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Sample records for acidic conditions resulting

  1. Preliminary Results: Release Of Metals From Acid-Mine Drainage Contaminated Streambed Sediments Under Anaerobic Conditions

    EPA Science Inventory

    Many miles of streams in the western U.S. are contaminated with acid-mine drainage (AMD) from abandoned metal mines. Treatment of these streams may include removal of the existing sediments, with subsequent burial (e.g., in a repository). Burial of previously aerobic sediments ma...

  2. K Basin Sludge Conditioning Process Testing Project Results from Test 4, ''Acid Digestion of Mixed-Bed Ion Exchange Resin''

    SciTech Connect

    Pool, K.H.; Delegard, C.H.; Schmidt, A.J.; Thornton, B.M.; Silvers, K.L.

    1999-04-02

    Approximately 73 m{sup 3} of heterogeneous solid material, ''sludge,'' (upper bound estimate, Packer 1997) have accumulated at the bottom of the K Basins in the 100 K Area of the Hanford Site. This sludge is a mixture of spent fuel element corrosion products, ion exchange materials (organic and inorganic), graphite-based gasket materials, iron and aluminum metal corrosion products, sand, and debris (Makenas et al. 1996, 1997). In addition, small amounts of polychlorinated biphenyls (PCBs) have been found. Ultimately, it is planned to transfer the K Basins sludge to the Hanford double shell tanks (DSTs). The Hanford Spent Nuclear Fuel (HSNF) project has conducted a number of evaluations to examine technology and processing alternatives to pretreat K Basin sludge to meet storage and disposal requirements. From these evaluations, chemical pretreatment has been selected to address criticality issues, reactivity, and the destruction or removal of PCBs before the K Basin sludge can be transferred to the DSTs. Chemical pretreatment, referred to as the K Basin sludge conditioning process, includes nitric acid dissolution of the sludge (with removal of acid insoluble solids), neutrons absorber addition, neutralization, and reprecipitation. Laboratory testing is being conducted by the Pacific Northwest National Laboratory (PNNL) to provide data necessary to develop the sludge conditioning process.

  3. Decreased bile-acid synthesis in livers of hepatocyte-conditional NADPH-cytochrome P450 reductase-null mice results in increased bile acids in serum.

    PubMed

    Cheng, Xingguo; Zhang, Youcai; Klaassen, Curtis D

    2014-10-01

    NADPH-cytochrome P450 reductase (Cpr) is essential for the function of microsomal cytochrome P450 monooxygenases (P450), including those P450s involved in bile acid (BA) synthesis. Mice with hepatocyte-specific deletion of NADPH-cytochrome P450 reductase (H-Cpr-null) have been engineered to understand the in vivo function of hepatic P450s in the metabolism of xenobiotics and endogenous compounds. However, the impact of hepatic Cpr on BA homeostasis is not clear. The present study revealed that H-Cpr-null mice had a 60% decrease in total BA concentration in liver, whereas the total BA concentration in serum was almost doubled. The decreased level of cholic acid (CA) in both serum and livers of H-Cpr-null mice is likely due to diminished enzyme activity of Cyp8b1 that is essential for CA biosynthesis. Feedback mechanisms responsible for the reduced liver BA concentrations and/or increased serum BA concentrations in H-Cpr-null mice included the following: 1) enhanced alternative BA synthesis pathway, as evidenced by the fact that classic BA synthesis is diminished but chenodeoxycholic acid still increases in both serum and livers of H-Cpr-null mice; 2) inhibition of farnesoid X receptor activation, which increased the mRNA of Cyp7a1 and 8b1; 3) induction of intestinal BA transporters to facilitate BA absorption from the intestine to the circulation; 4) induction of hepatic multidrug resistance-associated protein transporters to increase BA efflux from the liver to blood; and 5) increased generation of secondary BAs. In summary, the present study reveals an important contribution of the alternative BA synthesis pathway and BA transporters in regulating BA concentrations in H-Cpr-null mice. PMID:25034404

  4. Dissolution of Columbia River Basalt Under Mildly Acidic Conditions as a Function of Temperature: Experimental Results Relevant to the Geological Sequestration of Carbon Dioxide

    SciTech Connect

    Schaef, Herbert T.; McGrail, B. Peter

    2009-05-01

    Increasing attention is being focused on the rapid rise of carbon dioxide levels in the atmosphere, which many believe to be the major contributing factor to global climate change. Sequestering CO2 in deep geological formations has been proposed as a long-term solution to help stabilize CO2 levels. However, before such technology can be developed and implemented, a basic understanding of H2O-CO2 systems and the chemical interactions of these fluids with the host formation must be obtained. Important issues concerning mineral stability, reaction rates, and carbonate formation are all controlled or at least significantly impacted by the kinetics of rock-water reactions in mildly acidic, CO2-saturated solutions. Basalt has recently been identified as a potentially important host formation for geological sequestration. Dissolution kinetics of the Columbia River Basalt (CRB) were measured for a range of temperatures (25° to 90°C) under mildly acidic to neutral pH conditions using the single-pass flow-through test method. Under anaerobic conditions, the normalized dissolution rates for CRB decrease with increasing pH (3≤pH≤7) with a slope, η, of -0.12 ± 0.02. An activation energy, Ea, has been estimated at 30.3 ± 2.4 kJ mol-1. Dissolution kinetics measurements like these are essential for modeling the rate at which the CO2 reacts with basalt and ultimately converted to carbonate minerals in situ.

  5. Mechanisms of lactone hydrolysis in acidic conditions.

    PubMed

    Gómez-Bombarelli, Rafael; Calle, Emilio; Casado, Julio

    2013-07-19

    The acid-catalyzed hydrolysis of linear esters and lactones was studied using a hybrid supermolecule-polarizable continuum model (PCM) approach including up to six water molecules. The compounds studied included two linear esters, four β-lactones, two γ-lactones, and one δ-lactone: ethyl acetate, methyl formate, β-propiolactone, β-butyrolactone, β-isovalerolactone, diketene (4-methyleneoxetan-2-one), γ-butyrolactone, 2(5H)-furanone, and δ-valerolactone. The theoretical results are in good quantitative agreement with the experimental measurements reported in the literature and also in excellent qualitative agreement with long-held views regarding the nature of the hydrolysis mechanisms at molecular level. The present results help to understand the balance between the unimolecular (A(AC)1) and bimolecular (A(AC)2) reaction pathways. In contrast to the experimental setting, where one of the two branches is often occluded by the requirement of rather extreme experimental conditions, we have been able to estimate both contributions for all the compounds studied and found that a transition from A(AC)2 to A(AC)1 hydrolysis takes place as acidity increases. A parallel work addresses the neutral and base-catalyzed hydrolysis of lactones. PMID:23731203

  6. NAPAP (National Acid Precipitation Assessment Program) results on acid rain

    SciTech Connect

    Not Available

    1990-06-01

    The National Acid Precipitation Assessment Program (NAPAP) was mandated by Congress in 1980 to study the effects of acid rain. The results of 10 years of research on the effect of acid deposition and ozone on forests, particularly high elevation spruce and fir, southern pines, eastern hardwoods and western conifers, will be published this year.

  7. Selective oxidation of glycerol under acidic conditions using gold catalysts

    SciTech Connect

    Villa, Alberto; Veith, Gabriel M; Prati, Laura

    2010-01-01

    H-mordenite-supported PtAu nanoparticles are highly active and selective in the oxidation of glycerol under acidic conditions, which allows the direct preparation of free acids (see picture). The high selectivity for C{sub 3} compounds results from the negligible formation of H{sub 2}O{sub 2}, in contrast to PtAu nanoparticles supported on activated carbon.

  8. Amygdala priming results in conditioned place avoidance.

    PubMed

    Thielen, Shelley K; Shekhar, Anantha

    2002-03-01

    Priming involves daily stimulation of the basolateral nucleus of the amygdala (BLA) for 5 days using a dose of the GABA(A) receptor antagonist, bicuculline methiodide (BMI), that is subthreshold to generate anxiogenic-like responses. The coordinated physiological and behavioral response of the primed rat is similar to the symptoms of human panic disorder and has been used as a model to study panic attacks. If the priming procedure is indeed similar to human panic disorder, then the context in which priming occurs should become associated with aversive conditioning and avoidance as seen in secondary agoraphobia following panic attacks in humans. Therefore, the purpose of this study was to further characterize the behavioral response of priming using the conditioned place avoidance (CPA) task that utilizes distinct tactile cues of a grid floor (Grid+) or hole floor (Grid-). Male Wistar rats (275-300 g) were implanted bilaterally with guide cannulae positioned 1 mm above the BLA. Grid+ animals were placed in the conditioning chamber containing grid floors immediately after a 6-pmol (in 250 nl) BMI injection into the BLA and on hole floors following a sham (250 nl vehicle) injection. Grid animals were placed in the chamber containing hole floors after the BMI injection and on grid floors following the sham injection. Animals were placed in the chamber for 20 min following each injection and injections were separated by 4 h. After 5 days of this treatment, the animals were primed. Two days later, during avoidance testing, each animal was placed in the chamber containing both floors for 30 min. Priming with daily 6-pmol BMI injections into the BLA results in CPA or an aversion to the floor paired with the BMI injection. These results suggest that priming may result in phobic-like responses, similar to the avoidance behavior exhibited by panic disorder patients. PMID:11830174

  9. How does Listeria monocytogenes combat acid conditions?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Listeria monocytogenes, a major foodborne pathogen, possesses a number of mechanisms which enable it to combat the challenges posed by acidic environments such as acidic foods and the acidity in the gastrointestinal tract. These mechanisms include the acid tolerance response, a two-component regula...

  10. Multiphase Chemistry of Pyruvic Acid Under Atmospherically Relevant Conditions

    NASA Astrophysics Data System (ADS)

    Vaida, V.; Monod, A.; Doussin, J. F.; Reed Harris, A. E.; Griffith, E. C.; Kroll, J. A.; Rapf, R.

    2014-12-01

    Chemistry in the natural environment proceeds in multiple phases and is subject to effects from atmospheric constituents and conditions. This presentation will use pyruvic acid as a case study to demonstrate the complexity of atmospheric multiphase chemistry. The photophysics and photochemistry of pyruvic acid proceeds on different potential energy surfaces with different reaction mechanisms, rates, and products in gas versus the aqueous phase. While the gas phase reaction generally decreases the complexity of products, the aqueous chemistry creates higher molecular weight, surface-active compounds. The studies presented involve a combination of laboratory studies that focus on the photochemistry of pyruvic acid in both the gas and aqueous phases. Further, experiments in an environmental simulation chamber (CESAM) that follow the photochemistry chemistry of pyruvic acid under atmospherically relevant conditions will be presented to highlight the effect of pressure, oxygen, relative humidity, and phase on the photochemistry of pyruvic acid. The results provide new input for atmospheric chemistry models that is required to better describe the behavior of α-keto acids in the environment.

  11. Accelerated aging of outdoor insulation under acid rain conditions

    NASA Astrophysics Data System (ADS)

    Frost, Nancy Ellen

    2000-11-01

    Outdoor insulation has evolved from glass to ceramics to epoxy in the past decades, and more recently into the area of polymer composites. Accelerated aging must be performed to examine the effectiveness of materials prior to use under actual service conditions. Traditionally this aging has been performed with sodium chloride as the conductive component in the high humidity and wet tests. This approach does not necessarily represent actual service conditions, as globally the precipitation is acidic in nature and contains many constituents in addition to sodium and chloride. The main focus of this work was to examine the effect of acid precipitation on materials used in outdoor insulation applications. This was achieved through the use of a rotating tracking wheel and a controlled high humidity chamber with the application of a synthetic acid rain solution. The analysis techniques utilized to examine the results of the accelerated aging were leakage current monitoring, evaluation of changes in dielectric properties as well as electron microscopy. In addition, changes in hydrophobicity were quantified. Based on experimental observations, a first order life prediction model was developed to investigate the usefulness of the acid rain aging technique. This model was founded on the results of a series of tests conducted with varying solution conductivity, while maintaining constant acid content. This model permits the prediction of the life of a material at normal precipitation conductivity levels.

  12. Synthesis and chirality of amino acids under interstellar conditions.

    PubMed

    Giri, Chaitanya; Goesmann, Fred; Meinert, Cornelia; Evans, Amanda C; Meierhenrich, Uwe J

    2013-01-01

    Amino acids are the fundamental building blocks of proteins, the biomolecules that provide cellular structure and function in all living organisms. A majority of amino acids utilized within living systems possess pre-specified orientation geometry (chirality); however the original source for this specific orientation remains uncertain. In order to trace the chemical evolution of life, an appreciation of the synthetic and evolutional origins of the first chiral amino acids must first be gained. Given that the amino acids in our universe are likely to have been synthesized in molecular clouds in interstellar space, it is necessary to understand where and how the first synthesis might have occurred. The asymmetry of the original amino acid synthesis was probably the result of exposure to chiral photons in the form of circularly polarized light (CPL), which has been detected in interstellar molecular clouds. This chirality transfer event, from photons to amino acids, has been successfully recreated experimentally and is likely a combination of both asymmetric synthesis and enantioselective photolysis. A series of innovative studies have reported successful simulation of these environments and afforded production of chiral amino acids under realistic circumstellar and interstellar conditions: irradiation of interstellar ice analogues (CO, CO2, NH3, CH3OH, and H2O) with circularly polarized ultraviolet photons at low temperatures does result in enantiomer enriched amino acid structures (up to 1.3% ee). This topical review summarizes current knowledge and recent discoveries about the simulated interstellar environments within which amino acids were probably formed. A synopsis of the COSAC experiment onboard the ESA cometary mission ROSETTA concludes this review: the ROSETTA mission will soft-land on the nucleus of the comet 67P/Churyumov-Gerasimenko in November 2014, anticipating the first in situ detection of asymmetric organic molecules in cometary ices. PMID:22976459

  13. Ion-exchange properties of strontium hydroxyapatite under acidic conditions

    SciTech Connect

    Sugiyama, Shigeru; Nishioka, Hitoshi; Moriga, Toshihiro; Hayashi, Hiromu; Moffat, J.B.

    1998-09-01

    The ion exchange of strontium hydroxyapatite (SrHAp) with Pb{sup 2+} has been investigated under acidic conditions at 293 K. The addition of various acids to the exchanging solution enhanced the exchange capacity in the order HCl > HBr > HF > HNO{sub 3} > no acid, corresponding to the formation of halogen apatites with the former three acids or hydrogen phosphate with HNO{sub 3}. Since the ion-exchange capacity of SrHAp under nonacidic conditions is higher than that of chlorapatite, the aforementioned observations can be attributed to the participation of the protons introduced by the acids.z

  14. Batch salicylic acid nitration by nitric acid/acetic acid mixture under isothermal, isoperibolic and adiabatic conditions.

    PubMed

    Andreozzi, R; Canterino, M; Caprio, V; Di Somma, I; Sanchirico, R

    2006-12-01

    Runaway phenomena and thermal explosions can originate during the nitration of salicylic acid by means of a nitric acid/acetic acid mixture when the thermal control is lost, mainly as a result of the formation and thermal decomposition of picric acid. The prediction of the behaviour of this system is thus of great importance in view of possible industrial applications and the need to avoid the occurrence of unwanted dangerous events. During a previous investigation a model was developed to simulate its behaviour when the starting concentration of the substrate is too low, thus, preventing the precipitation of poor soluble intermediates. In this work this model is extended to deal with more concentrated systems even in case of a solid phase separating during the process. To this purpose the previously assessed dependence of the solubility of 3-nitro and 5-nitrosalicylic acids upon temperature and nitric acid concentration is included in the model. It is assumed that when 3-nitro and 5-nitrosalicylic acids are partially suspended in the reacting medium a kinetic regime of "dissolution with reaction" is established; that is, the redissolution of these species is a fast process compared to the successive nitration to give dinitroderivatives. Good results are obtained in the comparison of the experimental data with those calculated both in isoperibolic and adiabatic conditions when the revised model is used. PMID:16842908

  15. RESULTS FROM THE MOUNTAIN ACID DEPOSITION PROGRAM

    EPA Science Inventory

    The Mountain Acid Deposition Program (MADPro) was initiated in 1993 as part of the research necessary to support the objectives of the Clean Air Status and Trends Network (CASTNet), which was created to address the. requirements of the Clean Air Act Amendments (CAAA). The main ob...

  16. Adaptive acid tolerance response of Vibrio parahaemolyticus as affected by acid adaptation conditions, growth phase, and bacterial strains.

    PubMed

    Chiang, Ming-Lun; Chou, Cheng-Chun; Chen, Hsi-Chia; Tseng, Yu-Ting; Chen, Ming-Ju

    2012-08-01

    Vibrio parahaemolyticus strain 690 was isolated from gastroenteritis patients. Its thermal and ethanol stress responses have been reported in our previous studies. In this study, we further investigated the effects of various acid adaptation conditions including pH (5.0-6.0) and time (30-90 min) on the acid tolerance in different growth phases of V. parahaemolyticus 690. Additionally, the adaptive acid tolerance among different V. parahaemolyticus strains was compared. Results indicated that the acid tolerance of V. parahaemolyticus 690 was significantly increased after acid adaptation at pH 5.5 and 6.0 for 30-90 min. Among the various acid adaptation conditions examined, V. parahaemolyticus 690 acid-adapted at pH 5.5 for 90 min exhibited the highest acid tolerance. The acid adaptation also influenced the acid tolerance of V. parahaemolyticus 690 in different growth phases with late-exponential phase demonstrating the greatest acid tolerance response (ATR) than other phases. Additionally, the results also showed that the induction of adaptive ATR varied with different strains of V. parahaemolyticus. An increase in acid tolerance of V. parahaemolyticus was observed after prior acid adaptation in five strains (556, 690, BCRC 13023, BCRC 13025, and BCRC 12864), but not in strains 405 and BCRC 12863. PMID:22827515

  17. Gallic Acid Promotes Wound Healing in Normal and Hyperglucidic Conditions.

    PubMed

    Yang, Dong Joo; Moh, Sang Hyun; Son, Dong Hwee; You, Seunghoon; Kinyua, Ann W; Ko, Chang Mann; Song, Miyoung; Yeo, Jinhee; Choi, Yun-Hee; Kim, Ki Woo

    2016-01-01

    Skin is the outermost layer of the human body that is constantly exposed to environmental stressors, such as UV radiation and toxic chemicals, and is susceptible to mechanical wounding and injury. The ability of the skin to repair injuries is paramount for survival and it is disrupted in a spectrum of disorders leading to skin pathologies. Diabetic patients often suffer from chronic, impaired wound healing, which facilitate bacterial infections and necessitate amputation. Here, we studied the effects of gallic acid (GA, 3,4,5-trihydroxybenzoic acid; a plant-derived polyphenolic compound) on would healing in normal and hyperglucidic conditions, to mimic diabetes, in human keratinocytes and fibroblasts. Our study reveals that GA is a potential antioxidant that directly upregulates the expression of antioxidant genes. In addition, GA accelerated cell migration of keratinocytes and fibroblasts in both normal and hyperglucidic conditions. Further, GA treatment activated factors known to be hallmarks of wound healing, such as focal adhesion kinases (FAK), c-Jun N-terminal kinases (JNK), and extracellular signal-regulated kinases (Erk), underpinning the beneficial role of GA in wound repair. Therefore, our results demonstrate that GA might be a viable wound healing agent and a potential intervention to treat wounds resulting from metabolic complications. PMID:27399667

  18. Influences of acidic reaction and hydrolytic conditions on monosaccharide composition analysis of acidic, neutral and basic polysaccharides.

    PubMed

    Wang, Qing-Chi; Zhao, Xia; Pu, Jiang-Hua; Luan, Xiao-Hong

    2016-06-01

    Monosaccharide composition analysis is important for structural characterization of polysaccharides. To investigate the influences of acidic reaction and hydrolytic conditions on monosaccharide composition analysis of polysaccharides, we chose alginate, starch, chitosan and chondroitin sulfate as representative of acidic, neutral, basic and complex polysaccharides to compare the release degree of monosaccharides under different hydrolytic conditions. The hydrolysis stability of 10 monosaccharide standards was also explored. Results showed that the basic sugars were hard to release but stable, the acidic sugars (uronic acids) were easy to release but unstable, and the release and stability of neutral sugars were in between acidic and basic sugars. In addition, the hydrolysis process was applied to monosaccharide composition analysis of Hippocampus trimaculatus polysaccharide and the appropriate hydrolytic condition was accorded with that of the above four polysaccharides. Thus, different hydrolytic conditions should be used for the monosaccharide composition analysis of polysaccharides based on their structural characteristics. PMID:27083372

  19. Acid deposition in Maryland: Implications of the results of the National Acid Precipitation Assessment Program

    SciTech Connect

    DeMuro, J.; Bowmann, M.; Ross, J.; Blundell, C.; Price, R.

    1991-07-01

    Acid deposition, commonly referred to as 'acid rain,' is a major global environmental concern. Acid deposition has reportedly resulted in damage to aquatic, terrestrial, and physical resources and has potentially adverse effects on human health. A component of the Maryland acid deposition program is the preparation of an annual report that summarizes yearly activities and costs of ongoing acid deposition research and monitoring programs.

  20. Activated Persulfate Oxidation of Perfluorooctanoic Acid (PFOA) in Groundwater under Acidic Conditions.

    PubMed

    Yin, Penghua; Hu, Zhihao; Song, Xin; Liu, Jianguo; Lin, Na

    2016-01-01

    Perfluorooctanoic acid (PFOA) is an emerging contaminant of concern due to its toxicity for human health and ecosystems. However, successful degradation of PFOA in aqueous solutions with a cost-effective method remains a challenge, especially for groundwater. In this study, the degradation of PFOA using activated persulfate under mild conditions was investigated. The impact of different factors on persulfate activity, including pH, temperature (25 °C-50 °C), persulfate dosage and reaction time, was evaluated under different experimental conditions. Contrary to the traditional alkaline-activated persulfate oxidation, it was found that PFOA can be effectively degraded using activated persulfate under acidic conditions, with the degradation kinetics following the pseudo-first-order decay model. Higher temperature, higher persulfate dosage and increased reaction time generally result in higher PFOA degradation efficiency. Experimental results show that a PFOA degradation efficiency of 89.9% can be achieved by activated persulfate at pH of 2.0, with the reaction temperature of 50 °C, molar ratio of PFOA to persulfate as 1:100, and a reaction time of 100 h. The corresponding defluorination ratio under these conditions was 23.9%, indicating that not all PFOA decomposed via fluorine removal. The electron paramagnetic resonance spectrometer analysis results indicate that both SO₄(-)• and •OH contribute to the decomposition of PFOA. It is proposed that PFOA degradation occurs via a decarboxylation reaction triggered by SO₄(-)•, followed by a HF elimination process aided by •OH, which produces one-CF₂-unit-shortened perfluoroalkyl carboxylic acids (PFCAs, Cn-1F2n-1COOH). The decarboxylation and HF elimination processes would repeat and eventually lead to the complete mineralization all PFCAs. PMID:27322298

  1. Activated Persulfate Oxidation of Perfluorooctanoic Acid (PFOA) in Groundwater under Acidic Conditions

    PubMed Central

    Yin, Penghua; Hu, Zhihao; Song, Xin; Liu, Jianguo; Lin, Na

    2016-01-01

    Perfluorooctanoic acid (PFOA) is an emerging contaminant of concern due to its toxicity for human health and ecosystems. However, successful degradation of PFOA in aqueous solutions with a cost-effective method remains a challenge, especially for groundwater. In this study, the degradation of PFOA using activated persulfate under mild conditions was investigated. The impact of different factors on persulfate activity, including pH, temperature (25 °C–50 °C), persulfate dosage and reaction time, was evaluated under different experimental conditions. Contrary to the traditional alkaline-activated persulfate oxidation, it was found that PFOA can be effectively degraded using activated persulfate under acidic conditions, with the degradation kinetics following the pseudo-first-order decay model. Higher temperature, higher persulfate dosage and increased reaction time generally result in higher PFOA degradation efficiency. Experimental results show that a PFOA degradation efficiency of 89.9% can be achieved by activated persulfate at pH of 2.0, with the reaction temperature of 50 °C, molar ratio of PFOA to persulfate as 1:100, and a reaction time of 100 h. The corresponding defluorination ratio under these conditions was 23.9%, indicating that not all PFOA decomposed via fluorine removal. The electron paramagnetic resonance spectrometer analysis results indicate that both SO4−• and •OH contribute to the decomposition of PFOA. It is proposed that PFOA degradation occurs via a decarboxylation reaction triggered by SO4−•, followed by a HF elimination process aided by •OH, which produces one-CF2-unit-shortened perfluoroalkyl carboxylic acids (PFCAs, Cn−1F2n−1COOH). The decarboxylation and HF elimination processes would repeat and eventually lead to the complete mineralization all PFCAs. PMID:27322298

  2. Proboscis conditioning experiments with honeybees, Apis mellifera caucasica, with butyric acid and DEET mixture as conditioned and unconditioned stimuli.

    PubMed

    Abramson, Charles I; Giray, Tugrul; Mixson, T Andrew; Nolf, Sondra L; Wells, Harrington; Kence, Aykut; Kence, Meral

    2010-01-01

    Three experiments are described investigating whether olfactory repellents DEET and butyric acid can support the classical conditioning of proboscis extension in the honeybee, Apis mellifera caucasica (Hymenoptera: Apidae). In the first experiment DEET and butyric acid readily led to standard acquisition and extinction effects, which are comparable to the use of cinnamon as a conditioned stimulus. These results demonstrate that the odor of DEET or butyric acid is not intrinsically repellent to honey bees. In a second experiment, with DEET and butyric acid mixed with sucrose as an unconditioned stimulus, proboscis conditioning was not established. After several trials, few animals responded to the unconditioned stimulus. These results demonstrate that these chemicals are gustatory repellents when in direct contact. In the last experiment a conditioned suppression paradigm was used. Exposing animals to butyric acid or DEET when the proboscis was extended by direct sucrose stimulation or by learning revealed that retraction of the proboscis was similar to another novel odor, lavender, and in all cases greatest when the animal was not permitted to feed. These results again demonstrate that DEET or butyric acid are not olfactory repellents, and in addition, conditioned suppression is influenced by feeding state of the bee. PMID:20879917

  3. Formation of diphenylthioarsinic acid from diphenylarsinic acid under anaerobic sulfate-reducing soil conditions.

    PubMed

    Hisatomi, Shihoko; Guan, Ling; Nakajima, Mami; Fujii, Kunihiko; Nonaka, Masanori; Harada, Naoki

    2013-11-15

    Diphenylarsinic acid (DPAA) is a toxic phenylarsenical compound often found around sites contaminated with phenylarsenic chemical warfare agents, diphenylcyanoarsine or diphenylchloroarsine, which were buried in soil after the World Wars. This research concerns the elucidation of the chemical structure of an arsenic metabolite transformed from DPAA under anaerobic sulfate-reducing soil conditions. In LC/ICP-MS analysis, the retention time of the metabolite was identical to that of a major phenylarsenical compound synthesized by chemical reaction of DPAA and hydrogen sulfide. Moreover the mass spectra for the two compounds measured using LC/TOF-MS were similar. Subsequent high resolution mass spectral analysis indicated that two major ions at m/z 261 and 279, observed on both mass spectra, were attributable to C12H10AsS and C12H12AsSO, respectively. These findings strongly suggest that the latter ion is the molecular-related ion ([M+H](+)) of diphenylthioarsinic acid (DPTA; (C6H5)2AsS(OH)) and the former ion is its dehydrated fragment. Thus, our results reveal that DPAA can be transformed to DPTA, as a major metabolite, under sulfate-reducing soil conditions. Moreover, formation of diphenyldithioarsinic acid and subsequent dimerization were predicted by the chemical reaction analysis of DPAA with hydrogen sulfide. This is the first report to elucidate the occurrence of DPAA-thionation in an anaerobic soil. PMID:24007995

  4. Selection of acid compositions in well construction in difficult geological conditions

    NASA Astrophysics Data System (ADS)

    Mishchenko, M. V.; Kamartdinov, M. R.

    2016-03-01

    Within the scope of the current work we have presented an approach towards selecting and substantiation of acid composition in accordance with petrophysical characteristics of formations for acid treatment of bottom-hole formation zones. Article presents the results of lab tests of selected acid compositions, in conditions, which model thermobaric conditions of a payzone, combined with an evaluation of hydraulic permeability change, and this, in its turn, should allow us to evaluate the quality of impact of the acid composition recipe on the reservoir formation.

  5. Amyloid Aggregates Arise from Amino Acid Condensations under Prebiotic Conditions.

    PubMed

    Greenwald, Jason; Friedmann, Michael P; Riek, Roland

    2016-09-12

    Current theories on the origin of life reveal significant gaps in our understanding of the mechanisms that allowed simple chemical precursors to coalesce into the complex polymers that are needed to sustain life. The volcanic gas carbonyl sulfide (COS) is known to catalyze the condensation of amino acids under aqueous conditions, but the reported di-, tri-, and tetra-peptides are too short to support a regular tertiary structure. Here, we demonstrate that alanine and valine, two of the proteinogenic amino acids believed to have been among the most abundant on a prebiotic earth, can polymerize into peptides and subsequently assemble into ordered amyloid fibers comprising a cross-β-sheet quaternary structure following COS-activated continuous polymerization of as little as 1 mm amino acid. Furthermore, this spontaneous assembly is not limited to pure amino acids, since mixtures of glycine, alanine, aspartate, and valine yield similar structures. PMID:27511635

  6. Degradation rates of glycerol polyesters at acidic and basic conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polyesters prepared from glycerol with mixtures of adipic and citric acids were evaluated in the laboratory to estimate degradation rates over a range of pH conditions. These renewable polymers provide a market for glycerol that is generated during biodiesel production. The polyesters were prepared...

  7. SULFURIC ACID REMOVAL PROCESS EVALUATION: SHORT-TERM RESULTS

    SciTech Connect

    Gary M. Blythe; Richard McMillan

    2002-02-04

    the results of the short-term tests; the long-term test results will be reported in a later document. The short-term test results showed that three of the four reagents tested, dolomite powder, commercial magnesium hydroxide slurry, and byproduct magnesium hydroxide slurry, were able to achieve 90% or greater removal of sulfuric acid compared to baseline levels. The molar ratio of alkali to flue gas sulfuric acid content (under baseline conditions) required to achieve 90% sulfuric acid removal was lowest for the byproduct magnesium hydroxide slurry. However, this result may be confounded because this was the only one of the three slurries tested with injection near the top of the furnace across from the pendant superheater platens. Injection at the higher level was demonstrated to be advantageous for this reagent over injection lower in the furnace, where the other slurries were tested.

  8. SULFURIC ACID REMOVAL PROCESS EVALUATION: SHORT-TERM RESULTS

    SciTech Connect

    Gary M. Blythe; Richard McMillan

    2002-03-04

    results of the short-term tests; the long-term test results will be reported in a later document. The short-term test results showed that three of the four reagents tested, dolomite powder, commercial magnesium hydroxide slurry, and byproduct magnesium hydroxide slurry, were able to achieve 90% or greater removal of sulfuric acid compared to baseline levels. The molar ratio of alkali to flue gas sulfuric acid content (under baseline conditions) required to achieve 90% sulfuric acid removal was lowest for the byproduct magnesium hydroxide slurry. However, this result may be confounded because this was the only one of the three slurries tested with injection near the top of the furnace across from the pendant superheater platens. Injection at the higher level was demonstrated to be advantageous for this reagent over injection lower in the furnace, where the other slurries were tested.

  9. Lipid production on free fatty acids by oleaginous yeasts under non-growth conditions.

    PubMed

    Yang, Xiaobing; Jin, Guojie; Wang, Yandan; Shen, Hongwei; Zhao, Zongbao K

    2015-10-01

    Microbial lipids produced by oleaginous yeasts serve as promising alternatives to traditional oils and fats for the production of biodiesel and oleochemicals. To improve its techno-economics, it is pivotal to use wastes and produce high quality lipids of special fatty acid composition. In the present study, four oleaginous yeasts were tested to use free fatty acids for lipid production under non-growth conditions. Microbial lipids of exceptionally high fatty acid relative contents, e.g. those contained over 70% myristic acid or 80% oleic acid, were produced that may be otherwise inaccessible by growing cells on various carbon sources. It was found that Cryptococcus curvatus is a robust strain that can efficiently use oleic acid as well as even-numbered saturated fatty acids with carbon atoms ranging from 10 to 20. Our results provided new opportunity for the production of functional lipids and for the exploitation of organic wastes rich in free fatty acids. PMID:26159379

  10. Modeling of matrix acidizing process under reservoir conditions

    NASA Astrophysics Data System (ADS)

    Turegeldieva, Karlygash; Assilbekov, Bakhytzhan; Zhapbasbayev, Uzak; Zolotukhin, Anatoly; Bekibaev, Timur; Kenzhebekov, Nurlan; Gubkin Russian State University of oil; gas Collaboration

    2013-11-01

    Effectiveness of the process depends on the parameters: well choice, geological structure of the reservoir, definition of physical and chemical properties of rocks and fluids, agent choice. There are different mathematical models of the matrix acidizing, including the two scale model. These models describe the process in the core scale and Darcy scale, i.e. in an area with dimensions of several centimeters. It leads to the main problem - how to use these models to the near wellbore scale under reservoir conditions. Some authors have increased the dimensions of the cores in numerical simulations and investigated the influence of the core dimensions to acidizing process. In this paper effort to indirectly solve this problem made. It based on boundary conditions alteration and simultaneous solution of matrix acidizing in damaged zone and reservoir fluid flow models. Furthermore in this work the criterion of the acid injection shut down for optimal breakthrough volume calculation was modified. Influence of boundary conditions on near well-bore zone treatment process was investigated. Science Committee of Ministry of Education and Science of Republic of Kazakhstan.

  11. Polymerization of amino acids under primitive earth conditions.

    NASA Technical Reports Server (NTRS)

    Flores, J. J.; Ponnamperuma, C.

    1972-01-01

    Small amounts of peptides were obtained when equal amounts of methane and ammonia were reacted with vaporized aqueous solutions of C14-labeled glycine, L-alanine, L-aspartic acid, L-glutamic acid and L-threonine in the presence of a continuous spark discharge in a 24-hr cyclic process. The experiment was designed to demonstrate the possibility of peptide synthesis under simulated primeval earth conditions. It is theorized that some dehydration-condensation processes may have taken place, with ammonium cyanide, the hydrogencyanide tetramer or aminonitriles as intermediate products, during the early chemical evolution of the earth.

  12. Hydrolysis of aceto-hydroxamic acid under UREX+ conditions

    SciTech Connect

    Alyapyshev, M.; Paulenova, A.; Tkac, P.; Cleveland, M.A.; Bruso, J.E.

    2007-07-01

    Aceto-hydroxamic acid (AHA) is used as a stripping agent In the UREX process. While extraction yields of uranium remain high upon addition of AHA, hexavalent plutonium and neptunium are rapidly reduced to the pentavalent state while the tetravalent species and removed from the product stream. However, under acidic conditions, aceto-hydroxamic acid undergoes hydrolytic degradation. In this study, the kinetics of the hydrolysis of aceto-hydroxamic acid in nitric and perchloric acid media was investigated at several temperatures. The decrease of the concentration of AHA was determined via its ferric complex using UV-Vis spectroscopy. The data obtained were analyzed using the method of initial rates. The data follow the pseudo-first order reaction model. Gamma irradiation of AHA/HNO{sub 3} solutions with 33 kGy/s caused two-fold faster degradation of AHA. The rate equation and thermodynamic data will be presented for the hydrolysis reaction with respect to the concentrations of aceto-hydroxamic acid, nitrate and hydronium ions, and radiation dose. (authors)

  13. U.S. gas conditioning and processing plant survey results

    SciTech Connect

    Tannehill, C.; Echterhoff, L.; Trimble, K.

    1995-11-01

    A database of information on 1,427 natural gas conditioning and processing plants in the lower 48 states has been compiled with the assistance of over 50 operating companies and several engineering and construction firms. The database was updated in 1994 with NGL recovery plants now numbering 724. Acid gas (CO{sub 2} and H{sub 2}S) is removed by 617 plants. Sulfur is recovered at over 100 plants. Nitrogen is rejected at 12 plants, and helium is recovered at eight plants. The plants are categorized into 12 regions with the number of plants and combined inlet capacity for each region categorized as follows: Built before 1970; Built in each year between 1970 and 1994; Removing H{sub 2}S and/or CO{sub 2}; Using direct conversion H{sub 2}S removal processes (iron sponge, ARI LO-CAT{reg_sign}, SulFerox); Using chemical solvents for acid gas removal (MEA, DEA, MDEA, DGA, Benfield, Other); Using physical solvents for acid gas removal (Sulfinol, Selexol, other); Recovering sulfur (Claus, Selectox, other); Tail gas clean-up (SCOT, CBA, MCRC, other); NGL recovery (refrigeration, cryogenic expander, refrigerated lean oil, adsorption, other); Nitrogen rejection; Helium recovery; and Shutdown plants.

  14. Fatty acid patterns in Chlamydomonas sp. as a marker for nutritional regimes and temperature under extremely acidic conditions.

    PubMed

    Poerschmann, J; Spijkerman, E; Langer, U

    2004-07-01

    Fatty acid profiles were used to characterize nutritional pathways in Chlamydomonas sp. isolated from an acidic mining lake (pH 2.7). Surprisingly, profiles of Chlamydomonas sp. grown in the lab under photoautotrophic, mixotrophic, and heterotrophic conditions at in situ deep strata lake water temperatures (8 degrees C) were very similar, polyunsaturated fatty acids including alpha-linolenic acid (18:3omega3) and 16:4omega3 along with palmitic acid (16:0) being most abundant. Therefore, heterotrophic growth of Chlamydomonas sp. at low temperatures can result in high concentrations of polyunsaturated fatty acids, as previously only described for some psychrophilic bacteria. By contrast, the cultivation of isolated Chlamydomonas sp. at 20 degrees C, reflecting surface water temperatures, provided fatty acid patterns characteristic of the nutrition strategy applied: the concentration of polyunsaturated fatty acids decreased when the growth pathway changed from photoautotrophic via mixotrophic to heterotrophic. Total fatty acid concentration also diminished in this order. Principal component analysis confirmed the significance of FA profiling to mirror nutritional pathways. Lake-water analysis revealed low concentrations of dissolved organic carbon, mainly consisting of polymeric fulvic acids that are unable to support heterotrophic growth of Chlamydomonas sp. Polymeric fulvic acids present in the deeper strata of the lake turned out to be formed in situ on the basis of organic monomers including reduced sulfur-containing ones, as revealed by thermochemolysis and pyrolysis. Growth of Chlamydomonas sp. in the deep chlorophyll maximum is therefore assumed to mainly result from photosynthesis, despite very low photon densities. Phytol-including metabolites proved to be significant biomarkers to indicate the nutritional pathway of Chlamydomonas sp. alpha, omega-Dicarboxylic acids-light-induced degradation products of unsaturated fatty acids-appeared to be good indicators

  15. Selecting Presuppositions in Conditional Clauses. Results from a Psycholinguistic Experiment

    PubMed Central

    Domaneschi, Filippo; Carrea, Elena; Penco, Carlo; Greco, Alberto

    2016-01-01

    In this paper, we propose an experiment concerning presupposition selection in conditional sentences containing a presupposition trigger in the consequent. Many theories claim that sentences like if p, qq'—where q is the presupposition of the assertive component q'—have unconditional presuppositions, namely, they simply project q. Other theories suggest that these kinds of conditional sentences project conditional presuppositions of the form if p, q. Data collected suggest two results: (i) in accordance with other experiments (by Romoli), dependence between the presupposition q and the antecedent p favors the selection of a conditional presupposition if p, q. (ii) presupposition selection in conditional sentences with a trigger in the consequent is affected by speakers' cognitive load: if speakers are highly cognitive loaded, then they are less disposed to select a conditional presupposition. We conclude by arguing that cognitive load represents a key factor for the analysis of linguistic and philosophical theories of context. PMID:26793146

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

    PubMed

    Dijck-Brouwer, D A Janneke; Hadders-Algra, Mijna; Bouwstra, Hylco; Decsi, Tamás; Boehm, Günther; Martini, Ingrid A; Boersma, E Rudy; Muskiet, Frits A J

    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 infants. Neurological condition was summarized as a clinical classification and a 'neurological optimality score' (NOS). Neurologically abnormal infants (n=27) had lower UV DHA and essential fatty acid (EFA) status. NOS correlated positively with AA (UV), and EFA (UV) and DHA status (UV and UA) and negatively with 18:2omega6 and omega9 (UV), and 20:3omega9, omega7 and C18 trans fatty acids (UV and UA). UV DHA, AA, saturated fatty acids, gestational age and obstetrical optimality score explained 16.2% of the NOS variance. Early postnatal neurological condition seems negatively influenced by lower fetal DHA, AA and EFA status. C18 trans fatty acids and 18:2omega6 may exert negative effects by impairment of LCP status. PMID:15589396

  17. Growth Conditions To Reduce Oxalic Acid Content of Spinach

    NASA Technical Reports Server (NTRS)

    Johnson-Rutzke, Corinne

    2003-01-01

    A controlled-environment agricultural (CEA) technique to increase the nutritive value of spinach has been developed. This technique makes it possible to reduce the concentration of oxalic acid in spinach leaves. It is desirable to reduce the oxalic acid content because oxalic acid acts as an anti-nutritive calcium-binding component. More than 30 years ago, an enzyme (an oxidase) that breaks down oxalic acid into CO2 and H2O2 was discovered and found to be naturally present in spinach leaves. However, nitrate, which can also be present because of the use of common nitratebased fertilizers, inactivates the enzyme. In the CEA technique, one cuts off the supply of nitrate and keeps the spinach plants cool while providing sufficient oxygen. This technique provides the precise environment that enables the enzyme to naturally break down oxalate. The result of application of this technique is that the oxalate content is reduced by 2/3 in one week.

  18. Smectite Formation from Basaltic Glass Under Acidic Conditions on Mars

    NASA Technical Reports Server (NTRS)

    Peretyazhko, T. S.; Sutter, B.; Morris, R. V.; Agresti, D. G.; Le, L.; Ming, D. W.

    2015-01-01

    Massive deposits of phyllosilicates of the smectite group, including Mg/Fe-smectite, have been identified in Mars's ancient Noachian terrain. The observed smectite is hypothesized to form through aqueous alteration of basaltic crust under neutral to alkaline pH conditions. These pH conditions and the presence of a CO2-rich atmosphere suggested for ancient Mars were favorable for the formation of large carbonate deposits. However, the detection of large-scale carbonate deposits is limited on Mars. We hypothesized that smectite deposits may have formed under acidic conditions that prevented carbonate precipitation. In this work we investigated formation of saponite at a pH of approximately 4 from Mars-analogue synthetic Adirondack basaltic glass of composition similar to Adirondack class rocks located at Gusev crater. Hydrothermal (200º Centigrade) 14 day experiments were performed with and without 10 millimoles Fe(II) or Mg under anoxic condition [hereafter denoted as anoxic_Fe, anoxic_Mg and anoxic (no addition of Fe(II) or Mg)] and under oxic condition [hereafter denoted as oxic (no addition of Fe(II) or Mg)]. Characterization and formation conditions of the synthesized saponite provided insight into the possible geochemical conditions required for saponite formation on Mars.

  19. Arsenate precipitation using ferric iron in acidic conditions

    SciTech Connect

    Cadena, F.; Kirk, T.L.

    1995-12-31

    Arsenates (i.e., As(V)) can be removed from aqueous solution by precipitation with ferric iron (i.e., Fe(III)). The chemistry of arsenic acid describes the main properties of arsenates. This triprotic acid resembles the phosphoric acid system. For example, free arsenate ions (i.e., AsO{sub 4}{sup 3-}), like free phosphates, are present in significant concentration at pH values above pK{sub a,3}. On the other hand, the concentration of free ferric iron in solution, Fe{sup 3+}, is limited by ferric hydroxide precipitation and hydroxy complexation under neutral or basic conditions. Fe{sup 3+} is the predominant iron form only under very acidic conditions. Therefore, the absence of either ferric ions or arsenate ligands prevents ferric arsenate (FeAsO{sub 4}) precipitation in extreme pH conditions. Precipitation studies using ferric chloride show that the formation of ferric arsenate in water containing 0.667 mM/L (50 mg/L as As) is favored in the pH range between 3 and 4. Ferric iron dose required to remove arsenic from solution increases with pH in the range of 3 to 10. Sludge production also increases with increasing pH conditions. Optimum ferric iron doses at pH 3 and 4 are 4.8 and 10.0 mM/L, respectively, where the arsenate is removed from solution by 98.72 and 99.68 percent. Corresponding iron requirement to arsenate ratios at these two pH conditions are 7.2 and 15.0. Adverse effects on arsenic removal are observed at pH = 3, where the concentration of applied ferric iron exceeds the optimal dose. This effect is probably due to charge reversal on the surface of the precipitates. Overdosing above the optimal iron concentration at pH = 4 does not reduce treatment efficiency significantly. Presence of sodium chloride in solution at a concentration of 171 mM/L (10,000 mg/L as NaCl) does not impair system performance. However, sodium sulfate at a concentration of 104 mM/L (10,000 mg/L) affects adversely treatment performance.

  20. Condition of chromic acid anodized aluminum clamps flown

    NASA Technical Reports Server (NTRS)

    Plagemann, W. L.

    1991-01-01

    A survey of the condition of the chromic acid anodized (CAA) coating on selected LDEF tray clamps was carried out. Measurements of solar absorptance and thermal emittance were carried out at multiple locations on both the space exposed and spacecraft facing sides of the clamps. Multiple clamps from each available angle relative to the ram direction were examined. The diffuse component of the reflectance spectrum was measured for a selected subset of the clamps. The thickness of the CAA was determined for a small set of clamps. Examples of variation in integrity of the coatings from leading to trailing edge will be shown.

  1. Experimental results from containment piping bellows subjected to severe accident conditions: Results from bellows tested in corroded conditions. Volume 2

    SciTech Connect

    Lambert, L.D.; Parks, M.B.

    1995-10-01

    Bellows are an integral part of the containment pressure boundary in nuclear power plants. They are used at piping penetrations to allow relative movement between piping and the containment wall, while minimizing the load imposed on the piping and wall. Piping bellows are primarily used in steel containments; however, they have received limited use in some concrete (reinforced and prestressed) containments. In a severe accident they may be subjected to pressure and temperature conditions that exceed the design values, along with a combination of axial and lateral deflections. A test program to determine the leak-tight capacity of containment penetration bellows is being conducted at Sandia National Laboratories under the sponsorship of the US Nuclear Regulatory Commission. Several different bellows geometries, representative of actual containment bellows, have been subjected to extreme deflections along with pressure and temperature loads. The bellows geometries and loading conditions are described along with the testing apparatus and procedures. A total of nineteen bellows have been tested. Thirteen bellows were tested in ``like-new`` condition (results reported in Volume 1), and six were tested in a corroded condition. The tests showed that bellows in ``like-new`` condition are capable of withstanding relatively large deformations, up to, or near, the point of full compression or elongation, before developing leakage, while those in a corroded condition did not perform as well, depending on the amount of corrosion. The corroded bellows test program and results are presented in this report.

  2. Investigation of fatty acid accumulation in the engineered Saccharomyces cerevisiae under nitrogen limited culture condition.

    PubMed

    Tang, Xiaoling; Chen, Wei Ning

    2014-06-01

    In this study, the Saccharomyces cerevisiae wild type strain and engineered strain with an overexpressed heterologous ATP-citrate lyase (acl) were cultured in medium with different carbon and nitrogen concentrations, and their fatty acid production levels were investigated. The results showed that when the S. cerevisiae engineered strain was cultivated under nitrogen limited culture condition, the yield of mono-unsaturated fatty acids showed higher than that under non-nitrogen limited condition; with the carbon concentration increased, the accumulation become more apparent, whereas in the wild type strain, no such correlation was found. Besides, the citrate level in the S. cerevisiae under nitrogen limited condition was found to be much higher than that under non-nitrogen limited condition, which indicated a relationship between the diminution of nitrogen and accumulation of citrate in the S. cerevisiae. The accumulated citrate could be further cleaved by acl to provide substrate for fatty acid synthesis. PMID:24755317

  3. Influence of mineralogy on the preservation of amino acids under simulated Mars conditions

    NASA Astrophysics Data System (ADS)

    dos Santos, Renato; Patel, Manish; Cuadros, Javier; Martins, Zita

    2016-10-01

    The detection of organic molecules associated with life on Mars is one of the main goals of future life-searching missions such as the ESA-Roscosmos ExoMars and NASA 2020 mission. In this work we studied the preservation of 25 amino acids that were spiked onto the Mars-relevant minerals augite, enstatite, goethite, gypsum, hematite, jarosite, labradorite, montmorillonite, nontronite, olivine and saponite, and on basaltic lava under simulated Mars conditions. Simulations were performed using the Open University Mars Chamber, which mimicked the main aspects of the martian environment, such as temperature, UV radiation and atmospheric pressure. Quantification and enantiomeric separation of the amino acids were performed using gas-chromatography-mass spectrometry (GC-MS). Results show that no amino acids could be detected on the mineral samples spiked with 1 μM amino acid solution (0.1 μmol of amino acid per gram of mineral) subjected to simulation, possibly due to complete degradation of the amino acids and/or low extractability of the amino acids from the minerals. For higher amino acid concentrations, nontronite had the highest preservation rate in the experiments in which 50 μM spiking solution was used (5 μmol/g), while jarosite and gypsum had a higher preservation rate in the experiments in which 25 and 10 μM spiking solutions were used (2.5 and 1 μmol/g), respectively. Overall, the 3 smectite minerals (montmorillonite, saponite, nontronite) and the two sulfates (gypsum, jarosite) preserved the highest amino acid proportions. Our data suggest that clay minerals preserve amino acids due to their high surface areas and small pore sizes, whereas sulfates protect amino acids likely due to their opacity to UV radiation or by partial dissolution and crystallization and trapping of the amino acids. Minerals containing ferrous iron (such as augite, enstatite and basaltic lava) preserved the lowest amount of amino acids, which is explained by iron (II) catalyzed

  4. Additional Results of Ice-Accretion Scaling at SLD Conditions

    NASA Technical Reports Server (NTRS)

    Bond, Thomas H. (Technical Monitor); Anderson, David N.; Tsao, Jen-Ching

    2005-01-01

    To determine scale velocity an additional similarity parameter is needed to supplement the Ruff scaling method. A Weber number based on water droplet MVD has been included in several studies because the effect of droplet splashing on ice accretion was believed to be important, particularly for SLD conditions. In the present study, ice shapes recorded at Appendix-C conditions and recent results at SLD conditions are reviewed to show that droplet diameter cannot be important to main ice shape, and for low airspeeds splashing does not appear to affect SLD ice shapes. Evidence is presented to show that while a supplementary similarity parameter probably has the form of a Weber number, it must be based on a length proportional to model size rather than MVD. Scaling comparisons were made between SLD reference conditions and Appendix-C scale conditions using this Weber number. Scale-to-reference model size ratios were 1:1.7 and 1:3.4. The reference tests used a 91-cm-chord NACA 0012 model with a velocity of approximately 50 m/s and an MVD of 160 m. Freezing fractions of 0.3, 0.4, and 0.5 were included in the study.

  5. Anaerobic conditions improve germination of a gibberellic acid deficient rice

    NASA Technical Reports Server (NTRS)

    Frantz, Jonathan M.; Bugbee, Bruce

    2002-01-01

    Dwarf plants are useful in research because multiple plants can be grown in a small area. Rice (Oryza sativa L.) is especially important since its relatively simple genome has recently been sequenced. We are characterizing a gibberellic acid (GA) mutant of rice (japonica cv 'Shiokari,' line N-71) that is extremely dwarf (20 cm tall). Unfortunately, this GA mutation is associated with poor germination (70%) under aerobic conditions. Neither exogenous GA nor a dormancy-breaking heat treatment improved germination. However, 95% germination was achieved by germinating the seeds anaerobically, either in a pure N2 environment or submerged in unstirred tap water. The anaerobic conditions appear to break a mild post-harvest dormancy in this rice cultivar. Copyright 2002 Crop Science Society of America.

  6. Partitioning the Relative Importance of Phylogeny and Environmental Conditions on Phytoplankton Fatty Acids.

    PubMed

    Galloway, Aaron W E; Winder, Monika

    2015-01-01

    Essential fatty acids (EFA), which are primarily generated by phytoplankton, limit growth and reproduction in diverse heterotrophs. The biochemical composition of phytoplankton is well-known to be governed both by phylogeny and environmental conditions. Nutrients, light, salinity, and temperature all affect both phytoplankton growth and fatty acid composition. However, the relative importance of taxonomy and environment on algal fatty acid content has yet to be comparatively quantified, thus inhibiting predictions of changes to phytoplankton food quality in response to global environmental change. We compiled 1145 published marine and freshwater phytoplankton fatty acid profiles, consisting of 208 species from six major taxonomic groups, cultured in a wide range of environmental conditions, and used a multivariate distance-based linear model to quantify the total variation explained by each variable. Our results show that taxonomic group accounts for 3-4 times more variation in phytoplankton fatty acids than the most important growth condition variables. The results underscore that environmental conditions clearly affect phytoplankton fatty acid profiles, but also show that conditions account for relatively low variation compared to phylogeny. This suggests that the underlying mechanism determining basal food quality in aquatic habitats is primarily phytoplankton community composition, and allows for prediction of environmental-scale EFA dynamics based on phytoplankton community data. We used the compiled dataset to calculate seasonal dynamics of long-chain EFA (LCEFA; ≥C20 ɷ-3 and ɷ-6 polyunsaturated fatty acid) concentrations and ɷ-3:ɷ-6 EFA ratios in Lake Washington using a multi-decadal phytoplankton community time series. These analyses quantify temporal dynamics of algal-derived LCEFA and food quality in a freshwater ecosystem that has undergone large community changes as a result of shifting resource management practices, highlighting diatoms

  7. Partitioning the Relative Importance of Phylogeny and Environmental Conditions on Phytoplankton Fatty Acids

    PubMed Central

    Galloway, Aaron W. E.; Winder, Monika

    2015-01-01

    Essential fatty acids (EFA), which are primarily generated by phytoplankton, limit growth and reproduction in diverse heterotrophs. The biochemical composition of phytoplankton is well-known to be governed both by phylogeny and environmental conditions. Nutrients, light, salinity, and temperature all affect both phytoplankton growth and fatty acid composition. However, the relative importance of taxonomy and environment on algal fatty acid content has yet to be comparatively quantified, thus inhibiting predictions of changes to phytoplankton food quality in response to global environmental change. We compiled 1145 published marine and freshwater phytoplankton fatty acid profiles, consisting of 208 species from six major taxonomic groups, cultured in a wide range of environmental conditions, and used a multivariate distance-based linear model to quantify the total variation explained by each variable. Our results show that taxonomic group accounts for 3-4 times more variation in phytoplankton fatty acids than the most important growth condition variables. The results underscore that environmental conditions clearly affect phytoplankton fatty acid profiles, but also show that conditions account for relatively low variation compared to phylogeny. This suggests that the underlying mechanism determining basal food quality in aquatic habitats is primarily phytoplankton community composition, and allows for prediction of environmental-scale EFA dynamics based on phytoplankton community data. We used the compiled dataset to calculate seasonal dynamics of long-chain EFA (LCEFA; ≥C20 ɷ-3 and ɷ-6 polyunsaturated fatty acid) concentrations and ɷ-3:ɷ-6 EFA ratios in Lake Washington using a multi-decadal phytoplankton community time series. These analyses quantify temporal dynamics of algal-derived LCEFA and food quality in a freshwater ecosystem that has undergone large community changes as a result of shifting resource management practices, highlighting diatoms

  8. Stability of amino acids and their oligomerization under high-pressure conditions: implications for prebiotic chemistry.

    PubMed

    Otake, Tsubasa; Taniguchi, Takashi; Furukawa, Yoshihiro; Kawamura, Fumio; Nakazawa, Hiromoto; Kakegawa, Takeshi

    2011-10-01

    The polymerization of amino acids leading to the formation of peptides and proteins is a significant problem for the origin of life. This problem stems from the instability of amino acids and the difficulty of their oligomerization in aqueous environments, such as seafloor hydrothermal systems. We investigated the stability of amino acids and their oligomerization reactions under high-temperature (180-400°C) and high-pressure (1.0-5.5 GPa) conditions, based on the hypothesis that the polymerization of amino acids occurred in marine sediments during diagenesis and metamorphism, at convergent margins on early Earth. Our results show that the amino acids glycine and alanine are stabilized by high pressure. Oligomers up to pentamers were formed, which has never been reported for alanine in the absence of a catalyst. The yields of peptides at a given temperature and reaction time were higher under higher-pressure conditions. Elemental, infrared, and isotopic analyses of the reaction products indicated that deamination is a key degradation process for amino acids and peptides under high-pressure conditions. A possible NH(3)-rich environment in marine sediments on early Earth may have further stabilized amino acids and peptides by inhibiting their deamination. PMID:21961531

  9. Additional Results of Glaze Icing Scaling in SLD Conditions

    NASA Technical Reports Server (NTRS)

    Tsao, Jen-Ching

    2016-01-01

    New guidance of acceptable means of compliance with the super-cooled large drops (SLD) conditions has been issued by the U.S. Department of Transportation's Federal Aviation Administration (FAA) in its Advisory Circular AC 25-28 in November 2014. The Part 25, Appendix O is developed to define a representative icing environment for super-cooled large drops. Super-cooled large drops, which include freezing drizzle and freezing rain conditions, are not included in Appendix C. This paper reports results from recent glaze icing scaling tests conducted in NASA Glenn Icing Research Tunnel (IRT) to evaluate how well the scaling methods recommended for Appendix C conditions might apply to SLD conditions. The models were straight NACA 0012 wing sections. The reference model had a chord of 72 in. and the scale model had a chord of 21 in. Reference tests were run with airspeeds of 100 and 130.3 kn and with MVD's of 85 and 170 micron. Two scaling methods were considered. One was based on the modified Ruff method with scale velocity found by matching the Weber number WeL. The other was proposed and developed by Feo specifically for strong glaze icing conditions, in which the scale liquid water content and velocity were found by matching reference and scale values of the nondimensional water-film thickness expression and the film Weber number Wef. All tests were conducted at 0 deg AOA. Results will be presented for stagnation freezing fractions of 0.2 and 0.3. For nondimensional reference and scale ice shape comparison, a new post-scanning ice shape digitization procedure was developed for extracting 2-D ice shape profiles at any selected span-wise location from the high fidelity 3-D scanned ice shapes obtained in the IRT.

  10. Terminal acidic shock inhibits sour beer bottle conditioning by Saccharomyces cerevisiae.

    PubMed

    Rogers, Cody M; Veatch, Devon; Covey, Adam; Staton, Caleb; Bochman, Matthew L

    2016-08-01

    During beer fermentation, the brewer's yeast Saccharomyces cerevisiae experiences a variety of shifting growth conditions, culminating in a low-oxygen, low-nutrient, high-ethanol, acidic environment. In beers that are bottle conditioned (i.e., carbonated in the bottle by supplying yeast with a small amount of sugar to metabolize into CO2), the S. cerevisiae cells must overcome these stressors to perform the ultimate act in beer production. However, medium shock caused by any of these variables can slow, stall, or even kill the yeast, resulting in production delays and economic losses. Here, we describe a medium shock caused by high lactic acid levels in an American sour beer, which we refer to as "terminal acidic shock". Yeast exposed to this shock failed to bottle condition the beer, though they remained viable. The effects of low pH/high [lactic acid] conditions on the growth of six different brewing strains of S. cerevisiae were characterized, and we developed a method to adapt the yeast to growth in acidic beer, enabling proper bottle conditioning. Our findings will aid in the production of sour-style beers, a trending category in the American craft beer scene. PMID:27052714

  11. Acid-sensing ion channels in pathological conditions

    PubMed Central

    Chu, Xiang-Ping; Xiong, Zhi-Gang

    2013-01-01

    Acid-sensing ion channels (ASICs), a novel family of proton-gated amiloride-sensitive cation channels, are expressed primarily in neurons of peripheral sensory and central nervous systems. Recent studies have shown that activation of ASICs, particularly the ASIC1a channels, plays a critical role in neuronal injury associated with neurological disorders such as brain ischemia, multiple sclerosis, and spinal cord injury, etc. In normal conditions in vitro, ASIC1a channels desensitize rapidly in the presence of a continuous acidosis or following a pre-exposure to minor pH drop, raising doubt for their contributions to the acidosis-mediated neuronal injury. It is now known that the properties of ASICs can be dramatically modulated by signaling molecules or biochemical changes associated with pathological conditions. Modulation of ASICs by these molecules can lead to dramatically enhanced and/or prolonged activities of these channels thus promoting their pathological functions. Understanding of how ASICs behave in pathological conditions may help define new strategies for the treatment and/or prevention of neuronal injury associated with various neurological disorders. PMID:23224900

  12. Polymorphic transformation of antibiotic clarithromycin under acidic condition.

    PubMed

    Noguchi, Shuji; Takiyama, Kei; Fujiki, Sadahiro; Iwao, Yasunori; Miura, Keiko; Itai, Shigeru

    2014-02-01

    Clarithromycin (CAM) is a 14-membered semisynthetic macrolide antibiotic used to treat the infection of various bacteria including Helicobacter pylori. The polymorphic transformation of CAM form II crystals under acidic conditions is, however, still unclear, and was investigated using X-ray powder diffraction method. Gel of CAM, which was immediately formed by mixing form II crystals with the hydrochloric acid solution, transformed at first to unstable form A crystals and then to form B crystals. Both forms A and B crystals are hydrochloride salts. Analyses using Hancock-Sharp equation revealed that the mechanism of form B formation was three-dimensional growth of nuclei. The rate constant of the transformation indicated that the times for 95% of form A transforming to form B at 37 °C are 0.69, 1.90, and 3.79 h at pH 1.5, 2.5, and 3.4, respectively. These suggest that the transformation from form II to form B via gel and form A could occur on the surface of form II formulation of prolonged gastric residence time, in the case that the pH in stomach stays low. PMID:24375227

  13. EVALUATING CHANGES IN FOREST CONDITION POTENTIALLY RELATED TO ACIDIC DEPOSITION: AN EXAMPLE USING RED SPRUCE

    EPA Science Inventory

    As a result of concern about forest decline in Europe and the USA, research has been conducted to investigate changes in forest condition that might be associated with acidic deposition and related pollutants (principally ozone). ymptoms of tree decline observed in the field typi...

  14. pH-Dependent Uptake of Fumaric Acid in Saccharomyces cerevisiae under Anaerobic Conditions

    PubMed Central

    Jamalzadeh, Elaheh; Verheijen, Peter J. T.; Heijnen, Joseph J.

    2012-01-01

    Microbial production of C4 dicarboxylic acids from renewable resources has gained renewed interest. The yeast Saccharomyces cerevisiae is known as a robust microorganism and is able to grow at low pH, which makes it a suitable candidate for biological production of organic acids. However, a successful metabolic engineering approach for overproduction of organic acids requires an incorporation of a proper exporter to increase the productivity. Moreover, low-pH fermentations, which are desirable for facilitating the downstream processing, may cause back diffusion of the undissociated acid into the cells with simultaneous active export, thereby creating an ATP-dissipating futile cycle. In this work, we have studied the uptake of fumaric acid in S. cerevisiae in carbon-limited chemostat cultures under anaerobic conditions. The effect of the presence of fumaric acid at different pH values (3 to 5) has been investigated in order to obtain more knowledge about possible uptake mechanisms. The experimental results showed that at a cultivation pH of 5.0 and an external fumaric acid concentration of approximately 0.8 mmol · liter−1, the fumaric acid uptake rate was unexpectedly high and could not be explained by diffusion of the undissociated form across the plasma membrane alone. This could indicate the presence of protein-mediated import. At decreasing pH levels, the fumaric acid uptake rate was found to increase asymptotically to a maximum level. Although this observation is in accordance with protein-mediated import, the presence of a metabolic bottleneck for fumaric acid conversion under anaerobic conditions could not be excluded. PMID:22113915

  15. Fe/Mg smectite formation under acidic conditions on early Mars

    NASA Astrophysics Data System (ADS)

    Peretyazhko, T. S.; Sutter, B.; Morris, R. V.; Agresti, D. G.; Le, L.; Ming, D. W.

    2016-01-01

    Phyllosilicates of the smectite group detected in Noachian and early Hesperian terrains on Mars have been hypothesized to form under neutral to alkaline conditions. These pH conditions would also be favorable for formation of widespread carbonate deposits which have not been detected on Mars. We propose that smectite deposits on Mars formed under moderately acidic conditions inhibiting carbonate formation. We report here the first synthesis of Fe/Mg smectite in an acidic hydrothermal system [200 °C, pHRT ∼ 4 (pH measured at room temperature) buffered with acetic acid] from Mars-analogue, glass-rich, basalt simulant with and without aqueous Mg or Fe(II) addition under N2-purged anoxic and ambient oxic redox conditions. Synthesized Fe/Mg smectite was examined by X-ray-diffraction, Mössbauer spectroscopy, visible and near-infrared reflectance spectroscopy, scanning electron microscopy and electron microprobe to characterize mineralogy, morphology and chemical composition. Alteration of the glass phase of basalt simulant resulted in formation of the Fe/Mg smectite mineral saponite with some mineralogical and chemical properties similar to the properties reported for Fe/Mg smectite on Mars. Our experiments are evidence that neutral to alkaline conditions on early Mars are not necessary for Fe/Mg smectite formation as previously inferred. Phyllosilicate minerals could instead have formed under mildly acidic pH conditions. Volcanic SO2 emanation and sulfuric acid formation is proposed as the major source of acidity for the alteration of basaltic materials and subsequent formation of Fe/Mg smectite.

  16. Competition effects in cation binding to humic acid: Conditional affinity spectra for fixed total metal concentration conditions

    NASA Astrophysics Data System (ADS)

    David, Calin; Mongin, Sandrine; Rey-Castro, Carlos; Galceran, Josep; Companys, Encarnació; Garcés, José Luis; Salvador, José; Puy, Jaume; Cecilia, Joan; Lodeiro, Pablo; Mas, Francesc

    2010-09-01

    Information on the Pb and Cd binding to a purified Aldrich humic acid (HA) is obtained from the influence of different fixed total metal concentrations on the acid-base titrations of this ligand. NICA (Non-Ideal Competitive Adsorption) isotherm has been used for a global quantitative description of the binding, which has then been interpreted by plotting the Conditional Affinity Spectra of the H + binding at fixed total metal concentrations (CAScTM). This new physicochemical tool, here introduced, allows the interpretation of binding results in terms of distributions of proton binding energies. A large increase in the acidity of the phenolic sites as the total metal concentration increases, especially in presence of Pb, is revealed from the shift of the CAScTM towards lower affinities. The variance of the CAScTM distribution, which can be used as a direct measure of the heterogeneity, also shows a significant dependence on the total metal concentration. A discussion of the factors that influence the heterogeneity of the HA under the conditions of each experiment is provided, so that the smoothed pattern exhibited by the titration curves can be justified.

  17. Construction-conditioned rollback in total knee replacement: fluoroscopic results.

    PubMed

    Wachowski, Martin Michael; Fiedler, Christoph; Walde, Tim Alexander; Balcarek, Peter; Schüttrumpf, Jan Philipp; Frosch, Stephan; Frosch, Karl-Heinz; Fanghänel, Jochen; Gezzi, Riccardo; Kubein-Meesenburg, Dietmar; Nägerl, Hans

    2011-01-01

    Firstly, the way of implementing approximatively the initial rollback of the natural tibiofemoral joint (TFJ) in a total knee replacement (AEQUOS G1 TKR) is discussed. By configuration of the curvatures of the medial and lateral articulating surfaces a cam gear mechanism with positive drive can be installed, which works under force closure of the femoral and tibial surfaces. Briefly the geometric design features in flexion/extension are described and construction-conditioned kinematical and functional properties that arise are discussed. Due to a positive drive of the cam gear under the force closure during the stance phase of gait the articulating surfaces predominantly roll. As a result of rolling, a sliding friction is avoided, thus the resistance to motion is reduced during the stance phase. Secondly, in vivo fluoroscopic measurements of the patella tendon angle during flexion/extension are presented. The patella tendon angle/ knee flexion angle characteristic and the kinematic profile in trend were similar to those observed in the native knee during gait (0°-60°). PMID:22098089

  18. Using Acid Number as a Leading Indicator of Refrigeration and Air Conditioning System Performance

    SciTech Connect

    Dennis Cartlidge; Hans Schellhase

    2003-07-31

    number (TAN), which includes both mineral acids and organic acids, is therefore a useful indicator which can be used to monitor the condition of the system in order to perform remedial maintenance, when required, to prevent system failure. The critical TAN value is the acid level at which remedial action should be taken to prevent the onset of rapid acid formation which can result in system failure. The level of 0.05 mg KOH/g of oil was established for CFC/mineral oil systems based on analysis of 700 used lubricants from operating systems and failed units. There is no consensus within the refrigeration industry as to the critical TAN value for HFC/POE systems, however, the value will be higher than the CFC/mineral oil systems critical TAN value because of the much weaker organic acids produced from POE. A similar study of used POE lubricants should be performed to establish a critical TAN limit for POE systems. Titrimetric analysis per ASTM procedures is the most commonly used method to determine TAN values in lubricants in the refrigeration industry and other industries dealing with lubricating oils. For field measurements, acid test kits are often used since they provide rapid, semi-quantitative TAN results.

  19. Effect of environmental conditions on the fatty acid fingerprint of microbial communities

    NASA Astrophysics Data System (ADS)

    Biryukov, Mikhail; Dippold, Michaela; Kuzyakov, Yakov

    2014-05-01

    Lipid biomarkers, especially phospholipids, are routinely used to characterize microbial community structure in environmental samples. Interpretations of these fingerprints mainly depend on rare results of pure cultures which were cultivated under standardized batch conditions. However, membrane lipids (e.g. phopholipid biomarker) build up the interface between microorganisms and their environment and consequently are prone to be adapted according to the environmental conditions. We cultivated several bacteria, isolated from soil (gram-positive and gram-negative) under various conditions e.g. C supply and temperature regimes. Effect of growth conditions on phospholipids fatty acid (PLFA) as well as neutral lipid fatty acids (NLFA) and glycolipid fatty acids (GLFA) was investigated by conventional method of extraction and derivatization, followed by assessments with gas chromatography mass spectrometry (GC-MS). In addition, phospholipids were measured as intact molecules by ultra high performance liquid chromatography - quadrupole - time of flight mass spectrometer (UHPLC-Q-ToF) to further assess the composition of headgroups with fatty acids residues and their response on changing environmental conditions. PLFA fingerprints revealed a strong effect of growth stage, C supply and temperature e.g. decrease of temperature increased the amount of branched and/or unsaturated fatty acids to maintain the membrane fluidity. This strongly changes the ratio of specific to unspecific fatty acids depending on environmental conditions. Therefore, amounts of specific fatty acids cannot be used to assess biomass of a functional microbial group in soil. Intracellular neutral lipids depended less on environmental conditions reflecting a more stable biomarker group but also showed less specific fatty acids then PLFA. Therefore, combination of several lipid classes is suggested as more powerful tool to assess amounts and functionality of environmental microbial communities. Further

  20. SULFURIC ACID REMOVAL PROCESS EVALUATION: LONG-TERM RESULTS

    SciTech Connect

    Gary M. Blythe; Richard McMillan

    2002-07-03

    longer-term (approximately 25-day) full-scale tests on two different units. The longer-term tests were conducted to confirm the effectiveness of the sorbents tested over extended operation on two different boilers, and to determine balance-of-plant impacts. The first long-term test was conducted on FirstEnergy's BMP, Unit 3, and the second test was conducted on AEP's Gavin Plant, Unit 1. The Gavin Plant testing provided an opportunity to evaluate the effects of sorbent injected into the furnace on SO{sub 3} formed across an operating SCR reactor. This report presents the results from those long-term tests. The tests determined the effectiveness of injecting commercially available magnesium hydroxide slurry (Gavin Plant) and byproduct magnesium hydroxide slurry (both Gavin Plant and BMP) for sulfuric acid control. The results show that injecting either slurry could achieve up to 70 to 75% overall sulfuric acid removal. At BMP, this overall removal was limited by the need to maintain acceptable electrostatic precipitator (ESP) particulate control performance. At Gavin Plant, the overall sulfuric acid removal was limited because the furnace injected sorbent was less effective at removing SO{sub 3} formed across the SCR system installed on the unit for NOX control than at removing SO{sub 3} formed in the furnace. The long-term tests also determined balance-of-plant impacts from slurry injection during the two tests. These include impacts on boiler back-end temperatures and pressure drops, SCR catalyst properties, ESP performance, removal of other flue gas species, and flue gas opacity. For the most part the balance-of-plant impacts were neutral to positive, although adverse effects on ESP performance became an issue during the BMP test.

  1. EFFECTIVE ACIDITY CONSTANT BEHAVIOR NEAR ZERO CHARGE CONDITIONS

    EPA Science Inventory

    Surface site (>SOH group) acidity reactions require expressions of the form: Ka = [>SOHn-1(z-1)]aH+EXP(-DG/RT)/[>SOHnz] (where all variables have their usual meaning). One can rearrange this expression to generate an effective acidity constant historically defined as: Qa = Ka...

  2. Influence of propionic acid on growth and aflatoxin production by Aspergillus flavus in liquid submerged and solid substrate conditions.

    PubMed

    al-Hilli, A L; Smith, J E

    1992-01-01

    The present experiments demonstrate that sublethal concentrations of propionic acid stimulated aflatoxin production considerably in submerged shaken culture and solid substrate culture of Aspergillus flavus. In liquid conditions aflatoxin formation was significantly influenced by the time of addition of propionic acid. The spores initially swelled into large spherical cells, and the resultant hyphae developed into a swollen, stunted, and excessively branched mycelium. PMID:1573566

  3. Screening of Burkholderia sp. WGB31 producing anisic acid from anethole and optimization of fermentation conditions.

    PubMed

    Shen, Peihong; Song, Zhangyang; Zhang, Zhenyong; Zeng, Huahe; Tang, Xianlai; Jiang, Chengjian; Li, Junfang; Wu, Bo

    2014-11-01

    Anisic acid, the precursor of a variety of food flavors and industrial raw materials, can be bioconversed from anethole which extracted from star anise fruits. WGB31 strain with anisic acid molar production rate of 10.25% was isolated and identified as Burkholderia sp. Three significant influential factors, namely, glucose concentration, initial pH value, and medium volume were selected and their effects were evaluated by Box-Behnken Design (BBD). Regression analysis was performed to determine response surface methodology and the significance was tested to obtain the process model of optimal conditions for producing anisic acid. The fermentation conditions at the stable point of the model were obtained: glucose 6 g L(-1) , pH 6.2, culture medium volume 61 mL in a triangular flask with 250 ml volume. Verification test indicated that the production rate of anisic acid was 30.7%, which was three times of that before optimizing. The results provide a basis and reference for producing anisic acid by microbial transformation. PMID:25100156

  4. The Formation of Fe/Mg Smectite Under Mildly Acidic Conditions on Early Mars

    NASA Technical Reports Server (NTRS)

    Sutter, Brad; Golden, D. C.; Ming, Douglas W.; Niles, P. B.

    2011-01-01

    The detection of Fe/Mg smectites and carbonate in Noachian and early Hesperian terrain of Mars has been used to suggest that neutral to mildly alkaline conditions prevailed during the early history of Mars. However, if early Mars was neutral to moderately alkaline with a denser CO2 atmosphere than today, then large carbonates deposits should be more widely detected in Noachian terrain. The critical question is: Why have so few carbonate deposits been detected compared to Fe/Mg smectites? We suggest that Fe/Mg smectites on early Mars formed under mildly acidic conditions, which would inhibit the extensive formation of carbonate deposits. The goal of this work is to evaluate the formation of Fe/Mg smectites under mildly acidic conditions. The stability of smectites under mildly acidic conditions is attributed to elevated Fe/Mg activities that inhibit smectite dissolution. Beidelite and saponite have been shown to form from hydrothermal alteration of basaltic glass at pH 3.5-4.0 in seawater solutions. Nontronite is also known to be stable in mildly acidic systems associated with mafic and ultramafic rock. Nontronite was shown to form in acid sulfate soils in the Bangkok Plain, Thailand due to oxidation of Fe-sulfides that transformed saponite to nontronite. Smectite is known to transform to kaolinite in naturally acid soils due to selective leaching of Mg. However, if Mg removal is limited, then based on equilibrium relationships, the dissolution of smectite should be minimized. If Fe and Mg solution activities are sufficiently high, such as might be found in a low water/rock ratio system that is poorly drained, smectite could form and remain stable under mildly acidic conditions on Mars. The sources of mild acidity on early Mars includes elevated atmospheric CO2 levels, Fe-hydrolysis reactions, and the presence of volcanic SO2 aerosols. Equilibrium calculations dictate that water equilibrated with an early Mars CO2 atmosphere at 1 to 4 bar yields a pH of 3.6 to 3

  5. The Formation of Fe/Mg Smectite Under Mildly Acidic Conditions on Early Mars

    NASA Astrophysics Data System (ADS)

    Sutter, B.; Golden, D. C.; Ming, D.; Niles, P. B.

