hepatic post-mitochondrial supernatants.RESULTS: UDCA at a concentration as high as 1 mmol/Ldid not impair the ability of the X-XO system to generate O2-, but could scavenge O2- at concentrations of 0.5 and 1 mmol/L, and decrease the rate of AA oxidation at a concentration of 100 μmol/L.CONCLUSION: UDCA can scavenge O2-, an action that may be beneficial to patients with primary biliary cirrhosis.

  8. Signalling properties of lysophosphatidic acid.

    Science.gov (United States)

    Durieux, M E; Lynch, K R

    1993-06-01

    Lysophosphatidic acid (LPA) is the simplest natural phospholipid, primarily known as a membrane component and metabolic intermediate. However, a remarkable variety of biological effects of this compound have come to light, seemingly pointing to an additional role for LPA as a signalling molecule. In this review, Marcel Durieux and Kevin Lynch integrate the recent information that indicates that LPA could be an intercellular messenger, possibly acting through a G protein-coupled receptor, and with a role in cell growth and motility.

  9. Diagnostic relevance of uric acid

    OpenAIRE

    2015-01-01

    Uric acid, the final product of purine metabolism, is one of the most recognized biological markers, a catalyzed reaction by xantina oxidoreductasa (XOR). This bifunctional enzyme in its dehydrogenated shape (XDH), produces AU, and nicotidamide adenine dinucleotide and in oxidase (XO), AU and Superoxide (O2•-). Hyperuricemia (HAU) is an indicator of over-regulation of XO activity, a powerful system producer of species of reactive oxygen (ROS), in human physiology. Accumulation of these radica...

  10. Nucleic acid detection using MNAzymes.

    Science.gov (United States)

    Gerasimova, Yulia V; Kolpashchikov, Dmitry M

    2010-02-26

    Deoxyribozymes are promising biotechnological tools. In a recent JACS article, Mokany et al. reported on the design of multi-component deoxyribozyme (MNAzyme) sensors based on 10-23 and 8-17 DNA enzymes. The sensors can detect down to 5 pM of a specific nucleic acid. The versatility of MNAzyme platform allows the design of catalytic cascades for signal amplification. This work is a step forward to PCR-free molecular diagnostics.

  11. Bile acids for primary sclerosing cholangitis

    DEFF Research Database (Denmark)

    Chen, Weikeng; Gluud, C

    2003-01-01

    Bile acids have been used for treating primary sclerosing cholangitis, but their beneficial and harmful effects remain unclear.......Bile acids have been used for treating primary sclerosing cholangitis, but their beneficial and harmful effects remain unclear....

  12. 21 CFR 184.1007 - Aconitic acid.

    Science.gov (United States)

    2010-04-01

    ... salt from cane sugar or molasses. It may be synthesized by sulfuric acid dehydration of citric acid... availability of this incorporation by reference is given in paragraph (b)(1) of this section. (7) Residue...

  13. Biobased synthesis of acrylonitrile from glutamic acid

    NARCIS (Netherlands)

    Notre, le J.E.L.; Scott, E.L.; Franssen, M.C.R.; Sanders, J.P.M.

    2011-01-01

    Glutamic acid was transformed into acrylonitrile in a two step procedure involving an oxidative decarboxylation in water to 3-cyanopropanoic acid followed by a decarbonylation-elimination reaction using a palladium catalyst

  14. Lactic acid fermentation-aided biomass conversion

    Energy Technology Data Exchange (ETDEWEB)

    Martin, A.M. [Memorial Univ. of Newfoundland, St. John`s, NF (Canada). Dept. of Biochemistry

    1996-09-01

    The preservation of fisheries biomass by lactic acid fermentation is discussed. This method is favourably compared to acid ensiling and fish meal production in terms of safety considerations, energy requirements, simplicity of process and product quality. (Author)

  15. Self-breaking retarded acid emulsion

    Energy Technology Data Exchange (ETDEWEB)

    Scherubel, G.A.

    1979-02-20

    A subterranean formation is acidized with an acid-in-oil emulsion consisting of an aqueous acidizing solution, an oil, an alkyl C/sub 8/ to C/sub 18/ primary fatty amine, and at least one diethanolamide of at least one C/sub 8/ to C/sub 18/ fatty acid. The present invention is an improved acid-in-oil acidizing emulsion, and acidizing method such as an emulsion, the emulsion being of the type containing an effective amount of at least one C/sub 8/ to C/sub 18/ primary amine as a cationic surfactant to increase the normal reaction. The diethanolamine is a nonionic surfactant which causes the emulsion to break as the acidizing capacity of the emulsion becomes substantially depleted, i.e., spent, on the formation. 41 claims.

  16. Acid Rain Program Opt-in Factsheet

    Science.gov (United States)

    Learn about the Opt-in Program, which allows sources not required to participate in the Acid Rain Program the opportunity to enter the program on a voluntary basis and receive Acid Rain Program allowances.

  17. Histidine-Containing Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2000-01-01

    Peptide nucleic acids containing histidine moieties are provided. These compounds have applications including diagnostics, research and potential therapeutics.......Peptide nucleic acids containing histidine moieties are provided. These compounds have applications including diagnostics, research and potential therapeutics....

