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Sample records for 5-aminosalicylic acid enhance

  1. Design, Synthesis, and Testing of a Molecular Truck for Colonic Delivery of 5-Aminosalicylic Acid

    PubMed Central

    2012-01-01

    A molecular scaffold bearing eight terminal alkyne groups was synthesized from sucrose. Eight copies of an azide-terminated, azo-linked precursor to 5-aminosalicylic acid were attached to the scaffold via copper(I)-catalyzed azide–alkyne cycloaddition. The resulting compound was evaluated in a DSS model of colitis in BALB/c mice against sulfasalazine as a control. Two independent studies verified that the novel pro-drug, administered in a dose calculated to result in an equimolar 5-ASA yield, outperformed sulfasalazine in terms of protection from mucosal inflammation and T cell activation. A separate study established that 5-ASA appeared in feces produced 24–48 h following administration of the pro-drug. Thus, a new, orally administered pro-drug form of 5-aminosalicylic acid has been developed and successfully demonstrated. PMID:23029601

  2. Retrograde spread of 5-aminosalicylic acid enemas in patients with active ulcerative colitis

    SciTech Connect

    Campieri, M.; Lanfranchi, G.A.; Brignola, C.; Bazzocchi, G.; Gionchetti, P.; Minguzzi, M.R.; Cappello, I.P.; Corbelli, C.; Boschi, S.

    1986-02-01

    In an attempt to know the exact retrograde spread of high-dosage 5-aminosalicylic acid enemas, we have studied eight patients with active left-sided colitis, by adding a small amount of barium sulfate to the enemas and by checking the spread radiologically after 15 minutes, 1 hour, and 6 hours. Four grams of 5-aminosalicylic acid in 100-ml enemas and 4 gm in 200-ml enemas were used. The same experiment was repeated in a subsequent attack, with enemas labeled with technetium-99m and checked by scintiscans in five of these patients. We always have observed a volume-dependent spread of enemas but, interestingly, in the patients studied with technetium-99m there was always a wider spread than that which was detected with barium enemas. In all five patients, 100-ml enemas reached the splenic flexure. In two patients with total colitis, a progression of 100-ml technetium-99m enemas was performed in the transverse colon, but the maximum opacity remained in the left side. We can conclude that 4 gm of 5-aminosalicylic acid in 100-ml enemas can be suitable for treating patients with left-sided colitis, and will represent a valid addition for patients with more extensive colitis.

  3. Release kinetics of 5-aminosalicylic acid from halloysite.

    PubMed

    Aguzzi, C; Viseras, C; Cerezo, P; Salcedo, I; Sánchez-Espejo, R; Valenzuela, C

    2013-05-01

    This paper investigates desorption of 5-aminosalicilyc acid (5-ASA) adsorbed onto halloysite (HL). Desorption isotherms were fitted according to kinetic laws obtained considering release of 5-ASA from HL as the phase of desorption of the previously adsorbed drug molecules both inside the nanotubes of HL as onto the surface of clay particles and/or in the inter-particle spaces of their aggregates. Desorption isotherms has been also fitted with other equations frequently used in drug release kinetics studies. The best fitting corresponded to the kinetic model proposed; in agreement with the results of adsorption.

  4. Failure of 5-aminosalicylic acid enemas to improve chronic radiation proctitis

    SciTech Connect

    Baum, C.A.; Biddle, W.L.; Miner, P.B. Jr.

    1989-05-01

    Radiation proctitis is a well-known complication of abdominal and pelvic radiation. Conventional medical and surgical treatment often is disappointing. 5-Aminosalicylic acid (5-ASA) is the active component in sulfasalazine and is effective in the treatment of distal ulcerative colitis. Four patients with radiation proctitis were treated with 4 g 5-ASA by enema nightly for two to six months. Patients were seen monthly, interviewed, and a sigmoidoscopic exam performed. No change was seen in the degree of mucosal inflammation on follow-up sigmoidoscopic exams. Three patients noted no change in their symptoms of bleeding, pain, or tenesmus. One patient noted initial improvement, but this was not sustained. 5-ASA enemas do not appear to be effective in the treatment of radiation proctitis.

  5. 5-Aminosalicylic acid attenuates allergen-induced airway inflammation and oxidative stress in asthma.

    PubMed

    Raju, K Rama Satyanarayana; Kumar, M N Sathish; Gupta, Saurabh; Naga, Srinivas T; Shankar, Jaya K; Murthy, Vishakantha; Madhunapanthula, Subba Rao V; Mulukutla, Shashank; Ambhore, Nilesh S; Tummala, Shashank; Vishnuvarthan, V J; Azam, Afzal; Elango, Kannan

    2014-12-01

    Pro-inflammatory cytokines regulate the magnitude of allergic reactions during asthma. Tumor necrosis factor--alpha (TNF-α), interleukin-6 (IL-6) and interleukin-13 (IL-13) play a crucial role in aggravating the inflammatory conditions during allergic asthma. In addition, oxidative stress contributes to the pathogenesis of asthma by altering the physiological condition resulting in the development of status asthmaticus. Anti-inflammatory corticosteroids are being widely used for treating allergic asthma. In the present study 5-aminosalicylic acid (5-ASA), a salicylic acid derivative, was evaluated, in vivo for its potential to suppress TNF-α, IL-6 and IL-13 using ovalbumin (OVA) induced allergic asthma in Balb/C mice. Oral administration of 65, 130 and 195 mg/kg 5-ASA significantly reduced the OVA induced total and differential leucocyte count, TNF-α, IL-6, IL-13, nitrite, nitrate, MDA, MPO and TPL levels in the lung lavage samples. Collectively, these findings suggest that 5-ASA is a potent immunomodulator and suppresses key Th2 cytokines production and oxidative stress in OVA-induced asthma.

  6. Effects of processing on the release profiles of matrix systems containing 5-aminosalicylic acid.

    PubMed

    Korbely, Anita; Kelemen, András; Kása, Péter; Pintye-Hódi, Klára

    2012-12-01

    The aim of this study was to investigate the influence of different processing methods on the profiles of 5-aminosalicylic acid dissolution from controlled-release matrix systems based on Eudragit® RL and Eudragit® RS water-insoluble polymers. The pure polymers and their mixtures were studied as matrix formers using different processing methods, i.e., direct compression, wet granulation of the active ingredient with the addition of polymer(s) to the external phase, wet granulation with water, and wet granulation with aqueous dispersions. In comparison with the directly compressed tablets, tablets made by wet granulation with water demonstrated a 6-19% increase in final drug dissolution, whereas when polymers were applied in the external phase during compression, a 0-13% decrease was observed in the amount of drug released. Wet granulation with aqueous polymer dispersions delayed the release of the drug; this was especially marked (a 54-56% decrease in drug release) in compositions, which contained a high amount of Eudragit RL 30D. The release profiles were mostly described by the Korsmeyer-Peppas model or the Hopfenberg model. PMID:23054987

  7. Quantitative distribution of radiolabeled 5-aminosalicylic acid enemas in patients with left-sided ulcerative colitis

    SciTech Connect

    Vitti, R.A.; Meyers, F.; Knight, L.C.; Siegel, J.A.; Malmud, L.S.; Fisher, R.S. )

    1989-11-01

    Rectally administered suspensions of 5-aminosalicylic acid (5-ASA) are topically effective in treating left-sided ulcerative colitis. The extent to which the contents of these enemas are distributed to inflamed mucosal linings has not previously been determined. This study was undertaken to validate a technique for labeling 5-ASA with 99mTc and to quantitate the distribution of (99mTc)5-ASA in eight patients with left-sided ulcerative colitis. Eight patients underwent three colonic scintigraphic exams within five days, receiving a 60-ml radiolabeled 5-ASA enema into the unprepared rectum for each study, with sequential anterior abdominal images obtained for 4 hr. Activity within the rectum, sigmoid, descending, transverse, and ascending colon was quantitated. Over 50% of the labeled enema had advanced beyond the rectum in five of eight patients and in six of eight patients by 30 min and 60 min, respectively. The distribution of (99mTc)5-ASA was quantitatively reproducible when repeated in the same patient on different days, despite apparent visual differences. By 2 hr, the amount of the enema present within the rectum decreased significantly (P less than 0.05) compared to the initial distribution. The amount of enema present within the descending colon was increased significantly at 0.5 hr (P less than 0.05) and at 2 hr (P less than 0.01). There were no significant changes in the distribution from initial values for the sigmoid, transverse, or ascending colon at any time. In each of these cases the spread of the enema to or beyond the extent of disease was documented. In patients with left-sided ulcerative colitis, small volume (99mTc)5-ASA enemas reliably reach the area of inflammation.

  8. Preparation and evaluation of colon adhesive pellets of 5-aminosalicylic acid.

    PubMed

    Xu, Meixia; Sun, Minjie; Qiao, Hongzhi; Ping, Qineng; Elamin, Eltayeb Suliman

    2014-07-01

    Oral modified-release delivery systems, such as bio-adhesive one, enable drug delivery to affected regions and minimize the side effects by reducing the systemic absorption. Our aim was to develop colon adhesive pellets of 5-aminosalicylic acid (5-ASA) for the treatment of ulcerative colitis. The core of the pellet was formulated from bioadhesive agents, Carbomer 940 and hydroxypropyl cellulose (HPC), by extrusion/spheronization method and coated with Surelease(®) as inner layer for waterproof and with Eudragit(®) S100 as outer layer for pH control. The rat model of ulcerative colitis was used to evaluate the efficiency of our loaded pellets as a drug carrier. Microcrystalline cellulose 101 (PH 301) was found to be the best agent for pellet core. The ratio of CP940 to HPC should be kept as (1:1) to achieve high bioadhesion. When the amount of Surelease(®) was from 16% to 20% and of Eudragit(®) S100 was 28%, the dissolution profiles of coated pellets revealed no drug release in the artificial gastric fluid (pH 1.0) within 2h and less than 10% was released in phosphate buffer (pH 6.0) within 2h whereas complete dissolution was observed in colonic fluid of pH 7.4 for 20 h. The animal experiment showed that 5-ASA loaded colon adhesive pellets had optimal therapeutic effect. We showed a novel approach to prepare effective bioadhesive pellets as colon targeted drug delivery system. PMID:24746693

  9. Toxicity of 50-nm polystyrene particles co-administered to mice with acetaminophen, 5-aminosalicylic acid or tetracycline.

    PubMed

    Isoda, K; Nozawa, T; Tezuka, M; Ishida, I

    2014-09-01

    We investigated whether nano-sized polystyrene particles affect drug-induced toxicity. The particles, which are widely used industrially, had diameters of 50 (NPP50), 200 (NPP200) or 1000 (NPP1000) nm. The toxic chemicals tested were acetaminophen (APAP), 5-aminosalicylic acid (5-ASA), tetracycline (TC), and sodium valproate (VPA). All treatments in the absence of the nanoparticles were non-lethal and did not result in severe toxicity. However, when mice were injected with APAP, 5-ASA or TC together with polystyrene particles, synergistic, enhanced toxicity was observed in mice injected with NPP50. These synergic effects were not observed in mice co-injected with NPP200 or NPP1000. On the other hand, co-administration of VPA and NPP50, NPP200 or NPP1000 did not elevate toxicity. The results show that NPP50 differs in hepatotoxicity depending on the drug co-administered. These findings suggest that further evaluation of the interactions between polystyrene nanoparticles and drugs is a critical prerequisite to the pharmaceutical application of nanotechnology.

  10. Effect of 70-nm silica particles on the toxicity of acetaminophen, tetracycline, trazodone, and 5-aminosalicylic acid in mice.

    PubMed

    Li, X; Kondoh, M; Watari, A; Hasezaki, T; Isoda, K; Tsutsumi, Y; Yagi, K

    2011-04-01

    Exposure to nano-sized particles is increasing because they are used in a wide variety of industrial products, cosmetics, and pharmaceuticals. Some animal studies indicate that such nanomaterials may have some toxicity, but their synergistic actions on the adverse effects of drugs are not well understood. In this study, we investigated whether 70-nm silica particles (nSP70), which are widely used in cosmetics and drug delivery, affect the toxicity of a drug for inflammatory bowel disease (5-aminosalicylic acid), an antibiotic drug (tetracycline), an antidepressant drug (trazodone), and an antipyretic drug (acetaminophen) in mice. Co-administration of nSP70 with trazodone did not increase a biochemical marker of liver injury. In contrast, co-administration increased the hepatotoxicity of the other drugs. Co-administration of nSP70 and tetracycline was lethal. These findings indicate that evaluation of synergistic adverse effects is important for the application of nano-sized materials.

  11. Assessment of salicylate derivatives for potential use in ulcerative colitis: proposal for a new action of 5-aminosalicylic acid?

    PubMed

    Roediger, W E; Deakin, E J; Walker, G; Nance, S H

    1989-01-01

    The therapeutic efficacy of salicylate drugs for ulcerative colitis in vivo is related to the capacity of each drug to suppress fatty acid oxidation in colonocytes in vitro. The suppression index of fatty acid oxidation (SIFO) was assessed with 17 salicylate drugs of either known or unknown therapeutic efficacy. The high SIFO value of 5-aminosalicylic acid (5-ASA) was reduced to zero when the amino group was replaced with a methyl, nitro, hydroxyl or bromine group. The SIFO of 3-ASA was dose-related and 2- to 3-fold greater than the SIFO of 5-ASA. The antioxidants methyl- or propyl-4-hydroxybenzoate have a high SIFO, but show a 'toxic' action towards colonocytes not observed with 3-ASA, 4-ASA or 5-ASA. A new cellular action proposed for 5-ASA is that acetylation of the amino group of 5-ASA in colonocytes releases free CoA countering sequestration of CoA observed in epithelial cells during active colitis. PMID:2511578

  12. Synthesis and evaluation of mutual azo prodrug of 5-aminosalicylic acid linked to 2-phenylbenzoxazole-2-yl-5-acetic acid in ulcerative colitis

    PubMed Central

    Jilani, Jamal A; Shomaf, Maha; Alzoubi, Karem H

    2013-01-01

    In this study, the syntheses of 4-aminophenylbenzoxazol-2-yl-5-acetic acid, (an analogue of a known nonsteroidal anti-inflammatory drug [NSAID]) and 5-[4-(benzoxazol-2-yl-5-acetic acid)phenylazo]-2-hydroxybenzoic acid (a novel mutual azo prodrug of 5-aminosalicylic acid [5-ASA]) are reported. The structures of the synthesized compounds were confirmed using infrared (IR), hydrogen-1 nuclear magnetic resonance (1H NMR), and mass spectrometry (MS) spectroscopy. Incubation of the azo compound with rat cecal contents demonstrated the susceptibility of the prepared azo prodrug to bacterial azoreductase enzyme. The azo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were evaluated for inflammatory bowel diseases, in trinitrobenzenesulfonic acid (TNB)-induced colitis in rats. The synthesized diazo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were found to be as effective as 5-aminosalicylic acid for ulcerative colitis. The results of this work suggest that the 4-aminophenylbenzoxazol-2-yl-5-acetic acid may represent a new lead for treatment of ulcerative colitis. PMID:23983456

  13. Effect of 5-aminosalicylic acid (5-ASA) and other salicylates on short-chain fat metabolism in the colonic mucosa. Pharmacological implications for ulcerative colitis.

    PubMed

    Roediger, W; Schapel, G; Lawson, M; Radcliffe, B; Nance, S

    1986-01-15

    5-Aminosalicylic acid (5-ASA) suppressed nitrite-stimulated oxidation of the fatty acid n-butyrate in a dose-dependent manner in isolated human and rat colonic epithelial cells. 4-ASA had one-sixth of the capacity of 5-ASA and sulphapyridine (SP) little of the capacity of 5-ASA to suppress fatty acid oxidation in human colonic epithelial cells. Sulphasalazine (SASP), azodisalicylic acid (ADS), acetyl-5-ASA and acetyl salicylic acid (ASA) did not suppress fatty acid oxidation in rat colonocytes. The suppression index of fatty acid oxidation (SIFO) of respective salicylic acids correlated with the reported clinical effectiveness of each drug against ulcerative colitis (UC). The capacity of 5-ASA to affect nitrite-stimulated oxidation of fat in the colonic mucosa suggests that nitrite ions and control of fatty acid oxidation play a central role in the development and therapy of active UC. PMID:2867767

  14. The effect of probiotic Escherichia coli strain Nissle 1917 lipopolysaccharide on the 5-aminosalicylic acid transepithelial transport across Caco-2 cell monolayers.

    PubMed

    Stětinová, Věra; Smetanová, Libuše; Kholová, Dagmar; Květina, Jaroslav; Svoboda, Zbyněk; Zídek, Zdeněk; Tlaskalová-Hogenová, Helena

    2013-09-01

    The object of this study was to investigate the effect of probiotic Escherichia coli strain Nissle 1917 (EcN) (i) EcN lipopolysaccharide (EcN LPS) and (ii) bacteria-free supernatant of EcN suspension (EcN supernatant) on in vitro transepithelial transport of mesalazine (5-aminosalicylic acid, 5-ASA), the most commonly prescribed anti-inflammatory drug in inflammatory bowel disease (IBD). Effect of co-administered EcN LPS (100 µg/ml) or EcN supernatant (50 µg/ml) on the 5-ASA transport (300 µmol/l) was studied using the Caco-2 monolayer (a human colon carcinoma cell line) as a model of human intestinal absorption. Permeability characteristics for absorptive and secretory transport of parent drug and its intracellularly-formed metabolite were determined. The quantification of 5-ASA and its main metabolite N-acetyl-5-amino-salicylic acid (N-Ac-5-ASA) was performed by high performance liquid chromatography. Obtained results suggest that neither EcN LPS nor EcN supernatant had effect on the total 5-ASA transport (secretory flux greater than absorptive flux) and on the transport of intracellularly formed N-Ac-5-ASA (preferentially transported in the secretory direction). The percent cumulative transport of the total 5-ASA alone or in combination with EcN LPS or EcN supernatant did not exceed 1%. PMID:23846256

  15. Addition of Berberine to 5-Aminosalicylic Acid for Treatment of Dextran Sulfate Sodium-Induced Chronic Colitis in C57BL/6 Mice.