    2011-12-01

    The detection of Fe/Mg smectites and carbonate in Noachian and early Hesperian terrain of Mars has been used to suggest that neutral to mildly alkaline conditions prevailed during the early history of Mars. However, if early Mars was neutral to moderately alkaline with a denser CO2 atmosphere than today, then "large" carbonates deposits should be more widely detected in Noachian terrain. The critical question is: Why have so few carbonate deposits been detected compared to Fe/Mg smectites? We suggest that Fe/Mg smectites on early Mars formed under mildly acidic conditions, which would inhibit the extensive formation of carbonate deposits. The goal of this work is to evaluate the formation of Fe/Mg smectites under mildly acidic conditions. The stability of smectites under mildly acidic conditions is attributed to elevated Fe/Mg activities that inhibit smectite dissolution. Beidelite and saponite have been shown to form from hydrothermal alteration of basaltic glass at pH 3.5-4.0 in seawater solutions. Nontronite is also known to be stable in mildly acidic systems associated with mafic and ultramafic rock. Nontronite was shown to form in acid sulfate soils in the Bangkok Plain, Thailand due to oxidation of Fe-sulfides that transformed saponite to nontronite. Smectite is known to transform to kaolinite in naturally acid soils due to selective leaching of Mg. However, if Mg removal is limited, then based on equilibrium relationships, the dissolution of smectite should be minimized. If Fe and Mg solution activities are sufficiently high, such as might be found in a low water/rock ratio system that is poorly drained, smectite could form and remain stable under mildly acidic conditions on Mars. The sources of mild acidity on early Mars includes elevated atmospheric CO2 levels, Fe-hydrolysis reactions, and the presence of volcanic SO2 aerosols. Equilibrium calculations dictate that water equilibrated with an early Mars CO2 atmosphere at 1 to 4 bar yields a pH of 3.6 to 3

  6. Nitric acid uptake by sulfuric acid solutions under stratospheric conditions - Determination of Henry's Law solubility

    NASA Technical Reports Server (NTRS)

    Reihs, Christa M.; Golden, David M.; Tolbert, Margaret A.

    1990-01-01

    The uptake of nitric acid by sulfuric acid solutions representative of stratospheric particulate at low temperatures was measured to determine the solubility of nitric acid in sulfuric acid solutions as a function of H2SO4 concentration and solution temperature. Solubilities are reported for sulfuric acid solutions ranging from 58 to 87 wt pct H2SO4 over a temperature range from 188 to 240 K, showing that, in general, the solubility of nitric acid increases with decreasing sulfuric acid concentration and with decreasing temperature. The measured solubilities indicate that nitric acid in the global stratosphere will be found predominantly in the gas phase.

  7. Changes of nucleic acids of wheat seedlings under spaceflight conditions

    NASA Technical Reports Server (NTRS)

    Sytnyk, K. M.; Musatenko, L. I.

    1983-01-01

    The effects of space flight on the growth of wheat seedlings and their nucleic acid content were studied. It was shown that both space and ground seedlings have almost the same appearance, dry weight and nucleic acid content in the root, coleoptile and leaves. The only difference found is in the RNA and DNA content, which is twice as much in the ground seedling apices as in the space-grown seedlings.

  8. Some results for the primitive equations with physical boundary conditions

    NASA Astrophysics Data System (ADS)

    Evans, Lawrence Christopher; Gastler, Robert

    2013-12-01

    In this paper, we consider the (simplified) 3-dimensional primitive equations with physical boundary conditions. We show that the equations with constant forcing have a bounded absorbing ball in the H 1-norm and that a solution to the unforced equations has its H 1-norm decay to 0. From this, we argue that there exists an invariant measure (on H 1) for the equations under random kick-forcing.

  9. High Xylose Yields from Dilute Acid Pretreatment of Corn Stover Under Process-Relevant Conditions

    SciTech Connect

    Weiss, N. D.; Nagle, N. J.; Tucker, M. P.; Elander, R. T.

    2009-01-01

    Pretreatment experiments were carried out to demonstrate high xylose yields at high solids loadings in two different batch pretreatment reactors under process-relevant conditions. Corn stover was pretreated with dilute sulfuric acid using a 4-l Steam Digester and a 4-l stirred ZipperClave{reg_sign} reactor. Solids were loaded at 45% dry matter (wt/wt) after sulfuric acid catalyst impregnation using nominal particle sizes of either 6 or 18 mm. Pretreatment was carried out at temperatures between 180 and 200 C at residence times of either 90 or 105 s. Results demonstrate an ability to achieve high xylose yields (>80%) over a range of pretreatment conditions, with performance showing little dependence on particle size or pretreatment reactor type. The high xylose yields are attributed to effective catalyst impregnation and rapid rates of heat transfer during pretreatment.

  10. Investigation of acyl migration in mono- and dicaffeoylquinic acids under aqueous basic, aqueous acidic, and dry roasting conditions.

    PubMed

    Deshpande, Sagar; Jaiswal, Rakesh; Matei, Marius Febi; Kuhnert, Nikolai

    2014-09-17

    Acyl migration in chlorogenic acids describes the process of migration of cinnamoyl moieties from one quinic acid alcohol group to another, thus interconverting chlorogenic acid regioisomers. It therefore constitutes a special case of transesterification reaction. Acyl migration constitutes an important reaction pathway in both coffee roasting and brewing, altering the structure of chlorogenic acid initially present in the green coffee bean. In this contribution we describe detailed and comprehensive mechanistic studies comparing inter- and intramolecular acyl migration involving the seven most common chlorogenic acids in coffee. We employe aqueous acidic and basic conditions mimicking the brewing of coffee along with dry roasting conditions. We show that under aqueous basic conditions intramolecular acyl migration is fully reversible with basic hydrolysis competing with acyl migration. 3-Caffeoylquinic acid was shown to be most labile to basic hydrolysis. We additionally show that the acyl migration process is strongly pH dependent with increased transesterification taking place at basic pH. Under dry roasting conditions acyl migration competes with dehydration to form lactones. We argue that acyl migration precedes lactonization, with 3-caffeoylquinic acid lactone being the predominant product. PMID:25116442

  11. Role of Organic Acids in Bioformation of Kaolinite: Results of Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Bontognali, T. R. R.; Vasconcelos, C.; McKenzie, J. A.

    2012-04-01

    Clay minerals and other solid silica phases have a broad distribution in the geological record and greatly affect fundamental physicochemical properties of sedimentary rocks, including porosity. An increasing number of studies suggests that microbial activity and microbially produced organic acids might play an important role in authigenic clay mineral formation, at low temperatures and under neutral pH conditions. In particular, early laboratory experiments (Linares and Huertas, 1971) reported the precipitation of kaolinite in solutions of SiO2 and Al2O3 with different molar ratios SiO2/Al2O3, together with fulvic acid (a non-characterized mixture of many different acids containing carboxyl and phenolate groups) that was extracted from peat soil. Despite many attempts, these experiments could not be reproduced until recently. Fiore et al. (2011) hypothesized that the non-sterile fulvic acid might have contained microbes that participated in the formation of kaolinite. Using solutions saturated with Si and Al and containing oxalate and/or mixed microbial culture extracted from peat-moss soil, they performed incubation experiments, which produced kaolinite exclusively in solutions containing oxalate and microbes. We proposed to test the role of specific organic acids for kaolinite formation, conducting laboratory experiments at 25˚C, with solutions of sodium silicate, aluminum chloride and various organic compounds (i.e. EDTA, citric acid, succinic acid and oxalic acid). Specific organic acids may stabilize aluminum in octahedral coordination positions, which is crucial for the initial nucleation step. In our experiments, a poorly crystalline mineral that is possibly a kaolinite precursor formed exclusively in the presence of succinic acid. In experiments with other organic compounds, no incorporation of Al was observed, and amorphous silica was the only precipitated phase. In natural environments, succinic acid is produced by a large variety of microbes as an

  12. Prebiotic Nitrogen Fixation by FeS Reduction of Nitrite Under Acidic Conditions

    NASA Technical Reports Server (NTRS)

    Summers, David P.; Mead, Susan C. (Technical Monitor)

    1999-01-01

    Theories for the origin of life require the availability of reduced nitrogen for the formation of such species as amino acid and nucleic acids. In a strongly reducing atmosphere, compounds essential to the chemical evolution of life, such as amino acids, can form by reactions between HCN, NH3, and carbonyl compounds produced in spark discharges. However, under non-reducing atmospheres, electric discharges produced NO rather than HCN or NH3. This raises the questions of; how ammonia can be formed under a neutral atmosphere, and what conditions are needed such formation to occur? On possibility is the conversion of NO into nitric and nitrous acids (through HNO) and rained into the oceans. The reduction of nitrite by aqueous Fe(II) (6 Fe(+2) + 7 H(+) + NO2(-) yields 6 Fe(III) + 2 H2O + NH3) such as was present on the early Earth could then have produced ammonia. However, this reaction does not proceed at pHs less than 7.3. An alternative is reduction by other forms of Fe(II), such as FeS. We will present results that show that FeS can reduce nitrite to ammonia at pHs as low as pH 5 under a variety of conditions.

  13. Organic Acids Over Equatorial Africa: Results from DECAFE 88

    NASA Astrophysics Data System (ADS)

    Helas, Günter; Bingemer, Heinz; Andreae, Meinrat O.

    1992-04-01

    Gaseous short chain organic acids were measured during the dry season (February) in and above the rain forest of the northern Congo. Samples were taken at ground level and during several flights up to 4 km altitude. The organic acids were concentrated from the atmosphere by using "mist scrubbers," which expose a mist of deionized water to the air to be probed. The organic acids absorbed in the water were subsequently analyzed by ion chromatography. Formic, acetic, and pyruvic acids were identified in the samples. At ground level, average mixing ratios of gaseous formic and acetic acid of 0.5±0.6 and 0.6±0.7 parts per billion by volume (ppbv) (1 s), respectively, were found. Boundary layer mixing ratios, however, were significantly higher (3.7±1.0 and 2.7±0.9 ppbv). This indicates a downward net flux of these atmospheric trace components from the boundary layer to the surface. Free tropospheric samples taken above the cloud convection layer show lower mixing ratios again (0.9±0.3 and 0.7±0.1 ppbv). On the basis of this vertical distribution, direct emission by vegetation is not considered to be the dominant source. Biomass burning and photochemical oxidation of biogenic precursors are the major processes contributing to the enhancement of organic acids observed in the boundary layer. The organic acids parallel the profiles of ozone and CO, which suggests that their generation processes are closely related. Pyruvic acid is not correlated with formic acid, indicating that the oxidation of isoprene is not of major importance. In emissions from biomass fires, CO correlates well with formic and acetic acid, and thus some of the enhancement of organic acids in the boundary layer can be explained due to burning. However, an additional gas phase source for organic acids must exist to explain the observed ratio of formic to acetic acid. This is most likely the ozonolysis of olefins which were released as pyrolysis products from biomass burning.

  14. Formation of Organic Tracers for Isoprene SOA under Acidic Conditions

    EPA Science Inventory

    The chemical compositions of a series of secondary organic aerosol (SOA) samples, formed by irradiating mixtures of isoprene and NO in a smog chamber in the absence or presence of acidic aerosols, were analyzed using derivatization-based GC-MS methods. In addition to the known is...

  15. Emissions involved in acidic deposition processes: Methodology and results

    SciTech Connect

    Placet, M.

    1990-01-01

    Data on the emissions involved in atmospheric acid-base chemistry are crucial to the assessment of acidic deposition and its effects. Sulfur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}), and volatile organic compounds (VOCs) are the primary chemical compounds involved in acidic deposition processes. In addition, other emission species -- e.g., ammonia, alkaline dust particles, hydrogen chloride, and hydrogen fluoride -- are involved in atmospheric acid-base chemistry, either by contributing acidic constituents or by neutralizing acidic species. Several emissions data bases have been developed under the auspices of the National Acid Precipitation Program (NAPAP). In addition to those developed by NAPAP, emissions data bases and emissions trends estimates also have been developed by organizations such as the Electric Power Research Institute (EPRI) and the U.S. Environmental Protection Agency (EPA). This paper briefly describes and compares the methods used in developing these emissions data bases and presents an overview of their emissions estimates. A more detailed discussion of these topics can be found in the State-of-Science Report on emissions recently released by NAPAP and in the references cited in that report. 14 refs., 4 figs., 1 tab.

  16. Pseudomonas putida response in membrane bioreactors under salicylic acid-induced stress conditions.

    PubMed

    Collado, Sergio; Rosas, Irene; González, Elena; Gutierrez-Lavin, Antonio; Diaz, Mario

    2014-02-28

    Starvation and changing feeding conditions are frequently characteristics of wastewater treatment plants. They are typical causes of unsteady-state operation of biological systems and provoke cellular stress. The response of a membrane bioreactor functioning under feed-induced stress conditions is studied here. In order to simplify and considerably amplify the response to stress and to obtain a reference model, a pure culture of Pseudomonas putida was selected instead of an activated sludge and a sole substrate (salicylic acid) was employed. The system degraded salicylic acid at 100-1100mg/L with a high level of efficiency, showed rapid acclimation without substrate or product inhibition phenomena and good stability in response to unsteady states caused by feed variations. Under starvation conditions, specific degradation rates of around 15mg/gh were achieved during the adaptation of the biomass to the new conditions and no biofilm formation was observed during the first days of experimentation using an initial substrate to microorganisms ratio lower than 0.1. When substrate was added to the reactor as pulses resulting in rapidly changing concentrations, P. putida growth was observed only for substrate to microorganism ratios higher than 0.6, with a maximum YX/S of 0.5g/g. Biofilm development under changing feeding conditions was fast, biomass detachment only being significant for biomass concentrations on the membrane surface that were higher than 16g/m(2). PMID:24413046

  17. Effects of Testing Conditions on Conceptual Survey Results

    ERIC Educational Resources Information Center

    Ding, Lin; Reay, Neville W.; Lee, Albert; Bao, Lei

    2008-01-01

    Pre-testing and post-testing is a commonly used method in Physics Education Research to assess student learning gains. It is well recognized in the community that timings and incentives in delivering conceptual tests can impact test results. However, it is difficult to control these variables across different studies. As a common practice, a…

  18. Comparative characterization of the deamidation of carboxylic acid deamidated wheat gluten by altering the processing conditions.

    PubMed

    Liao, Lan; Han, Xueyue; Chen, Lin-Ping; Ni, Li; Liu, Zhi-Bin; Zhang, Wen; Chen, Qing

    2016-11-01

    The physicochemical, structural and functional properties of citric-acid-deamidated wheat gluten at controlled degrees of deamidation (25%, 40% and 55%), which were obtained by using different acid concentrations (3.93×10(-5), 3.14×10(-3) and 2.36×10(-2)mol/L) and temperatures (70°C 2h, 90°C 1h and 110°C 40min), were compared. Various deamidation processing conditions leading to the same degree of deamidation resulted in proteins with different physicochemical and structural characteristics, as indicted by the degree of hydrolysis, Z-potential, surface hydrophobicity, particle size, SDS-PAGE results, SEC-HPLC results, intrinsic fluorescence and FTIR spectra. Agglomerative hierarchical clustering analysis and principal component analysis qualitatively indicated a significant effect of pH on protein deamidation. Three samples at 40% deamidation, which were produced by a moderate acid concentration, showed the best emulsifying and foaming properties. Processes conducted at greater than 90°C causing protein aggregation and at a high acid concentration rupturing peptide bonds, impaired protein quality. These findings demonstrated that a limited amount of H(+) could function well in the catalysis of the deamidation of amide groups without an excess of H(+), which hydrolyses peptide bonds in a stronger hydrothermal treatment. PMID:27211678

  19. Interaction of Polyelectrolytes with Salivary Pellicles on Hydroxyapatite Surfaces under Erosive Acidic Conditions.

    PubMed

    Delvar, Alice; Lindh, Liselott; Arnebrant, Thomas; Sotres, Javier

    2015-09-30

    The modification of acidic beverage formulations with food-approved, nonhazardous substances with antierosive properties has been identified as a key strategy for counteracting the prevalence of dental erosion, i.e., the acid-induced dissolution of hydroxyapatite (HA, the main mineral component of tooth surfaces). While many of such substances have been reported, very little is known on how they interact with teeth and inhibit their acid-induced dissolution. With the aim of filling this gap in knowledge, we have studied under acidic conditions the interaction between two polyelectrolytes of differing ionic character, carboxymethyl cellulose (CMC) and chitosan, and saliva-coated hydroxyapatite, i.e., a model for the outer surface of teeth. These studies were performed by means of ellipsometry, quartz crystal microbalance with dissipation monitoring, and atomic force microscopy. We also studied, by means of pH variations, how dissolution of saliva-coated HA is affected by including these polyelectrolytes in the erosive solutions. Our results confirm that salivary films protect HA from acid-induced dissolution, but only for a limited time. If the acid is modified with CMC, this polyelectrolyte incorporates into the salivary films prolonging in time their protective function. Eventually, the CMC-modified salivary films are removed from the HA surfaces. From this moment, HA is continuously coated with CMC, but this offers only a weak protection against erosion. When the acid is modified with the cationic chitosan, the polyelectrolyte adsorbs on top of the salivary films. Chitosan-modified salivary films are also eventually replaced by bare chitosan films. In this case both coatings offer a similar protection against HA dissolution, which is nevertheless notably higher than that offered by CMC. PMID:26368580

  20. [Cardioprotective properties of new glutamic acid derivative under stress conditions].

    PubMed

    Perfilova, V N; Sadikova, N V; Berestovitskaia, V M; Vasil'eva, O S

    2014-01-01

    The effect of new glutamic acid derivative on the cardiac ino- and chronotropic functions has been studied in experiments on rats exposed to 24-hour immobilization-and-pain stress. It is established that glutamic acid derivative RGPU-238 (glufimet) at a dose of 28.7 mg/kg increases the increment of myocardial contractility and relaxation rates and left ventricular pressure in stress-tested animals by 13 1,1, 72.4, and 118.6%, respectively, as compared to the control group during the test for adrenoreactivity. Compound RGPU-238 increases the increment of the maximum intensity of myocardium functioning by 196.5 % at 30 sec of isometric workload as compared to the control group. The cardioprotective effect of compound RGPU-238 is 1.5 - 2 times higher than that of the reference drug phenibut. PMID:25365864

  1. Carboxylic Acids as Indicators of Parent Body Conditions

    NASA Technical Reports Server (NTRS)

    Lerner N. R.; Chang, Sherwood (Technical Monitor)

    1995-01-01

    Alpha-hydroxy and alpha-amino carboxylic acids found on the Murchison meteorite are deuterium enriched. It is postulated that they arose from a common interstellar scurce: the reaction of carbonyl compounds in an aqueous mixture containing HCN and NH3. Carbonyl compounds react with HCN to form alpha-hydroxy nitriles, RR'CO + HCN right and left arrow RR'C(OH)CN. If ammonia is also present, the alpha-hydroxy nitriles will exist in equilibrium with the alpha-amino nitriles, RR'C(OH)CN + NH3 right and left arrow - RRCNH2CN + H2O. Both nitrites are hydrolyzed by water to form carboxylic acids: RR'C(OH)CN + H2O yields RR'C(OH)CO2H and RR'C(NH2)CN + H2O yields RR'C(NH2)CO2H.

  2. Insights into the formation mechanism of chloropropanol fatty acid esters under laboratory-scale deodorization conditions.

    PubMed

    Hori, Katsuhito; Hori-Koriyama, Natsuko; Tsumura, Kazunobu; Fukusaki, Eiichiro; Bamba, Takeshi

    2016-08-01

    Chloropropanol fatty acid esters (CPFAEs) are well-known contaminants in refined oils and fats, and several research groups have studied their formation. However, the results obtained in these studies were not satisfactory because the CPFAEs were not analyzed comprehensively. Thus, in the present study, a comprehensive analysis was performed to obtain new details about CPFAE formation. Each lipid (monopalmitin, dipalmitin, tripalmitin, monoolein, diolein, triolein, and crude palm oil) was heated at 250°C for 90 min, and the CPFAEs were analyzed using supercritical fluid chromatography/tandem mass spectrometry. It was found that CP fatty acid monoesters were formed from monoacylglycerols and diacylglycerols after heating in the presence of a chlorine compound. In addition, CP fatty acid diesters were formed from diacylglycerols and triacylglycerols under the same conditions. In the case of crude palm oil, only CP fatty acid diesters were formed. Therefore, these results indicated that CPFAEs in refined palm oil were formed mainly from triacylglycerols. PMID:26822095

  3. Culture Conditions stimulating high γ-Linolenic Acid accumulation by Spirulina platensis

    PubMed Central

    Ronda, Srinivasa Reddy; Lele, S.S.

    2008-01-01

    Gamma-linolenic acid (GLA) production by Spirulina platensis under different stress-inducing conditions was studied. Submerged culture studies showed that low temperature (25°C), strong light intensity (6 klux) and primrose oil supplement (0.8%w/v) induced 13.2 mg/g, 14.6 mg/g and 13.5 mg linolenic acid per gram dry cell weight respectively. A careful observation of fatty acid profile of the cyanobacteria shows that, oleic acid and linoleic acid, in experiments with varying growth temperature and oil supplements respectively, helped in accumulating excess γ-linolenic acid. In addition, cultures grown at increasing light regimes maintained the γ-linolenic acid to the total fatty acid ratio(GLA/TFA) constant, despite any change in γ-linolenic acid content of the cyanobacteria. PMID:24031291

  4. Dewaterability of sludge conditioned with surfactant DDBAC pretreatment by acid/alkali.

    PubMed

    Hong, Chen; Xing, Yi; Hua, Xiufu; Si, Yanxiao; Qiao, Geng; Wang, Zhiqiang

    2015-07-01

    The potential benefits of surfactant-conditioned sludge dewatering treatment with acid/alkali pretreatment were investigated in this study. The water content of dewatered sludge (W C) and specific resistance of filtration (SRF) were used to evaluate sludge dewaterability. Extracellular polymeric substance (EPS) content, bound water content, zeta potential, and rheological properties were measured to explain the change of dewaterability observed in the conditioning process. By introducing dodecyl dimethyl benzyl ammonium chloride (DDBAC), the EPS content of the sludge supernatant changed, and bound water content, charge strength, and apparent viscosity decreased simultaneously. Although DDBAC-conditioned sludge in strong alkaline had low bound water content, W C and SRF increased rapidly because of the dramatically increasing of EPS in sludge supernatant. Remarkable decrement was observed in bound water content and W C in DDBAC-conditioned sludge which was in weak acid environment for comparison. The results indicated that 75 mg/g of DDBAC at pH 4.84 was the optimum under which W C and SRF were at their lowest point in sludge, 58.22 % and 0.521 × 10(13) m/kg, respectively. PMID:25744646

  5. Long-term geochemical evolution of acidic mine wastes under anaerobic conditions.

    PubMed

    Lu, Wenzhou; Lin, Chuxia; Ma, Yingqun

    2013-08-01

    A nearly 5-year anaerobic incubation experiment was conducted to observe the geochemical evolution of an acidic mine waste. Long-term storage of the mine waste under strict anaerobic conditions caused marked increase in aqueous sulfur, while aqueous iron showed no remarkable change. Co-existing oxidation and reduction of elemental sulfur appeared to play a central role in controlling the evolutionary trends of aqueous sulfur and iron. Addition of organic matter increased the aqueous Fe concentration, possibly due to enhanced iron mobilization by microbial iron reduction and increased iron solubility by forming organically complexed Fe species. Further addition of CaCO3 resulted in immobilization of aqueous iron and sulfur due to elevated pH and gypsum formation. The chemical behaviors of environmentally significant metals were markedly affected by the added organic matter; Al, Cr, Cu, Ni and Zn tended to be immobilized probably due to elevated pH and complexation with insoluble organic molecules, while As and Pb tended to be mobilized. Jarosite exhibited high stability after nearly 5 years of anaerobic incubation and even under circumneutral pH conditions. Long-term weathering of aluminosilicate through acid attack raised pH, while continuous reaction between the added CaCO3 and mine waste-borne stored acid decreased pH. PMID:23529626

  6. Chemometric analysis of the interactions among different parameters describing health conditions, breast cancer risk and fatty acids profile in serum of rats supplemented with conjugated linoleic acids.

    PubMed

    Białek, Agnieszka; Zagrodzki, Paweł; Tokarz, Andrzej

    2016-03-01

    We investigated how different doses of conjugated linoleic acids applied for various periods of time influence breast cancer risk and fatty acids profile in serum of rats treated or not with 7,12-dimethylbenz[a]anthracene (DMBA). We also search for interactions among parameters describing health conditions and cancer risk. Animals were divided into 18 groups with different diet modifications (vegetable oil, 1.0%, 2.0% additions of CLA) and different periods of supplementation. In groups treated with DMBA mammary adenocarcinomas appeared. Due to the complexity of experiment apart from statistical analysis a chemometric tool-Partial Least Square method was applied. Analysis of pairs of correlated parameters allowed to identify some regularities concerning the relationships between fatty acid profiles and clinical features of animals. Fatty acids profile was the result of prolonged exposure to high dose of CLA and DMBA administration. These two factors underlined the differences in fatty acids profiles among clusters of animals. PMID:26926361

  7. Contribution of acetic acid to the hydrolysis of lignocellulosic biomass under abiotic conditions.

    PubMed

    Trzcinski, Antoine P; Stuckey, David C

    2015-06-01

    Acetic acid was used in abiotic experiments to adjust the solution pH and investigate its influence on the chemical hydrolysis of the Organic Fraction of Municipal Solid Waste (OFMSW). Soluble chemical oxygen demand (SCOD) was used to measure the hydrolysis under oxidative conditions (positive oxidation-reduction potential values), and pH 4 allowed for 20% (±2%) of the COD added to be solubilized, whereas only 12% (±1%) was solubilized at pH7. Under reducing conditions (negative oxidation-reduction potential values) and pH 4, 32.3% (±3%) of the OFMSW was solubilized which shows that acidogenesis at pH 4 during the anaerobic digestion of solid waste can result in chemical hydrolysis. In comparison, bacterial hydrolysis resulted in 54% (±6%) solubilization. PMID:25794810

  8. Effects of inescapable shock and conditioned fear on the release of excitatory and inhibitory amino acids in the locus coeruleus.

    PubMed

    Kaehler, S T; Sinner, C; Kouvelas, D; Philippu, A

    2000-02-01

    electric shock. The results suggest that an excitatory amino acid (aspartate) and an inhibitory amino acid (taurine) of the locus coeruleus are implicated in conditioned fear. PMID:10685876

  9. Gas dilution system results and application to acid rain utilities

    SciTech Connect

    Jolley-Souders, K.; Geib, R.; Dunn, C.

    1997-12-31

    In 1997, the United States EPA will remove restrictions preventing acid rain utilities from using gas dilution systems for calibration or linearity studies for continuous emissions monitoring, Test Method 205 in 40CFR51 requires that a gas dilution system must produce calibration gases whose measured values are within {+-}2% of predicted values. This paper presents the evaluation of the Environics/CalMat 2020 Dilution System for use in calibration studies. Internal studies show that concentrations generated by this unit are within {+-}0.5% of predicted values. Studies are being conducted by several acid rain utilities to evaluate the Environics/CalMat system using single minor component calibration standards. In addition, an internally generated study is being performed to demonstrate the system`s accuracy using a multi-component gas mixture. Data from these tests will be presented in the final version of the paper.

  10. Laboratory simulations of acid-sulfate weathering under volcanic hydrothermal conditions: Implications for early Mars

    PubMed Central

    Marcucci, Emma C; Hynek, Brian M

    2014-01-01

    We have completed laboratory experiments and thermochemical equilibrium models to investigate secondary mineral formation under conditions akin to volcanic, hydrothermal acid-sulfate weathering systems. Our research used the basaltic mineralogy at Cerro Negro Volcano, Nicaragua, characterized by plagioclase, pyroxene, olivine, and volcanic glass. These individual minerals and whole-rock field samples were reacted in the laboratory with 1 molal sulfuric acid at varying temperatures (65, 150, and 200°C), fluid:rock weight ratios (1:1, 4:1, and 10:1), and durations (1–60 days). Thermochemical equilibrium models were developed using Geochemist's Workbench. To understand the reaction products and fluids, we employed scanning electron microscopy/energy dispersive spectroscopy, X-ray diffraction, and inductively coupled plasma-atomic emission spectroscopy. The results of our experiments and models yielded major alteration minerals that include anhydrite, natroalunite, minor iron oxide, and amorphous Al-Si gel. We found that variations in experimental parameters did not drastically change the suite of minerals produced; instead, abundance, size, and crystallographic shape changed. Our results also suggest that it is essential to separate phases formed during experiments from those formed during fluid evaporation to fully understand the reaction processes. Our laboratory reacted and model predicted products are consistent with the mineralogy observed at places on Mars. However, our results indicate that determination of the formation conditions requires microscopic imagery and regional context, as well as a thorough understanding of contributions from both experiment precipitation and fluid evaporation minerals. PMID:26213665

  11. Laboratory simulations of acid-sulfate weathering under volcanic hydrothermal conditions: Implications for early Mars

    NASA Astrophysics Data System (ADS)

    Marcucci, Emma C.; Hynek, Brian M.

    2014-03-01

    We have completed laboratory experiments and thermochemical equilibrium models to investigate secondary mineral formation under conditions akin to volcanic, hydrothermal acid-sulfate weathering systems. Our research used the basaltic mineralogy at Cerro Negro Volcano, Nicaragua, characterized by plagioclase, pyroxene, olivine, and volcanic glass. These individual minerals and whole-rock field samples were reacted in the laboratory with 1 molal sulfuric acid at varying temperatures (65, 150, and 200°C), fluid:rock weight ratios (1:1, 4:1, and 10:1), and durations (1-60 days). Thermochemical equilibrium models were developed using Geochemist's Workbench. To understand the reaction products and fluids, we employed scanning electron microscopy/energy dispersive spectroscopy, X-ray diffraction, and inductively coupled plasma-atomic emission spectroscopy. The results of our experiments and models yielded major alteration minerals that include anhydrite, natroalunite, minor iron oxide, and amorphous Al-Si gel. We found that variations in experimental parameters did not drastically change the suite of minerals produced; instead, abundance, size, and crystallographic shape changed. Our results also suggest that it is essential to separate phases formed during experiments from those formed during fluid evaporation to fully understand the reaction processes. Our laboratory reacted and model predicted products are consistent with the mineralogy observed at places on Mars. However, our results indicate that determination of the formation conditions requires microscopic imagery and regional context, as well as a thorough understanding of contributions from both experiment precipitation and fluid evaporation minerals.

  12. Hetropolyacid-Catalyzed Oxidation of Glycerol into Lactic Acid under Mild Base-Free Conditions.

    PubMed

    Tao, Meilin; Yi, Xiaohu; Delidovich, Irina; Palkovits, Regina; Shi, Junyou; Wang, Xiaohong

    2015-12-21

    Lactic acid (LA) is a versatile platform molecule owing to the opportunity to transform this compound into useful chemicals and materials. Therefore, efficient production of LA based on inexpensive renewable feedstocks is of utmost importance for insuring its market availability. Herein, we report the efficient conversion of glycerol into LA catalyzed by heteropolyacids (HPAs) under mild base-free conditions. The catalytic performance of molecular HPAs appears to correlate with their redox potential and Brønsted acidity. Namely, H3 PMo(12)O(40) (HPMo) exhibits the best selectivity towards LA (90 %) with 88 % conversion of glycerol. Loading of HPMo onto a carbon support (HPMo/C) further improves LA productivity resulting in 94 % selectivity at 98 % conversion under optimized reaction conditions. The reaction takes place through the formation of dihydroxyacetone/glyceraldehyde and pyruvaldehyde as intermediates. No leaching of HPMo was observed under the applied reaction conditions and HPMo/C could be recycled 5 times without significant loss of activity. PMID:26611678

  13. Leaching of Glyphosate and Aminomethylphosphonic Acid through Silty Clay Soil Columns under Outdoor Conditions.

    PubMed

    Napoli, Marco; Cecchi, Stefano; Zanchi, Camillo A; Orlandini, Simone

    2015-09-01

    Glyphosate [-(phosphono-methyl)-glycine] is the main herbicide used in the Chianti vineyards. Considering the pollution risk of the water table and that the vineyard tile drain may deliver this pollutant into nearby streams, the objective of the present study was to estimate the leaching losses of glyphosate under natural rainfall conditions in a silty clay soil in the Chianti area. The leaching of glyphosate and its metabolite (aminomethylphosphonic acid [AMPA]) through soils was studied in 1-m-deep soil columns under outdoor conditions over a 3-yr period. Glyphosate was detected in the leachates for up to 26 d after treatments at concentrations ranging between 0.5 and 13.5 μg L. The final peak (0.28 μg L) appeared in the leachates approximately 319 d after the first annual treatment. Aminomethylphosphonic acid first appeared (21.3 μg L) in the soil leachate 6.8 d after the first annual treatment. Aminomethylphosphonic acid detection frequency and measured concentration in the leachates were more than that observed for the glyphosate. Aminomethylphosphonic acid was detected in 20% of the soil leachates at concentrations ranging from 1 to 24.9 μg L. No extractable glyphosate was detected in the soil profile. However, the AMPA content in the lowest layer ranged from 13.4 to 21.1 mg kg, and on the surface layer, it ranged from 86.7 to 94 mg kg. Overall, these results indicate that both glyphosate and AMPA leaching through a 1-m soil column may be potential groundwater contaminants. PMID:26436283

  14. Fatty acids, essential oil, and phenolics modifications of black cumin fruit under NaCl stress conditions.

    PubMed

    Bourgou, Soumaya; Bettaieb, Iness; Saidani, Moufida; Marzouk, Brahim

    2010-12-01

    This research evaluated the effect of saline conditions on fruit yield, fatty acids, and essential oils compositions and phenolics content of black cumin (Nigella sativa). This plant is one of the most commonly found aromatics in the Mediterranean kitchen. Increasing NaCl levels to 60 mM decreased significantly the fruits yield by 58% and the total fatty acids amount by 35%. Fatty acids composition analysis indicated that linoleic acid was the major fatty acid (58.09%) followed by oleic (19.21%) and palmitic (14.77%) acids. Salinity enhanced the linoleic acid percentage but did not affect the unsaturation degree of the fatty acids pool and thus the oil quality. The essential oil yield was 0.39% based on the dry weight and increased to 0.53, 0.56, and 0.72% at 20, 40, and 60 mM NaCl. Salinity results on the modification of the essential oil chemotype from p-cymene in controls to γ-terpinene/p-cymene in salt-stressed plants. The amounts of total phenolics were lower in the treated plants. Salinity decreased mainly the amount of the major class, benzoics acids, by 24, 29, and 44% at 20, 40, and 60 mM NaCl. The results suggest that salt treatment may regulate bioactive compounds production in black cumin fruits, influencing their nutritional and industrial values. PMID:21049998

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  16. Pickled egg production: effect of brine acetic acid concentration and packing conditions on acidification rate.

    PubMed

    Acosta, Oscar; Gao, Xiaofan; Sullivan, Elizabeth K; Padilla-Zakour, Olga I

    2014-05-01

    U.S. federal regulations require that acidified foods must reach a pH of 4.6 or lower within 24 h of packaging or be kept refrigerated until then. Processes and formulations should be designed to satisfy this requirement, unless proper studies demonstrate the safety of other conditions. Our objective was to determine the effect of brine acetic acid concentration and packing conditions on the acidification rate of hard-boiled eggs. Eggs were acidified (60/40 egg-to-brine ratio) at various conditions of brine temperature, heat treatment to filled jars, and postpacking temperature: (i) 25 °C/none/25 °C (cold fill), (ii) 25 °C/none/2 °C (cold fill/refrigerated), (iii) 85 °C/none/25 °C (hot fill), and (iv) 25 °C/100 °C for 16 min/25 °C (water bath). Three brine concentrations were evaluated (7.5, 4.9, and 2.5% acetic acid) and egg pH values (whole, yolk, four points within egg) were measured from 4 to 144 h, with eggs equilibrating at pH 3.8, 4.0, and 4.3, respectively. Experiments were conducted in triplicate, and effects were considered significant when P < 0.05. Multiple linear regression analysis was conducted to evaluate the effect on pH values at the center of the yolk. Regression analysis showed that brine concentration of 2.5% decreased the acidification rate, while packing conditions of the hot fill trial increased it. Inverse prediction was used to determine the time for the center of the yolk and the total yolk to reach a pH value of 4.6. These results demonstrate the importance of conducting acidification studies with proper pH measurements to determine safe conditions to manufacture commercially stable pickled eggs. PMID:24780334

  17. Gas-Phase Formation Rates of Nitric Acid and Its Isomers Under Urban Conditions

    NASA Technical Reports Server (NTRS)

    Okumura, M.; Mollner, A. K.; Fry, J. L.; Feng, L.

    2005-01-01

    Ozone formation in urban smog is controlled by a complex set of reactions which includes radical production from photochemical processes, catalytic cycles which convert NO to NO2, and termination steps that tie up reactive intermediates in long-lived reservoirs. The reaction OH + NO2 + M -4 HONO2 + M (la) is a key termination step because it transforms two short-lived reactive intermediates, OH and NO2, into relatively long-lived nitric acid. Under certain conditions (low VOC/NOx), ozone production in polluted urban airsheds can be highly sensitive to this reaction, but the rate parameters are not well constrained. This report summarizes the results of new laboratory studies of the OH + NO2 + M reaction including direct determination of the overall rate constant and branching ratio for the two reaction channels under atmospherically relevant conditions.

  18. Formation of phenol under conditions of the reaction of oxidative carbonylation of benzene to benzoic acid

    SciTech Connect

    Kalinovsky, I.O.; Leshcheva, A.N.; Pogorelov, V.V.; Gelbshtein, A.I.

    1993-12-31

    This paper describes conditions for the oxidation of benzene to phenol. It is shown that a reaction mixture of water, carbon monoxide, and oxygen are essential to the oxidation. The oxidation is a side reaction found to occur during the oxidative carbonylation of benzene to benzoic acid in a medium of trifluoroacetic acid.

  19. Polysaccharides isolated from sugar beet pulp by quaternization under acidic conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugar beet pulp was extracted and chemically modified under acidic conditions using glycidyltrimethylammonium chloride in the presence of trifuoroacetic (TFA), HCl or H3PO4. The goal was to find out how the type of acid used and quaternization could affect the yield of soluble polysaccharide, its mo...

  20. Intracellular pH Recovery Rates in Bivalve Hemocytes Following Exposure to Acidic Environmental Conditions

    NASA Astrophysics Data System (ADS)

    Croxton, A.; Wikfors, G. H.

    2012-12-01

    Predictions of ocean acidification effects upon carbonate shell-forming species have caused great concern for the future of shellfisheries. Nevertheless, bivalve species inhabiting an estuarine environment have evolved in these environments with fluctuating pH levels. Previous experimental studies conducted in our laboratory have demonstrated the ability of oyster hemocytes to maintain intracellular homeostasis under acidic external conditions. However, little information is known of this homeostatic mechanism in other molluscan shellfish species present in these same habitats. In the current study we propose to determine if other bivalve species of aquaculture interest also possess this intracellular regulation by applying an in vitro hemocyte pH-recovery assay, previously developed for oysters, on the northern quahog, Mercenaria mercenaria, the blue mussel, Mytilus edulis, and the softshell clam, Mya arenaria. Preliminary results from the determination of initial intracellular pH levels, the initial step in the rate recovery assay, indicated a pH range between 7.0-7.4. This range was comparable to initial values measured in oysters, and consistent with data reported in the current literature. The second step of the hemocyte pH-recovery assay involves exposing oyster hemocytes to acidic external conditions and measuring the ability of the hemocyte intracellular pH to maintain homeostasis (i.e. recovery rate). Results from the recovery rate process will be presented.

  1. The stability of some selected amino acids under attempted redox constrained hydrothermal conditions.

    PubMed

    Andersson, E; Holm, N G

    2000-02-01

    In order to evaluate the stability of aspartic acid, serine, leucine, and alanine under redox buffered hydrothermal conditions, a series of experiments have been performed. The pyrite-pyrrhotite-magnetite (PPM) mineral assemblage was used in the experimental systems in order to constrain the oxygen fugacity. Likewise, the K-feldspar-muscovite-quartz (KMQ) assemblage was added to control the hydrogen ion activity during the experiments. The purpose was to compare the relative stabilities in buffered and unbuffered experiments. The experiments were conducted at 200 degrees C and 50 bar in Teflon coated autoclaves. Glycine, which was not present initially, started to appear at an early stage in the experimental systems and is believed to be the result of decomposition of serine. Similarly, the increase in relative abundance of alanine is likely to be the result of decomposition of serine. Decomposition rates of leucine, alanine and aspartic acid were found to be lower in experiments containing the redox buffer assemblage pyrite-pyrrhotite-magnetite than in non-redox buffered experiments. The decomposition rate of serine was higher in buffered experiments, which indicates that a transformation pathway via dehydration of serine to dehydroalanine followed by reduction to alanine is promoted by reducing conditions. PMID:10836261

  2. Chemoselective O-acylation of hydroxyamino acids and amino alcohols under acidic reaction conditions: History, scope and applications.

    PubMed

    Kristensen, Tor E

    2015-01-01

    Amino acids, whether natural, semisynthetic or synthetic, are among the most important and useful chiral building blocks available for organic chemical synthesis. In principle, they can function as inexpensive, chiral and densely functionalized starting materials. On the other hand, the use of amino acid starting materials routinely necessitates protective group chemistry, and in reality, large-scale preparations of even the simplest side-chain derivatives of many amino acids often become annoyingly strenuous due to the necessity of employing protecting groups, on one or more of the amino acid functionalities, during the synthetic sequence. However, in the case of hydroxyamino acids such as hydroxyproline, serine, threonine, tyrosine and 3,4-dihydroxyphenylalanine (DOPA), many O-acyl side-chain derivatives are directly accessible via a particularly expedient and scalable method not commonly applied until recently. Direct acylation of unprotected hydroxyamino acids with acyl halides or carboxylic anhydrides under appropriately acidic reaction conditions renders possible chemoselective O-acylation, furnishing the corresponding side-chain esters directly, on multigram-scale, in a single step, and without chromatographic purification. Assuming a certain degree of stability under acidic reaction conditions, the method is also applicable for a number of related compounds, such as various amino alcohols and the thiol-functional amino acid cysteine. While the basic methodology underlying this approach has been known for decades, it has evolved through recent developments connected to amino acid-derived chiral organocatalysts to become a more widely recognized procedure for large-scale preparation of many useful side-chain derivatives of hydroxyamino acids and related compounds. Such derivatives are useful in peptide chemistry and drug development, as amino acid amphiphiles for asymmetric catalysis, and as amino acid acrylic precursors for preparation of catalytically

  3. Chemoselective O-acylation of hydroxyamino acids and amino alcohols under acidic reaction conditions: History, scope and applications

    PubMed Central

    2015-01-01

    Summary Amino acids, whether natural, semisynthetic or synthetic, are among the most important and useful chiral building blocks available for organic chemical synthesis. In principle, they can function as inexpensive, chiral and densely functionalized starting materials. On the other hand, the use of amino acid starting materials routinely necessitates protective group chemistry, and in reality, large-scale preparations of even the simplest side-chain derivatives of many amino acids often become annoyingly strenuous due to the necessity of employing protecting groups, on one or more of the amino acid functionalities, during the synthetic sequence. However, in the case of hydroxyamino acids such as hydroxyproline, serine, threonine, tyrosine and 3,4-dihydroxyphenylalanine (DOPA), many O-acyl side-chain derivatives are directly accessible via a particularly expedient and scalable method not commonly applied until recently. Direct acylation of unprotected hydroxyamino acids with acyl halides or carboxylic anhydrides under appropriately acidic reaction conditions renders possible chemoselective O-acylation, furnishing the corresponding side-chain esters directly, on multigram-scale, in a single step, and without chromatographic purification. Assuming a certain degree of stability under acidic reaction conditions, the method is also applicable for a number of related compounds, such as various amino alcohols and the thiol-functional amino acid cysteine. While the basic methodology underlying this approach has been known for decades, it has evolved through recent developments connected to amino acid-derived chiral organocatalysts to become a more widely recognized procedure for large-scale preparation of many useful side-chain derivatives of hydroxyamino acids and related compounds. Such derivatives are useful in peptide chemistry and drug development, as amino acid amphiphiles for asymmetric catalysis, and as amino acid acrylic precursors for preparation of

  4. Increased betulinic acid induced cytotoxicity and radiosensitivity in glioma cells under hypoxic conditions

    PubMed Central

    2011-01-01

    Background Betulinic acid (BA) is a novel antineoplastic agent under evaluation for tumor therapy. Because of the selective cytotoxic effects of BA in tumor cells (including gliomas), the combination of this agent with conservative therapies (such as radiotherapy and chemotherapy) may be useful. Previously, the combination of BA with irradiation under hypoxic conditions had never been studied. Methods In this study, the effects of 3 to 30 μM BA on cytotoxicity, migration, the protein expression of PARP, survivin and HIF-1α, as well as radiosensitivity under normoxic and hypoxic conditions were analyzed in the human malignant glioma cell lines U251MG and U343MG. Cytotoxicity and radiosensitivity were analyzed with clonogenic survival assays, migration was analyzed with Boyden chamber assays (or scratch assays) and protein expression was examined with Western blot analyses. Results Under normoxic conditions, a half maximal inhibitory concentration (IC50) of 23 μM was observed in U251MG cells and 24 μM was observed in U343MG cells. Under hypoxic conditions, 10 μM or 15 μM of BA showed a significantly increased cytotoxicity in U251MG cells (p = 0.004 and p = 0.01, respectively) and U343MG cells (p < 0.05 and p = 0.01, respectively). The combination of BA with radiotherapy resulted in an additive effect in the U343MG cell line under normoxic and hypoxic conditions. Weak radiation enhancement was observed in U251MG cell line after treatment with BA under normoxic conditions. Furthermore, under hypoxic conditions, the incubation with BA resulted in increased radiation enhancement. The enhancement factor, at an irradiation dose of 15 Gy after treatment with 10 or 15 μM BA, was 2.20 (p = 0.02) and 4.50 (p = 0.03), respectively. Incubation with BA led to decreased cell migration, cleavage of PARP and decreased expression levels of survivin in both cell lines. Additionally, BA treatment resulted in a reduction of HIF-1α protein under hypoxic conditions. Conclusion Our

  5. Excellent amino acid racemization results from Holocene sand dollars

    NASA Astrophysics Data System (ADS)

    Kosnik, M.; Kaufman, D. S.; Kowalewski, M.; Whitacre, K.

    2015-12-01

    Amino acid racemization (AAR) is widely used as a cost-effective method to date molluscs in time-averaging and taphonomic studies, but it has not been attempted for echinoderms despite their paleobiological importance. Here we demonstrate the feasibility of AAR geochronology in Holocene aged Peronella peronii (Echinodermata: Echinoidea) collected from Sydney Harbour (Australia). Using standard HPLC methods we determined the extent of AAR in 74 Peronella tests and performed replicate analyses on 18 tests. We sampled multiple areas of two individuals and identified the outer edge as a good sampling location. Multiple replicate analyses from the outer edge of 18 tests spanning the observed range of D/Ls yielded median coefficients of variation < 4% for Asp, Phe, Ala, and Glu D/L values, which overlaps with the analytical precision. Correlations between D/L values across 155 HPLC injections sampled from 74 individuals are also very high (pearson r2 > 0.95) for these four amino acids. The ages of 11 individuals spanning the observed range of D/L values were determined using 14C analyses, and Bayesian model averaging was used to determine the best AAR age model. The averaged age model was mainly composed of time-dependent reaction kinetics models (TDK, 71%) based on phenylalanine (Phe, 94%). Modelled ages ranged from 14 to 5539 yrs, and the median 95% confidence interval for the 74 analysed individuals is ±28% of the modelled age. In comparison, the median 95% confidence interval for the 11 calibrated 14C ages was ±9% of the median age estimate. Overall Peronella yields exceptionally high-quality AAR D/L values and appears to be an excellent substrate for AAR geochronology. This work opens the way for time-averaging and taphonomic studies of echinoderms similar to those in molluscs.

  6. Dietary supply with polyunsaturated fatty acids and resulting maternal effects influence host – parasite interactions

    PubMed Central

    2013-01-01

    Background Interactions between hosts and parasites can be substantially modulated by host nutrition. Polyunsaturated fatty acids (PUFAs) are essential dietary nutrients; they are indispensable as structural components of cell membranes and as precursors for eicosanoids, signalling molecules which act on reproduction and immunity. Here, we explored the potential of dietary PUFAs to affect the course of parasitic infections using a well-established invertebrate host – parasite system, the freshwater herbivore Daphnia magna and its bacterial parasite Pasteuria ramosa. Results Using natural food sources differing in their PUFA composition and by experimentally modifying the availability of dietary arachidonic acid (ARA) and eicosapentaenoic acid (EPA) we examined PUFA-mediated effects resulting from direct consumption as well as maternal effects on offspring of treated mothers. We found that both host and parasite were affected by food quality. Feeding on C20 PUFA-containing food sources resulted in higher offspring production of hosts and these effects were conveyed to a great extent to the next generation. While feeding on a diet containing high PUFA concentrations significantly reduced the likelihood of becoming infected, the infection success in the next generation increased whenever the maternal diet contained PUFAs. We suggest that this opposing effect was caused by a trade-off between reproduction and immunity in the second generation. Conclusions Considering the direct and maternal effects of dietary PUFAs on host and parasite we propose that host – parasite interactions and thus disease dynamics under natural conditions are subject to the availability of dietary PUFAs. PMID:24175981

  7. Structural Characterization of the Degradation Products of a Minor Natural Sweet Diterpene Glycoside Rebaudioside M under Acidic Conditions

    PubMed Central

    Prakash, Indra; Chaturvedula, Venkata Sai Prakash; Markosyan, Avetik

    2014-01-01

    Degradation of rebaudioside M, a minor sweet component of Stevia rebaudiana Bertoni, under conditions that simulated extreme pH and temperature conditions has been studied. Thus, rebaudioside M was treated with 0.1 M phosphoric acid solution (pH 2.0) and 80 °C temperature for 24 h. Experimental results indicated that rebaudioside M under low pH and higher temperature yielded three minor degradation compounds, whose structural characterization was performed on the basis of 1D (1H-, 13C-) & 2D (COSY, HSQC, HMBC) NMR, HRMS, MS/MS spectral data as well as enzymatic and acid hydrolysis studies. PMID:24424316

  8. Structural characterization of the degradation products of a minor natural sweet diterpene glycoside Rebaudioside M under acidic conditions.

    PubMed

    Prakash, Indra; Chaturvedula, Venkata Sai Prakash; Markosyan, Avetik

    2014-01-01

    Degradation of rebaudioside M, a minor sweet component of Stevia rebaudiana Bertoni, under conditions that simulated extreme pH and temperature conditions has been studied. Thus, rebaudioside M was treated with 0.1 M phosphoric acid solution (pH 2.0) and 80 °C temperature for 24 h. Experimental results indicated that rebaudioside M under low pH and higher temperature yielded three minor degradation compounds, whose structural characterization was performed on the basis of 1D (1H-, 13C-) & 2D (COSY, HSQC, HMBC) NMR, HRMS, MS/MS spectral data as well as enzymatic and acid hydrolysis studies. PMID:24424316

  9. Relative importance of nitrite oxidation by hypochlorous acid under chloramination conditions.

    PubMed

    Wahman, David G; Speitel, Gerald E

    2012-06-01

    Nitrification can occur in water distribution systems where chloramines are used as the disinfectant. The resulting product, nitrite, can be oxidized by monochloramine and hypochlorous acid (HOCl), potentially leading to rapid monochloramine loss. This research characterizes the importance of the HOCl reaction, which has typically been ignored because of HOCl's low concentration. Also, the general acid-assisted rate constants for carbonic acid and bicarbonate ion were estimated for the monochloramine reaction. The nitrite oxidation reactions were incorporated into a widely accepted chloramine autodecomposition model, providing a comprehensive model that was implemented in AQUASIM. Batch kinetic experiments were conducted to evaluate the significance of the HOCl reaction and to estimate carbonate buffer rate constants for the monochloramine reaction. The experimental data and model simulations indicated that HOCl may be responsible for up to 60% of the nitrite oxidation, and that the relative importance of the HOCl reaction for typical chloramination conditions peaks between pH 7.5 and 8.5, generally increasing with (1) decreasing nitrite concentration, (2) increasing chlorine to nitrogen mass ratio, and (3) decreasing monochloramine concentration. Therefore, nitrite's reaction with HOCl may be important during chloramination and should be included in water quality models to simulate nitrite and monochloramine's fate. PMID:22571335

  10. Tetrahydrocannabinolic acid reduces nausea-induced conditioned gaping in rats and vomiting in Suncus murinus

    PubMed Central

    Rock, E M; Kopstick, R L; Limebeer, C L; Parker, L A

    2013-01-01

    BACKGROUND AND PURPOSE We evaluated the anti-emetic and anti-nausea properties of the acid precursor of Δ9-tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), and determined its mechanism of action in these animal models. EXPERIMENTAL APPROACH We investigated the effect of THCA on lithium chloride- (LiCl) induced conditioned gaping (nausea-induced behaviour) to a flavour, and context (a model of anticipatory nausea) in rats, and on LiCl-induced vomiting in Suncus murinus. Furthermore, we investigated THCA's ability to induce hypothermia and suppress locomotion [rodent tasks to assess cannabinoid1 (CB1) receptor agonist-like activity], and measured plasma and brain THCA and THC levels. We also determined whether THCA's effect could be blocked by pretreatment with SR141716 (SR, a CB1 receptor antagonist). KEY RESULTS In rats, THCA (0.05 and/or 0.5 mg·kg−1) suppressed LiCl-induced conditioned gaping to a flavour and context; the latter effect blocked by the CB1 receptor antagonist, SR, but not by the 5-hydroxytryptamine-1A receptor antagonist, WAY100635. In S. murinus, THCA (0.05 and 0.5 mg·kg−1) reduced LiCl-induced vomiting, an effect that was reversed with SR. A comparatively low dose of THC (0.05 mg·kg−1) did not suppress conditioned gaping to a LiCl-paired flavour or context. THCA did not induce hypothermia or reduce locomotion, indicating non-CB1 agonist-like effects. THCA, but not THC was detected in plasma samples. CONCLUSIONS AND IMPLICATIONS THCA potently reduced conditioned gaping in rats and vomiting in S. murinus, effects that were blocked by SR. These data suggest that THCA may be a more potent alternative to THC in the treatment of nausea and vomiting. PMID:23889598

  11. Fungicidal mechanism of action of D0870 against Cryptococcus neoformans under acidic conditions.

    PubMed Central

    Yamada, H; Watanabe, T; Kato, K; Mochizuki, H

    1997-01-01

    The fungicidal mechanism of the triazole D0870 against Cryptococcus neoformans under acidic conditions was investigated. D0870 reduced the intracellular K+ content of C. neoformans at pH 4 to about half the value at pH 7 after 12 h of incubation. The 50% inhibitory concentrations of D0870 for ergosterol biosynthesis were almost the same at both pH 4 (0.017 microg/ml) and 7 (0.014 microg/ml); however, D0870 caused a marked accumulation of an unknown lipid and methylated sterols in C. neoformans cultured at pH 4. Extracted fractions containing the unknown lipid or methylated sterols showed strong fungicidal activities against C. neoformans both at pH 4 and 7 in phosphate-citrate buffer not containing D0870. Gas chromatographic-mass spectrometric analysis showed that the unknown lipid was obtusifolione. These results suggest that D0870 kills C. neoformans by disturbing the permeability of the cell membrane through the accumulation of obtusifolione and methylated sterols in the cell membrane under acidic conditions. PMID:9420043

  12. Carboxymethylcellulose Obtained by Ethanol/Water Organosolv Process Under Acid Conditions

    NASA Astrophysics Data System (ADS)

    Ruzene, Denise S.; Gonçalves, Adilson R.; Teixeira, José A.; Pessoa de Amorim, Maria T.

    Sugar cane bagasse pulps were obtained by ethanol/water organosolv process under acid and alkaline conditions. The best condition of acid pulping for the sugarcane bagasse was 0.02 mol/L sulfuric acid at 160°C, for 1h, whereas the best condition for alkaline pulping was 5% sodium hydroxide (base pulp) at 160°C, for 3h. For the residual lignin removal, the acid and alkaline pulps were submitted to a chemical bleaching using sodium chlorite. Pulps under acid and alkaline conditions bleached with sodium chlorite presented viscosities of 3.6 and 7.8 mPas, respectively, and μ-kappa numbers of 1.1 and 2.4, respectively. The pulp under acid condition, bleached with sodium chlorite was used to obtain carboxymethylcellulose (CMC). CMC yield was 35% (pulp based), showing mass gain after the carboxymethylation reaction corresponding to 23.6% of substitution or 0.70 groups-CH2COONa per unit of glucose residue. The infrared spectra showed the CMC characteristic bands and by the infrared technique it was possible to obtain a substitution degree (0.63), similar to the substitution degree calculated by mass gain (0.70).

  13. Optimizing ultrasonic ellagic acid extraction conditions from infructescence of Platycarya strobilacea using response surface methodology.

    PubMed

    Zhang, Liang-Liang; Xu, Man; Wang, Yong-Mei; Wu, Dong-Mei; Chen, Jia-Hong

    2010-11-01

    The infructescence of Platycarya strobilacea is a rich source of ellagic acid (EA) which has shown antioxidant, anticancer and antimutagen properties. Response surface methodology (RSM) was used to optimize the conditions for ultrasonic extraction of EA from infructescence of P. strobilacea. A central composite design (CCD) was used for experimental design and analysis of the results to obtain the optimal processing parameters. The content of EA in the extracts was determined by HPLC with UV detection. Three independent variables such as ultrasonic extraction temperature (°C), liquid:solid ratio (mL/g), and ultrasonic extraction time (min) were investigated. The experimental data obtained were fitted to a quadratic equation using multiple regression analysis and also analyzed by appropriate statistical methods. The 3-D response surface and the contour plots derived from the mathematical models were applied to determine the optimal conditions. The optimum ultrasonic extraction conditions were as follows: ultrasonic extraction temperature 70 °C, liquid:solid ratio 22.5, and ultrasonic extraction time 40 min. Under these conditions, the experimental percentage value was 1.961%, which is in close agreement with the value predicted by the model. PMID:21060299

  14. Screening and characterization of Isochrysis strains and optimization of culture conditions for docosahexaenoic acid production.

    PubMed

    Liu, Jin; Sommerfeld, Milton; Hu, Qiang

    2013-06-01

    Isochrysis is a genus of marine unicellular microalgae that produces docosahexaenoic acid (DHA, C22:6), a very long chain polyunsaturated fatty acid (PUFA) of significant health and nutritional value. Mass cultivation of Isochrysis for DHA production for human consumption has not been established due to disappointing low DHA productivity obtained from commonly used Isochrysis strains. In this study, 19 natural Isochrysis strains were screened for DHA yields and the results showed that the cellular DHA content ranged from 6.8 to 17.0 % of total fatty acids with the highest DHA content occurring in the exponential growth phase. Isochrysis galbana #153180 exhibited the greatest DHA production potential and was selected for further investigation. The effects of different light intensities, forms, and concentrations of nitrogen, phosphorus, and salinity on growth and DHA production of I. galbana #153180 were studied in a bubble column photobioreactor (PBR). Under favorable culture conditions, I. galbana #153180 contained DHA up to 17.5 % of total fatty acids or 1.7 % of cell dry weight. I. galbana #153180 was further tested in outdoor flat-plate PBRs varying in light path length, starting cell density (SCD), and culture mode (batch versus semicontinuous). When optimized, record high biomass and DHA productivity of I. galbana #153180 of 0.72 g L(-1) day(-1) and 13.6 mg L(-1) day(-1), or 26.4 g m(-2) day(-1) and 547.7 mg m(-2) day(-1), respectively, were obtained, suggesting that I. galbana #153180 may be a desirable strain for commercial production of DHA. PMID:23423326

  15. Dynamics of Nucleic Acid/Cationic Polymer Complexation and Disassembly under Biologically Simulated Conditions Using In Situ Atomic Force Microscopy

    PubMed Central

    Shim, Min Suk; Wang, Xi; Ragan, Regina; Kwon, Young Jik

    2010-01-01

    Elucidating dynamic morphological changes of gene-carrying vectors and their nucleic acid release under varying intracellular conditions has been a technical challenge. Atomic force microscopy (AFM) was employed to observe nucleic acid/polymer polyplexes under endosomal and reducible cytosolic conditions. Both ketalized (acid-degradable) and unmodified (non-degradable) polyethylenimine (PEI) in linear and branched forms were used to prepare plasmid DNA- or siRNA-complexing polyplexes. Then, the polyplexes’ complexation and disassembly were observed by in situ AFM in various differentially changing buffers that represent intracellular conditions. Results demonstrated obvious morphological destruction of DNA/ketalized linear PEI (KL-PEI) polyplexes under mildly acidic endosomal conditions, while no morphological changes were observed by DNA/ketalized branched PEI (KB-PEI) under the same conditions. In addition, siRNA was more efficiently dissociated from KL-PEI than KB-PEI under the same conditions. Non-degradable PEI did not show any evidence that DNA or siRNA was released. Anionic biomacromolecules (e.g., heparan sulfate), which was hypothesized to dissociate nucleic acids from cationic polymers, did not successfully disassemble polyplexes but appeared to be adsorbed on cationic polymers. The in situ AFM results combined with in vitro cellular transfection and gene silencing indicated that efficient endosomal escape of plasmid DNA in a compact polyplex form is required for efficient gene expression. On the contrary, rapid dissociation of siRNA from its cationic carrier is crucial for efficient gene silencing. The findings of this study may provide new insightful information for designing stimuli-responsive nonviral gene vectors as well as expanding tools for investigating nonviral vectors in nano scales under biologically inspired conditions. PMID:20803694

  16. Effect of 1-naphthaleneacetic acid on organic acid exudation by the roots of white lupin plants grown under phosphorus-deficient conditions.

    PubMed

    Gómez, Diego A; Carpena, Ramón O

    2014-09-15

    The effect of NAA (1-naphthaleneacetic acid) on organic acid exudation in white lupin plants grown under phosphorus deficiency was investigated. Plants were sampled periodically for collecting of organic acids (citrate, malate, succinate), and also were used to study the effect on proton extrusion and release of Na(+), K(+), Ca(2+) and Mg(2+). The tissues were later processed to quantify the organic acids in tissues, the phosphorus content and the effects on plant biomass. The exogenous addition of NAA led to an increase in organic acid exudation, but this response was not proportional to the concentration of the dose applied, noticing the largest increments with NAA 10(-8)M. In contrast the increase in root weight was proportional to the dose applied, which shows that with higher doses the roots produced are not of proteoid type. Proton extrusion and the release of cations were related to the NAA dose, the first was proportional to the dose applied and the second inversely proportional. Regarding the analysis of tissues, the results of citrate and phosphorus content in shoots show that the overall status of these parts are the main responsible of the organic acids exuded. NAA served as an enhancer of the organic acid exudation that occurs under phosphorus deficient conditions, with a response that depends on the dose applied, not only in its magnitude, but also in the mechanism of action of the plant hormone. PMID:25046756

  17. Kinetic studies of synthetic metaschoepite under acidic conditions in batch and flow experiments.

    PubMed

    Riba, Olga; Walker, Colin; Ragnarsdottir, K Vala

    2005-10-15

    The weathering and corrosion of depleted uranium (DU) forms a complex series of oxidation reactions, ultimately resulting in metaschoepite, UO3.2H2O. The present work focused on studying the dissolution rate of synthetic UO3. 2H2O using batch and flow-through reactors. Under acidic conditions (pH = 4.4-5.4), atmospheric CO2, room temperature, and 0.1 mionic strength,the log solubility product, log Ksp = 5.26 at equilibrium and a pH-dependent rate law Ro = (0.30 +/- 0.15)[H+]0.83+/-0.1 were established. For consistency, these results were incorporated into the computer program PHREEQC 2.6, and the experimental conditions were simulated. There is generally good agreement between the experimental results and the modeled results. Batch experiments revealed a fast dissolution rate of UO3.2H20 in the first hour, followed by fluctuations in uranium concentration before equilibrium was attained after 3000 h. PMID:16295856

  18. Evaluation of Culture Conditions to Obtain Fatty Acids from Saline Microalgae Species: Dunaliella salina, Sinecosyfis sp., and Chroomonas sp.

    PubMed Central

    Castilla Casadiego, D. A.; Albis Arrieta, A. R.; Angulo Mercado, E. R.; Cervera Cahuana, S. J.; Baquero Noriega, K. S.; Suárez Escobar, A. F.; Morales Avendaño, E. D.

    2016-01-01

    The use of the saline microalgae, Dunaliella salina, Sinecosyfis sp., and Chroomonas sp., was explored as an alternative source for the production of fatty acids using fertilizer and glycerol as culture media. The nutrient medium used contained “Nutrifoliar,” a commercial fertilizer, and/or glycerol, in natural sea water. The microalgae were placed in cultures with different conditions. The parameters that favored the largest production of fatty acids were 24 hours of agitation and illumination, 1620 L/day of air supply, 2.25 L of air/min, and a temperature of 32°C using “Nutrifoliar” as the culture media. Results indicated that, from 3 g of microalgae in wet base of Chroomonas sp., 54.43 mg of oil was produced. The chromatographic characterization of oil obtained revealed the presence of essential fatty acids such as 9,12,15-octadecatrienoic acid (omega-3) and 4,7,10-hexadecatrienoic acid (omega-6) from the species Dunaliella salina. On the other hand, 9,12-octadecadienoic acid (omega-6) and cis-11-eicosenoic acid (omega-9) were identified from the species Chroomonas sp. The temperature variations played an important role in the velocity of growth or the production of the algae biomass, the amount of oil, and the ability to produce fatty acids. PMID:27376085

  19. Effect of oxalic acid treatment on sediment arsenic concentrations and lability under reducing conditions.

    PubMed

    Sun, Jing; Bostick, Benjamin C; Mailloux, Brian J; Ross, James M; Chillrud, Steven N

    2016-07-01

    Oxalic acid enhances arsenic (As) mobilization by dissolving As host minerals and competing for sorption sites. Oxalic acid amendments thus could potentially improve the efficiency of widely used pump-and-treat (P&T) remediation. This study investigates the effectiveness of oxalic acid on As mobilization from contaminated sediments with different As input sources and redox conditions, and examines whether residual sediment As after oxalic acid treatment can still be reductively mobilized. Batch extraction, column, and microcosm experiments were performed in the laboratory using sediments from the Dover Municipal Landfill and the Vineland Chemical Company Superfund sites. Oxalic acid mobilized As from both Dover and Vineland sediments, although the efficiency rates were different. The residual As in both Dover and Vineland sediments after oxalic acid treatment was less vulnerable to microbial reduction than before the treatment. Oxalic acid could thus improve the efficiency of P&T. X-ray absorption spectroscopy analysis indicated that the Vineland sediment samples still contained reactive Fe(III) minerals after oxalic acid treatment, and thus released more As into solution under reducing conditions than the treated Dover samples. Therefore, the efficacy of enhanced P&T must consider sediment Fe mineralogy when evaluating its overall potential for remediating groundwater As. PMID:26970042

  20. Copper binding to soil fulvic and humic acids: NICA-Donnan modeling and conditional affinity spectra.

    PubMed

    Xu, Jinling; Tan, Wenfeng; Xiong, Juan; Wang, Mingxia; Fang, Linchuan; Koopal, Luuk K

    2016-07-01

    Binding of Cu(II) to soil fulvic acid (JGFA), soil humic acids (JGHA, JLHA), and lignite-based humic acid (PAHA) was investigated through NICA-Donnan modeling and conditional affinity spectrum (CAS). It is to extend the knowledge of copper binding by soil humic substances (HS) both in respect of enlarging the database of metal ion binding to HS and obtaining a good insight into Cu binding to the functional groups of FA and HA by using the NICA-Donnan model to unravel the intrinsic and conditional affinity spectra. Results showed that Cu binding to HS increased with increasing pH and decreasing ionic strength. The amount of Cu bound to the HAs was larger than the amount bound to JGFA. Milne's generic parameters did not provide satisfactory predictions for the present soil HS samples, while material-specific NICA-Donnan model parameters described and predicted Cu binding to the HS well. Both the 'low' and 'high' concentration fitting procedures indicated a substantial bidentate structure of the Cu complexes with HS. By means of CAS underlying NICA isotherm, which was scarcely used, the nature of the binding at different solution conditions for a given sample and the differences in binding mode were illustrated. It was indicated that carboxylic group played an indispensable role in Cu binding to HS in that the carboxylic CAS had stronger conditional affinity than the phenolic distribution due to its large degree of proton dissociation. The fact was especially true for JGFA and JLHA which contain much larger amount of carboxylic groups, and the occupation of phenolic sites by Cu was negligible. Comparable amounts of carboxylic and phenolic groups on PAHA and JGHA, increased the occupation of phenolic type sites by Cu. The binding strength of PAHA-Cu and JGHA-Cu was stronger than that of JGFA-Cu and JLHA-Cu. The presence of phenolic groups increased the chance of forming more stable complexes, such as the salicylate-Cu or catechol-Cu type structures. PMID:27061366

  1. A comparative study of thermal and acid inactivation kinetics in fruit juices of Salmonella enterica serovar Typhimurium and Salmonella enterica serovar Senftenberg grown at acidic conditions.

    PubMed

    Alvarez-Ordóñez, Avelino; Fernández, Ana; Bernardo, Ana; López, Mercedes

    2009-11-01

    Acid and heat inactivation in orange and apple juices of Salmonella enterica serovar Typhimurium Colección Española de Cultivos Tipo (i.e., Spanish Type Culture Collection) 443 (CECT 443) (Salmonella Typhimurium) and S. enterica serovar Senftenberg CECT 4384 (Salmonella Senftenberg) grown in buffered brain heart infusion (pH 7.0) and acidified brain heart infusion up to pH 4.5 with acetic, citric, lactic, and hydrochloric acids was evaluated. Acid adaptation induced an adaptive response that increased the subsequent resistance to extreme pH conditions (pH 2.5) and to heat, although the magnitude of these responses differed between the two isolates and fruit juices. The acid resistance in orange juice for acid-adapted cells (D-values of 28.3-34.5 min for Salmonella Senftenberg and 30.0-39.2 min for Salmonella Typhimurium) resulted to be about two to three times higher than that corresponding to non-acid-adapted cells. In apple juice, acid-adapted Salmonella Senftenberg cells survived better than those of Salmonella Typhimurium, obtaining mean D-values of 114.8 +/- 12.3 and 41.9 +/- 2.5 min, respectively. The thermotolerance of non-acid-adapted Salmonella Typhimurium in orange (D(58)-value: 0.028 min) and apple juices (D(58)-value: 0.10 min) was approximately double for acid-adapted cells. This cross-protection to heat was more strongly expressed in Salmonella Senftenberg. D(58)-values obtained for non-acid-adapted cells in orange (0.11 min) and apple juices (0.19 min) increased approximately 10 and 5 times, respectively, after their growth in acidified media. The conditions prevailing during bacterial growth and heat treatment did not significantly influence the z-values observed (6.0 +/- 0.3 degrees C for Salmonella Typhimurium and 7.0 +/- 0.3 degrees C for Salmonella Senftenberg). The enhanced acid resistance found for both isolates could enable them to survive for prolonged time periods in the gastrointestinal tract, increasing the risk of illness. Further, it

  2. Photosensitivity of the isolated pigment epithelium and arachidonic acid metabolism: preliminary results.

    PubMed

    Pautler, E L

    1994-09-01

    The administration of 0.1-0.5% of ethanol produces a slow increase in the transepithelial potential (TEP) of about 2 mV in the bovine pigment epithelium (RPE) under ordinary room lighting. However, virtually no response could be observed when ethanol was administered in the dark. Because of this apparent light sensitivity, the ethanol induced response (EIR) was investigated to determine its spectral response characteristics, temporal interaction with light, and the effects of a variety of metabolic inhibitors as well as pertussis and cholera toxins. The spectral response curve peaked at 520 nm with a narrow half width. The EIR was found to be inhibited by pertussis toxin but not cholera toxin. Inhibition of either phospholipase A2 or lipoxygenase/cyclooxygenase resulted in a marked inhibition of the EIR. The incubating solutions of the apical surface of bovine and cultured chick embryo RPE were analyzed by RP-HPLC under conditions of weak white light and darkness. Two peaks in the chromatogram were observed to vary with these conditions and the presence of nordihydroguaiaretic acid simulated the effects of darkness. The RP-HPLC studies did not involve the employment of ethanol. Two different experimental procedures revealed the photosensitivity of the isolated RPE to weak light and suggest that light initiates or promotes arachidonic acid metabolism. A possible regulatory effect of retinoids was also indicated. PMID:7805400

  3. Modeling Sucrose Hydrolysis in Dilute Sulfuric Acid Solutions at Pretreatment Conditions for Lignocellulosic Biomass

    SciTech Connect

    Bower, S.; Wickramasinghe, R.; Nagle, N. J.; Schell, D. J.

    2008-01-01

    Agricultural and herbaceous feedstocks may contain appreciable levels of sucrose. The goal of this study was to evaluate the survivability of sucrose and its hydrolysis products, fructose and glucose, during dilute sulfuric acid processing at conditions typically used to pretreat lignocellulose biomass. Solutions containing 25 g/l sucrose with 0.1-2.0% (w/w) sulfuric acid concentrations were treated at temperatures of 160-200 C for 3-12 min. Sucrose was observed to completely hydrolyze at all treatment conditions. However, appreciable concentrations of fructose and glucose were detected and glucose was found to be significantly more stable than fructose. Different mathematical approaches were used to fit the kinetic parameters for acid-catalyzed thermal degradation of these sugars. Since both sugars may survive dilute acid pretreatment, they could provide an additional carbon source for production of ethanol and other bio-based products.

  4. Cementation and Aqueous Alteration of a Sandstone Unit Under Acidic Conditions in Gale Crater, Mars

    NASA Technical Reports Server (NTRS)

    Yen, A. S.; Blake, D. F.; Ming, D. W.; Morris, R. V.; Gellert, R.; Clark, B.; Vaniman, D. T.; Chipera, S. J.; Thompson, L. M.; Bristow, T. F.; Rampe, E. B.; Crisp, J. A.

    2016-01-01

    The Curiosity rover landed on Mars in August 2012 to explore the sedimentary history and to assess the habitability of Gale Crater. After 1200 sols of surface operations and over 12 km of traverse distance, the mineralogy of 10 samples has been determined by the CheMin X-ray diffractometer (XRD) and the chemical composition of nearly 300 targets has been established by the Alpha Particle X-ray Spectrometer (APXS). Light-toned fracture zones containing elevated concentrations of silica have been studied by Curiosity's instruments to determine the nature of the fluids that resulted in the enrichment of SiO2. Multiple fluid exposures are evident, and the chemistry and mineralogy data indicate at least two aqueous episodes may have occurred under acidic conditions.

  5. Prebiotic Synthesis of Adenine and Amino Acids Under Europa-like Conditions

    NASA Technical Reports Server (NTRS)

    Levy, Matthew; Miller, Stanley L.; Brinton, Karen; Bada, Jeffrey L.

    2003-01-01

    In order to simulate prebiotic synthetic processes on Europa and other ice-covered planets and satellites. we have investigated the prebiotic synthesis of organic compounds from dilute solutions of NH4CN frozen for 25 year at -20 and -78 C. In addition the aqueous products of spark discharge reactions from a reducing atmosphere were frozen for 5 years at -20%. We find that both adenine and guanine, as well as a simple set of amino acids dominated by glycine, are produced in substantial yields under these conditions. These results indicate that some of the key components necessary for the origin of life may have been available on Europa throughout its history and suggest that the circumstellar zone where life might arise may be m der than previously thought.