  18. Acupuncture and gastric acid studies.

    Science.gov (United States)

    Sodipo, J O; Falaiye, J M

    1979-01-01

    The effects of therapeutic acupuncture on gastric acid secretion on pain relief in chronic duodenal ulcer patients were studied. Ten adult Nigerian patients with clinical, endoscopic as well as radiological evidence of duodenal ulcer constituted the "Ulcer Group." Four other patients who gave history of dyspepsia formed the "Dyspeptic Group." Pentagastrin stimulation test was performed on all subjects pre- and post-acupuncture therapy. The classical Chinese acupuncture loci were employed. The mean Basal Acid Output (BAO) in the duodenal ulcer group was markedly reduced from 4.04 +/- 1.01 mMols/hour to 1.05 +/- 2.5 mMols/hour. The mean Maximal Acid Output (MAO) was lowered from 34.72 +/- 13.81 mMols/hour to 15.34 +/- 4.01 mMols/hour. The difference was statistically significant (P less than 0.001). It is more probable, therefore, that the relief of pain is attributable to the therapeutic inhibition of gastric hyperacidity in our patients. Thus, though pain relief has been previously demonstrated in response to acupuncture, the results of this investigation have gone further to show that acupunture achieves symptomatic relief through therapeutic gastric depression in duodenal ulcer patients.

  19. Dilute Acid and Autohydrolysis Pretreatment

    Science.gov (United States)

    Yang, Bin; Wyman, Charles E.

    Exposure of cellulosic biomass to temperatures of about 120-210°C can remove most of the hemicellulose and produce cellulose-rich solids from which high glucose yields are possible with cellulase enzymes. Furthermore, the use of dilute sulfuric acid in this pretreatment operation can increase recovery of hemicellulose sugars substantially to about 85-95% of the maximum possible versus only about 65% if no acid is employed. The use of small-diameter tubes makes it possible to employ high solids concentrations similar to those preferred for commercial operations, with rapid heat-up, good temperature control, and accurate closure of material balances. Mixed reactors can be employed to pretreat larger amounts of biomass than possible in such small-diameter tubes, but solids concentrations are limited to about 15% or less to provide uniform temperatures. Pretreatment of large amounts of biomass at high solids concentrations is best carried out using direct steam injection and rapid pressure release, but closure of material balances in such “steam gun” devices is more difficult. Although flow of water alone or containing dilute acid is not practical commercially, such flow-through configurations provide valuable insight into biomass deconstruction kinetics not possible in the batch tubes, mixed reactors, or steam gun systems.

  20. Capture and release of acid-gasses with acid-gas binding organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Heldebrant, David J; Yonker, Clement R; Koech, Phillip K

    2015-03-17

    A system and method for acid-gas capture wherein organic acid-gas capture materials form hetero-atom analogs of alkyl-carbonate when contacted with an acid gas. These organic-acid gas capture materials include combinations of a weak acid and a base, or zwitterionic liquids. This invention allows for reversible acid-gas binding to these organic binding materials thus allowing for the capture and release of one or more acid gases. These acid-gas binding organic compounds can be regenerated to release the captured acid gasses and enable these organic acid-gas binding materials to be reused. This enables transport of the liquid capture compounds and the release of the acid gases from the organic liquid with significant energy savings compared to current aqueous systems.

  1. Incorporation of conjugated linoleic acid (CLA and α-linolenic acid (LNA in pacu fillets

    Directory of Open Access Journals (Sweden)

    Deoclécio José Barilli

    2014-03-01

    Full Text Available The objective of this study was to evaluate the incorporation of conjugated linoleic acid and α-linolenic acid in fillets of pacu fish raised in net cages and fed diets enriched with these acids. The fish were fed for 49 days, and at the end of this period the fatty acid content in the fillets was determined by gas chromatography. Concentrations of α-linolenic acid, eicosapentaenoic acid, and the total omega-3 (n-3 fatty acid in the fillets increased, improving the n-6/n-3 ratio. In addition, the incorporation of conjugated linoleic acid in the fish fillets proved well established. This study showed that the use of diets enriched with conjugated linoleic acid and α-linolenic acid results in the incorporation of these acids in the of pacu fish fillets, improving their nutritional quality.

  2. Profile of Fatty Acids, Amino Acids, Carotenoid Total, and α-Tocopherol from Flying Fish Eggs

    Directory of Open Access Journals (Sweden)

    Aulia Azka

    2015-12-01

    Full Text Available Flying fish are found in waters of eastern Indonesia, which until now is still limited information about nutritional content. The purpose of this research was determine the composition of fatty acids, amino acids, total carotenoids, α-tocopherol flying fish eggs (Hyrundicthys sp.. The composition of fatty acid was measured by gas chromatography (GC, while amino acids, total carotenoids, α-tocopherol was measured by High performanced Liquid Chromatography (HPLC. Egg contained 22 fatty acids such as saturated fatty acid 29.71%, monounsaturated fatty acid 7.86%, and polysaturated fatty acid 13.64%. The result showed that eggs flying fish contained 17 amino acids, such as essential amino acid 14.96% and non-essential amino acids 20.27%. Eggs contained a total carotenoid of 245.37 ppm. α-tocopherol content of flying fish eggs by 1.06 ppm.

  3. Levulinic acid production from waste biomass

    OpenAIRE

    Anna Maria Raspolli Galletti,; Claudia Antonetti; Valentina De Luise,; Domenico Licursi,; Nicoletta Nassi

    2012-01-01

    The hydrothermal conversion of waste biomass to levulinic acid was investigated in the presence of homogeneous acid catalysts. Different cheap raw materials (poplar sawdust, paper mill sludge, tobacco chops, wheat straw, olive tree pruning) were employed as substrates. The yields of levulinic acid were improved by optimization of the main reaction parameters, such as type and amount of acid catalyst, temperature, duration, biomass concentration, and electrolyte addition. The catalytic perform...