    PubMed

    Li, Yan-hong; Zhang, Man; Xiao, Hai-tao; Fu, Hai-bo; Ho, Alan; Lin, Cheng-yuan; Huang, Yu; Lin, Ge; Bian, Zhao-xiang

    2015-01-01

    Ulcerative colitis (UC) is a common chronic remitting disease but without satisfactory treatment. Alternative medicine berberine has received massive attention for its potential in UC treatment. Conventional therapies with the addition of berberine are becoming attractive as novel therapies in UC. In the present study, we investigated the preclinical activity of a conventional oral 5-aminosalicylic acid (5-ASA) therapy plus berberine in experimental colitis. A subclinical dose of 5-ASA (200 mg/kg/day) alone or 5-ASA plus berberine (20 mg/kg/day) was orally administered for 30 days to C57BL/6 mice with colitis induced by three cycles of 2% dextran sulfate sodium (DSS). The disease severity, inflammatory responses, drug accumulation and potential toxicity of colitis mice were examined. The results showed that comparing to 5-ASA alone, 5-ASA plus berberine more potently ameliorated DSS-induced disease severity, colon shortening, and colon histological injury. Further, the up-regulation in mRNA level of colonic TNF-α as well as NFκB and JAK2 phosphorylation caused by DSS were more pronouncedly reversed in animals treated with the combination therapy than those treated with 5-ASA alone. Moreover, the addition of berberine to 5-ASA more significantly inhibited lymphocyte TNF-α secretion of DSS mice than 5-ASA alone. In the meanwhile, no extra drug accumulation or potential toxicity to major organs of colitis mice was observed with this combination treatment. In summary, our studies provide preclinical rationale for the addition of berberine to 5-ASA as a promising therapeutic strategy in clinic by reducing dose of standard therapy.

  16. Pharmacokinetics in Wistar Rats of 5-[(4-Carboxybutanoyl)Amino]-2-Hydroxybenzoic Acid: A Novel Synthetic Derivative of 5-Aminosalicylic Acid (5-ASA) with Possible Anti-Inflammatory Activity.

    PubMed

    Romero-Castro, Aurelio; Gutiérrez-Sánchez, Mara; Correa-Basurto, José; Rosales Hernández, Martha Cecilia; Padilla Martínez, Itzia Irene; Mendieta-Wejebe, Jessica Elena

    2016-01-01

    5-[(4-carboxybutanoyl)amino]-2-hydroxybenzoic acid (C2) is a novel synthetic derivative of 5-aminosalicylic acid (5-ASA), which is currently being evaluated ex vivo as an anti-inflammatory agent and has shown satisfactory results. This study aimed to obtain the pharmacokinetic profiles, tissue distribution and plasma protein binding of C2 in Wistar Rats. Additionally, an HPLC method was developed and validated to quantify C2 in rat plasma. The pharmacokinetic profiles of intragastric, intravenous and intraperitoneal administration routes at singles doses of 100, 50, and 100 mg/kg, respectively, were studied in Wistar rats. The elimination half-life of intravenously administered C2 was approximately 33 min. The maximum plasma level of C2 was reached approximately 24 min after intragastric administration, with a Cmax value of 2.5 g/mL and an AUCtot value of 157 μg min-1/mL; the oral bioavailability was approximately 13%. Following a single intragastric or oral dose (100 mg/kg), C2 was distributed and detected in all examined tissues (including the brain and colon). The results showed that C2 accumulates over time. The plasma protein binding results indicated that the unbound fraction of C2 at concentrations of 1 to 20 μg/mL ranged from 89.8% to 92.5%, meaning that this fraction of C2 is available to cross tissues. Finally, the blood-plasma partitioning (BP ratio) of C2 in rat plasma was 0.71 and 0.6 at concentrations of 5 and 10 μg/mL, respectively, which indicates that C2 is free in the plasmatic phase and not inside blood cells. The results of this study suggest that a fraction of the administered C2 dose is absorbed in the stomach, and the fraction that is not absorbed reaches the small intestine and colon. This distribution constitutes the main advantage of C2 compared with 5-ASA for the treatment of ulcerative colitis (UC) and Crohn's disease (CD). PMID:27454774

  17. Pharmacokinetics in Wistar Rats of 5-[(4-Carboxybutanoyl)Amino]-2-Hydroxybenzoic Acid: A Novel Synthetic Derivative of 5-Aminosalicylic Acid (5-ASA) with Possible Anti-Inflammatory Activity

    PubMed Central

    Correa-Basurto, José; Rosales Hernández, Martha Cecilia; Padilla Martínez, Itzia Irene; Mendieta-Wejebe, Jessica Elena

    2016-01-01

    5-[(4-carboxybutanoyl)amino]-2-hydroxybenzoic acid (C2) is a novel synthetic derivative of 5-aminosalicylic acid (5-ASA), which is currently being evaluated ex vivo as an anti-inflammatory agent and has shown satisfactory results. This study aimed to obtain the pharmacokinetic profiles, tissue distribution and plasma protein binding of C2 in Wistar Rats. Additionally, an HPLC method was developed and validated to quantify C2 in rat plasma. The pharmacokinetic profiles of intragastric, intravenous and intraperitoneal administration routes at singles doses of 100, 50, and 100 mg/kg, respectively, were studied in Wistar rats. The elimination half-life of intravenously administered C2 was approximately 33 min. The maximum plasma level of C2 was reached approximately 24 min after intragastric administration, with a Cmax value of 2.5 g/mL and an AUCtot value of 157 μg min-1/mL; the oral bioavailability was approximately 13%. Following a single intragastric or oral dose (100 mg/kg), C2 was distributed and detected in all examined tissues (including the brain and colon). The results showed that C2 accumulates over time. The plasma protein binding results indicated that the unbound fraction of C2 at concentrations of 1 to 20 μg/mL ranged from 89.8% to 92.5%, meaning that this fraction of C2 is available to cross tissues. Finally, the blood-plasma partitioning (BP ratio) of C2 in rat plasma was 0.71 and 0.6 at concentrations of 5 and 10 μg/mL, respectively, which indicates that C2 is free in the plasmatic phase and not inside blood cells. The results of this study suggest that a fraction of the administered C2 dose is absorbed in the stomach, and the fraction that is not absorbed reaches the small intestine and colon. This distribution constitutes the main advantage of C2 compared with 5-ASA for the treatment of ulcerative colitis (UC) and Crohn's disease (CD). PMID:27454774

  18. Pharmacokinetics in Wistar Rats of 5-[(4-Carboxybutanoyl)Amino]-2-Hydroxybenzoic Acid: A Novel Synthetic Derivative of 5-Aminosalicylic Acid (5-ASA) with Possible Anti-Inflammatory Activity.

    PubMed

    Romero-Castro, Aurelio; Gutiérrez-Sánchez, Mara; Correa-Basurto, José; Rosales Hernández, Martha Cecilia; Padilla Martínez, Itzia Irene; Mendieta-Wejebe, Jessica Elena

    2016-01-01

    5-[(4-carboxybutanoyl)amino]-2-hydroxybenzoic acid (C2) is a novel synthetic derivative of 5-aminosalicylic acid (5-ASA), which is currently being evaluated ex vivo as an anti-inflammatory agent and has shown satisfactory results. This study aimed to obtain the pharmacokinetic profiles, tissue distribution and plasma protein binding of C2 in Wistar Rats. Additionally, an HPLC method was developed and validated to quantify C2 in rat plasma. The pharmacokinetic profiles of intragastric, intravenous and intraperitoneal administration routes at singles doses of 100, 50, and 100 mg/kg, respectively, were studied in Wistar rats. The elimination half-life of intravenously administered C2 was approximately 33 min. The maximum plasma level of C2 was reached approximately 24 min after intragastric administration, with a Cmax value of 2.5 g/mL and an AUCtot value of 157 μg min-1/mL; the oral bioavailability was approximately 13%. Following a single intragastric or oral dose (100 mg/kg), C2 was distributed and detected in all examined tissues (including the brain and colon). The results showed that C2 accumulates over time. The plasma protein binding results indicated that the unbound fraction of C2 at concentrations of 1 to 20 μg/mL ranged from 89.8% to 92.5%, meaning that this fraction of C2 is available to cross tissues. Finally, the blood-plasma partitioning (BP ratio) of C2 in rat plasma was 0.71 and 0.6 at concentrations of 5 and 10 μg/mL, respectively, which indicates that C2 is free in the plasmatic phase and not inside blood cells. The results of this study suggest that a fraction of the administered C2 dose is absorbed in the stomach, and the fraction that is not absorbed reaches the small intestine and colon. This distribution constitutes the main advantage of C2 compared with 5-ASA for the treatment of ulcerative colitis (UC) and Crohn's disease (CD).

  19. Common misconceptions about 5-aminosalicylates and thiopurines in inflammatory bowel disease

    PubMed Central

    Gisbert, Javier P; Chaparro, María; Gomollón, Fernando

    2011-01-01

    Misconceptions are common in the care of patients with inflammatory bowel disease (IBD). In this paper, we state the most commonly found misconceptions in clinical practice and deal with the use of 5-aminosalicylates and thiopurines, to review the related scientific evidence, and make appropriate recommendations. Prevention of errors needs knowledge to avoid making such errors through ignorance. However, the amount of knowledge is increasing so quickly that one new danger is an overabundance of information. IBD is a model of a very complex disease and our goal with this review is to summarize the key evidence for the most common daily clinical problems. With regard to the use of 5-aminosalicylates, the best practice may to be consider abandoning the use of these drugs in patients with small bowel Crohn’ s disease. The combined approach with oral plus topical 5-aminosalicylates should be the first-line therapy in patients with active ulcerative colitis; once-daily treatment should be offered as a first choice regimen due to its better compliance and higher efficacy. With regard to thiopurines, they seem to be as effective in ulcerative colitis as in Crohn’ s disease. Underdosing of thiopurines is a form of undertreatment. Thiopurines should probably be continued indefinitely because their withdrawal is associated with a high risk of relapse. Mercaptopurine is a safe alternative in patients with digestive intolerance or hepatotoxicity due to azathioprine. Finally, thiopurine methyltransferase (TPMT) screening cannot substitute for regular monitoring because the majority of cases of myelotoxicity are not TPMT-related. PMID:21941413

  20. Cost-Effectiveness of Ulcerative Colitis Surveillance in the Setting of 5-Aminosalicylates

    PubMed Central

    Rubenstein, Joel H.; Waljee, Akbar; Jeter, Joanne; Velayos, Fernando; Ladabaum, Uri; Higgins, Peter D.R.

    2009-01-01

    Background Colorectal cancer (CRC) is a feared complication of chronic ulcerative colitis (UC). Annual endoscopic surveillance is recommended to detect early neoplasia. 5-aminosalicylates (5-ASAs) may prevent some UC-associated CRC. Therefore, in patients prescribed 5-ASAs for maintenance of remission, annual surveillance might be overly burdensome and inefficient. We aimed to determine the ideal frequency of surveillance in patients with UC maintained on 5-ASAs. Methods We performed systematic reviews of the literature, and created a Markov computer model simulating a cohort of 35 year-old men with chronic UC, followed until age 90. Twenty-two strategies were modeled: Natural History (no 5-ASA or surveillance), surveillance without 5-ASA at intervals of 1 to 10 years, 5-ASA plus surveillance every 1 to 10 years, and 5-ASA alone. The primary outcome was the ideal interval of surveillance in the setting of 5-ASA maintenance, assuming a third-party payer was willing to pay $100,000 for each quality-adjusted life-year (QALY) gained. Results In the Natural History strategy, the CRC incidence was 30%. Without 5-ASA, annual surveillance was the ideal strategy, preventing 89% of CRC and costing $69,100 per QALY gained compared to surveillance every 2 years. 5-ASA alone prevented 49% of CRC. In the setting of 5-ASA, surveillance every 3 years was ideal, preventing 87% of CRC. 5-ASA with surveillance every 2 years cost an additional 147,500 per QALY gained, and 5-ASA with annual surveillance cost nearly $1 million additional per QALY gained compared to every 2 years. In Monte Carlo simulations, surveillance every 2 years or less often was ideal in 95% of simulations. Conclusions If 5-ASA is efficacious chemoprevention for UC-associated CRC, endoscopic surveillance might be safely performed every 2 years or less often. Such practice could decrease burdens to patients and to endoscopic resources with a minimal decrease in quality-adjusted length of life, since 5-ASA with

  1. Prandial and diurnal effects on the absorption of orally administered enteric coated 5-aminosalicylic acid (5-ASA).

    PubMed

    De Mey, C; Meineke, I

    1992-02-01

    Plasma and urine concentrations of 5-ASA and its N-acetyl metabolite 5-AcASA were measured over 48 h in 12 young healthy male subjects, who received three doses of three times enteric coated 500 mg 5-ASA tablets at 7 h interval, on two occasions 14 days apart. On one occasion the doses were given after standard meals; on the other occasion, they were given 1 h before meals. Administration of the tablets after meals delayed systemic drug absorption but did not affect the extent of absorption. There was a sharp rise in the plasma concentrations of 5-ASA and 5-AcASA in the early morning (i.e. circa 24 h after administration of the 1st dose) independent of when the tablets were taken with respect to the meals. This suggests that tablets or tablet fragments remained in the stomach until the later part of the night. Thus, diurnal effects may be more important than prandial effects in the evaluation of the kinetics of 5-ASA and its metabolites after peroral administration of enteric coated tablets.

  2. Oral 5-Aminosalicylate, Mesalamine Suppository, and Mesalamine Enema as Initial Therapy for Ulcerative Proctitis in Clinical Practice with Quality of Care Implications

    PubMed Central

    Richter, James M.; Arshi, Nabeela K.; Oster, Gerry

    2016-01-01

    Background. Ulcerative proctitis (UP) is typically treated initially with oral 5-aminosalicylate (“5-ASA”), mesalamine suppository, or mesalamine enema (“UP Rx”). Little is known about their effectiveness in practice. Methods. Using a US health insurance database, we identified new-onset UP patients between January 1, 2005, and December 31, 2007, based on the following: (1) initiation of UP Rx; (2) endoscopy in prior 30 days resulting in diagnosis of UP; and (3) no prior encounters for ulcerative colitis or Crohn's disease. We examined the incidence of therapy escalation and total costs in relation to initial UP Rx. Results. We identified 548 patients: 327 received mesalamine suppository, 138 received oral 5-ASA, and 83 received mesalamine enema, as initial UP Rx. One-third receiving oral 5-ASA experienced therapy escalation over 12 months, 21% for both mesalamine suppository and enema. Mean cumulative total cost of UP Rx over 12 months was $1552, $996, and $986 for patients beginning therapy with oral 5-ASA, mesalamine enema, and mesalamine suppository, respectively. Contrary to expert recommendations the treatments were often not continued prophylactically. Conclusions. Treatment escalation was common, and total costs of therapy were higher, in patients who initiated treatment with oral 5-ASA. Further study is necessary to assess the significance of these observations. PMID:27446860

  3. Efficacy and Safety of Beclomethasone Dipropionate versus 5-Aminosalicylic Acid in the Treatment of Ulcerative Colitis: A Systematic Review and Meta-Analysis

    PubMed Central

    Ma, Tao; Wang, ChunLi; Wang, Jun; You, ShengYi

    2016-01-01

    Background Ulcerative colitis (UC) is a chronic and remitting inflammatory disease that is characterized by chronic idiopathic inflammation of the colon and bloody diarrhea. Currently drug treatment is the main intervention for patients with mild to moderate UC. Mesalazine (5-ASA) and beclomethasone dipropionate (BDP) have been widely used for the treatment of UC and have yielded satisfactory results. This study compared the effectiveness of 5-ASA and BDP in the treatment of UC. Methods The PubMed, Medline, SinoMed, Embase, and Cochrane Librinary databases were searched for eligible studies. Data were extracted by two of the coauthors independently and were analyzed using RevMan statistical software, version 5.3. Weighted mean differences (WMDs), odds ratios (ORs), and 95% confidence intervals (CIs) were calculated. Cochrane Collaboration’s Risk of Bias Tool was used to assess the risk of bias. Results Seven randomized controlled trials that compared BDP with 5-ASA in treating UC were identified as eligible. The methodological quality of the trials ranged from low to moderate. A pooled analysis of effectiveness based on the Disease Activity Index (DAI) or other assessment method after treatment revealed that in the treatment of UC, there are no obvious differences between BDP and 5-ASA in inducing remission and clinical improvement (OR = 0.76, 95% CI = 0.56–1.03, P = 0.08). The total numbers of adverse events associated with BDP and 5-ASA treatments for UC were similar (OR = 1.21, 95% CI = 0.71–2.09, P = 0.48). The safety profiles for these two drugs are good. According to subgroup-analysis, we found no obvious differences of clinical efficacy between BDP and 5-ASA no matter oral or enema administration was used in the treatment of UC. A sensitivity analysis demonstrated the stability of the pooled results. Conclusion During induction treatment of mild to moderate UC, there is no obvious difference between the two groups with respect to remission and clinical improvement. Given that the upper confidence limit for the OR barely exceeds 1.0 and that the p-value is close to 0.05 for this primary efficacy outcome as well as that the horizontal block lies to the left of the vertical line, it indicates that the clinical efficacy of BDP may be better than 5-ASA. However, taking into account that BDP has the risk of hypothalamic-pituitary-adrenal axis (HPA) suppression, 5-ASA has a potential advantage of safety in the treatment of mild to moderate UC. PMID:27501314

  4. Bacterial Lipoteichoic Acid Enhances Cryosurvival

    PubMed Central

    Rice, Charles V.; Middaugh, Amy; Wickham, Jason R.; Friedline, Anthony; Thomas, Kieth J.; Scull, Erin; Johnson, Karen; Zachariah, Malcolm; Garimella, Ravindranth

    2015-01-01

    Antifreeze proteins in fish, plants, and insects provide protection to a few degrees below freezing. Microbes have been found to survive at even lower temperatures, and with a few exceptions, antifreeze proteins are missing. We show that lipoteichoic acid (LTA), a biopolymer in the cell wall of Gram-positive bacteria, can be added to B. subtilis cultures and increase freeze tolerance. At 1% w/v, LTA enables a 50% survival rate, similar to the results obtained with 1% w/v glycerol as measured with the resazurin cell viability assay. In the absence of added LTA or glycerol, a very small number of B. subtilis cells survive freezing. This suggests that an innate freeze tolerance mechanism exists. While cryoprotection can be provided by extracellular polymeric substances (EPS), our data demonstrate a role for LTA in cryoprotection. Currently, the exact mode of action for LTA cryoprotection is unknown. With a molecular weight of 3-5 kDa, it is unlikely to enter the cell cytoplasm. However, low temperature microscopy data show small ice crystals aligned along channels of liquid water. Our observations suggest that teichoic acids could protect liquid water within biofilms and planktonic bacteria, augmenting the role of brine while also raising the possibility for survival without brine present. PMID:25477208