  6. Prebiotic synthesis of adenine and amino acids under Europa-like conditions

    NASA Technical Reports Server (NTRS)

    Levy, M.; Miller, S. L.; Brinton, K.; Bada, J. L.

    2000-01-01

    In order to simulate prebiotic synthetic processes on Europa and other ice-covered planets and satellites, we have investigated the prebiotic synthesis of organic compounds from dilute solutions of NH4CN frozen for 25 years at -20 and -78 degrees C. In addition, the aqueous products of spark discharge reactions from a reducing atmosphere were frozen for 5 years at -20 degrees C. We find that both adenine and guanine, as well as a simple set of amino acids dominated by glycine, are produced in substantial yields under these conditions. These results indicate that some of the key components necessary for the origin of life may have been available on Europa throughout its history and suggest that the circumstellar zone where life might arise may be wider than previously thought.

  7. Shear conditions in clavulanic acid production by Streptomyces clavuligerus in stirred tank and airlift bioreactors.

    PubMed

    Cerri, M O; Badino, A C

    2012-08-01

    In biochemical processes involving filamentous microorganisms, the high shear rate may damage suspended cells leading to viability loss and cell disruption. In this work, the influence of the shear conditions in clavulanic acid (CA) production by Streptomyces clavuligerus was evaluated in a 4-dm(3) conventional stirred tank (STB) and in 6-dm(3) concentric-tube airlift (ALB) bioreactors. Batch cultivations were performed in a STB at 600 and 800 rpm and 0.5 vvm (cultivations B1 and B2) and in ALB at 3.0 and 4.1 vvm (cultivations A1 and A2) to define two initial oxygen transfer conditions in both bioreactors. The average shear rate ([Formula: see text]) of the cultivations was estimated using correlations of recent literature based on experimental data of rheological properties of the broth (consistency index, K, and flow index, n) and operating conditions, impeller speed (N) for STB and superficial gas velocity in the riser (UGR) for ALB. In the same oxygen transfer condition, the [Formula: see text] values for ALB were higher than those obtained in STB. The maximum [Formula: see text] presented a strong correlation with a maximum consistency index (K (max)) of the broth. Close values of maximum CA production were obtained in cultivations A1 and A2 (454 and 442 mg L(-1)) with similar maximum [Formula: see text] values of 4,247 and 4,225 s(-1). In cultivations B1 and B2, the maximum CA production of 269 and 402 mg L(-1) were reached with a maximum [Formula: see text] of 904 and 1,786 s(-1). The results show that high values of average shear rate increase the CA production regardless of the oxygen transfer condition and bioreactor model. PMID:22271253

  8. Short-fiber protein of ad40 confers enteric tropism and protection against acidic gastrointestinal conditions.

    PubMed

    Rodríguez, Ester; Romero, Carolina; Río, Adolfo; Miralles, Marta; Raventós, Aida; Planells, Laura; Burgueño, Joan F; Hamada, Hirofumi; Perales, Jose Carlos; Bosch, Assumpció; Gassull, Miguel Angel; Fernández, Ester; Chillon, Miguel

    2013-08-01

    The lack of vectors for selective gene delivery to the intestine has hampered the development of gene therapy strategies for intestinal diseases. We hypothesized that chimeric adenoviruses of Ad5 (species C) displaying proteins of the naturally enteric Ad40 (species F) might hold the intestinal tropism of the species F and thus be useful for gene delivery to the intestine. As oral-fecal dissemination of enteric adenovirus must withstand the conditions encountered in the gastrointestinal tract, we studied the resistance of chimeric Ad5 carrying the short-fiber protein of Ad40 to acid milieu and proteases and found that the Ad40 short fiber confers resistance to inactivation in acidic conditions and that AdF/40S was further activated upon exposure to low pH. In contrast, the chimeric AdF/40S exhibited only a slightly higher protease resistance compared with Ad5 to proteases present in simulated gastric juice. Then, the biodistribution of different chimeric adenoviruses by oral, rectal, and intravenous routes was tested. Expression of reporter β-galactosidase was measured in extracts of 15 different organs 3 days after administration. Our results indicate that among the chimeric viruses, only intrarectally given AdF/40S infected the colon (preferentially enteroendocrine cells and macrophages) and to a lesser extent, the small intestine, whereas Ad5 infectivity was very poor in all tissues. Additional in vitro experiments showed improved infectivity of AdF/40S also in different human epithelial cell lines. Therefore, our results point at the chimeric adenovirus AdF/40S as an interesting vector for selective gene delivery to treat intestinal diseases. PMID:23746215

  9. Selection method of pH conditions to establish Pseudomonas taetrolens physiological states and lactobionic acid production.

    PubMed

    Alonso, Saúl; Rendueles, Manuel; Díaz, Mario

    2013-05-01

    Microbial physiological responses resulting from inappropriate bioprocessing conditions may have a marked impact on process performance within any fermentation system. The influence of different pH-control strategies on physiological status, microbial growth and lactobionic acid production from whey by Pseudomonas taetrolens during bioreactor cultivations has been investigated for the first time in this work. Both cellular behaviour and bioconversion efficiency from P. taetrolens were found to be negatively influenced by pH-control modes carried out at values lower than 6.0 and higher than 7.0. Production schemes were also influenced by the operational pH employed, with asynchronous production from damaged and metabolically active subpopulations at pH values lower than 6.0. Moreover, P. taetrolens showed reduced cellular proliferation and a subsequent delay in the onset of the production phase under acidic conditions (pH < 6.0). Unlike cultivations performed at 6.5, both pH-shift and pH-stat cultivation strategies performed at pH values lower than 6.0 resulted in decreased lactobionic acid production. Whereas the cellular response showed a stress-induced physiological response under acidic conditions, healthy functional cells were predominant at medium operational pH values (6.5-7.0). P. taetrolens thus displayed a robust physiological status at initial pH value of 6.5, resulting in an enhanced bioconversion yield and lactobionic acid productivity (7- and 4-fold higher compared to those attained at initial pH values of 4.5 and 5.0, respectively). These results have shown that pH-control modes strongly affected both the physiological response of cells and the biological performance of P. taetrolens, providing key information for bio-production of lactobionic acid on an industrial scale. PMID:23254761

  10. Jasmonic acid interacts with abscisic acid to regulate plant responses to water stress conditions

    PubMed Central

    de Ollas, Carlos; Arbona, Vicent; Gómez-Cadenas, Aurelio

    2015-01-01

    Phytohormones are key players in signaling environmental stress conditions. Hormone profiling together with proline accumulation were studied in leaves and roots of different mutant lines of Arabidopsis. Regulation of proline accumulation in this system seems complex and JA-deficient (jar1-1) and JA-insensitive (jai1) lines accumulating high levels of proline despite their very low ABA levels seems to discard an ABA-dependent response. However, the pattern of proline accumulation in jai1 seedlings parallels that of ABA. Under stress conditions, there is an opposite pattern of ABA accumulation in roots of jar1-1/coi1-16 (in which ABA only slightly increase) and jai1 (in which ABA increase is even higher than in WT plants). This also makes JA-ABA crosstalk complex and discards any lineal pathway that could explain this hormonal interaction. PMID:26340066

  11. Jasmonic acid interacts with abscisic acid to regulate plant responses to water stress conditions.

    PubMed

    de Ollas, Carlos; Arbona, Vicent; Gómez-Cadenas, Aurelio

    2015-01-01

    Phytohormones are key players in signaling environmental stress conditions. Hormone profiling together with proline accumulation were studied in leaves and roots of different mutant lines of Arabidopsis. Regulation of proline accumulation in this system seems complex and JA-deficient (jar1-1) and JA-insensitive (jai1) lines accumulating high levels of proline despite their very low ABA levels seems to discard an ABA-dependent response. However, the pattern of proline accumulation in jai1 seedlings parallels that of ABA. Under stress conditions, there is an opposite pattern of ABA accumulation in roots of jar1-1/coi1-16 (in which ABA only slightly increase) and jai1 (in which ABA increase is even higher than in WT plants). This also makes JA-ABA crosstalk complex and discards any lineal pathway that could explain this hormonal interaction. PMID:26340066

  12. Stable condition of dimethylmonothioarsinic acid (DMMTAV) and dimethyldithioarsinic acid ( DMDTAV) in landfill leachate

    NASA Astrophysics Data System (ADS)

    Kwon, E.; Yoon, H. O.; Kim, J. A.; Lee, H.; Jung, S.; Kim, Y. T.

    2015-12-01

    When waste containing arsenic (As) are disposed of landfill, such facilities (i.e., landfill) can play an important role in disseminating As to the surrounding environment. These disposal of waste containing As might cause a serious environmental pollution due to potentially As remobilization in landfill. Especially, As species containing sulfur such as DMDTAv and DMMTAv found occasionally high concentration in landfill leachate. These As species (i.e., DMDTAv and DMMTAv) had the higher toxicity to human cells compared to other pentavalent As species. However, there was no chemical standard material of these As species (i.e., DMDTAv and DMMTAv) commercially. In this study, we synthesized DMDTAv and DMMTAv by simulating reaction with the sufficient sulfur condition from DMAv. DMMTAv was quite changeable to DMDTAv due to its short life time from our preliminary study. Thus, it is important to find the stable condition of synthesis process for DMDTAv and DMMTAv under suitable environmental condition. This study can be very significant in quantitative analysis area to detect the various As species in environmental media such as landfill.

  13. Water oxidation catalysis with nonheme iron complexes under acidic and basic conditions: homogeneous or heterogeneous?

    PubMed

    Hong, Dachao; Mandal, Sukanta; Yamada, Yusuke; Lee, Yong-Min; Nam, Wonwoo; Llobet, Antoni; Fukuzumi, Shunichi

    2013-08-19

    Thermal water oxidation by cerium(IV) ammonium nitrate (CAN) was catalyzed by nonheme iron complexes, such as Fe(BQEN)(OTf)2 (1) and Fe(BQCN)(OTf)2 (2) (BQEN = N,N'-dimethyl-N,N'-bis(8-quinolyl)ethane-1,2-diamine, BQCN = N,N'-dimethyl-N,N'-bis(8-quinolyl)cyclohexanediamine, OTf = CF3SO3(-)) in a nonbuffered aqueous solution; turnover numbers of 80 ± 10 and 20 ± 5 were obtained in the O2 evolution reaction by 1 and 2, respectively. The ligand dissociation of the iron complexes was observed under acidic conditions, and the dissociated ligands were oxidized by CAN to yield CO2. We also observed that 1 was converted to an iron(IV)-oxo complex during the water oxidation in competition with the ligand oxidation. In addition, oxygen exchange between the iron(IV)-oxo complex and H2(18)O was found to occur at a much faster rate than the oxygen evolution. These results indicate that the iron complexes act as the true homogeneous catalyst for water oxidation by CAN at low pHs. In contrast, light-driven water oxidation using [Ru(bpy)3](2+) (bpy = 2,2'-bipyridine) as a photosensitizer and S2O8(2-) as a sacrificial electron acceptor was catalyzed by iron hydroxide nanoparticles derived from the iron complexes under basic conditions as the result of the ligand dissociation. In a buffer solution (initial pH 9.0) formation of the iron hydroxide nanoparticles with a size of around 100 nm at the end of the reaction was monitored by dynamic light scattering (DLS) in situ and characterized by X-ray photoelectron spectra (XPS) and transmission electron microscope (TEM) measurements. We thus conclude that the water oxidation by CAN was catalyzed by short-lived homogeneous iron complexes under acidic conditions, whereas iron hydroxide nanoparticles derived from iron complexes act as a heterogeneous catalyst in the light-driven water oxidation reaction under basic conditions. PMID:23895380

  14. Unravelling the Ru-Catalyzed Hydrogenolysis of Biomass-Based Polyols under Neutral and Acidic Conditions.

    PubMed

    Hausoul, Peter J C; Negahdar, Leila; Schute, Kai; Palkovits, Regina

    2015-10-12

    The aqueous Ru/C-catalyzed hydrogenolysis of biomass-based polyols such as erythritol, xylitol, sorbitol, and cellobitol is studied under neutral and acidic conditions. For the first time, the complete product spectrum of C2 C6 polyols is identified and, based on a thorough analysis of the reaction mixtures, a comprehensive reaction mechanism is proposed, which consists of (de)hydrogenation, epimerization, decarbonylation, and deoxygenation reactions. The data reveal that the Ru-catalyzed deoxygenation reaction is highly selective for the cleavage of terminal hydroxyl groups. Changing from neutral to acidic conditions suppresses decarbonylation, consequently increasing the selectivity towards deoxygenation. PMID:26448526

  15. Conditioned Medium Reconditions Hippocampal Neurons against Kainic Acid Induced Excitotoxicity: An In Vitro Study

    PubMed Central

    Bevinahal, Pradeep Kumar K.; Venugopal, Chaitra; Yencharla, Harish Chandra Prasad S.; Chandanala, Shashank; Trichur, Raju R.; Talakad, Sathyaprabha N.; Bhonde, Ramesh R.; Dhanushkodi, Anandh

    2014-01-01

    Stem cell therapy is gaining attention as a promising treatment option for neurodegenerative diseases. The functional efficacy of grafted cells is a matter of debate and the recent consensus is that the cellular and functional recoveries might be due to “by-stander” effects of grafted cells. In the present study, we investigated the neuroprotective effect of conditioned medium (CM) derived from human embryonic kidney (HEK) cells in a kainic acid (KA) induced hippocampal degeneration model system in in vitro condition. Hippocampal cell line was exposed to KA (200 µM) for 24 hrs (lesion group) whereas, in the treatment group, hippocampal cell line was exposed to KA in combination with HEK-CM (KA + HEK-CM). We observed that KA exposure to cells resulted in significant neuronal loss. Interestingly, HEK-CM cotreatment completely attenuated the excitotoxic effects of KA. In HEK-CM cotreatment group, the cell viability was ~85–95% as opposed to 47% in KA alone group. Further investigation demonstrated that treatment with HEK-CM stimulated the endogenous cell survival factors like brain derived neurotrophic factors (BDNF) and antiapoptotic factor Bcl-2, revealing the possible mechanism of neuroprotection. Our results suggest that HEK-CM protects hippocampal neurons against excitotoxicity by stimulating the host's endogenous cell survival mechanisms. PMID:25505907

  16. The influence of minerals on decomposition of the n-alkyl-α-amino acid norvaline under hydrothermal conditions

    NASA Astrophysics Data System (ADS)

    McCollom, Thomas M.

    2013-03-01

    Laboratory experiments were conducted to observe the effect of iron oxide and sulfide minerals on decomposition reactions of norvaline, a representative of a group of alkyl-α-amino acids observed in meteorites and prebiotic synthesis experiments. The primary products observed during heating of aqueous solutions of norvaline at temperatures of 156-186 °C in the presence of minerals included CO2, NH3, butyric acid, and valeric acid. The products indicated that norvaline predominantly decomposed by a combination of pathways that included both decarboxylation followed rapidly by oxidative deamination (norvaline → butanamide + CO2 → butyric acid + NH3) and deamination directly to valeric acid (norvaline → valeric acid + NH3). An experiment performed with alanine under similar conditions showed it decomposed by analogous reactions that produced acetic and propionic acids along with CO2 and NH3. For both amino acids, the presence of minerals accelerated decomposition rates as well as altered the final products of reaction, when compared with decomposition in the absence of mineral substrates. In addition, decomposition of norvaline was found to proceed much faster in the presence of the mineral assemblage hematite-magnetite-pyrite (HMP) than with the assemblage pyrite-pyrrhotite-magnetite (PPM), a trend that has been observed for several other organic compounds. The influence of minerals on decomposition reactions of these amino acids appears to be attributable to a combination of surface catalysis and production of dissolved sulfur compounds. Overall, the results indicate that minerals may exert a substantial influence on amino acid stability in many geologic environments, and emphasize the need to consider the impact of minerals when evaluating the lifetimes and decomposition rates of amino acids in terrestrial and planetary systems. Estimated half-lives for alkyl-α-amino acids based on the experimental results indicate that moderately hot hydrothermal

  17. Deletions of the SACPD-C locus elevate seed stearic acid levels but also result in fatty acid and morphological alterations in nitrogen fixing nodules

    PubMed Central

    2014-01-01

    Background Soybean (Glycine max) seeds are the primary source of edible oil in the United States. Despite its widespread utility, soybean oil is oxidatively unstable. Until recently, the majority of soybean oil underwent chemical hydrogenation, a process which also generates trans fats. An alternative to chemical hydrogenation is genetic modification of seed oil through identification and introgression of mutant alleles. One target for improvement is the elevation of a saturated fat with no negative cardiovascular impacts, stearic acid, which typically constitutes a minute portion of seed oil (~3%). Results We examined radiation induced soybean mutants with moderately increased stearic acid (10-15% of seed oil, ~3-5 X the levels in wild-type soybean seeds) via comparative whole genome hybridization and genetic analysis. The deletion of one SACPD isoform encoding gene (SACPD-C) was perfectly correlated with moderate elevation of seed stearic acid content. However, SACPD-C deletion lines were also found to have altered nodule fatty acid composition and grossly altered morphology. Despite these defects, overall nodule accumulation and nitrogen fixation were unaffected, at least under laboratory conditions. Conclusions Although no yield penalty has been reported for moderate elevated seed stearic acid content in soybean seeds, our results demonstrate that genetic alteration of seed traits can have unforeseen pleiotropic consequences. We have identified a role for fatty acid biosynthesis, and SACPD activity in particular, in the establishment and maintenance of symbiotic nitrogen fixation. PMID:24886084

  18. Direct fermentation of potato starch and potato residues to lactic acid by Geobacillus stearothermophilus under non-sterile conditions

    PubMed Central

    Smerilli, Marina; Neureiter, Markus; Wurz, Stefan; Haas, Cornelia; Frühauf, Sabine; Fuchs, Werner

    2015-01-01

    BACKGROUND Lactic acid is an important biorefinery platform chemical. The use of thermophilic amylolytic microorganisms to produce lactic acid by fermentation constitutes an efficient strategy to reduce operating costs, including raw materials and sterilization costs. RESULTS A process for the thermophilic production of lactic acid by Geobacillus stearothermophilus directly from potato starch was characterized and optimized. Geobacillus stearothermophilus DSM 494 was selected out of 12 strains screened for amylolytic activity and the ability to form lactic acid as the major product of the anaerobic metabolism. In total more than 30 batches at 3–l scale were run at 60 °C under non-sterile conditions. The process developed produced 37 g L−1 optically pure (98%) L-lactic acid in 20 h from 50 g L−1 raw potato starch. As co-metabolites smaller amounts (<7% w/v) of acetate, formate and ethanol were formed. Yields of lactic acid increased from 66% to 81% when potato residues from food processing were used as a starchy substrate in place of raw potato starch. CONCLUSIONS Potato starch and residues were successfully converted to lactic acid by G. stearothermophilus. The process described in this study provides major benefits in industrial applications and for the valorization of starch-rich waste streams. © 2015 The Authors.Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:25937690

  19. Influence of concentration, time and method of application of citric acid and sodium citrate in root conditioning

    PubMed Central

    CAVASSIM, Rodrigo; LEITE, Fábio Renato Manzolli; ZANDIM, Daniela Leal; DANTAS, Andrea Abi Rached; RACHED, Ricardo Samih Georges Abi; SAMPAIO, José Eduardo Cezar

    2012-01-01

    Objective The aim of this study was to establish the parameters of concentration, time and mode of application of citric acid and sodium citrate in relation to root conditioning. Material and Methods A total of 495 samples were obtained and equally distributed among 11 groups (5 for testing different concentrations of citric acid, 5 for testing different concentrations of sodium citrate and 1 control group). After laboratorial processing, the samples were analyzed under scanning electron microscopy. A previously calibrated and blind examiner evaluated micrographs of the samples. Non-parametric statistical analysis was performed to analyze the data obtained. Results Brushing 25% citric acid for 3 min, promoted greater exposure of collagen fibers in comparison with the brushing of 1% citric acid for 1 minute and its topical application at 1% for 3 min. Sodium citrate exposed collagen fibers in a few number of samples. Conclusion Despite the lack of statistical significance, better results for collagen exposure were obtained with brushing application of 25% citric acid for 3 min than with other application parameter. Sodium citrate produced a few number of samples with collagen exposure, so it is not indicated for root conditioning. PMID:22858707

  20. The Formation of Fe/Mg Smectite Under Mildly Acidic Conditions on Early Mars

    NASA Technical Reports Server (NTRS)

    Sutter, B.; Golden, D. C.; Ming, Douglas W.; Niles, P. B.

    2011-01-01

    The detection of Fe/Mg smectites and carbonate in Noachian and early Hesperian terrain of Mars suggests that neutral to mildly alkaline conditions prevailed during the early history of Mars. If early Mars surface geochemical conditions were neutral to moderately alkaline with a denser CO2 atmosphere than today, then large carbonates deposits should be more widely detected in Noachian terrain. Why have so few carbonate deposits been detected compared to Fe/Mg smectites? Fe/Mg smectites on early Mars formed under mildly acidic conditions, which would preclude the extensive formation of carbonate deposits. The goal of the proposed work is to evaluate the formation of Fe/Mg smectites under mildly acidic conditions.

  1. Distinct stress conditions result in aggregation of proteins with similar properties.

    PubMed

    Weids, Alan J; Ibstedt, Sebastian; Tamás, Markus J; Grant, Chris M

    2016-01-01

    Protein aggregation is the abnormal association of proteins into larger aggregate structures which tend to be insoluble. This occurs during normal physiological conditions and in response to age or stress-induced protein misfolding and denaturation. In this present study we have defined the range of proteins that aggregate in yeast cells during normal growth and after exposure to stress conditions including an oxidative stress (hydrogen peroxide), a heavy metal stress (arsenite) and an amino acid analogue (azetidine-2-carboxylic acid). Our data indicate that these three stress conditions, which work by distinct mechanisms, promote the aggregation of similar types of proteins probably by lowering the threshold of protein aggregation. The proteins that aggregate during physiological conditions and stress share several features; however, stress conditions shift the criteria for protein aggregation propensity. This suggests that the proteins in aggregates are intrinsically aggregation-prone, rather than being proteins which are affected in a stress-specific manner. We additionally identified significant overlaps between stress aggregating yeast proteins and proteins that aggregate during ageing in yeast and C. elegans. We suggest that similar mechanisms may apply in disease- and non-disease settings and that the factors and components that control protein aggregation may be evolutionary conserved. PMID:27086931

  2. Distinct stress conditions result in aggregation of proteins with similar properties

    PubMed Central

    Weids, Alan J.; Ibstedt, Sebastian; Tamás, Markus J.; Grant, Chris M.

    2016-01-01

    Protein aggregation is the abnormal association of proteins into larger aggregate structures which tend to be insoluble. This occurs during normal physiological conditions and in response to age or stress-induced protein misfolding and denaturation. In this present study we have defined the range of proteins that aggregate in yeast cells during normal growth and after exposure to stress conditions including an oxidative stress (hydrogen peroxide), a heavy metal stress (arsenite) and an amino acid analogue (azetidine-2-carboxylic acid). Our data indicate that these three stress conditions, which work by distinct mechanisms, promote the aggregation of similar types of proteins probably by lowering the threshold of protein aggregation. The proteins that aggregate during physiological conditions and stress share several features; however, stress conditions shift the criteria for protein aggregation propensity. This suggests that the proteins in aggregates are intrinsically aggregation-prone, rather than being proteins which are affected in a stress-specific manner. We additionally identified significant overlaps between stress aggregating yeast proteins and proteins that aggregate during ageing in yeast and C. elegans. We suggest that similar mechanisms may apply in disease- and non-disease settings and that the factors and components that control protein aggregation may be evolutionary conserved. PMID:27086931

  3. Comparison of fibrin clot adhesion to dentine conditioned with citric acid, tetracycline, and ethylene diamine tetra acetic acid: An in vitro scanning electron microscopic study

    PubMed Central

    Minocha, Tanuj; Rahul, Aparna

    2012-01-01

    Aim: The purpose of this study was to evaluate and compare the root surface changes subsequent to the application of citric acid, tetracycline, Ethylenediaminetetraacetic acid (EDTA), and the combination of citric acid and tetracycline, and its influence on the adhesion of a fibrin clot with and without mild disruptive forces. Materials and Methods: A total of 100 periodontally diseased root specimens were grouped into Saline (control Group I), 24% EDTA gel (Group-II), Citric acid (Group-III), Tetracycline (Group IV), and Citric acid + tetracycline (Group V) treatment groups containing 20 in each. After root conditioning, fresh human blood was applied to each root specimen and was allowed to clot. Ten specimens in each group were rinsed in phosphate-buffered saline and designated as ′Non-agitated′. The remaining ten specimens from each group were rinsed in phosphate-buffered saline on a rotary shaker and designated as ′Agitated′. The roots were processed for scanning electron microscopy (SEM) to assess and compare the clot adhesion on them. The scores were compared through standard statistical packages. Results: The highest mean blood clot adhesion score was observed in roots treated with a combination of citric acid and tetracycline, whereas, the least score was observed in roots treated with saline. Conclusion: The root specimens treated with the combination of citric acid and tetracycline as well as citric acid alone, best supported the fibrin clot. Tetracycline alone appeared to be less effective in supporting the clot. EDTA gel of 24% was least effective to promote the adhesion of a fibrin clot. PMID:23162325

  4. HANDBOOK: GUIDANCE ON SETTING PERMIT CONDITIONS AND REPORTING TRIAL BURN RESULTS

    EPA Science Inventory

    This Handbook provides guidance for establishing operational conditions for incinerators. he document provides a means for state and local agencies to achieve a level of consistency in setting permit conditions that will result in establishment of more uniform permit conditions n...

  5. Carbonylative Suzuki Couplings of Aryl Bromides with Boronic Acid Derivatives under Base-Free Conditions

    PubMed Central

    2015-01-01

    The carbonylative Suzuki–Miyaura reaction between aryl bromides and arylboronic acid equivalents is herein reported, using base-free conditions and a limited excess of carbon monoxide generated ex situ from stable CO-precursors. Under these conditions, unsymmetrical biaryl ketones were obtained in modest to excellent yields. This method was adapted to the synthesis of the triglyceride and cholesterol regulator drug, fenofibrate, and its 13C-labeled derivative in good yields from the appropriate CO-precursor. PMID:24635142

  6. Effects of environmental conditions on aerobic degradation of a commercial naphthenic acid.

    PubMed

    Kinley, Ciera M; Gaspari, Daniel P; McQueen, Andrew D; Rodgers, John H; Castle, James W; Friesen, Vanessa; Haakensen, Monique

    2016-10-01

    Naphthenic acids (NAs) are problematic constituents in energy-derived waters, and aerobic degradation may provide a strategy for mitigating risks to aquatic organisms. The overall objective of this study was to determine the influence of concentrations of N (as ammonia) and P (as phosphate), and DO, as well as pH and temperatures on degradation of a commercial NA in bench-scale reactors. Commercial NAs provided replicable compounds necessary to compare influences of environmental conditions on degradation. NAs were quantified using high performance liquid chromatography. Microbial diversity and relative abundance were measured in treatments as explanatory parameters for potential effects of environmental conditions on microbial populations to support analytically measured NA degradation. Environmental conditions that positively influenced degradation rates of Fluka NAs included nutrients (C:N 10:1-500:1, C:P 100:1-5000:1), DO (4.76-8.43 mg L(-1)), pH (6-8), and temperature (5-25 °C). Approximately 50% removal of 61 ± 8 mg L(-1) was achieved in less than 2 d after NA introduction, achieving the method detection limit (5 mg L(-1)) by day 6 of the experiment in treatments with a C:N:P ratio of 100:10:1, DO > 8 mg L(-1), pH ∼8-9, and temperatures >23 °C. Microbial diversity was lowest in lower temperature treatments (6-16 °C), which may have resulted in observed slower NA degradation. Based on results from this study, when macro- and micronutrients were available, DO, pH, and temperature (within environmentally relevant ranges) influenced rates of aerobic degradation of Fluka NAs. This study could serve as a model for systematically evaluating environmental factors that influence NA degradation in field scenarios. PMID:27459161

  7. Aquatic fulvic acids in microbially based ecosystems: results from two desert lakes in Antarctica

    USGS Publications Warehouse

    McKnight, Diane M.; Aiken, G.R.; Smith, R.L.

    1991-01-01

    These lakes receive very limited input of organic material from the surrounding barren desert, but they sustain algal and bacterial populations under permanent ice cover. One lake has an extensive anoxic zone and high salinities; the other is oxic and has low salinities. Despite these differences, fulvic acids from both lakes had similar elemental compositions, carbon distributions, and amino acid contents, indicating that the chemistry of microbially derived fulvic acvids is not strongly influenced by chemical conditions in the water column. Compared to fulvic acids from other natural waters, these fulvic acids have low C:N atomic ratios (19-25) and low contents of aromatic carbons (5-7% of total carbon atoms); they are most similar to marine fulvic acids. -from Authors

  8. Differential Radiosensitizing Effect of Valproic Acid in Differentiation Versus Self-Renewal Promoting Culture Conditions

    SciTech Connect

    Debeb, Bisrat G.; Xu Wei; Mok, Henry; Li Li; Robertson, Fredika; Ueno, Naoto T.; Reuben, Jim; Lucci, Anthony; Cristofanilli, Massimo; Woodward, Wendy A.

    2010-03-01

    Purpose: It has been shown that valproic acid (VA) enhances the proliferation and self-renewal of normal hematopoietic stem cells and that breast cancer stem/progenitor cells can be resistant to radiation. From these data, we hypothesized that VA would fail to radiosensitize breast cancer stem/progenitor cells grown to three-dimensional (3D) mammospheres. Methods and Materials: We used the MCF7 breast cancer cell line grown under stem cell-promoting culture conditions (3D mammosphere) and standard nonstem cell monolayer culture conditions (two-dimensional) to examine the effect of pretreatment with VA on radiation sensitivity in clonogenic survival assays and on the expression of embryonic stem cell transcription factors. Results: 3D-cultured MCF-7 cells expressed higher levels of Oct4, Nanog, and Sox2. The 3D passage enriched self-renewal and increased radioresistance in the 3D mammosphere formation assays. VA radiosensitized adherent cells but radioprotected 3D cells in single-fraction clonogenic assays. Moreover, fractionated radiation sensitized VA-treated adherent MCF7 cells but did not have a significant effect on VA-treated single cells grown to mammospheres. Conclusion: We have concluded that VA might preferentially radiosensitize differentiated cells compared with those expressing stem cell surrogates and that stem cell-promoting culture is a useful tool for in vitro evaluation of novel cancer therapeutic agents and radiosensitizers.

  9. Stability of β-Lapachone upon Exposure to Various Stress Conditions: Resultant Efficacy and Cytotoxicity.

    PubMed

    Kim, Ki Hyun; Park, So-Hyun; Adhikary, Pratik; Cho, Jin Hun; Kang, Nae-Gyu; Jeong, Seong Hoon

    2016-01-01

    Even though β-lapachone is a promising compound with antitumor, antiinflammatory, antineoplastic, and wound-healing effects, there are still issues concerning its chemical stability and degradation mechanisms. The objective of this study was to obtain degradation profiles of β-lapachone and evaluate its chemical stability under various stress conditions. Moreover, the correlation between stability and efficacy was evaluated. The degradation study of β-lapachone was performed using heat, acid, base, oxidation, and light conditions. Kinetics and degradation profiles were investigated with HPLC and LC-MS. The stability indicated in the LC method was validated according to the International Conference on Harmonization guidelines. Human dermal fibroblast (HDF) cells were cultured with the standard and its degraded samples in the cellular activity and cytotoxicity test. β-Lapachone was relatively unstable upon exposure to light, and its photodegradation was accelerated with high relative humidity. Three degradants were identified, and their degradation followed zero-order kinetics. It was shown to degrade to phthalic acid under oxidative conditions, and the degradation kinetics were dependent on the concentration of hydrogen peroxide. Two degradation products were identified upon exposure to basic conditions, which followed first-order kinetics. β-Lapachone was relatively stable under acidic and thermal conditions. It increased the synthesis of collagen compared with the control. However, as the contents decreased, the synthesis of collagen also decreased in the photodegraded samples. β-Lapachone did not exert cytotoxic effects at the effective concentration in the cytotoxicity test. Therefore, in order to ensure efficacy and safety, the chemical stability of β-lapachone needs to be controlled carefully while considering instability mechanisms. PMID:27150470

  10. Aldocyanoin microspheres: partial amino acid analysis of the microparticulates formed from simple reactants under various conditions.

    PubMed

    Pollock, G E; Heiderer, R

    1979-10-01

    The work of Kenyon and Nissenbaum on aldocyanoin microspheres was repeated and extended. It was determined that the microspheres contained amino acids and that specific amino acids could be incorporated into the microspheres by adding the requisite aldehyde or ketone precursor to the model mixture. Microsphere formation was found to be dependent on the availability of oxygen. Under anaerobic conditions of synthesis, no microspheres formed in the time allotted and the amino acid composition of the macromolecular material was simple. Microparticulate material synthesized by C. Folsome using a quenched spark technique was analyzed and found to contain amino acids that had a qualitative composition similar to both a Miller-Urey discharge and the Kenyon-Nissenbaum microspheres. PMID:501747

  11. Palladium-Catalyzed Construction of Amidines from Arylboronic Acids under Oxidative Conditions.

    PubMed

    Zhu, Fengxiang; Li, Yahui; Wang, Zechao; Orru, Romano V A; Maes, Bert U W; Wu, Xiao-Feng

    2016-06-01

    A valuable palladium-catalyzed three-component coupling reaction for the synthesis of amidines has been developed. Using arylboronic acids, isocyanides, and anilines as the reactants under oxidative conditions, various amidines were isolated in good yields with good functional group tolerances. PMID:27061735

  12. The Histone Deacetylase Inhibitor Valproic Acid Enhances Acquisition, Extinction, and Reconsolidation of Conditioned Fear

    ERIC Educational Resources Information Center

    Bredy, Timothy W.; Barad, Mark

    2008-01-01

    Histone modifications contribute to the epigenetic regulation of gene expression, a process now recognized to be important for the consolidation of long-term memory. Valproic acid (VPA), used for many years as an anticonvulsant and a mood stabilizer, has effects on learning and memory and enhances the extinction of conditioned fear through its…

  13. Involvement of Intermediate Sulfur Species in Biological Reduction of Elemental Sulfur under Acidic, Hydrothermal Conditions

    PubMed Central

    Druschel, Gregory K.

    2013-01-01

    The thermoacidophile and obligate elemental sulfur (S80)-reducing anaerobe Acidilobus sulfurireducens 18D70 does not associate with bulk solid-phase sulfur during S80-dependent batch culture growth. Cyclic voltammetry indicated the production of hydrogen sulfide (H2S) as well as polysulfides after 1 day of batch growth of the organism at pH 3.0 and 81°C. The production of polysulfide is likely due to the abiotic reaction between S80 and the biologically produced H2S, as evinced by a rapid cessation of polysulfide formation when the growth temperature was decreased, inhibiting the biological production of sulfide. After an additional 5 days of growth, nanoparticulate S80 was detected in the cultivation medium, a result of the hydrolysis of polysulfides in acidic medium. To examine whether soluble polysulfides and/or nanoparticulate S80 can serve as terminal electron acceptors (TEA) supporting the growth of A. sulfurireducens, total sulfide concentration and cell density were monitored in batch cultures with S80 provided as a solid phase in the medium or with S80 sequestered in dialysis tubing. The rates of sulfide production in 7-day-old cultures with S80 sequestered in dialysis tubing with pore sizes of 12 to 14 kDa and 6 to 8 kDa were 55% and 22%, respectively, of that of cultures with S80 provided as a solid phase in the medium. These results indicate that the TEA existed in a range of particle sizes that affected its ability to diffuse through dialysis tubing of different pore sizes. Dynamic light scattering revealed that S80 particles generated through polysulfide rapidly grew in size, a rate which was influenced by the pH of the medium and the presence of organic carbon. Thus, S80 particles formed through abiological hydrolysis of polysulfide under acidic conditions appeared to serve as a growth-promoting TEA for A. sulfurireducens. PMID:23335768

  14. 49 CFR 236.528 - Restrictive condition resulting from open hand-operated switch; requirement.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Restrictive condition resulting from open hand... Instructions; Roadway § 236.528 Restrictive condition resulting from open hand-operated switch; requirement. When a facing point hand-operated switch is open one-fourth inch or more, a trailing point...

  15. 49 CFR 236.528 - Restrictive condition resulting from open hand-operated switch; requirement.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Restrictive condition resulting from open hand... Instructions; Roadway § 236.528 Restrictive condition resulting from open hand-operated switch; requirement. When a facing point hand-operated switch is open one-fourth inch or more, a trailing point...

  16. 49 CFR 236.528 - Restrictive condition resulting from open hand-operated switch; requirement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Restrictive condition resulting from open hand... Instructions; Roadway § 236.528 Restrictive condition resulting from open hand-operated switch; requirement. When a facing point hand-operated switch is open one-fourth inch or more, a trailing point...

  17. 49 CFR 236.528 - Restrictive condition resulting from open hand-operated switch; requirement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Restrictive condition resulting from open hand... Instructions; Roadway § 236.528 Restrictive condition resulting from open hand-operated switch; requirement. When a facing point hand-operated switch is open one-fourth inch or more, a trailing point...

  18. 49 CFR 236.528 - Restrictive condition resulting from open hand-operated switch; requirement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Restrictive condition resulting from open hand... Instructions; Roadway § 236.528 Restrictive condition resulting from open hand-operated switch; requirement. When a facing point hand-operated switch is open one-fourth inch or more, a trailing point...

  19. Simulation of acid-base condition and copper speciation in the fish gill microenvironment.

    PubMed

    Tao, S; Wen, Y; Long, A; Dawson, R; Cao, J; Xu, F

    2001-05-01

    pH, alkalinity, and mucus content in the fish gill microenvironment of carp (Cyprinus carpio) were measured by exposing fish to copper at various water pH levels using an apparatus which separates inspired and expired water. The relationship between pH levels inside and outside of the gill microenvironment, between pH and alkalinity, and between mucus secretion, pH, and copper exposure concentration were modeled. Copper speciation in the surrounding water and in the fish gill microenvironment was simulated using MINTEQA2 chemical equilibrium calculation software. The results of the modeling for pH, alkalinity, and mucus calculation were then adopted as inputs for purposes of parameter identification in the speciation modeling. The differences observed in the copper species distribution between that of the fish gill microenvironment and the surrounding water were based on the speciation modeling. The change in copper bioavailability for fish uptake was also examined. The results indicate the presence of an experimental pH balance point at 6.9, where the pH in the fish gill microenvironment is identical to that of the surrounding water. The observed deviation range in pH levels between that found at the gills and that of the surrounding water varied from -0.4 to 0.8 units. A sinusoidal model was developed for calculation of gill pH based on the pH of the surrounding water. Models calculating alkalinity either in the gill microenvironment or in the surrounding water and for estimating mucus secretion were also developed. The results of the chemical equilibrium calculations demonstrate that, within a pH range of 6-9, the dominant species of copper in bulk solution shifted from free ions to that of the hydroxo complex. With respect to the fish gill microenvironment, the dominant species found under acidic conditions were the mucus copper complex and free ions. Because of the influence of mucus complexation and pH change, bioavailable copper species in the fish gill

  20. Fermentation Conditions that Affect Clavulanic Acid Production in Streptomyces clavuligerus: A Systematic Review.

    PubMed

    Ser, Hooi-Leng; Law, Jodi Woan-Fei; Chaiyakunapruk, Nathorn; Jacob, Sabrina Anne; Palanisamy, Uma Devi; Chan, Kok-Gan; Goh, Bey-Hing; Lee, Learn-Han

    2016-01-01

    The β-lactamase inhibitor, clavulanic acid is frequently used in combination with β-lactam antibiotics to treat a wide spectrum of infectious diseases. Clavulanic acid prevents drug resistance by pathogens against these β-lactam antibiotics by preventing the degradation of the β-lactam ring, thus ensuring eradication of these harmful microorganisms from the host. This systematic review provides an overview on the fermentation conditions that affect the production of clavulanic acid in the firstly described producer, Streptomyces clavuligerus. A thorough search was conducted using predefined terms in several electronic databases (PubMed, Medline, ScienceDirect, EBSCO), from database inception to June 30th 2015. Studies must involve wild-type Streptomyces clavuligerus, and full texts needed to be available. A total of 29 eligible articles were identified. Based on the literature, several factors were identified that could affect the production of clavulanic acid in S. clavuligerus. The addition of glycerol or other vegetable oils (e.g., olive oil, corn oil) could potentially affect clavulanic acid production. Furthermore, some amino acids such as arginine and ornithine, could serve as potential precursors to increase clavulanic acid yield. The comparison of different fermentation systems revealed that fed-batch fermentation yields higher amounts of clavulanic acid as compared to batch fermentation, probably due to the maintenance of substrates and constant monitoring of certain entities (such as pH, oxygen availability, etc.). Overall, these findings provide vital knowledge and insight that could assist media optimization and fermentation design for clavulanic acid production in S. clavuligerus. PMID:27148211

  1. Fermentation Conditions that Affect Clavulanic Acid Production in Streptomyces clavuligerus: A Systematic Review

    PubMed Central

    Ser, Hooi-Leng; Law, Jodi Woan-Fei; Chaiyakunapruk, Nathorn; Jacob, Sabrina Anne; Palanisamy, Uma Devi; Chan, Kok-Gan; Goh, Bey-Hing; Lee, Learn-Han

    2016-01-01

    The β-lactamase inhibitor, clavulanic acid is frequently used in combination with β-lactam antibiotics to treat a wide spectrum of infectious diseases. Clavulanic acid prevents drug resistance by pathogens against these β-lactam antibiotics by preventing the degradation of the β-lactam ring, thus ensuring eradication of these harmful microorganisms from the host. This systematic review provides an overview on the fermentation conditions that affect the production of clavulanic acid in the firstly described producer, Streptomyces clavuligerus. A thorough search was conducted using predefined terms in several electronic databases (PubMed, Medline, ScienceDirect, EBSCO), from database inception to June 30th 2015. Studies must involve wild-type Streptomyces clavuligerus, and full texts needed to be available. A total of 29 eligible articles were identified. Based on the literature, several factors were identified that could affect the production of clavulanic acid in S. clavuligerus. The addition of glycerol or other vegetable oils (e.g., olive oil, corn oil) could potentially affect clavulanic acid production. Furthermore, some amino acids such as arginine and ornithine, could serve as potential precursors to increase clavulanic acid yield. The comparison of different fermentation systems revealed that fed-batch fermentation yields higher amounts of clavulanic acid as compared to batch fermentation, probably due to the maintenance of substrates and constant monitoring of certain entities (such as pH, oxygen availability, etc.). Overall, these findings provide vital knowledge and insight that could assist media optimization and fermentation design for clavulanic acid production in S. clavuligerus. PMID:27148211

  2. Indole-3-butyric acid synthesis in ecotypes and mutants of Arabidopsis thaliana under different growth conditions.

    PubMed

    Ludwig-Müller, Jutta

    2007-01-01

    Although IBA is a naturally occurring auxin, its role in plant development is still under debate. In this study a set of Arabidopsis mutants was used to analyze the biosynthesis of IBA in vitro. The mutants chosen for this study can be classified as: (1) involvement in auxin metabolism, transport or synthesis (amt1, aux1, ilr1, nit1, rib1, sur1, trp1-100); (2) other hormones possibly involved in the regulation of IBA synthesis (aba1, aba3, eto2, fae1, hls1, jar1); (3) photomorphogenesis (det1, det2, det3); and (4) root architecture (cob1, cob2, scr1). In addition, two transgenic lines overexpressing the IAA glucose synthase (iaglu) gene from maize were analyzed. The ecotypes No-0 and Wassilewskija showed the highest IBA synthetase activity under control conditions, followed by Columbia, Enkheim and Landsberg erecta. In the mutant lines IBA synthetase activity differed in most cases from the wild type, however no particular pattern of up- or down-regulation, which could be correlated to their possible function, was found. For rib1 mutant seedlings it was tested whether reduced IBA synthetase activity correlates with the endogenous IBA levels. Free IBA differed only depending on the culture conditions, but gave no clear correlation with IBA synthetase activity compared to the wild type. Since drought and osmotic stress as well as abscisic acid (ABA) application enhanced IBA synthesis in maize, it was tested whether IBA synthetase from Arabidopsis is also inducible by drought stress conditions. This was confirmed for the two ecotypes Col and Ler which showed different IBA synthetase activity when cultivated with various degrees of drought stress. IBA synthetase was also determined in photomorphogenic mutants under different light regimes. Induction of IBA synthetase in det1 and det3 plants was found under short day plus a red light pulse or in the dark, respectively. The results are discussed with respect to the functions of the mutated genes. PMID:16325963

  3. Polymerization of amino acids under high-pressure conditions: Implication to chemical evolution on the early Earth

    NASA Astrophysics Data System (ADS)

    Kakegawa, T.; Ohara, S.; Ishiguro, T.; Abiko, H.; Nakazawa, H.

    2008-12-01

    Prebiotic polymerization of amino acids is the most fundamental reaction to promote the chemical evolution for origin of life. Polymerization of amino acids is the dehydration reaction. This questions as to if submarine hydrothermal conditions, thus hydrated enironments, were appropreate for peptide formations. Our previous experiments implied that non-aqueous and high-pressure environments (more than 20 MPa) would be suitable for polymerization of amino acids (Ohara et al., 2006). This leads to the hypothesis that the first peptides may have formed in the Hadean oceanic crustal environments, where dehydration proceeded with availability of appropriate temperatures and pressures. In the present study, experiments simulating the crustal conditions were performed with various pressures (1-175 MPa) and temperatures (100- 200 C degree) using autoclaves. Purified powders (100 mg) of alanine, glycine, valine and aspartic acid were used in the experiments without mixing water in order to examine the solid-solid reactions. The products were analyzed using HPLC and LC-MS. Results indicate that: (1) longer time is required to form peptide compared to those of previous aqueous experiments; (2) pressure has a role to limit the production of melanoidine and cyclic amino acids, which are inhibitors for elongation of peptides; (3) glycine was polymerized up to 11-mer, which was not formed in any previous experiments without catalyses; (4) valine was polymerized up to 3-mer; and (5) aspartic acid was polymerized to 4-mer, accompanied with production of other amino acids. It is noteworthy that high-pressure environments favor all examined polymerization reactions. Such situations would have happened inside of deep oceanic crusts of the early Earth.

  4. The PROCESS experiment: amino and carboxylic acids under Mars-like surface UV radiation conditions in low-earth orbit.

    PubMed

    Noblet, Audrey; Stalport, Fabien; Guan, Yuan Yong; Poch, Olivier; Coll, Patrice; Szopa, Cyril; Cloix, Mégane; Macari, Frédérique; Raulin, Francois; Chaput, Didier; Cottin, Hervé

    2012-05-01

    The search for organic molecules at the surface of Mars is a top priority of the next Mars exploration space missions: Mars Science Laboratory (NASA) and ExoMars (ESA). The detection of organic matter could provide information about the presence of a prebiotic chemistry or even biological activity on this planet. Therefore, a key step in interpretation of future data collected by these missions is to understand the preservation of organic matter in the martian environment. Several laboratory experiments have been devoted to quantifying and qualifying the evolution of organic molecules under simulated environmental conditions of Mars. However, these laboratory simulations are limited, and one major constraint is the reproduction of the UV spectrum that reaches the surface of Mars. As part of the PROCESS experiment of the European EXPOSE-E mission on board the International Space Station, a study was performed on the photodegradation of organics under filtered extraterrestrial solar electromagnetic radiation that mimics Mars-like surface UV radiation conditions. Glycine, serine, phthalic acid, phthalic acid in the presence of a mineral phase, and mellitic acid were exposed to these conditions for 1.5 years, and their evolution was determined by Fourier transform infrared spectroscopy after their retrieval. The results were compared with data from laboratory experiments. A 1.5-year exposure to Mars-like surface UV radiation conditions in space resulted in complete degradation of the organic compounds. Half-lives between 50 and 150 h for martian surface conditions were calculated from both laboratory and low-Earth orbit experiments. The results highlight that none of those organics are stable under low-Earth orbit solar UV radiation conditions. PMID:22680690

  5. Improvement of enamel bond strengths for conventional and resin-modified glass ionomers: acid-etching vs. conditioning*

    PubMed Central

    Zhang, Ling; Tang, Tian; Zhang, Zhen-liang; Liang, Bing; Wang, Xiao-miao; Fu, Bai-ping

    2013-01-01

    Objective: This study deals with the effect of phosphoric acid etching and conditioning on enamel micro-tensile bond strengths (μTBSs) of conventional and resin-modified glass ionomer cements (GICs/RMGICs). Methods: Forty-eight bovine incisors were prepared into rectangular blocks. Highly-polished labial enamel surfaces were either acid-etched, conditioned with liquids of cements, or not further treated (control). Subsequently, two matching pre-treated enamel surfaces were cemented together with one of four cements [two GICs: Fuji I (GC), Ketac Cem Easymix (3M ESPE); two RMGICs: Fuji Plus (GC), RelyX Luting (3M ESPE)] in preparation for μTBS tests. Pre-treated enamel surfaces and cement-enamel interfaces were analyzed by scanning electron microscopy (SEM). Results: Phosphoric acid etching significantly increased the enamel μTBS of GICs/RMGICs. Conditioning with the liquids of the cements produced significantly weaker or equivalent enamel μTBS compared to the control. Regardless of etching, RMGICs yielded stronger enamel μTBS than GICs. A visible hybrid layer was found at certain enamel-cement interfaces of the etched enamels. Conclusions: Phosphoric acid etching significantly increased the enamel μTBSs of GICs/RMGICs. Phosphoric acid etching should be recommended to etch the enamel margins before the cementation of the prostheses such as inlays and onlays, using GICs/RMGICs to improve the bond strengths. RMGICs provided stronger enamel bond strength than GICs and conditioning did not increase enamel bond strength. PMID:24190447

  6. 78 FR 34338 - Citric Acid and Certain Citrate Salts From Canada: Preliminary Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-07

    ...: Antidumping Duty Orders, 74 FR 25703 (May 29, 2009) (Citric Acid Duty Orders). Methodology The Department has...: Assessment of Antidumping Duties, 68 FR 23954 (May 6, 2003). Cash Deposit Requirements The following deposit... International Trade Administration Citric Acid and Certain Citrate Salts From Canada: Preliminary Results...

  7. 78 FR 34648 - Citric Acid and Certain Citrate Salts: Preliminary Results of Countervailing Duty Administrative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-10

    ... Countervailing Duty Order, 74 FR 25705 (May 29, 2009), remains dispositive. A full description of the scope of... International Trade Administration Citric Acid and Certain Citrate Salts: Preliminary Results of Countervailing... review of the countervailing duty (CVD) order on citric acid and citrate salts from the People's...

  8. 78 FR 64914 - Citric Acid and Certain Citrate Salts From Canada: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-30

    ... China: Antidumping Duty Orders, 74 FR 25703 (May 29, 2009) (Citric Acid Duty Orders). Period of Review...-others rate made effective by the LTFV investigation. See Citric Acid Duty Orders, 74 FR 25703. These... Salts from Canada: Preliminary Results of Antidumping Duty Administrative Review; 2011- 2012, 78...

  9. Comparative metabolomics analysis of docosahexaenoic acid fermentation processes by Schizochytrium sp. under different oxygen availability conditions.

    PubMed

    Li, Juan; Ren, Lu-Jing; Sun, Guan-Nan; Qu, Liang; Huang, He

    2013-05-01

    The intracellular metabolic profile characterization of Schizochytrium sp. throughout docosahexaenoic acid fermentation was investigated using gas chromatography-mass spectrometry (GC-MS). Metabolite profiles originating from Schizochytrium sp. under normal and limited oxygen supply conditions were distinctive and distinguished by principal components analysis (PCA). A total of more than 60 intracellular metabolites were detected and quantified with the levels of some metabolites involved in central carbon metabolism varying throughout both processes. Both fermentation processes were differentiated into three main phases by principal components analysis. Potential biomarkers responsible for distinguishing the different fermentation phases were identified as glutamic acid, proline, glycine, alanine, and glucose. In addition, alanine, glutamic acid, glucose, inositol, ornithine, and galactose were found to make great contribution for dry cell weight and fatty acid composition during normal and limited oxygen supply fermentations. Furthermore, significantly higher levels of succinate and several amino acids in cells of limited oxygen supply fermentation revealed that they might play important roles in resisting oxygen deficiency and increasing DHA synthesis during the lipid accumulation. These findings provide novel insights into the metabolomic characteristics during docosahexaenoic acid fermentation processes by Schizochytrium sp. PMID:23586678

  10. Evaluation of the antineoplastic activity of gallic acid in oral squamous cell carcinoma under hypoxic conditions.

    PubMed

    Guimaraes, Talita A; Farias, Lucyana C; Fraga, Carlos A; Feltenberger, John D; Melo, Geraldo A; Coletta, Ricardo D; Souza Santos, Sergio H; de Paula, Alfredo M B; Guimaraes, Andre L

    2016-06-01

    The purpose of the current study was to develop and test a theoretical model that could explain the mechanism of action of gallic acid (GA) in the oral squamous cell carcinoma context for the first time. The theoretical model was developed using bioinformatics and interaction network analysis to evaluate the effect of GA on oral squamous cell carcinoma. In a second step to confirm theoretical results, migration, invasion, proliferation, and gene expression (Col1A1, E-cadherin, HIF-1α, and caspase-3) were performed under normoxic and hypoxic conditions. Our study indicated that treatment with GA resulted in the inhibition of cell proliferation, migration, and invasion in neoplastic cells. Observation of the molecular mechanism showed that GA upregulates E-cadherin expression and downregulates Col1A1 and HIF-1α expression, suggesting that GA might be a potential anticancer compound. In conclusion, the present study demonstrated that GA significantly reduces cell proliferation, invasion, and migration by increasing E-cadherin and repressing Col1A1. PMID:26849170

  11. Methane production from acid hydrolysates of Agave tequilana bagasse: evaluation of hydrolysis conditions and methane yield.

    PubMed

    Arreola-Vargas, Jorge; Ojeda-Castillo, Valeria; Snell-Castro, Raúl; Corona-González, Rosa Isela; Alatriste-Mondragón, Felipe; Méndez-Acosta, Hugo O

    2015-04-01

    Evaluation of diluted acid hydrolysis for sugar extraction from cooked and uncooked Agave tequilana bagasse and feasibility of using the hydrolysates as substrate for methane production, with and without nutrient addition, in anaerobic sequencing batch reactors (AnSBR) were studied. Results showed that the hydrolysis over the cooked bagasse was more effective for sugar extraction at the studied conditions. Total sugars concentration in the cooked and uncooked bagasse hydrolysates were 27.9 g/L and 18.7 g/L, respectively. However, 5-hydroxymethylfurfural was detected in the cooked bagasse hydrolysate, and therefore, the uncooked bagasse hydrolysate was selected as substrate for methane production. Interestingly, results showed that the AnSBR operated without nutrient addition obtained a constant methane production (0.26 L CH4/g COD), whereas the AnSBR operated with nutrient addition presented a gradual methane suppression. Molecular analyses suggested that methane suppression in the experiment with nutrient addition was due to a negative effect over the archaeal/bacterial ratio. PMID:25647030

  12. [Influences of humic acids on the dissimilatory iron reduction of red soil in anaerobic condition].

    PubMed

    Xu, Li-na; Li, Zhong-pei; Che, Yu-ping

    2009-01-01

    Iron oxide is abundant in red soil. Reduction and oxidation of iron oxide are important biogeochemical processes. In this paper, we reported the effects of humic acid on dissimilatory iron reduction (DISSIR) in red soil by adding glucose or humic acid (HA), under an anaerobic condition. Results indicated that DISSIR is weak for the red soil with a low content of organic matter, Glucose that act as electron donators promoted the process of DISSIR in red soil. HA added to soil solely didn't accelerate the DISSIR since it couldn't provide electron donators to microbe. However, adding of both glucose and HA promoted the DISSIR at the beginning of the incubation but then inhibited the process, which maybe caused by the effects of precipitation and adsorption of red soil. Concentrations of HA strongly affected the DISSIR, HA at low concentrations(0.20 and 0.02 g/kg) had weak effects, while HA at a high concentration (2.00 g/kg) promoted the process at the beginning and then inhibited it. HA extracted from different materials had distinct effects on the DISSIR. HA from Weathering coal of Datong in Shanxi Province (HAs), lignite of Gongxian in Henan Province (HAh) and Dianchi Lake sediment in Kunming of Yunnan Province (HAk) all promoted the DISSIR at the beginning of the incubation. However, at the end of incubation, HAk with a low aromaticity still promoted the process, while HAs and HAh with a higher aromaticity weakened the DISSIR. This may be due to the increase in adsorption of soil with the aromaticity of HA. PMID:19353884

  13. Extended survival of several organisms and amino acids under simulated martian surface conditions

    NASA Astrophysics Data System (ADS)

    Johnson, A. P.; Pratt, L. M.; Vishnivetskaya, T.; Pfiffner, S.; Bryan, R. A.; Dadachova, E.; Whyte, L.; Radtke, K.; Chan, E.; Tronick, S.; Borgonie, G.; Mancinelli, R. L.; Rothschild, L. J.; Rogoff, D. A.; Horikawa, D. D.; Onstott, T. C.

    2011-02-01

    Recent orbital and landed missions have provided substantial evidence for ancient liquid water on the martian surface as well as evidence of more recent sedimentary deposits formed by water and/or ice. These observations raise serious questions regarding an independent origin and evolution of life on Mars. Future missions seek to identify signs of extinct martian biota in the form of biomarkers or morphological characteristics, but the inherent danger of spacecraft-borne terrestrial life makes the possibility of forward contamination a serious threat not only to the life detection experiments, but also to any extant martian ecosystem. A variety of cold and desiccation-tolerant organisms were exposed to 40 days of simulated martian surface conditions while embedded within several centimeters of regolith simulant in order to ascertain the plausibility of such organisms' survival as a function of environmental parameters and burial depth. Relevant amino acid biomarkers associated with terrestrial life were also analyzed in order to understand the feasibility of detecting chemical evidence for previous biological activity. Results indicate that stresses due to desiccation and oxidation were the primary deterrent to organism survival, and that the effects of UV-associated damage, diurnal temperature variations, and reactive atmospheric species were minimal. Organisms with resistance to desiccation and radiation environments showed increased levels of survival after the experiment compared to organisms characterized as psychrotolerant. Amino acid analysis indicated the presence of an oxidation mechanism that migrated downward through the samples during the course of the experiment and likely represents the formation of various oxidizing species at mineral surfaces as water vapor diffused through the regolith. Current sterilization protocols may specifically select for organisms best adapted to survival at the martian surface, namely species that show tolerance to radical

  14. Biomineralization of arsenate to arsenic sulfides is greatly enhanced at mildly acidic conditions.

    PubMed

    Rodriguez-Freire, Lucia; Sierra-Alvarez, Reyes; Root, Robert; Chorover, Jon; Field, James A

    2014-12-01

    Arsenic (As) is an important water contaminant due to its high toxicity and widespread occurrence. Arsenic-sulfide minerals (ASM) are formed during microbial reduction of arsenate (As(V)) and sulfate (SO4(2-)). The objective of this research is to study the effect of the pH on the removal of As due to the formation of ASM in an iron-poor system. A series of batch experiments was used to study the reduction of SO4(2-) and As(V) by an anaerobic biofilm mixed culture in a range of pH conditions (6.1-7.2), using ethanol as the electron donor. Total soluble concentrations and speciation of S and As were monitored. Solid phase speciation of arsenic was characterized by x-ray adsorption spectroscopy (XAS). A marked decrease of the total aqueous concentrations of As and S was observed in the inoculated treatments amended with ethanol, but not in the non-inoculated controls, indicating that the As-removal was biologically mediated. The pH dramatically affected the extent and rate of As removal, as well as the stoichiometric composition of the precipitate. The amount of As removed was 2-fold higher and the rate of the As removal was up to 17-fold greater at pH 6.1 than at pH 7.2. Stoichiometric analysis and XAS results confirmed the precipitate was composed of a mixture of orpiment and realgar, and the proportion of orpiment in the sample increased with increasing pH. The results taken as a whole suggest that ASM formation is greatly enhanced at mildly acidic pH conditions. PMID:25222328

  15. Biomineralization of Arsenate to Arsenic Sulfides is Greatly Enhanced at Mildly Acidic Conditions

    PubMed Central

    Rodriguez-Freire, Lucia; Sierra-Alvarez, Reyes; Root, Robert; Chorover, Jon; Field, James A.

    2014-01-01

    Arsenic (As) is an important water contaminant due to its high toxicity and widespread occurrence. Arsenic-sulfide minerals (ASM) are formed during microbial reduction of arsenate (AsV) and sulfate (SO42−). The objective of this research is to study the effect of the pH on the removal of As due to the formation of ASM in an iron-poor system. A series of batch experiments was used to study the reduction of SO42− and AsV by an anaerobic biofilm mixed culture in a range of pH conditions (6.1–7.2), using ethanol as the electron donor. Total soluble concentrations and speciation of S and As were monitored. Solid phase speciation of arsenic was characterized by x-ray adsorption spectroscopy (XAS). A marked decrease of the total aqueous concentrations of As and S was observed in the inoculated treatments amended with ethanol, but not in the non-inoculated controls, indicating that the As-removal was biologically mediated. The pH dramatically affected the extent and rate of As removal, as well as the stoichiometric composition of the precipitate. The amount of As removed was 2-fold higher and the rate of the As removal was up to 17-fold greater at pH 6.1 than at pH 7.2. Stoichiometric analysis and XAS results confirmed the precipitate was composed of a mixture of orpiment and realgar, and the proportion of orpiment in the sample increased with increasing pH. The results taken as a whole suggest that ASM formation is greatly enhanced at mildly acidic pH conditions. PMID:25222328

  16. Characterization of citrus pectin samples extracted under different conditions: influence of acid type and pH of extraction

    PubMed Central

    Kaya, Merve; Sousa, António G.; Crépeau, Marie-Jeanne; Sørensen, Susanne O.; Ralet, Marie-Christine

    2014-01-01

    Background and Aims Pectin is a complex macromolecule, the fine structure of which is influenced by many factors. It is used as a gelling, thickening and emulsifying agent in a wide range of applications, from food to pharmaceutical products. Current industrial pectin extraction processes are based on fruit peel, a waste product from the juicing industry, in which thousands of tons of citrus are processed worldwide every year. This study examines how pectin components vary in relation to the plant source (orange, lemon, lime, grapefruit) and considers the influence of extraction conditions on the chemical and macromolecular characteristics of pectin samples. Methods Citrus peel (orange, lemon, lime and grapefruit) from a commercial supplier was used as raw material. Pectin samples were obtained on a bulk plant scale (kilograms; harsh nitric acid, mild nitric acid and harsh oxalic acid extraction) and on a laboratory scale (grams; mild oxalic acid extraction). Pectin composition (acidic and neutral sugars) and physicochemical properties (molar mass and intrinsic viscosity) were determined. Key Results Oxalic acid extraction allowed the recovery of pectin samples of high molecular weight. Mild oxalic acid-extracted pectins were rich in long homogalacturonan stretches and contained rhamnogalacturonan I stretches with conserved side chains. Nitric acid-extracted pectins exhibited lower molecular weights and contained rhamnogalacturonan I stretches encompassing few and/or short side chains. Grapefruit pectin was found to have short side chains compared with orange, lime and lemon. Orange and grapefruit pectin samples were both particularly rich in rhamnogalacturonan I backbones. Conclusions Structural, and hence macromolecular, variations within the different citrus pectin samples were mainly related to their rhamnogalacturonan I contents and integrity, and, to a lesser extent, to the length of their homogalacturonan domains. PMID:25081519

  17. Disruption of Adenovirus Type 7 by Lithium Iodide Resulting in the Release of Viral Deoxyribonucleic Acid

    PubMed Central

    Neurath, A. Robert; Stasny, John T.; Rubin, Benjamin A.

    1970-01-01

    Adenovirus type 7 exposed to solutions of LiI was progressively converted into slower sedimenting deoxyribonucleic acid (DNA)-containing particles, and, ultimately, under proper conditions, DNA free or almost free from protein was released from the virus. The degree of viral degradation was dependent on the time of treatment, on the temperature, and on the concentration of the reagent. PMID:4988267

  18. Transcriptome Profiling and Functional Analysis of Agrobacterium tumefaciens Reveals a General Conserved Response to Acidic Conditions (pH 5.5) and a Complex Acid-Mediated Signaling Involved in Agrobacterium-Plant Interactions▿

    PubMed Central

    Yuan, Ze-Chun; Liu, Pu; Saenkham, Panatda; Kerr, Kathleen; Nester, Eugene W.

    2008-01-01

    Agrobacterium tumefaciens transferred DNA (T-DNA) transfer requires that the virulence genes (vir regulon) on the tumor-inducing (Ti) plasmid be induced by plant phenolic signals in an acidic environment. Using transcriptome analysis, we found that these acidic conditions elicit two distinct responses: (i) a general and conserved response through which Agrobacterium modulates gene expression patterns to adapt to environmental acidification and (ii) a highly specialized acid-mediated signaling response involved in Agrobacterium-plant interactions. Overall, 78 genes were induced and 74 genes were repressed significantly under acidic conditions (pH 5.5) compared to neutral conditions (pH 7.0). Microarray analysis not only confirmed previously identified acid-inducible genes but also uncovered many new acid-induced genes which may be directly involved in Agrobacterium-plant interactions. These genes include virE0, virE1, virH1, and virH2. Further, the chvG-chvI two-component system, previously shown to be critical for virulence, was also induced under acid conditions. Interestingly, acidic conditions induced a type VI secretion system and a putative nonheme catalase. We provide evidence suggesting that acid-induced gene expression was independent of the VirA-VirG two-component system. Our results, together with previous data, support the hypothesis that there is three-step sequential activation of the vir regulon. This process involves a cascade regulation and hierarchical signaling pathway featuring initial direct activation of the VirA-VirG system by the acid-activated ChvG-ChvI system. Our data strengthen the notion that Agrobacterium has evolved a mechanism to perceive and subvert the acidic conditions of the rhizosphere to an important signal that initiates and directs the early virulence program, culminating in T-DNA transfer. PMID:17993523

  19. Aluminium-phosphate-sulphate minerals as markers of sustained acidic conditions during the Permian-Triassic transition in E Iberia.

    NASA Astrophysics Data System (ADS)

    Borruel-Abadía, Violeta; Belén Galán-Abellán, Ana; Barrenechea, José F.; De la Horra, Raúl; Luque, Francisco Javier; Alonso-Azcárate, Jacinto; López-Gómez, José

    2016-04-01

    Strontium-rich hydrated Aluminium phosphate-sulphate (APS) minerals are markers of an acidic formation environment due to their precipitation at low pH conditions. However, their small size (0.5-6 μm), low concentrations, and optical properties represent the main problems to quantify these minerals. This study provides quantitative data on APS mineral concentrations for the Late Permian and Early-Middle Triassic in different continental sections of East Iberia. By quantifying APS minerals useful insight can be obtained into the environmental conditions that prevailed during the biotic crisis of the PTB and during the later recovery of life at the end of the Early Triassic. For that, a quantification method based on element mapping of randomly selected areas of thin sections on the electron microprobe is proposed, with relative errors ranging from 5.6% to 11.7%. The results are considered on a detailed petrographic, sedimentological, and palaeontological framework, and compared with other geochemical. Thus, in the first sedimentary record after the Permian-Triassic boundary (Olenekian), it has been possible to correlate relatively high concentration levels of APS minerals with the lack of signs of living organisms. Our findings suggest a long period of sustained acidic conditions followed by an environmental change that permitted the recovery of life, as reflected by lower APS mineral contents detected at the end of the Spathian and the first presence of bioturbation, paleosols, footprints, and plant remains. Early Anisian acidic episodes were much more sporadic than those during the Olenekian deposition, in which APS mineral concentrations were an order of magnitude higher. This fact would indicate punctual acidic conditions still during the beginning of the Anisian. Based on these results, this method is proposed as a tool for addressing environmental changes that took place during the Permian-Triassic transition in continental environments.

  20. Use of the ion exchange method for the determination of stability constants of trivalent metal complexes with humic and fulvic acids--part I: Eu3+ and Am3+ complexes in weakly acidic conditions.

    PubMed

    Wenming, Dong; Hongxia, Zhang; Meide, Huang; Zuyi, Tao

    2002-06-01

    The conditional stability constants for tracer concentrations of Eu(III) and Am(III) with a red earth humic acid (REHA), a red earth fulvic acid (REFA) and a fulvic acid from weathered coal (WFA) were determined at pH 5.2-6.4 (such values are similar to those in non-calcareous soils) in the presence of HAc/NaAc or NaNO3 by using the cation exchange method. It was found that 1:1 complexes were predominately formed in weakly acidic conditions. The total exchangeable proton capacities and the degrees of dissociation of these humic substances were determined by using a potentiometric titration method. The key parameters necessary for the experimental determination of the conditional stability constants of metal ions with humic substances in weakly acidic conditions by using the cation exchange method were discussed. The conditional stability constants of 1:1 complexes obtained in this paper were compared with the literature data of Am(III) determined by using the ion exchange method and the solvent extraction method and with the stability constants of 1:1 complexes of UO2(2+) and Th4+ with the same soil humic substances. These results indicate the great stability of bivalent UO2(2+), trivalent Eu3+, Am3+ and tetravalent Th4+ complexes with humic and fulvic acids in weakly acidic conditions. PMID:12102358

  1. Condition-based use of antimicrobials in cats in Finland: results from two surveys.

    PubMed

    Thomson, Katariina H; Rantala, Merja H J; Viita-Aho, Teija K; Vainio, Outi M; Kaartinen, Liisa A

    2009-06-01

    Two surveys were carried out to investigate how antimicrobials are used in cats in Finland. Information was retrieved from 419 prescriptions and 311 questionnaire sheets concerning antimicrobial treatment for feline patients. Infected wounds, skin disorders and urinary tract infections were the most common reasons for antimicrobial treatment in cats. Compliance with prudent use guidelines was good. beta-Lactams such as amoxycillin and amoxycillin with clavulanic acid were frequently used. Fluoroquinolones were used judiciously. The median length of treatment was 10 days for most conditions. Diagnosis was mainly based on clinical signs, and bacteriological culture and sensitivity testing was rarely performed. This study provides basic descriptive information on how antimicrobials are used in cats and that could help when revising guidelines for the condition-based use of antimicrobials in animals. PMID:19111491

  2. The conditioning effect of large doses of ascorbic acid in guinea pigs.

    PubMed

    Basu, T K

    1985-05-01

    The influence of prolonged exposure of guinea pigs to excessive ascorbic acid (AA) on the outcome of pregnancy, as well as the adaptive effect of the vitamin either during preweanling life or following weaning, were examined. Continuous exposure to AA (1 mg/mL drinking water) from the time they were first mated up to the time of second pregnancy, had no significant effect on the number of offspring and on their weights at birth, when compared with that of the animals receiving 0.1 mg AA/mL drinking water. However, change in AA intake from 1 to 0.1 mg/mL drinking water, at the age of 21 days, resulted in a significant loss in body weight and reductions in the plasma, leukocyte, and adrenal concentrations of AA, as compared with those of the pair-fed animals receiving 0.1 mg/mL drinking water throughout. The present study also indicated that the conditioning effect is less pronounced in guinea pigs when exposed to the high AA following weanling age than in utero. PMID:4041985

  3. Effects of culture conditions on growth and docosahexaenoic acid production from Schizochytrium limacinum

    NASA Astrophysics Data System (ADS)

    Zhu, Luying; Zhang, Xuecheng; Ren, Xueying; Zhu, Qinghua

    2008-02-01

    The effects of temperature, initial pH, salinity of culture medium, and carbon and nitrogen sources on growth and docosahexaenoic acid (C22: 6 n-3, DHA) production from Schizochytrium limacinum OUC88 were investigated in the present study. The results revealed that the optimal temperature, initial pH and salinity level of the medium for DHA production were 23°C, 7.0 and 18, respectively. Glucose was proved the best carbon source for the growth and DHA production from S. limacinum. Among the nitrogen sources tested, soybean cake hydrolysate, a cheap by-product, was found to be effective for the accumulation of DHA in S. limacinum cells. In addition, increasing the concentration of carbon sources in the medium caused a significant increase in cell biomass; however, accumulation of DHA in cells was mainly stimulated by the ratio of C/N in the medium. Under the optimal culture conditions, the maximum DHA yield achieved in flasks was 4.08 g L-1 after 5 d of cultivation.

  4. Formation Sequences of Iron Minerals in the Acidic Alteration Products and Variation of Hydrothermal Fluid Conditions

    NASA Astrophysics Data System (ADS)

    Isobe, H.; Yoshizawa, M.

    2008-12-01

    Iron minerals have important role in environmental issues not only on the Earth but also other terrestrial planets. Iron mineral species related to alteration products of primary minerals with surface or subsurface fluids are characterized by temperature, acidity and redox conditions of the fluids. We can see various iron- bearing alteration products in alteration products around fumaroles in geothermal/volcanic areas. In this study, zonal structures of iron minerals in alteration products of the geothermal area are observed to elucidate temporal and spatial variation of hydrothermal fluids. Alteration of the pyroxene-amphibole andesite of Garan-dake volcano, Oita, Japan occurs by the acidic hydrothermal fluid to form cristobalite leaching out elements other than Si. Hand specimens with unaltered or weakly altered core and cristobalite crust show various sequences of layers. XRD analysis revealed that the alteration degree is represented by abundance of cristobalite. Intermediately altered layers are characterized by occurrence including alunite, pyrite, kaolinite, goethite and hematite. A specimen with reddish brown core surrounded by cristobalite-rich white crust has brown colored layers at the boundary of core and the crust. Reddish core is characterized by occurrence of crystalline hematite by XRD. Another hand specimen has light gray core, which represents reduced conditions, and white cristobalite crust with light brown and reddish brown layers of ferric iron minerals between the core and the crust. On the other hand, hornblende crystals, typical ferrous iron-bearing mineral of the host rock, are well preserved in some samples with strongly decolorized cristobalite-rich groundmass. Hydrothermal alteration experiments of iron-rich basaltic material shows iron mineral species depend on acidity and temperature of the fluid. Oxidation states of the iron-bearing mineral species are strongly influenced by the acidity and redox conditions. Variations of alteration

  5. A stable enol from a 6-substituted benzanthrone and its unexpected behaviour under acidic conditions

    PubMed Central

    Debeaux, Marc; Brandhorst, Kai; Jones, Peter G; Hopf, Henning; Grunenberg, Jörg; Kowalsky, Wolfgang

    2009-01-01

    Summary Treatment of benzanthrone (1) with biphenyl-2-yl lithium leads to the surprisingly stable enol 4, which is converted by dehydrogenation into the benzanthrone derivative 7. Under acidic conditions 4 isomerises to the spiro compound 11 and the bicyclo[4.3.1]decane derivative 12. Furthermore, the formation of 7 and the hydrogenated compound 13 is observed. A mechanism for the formation of the reaction products is proposed and supported by DFT calculations. PMID:19597557

  6. Manganese ore tailing: optimization of acid leaching conditions and recovery of soluble manganese.

    PubMed

    Santos, Olívia de Souza Heleno; Carvalho, Cornélio de Freitas; Silva, Gilmare Antônia da; Santos, Cláudio Gouvêa Dos

    2015-01-01

    Manganese recovery from industrial ore processing waste by means of leaching with sulfuric acid was the objective of this study. Experimental conditions were optimized by multivariate experimental design approaches. In order to study the factors affecting leaching, a screening step was used involving a full factorial design with central point for three variables in two levels (2(3)). The three variables studied were leaching time, concentration of sulfuric acid and sample amount. The three factors screened were shown to be relevant and therefore a Doehlert design was applied to determine the best working conditions for leaching and to build the response surface. By applying the best leaching conditions, the concentrations of 12.80 and 13.64 %w/w of manganese for the global sample and for the fraction -44 + 37 μm, respectively, were found. Microbeads of chitosan were tested for removal of leachate acidity and recovering of soluble manganese. Manganese recovery from the leachate was 95.4%. Upon drying the leachate, a solid containing mostly manganese sulfate was obtained, showing that the proposed optimized method is efficient for manganese recovery from ore tailings. PMID:25284800

  7. High-quality green tea leaf production by artificial cultivation under growth chamber conditions considering amino acids profile.