  4. 21 CFR 184.1005 - Acetic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acetic acid. 184.1005 Section 184.1005 Food and... Substances Affirmed as GRAS § 184.1005 Acetic acid. (a) Acetic acid (C2H4O2, CAS Reg. No. 64-19-7) is known as ethanoic acid. It occurs naturally in plant and animal tissues. It is produced by fermentation...

  5. Microbial production of natural poly amino acid

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Three kinds of poly amino acids, poly-γ-glutamic acid, poly(ε-L-lysine) and multi-L-arginyl-poly (L-aspartic acid) can be synthesized by enzymatic process independently from ribosomal protein biosynthesis pathways in microorganism. These biosynthesized polymers have attracted more and more attentions because of their unique properties and various applications. In this review, the current knowledge on the biosynthesis, biodegradations and applications of these three poly amino acids are summarized.

  6. Production of high molecular weight polylactic acid

    Science.gov (United States)

    Bonsignore, Patrick V.

    1995-01-01

    A degradable high molecular weight poly(lactic acid). A poly(lactic acid) has a terminal end group of one of carboxyl or hydroxyl groups with low molecular weight poly(lactic acid) units coupled with linking agents of di-isocyanates, bis-epoxides, bis-oxazolines and bis-ortho esters. The resulting high molecular weight poly(lactic acid) can be used for applications taking advantage of the improved physical properties.

  7. The beneficial biological properties of salicylic acid

    OpenAIRE

    Randjelović Pavle; Veljković Slavimir; Stojiljković Nenad; Sokolović Dušan; Ilić Ivan; Laketić Darko; Randjelović Dušica; Randjelović Nebojša

    2015-01-01

    Salicylic acid is a phytochemical with beneficial effects on human well-being. Salicylic acid is a phenolic compound and is present in various plants where it has a vital role in protection against pathogenic agents. Natural sources include fruits, vegetables and spices. The most famous and defined effect of salicylic acid is prostaglandin synthesis inhibition. Salicylic acid has antiinflammatory effects through suppression of transcription of genes for cyclooxygenase. Most of the pharmacolog...

  8. Enhancement of colposcopic image by sulphosalicylic acid.

    Directory of Open Access Journals (Sweden)

    Khilnani P

    1993-01-01

    Full Text Available Acetic acid is used conventionally for enhancement of the colposcopic image. We used sulphosalicylic acid instead of acetic acid in 50 normal cases. The normal appearance was enhanced in all cases. The image was also enhanced in 70% cases of cervical intraepithelial neoplasia and 90% cases of cervical condyloma accuminata. The image was not inferior to that with acetic acid in any of the cases.

  9. Fatty Acid Composition of Agaricus bisporus (Lange) Sing.

    OpenAIRE

    Aktümsek, Abdurrahman; ÖZTÜRK, Celâleddin; KAŞIK, Giyasettin

    1998-01-01

    Fatty acid compositions of fruit body, stem, lamellae and total of Agaricus bisporus were seperately analysed by GLC. In the all fatty acid compositions of A. bisporus, linoleic acid were predominant. Percentages of linoleic acid were varied between 53.45 - 68.78%. It was showed that the other major fatty acids were palmitic, oleic and stearic acid in the fatty acid compositions.

  10. Chicoric Acid Found in Basil (Ocimum basilicum L.) Leaves

    Science.gov (United States)

    This is the first report to identify the presence of chicoric acid (cichoric acid; also known as dicaffeoyltartaric acid) in basil leaves. Rosmarinic acid, chicoric acid, and caftaric acid (in the order of most abundant to least; all derivatives of caffeic acid) were identified in fresh basil leaves...

  11. Unnatural reactive amino acid genetic code additions

    Science.gov (United States)

    Deiters, Alexander; Cropp, Ashton T; Chin, Jason W; Anderson, Christopher J; Schultz, Peter G

    2013-05-21

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  12. Genetics of proteinases of lactic acid bacteria

    NARCIS (Netherlands)

    Kok, Jan; Venema, Gerhardus

    1988-01-01

    Because it is essential for good growth with concomitant rapid acid production, and for the production of flavorous peptides and amino acids, the proteolytic ability of lactic acid bacteria is of crucial importance for reliable dairy product quality. In view of this importance, considerable research

  13. Unnatural reactive amino acid genetic code additions

    Science.gov (United States)

    Deiters, Alexander; Cropp, T. Ashton; Chin, Jason W.; Anderson, J. Christopher; Schultz, Peter G.

    2014-08-26

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  14. Tranexamic acid for upper gastrointestinal bleeding

    DEFF Research Database (Denmark)

    Gluud, Lise Lotte; Klingenberg, Sarah Louise; Langholz, Ebbe

    2012-01-01

    Tranexamic acid reduces haemorrhage through its antifibrinolytic effects. In a previous version of the present review, we found that tranexamic acid may reduce mortality. The present review includes updated searches of randomised trials on tranexamic acid versus placebo, cimetidine or lansoprazole....

  15. 21 CFR 182.1045 - Glutamic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Glutamic acid. 182.1045 Section 182.1045 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN....1045 Glutamic acid. (a) Product. Glutamic acid. (b) (c) Limitations, restrictions, or explanation....

  16. Maastricht essential fatty acid birth cohort

    NARCIS (Netherlands)

    Van der Wurff, Inge; De Groot, Renate; Stratakis, Nikos; Gielen, Marij; Hornstra, Gerard; Zeegers, Maurice

    2016-01-01

    The Maastricht Essential Fatty Acid Birth cohort (MEFAB) was established in 1989 to study the changes in fatty acid concentration during pregnancy and how this related to the fatty acid concentrations of the neonate. The original sample contains data of 1203 subjects. Some participants whom particip

  17. 21 CFR 582.6033 - Citric acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Citric acid. 582.6033 Section 582.6033 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 2 § 582.6033 Citric acid. (a) Product. Citric acid. 2 For the purpose of this subpart, no attempt has been made...