  5. Essential Fatty Acids as Transdermal Penetration Enhancers.

    PubMed

    van Zyl, Lindi; du Preez, Jan; Gerber, Minja; du Plessis, Jeanetta; Viljoen, Joe

    2016-01-01

    The aim of this study was to investigate the effect of different penetration enhancers, containing essential fatty acids (EFAs), on the transdermal delivery of flurbiprofen. Evening primrose oil (EPO), vitamin F, and Pheroid technology all contain fatty acids and were compared using a cream-based formulation. This selection was to ascertain whether EFAs solely, or EFAs in a Pheroid delivery system, would have a significant increase in the transdermal delivery of a compound. Membrane release studies were performed, and the results indicated the following rank order for flurbiprofen release from the different formulations: vitamin F > control > EPO > Pheroid. Topical skin delivery results indicated that flurbiprofen was present in the stratum corneum-epidermis and the epidermis-dermis. The average percentage flurbiprofen diffused to the receptor phase (representing human blood) indicated that the EPO formulation showed the highest average percentage diffused. The Pheroid formulation delivered the lowest concentration with a statistical significant difference (p < 0.05) compared with the control formulation (containing 1% flurbiprofen and no penetration enhancers). The control formulation presented the highest average flux, with the EPO formulation following the closest. It could, thus, be concluded that EPO is the most favorable chemical penetration enhancer when used in this formulation. PMID:26852854

  6. Enhancement of Platelet Aggregation by Ursolic Acid and Oleanolic Acid

    PubMed Central

    Kim, Mikyung; Han, Chang-ho; Lee, Moo-Yeol

    2014-01-01

    The pentacyclic triterpenoid ursolic acid (UA) and its isomer oleanolic acid (OA) are ubiquitous in food and plant medicine, and thus are easily exposed to the population through natural contact or intentional use. Although they have diverse health benefits, reported cardiovascular protective activity is contentious. In this study, the effect of UA and OA on platelet aggregation was examined on the basis that alteration of platelet activity is a potential process contributing to cardiovascular events. Treatment of UA enhanced platelet aggregation induced by thrombin or ADP, which was concentration-dependent in a range of 5–50 μM. Quite comparable results were obtained with OA, in which OA-treated platelets also exhibited an exaggerated response to either thrombin or ADP. UA treatment potentiated aggregation of whole blood, while OA failed to increase aggregation by thrombin. UA and OA did not affect plasma coagulation assessed by measuring prothrombin time and activated partial thromboplastin time. These results indicate that both UA and OA are capable of making platelets susceptible to aggregatory stimuli, and platelets rather than clotting factors are the primary target of them in proaggregatory activity. These compounds need to be used with caution, especially in the population with a predisposition to cardiovascular events. PMID:25009707

  7. Skin permeation enhancement of diclofenac by fatty acids.

    PubMed

    Kim, Min-Jung; Doh, Hea-Jeong; Choi, Min-Koo; Chung, Suk-Jae; Shim, Chang-Koo; Kim, Dae-Duk; Kim, Jung Sun; Yong, Chul-Soon; Choi, Han-Gon

    2008-08-01

    This study systematically investigated the enhancing effect of fatty acids on the skin permeation of diclofenac. The fatty acids were evaluated in terms of their carbon-chain length, the degree of unsaturation, and their functional groups. The rat-skin permeation rates of diclofenac, saturated in propylene glycol (PG) containing 1% (w/v) fatty acid, were determined using the Keshary-Chien diffusion cells at 37 degrees C. The effect of fatty acids on the saturated solubility of diclofenac in PG was also determined at 37 degrees C using high-performance liquid chromatography. Among the saturated fatty acids tested, palmitic acid (C16:0) showed the most potent skin permeation-enhancing effect. A parabolic correlation was observed between the enhancement effect and the fatty acid carbon-chain length among these saturated fatty acids of C12-C20 units. For the monounsaturated fatty acid series, an increase in permeation was observed as the carbon-chain length increased, and oleic acid (C18:1) showed the highest permeation-enhancing effect. Increasing the number of double bonds in the octadecanoic acids resulted in a parabolic effect in the permeation of diclofenac, revealing oleic acid as the most effective enhancer used in this study. When the carboxylic acid moiety of oleic acid was changed to an amide (oleamide) or hydroxyl (oleyl alcohol) group, a decrease in permeation activity was observed. These results, therefore, suggest that the cis-monounsaturated configuration and the carboxylic acid moiety of an 18-carbon unit fatty acid in PG are the optimum requirements for the effective skin permeation of diclofenac.

  8. Sulfasalazine and the 5-Aminosalicylates (Beyond the Basics)

    MedlinePlus

    ... the Licensed Materials from any location via the Internet. b. STANDALONE WORKSTATION: A standalone subscription permits multiple ... computer. A Standalone Workstation license does not include Internet access to the Licensed Materials. c. INSTITUTIONAL SUBSCRIPTION: ...

  9. Trehalose accumulation enhances tolerance of Saccharomyces cerevisiae to acetic acid.

    PubMed

    Yoshiyama, Yoko; Tanaka, Koichi; Yoshiyama, Kohei; Hibi, Makoto; Ogawa, Jun; Shima, Jun

    2015-02-01

    Trehalose confers protection against various environmental stresses on yeast cells. In this study, trehalase gene deletion mutants that accumulate trehalose at high levels showed significant stress tolerance to acetic acid. The enhancement of trehalose accumulation can thus be considered a target in the breeding of acetic acid-tolerant yeast strains.

  10. Metabolic engineering as a tool for enhanced lactic acid production.

    PubMed

    Upadhyaya, Bikram P; DeVeaux, Linda C; Christopher, Lew P

    2014-12-01

    Metabolic engineering is a powerful biotechnological tool that finds, among others, increased use in constructing microbial strains for higher lactic acid productivity, lower costs and reduced pollution. Engineering the metabolic pathways has concentrated on improving the lactic acid fermentation parameters, enhancing the acid tolerance of production organisms and their abilities to utilize a broad range of substrates, including fermentable biomass-derived sugars. Recent efforts have focused on metabolic engineering of lactic acid bacteria as they produce high yields and have a small genome size that facilitates their genetic manipulation. We summarize here the current trends in metabolic engineering techniques and strategies for manipulating lactic acid producing organisms developed to address and overcome major challenges in the lactic acid production process.

  11. Enhancing charge storage of conjugated polymer electrodes with phenolic acids

    NASA Astrophysics Data System (ADS)

    Wagner, Michal; Rębiś, Tomasz; Inganäs, Olle

    2016-01-01

    We here present studies of electrochemical doping of poly(1-aminoanthraquinone) (PAAQ) films with three structurally different phenolic acids. The examined phenolic acids (sinapic, ferulic and syringic acid) were selected due to their resemblance to redox active groups, which can be found in lignin. The outstanding electrochemical stability of PAAQ films synthesized for this work enabled extensive cycling of phenolic acid-doped PAAQ films. Potentiodynamic and charge-discharge studies revealed that phenolic acid-doped PAAQ films exhibited enhanced capacitance in comparison to undoped PAAQ films, together with appearance of redox activity characteristics specific for each dopant. Electrochemical kinetic studies performed on microelectrodes affirmed the fast electron transfer for hydroquinone-to-quinone reactions with these phenolic compounds. These results imply the potential application of phenolic acids in cheap and degradable energy storage devices.

  12. Acid tolerance response (ATR) of microbial communities during the enhanced biohydrogen process via cascade acid stress.

    PubMed

    Lin, Xiaoqin; Xia, Yan; Yan, Qun; Shen, Wei; Zhao, Mingxing

    2014-03-01

    Enhanced biohydrogen production via cascade acid stress on microbial communities, structure patterns of the microbial communities revealed by PLFAs, and the succession of biohydrogen related species against cascade acid stress were all investigated. It was found that hydrogen production could be improved from 48.7 to 79.4mL/gVS after cascade acid stress. In addition, the Gram negative (G(-)) bacteria were found to be more tolerant to organic acids than those of the Gram positive (G(+)) bacteria, regardless of the dominance of G(+) bacteria within the microbial communities. Moreover, Clostridium butyricum, Clostridium aciditolerans and Azospira oryzae, were proved to be enriched, and then might play indispensable roles for the enhanced biohydrogen production after cascade acid stress, as which were responsible for the biohydrogen accumulation, acid tolerance and nitrogen removal, respectively.

  13. An Effective Acid Combination for Enhanced Properties and Corrosion Control of Acidizing Sandstone Formation

    NASA Astrophysics Data System (ADS)

    Umer Shafiq, Mian; Khaled Ben Mahmud, Hisham

    2016-03-01

    To fulfill the demand of the world energy, more technologies to enhance the recovery of oil production are being developed. Sandstone acidizing has been introduced and it acts as one of the important means to increase oil and gas production. Sandstone acidizing operation generally uses acids, which create or enlarge the flow channels of formation around the wellbore. In sandstone matrix acidizing, acids are injected into the formation at a pressure below the formation fracturing pressure, in which the injected acids react with mineral particles that may restrict the flow of hydrocarbons. Most common combination is Hydrofluoric Acid - Hydrochloric with concentration (3% HF - 12% HCl) known as mud acid. But there are some problems associated with the use of mud acid i.e., corrosion, precipitation. In this paper several new combinations of acids were experimentally screened to identify the most effective combination. The combinations used consist of fluoboric, phosphoric, formic and hydrofluoric acids. Cores were allowed to react with these combinations and results are compared with the mud acid. The parameters, which are analyzed, are Improved Permeability Ratio, strength and mineralogy. The analysis showed that the new acid combination has the potential to be used in sandstone acidizing.

  14. Polypeptides having cellulolytic enhancing activity and nucleic acids encoding same

    SciTech Connect

    Brown, Kimberly; Harris, Paul; Zaretsky, Elizabeth; Re, Edward; Vlasenko, Elena; McFarland, Keith; Lopez de Leon, Alfredo

    2012-10-16

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  15. Polypeptides having cellulolytic enhancing activity and nucleic acids encoding same

    SciTech Connect

    Brown, Kimberly; Harris, Paul; Zaretsky, Elizabeth; Re, Edward; Vlasenko, Elena; McFarland, Keith; Lopez de Leon, Alfredo

    2014-09-30

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  16. Electroporation-enhanced delivery of nucleic acid vaccines.

    PubMed

    Broderick, Kate E; Humeau, Laurent M

    2015-02-01

    The naked delivery of nucleic acid vaccines is notoriously inefficient, and an enabling delivery technology is required to direct efficiently these constructs intracellularly. A delivery technology capable of enhancing nucleic acid uptake in both cells in tissues and in culture is electroporation (EP). EP is a physical delivery mechanism that increases the permeability of mammalian cell membranes and allows the trafficking of large macromolecules into the cell. EP has now been used extensively in the clinic and been shown to be an effective method to increase both the uptake of the construct and the breadth and magnitude of the resulting immune responses. Excitingly, 2014 saw the announcement of the first EP-enhanced DNA vaccine Phase II trial demonstrating clinical efficacy. This review seeks to introduce the reader to EP as a technology to enhance the delivery of DNA and RNA vaccines and highlight several published clinical trials using this delivery modality.

  17. Enhanced formic acid oxidation on Cu-Pd nanoparticles

    NASA Astrophysics Data System (ADS)

    Dai, Lin; Zou, Shouzhong

    Developing catalysts with high activity and high resistance to surface poisoning remains a challenge in direct formic acid fuel cell research. In this work, copper-palladium nanoparticles were formed through a galvanic replacement process. After electrochemically selective dissolution of surface Cu, Pd-enriched Cu-Pd nanoparticles were formed. These particles exhibit much higher formic acid oxidation activities than that on pure Pd nanoparticles, and they are much more resistant to the surface poisoning. Possible mechanisms of catalytic activity enhancement are briefly discussed.

  18. Nucleic acid molecules conferring enhanced ethanol tolerance and microorganisms having enhanced tolerance to ethanol

    SciTech Connect

    Brown, Steven; Guss, Adam; Yang, Shihui; Karpinets, Tatiana; Lynd, Lee; Shao, Xiongjun

    2014-01-14

    The present invention provides isolated nucleic acid molecules which encode a mutant acetaldehyde-CoA/alcohol dehydrogenase or mutant alcohol dehydrogenase and confer enhanced tolerance to ethanol. The invention also provides related expression vectors, genetically engineered microorganisms having enhanced tolerance to ethanol, as well as methods of making and using such genetically modified microorganisms for production of biofuels based on fermentation of biomass materials.

  19. Simple Amides of Oleanolic Acid as Effective Penetration Enhancers

    PubMed Central

    Bednarczyk-Cwynar, Barbara; Partyka, Danuta; Zaprutko, Lucjusz

    2015-01-01

    Transdermal transport is now becoming one of the most convenient and safe pathways for drug delivery. In some cases it is necessary to use skin penetration enhancers in order to allow for the transdermal transport of drugs that are otherwise insufficiently skin-permeable. A series of oleanolic acid amides as potential transdermal penetration enhancers was formed by multistep synthesis and the synthesis of all newly prepared compounds is presented. The synthetized amides of oleanolic acid were tested for their in vitro penetration promoter activity. The above activity was evaluated by means of using the Fürst method. The relationships between the chemical structure of the studied compounds and penetration activity are presented. PMID:26010090

  20. Plant-enhanced phenanthrene and pyrene biodegradation in acidic soil.

    PubMed

    Chouychai, Waraporn; Thongkukiatkul, Amporn; Upatham, Suchart; Lee, Hung; Pokethitiyook, Prayad; Kruatrachue, Maleeya

    2009-01-01

    A study was undertaken to assess if corn plant (Zea may L.) maybe able to enhance the degradation of phenanthrene and pyrene in acidic soil inoculated with a bacterial strain (Pseudomonas putida MUB1) capable of degrading polycyclic aromatic hydrocarbons (PAHs). Planting with corn, inoculating with MUB1, ora combination of the two were found to promote the degradation of phenanthrene and pyrene in acidic soil at different rates. In the presence of corn plants, the rates of phenanthrene and pyrene removal were 41.7 and 38.8% in the first 10 days, while the rates were 58.8 and 53.6%, respectively in the treatment which received MUB1 only. After 60 days, the corn + MUB1 treatment led to the greatest reduction in both phenanthrene and pyrene biodegradation (89 and 88.2%, respectively). In control autoclaved soil, the rates of phenanthrene and pyrene removal were 14.2 and 28.7%, respectively while in non-autoclaved soil, the rates were 68.7 and 53.2%, respectively. These results show that corn, which was previously shown to grow well in PAH-contaminated acidic soil, also can enhance PAH degradation in such soil. Inoculation with a known PAH degrader further enhanced PAH degradation in the presence of corn.

  1. Energetic particle-induced enhancements of stratospheric nitric acid

    NASA Technical Reports Server (NTRS)

    Aikin, Arthur C.

    1994-01-01

    Inclusion of complete ion chemistry in the calculation of minor species production during energetic particle deposition events leads to significant enhancement in the calculated nitric acid concentration during precipitation. An ionization rate of 1.2 x 10(exp 3)/cu cm/s imposed for 1 day increases HNO3 from 3 x 10(exp 5) to 6 x 10(exp 7)/cu cm at 50 km. With an ionization rate of 600 cu cm/s, the maximum HNO3 is 3 x 10(exp 7)/cu cm. Calculations which neglect negative ions predict the nitric acid will fall during precipitation events. The decay time for converting HNO3 into odd nitrogen and hydrogen is more than 1 day for equinoctial periods at 70 deg latitude. Examination of nitric acid data should yield important information on the magnitude and frequency of charged particle events.

  2. Dynamic hydroxymethylation of deoxyribonucleic acid marks differentiation-associated enhancers.

    PubMed

    Sérandour, Aurélien A; Avner, Stéphane; Oger, Frédérik; Bizot, Maud; Percevault, Frédéric; Lucchetti-Miganeh, Céline; Palierne, Gaëlle; Gheeraert, Céline; Barloy-Hubler, Frédérique; Péron, Christine Le; Madigou, Thierry; Durand, Emmanuelle; Froguel, Philippe; Staels, Bart; Lefebvre, Philippe; Métivier, Raphaël; Eeckhoute, Jérôme; Salbert, Gilles

    2012-09-01

    Enhancers are developmentally controlled transcriptional regulatory regions whose activities are modulated through histone modifications or histone variant deposition. In this study, we show by genome-wide mapping that the newly discovered deoxyribonucleic acid (DNA) modification 5-hydroxymethylcytosine (5hmC) is dynamically associated with transcription factor binding to distal regulatory sites during neural differentiation of mouse P19 cells and during adipocyte differentiation of mouse 3T3-L1 cells. Functional annotation reveals that regions gaining 5hmC are associated with genes expressed either in neural tissues when P19 cells undergo neural differentiation or in adipose tissue when 3T3-L1 cells undergo adipocyte differentiation. Furthermore, distal regions gaining 5hmC together with H3K4me2 and H3K27ac in P19 cells behave as differentiation-dependent transcriptional enhancers. Identified regions are enriched in motifs for transcription factors regulating specific cell fates such as Meis1 in P19 cells and PPARγ in 3T3-L1 cells. Accordingly, a fraction of hydroxymethylated Meis1 sites were associated with a dynamic engagement of the 5-methylcytosine hydroxylase Tet1. In addition, kinetic studies of cytosine hydroxymethylation of selected enhancers indicated that DNA hydroxymethylation is an early event of enhancer activation. Hence, acquisition of 5hmC in cell-specific distal regulatory regions may represent a major event of enhancer progression toward an active state and participate in selective activation of tissue-specific genes.