    PubMed

    Miyauchi, Shunsuke; Yuki, Takayuki; Fuji, Hiroshi; Kojima, Kunio; Yonetani, Tsutomu; Tomio, Ayako; Bamba, Takeshi; Fukusaki, Eiichiro

    2014-12-01

    The current study focused on the tea plant (Camellia sinensis) as a target for artificial cultivation because of the variation in its components in response to light conditions. We analyzed its sensory quality by multi-marker profiling using multicomponent data based on metabolomics to optimize the conditions of light and the environment during cultivation. From the analysis of high-quality tea samples ranked in a tea contest, the ranking predictive model was created by the partial least squares (PLS) regression analysis to examine the correlation between the amino-acid content (X variables) and the ranking in the tea contest (Y variables). The predictive model revealed that glutamine, arginine, and theanine were the predominant amino acids present in high-ranking teas. Based on this result, we established a cover-culture condition (i.e., a low-light intensity condition) during the later stage of the culture process and obtained artificially cultured tea samples, which were predicted to be high-quality teas. The aim of the current study was to optimize the light conditions for the cultivation of tea plants by performing data analysis of their sensory qualities through multi-marker profiling in order to facilitate the development of high-quality teas by plant factories. PMID:24915994

  8. A novel system combining biocatalytic dephosphorylation of L-ascorbic acid 2-phosphate and electrochemical oxidation of resulting ascorbic acid.

    PubMed

    Kuwahara, Takashi; Homma, Toshimasa; Kondo, Mizuki; Shimomura, Masato

    2011-03-15

    An enzyme electrode was prepared with acid phosphatase (ACP) for development of a new electric power generation system using ascorbic acid 2-phosphate (AA2P) as a fuel. The properties of the electrode were investigated with respect to biocatalytic dephosphorylation of AA2P and electrochemical oxidation of resulting ascorbic acid (AA). The enzyme electrode was fabricated by immobilization of ACP through amide linkage onto a self-assembled monolayer of 3-mercaptopropionic acid on a gold electrode. AA2P was not oxidized on a bare gold electrode in the potential sweep range from -0.1 to +0.5 V vs. Ag/AgCl. However, the enzyme electrode gave an oxidation current in citric buffer solution of pH 5 containing 10 mM of AA2P. The oxidation current began to increase at +0.2V, and reached to 5.0 μA cm(-2) at +0.5 V. The potential +0.2 V corresponded to the onset of oxidation of ascorbic acid (AA). These results suggest that the oxidation current observed with the enzyme electrode is due to AA resulting from dephosphorylation of AA2P. The oxidation current increased with increasing concentration of AA2P and almost leveled off at around the concentration of 5mM. Thus the enzyme electrode brought about biocatalytic conversion of AA2P to AA, followed by electrochemical oxidation of the AA. The oxidation current is likely to be controlled by the biocatalytic reaction. PMID:21247749

  9. Effect of fermentation conditions on L-lactic acid production from soybean straw hydrolysate.

    PubMed

    Wang, Juan; Wang, Qunhui; Xu, Zhong; Zhang, Wenyu; Xiang, Juan

    2015-01-01

    Four types of straw, namely, soybean, wheat, corn, and rice, were investigated for use in lactic acid production. These straws were mainly composed of cellulose, hemicellulose, and lignin. After pretreatment with ammonia, the cellulose content increased, whereas the hemicellulose and lignin contents decreased. Analytical results also showed that the liquid enzymatic hydrolysates were primarily composed of glucose, xylose, and cellobiose. Preliminary experiments showed that a higher lactic acid concentration could be obtained from the wheat and soybean straw. However, soybean straw was chosen as the substrate for lactic acid production owing to its high protein content. The maximum lactic acid yield (0.8 g/g) and lactic acid productivity (0.61 g/(l/h)) were obtained with an initial reducing sugar concentration of 35 g/l at 30°C when using Lactobacillus casei (10% inoculum) for a 42 h fermentation period. Thus, the experimental results demonstrated the feasibility of using a soybean straw enzymatic hydrolysate as a substrate for lactic acid production. PMID:25152056

  10. Spatial variation of stratospheric aerosol acidity and model refractive index - Implications of recent results

    NASA Technical Reports Server (NTRS)

    Russell, P. B.; Hamill, P.

    1984-01-01

    Recent experimental results indicate that little or no solid ammonium sulfate is present in background stratospheric aerosols. Other results allow straightforward calculation of sulfuric acid/water droplet properties (acidity, specific gravity, refractive index) as functions of stratospheric temperature and humidity. These results are combined with a variety of latitudinal and seasonal temperature and humidity profiles to obtain corresponding profiles of droplet properties. These profiles are used to update a previous model of stratospheric aerosol refractive index. The new model retains the simplifying approximation of vertically constant refractive index in the inner stratosphere, but has sulfuric acid/water refractive index values that significantly exceed the previously used room temperature values. Mean conversion ratios (e.g., extinction-to-number, backscatter-to-volume) obtained using Mie scattering calculations with the new refractive indices are very similar to those obtained for the old indices, because the effects of deleting ammonium sulfate and increasing acid indices tend to cancel each other.

  11. Expression of a coriander desaturase results in petroselinic acid production in transgenic tobacco

    SciTech Connect

    Cahoon, E.B.; Shanklin, J.; Ohlrogge, J.B. )

    1992-12-01

    Little is known about the metabolic origin of petroselinic acid (18:1[Delta][sup 6cis]), the principal fatty acid of the seed oil of most Umbelliferae, Araliaceae, and Garryaceae species. To examine the possibility that petroselinic acid is the product of an acyl-acyl carrier protein (ACP) desaturase, Western blots of coriander and other Umbelliferae seed extracts were probed with antibodies against the [Delta][sup 9]-stearoyl-ACP desaturase of avocado. In these extracts, proteins of 39 and 36 kDa were detected. Of these, only the 36-kDa peptide was specific to tissues which synthesize petroselinic acid. A cDNA encoding the 36-kDa peptide was isolated from a coriander endosperm cDNA library, placed under control of the cauliflower mosaic virus 35S promoter, and introduced into tobacco by Agrobacterium tumefaciens-mediated transformation. Expression of this cDNA in transgenic tobacco callus was accompanied by the accumulation of petroselinic acid and [Delta][sup 4]-hexadecenoic acid, both of which were absent from control callus. These results demonstrate the involvement of a 36-kDa putative acyl-ACP desaturase in the biosynthetic pathway of petroselinic acid and the ability to produce fatty acids of unusual structure in transgenic plants by the expression of the gene for this desaturase. 27 refs., 5 figs.

  12. Expression of a coriander desaturase results in petroselinic acid production in transgenic tobacco.

    PubMed Central

    Cahoon, E B; Shanklin, J; Ohlrogge, J B

    1992-01-01

    Little is known about the metabolic origin of petroselinic acid (18:1 delta 6cis), the principal fatty acid of the seed oil of most Umbelliferae, Araliaceae, and Garryaceae species. To examine the possibility that petroselinic acid is the product of an acyl-acyl carrier protein (ACP) desaturase, Western blots of coriander and other Umbelliferae seed extracts were probed with antibodies against the delta 9-stearoyl-ACP desaturase of avocado. In these extracts, proteins of 39 and 36 kDa were detected. Of these, only the 36-kDa peptide was specific to tissues which synthesize petroselinic acid. A cDNA encoding the 36-kDa peptide was isolated from a coriander endosperm cDNA library, placed under control of the cauliflower mosaic virus 35S promoter, and introduced into tobacco by Agrobacterium tumefaciens-mediated transformation. Expression of this cDNA in transgenic tobacco callus was accompanied by the accumulation of petroselinic acid and delta 4-hexadecenoic acid, both of which were absent from control callus. These results demonstrate the involvement of a 36-kDa putative acyl-ACP desaturase in the biosynthetic pathway of petroselinic acid and the ability to produce fatty acids of unusual structure in transgenic plants by the expression of the gene for this desaturase. Images PMID:1454797

  13. Rhodobacter sphaeroides mutants which accumulate 5-aminolevulinic acid under aerobic and dark conditions.

    PubMed

    Nishikawa, S; Watanabe, K; Tanaka, T; Miyachi, N; Hotta, Y; Murooka, Y

    1999-01-01

    The photosynthetic bacterium Rhodobacter sphaeroides accumulates 5-aminolevulinic acid (ALA), which is a precursor in tetrapyrrole biosynthesis, under light illumination and upon addition of levulinic acid as an inhibitor of ALA dehydratase. To generate an industrial strain which produces ALA in the absence of light, we sequentially mutated R. sphaeroides CR-286 using N-methyl-N'-nitro-N-nitrosoguanidine (NTG). The mutant strains were screened by cultivating in the absence of light and assayed for ALA by the Ehrlich reaction in a 96-well microtiter plate. The mutant strain CR-386, derived from R. sphaeroides CR-286, was selected as a mutant that exhibited significant ALA accumulation. While CR-286 required light illumination for ALA production, CR-386 was able to accumulate 1.5 mM ALA in the presence of 50 mM glucose, 60 mM glycine, 15 mM levulinic acid and 1.0% (w/v) yeast extract under conditions of agitation in the absence of light. The mutant strain CR-450, derived from strain CR-386, was selected further as a mutant that exhibited significant ALA accumulation but no accumulation of aminoacetone, analogue of ALA. CR-450 accumulated 3.8 mM ALA under the same conditions. In the presence of 50 mM glucose, 60 mM glycine, 5 mM levulinic acid and 1.0% (w/v) yeast extract, the mutant strain CR-520, derived from strain CR-450, and strain CR-606, derived from strain CR-520, accumulated 8.1 mM and 11.2 mM ALA, respectively. In batch fermentation, the strain CR-606 accumulated 20 mM ALA over 18 h after the addition of glycine, levulinic acid, glucose and yeast extract. PMID:16232557

  14. Acidic pH conditions induce dissociation of the haem from the protein and destabilise the catalase isolated from Aspergillus terreus.

    PubMed

    Vatsyayan, Preety; Goswami, Pranab

    2011-02-01

    The stability (half-life, t(½)) of the large catalase (CAT) isolated from Aspergillus terreus was decreased under acidic conditions (maximum t(½) approximately 8.5 months at pH ≤ 6) versus alkaline conditions (t(½) approximately 15 months at pH 8-12). Acidic conditions induce the dissociation of haem from CAT, as revealed from a reduction in the Soret peak intensity at 405 nm and an increase in the peak current at Fe(3+)/Fe(2+) redox potentials. This increase in current is attributed to the facile electron transfer from the free haem generated on the electrode surface as a result of its disintegration from the insulating protein matrix. The haem isolated from CAT at acidic condition was reconstituted with apo-CAT at alkaline denaturing conditions to regenerate the CAT activity. PMID:20972700

  15. Screening of phenylpyruvic acid producers and optimization of culture conditions in bench scale bioreactors.

    PubMed

    Coban, Hasan B; Demirci, Ali; Patterson, Paul H; Elias, Ryan J

    2014-11-01

    Alpha keto acids are deaminated forms of amino acids that have received significant attention as feed and food additives in the agriculture and medical industries. To date, their production has been commonly performed at shake-flask scale with low product concentrations. In this study, production of phenylpyruvic acid (PPA), which is the alpha keto acid of phenylalanine was investigated. First, various microorganisms were screened to select the most efficient producer. Thereafter, growth parameters (temperature, pH, and aeration) were optimized in bench scale bioreactors to maximize both PPA and biomass concentration in bench scale bioreactors, using response surface methodology. Among the four different microorganisms evaluated, Proteus vulgaris was the most productive strain for PPA production. Optimum temperature, pH, and aeration conditions were determined as 34.5 °C, 5.12, and 0.5 vvm for PPA production, whereas 36.9 °C, pH 6.87, and 0.96 vvm for the biomass production. Under these optimum conditions, PPA concentration was enhanced to 1,054 mg/L, which was almost three times higher than shake-flask fermentation concentrations. Moreover, P. vulgaris biomass was produced at 3.25 g/L under optimum conditions. Overall, this study demonstrated that optimization of growth parameters improved PPA production in 1-L working volume bench-scale bioreactors compared to previous studies in the literature and was a first step to scale up the production to industrial production. PMID:24861313

  16. Modification of Pulsed Electric Field Conditions Results in Distinct Activation Profiles of Platelet-Rich Plasma

    PubMed Central

    Frelinger, Andrew L.; Gerrits, Anja J.; Garner, Allen L.; Torres, Andrew S.; Caiafa, Antonio; Morton, Christine A.; Berny-Lang, Michelle A.; Carmichael, Sabrina L.; Neculaes, V. Bogdan; Michelson, Alan D.

    2016-01-01

    Background Activated autologous platelet-rich plasma (PRP) used in therapeutic wound healing applications is poorly characterized and standardized. Using pulsed electric fields (PEF) to activate platelets may reduce variability and eliminate complications associated with the use of bovine thrombin. We previously reported that exposing PRP to sub-microsecond duration, high electric field (SMHEF) pulses generates a greater number of platelet-derived microparticles, increased expression of prothrombotic platelet surfaces, and differential release of growth factors compared to thrombin. Moreover, the platelet releasate produced by SMHEF pulses induced greater cell proliferation than plasma. Aims To determine whether sub-microsecond duration, low electric field (SMLEF) bipolar pulses results in differential activation of PRP compared to SMHEF, with respect to profiles of activation markers, growth factor release, and cell proliferation capacity. Methods PRP activation by SMLEF bipolar pulses was compared to SMHEF pulses and bovine thrombin. PRP was prepared using the Harvest SmartPreP2 System from acid citrate dextrose anticoagulated healthy donor blood. PEF activation by either SMHEF or SMLEF pulses was performed using a standard electroporation cuvette preloaded with CaCl2 and a prototype instrument designed to take into account the electrical properties of PRP. Flow cytometry was used to assess platelet surface P-selectin expression, and annexin V binding. Platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), endothelial growth factor (EGF) and platelet factor 4 (PF4), and were measured by ELISA. The ability of supernatants to stimulate proliferation of human epithelial cells in culture was also evaluated. Controls included vehicle-treated, unactivated PRP and PRP with 10 mM CaCl2 activated with 1 U/mL bovine thrombin. Results PRP activated with SMLEF bipolar pulses or thrombin had similar light scatter profiles, consistent with the

  17. Photoproduction of Amino Acids in Simulated Interstellar Pre-Cometary Conditions

    NASA Astrophysics Data System (ADS)

    Muñoz Caro, G. M.

    2007-08-01

    Amino acids are the essential molecular components of living organisms. The delivery of extraterrestrial organic compounds was likely a source of prebiotic matter on the early Earth. Amino acids from space were certainly delivered to our planet since they are present in several carbonaceous chondrites; these and other organic molecules observed in comets and meteorites could have been formed by UV and cosmic ray irradiation of icy grain mantles in the solar nebula. Five years after the publication that reported the laboratory synthesis of amino acids by vacuum UV-photoprocessing of circumstellar and interstellar ice analogs (Muñoz Caro et al. 2002, Nature, 416, 403), we re-evaluate those results. We will discuss the influence of several parameters on the amino acid outcome of the experiments, such as: the composition of the starting ice mixture, the temperature of formation, the alternative use of circularly polarized UV light, the use of HCl-hydrolysis as part of the analysis protocol, and the detection technique (gas chromatography vs. liquid chromatography). We will also make a comparison between the amino acid content of the Murchison meteorite and the amino acids generated in our experiments. A possible scenario for the formation of organic grain mantles in the solar nebula, containing prebiotic species, and their incorporation into small solar system bodies, will be presented.

  18. Investigation of malic acid production in Aspergillus oryzae under nitrogen starvation conditions.

    PubMed

    Knuf, Christoph; Nookaew, Intawat; Brown, Stephen H; McCulloch, Michael; Berry, Alan; Nielsen, Jens

    2013-10-01

    Malic acid has great potential for replacing petrochemical building blocks in the future. For this application, high yields, rates, and titers are essential in order to sustain a viable biotechnological production process. Natural high-capacity malic acid producers like the malic acid producer Aspergillus flavus have so far been disqualified because of special growth requirements or the production of mycotoxins. As A. oryzae is a very close relative or even an ecotype of A. flavus, it is likely that its high malic acid production capabilities with a generally regarded as safe (GRAS) status may be combined with already existing large-scale fermentation experience. In order to verify the malic acid production potential, two wild-type strains, NRRL3485 and NRRL3488, were compared in shake flasks. As NRRL3488 showed a volumetric production rate twice as high as that of NRRL3485, this strain was selected for further investigation of the influence of two different nitrogen sources on malic acid secretion. The cultivation in lab-scale fermentors resulted in a higher final titer, 30.27 ± 1.05 g liter(-1), using peptone than the one of 22.27 ± 0.46 g liter(-1) obtained when ammonium was used. Through transcriptome analysis, a binding site similar to the one of the Saccharomyces cerevisiae yeast transcription factor Msn2/4 was identified in the upstream regions of glycolytic genes and the cytosolic malic acid production pathway from pyruvate via oxaloacetate to malate, which suggests that malic acid production is a stress response. Furthermore, the pyruvate carboxylase reaction was identified as a target for metabolic engineering, after it was confirmed to be transcriptionally regulated through the correlation of intracellular fluxes and transcriptional changes. PMID:23892740

  19. Investigation of Malic Acid Production in Aspergillus oryzae under Nitrogen Starvation Conditions

    PubMed Central

    Knuf, Christoph; Nookaew, Intawat; Brown, Stephen H.; McCulloch, Michael; Berry, Alan

    2013-01-01

    Malic acid has great potential for replacing petrochemical building blocks in the future. For this application, high yields, rates, and titers are essential in order to sustain a viable biotechnological production process. Natural high-capacity malic acid producers like the malic acid producer Aspergillus flavus have so far been disqualified because of special growth requirements or the production of mycotoxins. As A. oryzae is a very close relative or even an ecotype of A. flavus, it is likely that its high malic acid production capabilities with a generally regarded as safe (GRAS) status may be combined with already existing large-scale fermentation experience. In order to verify the malic acid production potential, two wild-type strains, NRRL3485 and NRRL3488, were compared in shake flasks. As NRRL3488 showed a volumetric production rate twice as high as that of NRRL3485, this strain was selected for further investigation of the influence of two different nitrogen sources on malic acid secretion. The cultivation in lab-scale fermentors resulted in a higher final titer, 30.27 ± 1.05 g liter−1, using peptone than the one of 22.27 ± 0.46 g liter−1 obtained when ammonium was used. Through transcriptome analysis, a binding site similar to the one of the Saccharomyces cerevisiae yeast transcription factor Msn2/4 was identified in the upstream regions of glycolytic genes and the cytosolic malic acid production pathway from pyruvate via oxaloacetate to malate, which suggests that malic acid production is a stress response. Furthermore, the pyruvate carboxylase reaction was identified as a target for metabolic engineering, after it was confirmed to be transcriptionally regulated through the correlation of intracellular fluxes and transcriptional changes. PMID:23892740

  20. Electrochemical efficacy of a carboxylated multiwalled carbon nanotube filter for the removal of ibuprofen from aqueous solutions under acidic conditions.

    PubMed

    Bakr, Ahmed Refaat; Rahaman, Md Saifur

    2016-06-01

    This study provides insight into the efficiency of a functionalized multiwalled carbon nanotube filter for the removal of an anti-inflammatory drug, ibuprofen, through conventional filtration and electrochemical filtration processes. A comparison was made between carboxylated multiwalled carbon nanotubes (MWNTs-COOH) and pristine multiwalled carbon nanotubes (MWNTs) in order to emphasize the enhanced performance of MWNTs-COOH for the removal of ibuprofen using an electrochemical filtration process under acidic conditions. Ibuprofen-removal trials were evaluated based on absorbance values obtained using a UV/Vis spectrophotometer, and possible degradation products were identified using liquid chromatography mass spectrometry (LC-MS). The results exhibited near complete removal of ibuprofen by MWNTs-COOH at lower applied potentials (2 V), at lower flow rates, and under acidic conditions, which can be attributed to the generation of superoxides and their active participation in simultaneous degradation of ibuprofen, and its by-products, under these conditions. At higher applied potential (3 V), the possible participation of both bulk indirect oxidation reactions, and direct electron transfer were hypothesized for the removal behavior over time (breakthrough). At 3 V under acidic conditions, near 100% removal of the target molecule was achieved and was attributed to the enhanced generation of electroactive species toward bulk chemical reactions and a possible contribution from direct electron transfer under these conditions. The degradation by-products of ibuprofen were effectively removed by allowing longer residence time during the filtration process. Moreover, the effect of temperature was studied, yet showed a non-significant effect on the overall removal process. PMID:27035389

  1. Synthesis of boron suboxide from boron and boric acid under mild pressure and temperature conditions

    SciTech Connect

    Jiao, Xiaopeng; Jin, Hua; Ding, Zhanhui; Yang, Bin; Lu, Fengguo; Zhao, Xudong; Liu, Xiaoyang; Peng, Liping

    2011-05-15

    Graphical abstract: Well-crystallized and icosahedral B{sub 6}O crystals were prepared by reacting boron and boric acid at milder reaction conditions (1 GPa and 1300 {sup o}C for 2 h) as compared to previous work.. Research highlights: {yields} Well-crystallized icosahedral B{sub 6}O was synthesized by reacting boric acid and boron. {yields} The synthesis conditions (1 GPa and 1300 {sup o}C for 2 h) are milder in comparison with previous work. {yields} The more practical synthesis method may make B{sub 6}O as a potential substitute for diamond in industry. -- Abstract: Boron suboxide (B{sub 6}O) was synthesized by reacting boron and boric acid (H{sub 3}BO{sub 3}) at pressures between 1 and 10 GPa, and at temperatures between 1300 and 1400 {sup o}C. The B{sub 6}O samples prepared were icosahedral with diameters ranging from 20 to 300 nm. Well-crystallized and icosahedral crystals with an average size of {approx}100 nm can be obtained at milder reaction conditions (1 GPa and 1300 {sup o}C for 2 h) as compared to previous work. The bulk B{sub 6}O sample was stable in air at 600 {sup o}C and then slowly oxidized up to 1000 {sup o}C. The relatively mild synthetic conditions developed in this study provide a more practical synthesis of B{sub 6}O, which may potentially be used as a substitute for diamond in industry as a new superhard material.

  2. Understanding E2 versus SN2 Competition under Acidic and Basic Conditions

    PubMed Central

    Wolters, Lando P; Ren, Yi; Bickelhaupt, F Matthias

    2014-01-01

    Our purpose is to understand the mechanism through which pH affects the competition between base-induced elimination and substitution. To this end, we have quantum chemically investigated the competition between elimination and substitution pathways in H2O+C2H5OH2+ and OH−+C2H5OH, that is, two related model systems that represent, in a generic manner, the same reaction under acidic and basic conditions, respectively. We find that substitution is favored in the acidic case while elimination prevails under basic conditions. Activation-strain analyses of the reaction profiles reveal that the switch in preferred reactivity from substitution to elimination, if one goes from acidic to basic catalysis, is related to (1) the higher basicity of the deprotonated base, and (2) the change in character of the substrates LUMO from Cβ−H bonding in C2H5OH2+ to Cβ−H antibonding in C2H5OH. PMID:24688892

  3. Microbial mediated formation of Fe-carbonate minerals under extreme acidic conditions

    PubMed Central

    Sánchez-Román, Mónica; Fernández-Remolar, David; Amils, Ricardo; Sánchez-Navas, Antonio; Schmid, Thomas; Martin-Uriz, Patxi San; Rodríguez, Nuria; McKenzie, Judith A.; Vasconcelos, Crisogono

    2014-01-01

    Discovery of Fe-carbonate precipitation in Rio Tinto, a shallow river with very acidic waters, situated in Huelva, South-western Spain, adds a new dimension to our understanding of carbonate formation. Sediment samples from this low-pH system indicate that carbonates are formed in physico-chemical conditions ranging from acid to neutral pH. Evidence for microbial mediation is observed in secondary electron images (Fig. 1), which reveal rod-shaped bacteria embedded in the surface of siderite nanocrystals. The formation of carbonates in Rio Tinto is related to the microbial reduction of ferric iron coupled to the oxidation of organic compounds. Herein, we demonstrate for the first time, that Acidiphilium sp. PM, an iron-reducing bacterium isolated from Rio Tinto, mediates the precipitation of siderite (FeCO3) under acidic conditions and at a low temperature (30°C). We describe nucleation of siderite on nanoglobules in intimate association with the bacteria cell surface. This study has major implications for understanding carbonate formation on the ancient Earth or extraterrestrial planets. PMID:24755961

  4. Evaluation of the performance degradation at PAFC effect of operating conditions on acid loss

    SciTech Connect

    Miyoshi, Hideaki; Uchida, Hiroyuki; Watanabe, Masahiro

    1996-12-31

    As a complimentary research project to the demonstration project of 5MW and 1 MW PAFC plants, the mechanism and rate of deterioration of the cells and stacks have been studied from 1995 FY conducted by NEDO, with the objective of establishing an estimation method for the service life-time of the cell stacks. As part of this project, this work has been performed to clarify basic phenomena of the performance degradation at PAFCs jointly by Yamanashi University, PAFC-TRA and PAFC manufacturers. The acid loss into exhaust gases is one of life limiting factors in PAFCs. To design the cells of long-life, it is important to estimate the phosphoric acid loss and to contrive ideas eliminating it. With the objective of obtaining basic data for simulating the acid loss in the large size cells, the effect of the operating conditions on the acid loss into exhaust gases has been studied experimentally by using a single cell with an active electrode area of 100 cm{sup 2}.

  5. Interface engineering of hybrid perovskite solar cells with poly(3-thiophene acetic acid) under ambient conditions.

    PubMed

    Shit, Arnab; Nandi, Arun K

    2016-04-21

    The properties of methyl ammonium lead iodide (MAPbI3) perovskite solar cells with poly(3-thiophene acetic acid) (P3TAA) as a hole transporting material (HTM) and a dense layer of ZnO nanoparticle film as an electron transporting material (ETM) are described using the conventional ZnO (n)/perovskite (i)/P3TAA (p) (n-i-p) architecture. The FT-IR spectra of a MAPbI3/P3TAA mixture indicate a shift of the N-H stretching and the abolition of the N-H bending peak indicating the interaction between the components. UV-Vis spectra of the mixture exhibit a large red shift of the π-π* transition peak of the conjugated chain arising from the interaction causing an increase of the conjugation length. The cross-sectional SEM image of the device shows the sequence of the individual layers of ZnO, MAPbI3, P3TAA and Ag, respectively. The current density (J)-voltage (V) curves obtained upon illumination with a light of 100 mW cm(-2) indicate the average PCE to be 7.38 ± 0.59% under ambient conditions. The IPCE values of these cells reach about 63% across a broad range of wavelength (300-800 nm). The HOMO and the LUMO of P3TAA are measured using cyclic voltammetry and the optical band gap and the relative energy level of the components explain the operation of photocurrent in the cell. For comparison purposes a device using poly(3-hexyl thiophene) (P3HT) as the HTM is fabricated under similar conditions and it exhibits a lower PCE (5.85 ± 0.51%) than that of the P3TAA based device. The longevity of the P3TAA based cell is also found to be better than that of the P3HT based cell for storing in air. The UV-Vis and impedance spectral results clearly explain the above results, signifying the influence of the interface on the performance of hybrid solar cells. PMID:27020145

  6. Repeated Activation of a CS-US-Contingency Memory Results in Sustained Conditioned Responding.

    PubMed

    Joos, Els; Vansteenwegen, Debora; Vervliet, Bram; Hermans, Dirk

    2013-01-01

    Individuals seem to differ in conditionability, i.e., the ease by which the contingent presentation of two stimuli will lead to a conditioned response. In contemporary learning theory, individual differences in the etiology and maintenance of anxiety disorders are, among others, explained by individual differences in temperamental variables (Mineka and Zinbarg, 2006). One such individual difference variable is how people process a learning experience when the conditioning stimuli are no longer present. Repeatedly thinking about the conditioning experience, as in worry or rumination, might prolong the initial (fear) reactions and as such, might leave certain individuals more vulnerable to developing an anxiety disorder. However, in human conditioning research, relatively little attention has been devoted to the processing of a memory trace after its initial acquisition, despite its potential influences on subsequent performance. Post-acquisition processing can be induced by mental reiteration of a conditioned stimulus-unconditioned stimulus (CS-US)-contingency. Using a human conditioned suppression paradigm, we investigated the effect of repeated activations of a CS-US-contingency memory on the level of conditioned responding at a later test. Results of three experiments showed more sustained responding to a "rehearsed" CS+ as compared to a "non-rehearsed" CS+. Moreover, the second experiment showed no effect of rehearsal when only the CS was rehearsed instead of the CS-US-contingency. The third experiment demonstrated that mental CS-US-rehearsal has the same effect regardless of whether it was cued by the CS and a verbal reference to the US or by a neutral signal, making the rehearsal "purely mental." In sum, it was demonstrated that post-acquisition activation of a CS-US-contingency memory can impact conditioned responding, underlining the importance of post-acquisition processes in conditioning. This might indicate that individuals who are more prone to mentally

  7. Production of Retrovirus-Based Vectors in Mildly Acidic pH Conditions.

    PubMed

    Holic, Nathalie; Fenard, David

    2016-01-01

    Gene transfer vectors based on retroviridae are increasingly becoming a tool of choice for biomedical research and for the development of biotherapies in rare diseases or cancers. To meet the challenges of preclinical and clinical production, different steps of the production process of self-inactivating γ-retroviral (RVs) and lentiviral vectors (LVs) have been improved (e.g., transfection, media optimization, cell culture conditions). However, the increasing need for mass production of such vectors is still a challenge and could hamper their availability for therapeutic use. Recently, we observed that the use of a neutral pH during vector production is not optimal. The use of mildly acidic pH conditions (pH 6) can increase by two- to threefold the production of RVs and LVs pseudotyped with the vesicular stomatitis virus G (VSV-G) or gibbon ape leukemia virus (GALV) glycoproteins. Here, we describe the production protocol in mildly acidic pH conditions of GALVTR- and VSV-G-pseudotyped LVs using the transient transfection of HEK293T cells and the production protocol of GALV-pseudotyped RVs produced from a murine producer cell line. These protocols should help to achieve higher titers of vectors, thereby facilitating experimental research and therapeutic applications. PMID:27317171

  8. Monitoring photo-induced transformations in crystals of 2,6-difluorocinnamic acid under ambient conditions.

    PubMed

    Galica, Tomasz; Bąkowicz, Julia; Broda, Piotr; Turowska-Tyrk, Ilona

    2016-07-01

    Several conditions need to be fulfilled for a photochemical reaction to proceed in crystals. Some of these conditions, for example, geometrical conditions, depend on the particular type of photochemical reaction, but the rest are common for all reactions. The mutual directionality of two neighbouring molecules determines the kind of product obtained. The influence of temperature on the probability of a photochemical reaction occurring varies for different types of photochemical reaction and different compounds. High pressure imposed on crystals also has a big influence on the free space and the reaction cavity. The wavelength of the applied UV light is another factor which can initiate a reaction and sometimes determine the structure of a product. It is possible, to a certain degree, to control the packing of molecules in stacks by using fluoro substituents on benzene rings. The crystal and molecular structure of 2,6-difluorocinnamic acid [systematic name: 3-(2,6-difluorophenyl)prop-2-enoic acid], C9H6F2O2, (I), was determined and analysed in terms of a photochemical [2 + 2] dimerization. The molecules are arranged in stacks along the a axis and the values of the intermolecular geometrical parameters indicate that they may undergo this photochemical reaction. The reaction was carried out in situ and the changes of the unit-cell parameters during crystal irradiation by a UV beam were monitored. The values of the unit-cell parameters change in a different manner, viz. cell length a after an initial increase starts to decrease, b after a decrease starts to increase, c increases and the unit-cell volume V after a certain increase starts to decrease. The structure of a partially reacted crystal, i.e. containing both the reactant and the product, namely 2,6-difluorocinnamic acid-3,4-bis(2,6-difluorophenyl)cyclobutane-1,2-dicarboxylic acid (0.858/0.071), 0.858C9H6F2O2·0.071C18H12F4O4, obtained in situ, is also presented. The powder of compound (I) was irradiated with

  9. Effect of Varying Acid Hydrolysis Condition in Gracilaria Sp. Fermentation Using Sasad

    NASA Astrophysics Data System (ADS)

    Mansuit, H.; Samsuri, M. D. C.; Sipaut, C. S.; Yee, C. F.; Yasir, S. M.; Mansa, R.

    2015-04-01

    Macroalgae or seaweed is being considered as promising feedstock for bioalcohol production due to high polysaccharides content. Polysaccharides can be converted into fermentable sugar through acid hydrolysis pre-treatment. In this study, the potential of using carbohydrate-rich macroalgae, Gracilaria sp. as feedstock for bioalcohol production via various acid hydrolysis conditions prior to the fermentation process was investigated and evaluated. The seaweed used in this research was from the red algae group, using species of Gracilaria sp. which was collected from Sg. Petani Kedah, Malaysia. Pre-treatment of substrate was done using H2SO4 and HCl with molarity ranging from 0.2M to 0.8M. The pretreatment time were varied in the range of 15 to 30 minutes. Fermentation was conducted using Sasad, a local Sabahan fermentation agent as a starter culture. Alcohol extraction was done using a distillation unit. Reducing sugar analysis was done by Benedict test method. Alcohol content analysis was done using specific gravity test. After hydrolysis, it was found out that acid hydrolysis at 0.2M H2SO4 and pre-treated for 20 minutes at 121°C has shown the highest reducing sugar content which has yield (10.06 mg/g) of reducing sugar. It was followed by other samples hydrolysis using 0.4M HCl with 30 minutes pre-treatment and 0.2M H2SO4, 15 minutes pre-treatment with yield of 8.06 mg/g and 5.75 mg/g reducing sugar content respectively. In conclusion, acid hydrolysis of Gracilaria sp. can produce higher reducing sugar yield and thus it can further enhance the bioalcohol production yield. Hence, acid hydrolysis of Gracilaria sp. should be studied more as it is an important step in the bioalcohol production and upscaling process.

  10. The effect of extrusion conditions on the acidic polysaccharide, ginsenoside contents and antioxidant properties of extruded Korean red ginseng

    PubMed Central

    Gui, Ying; Ryu, Gi Hyung

    2013-01-01

    This study was conducted to investigate the effect of extrusion conditions (moisture content 20% and 30%, screw speed 200 and 250 rpm, barrel temperature 115℃ and 130℃) on the acidic polysaccharide, ginsenoside contents and antioxidant properties of extruded Korean red ginseng (KRG). Extruded KRGs showed relatively higher amounts of acidic polysaccharide (6.80% to 9.34%) than nonextruded KRG (4.34%). Increased barrel temperature and screw speed significantly increased the content of acidic polysaccharide. The major ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf, Rg2s, Rg3s, Rh1, and Rg3r) of KRG increased through extrusion, while the ginsenoside (Rg1) decreased. The EX8 (moisture 30%, screw speed 250 rpm, and temperature 130℃) had more total phenolics and had a better scavenging effect on 2,2-diphenyl-1-picrylhydrazyl radicals than those of extruded KRG samples. The extrusion cooking showed a significant increase (6.8% to 20.9%) in reducing power. Increased barrel temperature significantly increased the values of reducing power, the highest value was 1.152 obtained from EX4 (feed moisture 20%, screw speed 250 rpm, and temperature 130℃). These results suggest that extrusion conditions can be optimized to retain the health promoting compounds in KRG products. PMID:23717175

  11. Simulated moving bed chromatography for the separation of ethyl esters of eicosapentaenoic acid and docosahexaenoic acid under nonlinear conditions.

    PubMed

    Li, Min; Bao, Zongbi; Xing, Huabin; Yang, Qiwei; Yang, Yiwen; Ren, Qilong

    2015-12-18

    In this study, ethyl esters of eicosapentaenoic acid and docosahexaenoic acid were separated with simulated moving bed (SMB) chromatography, where the stationary phase was C18 silica gel with particle size of 10μm packed in eight columns, and the mobile phase was pure methanol. The Henry constants, transport parameters and total porosity were measured from pulse response chromatographic experiments using a single column. The Henry constants were obtained from the first moment analysis. The transport parameters including axial dispersion coefficients and effective mass transfer coefficients were obtained from the second moment analysis. Nonlinear adsorption equilibrium isotherms for the pure components and their mixture were determined from adsorption-desorption method. The Langmuir model was used to fit the experimental data, and the corresponding parameters were further used to predict the competitive adsorption equilibria of the mixture. The validity of mathematical model parameters was checked by a frontal chromatography experiment. The simulated results of the SMB process using these parameters agreed well with the experimental results. At the feed concentration of 100g/L, the SMB separation was able to produce both solutes with relative purity above 99%, productivity of 13.11g/L adsorbent/h, and solvent consumption of 0.46L/g. PMID:26620595

  12. Enhancement of sludge anaerobic biodegradability by combined microwave-H2O2 pretreatment in acidic conditions.

    PubMed

    Eswari, Parvathy; Kavitha, S; Kaliappan, S; Yeom, Ick-Tae; Banu, J Rajesh

    2016-07-01

    The aim of this study was to increase the sludge disintegration and reduce the cost of microwave (MW) pretreatment. Thermodynamic analysis of MW hydrolysis revealed the best fit with a first-order kinetic model at a specific energy of 18,600 kJ/kg total solids (TS). Combining H2O2 with MW resulted in a significant increment in solubilization from 30 to 50 % at 18,600 kJ/kg TS. The pH of H2O2-assisted MW-pretreated sludge (MW + H2O2) was in the alkaline range (pH 9-10), and it made the sludge unfavorable for subsequent anaerobic digestion and inhibits methane production. In order to nullify the alkaline effect caused by the MW + H2O2 combination, the addition of acid was considered for pH adjustment. H2O2-assisted MW-pretreated sludge in acidic conditions (MW + H2O2 + acid) showed a maximum methane production of 323 mL/g volatile solids (VS) than others during anaerobic biodegradability. A cost analysis of this study reveals that MW + H2O2 + acid was the most economical method with a net profit of 59.90 €/t of sludge. PMID:27026550

  13. Effect of hydrolysis conditions on hydrous TiO2 polymorphs precipitated from a titanyl sulfate and sulfuric acid solution

    NASA Astrophysics Data System (ADS)

    Song, Hao; Liang, Bin; Lü, Li; Wu, Pan; Li, Chun

    2012-07-01

    The relationship between hydrolysis conditions and hydrous titania polymorphs obtained in a titanyl sulfate and sulfuric acid solution was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM). The results revealed that the feeding rate of the titanyl sulfate stock solution, the concentration of sulfuric acid, and the seed dosage of rutile crystal could significantly affect the hydrolysis rate, thus influencing the titania crystal phase. Hydrous TiO2 in the form of rutile, anatase, or the mixture of both could be obtained in solutions of low titanium concentrations and 2.5wt% to 15wt% sulfuric acid at 100°C. When the hydrolysis rate of titanium expressed by TiO2 was more than or equal to 0.04 g/(L·min), the hydrolysate was almost phase-pure anatase, while the main phase state was rutile when the hydrolysis rate was less than or equal to 0.01 g/(L·min). With the hydrolysis rate between 0.02 and 0.03 g/(L·min), the hydrolysate contained almost equal magnitude of rutile and anatase. It seems that although rutile phase is thermodynamically stable in very acidic solutions, anatase is a kinetically stable phase.

  14. Chemical Composition and Fatty Acid Content of Some Spices and Herbs under Saudi Arabia Conditions

    PubMed Central

    Al-Jasass, Fahad Mohammed; Al-Jasser, Mohammed Saud

    2012-01-01

    Some Saudi herbs and spices were analyzed. The results indicated that mustard, black cumin, and cress seeds contain high amount of fat 38.45%, 31.95% and 23.19%, respectively, as compared to clove (16.63%), black pepper (5.34%) and fenugreek (4.51%) seeds. Cress, mustard, black cumin and black pepper contain higher protein contents ranging from 26.61 to 25.45%, as compared to fenugreek (12.91%) and clove (6.9%). Crude fiber and ash content ranged from 6.36 to 23.6% and from 3.57 to 7.1%, respectively. All seeds contain high levels of potassium (ranging from 383 to 823 mg/100g), followed by calcium (ranging from 75 to 270 mg/100g), Magnesium (ranged from 42 to 102 mg/100g) and iron (ranged from 20.5 to 65 mg/100g). However, zinc, manganese and copper were found at low levels. The major fatty acids in cress and mustard were linolenic acid (48.43%) and erucic acid (29.81%), respectively. The lenoleic acid was the major fatty acid in black cumin, fenugreek, black pepper and clove oils being 68.07%, 34.85%, 33.03% and 44.73%, respectively. Total unsaturated fatty acids were 83.24, 95.62, 86.46, 92.99, 81.34 and 87.82% for cress, mustard, black cumin, fenugreek, black pepper and clove, respectively. The differences in the results obtained are due to environmental factors, production areas, cultivars used to produce seeds and also due to the different methods used to prepare these local spices. PMID:23319888

  15. SORPTION BEHAVIOR OF MONOSODIUM TITANATE AND AMORPHOUS PEROXOTITANATE MATERIALS UNDER WEAKLY ACIDIC CONDITIONS

    SciTech Connect

    Hobbs, D.; Elvington, M.; Click, D.

    2009-11-11

    Inorganic, titanate-based sorbents are tested with respect to adsorption of a variety of sorbates under weakly acidic conditions (pH 3). Specifically, monosodium titanate (MST) and amorphous peroxotitanate (APT) sorption characteristics are initially probed through a screening process consisting of a pair of mixed metal solutions containing a total of 29 sorbates including alkali metals, alkaline earth metals, transition metals, metalloids and nonmetals. MST and APT sorption characteristics are further analyzed individually with chromium(III) and cadmium(II) using a batch method at ambient laboratory temperature, varying concentrations of the sorbents and sorbates and contact times. Maximum sorbate loadings are obtained from the respective adsorption isotherms.

  16. Aza-Michael Mono-addition Using Acidic Alumina under Solventless Conditions.

    PubMed

    Bosica, Giovanna; Abdilla, Roderick

    2016-01-01

    Aza-Michael reactions between primary aliphatic and aromatic amines and various Michael acceptors have been performed under environmentally-friendly solventless conditions using acidic alumina as a heterogeneous catalyst to selectively obtain the corresponding mono-adducts in high yields. Ethyl acrylate was the main acceptor used, although others such as acrylonitrile, methyl acrylate and acrylamide were also utilized successfully. Bi-functional amines also gave the mono-adducts in good to excellent yields. Such compounds can serve as intermediates for the synthesis of anti-cancer and antibiotic drugs. PMID:27338336

  17. Fatty acids intake in the Mexican population. Results of the National Nutrition Survey 2006

    PubMed Central

    2011-01-01

    Background There is growing evidence that quality, rather that quantity of fat is the determinant of cardiovascular risk. The objective of the study is to describe quantitatively the intake and adequacy of fatty acid classes among the Mexican population aged 5-90 years from a probabilistic survey. Methods Dietary intake of individual and classes of fatty acids was computed from the dataset of the 2006 Mexican National Health and Nutrition Survey (ENSANUT2006), collected by a food frequency questionnaire. Adequacy was calculated in reference to authoritative recommendations. Results The mean intake of total fatty acids (TFA ≈ 25%E) fell within WHO recommendations; the intakes of saturated fatty acids (SFA) among all age-groups (45-60%) and of trans fatty acids (TrFA) in 30% of school-age children and adolescents and 20% of adults exceeded international recommendations. The mean intake of polyunsaturated fatty acids (PUFA) and particularly of n6 and n3 PUFAS, was inadequately insufficient in 50% of the sample. Conclusions The main public health concerns are the high intake of SFA and the suboptimal intake of PUFA in Mexican population. The TrFA intake represents a low public health risk. PMID:21651771

  18. Transcriptome-based identification of new anti-anti-inflammatory and vasodilating properties of the n-3 fatty acid docosahexaenoic acid in vascular endothelial cell under proinflammatory conditions

    PubMed Central

    Gatta, Valentina; Scoditti, Egeria; Pellegrino, Mariangela; Carluccio, Maria Annunziata; Calabriso, Nadia; Buonomo, Tonia; Stuppia, Liborio; Storelli, Carlo; De Caterina, Raffaele

    2015-01-01

    Scope High intakes of n-3 fatty acids exert anti-inflammatory effects and cardiovascular protection, but the underlying molecular basis is incompletely defined. By genome-wide analysis we searched for novel effects of docosahexaenoic acid (DHA) on gene expression and pathways in human vascular endothelium under pro-inflammatory conditions. Methods and Results Human umbilical vein endothelial cells were treated with DHA and then stimulated with interleukin(IL)-1β. Total RNA was extracted, and gene expression examined by DNA microarray. DHA alone altered the expression of 188 genes, decreasing 92 and increasing 96. IL-1β changed the expression of 2031 genes, decreasing 997 and increasing 1034. Treatment with DHA before stimulation significantly affected the expression of 116 IL-1β-deregulated genes, counter-regulating the expression of 55 genes among those decreased and of 61 among those increased. Functional and network analyses identified immunological, inflammatory and metabolic pathways as the most affected. Newly identified DHA-regulated genes are involved in stemness, cellular growth, cardiovascular system function and cancer, and included cytochrome p450 4F2(CYP4F2), transforming growth factor(TGF)-β2, Cluster of Differentiation (CD)47, caspase recruitment domain(CARD)11 and phosphodiesterase(PDE)5α. Conclusions Endothelial exposure to DHA regulates novel genes and related pathways. Such unbiased identification should increase our understanding of mechanisms by which n-3 fatty acids affect human diseases. PMID:26114549

  19. Inhibition of aconitase in citrus fruit callus results in a metabolic shift towards amino acid biosynthesis.

    PubMed

    Degu, Asfaw; Hatew, Bayissa; Nunes-Nesi, Adriano; Shlizerman, Ludmila; Zur, Naftali; Katz, Ehud; Fernie, Alisdair R; Blumwald, Eduardo; Sadka, Avi

    2011-09-01

    Citrate, a major determinant of citrus fruit quality, accumulates early in fruit development and declines towards maturation. The isomerization of citrate to isocitrate, catalyzed by aconitase is a key step in acid metabolism. Inhibition of mitochondrial aconitase activity early in fruit development contributes to acid accumulation, whereas increased cytosolic activity of aconitase causes citrate decline. It was previously hypothesized that the block in mitochondrial aconitase activity, inducing acid accumulation, is caused by citramalate. Here, we investigated the effect of citramalate and of another aconitase inhibitor, oxalomalate, on aconitase activity and regulation in callus originated from juice sacs. These compounds significantly increased citrate content and reduced the enzyme's activity, while slightly inducing its protein level. Citramalate inhibited the mitochondrial, but not cytosolic form of the enzyme. Its external application to mandarin fruits resulted in inhibition of aconitase activity, with a transient increase in fruit acidity detected a few weeks later. The endogenous level of citramalate was analyzed in five citrus varieties: its pattern of accumulation challenged the notion of its action as an endogenous inhibitor of mitochondrial aconitase. Metabolite profiling of oxalomalate-treated cells showed significant increases in a few amino acids and organic acids. The activities of alanine transaminase, aspartate transaminase and aspartate kinase, as well as these of two γ-aminobutyrate (GABA)-shunt enzymes, succinic semialdehyde reductase (SSAR) and succinic semialdehyde dehydrogenase (SSAD) were significantly induced in oxalomalate-treated cells. It is suggested that the increase in citrate, caused by aconitase inhibition, induces amino acid synthesis and the GABA shunt, in accordance with the suggested fate of citrate during the acid decline stage in citrus fruit. PMID:21528417

  20. Working Conditions of Foreign Language Teachers: Results from a Pilot Survey

    ERIC Educational Resources Information Center

    Lopez-Gomez, Coral; Albright, Jeremy J.

    2009-01-01

    Recent research has consistently shown that teacher working conditions are highly predictive of faculty turnover and student performance. However, very little work investigates specifically the experiences of foreign-language instructors. This paper reports results from a pilot survey of language teachers in public and private schools from across…

  1. 38 CFR 21.7139 - Conditions which result in reduced rates or no payment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... in reduced rates or no payment. 21.7139 Section 21.7139 Pensions, Bonuses, and Veterans' Relief... Educational Assistance Program (Montgomery GI Bill-Active Duty) Payments-Educational Assistance § 21.7139 Conditions which result in reduced rates or no payment. The monthly rates established in §§ 21.7136,...

  2. INVITED SESSION: THE 2011 NATIONAL WETLAND CONDITION ASSESSMENT: TECHNICAL UNDERPINNINGS AND RESULTS

    EPA Science Inventory

    The first-ever National Wetland Condition Assessment (NWCA) was conducted in 2011 by the US Environmental Protection Agency (USEPA) and its federal and state partners, using a survey design allowing extrapolation of results to national and regional scales. At each of 1138 locatio...

  3. 24 CFR 902.68 - Technical review of results of PHAS physical condition indicator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 4 2012-04-01 2012-04-01 false Technical review of results of PHAS physical condition indicator. 902.68 Section 902.68 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING AND...

  4. Results of the Housing Building Condition Evaluation Survey at the University of Georgia.

    ERIC Educational Resources Information Center

    Casey, John M.

    A complete campus building condition evaluation survey was conducted at the University of Georgia in 1989 and results for the housing department were analyzed. The survey design was based on a model developed by Harlan Bareither at the University of Illinois that separates building deficiencies into seven general headings. Data were collected at…

  5. Hippocampal Structural Plasticity Accompanies the Resulting Contextual Fear Memory Following Stress and Fear Conditioning

    ERIC Educational Resources Information Center

    Giachero, Marcelo; Calfa, Gaston D.; Molina, Victor A.

    2013-01-01

    The present research investigated the resulting contextual fear memory and structural plasticity changes in the dorsal hippocampus (DH) following stress and fear conditioning. This combination enhanced fear retention and increased the number of total and mature dendritic spines in DH. Intra-basolateral amygdala (BLA) infusion of midazolam prior to…

  6. 38 CFR 21.9675 - Conditions that result in reduced rates or no payment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2014-07-01 2014-07-01 false Conditions that result in reduced rates or no payment. 21.9675 Section 21.9675 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill...

  7. 38 CFR 21.9675 - Conditions that result in reduced rates or no payment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2012-07-01 2012-07-01 false Conditions that result in reduced rates or no payment. 21.9675 Section 21.9675 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill Payments-Educational Assistance § 21.9675...

  8. 38 CFR 21.9675 - Conditions that result in reduced rates or no payment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Conditions that result in reduced rates or no payment. 21.9675 Section 21.9675 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill...

  9. 38 CFR 21.9675 - Conditions that result in reduced rates or no payment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2013-07-01 2013-07-01 false Conditions that result in reduced rates or no payment. 21.9675 Section 21.9675 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill...

  10. Identification of Organic Sulfate Esters in d-Limonene Ozonolysis SOA Under Acidic Condition

    NASA Astrophysics Data System (ADS)

    Iinuma, Y.; Mueller, C.; Boege, O.; Herrmann, H.

    2006-12-01

    Secondary organic aerosol (SOA) components from gas phase ozonolysis of d-limonene were investigated in a series of indoor chamber experiments. The compounds smaller than 300 Da were quantified using capillary electrophoresis coupled to electrospray ionisation ion trap mass spectrometry (CE/ESI-ITMS). HPLC coupled to an ESI-TOFMS and an ESI-ITMS was used for structural study of dimmers and oligomers. Only 10% of the produced SOA could be attributed to low molecular weight carboxylic acids (Mw<300). The oxidation products which have molecular weights over 300 were detected regardless of the seed particle acidity but the concentrations of these compounds were much higher for acidic seed particle experiments. Strong signals of the compounds with mass to charge ratios (m/z) 281, 465 and 481 were detected when sulphuric acid was used in the seed particles. These compounds showed a strong fragment of m/z 97 in MS2 or MS3 spectra indicating the presence of sulfate in the structures. HPLC/ESI-TOFMS analysis suggests the elemental compositions of C10H17O7S-, C20H33O10S- and C20H33O11S- for m/z 281, 465 and 481, respectively. Based on MS^{n} and TOFMS results, they are most likely organic sulfate esters, possibly formed by a heterogeneous acid catalyzed reaction of a limonene oxidation product and sulfuric acid in the particle phase. The concentrations of the organic sulfate ester were as high as 3.7 μgm-3 for m/z 281.

  11. Sorption Behavior of Iodine on Allophane under Acid and Alkaline Conditions - 12203

    SciTech Connect

    Amemiya, Kiyoshi; Nakano, Masashi

    2012-07-01

    In the safety assessment of TRU geological disposal, Iodine-129 (I-129) is considered a key radionuclide. In Japan the reference buffer material within the repository is a bentonite based sand mixture, which is lacking in iodine adsorbent capacity. Additives or alternative buffer materials that can enhance iodine adsorption are desired. Allophane, a common soil material in Japan, is a potential candidate to aid in iodine retention. In order to assess the potential for improvement of buffer and backfill material to limit release of I-129, the sorption behavior of iodine (IO{sub 3}{sup -} and I{sup -}) on allophane was examined in this research. The sorption behavior of IO{sub 3}{sup -} by allophane is strong in acidic conditions, and markedly reduced in alkaline conditions. The K{sub d} values of IO{sub 3}{sup -} are approximately 0.4 m{sup 3}/kg (pH=5), 0.03 m{sup 3}/kg (pH=8), 0.011 m{sup 3}/kg (pH=9), 0.005 m{sup 3}/kg (pH=10). Conversely, the K{sub d} value of I{sup -} is as small as 0.01 m{sup 3}/kg in acidic conditions, and much smaller in alkaline conditions. The numerical analysis shows that a maximum release rate of I-129 from the engineered barrier in the geological disposal system decreased approximately one order of magnitude and the K{sub d} of the buffer increased up to 0.1 m{sup 3}/kg by applying allophane soils to engineered barriers. (authors)

  12. Interference of Nitrite with Pyrite under Acidic Conditions: Implications for Studies of Chemolithotrophic Denitrification.

    PubMed

    Yan, Ruiwen; Kappler, Andreas; Peiffer, Stefan

    2015-10-01

    Chemolithotrophic denitrification coupled to pyrite oxidation is regarded a key process in the removal of nitrate in aquifers. A common product is nitrite, which is a strong oxidant under acidic conditions. Nitrite may thus interfere with Fe(II) during acidic extraction, a procedure typically used to quantify microbial pyrite oxidation, in overestimating Fe(III) production. We studied the reaction between pyrite (5-125 mM) and nitrite (40-2000 μM) at pH 0, 5.5, and 6.8 in the absence and presence of oxygen. Significant oxidation of pyrite was measured at pH 0 with a yield of 100 μM Fe(III) after 5 mM pyrite was incubated with 2000 μM nitrite for 24 h. Dissolved oxygen increased the rate at pH 0. No oxidation of pyrite was observed at pH 5.5 and 6.8. Our data imply a cyclic model for pyrite oxidation by Fe(III) on the basis of the oxidation of residual Fe(II) by NO and NO2. Interference by nitrite could be avoided if nitrite was removed from the pyrite suspensions through a washing procedure prior to acidic extraction. We conclude that such interferences should be considered in studies on microbially mediated pyrite oxidation with nitrate. PMID:26335043

  13. Physiological responses of dogs on exposure to hot, arid conditions. Acid-base status.

    PubMed

    Krausz, S; Marder, J

    1977-09-16

    Acid-base parameters were determined in chronically cannulated dogs exposed to ambient temperatures increasing from 25-47 degrees C (with relative humidity below 30%). pH increased from 7.409 +/- 0.004 (S.E.M.) to 7.538 +/- 0.017, PaCO2 decreased from 33.0 +/- 0.5 to 20.9 +/- 1.2 torr, and [HCO3-] decreased from 20.9 +/- 0.3 to 17.2 +/- 0.4 mEq/l. Minimal base excess change, together with a rapid return to normal parameters upon recooling to 25 degrees C, suggests that the stress is almost exclusively respiratory, with little metabolic involvement. Analysis of serial exposures shows no acclimatization effect in acid-base status. This suggests the possible existence of natural acclimation to heat in dogs maintained in a warm climate, permitting excellent tolerance of hot, arid conditions with limited acid-base disturbance. PMID:563058

  14. Amino acid composition, including key derivatives of eccrine sweat: potential biomarkers of certain atopic skin conditions.

    PubMed

    Mark, Harker; Harding, Clive R

    2013-04-01

    The free amino acid (AA) composition of eccrine sweat is different from other biological fluids, for reasons which are not properly understood. We undertook the detailed analysis of the AA composition of freshly isolated pure human eccrine sweat, including some of the key derivatives of AA metabolism, to better understand the key biological mechanisms governing its composition. Eccrine sweat was collected from the axillae of 12 healthy subjects immediately upon formation. Free AA analysis was performed using an automatic AA analyser after ninhydrin derivatization. Pyrrolidine-5-carboxylic acid (PCA) and urocanic acid (UCA) levels were determined using GC/MS. The free AA composition of sweat was dominated by the presence of serine accounting for just over one-fifth of the total free AA composition. Glycine was the next most abundant followed by PCA, alanine, citrulline and threonine, respectively. The data obtained indicate that the AA content of sweat bears a remarkable similarity to the AA composition of the epidermal protein profilaggrin. This protein is the key source of free AAs and their derivatives that form a major part of the natural moisturizing factor (NMF) within the stratum corneum (SC) and plays a major role in maintaining the barrier integrity of human skin. As perturbations in the production of NMF can lead to abnormal barrier function and can arise as a consequence of filaggrin genotype, we propose the quantification of AAs in sweat may serve as a non-invasive diagnostic biomarker for certain atopic skin conditions, that is, atopic dermatitis (AD). PMID:23075272

  15. Results of fibre and toner flotation depending on oleic acid dosage.

    PubMed

    Trumic, Maja S; Trumic, Milan Z; Vujic, Bogdana; Andric, Ljubisa; Bogdanovic, Grozdanka

    2016-09-01

    The literature was reviewed with respect to deinking flotation methods with toner samples, specifically emphasizing the speciation of copy machine and laser printing, which produce an increasing quantity of paper that is difficult to recycle. Speciation here refers to the physical-chemical characteristics of the toner, which change because of the polymerization (fusion) and oxidation process, due to exposure to heat, light and oxygen (air) during the printing process. To simulate the deinking flotation, after the ideal disintegration process, samples of toner were prepared in order to provide free toner particles. Synthetic toner has iron content and the same physical-chemical features as free disintegrated printed toner particles.We report the toner (I) and fibre (Y) recovery and the brightness (B) of laboratory filter pads formed of deinked product as deinking efficiencies. The application of oleic acid as the collector in the flotation stage gives a better flotation recovery in alkaline than in acidic conditions. The highest brightness (BF = 93.66%) and flotation recoveries (I = 90, Y = 92.82%) were achieved during testing at an oleic acid concentration of 3.38·10(-6) mol l(-1), which is the lowest dose used. This makes the use of oleic acid economical and environmentally friendly. PMID:27354017

  16. Mechanisms of hydroxyl radical production from abiotic oxidation of pyrite under acidic conditions

    NASA Astrophysics Data System (ADS)

    Zhang, Peng; Yuan, Songhu; Liao, Peng

    2016-01-01

    Hydroxyl radicals (radOH) produced from pyrite oxidation by O2 have been recognized, but mechanisms regarding the production under anoxic and oxic conditions are not well understood. In this study, the mechanisms of radOH production from pyrite oxidation under anoxic and oxic conditions were explored using benzoic acid (BA) as an radOH probe. Batch experiments were conducted at pH 2.6 to explore radOH production under anoxic and oxic conditions. The cumulative radOH concentrations produced under anoxic and oxic conditions increased linearly to 7.5 and 52.2 μM, respectively within 10 h at 10 g/L pyrite. Under anoxic conditions, radOH was produced from the oxidation of H2O on the sulfur-deficient sites on pyrite surface, showing an increased production with the increase of pyrite surface exposure due to oxidation. Under oxic conditions, the formation of radOH proceeds predominantly via the two-electron reduction of O2 on pyrite surface along with a minor contribution from the oxidation of H2O on surface sulfur-defects and the reactions of Fe2+/sulfur intermediates with O2. For both O2 reduction and H2O oxidation on the surface sulfur-defects, H2O2 was the predominant intermediate, which subsequently transformed to radOH through Fenton mechanism. The radOH produced had a significant impact on the transformation of contaminants in the environment. Anoxic pyrite suspensions oxidized 13.9% As(III) (C0 = 6.67 μM) and 17.6% sulfanilamide (C0 = 2.91 μM) within 10 h at pH 2.6 and 10 g/L pyrite, while oxic pyrite suspensions improved the oxidation percentages to 55.4% for As(III) and 51.9% for sulfanilamide. The ratios of anoxic to oxic oxidation are consistent with the relative contribution of surface sulfur-defects to radOH production. However, Fe2+ produced from pyrite oxidation competed with the contaminants for radOH, which is of particular significance with the increase of time in a static environment. We conclude that radOH can be produced from abiotic oxidation of

  17. Effect of culture conditions on growth, lipid content, and fatty acid composition of Aurantiochytrium mangrovei strain BL10

    PubMed Central

    2012-01-01

    This study explored the influence of various culture conditions on the biomass, lipid content, production of docosahexaenoic acid (DHA), and fatty acid composition of Aurantiochytrium mangrovei strain BL10. The variables examined in this study include the species and concentration of salt, the concentrations of the two substrates glucose and yeast extract, the level of dissolved oxygen, the cerulenin treatment, and the stages of BL10 growth. Our results demonstrate that BL10 culture produces maximum biomass when salinity levels are between 0.2 and 3.0%. Decreasing salinity to 0.1% resulted in a considerable decrease in the biomass, lipid content, DHA production, and DHA to palmitic acid (PA) (DHA/PA) ratio, signifying deterioration in the quality of the oil produced. The addition of 0.9% sodium sulfate to replenish salinity from 0.1% to 1.0% successfully recovered biomass, lipid content and DHA production levels; however, this also led to a decrease in DHA/PA ratio. An increase in oxygen and cerulenin levels resulted in a concomitant decrease in the DHA to docosapentaenoic acid (DPA) (DHA/DPA) ratio in BL10 oil. Furthermore, the DHA/DPA and DHA/PA ratios varied considerably before and after the termination of cell division, which occurred around the 24 hour mark. These results could serve as a foundation for elucidating the biochemistry underlying the accumulation of lipids, and a definition of the extrinsic (environmental or nutritional) and intrinsic (cell growth stage) factors that influence lipid quality and the production of DHA by BL10. PMID:22883641

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

    PubMed

    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). PMID:26511087

  19. THE ADIPIC ACID ENHANCED FLUE GAS DESULFURIZATION PROCESS FOR INDUSTRIAL BOILERS. VOLUME 1. FIELD TEST RESULTS

    EPA Science Inventory

    The report gives results of an evaluation of the effect of adding adipic acid on the SO2 removal of a wet limestone flue gas desulfurization (FGD) system on a coal-fired industrial boiler at Rickenbacker Air National Guard Base near Columbus, OH. Emission data were collected in a...

  20. COMPARISON OF SULFUR MEASUREMENTS FROM A REGIONAL FINE PARTICLE NETWORK WITH CONCURRENT ACID MODES NETWORK RESULTS

    EPA Science Inventory

    The Fine Particle Network (FPN), a system of fine particle (less than 2.5 um) samplers, was operated at 41 sites selected from the Environmental Protection Agency Acid MODES program during a two year period in 1988-90. he 24-hour sample results included fine particle mass and the...

  1. 77 FR 6061 - Citric Acid and Certain Citrate Salts From Canada: Preliminary Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-07

    ... and Countervailing Duty Administrative Reviews and Request for Revocation in Part, 76 FR 37781 (June... Duty Orders, 74 FR 25703 (May 29, 2009) (Citric Acid Duty Orders). \\2\\ Archer Daniels Midland Company... Rescind in Part, 70 FR 39735, 39737 (July 11, 2005), unchanged in Notice of Final Results and...

  2. Results on the survival of cryptobiotic cyanobacteria samples after exposure to Mars-like environmental conditions

    NASA Astrophysics Data System (ADS)

    de Vera, J.-P.; Dulai, S.; Kereszturi, A.; Koncz, L.; Lorek, A.; Mohlmann, D.; Marschall, M.; Pocs, T.

    2014-01-01

    Tests on cyanobacteria communities embedded in cryptobiotic crusts collected in hot and cold deserts on Earth were performed under Mars-like conditions. The simulations were realized as a survey, to find the best samples for future research. During the tests organisms have to resist Mars-like conditions such as atmospheric composition, pressure, variable humidity (saturated and dry conditions) and partly strong UV irradiation. Organisms were tested within their original habitat inside the crust. Nearly half of the cryptobiotic samples from various sites showed survival of a substantial part of their coexisting organisms. The survival in general depended more on the nature of the original habitat and type of the sample than on the different conditions they were exposed to. The best survival was observed in samples from United Arab Emirates (Jebel Ali, 25 km SW of Dubai town) and from Western Australia (near the South edge of Lake Barley), by taxa: Tolypothrix byssoidea, Gloeocapsopsis pleurocapsoides, Nostoc microscopicum, Leptolyngbya or Symploca sp. At both places in salty desert areas members of the Chenopodiaceae family dominated among the higher plants and in the cryptobiotic crust cyanobacterial taxa Tolypothrix was dominant. These organisms were all living in salty locations with dry conditions most of the year. Among them Tolypothrix, Gloeocapsopsis and Symploca sp. were tested in Mars simulation chambers for the first time. The results suggest that extremophiles should be tested with taken into account the context of their original microenvironment, and also the importance to analyse communities of microbes beside single organisms.

  3. K Basin Sludge Conditioning Testing: Nitric Acid Dissolution Testing of K East Canister Sludge

    SciTech Connect

    Carlson, C.D.; Delegard, C.H.; Burgeson, I.E.: Schmidt, A.J.; Bredt, P.R.; Silvers, K.L.

    1999-04-01

    This report describes tests performed by Pacific Northwest National Laboratory (PNNL) for Numatec Hanford Corporation (NHC) as part of the overall activities for the development of the K Basin Sludge Treatment System. These tests were conducted to examine the dissolution behavior of a K East Basin canister sludge composite in nitric acid at the following concentrations: 2 M, 4 M, 6 M, 7.8 M and 10 M and temperatures of 25 C and boiling. Assuming that the sludge was 100% uranium metal, a 4X stoichiometric excess of nitric acid was used for all testing, except that conducted at 4 M. In the 4 M nitric acid dissolution test, 50% excess nitric acid was used resulting in a dissolver solution with a significantly higher solids loading. The boiling tests were conducted for 11 hr, the 25 C dissolution tests were conducted from 24 hr to 2 weeks. For the 25 C dissolution testing, the weight percent residual solids was determined, however, chemical and radiochemical analyses were not performed.

  4. Light to liquid fuel: theoretical and realized energy conversion efficiency of plants using crassulacean acid metabolism (CAM) in arid conditions.

    PubMed

    Davis, Sarah C; LeBauer, David S; Long, Stephen P

    2014-07-01

    There has been little attention paid to crassulacean acid metabolism (CAM) as a mechanism for bioenergy crop tolerance to water limitation, in part, because potential yields of CAM plants have been assumed to be lower than those of most commonly studied bioenergy crops. The photochemical efficiency, water-use efficiency (WUE), biomass production, and fuel yield potentials of CAM, C3, and C4 plants that are considered or already in use for bioenergy are reviewed here. The theoretical photosynthetic efficiency of CAM plants can be similar to or greater than other photosynthetic pathways. In arid conditions, the greater WUE of CAM species results in theoretical biomass yield potentials that are 147% greater than C4 species. The realized yields of CAM plants are similar to the theoretical yields that account for water-limiting conditions. CAM plants can potentially be viable commercial bioenergy crops, but additional direct yield measurements from field trials of CAM species are still needed. PMID:24744431

  5. Stability of Bovine viral diarrhea virus 1 nucleic acid in fetal bovine samples stored under different conditions.

    PubMed

    Ridpath, Julia F; Neill, John D; Chiang, Yu-Wei; Waldbillig, Jill

    2014-01-01

    Infection of pregnant cattle with both species of Bovine viral diarrhea virus (BVDV) can result in reproductive disease that includes fetal reabsorption, mummification, abortion, stillbirths, congenital defects affecting structural, neural, reproductive, and immune systems, and the birth of calves persistently infected with BVDV. Accurate diagnosis of BVDV-associated reproductive disease is important to control BVDV at the production unit level and assessment of the cost of BVDV infections in support of BVDV control programs. The purpose of the current study was to examine the stability of viral nucleic acid in fetal tissues exposed to different conditions, as measured by detection by polymerase chain reaction. Five different types of fetal tissue, including brain, skin and muscle, ear, and 2 different pooled organ samples, were subjected to conditions that mimicked those that might exist for samples collected after abortions in production settings or possible storage conditions after collection and prior to testing. In addition, tissues were archived for 36 months at -20°C and then retested, to mimic conditions that might occur in the case of retrospective surveillance studies. Brain tissue showed the highest stability under the conditions tested. The impact of fecal contamination was increased following archiving in all tissue types suggesting that, for long-term storage, effort should be made to reduce environmental contaminants before archiving. PMID:24352225

  6. Acid back-diffusion and mucosal H+ handling in the rat stomach under normal and stress-induced conditions.

    PubMed

    Takeuchi, K; Okabe, S

    1983-02-01

    We determined acid back-diffusion and pepsin output simultaneously in vagotomized rats after instillation of HCl into the stomach under normal and stress-induced conditions. With exposure to 6 ml of 100 mM HCl, spontaneous acid back-diffusion increased with the duration of the experiment under both conditions, and the magnitude of the acid back-diffusion was decreased significantly by stress. There was no change in the output of pepsin. While disappearance of luminal acid caused by aspirin or taurocholic acid was not altered by stress, the pepsin output in response to H+ increased significantly in the stressed rats. With exposure to various concentrations of HCl for 3 hr, disappearance of the luminal acid increased linearly with the grade of HCl under both conditions. Except for the concentration of 300 mM, the magnitude of the acid back-diffusion was triple in the normal condition, and the ratio of pepsin output/net flux of H+ was significantly increased by stress. Thus, (1) spontaneous acid back-diffusion decreased with stress, while diffusion induced by chemical barrier breakers remained the same; (2) the action of H+ diffused back into the mucosa did not always parallel the amount of diffusion determined from the loss of H+ in the lumen; (3) intramucosal H+ may be largely dissipated in normal mucosa; and (4) the initiation or aggravation of drug-induced mucosal damages by stress may be related to insufficiency of the H+ dissipating mechanisms. PMID:6410110

  7. LITHOCHOLIC ACID FEEDING RESULTS IN DIRECT HEPATO-TOXICITY INDEPENDENT OF NEUTROPHIL FUNCTION IN MICE

    PubMed Central

    Woolbright, Benjamin L.; Li, Feng; Xie, Yuchao; Farhood, Anwar; Fickert, Peter; Trauner, Michael; Jaeschke, Hartmut

    2014-01-01

    Lithocholic acid (LCA) supplementation in the diet results in intrahepatic cholestasis and bile infarcts. Previously we showed that an innate immune response is critical for cholestatic liver injury in the bile duct ligated mice. Thus, the purpose of this study was to investigate the role of neutrophils in the mechanism of liver injury caused by feeding mice a diet containing LCA. C57BL/6 mice were given control or 1% LCA containing diet for 24–96h and then examined for parameters of hepatotoxicity. Plasma ALT levels were significantly increased by 48h after LCA feeding, which correlated with both neutrophil recruitment to the liver and upregulation of numerous pro-inflammatory genes. The injury was confirmed by histology. Deficiency in intercellular adhesion molecule-1 (ICAM-1) expression or inhibition of neutrophil function failed to protect against the injury. Bile acid levels were quantified in plasma and bile of LCA-fed mice after 48 and 96h. Only the observed biliary levels of taurochenodeoxycholic acid and potentially tauro-LCA caused direct cytotoxicity in mouse hepatocytes. These data support the conclusion that neutrophil recruitment occurs after the onset of bile acid-induced necrosis in LCA-fed animals, and is not a primary mechanism of cell death when cholestasis occurs through accumulation of hydrophobic bile acids. PMID:24742700

  8. Lithocholic acid feeding results in direct hepato-toxicity independent of neutrophil function in mice.

    PubMed

    Woolbright, Benjamin L; Li, Feng; Xie, Yuchao; Farhood, Anwar; Fickert, Peter; Trauner, Michael; Jaeschke, Hartmut

    2014-07-01

    Lithocholic acid (LCA) supplementation in the diet results in intrahepatic cholestasis and bile infarcts. Previously we showed that an innate immune response is critical for cholestatic liver injury in the bile duct ligated mice. Thus, the purpose of this study was to investigate the role of neutrophils in the mechanism of liver injury caused by feeding mice a diet containing LCA. C57BL/6 mice were given control or 1% LCA containing diet for 24-96 h and then examined for parameters of hepatotoxicity. Plasma ALT levels were significantly increased by 48 h after LCA feeding, which correlated with both neutrophil recruitment to the liver and upregulation of numerous pro-inflammatory genes. The injury was confirmed by histology. Deficiency in intercellular adhesion molecule-1 (ICAM-1) expression or inhibition of neutrophil function failed to protect against the injury. Bile acid levels were quantified in plasma and bile of LCA-fed mice after 48 and 96 h. Only the observed biliary levels of taurochenodeoxycholic acid and potentially tauro-LCA caused direct cytotoxicity in mouse hepatocytes. These data support the conclusion that neutrophil recruitment occurs after the onset of bile acid-induced necrosis in LCA-fed animals, and is not a primary mechanism of cell death when cholestasis occurs through accumulation of hydrophobic bile acids. PMID:24742700

  9. Protein–Protein Interactions in Dilute to Concentrated Solutions: α-Chymotrypsinogen in Acidic Conditions

    PubMed Central

    2015-01-01

    Protein–protein interactions were investigated for α-chymotrypsinogen by static and dynamic light scattering (SLS and DLS, respectively), as well as small-angle neutron scattering (SANS), as a function of protein and salt concentration at acidic conditions. Net protein–protein interactions were probed via the Kirkwood–Buff integral G22 and the static structure factor S(q) from SLS and SANS data. G22 was obtained by regressing the Rayleigh ratio versus protein concentration with a local Taylor series approach, which does not require one to assume the underlying form or nature of intermolecular interactions. In addition, G22 and S(q) were further analyzed by traditional methods involving fits to effective interaction potentials. Although the fitted model parameters were not always physically realistic, the numerical values for G22 and S(q → 0) were in good agreement from SLS and SANS as a function of protein concentration. In the dilute regime, fitted G22 values agreed with those obtained via the osmotic second virial coefficient B22 and showed that electrostatic interactions are the dominant contribution for colloidal interactions in α-chymotrypsinogen solutions. However, as protein concentration increases, the strength of protein–protein interactions decreases, with a more pronounced decrease at low salt concentrations. The results are consistent with an effective “crowding” or excluded volume contribution to G22 due to the long-ranged electrostatic repulsions that are prominent even at the moderate range of protein concentrations used here (<40 g/L). These apparent crowding effects were confirmed and quantified by assessing the hydrodynamic factor H(q → 0), which is obtained by combining measurements of the collective diffusion coefficient from DLS data with measurements of S(q → 0). H(q → 0) was significantly less than that for a corresponding hard-sphere system and showed that hydrodynamic nonidealities can lead to qualitatively incorrect

  10. Effects of Solar Wind Conditions on the Plasma Wake Within a Polar Crater: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Zimmerman, M. I.; Farrell, W. M.; Stubbs, T. J.

    2011-01-01

    As the solar wind sweeps horizontally past a shadowed lunar crater it simultaneously diffuses toward the surface through an ambipolar process, forming a plasma wake (e.g., Figure 1). Importantly, the resulting electric field structure diverts solar wind protons toward the cold crater floor where they may represent a source of surficial hydrogen. We present a handful of two-dimensional kinetic simulations exploring the range of wake structures and surface particle fluxes possible under various background plasma conditions.

  11. Alteration of Basaltic Glass to Mg/Fe-Smectite under Acidic Conditions: A Potential Smectite Formation Mechanism on Mars

    NASA Technical Reports Server (NTRS)

    Peretyazhko, Tanya; Sutter, Brad; Ming, Douglas W.