  18. 21 CFR 582.1033 - Citric acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Citric acid. 582.1033 Section 582.1033 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1033 Citric acid. (a) Product. Citric acid. (b) Conditions of use. This substance is...

  19. Treating burns caused by hydrofluoric acid.

    Science.gov (United States)

    Summers, Anthony

    2011-06-01

    Hydrofluoric acid is an ingredient of many common household and industrial solutions. Even seemingly minor burns caused by this acid can have catastrophic effects if they are treated inappropriately or late. This article describes the signs and symptoms, the pathophysiology and the emergency management of hydrofluoric acid burns.

  20. More on Effects Controlling Carboxylic Acidity.

    Science.gov (United States)

    Schwartz, Lowell M.

    1981-01-01

    Gas phase acidity data shown are offered to writers of elementary organic chemistry texts for replacement of the aqueous phase data that are universally used. Relative acidities in the gas phase are controlled virtually exclusively by enthalpic factors. Structural-energetic explanations of acidic trends can therefore be used. (SK)

  1. 21 CFR 582.1005 - Acetic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  2. 21 CFR 182.8013 - Ascorbic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ascorbic acid. 182.8013 Section 182.8013 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8013 Ascorbic acid. (a) Product. Ascorbic acid. (b) Conditions of use. This substance is generally recognized as safe when used...

  3. 21 CFR 182.3013 - Ascorbic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ascorbic acid. 182.3013 Section 182.3013 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3013 Ascorbic acid. (a) Product. Ascorbic acid. (b) Conditions of use. This substance is generally recognized as...

  4. 21 CFR 582.3013 - Ascorbic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ascorbic acid. 582.3013 Section 582.3013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Ascorbic acid. (a) Product. Ascorbic acid. (b) Conditions of use. This substance is generally recognized...

  5. 21 CFR 172.130 - Dehydroacetic acid.

    Science.gov (United States)

    2010-04-01

    ... Food Preservatives § 172.130 Dehydroacetic acid. The food additive dehydroacetic acid and/or its sodium... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Dehydroacetic acid. 172.130 Section 172.130 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  6. Dietary arachidonic acid in perinatal nutrition

    DEFF Research Database (Denmark)

    Lauritzen, Lotte; Fewtrell, Mary; Agostoni, Carlo

    2015-01-01

    Arachidonic acid (AA) is supplied together with docosahexaenoic acid (DHA) in infant formulas, but we have limited knowledge about the effects of supplementation with either of these long-chain polyunsaturated fatty acids (LCPUFA) on growth and developmental outcomes. AA is present in similar lev...

  7. 21 CFR 582.1061 - Lactic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Lactic acid. 582.1061 Section 582.1061 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1061 Lactic acid. (a) Product. Lactic acid. (b) Conditions of use. This substance is...

  8. Acrylic Acid and Esters Will Be Oversupply

    Institute of Scientific and Technical Information of China (English)

    Zheng Chengwang

    2007-01-01

    @@ Drastic capacity growth The production capacity of acrylic acid in China has grown drastically in recent years. With the completion of the 80 thousand t/a acrylic acid and 130 thous and t/a acrylic ester project in Shenyang Paraffin Chemical Industrial Co., Ltd., (CCR2006,No. 31) the capacity of acrylic acid in China has reached 882 thousand t/a.

  9. Acid Rain: What We Must Do.

    Science.gov (United States)

    Gorham, Eville

    1983-01-01

    Addresses questions about the nature, source, and history of acid rain. In addition, discusses the questions: Why is acid rain a problem? Is acid rain getting worse? What is the threat of further problems? Concludes that it is time to act on the problem and recommends an appropriate course of action. (JN)

  10. Acid Rain. LC Science Tracer Bullet.

    Science.gov (United States)

    Hollmann, Pauline, Comp.

    The term "acid rain," also called "acid precipitation," generally refers to any precipitation having a pH value of less than 5.6. This guide to the literature on acid rain in the collections of the Library of Congress is not necessarily intended to be a comprehensive bibliography. It is designed to provide the reader with a set…

  11. 21 CFR 556.590 - Salicylic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Salicylic acid. 556.590 Section 556.590 Food and... Residues of New Animal Drugs § 556.590 Salicylic acid. A tolerance of zero is established for residues of salicylic acid in milk from dairy animals....

  12. Amino acids as antioxidants for frying oil

    Science.gov (United States)

    Amino acids, proteins and hydrolysates of proteins have been known to protect edible oils from oxidation. While amino acids and related materials have high potential as antioxidants for frying oil, effectiveness of each amino acid and mechanisms of their activities are not well understood yet. Propo...

  13. 21 CFR 582.1073 - Phosphoric acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Phosphoric acid. 582.1073 Section 582.1073 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1073 Phosphoric acid. (a) Product. Phosphoric acid. (b) Conditions of use. This substance...

  14. 21 CFR 182.1073 - Phosphoric acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Phosphoric acid. 182.1073 Section 182.1073 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN....1073 Phosphoric acid. (a) Product. Phosphoric acid. (b) Conditions of use. This substance is...