  3. Dynamic hydroxymethylation of deoxyribonucleic acid marks differentiation-associated enhancers

    PubMed Central

    Sérandour, Aurélien A.; Avner, Stéphane; Oger, Frédérik; Bizot, Maud; Percevault, Frédéric; Lucchetti-Miganeh, Céline; Palierne, Gaëlle; Gheeraert, Céline; Barloy-Hubler, Frédérique; Péron, Christine Le; Madigou, Thierry; Durand, Emmanuelle; Froguel, Philippe; Staels, Bart; Lefebvre, Philippe; Métivier, Raphaël; Eeckhoute, Jérôme; Salbert, Gilles

    2012-01-01

    Enhancers are developmentally controlled transcriptional regulatory regions whose activities are modulated through histone modifications or histone variant deposition. In this study, we show by genome-wide mapping that the newly discovered deoxyribonucleic acid (DNA) modification 5-hydroxymethylcytosine (5hmC) is dynamically associated with transcription factor binding to distal regulatory sites during neural differentiation of mouse P19 cells and during adipocyte differentiation of mouse 3T3-L1 cells. Functional annotation reveals that regions gaining 5hmC are associated with genes expressed either in neural tissues when P19 cells undergo neural differentiation or in adipose tissue when 3T3-L1 cells undergo adipocyte differentiation. Furthermore, distal regions gaining 5hmC together with H3K4me2 and H3K27ac in P19 cells behave as differentiation-dependent transcriptional enhancers. Identified regions are enriched in motifs for transcription factors regulating specific cell fates such as Meis1 in P19 cells and PPARγ in 3T3-L1 cells. Accordingly, a fraction of hydroxymethylated Meis1 sites were associated with a dynamic engagement of the 5-methylcytosine hydroxylase Tet1. In addition, kinetic studies of cytosine hydroxymethylation of selected enhancers indicated that DNA hydroxymethylation is an early event of enhancer activation. Hence, acquisition of 5hmC in cell-specific distal regulatory regions may represent a major event of enhancer progression toward an active state and participate in selective activation of tissue-specific genes. PMID:22730288

  4. Study of Valproic Acid-Enhanced Hepatocyte Steatosis.

    PubMed

    Chang, Renin; Chou, Mei-Chia; Hung, Li-Ying; Wang, Mu-En; Hsu, Meng-Chieh; Chiu, Chih-Hsien

    2016-01-01

    Valproic acid (VPA) is one of the most widely used antiepilepsy drugs. However, several side effects, including weight gain and fatty liver, have been reported in patients following VPA treatment. In this study, we explored the molecular mechanisms of VPA-induced hepatic steatosis using FL83B cell line-based in vitro model. Using fluorescent lipid staining technique, we found that VPA enhanced oleic acid- (OLA-) induced lipid accumulation in a dose-dependent manner in hepatocytes; this may be due to upregulated lipid uptake, triacylglycerol (TAG) synthesis, and lipid droplet formation. Real-time PCR results showed that, following VPA treatment, the expression levels of genes encoding cluster of differentiation 36 (Cd36), low-density lipoprotein receptor-related protein 1 (Lrp1), diacylglycerol acyltransferase 2 (Dgat2), and perilipin 2 (Plin2) were increased, that of carnitine palmitoyltransferase I a (Cpt1a) was not affected, and those of acetyl-Co A carboxylase α (Acca) and fatty acid synthase (Fasn) were decreased. Furthermore, using immunofluorescence staining and flow cytometry analyses, we found that VPA also induced peroxisome proliferator-activated receptor γ (PPARγ) nuclear translocation and increased levels of cell-surface CD36. Based on these results, we propose that VPA may enhance OLA-induced hepatocyte steatosis through the upregulation of PPARγ- and CD36-dependent lipid uptake, TAG synthesis, and lipid droplet formation. PMID:27034954

  5. Activation of PPARα by Fatty Acid Accumulation Enhances Fatty Acid Degradation and Sulfatide Synthesis.

    PubMed

    Yang, Yang; Feng, Yuyao; Zhang, Xiaowei; Nakajima, Takero; Tanaka, Naoki; Sugiyama, Eiko; Kamijo, Yuji; Aoyama, Toshifumi

    2016-01-01

    Very-long-chain acyl-CoA dehydrogenase (VLCAD) catalyzes the first reaction in the mitochondrial fatty acid β-oxidation pathway. VLCAD deficiency is associated with the accumulation of fat in multiple organs and tissues, which results in specific clinical features including cardiomyopathy, cardiomegaly, muscle weakness, and hepatic dysfunction in infants. We speculated that the abnormal fatty acid metabolism in VLCAD-deficient individuals might cause cell necrosis by fatty acid toxicity. The accumulation of fatty acids may activate peroxisome proliferator-activated receptor (PPAR), a master regulator of fatty acid metabolism and a potent nuclear receptor for free fatty acids. We examined six skin fibroblast lines, derived from VLCAD-deficient patients and identified fatty acid accumulation and PPARα activation in these cell lines. We then found that the expression levels of three enzymes involved in fatty acid degradation, including long-chain acyl-CoA synthetase (LACS), were increased in a PPARα-dependent manner. This increased expression of LACS might enhance the fatty acyl-CoA supply to fatty acid degradation and sulfatide synthesis pathways. In fact, the first and last reactions in the sulfatide synthesis pathway are regulated by PPARα. Therefore, we also measured the expression levels of enzymes involved in sulfatide metabolism and the regulation of cellular sulfatide content. The levels of these enzymes and cellular sulfatide content both increased in a PPARα-dependent manner. These results indicate that PPARα activation plays defensive and compensative roles by reducing cellular toxicity associated with fatty acids and sulfuric acid. PMID:27644403

  6. Fatty acid conjugation enhances the activities of antimicrobial peptides.

    PubMed

    Li, Zhining; Yuan, Penghui; Xing, Meng; He, Zhumei; Dong, Chuanfu; Cao, Yongchang; Liu, Qiuyun

    2013-04-01

    Antimicrobial peptides are small molecules that play a crucial role in innate immunity in multi-cellular organisms, and usually expressed and secreted constantly at basal levels to prevent infection, but local production can be augmented upon an infection. The clock is ticking as rising antibiotic abuse has led to the emergence of many drug resistance bacteria. Due to their broad spectrum antibiotic and antifungal activities as well as anti-viral and anti-tumor activities, efforts are being made to develop antimicrobial peptides into future microbial agents. This article describes some of the recent patents on antimicrobial peptides with fatty acid conjugation. Potency and selectivity of antimicrobial peptide can be modulated with fatty acid tails of variable length. Interaction between membranes and antimicrobial peptides was affected by fatty acid conjugation. At concentrations above the critical miscelle concentration (CMC), propensity of solution selfassembly hampered binding of the peptide to cell membranes. Overall, fatty acid conjugation has enhanced the activities of antimicrobial peptides, and occasionally it rendered inactive antimicrobial peptides to be bioactive. Antimicrobial peptides can not only be used as medicine but also as food additives.

  7. Enhanced Production of Docosahexaenoic Acid in Mammalian Cells

    PubMed Central

    Zhu, Guiming; Jiang, Xudong; Ou, Qin; Zhang, Tao; Wang, Mingfu; Sun, Guozhi; Wang, Zhao; Sun, Jie; Ge, Tangdong

    2014-01-01

    Docosahexaenoic acid (DHA), one of the important polyunsaturated fatty acids (PUFA) with pharmaceutical and nutraceutical effects, may be obtained through diet or synthesized in vivo from dietary a-linolenic acid (ALA). However, the acumulation of DHA in human body or other mammals relies on the intake of high dose of DHA for a certain period of time, and the bioconversion of dietary ALA to DHA is very limited. Therefore the mammalian cells are not rich in DHA. Here, we report a new technology for increased prodution of DHA in mammalian cells. By using transient transfection method, Siganus canaliculatus Δ4 desaturase was heterologously expressed in chinese hamster ovary (CHO) cells, and simultaneously, mouse Δ6-desaturase and Δ5-desaturase were overexpressed. The results demonstrated that the overexpression of Δ6/Δ5-desaturases significantly enhanced the ability of transfected cells to convert the added ALA to docosapentaenoic acid (DPA) which in turn get converted into DHA directly and efficiently by the heterologously expressed Δ4 desaturase. This technology provides the basis for potential utility of these gene constructs in the creation of transgenic livestock for increased production of DHA/related products to meet the growing demand of this important PUFA. PMID:24788769

  8. Surface-enhanced vibrational microspectroscopy of fulvic acid micelles.

    PubMed

    Alvarez-Puebla, Ramón A; Garrido, Julian J; Aroca, Ricardo F

    2004-12-01

    Micro-Raman spectroscopy, infrared absorption microspectroscopy, and AFM images of nano- or microsized micelles formed by fulvic acid (FA) solutions, prepared at different pHs, and cast on glass slides or gold island films, are reported. FA films cast on gold islands are characterized by surface-enhanced infrared absorption (SEIRA), surface-enhanced infrared reflection absorption, and surface-enhanced Raman scattering (SERS). Based on spectral evidence, it is expected that the chemisorption of FA on gold island films takes place through thiol groups, which become more active as pH increases. The SEIRA spectra of these films show increased peak intensity, as well as improved band resolution. Microspectroscopy SERS studies show that, at pH 5, FA form small aggregates on gold surfaces. At pH 8, FA tends to expand due to electrostatic repulsion, giving rise to a fractal surface composed of different domains. SERS studies of these domains reveal that the most polar molecules are located on the external faces. At pH 11, fractal conformations are even more pronounced and give rise to radial patterned structures. At this pH, the position of fulvic acid molecules in the fractal micelles is the same as observed at pH 8. In this way, SERS can be viewed as a powerful tool for the analysis of the composition, apparent contribution of the surface functional groups of FA films, and the FA building blocks (i.e., catechol, gallic, salicylic, or ftalic acids) in the structures of these materials. PMID:15571368

  9. Guanidinoacetic acid as a performance-enhancing agent.

    PubMed

    Ostojic, Sergej M

    2016-08-01

    Guanidinoacetic acid (GAA; also known as glycocyamine or guanidinoacetate) is the natural precursor of creatine, and under investigation as a novel dietary agent. It was first identified as a natural compound in humans ~80 years ago. In the 1950s, GAA's use as a therapeutic agent was explored, showing that supplemental GAA improved patient-reported outcomes and work capacity in clinical populations. Recently, a few studies have examined the safety and efficacy of GAA and suggest potential ergogenic benefits for physically active men and women. The purpose of this review is to examine possible applications of GAA supplementation for exercise performance enhancement, safety, and legislation issues. PMID:26445773

  10. Pipecolic acid enhances resistance to bacterial infection and primes salicylic acid and nicotine accumulation in tobacco.

    PubMed

    Vogel-Adghough, Drissia; Stahl, Elia; Návarová, Hana; Zeier, Juergen

    2013-11-01

    Distinct amino acid metabolic pathways constitute integral parts of the plant immune system. We have recently identified pipecolic acid (Pip), a lysine-derived non-protein amino acid, as a critical regulator of systemic acquired resistance (SAR) and basal immunity to bacterial infection in Arabidopsis thaliana. In Arabidopsis, Pip acts as an endogenous mediator of defense amplification and priming. For instance, Pip conditions plants for effective biosynthesis of the phenolic defense signal salicylic acid (SA), accumulation of the phytoalexin camalexin, and expression of defense-related genes. Here, we show that tobacco plants respond to leaf infection by the compatible bacterial pathogen Pseudomonas syringae pv tabaci (Pstb) with a significant accumulation of several amino acids, including Lys, branched-chain, aromatic, and amide group amino acids. Moreover, Pstb strongly triggers, alongside the biosynthesis of SA and increases in the defensive alkaloid nicotine, the production of the Lys catabolites Pip and α-aminoadipic acid. Exogenous application of Pip to tobacco plants provides significant protection to infection by adapted Pstb or by non-adapted, hypersensitive cell death-inducing P. syringae pv maculicola. Pip thereby primes tobacco for rapid and strong accumulation of SA and nicotine following bacterial infection. Thus, our study indicates that the role of Pip as an amplifier of immune responses is conserved between members of the rosid and asterid groups of eudicot plants and suggests a broad practical applicability for Pip as a natural enhancer of plant disease resistance.

  11. Folic acid induces salicylic acid-dependent immunity in Arabidopsis and enhances susceptibility to Alternaria brassicicola.

    PubMed

    Wittek, Finni; Kanawati, Basem; Wenig, Marion; Hoffmann, Thomas; Franz-Oberdorf, Katrin; Schwab, Wilfried; Schmitt-Kopplin, Philippe; Vlot, A Corina

    2015-08-01

    Folates are essential for one-carbon transfer reactions in all organisms and contribute, for example, to de novo DNA synthesis. Here, we detected the folate precursors 7,8-dihydropteroate (DHP) and 4-amino-4-deoxychorismate (ADC) in extracts from Arabidopsis thaliana plants by Fourier transform ion cyclotron resonance-mass spectrometry. The accumulation of DHP, but not ADC, was induced after infection of plants with Pseudomonas syringae delivering the effector protein AvrRpm1. Application of folic acid or the DHP precursor 7,8-dihydroneopterin (DHN) enhanced resistance in Arabidopsis to P. syringae and elevated the transcript accumulation of the salicylic acid (SA) marker gene pathogenesis-related1 in both the treated and systemic untreated leaves. DHN- and folic acid-induced systemic resistance was dependent on SA biosynthesis and signalling. Similar to SA, folic acid application locally enhanced Arabidopsis susceptibility to the necrotrophic fungus Alternaria brassicicola. Together, the data associate the folic acid pathway with innate immunity in Arabidopsis, simultaneously activating local and systemic SA-dependent resistance to P. syringae and suppressing local resistance to A. brassicicola.

  12. epsilon-Aminocaproic acid esters as transdermal penetration enhancing agents.

    PubMed

    Dolezal, P; Hrabálek, A; Semecký, V

    1993-07-01

    The synthesis of epsilon-aminocaproic acid esters is described. Two representative members from a group of five of the 1-alkyl homologues synthetized as flexible analogues of 1-alkylazacyclohepatanone derivatives were evaluated in vitro for their effectiveness on the transport of theophylline through the excised human cadaver skin in comparison with Azone. The 1-octyl- and 1-dodecyl-epsilon-aminocaproic acid esters (OCEAC and DDEAC) show excellent penetration enhancement. Donor samples contained 2.5% theophylline and 1% enhancers tested in three different vehicles. Fluxes of theophylline were increased with OCEAC about 19 times from olive oil, 45 times from water, and about 38 times from water-propylene glycol (3:2) vehicle toward controls (with DDEAC about 17, 39, and 35 times, respectively) and they were markedly higher than Azone under the given conditions. Acute LD50's (i.p. in mice) of OCEAC (DDEAC) were 245 mg/kg (352 mg/kg), with a slightly lower toxicity than Azone. OCEAC and DDEAC did not exhibit acute dermal irritation in vivo on rabbits at a 5% concentration in white petrolatum.

  13. Enhancement of Curcumin Fluorescence by Ascorbic Acid in Bicontinuous Microemulsion.

    PubMed

    Iwunze, Maurice O

    2015-07-01

    Steady-state fluorescence spectro-photometric technique is used in this work to determine the chemical parameters of the complex formed between curcumin and ascorbic acid in bicontinuous microemuslion (Bμen). The Bμen liquid used is made up of a four-components system (water-oil-surfactant and co-surfactant (1-pentanol)) in the ratio of 42.11:13.7:21.34:22.85 % w/w. The oil and surfactant used are tetradecane and cetyltrimethylammonium bromide. Curcumin is known to have low solubility in water, but liberally soluble in Bμen, hence the use of Bμen in this study. The observed fluorescence intensity of curcumin was enhanced by introduction of ascorbic acid to the curcumin solution. The increase in the fluorescence intensity showed a very good linearity with a regression coefficient of 0.9974. The association constant, Ka, that resulted between curcumin and ascorbic acid was calculated as 2.15 × 10(4) with the free energy of association, ∆Ga, of -24.71 kJ/mol. The ratio of the complex that was formed by these two molecules was determined as 1:1. PMID:25943984

  14. Enhancement of Commercial Antifungal Agents by Kojic Acid

    PubMed Central

    Kim, Jong H.; Chang, Perng-Kuang; Chan, Kathleen L.; Faria, Natália C. G.; Mahoney, Noreen; Kim, Young K.; Martins, Maria de L.; Campbell, Bruce C.

    2012-01-01

    Natural compounds that pose no significant medical or environmental side effects are potential sources of antifungal agents, either in their nascent form or as structural backbones for more effective derivatives. Kojic acid (KA) is one such compound. It is a natural by-product of fungal fermentation commonly employed by food and cosmetic industries. We show that KA greatly lowers minimum inhibitory (MIC) or fungicidal (MFC) concentrations of commercial medicinal and agricultural antifungal agents, amphotericin B (AMB) and strobilurin, respectively, against pathogenic yeasts and filamentous fungi. Assays using two mitogen-activated protein kinase (MAPK) mutants, i.e., sakAΔ, mpkCΔ, of Aspergillus fumigatus, an agent for human invasive aspergillosis, with hydrogen peroxide (H2O2) or AMB indicate such chemosensitizing activity of KA is most conceivably through disruption of fungal antioxidation systems. KA could be developed as a chemosensitizer to enhance efficacy of certain conventional antifungal drugs or fungicides. PMID:23203038

  15. Desorption of copper and cadmium from soils enhanced by organic acids.

    PubMed

    Yuan, Songhu; Xi, Zhimin; Jiang, Yi; Wan, Jinzhong; Wu, Chan; Zheng, Zhonghua; Lu, Xiaohua

    2007-07-01

    The adsorption/desorption behavior of copper and cadmium on soils was investigated in this study. The adsorption isotherm of copper and cadmium conformed to Langmuir equation better than Freundlich equation. The effect of ionic strength, pH, and organic acid, including ethylenediamine tetraacetic disodium acid salt (EDTA), citric acid, oxalic acid and tartaric acid, on the desorption of copper and cadmium was studied. The desorption of copper and cadmium increased with the increase of ionic strength, while the desorption decreased with the rise of pH. The desorption of copper and cadmium enhanced by organic acids was influenced by pH. EDTA showed excellent enhancement on the desorption of both copper and cadmium; citric acid demonstrated great enhancement on the desorption of copper but negligible enhancement on the desorption of cadmium; oxalic acid enhanced the desorption of copper only at pH around 6.4 and enhanced the desorption of cadmium in the pH range from 6.4 to 10.7; tartaric acid slightly enhanced the desorption of copper but negligibly enhanced the desorption of cadmium. The desorption mechanism in the presence of organic acids were explained as the competition of complexation, adsorption and precipitation. The net effect determined the desorption efficiency. This study provided guidance for the selection of organic acids to enhance the electrokinetic (EK) remediation of copper and cadmium from contaminated soils. PMID:17349675

  16. Abscisic acid enhances resistance to Alternaria solani in tomato seedlings.

    PubMed

    Song, Weiwei; Ma, Xinrong; Tan, Hong; Zhou, Jinyan

    2011-07-01

    The plant hormone abscisic acid (ABA) is an important regulator in many aspects of plant growth and development, as well as stress resistance. Here, we investigated the effects of exogenous ABA application on the interaction between tomato (Solanum lycopersicon L.) and Alternaria solani (early blight). Foliar spraying of 7.58 μM ABA was effective in reducing disease severity in tomato plants. Previously, increased activities of phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO) and peroxidase (POD) were observed in exogenous ABA-treated tomato leaves. Moreover, these enzyme activities were maintained at higher levels in ABA-pretreated and A. solani challenged tomato plants. Tomato defense genes, such as PR1, β-1, 3-glucanase (GLU), PPO, POD, and superoxide dismutase (SOD), were rapidly and significantly up-regulated by exogenous ABA treatment. Furthermore, a subsequent challenge of ABA-pretreated plants with the pathogen A. solani resulted in higher expression of defense genes, compared to water-treated or A. solani inoculated plants. Therefore, our results suggest that exogenous ABA could enhance disease resistance against A. solani infection in tomato through the activation of defense genes and via the enhancement of defense-related enzymatic activities.