    2014-01-01

    Phyllosilicates of the smectite group including Mg- and Fe-saponite and Fe(III)-rich nontronite have been identified on Mars. Smectites are believed to be formed under neutral to alkaline conditions that prevailed on early Mars. This hypothesis is supported by the observation of smectite and carbonate deposits in Noachian terrain on Mars. However, smectite may have formed under mildly acidic conditions. Abundant smectite formations have been detected as layered deposits hundreds of meters thick in intracrater depositional fans and plains sediments, while no large deposits of carbonates are found. Development of mildly acidic conditions at early Mars might allow formation of smectite but inhibit widespread carbonate precipitation. Little is known regarding the mechanisms of smectite formation from basaltic glass under acidic conditions. The objective of this study was to test a hypothesis that Mars-analogue basaltic glass alters to smectite minerals under acidic conditions (pH 4). The effects of Mg and Fe concentrations and temperature on smectite formation from basaltic glass were evaluated. Phyllosilicate synthesis was performed in batch reactors (Parr acid digestion vessel) under reducing hydrothermal conditions at 200 C and 100 C. Synthetic basaltic glass with a composition similar to that of the Gusev crater rock Adirondack (Ground surface APXS measurement) was used in these experiments. Basaltic glass was prepared by melting and quenching procedures. X-ray diffraction (XRD) analysis indicated that the synthesized glass was composed of olivine, magnetite and X-ray amorphous phase. Samples were prepared by mixing 250 mg Adirondack with 0.1 M acetic acid (final pH 4). In order to study influence of Mg concentration on smectite formation, experiments were performed with addition of 0, 1 and 10 mM MgCl2. After 1, 7 and 14 day incubations the solution composition was analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and the altered glass and formed

  12. Transient thermal behaviour of a compressor rotor with ventilation: Test results under simulated engine conditions

    NASA Astrophysics Data System (ADS)

    Reile, E.; Radons, U.; Hennecke, D. K.

    1985-09-01

    The development of advanced compressors for modern aero-engines requires detailed knowledge of the transient thermal behavior of the rotor disks to enable accurate prediction of rotor life and, additionally, of the thermal growth of the rotor for the evaluation of tip clearances. In the quest for longer life and higher reliability of the parts as well as reduced clearances even at transient conditions, the designer has to be able to influence the thermal behavior of the rotor. A very effective way is to vent small amounts of air through the rotor cavities. The design of such a vented rotor is presented. The main emphasis is placed on a detailed description of a test rig specially built for this purpose. The testing was carried out under simulated engine conditions for a wide range of parameters. The results are compared with those obtained with a theoretical model derived from fundamental tests at the University of Sussex, where heat transfer in rotating cavities is investigated. Good agreement is observed. Some final tests were done in an engine. The results also exhibit good agreement with the rig results under simulated conditions, when the proper dimensionless parameters are considered, providing the validity of the simulation.

  13. Ferrous iron oxidation by molecular oxygen under acidic conditions: The effect of citrate, EDTA and fulvic acid

    NASA Astrophysics Data System (ADS)

    Jones, Adele M.; Griffin, Philippa J.; Waite, T. David

    2015-07-01

    In this study, the rates of Fe(II) oxidation by molecular oxygen in the presence of citrate, ethylenediaminetetraacetic acid (EDTA) and Suwannee River fulvic acid (SRFA) were determined over the pH range 4.0-5.5 and, for all of the ligands investigated, found to be substantially faster than oxidation rates in the absence of any ligand. EDTA was found to be particularly effective in enhancing the rate of Fe(II) oxidation when sufficient EDTA was available to complex all Fe(II) present in solution, with a kinetic model of the process found to adequately describe all results obtained. When Fe(II) was only partially complexed by EDTA, reactions with reactive oxygen species (ROS) and heterogeneous Fe(II) oxidation were found to contribute significantly to the removal rate of iron from solution at different stages of oxidation. This was possible due to the rapid rate at which EDTA enhanced Fe(II) oxidation and formed ROS and Fe(III). The rapid rate of Fe(III) generation facilitated the formation of free ferric ion activities in excess of those required for ferric oxyhydroxide precipitation following Fe(III)-EDTA dissociation. In comparison, the rate of Fe(II) oxidation was slower in the presence of citrate, and therefore the concentrations of free Fe(III) able to form in the initial stages of Fe(II) oxidation were much lower than those formed in the presence of EDTA, despite the resultant Fe(III)-citrate complex being less stable than that of Fe(III)-EDTA. The slower rate of citrate enhanced oxidation also resulted in slower rates of ROS generation, and, as such, oxidation of the remaining inorganic Fe(II) species by ROS was negligible. Overall, this study demonstrates that organic ligands may substantially enhance the rate of Fe(II) oxidation. Even under circumstances where the ligand is not present at sufficient concentrations to complex all of the Fe(II) in solution, ensuing oxidative processes may sustain an enhanced rate of Fe(II) oxidation relative to that of

  14. Theoretical results on fractionally integrated exponential generalized autoregressive conditional heteroskedastic processes

    NASA Astrophysics Data System (ADS)

    Lopes, Sílvia R. C.; Prass, Taiane S.

    2014-05-01

    Here we present a theoretical study on the main properties of Fractionally Integrated Exponential Generalized Autoregressive Conditional Heteroskedastic (FIEGARCH) processes. We analyze the conditions for the existence, the invertibility, the stationarity and the ergodicity of these processes. We prove that, if { is a FIEGARCH(p,d,q) process then, under mild conditions, { is an ARFIMA(q,d,0) with correlated innovations, that is, an autoregressive fractionally integrated moving average process. The convergence order for the polynomial coefficients that describes the volatility is presented and results related to the spectral representation and to the covariance structure of both processes { and { are discussed. Expressions for the kurtosis and the asymmetry measures for any stationary FIEGARCH(p,d,q) process are also derived. The h-step ahead forecast for the processes {, { and { are given with their respective mean square error of forecast. The work also presents a Monte Carlo simulation study showing how to generate, estimate and forecast based on six different FIEGARCH models. The forecasting performance of six models belonging to the class of autoregressive conditional heteroskedastic models (namely, ARCH-type models) and radial basis models is compared through an empirical application to Brazilian stock market exchange index.

  15. Hepatocyte-specific ablation of Foxa2 alters bile acid homeostasis and results in ER stress

    PubMed Central

    Bochkis, Irina M.; Rubins, Nir E.; White, Peter; Furth, Emma E.; Friedman, Joshua R.; Kaestner, Klaus H.

    2014-01-01

    Summary Production of bile by the liver is crucial for the absorption of lipophilic nutrients. Dysregulation of bile acid homeostasis can lead to cholestatic liver disease and ER stress. We show using global location analysis (“ChIP-on-Chip”) and cell-type specific gene ablation that the winged helix transcription factor Foxa2 is required for normal bile acid homeostasis. As suggested by the location analysis, deletion of Foxa2 in hepatocytes in Foxa2loxP/loxPAlfp.Cre mice leads to decreased transcription of genes encoding bile acid transporters on both the basolateral and canalicular membranes, resulting in intrahepatic cholestasis. Foxa2-deficient mice are strikingly sensitive to a diet containing cholic acid, which results in toxic accumulation of hepatic bile salts, ER stress, and liver injury. In addition, we demonstrate that expression of FOXA2 is dramatically decreased in liver samples from patients with different cholestatic syndromes, suggesting that reduced FOXA2 levels could exacerbate the injury. PMID:18660816

  16. Influence of abscisic acid on growth, biomass and lipid yield of Scenedesmus quadricauda under nitrogen starved condition.

    PubMed

    Sulochana, Sujitha Balakrishnan; Arumugam, Muthu

    2016-08-01

    Scenedesmus quadricauda, accumulated more lipid but with a drastic reduction in biomass yield during nitrogen starvation. Abscisic acid (ABA) being a stress responsible hormone, its effect on growth and biomass with sustainable lipid yield during nitrogen depletion was studied. The result revealed that the ABA level shoots up at 24h (27.21pmol/L) during the onset of nitrogen starvation followed by a sharp decline. The external supplemented ABA showed a positive effect on growth pattern (38×10(6)cells/ml) at a lower concentration. The dry biomass yield is also increasing up to 2.1 fold compared to nitrogen deficient S. quadricauda. The lipid content sustains in 1 and 2μM concentration of ABA under nitrogen-deficient condition. The fatty acid composition of ABA treated S. quadricauda cultures with respect to nitrogen-starved cells showed 11.17% increment in saturated fatty acid content, the desired lipid composition for biofuel application. PMID:26949054

  17. The Key to Acetate: Metabolic Fluxes of Acetic Acid Bacteria under Cocoa Pulp Fermentation-Simulating Conditions

    PubMed Central

    Adler, Philipp; Frey, Lasse Jannis; Berger, Antje; Bolten, Christoph Josef; Hansen, Carl Erik

    2014-01-01

    Acetic acid bacteria (AAB) play an important role during cocoa fermentation, as their main product, acetate, is a major driver for the development of the desired cocoa flavors. Here, we investigated the specialized metabolism of these bacteria under cocoa pulp fermentation-simulating conditions. A carefully designed combination of parallel 13C isotope labeling experiments allowed the elucidation of intracellular fluxes in the complex environment of cocoa pulp, when lactate and ethanol were included as primary substrates among undefined ingredients. We demonstrate that AAB exhibit a functionally separated metabolism during coconsumption of two-carbon and three-carbon substrates. Acetate is almost exclusively derived from ethanol, while lactate serves for the formation of acetoin and biomass building blocks. Although this is suboptimal for cellular energetics, this allows maximized growth and conversion rates. The functional separation results from a lack of phosphoenolpyruvate carboxykinase and malic enzymes, typically present in bacteria to interconnect metabolism. In fact, gluconeogenesis is driven by pyruvate phosphate dikinase. Consequently, a balanced ratio of lactate and ethanol is important for the optimum performance of AAB. As lactate and ethanol are individually supplied by lactic acid bacteria and yeasts during the initial phase of cocoa fermentation, respectively, this underlines the importance of a well-balanced microbial consortium for a successful fermentation process. Indeed, AAB performed the best and produced the largest amounts of acetate in mixed culture experiments when lactic acid bacteria and yeasts were both present. PMID:24837393

  18. IMAGE Project: Results of Laboratory Tests on Tracers for Supercritical Conditions.

    NASA Astrophysics Data System (ADS)

    Brandvoll, Øyvind; Opsahl Viig, Sissel; Nardini, Isabella; Muller, Jiri

    2016-04-01

    The use of tracers is a well-established technique for monitoring dynamic behaviour of water and gas through a reservoir. In geothermal reservoirs special challenges are encountered due to high temperatures and pressures. In this work, tracer candidates for monitoring water at supercritical conditions (temperature > 374°C, pressure ca 218 bar), are tested in laboratory experiments. Testing of tracers at supercritical water conditions requires experimental set-ups which tolerate harsh conditions with respect to high temperature and pressure. In addition stringent HES (health, environment and safety) factors have to be taken into consideration when designing and performing the experiments. The setup constructed in this project consists of a pressure vessel, high pressure pump, instrumentation for pressure and temperature control and instrumentation required for accurate sampling of tracers. In order to achieve accurate results, a special focus has been paid to the development of the tracer sampling technique. Perfluorinated cyclic hydrocarbons (PFCs) have been selected as tracer candidates. This group of compounds is today commonly used as gas tracers in oil reservoirs. According to the literature they are stable at temperatures up to 400°C. To start with, five PFCs have been tested for thermal stability in static experiments at 375°C and 108 bar in the experimental setup described above. The tracer candidates will be further tested for several months at the relevant conditions. Preliminary results indicate that some of the PFC compounds show stability after three months. However, in order to arrive at conclusive results, the experiments have to be repeated over a longer period and paying special attention to more accurate sampling procedures.

  19. A single amino acid substitution results in a retinoblastoma protein defective in phosphorylation and oncoprotein binding

    SciTech Connect

    Kaye, F.J.; Gerster, J.L. Uniformed Services Univ. of Health Sciences, Bethesda, MD ); Kratzke, R.A. ); Horowitz, J.M. )

    1990-09-01

    The authors have previously identified a small-cell lung cancer cell line (NCI-H209) that expresses an aberrant, underphosphorylated form of the retinoblastoma protein RB1. Molecular analysis of RB1 mRNA from this cell line revealed a single point mutation within exon 21 that resulted in a nonconservative amino acid substitution (cysteine to phenylalanine) at codon 706. Stable expression of this mutant RB1 cDNA in a human cell line lacking endogenous RB1 demonstrated that this amino acid change was sufficient to inhibit phosphorylation. In addition, this cysteine-to-phenylalanine substitution also resulted in loss of RB1 binding to the simian virus 40 large tumor and adenovirus E1A transforming proteins. These results confirm the importance of exon 21 coding sequences and suggest that the cysteine residue at codon 706 may play a role in achieving a specific protein conformation essential for protein-protein interactions.

  20. Effects of acidic deposition on the erosion of carbonate stone - experimental results from the U.S. National Acid Precipitation Assessment Program (NAPAP)

    USGS Publications Warehouse

    Baedecker, P.A.; Reddy, M.M.; Reimann, K.J.; Sciammarella, C.A.

    1992-01-01

    One of the goals of NAPAP-sponsored research on the effects of acidic deposition on carbonate stone has been to quantify the incremental effects of wet and dry deposition of hydrogen ion, sulfur dioxide and nitrogen oxides on stone erosion. Test briquettes and slabs of freshly quarried Indiana limestone and Vermont marble have been exposed to ambient environmental conditions in a long-term exposure program. Physical measurements of the recession of test stones exposed to ambient conditions at an angle of 30?? to horizontal at the five NAPAP materials exposure sites range from ~15 to ~30?? ??m yr-1 for marble, and from ~25 to ~45 ??m yr -1 for limestone, and are approximately double the recession estimates based on the observed calcium content of run-off solutions from test slabs. The difference between the physical and chemical recession measurements is attributed to the loss of mineral grains from the stone surfaces that are not measured in the run-off experiments. The erosion due to grain loss does not appear to be influenced by rainfall acidity, however, preliminary evidence suggests that grain loss may be influenced by dry deposition of sulfur dioxide between rainfall events. Chemical analyses of the run-off solutions and associated rainfall blanks suggest that ~30% of erosion by dissolution can be attributed to the wet deposition of hydrogen ion and the dry deposition of sulfur dioxide and nitric acid between rain events. The remaining ~70% of erosion by dissolution is accounted for by the solubility of carbonate stone in rain that is in equilibrium with atmospheric carbon dioxide ('clean rain'). These results are for marble and limestone slabs exposed at an angle of 30?? from horizontal. The relative contribution of sulfur dioxide to chemical erosion is significantly enhanced for stone slabs having an inclination of 60?? or 85??. The dry deposition of alkaline particulate material has a mitigating effect at the two urban field exposure sites at Washington, DC

  1. Cu-Catalyzed Consecutive Hydroxylation and Aerobic Oxidative Cycloetherification under Microwave Conditions: Entry to 2-Arylbenzofuran-3-carboxylic Acids.

    PubMed

    Xu, Tianlong; Zhang, Ensheng; Wang, Dejian; Wang, Yan; Zou, Yong

    2015-05-01

    A convenient one-pot synthesis of 2-arylbenzofuran-3-carboxylic acids from (E)-2-(2-bromophenyl)-3-phenylacrylic acids via Cu-catalyzed consecutive hydroxylation and aerobic oxidative cycloetherification under microwave conditions has been developed. This protocol employed the reagent combination of Cu(OAc)2, 1,10-phen, and KOH in DMSO/H2O (1:1), all of which are cost-effective, readily available, and easily removable from the reaction mixture. Utilizing this synthetic protocol, various 2-arylbenzofuran-3-carboxylic acids as well as the natural product moracin M have been synthesized in satisfactory yields under mild conditions. PMID:25836742

  2. Sulfate-reducing bacteria mediate thionation of diphenylarsinic acid under anaerobic conditions.

    PubMed

    Guan, Ling; Shiiya, Ayaka; Hisatomi, Shihoko; Fujii, Kunihiko; Nonaka, Masanori; Harada, Naoki

    2015-02-01

    Diphenylarsinic acid (DPAA) is often found as a toxic intermediate metabolite of diphenylchloroarsine or diphenylcyanoarsine that were produced as chemical warfare agents and were buried in soil after the World Wars. In our previous study Guan et al. (J Hazard Mater 241-242:355-362, 2012), after application of sulfate and carbon sources, anaerobic transformation of DPAA in soil was enhanced with the production of diphenylthioarsinic acid (DPTAA) as a main metabolite. This study aimed to isolate and characterize anaerobic soil microorganisms responsible for the metabolism of DPAA. First, we obtained four microbial consortia capable of transforming DPAA to DPTAA at a high transformation rate of more than 80% after 4 weeks of incubation. Sequencing for the bacterial 16S rRNA gene clone libraries constructed from the consortia revealed that all the positive consortia contained Desulfotomaculum acetoxidans species. In contrast, the absence of dissimilatory sulfite reductase gene (dsrAB) which is unique to sulfate-reducing bacteria was confirmed in the negative consortia showing no DPAA reduction. Finally, strain DEA14 showing transformation of DPAA to DPTAA was isolated from one of the positive consortia. The isolate was assigned to D. acetoxidans based on the partial 16S rDNA sequence analysis. Thionation of DPAA was also carried out in a pure culture of a known sulfate-reducing bacterial strain, Desulfovibrio aerotolerans JCM 12613(T). These facts indicate that sulfate-reducing bacteria are microorganisms responsible for the transformation of DPAA to DPTAA under anaerobic conditions. PMID:25228086

  3. Toxic effects of Al-based coagulants on Brassica chinensis and Raphanus sativus growing in acid and neutral conditions.

    PubMed

    Zhang, Kaisong; Zhou, Qixing

    2005-04-01

    The ecotoxicological effects of aluminum (Al)-based coagulants are of concern because of their wide-ranging applications in wastewater treatment and water purification. As important Al-based coagulants, AlCl(3) and PAC (polyaluminum-chloride) were selected as examples to examine the toxic effects on representative vegetables including the cabbage Brassica chinensis and the radish Raphanus sativus over a range of exposure concentrations in neutral (pH 7.00) and acidic (pH 4.00) conditions, using seed germination and root elongation in the early-growth stage as indicators of toxicity. The results showed that root elongation of the two vegetables was a more sensitive indicator than was seed germination for evaluating the toxicity of Al. As a single influencing factor, H(+) had no significant direct effects on root elongation of Brassica chinensis and Raphanus sativus under the experimental conditions. The toxicity of Al played the main role in inhibiting root elongation and seed germination and was strongly related to changes in pH. There was a markedly positive relationship between the inhibitory rate of root elongation, seed germination, and the concentration of Al at pH 4.00 (p < 0.01). The toxic effect of AlCl(3) on Brassica chinensis was less with a neutral pH than at pH 4.00, but Raphanus sativus was more susceptible to AlCl(3) toxicity at a neutral pH than at pH 4.00. Both Raphanus sativus and Brassica chinensis had a more toxic response to a low concentration (<64 mg . L(-1)) of PAC in a neutral condition than in an acidic condition. Undoubtedly, the Al toxicity caused by Al-based coagulants at a neutral pH is relevant when treatment solids are used in agriculture. PMID:15793823

  4. Exome sequencing results in successful riboflavin treatment of a rapidly progressive neurological condition

    PubMed Central

    Petrovski, Slavé; Shashi, Vandana; Petrou, Steven; Schoch, Kelly; McSweeney, Keisha Melodi; Dhindsa, Ryan S.; Krueger, Brian; Crimian, Rebecca; Case, Laura E.; Khalid, Roha; El-Dairi, Maysantoine A.; Jiang, Yong-Hui; Mikati, Mohamad A.; Goldstein, David B.

    2015-01-01

    Genetically targeted therapies for rare Mendelian conditions are improving patient outcomes. Here, we present the case of a 20-mo-old female suffering from a rapidly progressing neurological disorder. Although diagnosed initially with a possible autoimmune condition, analysis of the child's exome resulted in a diagnosis of Brown–Vialetto–Van Laere syndrome 2 (BVVLS2). This new diagnosis led to a change in the therapy plan from steroids and precautionary chemotherapy to high-dose riboflavin. Improvements were reported quickly, including in motor strength after 1 mo. In this case, the correct diagnosis and appropriate treatment would have been unlikely in the absence of exome sequencing and careful interpretation. This experience adds to a growing list of examples that emphasize the importance of early genome-wide diagnostics. PMID:27148561

  5. Exome sequencing results in successful riboflavin treatment of a rapidly progressive neurological condition.

    PubMed

    Petrovski, Slavé; Shashi, Vandana; Petrou, Steven; Schoch, Kelly; McSweeney, Keisha Melodi; Dhindsa, Ryan S; Krueger, Brian; Crimian, Rebecca; Case, Laura E; Khalid, Roha; El-Dairi, Maysantoine A; Jiang, Yong-Hui; Mikati, Mohamad A; Goldstein, David B

    2015-10-01

    Genetically targeted therapies for rare Mendelian conditions are improving patient outcomes. Here, we present the case of a 20-mo-old female suffering from a rapidly progressing neurological disorder. Although diagnosed initially with a possible autoimmune condition, analysis of the child's exome resulted in a diagnosis of Brown-Vialetto-Van Laere syndrome 2 (BVVLS2). This new diagnosis led to a change in the therapy plan from steroids and precautionary chemotherapy to high-dose riboflavin. Improvements were reported quickly, including in motor strength after 1 mo. In this case, the correct diagnosis and appropriate treatment would have been unlikely in the absence of exome sequencing and careful interpretation. This experience adds to a growing list of examples that emphasize the importance of early genome-wide diagnostics. PMID:27148561

  6. Experimental results from containment piping bellows subjected to severe accident conditions. Volume 1, Results from bellows tested in `like-new` conditions

    SciTech Connect

    Lambert, L.D.; Parks, M.B.

    1994-09-01

    Bellows are an integral part of the containment pressure boundary in nuclear power plants. They are used at piping penetrations to allow relative movement between piping and the containment wall, while minimizing the load imposed on the piping and wall. Piping bellows are primarily used in steel containments; however, they have received limited use in some concrete (reinforced and prestressed) containments. In a severe accident they may be subjected to pressure and temperature conditions that exceed the design values, along with a combination of axial and lateral deflections. A test program to determine the leak-tight capacity of containment penetration bellows is being conducted under the sponsorship of the US Nuclear Regulatory Commission at Sandia National Laboratories. Several different bellows geometries, representative of actual containment bellows, have been subjected to extreme deflections along with pressure and temperature loads. The bellows geometries and loading conditions are described along with the testing apparatus and procedures. A total of thirteen bellows have been tested, all in the `like-new` condition. (Additional tests are planned of bellows that have been subjected to corrosion.) The tests showed that bellows are capable of withstanding relatively large deformations, up to, or near, the point of full compression or elongation, before developing leakage. The test data is presented and discussed.

  7. Mineral-microorganism interactions in Acid Mine Drainage environments: preliminary results

    NASA Astrophysics Data System (ADS)

    Carbone, Cristina; Zotti, Mirca; Pozzolini, Marina; Giovine, Marco; Di Piazza, Simone; Mariotti, Mauro; Lucchetti, Gabriella

    2014-05-01

    Minerals play a key role in controlling the mobility and distribution of metals and metalloids of environmental concern in supergenic environments. These are involved in a variety of processes, spanning the alteration of primary minerals to the formation of secondary authigenic phases and can represent a source or a trap for Potentially Ecotoxic Elements (PTEs). Soil, sediments, and waters heavily polluted with PTEs through AMD processes are a reservoir of a unusual bacteria and fungi well adapted to these toxic environments. Classical studies of biotic weathering have mainly focused on water-mineral interaction and on the ability of microorganism to influence the soil solution chemical composition. In this work, we analyzed two different representative ochreous and greenish-blue AMD colloidal precipitates in order to i) characterize the biota population present in these colloidal minerals and ii) verify the bioaccumulation of PTEs into the fungi and the potential impact of bacteria in the geochemistry of the system. The samples are composed by nanocrystalline goethite which contains high amounts of Fe, Cu, Zn, Pb, and Ni and woodwardite that is characterized by Cu, Zn, Ni, Y, and Ce. These precipitates were examined in order to evaluate the presence of fungal strains and to extract bacteria DNA. The preliminary results of fungi characterization show an interesting and selected mycobiota able to survive under unfavourable environmental conditions. A significant number of fungal strains was isolated in pure culture. Most of them belong to the genus Mucor and Penicillium. It is worth noting the presence of Trametes versicolor, a macrofungal lignicolous species already known for heavy metal biosorption capability from aqueous solution (Gülay et al 2003). The same colloidal precipitates have been processed to extract bacteria DNA, using a specific procedure developed for DNA extraction from sediments. The results gave a good yield of nucleic acids and the positive PCR

  8. Whole Lichen Thalli Survive Exposure to Space Conditions: Results of Lithopanspermia Experiment with Aspicilia fruticulosa

    NASA Astrophysics Data System (ADS)

    Raggio, J.; Pintado, A.; Ascaso, C.; De La Torre, R.; De Los Ríos, A.; Wierzchos, J.; Horneck, G.; Sancho, L. G.

    2011-05-01

    The Lithopanspermia space experiment was launched in 2007 with the European Biopan facility for a 10-day spaceflight on board a Russian Foton retrievable satellite. Lithopanspermia included for the first time the vagrant lichen species Aspicilia fruticulosa from Guadalajara steppic highlands (Central Spain), as well as other lichen species. During spaceflight, the samples were exposed to selected space conditions, that is, the space vacuum, cosmic radiation, and different spectral ranges of solar radiation (λ ≥ 110, ≥ 200, ≥ 290, or ≥ 400 nm, respectively). After retrieval, the algal and fungal metabolic integrity of the samples were evaluated in terms of chlorophyll a fluorescence, ultrastructure, and CO2 exchange rates. Whereas the space vacuum and cosmic radiation did not impair the metabolic activity of the lichens, solar electromagnetic radiation, especially in the wavelength range between 100 and 200 nm, caused reduced chlorophyll a yield fluorescence; however, there was a complete recovery after 72 h of reactivation. All samples showed positive rates of net photosynthesis and dark respiration in the gas exchange experiment. Although the ultrastructure of all flight samples showed some probable stress-induced changes (such as the presence of electron-dense bodies in cytoplasmic vacuoles and between the chloroplast thylakoids in photobiont cells as well as in cytoplasmic vacuoles of the mycobiont cells), we concluded that A. fruticulosa was capable of repairing all space-induced damage. Due to size limitations within the Lithopanspermia hardware, the possibility for replication on the sun-exposed samples was limited, and these first results on the resistance of the lichen symbiosis A. fruticulosa to space conditions and, in particular, on the spectral effectiveness of solar extraterrestrial radiation must be considered preliminary. Further testing in space and under space-simulated conditions will be required. Results of this study indicate that the

  9. Whole lichen thalli survive exposure to space conditions: results of Lithopanspermia experiment with Aspicilia fruticulosa.

    PubMed

    Raggio, J; Pintado, A; Ascaso, C; De La Torre, R; De Los Ríos, A; Wierzchos, J; Horneck, G; Sancho, L G

    2011-05-01

    The Lithopanspermia space experiment was launched in 2007 with the European Biopan facility for a 10-day spaceflight on board a Russian Foton retrievable satellite. Lithopanspermia included for the first time the vagrant lichen species Aspicilia fruticulosa from Guadalajara steppic highlands (Central Spain), as well as other lichen species. During spaceflight, the samples were exposed to selected space conditions, that is, the space vacuum, cosmic radiation, and different spectral ranges of solar radiation (λ ≥ 110, ≥200, ≥290, or ≥400 nm, respectively). After retrieval, the algal and fungal metabolic integrity of the samples were evaluated in terms of chlorophyll a fluorescence, ultrastructure, and CO(2) exchange rates. Whereas the space vacuum and cosmic radiation did not impair the metabolic activity of the lichens, solar electromagnetic radiation, especially in the wavelength range between 100 and 200 nm, caused reduced chlorophyll a yield fluorescence; however, there was a complete recovery after 72 h of reactivation. All samples showed positive rates of net photosynthesis and dark respiration in the gas exchange experiment. Although the ultrastructure of all flight samples showed some probable stress-induced changes (such as the presence of electron-dense bodies in cytoplasmic vacuoles and between the chloroplast thylakoids in photobiont cells as well as in cytoplasmic vacuoles of the mycobiont cells), we concluded that A. fruticulosa was capable of repairing all space-induced damage. Due to size limitations within the Lithopanspermia hardware, the possibility for replication on the sun-exposed samples was limited, and these first results on the resistance of the lichen symbiosis A. fruticulosa to space conditions and, in particular, on the spectral effectiveness of solar extraterrestrial radiation must be considered preliminary. Further testing in space and under space-simulated conditions will be required. Results of this study indicate

  10. Adaptive learning can result in a failure to profit from good conditions: implications for understanding depression

    PubMed Central

    Trimmer, Pete C.; Higginson, Andrew D.; Fawcett, Tim W.; McNamara, John M.; Houston, Alasdair I.

    2015-01-01

    Background and objectives: Depression is a major medical problem diagnosed in an increasing proportion of people and for which commonly prescribed psychoactive drugs are frequently ineffective. Development of treatment options may be facilitated by an evolutionary perspective; several adaptive reasons for proneness to depression have been proposed. A common feature of many explanations is that depressive behaviour is a way to avoid costly effort where benefits are small and/or unlikely. However, this viewpoint fails to explain why low mood persists when the situation improves. We investigate whether a behavioural rule that is adapted to a stochastically changing world can cause inactivity which appears similar to the effect of depression, in that it persists after the situation has improved. Methodology: We develop an adaptive learning model in which an individual has repeated choices of whether to invest costly effort that may result in a net benefit. Investing effort also provides information about the current conditions and rates of change of the conditions. Results: An individual following the optimal behavioural strategy may sometimes remain inactive when conditions are favourable (i.e. when it would be better to invest effort) when it is poorly informed about the current environmental state. Initially benign conditions can predispose an individual to inactivity after a relatively brief period of negative experiences. Conclusions and implications: Our approach suggests that the antecedent factors causing depressed behaviour could go much further back in an individual s history than is currently appreciated. The insights from our approach have implications for the ongoing debate about best treatment options for patients with depressive symptoms. PMID:25916884

  11. Passive treatment of acid mine drainage using coal combustion by-products and spent mushroom substrate: Results of column study

    SciTech Connect

    Crisp, T.E.; Nairn, R.W.; Strevett, K.A.; Everett, J.

    1998-12-31

    A column study was conducted to evaluate the feasibility of using of coal combustion by-products (CCB) as alkaline materials in a field scale downflow constructed wetlands for acid mine drainage treatment. Five columns (15.24 cm in diameter and 91.44 cm high) were constructed and filled with a combination of spent mushroom substrate (SMS) and one of three alkaline materials (limestone, hydrated fly ash, or fluidized bed ash). The five mixtures utilized were 10% fluidized bed ash/40% limestone (FBA/LS), 10% fluidized bed ash (FBA), 50% limestone (LS), 50% hydrated fly ash (HFA),m and 50% sieved (>1.5 cm) hydrated fly ash (S. HFA) with the remainder as SMS on a w/w basis. Column received synthetic acid mine drainage containing: 400 mg/L iron, 59 mg/L aluminum, 11 mg/L manganese, 50% mg/L magnesium, 40 mg/L calcium, and 1200 mg/L sulfate for 5 months. Anoxic conditions in the influent reservoirs were maintained by a positive nitrogen pressure head. Flow rates of 2.0 mL/minute to each column were maintained by a multichannel peristaltic pump. For all columns, effluent acidity concentrations were less than influent acidity concentration (877{sup {minus}}30, n = 75f). Mean effluent acidity concentrations were 241 mg/L (FBA/LS), 186 mg/L (FBA), 419 mg/L (LS), {minus}28.5 mg/L (HFA), and 351 mg/L (S. HFA), respectively. While all column produced measurable alkalinity, only the HFA column produced a net alkaline discharge. The results of these column studies are applicable to the design and sizing of innovative field scale systems using alkaline-rich CCB`s.

  12. Whiteness improvement of citric acid crosslinked cotton fabrics: H2O2 bleaching under alkaline condition.

    PubMed

    Tang, Peixin; Ji, Bolin; Sun, Gang

    2016-08-20

    Polycarboxylic acids have been employed as formaldehyde-free crosslinking agents in anti-wrinkle treatment for cotton fabrics. Cotton fabrics treated by citric acid (CA) catalyzed with effective catalysts have shown satisfactory anti-wrinkle properties. Meanwhile, CA is a natural-based and environmental friendly compound. However, the yellowing of CA treated fabrics is a stumbling block for its practical application. Due to the fact that CA firstly forms aconitic acid (AA) before forming anhydrides, the cause of the yellowing, hydrogen peroxide (H2O2) bleaching was adopted to treat the CA treated fabrics in order to break the CC bond structure and reduce the yellow color but retaining the desired anti-wrinkle properties. Thermogravimetric analysis and Fourier transformed infrared spectroscopy were employed to investigate the reactions. The results revealed that the H2O2 bleaching can effectively improve the whiteness and also maintain a good anti-wrinkle performance of the CA treated fabrics under an appropriate bleaching temperature and time. PMID:27178918

  13. Role of Chlorogenic Acids in Controlling Oxidative and Inflammatory Stress Conditions

    PubMed Central

    Liang, Ningjian; Kitts, David D.

    2015-01-01

    Chlorogenic acids (CGAs) are esters formed between caffeic and quinic acids, and represent an abundant group of plant polyphenols present in the human diet. CGAs have different subgroups that include caffeoylquinic, p-coumaroylquinic, and feruloyquinic acids. Results of epidemiological studies suggest that the consumption of beverages such as coffee, tea, wine, different herbal infusions, and also some fruit juices are linked to reduced risks of developing different chronic diseases. These beverages contain CGAs present in different concentrations and isomeric mixtures. The underlying mechanism(s) for specific health benefits attributed to CGAs involves mitigating oxidative stress, and hence the related adverse effects associated with an unbalanced intracellular redox state. There is also evidence to show that CGAs exhibit anti-inflammatory activities by modulating a number of important metabolic pathways. This review will focus on three specific aspects of the relevance of CGAs in coffee beverages; namely: (1) the relative composition of different CGA isomers present in coffee beverages; (2) analysis of in vitro and in vivo evidence that CGAs and individual isomers can mitigate oxidative and inflammatory stresses; and (3) description of the molecular mechanisms that have a key role in the cell signaling activity that underlines important functions. PMID:26712785

  14. Acidogenic fermentation of Scenedesmus sp.-AMDD: Comparison of volatile fatty acids yields between mesophilic and thermophilic conditions.

    PubMed

    Gruhn, Marvin; Frigon, Jean-Claude; Guiot, Serge R

    2016-01-01

    This study compared the acidogenic fermentation of Scenedesmus sp.-AMDD at laboratory-scale, under mesophilic (35°C) and thermophilic conditions (55°C). Preliminary batch tests were performed to evaluate best conditions for volatile fatty acid (VFA) production from microalgal biomass, with respect to the inoculum, pH and nutrients. The use of bovine manure as inoculum, the operating pH of 4.5 and the addition of a nutrient mix, resulted in a high VFA production of up to 222mgg(-1) total volatile solid (TVS), with a butyrate share of 27%. Both digesters displayed similar hydrolytic activity with 0.38±0.02 and 0.42±0.03 g soluble chemical oxygen demand (COD)g(-1) TVS for the digesters operated at 35 and 55°C, respectively. Mesophilic conditions were more favorable for VFA production, which reached 171±5, compared to 88±12 mg soluble CODg(-1) TVS added under thermophilic conditions (94% more). It was shown that in both digesters, butyrate was the predominant VFA. PMID:26551650

  15. Australian Acid Playa Lake as a Mars Analog: Results from Sediment Lipid Analysis

    NASA Astrophysics Data System (ADS)

    Graham, H.; Baldridge, A. M.; Stern, J. C.

    2015-12-01

    The ephemeral saline acidic lakes on the Yilgarn Craton of Western Australia have been suggested as geochemical analogues to martian terrains. Both are characterized by interbedded phyllosilicates and hydrated sulfates. On Mars, these areas indicate shifting environmental conditions, from the neutral/alkaline and wet conditions that dominated during the Noachian era to the more familiar dry, acidic conditions that began in the Hesperian. The habitability of such a dynamic environment can be informed by investigation of the Yilgarn Lake system. Previous work has found phospholipid fatty acids (PLFA) evidence of microbial communities in sections of sediment cores taken from Lake Gilmore. These communities include both Gram-positive and -negative bacteria, Actinomycetes, and even methanotrophs. Given recurring detection of methane on the martian surface, evidence of a methane cycling community in an analogous environment is of particular interest. In this study we analyze the carbon isotope composition of bulk organic material as well as extracted lipids from the Lake Gilmore sediment cores at both a near-shore and mid-lake location. These analyses reveal very low accumulations of organic carbon, concentrated primarily in the gypsum-rich near-shore core. The near-shore sediments show a down-core decrease in abundance of organic carbon as well as depletion in the carbon isotope composition (δ13C) with depth. Bulk carbon did not exhibit the unique, highly depleted, diagnostic signature associated with methanotrophic biomass. Compound-specific isotope analysis (CSIA) of carbon in extracted methanotroph PFLAs can confirm the presence of a methane cycling metabolism at depth. Also, additional extractions have isolated lipids associated with lake-edge grasses. These analyses consider both the chain-length distribution and carbon CSIA of these lipids in order to understand the effect of terrestrial detritus on any preserved methanotroph carbon signal, given the very low

  16. Formation of N-nitrosamine and N-nitrosamino acids from food products and nitrite under simulated gastric conditions.

    PubMed

    Groenen, P J; de Cock-Bethbeder, M W; Bouwman, J; Dhont, J H

    1980-01-01

    Average-sized portions of a variety of food products were reacted with nitrite under realistically simulated gastric conditions. The aqueous incubation medium contained sodium nitrite (10 mg/l) and potassium thiocyanate to mimic the incoming flux of saliva, as well as pepsin, sodium chloride and hydrochloric acid, reflecting the composition of gastric juice. After incubation for 2 hr at 37 degrees C, volatile N-nitrosamines and N-nitrosamino acids were determined in the reaction mixtures. Nitrosodimethylamine (NDMA) was present in the incubation mixtures of smoked mackerel (8.5 micrograms per portion), canned herring (0.66 micrograms per portion) and beer (0.70 micrograms per 'portion'). Smaller amounts per portion, sometimes of other nitrosamines as well, were observed with canned salmon and anchovy, mustard, yoghurt and coffee brew. Negative results were obtained for canned tuna, soya sauce, ketchup, white bread, 'nasi goreng', tea brew and cocoa milk. Nitrosamino acids were detected in the reaction mixtures of smoked mackerel (58 micrograms per portion), soya sauce (24 micrograms per portion) and canned salmon (6.9 micrograms per portion) and in smaller amounts in those of canned herring, anchovy and cocoa milk. In order to reduce the number of analyses to be performed, most products have been studied only after incubation, so that the nitrosamines and nitrosamino acids found may already have been present -- wholly or partly -- in the original products, before incubation. Such is the case for part of the NDMA in the reaction mixture of smoked mackerel and for all the NDMA in beer. The toxicological implications of these findings remain to be established. PMID:7228254

  17. Effect of synthetic conditions on the adsorption properties of the resulting offretite-type zeolite

    NASA Astrophysics Data System (ADS)

    Gorshunova, K. K.; Travkina, O. S.; Kapustin, G. I.; Kustov, L. M.; Pavlov, M. L.; Kutepov, B. I.

    2015-05-01

    The effect of the nature of the silicon-containing component of the reaction mixture and that of the crystallization conditions on characteristics of the resulting offretite-type zeolite powder, including its degree of crystallinity, particle-size distribution, and adsorption properties with respect to toluene, cyclohexane, n-hexane, and water molecules, are considered. The thermal desorption of toluene from cationic forms of the offretite-type zeolite is reported. The K-forms of this zeolite can retain adsorbed toluene up to 300-400°C.

  18. Lysophosphatidic acid enhances survival of human CD34+ cells in ischemic conditions

    PubMed Central

    Kostic, Ivana; Fidalgo-Carvalho, Isabel; Aday, Sezin; Vazão, Helena; Carvalheiro, Tiago; Grãos, Mário; Duarte, António; Cardoso, Carla; Gonçalves, Lino; Carvalho, Lina; Paiva, Artur; Ferreira, Lino

    2015-01-01

    Several clinical trials are exploring therapeutic effect of human CD34+ cells in ischemic diseases, including myocardial infarction. Unfortunately, most of the cells die few days after delivery. Herein we show that lysophosphatidic acid (LPA)-treated human umbilical cord blood-derived CD34+ cells cultured under hypoxic and serum-deprived conditions present 2.2-fold and 1.3-fold higher survival relatively to non-treated cells and prostaglandin E2-treated cells, respectively. The pro-survival effect of LPA is concentration- and time-dependent and it is mediated by the activation of peroxisome proliferator-activator receptor γ (PPARγ) and downstream, by the activation of pro-survival ERK and Akt signaling pathways and the inhibition of mitochondrial apoptotic pathway. In hypoxia and serum-deprived culture conditions, LPA induces CD34+ cell proliferation without maintaining the their undifferentiating state, and enhances IL-8, IL-6 and G-CSF secretion during the first 12 h compared to non-treated cells. LPA-treated CD34+ cells delivered in fibrin gels have enhanced survival and improved cardiac fractional shortening at 2 weeks on rat infarcted hearts as compared to hearts treated with placebo. We have developed a new platform to enhance the survival of CD34+ cells using a natural and cost-effective ligand and demonstrated its utility in the preservation of the functionality of the heart after infarction. PMID:26553339

  19. Hydrolysis of Indole-3-Acetic Acid Esters Exposed to Mild Alkaline Conditions 1

    PubMed Central

    Baldi, Bruce G.; Maher, Barbara R.; Cohen, Jerry D.

    1989-01-01

    Ester conjugates of indole-3-acetic acid are hydrolyzed easily in basic solutions; however, quantitative data have not been available on the relationship between pH and rate of hydrolysis of the known ester conjugates. The use of basic conditions during extraction or purification of IAA by several laboratories suggested that a more systematic analysis of this process was needed. In this report we present data indicating: (a) that measurable hydrolysis of IAA-glucose (from standard solutions) and IAA-esters (from maize kernel extracts) occurs with only a few hours of treatment at pH 9 or above; (b) that the lability of some ester conjugates is even greater than that of IAA-glucose; and (c) that ester hydrolysis of standard compounds, IAA-glucose and IAA-p-nitrophenol, occurs in the `three phase extraction system' proposed by Liu and Tillberg ([1983] Physiol Plant 57: 441-447). These data indicate that the potential for problems with inadvertent hydrolysis of ester conjugates of IAA exists even at moderate pH values and in the multiphase system where exposure to basic conditions was thought to be limited. PMID:16667049

  20. Karrikins delay soybean seed germination by mediating abscisic acid and gibberellin biogenesis under shaded conditions

    PubMed Central

    Meng, Yongjie; Chen, Feng; Shuai, Haiwei; Luo, Xiaofeng; Ding, Jun; Tang, Shengwen; Xu, Shuanshuan; Liu, Jianwei; Liu, Weiguo; Du, Junbo; Liu, Jiang; Yang, Feng; Sun, Xin; Yong, Taiwen; Wang, Xiaochun; Feng, Yuqi; Shu, Kai; Yang, Wenyu

    2016-01-01

    Karrikins (KAR) are a class of signal compounds, discovered in wildfire smoke, which affect seed germination. Currently, numerous studies have focused on the model plant Arabidopsis in the KAR research field, rather than on crops. Thus the regulatory mechanisms underlying KAR regulation of crop seed germination are largely unknown. Here, we report that KAR delayed soybean seed germination through enhancing abscisic acid (ABA) biosynthesis, while impairing gibberellin (GA) biogenesis. Interestingly, KAR only retarded soybean seed germination under shaded conditions, rather than under dark and white light conditions, which differs from in Arabidopsis. Phytohormone quantification showed that KAR enhanced ABA biogenesis while impairing GA biosynthesis during the seed imbibition process, and subsequently, the ratio of active GA4 to ABA was significantly reduced. Further qRT-PCR analysis showed that the transcription pattern of genes involved in ABA and GA metabolic pathways are consistent with the hormonal measurements. Finally, fluridone, an ABA biogenesis inhibitor, remarkably rescued the delayed-germination phenotype of KAR-treatment; and paclobutrazol, a GA biosynthesis inhibitor, inhibited soybean seed germination. Taken together, these evidences suggest that KAR inhibit soybean seed germination by mediating the ratio between GA and ABA biogenesis. PMID:26902640

  1. Mineral-catalyzed dehydrogenation of C6 cyclic hydrocarbons: results from experimental studies under hydrothermal conditions

    NASA Astrophysics Data System (ADS)

    Venturi, S.; Tassi, F.; Gould, I.; Shock, E.; Lorance, E. D.; Bockisch, C.; Fecteau, K.

    2015-12-01

    Volatile organic compounds (VOCs) are ubiquitously present in volcanic and hydrothermal gases. Their relative abundances have been demonstrated to be sensitive to physical and chemical parameters, suggesting VOCs as potential tools for evaluating deep reservoir conditions. Nevertheless, reaction pathways for VOC production at hydrothermal conditions are still poorly understood. Reversible catalytic reforming may be responsible for the high abundance of benzene observed in hydrothermal gases relative to saturated hydrocarbons. The dehydrogenation of n-hexane to benzene could proceed with C6 cyclic hydrocarbons as intermediates, as suggested by the relative enrichment in cyclic hydrocarbons observed in gases originating at T <150 °C. In this study, laboratory experiments were carried out to investigate the production of benzene from cyclic hydrocarbons at 300°C and 85 bar. At these conditions in pure water, negligible benzene is produced from cyclohexane after 10 days. The presence of a mineral phase, especially sphalerite, favored the formation of both benzene and cyclohexene. The efficiency of dehydroaromatization reaction increased at increasing mineral/cyclohexane ratio, pointing to a surface catalyzed reaction. The catalytic action of sphalerite on the C-H bonds was confirmed by the large abundance of deuterated cyclohexane resulted in D2O experiments. The same experiment carried out using cyclohexene in pure water mainly produced methyl-cyclopentenes (via isomerization) and cyclohexanol (via oxygenation). In presence of sphalerite, the production of significant amounts of benzene confirmed the critical role of this mineral for the aromatization of cyclic compounds under hydrothermal conditions. Contrarily, products from cyclohexene solution phase oxidation using Cu(II) mainly consisted of oxygenated VOCs.

  2. 77 FR 9891 - Citric Acid and Certain Citrate Salts from the People's Republic of China: Amended Final Results...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-21

    ... Republic of China: Final Results of the First Administrative Review of the Antidumping Duty Order, 76 FR... International Trade Administration Citric Acid and Certain Citrate Salts from the People's Republic of China... antidumping duty order on citric acid and certain citrate salts (``citric acid'') from the People's...

  3. Acid-Labile Thermoresponsive Copolymers That Combine Fast pH-Triggered Hydrolysis and High Stability under Neutral Conditions.

    PubMed

    Zhang, Qilu; Hou, Zhanyao; Louage, Benoit; Zhou, Dingying; Vanparijs, Nane; De Geest, Bruno G; Hoogenboom, Richard

    2015-09-01

    Biodegradable polymeric materials are intensively used in biomedical applications. Of particular interest for drug-delivery applications are polymers that are stable at pH 7.4, that is, in the blood stream, but rapidly hydrolyze under acidic conditions, such as those encountered in the endo/lysosome or the tumor microenvironment. However, an increase in the acidic-degradation rate of acid-labile groups goes hand in hand with higher instability of the polymer at pH 7.4 or during storage, thus posing an intrinsic limitation on fast degradation under acidic conditions. Herein, we report that a combination of acid-labile dimethyldioxolane side chains and hydroxyethyl side chains leads to acid-degradable thermoresponsive polymers that are quickly hydrolyzed under slightly acidic conditions but stable at pH 7.4 or during storage. We ascribe these properties to high hydration of the hydroxy-containing collapsed polymer globules in conjunction with autocatalytic acceleration of the hydrolysis reactions by the hydroxy groups. PMID:26212481

  4. Ethanol Production by Selected Intestinal Microorganisms and Lactic Acid Bacteria Growing under Different Nutritional Conditions.

    PubMed

    Elshaghabee, Fouad M F; Bockelmann, Wilhelm; Meske, Diana; de Vrese, Michael; Walte, Hans-Georg; Schrezenmeir, Juergen; Heller, Knut J

    2016-01-01

    To gain some specific insight into the roles microorganisms might play in non-alcoholic fatty liver disease (NAFLD), some intestinal and lactic acid bacteria and one yeast (Anaerostipes caccae, Bacteroides thetaiotaomicron, Bifidobacterium longum, Enterococcus fecalis, Escherichia coli, Lactobacillus acidophilus, Lactobacillus fermentum, Lactobacillus plantarum, Weissella confusa, Saccharomyces cerevisiae) were characterized by high performance liquid chromatography for production of ethanol when grown on different carbohydrates: hexoses (glucose and fructose), pentoses (arabinose and ribose), disaccharides (lactose and lactulose), and inulin. Highest amounts of ethanol were produced by S. cerevisiae, L. fermentum, and W. confusa on glucose and by S. cerevisiae and W. confusa on fructose. Due to mannitol-dehydrogenase expressed in L. fermentum, ethanol production on fructose was significantly (P < 0.05) reduced. Pyruvate and citrate, two potential electron acceptors for regeneration of NAD(+)/NADP(+), drastically reduced ethanol production with acetate produced instead in L. fermentum grown on glucose and W. confusa grown on glucose and fructose, respectively. In fecal slurries prepared from feces of four overweight volunteers, ethanol was found to be produced upon addition of fructose. Addition of A. caccae, L. acidophilus, L. fermentum, as well as citrate and pyruvate, respectively, abolished ethanol production. However, addition of W. confusa resulted in significantly (P < 0.05) increased production of ethanol. These results indicate that microorganisms like W. confusa, a hetero-fermentative, mannitol-dehydrogenase negative lactic acid bacterium, may promote NAFLD through ethanol produced from sugar fermentation, while other intestinal bacteria and homo- and hetero-fermentative but mannitol-dehydrogenase positive lactic acid bacteria may not promote NAFLD. Also, our studies indicate that dietary factors interfering with gastrointestinal microbiota and microbial

  5. Ethanol Production by Selected Intestinal Microorganisms and Lactic Acid Bacteria Growing under Different Nutritional Conditions

    PubMed Central

    Elshaghabee, Fouad M. F.; Bockelmann, Wilhelm; Meske, Diana; de Vrese, Michael; Walte, Hans-Georg; Schrezenmeir, Juergen; Heller, Knut J.

    2016-01-01

    To gain some specific insight into the roles microorganisms might play in non-alcoholic fatty liver disease (NAFLD), some intestinal and lactic acid bacteria and one yeast (Anaerostipes caccae, Bacteroides thetaiotaomicron, Bifidobacterium longum, Enterococcus fecalis, Escherichia coli, Lactobacillus acidophilus, Lactobacillus fermentum, Lactobacillus plantarum, Weissella confusa, Saccharomyces cerevisiae) were characterized by high performance liquid chromatography for production of ethanol when grown on different carbohydrates: hexoses (glucose and fructose), pentoses (arabinose and ribose), disaccharides (lactose and lactulose), and inulin. Highest amounts of ethanol were produced by S. cerevisiae, L. fermentum, and W. confusa on glucose and by S. cerevisiae and W. confusa on fructose. Due to mannitol-dehydrogenase expressed in L. fermentum, ethanol production on fructose was significantly (P < 0.05) reduced. Pyruvate and citrate, two potential electron acceptors for regeneration of NAD+/NADP+, drastically reduced ethanol production with acetate produced instead in L. fermentum grown on glucose and W. confusa grown on glucose and fructose, respectively. In fecal slurries prepared from feces of four overweight volunteers, ethanol was found to be produced upon addition of fructose. Addition of A. caccae, L. acidophilus, L. fermentum, as well as citrate and pyruvate, respectively, abolished ethanol production. However, addition of W. confusa resulted in significantly (P < 0.05) increased production of ethanol. These results indicate that microorganisms like W. confusa, a hetero-fermentative, mannitol-dehydrogenase negative lactic acid bacterium, may promote NAFLD through ethanol produced from sugar fermentation, while other intestinal bacteria and homo- and hetero-fermentative but mannitol-dehydrogenase positive lactic acid bacteria may not promote NAFLD. Also, our studies indicate that dietary factors interfering with gastrointestinal microbiota and microbial

  6. Safe conditions for contacting nitric acid or nitrates with tri-n-butyl phosphate (TBP)

    SciTech Connect

    Hyder, M.L

    1994-01-01

    In response to a request from DOE-SR, the current state of knowledge of the reactions between TBP and aqueous nitrate solutions is critically reviewed, and recommendations are made for the safe operation of SRS separations equipment in which this combination of chemicals may be present. The existing limits for evaporation are validated. Guidelines are presented for cases in which general limits do not apply. The rate of reaction between nitric acid and TBP appears to be controlled by the rate of TBP hydrolysis. The hydrolysis reaction produces dibutyl phosphate and n-butanol. The hydrolysis rate is a strong function of temperature, and becomes very fast at temperatures in the range 130{degrees} to 150{degrees}C. The resulting n-butanol is volatile at high temperatures, boiling at 117.5{degrees}C, but is also subject to exothermic oxidation by nitric acid or nitrates. If oxidation occurs before the n-butanol evaporates, the heat of oxidation may exceed local cooling by convection. The resulting heating will further accelerate the reaction, leading to an energetic runaway and possibly (in confined systems) an explosion. Extensive experiments and practice have shown that in a well-mixed and well-vented aqueous system such as an evaporator, at moderate acidities and temperatures below 130{degrees}C, the heat of reaction is adequately removed by vaporization of steam. In general, the heating will be so slow that natural processes provide adequate cooling at temperatures below 80{degrees}C. Above this temperature, care should be taken to ensure that adequate cooling is available for the amount of TBP that may be present. Experiments suggest that in well-ventilated systems n-butanol evaporation and convective cooling are sufficient to control the reaction at temperatures up to 120{degrees}C.

  7. Electrochemical antimony removal from accumulator acid: results from removal trials in laboratory cells.

    PubMed

    Bergmann, M E Henry; Koparal, A Savas

    2011-11-30

    Regeneration of spent accumulator acid could be an alternative process for crystallization, neutralisation and disposal. Therefore, for the first time in a study of the possibilities of electrochemical removal of antimony and accumulator acid regeneration on a laboratory scale, two synthetic and several real systems containing sulfuric acid of concentrations ranging between 28% and 36%, and antimony species were tested. Discontinuous electrochemical reactors with anion exchange membranes were successfully used in these experiments, which were conducted at a temperature of 35°C. Removal of antimony using cells that were not divided by a separator, however, was not possible. In selected experiments, by varying the electrode material, type of electrolyte, and cell current, the concentration of antimony could be reduced from the range of 5 ppm to 0.15 ppm. This resulted in current efficiencies between 0.00002% and 0.001%, and in specific electroenergy demands between 100 Wh L(-1) and 2000 Wh L(-1). In other experiments on substances with antimony contents up to 3500 mg L(-1), the current efficiencies obtained were more than a thousandfold higher. In contrast to the formally high relative energy consumption parameters absolute demand parameters are relatively small and favour the electrochemical method in small scale application. Besides plate electrodes, 3D-cathodes were used. Copper- and graphite cathodes produced the best results. PMID:21978586

  8. Conditional depletion of KasA, a key enzyme of mycolic acid biosynthesis, leads to mycobacterial cell lysis.

    PubMed

    Bhatt, Apoorva; Kremer, Laurent; Dai, Annie Z; Sacchettini, James C; Jacobs, William R

    2005-11-01

    Inhibition or inactivation of InhA, a fatty acid synthase II (FASII) enzyme, leads to mycobacterial cell lysis. To determine whether inactivation of other enzymes of the mycolic acid-synthesizing FASII complex also leads to lysis, we characterized the essentiality of two beta-ketoacyl-acyl carrier protein synthases, KasA and KasB, in Mycobacterium smegmatis. Using specialized transduction for allelic exchange, null kasB mutants, but not kasA mutants, could be generated in Mycobacterium smegmatis, suggesting that unlike kasB, kasA is essential. To confirm the essentiality of kasA, and to detail the molecular events that occur following depletion of KasA, we developed CESTET (conditional expression specialized transduction essentiality test), a genetic tool that combines conditional gene expression and specialized transduction. Using CESTET, we were able to generate conditional null inhA and kasA mutants. We studied the effects of depletion of KasA in M. smegmatis using the former strain as a reference. Depletion of either InhA or KasA led to cell lysis, but with different biochemical and morphological events prior to lysis. While InhA depletion led to the induction of an 80-kDa complex containing both KasA and AcpM, the mycobacterial acyl carrier protein, KasA depletion did not induce the same complex. Depletion of either InhA or KasA led to inhibition of alpha and epoxy mycolate biosynthesis and to accumulation of alpha'-mycolates. Furthermore, scanning electron micrographs revealed that KasA depletion resulted in the cell surface having a "crumpled" appearance, in contrast to the blebs observed on InhA depletion. Thus, our studies support the further exploration of KasA as a target for mycobacterial-drug development. PMID:16267284

  9. Corrosion Behavior of 35CrMn and Q235 Steel in Simulated Acid Rain Conditions

    NASA Astrophysics Data System (ADS)

    Zuo, Xiu-li; Xiang, Bin; Li, Xing; Wei, Zi-dong

    2012-04-01

    Effects of pH value, chloride ion concentration and alternation of wetting and drying time in acid rain on the corrosion of 35CrMn and Q235 steel were investigated through the measurement of polarization curves, electrochemical impedance spectroscopy, x-ray diffraction, and quantum mechanical calculations. The corrosion rate of 35CrMn and Q235 steel increased with decreasing pH values of the simulated acid rain, whereas the corrosion potential of 35CrMn and Q235 steel became more negative. The impedance became higher and the corrosion rate decreased with increasing test time. The dissolution rate of samples increased with chloride ion concentration. Results suggested that the corrosion rate of 35CrMn steel was obviously lower than that of Q235 steel for a more compact rust, α-FeOOH. Quantum chemical calculations further revealed that the increase in corrosion rate of the steel resulted from pitting corrosion caused by the corrosive chloride ion.

  10. Keto analogue and amino acid supplementation and its effects on ammonemia and performance under thermoneutral conditions.

    PubMed

    Camerino, Saulo Rodrigo Alves e Silva; Lima, Rafaela Carvalho Pereira; França, Thássia Casado Lima; Herculano, Edla de Azevedo; Rodrigues, Daniela Souza Araújo; Gouveia, Marcos Guilherme de Sousa; Cameron, L C; Prado, Eduardo Seixas

    2016-02-01

    Alterations of cerebral function, fatigue and disturbance in cognitive-motor performance can be caused by hyperammonemia and/or hot environmental conditions during exercise. Exercise-induced hyperammonemia can be reduced through supplementation with either amino acids or combined keto analogues and amino acids (KAAA) to improve exercise tolerance. In the present study, we evaluated KAAA supplementation on ammonia metabolism and cognitive-motor performance after high-intensity exercise under a low heat stress environment. Sixteen male cyclists received a ketogenic diet for 2 d and were divided into two groups, KAAA (KEx) or placebo (CEx) supplementation. The athletes performed a 2 h cycling session followed by a maximum test (MAX), and blood samples were obtained at rest and during exercise. Cognitive-motor tasks were performed before and after the protocol, and the exhaustion time was used to evaluate physical performance. The hydration status was also evaluated. The CEx group showed a significant increase (∼ 70%) in ammonia concentration at MAX, which did not change in the KEx group. The non-supplemented group showed a significant increase in uremia. Both the groups had a significant increase in blood urate concentrations at 120 min, and an early significant increase from 120 min was observed in the CEx group. There was no change in the glucose concentrations of the two groups. A significant increase in lactate was observed at the MAX moment in both groups. There was no significant difference in the exhaustion times between the groups. No changes were observed in the cognitive-motor tasks after the protocol. We suggest that KAAA supplementation decreases ammonia concentration during high-intensity exercise but does not affect physical or cognitive-motor performances under a low heat stress environment. PMID:26679329

  11. The role of carboxylic acids in albite and quartz dissolution: An experimental study under diagenetic conditions

    SciTech Connect

    Franklin, S.P. ); Hajash, A. Jr.; Tieh, T.T. ); Dewers, T.A. )

    1994-10-01

    Simple water soluble organic acids may promote secondary porosity development in sandstones during diagenesis by increasing feldspar solubility and dissolution rate. To test this hypothesis, Amelia albite and Brazilian hydrothermal quartz were reacted with 0.07 m acetate and 0.07 m acetate-0.005 m oxalate solutions at selected pH values, and distilled water. Pore fluid chemistry was monitored through time at various flow rates to obtain both solubility and dissolution rate data. The experiments were conducted in large volume, semi-static, flow-through systems at 100[degrees]C and 347 bars. These systems simulate subsurface flow rates, low mass water/rock, and high surface area/fluid mass. Acetate and acetate + oxalate solutions significantly increase albite solubility at temperatures, pressures, and pH values typical of diagenetic environments. Albite solubilities increased in acetate and acetate + oxalate solutions by factors of 2 and 3.4, respectively, compared to distilled water. In these same solutions, Al concentrations were [approx] 140 and [approx] 480 times higher than that calculated for kaolinite solubility at the same conditions without organic species. These enhanced solubilities occur at pH values (4.6-4.8) that may overlap with formation waters. In contrast to albite, quartz solubility was essentially identical in all solutions investigated. Dissolution rates in the acid region decreased with increasing pH in the acetate and acetate + oxalate solutions. Slopes of log rate vs. pH curves were [approx] 0.6 for acetate and [approx] 0.3 for acetate + oxalate. Although the effects of acetate on the dissolution rate are small, the effects of oxalate are significant. A rate law valid for albite dissolution at 100[degrees]C, oxalate concentrations to 0.01 m, and pH values ranging from 3.4 to 5.5 is given.

  12. Effects of Acidity and Stress on Stomach Motility, Assessed by Biomagnetic Technique: Preliminary Results

    NASA Astrophysics Data System (ADS)

    Córdova-Fraga, T.; Sosa-Aquino, M.; Huerta-Franco, R.; Vargas-Luna, M.; Gutiérrez-Juárez, G.; Bernal-Alvarado, J.

    2004-09-01

    The human stomach is a J shaped hollowed organ that undergoes a variable luminal volume without significant pressure changes. This organ has two valves: the cardiac localized in the upper part, and the pillory on the lower part of the organ respectively. The main functions of these valves are to storage, carry, triturate and empty the lumen content. However, their activity could be affected for different agents such as chemical stimulus (alcoholic beverages) and psychological stress. In this contribution we show by the first time, the importance of biomagnetic signal technique in order to measure the human stomach peristaltic frequency in healthy subjects who were evaluated in basal conditions, and after to be submitted at the effects of: acidity caused by alcoholic beverages and psychological stress.

  13. Influence of Earth crust composition on continental collision style in Precambrian conditions: Results of supercomputer modelling

    NASA Astrophysics Data System (ADS)

    Zavyalov, Sergey; Zakharov, Vladimir

    2016-04-01

    A number of issues concerning Precambrian geodynamics still remain unsolved because of uncertainity of many physical (thermal regime, lithosphere thickness, crust thickness, etc.) and chemical (mantle composition, crust composition) parameters, which differed considerably comparing to the present day values. In this work, we show results of numerical supercomputations based on petrological and thermomechanical 2D model, which simulates the process of collision between two continental plates, each 80-160 km thick, with various convergence rates ranging from 5 to 15 cm/year. In the model, the upper mantle temperature is 150-200 ⁰C higher than the modern value, while the continental crust radiogenic heat production is higher than the present value by the factor of 1.5. These settings correspond to Archean conditions. The present study investigates the dependence of collision style on various continental crust parameters, especially on crust composition. The 3 following archetypal settings of continental crust composition are examined: 1) completely felsic continental crust; 2) basic lower crust and felsic upper crust; 3) basic upper crust and felsic lower crust (hereinafter referred to as inverted crust). Modeling results show that collision with completely felsic crust is unlikely. In the case of basic lower crust, a continental subduction and subsequent continental rocks exhumation can take place. Therefore, formation of ultra-high pressure metamorphic rocks is possible. Continental subduction also occurs in the case of inverted continental crust. However, in the latter case, the exhumation of felsic rocks is blocked by upper basic layer and their subsequent interaction depends on their volume ratio. Thus, if the total inverted crust thickness is about 15 km and the thicknesses of the two layers are equal, felsic rocks cannot be exhumed. If the total thickness is 30 to 40 km and that of the felsic layer is 20 to 25 km, it breaks through the basic layer leading to

  14. Psychiatric morbidity in pain conditions: Results from the Singapore Mental Health Study

    PubMed Central

    Subramaniam, Mythily; Vaingankar, Janhavi Ajit; Abdin, Edimansyah; Chong, Siow Ann

    2013-01-01

    BACKGROUND: Chronic pain is a common problem among the general population and has been found to be associated with psychiatric disorders in studies based on both clinical samples and epidemiological surveys. OBJECTIVES: To establish the prevalence, correlates and comorbidities of chronic pain disorders among the adult population of Singapore. METHODS: The data used in the present analysis were derived from the Singapore Mental Health Study, a cross-sectional epidemiological survey of a representative sample of the adult resident population of Singapore. Diagnoses of psychiatric disorders were established using the Composite International Diagnostic Interview version 3.0. A modified version of the Composite International Diagnostic Interview 3.0 checklist of chronic medical disorders was used, in which the chronic medical disorders were reclassified into eight types of physical disorders. Chronic pain disorders included arthritis or rheumatism, back problems including disk or spine problems, and migraine headaches. RESULTS: The lifetime prevalence estimates for arthritis, back pain and migraine in the Singapore general population were 6.0% (n=282), 7.0% (n=436) and 5.6% (n=446), respectively. After adjusting for sociodemographic factors, comorbid pain disorders and the presence of other chronic physical conditions, migraine remained significantly associated with major depressive disorder (adjusted OR=2.4), generalized anxiety disorder (adjusted OR=3.0) and alcohol use disorders (adjusted OR=2.1), while back pain was significantly associated with major depressive disorder (adjusted OR=2.0). CONCLUSIONS: The significant association between pain and psychiatric disorders emphasizes the need to screen individuals with chronic pain conditions for psychiatric disorders, particularly depression. There is a need to develop integrated pharmacological and psychological treatments for both conditions. PMID:23936892

  15. Complex investigation of the effects of lambertianic acid amide in female mice under conditions of social discomfort.

    PubMed

    Avgustinovich, D F; Fomina, M K; Sorokina, I V; Tolstikova, T G

    2014-09-01

    The effects of chronic administration of a new substance lambertianic acid amide and previously synthesized methyl ester of this acid were compared in female mice living under conditions of social discomfort. For modeling social discomfort, female mouse was housed for 30 days in a cage with aggressive male mouse kept behind a transparent perforated partition and observed its confrontations with another male mouse daily placed to the cage. The new agent more effectively than lambertianic acid methyl ester improved communicativeness and motor activity of animals, reduced hypertrophy of the adrenal glands, and enhanced catalase activity in the blood. These changes suggest that lambertianic acid amide produces a pronounced stress-protective effect under conditions of social discomfort. PMID:25257419

  16. Novel Extracellular PHB Depolymerase from Streptomyces ascomycinicus: PHB Copolymers Degradation in Acidic Conditions

    PubMed Central

    García-Hidalgo, Javier; Hormigo, Daniel; Arroyo, Miguel; de la Mata, Isabel

    2013-01-01

    The ascomycin-producer strain Streptomyces ascomycinicus has been proven to be an extracellular poly(R)-3-hydroxybutyrate (PHB) degrader. The fkbU gene, encoding a PHB depolymerase (PhaZSa), has been cloned in E. coli and Rhodococcus sp. T104 strains for gene expression. Gram-positive host Rhodococcus sp. T104 was able to produce and secrete to the extracellular medium an active protein form. PhaZSa was purified by two hydrophobic interaction chromatographic steps, and afterwards was biochemically as well as structurally characterized. The enzyme was found to be a monomer with a molecular mass of 48.4 kDa, and displayed highest activity at 45°C and pH 6, thus being the first PHB depolymerase from a gram-positive bacterium presenting an acidic pH optimum. The PHB depolymerase activity of PhaZSa was increased in the presence of divalent cations due to non-essential activation, and also in the presence of methyl-β-cyclodextrin and PEG 3350. Protein structure was analyzed, revealing a globular shape with an alpha-beta hydrolase fold. The amino acids comprising the catalytic triad, Ser131-Asp209-His269, were identified by multiple sequence alignment, chemical modification of amino acids and site-directed mutagenesis. These structural results supported the proposal of a three-dimensional model for this depolymerase. PhaZSa was able to degrade PHB, but also demonstrated its ability to degrade films made of PHB, PHBV copolymers and a blend of PHB and starch (7∶3 proportion wt/wt). The features shown by PhaZSa make it an interesting candidate for industrial applications involving PHB degradation. PMID:23951224

  17. The role of methanogens in acetic acid production under different salinity conditions.

    PubMed

    Xiao, Keke; Guo, Chenghong; Maspolim, Yogananda; Zhou, Yan; Ng, Wun Jern

    2016-10-01

    In this study, a fed-batch acidogenic reactor was operated at a 3 d hydraulic retention time (HRT) and fed with alkaline pre-treated sludge to investigate salinity effects on methanogens' abundance, activities and their consumption of produced acetic acid (HAc) and total volatile fatty acids (VFAs). The salinity concentration was increased step-wise by adding sodium chloride. At 3‰ (parts per thousand) salinity, the average produced volatile fatty acids (VFAs) concentration was 2410.16 ± 637.62 mg COD L(-1) and 2.70 ± 0.36 L methane was produced daily in the acidogenic reactor. Further batch tests indicated methanogens showed a HAc degradation rate of 3.81 mg COD g(-1) VSS h(-1) at initial HAc concentration of 1150 mg COD L(-1), and showed tolerance up to 16‰ salinity (3.76 g Na(+) L(-1)) as indicated by a constant HAc degradation rate. The microbiological study indicated this can be related to the predominance of acetate-utilizing Methanosarcinaceae and Methanomicrobiales in the reactor. However, with salinity increased to 20‰ and 40‰, increases in VFAs and HAc production and decreases in methane production, methanogens population, acidogenic bacteria population and acidification extent were observed. This study demonstrated presence of acetate-utilizing methanogens in an acidogenic reactor and their high tolerance to salinity, as well as their negative impacts on net VFAs production. The results would suggest the presence of methanogens in the acidogenic reactor should not be ignored and the recovery of methane from the acidogenic reactor needs to be considered to avoid carbon loss. PMID:27421101

  18. Decomposition of cyclohexanoic acid by the UV/H2O2 process under various conditions.

    PubMed

    Afzal, Atefeh; Drzewicz, Przemysław; Martin, Jonathan W; Gamal El-Din, Mohamed

    2012-06-01

    Naphthenic acids (NAs) are a broad range of alicyclic and aliphatic compounds that are persistent and contribute to the toxicity of oil sands process affected water (OSPW). In this investigation, cyclohexanoic acid (CHA) was selected as a model naphthenic acid, and its oxidation was investigated using advanced oxidation employing a low-pressure ultraviolet light in the presence of hydrogen peroxide (UV/H(2)O(2) process). The effects of two pHs and common OSPW constituents, such as chloride (Cl(-)) and carbonate (CO(3)(2-)) were investigated in ultrapure water. The optimal molar ratio of H(2)O(2) to CHA in the treatment process was also investigated. The pH had no significant effect on the degradation, nor on the formation and degradation of byproducts in ultrapure water. The presence of CO(3)(2-) or Cl(-) significantly decreased the CHA degradation rate. The presence of 700 mg/L CO(3)(2-) or 500 mg/L Cl(-), typical concentrations in OSPW, caused a 55% and 23% decrease in the pseudo-first order degradation rate constants for CHA, respectively. However, no change in byproducts or in the degradation trend of byproducts, in the presence of scavengers was observed. A real OSPW matrix also had a significant impact by decreasing the CHA degradation rate, such that by spiking CHA into the OSPW, the degradation rate decreased up to 82% relative to that in ultrapure water. The results of this study show that UV/H(2)O(2) AOP is capable of degrading CHA as a model NA in ultrapure water. However, in the real applications, the effect of radical scavengers should be taken into consideration for the achievement of best performance of the process. PMID:22521165

  19. Acetylation of bacterial cellulose catalyzed by citric acid: Use of reaction conditions for tailoring the esterification extent.

    PubMed

    Ávila Ramírez, Jhon Alejandro; Gómez Hoyos, Catalina; Arroyo, Silvana; Cerrutti, Patricia; Foresti, María Laura

    2016-11-20

    Bacterial cellulose (BC) nanoribbons were partially acetylated by a simple direct solvent-free route catalyzed by citric acid. The assay of reaction conditions within chosen intervals (i.e. esterification time (0.5-7h), catalyst content (0.08-1.01mmol/mmol AGU), and temperature (90-140°C)), illustrated the flexibility of the methodology proposed, with reaction variables which can be conveniently manipulated to acetylate BC to the required degree of substitution (DS) within the 0.20-0.73 interval. Within this DS interval, characterization results indicated a surface-only process in which acetylated bacterial cellulose with tunable DS, preserved fibrous structure and increased hydrophobicity could be easily obtained. The feasibility of reusing the catalyst/excess acylant in view of potential scale-up was also illustrated. PMID:27561540

  20. Biotite-brine interactions under acidic hydrothermal conditions: fibrous illite, goethite, and kaolinite formation and biotite surface cracking.

    PubMed

    Hu, Yandi; Ray, Jessica R; Jun, Young-Shin

    2011-07-15

    To ensure safe and efficient geologic CO(2) sequestration (GCS), it is crucial to have a better understanding of CO(2)-brine-rock interactions under GCS conditions. In this work, using biotite (K(Mg,Fe)(3)AlSi(3)O(10)(OH,F)(2)) as a model clay mineral, brine-biotite interactions were studied under conditions relevant to GCS sites (95 °C, 102 atm CO(2), and 1 M NaCl solution). After reaction for 3-17 h, fast growth of fibrous illite on flat basal planes of biotite was observed. After 22-70 h reaction, the biotite basal surface cracked, resulting in illite detaching from the surface. Later on (96-120 h), the cracked surface layer was released into solution, thus the inner layer was exposed as a renewed flat basal surface. The cracking and detachment of the biotite surface layer increased the surface area in contact with solution and accelerated biotite dissolution. On biotite edge surfaces, Al-substituted goethite and kaolinite precipitated. In control experiments with water under the same temperature and pressure, neither macroscopic fibrous illite nor cracks were observed. This work provides unique information on biotite-brine interaction under acidic hydrothermal conditions. PMID:21696218

  1. Preliminary results on the ability of pentatomidae to transfer fire blight Erwinia amylovora under controlled conditions.

    PubMed

    Peusens, G; Schoofs, H; Deckers, T; Belien, T

    2013-01-01

    With their piercing-sucking mouthparts stink bugs (Heteroptera: Pentatomidae), a major pest in especially organic orchards, create wounds in fruit of pear trees. As Erwinia amylovora (Burrill, Winslow et al.), a wide spread bacterial disease affecting many rosaceous plants including pome fruit trees and hawthorn, enters through openings in flowers, leaves, shoots and fruit, feeding punctures caused by these bugs might be inoculated with Erwinia bacteria. In order to investigate the ability of the bugs Pentotoma rufipes L. and Polomena prasina L. to transmit fire blight, insects were caught in an organically managed orchard without fire blight, brought into contact with artificially inoculated immature pear fruit/slices and transferred to healthy, mechanically wounded pear fruit/slices. After an incubation period potential transmission of bacteria was examined by evaluation of symptom expression (necrosis, ooze production). To assess the presence of bacteria on the exoskeleton of the tested bugs, all bugs were forced to walk on a semiselective nutrient agar medium. In another experiment the viability of Ea on the exoskeleton was tested -after previous contact with ooze- through washing and plating of the wash water. All experiments were conducted under optimal climatological conditions and according to quarantine standards. Results demonstrated the ability of stink bugs to transfer E. amylovora to fruit and the viability of bacteria on stink bugs externally - both under lab conditions. PMID:25145257

  2. Accumulation of pharmaceuticals in groundwater under arid climate conditions - Results from unsaturated column experiments.

    PubMed

    Zemann, M; Majewsky, M; Wolf, L

    2016-07-01

    Intense reuse of treated wastewater in agriculture is practiced all over the world, especially in arid and water-scarce regions. In doing so, pharmaceutical residues in the water are irrigated to the soil and subsequently can percolate into the local aquifers. Since evaporation rates in these areas are typically high, persistent substances might enrich in the groundwater recharge of closed catchments like the Jordan Valley. Against this background, unsaturated column tests were conducted to investigate the potential for evaporative accumulation of the two pharmaceuticals bezafibrate and carbamazepine under simulated arid climate conditions. Parallel tests were conducted with inhibited microbiological activity where both substances showed an increase in the effluent concentrations proportional to the evaporation loss of the inflow solution. The mean accumulation factors of the pharmaceuticals correspond to the evaporated water loss. The experiments indicate the accumulation potential for pharmaceuticals with high persistence against biodegradation. For the first time, the overall potential for evaporative enrichment could be demonstrated for pharmaceuticals. Under the given experimental conditions, the two investigated pharmaceuticals did not enrich faster than chloride, which might result in soil salting prior to reaching harmful pharmaceutical concentrations in soil water. The findings are relevant to future assessments of environmental impacts of persistent trace substances, which need to take into account that concentrations in the aquatic cycle might increase further due to evaporative enrichment. PMID:27085060

  3. Effect of Phospholipid on Pyrite Oxidation and Microbial Communities under Simulated Acid Mine Drainage (AMD) Conditions.