  15. Hydrofluoric acid on dentin should be avoided.

    NARCIS (Netherlands)

    Loomans, B.A.C.; Mine, A.; Roeters, F.J.M.; Opdam, N.J.M.; Munck, J. De; Huysmans, M.C.D.N.J.M.; Meerbeek, B. Van

    2010-01-01

    Hydrofluoric acid can be used for intra-oral repair of restorations. Contamination of tooth substrate with hydrofluoric acid cannot always be avoided. OBJECTIVES: To investigate the bonding effectiveness to hydrofluoric acid contaminated dentin by, micro-tensile bond strength testing, SEM and TEM. M

  16. Hyaluronic acid for anticancer drug and nucleic acid delivery.

    Science.gov (United States)

    Dosio, Franco; Arpicco, Silvia; Stella, Barbara; Fattal, Elias

    2016-02-01

    Hyaluronic acid (HA) is widely used in anticancer drug delivery, since it is biocompatible, biodegradable, non-toxic, and non-immunogenic; moreover, HA receptors are overexpressed on many tumor cells. Exploiting this ligand-receptor interaction, the use of HA is now a rapidly-growing platform for targeting CD44-overexpressing cells, to improve anticancer therapies. The rationale underlying approaches, chemical strategies, and recent advances in the use of HA to design drug carriers for delivering anticancer agents, are reviewed. Comprehensive descriptions are given of HA-based drug conjugates, particulate carriers (micelles, liposomes, nanoparticles, microparticles), inorganic nanostructures, and hydrogels, with particular emphasis on reports of preclinical/clinical results.

  17. Radiolysis of Sulfuric Acid, Sulfuric Acid Monohydrate, and Sulfuric Acid Tetrahydrate and Its Relevance to Europa

    Science.gov (United States)

    Loeffler, M. J.; Hudson, R. L.; Moore, M. H.; Carlson, R. W.

    2011-01-01

    We report laboratory studies on the 0.8 MeV proton irradiation of ices composed of sulfuric acid (H2SO4), sulfuric acid monohydrate (H2SO4 H2O), and sulfuric acid tetrahydrate (H2SO4 4H2O) between 10 and 180 K. Using infrared spectroscopy, we identify the main radiation products as H2O, SO2, (S2O3)x, H3O+, HSO4(exp -), and SO4(exp 2-). At high radiation doses, we find that H2SO4 molecules are destroyed completely and that H2SO4 H2O is formed on subsequent warming. This hydrate is significantly more stable to radiolytic destruction than pure H2SO4, falling to an equilibrium relative abundance of 50% of its original value on prolonged irradiation. Unlike either pure H2SO4 or H2SO4 H2O, the loss of H2SO4 4H2O exhibits a strong temperature dependence, as the tetrahydrate is essentially unchanged at the highest irradiation temperatures and completely destroyed at the lowest ones, which we speculate is due to a combination of radiolytic destruction and amorphization. Furthermore, at the lower temperatures it is clear that irradiation causes the tetrahydrate spectrum to transition to one that closely resembles the monohydrate spectrum. Extrapolating our results to Europa s surface, we speculate that the variations in SO2 concentrations observed in the chaotic terrains are a result of radiation processing of lower hydration states of sulfuric acid and that the monohydrate will remain stable on the surface over geological times, while the tetrahydrate will remain stable in the warmer regions but be destroyed in the colder regions, unless it can be reformed by other processes, such as thermal reactions induced by diurnal cycling.

  18. The influence of dicarboxylic acids: Oxalic acid and tartaric acid on the compressive strength of glass ionomer cements

    Science.gov (United States)

    Permana, Ahmadi Jaya; Setyawati, Harsasi; Hamami, Murwani, Irmina Kris

    2016-03-01

    Glass ionomer cement (GIC) has limitation on the mechanical properties especially compressive strength. The change of compressive strength of GIC by adding oxalic acid and tartaric acid has been investigated. Oxalic acid and tartaric acid was added to the liquid components at concentrations of 0 - 15% (w/w). Powder component of GIC was made from optimum experimental powder glass SiO2-Al2O3-CaF2. GIC was characterized by compressive strength test, SEM-EDX and FTIR. The addition of tartaric acid to GIC has greater improvement than addition of oxalic acid. The addition of tartaric acid at 10 % (w/w) to GIC has greatest value of compressive strength.

  19. Nucleic acid-binding glycoproteins which solubilize nucleic acids in dilute acid: re-examination of the Ustilago maydis glycoproteins

    Energy Technology Data Exchange (ETDEWEB)

    Unrau, P.; Champ, D.R.; Young, J.L.; Grant, C.E.

    1980-01-01

    Holloman reported the isolation from Ustilago maydis of a glycoprotein which prevented the precipitation of nucleic acids in cold 5% trichloroacetic acid. Two glycoprotein fractions from U. maydis with this nucleic acid-solubilizing activity were isolated in our laboratory using improved purification procedures. The activity was not due to nuclease contamination. The glycoproteins are distinguished by: their ability to bind to concanavalin A-Sepharose; their differential binding to double- and single-stranded deoxyribonucleic acid, and to ribonucleic acid; their molecular weights (46,000 and 69,000); and the relative amounts present in growing versus nongrowing cells. Both fractions required sulfhydryl-reducing conditions for optimal yields, specific activity, and stability. Nucleic acid binding was cooperative, the minimum number of glycoproteins required to make a native T7 DNA molecule soluble in dilute acid being estimated at 2 and 15, respectively.