  17. Pregnancy-secreted Acid phosphatase, uteroferrin, enhances fetal erythropoiesis.

    PubMed

    Ying, Wei; Wang, Haiqing; Bazer, Fuller W; Zhou, Beiyan

    2014-11-01

    Uteroferrin (UF) is a progesterone-induced acid phosphatase produced by uterine glandular epithelia in mammals during pregnancy and targeted to sites of hematopoiesis throughout pregnancy. The expression pattern of UF is coordinated with early fetal hematopoietic development in the yolk sac and then liver, spleen, and bone to prevent anemia in fetuses. Our previous studies suggested that UF exerts stimulatory impacts on hematopoietic progenitor cells. However, the precise role and thereby the mechanism of action of UF on hematopoiesis have not been investigated previously. Here, we report that UF is a potent regulator that can greatly enhance fetal erythropoiesis. Using primary fetal liver hematopoietic cells, we observed a synergistic stimulatory effect of UF with erythropoietin and other growth factors on both burst-forming unit-erythroid and colony-forming unit-erythroid formation. Further, we demonstrated that UF enhanced erythropoiesis at terminal stages using an in vitro culture system. Surveying genes that are crucial for erythrocyte formation at various stages revealed that UF, along with erythropoietin, up-regulated transcription factors required for terminal erythrocyte differentiation and genes required for synthesis of hemoglobin. Collectively, our results demonstrate that UF is a cytokine secreted by uterine glands in response to progesterone that promotes fetal erythropoiesis at various stages of pregnancy, including burst-forming unit-erythroid and colony-forming unit-erythroid progenitor cells and terminal stages of differentiation of hematopoietic cells in the erythroid lineage. PMID:25093463

  18. Oleic Acid: Natural variation and potential enhancement in oilseed crops.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oleic acid is a monounsaturated omega 9 fatty acid (MUFA, C18:1) which can be found in various plant lipids and animal fats. Unlike omega 3 (a-linolenic acid, C18:3) and omega 6 (linoleic acid, C18:2) fatty acids which are essential because they cannot be synthesized by humans and must be obtained f...

  19. Enhancement of the mutagenicity of amino acid pyrolysates by phthalate esters.

    PubMed

    Sato, T; Nagase, H; Sato, K; Niikawa, M; Kito, H

    1994-01-01

    The ability of phthalic acid, phthalic acid anhydride, and various phthalate esters to enhance the mutagenicity of many amino acid pyrolysates was observed with the Ames test (Salmonella typhimurium TA98), but not the SOS Chromotest. Phthalate enhancement of the mutagenicity of 4-nitroquinoline-1-oxide, 2-nitrofluorene, and benzo[a]pyrene was not observed with either test. The mutagenicity-enhancing ability may be related to the induction of enzymes such as P450IIB, that metabolize amino acid pyrolysates. By quantitative structure activity relationship (QSAR) analysis, a good correlation was observed between the mutagenicity-enhancing activity of phthalates and their octanol-water partition coefficients. PMID:7851345

  20. Gibberellic Acid enhancement of DNA turnover in barley aleurone cells.

    PubMed

    Taiz, L; Starks, J E

    1977-08-01

    When imbibed, deembryonated halfseeds from barley (Hordeum vulgare L., var. Himalaya) are incubated in buffer, the DNA content of the aleurone layer increases 25 to 40% over a 24-hour period. In contrast, the DNA of isolated aleurone layers declines by 20% over the same time period. Gibberellic acid (GA) causes a reduction in DNA levels in both halfseed aleurone layers and isolated aleurone layers. GA also increases the specific radioactivity of [(3)H]thymidine-labeled halfseed aleurone layer DNA during the first 12 hours of treatment. Pulse-chase studies demonstrated that the newly synthesized DNA is metabolically labile.The buoyant density on CsCl density gradients of hormone-treated aleurone DNA is identical with that of DNA extracted from whole seedlings. After density-labeling halfseed DNA with 5-bromodeoxyuridine, a bimodal absorption profile is obtained in neutral CsCl. The light band (1.70 g/ml) corresponds to unsubstituted DNA, while the heavy band (1.725-1.74 g/ml) corresponds to a hybrid density-labeled species. GA increases the relative amount of the heavy (hybrid) peak in halfseed aleurone layer DNA, further suggesting that the hormone enhances semiconservative replication in halfseeds.DNA methylation was also demonstrated. Over 60% of the radioactivity from [(3)H-Me]methionine is incorporated into 5-methylcytosine. GA has no effect on the percentage distribution of label among the bases.It was concluded that GA enhances the rate of DNA degradation and DNA synthesis (turnover) in halfseeds, but primarily DNA degradation in isolated aleurone layers. Incorporation by isolated aleurone layers is due to DNA repair. Semiconservative replication apparently plays no physiological role in the hormone response, since both isolated aleurone layers and gamma-irradiated halfseeds respond normally. The hypothesis was advanced that endoreduplication and DNA degradation are means by which the seed stores and mobilizes deoxyribonucleotides for the embryo during

  1. Mechanism involved in enhancement of osteoblast differentiation by hyaluronic acid

    SciTech Connect

    Kawano, Michinao; Ariyoshi, Wataru; Iwanaga, Kenjiro; Okinaga, Toshinori; Habu, Manabu; Yoshioka, Izumi; Tominaga, Kazuhiro; Nishihara, Tatsuji

    2011-02-25

    Research highlights: {yields} In this study was to investigate the effects of HA on osteoblast differentiation induced by BMP-2. {yields} MG63 cells were incubated with BMP-2 and HA for various time periods. {yields} Phosphorylation of Smad 1/5/8, p38, and ERK proteins was determined by western blot analysis. To elucidate the nuclear translocation of phosphorylated Smad 1/5/8, stimulated cells were subjected to immunofluorescence microscopy. {yields} HA enhanced BMP-2 induces osteoblastic differentiation in MG63 cells via down-regulation of BMP-2 antagonists and ERK phosphorylation. -- Abstract: Objectives: Bone morphogenetic protein-2 (BMP-2) is expected to be utilized to fill bone defects and promote healing of fractures. However, it is unable to generate an adequate clinical response for use in bone regeneration. Recently, it was reported that glycosaminoglycans, including heparin, heparan sulfate, keratan sulfate, dermatan sulfate, chondroitin-4-sulfate, chondroitin-6-sulfate, and hyaluronic acid (HA), regulate BMP-2 activity, though the mechanism by which HA regulates osteogenic activities has not been fully elucidated. The aim of this study was to investigate the effects of HA on osteoblast differentiation induced by BMP-2. Materials and methods: Monolayer cultures of osteoblastic lineage MG63 cells were incubated with BMP-2 and HA for various time periods. To determine osteoblastic differentiation, alkaline phosphatase (ALP) activity in the cell lysates was quantified. Phosphorylation of Smad 1/5/8, p38, and ERK proteins was determined by Western blot analysis. To elucidate the nuclear translocation of phosphorylated Smad 1/5/8, stimulated cells were subjected to immunofluorescence microscopy. To further elucidate the role of HA in enhancement of BMP-2-induced Smad signaling, mRNA expressions of the BMP-2 receptor antagonists noggin and follistatin were detected using real-time RT-PCR. Results: BMP-2-induced ALP activation, Smad 1/5/8 phosphorylation, and

  2. Enhancement of cell viability after treatment with polyunsaturated fatty acids.

    PubMed

    Bartl, J; Walitza, S; Grünblatt, E

    2014-01-24

    Attention-deficit/hyperactivity disorder (ADHD) is highly prevalent in children and adolescents and both environmental and genetic factors play major roles. Polyunsaturated fatty acids (PUFAs) are postulated to contribute to the development of the infant brain and an imbalance in these may increase the risk of ADHD. In recent clinical studies, supplementation with PUFAs improved symptoms of ADHD in some cases. Similarly, some beneficial effects were observed with PUFA treatment in neuronal cell cultures. Therefore, in this study, we hypothesized that a specific PUFA combination (available on the market as Equazen™ [Vifor Pharma, Switzerland]) along with iron, zinc, or vitamin B5 (vitB5) would produce an additive beneficial effect on the viability of rat pheochromocytoma-12 dopaminergic cells. The specific PUFA combination alone, as well as added to each of the three nutrients, was tested in a dose-response manner. The specific PUFAs significantly improved cell viability, starting at very low doses (100pM) from 60h up to 90h; while the combined treatment with vitB5 and minerals did not provide additional benefit. Our results confirmed the beneficial effect of the specific PUFAs on neuronal cell viability; although supplementation with minerals and vitB5 did not enhance this effect.

  3. Accumulation of eicosapolyenoic acids enhances sensitivity to abscisic acid and mitigates the effects of drought in transgenic Arabidopsis thaliana.

    PubMed

    Yuan, Xiaowei; Li, Yaxiao; Liu, Shiyang; Xia, Fei; Li, Xinzheng; Qi, Baoxiu

    2014-04-01

    IgASE1, a C₁₈ Δ(9)-specific polyunsaturated fatty acid elongase from the marine microalga Isochrysis galbana, is able to convert linoleic acid and α-linolenic acid to eicosadienoic acid and eicosatrienoic acid in Arabidopsis. Eicosadienoic acid and eicosatrienoic acid are precursors of arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid, which are synthesized via the Δ(8) desaturation biosynthetic pathways. This study shows that the IgASE1-expressing transgenic Arabidopsis exhibited altered morphology (decreased leaf area and biomass) and enhanced drought resistance compared to wild-type plants. The transgenic Arabidopsis were hypersensitive to abscisic acid (ABA) during seed germination, post-germination growth, and seedling development. They had elevated leaf ABA levels under well-watered and dehydrated conditions and their stomata were more sensitive to ABA. Exogenous application of eicosadienoic acid and eicosatrienoic acid can mimic ABA and drought responses in the wild type plants, similar to that found in the transgenic ones. The transcript levels of genes involved in the biosynthesis of ABA (NCED3, ABA1, AAO3) as well as other stress-related genes were upregulated in this transgenic line upon osmotic stress (300 mM mannitol). Taken together, these results indicate that these two eicosapolyenoic acids or their derived metabolites can mitigate the effects of drought in transgenic Arabidopsis, at least in part, through the action of ABA. PMID:24609499

  4. Accumulation of eicosapolyenoic acids enhances sensitivity to abscisic acid and mitigates the effects of drought in transgenic Arabidopsis thaliana.

    PubMed

    Yuan, Xiaowei; Li, Yaxiao; Liu, Shiyang; Xia, Fei; Li, Xinzheng; Qi, Baoxiu

    2014-04-01

    IgASE1, a C₁₈ Δ(9)-specific polyunsaturated fatty acid elongase from the marine microalga Isochrysis galbana, is able to convert linoleic acid and α-linolenic acid to eicosadienoic acid and eicosatrienoic acid in Arabidopsis. Eicosadienoic acid and eicosatrienoic acid are precursors of arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid, which are synthesized via the Δ(8) desaturation biosynthetic pathways. This study shows that the IgASE1-expressing transgenic Arabidopsis exhibited altered morphology (decreased leaf area and biomass) and enhanced drought resistance compared to wild-type plants. The transgenic Arabidopsis were hypersensitive to abscisic acid (ABA) during seed germination, post-germination growth, and seedling development. They had elevated leaf ABA levels under well-watered and dehydrated conditions and their stomata were more sensitive to ABA. Exogenous application of eicosadienoic acid and eicosatrienoic acid can mimic ABA and drought responses in the wild type plants, similar to that found in the transgenic ones. The transcript levels of genes involved in the biosynthesis of ABA (NCED3, ABA1, AAO3) as well as other stress-related genes were upregulated in this transgenic line upon osmotic stress (300 mM mannitol). Taken together, these results indicate that these two eicosapolyenoic acids or their derived metabolites can mitigate the effects of drought in transgenic Arabidopsis, at least in part, through the action of ABA.

  5. Structure/effect studies of fatty acid isomers as skin penetration enhancers and skin irritants.

    PubMed

    Aungst, B J

    1989-03-01

    Comparisons were made of branched vs unbranched saturated fatty acids and cis vs trans unsaturated fatty acids as skin penetration enhancers and primary skin irritants. Skin penetration studies used naloxone base as the diffusant, propylene glycol as the vehicle, and human skin. Maximum naloxone flux was with C9-12-branched and unbranched fatty acids. For C5-14 fatty acids, branched and unbranched isomers had similar effects. One branched C18 fatty acid isomer (C16-branched isostearic acid) was more effective in enhancing skin penetration than a differently branched (C2-branched isostearic acid) or unbranched C18 isomer (stearic acid). There was no significant difference between cis and trans unsaturated C16-18 fatty acid isomers in their effects on naloxone flux, and all unsaturated fatty acids were more effective enhancers than the corresponding saturated isomers. Several of these fatty acid/propylene glycol vehicles were evaluated in a rabbit primary skin irritation test. Irritation indices were poorly correlated with the effectiveness of the vehicles in enhancing naloxone flux. It was possible to enhance naloxone skin penetration greatly with a vehicle with only minimal skin irritation potential.

  6. Enhancement of arachidonic acid signaling pathway by nicotinic acid receptor HM74A

    SciTech Connect

    Tang, Yuting . E-mail: ytang@prdus.jnj.com; Zhou, Lubing; Gunnet, Joseph W.; Wines, Pamela G.; Cryan, Ellen V.; Demarest, Keith T.

    2006-06-23

    HM74A is a G protein-coupled receptor for nicotinic acid (niacin), which has been used clinically to treat dyslipidemia for decades. The molecular mechanisms whereby niacin exerts its pleiotropic effects on lipid metabolism remain largely unknown. In addition, the most common side effect in niacin therapy is skin flushing that is caused by prostaglandin release, suggesting that the phospholipase A{sub 2} (PLA{sub 2})/arachidonic acid (AA) pathway is involved. Various eicosanoids have been shown to activate peroxisome-proliferator activated receptors (PPAR) that play a diverse array of roles in lipid metabolism. To further elucidate the potential roles of HM74A in mediating the therapeutic effects and/or side effects of niacin, we sought to explore the signaling events upon HM74A activation. Here we demonstrated that HM74A synergistically enhanced UTP- and bradykinin-mediated AA release in a pertussis toxin-sensitive manner in A431 cells. Activation of HM74A also led to Ca{sup 2+}-mobilization and enhanced bradykinin-promoted Ca{sup 2+}-mobilization through Gi protein. While HM74A increased ERK1/2 activation by the bradykinin receptor, it had no effects on UTP-promoted ERK1/2 activation.Furthermore, UTP- and bradykinin-mediated AA release was significantly decreased in the presence of both MAPK kinase inhibitor PD 098059 and PKC inhibitor GF 109203X. However, the synergistic effects of HM74A were not dramatically affected by co-treatment with both inhibitors, indicating the cross-talk occurred at the receptor level. Finally, stimulation of A431 cells transiently transfected with PPRE-luciferase with AA significantly induced luciferase activity, mimicking the effects of PPAR{gamma} agonist rosiglitazone, suggesting that alteration of AA signaling pathway can regulate gene expression via endogenous PPARs.

  7. Enhancement of hydrolysis of Chlorella vulgaris by hydrochloric acid.

    PubMed

    Park, Charnho; Lee, Ja Hyun; Yang, Xiaoguang; Yoo, Hah Young; Lee, Ju Hun; Lee, Soo Kweon; Kim, Seung Wook

    2016-06-01

    Chlorella vulgaris is considered as one of the potential sources of biomass for bio-based products because it consists of large amounts of carbohydrates. In this study, hydrothermal acid hydrolysis with five different acids (hydrochloric acid, nitric acid, peracetic acid, phosphoric acid, and sulfuric acid) was carried out to produce fermentable sugars (glucose, galactose). The hydrothermal acid hydrolysis by hydrochloric acid showed the highest sugar production. C. vulgaris was hydrolyzed with various concentrations of hydrochloric acid [0.5-10 % (w/w)] and microalgal biomass [20-140 g/L (w/v)] at 121 °C for 20 min. Among the concentrations examined, 2 % hydrochloric acid with 100 g/L biomass yielded the highest conversion of carbohydrates (92.5 %) into reducing sugars. The hydrolysate thus produced from C. vulgaris was fermented using the yeast Brettanomyces custersii H1-603 and obtained bioethanol yield of 0.37 g/g of algal sugars. PMID:26899601

  8. An optimized probucol microencapsulated formulation integrating a secondary bile acid (deoxycholic acid) as a permeation enhancer

    PubMed Central

    Mooranian, Armin; Negrulj, Rebecca; Chen-Tan, Nigel; Watts, Gerald F; Arfuso, Frank; Al-Salami, Hani

    2014-01-01

    The authors have previously designed, developed, and characterized a novel microencapsulated formulation as a platform for the targeted delivery of therapeutics in an animal model of type 2 diabetes, using the drug probucol (PB). The aim of this study was to optimize PB microcapsules by incorporating the bile acid deoxycholic acid (DCA), which has good permeation-enhancing properties, and to examine its effect on microcapsules’ morphology, rheology, structural and surface characteristics, and excipients’ chemical and thermal compatibilities. Microencapsulation was carried out using a BÜCHI-based microencapsulating system established in the authors’ laboratory. Using the polymer sodium alginate (SA), two microencapsulated formulations were prepared: PB-SA (control) and PB-DCA-SA (test) at a constant ratio (1:30 and 1:3:30, respectively). Complete characterization of the microcapsules was carried out. The incorporation of DCA resulted in better structural and surface characteristics, uniform morphology, and stable chemical and thermal profiles, while size and rheological parameters remained similar to control. In addition, PB-DCA-SA microcapsules showed good excipients’ compatibilities, which were supported by data from differential scanning calorimetry, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray studies, suggesting microcapsule stability. Hence, PB-DCA-SA microcapsules have good rheological and compatibility characteristics and may be suitable for the oral delivery of PB in type 2 diabetes. PMID:25302020

  9. An optimized probucol microencapsulated formulation integrating a secondary bile acid (deoxycholic acid) as a permeation enhancer.