    PubMed

    Pierre Louis, Andro-Marc; Yu, Hui; Shumlas, Samantha L; Van Aken, Benoit; Schoonen, Martin A A; Strongin, Daniel R

    2015-07-01

    The effect of phospholipid on the biogeochemistry of pyrite oxidation, which leads to acid mine drainage (AMD) chemistry in the environment, was investigated. Metagenomic analyses were carried out to understand how the microbial community structure, which developed during the oxidation of pyrite-containing coal mining overburden/waste rock (OWR), was affected by the presence of adsorbed phospholipid. Using columns packed with OWR (with and without lipid adsorption), the release of sulfate (SO4(2-)) and soluble iron (FeTot) was investigated. Exposure of lipid-free OWR to flowing pH-neutral water resulted in an acidic effluent with a pH range of 2-4.5 over a 3-year period. The average concentration of FeTot and SO4(2-) in the effluent was ≥20 and ≥30 mg/L, respectively. In contrast, in packed-column experiments where OWR was first treated with phospholipid, the effluent pH remained at ∼6.5 and the average concentrations of FeTot and SO4(2-) were ≤2 and l.6 mg/L, respectively. 16S rDNA metagenomic pyrosequencing analysis of the microbial communities associated with OWR samples revealed the development of AMD-like communities dominated by acidophilic sulfide-oxidizing bacteria on untreated OWR samples, but not on refuse pretreated with phospholipid. PMID:26018867

  4. Carbonate precipitation under bulk acidic conditions as a potential biosignature for searching life on Mars

    NASA Astrophysics Data System (ADS)

    Fernández-Remolar, David C.; Preston, Louisa J.; Sánchez-Román, Mónica; Izawa, Matthew R. M.; Huang, L.; Southam, Gordon; Banerjee, Neil R.; Osinski, Gordon R.; Flemming, Roberta; Gómez-Ortíz, David; Prieto Ballesteros, Olga; Rodríguez, Nuria; Amils, Ricardo; Darby Dyar, M.

    2012-10-01

    Recent observations of carbonate minerals in ancient Martian rocks have been interpreted as evidence for the former presence of circumneutral solutions optimal for carbonate precipitation. Sampling from surface and subsurface regions of the low-pH system of Río Tinto has shown, unexpectedly, that carbonates can form under diverse macroscopic physicochemical conditions ranging from very low to neutral pH (1.5-7.0). A multi-technique approach demonstrates that carbonate minerals are closely associated with microbial activity. Carbonates occur in the form of micron-size carbonate precipitates under bacterial biofilms, mineralization of subsurface colonies, and possible biogenic microstructures including globules, platelets and dumbbell morphologies. We propose that carbonate precipitation in the low-pH environment of Río Tinto is a process enabled by microbially-mediated neutralization driven by the reduction of ferric iron coupled to the oxidation of biomolecules in microbially-maintained circumneutral oases, where the local pH (at the scale of cells or cell colonies) can be much different than in the macroscopic environment. Acidic conditions were likely predominant in vast regions of Mars over the last four billion years of planetary evolution. Ancient Martian microbial life inhabiting low-pH environments could have precipitated carbonates similar to those observed at Río Tinto. Preservation of carbonates at Río Tinto over geologically significant timescales suggests that similarly-formed carbonate minerals could also be preserved on Mars. Such carbonates could soon be observed by the Mars Science Laboratory, and by future missions to the red planet.

  5. Catalysis of Glyceraldehyde Synthesis by Primary or Secondary Amino Acids Under Prebiotic Conditions as a Function of pH

    NASA Astrophysics Data System (ADS)

    Breslow, Ronald; Ramalingam, Vijayakumar; Appayee, Chandrakumar

    2013-10-01

    The synthesis of an excess of D-glyceraldehyde by coupling glycolaldehyde with formaldehyde under prebiotic conditions is catalyzed by L amino acids having primary amino groups at acidic pH's, but at neutral or higher pH's they preferentially form L-glyceraldehyde. L Amino acids having secondary amino groups, such as proline, have the reverse preferences, affording excess L-glyceraldehyde at low pH but excess D-glyceraldehyde at higher pHs. Detailed mechanistic proposals make these preferences understandable. The relevance of these findings to the origin of D sugars on prebiotic Earth is described.

  6. Short Term Results After Local Application of Steroids and Anesthetics in Patients with Painful Spine Conditions

    PubMed Central

    Hadziahmetovic, Narcisa Vavra; Aganovic, Damir; Kadic, Aldijana; Biscevic, Mirza

    2014-01-01

    ABSTRACT Introduction: Spinal pain is the most common of all chronic pain disorders. Imaging studies can be used to determine whether a pathological process is associated with the patient’s symptoms. Objective: To determine the short-term efficiency of local instillation of steroids in patients with painful spine conditions. Materials and methods: A prospective study included 35 patients with diagnosis of lumbar or cervical radiculopathy, or cervical and lumbar syndrome at the Department for the Physical Medicine and Rehabilitation, Department for the Orthopedics and Traumatology, and Department for the Neurosurgery, Clinical Canter University of Sarajevo (KCUS). A clinical examination, visual pain scale (VAS) and Oswestry Disability Index (ODI) were performed prior to the needle procedure and seven days after it. Descriptive and comparative statistics were used for comparison of pre and post-interventional results. This procedure was done for the first time in our region. Results: The males and females were equally represented in this study (17:18). The patients were 29 to 80 years old. The highest number of patients have been between 40-60 years, older then that have been 44,2% of patients, and younger only 8,5%. Patients have complained about the radicular pain along the legs or arms or back or neck pain. Most of them had disc herniation–57,14%, 8,57% had bulging disc, 8,57% had spinal canal stenosis, 5,71% had fasetarthrosis, rest of them had combination of those conditions. There was a statistically significant difference between the value of ODI score before procedure and 7 days later (26±10:16±12; p<0,001). The difference was also statistically significant in VAS values (7±1:1±1; p <0,001). Discussion: Our study suggests that needle instillation of steroid and lidocaine is effective in short-term pain occurs in different painful spine conditions (Sy cervicale, lumbare and radiculopathy). It is valuable alternative to the classic methods of physical

  7. Results comparison and model validation for flood loss functions in Australian geographical conditions

    NASA Astrophysics Data System (ADS)

    Hasanzadeh Nafari, R.; Ngo, T.; Lehman, W.

    2015-06-01

    Rapid urbanisation, climate change and unsustainable developments are increasing the risk of floods, namely flood frequency and intensity. Flood is a frequent natural hazard that has significant financial consequences for Australia. The emergency response system in Australia is very successful and has saved many lives over the years. However, the preparedness for natural disaster impacts in terms of loss reduction and damage mitigation has been less successful. This study aims to quantify the direct physical damage to residential structures that are prone to flood phenomena in Australia. In this paper, the physical consequences of two floods from Queensland have been simulated, and the results have been compared with the performance of two selected methodologies and one newly derived model. Based on this analysis, the adaptability and applicability of the selected methodologies will be assessed in terms of Australian geographical conditions. Results obtained from the new empirically-based function and non-adapted methodologies indicate that it is apparent that the precision of flood damage models are strongly dependent on selected stage damage curves, and flood damage estimation without model validation results in inaccurate prediction of losses. Therefore, it is very important to be aware of the associated uncertainties in flood risk assessment, especially if models have not been adapted with real damage data.

  8. Preserving ground water samples with hydrochloric acid does not result in the formation of chloroform

    USGS Publications Warehouse

    Squillace, Paul J.; Pankow, James F.; Barbash, Jack E.; Price, Curtis V.; Zogorski, John S.

    1999-01-01

    Water samples collected for the determination of volatile organic compounds (VOCs) are often preserved with hydrochloric acid (HCl) to inhibit the biotransformation of the analytes of interest until the chemical analyses can he performed. However, it is theoretically possible that residual free chlorine in the HCl can react with dissolved organic carbon (DOC) to form chloroform via the haloform reaction. Analyses of 1501 ground water samples preserved with HCl from the U.S. Geological Survey's National Water-Quality Assessment Program indicate that chloroform was the most commonly detected VOC among 60 VOCs monitored. The DOC concentrations were not significantly larger in samples with detectable chloroform than in those with no delectable chloroform, nor was there any correlation between the concentrations of chloroform and DOC. Furthermore, chloroform was detected more frequently in shallow ground water in urban areas (28.5% of the wells sampled) than in agricultural areas (1.6% of the wells sampled), which indicates that its detection was more related to urban land-use activities than to sample acidification. These data provide strong evidence that acidification with HCl does not lead to the production of significant amounts of chloroform in ground water samples. To verify these results, an acidification study was designed to measure the concentrations of all trihalomethanes (THMs) that can form as a result of HCl preservation in ground water samples and to determine if ascorbic acid (C6H8O6) could inhibit this reaction if it did occur. This study showed that no THMs were formed as a result of HCl acidification, and that ascorbic acid had no discernible effect on the concentrations of THMs measured.

  9. Neutral molecular cluster formation of sulfuric acid-dimethylamine observed in real time under atmospheric conditions.

    PubMed

    Kürten, Andreas; Jokinen, Tuija; Simon, Mario; Sipilä, Mikko; Sarnela, Nina; Junninen, Heikki; Adamov, Alexey; Almeida, João; Amorim, Antonio; Bianchi, Federico; Breitenlechner, Martin; Dommen, Josef; Donahue, Neil M; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Hutterli, Manuel; Kangasluoma, Juha; Kirkby, Jasper; Laaksonen, Ari; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Mathot, Serge; Onnela, Antti; Petäjä, Tuukka; Praplan, Arnaud P; Riccobono, Francesco; Rissanen, Matti P; Rondo, Linda; Schobesberger, Siegfried; Seinfeld, John H; Steiner, Gerhard; Tomé, António; Tröstl, Jasmin; Winkler, Paul M; Williamson, Christina; Wimmer, Daniela; Ye, Penglin; Baltensperger, Urs; Carslaw, Kenneth S; Kulmala, Markku; Worsnop, Douglas R; Curtius, Joachim

    2014-10-21

    For atmospheric sulfuric acid (SA) concentrations the presence of dimethylamine (DMA) at mixing ratios of several parts per trillion by volume can explain observed boundary layer new particle formation rates. However, the concentration and molecular composition of the neutral (uncharged) clusters have not been reported so far due to the lack of suitable instrumentation. Here we report on experiments from the Cosmics Leaving Outdoor Droplets chamber at the European Organization for Nuclear Research revealing the formation of neutral particles containing up to 14 SA and 16 DMA molecules, corresponding to a mobility diameter of about 2 nm, under atmospherically relevant conditions. These measurements bridge the gap between the molecular and particle perspectives of nucleation, revealing the fundamental processes involved in particle formation and growth. The neutral clusters are found to form at or close to the kinetic limit where particle formation is limited only by the collision rate of SA molecules. Even though the neutral particles are stable against evaporation from the SA dimer onward, the formation rates of particles at 1.7-nm size, which contain about 10 SA molecules, are up to 4 orders of magnitude smaller compared with those of the dimer due to coagulation and wall loss of particles before they reach 1.7 nm in diameter. This demonstrates that neither the atmospheric particle formation rate nor its dependence on SA can simply be interpreted in terms of cluster evaporation or the molecular composition of a critical nucleus. PMID:25288761

  10. Validating a Stability Indicating HPLC Method for Kinetic Study of Cetirizine Degradation in Acidic and Oxidative Conditions

    PubMed Central

    Souri, Effat; Hatami, Ali; Shabani Ravari, Nazanin; Alvandifar, Farhad; Barazandeh Tehrani, Maliheh

    2013-01-01

    A stability indicating High-Performance Liquid Chromatography (HPLC) method was validated and used to study the degradation of cetirizine dihydrochloride in acidic and oxidative conditions. The separation was carried out on a Symmetry C18 column and a mixture of 50 mM KH2PO4 and acetonitrile (60:40 v/v, pH = 3.5) was used as the mobile phase. The method was linear over the range of 1-20 μg/mL of cetirizine dihydrochloride (r2 > 0.999) and the within-day and between-day precision values were less than 1.5%. The results showed that cetirizine dihydrochloride was unstable in 2 M HCl and 0.5% H2O2. The kinetics of the acidic degradation showed a pseudo-first-order reaction in the temperature range of 70-90°C. In addition, the kinetics of hydrogen peroxide mediated degradation was pseudo-first-order in the temperature range of 50-80°C. PMID:24250602

  11. Transport of perfluoroalkyl acids in a water-saturated sediment column investigated under near-natural conditions.

    PubMed

    Vierke, Lena; Möller, Axel; Klitzke, Sondra

    2014-03-01

    The aim of this study was to gain an understanding of the transport of C4-10 perfluoroalkyl carboxylic acids (PFCAs) and C4,6,8 perfluoroalkyl sulfonic acids (PFSAs) in a water-saturated sediment column representing a riverbank filtration scenario under near-natural conditions. Short-chain PFCAs and PFSAs with up to six C-atoms showed complete tracer-like breakthrough. Longer chain ones were retarded due to sorption to the sediment or due to other processes in the aqueous phase. The study reports the first column derived sediment-water partition coefficients ranging from 0.01 cm(3) g(-1) to 0.41 cm(3) g(-1) for C4,6 PFSAs and from 0.0 cm(3) g(-1) to 6.5 cm(3) g(-1) for C4,5,6,8,9 PFCAs. The results clearly indicate that short-chain PFCAs and PFSAs may pose a problem if contaminated surface waters are used for drinking water production via riverbank filtration. PMID:24333660

  12. Do acid volatile sulfides (AVS) influence the accumulation of sediment-bound metals to benthic invertebrates under natural field conditions?

    PubMed

    De Jonge, Maarten; Dreesen, Freja; De Paepe, Josefina; Blust, Ronny; Bervoets, Lieven

    2009-06-15

    The present study evaluates the influence of acid volatile sulfides (AVS) on accumulation of sediment-bound metals in benthic invertebrates under natural field conditions. Natural sediments, pore water, surface water, and two species of widespread benthic invertebrates (Chironomus gr. thummi and Tubifex tubifex) were collected from 17 historical polluted Flemish lowland rivers and measured for metal concentrations. Different sediment characteristics were determined (AVS, organic matter, clay content) and multiple regression was used to study their relationship with accumulated metals in the invertebrates. Physical and chemical analysis of the field samples indicated low metal concentrations in the water and pore water, but very high metal concentrations in the sediment and the invertebrates, especially for Pb (5.99 micromol/ g). In general, metal accumulation in chironomids and tubificid worms was most strongly correlated with total metal concentrations in the sediment and sediment metal concentrations normalized for organic matter and clay content. Following the results of the linear regression model, AVS did not turn out to be a significant variable in describing variation in metal accumulation. Our study clearly demonstrates that, in addition to the results gained from experiments under lab conditions, benthic invertebrates can accumulate metals from unspiked field sediments even when there's an excess of AVS. PMID:19603670

  13. Sport Engagement by Accelerometry under Field Conditions in German Adolescents: Results from GINIPlus

    PubMed Central

    Smith, Maia; Berdel, Dietrich; Nowak, Dennis; Heinrich, Joachim; Schulz, Holger

    2015-01-01

    Introduction Sporting activities differ in their ability to promote moderate-to-vigorous physical activity (MVPA). To assess adolescents’ engagement in sport under field conditions we used accelerometers to measure their MVPA levels during sport. We pay special attention to differences between team and individual sport and between common sports. Methods Diary data and 7-day accelerometry from 1054 Germans ages 15–17 were combined to measure physical activity. 1373 diaried episodes of more than 40 common sports were identified from 626 participants and grouped into team and individual sport. We modeled the effect of team and individual sport, and described levels of MVPA and episodes of no MVPA for all recorded sports. Results German boys and girls averaged 43 (SD 21) and 37 (SD 24) minutes MVPA per day. Boys got 2.2 times as much MVPA per minute during team compared to individual sport (p<0.0001) but there was no significant difference for girls. Percent of time spent in MVPA during sport ranged from 6% for weight training to 74% for jogging, with individual sports averaging 10–30% and team sports 30–50%. 11% of sport episodes had no MVPA: half of episodes of cycling, 5% of jogging, and none for tennis or badminton. An episode of individual sport was 17 times more likely to have no MVPA than an episode of team sport (p<0.0001). Conclusion Under field condition, adolescents were active for only a fraction of diaried sporting time. As measured by accelerometry, individual sport often produced no MVPA. Characteristics of the sport, such as team vs. individual, were more predictive of MVPA than were characteristics of the participant, such as background activity levels. PMID:26291984

  14. Hybridization within Saccharomyces Genus Results in Homoeostasis and Phenotypic Novelty in Winemaking Conditions

    PubMed Central

    Dillmann, Christine; Bely, Marina; la Guerche, Stéphane; Giraud, Christophe; Huet, Sylvie; Sicard, Delphine; Masneuf-Pomarede, Isabelle; de Vienne, Dominique; Marullo, Philippe

    2015-01-01

    Despite its biotechnological interest, hybridization, which can result in hybrid vigor, has not commonly been studied or exploited in the yeast genus. From a diallel design including 55 intra- and interspecific hybrids between Saccharomyces cerevisiae and S. uvarum grown at two temperatures in enological conditions, we analyzed as many as 35 fermentation traits with original statistical and modeling tools. We first showed that, depending on the types of trait – kinetics parameters, life-history traits, enological parameters and aromas –, the sources of variation (strain, temperature and strain * temperature effects) differed in a large extent. Then we compared globally three groups of hybrids and their parents at two growth temperatures: intraspecific hybrids S. cerevisiae * S. cerevisiae, intraspecific hybrids S. uvarum * S. uvarum and interspecific hybrids S. cerevisiae * S. uvarum. We found that hybridization could generate multi-trait phenotypes with improved oenological performances and better homeostasis with respect to temperature. These results could explain why interspecific hybridization is so common in natural and domesticated yeast, and open the way to applications for wine-making. PMID:25946464

  15. Hybridization within Saccharomyces Genus Results in Homoeostasis and Phenotypic Novelty in Winemaking Conditions.

    PubMed

    da Silva, Telma; Albertin, Warren; Dillmann, Christine; Bely, Marina; la Guerche, Stéphane; Giraud, Christophe; Huet, Sylvie; Sicard, Delphine; Masneuf-Pomarede, Isabelle; de Vienne, Dominique; Marullo, Philippe

    2015-01-01

    Despite its biotechnological interest, hybridization, which can result in hybrid vigor, has not commonly been studied or exploited in the yeast genus. From a diallel design including 55 intra- and interspecific hybrids between Saccharomyces cerevisiae and S. uvarum grown at two temperatures in enological conditions, we analyzed as many as 35 fermentation traits with original statistical and modeling tools. We first showed that, depending on the types of trait--kinetics parameters, life-history traits, enological parameters and aromas -, the sources of variation (strain, temperature and strain * temperature effects) differed in a large extent. Then we compared globally three groups of hybrids and their parents at two growth temperatures: intraspecific hybrids S. cerevisiae * S. cerevisiae, intraspecific hybrids S. uvarum * S. uvarum and interspecific hybrids S. cerevisiae * S. uvarum. We found that hybridization could generate multi-trait phenotypes with improved oenological performances and better homeostasis with respect to temperature. These results could explain why interspecific hybridization is so common in natural and domesticated yeast, and open the way to applications for wine-making. PMID:25946464

  16. Deuterium Enrichment of Amino and Hydroxy Acids Found in the Murchison Meteorite: Constraints on Parent Body Conditions

    NASA Technical Reports Server (NTRS)

    Lerner, Narcinda R.; Chang, Sherwood (Technical Monitor)

    1997-01-01

    The alpha-amino and alpha-hydroxy acids found in the Murchison carbonaceous chondrite are deuterium enriched. These compounds are thought to have originated from common deuterium enriched carbonyl precursors, by way of a Strecker synthesis which took place in a solution of HCN, NH3, and carbonyl compounds during the period of aqueous alteration of the meteorite parent body. However, the hydroxy acids found on Murchison are less deuterium enriched than the amino acids. With the objective of determining if the discrepancy in deuterium enrichment between the amino acids and the hydroxy acids found on Murchison is consistent with their formation in a Strecker synthesis, we have measured the deuterium content of alpha-amino and alpha-hydroxy acids produced in solutions of deuterated carbonyl compounds, KCN and NH4Cl, and also in mixtures of such solutions and Allende dust at 263 K and 295 K. Retention of the isotopic signature of the starting carbonyl by both alpha amino acids and alpha hydroxy acids is more dependent upon temperature, concentration and pH than upon the presence of meteorite dust in the solution. The constraints these observations place on Murchison parent body conditions will be discussed.

  17. Adding an appropriate amino acid during crosslinking results in more stable crosslinked enzyme aggregates.

    PubMed

    Mukherjee, Joyeeta; Majumder, Abir Baran; Gupta, Munishwar Nath

    2016-08-15

    Carrier free immobilization, especially crosslinked enzyme aggregates (CLEAs), has become an important design for biocatalysis in several areas. Adding amino acids during formation of CLEAs was found to give biocatalysts more stable at 55 °C and in the presence of 60% acetonitrile. The half-lives of CLEAs prepared with and without Arg addition were 21 and 15 h (subtilisin) and 4 and 1.6 h (α-chymotrypsin) at 55 °C, respectively. The corresponding half-lives during acetonitrile presence were 4.1 and 3.0 h (subtilisin) and 39 and 22 min (α-chymotrypsin), respectively. CLEAs made with Arg had higher percentages of alpha helix. CLEAs made by adding Lys, Ala, or Asp also were more stable. In the case of Thermomyces lanuginosus lipase (TLL), CLEA with Ala was even more stable than CLEA with Arg. The addition of a suitable amino acid, thus, enhances CLEA stabilities. The results are discussed in the light of earlier results on chemical modification of proteins and the observation that the Arg/Lys ratio is invariably high in the case of enzymes from thermophiles. PMID:27237371

  18. Impaired oxidoreduction by 11β-hydroxysteroid dehydrogenase 1 results in the accumulation of 7-oxolithocholic acid[S

    PubMed Central

    Penno, Carlos A.; Morgan, Stuart A.; Vuorinen, Anna; Schuster, Daniela; Lavery, Gareth G.; Odermatt, Alex

    2013-01-01

    11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) mediates glucocorticoid activation and is currently considered as therapeutic target to treat metabolic diseases; however, biomarkers to assess its activity in vivo are still lacking. Recent in vitro experiments suggested that human 11β-HSD1 metabolizes the secondary bile acid 7-oxolithocholic acid (7-oxoLCA) to chenodeoxycholic acid (CDCA) and minor amounts of ursodeoxycholic acid (UDCA). Here, we provide evidence from in vitro and in vivo studies for a major role of 11β-HSD1 in the oxidoreduction of 7-oxoLCA and compare its level and metabolism in several species. Hepatic microsomes from liver-specific 11β-HSD1-deficient mice were devoid of 7-oxoLCA oxidoreductase activity. Importantly, circulating and intrahepatic levels of 7-oxoLCA and its taurine conjugate were significantly elevated in mouse models of 11β-HSD1 deficiency. Moreover, comparative enzymology of 11β-HSD1-dependent oxidoreduction of 7-oxoLCA revealed that the guinea-pig enzyme is devoid of 7-oxoLCA oxidoreductase activity. Unlike in other species, 7-oxoLCA and its glycine conjugate are major bile acids in guinea-pigs. In conclusion, the oxidoreduction of 7-oxoLCA and its conjugated metabolites are catalyzed by 11β-HSD1, and the lack of this activity leads to the accumulation of these bile acids in guinea-pigs and 11β-HSD1-deficient mice. Thus, 7-oxoLCA and its conjugates may serve as biomarkers of impaired 11β-HSD1 activity. PMID:23933573

  19. Control of enzymatic browning in apple slices by using ascorbic acid under different conditions.

    PubMed

    el-Shimi, N M

    1993-01-01

    Control of phenol oxidase activity in apple slices by the use of ascorbic acid at different pH values, temperature and time of incubation was investigated. The enzyme was almost inactivated at 1% and 1.5% ascorbic acid. Ascorbic acid solution (1%) caused a remarkable inhibition with the increasing acidity up to pH = 1. Heating treatments for apple slices dipped in 1% ascorbic acid caused a reduction of enzymatic browning, optimum temperature for inactivation of the enzyme was between 60-70 degrees C for 15 minutes. Increasing the time of dipping apple slices in 1% ascorbic acid solutions and at different pH values reduce phenolase activity. PMID:8464847

  20. Arizona Teacher Working Conditions: Designing Schools for Educator and Student Success. Results of the 2006 Phase-In Teacher Working Conditions Survey

    ERIC Educational Resources Information Center

    Hirsch, Eric; Emerick, Scott

    2006-01-01

    Many schools across the country face persistent teacher working condition challenges that are closely related to high teacher turnover rates and chronic difficulties in recruiting and retaining teachers. Center for Teaching Quality (CTQ) research examining working conditions survey results in both North Carolina and South Carolina demonstrates…

  1. Effects of acetic acid injection and operating conditions on NO emission in a vortexing fluidized bed combustor using response surface methodology

    SciTech Connect

    Fuping Qian; Chiensong Chyang; Weishen Yen

    2009-07-15

    The effects of acetic acid injection and operating conditions on NO emission were investigated in a pilot scale vortexing fluidized bed combustor (VFBC), an integration of circular freeboard and a rectangular combustion chamber. Operating conditions, such as the stoichiometric oxygen in the combustion chamber, the bed temperature and the injecting location of acetic acid, were determined by means of response surface methodology (RSM), which enables the examination of parameters with a moderate number of experiments. In RSM, NO emission concentration after acetic acid injection and NO removal percentage at the exit of the VFBC are used as the objective function. The results show that the bed temperature has a more important effect on the NO emission than the injecting location of acetic acid and the stoichiometric oxygen in the combustion chamber. Meanwhile, the injecting location of acetic acid and the stoichiometric oxygen in the combustion chamber have a more important effect on the NO removal percentage than the bed temperature. NO emission can be decreased by injecting the acetic acid into the combustion chamber, and NO emission decreases with the height of the acetic acid injecting location above the distributor. On the other hand, NO removal percentage increases with the height of the acetic acid injecting location, and NO emission increases with the stoichiometric oxygen in the combustion chamber and the bed temperature. NO removal percentage increases with the stoichiometric oxygen, and increases first, then decreases with the bed temperature. Also, a higher NO removal percentage could be obtained at 850{sup o}C. 26 refs., 12 figs., 8 tabs.

  2. Bile Acid Malabsorption After Pelvic and Prostate Intensity Modulated Radiation Therapy: An Uncommon but Treatable Condition

    SciTech Connect

    Harris, Victoria; Benton, Barbara; Sohaib, Aslam; Dearnaley, David; Andreyev, H. Jervoise N.

    2012-12-01

    Purpose: Intensity modulated radiation therapy (IMRT) is a significant therapeutic advance in prostate cancer, allowing increased tumor dose delivery and increased sparing of normal tissues. IMRT planning uses strict dose constraints to nearby organs to limit toxicity. Bile acid malabsorption (BAM) is a treatable disorder of the terminal ileum (TI) that presents with symptoms similar to radiation therapy toxicity. It has not been described in patients receiving RT for prostate cancer in the contemporary era. We describe new-onset BAM in men after IMRT for prostate cancer. Methods and Materials: Diagnosis of new-onset BAM was established after typical symptoms developed, selenium-75 homocholic acid taurine (SeHCAT) scanning showed 7-day retention of <15%, and patients' symptoms unequivocally responded to a bile acid sequestrant. The TI was identified on the original radiation therapy plan, and the radiation dose delivered was calculated and compared with accepted dose-volume constraints. Results: Five of 423 men treated in a prospective series of high-dose prostate and pelvic IMRT were identified with new onset BAM (median age, 65 years old). All reported having normal bowel habits before RT. The volume of TI ranged from 26-141 cc. The radiation dose received by the TI varied between 11.4 Gy and 62.1 Gy (uncorrected). Three of 5 patients had TI treated in excess of 45 Gy (equivalent dose calculated in 2-Gy fractions, using an {alpha}/{beta} ratio of 3) with volumes ranging from 1.6 cc-49.0 cc. One patient had mild BAM (SeHCAT retention, 10%-15%), 2 had moderate BAM (SeHCAT retention, 5%-10%), and 2 had severe BAM (SeHCAT retention, <5%). The 3 patients whose TI received {>=}45 Gy developed moderate to severe BAM, whereas those whose TI received <45 Gy had only mild to moderate BAM. Conclusions: Radiation delivered to the TI during IMRT may cause BAM. Identification of the TI from unenhanced RT planning computed tomography scans is difficult and may impede accurate

  3. The role of carboxylic acids in albite and quartz dissolution: An experimental study under diagenetic conditions

    NASA Astrophysics Data System (ADS)

    Franklin, Stan P.; Hajash, Andrew, Jr.; Dewers, Thomas A.; Tieh, Thomas T.

    1994-10-01

    Simple water soluble organic acids may promote secondary porosity development in sandstones during diagenesis by increasing feldspar solubility and dissolution rate. To test this hypothesis, Amelia albite and Brazilian hydrothermal quartz were reacted with 0.07 m acetate and 0.07 m acetate-0.005 m oxalate solutions at selected pH values, and distilled water. Pore fluid chemistry was monitored through time at various flow rates to obtain both solubility and dissolution rate data. The experiments were conducted in large volume, semi-static, flow-through systems at 100°C and 347 bars. These systems simulate subsurface flow rates, low mass water/rock, and high surface area/fluid mass. Acetate and acetate + oxalate solutions significantly increase albite solubility at temperatures, pressures, and pH values typical of diagenetic environments. Albite solubilities increased in acetate and acetate + oxalate solutions by factors of 2 and 3.4, respectively, compared to distilled water. In these same solutions, Al concentrations were ≈ 140 and ≈480 times higher than that calculated for kaolinite solubility at the same conditions without organic species. These enhanced solubilities occur at pH values (4.6-4.8) that may overlap with formation waters. In contrast to albite, quartz solubility was essentially identical in all solutions investigated. Dissolution rates in the acid region decreased with increasing pH in the acetate and acetate + oxalate solutions. Slopes of log rate vs. pH curves were ≈0.6 for acetate and ≈0.3 for acetate + oxalate. Although the effects of acetate on the dissolution rate are small, the effects of oxalate are significant. A rate law valid for albite dissolution at 100°C, oxalate concentrations to 0.01 m, and pH values ranging from 3.4 to 5.5 is given below (assuming activity coefficients = 1 and acetate rate ≈ the proton-promoted rate): Rtotal = 5.88 × 10 -11+ 5.01 × 10 -8m 0.56H+ + 6.7 ×10 -102.3 × 10 -4m O x/(1.0+2.3 × 10 -4 m O x

  4. Effect of formic acid formulations on honey bee (Hymenoptera: Apidae) colonies and influence of colony and ambient conditions on formic acid concentration in the hive.

    PubMed

    Ostermann, David J; Currie, Robert W

    2004-10-01

    The interaction between the effects of varroa, Varroa destructor Anderson & Trueman, and formic acid treatments on colonies of honey bees, Apis mellifera L., were examined in two field experiments. In experiment 1, colonies with low varroa levels were exposed to two different slow-release formulations and compared with untreated colonies. In experiment 2, colonies inoculated with varroa and uninoculated colonies were exposed to a slow-release formulation, a pour-on formulation, or were left untreated. The effects of treatments, hive temperature, and hive relative humidity on formic acid concentration in hive air also were examined. Slow-release formic acid application improved colony development in colonies that had been inoculated with varroa. However, in uninoculated colonies where the mean abundance of varroa was low, slow-release formic acid application suppressed colony development. The pour-on application did not have a negative impact on worker population growth in uninoculated colonies, but also it was not as effective as the slow-release treatment in improving population growth in varroa-inoculated colonies. Equivalent volumes of acid applied in pour-on and slow-release formulations provided the same cumulative dose in hive air but differed in the daily pattern of formic acid release. Colonies that were not inoculated with varroa had higher concentrations of formic acid in hive air than colonies that were inoculated with varroa on three of the five pour-on application dates. The data suggest that reductions in worker population and/or activity caused by varroa can interact with ambient conditions to affect the volatilization or sorption of formic acid in the hive. PMID:15568335

  5. Carotenoid and fatty acid compositions of an indigenous Ettlia texensis isolate (Chlorophyceae) under phototrophic and mixotrophic conditions.

    PubMed

    Yıldırım, Arzu; Demirel, Zeliha; İşleten-Hoşoğlu, Müge; Akgün, İsmail Hakkı; Hatipoğlu-Uslu, Sevde; Conk-Dalay, Meltem

    2014-02-01

    Ettlia oleoabundance (formerly known as Neochloris oleoabundance) is an attractive candidate for biodiesel production because of its high lipid accumulation, and it's taking the majority of the attention among the strains of Ettlia genus; however, potential of the other genus members is unknown. An indigenous strain from Salda Lake (South West Turkey) identified by 18S rDNA sequencing as Ettlia texensis (GenBank accession no: JQ038221), and its fatty acid and carotenoid compositions under phototrophic and mixotrophic conditions was investigated to evaluate the potential of the strain for commercial uses. A threefold increase was observed in total lipid content (total fatty acids; from 13% to 37%) in mixotrophic culture respect to the phototrophic growth conditions. The oleic acid (C18:1) and alpha-linolenic acid (18:3) were the major unsaturated fatty acids accounting for 40% and 13.2% of total fatty acids in mixotrophic culture, respectively. Carotenoid analyses of the mixotrophic culture revealed the metabolite canthaxanthin, a commercially valuable carotenoid used mainly for food coloring, was the major constituent among other pigments. The possible use of E. texensis in biotechnological applications is discussed. PMID:24166102

  6. Experimental results and modeling tests of an adsorptive air-conditioning unit

    SciTech Connect

    Guilleminot, J.J.; Poyelle, F.; Meunier, F.

    1998-10-01

    Experimental tests have been performed on a zeolite-water adsorptive system suitable for air conditioning and consisting of two adsorbers filled with a consolidated composite made of zeolite mixed with a highly conductive matrix. This paper describes the experimental results of such a heat pump unit operating with a heat and mass recovery cycle. An important enhancement of the specific cooling power (SCP) has been achieved. At evaporating temperature T = 4 C, mass transfer resistance controls the process and limits the expected COP. Tests carried out at higher evaporating pressure make it possible to achieve the predicted COP and SCP. A predictive model developed and validated elsewhere in order to describe the temperature evolution of components and the heat and mass transfer in the adsorbers explains the mass transfer resistance in the adsorbent. Last, a new highly conductive adsorbent composite with good mass transfer properties is developed. The model is used to predict the performances of this new material. Very good SCP and COP can be achieved.

  7. Subtypes of Nonmedical Opioid Users: Results from the National Epidemiologic Survey on Alcohol and Related Conditions

    PubMed Central

    Wu, Li-Tzy; Woody, George E.; Yang, Chongming; Blazer, Dan G.

    2010-01-01

    Aims To identify subtypes of nonmedical opioid users, gender variations in psychiatric disorders, and quality of life in a representative sample of adults. Methods Analyses of data from the 2001–2002 National Epidemiologic Survey on Alcohol and Related Conditions (N=43,093). Latent class analysis (LCA) and multinomial logistic regression procedures examined subtypes of nonmedical opioid users. Results Approximately 5% (n=1,815) of adults used nonmedical opioids. LCA identified four subtypes: opioid–marijuana users (33%), opioid–other prescription drug users (9%), opioid–marijuana–hallucinogen users (28%), and opioid–polydrug users (30%). Subtypes were distinguished by race/ethnicity, gender, familial substance abuse, personal history of substance abuse treatment, and patterns of psychiatric disorders. Whites and men had increased odds of being in the opioid–polydrug and opioid–marijuana–hallucinogen subtypes. The opioid–other prescription drug use subtype had disproportionately affected women who were characterized by high rates of mood/anxiety disorders and low quality of life. Across all subtypes, women and men had similarly problematic substance use disorders; however, women had more major depression and disability in the mental health domain. Conclusions The generally high prevalence of psychiatric disorders among nonmedical opioid users, particularly women, underscores the need for comprehensive assessment and coordinated delivery of services to match needs with treatment, as well as continued monitoring of trends in opioid use and related problems. PMID:20580168

  8. Glutamate Decarboxylase-Dependent Acid Resistance in Brucella spp.: Distribution and Contribution to Fitness under Extremely Acidic Conditions

    PubMed Central

    Damiano, Maria Alessandra; Bastianelli, Daniela; Al Dahouk, Sascha; Köhler, Stephan; Cloeckaert, Axel

    2014-01-01

    Brucella is an expanding genus of major zoonotic pathogens, including at least 10 genetically very close species occupying a wide range of niches from soil to wildlife, livestock, and humans. Recently, we have shown that in the new species Brucella microti, the glutamate decarboxylase (Gad)-dependent system (GAD system) contributes to survival at a pH of 2.5 and also to infection in mice by the oral route. In order to study the functionality of the GAD system in the genus Brucella, 47 isolates, representative of all known species and strains of this genus, and 16 strains of the closest neighbor genus, Ochrobactrum, were studied using microbiological, biochemical, and genetic approaches. In agreement with the genome sequences, the GAD system of classical species was not functional, unlike that of most strains of Brucella ceti, Brucella pinnipedialis, and newly described species (B. microti, Brucella inopinata BO1, B. inopinata-like BO2, and Brucella sp. isolated from bullfrogs). In the presence of glutamate, these species were more acid resistant in vitro than classical terrestrial brucellae. Expression in trans of the gad locus from representative Brucella species in the Escherichia coli MG1655 mutant strain lacking the GAD system restored the acid-resistant phenotype. The highly conserved GAD system of the newly described or atypical Brucella species may play an important role in their adaptation to acidic external and host environments. Furthermore, the GAD phenotype was shown to be a useful diagnostic tool to distinguish these latter Brucella strains from Ochrobactrum and from classical terrestrial pathogenic Brucella species, which are GAD negative. PMID:25381237

  9. Acid rain and weathering damage to carbonate building stone: Results of material loss measurements

    SciTech Connect

    Reddy, M.; Youngdahl, C.A.

    1987-01-01

    Marble and limestone specimens were exposed to atmospheric conditions at four eastern U.S. sites. A number of methods were employed for damage assessment; this paper describes the results of chemical and physical measurements of material loss. Good agreement was observed among results obtained with different methods. A rate of surface recession near 15 ..mu..m/y was observed for skyward surfaces of marble tested in North Carolina, and comparable results were obtained at the other test sites. Response of the porous limestone was assessed with greater difficulty; a rate of loss similar to that of marble was inferred. Initial correlations of material loss with environmental factors are briefly discussed.

  10. Acid rain and weathering damage to carbonate building stone: Results of material loss measurements

    SciTech Connect

    Reddy, M.M.; Youngdahl, C.A.

    1986-11-01

    Marble and limestone specimens were exposed to atmospheric conditions at four eastern US sites. A number of methods were employed for damage assessment; this paper describes the results of chemical and physical measurements of material loss. Good agreement was observed among results obtained with different methods. A rate of surface recession near 15 ..mu..m/y was observed for skyward surfaces of marble tested in North Carolina, and comparable results were obtained at the other test sites. Response of the porous limestone was assessed with greater difficulty; a rate of loss similar to that of marble was inferred. Initial correlations of material loss with environmental factors are briefly discussed.

  11. Effect of cyanuric acid on the inactivation of Cryptosporidium parvum under hyperchlorination conditions.

    PubMed

    Murphy, Jennifer L; Arrowood, Michael J; Lu, Xin; Hlavsa, Michele C; Beach, Michael J; Hill, Vincent R

    2015-06-16

    Cyanuric acid (CYA) is a chlorine stabilizer used in swimming pools to limit UV degradation of chlorine, thus reducing chlorine use and cost. However, CYA has been shown to decrease the efficacy of chlorine disinfection. In the event of a diarrheal incident, CDC recommends implementing 3-log10 inactivation conditions for Cryptosporidium (CT value = 15 300 mg·min/L) to remediate pools. Currently, CYA's impact on Cryptosporidium inactivation is not fully determined. We investigated the impact of multiple concentrations of CYA on C. parvum inactivation (at 20 and 40 mg/L free chlorine; average pH 7.6; 25 °C). At 20 mg/L free chlorine, average estimated 3-log10 CT values were 17 800 and 31 500 mg·min/L with 8 and 16 mg/L CYA, respectively, and the average estimated 1-log10 CT value was 76 500 mg·min/L with 48 mg/L CYA. At 40 mg/L free chlorine, 3-log10 CT values were lower than those at 20 mg/L, but still higher than those of free chlorine-only controls. In the presence of ∼100 mg/L CYA, average 0.8- and 1.4-log10 reductions were achieved by 72 h at 20 and 40 mg/L free chlorine, respectively. This study demonstrates CYA significantly delays chlorine inactivation of Cryptosporidium oocysts, emphasizing the need for additional pool remediation options following fecal incidents. PMID:26042636

  12. The histone deacetylase (HDAC) inhibitor valproic acid reduces ethanol consumption and ethanol-conditioned place preference in rats.

    PubMed

    Al Ameri, Mouza; Al Mansouri, Shamma; Al Maamari, Alyazia; Bahi, Amine

    2014-10-01

    Recent evidence suggests that epigenetic mechanisms such as chromatin modification (specifically histone acetylation) may play a crucial role in the development of addictive behavior. However, little is known about the role of epigenetic modifications in the rewarding properties of ethanol. In the current study, we studied the effects of systemic injection of the histone deacetylase (HDAC) inhibitor, valproic acid (VPA) on ethanol consumption and ethanol-elicited conditioned place preference (CPP). The effect of VPA (300 mg/kg) on voluntary ethanol intake and preference was assessed using continuous two-bottle choice procedure with escalating concentrations of alcohol (2.5-20% v/v escalating over 4 weeks). Taste sensitivity was studies using saccharin (sweet; 0.03% and 0.06%) and quinine (bitter; 20 µM and 40 µM) tastants solutions. Ethanol conditioned reward was investigated using an unbiased CPP model. Blood ethanol concentration (BEC) was also measured. Compared to vehicle, VPA-injected rats displayed significantly lower preference and consumption of ethanol in a two-bottle choice paradigm, with no significant difference observed with saccharin and quinine. More importantly, 0.5 g/kg ethanol-induced-CPP acquisition was blocked following VPA administration. Finally, vehicle- and VPA-treated mice had similar BECs. Taken together, our results implicated HDAC inhibition in the behavioral and reinforcement-related effects of alcohol and raise the question of whether specific drugs that target HDAC could potentially help to tackle alcoholism in humans. PMID:25108044

  13. Shelf life extension and antioxidant activity of 'Hayward' kiwi fruit as a result of prestorage conditioning and 1-methylcyclopropene treatment.

    PubMed

    Park, Yong Seo; Im, Myeng He; Gorinstein, Shela

    2015-05-01

    Kiwi fruits (Actinidia deliciosa C.F. Liang et A.R. Ferguson) were treated by prestorage conditioning (20 °C for 2 days), 1-methylcyclopropene (1-MCP, 1 ppm for 16 h) and conditioning plus 1-MCP. After the treatment the fruits were immediately stored at 0 °C during 24 weeks. Flesh firmness gradually decreased with storage time and the rate of its loss was lower in 1-MCP and conditioning plus 1-MCP treatments than those of control or conditioning. However, SSC, acidity and pH did not change among treatments. Starch content decreased during the storage time regardless of treatments. Oppositely the amount of reducing sugars increased at the same duration of the treatments. Rate and incidence of fruit decay was the lowest in fruit treated with conditioning plus 1-MCP treatment. Fruit decay mainly caused pathogen Botrytis cinerea and its rate significantly decreased with conditioning plus 1-MCP treatment. Ethylene and respiration abruptly increased after 8 weeks of storage, but their contents were lower in 1-MCP and conditioning plus 1-MCP. Total soluble phenolics, flavonoids, and total antioxidant capacities were much higher than in other treatments. Kiwi fruits treated with conditioning plus 1-MCP extended the shelf life by reducing the rate of fruit decay and softening during the storage. The bioactive compounds and total antioxidant status of fruits increased during the treatment. PMID:25892768

  14. General roles of abscisic and jasmonic acids in gene activation as a result of mechanical wounding.

    PubMed Central

    Hildmann, T; Ebneth, M; Peña-Cortés, H; Sánchez-Serrano, J J; Willmitzer, L; Prat, S

    1992-01-01

    Exogenous application of abscisic acid (ABA) has been shown to induce a systemic pattern of proteinase inhibitor II (pin2) mRNA accumulation identical to that induced by mechanical wounding. Evidence is presented that the ABA-specific response is not restricted to pin2 genes but appears to be part of a general reaction to wound stress. Four other wound-induced, ABA-responsive genes that encode two additional proteinase inhibitors, the proteolytic enzyme leucine aminopeptidase, and the biosynthetic enzyme threonine deaminase were isolated from potato plants. Wounding or treatment with ABA resulted in a pattern of accumulation of these mRNAs very similar to that of pin2. ABA-deficient plants did not accumulate any of the mRNAs upon wounding, although they showed normal levels of expression upon ABA treatment. Also, application of methyl jasmonate (MeJA) induced a strong accumulation of these transcripts, both in wild-type and in ABA-deficient plants, thus supporting a role for jasmonic acid as an intermediate in the signaling pathway that leads from ABA accumulation in response to wounding to the transcriptional activation of the genes. PMID:1392612

  15. Merging Photoredox with Palladium Catalysis: Decarboxylative ortho-Acylation of Acetanilides with α-Oxocarboxylic Acids under Mild Reaction Conditions.

    PubMed

    Zhou, Chao; Li, Pinhua; Zhu, Xianjin; Wang, Lei

    2015-12-18

    A room temperature decarboxylative ortho-acylation of acetanilides with α-oxocarboxylic acids has been developed via a novel Eosin Y with Pd dual catalytic system. This dual catalytic reaction shows a broad substrate scope and good functional group tolerance, and an array of ortho-acylacetanilides can be afforded in high yields under mild conditions. PMID:26646667

  16. Visible-light initiated oxidative cyclization of phenyl propiolates with sulfinic acids to coumarin derivatives under metal-free conditions.

    PubMed

    Yang, Wenchao; Yang, Shuai; Li, Pinhua; Wang, Lei

    2015-05-01

    A visible-light initiated oxidative cyclization of phenyl propiolates with sulfinic acids has been developed. The arylsulfonylation of alkynes was performed at room temperature under metal-free conditions to generate coumarin derivatives with wide functional group tolerance, good yields and high regioselectivity. PMID:25838160

  17. A Novel Phytase Derived from an Acidic Peat-Soil Microbiome Showing High Stability under Acidic Plus Pepsin Conditions.

    PubMed

    Tan, Hao; Wu, Xiang; Xie, Liyuan; Huang, Zhongqian; Peng, Weihong; Gan, Bingcheng

    2016-01-01

    Four novel phytases of the histidine acid phosphatase family were identified in two publicly available metagenomic datasets of an acidic peat-soil microbiome in northeastern Bavaria, Germany. These enzymes have low similarity to all the reported phytases. They were overexpressed in Escherichia coli and purified. Catalytic efficacy in simulated gastric fluid was measured and compared among the four candidates. The phytase named rPhyPt4 was selected for its high activity. It is the first phytase identified from unculturable Acidobacteria. The phytase showed a longer half-life than all the gastric-stable phytases that have been reported to date, suggesting a strong resistance to low pH and pepsin. A wide pH profile was observed between pH 1.5 and 5.0. At the optimum pH (2.5) the activity was 2,790 μmol/min/mg at the physiological temperature of 37°C and 3,989 μmol/min/mg at the optimum temperature of 60°C. Due to the competent activity level as well as the high gastric stability, the phytase could be a potential candidate for practical use in livestock and poultry feeding. PMID:27336313

  18. EFFECT OF ACIDIC CONDITIONS ON CADMIUM UPTAKE BY THREE AQUATIC PLANTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acidic runoff from mining and storage of mined materials creates an undesirable environmental impact on both flora and fauna. Presence of heavy metals such as Cadmium (CD) creates an additional negative factor in acidic environments. Accumulation of Cd in plant tissues of aquatic vascular plants i...

  19. Complementary and Alternative Medicine Use by U.S. Adults with Gastrointestinal Conditions: Results from the 2012 National Health Interview Survey

    PubMed Central

    Dossett, Michelle L.; Davis, Roger B.; Lembo, Anthony J.; Yeh, Gloria Y.

    2015-01-01

    Objectives Use of complementary and alternative medicine (CAM) has increased over the past two decades, and a growing body of evidence suggests that some CAM modalities may be useful in addressing gastrointestinal (GI) conditions. However, the overall patterns of CAM use for GI conditions remains unknown. We sought to elucidate the prevalence and patterns of CAM use among U.S. adults with GI conditions. Methods We used the 2012 National Health Interview Survey (n=34,525), a nationally representative survey of the civilian, non-institutionalized U.S. population, to estimate the prevalence of CAM use among adults with GI conditions (abdominal pain, acid reflux/heartburn, digestive allergy, liver condition, nausea and/or vomiting, stomach or intestinal illness, ulcer). We also examined the reasons for CAM use, perceived helpfulness, and disclosure of use to health care providers among individuals who specifically used CAM to address a GI condition. Prevalence estimates were weighted to reflect the complex sampling design of the survey. Results Of 13,505 respondents with a GI condition in the past year, 42% (n=5629) used CAM in the past year and 3% (n=407) used at least one CAM modality to address a GI condition. The top 3 modalities among those using CAM to address GI conditions were herbs and supplements, mind body therapies, and manipulative therapies. Of those using CAM to address a GI condition, 47% used 3 or more CAM therapies, and over 80% felt that it was helpful in addressing a GI condition and was important in maintaining health and well-being. Respondents told their health care provider about use of these therapies 70% of the time. Conclusions CAM was used by 42% of respondents with a GI condition in the past year. A small proportion use CAM specifically to address their GI condition, but the majority who do find it helpful. The most commonly used modalities in this group are herbs and supplements, mind body, and manipulative therapies. PMID:25001257

  20. Assessment of thermal load on transported goats administered with ascorbic acid during the hot-dry conditions

    NASA Astrophysics Data System (ADS)

    Minka, N. S.; Ayo, J. O.

    2012-03-01

    The major factor in the induction of physiological stress during road transportation of livestock is the complex fluctuations of the thermal transport microenvironment, encountered when animals are transported across different ecological zones. Recommended guidelines on optimum "on-board" conditions in which goats should be transported are lacking, and there are no acceptable ranges and limits for the thermal loads to which goats may be subjected during long-distance road transportation in hot-dry conditions. Panting score (PS), rectal temperature (RT), heart rate (HR) and respiratory rate (RR) were employed as reliable stress indices to assess the effects of different thermal loads, measured as temperature humidity index (THI), encountered in the vehicle during 12 h of road transportation of 40 goats, and to suggest the administration of 100 mg/kg body weight of ascorbic acid (AA) as an ameliorating agent. The results obtained showed that the PS, RT, HR and RR rose above normal reference values with increase in the THI and journey duration. The rise in PS value, which is a visual indicator of the severity of thermal load, was the most pronounced. The results suggest that values of THI in the vehicle up to 94.6 constitute no risk, while at of 100 it presents a moderate risk and above 100 may result in severe stress. The relationships between the thermal load and the physiological variables were positive and significant ( P < 0.05). They reflect the degree of stress imposed by each THI value during the transportation, and may be used as recommended ranges and limit thermal load values in transported goats. The results demonstrated that administration of 100 mg/kg body weight of AA before road transportation mitigated the risk of adverse effects of high THI values and other stress factors due to road transportation in goats.

  1. Efficient lactobionic acid production from whey by Pseudomonas taetrolens under pH-shift conditions.

    PubMed

    Alonso, Saúl; Rendueles, Manuel; Díaz, Mario

    2011-10-01

    Lactobionic acid finds applications in the fields of pharmaceuticals, cosmetics and medicine. The production of lactobionic acid from whey by Pseudomonas taetrolens was studied in shake-flasks and in a bioreactor. Shake-flask experiments showed that lactobionic acid was a non-growth associated product. A two-stage pH-shift bioconversion strategy with a pH-uncontrolled above 6.5 during the growth phase and maintained at 6.5 during cumulative production was adopted in bioreactor batch cultures. An inoculation level of 30% promoted high cell culture densities that triggered lactobionic acid production at a rate of 1.12 g/Lh. This methodology displayed efficient bioconversion with cheese whey as an inexpensive substrate for lactobionic acid production. PMID:21862326

  2. Comparative study of emulsifying properties in acidic condition of soluble polysaccharides fractions obtained from soy hull and defatted soy flour.

    PubMed

    Porfiri, María Cecilia; Cabezas, Darío Marcelino; Wagner, Jorge Ricardo

    2016-02-01

    The present study compares the emulsifying properties in acidic conditions of hull soluble polysaccharides (HSPS), soybean soluble polysaccharides (SSPS) and its mixtures. These fractions were obtained from byproducts of soybean processing industry (soy hull and residual fiber after isolation of soy cotyledon protein, respectively). Although SSPS is already characterized, HSPS is a novel fraction which has not been studied in deep and it is still unexplored as emulsifier. Dispersions of both fraction and a mixture 50:50 of them at pH 3.0 were used as aqueous phase (1.0-3.0 % w/w) in coarse and fine oil-in-water emulsions (oil mass fraction = 0.3). Its stability was evaluated through the evolution of backscattering profiles (%BS), particle size distribution and mean particle diameters. The rheology of the emulsions was also analyzed. Both fractions provided stability to creaming when increasing the polysaccharide concentration and energy of homogenization. While coarse emulsions were unstable systems, fine emulsions were stable enough and allowed a deeper analysis of the destabilizing processes. A bridging flocculation phenomenon in the presence of HSPS and HSPS/SSPS mixtures is suggested, which influences the creaming and rheological behavior. Also, coalescence index increases according HSPS and HSPS/SSPS concentrations, but particle sizes reached were smaller than in SSPS emulsions. Fine emulsions with 3 % of HSPS/SSPS mixtures yielded the best results on the overall stability at 28 days. So, functional properties of the fractions may improve by the formulation of emulsions consisting in mixtures of them. These results are of interest to the manufacturing of acidic foods, taking advantage of obtaining byproducts from residual materials. PMID:27162375

  3. Cocaine Use in the Infertile Male Population: A Marker for Conditions Resulting in Subfertility

    PubMed Central

    Samplaski, Mary K.; Bachir, Bassel G.; Lo, Kirk C.; Grober, Ethan D.; Lau, Susan; Jarvi, Keith A.

    2015-01-01

    Introduction We sought to evaluate the incidence and effect of cocaine use in the infertile male population. Materials and Methods Men presenting for fertility evaluation reporting cocaine usage were identified via prospectively collected database. Data were analyzed for usage patterns, reproductive history, associated drug use and medical conditions, hormonal and semen parameters. Results Thirty-eight out of 4,400 (0.9%) men reported cocaine use. Most used cocaine every 3 months or less. Compared with non-cocaine using men, cocaine users reported more recreational drug use (89 vs. 9.2%), marijuana use (78.9 vs. 11.4%), chlamydia (10.5 vs. 3%), herpes (7.9 vs. 2.5%), and tobacco use (55.3 vs. 19.5%). After excluding men with causes for azoospermia, the mean semen parameters for cocaine users were: volume 2.47 ± 1.02 ml; concentration 53.55 ± 84.04 × 106/ml; motility 15.72 ± 12.26%; total motile sperm count 76.67 ± 180.30 × 106. Conclusions Few (< 1%) men in our infertile population reported the use of cocaine, and the frequency of use was low. Given the low use rates and limitations of reporting bias, it is difficult to determine the direct effect of cocaine use on male fertility. However, while infrequent cocaine use seems to have limited impact on semen parameters, men reporting cocaine use represent a different cohort of men than the overall infertile population, with higher rates of concurrent substance abuse, tobacco use and infections, all of which may negatively impact their fertility. Reported cocaine users should be screened for concurrent drug use and infections. PMID:26195962

  4. Comparison of sulfur measurements from a regional fine particle network with concurrent acid modes network results

    SciTech Connect

    Bennett, R.L.; Stockburger, L.; Barnes, H.M.

    1994-01-01

    The Fine Particle Network (FPN), a system of fine particle (less than 2.5 micrometers) samplers, was operated at 41 sites selected from the Enviromental Protection Agency Acid MODES program during the two year period in 1988-90. The 24-hour sample results included fine particle mass and the most predominant chemical element concentrations determined by wavelength dispersive x-ray fluorescence analysis. Statistical summaries of the fine mass and sulfur concentrations by site and season were prepared. The availability of simultaneous particulate sulfate measurements from independent collection and analytical procedures provided an opportunity to examine their agreement and provide a more reliable data base for evaluation of regional particulate models and estimation of contribution to urban aerosol concentration.

  5. Modifications in membrane fatty acid composition of Salmonella typhimurium in response to growth conditions and their effect on heat resistance.

    PubMed

    Alvarez-Ordóñez, Avelino; Fernández, Ana; López, Mercedes; Arenas, Ricardo; Bernardo, Ana

    2008-04-30

    The effects of growth temperature (in the range 10-45 degrees C) and acidification up to pH 4.5 of the culture medium (Brain Heart Infusion, BHI) with different organic acids (acetic, citric and lactic) and hydrochloric acid on membrane fatty acid composition and heat resistance of Salmonella typhimurium CECT 443 were studied. The heat resistance was maximal in cells grown at 45 degrees C (cells grown in non-acidified BHI showed a D58-value of 0.90 min) and decreased with decreasing growth temperature up to 10 degrees C (D58-value of 0.09 min). The growth of cells in acidified media caused an increase in their heat resistance. In general, acid adapted cells showed D-values of between 1.5 and 2 times higher than the corresponding for non-acid adapted control cells. This cross-protection response, which has important implications in food processing, was not dependent on the pH value and the acid used to acidify the growth medium. A membrane adaptation corresponding to an increase in the unsaturated to saturated fatty acids ratio (UFA/SFA) and membrane fluidity was observed at low growth temperature. Moreover, the acidification of the growth medium caused a decrease in UFA/SFA ratio and in the C18:1 relative concentration, and an increase in cyclopropane fatty acids (CFA) content mainly due to the increase in cyc19 relative concentration. Thus, acid adapted cells showed CFA levels 1.5 times higher than non-acid adapted control cells. A significant proportion of unsaturated fatty acids were converted to their cyclopropane derivatives during acid adaptation. These changes in membrane fatty acid composition result in cells with decreased membrane fluidity. A clear relation between membrane fatty acid composition and heat resistance was observed. In general, D-values were maximum for cells with low UFA/SFA ratio, and, consequently, with low membrane fluidity. Moreover, CFA formation played a major role in protecting acid adapted cells from heat inactivation. However

  6. Branched-chain amino acids suppress the cumulative recurrence of hepatocellular carcinoma under conditions of insulin-resistance

    PubMed Central

    YOSHIJI, HITOSHI; NOGUCHI, RYUICHI; NAMISAKI, TADASHI; MORIYA, KEI; KITADE, MITSUTERU; AIHARA, YOSUKE; DOUHARA, AKITOSHI; YAMAO, JUNICHI; FUJIMOTO, MASAO; TOYOHARA, MASAHISA; MITORO, AKIRA; SAWAI, MASAYOSHI; YOSHIDA, MOTOYUKI; MORIOKA, CHIE; UEJIMA, MASAKAZU; UEMURA, MASAHITO; FUKUI, HIROSHI

    2013-01-01

    Branched-chain amino acids (BCAAs) reportedly inhibit the incidence of hepatocellular carcinoma (HCC) in patients with liver cirrhosis and obesity that is frequently associated with insulin resistance (IR). We previously reported that BCAAs exert a chemopreventive effect against HCC under IR conditions in rats. The aim of the present study was to examine the effect of BCAAs on the cumulative recurrence of HCC under IR conditions in the clinical practice. BCAA granules (Livact®, 12 g/day) were administered for 60 months following the local curative therapy for HCC, and several indices were determined. Treatment with BCAAs markedly inhibited the cumulative recurrence of HCC in patients with a high IR index [homeostasis model assessment (HOMA)-IR >2.5], but not in patients with HOMA-IR of ≤2.5. BCAA also improved the HOMA-IR, and the inhibitory effect was observed regardless of the serum albumin (Alb) levels. Similarly, BCAA treatment revealed a marked suppressive effect in patients with high fasting insulin [immune reactive insulin (IRI) >15 U/ml], but not with IRI of ≤15. BCAA treatment did not result in differences in HCC recurrence in patients with high and low glucose levels [fasting blood sugar (FBS) >110 and ≤110, respectively]. Furthermore, serum levels of the soluble form of vascular endothelial growth factor receptor 2 (sVEGFR2) were significantly inhibited along with these clinical effects. Our findings indicate that the inhibitory effect of BCAAs was achieved, at least partly, by coordinated effects of anti-angiogenesis and IR improvement. Since BCAAs are widely and safely used in clinical practice to treat patients with chronic liver diseases, BCAAs may represent a new strategy for secondary chemoprevention for HCC patients with IR. Moreover, our findings suggest that sVEGFR2 may be a useful clinical predictive marker for BCAA treatment under IR conditions. PMID:23708326

  7. Branched-chain amino acids suppress the cumulative recurrence of hepatocellular carcinoma under conditions of insulin-resistance.

    PubMed

    Yoshiji, Hitoshi; Noguchi, Ryuichi; Namisaki, Tadashi; Moriya, Kei; Kitade, Mitsuteru; Aihara, Yosuke; Douhara, Akitoshi; Yamao, Junichi; Fujimoto, Masao; Toyohara, Masahisa; Mitoro, Akira; Sawai, Masayoshi; Yoshida, Motoyuki; Morioka, Chie; Uejima, Masakazu; Uemura, Masahito; Fukui, Hiroshi

    2013-08-01

    Branched-chain amino acids (BCAAs) reportedly inhibit the incidence of hepatocellular carcinoma (HCC) in patients with liver cirrhosis and obesity that is frequently associated with insulin resistance (IR). We previously reported that BCAAs exert a chemopreventive effect against HCC under IR conditions in rats. The aim of the present study was to examine the effect of BCAAs on the cumulative recurrence of HCC under IR conditions in the clinical practice. BCAA granules (Livact®, 12 g/day) were administered for 60 months following the local curative therapy for HCC, and several indices were determined. Treatment with BCAAs markedly inhibited the cumulative recurrence of HCC in patients with a high IR index [homeostasis model assessment (HOMA)-IR >2.5], but not in patients with HOMA-IR of ≤2.5. BCAA also improved the HOMA-IR, and the inhibitory effect was observed regardless of the serum albumin (Alb) levels. Similarly, BCAA treatment revealed a marked suppressive effect in patients with high fasting insulin [immune reactive insulin (IRI)>15 U/ml], but not with IRI of ≤15. BCAA treatment did not result in differences in HCC recurrence in patients with high and low glucose levels [fasting blood sugar (FBS)>110 and ≤110, respectively]. Furthermore, serum levels of the soluble form of vascular endothelial growth factor receptor 2 (sVEGFR2) were significantly inhibited along with these clinical effects. Our findings indicate that the inhibitory effect of BCAAs was achieved, at least partly, by coordinated effects of anti-angiogenesis and IR improvement. Since BCAAs are widely and safely used in clinical practice to treat patients with chronic liver diseases, BCAAs may represent a new strategy for secondary chemoprevention for HCC patients with IR. Moreover, our findings suggest that sVEGFR2 may be a useful clinical predictive marker for BCAA treatment under IR conditions. PMID:23708326

  8. Determination of the optimum conditions for boric acid extraction with carbon dioxide gas in aqueous media from colemanite containing arsenic

    SciTech Connect

    Ata, O.N.; Colak, S.; Copur, M.; Celik, C.

    2000-02-01

    The Taguchi method was used to determine optimum conditions for the boric acid extraction from colemanite ore containing As in aqueous media saturated by CO{sub 2} gas. After the parameters were determined to be efficient on the extraction efficiency, the experimental series with two steps were carried out. The chosen experimental parameters for the first series of experiments and their ranges were as follows: (1) reaction temperature, 25--70 C; (2) solid-to-liquid ratio (by weight), 0.091 to 0.333; (3) gas flow rate (in mL/min), 66.70--711; (4) mean particle size, {minus}100 to {minus}10 mesh; (5) stirring speed, 200--600 rpm; (6) reaction time, 10--90 min. The optimum conditions were found to be as follows: reaction temperature, 70 C; solid-to-liquid ratio, 0.091; gas flow rate, 711 (in mL/min); particle size, {minus}100 mesh; stirring speed, 500 rpm; reaction time, 90 min. Under these optimum conditions, the boric acid extraction efficiency from the colemanite containing As was approximately 54%. Chosen experimental parameters for the second series of experiments and their ranges were as follows: (1) reaction temperature, 60--80 C; (2) solid-to-liquid ratio (by weight), 0.1000 to 0.167; (3) gas pressure (in atm), 1.5; 2.7; (4) reaction time, 45--120 min. The optimum conditions were found to be as follows: reaction temperature, 70 C; solid-to-liquid ratio, 0.1; gas pressure, 2.7 atm; reaction time, 120 min. Under these optimum conditions the boric acid extraction efficiency from the colemanite ore was approximately 75%. Under these optimum conditions, the boric acid extraction efficiency from calcined colemanite ore was approximately 99.55%.

  9. The crystallinity of calcium phosphate powders influenced by the conditions of neutralized procedure with citric acid additions

    SciTech Connect

    Li Chengfeng

    2009-05-06

    Calcium phosphate powders with nano-sized crystallinity were synthesized by neutralization using calcium hydroxide and orthophosphoric acid with the assistance of citric acid. The influence of processing parameters, such as free or additive citric acid, synthetic temperature and ripening time, on the crystallinity of hydroxyapatite were investigated. The results of X-ray diffraction and microstructure observations showed that the crystallinity and morphology of nano-sized hydroxyapatite particles were influenced by the presence or absence of citric acid. It was found that the crystallinities and crystallite sizes of hydroxyapatite powders prepared with the additive citric acid increased with increasing synthetic temperature and ripening time. Especially, the crystallinities of (h k 0) planes were raised and more homogeneously grown particles were obtained with increasing synthetic temperature.

  10. 17 CFR 229.303 - (Item 303) Management's discussion and analysis of financial condition and results of operations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Regulation S-X (17 CFR 210), a management's discussion and analysis of the financial condition and results of... discussion and analysis of financial condition and results of operations. 229.303 Section 229.303 Commodity... 1975-REGULATION S-K Financial Information § 229.303 (Item 303) Management's discussion and analysis...

  11. Direct production of organic acids from starch by cell surface-engineered Corynebacterium glutamicum in anaerobic conditions

    PubMed Central

    2013-01-01

    We produced organic acids, including lactate and succinate, directly from soluble starch under anaerobic conditions using high cell-density cultures of Corynebacterium glutamicum displaying α-amylase (AmyA) from Streptococcus bovis 148 on the cell surface. Notably, reactions performed under anaerobic conditions at 35 and 40°C, which are higher than the optimal growth temperature of 30°C, showed 32% and 19%, respectively, higher productivity of the organic acids lactate, succinate, and acetate compared to that at 30°C. However, α-amylase was not stably anchored and released into the medium from the cell surface during reactions at these higher temperatures, as demonstrated by the 61% and 85% decreases in activity, respectively, from baseline, compared to the only 8% decrease at 30°C. The AmyA-displaying C. glutamicum cells retained their starch-degrading capacity during five 10 h reaction cycles at 30°C, producing 107.8 g/l of total organic acids, including 88.9 g/l lactate and 14.0 g/l succinate. The applicability of cell surface-engineering technology for the production of organic acids from biomass by high cell-density cultures of C. glutamicum under anaerobic conditions was demonstrated. PMID:24342107

  12. Direct production of organic acids from starch by cell surface-engineered Corynebacterium glutamicum in anaerobic conditions.

    PubMed

    Tsuge, Yota; Tateno, Toshihiro; Sasaki, Kengo; Hasunuma, Tomohisa; Tanaka, Tsutomu; Kondo, Akihiko

    2013-01-01

    We produced organic acids, including lactate and succinate, directly from soluble starch under anaerobic conditions using high cell-density cultures of Corynebacterium glutamicum displaying α-amylase (AmyA) from Streptococcus bovis 148 on the cell surface. Notably, reactions performed under anaerobic conditions at 35 and 40°C, which are higher than the optimal growth temperature of 30°C, showed 32% and 19%, respectively, higher productivity of the organic acids lactate, succinate, and acetate compared to that at 30°C. However, α-amylase was not stably anchored and released into the medium from the cell surface during reactions at these higher temperatures, as demonstrated by the 61% and 85% decreases in activity, respectively, from baseline, compared to the only 8% decrease at 30°C. The AmyA-displaying C. glutamicum cells retained their starch-degrading capacity during five 10 h reaction cycles at 30°C, producing 107.8 g/l of total organic acids, including 88.9 g/l lactate and 14.0 g/l succinate. The applicability of cell surface-engineering technology for the production of organic acids from biomass by high cell-density cultures of C. glutamicum under anaerobic conditions was demonstrated. PMID:24342107

  13. On the growth of nitric and sulfuric acid aerosol particles under stratospheric conditions

    NASA Technical Reports Server (NTRS)

    Hamill, Patrick; Turco, R. P.; Toon, O. B.

    1988-01-01

    A theory for the formation of frozen aerosol particles in the Antarctic stratosphere was developed and applied to the formation of polar stratospheric clouds. The theory suggests that the condensed ice particles are composed primarily of nitric acid and water, with small admixtures of sulfuric and hydrochloric acids in solid solution. The proposed particle formation mechanism is in agreement with the magnitude and seasonal behavior of the optical extinction observed in the winter polar stratosphere.

  14. Targeted disruption of retinoic acid receptor alpha (RAR alpha) and RAR gamma results in receptor-specific alterations in retinoic acid-mediated differentiation and retinoic acid metabolism.

    PubMed Central

    Boylan, J F; Lufkin, T; Achkar, C C; Taneja, R; Chambon, P; Gudas, L J

    1995-01-01

    F9 embryonic teratocarcinoma stem cells differentiate into an epithelial cell type called extraembryonic endoderm when treated with retinoic acid (RA), a derivative of retinol (vitamin A). This differentiation is presumably mediated through the actions of retinoid receptors, the RARs and RXRs. To delineate the functions of each of the different retinoid receptors in this model system, we have generated F9 cell lines in which both copies of either the RAR alpha gene or the RAR gamma gene are disrupted by homologous recombination. The absence of RAR alpha is associated with a reduction in the RA-induced expression of both the CRABP-II and Hoxb-1 (formerly 2.9) genes. The absence of RAR gamma is associated with a loss of the RA-inducible expression of the Hoxa-1 (formerly Hox-1.6), Hoxa-3 (formerly Hox-1.5), laminin B1, collagen IV (alpha 1), GATA-4, and BMP-2 genes. Furthermore, the loss of RAR gamma is associated with a reduction in the metabolism of all-trans-RA to more polar derivatives, while the loss of RAR alpha is associated with an increase in metabolism of RA relative to wild-type F9 cells. Thus, each of these RARs exhibits some specificity with respect to the regulation of differentiation-specific gene expression. These results provide an explanation for the expression of multiple RAR types within one cell type and suggest that each RAR has specific functions. PMID:7823950

  15. The effect of processing conditions on the stability of fructooligosaccharides in acidic food products.

    PubMed

    Vega, Roberto; Zuniga-Hansen, M E

    2015-04-15

    The effect of processing conditions (temperature and degree of polymerisation, DP) on the stability of short-chain fructooligosaccharides (sc-FOS) was investigated in three reaction media (sodium citrate buffer and orange and tomato juices) in a kinetic study at pH 3.5. In addition, kinetic equations as a function of temperature and pH were developed, using published data. Pentasaccharides were more stable to heat treatment than were trisaccharides under all of the conditions tested. In addition, the sc-FOS were more stable in orange juice, followed by tomato juice and citrate buffer. The results showed that, in addition to temperature and pH, the DP and food matrix, including the type of pasteurisation, must be considered when processing foods enriched with sc-FOS. Furthermore, the continuous thermal processing simulation for each of the equivalent processes at 90 °C revealed that the percent retention of sc-FOS is greater than 95% at temperatures above 95 °C. PMID:25466090

  16. Mobility of Po and U-isotopes under acid mine drainage conditions: an experimental approach with samples from Río Tinto area (SW Spain).

    PubMed

    Barbero, L; Gázquez, M J; Bolívar, J P; Casas-Ruiz, M; Hierro, A; Baskaran, M; Ketterer, M E

    2014-12-01

    Under acid mine drainage (AMD) conditions, the solubilities and mobilities of many elements are vastly different from conditions prevailing in most natural waters. Studies are underway in the Río Tinto area (Iberian Pyrite Belt), in order to understand the behavior and mobility of long-lived U-series radionuclides under AMD conditions. A set of leaching experiments utilizing typical country rocks from the Tinto River basin, waste rock pile composite materials, iron-rich riverbed sediments and gossan (weathered naturally rock) were performed towards this purpose. Initial leaching experiments using distilled water kept in contact with solid material for 300, 100, 50 and 1 h resulted in very low concentrations of U with (234)U/(238)U activity ratios close to equilibrium and activity concentrations of (210)Po < 0.03 mBq/g. Leaching experiments performed with sulfuric acid media (0.1 and 0.01 M), and contact times between the solid and solution for 24 h were conducted to quantify the amount of U-isotopes and (210)Po leached, and the radioactive disequilibria generated between the radionuclides in the leachate. These experiments show that Po mobility in acidic conditions (pH around 1-2) is very low, with (210)Po activity in the leachate to be 6% in average for the solid sample. By contrast, mobility of U-isotopes is higher than that of Po, around 1.2%. PMID:24308958

  17. The results of HLW processing using zirconium salt of dibutyl phosphoric acid

    SciTech Connect

    Fedorov, Yury; Zilberman, Boris; Shmidt, Olga; Saprikin, Vladimir; Ryasantsev, Valery

    2007-07-01

    Available in abstract form only. Full text of publication follows: Zirconium salt of dibutyl-phosphoric acid (ZS HDBP) dissolved in a diluent, is a promising solvent for liquid HLW processing. The investigations carried out earlier showed that ZS HDBP can recover a series of radionuclides (TPE, RE, U, Pu, Np, Sr) and some other elements (Mo, Ca, Fe) from aqueous solutions. The possibility of TPE and RE effective recovery and separation into appropriate fractions with high purification from each other was demonstrated as well. The results of extraction tests in the mixer-settlers in the course of liquid HLW treatment in hot cells, using ZS HDBP (0.4 M HDBP and 0.044 M Zr) dissolved in 30% TBP are presented. 30 liters of the feed solution containing TPE, RE, Sr and Cs with the total specific activity of 520 MBq/L and acidity of 2 M HNO{sub 3} were processed using the two-cycle flowsheet. TPE and RE recovery with subsequent stripping was realized in the first cycle, while Sr was recovered and concentrated in the second cycle. Raffinate of the latter contained almost all Cs. The degree of TPE and RE recovery was 104, and that of Sr was {approx}10. Decontamination factor of TPE and RE from Cs and Sr was 104, and that of Sr from TPE and Cs was 103. So, ZS HDBP can be used for separation of long-lived radionuclides from HLW with respect to radio-toxic category of the process products. (authors)

  18. Carbonic acid salts at 25 or 45 degrees C to control loquat decay under shelf life conditions.

    PubMed

    Molinu, M G; D'Hallewin, G; Dore, A; Serusi, A; Venditti, T; Agabbio, M

    2005-01-01

    Generally recognised as save compounds (G.R.A.S) are attractive substitutes to synthetic chemicals in postharvest control diseases. They meet safety requirements, are cheap and able to be integrated with other disease control technologies. Among G.R.A.S compounds, carbonic acid salts have been investigated on carrots, bell pepper, melons, sweet cherries and their efficacy was also evaluated when combined with biological control agents. Moreover, the possibility to use sodium carbonate and sodium bicarbonate to prevent P. digitatum an P. italicum spread on Citrus fruit was studied since the begin of the 20th century. We explored the possibility to extend the use of carbonate-bicarbonate salts on loquat fruit in order to control the pathogens and to extend postharvest life. Loquat is a very perishable fruit, susceptible to decay, mechanical damage, moisture and nutritional losses during its postharvest life. We tested the combined effect of temperature and sodium or potassium carbonate-bicarbonate and ammonium carbonate. The fruit was dipped in the salt solutions at variable concentrations (0.5, 1 and 2% w/v) at 25 or 45 degrees C for two minutes and than stored under shelf life conditions (25 degrees C and 70% RH). Decay, weight loss, pH, titrable acidity and sugar content were detected after twelve days. Preliminary data show that the combined treatments were effective in decay control depending on salts. Best results were obtained with 2% potassium and sodium carbonate solution at 25 degrees C. Weight losses were related to treatment temperature and salts concentrations whereas, no differences were detected in the chemical parameters compared to the control. PMID:16637201

  19. NALC/MEXICO LAND-COVER MAPPING RESULTS: IMPLICATIONS FOR ASSESSING LANDSCAPE CONDITION

    EPA Science Inventory

    An inventory of land-cover conditions throughout Mexico was performed using North American Landscape Characterization (NLAC) Landsat Mult-Spectral Scann (MSS) 'triplicate' images, corresponding to the 1970s, 1980s and 1990s epoch periods. The equivalents of 300 image scenes were...