  20. Evaporation of methyl- and dimethyl-substituted malonic, succinic, glutaric and adipic acid particles at ambient temperatures

    DEFF Research Database (Denmark)

    Mønster, Jacob Garbrecht; Rosenørn, Thomas; Svenningsson, Birgitta

    2004-01-01

    Evaporation; organic aerosols; vapor pressure; dicarboxylic acid; maonic acid; succinic acid; glutaric acid; adipic acid......Evaporation; organic aerosols; vapor pressure; dicarboxylic acid; maonic acid; succinic acid; glutaric acid; adipic acid...

  1. Relationship between acid pocket and acid reflux in gastroesophageal reflux disease

    Institute of Scientific and Technical Information of China (English)

    姚东英

    2014-01-01

    Objective To explore the relationship between acid pocket and acid reflux in gastroesophageal reflux disease(GERD).Methods From March 2011 to January 2012,29 patients with GERD were enrolled and nine healthy individuals were set as control.All objects of this study accepted esophageal manometry test,acid pocket test,test of the occurrence time of acid pocket and ambulatory

  2. Effects of alkali or acid treatment on the isomerization of amino acids.

    Science.gov (United States)

    Ohmori, Taketo; Mutaguchi, Yuta; Doi, Katsumi; Ohshima, Toshihisa

    2012-10-01

    The effect of alkali treatment on the isomerization of amino acids was investigated. The 100×D/(D+L) values of amino acids from peptide increased with increase in the number of constituent amino acid residues. Furthermore, the N-terminal amino acid of a dipeptide was isomerized to a greater extent than the C-terminal residue.

  3. Kinetic resolution of racemic carboxylic acids through asymmetric protolactonization promoted by chiral phosphonous acid diester.

    Science.gov (United States)

    Sakuma, Masayuki; Sakakura, Akira; Ishihara, Kazuaki

    2013-06-07

    Chiral phosphonium salts induce the kinetic resolution of racemic α-substituted unsaturated carboxylic acids through asymmetric protolactonization. Both the lactones and the recovered carboxylic acids are obtained with high enantioselectivities and high S (= kfast/kslow) values. Asymmetric protolactonization also leads to the desymmetrization of achiral carboxylic acids. Notably, chiral phosphonous acid diester not only induced the enantioselectivity but also promoted protolactonization.

  4. The corrosion protection of several aluminum alloys by chromic acid and sulfuric acid anodizing

    Science.gov (United States)

    Danford, M. D.

    1994-01-01

    The corrosion protection afforded 7075-T6, 7075-T3, 6061-T6, and 2024-T3 aluminum alloys by chromic acid and sulfuric acid anodizing was examined using electrochemical techniques. From these studies, it is concluded that sulfuric acid anodizing provides superior corrosion protection compared to chromic acid anodizing.

  5. Identification of organic acids in wine that stimulate mechanisms of gastric acid secretion.

    Science.gov (United States)

    Liszt, Kathrin Ingrid; Walker, Jessica; Somoza, Veronika

    2012-07-18

    Wine may cause stomach irritation due to its stimulatory effect on gastric acid secretion, although the mechanisms by which wine or components thereof activate pathways of gastric acid secretion are poorly understood. Gastric pH was measured with a noninvasive intragastric probe, demonstrating that administration of 125 mL of white or red wine to healthy volunteers stimulated gastric acid secretion more potently than the administration of equivalent amounts of ethanol. Between both beverages, red wine showed a clear trend for being more active in stimulating gastric acid secretion than white wine (p = 0.054). Quantification of the intracellular proton concentration in human gastric tumor cells (HGT-1), a well-established indicator of proton secretion and, in turn, stomach acid formation in vivo, confirmed the stronger effect of red wine as compared to white wine. RT-qPCR experiments on cells exposed to red wine also revealed a more pronounced effect than white wine on the fold change expression of genes associated with gastric acid secretion. Of the quantitatively abundant organic acids in wine, malic acid and succinic acid most actively stimulated proton secretion in vitro. However, addition of ethanol to individual organic acids attenuated the secretory effect of tartaric acid, but not that of the other organic acids. It was concluded that malic acid for white wine and succinic acid for red wine are key organic acids that contribute to gastric acid stimulation.

  6. Simple synthesis of radiolabelled bromoacetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Abrams, D.N.; Gaudreault, R.C.; Noujaim, A.A.

    Bromoacetic acid has been used as a chemical precursor in the synthesis of a large number of biologically active compounds including uracil (1) and malonic acid. We required /sup 3/H and /sup 14/C labelled bromoacetic acid as an intermediate in the preparation of new bifunctional chelating agents for dual label studies with proteins and monoclonal antibodies. The sulfur catalyzed bromination of acetic acid proved to be a facile synthesis of radiolabelled bromoacetic acid directly from /sup 3/H and /sup 14/C sodium acetate.

  7. Lactic acid oligomers (OLAs) as prodrug moieties.

    Science.gov (United States)

    Kruse, J; Lachmann, B; Lauer, R; Eppacher, S; Noe, C R

    2013-02-01

    In this paper we propose the use of lactic acid oligomers (OLAs) as prodrug moieties. Two synthetic approaches are presented, on the one hand a non selective oligomerisation of lactic acid and on the other hand a block synthesis to tetramers of lactic acid. Dimers of lactic acid were investigated with respect to their plasma stability and their adsorption to albumine. Ibuprofen was chosen as the first drug for OLAylation. The ester 19 of LA(1)-ibuprofen was evaluated with respect to the degradation to human plasma and the adsorption to albumine. All results indicate that lactic acid oligomers are promising prodrug moieties.