    PubMed

    Mooranian, Armin; Negrulj, Rebecca; Chen-Tan, Nigel; Watts, Gerald F; Arfuso, Frank; Al-Salami, Hani

    2014-01-01

    The authors have previously designed, developed, and characterized a novel microencapsulated formulation as a platform for the targeted delivery of therapeutics in an animal model of type 2 diabetes, using the drug probucol (PB). The aim of this study was to optimize PB microcapsules by incorporating the bile acid deoxycholic acid (DCA), which has good permeation-enhancing properties, and to examine its effect on microcapsules' morphology, rheology, structural and surface characteristics, and excipients' chemical and thermal compatibilities. Microencapsulation was carried out using a BÜCHI-based microencapsulating system established in the authors' laboratory. Using the polymer sodium alginate (SA), two microencapsulated formulations were prepared: PB-SA (control) and PB-DCA-SA (test) at a constant ratio (1:30 and 1:3:30, respectively). Complete characterization of the microcapsules was carried out. The incorporation of DCA resulted in better structural and surface characteristics, uniform morphology, and stable chemical and thermal profiles, while size and rheological parameters remained similar to control. In addition, PB-DCA-SA microcapsules showed good excipients' compatibilities, which were supported by data from differential scanning calorimetry, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray studies, suggesting microcapsule stability. Hence, PB-DCA-SA microcapsules have good rheological and compatibility characteristics and may be suitable for the oral delivery of PB in type 2 diabetes. PMID:25302020

  10. Enhanced Production of Carboxylic Acids by Engineering of Rhizopus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungus Rhizopus is frequently used to convert, or ferment sugars obtained from agricultural crops to lactic acid. This natural product has long been utilized by the food industry as an additive for preservation, flavor, and acidity. Additionally, it is used for the manufacture of environmental...

  11. Enhanced functional properties of tannic acid after thermal hydrolysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thermal hydrolysis processing of fresh tannic acid was carried out in a closed reactor at four different temperatures (65, 100, 150 and 200°C). Pressures reached in the system were 1.3 and 4.8 MPa at 150 and 200°C, respectively. Hydrolysis products (gallic acid and pyrogallol) were separated and qua...

  12. Increased Production of Fatty Acids and Triglycerides in Aspergillus oryzae by Enhancing Expressions of Fatty Acid Synthesis-Related Genes

    SciTech Connect

    Tamano, Koichi; Bruno, Kenneth S.; Karagiosis, Sue A.; Culley, David E.; Deng, Shuang; Collett, James R.; Umemura, Myco; Koike, Hideaki; Baker, Scott E.; Machida, Masa

    2013-01-01

    Microbial production of fats and oils is being developedas a means of converting biomass to biofuels. Here we investigate enhancing expression of enzymes involved in the production of fatty acids and triglycerides as a means to increase production of these compounds in Aspergillusoryzae. Examination of the A.oryzaegenome demonstrates that it contains twofatty acid synthases and several other genes that are predicted to be part of this biosynthetic pathway. We enhancedthe expressionof fatty acid synthesis-related genes by replacing their promoters with thepromoter fromthe constitutively highly expressedgene tef1. We demonstrate that by simply increasing the expression of the fatty acid synthasegenes we successfullyincreasedtheproduction of fatty acids and triglyceridesby more than two fold. Enhancement of expression of the fatty acid pathway genes ATP-citrate lyase and palmitoyl-ACP thioesteraseincreasedproductivity to a lesser extent.Increasing expression ofacetyl-CoA carboxylase caused no detectable change in fatty acid levels. Increases in message level for each gene were monitored usingquantitative real-time RT-PCR. Our data demonstrates that a simple increase in the abundance of fatty acid synthase genes can increase the detectable amount of fatty acids.

  13. Organic acids for performance enhancement in pig diets.

    PubMed

    Partanen, K H; Mroz, Z

    1999-06-01

    Organic acids and their salts appear to be potential alternatives to prophylactic in-feed antibiotics and growth promoters in order to improve the performance of weaned piglets, fattening pigs and reproductive sows, although their growth-promoting effects are generally less than that of antibiotics. Based on an analysis of published data, the growth-promoting effect of formates, fumarates and citrates did not differ in weaned piglets. In fattening pigs, formates were the most effective followed by fumarates, whereas propionates did not improve growth performance. These acids improved the feedgain ratio of both weaned piglets and fattening pigs. In weaned piglets, the growth-promoting effects of dietary organic acids appear to depend greatly on their influence on feed intake. In sows, organic acids may have anti-agalactia properties. Successful application of organic acids in the diets for pigs requires an understanding of their modes of action. It is generally considered that dietary organic acids or their salts lower gastric pH, resulting in increased activity of proteolytic enzymes and gastric retention time, and thus improved protein digestion. Reduced gastric pH and increased retention time have been difficult to demonstrate, whereas improved apparent ileal digestibilities of protein and amino acids have been observed with growing pigs, but not in weaned piglets. Organic acids may influence mucosal morphology, as well as stimulate pancreatic secretions, and they also serve as substrates in intermediary metabolism. These may further contribute to improved digestion, absorption and retention of many dietary nutrients. Organic acid supplementation reduces dietary buffering capacity, which is expected to slow down the proliferation and|or colonization of undesirable microbes, e.g. Escherichia coli, in the gastro-ileal region. However, reduced scouring has been observed in only a few studies. As performance responses to dietary organic acids in pigs often varies

  14. Polystyrene sulphonic acid resins with enhanced acid strength via macromolecular self-assembly within confined nanospace

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaomin; Zhao, Yaopeng; Xu, Shutao; Yang, Yan; Liu, Jia; Wei, Yingxu; Yang, Qihua

    2014-01-01

    Tightening environmental legislation is driving the chemical industries to develop efficient solid acid catalysts to replace conventional mineral acids. Polystyrene sulphonic acid resins, as some of the most important solid acid catalysts, have been widely studied. However, the influence of the morphology on their acid strength—closely related to the catalytic activity—has seldom been reported. Herein, we demonstrate that the acid strength of polystyrene sulphonic acid resins can be adjusted through their reversible morphology transformation from aggregated to swelling state, mainly driven by the formation and breakage of hydrogen bond interactions among adjacent sulphonic acid groups within the confined nanospace of hollow silica nanospheres. The hybrid solid acid catalyst demonstrates high activity and selectivity in a series of important acid-catalysed reactions. This may offer an efficient strategy to fabricate hybrid solid acid catalysts for green chemical processes.

  15. Conjugates of unsaturated fatty acids with propylene glycol as potentially less-irritant skin penetration enhancers.

    PubMed

    Ben-Shabat, Shimon; Baruch, Nir; Sintov, Amnon C

    2007-11-01

    Fatty acids (FA) are well known as efficient enhancers for transdermal delivery of drugs; however, their frequent dermal toxicity limits their regular use. In order to utilize the fatty acid as a safe enhancer devoid of its irritant effect, we have synthesized and evaluated a series of fatty acids conjugated to propylene glycol (FA-PG). Each one of the conjugates was prepared as a mono- or di- acyl ester derivative. The effects of the synthetic enhancers on the porcine skin permeability were evaluated in a diffusion cell system using lidocaine as the model drug. In addition, in vivo examinations in rabbits were preformed for skin toxicological evaluation. The results indicate that among the FA-PG conjugates, oleic acid (C18:1(n-9))-PG, linoleic acid (C18:2(n-6))-PG and alpha-linolenic acid (C18:3(n-3))-PG, mono- or di-esters, enhance the penetration of lidocaine relatively to the vehicle (without enhancer). The conjugates of oleic acid (C18:1(n-9)) and linoleic acid (C18:2(n-6)) with PG have demonstrated a similar enhancing effect as the corresponding free fatty acids. Interestingly, although the mono- or the di- conjugates of alpha-linolenic acid (C18:3(n-3)) with PG enhanced the lidocaine flux as the other two fatty acid conjugates, they resulted in a reduced permeability as compared to the action of their free acid. In addition, the mono-conjugates of alpha-linolenic acid (C18:3(n-3)) with PG exhibited elevated skin irritation in rabbits (relative to the fatty acid alone) compared to the significantly reduced irritation of oleate-PG and linoeate-PG mono-conjugates. In conclusion, except saturated FA-PG and alpha-linolenic acid (C18:3(n-3)) - PG mono-conjugates, unsaturated fatty acids (e.g., oleic and linoleic acids) after conjugation to PG may be safe and effective enhancers for delivering topical drugs.

  16. Surface-enhanced infrared absorption of nucleic acids on gold substrate in FTIR reflectance mode

    NASA Astrophysics Data System (ADS)

    Dovbeshko, G. I.; Chegel, Vladimir I.; Gridina, Nina Y.; Repnytska, O. P.; Sekirin, I. V.; Shirshov, Yuri M.

    2001-06-01

    Data on surface enhanced infrared absorption (SEIRA) of nucleic acids deposited on the metal surface have been obtained in the experiment in FTIR reflectance mode. As metal surface, we used Au of 200 - 500 Angstrom thickness on quartz substrate. Roughness of Au was not greater than 50 Angstrom. In our experimental conditions, the enhancement factor of SEIRA was about 3 - 7. We obtained different enhancement factors for different vibrations of nuclei acids. Application of this method to the tumour brain nucleic acid gave a possibility to reveal some structural peculiarities of their sugar-phosphate backbone.

  17. Utilization of aminoaromatic acids by a methanogenic enrichment culture and by a novel Citrobacter freundii strain.

    PubMed

    Savelieva, Olga; Kotova, Irina; Roelofsen, Wim; Stams, Alfons J M; Netrusov, Alexander

    2004-02-01

    Following incubation of mesophilic methanogenic floccular sludge from a lab-scale upflow anaerobic sludge bed reactor used to treat cattle manure wastewater, a stable 5-aminosalicylate-degrading enrichment culture was obtained. Subsequently, a Citrobacter freundii strain, WA1, was isolated from the 5-aminosalicylate-degrading methanogenic consortium. The methanogenic enrichment culture degraded 5-aminosalicylate completely to CH4, CO2 and NH4+, while C. freundii strain WA1 reduced 5-aminosalicylate with simultaneous deamination to 2-hydroxybenzyl alcohol during anaerobic growth with electron donors such as pyruvate, glucose or serine. When grown on pyruvate, C. freundii WA1 converted 3-aminobenzoate to benzyl alcohol and also reduced benzaldehyde to benzyl alcohol. Pyruvate was fermented to acetate, CO2, H2 and small amounts of lactate, succinate and formate. Less lactate (30%) was produced from pyruvate when C. freundii WA1 grew with 5-aminosalicylate as co-substrate.

  18. Nucleic Acid Conjugated Nanomaterials for Enhanced Molecular Recognition

    PubMed Central

    Wang, Hao; Yang, Ronghua; Yang, Liu; Tan, Weihong

    2009-01-01

    Nucleic acids, whether designed or selected in vitro, play important roles in biosensing, medical diagnostics and therapy. Specifically, the conjugation of functional nucleic acid-based probe molecules and nanomaterials has resulted in an unprecedented improvement in the field of molecular recognition. With their unique physical and chemical properties, nanomaterials facilitate the sensing process and amplify the signal of recognition events. Thus, the coupling of nucleic acids with various nanomaterials opens up a promising future for molecular recognition. The literature offers a broad spectrum of recent advances in biosensing by employing different nano-platforms with designed nucleic acids, especially gold nanoparticles, carbon nanotubes, silica nanoparticles and quantum dots. The advantages of these novel combinations are discussed from the perspective of molecular recognition in chemistry, biology and medicine, along with the problems confronting future applications. PMID:19658387

  19. The memory-enhancing effect of erucic acid on scopolamine-induced cognitive impairment in mice.

    PubMed

    Kim, Eunji; Ko, Hae Ju; Jeon, Se Jin; Lee, Sunhee; Lee, Hyung Eun; Kim, Ha Neul; Woo, Eun-Rhan; Ryu, Jong Hoon

    2016-03-01

    Erucic acid is a monounsaturated omega-9 fatty acid isolated from the seed of Raphanus sativus L. that is known to normalize the accumulation of very long chain fatty acids in the brains of patients suffering from X-linked adrenoleukodystrophy. Here, we investigated whether erucic acid enhanced cognitive function or ameliorated scopolamine-induced memory impairment using the passive avoidance, Y-maze and Morris water maze tasks. Erucic acid (3mg/kg, p.o.) enhanced memory performance in normal naïve mice. In addition, erucic acid (3mg/kg, p.o.) ameliorated scopolamine-induced memory impairment, as assessed via the behavioral tasks. We then investigated the underlying mechanism of the memory-enhancing effect of erucic acid. The administration of erucic acid increased the phosphorylation levels of phosphatidylinositide 3-kinase (PI3K), protein kinase C zeta (PKCζ), extracellular signal-regulated kinase (ERK), cAMP response element-binding protein (CREB) and additional protein kinase B (Akt) in the hippocampus. These results suggest that erucic acid has an ameliorative effect in mice with scopolamine-induced memory deficits and that the effect of erucic acid is partially due to the activation of PI3K-PKCζ-ERK-CREB signaling as well as an increase in phosphorylated Akt in the hippocampus. Therefore, erucic acid may be a novel therapeutic agent for diseases associated with cognitive deficits, such as Alzheimer's disease. PMID:26780350

  20. Arachidonic acid enhances turnover of the dermal skeleton: studies on zebrafish scales.

    PubMed

    de Vrieze, Erik; Moren, Mari; Metz, Juriaan R; Flik, Gert; Lie, Kai Kristoffer

    2014-01-01

    In fish nutrition, the ratio between omega-3 and omega-6 poly-unsaturated fatty acids influences skeletal development. Supplementation of fish oils with vegetable oils increases the content of omega-6 fatty acids, such as arachidonic acid in the diet. Arachidonic acid is metabolized by cyclooxygenases to prostaglandin E2, an eicosanoid with effects on bone formation and remodeling. To elucidate effects of poly-unsaturated fatty acids on developing and existing skeletal tissues, zebrafish (Danio rerio) were fed (micro-) diets low and high in arachidonic acid content. Elasmoid scales, dermal skeletal plates, are ideal to study skeletal metabolism in zebrafish and were exploited in the present study. The fatty acid profile resulting from a high arachidonic acid diet induced mild but significant increase in matrix resorption in ontogenetic scales of adult zebrafish. Arachidonic acid affected scale regeneration (following removal of ontogenetic scales): mineral deposition was altered and both gene expression and enzymatic matrix metalloproteinase activity changed towards enhanced osteoclastic activity. Arachidonic acid also clearly stimulates matrix metalloproteinase activity in vitro, which implies that resorptive effects of arachidonic acid are mediated by matrix metalloproteinases. The gene expression profile further suggests that arachidonic acid increases maturation rate of the regenerating scale; in other words, enhances turnover. The zebrafish scale is an excellent model to study how and which fatty acids affect skeletal formation.

  1. Enhanced expression of aconitase raises acetic acid resistance in Acetobacter aceti.

    PubMed

    Nakano, Shigeru; Fukaya, Masahiro; Horinouchi, Sueharu

    2004-06-15

    Acetobacter spp. are used for industrial vinegar production because of their high ability to oxidize ethanol to acetic acid and high resistance to acetic acid. Two-dimensional gel electrophoretic analysis of a soluble fraction of Acetobacter aceti revealed the presence of several proteins whose production was enhanced, to various extents, in response to acetic acid in the medium. A protein with an apparent molecular mass of 100 kDa was significantly enhanced in amount by acetic acid and identified to be aconitase by NH2-terminal amino acid sequencing and subsequent gene cloning. Amplification of the aconitase gene by use of a multicopy plasmid in A. aceti enhanced the enzymatic activity and acetic acid resistance. These results showed that aconitase is concerned with acetic acid resistance. Enhancement of the aconitase activity turned out to be practically useful for acetic acid fermentation, because the A. aceti transformant harboring multiple copies of the aconitase gene produced a higher concentration of acetic acid with a reduced growth lag-time.

  2. Determination of nucleic acid by its enhancement effect on the fluorescence of Ellagic acid - Cationic surfactant system

    NASA Astrophysics Data System (ADS)

    Wang, Feng; Huang, Wei; Wang, Yanwei; Tang, Bo

    2010-04-01

    In this paper, nucleic acid can greatly enhance the fluorescence of Ellagic acid (EA) in the presence of cetylpyridine bromide (CPB). Experiments indicate that under the optimum conditions, the enhanced intensity of fluorescence is proportional to the concentration of nucleic acid in the range of 5.0 × 10 -9-3.5 × 10 -5 g mL -1 for hsDNA, 5.0 × 10 -9-3.5 × 10 -5 g mL -1 for ctDNA and 5.0 × 10 -9-3.5 × 10 -5 g mL -1 for yRNA. Their detection limits (S/N = 3) are 7.6 × 10 -9 g mL -1, 8.6 × 10 -9 g mL -1 and 6.1 × 10 -9 g mL -1, respectively. The method has been satisfactorily used for the determination of nucleic acid in actual samples. Resonance Light Scattering, Ultraviolet and other means are used to discuss its mechanism. It is considered that the charge-transfer complex EA-CPB aggregate in the extended nucleic acids by hydrogen bond and electric attraction. The hydrophobic microenvironment of nucleic acid makes the fluorescence intensity of EA-CPB-nucleic acid system much stronger.

  3. Effect of permeation enhancers and organic acids on the skin permeation of indapamide.

    PubMed

    Ren, Changshun; Fang, Liang; Li, Ting; Wang, Manli; Zhao, Ligang; He, Zhonggui

    2008-02-28

    The aim of present study was to investigate the transdermal properties of indapamide and to explore the efficacy of various permeation enhancers and organic acids with regard to the percutaneous absorption of indapamide. Permeation experiments were performed in vitro, using rat abdominal skin as a barrier. In the permeation studies, 2-chamber diffusion cells were used. The results obtained indicate that N-dodecylazepan-2-one, N-methyl-2-pyrrolidone, menthol and oleic acid had a strong enhancing effect on the permeation of indapamide and N-dodecylazepan-2-one exhibited the most potent enhancing effect. All eight of the organic acids chosen had a potent enhancing effect on the permeation of indapamide across rat abdominal skin. Among the organic acids examined, lactic acid had the greatest enhancing effect. The formation of an ion-pair between indapamide and organic acids may be responsible for the enhanced skin permeation of indapamide. Although the exact reason remains unknown, it is worth carrying out further investigations.

  4. Boric acid-enhanced embedding medium for cryomicrotomy.

    PubMed

    Lim, Jin Ik; Park, Hun-Kuk

    2012-05-01

    A polyvinyl alcohol (PVA)/polyethylene glycol (PEG)-based resin is commonly used as a cryoembedding medium for the histological analysis of frozen tissue sections. However, it is not easy to obtain sufficient numbers of satisfactory reproducible sections owing to the differences between the mechanical properties of the medium and embedded tissue and the low cohesive force of the medium. We describe a modified PVA-based cryoembedding medium, composed of PVA (10wt% and 15wt%) with the addition of boric acid (from 0 to 5wt%), that can improve the sectioning properties and efficiency of frozen tissue for histological analysis. The amount of load under the same compressive displacement as well as cohesive force increased with increasing boric acid and PVA contents. 15wt% PVA and 3wt% boric acid was determined as an optimal composition for cryoembedding material based on the sectioning efficiency measured by the numbers of unimpaired sectioned slices and the amount of load under the same compressive displacement test. On the basis of the results of routine hematoxylin and eosin staining of cryosections of tissue embedded in a medium with 3wt% boric acid and PVA, it was concluded that the modified PVA cryoembedding medium can improve the efficiency of cryosectioning for subsequent histological or histochemical analysis of various tissues.