  20. NALC/MEXICO LAND-COVER MAPPING RESULTS: IMPLICATIONS FOR ASSESSING LANDSCAPE CONDITION

    EPA Science Inventory

    An inventory of land-cover conditions throughout Mexico was performed using North American Landscap Characterization ( NALC) Landsat Multi-Spectral Scanner (MSS) 'triplicate' images, corresponding to the 1970s, 1980s and1990s epoch periods. The equivalent of 300 image scenes were...

  1. Preliminary Results from a Mesocosm Marsh Experiment with Treatments Simulating Three Tidal Flooding and Precipitation Conditions

    EPA Science Inventory

    Our goal was to observe and quantify the effects of low, medium and high tidal flooding regimes and various precipitation conditions on both Spartina alterniflora and Typha angustifolia in greenhouse mesocosms. The experiment was maintained for 4 months. Each of 3 tanks (600L) ha...

  2. Wooden breast condition results in reduced thaw loss in frozen-thawed broiler breast fillets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wooden breast condition (WBC) is an emerging quality issue with broiler breast meat that significantly affects both raw and cooked meat properties. The objective of this study was to investigate the effects of WBC on meat water-holding capacity (WHC) estimated with different methods. Broiler breast ...

  3. NATIONAL RESULTS FROM THE 2011 NATIONAL WETLAND CONDITION ASSESSMENT (NWCA) SOILS ANALYSIS

    EPA Science Inventory

    In 2011, US Environmental Protection Agency conducted the first National Wetland Condition Assessment (NWCA). Field crews conducted one-day surveys of over 1000 wetlands across the contiguous United States. For every wetland sampled, soils were collected by layer (i.e., horizon)...

  4. Assessing the potential of amino acid 13C patterns as a carbon source tracer in marine sediments: effects of algal growth conditions and sedimentary diagenesis

    NASA Astrophysics Data System (ADS)

    Larsen, T.; Bach, L. T.; Salvatteci, R.; Wang, Y. V.; Andersen, N.; Ventura, M.; McCarthy, M. D.

    2015-08-01

    Burial of organic carbon in marine sediments has a profound influence in marine biogeochemical cycles and provides a sink for greenhouse gases such as CO2 and CH4. However, tracing organic carbon from primary production sources as well as its transformations in the sediment record remains challenging. Here we examine a novel but growing tool for tracing the biosynthetic origin of amino acid carbon skeletons, based on naturally occurring stable carbon isotope patterns in individual amino acids (δ13CAA). We focus on two important aspects for δ13CAA utility in sedimentary paleoarchives: first, the fidelity of source diagnostic of algal δ13CAA patterns across different oceanographic growth conditions, and second, the ability of δ13CAA patterns to record the degree of subsequent microbial amino acid synthesis after sedimentary burial. Using the marine diatom Thalassiosira weissflogii, we tested under controlled conditions how δ13CAA patterns respond to changing environmental conditions, including light, salinity, temperature, and pH. Our findings show that while differing oceanic growth conditions can change macromolecular cellular composition, δ13CAA isotopic patterns remain largely invariant. These results emphasize that δ13CAA patterns should accurately record biosynthetic sources across widely disparate oceanographic conditions. We also explored how δ13CAA patterns change as a function of age, total nitrogen and organic carbon content after burial, in a marine sediment core from a coastal upwelling area off Peru. Based on the four most informative amino acids for distinguishing between diatom and bacterial sources (i.e., isoleucine, lysine, leucine and tyrosine), bacterially derived amino acids ranged from 10 to 15 % in the sediment layers from the last 5000 years, and up to 35 % during the last glacial period. The greater bacterial contributions in older sediments indicate that bacterial activity and amino acid resynthesis progressed, approximately as a

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

    PubMed Central

    Kalibatas, Vytenis; Kalibatienė, Lina

    2014-01-01

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

  6. A MULTISTAGE BIOLOGICALLY BASED MODEL FOR MOUSE LIVER TUMORS RESULTING FROM EXPOSURE TO DICHLOROACETIC ACID

    EPA Science Inventory

    Dichloroacetic Acid (DCA) is a major byproduct of the chlorine disinfection of humic acid containing drinking water sources. It is a hepatocarcinogen in mice and rats at exposure concentrations in drinking water that are at least 4 orders of magnitude above the concentrations in ...

  7. 76 FR 5782 - Citric Acid and Certain Citrate Salts From Canada: Preliminary Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-02

    ... Part, and Final Determination to Not Revoke Order in Part: Canned Pineapple Fruit from Thailand, 68 FR... Administrative Reviews and Requests for Revocation in Part, 75 FR 37759 (June 30, 2010). Also on June 30, 2010... Acid and Certain Citrate Salts from Canada, 74 FR 16843 (April 13, 2009) (Citric Acid LTFV)....

  8. Boundary conditions for creeping flow along periodic or random rough surfaces : experimental and theoretical results

    NASA Astrophysics Data System (ADS)

    Lecoq, Nicolas

    2012-12-01

    Hydrodynamic interactions between particles and walls are relevant for the open problem of specifying boundary conditions for suspension flows. The Reynolds number around a small particle close to a wall is usually low and creeping flow equations apply. From the solution of these equations, the drag coefficient on a sphere becomes infinite when the gap between the sphere and a smooth wall vanishes, so that contact may not occur. Physically, the drag is finite because of various reasons, one of them being the particle and wall roughness. Then, for vanishing gap, even though some layers of fluid molecules may be left between the particle and wall roughness peaks, it may conventionally be said that contact occurs. In this paper, we are considering the example of a smooth sphere moving towards a rough wall. The roughness considered here consist of random rough planes or parallel periodic wedges, the characteristic length of which is small compared with the sphere radius. This problem is considered both experimentally and theoretically. The motion of a millimetre size bead settling towards a corrugated horizontal wall in a viscous oil is measured with laser interferometry giving an accuracy on the displacement of 0.2μm. Several random rough planes and wedge shaped walls were used, with various wavelengths and wedge angles. From the results, it is observed that the velocity of the sphere is, except for small gaps, similar to that towards a smooth plane that is shifted down from the top of corrugations. For the periodic wedges, the creeping flow is calculated as a series in the slope of the roughness grooves. The convergence of the series for the shift distance in term of the slope is accelerated by use of Euler transformation and of the existence of a limit for large slope. The cases of a flow along and across the grooves are considered separately. The shift is larger in the former case. Slightly flattened tops of the wedges used in experiments are also considered in

  9. Effect of blood handling conditions on progesterone assay results obtained by chemiluminescence in the bitch.

    PubMed

    Tahir, M Z; Thoumire, S; Raffaelli, M; Grimard, B; Reynaud, K; Chastant-Maillard, S

    2013-10-01

    Assay of blood progesterone (P4) is commonly practiced to determine the time of ovulation, diagnose luteal insufficiency, and predict time of parturition in bitches. Because of practical constraints, most blood samples cannot be assayed on site immediately after collection. The aim of this work was to evaluate the effects of various sampling and storage conditions on concentrations of P4 as determined by chemiluminescence immunoassay. The blood of 5 Beagle bitches was collected from the jugular vein to study the effect of the type of collection tube (silicone, lithium heparin, EDTA), the storage time of unseparated or separated plasma (2 h to 14 d), and the number of freeze-thaw cycles (1-10) on P4. The effect of each factor was tested within one assay session. None of the factors significantly affected P4. Thus, P4 appears to remain relatively stable in canine blood samples exposed to various processing and storage conditions. PMID:23988180

  10. First results using TWINS-derived ion temperature boundary conditions in CRCM

    NASA Astrophysics Data System (ADS)

    Elfritz, J. G.; Keesee, A. M.; Buzulukova, N.; Fok, M.-C.; Scime, E. E.

    2014-05-01

    We have integrated dynamic, spatiotemporally resolved ion temperature boundary conditions into the Comprehensive Ring Current Model (CRCM), which are based on 2-D equatorial maps derived from the Two Wide-Angle Imaging Neutral-Atom Spectrometers (TWINS) energetic neutral atom (ENA) data. The high-speed stream-driven event on 22 July 2009 is simulated and compared against an identical simulation using a statistically derived boundary condition model. ENA-derived temperatures allow users to include event-specific observations associated with a dynamic plasma sheet. This method also provides temperatures in the important region between geosynchronous orbit and the plasma sheet, a region which existing empirical models exclude. We find that the spatial and energy distributions of ring current flux and pressure have sensitive dependence on boundary conditions during this event. The coupling of boundary conditions to the time history of the convection field strength also plays an important role by throttling the influence of the boundary plasma on the inner magnetosphere. Simulated moments and spectra from our simulations are compared with remotely imaged ion temperatures from TWINS and also in situ energy spectra and temperature moments from Time History of Events and Macroscale Interactions during Substorms-D. Storm time dusk-dawn asymmetries consistent with observational data, such as Zhang et al. (2006), are reproduced well when CRCM is provided with the event-specific boundary model. A hot localized structure observed by TWINS at geosynchronous midnight during a strong northward interplanetary magnetic field interval is also reproduced with this boundary model, whereas the empirical boundary model fails to yield this feature.

  11. Fuel performance under normal PWR conditions: A review of relevant experimental results and models

    NASA Astrophysics Data System (ADS)

    Charles, M.; Lemaignan, C.

    1992-06-01

    Experiments conducted at Grenoble (CEA/DRN) over the past 20 years in the field of nuclear fuel behaviour are reviewed. Of particular concern is the need to achieve a comprehensive understanding of and subsequently overcome the limitations associated with high burnup and load-following conditions (pellet-cladding interaction (PCI), fission gas release (FGR), water-side corrosion). A general view is given of the organization of research work as well as some experimental details (irradiation, postirradiation examination — PIE). Based on various experimental programmes (Cyrano, Medicis, Anemone, Furet, Tango, Contact, Cansar, Hatac, Flog, Decor), the main contributions of the thermomechanical behaviour of a PWR fuel rod are described: thermal conductivity, in-pile densification, swelling, fission gas release in steady state and moderate transient conditions, gap thermal conductance, formation of primary and secondary ridges under PCI conditions. Specific programmes (Gdgrif, Thermox, Grimox) are devoted to the behaviour of particular fuels (gadolinia-bearing fuel, MOX fuel). Moreover, microstructure-based studies have been undertaken on fission gas release (fine analysis of the bubble population inside irradiated fuel samples), and on cladding behaviour (PCI related studies on stress-corrosion cracking (SCO, irradiation effects on zircaloy microstructure).

  12. Evaluation of a chlorous acid-chlorine dioxide teat dip under experimental and natural exposure conditions.

    PubMed

    Drechsler, P A; Wildman, E E; Pankey, J W

    1990-08-01

    A postmilking teat dip containing chlorous acid-chlorine dioxide was evaluated by experimental challenge and in two herds under natural exposure. The test product had an efficacy of 78.9% against Staphylococcus aureus and 52.5% against Streptococcus agalactiae in the experimental challenge trial. The product was compared with a 1% iodine product in a 15-mo natural exposure study. Post-dipping with chlorous acid-chlorine dioxide reduced incidence of udder infection by major mastitis pathogens 36.1% when data were combined from the two herds. The 1% iodine and the chlorous acid-chlorine dioxide products were not equivalent for major mastitis pathogens; the test product was more effective. Incidence of udder infection by environmental mastitis pathogens was reduced 36.8% in both herds combined. Efficacy of the two teat dips was equivalent for environmental pathogens. PMID:2229601

  13. Activated acetic acid by carbon fixation on (Fe,Ni)S under primordial conditions.

    PubMed

    Huber, C; Wächtershäuser, G

    1997-04-11

    In experiments modeling the reactions of the reductive acetyl-coenzyme A pathway at hydrothermal temperatures, it was found that an aqueous slurry of coprecipitated NiS and FeS converted CO and CH3SH into the activated thioester CH3-CO-SCH3, which hydrolyzed to acetic acid. In the presence of aniline, acetanilide was formed. When NiS-FeS was modified with catalytic amounts of selenium, acetic acid and CH3SH were formed from CO and H2S alone. The reaction can be considered as the primordial initiation reaction for a chemoautotrophic origin of life. PMID:9092471

  14. Stability of uncoated and fulvic acids coated manufactured CeO2 nanoparticles in various conditions: From ultrapure to natural Lake Geneva waters.

    PubMed

    Oriekhova, Olena; Stoll, Serge

    2016-08-15

    Understanding the behavior of engineered nanoparticles in natural water and impact of water composition in changing conditions is of high importance to predict their fate once released into the environment. In this study we investigated the stability of uncoated and Suwannee River fulvic acids coated CeO2 manufactured nanoparticles in various environmental conditions. The effect of pH changes on the nanoparticle and coating stability was first studied in ultrapure water as well as the variation of zeta potentials and sizes with time in presence of fulvic acids at environmental pH. Then the stability of CeO2 in synthetic and natural Lake Geneva waters was investigated as a function of fulvic acids concentration. Our results indicate that the adsorption of environmentally relevant concentrations of Suwannee River fulvic acids promotes CeO2 stabilization in ultrapure water as well as synthetic water and that the coating stability is high upon pH variations. On the other hand in natural Lake Geneva water CeO2 NPs are found in all cases aggregated due to the effect of heterogeneous organic and inorganic compounds. PMID:27100013

  15. Improvement of Polyunsaturated Fatty Acid Production in Echium acanthocarpum Transformed Hairy Root Cultures by Application of Different Abiotic Stress Conditions

    PubMed Central

    Zárate, Rafael; Cequier-Sánchez, Elena; Rodríguez, Covadonga; Dorta-Guerra, Roberto; El Jaber-Vazdekis, Nabil; Ravelo, Ángel G.

    2013-01-01

    Fatty acids are of great nutritional, therapeutic, and physiological importance, especially the polyunsaturated n-3 fatty acids, possessing larger carbon chains and abundant double bonds or their immediate precursors. A few higher plant species are able to accumulate these compounds, like those belonging to the Echium genus. Here, the novel E. acanthocarpum hairy root system, which is able to accumulate many fatty acids, including stearidonic and α-linolenic acids, was optimized for a better production. The application of abiotic stress resulted in larger yields of stearidonic and α-linolenic acids, 60 and 35%, respectively, with a decrease in linoleic acid, when grown in a nutrient medium consisting of B5 basal salts, sucrose or glucose, and, more importantly, at a temperature of 15°C. The application of osmotic stress employing sorbitol showed no positive influence on the fatty acid yields; furthermore, the combination of a lower culture temperature and glucose did not show a cumulative boosting effect on the yield, although this carbon source was similarly attractive. The abiotic stress also influenced the lipid profile of the cultures, significantly increasing the phosphatidylglycerol fraction but not the total lipid neither their biomass, proving the appropriateness of applying various abiotic stress in this culture to achieve larger yields. PMID:25937970

  16. Constraining flooding conditions for early historic and prehistoric hurricanes from resultant deposits preserved in Florida sinkholes

    NASA Astrophysics Data System (ADS)

    Brandon, C. M.; Woodruff, J. D.; Lane, P.; Donnelly, J. P.

    2011-12-01

    Instrumental records of hurricane strikes in the United States are relatively short, extending back only ~160 years. Sediment deposits created by hurricane-induced coastal inundation serve as valuable proxies of storm activity and can extend these records back several millennia. Here we provide a record of hurricane inundation preserved within the sediments of Callahan Pond, a small coastal sinkhole located within the Florida Panhandle. This 15 m deep pond has remained relatively undisturbed over the last 2000 years allowing it to accumulate fine grained organic-rich sediments punctuated by well-preserved quartz sand layers likely associated with hurricane surges. An event deposit located within surface sediments from the pond likely corresponds to a hurricane that struck the area in 1941, and is used as a modern analogue to help evaluate flooding conditions for older event layers preserved within the depositional record. Grain size analyses are performed on each event-deposit to help constrain flow conditions required for erosion and transport. The Regional Ocean Modeling System (ROMS) is then employed to perform a series of 2-D coastal inundation simulations at the site to assess the near-shore flooding conditions required to produce each of the observed event-deposits. Probability distribution functions are generated to assess the Saffir-Simpson storm category for each event-deposit. Age constraints on the deposits are developed by using carbon-14 and cesium-137 radiometric dating techniques. A period of increased storm activity is observed from ~500 to ~1200 AD, encompassing the Medieval Warm Period and a period of decreased storm activity is observed from ~1450 AD to the present, encompassing the Little Ice Age.

  17. Modification of amino acids at shock pressures of 3 to 30 GPA: Initial results

    NASA Technical Reports Server (NTRS)

    Peterson, Etta; Horz, Friedrich; Haynes, Gerald; See, Thomas

    1991-01-01

    Since the discovery of amino acids in the Murchison meteorite, much speculation has focused on their origin and subsequent alteration, including the possible role of secondary processes, both terrestrial and extraterrestrial. As collisional processes and associated shock waves seem to have affected the silicate portions of many primitive meteorites, a mixture of powdered Allende (125-150 m grain size) and nine synthetic amino acids (six protein and three nonprotein) were subjected to controlled shock pressures from 3 to 30 GPa to determine the effect of shocks on amino acid survivability. Preliminary characterizations of the recovered shock products are presented.

  18. The effects of changing dairy intake on trans and saturated fatty acid levels- results from a randomized controlled study

    PubMed Central

    2014-01-01

    Background Dairy food is an important natural source of saturated and trans fatty acids in the human diet. This study evaluates the effect of dietary advice to change dairy food intake on plasma fatty acid levels known to be present in milk in healthy volunteers. Methods Twenty one samples of whole fat dairy milk were analyzed for fatty acids levels. Changes in levels of plasma phospholipid levels were evaluated in 180 healthy volunteers randomized to increase, not change or reduce dairy intake for one month. Fatty acids were measured by gas chromatography–mass spectrometry and levels are normalized to d-4 alanine. Results The long chain fatty acids palmitic (13.4%), stearic (16.7%) and myristic (18.9%) acid were most common saturated fats in milk. Four trans fatty acids constituted 3.7% of the total milk fat content. Increased dairy food intake by 3.0 (± 1.2) serves/ day for 1 month was associated with small increases in plasma levels of myristic (+0.05, 95% confidence level-0.08 to 0.13, p = 0.07), pentadecanoic (+0.014, 95% confidence level -0.016 to 0.048, p = 0.02) and margaric acid (+0.02, -0.03 to 0.05, p = 0.03). There was no significant change in plasma levels of 4 saturated, 4 trans and 10 unsaturated fatty acids. Decreasing dairy food intake by 2.5 (± 1.2) serves per day was not associated with change in levels of any plasma fatty acid levels. Conclusion Dietary advice to change dairy food has a minor effect on plasma fatty acid levels. Trial registration ACTRN12612000574842. PMID:24708591

  19. The Effect of Temperature on Fatty Acid Vesicle Formation in Simulated Deep-ocean Conditions

    NASA Astrophysics Data System (ADS)

    Shields, A.; Abbey, W.; Vance, S.

    2011-12-01

    Ice-covered worlds may harbor life beneath the ice within reservoirs of liquid water, or at water-rock interfaces in hydrothermal vent communities as have been observed in similar locales on Earth. One theory of life's emergence on Earth holds that initial metabolic and replication reactions took place in protobiotic cell membranes. These may have been composed of n- monocarboxylic acids (fatty acids) alone, rather than more complex phospholipid structures. Our experiments in the lab confirm that aqueous decanoic acid self-assembles into bilayer vesicles at standard temperature and pressure (25°C, 1 atm) in the pH range between 7 and 8.5, as indicated by stepwise increases in fluorescence induced by ultraviolet excitation of dye conjugated to decanoic acid solution. Life's chemical evolution in primordial oceans on Earth or elsewhere could have occurred over a range of temperatures, however. We explore the pH range for vesicle formation for temperatures from 0° C to 50° C. The role of pressure in the formation of protobiotic cell membranes is similarly important to whether life may have formed in deep-ocean environments on Earth, or on icy worlds in the solar system. Hydrostatic pressure has been shown to retard denaturation at above-optimal temperatures, but could affect the pH range for formation of protobiotic cell membranes.

  20. Environmental conditions that influence the ability of humic acids to induce permeability in model biomembranes.

    PubMed

    Ojwang', Loice M; Cook, Robert L

    2013-08-01

    The interaction of humic acids (HAs) with 1-palmitoyl-2-oleoyl-Sn-glycero-3-phosphocholine (POPC) large unilamellar vesicle (LUV) model biomembrane system was studied by fluorescence spectroscopy. HAs from aquatic and terrestrial (including coal) sources were studied. The effects of HA concentration and temperature over environmentally relevant ranges of 0 to 20 mg C/L and 10 to 30 °C, respectively, were investigated. The dosage studies revealed that the aquatic Suwannee River humic acid (SRHA) causes an increased biomembrane perturbation (percent leakage of the fluorescent dye, Sulforhodamine B) over the entire studied concentration range. The two terrestrial HAs, namely Leonardite humic acid (LAHA) and Florida peat humic acid (FPHA), at concentrations above 5 mg C/L, show a decrease or a plateau effect attributable to the competition within the HA mixture and/or the formation of "partial aggregates". The temperature studies revealed that biomembrane perturbation increases with decreasing temperature for all three HAs. Kinetic studies showed that the membrane perturbation process is complex with both fast and slow absorption (sorption into the bilayer) components and that the slow component could be fitted by first order kinetics. A mechanism based on "lattice errors" within the POPC LUVs is put forward to explain the fast and slow components. A rationale behind the concentration and temperature findings is provided, and the environmental implications are discussed. PMID:23805776

  1. The Effects of Salicylic Acid on Juvenile Zebrafish Danio rerio Under Flow-Through Conditions.

    PubMed

    Zivna, Dana; Blahova, Jana; Siroka, Zuzana; Plhalova, Lucie; Marsalek, Petr; Doubkova, Veronika; Zelinska, Gabriela; Vecerek, Vladimir; Tichy, Frantisek; Sehonova, Pavla; Svobodova, Zdenka

    2016-09-01

    The aquatic environment is becoming increasingly contaminated with pharmaceuticals. Salicylic acid (SA), which can be used individually or appear as a degradation product of the widely used acetylsalicylic acid was chosen for testing. Juvenile zebrafish Danio rerio were subjected to OECD test No. 215 (fish, juvenile growth test) with salicylic acid concentrations of 0.004; 0.04; 0.4; 4 and 40 mg/L. Specific growth rate (SGR), histological changes, and parameters of oxidative stress were evaluated. SA had no effects on histological changes, SGR, glutathione reductase, and lipid peroxidation. Increased catalytic activity of GPx was found at 0.04 mg/L compared to control, increased catalytic activity of catalase was found at 0.04 and 4 mg/L compared to control, and increased catalytic activity of glutathione-S-transferase was found at 0.004 and 0.04 mg/L compared to control (P < 0.05). Juvenile zebrafish turned out to be relatively insensitive to both environmentally relevant (0.004 mg/L) and higher concentrations of salicylic acid. PMID:27385367

  2. Injury and death of various Salmonella serotypes due to acidic conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acid injury of Salmonella could prevent detection of Salmonella in feed and feed-type samples. A previous study showed that after incubation in commonly used pre-enrichment media, mixed feeds and feed ingredients reached a pH (4.0 to 5.0) capable of injuring or killing Salmonella. Approximately 10...

  3. Braess's paradox in epidemic game: better condition results in less payoff.

    PubMed

    Zhang, Hai-Feng; Yang, Zimo; Wu, Zhi-Xi; Wang, Bing-Hong; Zhou, Tao

    2013-01-01

    Facing the threats of infectious diseases, we take various actions to protect ourselves, but few studies considered an evolving system with competing strategies. In view of that, we propose an evolutionary epidemic model coupled with human behaviors, where individuals have three strategies: vaccination, self-protection and laissez faire, and could adjust their strategies according to their neighbors' strategies and payoffs at the beginning of each new season of epidemic spreading. We found a counter-intuitive phenomenon analogous to the well-known Braess's Paradox, namely a better condition may lead to worse performance. Specifically speaking, increasing the successful rate of self-protection does not necessarily reduce the epidemic size or improve the system payoff. The range and degree of the Braess's Paradox are sensitive to both the parameters characterizing the epidemic spreading and the strategy payoff, while the existence of the Braess's Paradox is insensitive to the network topologies. This phenomenon can be well explained by a mean-field approximation. Our study demonstrates an important fact that a better condition for individuals may yield a worse outcome for the society. PMID:24256996

  4. Braess's Paradox in Epidemic Game: Better Condition Results in Less Payoff

    NASA Astrophysics Data System (ADS)

    Zhang, Hai-Feng; Yang, Zimo; Wu, Zhi-Xi; Wang, Bing-Hong; Zhou, Tao

    2013-11-01

    Facing the threats of infectious diseases, we take various actions to protect ourselves, but few studies considered an evolving system with competing strategies. In view of that, we propose an evolutionary epidemic model coupled with human behaviors, where individuals have three strategies: vaccination, self-protection and laissez faire, and could adjust their strategies according to their neighbors' strategies and payoffs at the beginning of each new season of epidemic spreading. We found a counter-intuitive phenomenon analogous to the well-known Braess's Paradox, namely a better condition may lead to worse performance. Specifically speaking, increasing the successful rate of self-protection does not necessarily reduce the epidemic size or improve the system payoff. The range and degree of the Braess's Paradox are sensitive to both the parameters characterizing the epidemic spreading and the strategy payoff, while the existence of the Braess's Paradox is insensitive to the network topologies. This phenomenon can be well explained by a mean-field approximation. Our study demonstrates an important fact that a better condition for individuals may yield a worse outcome for the society.

  5. Conditions for the formation of dilysyl-dipyrrolones A and B, and novel yellow dipyrrolone derivatives formed from xylose and amino acids in the presence of lysine.

    PubMed

    Nomi, Yuri; Sakamoto, Junko; Takenaka, Makiko; Ono, Hiroshi; Murata, Masatsune

    2011-01-01

    Foods derived from plants contain pentose in addition to hexose. It is well known that pentose contributes more to browning by the Maillard reaction than hexose does. We have recently found novel yellow compounds formed from xylose and lysine under weakly acidic conditions, named dilysyldipyrrolones (dilysyl-DPLs) A and B. We indicate in this study that dilysyl-DPLs were specifically formed under weakly acidic conditions from pentose, but not hexose. Moreover, we found novel DPL derivatives which were formed from xylose and such amino acids as alanine, arginine, aspartic acid, glutamic acid, isoleucine, leucine, phenylalanine, serine, and valine in the presence of lysine. PMID:21307606

  6. Advanced treatment of residual nitrogen from biologically treated coke effluent by a microalga-mediated process using volatile fatty acids (VFAs) under stepwise mixotrophic conditions.

    PubMed

    Ryu, Byung-Gon; Kim, Woong; Heo, Sung-Woon; Kim, Donghyun; Choi, Gang-Guk; Yang, Ji-Won

    2015-09-01

    This work describes the development of a microalga-mediated process for simultaneous removal of residual ammonium nitrogen (NH4(+)-N) and production of lipids from biologically treated coke effluent. Four species of green algae were tested using a sequential mixotrophic process. In the first phase-CO2-supplied mixotrophic condition-all microalgae assimilated NH4(+)-N with no evident inhibition. In second phase-volatile fatty acids (VFAs)-supplied mixotrophic condition-removal rates of NH4(+)-N and biomass significantly increased. Among the microalgae used, Arctic Chlorella sp. ArM0029B had the highest rate of NH4(+)-N removal (0.97 mg/L/h) and fatty acid production (24.9 mg/L/d) which were 3.6- and 2.1-fold higher than those observed under the CO2-supplied mixotrophic condition. Redundancy analysis (RDA) indicated that acetate and butyrate were decisive factors for increasing NH4(+)-N removal and fatty acid production. These results demonstrate that microalgae can be used in a sequential process for treatment of residual nitrogen after initial treatment of activated sludge. PMID:25881553

  7. Assessing the potential of amino acid δ13C patterns as a carbon source tracer in marine sediments: effects of algal growth conditions and sedimentary diagenesis

    NASA Astrophysics Data System (ADS)

    Larsen, T.; Bach, L. T.; Salvatteci, R.; Wang, Y. V.; Andersen, N.; Ventura, M.; McCarthy, M. D.

    2015-01-01

    Burial of organic carbon in marine sediments has a profound influence in marine biogeochemical cycles, and provides a sink for greenhouse gases such as CO2 and CH4. However, tracing organic carbon from primary production sources as well as its transformations in the sediment record remains challenging. Here we examine a novel but growing tool for tracing biosynthetic origin of amino acid carbon skeletons, based on natural occurring stable carbon isotope patterns in individual amino acids (δ13CAA). We focus on two important aspects for δ13CAA utility in sedimentary paleoarchives: first, the fidelity of source diagnostic of algal δ13CAA patterns across different oceanographic growth conditions; and second, the ability of δ13CAA patterns to record the degree of subsequent microbial amino acid synthesis after sedimentary burial. Using the marine diatom Thalassiosira weissflogii, we tested under controlled conditions how δ13CAA patterns respond to changing environmental conditions, including light, salinity, temperature, and pH. Our findings show that while differing oceanic growth conditions can change macromolecular cellular composition, δ13CAA isotopic patterns remain largely invariant. These results underscore that δ13CAA patterns should accurately record biosynthetic sources across widely disparate oceanographic conditions. We also explored how δ13CAA patterns change as a function of age, total nitrogen and organic carbon content after burial, in a marine sediment core from a coastal upwelling area off Peru. Based on the four most informative amino acids for distinguishing between diatom and bacterial sources (i.e. isoleucine, lysine, leucine and tyrosine), bacterial derived amino acids ranged from 10-15% in the sediment layers from the last 5000 years to 35% during the last glacial period. The larger bacterial fractions in older sediments indicate that bacterial activity and amino acid resynthesis progressed, approximately as a function of sediment age, to

  8. Salivary thiocyanate/nitrite inhibits hydroxylation of 2-hydroxybenzoic acid induced by hydrogen peroxide/Fe(II) systems under acidic conditions: possibility of thiocyanate/nitrite-dependent scavenging of hydroxyl radical in the stomach.

    PubMed

    Takahama, Umeo; Oniki, Takayuki

    2004-11-18

    Formation of OH radicals in the stomach is possible by Fenton-type reactions, as gastric juice contains ascorbic acid (AA), iron ions and H2O2. An objective of the present study is to elucidate the effects of salivary SCN- and NO2- on the hydroxylation of salicylic acid which was induced by H2O2/Fe(II) and AA/H2O2/Fe(II) systems. Thiocyanate ion inhibited the hydroxylation of salicylic acid by the above systems in acidic buffer solutions and in acidified saliva. The inhibition by SCN- was deduced to be due to SCN- -dependent scavenging of OH radicals. Nitrite ion could enhance the SCN- -dependent inhibition of the hydroxylation induced by AA/H2O2/Fe(II) systems. The enhancement was suggested to be due to scavenging of OH radicals by NO which was formed by the reactions among AA, HNO2 and SCN- contained in the reaction mixture. The concentrations of SCN- and NO2-, which were effective for the inhibition, were in ranges of their normal salivary concentrations. These results suggest that salivary SCN- can cooperate with NO2- to protect stomach from OH radicals formed by AA/H2O2/Fe(II) systems under acidic conditions. PMID:15535976

  9. Identifying Growth Conditions for Nicotiana benthimiana Resulting in Predictable Gene Expression of Promoter-Gus Fusion

    NASA Astrophysics Data System (ADS)

    Sandoval, V.; Barton, K.; Longhurst, A.

    2012-12-01

    Revoluta (Rev) is a transcription factor that establishes leaf polarity inArabidopsis thaliana. Through previous work in Dr. Barton's Lab, it is known that Revoluta binds to the ZPR3 promoter, thus activating the ZPR3 gene product inArabidopsis thaliana. Using this knowledge, two separate DNA constructs were made, one carrying revgene and in the other, the ZPR3 promoter fussed with the GUS gene. When inoculated in Nicotiana benthimiana (tobacco), the pMDC32 plasmid produces the Rev protein. Rev binds to the ZPR3 promoter thereby activating the transcription of the GUS gene, which can only be expressed in the presence of Rev. When GUS protein comes in contact with X-Gluc it produce the blue stain seen (See Figure 1). In the past, variability has been seen of GUS expression on tobacco therefore we hypothesized that changing the growing conditions and leaf age might improve how well it's expressed.

  10. Radiologic exposure conditions and resultant skin doses in application of xeroradiography to the orthodontic diagnosis

    SciTech Connect

    Nakasima, A.; Nakata, S.; Shimizu, K.; Takahama, Y.

    1980-12-01

    Xeroradiography is the recording of radiologic image by a photoelectric process rather than the photochemical one used in conventional radiography. In order to investigate the advantages and disadvantages of xeroradiography in the orthodontic field, minimum xeroradiologic exposure conditions for skull projections, joint projections, and hand projections were established by thirteen examiners and the relationship between the image production and x-ray radiation was compared with conventional film techniques. The advantages of xeroradiograph were finer and clear images caused by the edge effect and wide latitude of xeroradiography; the main hazard was the unavoidable larger skin dose required by the projection procedures. The skin doses with xeroradiography were 2.4 to 16.2 times larger than those with conventional film techniques.

  11. Can psychosocial work conditions protect against age-related cognitive decline? Results from a systematic review

    PubMed Central

    Nexø, Mette Andersen; Meng, Annette; Borg, Vilhelm

    2016-01-01

    According to the use it or lose it hypothesis, intellectually stimulating activities postpone age-related cognitive decline. A previous systematic review concluded that a high level of mental work demands and job control protected against cognitive decline. However, it did not distinguish between outcomes that were measured as cognitive function at one point in time or as cognitive decline. Our study aimed to systematically review which psychosocial working conditions were prospectively associated with high levels of cognitive function and/or changes in cognitive function over time. Articles were identified by a systematic literature search (MEDLINE, Web of Science (WOS), PsycNET, Occupational Safety and Health (OSH)). We included only studies with longitudinal designs examining the impact of psychosocial work conditions on outcomes defined as cognitive function or changes in cognitive function. Two independent reviewers compared title-abstract screenings, full-text screenings and quality assessment ratings. Eleven studies were included in the final synthesis and showed that high levels of mental work demands, occupational complexity or job control at one point in time were prospectively associated with higher levels of cognitive function in midlife or late life. However, the evidence to clarify whether these psychosocial factors also affected cognitive decline was insufficient, conflicting or weak. It remains speculative whether job control, job demands or occupational complexity can protect against cognitive decline. Future studies using methodological advancements can reveal whether workers gain more cognitive reserve in midlife and late life than the available evidence currently suggests. The public health implications of a previous review should thereby be redefined accordingly. PMID:27178844

  12. Can psychosocial work conditions protect against age-related cognitive decline? Results from a systematic review.

    PubMed

    Nexø, Mette Andersen; Meng, Annette; Borg, Vilhelm

    2016-07-01

    According to the use it or lose it hypothesis, intellectually stimulating activities postpone age-related cognitive decline. A previous systematic review concluded that a high level of mental work demands and job control protected against cognitive decline. However, it did not distinguish between outcomes that were measured as cognitive function at one point in time or as cognitive decline. Our study aimed to systematically review which psychosocial working conditions were prospectively associated with high levels of cognitive function and/or changes in cognitive function over time. Articles were identified by a systematic literature search (MEDLINE, Web of Science (WOS), PsycNET, Occupational Safety and Health (OSH)). We included only studies with longitudinal designs examining the impact of psychosocial work conditions on outcomes defined as cognitive function or changes in cognitive function. Two independent reviewers compared title-abstract screenings, full-text screenings and quality assessment ratings. Eleven studies were included in the final synthesis and showed that high levels of mental work demands, occupational complexity or job control at one point in time were prospectively associated with higher levels of cognitive function in midlife or late life. However, the evidence to clarify whether these psychosocial factors also affected cognitive decline was insufficient, conflicting or weak. It remains speculative whether job control, job demands or occupational complexity can protect against cognitive decline. Future studies using methodological advancements can reveal whether workers gain more cognitive reserve in midlife and late life than the available evidence currently suggests. The public health implications of a previous review should thereby be redefined accordingly. PMID:27178844

  13. Docosahexaenoic Acid Status in Pregnancy Determines the Maternal Docosahexaenoic Acid Status 3-, 6- and 12 Months Postpartum. Results from a Longitudinal Observational Study

    PubMed Central

    Markhus, Maria Wik; Rasinger, Josef Daniel; Malde, Marian Kjellevold; Frøyland, Livar; Skotheim, Siv; Braarud, Hanne Cecilie; Stormark, Kjell Morten; Graff, Ingvild Eide

    2015-01-01

    Background Essential fatty acid status as well as docosahexaenoic acid (DHA, 22:6n-3) declines during pregnancy and lactation. As a result, the DHA status may not be optimal for child development and may increase the risk for maternal postpartum depression. The objective of this study was to assess changes in the maternal fatty acid status from pregnancy to 12 months postpartum, and to study the impact of seafood consumption on the individual fatty acid status. Methods Blood samples and seafood consumption habits (gestation week 28, and three-, six- and 12 months postpartum) were collected in a longitudinal observational study of pregnant and postpartum women (n = 118). Multilevel linear modeling was used to assess both changes over time in the fatty acid status of red blood cells (RBC), and in the seafood consumption. Results Six fatty acids varied the most (>80%) across the four time points analyzed, including the derivative of the essential α-linoleic acid (ALA, 18:3n-3), DHA; the essential linoleic acid (LA, 18:2 n-6); and the LA derivative, arachidonic acid (AA, 20:4n-6). Over all, a large variation in individuals’ DHA- and AA status was observed; however, over the 15-month study period only small inter-individual differences in the longitudinal trajectory of DHA- and AA abundance in the RBC were detected. The median intake of seafood was lower than recommended. Regardless, the total weekly frequency of seafood and eicosapentaenoic acid (EPA, 20:5n-3)/DHA-supplement intake predicted the maternal level of DHA (μg/g RBC). Conclusion The period of depletion of the maternal DHA status during pregnancy and lactation, seem to turn to repletion from about six months postpartum towards one year after childbirth, irrespective of RBC concentration of DHA during pregnancy. Seafood and EPA/DHA-supplement intake predicted the DHA levels over time. Trial Registration www.helseforskning.etikkom.no 2009/570/REC, project number: 083.09 PMID:26331947

  14. Manipulation of culture conditions alters lipid content and fatty acid profiles of a wide variety of known and new oleaginous yeasts species

    PubMed Central

    Sitepu, Irnayuli R.; Sestric, Ryan; Ignatia, Laura; Levin, David; German, J. Bruce; Gillies, Laura A.; Almada, Luis A.G.; Boundy-Mills, Kyria L.

    2013-01-01

    Oleaginous yeasts have been studied for oleochemical production for over 80 years. Only a few species have been studied intensely. To expand the diversity of oleaginous yeasts available for lipid research, we surveyed a broad diversity of yeasts with indicators of oleaginicity including known oleaginous clades, and buoyancy. Sixty-nine strains representing 17 genera and 50 species were screened for lipid production. Yeasts belonged to Ascomycota families, Basidiomycota orders, and the yeast-like algal genus Prototheca. Total intracellular lipids and fatty acid composition were determined under different incubation times and nitrogen availability. Thirteen new oleaginous yeast species were discovered, representing multiple ascomycete and basidiomycete clades. Nitrogen starvation generally increased intracellular lipid content. The fatty acid profiles varied with the growth conditions regardless of taxonomic affiliation. The dominant fatty acids were oleic acid, palmitic acid, linoleic acid, and stearic acid. Yeasts and culture conditions that produced fatty acids appropriate for biodiesel were identified. PMID:23891835

  15. Synthesis of highly luminescent mercaptosuccinic acid-coated CdSe nanocrystals under atmospheric conditions.

    PubMed

    Dong, Meiting; Xu, Jingyi; Liu, Shuxian; Zhou, Ying; Huang, Chaobiao

    2014-11-01

    Here we report a facile one-pot method for the preparation of high-quality CdSe nanocrystals (NCs) in aqueous solution under an air atmosphere. Compared with the traditional use of NaHSe or H2 Se, the more stable sodium selenite is utilized as the Se source for preparing highly luminescent CdSe nanocrystals. By using mercaptosuccinic acid (MSA) as the capping agent and borate-citrate acid as the buffering solution, CdSe nanocrystals with high quantum yield (up to 70%) have been synthesized conveniently. The influence of different experimental parameters, such as the pH of the precursor solution, the molar ratio of Cd(2+) to Na2 SeO3 and Cd(2+) to MSA on the CdSe nanocrystals, has been systematically investigated. The prepared CdSe NCs were spherical with a size of ~ 5 nm. PMID:24639040

  16. Interactions in the solid state. I: Interactions of sodium bicarbonate and tartaric acid under compressed conditions.

    PubMed

    Usui, F; Carstensen, J T

    1985-12-01

    The interaction of NaHCO3 and tartaric acid in powder mixtures and compressed tablets has been studied. It has been found that in an open system the reaction is simply a decarboxylation of NaHCO3 and that the effect of compression on the reaction rate can be attributed to the brittle fracture (and subsequent surface area increase) that occurs on compaction. In a closed system the decomposition of the mixture is an interaction between the acid and the base, and it is mediated by the amount of moisture in the system. This latter is a product of reaction, and a suitable kinetic scheme is described for this. It is shown that "curing" the sodium bicarbonate by heating it to, e.g., 90 degrees C stabilizes the system by virtue of the formation of surface Na2CO3, which acts as a moisture scavenger. PMID:3003337

  17. Preliminary results of a miniaturized respiratory sensor system used under hypergravity conditions up to 9 gz

    NASA Astrophysics Data System (ADS)

    Guenther, A.; Baumann, R.; Meyer, C.; Schmiel, T.; Nehring, M.; Tajmar, M.

    2013-12-01

    Respiratory gas analyses are used to explore the influence of increased gravity on the physiology of breathing. Due to the mass, size and intricacy of standard measurement systems, previous studies were limited to a maximum acceleration of + 5 gz (head-to-foot direction). Furthermore, no in situ mainstream measurements of oxygen and carbon dioxide concentration were possible under hypergravity conditions so far. This paper shows a first study which demonstrates a respiratory sensor system developed at the Institute for Aerospace Engineering at TU Dresden. This system is suitable for an in situ measurement of respiratory changes up to + 9 gz (maximum acceleration of jet pilots) and therefore provides a possibility for detailed physiological analyses in future. Three jet pilots were equipped with this system and accelerated under a defined profile up to 7, 8 and + 9 gz. The breathing air flow, oxygen and carbon dioxide concentration were recorded with our miniaturized solid state electrolyte gas sensors, which are also described in this paper. The analysed data show significant changes of the measured respiratory parameters depending on the G-level, the acceleration rate (G-rate of onset [g s-1]) and the examination time.

  18. New Results in Two-Phase Pressure Drop Calculations at Reduced Gravity Conditions

    NASA Astrophysics Data System (ADS)

    Braisted, Jon; Kurwitz, Cable; Best, Frederick

    2004-02-01

    The mass, power, and volume energy savings of two-phase systems for future spacecraft creates many advantages over current single-phase systems. Current models of two-phase phenomena such as pressure drop, void fraction, and flow regime prediction are still not well defined for space applications. Commercially available two-phase modeling software has been developed for a large range of acceleration fields including reduced-gravity conditions. Recently, a two-phase experiment has been flown to expand the two-phase database. A model of the experiment was created in the software to determine how well the software could predict the pressure drop observed in the experiment. Of the simulations conducted, the computer model shows good agreement of the pressure drop in the experiment to within 30%. However, the software does begin to over-predict pressure drop in certain regions of a flow regime map indicating that some models used in the software package for reduced-gravity modeling need improvement.

  19. [Possible role of altered levels of plasma docosahexaenoic acid in the pathogenesis of retinitis pigmentosa. Preliminary results].

    PubMed

    Simonelli, F; Milone, A; Iura, A; Picardi, C; La Banca, A M; Cotticelli, L; Rinaldi, E

    1990-09-01

    Plasma samples obtained from Retinitis Pigmentosa (R.P.) patients and controls were assayed for docosahexaenoic acid (DXA), the major fatty acid in photoreceptor cells, in order to evaluate the possibility that abnormalities in PUFA metabolism could be involved in R.P. pathogenesis. Our preliminary results show levels of plasma DXA in dominantly inherited R.P. lower than in the recessive forms and controls. PMID:2149985

  20. Effect of processing conditions on phytic acid, calcium, iron, and zinc contents of lime-cooked maize.

    PubMed

    Bressani, Ricardo; Turcios, Juan Carlos; Colmenares de Ruiz, Ana Silvia; de Palomo, Patricia Palocios

    2004-03-10

    Tortillas are made by cooking maize in a lime solution during variable times and temperatures, steeping the grain for up to 12 h, washing and grinding it to a fine dough, and cooking portions as flat cakes for up to 6 min. The effects of the main processing steps on the chemical composition, nutritive value, and functional and physicochemical characteristics have been areas of research. The present work evaluates the effect of lime concentration (0, 1.2, 2.4, and 3.6%) and cooking times (45, 60, and 75 min) on phytic acid retention of whole maize, its endosperm, and germ, as well as on the content of calcium, iron, and zinc on the same samples. The effects of steeping time and temperature and steeping medium on the phytic acid of lime-cooked maize were also studied. Finally, phytic acid changes from raw maize to tortilla were also measured. The results indicated that lime concentration and cooking time reduce phytic acid content in whole grain (17.4%), in endosperm (45.8%), and in germ (17.0%). Statistical analyses suggested higher phytic acid loss with 1.2% lime and 75 min of cooking. Cooking with the lime solution is more effective in reducing phytic acid than cooking with water. Steeping maize in lime solution at 50 degrees C during 8 h reduced phytic acid an additional 8%. The total loss of phytic acid from maize to tortilla was 22%. Calcium content increased in whole maize, endosperm, and germ with lime concentration and cooking and steeping times. The increase was higher in the germ than in the endosperm. The level, however, can be controlled if steeping of the cooked grain is conducted in water. Iron and zinc contents were not affected by nixtamalization processing variables but were affected in steeping. PMID:14995114

  1. Subtypes of Disordered Gamblers: Results from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC)

    PubMed Central

    Nower, Lia; Martins, Silvia S.; Lin, Keng-Han; Blanco, Carlos

    2014-01-01

    Aims To derive empirical subtypes of problem gamblers based on etiological and clinical characteristics described in the Pathways Model, using data from a nationally representative survey of U.S. adults. Design & Measurement Data were collected from structured diagnostic face-to-face interviews using the Alcohol Use Disorder and Associated Disabilities Interview Schedule DSM-IV version IV (AUDADIS-IV). Setting The study utilized data from U.S. National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). Participants All disordered gambling participants (N = 581) from a nationally representative cross-sectional sample of civilian non-institutionalized adults aged 18 years or older. Findings Latent class analyses indicated the best-fitting model was a three-class solution. Those in the largest class (Class 1: 51%, n=295) reported the lowest overall levels of psychopathology including gambling problem severity and mood disorders. In contrast, respondents in Class 2 (20%, n=117) had a high probability of endorsing past-year substance use disorders, moderate probabilities of having parents with alcohol/drug problems and of having a personality disorder, and the highest probability for past-year mood disorders. Respondents in Class 3 (29%, n=169) had the highest probabilities of personality and prior-to-past year mood disorders, substance use disorders, separation/divorce, drinking-related physical fights, and parents with alcohol/drug problems and/or a history of ASPD. Conclusions Three subtypes of disordered gamblers can be identified, roughly corresponding to the sub-types of the Pathways Model, ranging from a subgroup with low levels of gambling severity and psychopathology to one with high levels of gambling problem severity and comorbid psychiatric disorders. PMID:23072599

  2. Survival of lichens and bacteria exposed to outer space conditions - Results of the Lithopanspermia experiments

    NASA Astrophysics Data System (ADS)

    de la Torre, Rosa; Sancho, Leopoldo G.; Horneck, Gerda; Ríos, Asunción de los; Wierzchos, Jacek; Olsson-Francis, Karen; Cockell, Charles S.; Rettberg, Petra; Berger, Thomas; de Vera, Jean-Pierre P.; Ott, Sieglinde; Frías, Jesus Martinez; Melendi, Pablo Gonzalez; Lucas, Maria Mercedes; Reina, Manuel; Pintado, Ana; Demets, René

    2010-08-01

    In the space experiments Lithopanspermia, experimental support was provided to the likelihood of the lithopanspermia concept that considers a viable transport of microorganisms between the terrestrial planets by means of meteorites. The rock colonising lichens Rhizocarpon geographicum and Xanthoria elegans, the vagrant lichen Aspicilia fruticulosa, and endolithic and endoevaporitic communities of cyanobacteria and bacteria with their natural rock substrate were exposed to space for 10 days onboard the Biopan facility of the European Space Agency (ESA). Biopan was closed during launch and re-entry. In addition, in the Stone facility, one sample of R. geographicum on its natural granitic substrate was attached at the outer surface of the re-entry capsule close to the stagnation point, only protected by a thin cover of glass textolite. Post-flight analysis, which included determination of the photosynthetic activity, LIVE/DEAD staining, and germination capacity of the ascospores, demonstrated that all three lichen were quite resistant to outer space conditions, which include the full spectrum of solar extraterrestrial electromagnetic radiation or selected wavelength ranges. This high resistance of the lichens to space appears to be due to their symbiotic nature and protection by their upper pigmented layer, the cortex. In contrast, the rock- or halite-inhabiting bacteria were severely damaged by the same exposure. After atmospheric re-entry, the granite of the Stone sample was transformed into a glassy, nearly homogenous material, with several friction striae. None of the lichen cells survived this re-entry process. The data suggest that lichens are suitable candidates for testing the concept of lithopanspermia, because they are extremely resistant to the harsh environment of outer space. The more critical event is the atmospheric re-entry after being captured by a planet. Experiments simulating the re-entry process of a microbe-carrying meteoroid did not show any

  3. 24 CFR 902.68 - Technical review of results of PHAS physical condition indicator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... these reviews, the burden of proof is on the PHA to show that an error occurred. (2) A request for... Review, 550 12th Street, SW., Suite 100, Washington, DC 20410 and must be received by HUD no later than 30 days following the issuance of the applicable results to the PHA. (b) Technical review of...

  4. 24 CFR 902.68 - Technical review of results of PHAS physical condition indicator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... these reviews, the burden of proof is on the PHA to show that an error occurred. (2) A request for... Review, 550 12th Street, SW., Suite 100, Washington, DC 20410 and must be received by HUD no later than 30 days following the issuance of the applicable results to the PHA. (b) Technical review of...

  5. 24 CFR 902.68 - Technical review of results of PHAS physical condition indicator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... these reviews, the burden of proof is on the PHA to show that an error occurred. (2) A request for... Review, 550 12th Street, SW., Suite 100, Washington, DC 20410 and must be received by HUD no later than 30 days following the issuance of the applicable results to the PHA. (b) Technical review of...

  6. Early results from a systems approach to improving the performance and lifetime of lead acid batteries

    NASA Astrophysics Data System (ADS)

    Kellaway, M. J.; Jennings, P.; Stone, D.; Crowe, E.; Cooper, A.

    Lead acid batteries offer important advantages in respect of unit cost and ease of recycling. They also have good power and low temperature performance. However, for hybrid electric vehicle (HEV) duty with their extreme rates and continuous PSoC operation, improvements are required to significantly extend service life. The Reliable Highly Optimised Lead Acid Battery (RHOLAB) project is taking a radical approach to the design of a lead acid HEV battery pack to address this issue, taking a systems approach to produce a complete pack that is attractive to vehicle manufacturers. This paper describes the project at an intermediate stage where some testing has been completed and the construction of the complete pack system is well under way.

  7. Results of electric-vehicle propulsion system performance on three lead-acid battery systems

    NASA Technical Reports Server (NTRS)

    Ewashinka, J. G.

    1984-01-01

    Three types of state of the art 6 V lead acid batteries were tested. The cycle life of lead acid batteries as a function of the electric vehicle propulsion system design was determined. Cycle life, degradation rate and failure modes with different battery types (baseline versus state of the art tubular and thin plate batteries) were compared. The effects of testing strings of three versus six series connected batteries on overall performance were investigated. All three types do not seem to have an economically feasible battery system for the propulsion systems. The tubular plate batteries on the load leveled profile attained 235 cycles with no signs of degradation and minimal capacity loss.

  8. Results of electric-vehicle propulsion system performance on three lead-acid battery systems

    NASA Technical Reports Server (NTRS)

    Ewashinka, J. G.

    1984-01-01

    Three types of state of the art 6 V lead acid batteries were tested. The cycle life of lead acid batteries as a function of the electric vehicle propulsion system design was determined. Cycle life, degradation rate and failure modes with different battery types (baseline versus state of the art tubular and thin plate batteries were compared. The effects of testing strings of three versus six series connected batteries on overall performance were investigated. All three types do not seem to have an economically feasible battery system for the propulsion systems. The tubular plate batteries on the load leveled profile attained 235 cycles with no signs of degradation and minimal capacity loss.

  9. Forecast of long term coal supply and mining conditions: Model documentation and results

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A coal industry model was developed to support the Jet Propulsion Laboratory in its investigation of advanced underground coal extraction systems. The model documentation includes the programming for the coal mining cost models and an accompanying users' manual, and a guide to reading model output. The methodology used in assembling the transportation, demand, and coal reserve components of the model are also described. Results presented for 1986 and 2000, include projections of coal production patterns and marginal prices, differentiated by coal sulfur content.

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

    PubMed

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

    2015-05-20

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

  11. AG Channel Measurement and Modeling Results for Over-Sea Conditions

    NASA Technical Reports Server (NTRS)

    Matolak, David; Sun, Rouyu

    2014-01-01

    This report describes results from flight tests conducted in an over-sea environment, for the purpose of characterizing the air-to-ground (AG) channel, for future unmanned aircraft system (UAS) communication system analysis and design. These results are for the first of a set of several flight tests conducted in different ground site (GS) environments. An ultimate aim of all these tests is the development of models for the AG channel that can be used in communication system evaluation. In this report we provide measured results for propagation path loss, root-mean square delay spread (RMS-DS), and the correlation coefficient of the primary received signal components on the four antennas (two antennas for C-band, two for L-band). For path loss, the curved-earth two-ray model provides a reasonable fit to the measured data, altered by several dB at the shortest link distances by aircraft antenna pattern effects. This two-ray model also accounts for the majority of measured RMS-DS results of a few tens of nanoseconds, except for the occasional intermittent reflections from surface objects. These intermittent reflections yield RMS-DS values up to several hundred nanoseconds. For portions of the flight path that were over a harbor area highly populated with boats, the channel was found to be more "continuously dispersive," with RMS-DS reaching approximately 250 ns. A separate model will be developed for this over-harbor setting. The correlation coefficient results are still undergoing analysis; preliminary observations are that correlation between signals on the same-band antennas is generally large (>0.6) for the C-band straight flight paths, whereas for the L-band signals and for the oval-shaped flight paths the correlation is generally small (below 0.4). Inter-band correlations are typically very small, and are well modeled as zero-mean Gaussian in distribution, with a standard deviation less than 0.2. Hence the over-sea channel effects in the two bands can be

  12. Conditions optimising on the yield of biomass, total lipid, and valuable fatty acids in two strains of Skeletonema menzelii.

    PubMed

    Jiang, Xiamin; Han, Qingxi; Gao, Xiuzhi; Gao, Guang

    2016-03-01

    Polyunsaturated fatty acids (PUFA) and eicosapentaenoic acid (EPA) are essential for the health of aquaculture organisms and human beings. A total of 9 species of diatoms were screened and two strains of Skeletonema menzelii were selected for further study due to their high growth rates, PUFA and EPA contents. The culture conditions for the yield of biomass, total lipid, EPA and PUFA were optimised. The quickest growth rates (0.28-0.41d(-1)) were achieved with moderate supplement of nitrogen, phosphorus, iron and silicon. The accumulation of total lipid (17.85-22.70% of dry weight) benefitted from deprivation of nitrogen, phosphorus and silicon, but a moderate iron supplement. Highest PUFA (38.26-50.48% of total fatty acids) or EPA (14.26-18.39% of total fatty acids) contents were observed under high nitrogen and phosphorus supplement, moderate available iron but deprivation of silicon. These findings make tangible contributions to culture S. menzelii for commercial production of PUFA or EPA. PMID:26471612

  13. Research results from the Advanced Lead-Acid Battery Consortium point the way to longer life and higher specific energy for lead/acid electric-vehicle batteries

    NASA Astrophysics Data System (ADS)

    Moseley, P. T.

    Amidst the welter of publicity devoted to the newer battery chemistries, the remarkable progress made by lead/acid battery technologists in response to the needs of the emerging electric-vehicle market has tended to be overlooked. The flooded design of battery, launched by Gaston Planté around 1860, has given way to a valve-regulated variant which has a history dating only from the 1970s. The key parameters of this `maintenance free' battery have been improved markedly during the course of the development programme of the Advanced Lead-Acid Battery Consortium (ALABC), and it is likely that lead/acid will continue to feature strongly in motive-power applications as a result of its cost advantage and of its enhanced effectiveness.

  14. Experimental and computational results from the NASA Lewis low-speed centrifugal impeller at design and part-flow conditions

    SciTech Connect

    Chriss, R.M.; Wood, J.R.; Hathaway, M.D.

    1996-01-01

    The NASA Lewis Low-Speed Centrifugal Compressor (LSCC) has been investigated with laser anemometry and computational analysis at two flow conditions: the design condition as well as a lower mass flow condition. Previously reported experimental and computational results at the design condition are in the literature (Hathaway et al., 1993). In that paper extensive analysis showed that inducer blade boundary layers are centrifuged outward and entrained into the tip clearance flow and hence contribute significantly to the throughflow wake. In this report results are presented for a lower mass flow condition along with further results from the design case. The data set contained herein consists of three-dimensional laser velocimeter results upstream, inside, and downstream of the impeller. In many locations data have been obtained in the blade and endwall boundary layers. The data are presented in the form of throughflow velocity contours as well as secondary flow vectors. The results reported herein illustrate the effects of flow rate on the development of the throughflow momentum wake as well as on the secondary flow. The computational results presented confirm the ability of modern computational tools to model the complex flow in a subsonic centrifugal compressor accurately. However, the blade tip shape and tip clearance must be known in order to properly simulate the flow physics. In addition, the ability to predict changes in the throughflow wake, which is largely fed by the tip clearance flow, as the impeller is throttled should give designers much better confidence in using computational tools to improve impeller performance.

  15. LLNL heart valve condition classification project anechoic testing results at the TRANSDEC evaluation facility

    SciTech Connect

    Candy, J V

    1999-10-31

    This report first briefly outlines the procedures and support/activation fixture developed at LLNL to perform the heart valve tests in an anechoic-like tank at the US Navy Transducer Evaluation Facility (TransDec) located in San Diego, CA. Next they discuss the basic experiments performed and the corresponding experimental plan employed to gather meaningful data systematically. The signal processing required to extract the desired information is briefly developed along with some of the data. Finally, they show the results of the individual runs for each valve, point out any of the meaningful features and summaries.

  16. Fatal autoimmunity results from the conditional deletion of Snai2 and Snai3

    PubMed Central

    Pioli, Peter D.; Chen, Xinjian; Weis, Janis J.; Weis, John H.

    2015-01-01

    Transcriptional regulation of gene expression is a key component of orchestrating proper immune cell development and function. One strategy for maintaining these transcriptional programs has been the evolution of transcription factor families with members possessing overlapping functions. Using the germ line deletion of Snai2 combined with the hematopoietic specific deletion of Snai3, we report that these factors function redundantly to preserve the development of B and T cells. Such animals display severe lymphopenia, alopecia and dermatitis as well as profound autoimmunity manifested by the production of high levels of autoantibodies as early as 3 weeks of age and die by 30 days after birth. Autoantibodies included both IgM and IgG isotypes and were reactive against cytoplasmic and membranous components. A regulatory T cell defect contributed to the autoimmune response in that adoptive transfer of wild type regulatory T cells alleviated symptoms of autoimmunity. Additionally, transplantation of Snai2/Snai3 double deficient bone marrow into Snai2 sufficient Rag2−/− recipients resulted in autoantibody generation. The results demonstrated that appropriate expression of Snai2 and Snai3 in cells of hematopoietic derivation plays an important role in development and maintenance of immune tolerance. PMID:25732600

  17. Impact of optimization conditions on the result at optimizing illumination and mask

    NASA Astrophysics Data System (ADS)

    Tsujita, Koichiro; Mikami, Koji; Ishii, Hiroyuki; Suzuki, Akiyoshi

    2008-03-01

    Illumination for SRAM device pattern with peripheral circuit is optimized applying OPC during optimization. At first the memory cell is targeted, next library patterns that represent the peripheral circuit are added as the targets one by one, and it is investigated how the optimized illumination varies. As optimized targets ILS and dose-focus window are used. For the case of ILS the optimized illumination shapes become milder as more patterns are evaluated and the OPC result becomes weaker correspondingly. For the case of window the tendency is similar but not so intense. The illuminations optimized by ILS and window are different. The optimized illuminations by optical and resist simulation are a little different. As practical application illumination defined by functions such as annular is evaluated, where the information of actual scanners are applied. At first 1/4 divided polarization plate is used instead of tangential polarization. Secondly illumination is searched in the solution space that consists of hardware design instead of numerical expression. By introducing the information the optimized illuminations are varied. From these results it turns out that the optimization tool should handle the information of actual scanners properly. And we have developed the solution tool (k1-TUNE).

  18. AG Channel Measurement and Modeling Results for Over-Water and Hilly Terrain Conditions

    NASA Technical Reports Server (NTRS)

    Matolak, David W.; Sun, Ruoyu

    2015-01-01

    This report describes work completed over the past year on our project, entitled "Unmanned Aircraft Systems (UAS) Research: The AG Channel, Robust Waveforms, and Aeronautical Network Simulations." This project is funded under the NASA project "Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS)." In this report we provide the following: an update on project progress; a description of the over-freshwater and hilly terrain initial results on path loss, delay spread, small-scale fading, and correlations; complete path loss models for the over-water AG channels; analysis for obtaining parameter statistics required for development of accurate wideband AG channel models; and analysis of an atypical AG channel in which the aircraft flies out of the ground site antenna main beam. We have modeled the small-scale fading of these channels with Ricean statistics, and have quantified the behavior of the Ricean K-factor. We also provide some results for correlations of signal components, both intra-band and inter-band. An updated literature review, and a summary that also describes future work, are also included.

  19. Fatal autoimmunity results from the conditional deletion of Snai2 and Snai3.

    PubMed

    Pioli, Peter D; Chen, Xinjian; Weis, Janis J; Weis, John H

    2015-05-01

    Transcriptional regulation of gene expression is a key component of orchestrating proper immune cell development and function. One strategy for maintaining these transcriptional programs has been the evolution of transcription factor families with members possessing overlapping functions. Using the germ line deletion of Snai2 combined with the hematopoietic specific deletion of Snai3, we report that these factors function redundantly to preserve the development of B and T cells. Such animals display severe lymphopenia, alopecia and dermatitis as well as profound autoimmunity manifested by the production of high levels of autoantibodies as early as 3 weeks of age and die by 30 days after birth. Autoantibodies included both IgM and IgG isotypes and were reactive against cytoplasmic and membranous components. A regulatory T cell defect contributed to the autoimmune response in that adoptive transfer of wild type regulatory T cells alleviated symptoms of autoimmunity. Additionally, transplantation of Snai2/Snai3 double deficient bone marrow into Snai2 sufficient Rag2(-/-) recipients resulted in autoantibody generation. The results demonstrated that appropriate expression of Snai2 and Snai3 in cells of hematopoietic derivation plays an important role in development and maintenance of immune tolerance. PMID:25732600

  20. 78 FR 25699 - 1-Hydroxyethylidene-1, 1-Diphosphonic Acid From India: Preliminary Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-02

    ...-Diphosphonic Acid from India and the People's Republic of China: Antidumping Duty Orders, 74 FR 19197 (April 28...: Final Modification, 77 FR 8101 (February 14, 2012). Where Aquapharm reported entered value for its U.S...: Assessment of Antidumping Duties, 68 FR 23954 (May 6, 2003). Cash Deposit Requirements The following...

  1. 77 FR 15357 - 1-Hydroxyethylidene-1, 1-Diphosphonic Acid From India: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-15

    ...-Hydroxyethylidene-1, 1-Diphosphonic Acid from India (76 FR 78237). We invited parties to comment on the preliminary...: Assessment of Antidumping Duties, 68 FR 23954 (May 6, 2003) (Assessment Policy Notice). This clarification... from India: Notice of Final Determination of Sales at Less Than Fair Value, 74 FR 10543 (March 11,...

  2. 76 FR 7532 - 1-Hydroxyethylidene-1, 1-Diphosphonic Acid from India: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-10

    ...-Hydroxyethylidene-1, 1-Diphosphonic Acid from India (75 FR 73042). We invited parties to comment on the preliminary...: Assessment of Antidumping Duties, 68 FR 23954 (May 6, 2003) (Assessment Policy Notice). This clarification... from India: Notice of Final Determination of Sales at Less Than Fair Value, 74 FR 10543 (March 11,...

  3. Boundary conditions and the critical Casimir force on an Ising model film: exact results in one and two dimensions.

    PubMed

    Rudnick, Joseph; Zandi, Roya; Shackell, Aviva; Abraham, Douglas

    2010-10-01

    Finite-size effects in certain critical systems can be understood as universal Casimir forces. Here, we compare the Casimir force for free, fixed, periodic, and antiperiodic boundary conditions in the exactly calculable case of the ferromagnetic Ising model in one and two dimensions. We employ a procedure which allows us to calculate the Casimir force with the aforementioned boundary conditions analytically in a transparent manner. Among other results, we find an attractive Casimir force for the case of periodic boundary conditions and a repulsive Casimir force in the antiperiodic case. PMID:21230249

  4. Performance tests of air source heat pumps under frosting conditions. Quality of results

    NASA Astrophysics Data System (ADS)

    Fahlen, P.

    This report focuses on the analysis of uncertainties in research regarding air-source heat pumps. The principles recommended by the Western European Calibration Conference (WECC) are applied and the generated information is condensed in the form of uncertainty budgets. The ensuring discussion, and the Measurement Assurance Program that was applied during the research work are also relevant to general testing of cooling coils, e.g. for air source heat pumps. The general conclusion of the analysis is that the method of determining frost mass by continuous weighing and frost density by inference from pressure drop considerations, which is presented in the report, has the potential to produce results with an accuracy on a par with the best previously used techniques to investigate frosting and defrosting phenomena. Furthermore, the methodology has the distinct advantage of yielding online measuring possibilities and being much less time consuming than traditional techniques.

  5. Electrical resistivity measurements of brine saturated porous media near reservoir conditions: Awibengkok preliminary results

    SciTech Connect

    Bonner, B; Duba, A; Roberts, J

    1999-06-28

    Laboratory measurements of the electrical resistivity of rocks and synthetic rocks with confining pressures up to 100 bars and temperatures between 20 and 211 C were performed to further investigate how the pore-size distribution and capillarity affects boiling in porous media. Similar to previous measurements on samples from The Geysers, CA, we observed a gradual increase in resistivity when pore pressure was decreased below the phase-boundary pressure of free water, an indication that boiling is controlled not only by temperature and pressure, but also by pore size distribution. Other important phenomena observed were strong resistance fluctuations during boiling that may be chaotic, and salt deposition that caused sample cracking. If confirmed in further experiments, these results may lead to a new geophysical diagnostic for locating boiling in high permeability areas of geothermal reservoirs and for methods of permeability alteration.

  6. Indoor air pollution due to tobacco smoke under real conditions. Preliminary results.

    PubMed

    Klus, H; Begutter, H; Nowak, A; Pinterits, G; Ultsch, I; Wihlidal, H

    1985-08-01

    A short review exploring the generation and composition of tobacco smoke is given. Experimental arrangements used to record sidestream smoke are critically discussed. Data from own experiments in a tobacco smoke polluted office room were presented and discussed. These data include nicotine, ammonia, formaldehyde, acetaldehyde, hydrogen cyanide, CO, NO and NO2. First results about the diameter of the particles in the smoke polluted room were also given. By the aid of the RINGOLD's equation the COHB content on basis of the CO-values of exhaled breath of active and passive smokers were determined. Data about the nitrosamine content in the air of the room during the smoke tests were also given and discussed. PMID:3836513

  7. Formation of Fe/mg Smectite Under Acidic Conditions from Synthetic Adirondack Basaltic Glass: an Analog to Fe/mg Smectite Formation on Mars

    NASA Technical Reports Server (NTRS)

    Sutter, B.; Peretyazhko, T.; Morris, R. V.; Ming, D. W.

    2014-01-01

    peaks. Moessbauer analysis coupled with future experiments are planned to verify if nontronite can be formed under mildly acidic and oxic conditions. Results of this work demonstrate that acidic conditions could have occurred on an early Mars, which allowed for smectite formation but inhibited carbonate formation.

  8. Formation of Fe/Mg Smectite under acidic conditions from synthetic Adirondack Basaltic Glass: An Analog to Fe/Mg Smectite Formation on Mars.

    NASA Astrophysics Data System (ADS)

    Sutter, B.; Peretyazhko, T.; Morris, R. V.; Ming, D. W.

    2014-12-01

    coupled with future experiments are planned to verify if nontronite can be formed under mildly acidic and oxic conditions. Results of this work demonstrate that acidic conditions could have occurred on an early Mars, which allowed for smectite formation but inhibited carbonate formation.

  9. Sensitive detection of strong acidic condition by a novel rhodamine-based fluorescent pH chemosensor.

    PubMed

    Tan, Jia-Lian; Yang, Ting-Ting; Liu, Yu; Zhang, Xue; Cheng, Shu-Jin; Zuo, Hua; He, Huawei

    2016-05-01

    A novel rhodamine-based fluorescent pH probe responding to extremely low pH values has been synthesized and characterized. This probe showed an excellent photophysical response to pH on the basis that the colorless spirocyclic structure under basic conditions opened to a colored and highly fluorescent form under extreme acidity. The quantitative relationship between fluorescence intensity and pH value (1.75-2.62) was consistent with the equilibrium equation pH = pKa + log[(Imax - I)/(I - Imin )]. This sensitive pH probe was also characterized with good reversibility and no interaction with interfering metal ions, and was successfully applied to image Escherichia coli under strong acidity. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26467547

  10. 76 FR 48142 - 1-Hydroxyethylidene-1, 1-Diphosphonic Acid From the People's Republic of China: Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-08

    ... Review in Part, 76 FR 19325 (April 7, 2011) (``Preliminary Results''). DATES: Effective Date: August 8... International Trade Administration 1-Hydroxyethylidene-1, 1-Diphosphonic Acid From the People's Republic of... results of the administrative review of the antidumping duty order on 1-hydroxyethylidene-1,...

  11. Condition Assessment of PCI Bridge Girder a Result of The Reduction Prestressing Force

    NASA Astrophysics Data System (ADS)

    Suangga, Made; Hidayat, Irpan; Lutter, Bobby

    2014-03-01

    PCI bridge girders is known and widely used for many construction e.g.: bridge, wharf, flyover, and other application. PC Bridge girders have two types: Pre - tensioned girders and post - tensioned girders. In pre tensioned girders, prestressing in carried out first then after that the fresh concrete poured. The prestressing process in only carried off after the concrete has sufficient strength. In this study, analysis was conducted for PCI bridge girder with span is 40 meters. Based on the data geometry bridge dimension girder, material girder, and material strands cable, it will be analyzed to calculate the natural frequencies and moment capacity using finite element program (Midas/Civil program). So it can be estimated how much the percentage reduction prestress force on the bridge until PCI bridge structure collapses. From the calculation, it found that the pattern comparison between reduction prestressing force and natural frequency are linear. These results are also similar for natural frequency versus moment capacity.PCI bridge will collapse when the reduction prestreesing force of 45 % to 50 % from the total loss of prestressing.

  12. Correction of the inertial effect resulting from a plate moving under low-friction conditions.

    PubMed

    Yang, Feng; Pai, Yi-Chung

    2007-01-01

    The purpose of the present study was to develop a set of equations that can be employed to remove the inertial effect introduced by the movable platform upon which a person stands during a slip induced in gait; this allows the real ground reaction force (GRF) and its center of pressure (COP) to be determined. Analyses were also performed to determine how sensitive the COP offsets were to the changes of the parameters in the equation that affected the correction of the inertial effect. In addition, the results were verified empirically using a low friction movable platform together with a stationary object, a pendulum, and human subjects during a slip induced during gait. Our analyses revealed that the amount of correction required for the inertial effect due to the movable component is affected by its mass and its center of mass (COM) position, acceleration, the friction coefficient, and the landing position of the foot relative to the COM. The maximum error in the horizontal component of the GRF was close to 0.09 (body weight) during the recovery from a slip in walking. When uncorrected, the maximum error in the COP measurement could reach as much as 4 cm. Finally, these errors were magnified in the joint-moment computation and propagated proximally, ranging from 0.2 to 1.0 Nm/body mass from the ankle to the hip. PMID:17306274

  13. Relative Importance of Nitrite Oxidation by Hypochlorous Acid under Chloramination Conditions

    EPA Science Inventory

    The importance of nitrite’s oxidation by tree chlorine under chloramination conditions was evaluated using batch kinetic experiments and a chloramine model implemented into the computer program AWUASIM. The experimental data was best represented with the inclusion of a reaction b...

  14. Direct Electric Current Treatment under Physiologic Saline Conditions Kills Staphylococcus epidermidis Biofilms via Electrolytic Generation of Hypochlorous Acid

    PubMed Central

    Sandvik, Elizabeth L.; McLeod, Bruce R.; Parker, Albert E.; Stewart, Philip S.

    2013-01-01

    The purpose of this study was to investigate the mechanism by which a direct electrical current reduced the viability of Staphylococcus epidermidis biofilms in conjunction with ciprofloxacin at physiologic saline conditions meant to approximate those in an infected artificial joint. Biofilms grown in CDC biofilm reactors were exposed to current for 24 hours in 1/10th strength tryptic soy broth containing 9 g/L total NaCl. Dose-dependent log reductions up to 6.7 log10 CFU/cm2 were observed with the application of direct current at all four levels (0.7 to 1.8 mA/cm2) both in the presence and absence of ciprofloxacin. There were no significant differences in log reductions for wells with ciprofloxacin compared to those without at the same current levels. When current exposures were repeated without biofilm or organics in the medium, significant generation of free chlorine was measured. Free chlorine doses equivalent to the 24 hour endpoint concentration for each current level were shown to mimic killing achieved by current application. Current exposure (1.8 mA/cm2) in medium lacking chloride and amended with sulfate, nitrate, or phosphate as alternative electrolytes produced diminished kills of 3, 2, and 0 log reduction, respectively. Direct current also killed Pseudomonas aeruginosa biofilms when NaCl was present. Together these results indicate that electrolysis reactions generating hypochlorous acid from chloride are likely a main contributor to the efficacy of direct current application. A physiologically relevant NaCl concentration is thus a critical parameter in experimental design if direct current is to be investigated for in vivo medical applications. PMID:23390518

  15. Resveratrol and N-acetylcysteine influence redox balance in equine articular chondrocytes under acidic and very low oxygen conditions

    PubMed Central

    Collins, John A.; Moots, Robert J.; Clegg, Peter D.; Milner, Peter I.