  8. Bile acids in regulation of intestinal physiology.

    LENUS (Irish Health Repository)

    Keating, Niamh

    2009-10-01

    In addition to their roles in facilitating lipid digestion and absorption, bile acids are recognized as important regulators of intestinal function. Exposure to bile acids can dramatically influence intestinal transport and barrier properties; in recent years, they have also become appreciated as important factors in regulating cell growth and survival. Indeed, few cells reside within the intestinal mucosa that are not altered to some degree by exposure to bile acids. The past decade saw great advances in the knowledge of how bile acids exert their actions at the cellular and molecular levels. In this review, we summarize the current understanding of the role of bile acids in regulation of intestinal physiology.

  9. Measurements of organic acids over central Germany

    Science.gov (United States)

    Hartmann, W. R.; Andreae, M. O.; Helas, G.

    During three flights over central western Germany, air samples were taken for determination of organic acids. In air masses rapidly adverting from the west, between 0.15 and 3 km altitude mixing ratios of 0.17±0.06 ppbv formic acid and 0.72±0.08 ppbv acetic acid were found. In a local high pressure system mixing ratios increased up to 2.76 ppbv for formic acid and 2.20 ppbv for acetic acid.

  10. The Specifications for Monitoring of Acid Rain

    Institute of Scientific and Technical Information of China (English)

    Tang Jie

    2011-01-01

    Background Since China is a country seriously affected by acid rain pollution,it is a long-term fundamental work for acid rain pollution prevention and control in China by getting well informed of the characteristics of spatial and temporal changes in acid rain and long-term trends of these changes.In order to reach the national demand for acid rain monitoring data,the China Meteorological Administration (CMA) began to construct the network of acid rain monitoring stations in 1992.By the end of 2010,the total number of monitoring stations has exceeded 340.

  11. Solvent extraction of metals with hydroxamic acids.

    Science.gov (United States)

    Vernon, F; Khorassani, J H

    1978-07-01

    Solvent extraction with hydroxamic acids has been investigated. with comparison of aliphatic and aromatic reagents for the extraction of iron, copper, cobalt and nickel. Caprylohydroxamic acid has been evaluated for use in extraction systems for titanium, vanadium, chromium, molybdenum and uranium, both in terms of acidity of aqueous phase and oxidation state of the metal. It has been established that caprylohydroxamic acid in 1-hexanol is a suitable extractant for the removal of titanium(IV), vanadium(V), chromium(VI), molybdenum(VI) and uranium(VI) from 6M hydrochloric acid.

  12. Intestinal transport of sulfanilic acid in rats immunized with protein-sulfanilic acid conjugate.

    Science.gov (United States)

    Yamamoto, A; Kawaratani, T; Kawashima, K; Hashida, M; Sezaki, H

    1990-07-01

    Intestinal transport of sulfanilic acid was examined by means of an in vitro everted sac technique in rats immunized with a bovine gamma-globulin-sulfanilic acid conjugate. At a low concentration of sulfanilic acid, the intestinal transport of sulfanilic acid was decreased in rats immunized with bovine gamma-globulin-sulfanilic acid conjugate. This phenomenon was dose dependent and antigen specific, since there was no difference in the transport of sulfanilic acid at a high concentration and of an unrelated hapten. These results suggested that parenteral immunization impaired not only the intestinal transport of macromolecular antigens, as previously shown, but also the transport of the low molecular weight hapten, sulfanilic acid.

  13. Current topics in the biotechnological production of essential amino acids, functional amino acids, and dipeptides.

    Science.gov (United States)

    Mitsuhashi, Satoshi

    2014-04-01

    Amino acids play important roles in both human and animal nutrition and in the maintenance of health. Here, amino acids are classified into three groups: first, essential amino acids, which are essential to nutrition; second, functional amino acids, recently found to be important in the promotion of physiological functions; and third, dipeptides, which are used to resolve problematic features of specific free amino acids, such as their instability or insolubility. This review focusses on recent researches concerning the microbial production of essential amino acids (lysine and methionine), functional amino acids (histidine and ornithine), and a dipeptide (L-alanyl-L-glutamine).

  14. Study of Synthesis of Copoly (lactic acid/glycolic acid) by Direct Melt Polycondensation

    Institute of Scientific and Technical Information of China (English)

    LAN Ping; GAO Qin-wei; SHAO Hui-li; HU Xue-chao

    2005-01-01

    A two steps direct copolymerisation process was developed. The first step is to produce oligomer and then the oligomer of lactic acid/glycolic acid (90/10) is polymerized with binary catalyst tin chloride dihydrate/ptoluenesulfonic acid. In this way, the direct synthesis of copoly (lactic acid/glycolic acid) without any organic solvent was investigated. The properties and structures of products were characterized by nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), X-ray diffraction and so on. The results show that comparatively high molecular weight copolymer of lactic acid and glycolic acid can be prepared by direct processing under appropriate technological conditions.

  15. Molecular pharmacology of 4-substituted glutamic acid analogues at ionotropic and metabotropic excitatory amino acid receptors

    DEFF Research Database (Denmark)

    Bräuner-Osborne, Hans; Nielsen, B; Stensbøl, T B;

    1997-01-01

    using rat brain ionotropic glutamate receptors, and in functional assays using cloned metabotropic glutamate (mGlu) receptors. As a notable result of these studies, (2S,4R)-4-methylglutamic acid and (2S,4S)-4-methylglutamic acid were shown to be selective for kainic acid receptors and mGlu receptors......The pharmacology of (2S,4R)-4-methylglutamic acid, (2S,4S)-4-methylglutamic acid and (S)- and (R)-4-methyleneglutamic acids (obtained in high chemical and enantiomeric purity from racemic 4-methyleneglutamic acid by chiral HPLC using a Crownpak CR(+) column), was examined in binding experiments...... (subtypes 1alpha and 2), respectively, whereas (S)-4-methyleneglutamic acid showed high but rather non-selective affinity for the (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA), kainic acid, NMDA and mGlu receptors (subtypes 1alpha and 2). Although none of the compounds were specific...