  5. KINETIC ASPECTS OF CATION-ENHANCED AGGREGATION IN AQUEOUS HUMIC ACIDS. (R822832)

    EPA Science Inventory

    The cation-enhanced formation of hydrophobic domains in aqueous humic acids has been shown to be a slow process, consistent with the evolution and disintegration of humic acid configurations over periods lasting from days to weeks. After the addition of a magnesium salt to a humi...

  6. Myristic Acid Enhances Diacylglycerol Kinase δ-Dependent Glucose Uptake in Myotubes.

    PubMed

    Wada, Yuko; Sakiyama, Shizuka; Sakai, Hiromichi; Sakane, Fumio

    2016-08-01

    Decreased expression of diacylglycerol kinase (DGK) δ in skeletal muscles attenuates glucose uptake and is closely related to the pathogenesis of type 2 diabetes. Therefore, up-regulation of DGKδ expression is thought to protect and improve glucose homoeostasis in type 2 diabetes. We recently determined that myristic acid (14:0), but not palmitic (16:0) or stearic (18:0) acid, significantly increased DGKδ2 protein expression in mouse C2C12 myotubes. In the current study, we analyzed whether myristic acid indeed enhances glucose uptake in C2C12 myotubes. We observed that myristic acid caused ~1.4-fold increase in insulin-independent glucose uptake. However, palmitic and stearic acids failed to enhance glucose uptake. DGKδ-specific siRNA decreased myristic acid-dependent increase of glucose uptake. Moreover, overexpression of DGKδ2 enhanced glucose uptake in C2C12 cells in the absence of myristic acid treatment. Taken together, these results strongly suggest that myristic acid enhances basal glucose uptake in myotubes in a DGKδ2 expression-dependent manner.

  7. Degradation of Fructans and Production of Propionic Acid by Bacteroides thetaiotaomicron are Enhanced by the Shortage of Amino Acids.

    PubMed

    Adamberg, Signe; Tomson, Katrin; Vija, Heiki; Puurand, Marju; Kabanova, Natalja; Visnapuu, Triinu; Jõgi, Eerik; Alamäe, Tiina; Adamberg, Kaarel

    2014-01-01

    Bacteroides thetaiotaomicron is commonly found in the human colon and stabilizes its ecosystem by catabolism of various polysaccharides. A model of cross-talk between the metabolism of amino acids and fructans in B. thetaiotaomicron was proposed. The growth of B. thetaiotaomicron DSM 2079 in two defined media containing mineral salts and vitamins, and supplemented with either 20 or 2 amino acids, was studied in an isothermal microcalorimeter. The polyfructans inulin (from chicory) and levan (synthesized using levansucrase from Pseudomonas syringae), two fructooligosaccharide preparations with different composition, sucrose and fructose were tested as substrates. The calorimetric power-time curves were substrate specific and typically multiauxic. A surplus of amino acids reduced the consumption of longer oligosaccharides (degree of polymerization > 3). Bacterial growth was not detected either in the carbohydrate free medium containing amino acids or in the medium with inulin as a sole carbohydrate. In amino acid-restricted medium, fermentation leading to acetic acid formation was dominant at the beginning of growth (up to 24 h), followed by increased lactic acid production, and mainly propionic and succinic acids were produced at the end of fermentation. In the medium supplemented with 20 amino acids, the highest production of d-lactate (82 ± 33 mmol/gDW) occurred in parallel with extensive consumption (up to 17 mmol/gDW) of amino acids, especially Ser, Thr, and Asp. The production of Ala and Glu was observed at growth on all substrates, and the production was enhanced under amino acid deficiency. The study revealed the influence of amino acids on fructan metabolism in B. thetaiotaomicron and showed that defined growth media are invaluable in elucidating quantitative metabolic profiles of the bacteria. Levan was shown to act as an easily degradable substrate for B. thetaiotaomicron. The effect of levan on balancing or modifying colon microbiota will

  8. Degradation of Fructans and Production of Propionic Acid by Bacteroides thetaiotaomicron are Enhanced by the Shortage of Amino Acids

    PubMed Central

    Adamberg, Signe; Tomson, Katrin; Vija, Heiki; Puurand, Marju; Kabanova, Natalja; Visnapuu, Triinu; Jõgi, Eerik; Alamäe, Tiina; Adamberg, Kaarel

    2014-01-01

    Bacteroides thetaiotaomicron is commonly found in the human colon and stabilizes its ecosystem by catabolism of various polysaccharides. A model of cross-talk between the metabolism of amino acids and fructans in B. thetaiotaomicron was proposed. The growth of B. thetaiotaomicron DSM 2079 in two defined media containing mineral salts and vitamins, and supplemented with either 20 or 2 amino acids, was studied in an isothermal microcalorimeter. The polyfructans inulin (from chicory) and levan (synthesized using levansucrase from Pseudomonas syringae), two fructooligosaccharide preparations with different composition, sucrose and fructose were tested as substrates. The calorimetric power-time curves were substrate specific and typically multiauxic. A surplus of amino acids reduced the consumption of longer oligosaccharides (degree of polymerization > 3). Bacterial growth was not detected either in the carbohydrate free medium containing amino acids or in the medium with inulin as a sole carbohydrate. In amino acid-restricted medium, fermentation leading to acetic acid formation was dominant at the beginning of growth (up to 24 h), followed by increased lactic acid production, and mainly propionic and succinic acids were produced at the end of fermentation. In the medium supplemented with 20 amino acids, the highest production of d-lactate (82 ± 33 mmol/gDW) occurred in parallel with extensive consumption (up to 17 mmol/gDW) of amino acids, especially Ser, Thr, and Asp. The production of Ala and Glu was observed at growth on all substrates, and the production was enhanced under amino acid deficiency. The study revealed the influence of amino acids on fructan metabolism in B. thetaiotaomicron and showed that defined growth media are invaluable in elucidating quantitative metabolic profiles of the bacteria. Levan was shown to act as an easily degradable substrate for B. thetaiotaomicron. The effect of levan on balancing or modifying colon microbiota will

  9. Surface enhanced Raman spectra of carbonate, hydrocarbonate, and substituted acetic acids on silver hydrosols

    NASA Astrophysics Data System (ADS)

    Kai, Sun; Chaozhi, Wan; Guangzhi, Xu

    1989-01-01

    The SERS spectra of carbonate, hydrocarbonate and several substituted acetic acids absorbed on silver hydrosols are recorded. The greatest enhancement of E' modes is shown in the spectrum of carbonate, from which the carbonate is deduced to be absorbed in an "end on" configuration, rather than flat on the surface. The spectrum of the hydrocarbonate solution shows the most enhanced bands at about 925 and 620 cm -1, which cannot be explained clearly. All the substituted acids have a most enhanced bands at about 1630 cm -1, revealing that the acids are initially adsorbed in a single bonding state through the carboxyl group. The change in the SERS spectra of the acids with time indicates that a bidentate bridging adsorbed state may be formed after some time.

  10. Gallic Acid Is an Antagonist of Semen Amyloid Fibrils That Enhance HIV-1 Infection.

    PubMed

    LoRicco, Josephine G; Xu, Changmingzi Sherry; Neidleman, Jason; Bergkvist, Magnus; Greene, Warner C; Roan, Nadia R; Makhatadze, George I

    2016-07-01

    Recent in vitro studies have demonstrated that amyloid fibrils found in semen from healthy and HIV-infected men, as well as semen itself, can markedly enhance HIV infection rates. Semen fibrils are made up of multiple naturally occurring peptide fragments derived from semen. The best characterized of these fibrils are SEVI (semen-derived enhancer of viral infection), made up of residues 248-286 of prostatic acidic phosphatase, and the SEM1 fibrils, made up of residues 86-107 of semenogelin 1. A small molecule screen for antagonists of semen fibrils identified four compounds that lowered semen-mediated enhancement of HIV-1 infectivity. One of the four, gallic acid, was previously reported to antagonize other amyloids and to exert anti-inflammatory effects. To better understand the mechanism by which gallic acid modifies the properties of semen amyloids, we performed biophysical measurements (atomic force microscopy, electron microscopy, confocal microscopy, thioflavin T and Congo Red fluorescence assays, zeta potential measurements) and quantitative assays on the effects of gallic acid on semen-mediated enhancement of HIV infection and inflammation. Our results demonstrate that gallic acid binds to both SEVI and SEM1 fibrils and modifies their surface electrostatics to render them less cationic. In addition, gallic acid decreased semen-mediated enhancement of HIV infection but did not decrease the inflammatory response induced by semen. Together, these observations identify gallic acid as a non-polyanionic compound that inhibits semen-mediated enhancement of HIV infection and suggest the potential utility of incorporating gallic acid into a multicomponent microbicide targeting both the HIV virus and host components that promote viral infection.

  11. Plasmon resonance enhancement of nonlinear properties of amino acids

    NASA Astrophysics Data System (ADS)

    de Araujo, Renato E.; Rativa, Diego; Gomes, Anderson S. L.

    2007-02-01

    Here we analyze the influence of 9 nm (mean diameter) silver particles on the nonlinear properties of intrinsic cell molecules. A novel high sensitivity thermal managed eclipse Z-scan technique with a femtosecond laser system was used to analyze the nonlinear susceptibility of water solution of fluorescent and non-fluorescent amino acids (Tryptophan, Tyrosine, Phenylalanine, Proline and Histidine) with different concentration of silver nanoparticles. The generalized Maxwell Garnett model is used to explain the behavior of the measured nonlinear refractive index with the change of the nanoparticles concentration in the sample.

  12. Clavulanic acid increases dopamine release in neuronal cells through a mechanism involving enhanced vesicle trafficking.

    PubMed

    Kost, Gina Chun; Selvaraj, Senthil; Lee, Young Bok; Kim, Deog Joong; Ahn, Chang-Ho; Singh, Brij B

    2011-10-24

    Clavulanic acid is a CNS-modulating compound with exceptional blood-brain barrier permeability and safety profile. Clavulanic acid has been proposed to have anti-depressant activity and is currently entering Phase IIb clinical trials for the treatment of Major Depressive Disorder (MDD). Studies have also shown that clavulanic acid suppresses anxiety and enhances sexual functions in rodent and primate models by a mechanism involving central nervous system (CNS) modulation, although its detailed mechanism of action has yet to be elucidated. To further examine its potential as a CNS modulating agent as well as its mechanism of action, we investigated the effects of clavulanic acid in neuronal cells. Our results indicate that clavulanic acid enhances dopamine release in PC12 and SH-SY5Y cells without affecting dopamine synthesis. Furthermore, using affinity chromatography we were able to identify two proteins, Munc18-1 and Rab4 that potentially bind to clavulanic acid and play a critical role in neurosecretion and the vesicle trafficking process. Consistent with this result, an increase in the translocation of Munc18-1 and Rab4 from the cytoplasm to the plasma membrane was observed in clavulanic acid treated cells. Overall, these data suggest that clavulanic acid enhances dopamine release in a mechanism involving Munc18-1 and Rab4 modulation and warrants further investigation of its therapeutic use in CNS disorders, such as depression.

  13. Clavulanic acid increases dopamine release in neuronal cells through a mechanism involving enhanced vesicle trafficking

    PubMed Central

    Kost, Gina Chun; Selvaraj, Senthil; Lee, Young Bok; Kim, Deog Joong; Ahn, Chang-Ho; Singh, Brij B

    2011-01-01

    Clavulanic acid is a CNS-modulating compound with exceptional blood-brain barrier permeability and safety profile. Clavulanic acid has been proposed to have anti-depressant activity and is currently entering Phase IIb clinical trials for the treatment of Major Depressive Disorder (MDD). Studies have also shown that clavulanic acid suppresses anxiety and enhances sexual functions in rodent and primate models by a mechanism involving central nervous system (CNS) modulation, although its detailed mechanism of action has yet to be elucidated. To further examine its potential as a CNS modulating agent as well as its mechanism of action, we investigated the effects of clavulanic acid in neuronal cells. Our results indicate that clavulanic acid enhances dopamine release in PC12 and SH-SY5Y cells without affecting dopamine synthesis. Furthermore, using affinity chromatography we were able to identify two proteins, Munc18-1 and Rab4 that potentially bind to clavulanic acid and play a critical role in neurosecretion and the vesicle trafficking process. Consistent with this result, an increase in the translocation of Munc18-1 and Rab4 from the cytoplasm to the plasma membrane was observed in clavulanic acid treated cells. Overall, these data suggest that clavulanic acid enhances dopamine release in a mechanism involving Munc18-1 and Rab4 modulation and warrants further investigation of its therapeutic use in CNS disorders, such as depression. PMID:21964384

  14. An enhanced procedure for measuring organic acids and methyl esters in PM2.5

    NASA Astrophysics Data System (ADS)

    Liu, F.; Duan, F.; He, K.; Ma, Y.; Rahn, K. A.; Zhang, Q.

    2015-03-01

    We have developed an enhanced analytical procedure to measure organic acids and methyl esters in fine aerosol with much greater specificity and sensitivity than previously available. This capability is important because of these species and their low concentrations, even in highly polluted atmospheres like Beijing, China. The procedure first separates the acids and esters from the other organic compounds with anion-exchange solid- phase extraction (SPE), then, quantifies them by gas chromatography coupled with mass spectrometry. This allows us to accurately quantify the C4-C11 dicarboxylic and the C8-C30 monocarboxylic acids. Then the acids are separated from the esters on an aminopropyl SPE cartridge, whose weak retention isolates and enriches the acids from esters prevents the fatty acids and dimethyl phthalate from being overestimated. The resulting correlations between the aliphatic acids and fatty acid methyl esters (FAMEs) suggest that FAMEs had sources similar to those of the carboxylic acids, or were formed by esterifying carboxylic acids, or that aliphatic acids were formed by hydrolyzing FAMEs. In all, 17 aromatic acids were identified and quantified using this procedure coupled with gas chromatography-tandem mass spectrometry, including the five polycyclic aromatic hydrocarbon (PAH) acids 2-naphthoic, biphenyl-4-carboxylic, 9-oxo-9H-fluorene-1-carboxylic, biphenyl-4,4´-dicarboxylic, and phenanthrene-1-carboxylic acid, plus 1,8-naphthalic anhydride. Correlations between the PAH-acids and the dicarboxylic and aromatic acids indicated that the first three acids and 1,8-naphthalic anhydride were mainly secondary, the last two mainly primary.

  15. Water-dispersible ascorbic-acid-coated magnetite nanoparticles for contrast enhancement in MRI

    NASA Astrophysics Data System (ADS)

    Sreeja, V.; Jayaprabha, K. N.; Joy, P. A.

    2015-04-01

    Superparamagnetic iron oxide nanoparticles of size ~5 nm surface functionalized with ascorbic acid (vitamin C) form a stable dispersion in water with a hydrodynamic size of ~30 nm. The anti-oxidant property of ascorbic acid is retained after capping, as evidenced from the capability of converting methylene blue to its reduced leuco form. NMR relaxivity studies show that the ascorbic-acid-coated superparamagnetic iron oxide aqueous nanofluid is suitable as a contrast enhancement agent for MRI applications, coupled with the excellent biocompatibility and medicinal values of ascorbic acid.

  16. Acetylated Hyaluronic Acid: Enhanced Bioavailability and Biological Studies

    PubMed Central

    Saturnino, Carmela; Sinicropi, Maria Stefania; Puoci, Francesco

    2014-01-01

    Hyaluronic acid (HA), a macropolysaccharidic component of the extracellular matrix, is common to most species and it is found in many sites of the human body, including skin and soft tissue. Not only does HA play a variety of roles in physiologic and in pathologic events, but it also has been extensively employed in cosmetic and skin-care products as drug delivery agent or for several biomedical applications. The most important limitations of HA are due to its short half-life and quick degradation in vivo and its consequently poor bioavailability. In the aim to overcome these difficulties, HA is generally subjected to several chemical changes. In this paper we obtained an acetylated form of HA with increased bioavailability with respect to the HA free form. Furthermore, an improved radical scavenging and anti-inflammatory activity has been evidenced, respectively, on ABTS radical cation and murine monocyte/macrophage cell lines (J774.A1). PMID:25114930

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

    PubMed

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

    2015-03-01

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

  18. Reduced Burst Release and Enhanced Oral Bioavailability in Shikimic Acid-Loaded Polylactic Acid Submicron Particles by Coaxial Electrospray.

    PubMed

    Wang, Miaomiao; Wang, Yuanwen; Omari-Siaw, Emmanuel; Wang, Shengli; Zhu, Yuan; Xu, Ximing

    2016-08-01

    In this study, using the coaxial electrospray method, we prepared submicron particles of the water-soluble drug shikimic acid (SA) with polylactic acid (PLA) as a polymer, to reduce the burst release and enhance the oral bioavailability. In vitro release study performed in HCl solution (pH 1.2) showed that the coaxial electrospray submicron particles could reduce burst release effect and presented a sustained release profile, compared with free SA and the particles prepared by electrospray method. The absorption of SA in the intestinal tract, studied using an in situ perfusion method in rats, also revealed jejunum as the main absorptive segment followed by duodenum and ileum. Moreover, the SA-loaded particles greatly enhanced the absorption of SA in the tested intestinal segments. The intestinal absorption rate was not enhanced with increasing drug concentration (5-15 μg/mL) which suggested that active transport or facilitated diffusion could play vital role in SA absorption. In addition, the SA-loaded PLA coaxial electrospray particle exhibited a prolonged plasma circulation with enhanced bioavailability after oral administration. In all, the coaxial electrospray technique could provide notable advantages for the oral delivery of SA, thereby enhancing its clinical application.

  19. Enhanced phagocytosis of group A streptococci M type 6 by oleic acid

    SciTech Connect

    Speert, D.P.; Quie, P.G.; Wannamaker, L.W.

    1981-04-01

    M protein, located on the surface fimbriae of group A streptococci, is antiphagocytic by unknown means. It is known that oleic acid kills group A streptococci and distorts the fimbriae. The effect of oleic acid on phagocytosis of group A streptococci was examined. Phagocytosis of a strain possessing M protein (M+) and its M- variant was assessed by uptake of radiolabeled bacteria and by chemiluminescence. The M- but not the M+ streptococci were well phagocytized and induced chemiluminescence. Oleic acid-killed and heat-killed streptococci (both M+ and M-) were readily phagocytized and induced sustained chemiluminescence. M+ streptococci killed by ultraviolet irradiation were inefficiently phagocytized and did not induce chemiluminescence. Oleic acid-killed M+ streptococci absorbed type-specific antibody. An extract of M protein reduced the bactericidal capacity of oleic acid. It is proposed that oleic acid may bind to and alter the M protein of group A streptococci and thereby enhance phagocytosis.