    2015-01-01

    Mature articular cartilage is an avascular tissue characterized by a low oxygen environment. In joint disease, acidosis and further reductions in oxygen levels occur, compromising cartilage integrity.This study investigated how acidosis and very low oxygen levels affect components of the cellular redox system in equine articular chondrocytesand whether the antioxidants resveratrol and N-acetylcysteine could modulate this system. We used articular chondrocytes isolated from nondiseased equine joints and cultured them in a 3-D alginate bead system for 48 h in <1, 2, 5, and 21% O2 at pH 7.2 or 6.2 in the absence or presence of the proinflammatory cytokine, interleukin-1β (10 ng/ml).In addition, chondrocytes were cultured with resveratrol (10 µM) or N-acetylcysteine (NAC) (2 mM).Cell viability, glycosaminoglycan (GAG) release, mitochondrial membrane potential (ΔΨm), reactive oxygen species (ROS), GSH:GSSG ratio, and SOD1 and SOD2 protein expression were measured. Very low levels of oxygen (<1%), acidosis (pH 6.2), and exposure to IL-1β led to reductions in cell viability, increased GAG release, alterations in ΔΨm and ROS levels, and reduced GSH:GSSG ratio. In addition, SOD1 and SOD2 protein expressions were reduced. Both resveratrol and NAC partially restored ΔΨm and ROS levels and prevented GAG release and cell loss and normalized SOD1 and SOD2 protein expression. In particular NAC was highly effective at restoring the GSH:GSSG ratio.These results show that the antioxidants resveratrol and N-acetylcysteine can counteract the redox imbalance in articular chondrocytes induced by low oxygen and acidic conditions. PMID:25998424

  16. Direct electric current treatment under physiologic saline conditions kills Staphylococcus epidermidis biofilms via electrolytic generation of hypochlorous acid.

    PubMed

    Sandvik, Elizabeth L; McLeod, Bruce R; Parker, Albert E; Stewart, Philip S

    2013-01-01

    The purpose of this study was to investigate the mechanism by which a direct electrical current reduced the viability of Staphylococcus epidermidis biofilms in conjunction with ciprofloxacin at physiologic saline conditions meant to approximate those in an infected artificial joint. Biofilms grown in CDC biofilm reactors were exposed to current for 24 hours in 1/10(th) strength tryptic soy broth containing 9 g/L total NaCl. Dose-dependent log reductions up to 6.7 log(10) CFU/cm(2) were observed with the application of direct current at all four levels (0.7 to 1.8 mA/cm(2)) both in the presence and absence of ciprofloxacin. There were no significant differences in log reductions for wells with ciprofloxacin compared to those without at the same current levels. When current exposures were repeated without biofilm or organics in the medium, significant generation of free chlorine was measured. Free chlorine doses equivalent to the 24 hour endpoint concentration for each current level were shown to mimic killing achieved by current application. Current exposure (1.8 mA/cm(2)) in medium lacking chloride and amended with sulfate, nitrate, or phosphate as alternative electrolytes produced diminished kills of 3, 2, and 0 log reduction, respectively. Direct current also killed Pseudomonas aeruginosa biofilms when NaCl was present. Together these results indicate that electrolysis reactions generating hypochlorous acid from chloride are likely a main contributor to the efficacy of direct current application. A physiologically relevant NaCl concentration is thus a critical parameter in experimental design if direct current is to be investigated for in vivo medical applications. PMID:23390518

  17. Use of in-vitro experimental results to model in-situ experiments: bio-denitrification under geological disposal conditions.

    PubMed

    Masuda, Kaoru; Murakami, Hiroshi; Kurimoto, Yoshitaka; Kato, Osamu; Kato, Ko; Honda, Akira

    2013-01-01

    Some of the low level radioactive wastes from reprocessing of spent nuclear fuels contain nitrates. Nitrates can be present in the form of soluble salts and can be reduced by various reactions. Among them, reduction by metal compounds and microorganisms seems to be important in the underground repository. Reduction by microorganism is more important in near field area than inside the repository because high pH and extremely high salt concentration would prevent microorganism activities. In the near field, pH is more moderate (pH is around 8) and salt concentration is lower. However, the electron donor may be limited there and it might be the control factor for microorganism's denitrification activities. In this study, in-vitro experiments of the nitrate reduction reaction were conducted using model organic materials purported to exist in underground conditions relevant to geological disposal. Two kinds of organic materials were selected. A super plasticizer was selected as being representative of the geological disposal system and humic acid was selected as being representative of pre-existing organic materials in the bedrock. Nitrates were reduced almost to N2 gas in the existence of super plasticizer. In the case of humic acids, although nitrates were reduced, the rate was much lower and, in this case, dead organism was used as an electron donor instead of humic acids. A reaction model was developed based on the in-vitro experiments and verified by running simulations against data obtained from in-situ experiments using actual groundwaters and microorganisms. The simulation showed a good correlation with the experimental data and contributes to the understanding of microbially mediated denitrification in geological disposal systems. PMID:24010028

  18. Oral intake of γ-aminobutyric acid affects mood and activities of central nervous system during stressed condition induced by mental tasks.

    PubMed

    Yoto, A; Murao, S; Motoki, M; Yokoyama, Y; Horie, N; Takeshima, K; Masuda, K; Kim, M; Yokogoshi, H

    2012-09-01

    γ-Aminobutyric acid (GABA) is a kind of amino acid contained in green tea leaves and other foods. Several reports have shown that GABA might affect brain protein synthesis, improve many brain functions such as memory and study capability, lower the blood pressure of spontaneously hypertensive rats, and may also have a relaxation effect in humans. However, the evidence for its mood-improving function is still not sufficient. In this study, we investigated how the oral intake of GABA influences human adults psychologically and physiologically under a condition of mental stress. Sixty-three adults (28 males, 35 females) participated in a randomized, single blind, placebo-controlled, crossover-designed study over two experiment days. Capsules containing 100 mg of GABA or dextrin as a placebo were used as test samples. The results showed that EEG activities including alpha band and beta band brain waves decreased depending on the mental stress task loads, and the condition of 30 min after GABA intake diminished this decrease compared with the placebo condition. That is to say, GABA might have alleviated the stress induced by the mental tasks. This effect also corresponded with the results of the POMS scores. PMID:22203366

  19. Soil acidification occurs under ambient conditions but is retarded by repeated drought: results of a field-scale climate manipulation experiment.

    PubMed

    Kopittke, G R; Tietema, A; Verstraten, J M

    2012-11-15

    Acid atmospheric emissions within Europe and North America have decreased strongly since 1985 and most recent acidification studies have focused on the changes occurring within ecosystems as a result of this decreased deposition. This current study documents a soil acidification trend under ambient N deposition conditions over a 13 year period, suggesting that acidification continues to be a process of concern at this Calluna vulgaris dominated heathland with an acidic sandy soil. The annual manipulation of climatic conditions on this heathland simulated the predicted summer rainfall reduction (drought) and resulted in a long term retardation of the soil acidification trend. The pH of the soil solution significantly decreased over the course of the trial for both treatments, however, in the final 2 years the decline continued only in the Control treatment. This retardation is primarily associated with the reduction in rainfall leading to lower drainage rates, reduced loss of cations and therefore reduced lowering of the soil acid neutralizing capacity (ANC). However, a change in the underlying mechanisms also indicated that N transformations became less important in the Drought treatment. This change corresponded to an increase in groundcover of an air-pollution tolerant moss species and it is hypothesized that this increasing moss cover filtered an increasing quantity of deposited N, thus reducing the N available for transformation. A soil acidification lag time is expected to increase between the two treatments due to the cumulative disparity in cation retention and rates of proton formation. To the authors' knowledge, this is the first study in which such acidification trends have been demonstrated in a field-scale climate manipulation experiment. PMID:23103759

  20. Production of extracellular acidic lipase by Rhizopus arrhizus as a function of culture conditions.

    PubMed

    Kumar, K K; Deshpande, B S; Ambedkar, S S

    1993-01-01

    Thermophilic strain of Rhizopus arrhizus accumulates an acidic lipase in culture fluid when grown in a medium containing ground nut oil, milk powder and inorganic salts. Addition of 2.0% ground nut oil yielded the highest productivity of enzyme. Soyabean meal and arabinose were found to be the best nitrogen and carbon sources for enzyme production respectively. Addition of metal ions such as MnCl2, SnCl2 and CaCl2 increased the enzyme productivity by 4 fold. The enzyme productivity in the fermenter was much higher (310 U/ml) than in shake-flask (180 U/ml). Crude lipase preparation showed pH and temperature activity optima at 3.5 and 45 degrees C respectively. The enzyme is thermostable and highly active in hydrolysing triglycerides and failed to hydrolyse-methyl esters of caprylate and palmitate. PMID:8181953

  1. Symbiotic essential amino acids provisioning in the American cockroach, Periplaneta americana (Linnaeus) under various dietary conditions

    PubMed Central

    Larsen, Thomas; Sabree, Zakee

    2016-01-01

    Insect gut microbes have been shown to provide nutrients such as essential amino acids (EAAs) to their hosts. How this symbiotic nutrient provisioning tracks with the host’s demand is not well understood. In this study, we investigated microbial essential amino acid (EAA) provisioning in omnivorous American cockroaches (Periplaneta americana), fed low-quality (LQD) and comparatively higher-quality dog food (DF) diets using carbon stable isotope ratios of EAAs (δ13CEAA). We assessed non-dietary EAA input, quantified as isotopic offsets (Δ13C) between cockroach (δ13CCockroach EAA) and dietary (δ13CDietary EAA) EAAs, and subsequently determined biosynthetic origins of non-dietary EAAs in cockroaches using 13C-fingerprinting with dietary and representative bacterial and fungal δ13CEAA. Investigation of biosynthetic origins of de novo non-dietary EAAs indicated bacterial origins of EAA in cockroach appendage samples, and a mixture of fungal and bacterial EAA origins in gut filtrate samples for both LQD and DF-fed groups. We attribute the bacteria-derived EAAs in cockroach appendages to provisioning by the fat body residing obligate endosymbiont, Blattabacterium and gut-residing bacteria. The mixed signatures of gut filtrate samples are attributed to the presence of unassimilated dietary, as well as gut microbial (bacterial and fungal) EAAs. This study highlights the potential impacts of dietary quality on symbiotic EAA provisioning and the need for further studies investigating the interplay between host EAA demands, host dietary quality and symbiotic EAA provisioning in response to dietary sufficiency or deficiency. PMID:27231663

  2. Core Fluxome and Metafluxome of Lactic Acid Bacteria under Simulated Cocoa Pulp Fermentation Conditions

    PubMed Central

    Adler, Philipp; Bolten, Christoph Josef; Dohnt, Katrin; Hansen, Carl Erik

    2013-01-01

    In the present work, simulated cocoa fermentation was investigated at the level of metabolic pathway fluxes (fluxome) of lactic acid bacteria (LAB), which are typically found in the microbial consortium known to convert nutrients from the cocoa pulp into organic acids. A comprehensive 13C labeling approach allowed to quantify carbon fluxes during simulated cocoa fermentation by (i) parallel 13C studies with [13C6]glucose, [1,2-13C2]glucose, and [13C6]fructose, respectively, (ii) gas chromatography-mass spectrometry (GC/MS) analysis of secreted acetate and lactate, (iii) stoichiometric profiling, and (iv) isotopomer modeling for flux calculation. The study of several strains of L. fermentum and L. plantarum revealed major differences in their fluxes. The L. fermentum strains channeled only a small amount (4 to 6%) of fructose into central metabolism, i.e., the phosphoketolase pathway, whereas only L. fermentum NCC 575 used fructose to form mannitol. In contrast, L. plantarum strains exhibited a high glycolytic flux. All strains differed in acetate flux, which originated from fractions of citrate (25 to 80%) and corresponding amounts of glucose and fructose. Subsequent, metafluxome studies with consortia of different L. fermentum and L. plantarum strains indicated a dominant (96%) contribution of L. fermentum NCC 575 to the overall flux in the microbial community, a scenario that was not observed for the other strains. This highlights the idea that individual LAB strains vary in their metabolic contribution to the overall fermentation process and opens up new routes toward streamlined starter cultures. L. fermentum NCC 575 might be one candidate due to its superior performance in flux activity. PMID:23851099

  3. Symbiotic essential amino acids provisioning in the American cockroach, Periplaneta americana (Linnaeus) under various dietary conditions.

    PubMed

    Ayayee, Paul A; Larsen, Thomas; Sabree, Zakee

    2016-01-01

    Insect gut microbes have been shown to provide nutrients such as essential amino acids (EAAs) to their hosts. How this symbiotic nutrient provisioning tracks with the host's demand is not well understood. In this study, we investigated microbial essential amino acid (EAA) provisioning in omnivorous American cockroaches (Periplaneta americana), fed low-quality (LQD) and comparatively higher-quality dog food (DF) diets using carbon stable isotope ratios of EAAs (δ (13)CEAA). We assessed non-dietary EAA input, quantified as isotopic offsets (Δ(13)C) between cockroach (δ (13)CCockroach EAA) and dietary (δ (13)CDietary EAA) EAAs, and subsequently determined biosynthetic origins of non-dietary EAAs in cockroaches using (13)C-fingerprinting with dietary and representative bacterial and fungal δ (13)CEAA. Investigation of biosynthetic origins of de novo non-dietary EAAs indicated bacterial origins of EAA in cockroach appendage samples, and a mixture of fungal and bacterial EAA origins in gut filtrate samples for both LQD and DF-fed groups. We attribute the bacteria-derived EAAs in cockroach appendages to provisioning by the fat body residing obligate endosymbiont, Blattabacterium and gut-residing bacteria. The mixed signatures of gut filtrate samples are attributed to the presence of unassimilated dietary, as well as gut microbial (bacterial and fungal) EAAs. This study highlights the potential impacts of dietary quality on symbiotic EAA provisioning and the need for further studies investigating the interplay between host EAA demands, host dietary quality and symbiotic EAA provisioning in response to dietary sufficiency or deficiency. PMID:27231663

  4. Monoamine acid metabolites and cerebrospinal fluid dynamics in normal pressure hydrocephalus: preliminary results.

    PubMed Central

    Maira, G; Bareggi, S R; Di Rocco, C; Calderini, G; Morselli, P L

    1975-01-01

    Lumbar and ventricular CSF concentration of homovanillic acid (HVA) and 5-hydroxy-indole-acetic acid (5-HIAA) have been determined in 13 patients admitted to hospital for suspected normal pressure hydrocephalus. Low values of HVA in lumbar CSF were found in all patients with reduced CSF absorption and CSF flow inversion. The HVA lumbar concentration remained low after shunt procedure; it increased if obstruction of the shunt occurred. The ventricular CSF concentration of HVA was normal before surgery; it became higher, in two cases, after surgery. No important variations were found in the lumbar and ventricular CSF concentration of 5-HIAA. The possible mechanisms and diagnostic value of these findings are discussed. PMID:1151392

  5. Postoperative enteral hyperalimentation results in earlier elevation of serum branched-chain amino acid levels.

    PubMed

    Moss, G; Naylor, E D

    1994-07-01

    To objectively document the immediate maintenance and successful exploitation of postoperative gastrointestinal (GI) function, elemental diet was infused into the more distal duodenum of 30 cholecystectomy patients at 300 kcal per hour, beginning on arrival at the recovery room. Approximately 4,600 kcal and 190 grams of amino acids were absorbed during the initial 16 hours. Serum branched-chain amino acids (BCAAs) had risen above basal levels at 4 hours, statistically significant only for leucine (+64%). The higher concentrations had reached statistical significance for all BCAAs by 6 hours, when leucine had risen by 83%, isoleucine by 54%, and valine by 47%. The elevated BCAA and glucose levels sustained throughout the hyperalimentation period objectively verify that postoperative GI function can be safely exploited, and may contribute to improved wound healing and sepsis resistance. PMID:8024096

  6. Binding of small basic peptides to membranes containing acidic lipids: theoretical models and experimental results.

    PubMed Central

    Ben-Tal, N; Honig, B; Peitzsch, R M; Denisov, G; McLaughlin, S

    1996-01-01

    We measured directly the binding of Lys3, Lys5, and Lys7 to vesicles containing acidic phospholipids. When the vesicles contain 33% acidic lipids and the aqueous solution contains 100 mM monovalent salt, the standard Gibbs free energy for the binding of these peptides is 3, 5, and 7 kcal/mol, respectively. The binding energies decrease as the mol% of acidic lipids in the membrane decreases and/or as the salt concentration increases. Several lines of evidence suggest that these hydrophilic peptides do not penetrate the polar headgroup region of the membrane and that the binding is mainly due to electrostatic interactions. To calculate the binding energies from classical electrostatics, we applied the nonlinear Poisson-Boltzmann equation to atomic models of the phospholipid bilayers and the basic peptides in aqueous solution. The electrostatic free energy of interaction, which arises from both a long-range coulombic attraction between the positively charged peptide and the negatively charged lipid bilayer, and a short-range Born or image charge repulsion, is a minimum when approximately 2.5 A (i.e., one layer of water) exists between the van der Waals surfaces of the peptide and the lipid bilayer. The calculated molar association constants, K, agree well with the measured values: K is typically about 10-fold smaller than the experimental value (i.e., a difference of about 1.5 kcal/mol in the free energy of binding). The predicted dependence of K (or the binding free energies) on the ionic strength of the solution, the mol% of acidic lipids in the membrane, and the number of basic residues in the peptide agree very well with the experimental measurements. These calculations are relevant to the membrane binding of a number of important proteins that contain clusters of basic residues. Images FIGURE 2 FIGURE 3 PMID:8842196

  7. Acid Sulfate Weathering on Mars: Results from the Mars Exploration Rover Mission

    NASA Technical Reports Server (NTRS)

    Ming, Douglas W.; Morris, R. V.; Golden, D. C.

    2006-01-01

    Sulfur has played a major role in the formation and alteration of outcrops, rocks, and soils at the Mars Exploration Rover landing sites on Meridiani Planum and in Gusev crater. Jarosite, hematite, and evaporite sulfates (e.g., Mg and Ca sulfates) occur along with siliciclastic sediments in outcrops at Meridiani Planum. The occurrence of jarosite is a strong indicator for an acid sulfate weathering environment at Meridiani Planum. Some outcrops and rocks in the Columbia Hills in Gusev crater appear to be extensively altered as suggested by their relative softness as compared to crater floor basalts, high Fe(3+)/FeT, iron mineralogy dominated by nanophase Fe(3+) oxides, hematite and/or goethite, corundum-normative mineralogies, and the presence of Mg- and Casulfates. One scenario for aqueous alteration of these rocks and outcrops is that vapors and/or fluids rich in SO2 (volcanic source) and water interacted with rocks that were basaltic in bulk composition. Ferric-, Mg-, and Ca-sulfates, phosphates, and amorphous Si occur in several high albedo soils disturbed by the rover's wheels in the Columbia Hills. The mineralogy of these materials suggests the movement of liquid water within the host material and the subsequent evaporation of solutions rich in Fe, Mg, Ca, S, P, and Si. The presence of ferric sulfates suggests that these phases precipitated from highly oxidized, low-pH solutions. Several hypotheses that invoke acid sulfate weathering environments have been suggested for the aqueous formation of sulfate-bearing phases on the surface of Mars including (1) the oxidative weathering of ultramafic igneous rocks containing sulfides; (2) sulfuric acid weathering of basaltic materials by solutions enriched by volcanic gases (e.g., SO2); and (3) acid fog (i.e., vapors rich in H2SO4) weathering of basaltic or basaltic-derived materials.

  8. Furan formation from fatty acids as a result of storage, gamma irradiation, UV-C and heat treatments.

    PubMed

    Fan, Xuetong

    2015-05-15

    The effects of gamma and UV-C irradiation in comparison with thermal processing and storage at 25°C on formation of furan from different fatty acids were investigated. Results showed that furan was generated from polyunsaturated fatty acids such as linoleic and linolenic acid during thermal (120°C, 25 min) and UV-C (11.5 J/cm(2)) treatments. Gamma irradiation (up to 20 kGy) did not induce formation of significant amounts of furan from any of the fatty acids studied. Storage of unsaturated fatty acid emulsions at 25°C for 3 days led to the formation of furan (7-11 ng/mL) even without prior thermal or non-thermal treatments. pH significantly impacted furan formation with >3.5 times more furan formed at pH 9 than at pHs 3 or 6 during 3 days at 25°C. The addition of Trolox, BHA, and propyl gallate had no significant effect on furan formation from linolenic acid while α-tocopherol and FeSO4 promoted furan formation. PMID:25577103

  9. [Sanitary-hygienic characteristics of work conditions and health status of workers in nitric acid production industry].

    PubMed

    Rumiantsev, G I; Kozlova, T A; Atiakina, I K; Pavlova, A P

    1990-01-01

    Workers engaged in thin nitric acid manufacturing are exhibited to the combined action of both physical and chemical factors (noise, heating microclimate, nitric oxides, ammonia). Within the working hours, ECG changes and arterial blood pressure instability are displayed in operators and technicians. Influenza, acute respiratory disorders and osseo-muscular diseases present the main causes of morbidity with temporary disability. Technicians are characterized by a markedly greater morbidity rate. Ammonia and nitric oxides, as aggressive media, lead to higher rates of oral mucoid, hard dental tissues and periodontium lesions. Health-related labour conditions improvement measures are proposed. PMID:2161779

  10. Effects of a New Glutamic Acid Derivative on Myocardial Contractility of Stressed Animals under Conditions of Nitric Oxide Synthesis Blockade.

    PubMed

    Tyurenkov, I N; Perfilova, V N; Sadikova, N V; Berestovitskaya, V M; Vasil'eva, O S

    2015-07-01

    Glufimet (glutamic acid derivative) in a dose of 28.7 mg/kg limited the reduction of the cardiac functional reserve in animals subjected to 24-h stress under conditions of nonselective NO synthase blockade with L-NAME (10 mg/kg). Adrenoreactivity and increased afterload tests showed that the increment of myocardial contraction/relaxation rates, left-ventricular pressure, and HR were significantly higher in glufimet-treated stressed animals with NO synthesis blockade than in animals which received no glufimet. The efficiency of glufimet was higher than that of phenibut (the reference drug). PMID:26205724

  11. Dietary docosahexaenoic acid alleviates autistic-like behaviors resulting from maternal immune activation in mice.

    PubMed

    Weiser, Michael J; Mucha, Brittany; Denheyer, Heather; Atkinson, Devon; Schanz, Norman; Vassiliou, Evros; Benno, Robert H

    2016-03-01

    The prevalence of autism spectrum disorders over the last several decades has risen at an alarming rate. Factors such as broadened clinical definitions and increased parental age only partially account for this precipitous increase, suggesting that recent changes in environmental factors may also be responsible. One such factor could be the dramatic decrease in consumption of anti-inflammatory dietary omega-3 (n-3) polyunsaturated fatty acids (PUFAs) relative to the amount of pro-inflammatory omega-6 (n-6) PUFAs and saturated fats in the Western diet. Docosahexaenoic acid (DHA) is the principle n-3 PUFA found in neural tissue and is important for optimal brain development, especially during late gestation when DHA rapidly and preferentially accumulates in the brain. In this study, we tested whether supplementation of a low n-3 PUFA diet with DHA throughout development could improve measures related to autism in a mouse model of maternal immune activation. We found that dietary DHA protected offspring from the deleterious effects of gestational exposure to the viral mimetic polyriboinosinic-polyribocytidilic acid on behavioral measures of autism and subsequent adulthood immune system reactivity. These data suggest that elevated dietary levels of DHA, especially during pregnancy and nursing, may help protect normal neurodevelopment from the potentially adverse consequences of environmental insults like maternal infection. PMID:26703213

  12. Fatigue strength of high-temperature alloys under conditions of cyclic temperature variation. Communication 1: Experimental procedure and results

    NASA Astrophysics Data System (ADS)

    Troshchenko, V. T.; Gryaznov, B. A.; Yamshanov, Yu. B.

    1994-03-01

    Determination of the serviceability of the material of gas-turbine engine blades, one of the most loaded elements of the engine, critical for the reliability of the turbine, is discussed. The NUM-3 setup, intended for studying fatigue strength of high-temperature alloys under conditions simulating service ones, is briefly described. The results of the investigation into the fatigue of alloys EP962 and EI698 under isothermal conditions and complex thermal-mechanical loading are presented. The analysis of the findings revealed a number of regularities in the effect of thermal cycling and resulting varying thermal stresses on the fatigue strength of the materials studied.

  13. Enhanced inactivation of Escherichia coli and Listeria monocytogenes by exposure to 405 nm light under sub-lethal temperature, salt and acid stress conditions.

    PubMed

    McKenzie, Karen; Maclean, Michelle; Timoshkin, Igor V; MacGregor, Scott J; Anderson, John G

    2014-01-17

    The antimicrobial effects of 405 nm light have generated interest in its use as an emerging disinfection technology with potential food-related applications. The aim of this study was to assess the bactericidal efficacy of 405 nm light for inactivation of Escherichia coli and Listeria monocytogenes under sub-lethally stressed environmental conditions. Bacteria were exposed to 405 nm light from a light emitting diode (LED) array under various temperature, salt (NaCl) and acid conditions to determine if bacterial susceptibility to 405 nm light inactivation is affected when exposed under these conditions. Non-stressed bacterial populations (10(5) CFU/mL) were exposed to increasing doses of 405 nm light (~70 mW/cm(2)) and the inactivation results were compared with those generated under stress conditions. Bacteria were held at various temperatures (4°C, 22°C and 45°C), acid concentrations (pH3, 3.5 and 7) and salt concentrations (0%, 0.8%, 10% and 15% NaCl), and simultaneously exposed to 405 nm light. Enhanced inactivation of both E. coli and L. monocytogenes was achieved when light exposure was combined with each of the sub-lethal stresses, with significantly increased inactivation rates compared to non-stressed populations (P≤0.05). One exception was with L. monocytogenes when light-exposed in the presence of 15% salt, as this combination reduced bacterial inactivation. The greatest enhancement of 405 nm light inactivation for both bacterial species was achieved when light exposure was combined with sub-lethal acid stress conditions at pH3. This was demonstrated by a 5-log10 reduction of E. coli following a 405 nm light dose of 84 J/cm(2) compared to 378 J/cm(2) for non-stressed populations (77% reduction in dose) and by a 5-log10 reduction of L. monocytogenes achieved with a dose of 42 J/cm(2) which corresponded to 50% of the dose required for the equivalent reduction of non-stressed populations. This acid-enhanced 405 nm light inactivation effect was

  14. Effects of varying nitrogen sources on amino acid synthesis costs in Arabidopsis thaliana under different light and carbon-source conditions.

    PubMed

    Arnold, Anne; Sajitz-Hermstein, Max; Nikoloski, Zoran

    2015-01-01

    Plants as sessile organisms cannot escape their environment and have to adapt to any changes in the availability of sunlight and nutrients. The quantification of synthesis costs of metabolites, in terms of consumed energy, is a prerequisite to understand trade-offs arising from energetic limitations. Here, we examine the energy consumption of amino acid synthesis in Arabidopsis thaliana. To quantify these costs in terms of the energy equivalent ATP, we introduce an improved cost measure based on flux balance analysis and apply it to three state-of-the-art metabolic reconstructions to ensure robust results. We present the first systematic in silico analysis of the effect of nitrogen supply (nitrate/ammonium) on individual amino acid synthesis costs as well as of the effect of photoautotrophic and heterotrophic growth conditions, integrating day/night-specific regulation. Our results identify nitrogen supply as a key determinant of amino acid costs, in agreement with experimental evidence. In addition, the association of the determined costs with experimentally observed growth patterns suggests that metabolite synthesis costs are involved in shaping regulation of plant growth. Finally, we find that simultaneous uptake of both nitrogen sources can lead to efficient utilization of energy source, which may be the result of evolutionary optimization. PMID:25706533

  15. Results.

    ERIC Educational Resources Information Center

    Zemsky, Robert; Shaman, Susan; Shapiro, Daniel B.

    2001-01-01

    Describes the Collegiate Results Instrument (CRI), which measures a range of collegiate outcomes for alumni 6 years after graduation. The CRI was designed to target alumni from institutions across market segments and assess their values, abilities, work skills, occupations, and pursuit of lifelong learning. (EV)

  16. Inhibition of phenolic acid metabolism results in precocious cell death and altered cell morphology in leaves of transgenic tobacco plants

    PubMed Central

    Tamagnone, L; Merida, A; Stacey, N; Plaskitt, K; Parr, A; Chang, CF; Lynn, D; Dow, JM; Roberts, K; Martin, C

    1998-01-01

    Several complex phenotypic changes are induced when the transcription factor AmMYB308 is overexpressed in transgenic tobacco plants. We have previously shown that the primary effect of this transcription factor is to inhibit phenolic acid metabolism. In the plants that we produced, two morphological features were prominent: abnormal leaf palisade development and induction of premature cell death in mature leaves. Evidence from the analysis of these transgenic plants suggests that both changes resulted from the lack of phenolic intermediates. These results emphasize the importance of phenolic secondary metabolites in the normal growth and development of tobacco. We suggest that phenolic acid derivatives are important signaling molecules in the final stages of leaf palisade formation and that phenolic acid derivatives also play a prominent role in tissue senescence. PMID:9811790

  17. Enhanced volatile fatty acids production of waste activated sludge under salinity conditions: Performance and mechanisms.

    PubMed

    Su, Gaoqiang; Wang, Shuying; Yuan, Zhiguo; Peng, Yongzhen

    2016-03-01

    Volatile fatty acids (VFAs) are essential for removing biological nitrogen and phosphorus in wastewater treatment plants. The purpose of this work was to investigate whether and how the addition of NaCl could improve the production of VFAs from waste activated sludge (WAS). Sludge solubilization was efficiently improved by the addition of NaCl. Both protein and carbohydrate in the fermentation liquid increased with the dosage of NaCl, and it provided a larger amount of organic compounds for the production of the VFAs. NaCl had inhibitory effects on the production of methane and a high dosage of NaCl could severely suppress the growth of methanogens, which decreased the consumption of the VFAs. Consequently, the production of VFAs was significantly enhanced by the addition of NaCl. The maximum production of VFAs was achieved with the highest dosage of NaCl (3316 mg (COD)/L at the NaCl dosage 0.5 mol/L; 783 mg (COD)/L without the addition of NaCl). Therefore, this study indicates that using NaCl could be an efficient method for improving the production of VFAs from WAS. PMID:26320405

  18. Clay mineralogical evolution as a function of acidic leaching conditions: implications for alteration pathways on Mars' surface

    NASA Astrophysics Data System (ADS)

    Mavris, Christian; Cuadros, Javier; Nieto, Jose Miguel; Bishop, Janice; Vega, Raquel; Michalski, Joe

    2015-04-01

    Combined satellite and in-situ measurements of Mars surface have detected mineral assemblages suggesting processes for which Earth analogues exist. One of these cases is represented by aluminous clay-sulphate assemblages, which suggest alteration by acidic fluids. The Riotinto mining district (SW Spain) provides an Earth analogue for such Martian processes. The parent rocks belong to an Upper Palaeozoic (Late Famennian-Tournaisian) volcano-sedimentary complex including siliciclastic sediments and mafic and felsic volcanics, all of which underwent hydrothermal alteration.The oxidation of an extensive pyrite-rich orebody provided extreme to mild acidic fluxes that leached the surrounding rocks for over 20 million years (1). Samples from several locations in the Riotinto area show a range of clay products: vermiculite, smectite, possibly halloysite, and kaolinite with a wide range of crystal order. Jarosite and iron oxides appear in the most intensely leached areas. The different alteration products are due to the nature of the original rocks and the conditions in which low-pH leaching took place. Both mineral assemblages and spectral features of clay minerals from Riotinto can be used to interpret acidic alteration on Mars' surface. (1) Essalhi et al., 2011. Mineralium Deposita 46, 981-999.

  19. Results of chopper-controlled discharge life cycling studies on lead acid batteries

    NASA Technical Reports Server (NTRS)

    Ewashinka, J. G.; Sidik, S. M.

    1982-01-01

    A group of 108 state of the art nominally 6 volt lead acid batteries were tested in a program of one charge/discharge cycle per day for over two years or to ultimate battery failure. The primary objective was to determine battery cycle life as a function of depth of discharge (25 to 75 percent), chopper frequency (100 to 1000 Hz), duty cycle (25 to 87.5 percent), and average discharge current (20 to 260 A). The secondary objective was to determine the types of battery failure modes, if any, were due to the above parameters. The four parameters above were incorporated in a statistically designed test program.

  20. Determination of operating conditions in an anaerobic acid-phase reactor treating dairy wastewater

    SciTech Connect

    Kasapgil, B.; Ince, O.; Anderson, G.K.

    1996-11-01

    Anaerobic digestion of organic material is a multistep process. Two groups of bacteria, namely acidogenic and methanogenic bacteria, are responsible for the acidification and for the methane formation, respectively. The growth requirements of the two groups of bacteria are rather different. In order to create optimum conditions for the process, it was first proposed to separate the process into two phases. Operating variables applicable for the selection and enrichment of microbial populations in phased digesters include digester loading, hydraulic retention time (HRT), pH, temperature, reactor design, and operating mode. By proper manipulation of these operating parameters it is possible to prevent any significant growth of methane bacteria and at the same time achieve the required level of acidification in the first reactor. Further enrichment of two cultures is possible by biomass recycle around each phase. Since the 1970s, phase separation has been introduced into anaerobic digestion technology. However, data concerning the optimization of operating conditions in both acidogenic and methanogenic phase reactors are scarce. This study was therefore carried out for the purposes given below. These were: (1) to determine the best combination of pH and temperature within the ranges studied for the pre-acidification of dairy wastewater; (2) to determine the maximum acidogenic conversion from COD to VFAs, and (3) to determine the changes in the distribution of major VFAs being produced during the pre-acidification of dairy wastewater.

  1. 17 CFR 229.303 - (Item 303) Management's discussion and analysis of financial condition and results of operations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Regulation S-X (17 CFR 210), a management's discussion and analysis of the financial condition and results of... is not excluded from the initial recognition and measurement provisions of FIN 45 pursuant to... or credit risk support to, or engages in leasing, hedging or research and development services...

  2. Production of starch nanoparticles using normal maize starch via heat-moisture treatment under mildly acidic conditions and homogenization.

    PubMed

    Park, Eun Young; Kim, Min-Jung; Cho, MyoungLae; Lee, Ju Hun; Kim, Jong-Yea

    2016-10-20

    Normal maize starch was subjected to heat-moisture treatment (HMT) under mildly acidic conditions (0.000, 0.050, or 0.075M H2SO4) for various treatment times (3, 5, or 8h) followed by homogenization up to 60min to prepare nanoparticles. The combination of HMT (0.075M, for 8h) and homogenization (60min) produced nanoparticles with diameters of less than 50nm at a yield higher than 80%. X-ray diffractometry and size-exclusion chromatography revealed that HMT under mildly acidic conditions selectively hydrolyzed the starch chains (especially amylose and/or long chains of amylopectin) in the amorphous region of the granules without significant damage to the crystalline structure, however, modification of the molecular structure in the amorphous region increased fragility of the granules during homogenization. Homogenization for 60min caused obvious damage in the long-range crystalline structure of the HMT starch (0.15N, for 8h), while the short-range chain associations (FT-IR) remained intact. PMID:27474568

  3. Differential effects of L-propionylcarnitine on the electrical and mechanical properties of guinea pig ventricular muscle in normal and acidic conditions.

    PubMed

    Aomine, M; Arita, M

    1987-11-01

    We studied the effects of L-propionylcarnitine (PC) on transmembrane action potentials and isometric contractile tension in isolated guinea pig ventricular papillary muscles. The effects of 5 concentrations of PC (10(-5), 10(-4), 10(-3), 10(-2) and 3 X 10(-2)M) were examined in both normal (pH 7.4) and acidic (pH 6.9) conditions. The concentrations of 10(-5) to 10(-2)M had no significant effect on action potential amplitude, maximum upstroke velocity of phase 0 and resting potential, in either condition. At pH 7.4, action potential duration (ADP) was significantly (P less than 0.05) or insignificantly shortened by the drug depending upon the concentration used. At pH 6.9, however, the APD was prolonged by moderate PC concentrations (10(-3) and 10(-2)M), in which the effective refractory period (ERP) was also lengthened, associated with an increased ERP/APD ratio. In both pH conditions, the highest concentration (3 X 10(-2)M) significantly (P less than 0.05) decreased all these action potential parameters. PC had a biphasic effect on the developed tension. In both pH conditions, low PC concentrations (10(-5) to 10(-3)M) produced an initial augmentation of the contraction, followed by subsequent reduction. The initial augmentation disappeared by pretreatment with reserpine or propranolol, suggesting the involvement of beta-adrenoceptors. In the steady state, all PC concentrations produced a negative inotropic effect at pH 7.4, while at pH 6.9 only high concentrations (10(-2)M and 3 X 10(-2)M) had this effect. These results suggest that the effects of PC in an acidic condition differ considerably from those in a normal pH condition and that limited concentrations of PC (10(-3) to 10(-2)M) may prevent re-entrant arrhythmias from developing under acidic conditions via lengthening of the ERP, without deleterious effects on the contractile force. PMID:3430099

  4. 77 FR 72323 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-05

    ...The Department of Commerce (the Department) has completed its administrative review of the countervailing duty (CVD) order on citric acid and certain citrate salts from the People's Republic of China for the period January 1, 2010, through December 31, 2010. On June 5, 2012, we published the preliminary results of this review.\\1\\......

  5. 76 FR 33243 - Sulfanilic Acid From India; Final Results of Expedited Sunset Review of Countervailing Duty Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-08

    ... section 751(c) of the Act. See Initiation of Five-Year (``Sunset'') Review, 76 FR 18163 (April 1, 2011... FR 41957 (July 7, 2000). The merchandise is currently classifiable under Harmonized Tariff Schedule... International Trade Administration Sulfanilic Acid From India; Final Results of Expedited Sunset Review...

  6. Molecular and Physiological Analysis of Al3+ and H+ Rhizotoxicities at Moderately Acidic Conditions1[W][OPEN

    PubMed Central

    Kobayashi, Yasufumi; Kobayashi, Yuriko; Watanabe, Toshihiro; Shaff, Jon E.; Ohta, Hiroyuki; Kochian, Leon V.; Wagatsuma, Tadao; Kinraide, Thomas B.; Koyama, Hiroyuki

    2013-01-01

    Al3+ and H+ toxicities predicted to occur at moderately acidic conditions (pH [water] = 5–5.5) in low-Ca soils were characterized by the combined approaches of computational modeling of electrostatic interactions of ions at the root plasma membrane (PM) surface and molecular/physiological analyses in Arabidopsis (Arabidopsis thaliana). Root growth inhibition in known hypersensitive mutants was correlated with computed {Al3+} at the PM surface ({Al3+}PM); inhibition was alleviated by increased Ca, which also reduced {Al3+}PM and correlated with cellular Al responses based on expression analysis of genes that are markers for Al stress. The Al-inducible Al tolerance genes ALUMINUM-ACTIVATED MALATE TRANSPORTER1 and ALUMINUM SENSITIVE3 were induced by levels of {Al3+}PM too low to inhibit root growth in tolerant genotypes, indicating that protective responses are triggered when {Al3+}PM was below levels that can initiate injury. Modeling of the H+ sensitivity of the SENSITIVE TO PROTON RHIZOTOXICITY1 knockout mutant identified a Ca alleviation mechanism of H+ rhizotoxicity, possibly involving stabilization of the cell wall. The phosphatidate phosphohydrolase1 (pah1) pah2 double mutant showed enhanced Al susceptibility under low-P conditions, where greater levels of negatively charged phospholipids in the PM occur, which increases {Al3+}PM through increased PM surface negativity compared with wild-type plants. Finally, we found that the nonalkalinizing Ca fertilizer gypsum improved the tolerance of the sensitive genotypes in moderately acidic soils. These findings fit our modeling predictions that root toxicity to Al3+ and H+ in moderately acidic soils involves interactions between both toxic ions in relation to Ca alleviation. PMID:23839867

  7. Formation of Complex Amino Acid Precursors in Simulated Primitive Atmosphere and Their Alteration under Simulated Submarine Hydrothermal Conditions

    NASA Astrophysics Data System (ADS)

    Kobayashi, Kensei; Kurihara, Hironari; Hirako, Tomoaki; Obayashi, Yumiko; Kaneko, Takeo; Takano, Yoshinori; Yoshimura, Yoshitaka

    Since late 1970's a great number of submarine hydrothermal systems (SHSs) has been dis-covered, and they are considered possible sites of chemical evolution and generation of life on the Earth since their discovery in late 1970s. A number of experiments simulating the con-ditions of SHSs were conducted, and abiotic production and polymerization of amino acids were reported. Free amino acids were frequently used as starting materials to examine possible organic reactions in the simulation experiments. In our early studies, not free amino acids but complex amino acids precursors with large molecular weights were formed abiotically from simulated primitive Earth atmosphere (a mixture of CO, N2 and H2 O) (Takano et al., 2004). Such complex organics (hereafter referred as to CNWs) should have been delivered to SHSs in Primitive Ocean, where they were subjected to further alteration. We examined possible alteration of the complex organics in high-temperature high-pressure environments by the su-percritical water flow reactor (SCWFR) (Islam et al.. 2003) and an autoclave. CNWs were quite hydrophilic compounds whose molecular weights were ca. 3000. After heating 573 K for 2 min in the SCWFR, aggregates of organics were formed, which were separated from aque-ous solution with a Nucleopore filter (pore size: 200 nm). We propose the following scenario of chemical evolution: (1) Complex organics including amino acid precursors were formed in primitive atmosphere and/or extraterrestrial environments, (ii) they were delivered to primor-dial SHSs, (iii) hydrothermal alteration occurred in SHSs to give organic aggregates, (iv) quite primitive molecular systems with subtle biological functions were generated in the competition among such aggregates. References: Islam, Md. N., Kaneko, T., and Kobayashi, K (2003). Reactions of Amino Acids with a Newly ConstructedSupercritical Water Flow Reactor Simulating Submarine Hydrothermal Systems. Bull. Chem. Soc. Jpn., 76, 1171. Takano, Y

  8. Water-Splitting Electrocatalysis in Acid Conditions Using Ruthenate-Iridate Pyrochlores**

    PubMed Central

    Sardar, Kripasindhu; Petrucco, Enrico; Hiley, Craig I; Sharman, Jonathan D B; Wells, Peter P; Russell, Andrea E; Kashtiban, Reza J; Sloan, Jeremy; Walton, Richard I

    2014-01-01

    The pyrochlore solid solution (Na0.33Ce0.67)2(Ir1−xRux)2O7 (0≤x≤1), containing B-site RuIV and IrIV is prepared by hydrothermal synthesis and used as a catalyst layer for electrochemical oxygen evolution from water at pH<7. The materials have atomically mixed Ru and Ir and their nanocrystalline form allows effective fabrication of electrode coatings with improved charge densities over a typical (Ru,Ir)O2 catalyst. An in situ study of the catalyst layers using XANES spectroscopy at the Ir LIII and Ru K edges shows that both Ru and Ir participate in redox chemistry at oxygen evolution conditions and that Ru is more active than Ir, being oxidized by almost one oxidation state at maximum applied potential, with no evidence for ruthenate or iridate in +6 or higher oxidation states. PMID:25196322

  9. Solubility of Fullerenes in Fatty Acids Esters: A New Way to Deliver In Vivo Fullerenes. Theoretical Calculations and Experimental Results

    NASA Astrophysics Data System (ADS)

    Cataldo, Franco

    The biological effects of fullerenes and, in particular, of C60 have been recognized since long time. One of the problems which hindered the application of fullerenes in medicinal chemistry regards their insolubility in water and water-based fluids. In the present chapter it is reported that C60 and C70 fullerenes are soluble in vegetable oils, in general, in esters of fatty acids and in free fatty acids. These results pave the way in the utilization of vegetable oils as vehicles in the delivery of fullerenes for both topical applications and internal use (e.g., intramuscular injection).

  10. Resistance of horse alpha 1-proteinase inhibitor to perchloric acid denaturation and a simplified purification procedure resulting therefrom.

    PubMed

    Pellegrini, A; Hägeli, G; von Fellenberg, R

    1986-11-21

    Addition of perchloric acid (6.4% w/v final concentration) to horse alpha 1-proteinase inhibitor or to horse plasma neither precipitated nor inactivated alpha 1-proteinase inhibitor. None of the isoinhibitors of alpha 1-proteinase inhibitor was altered by dilute perchloric acid. This unexpected behavior led to a simplified procedure for the purification of horse alpha 1-proteinase inhibitor, consisting of removal of the bulk of plasma proteins, by perchloric acid precipitation and by gel filtration on Sephadex G-75 and G-200. The resulting preparations of alpha 1-proteinase inhibitor were immunogenically pure. The simplified purification procedure permitted the immunochemical comparison of the isoinhibitors of alpha 1-proteinase inhibitor, which proved to be immunologically identical. PMID:3022814

  11. Absence of Rtt109p, a fungal-specific histone acetyltransferase, results in improved acetic acid tolerance of Saccharomyces cerevisiae.

    PubMed

    Cheng, Cheng; Zhao, Xinqing; Zhang, Mingming; Bai, Fengwu

    2016-03-01

    RTT109 is a histone acetyltransferase for the acetylation of histone H3. It is still not clear whether RTT109 plays a role in regulation of gene expression under environmental stresses. In this study, the involvement of RTT109 in acetic acid stress tolerance of Saccharomyces cerevisiae was investigated. It was revealed that the absence of RTT109 enhanced resistance to 5.5 g L(-1) acetic acid, which was indicated by improved growth of RTT109Δ mutant compared with that of the wild-type BY4741 strain. Meanwhile, the lag phase was shortened for 48 h and glucose consumption completed 36 h in advance for RTT109Δ mutant compared to the wild-type strain, with ethanol production rate increased from 0.39 to 0.60 g L(-1) h(-1). Significantly, elevated transcription levels of HSP12, CTT1 and GSH1, as well as increased activities of antioxidant enzymes were observed in RTT109Δ under acetic acid stress. Improved flocculation of RTT109Δ compared to that of the control strain BY4741 under the acetic acid stress was also observed. These results suggest that the absence of RTT109 not only activates transcription of stress responsive genes, but also improves resistance to oxidative stress, which ultimately contributes to improved acetic acid tolerance in S. cerevisiae. PMID:26851403

  12. Oxidizing dissolution mechanism of an irradiated MOX fuel in underwater aerated conditions at slightly acidic pH

    NASA Astrophysics Data System (ADS)

    Magnin, M.; Jégou, C.; Caraballo, R.; Broudic, V.; Tribet, M.; Peuget, S.; Talip, Z.

    2015-07-01

    The (U,Pu)O2 matrix behavior of an irradiated MIMAS-type (MIcronized MASter blend) MOX fuel, under radiolytic oxidation in aerated pure water at pH 5-5.5 was studied by combining chemical and radiochemical analyses of the alteration solution with Raman spectroscopy characterizations of the surface state. Two leaching experiments were performed on segments of irradiated fuel under different conditions: with or without an external γ irradiation field, over long periods (222 and 604 days, respectively). The gamma irradiation field was intended to be representative of the irradiation conditions for a fuel assembly in an underwater interim storage situation. The data acquired enabled an alteration mechanism to be established, characterized by uranium (UO22+) release mainly controlled by solubility of studtite over the long-term. The massive precipitation of this phase was observed for the two experiments based on high uranium oversaturation indexes of the solution and the kinetics involved depended on the irradiation conditions. External gamma irradiation accelerated the precipitation kinetics and the uranium concentrations (2.9 × 10-7 mol/l) were lower than for the non-irradiated reference experiment (1.4 × 10-5 mol/l), as the quantity of hydrogen peroxide was higher. Under slightly acidic pH conditions, the formation of an oxidized UO2+x phase was not observed on the surface and did not occur in the radiolysis dissolution mechanism of the fuel matrix. The Raman spectroscopy performed on the heterogeneous MOX fuel matrix surface, showed that the fluorite structure of the mainly UO2 phase surrounding the Pu-enriched aggregates had not been particularly impacted by any major structural change compared to the data obtained prior to leaching. For the plutonium, its behavior in solution involved a continuous release up to concentrations of approximately 3 × 10-6 mol L-1 with negligible colloid formation. This data appears to support a predominance of the +V oxidation

  13. Passive treatment of acid mine drainage in systems containing compost and limestone: Laboratory and field results

    SciTech Connect

    Watzlaf, G.R.; Pappas, D.M.

    1996-12-31

    Passive, down-flow systems, consisting of compost and limestone layers, termed successive alkalinity producing systems (SAPS), may be well suited for treatment of mine drainage containing ferric iron and/or aluminum. A column, simulating a SAPS, has been operated in the laboratory for 52 weeks. The 0.16-m diameter column consisted of a 0.30-m thick layer of limestone, a 0.76-m thick layer of spent mushroom compost thick layer of limestone, a 0.76-m thick layer of spent mushroom compost and 0.91 m of free standing water. Actual AMD (pH = 3.02, acidity = 218 mg/L (as CaCO{sub 3}), SO{sub 4} = 600 mg/L, Fe = 16.0 mg/L, Mn = 12.1 mg/L, and Al = 17.1 mg/L) was applied to the column at a rate of 3.8 mL/min. Effluent pH has remained above 6.2 (6.2-7.9) in the column system. A SAPS located in Jefferson County, PA has been monitored for the past 4.5 years. The SAPS has an approximate area of 1000 m{sup 2} and contains a 0.4-m thick layer of limestone, a 0.2-m thick layer of spent mushroom compost, and 1.5 m of free standing water. Mine water (acidity = 335 mg/L (as CaCO{sub 3}), SO{sub 4} = 1270 mg/L, Fe = 246 mg/L, Mn = 38.4 mg/L, and Al = <0.2 mg/L) flowed into the SAPS at a rate of 140 L/min. Water samples from the field and laboratory systems have been collected at strategic locations on a regular basis and analyzed for pH, alkalinity, acidity, Fe{sup 2+}, total Fe, Mn, Al, SO{sub 4}, Ca, Mg, Na, Co, Ni, and Zn. Alkalinity has been generated in both field and laboratory systems by a combination of limestone dissolution and sulfate reduction. The column generated an average of 378 mg/L of alkalinity; 74% due to limestone dissolution and 26% due to bacterial reduction of sulfate. The field SAPS generated an average of 231 mg/L of alkalinity and exhibited seasonal trends.

  14. Collision Cross Sections for 20 Protonated Amino Acids: Fourier Transform Ion Cyclotron Resonance and Ion Mobility Results

    NASA Astrophysics Data System (ADS)

    Anupriya; Jones, Chad A.; Dearden, David V.

    2016-08-01

    We report relative dephasing cross sections for the 20 biogenic protonated amino acids measured using the cross sectional areas by Fourier transform ion cyclotron resonance (CRAFTI) technique at 1.9 keV in the laboratory reference frame, as well as momentum transfer cross sections for the same ions computed from Boltzmann-weighted structures determined using molecular mechanics. Cross sections generally increase with increasing molecular weight. Cross sections for aliphatic and aromatic protonated amino acids are larger than the average trend, suggesting these side chains do not fold efficiently. Sulfur-containing protonated amino acids have smaller than average cross sections, reflecting the mass of the S atom. Protonated amino acids that can internally hydrogen-bond have smaller than average cross sections, reflecting more extensive folding. The CRAFTI measurements correlate well with results from drift ion mobility (IMS) and traveling wave ion mobility (TWIMS) spectrometric measurements; CRAFTI results correlate with IMS values approximately as well as IMS and TWIMS values from independent measurements correlate with each other. Both CRAFTI and IMS results correlate well with the computed momentum transfer cross sections, suggesting both techniques provide accurate molecular structural information. Absolute values obtained using the various methods differ significantly; in the case of CRAFTI, this may be due to errors in measurements of collision gas pressure, measurement of excitation voltage, and/or dependence of cross sections on kinetic energy.

  15. Collision Cross Sections for 20 Protonated Amino Acids: Fourier Transform Ion Cyclotron Resonance and Ion Mobility Results.

    PubMed

    Anupriya; Jones, Chad A; Dearden, David V

    2016-08-01

    We report relative dephasing cross sections for the 20 biogenic protonated amino acids measured using the cross sectional areas by Fourier transform ion cyclotron resonance (CRAFTI) technique at 1.9 keV in the laboratory reference frame, as well as momentum transfer cross sections for the same ions computed from Boltzmann-weighted structures determined using molecular mechanics. Cross sections generally increase with increasing molecular weight. Cross sections for aliphatic and aromatic protonated amino acids are larger than the average trend, suggesting these side chains do not fold efficiently. Sulfur-containing protonated amino acids have smaller than average cross sections, reflecting the mass of the S atom. Protonated amino acids that can internally hydrogen-bond have smaller than average cross sections, reflecting more extensive folding. The CRAFTI measurements correlate well with results from drift ion mobility (IMS) and traveling wave ion mobility (TWIMS) spectrometric measurements; CRAFTI results correlate with IMS values approximately as well as IMS and TWIMS values from independent measurements correlate with each other. Both CRAFTI and IMS results correlate well with the computed momentum transfer cross sections, suggesting both techniques provide accurate molecular structural information. Absolute values obtained using the various methods differ significantly; in the case of CRAFTI, this may be due to errors in measurements of collision gas pressure, measurement of excitation voltage, and/or dependence of cross sections on kinetic energy. Graphical Abstract ᅟ. PMID:27220844

  16. Collision Cross Sections for 20 Protonated Amino Acids: Fourier Transform Ion Cyclotron Resonance and Ion Mobility Results

    NASA Astrophysics Data System (ADS)

    Anupriya; Jones, Chad A.; Dearden, David V.

    2016-05-01

    We report relative dephasing cross sections for the 20 biogenic protonated amino acids measured using the cross sectional areas by Fourier transform ion cyclotron resonance (CRAFTI) technique at 1.9 keV in the laboratory reference frame, as well as momentum transfer cross sections for the same ions computed from Boltzmann-weighted structures determined using molecular mechanics. Cross sections generally increase with increasing molecular weight. Cross sections for aliphatic and aromatic protonated amino acids are larger than the average trend, suggesting these side chains do not fold efficiently. Sulfur-containing protonated amino acids have smaller than average cross sections, reflecting the mass of the S atom. Protonated amino acids that can internally hydrogen-bond have smaller than average cross sections, reflecting more extensive folding. The CRAFTI measurements correlate well with results from drift ion mobility (IMS) and traveling wave ion mobility (TWIMS) spectrometric measurements; CRAFTI results correlate with IMS values approximately as well as IMS and TWIMS values from independent measurements correlate with each other. Both CRAFTI and IMS results correlate well with the computed momentum transfer cross sections, suggesting both techniques provide accurate molecular structural information. Absolute values obtained using the various methods differ significantly; in the case of CRAFTI, this may be due to errors in measurements of collision gas pressure, measurement of excitation voltage, and/or dependence of cross sections on kinetic energy.

  17. Simplified Space Conditioning in Low-Load Homes: Results from the Fresno, California, Retrofit Unoccupied Test House

    SciTech Connect

    Stecher, Dave; Poerschke, Andrew

    2014-02-01

    In this study, the Building America team, IBACOS, sought to determine cost-effective, energy-efficient solutions for heating and cooling houses. To this end, the team performed field testing in a retrofit unoccupied test house in Fresno, California, to evaluate three air-based heating, ventilation, and air conditioning (HVAC) distribution systems during heating, cooling, and midseason conditions. These included a typical airflow ducted system to the bedrooms, a low airflow ducted system to the bedrooms, and a system with no ductwork to the bedrooms. The relative ability of each of the three systems was assessed with respect to relevant Air Conditioning Contractors of America (ACCA) and ASHRAE standards for house temperature uniformity and stability, respectively. Computational fluid dynamics modeling also was performed and refined based on comparison to field test results to determine the air flow rate into the bedrooms of over-door and bottom-of-door air transfer grilles.

  18. Simplified Space Conditioning in Low-Load Homes: Results from the Fresno, California, Retrofit Unoccupied Test House

    SciTech Connect

    Stecher, D.; Poerschke, A.

    2014-02-01

    Field testing was performed in a retrofit unoccupied test house in Fresno, California. Three air-based heating, ventilation, and air conditioning (HVAC) distribution systems -- a typical airflow ducted system to the bedrooms, a low airflow ducted system to the bedrooms, and a system with no ductwork to the bedrooms -- were evaluated during heating, cooling, and midseason conditions. The relative ability of each of the three systems was assessed with respect to relevant Air Conditioning Contractors of America (ACCA) and ASHRAE standards for house temperature uniformity and stability, respectively. Computational fluid dynamics (CFD) modeling also was performed and refined based on comparison to field test results to determine the air flow rate into the bedrooms of over-door and bottom-of-door air transfer grilles.

  19. Definitions of critical environmental conditions for selected Chesapeake Bay finfishes exposed to acidic episodes in spawning and nursery habitats. Final report

    SciTech Connect

    Klauda, R.J.

    1989-10-01

    Definitions of critical environmental conditions associated with acidic episodes are defined for yellow perch, alewife, blueback herring, American shad, and white perch, based on a review of field and laboratory data. These species are an important biological resource in the mid-Atlantic Coastal Plain. Values for blueback herring and alewife reproduction are an acid pulse between pH 5.5 and 6.2 with dissolved Ca at least 2 mg/l, with total monomeric Al levels between 15 and 137 microgram/l. Critical acidic conditions for American shad reproduction are an acid pulse between pH 5.7 and 6.7, dissolved Ca at least 2 micrograms/l, and total monomeric Al levels between 0 and 137 micrograms/l. Using data from the congeneric striped bass as a proxy, critical acidic conditions for white perch are an acid pulse between pH 6.5 and 6.7, total monomeric Al concentration of 25 microgram/l persisting for 7 days, and dissolved Ca at least 2 microgram/l. Based on a combination of life stage exposure and tolerance to acidic conditions the species can be ranked from high to low potential with regard to risks posed by acidic episodes on their early life stages: white perch, alewife/blueback herring, American shad, yellow perch.

  20. RESULTS OF THE 2H EVAPORATOR ACID CLEANING AND IN-POT NEUTRALIZATION

    SciTech Connect

    Wilmarth, B; Phillip Norris, P; Terry Allen, T

    2007-05-29

    The estimated 200 gallons of sodium aluminosilicate scale (NAS) present in the 242-16H Evaporator pot prior to chemical cleaning was subjected to four batches of 1.5 M (9 wt%) nitric acid. Each batch was neutralized with 19 M (50 wt %) sodium hydroxide (caustic) before transfer to Tank 38. The chemical cleaning process began on November 20, 2006, and was terminated on December 10, 2006. An inspection of the pot's interior was performed and based on data gathered during that inspection; the current volume of scale in the pot is conservatively estimated to be 36.3 gallons, which is well below the 200 gallon limit specified in the Technical Safety Requirements. In addition, the performance during all aspects of cleaning agreed well with the flowsheet developed at the bench and pilot scale. There were some lessons learned during the cleaning outage and are detailed in appendices of this report.

  1. Increase on the Initial Soluble Heme Levels in Acidic Conditions Is an Important Mechanism for Spontaneous Heme Crystallization In Vitro

    PubMed Central

    Egan, Timothy J.; Wright, David W.; Oliveira, Marcus F.

    2010-01-01

    Background Hemozoin (Hz) is a heme crystal that represents a vital pathway for heme disposal in several blood-feeding organisms. Recent evidence demonstrated that β-hematin (βH) (the synthetic counterpart of Hz) formation occurs under physiological conditions near synthetic or biological hydrophilic-hydrophobic interfaces. This seems to require a heme dimer acting as a precursor of Hz crystals that would be formed spontaneously in the absence of the competing water molecules bound to the heme iron. Here, we aimed to investigate the role of medium polarity on spontaneous βH formation in vitro. Methodology/Principal Findings We assessed the effect of water content on spontaneous βH formation by using the aprotic solvent dimethylsulfoxide (DMSO) and a series of polyethyleneglycols (PEGs). We observed that both DMSO and PEGs (3.350, 6.000, 8.000, and 22.000) increased the levels of soluble heme under acidic conditions. These compounds were able to stimulate the production of βH crystals in the absence of any biological sample. Interestingly, the effects of DMSO and PEGs on βH formation were positively correlated with their capacity to promote previous heme solubilization in acidic conditions. Curiously, a short chain polyethyleneglycol (PEG 300) caused a significant reduction in both soluble heme levels and βH formation. Finally, both heme solubilization and βH formation strongly correlated with reduced medium water activity provided by increased DMSO concentrations. Conclusions The data presented here support the notion that reduction of the water activity is an important mechanism to support spontaneous heme crystallization, which depends on the previous increase of soluble heme levels. PMID:20856937

  2. Adolescent traumatic stress experience results in less robust conditioned fear and post-extinction fear cue responses in adult rats.

    PubMed

    Moore, Nicole L T; Gauchan, Sangeeta; Genovese, Raymond F

    2014-05-01

    Early exposure to a traumatic event may produce lasting effects throughout the lifespan. Traumatic stress during adolescence may deliver a distinct developmental insult compared with more-often studied neonatal or juvenile traumatic stress paradigms. The present study describes the lasting effects of adolescent traumatic stress upon adulthood fear conditioning. Adolescent rats were exposed to a traumatic stressor (underwater trauma, UWT), then underwent fear conditioning during adulthood. Fear extinction was tested over five conditioned suppression extinction sessions three weeks later. The efficacies of two potential extinction-enhancing compounds, endocannabinoid reuptake inhibitor AM404 (10mg/kg) and M1 muscarinic positive allosteric modulator BQCA (10mg/kg), were also assessed. Finally, post-extinction fear responses were examined using a fear cue (light) as a prepulse stimulus. Rats traumatically stressed during adolescence showed blunted conditioned suppression on day 1 of extinction training, and AM404 reversed this effect. Post-extinction startle testing showed that fear conditioning eliminates prepulse inhibition to the light cue. Startle potentiation was observed only in rats without adolescent UWT exposure. AM404 and BQCA both ameliorated this startle potentiation, while BQCA increased startle in the UWT group. These results suggest that exposure to a traumatic stressor during adolescence alters developmental outcomes related to stress response and fear extinction compared to rats without adolescent traumatic stress exposure, blunting the adulthood fear response and reducing residual post-extinction fear expression. Efficacy of pharmacological interventions may also vary as a factor of developmental traumatic stress exposure. PMID:24491436

  3. Effect of imposed anaerobic conditions on metals release from acid-mine drainage contaminated streambed sediments.

    PubMed

    Butler, Barbara A

    2011-01-01

    Remediation of streams influenced by mine-drainage may require removal and burial of metal-containing bed sediments. Burial of aerobic sediments into an anaerobic environment may release metals, such as through reductive dissolution of metal oxyhydroxides. Mining-impacted aerobic streambed sediments collected from North Fork Clear Creek, Colorado were held under anaerobic conditions for four months. Eh, pH, and concentrations of Cd, Cu, Fe, Mn, and Zn (filtered at 1.5 μm, 0.45 μm, and 0.2 μm), sulfate, and dissolved organic carbon (DOC) were monitored in stream water/sediment slurries. Two sediment size fractions were examined (2 mm-63 μm and <63 μm). Sequential extractions evaluated the mineral phase with which metals were associated in the aerobic sediment. Released Cu was re-sequestered within 5 weeks, while Fe and Mn still were present at 16 weeks. Mn concentration was lower than in the initial stream water at and beyond 14 weeks for the smaller sized sediment. Cd was not released from either sediment size fraction. Zn was released at early times, but concentrations never exceeded those present in the initial stream water and all was re-sequestered over time. The greatest concentrations of Cu, Fe, Mn, and Zn were associated with the Fe/Mn reducible fraction. Sulfate and Fe were strongly correlated (r = 0.90), seeming to indicate anaerobic dissolution of iron oxy-hydroxy-sulfate minerals. DOC and sulfate were strongly correlated (r = 0.81), with iron having a moderately strong correlation with DOC (r = 0.71). Overall concentrations of DOC, sulfate, Cu, Fe, and Zn and pH were significantly higher (p < 0.05) in the water overlying the small sized sediment samples, while the concentrations of Mn released from the larger sized sediment samples were greater. PMID:20709348

  4. Down-regulation of crambe fatty acid desaturase and elongase in Arabidopsis and crambe resulted in significantly increased oleic acid content in seed oil.

    PubMed

    Li, Xueyuan; Mei, Desheng; Liu, Qing; Fan, Jing; Singh, Surinder; Green, Allan; Zhou, Xue-Rong; Zhu, Li-Hua

    2016-01-01

    High oleic oil is an important industrial feedstock that has been one of the main targets for oil improvement in a number of oil crops. Crambe (Crambe abyssinica) is a dedicated oilseed crop, suitable for industrial oil production. In this study, we down-regulated the crambe fatty acid desaturase (FAD) and fatty acid elongase (FAE) genes for creating high oleic seed oil. We first cloned the crambe CaFAD2, CaFAD3 and CaFAE1 genes. Multiple copies of each of these genes were isolated, and the highly homologous sequences were used to make RNAi constructs. These constructs were first tested in Arabidopsis, which led to the elevated oleic or linoleic levels depending on the genes targeted, indicating that the RNAi constructs were effective in regulating the expression of the target genes in nonidentical but closely related species. Furthermore, down-regulation of CaFAD2 and CaFAE1 in crambe with the FAD2-FAE1 RNAi vector resulted in even more significant increase in oleic acid level in the seed oil with up to 80% compared to 13% for wild type. The high oleic trait has been stable in subsequent five generations and the GM line grew normally in greenhouse. This work has demonstrated the great potential of producing high oleic oil in crambe, thus contributing to its development into an oil crop platform for industrial oil production. PMID:25998013

  5. Quinic acid could be a potential rejuvenating natural compound by improving survival of Caenorhabditis elegans under deleterious conditions.

    PubMed

    Zhang, Longze; Zhang, Junjing; Zhao, Baolu; Zhao-Wilson, Xi

    2012-12-01

    Quinic acid (QA) is an active ingredient of Cat's Claw (Uncaria tomentosa), which is found to be active in enhancing DNA repair and immunity in model systems and able to generate neuroprotective effects in neurons. However, QA's role in improving survival is not well studied. Here we report that QA can provide protection in Caenorhabidits elegans and improve worm survival under stress. Under heat stress and oxidative stress, QA-treated wild-type C. elegans N2 (N2) survived 17.8% and 29.7% longer, respectively, than the control worms. Our data suggest that under heat stress, QA can upregulate the expression of the small heat shock protein hsp-16.2 gene, which could help the worms survive a longer time. We also found that QA extended the C. elegans mutant VC475 [hsp-16.2 (gk249)] life span by 15.7% under normal culture conditions. However, under normal culture conditions, QA did not affect hsp-16.2 expression, but upregulated the expression of daf-16 and sod-3 in a DAF-16-dependent manner, and downregulated the level of reactive oxygen species (ROS), suggesting that under normal conditions QA acts in different pathways. As a natural product, QA demonstrates great potential as a rejuvenating compound. PMID:22950425

  6. Quinic Acid Could Be a Potential Rejuvenating Natural Compound by Improving Survival of Caenorhabditis elegans under Deleterious Conditions

    PubMed Central

    Zhang, Longze; Zhang, Junjing

    2012-01-01

    Abstract Quinic acid (QA) is an active ingredient of Cat's Claw (Uncaria tomentosa), which is found to be active in enhancing DNA repair and immunity in model systems and able to generate neuroprotective effects in neurons. However, QA's role in improving survival is not well studied. Here we report that QA can provide protection in Caenorhabidits elegans and improve worm survival under stress. Under heat stress and oxidative stress, QA-treated wild-type C. elegans N2 (N2) survived 17.8% and 29.7% longer, respectively, than the control worms. Our data suggest that under heat stress, QA can upregulate the expression of the small heat shock protein hsp-16.2 gene, which could help the worms survive a longer time. We also found that QA extended the C. elegans mutant VC475 [hsp-16.2 (gk249)] life span by 15.7% under normal culture conditions. However, under normal culture conditions, QA did not affect hsp-16.2 expression, but upregulated the expression of daf-16 and sod-3 in a DAF-16–dependent manner, and downregulated the level of reactive oxygen species (ROS), suggesting that under normal conditions QA acts in different pathways. As a natural product, QA demonstrates great potential as a rejuvenating compound. PMID:22950425

  7. Effect of Electrospray Ionization Source Conditions on the Tautomer Distribution of Deprotonated p-Hydroxybenzoic Acid in the Gas Phase.

    PubMed

    Xia, Hanxue; Attygalle, Athula B

    2016-06-01

    The deprotonation site of p-hydroxybenzoic acid upon electrospray ionization has been a subject of fervent debate in several articles in the Journal of the American Chemical Society and elsewhere. General consensus is that electrospray ionization mass spectrometry (ESI-MS) experimental results reflect the situation in solution to a considerable extent. Our research, using ion-mobility mass spectrometry, challenges the notion that ESI-MS results directly reflect solution-phase structures and demonstrates that the relative populations of the thermodynamically less favored gaseous carboxylate tautomer or the thermodynamically more favored gaseous phenoxide tautomer, generated from the same aqueous solution of p-hydroxybenzoic acid by ESI, can be varied back and forth by changing the probe position, capillary voltage, desolvation-gas temperature, sample infusion flow rate, and cone voltage. In other words, solvent effects are not the primary criteria that determine the relative population distributions of tautomeric carboxylate (C(-)) and phenoxide (P(-)) ions (m/z 137) generated by electrospray ionization of p-hydroxybenzoic acid. In addition, we propose that the observed ratio of the P(-) and C(-) forms indirectly reflects the relative contribution of the charge-residue or ion-evaporation process that occurs during the electrospray ion generation process. PMID:27164186

  8. Study on reduction and back extraction of Pu(IV) by urea derivatives in nitric acid conditions

    SciTech Connect

    Ye, G.A.; Xiao, S.T.; Yan, T.H.; Lin, R.S.; Zhu, Z.W.

    2013-07-01

    The reduction kinetics of Pu(IV) by hydroxyl-semicarbazide (HSC), hydroxyurea (HU) and di-hydroxyurea (DHU) in nitric acid solutions were investigated separately with adequate kinetic equations. In addition, counter-current cascade experiments were conducted for Pu split from U in nitric acid media using three kinds of reductant, respectively. The results show that urea derivatives as a kind of novel salt-free reductant can reduce Pu(IV) to Pu(III) rapidly in the nitric acid solutions. The stripping experimental results showed that Pu(IV) in the organic phase can be stripped rapidly to the aqueous phase by the urea derivatives, and the separation factors of plutonium /uranium can reach more than 10{sup 4}. This indicates that urea derivatives is a kind of promising salt-free agent for uranium/plutonium separation. In addition, the complexing effect of HSC with Np(IV) was revealed, and Np(IV) can be back-extracted by HSC with a separation factor of about 20.

  9. "Stereoscopic" 2D super-microporous phosphazene-based covalent organic framework: Design, synthesis and selective sorption towards uranium at high acidic condition.

    PubMed

    Zhang, Shuang; Zhao, Xiaosheng; Li, Bo; Bai, Chiyao; Li, Yang; Wang, Lei; Wen, Rui; Zhang, Meicheng; Ma, Lijian; Li, Shoujian

    2016-08-15

    So far, only five primary elements (C, H, O, N and B) and two types of spatial configuration (C2-C4, C6 and Td) are reported to build the monomers for synthesis of covalent organic frameworks (COFs), which have partially limited the route selection for accessing COFs with new topological structure and novel properties. Here, we reported the design and synthesis of a new "stereoscopic" 2D super-microporous phosphazene-based covalent organic framework (MPCOF) by using hexachorocyclotriphosphazene (a P-containing monomer in a C3-like spatial configuration) and p-phenylenediamine (a linker). The as-synthesized MPCOF shows high crystallinity, relatively high heat and acid stability and distinctive super-microporous structure with narrow pore-size distributions ranging from 1.0-2.1nm. The results of batch sorption experiments with a multi-ion solution containing 12 co-existing cations show that in the pH range of 1-2.5, MPCOF exhibits excellent separation efficiency for uranium with adsorption capacity more than 71mg/g and selectivity up to record-breaking 92%, and furthermore, an unreported sorption capacity (>50mg/g) and selectivity (>60%) were obtained under strong acidic condition (1M HNO3). Studies on sorption mechanism indicate that the uranium separation by MPCOF in acidic solution is realized mainly through both intra-particle diffusion and size-sieving effect. PMID:27107239

  10. 78 FR 40099 - 1-Hydroxyethylidene-1, 1-Diphosphonic Acid From India: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-03

    ...; 2011- 2012; Intent to Revoke Order (in Part), 78 FR 25699 (May 2, 2012) (Preliminary Results). DATES... Preliminary Results.\\3\\ No comments were submitted. \\3\\ See Preliminary Results, 78 FR at 25700. Scope of the... FR 19197 (April 28, 2009). Determination To Revoke Order, In Part The Department may revoke, in...

  11. Conditional deletion of Mecp2 in parvalbumin-expressing GABAergic cells results in the absence of critical period plasticity.

    PubMed

    He, Ling-jie; Liu, Nan; Cheng, Tian-lin; Chen, Xiao-jing; Li, Yi-ding; Shu, You-sheng; Qiu, Zi-long; Zhang, Xiao-hui

    2014-01-01

    Mutations in the X-linked gene encoding the transcriptional modulator methyl-CpG-binding protein 2 (MeCP2) impair postnatal development of the brain. Here we use neuronal-type specific gene deletion in mice to show that conditional Mecp2 deletion in GABAergic parvalbumin-expressing (PV) cells (PV-Mecp2(-/y)) does not cause most Rett-syndrome-like behaviours, but completely abolishes experience-dependent critical period plasticity of primary visual cortex (V1) that develops normal visual functions. However, selective loss of Mecp2 in GABAergic somatostatin-expressing cells or glutamatergic pyramidal cells does not affect the critical period plasticity. MeCP2-deficient PV cells exhibit high intrinsic excitability, selectively reduced efficacy of recurrent excitatory synapses in V1 layer 4 circuits, and decreased evoked visual responses in vivo. Enhancing cortical gamma-aminobutyric acid (GABA) inhibition with diazepam infusion can restore critical period plasticity in both young and adult PV-Mecp2(-/y) mice. Thus, MeCP2 expression in inhibitory PV cells during the critical period is essential for local circuit functions underlying experience-dependent cortical plasticity. PMID:25297674

  12. Corrosion inhibition of aminated hydroxyl ethyl cellulose on mild steel in acidic condition.

    PubMed

    Sangeetha, Y; Meenakshi, S; Sairam Sundaram, C

    2016-10-01

    Aminated hydroxyethyl cellulose (AHEC) was synthesized, characterized using Fourier Transform Infrared spectroscopy (FTIR) and the corrosion inhibition of AHEC on mild steel in 1M HCl was studied using chemical and electrochemical studies. Results obtained in weight loss method showed that inhibition efficiency increased with increase in concentration of AHEC. The adsorption of the inhibitor on metal surface followed Frumkin isotherm. Polarization studies revealed that the AHEC inhibits through mixed mode. Thermodynamic parameters and activation energy were calculated and discussed. FTIR and X-ray diffraction studies (XRD) confirmed the adsorption of the inhibitor. The surface morphology was studied using Scanning Electron Microscope (SEM) and Atomic Force Microscopy (AFM). PMID:27312608

  13. Effect of low doses of cannabidiolic acid and ondansetron on LiCl-induced conditioned gaping (a model of nausea-induced behaviour) in rats

    PubMed Central

    Rock, EM; Parker, LA

    2013-01-01

    Background and Purpose To determine the minimally effective dose of cannabidiolic acid (CBDA) that effectively reduces lithium chloride (LiCl)-induced conditioned gaping reactions (nausea-induced behaviour) in rats and to determine if these low systemic doses of CBDA (5–0.1 μg·kg−1) relative to those of CBD could potentiate the anti-nausea effects of the classic 5-hydroxytryptamine 3 (5-HT3) receptor antagonist, ondansetron (OND). Experimental Approach We investigated the efficacy of low doses of CBDA to suppress acute nausea, assessed by the establishment of conditioned gaping to a LiCl-paired flavour in rats. The potential of threshold and subthreshold doses of CBDA to enhance the reduction of nausea-induced conditioned gaping by OND were then determined. Key Results CBDA (at doses as low as 0.5 μg·kg−1) suppressed nausea-induced conditioned gaping to a flavour. A low dose of OND (1.0 μg·kg−1) alone reduced nausea-induced conditioned gaping, but when it was combined with a subthreshold dose of CBDA (0.1 μg·kg−1) there was an enhancement in the suppression of LiCl-induced conditioned gaping. Conclusions and Implications CBDA potently reduced conditioned gaping in rats, even at low doses and enhanced the anti-nausea effect of a low dose of OND. These findings suggest that combining low doses of CBDA and OND will more effectively treat acute nausea in chemotherapy patients. PMID:23488964