  16. Effect of acetylsalicylic acid on fatty acid omega-hydroxylation in rat liver.

    Science.gov (United States)

    Okita, R

    1986-12-01

    The effect of acetylsalicylic acid on the cytochrome P-450-mediated fatty acid omega-hydroxylation system was assessed in male Sprague-Dawley rats after they were fed a diet containing 1% (w/w) acetylsalicylic acid. A 3-fold increase in the specific activity of laurate omega-hydroxylation was observed in the acetylsalicylic acid fed rats in comparison to control rats. This effect of acetylsalicylic acid was unique as the specific activities of other cytochrome P-450-mediated reactions were not increased. The induction of the laurate omega-hydroxylation system was also manifested in a rapid formation of its dicarboxylic acid derivative, dodecanedioic acid, as the omega-hydroxy derivative was further oxidized by alcohol and aldehyde dehydrogenases. These results suggest the acetylsalicylic acid is similar to other peroxisomal proliferating agents in that it also induces the microsomal fatty acid omega-hydroxylation system and may account for the appearance of unique dicarboxylic acids in Reye's syndrome patients.

  17. Discriminative power of an assay for automated in vitro screening of teratogens

    DEFF Research Database (Denmark)

    Walmod, Peter S; Gravemann, Ute; Nau, Heinz

    2004-01-01

    -trans-retinoic acid, pentyl-4-yn-valproic acid, saccharin, salicylic acid and valproic acid. All compounds, with the exception of dimethadione inhibited proliferation in a linear dose-dependent manner, and there were statistically significant compound class-dependent differences between the IC(50)-values...... to teratogenicity were: 5-bromo-2(')-deoxyuridine, 6-aminonicotinamide, acrylamide, boric acid, D-(+)-camphor, dimethadione, dimethyl phthalate, diphenhydramine, hydroxyurea, isobutyl-ethyl-valproic acid, lithium chloride, methyl mercury chloride, methotrexate, methoxyacetic acid, penicillin G, all...

  18. Amino acid properties conserved in molecular evolution.

    Directory of Open Access Journals (Sweden)

    Witold R Rudnicki

    Full Text Available That amino acid properties are responsible for the way protein molecules evolve is natural and is also reasonably well supported both by the structure of the genetic code and, to a large extent, by the experimental measures of the amino acid similarity. Nevertheless, there remains a significant gap between observed similarity matrices and their reconstructions from amino acid properties. Therefore, we introduce a simple theoretical model of amino acid similarity matrices, which allows splitting the matrix into two parts - one that depends only on mutabilities of amino acids and another that depends on pairwise similarities between them. Then the new synthetic amino acid properties are derived from the pairwise similarities and used to reconstruct similarity matrices covering a wide range of information entropies. Our model allows us to explain up to 94% of the variability in the BLOSUM family of the amino acids similarity matrices in terms of amino acid properties. The new properties derived from amino acid similarity matrices correlate highly with properties known to be important for molecular evolution such as hydrophobicity, size, shape and charge of amino acids. This result closes the gap in our understanding of the influence of amino acids on evolution at the molecular level. The methods were applied to the single family of similarity matrices used often in general sequence homology searches, but it is general and can be used also for more specific matrices. The new synthetic properties can be used in analyzes of protein sequences in various biological applications.

  19. Gluconic acid production by Penicillium puberulum.

    Science.gov (United States)

    Elnaghy, M A; Megalla, S E

    1975-01-01

    Twenty-five Penicillium species isolated from Egyptian soil were examined for their ability to produce gluconic acid in surface culture. Of the eight species capable of producing gluconic acid, Penicillium puberulum gave the maximum yield (91% gluconic acid from glucose after 7 days of fermentation with 3% CaCO3). Peptone was the best nitrogen source for acid fermentation and glucose was superior to sucrose. Addition of low concentrations of KH2PO4 and MgSO4 - 7 H2O stimulated acid production. An initial pH of 6.1 was most favourable for acid accumulation and addition of CaCO3 was necessary for maximum acid production.

  20. Structure Property Relationships of Carboxylic Acid Isosteres.

    Science.gov (United States)

    Lassalas, Pierrik; Gay, Bryant; Lasfargeas, Caroline; James, Michael J; Tran, Van; Vijayendran, Krishna G; Brunden, Kurt R; Kozlowski, Marisa C; Thomas, Craig J; Smith, Amos B; Huryn, Donna M; Ballatore, Carlo

    2016-04-14

    The replacement of a carboxylic acid with a surrogate structure, or (bio)-isostere, is a classical strategy in medicinal chemistry. The general underlying principle is that by maintaining the features of the carboxylic acid critical for biological activity, but appropriately modifying the physicochemical properties, improved analogs may result. In this context, a systematic assessment of the physicochemical properties of carboxylic acid isosteres would be desirable to enable more informed decisions of potential replacements to be used for analog design. Herein we report the structure-property relationships (SPR) of 35 phenylpropionic acid derivatives, in which the carboxylic acid moiety is replaced with a series of known isosteres. The data set generated provides an assessment of the relative impact on the physicochemical properties that these replacements may have compared to the carboxylic acid analog. As such, this study presents a framework for how to rationally apply isosteric replacements of the carboxylic acid functional group.