  20. Enhanced crystallization of poly (lactic acid) through reactive aliphatic bisamide

    NASA Astrophysics Data System (ADS)

    Nanthananon, P.; Seadan, M.; Pivsa-Art, S.; Suttiruengwong, S.

    2015-07-01

    The poor crystallization rate of poly (lactic acid) (PLA) is a major drawback in terms of controlling the properties of final products. To overcome this, a nucleating agent is normally applied. In this work, the aliphatic bisamide, N, N'-(1,3-propylene) bis(10-undecenamide) (PBU), having reactive functional groups is used as a crystallization promoter for PLA by adding PBU in various concentration (0.1-0.7 wt%) into PLA together with peroxide via reactive melt blending. The conventional ethylene bis-stearamide(EBS) is used for a comparison. The extruded samples are characterized for gel content and FT-IR spectroscopy. The crystallization behaviour and rate, and spherulites morphology are investigated by differential scanning calorimetry (DSC) and polarized optical microscopy (POM), respectively. It is found that the addition of PBU into PLA results in the dramatic increase in crystallinity and crystallization rate of PLA compared with neat PLA and PLA added EBS. The crystallinity increases to 24.9-28.3% higher than neat PLA under even cooling rate of 7°C/min. The addition of 0.7 wt% PBU shows the fastest crystallization rate with t1/2 value isothermally crystallized at 130°C of only 6 min. POM images indicate the increase in the nucleation density and very fine spherulitesof PLA added PBU, promoting the fast crystallization.

  1. Ursolic acid enhances pentobarbital-induced sleeping behaviors via GABAergic neurotransmission in mice.

    PubMed

    Jeon, Se Jin; Park, Ho Jae; Gao, Qingtao; Pena, Irene Joy Dela; Park, Se Jin; Lee, Hyung Eun; Woo, Hyun; Kim, Hee Jin; Cheong, Jae Hoon; Hong, Eunyoung; Ryu, Jong Hoon

    2015-09-01

    Prunella vulgaris is widely used as a herbal medicine for cancers, inflammatory diseases, and other infections. Although it has long been used, few studies have examined its effects on central nervous system function. Here, we first observed that ethanolic extracts of P. vulgaris (EEPV) prolonged pentobarbital-induced sleep duration in mice. It is known that EEPV consists of many active components including triterpenoid (ursolic acid and oleanolic acid), which have many biological activities. Therefore, we evaluated which EEPV components induced sleep extension in pentobarbital-mediated sleeping model in mice. Surprisingly, despite their structural similarity and other common functions such as anti-inflammation, anti-cancer, and tissue protection, only ursolic acid enhanced sleep duration in pentobarbital-treated mice. These results were attenuated by bicuculline treatment, which is a GABAA receptor antagonist. The present results suggest that ursolic acid from P. vulgaris enhances sleep duration through GABAA receptor activation and could be a therapeutic candidate for insomnia treatment.

  2. Redox regulation of insulin sensitivity due to enhanced fatty acid utilization in the mitochondria.

    PubMed

    Rindler, Paul M; Crewe, Clair L; Fernandes, Jolyn; Kinter, Michael; Szweda, Luke I

    2013-09-01

    Obesity enhances the risk for the development of type 2 diabetes and cardiovascular disease. Loss in insulin sensitivity and diminished ability of muscle to take up and use glucose are characteristics of type 2 diabetes. Paradoxically, regulatory mechanisms that promote utilization of fatty acids appear to initiate diet-induced insulin insensitivity. In this review, we discuss recent findings implicating increased mitochondrial production of the prooxidant H2O2 due to enhanced utilization of fatty acids, as a signal to diminish reliance on glucose and its metabolites for energy. In the short term, the ability to preferentially use fatty acids may be beneficial, promoting a metabolic shift that ensures use of available fat by skeletal muscle and heart while preventing intracellular glucose accumulation and toxicity. However, with prolonged consumption of high dietary fat and ensuing obesity, the near exclusive dependence on fatty acid oxidation for production of energy by the mitochondria drives insulin resistance, diabetes, and cardiovascular disease.

  3. Elucidating the role of ferrous ion cocatalyst in enhancing dilute acid pretreatment of lignocellulosic biomass

    PubMed Central

    2011-01-01

    Background Recently developed iron cocatalyst enhancement of dilute acid pretreatment of biomass is a promising approach for enhancing sugar release from recalcitrant lignocellulosic biomass. However, very little is known about the underlying mechanisms of this enhancement. In the current study, our aim was to identify several essential factors that contribute to ferrous ion-enhanced efficiency during dilute acid pretreatment of biomass and to initiate the investigation of the mechanisms that result in this enhancement. Results During dilute acid and ferrous ion cocatalyst pretreatments, we observed concomitant increases in solubilized sugars in the hydrolysate and reducing sugars in the (insoluble) biomass residues. We also observed enhancements in sugar release during subsequent enzymatic saccharification of iron cocatalyst-pretreated biomass. Fourier transform Raman spectroscopy showed that major peaks representing the C-O-C and C-H bonds in cellulose are significantly attenuated by iron cocatalyst pretreatment. Imaging using Prussian blue staining indicated that Fe2+ ions associate with both cellulose/xylan and lignin in untreated as well as dilute acid/Fe2+ ion-pretreated corn stover samples. Analyses by scanning electron microscopy and transmission electron microscopy revealed structural details of biomass after dilute acid/Fe2+ ion pretreatment, in which delamination and fibrillation of the cell wall were observed. Conclusions By using this multimodal approach, we have revealed that (1) acid-ferrous ion-assisted pretreatment increases solubilization and enzymatic digestion of both cellulose and xylan to monomers and (2) this pretreatment likely targets multiple chemistries in plant cell wall polymer networks, including those represented by the C-O-C and C-H bonds in cellulose. PMID:22074910

  4. Elucidating the Role of Ferrous Ion Cocatalyst in Enhancing Dilute Acid Pretreatment of Lignocellulosic Biomass

    SciTech Connect

    Wei, H.; Donohoe, B. S.; Vinzant, T. B.; Ciesielski, P. N.; Wang, W.; Gedvilas, L. M.; Zeng, Y.; Johnson, D. K.; Ding, S. Y.; Himmel, M. E.; Tucker, M. P.

    2011-01-01

    Recently developed iron cocatalyst enhancement of dilute acid pretreatment of biomass is a promising approach for enhancing sugar release from recalcitrant lignocellulosic biomass. However, very little is known about the underlying mechanisms of this enhancement. In the current study, our aim was to identify several essential factors that contribute to ferrous ion-enhanced efficiency during dilute acid pretreatment of biomass and to initiate the investigation of the mechanisms that result in this enhancement. During dilute acid and ferrous ion cocatalyst pretreatments, we observed concomitant increases in solubilized sugars in the hydrolysate and reducing sugars in the (insoluble) biomass residues. We also observed enhancements in sugar release during subsequent enzymatic saccharification of iron cocatalyst-pretreated biomass. Fourier transform Raman spectroscopy showed that major peaks representing the C-O-C and C-H bonds in cellulose are significantly attenuated by iron cocatalyst pretreatment. Imaging using Prussian blue staining indicated that Fe{sup 2+} ions associate with both cellulose/xylan and lignin in untreated as well as dilute acid/Fe{sup 2+} ion-pretreated corn stover samples. Analyses by scanning electron microscopy and transmission electron microscopy revealed structural details of biomass after dilute acid/Fe{sup 2+} ion pretreatment, in which delamination and fibrillation of the cell wall were observed. By using this multimodal approach, we have revealed that (1) acid-ferrous ion-assisted pretreatment increases solubilization and enzymatic digestion of both cellulose and xylan to monomers and (2) this pretreatment likely targets multiple chemistries in plant cell wall polymer networks, including those represented by the C-O-C and C-H bonds in cellulose.

  5. Enhanced Nitrogen Availability in Karst Ecosystems by Oxalic Acid Release in the Rhizosphere.

    PubMed

    Pan, Fujing; Liang, Yueming; Zhang, Wei; Zhao, Jie; Wang, Kelin

    2016-01-01

    In karst ecosystems, a high level of CaCO3 enhances the stabilization of soil organic matter (SOM) and causes nitrogen (N) and/or phosphorus (P) limitation in plants. Oxalic acid has been suggested to be involved in the nutrient-acquisition strategy of plants because its addition can temporarily relieve nutrient limitation. Therefore, understanding how oxalic acid drives N availability may help support successful vegetation restoration in the karst ecosystems of southwest China. We tested a model suggested by Clarholm et al. (2015) where oxalate reacts with Ca bridges in SOM, thus exposing previously protected areas to enzymatic attacks in a way that releases N for local uptake. We studied the effects of oxalic acid, microbial biomass carbon (MBC), and β-1,4-N-acetylglucosaminidase (NAG) on potential N mineralization rates in rhizosphere soils of four plant species (two shrubs and two trees) in karst areas. The results showed that rhizosphere soils of shrubs grown on formerly deforested land had significantly lower oxalic acid concentrations and NAG activity than that of trees in a 200-year-old forest. The levels of MBC in rhizosphere soils of shrubs were significantly lower than those of trees in the growing season, but the measure of shrubs and trees were similar in the non-growing season; the potential N mineralization rates showed a reverse pattern. Positive relationships were found among oxalic acid, MBC, NAG activity, and potential N mineralization rates for both shrubs and trees. This indicated that oxalic acid, microbes, and NAG may enhance N availability for acquisition by plants. Path analysis showed that oxalic acid enhanced potential N mineralization rates indirectly through inducing microbes and NAG activities. We found that the exudation of oxalic acid clearly provides an important mechanism that allows plants to enhance nutrient acquisition in karst ecosystems.

  6. Enhanced Nitrogen Availability in Karst Ecosystems by Oxalic Acid Release in the Rhizosphere

    PubMed Central

    Pan, Fujing; Liang, Yueming; Zhang, Wei; Zhao, Jie; Wang, Kelin

    2016-01-01

    In karst ecosystems, a high level of CaCO3 enhances the stabilization of soil organic matter (SOM) and causes nitrogen (N) and/or phosphorus (P) limitation in plants. Oxalic acid has been suggested to be involved in the nutrient-acquisition strategy of plants because its addition can temporarily relieve nutrient limitation. Therefore, understanding how oxalic acid drives N availability may help support successful vegetation restoration in the karst ecosystems of southwest China. We tested a model suggested by Clarholm et al. (2015) where oxalate reacts with Ca bridges in SOM, thus exposing previously protected areas to enzymatic attacks in a way that releases N for local uptake. We studied the effects of oxalic acid, microbial biomass carbon (MBC), and β-1,4-N-acetylglucosaminidase (NAG) on potential N mineralization rates in rhizosphere soils of four plant species (two shrubs and two trees) in karst areas. The results showed that rhizosphere soils of shrubs grown on formerly deforested land had significantly lower oxalic acid concentrations and NAG activity than that of trees in a 200-year-old forest. The levels of MBC in rhizosphere soils of shrubs were significantly lower than those of trees in the growing season, but the measure of shrubs and trees were similar in the non-growing season; the potential N mineralization rates showed a reverse pattern. Positive relationships were found among oxalic acid, MBC, NAG activity, and potential N mineralization rates for both shrubs and trees. This indicated that oxalic acid, microbes, and NAG may enhance N availability for acquisition by plants. Path analysis showed that oxalic acid enhanced potential N mineralization rates indirectly through inducing microbes and NAG activities. We found that the exudation of oxalic acid clearly provides an important mechanism that allows plants to enhance nutrient acquisition in karst ecosystems. PMID:27252713

  7. Enhanced Nitrogen Availability in Karst Ecosystems by Oxalic Acid Release in the Rhizosphere.

    PubMed

    Pan, Fujing; Liang, Yueming; Zhang, Wei; Zhao, Jie; Wang, Kelin

    2016-01-01

    In karst ecosystems, a high level of CaCO3 enhances the stabilization of soil organic matter (SOM) and causes nitrogen (N) and/or phosphorus (P) limitation in plants. Oxalic acid has been suggested to be involved in the nutrient-acquisition strategy of plants because its addition can temporarily relieve nutrient limitation. Therefore, understanding how oxalic acid drives N availability may help support successful vegetation restoration in the karst ecosystems of southwest China. We tested a model suggested by Clarholm et al. (2015) where oxalate reacts with Ca bridges in SOM, thus exposing previously protected areas to enzymatic attacks in a way that releases N for local uptake. We studied the effects of oxalic acid, microbial biomass carbon (MBC), and β-1,4-N-acetylglucosaminidase (NAG) on potential N mineralization rates in rhizosphere soils of four plant species (two shrubs and two trees) in karst areas. The results showed that rhizosphere soils of shrubs grown on formerly deforested land had significantly lower oxalic acid concentrations and NAG activity than that of trees in a 200-year-old forest. The levels of MBC in rhizosphere soils of shrubs were significantly lower than those of trees in the growing season, but the measure of shrubs and trees were similar in the non-growing season; the potential N mineralization rates showed a reverse pattern. Positive relationships were found among oxalic acid, MBC, NAG activity, and potential N mineralization rates for both shrubs and trees. This indicated that oxalic acid, microbes, and NAG may enhance N availability for acquisition by plants. Path analysis showed that oxalic acid enhanced potential N mineralization rates indirectly through inducing microbes and NAG activities. We found that the exudation of oxalic acid clearly provides an important mechanism that allows plants to enhance nutrient acquisition in karst ecosystems. PMID:27252713

  8. Water solubility enhancement of some organic pollutants and pesticides by dissolved humic and fulvic acids

    USGS Publications Warehouse

    Chiou, C.T.; Malcolm, R.L.; Brinton, T.I.; Kile, D.E.

    1986-01-01

    Water solubility enhancements by dissolved humic and fulvic acids from soil and aquatic origins and by synthetic organic polymers have been determined for selected organic pollutants and pesticides (p,p???-DDT, 2,4,5,2???,5???-PCB, 2,4,4???-PCB, 1,2,3-trichlorobenzene, and lindane). Significant solubility enhancements of relatively water-insoluble solutes by dissolved organic matter (DOM) of soil and aquatic origins may be described in terms of a partition-like interaction of the the solutes with the microscopic organic environment of the high-molecular-weight DOM species; the apparent solute solubilities increase linearly with DOM concentration and show no competitive effect between solutes. With a given DOM sample, the solute partition coefficient (Kdom) increases with a decrease of solute solubility (Sw) or with an increase of the solute's octanol-water partition coefficient (Kow). The Kdom values of solutes with soil-derived humic acid are approximately 4 times greater than with soil fulvic acid and 5-7 times greater than with aquatic humic and fulvic acids. The effectiveness of DOM in enhancing solute solubility appears to be largely controlled by the DOM molecular size and polarity. The relative inability of high-molecular-weight poly(acrylic acids) to enhance solute solubility is attributed to their high polarities and extended chain structures that do not permit the formation of a sizable intramolecular nonpolar environment.

  9. [Enhancement of anaerobic digestion of excess sludge by acid-alkali pretreatment].

    PubMed

    Yuan, Guang-Huan; Zhou, Xing-Qiu; Wu, Jian-Dong

    2012-06-01

    In order to enhance the efficiency of anaerobic digestion of excess sludge, acid-alkali pretreatment method was studied. Three different pretreatment methods (alkali alone,acid-alkali, alkali-acid) were compared to investigate their impacts on hydrolysis and acidification of activated sludge. In addition, their influences on methane-producing in subsequent anaerobic digestion process were also studied. The results showed that the soluble chemical oxygen demand (SCOD) of alkaline treatment alone was about 16% higher than the combining of acid and alkali treatment, SCOD concentration increased to 5406.1 mg x L(-1) after 8 d pretreatment. After treated by acid (pH 4.0, 4 d) and alkali (pH 10.0, 4 d), the acetic acid production and its content in short-chain fatty acids (SCFAs) were higher than other pretreatment methods. And the acetic acid production (as COD/VSS) could reach 74.4 mg x g(-1), accounting for 60.5% of SCFAs. After acid-alkali pretreatment, the C: N ratio of the sludge mixed liquor was about 25, and the C: P ratio was between 35-40, which was more favorable than C: N and C: P ratio of alkali alone and alkali-acid to subsequent anaerobic digestion. The control experiments showed that, after acid-alkali pretreatment, anaerobic digestion cumulative methane yield (CH4/VSS(in)) reached to 136.1 mL x g(-1) at 15 d, which was about 2.5-, 1.6-, and 1.7-fold of the blank (unpretreated), alkali alone pretreatment and alkali-acid pretreatment, respectively. After acid-alkali pretreatment for 8 d and anaerobic digestion for 15 d, the removal efficiency of VSS was about 60.9%, and the sludge reduction effect was better than other pretreatments. It is obvious that the acid-alkali pretreatment method was more favorable to anaerobic digestion and sludge reduction.

  10. Deglacial diatom production in the tropical North Atlantic driven by enhanced silicic acid supply

    NASA Astrophysics Data System (ADS)

    Hendry, Katharine R.; Gong, Xun; Knorr, Gregor; Pike, Jennifer; Hall, Ian R.

    2016-03-01

    Major shifts in ocean circulation are thought to be responsible for abrupt changes in temperature and atmospheric CO2 during the last deglaciation, linked to variability in meridional heat transport and deep ocean carbon storage. There is also widespread evidence for shifts in biological production during these times of deglacial CO2 rise, including enhanced diatom production in regions such as the tropical Atlantic. However, it remains unclear as to whether this diatom production was driven by enhanced wind-driven upwelling or density-driven vertical mixing, or by elevated thermocline concentrations of silicic acid supplied to the surface at a constant rate. Here, we demonstrate that silicic acid supply at depth in the NE Atlantic was enhanced during the abrupt climate events of the deglaciation. We use marine sediment archives to show that an increase in diatom production during abrupt climate shifts could only occur in regions of the NE Atlantic where the deep supply of silicic acid could reach the surface. The associated changes are indicative of enhanced regional wind-driven upwelling and/or weakened stratification due to circulation changes during phases of weakened Atlantic meridional overturning. Globally near-synchronous pulses of diatom production and enhanced thermocline concentrations of silicic acid suggest that widespread deglacial surface-driven breakdown of stratification, linked to changes in atmospheric circulation, had major consequences for biological productivity and carbon cycling.

  11. Surface Enhanced Raman Scattering studies of L-amino acids adsorbed on silver nanoclusters

    NASA Astrophysics Data System (ADS)

    Botta, Raju; Rajanikanth, A.; Bansal, C.

    2015-01-01

    Silver nanocluster films were prepared using plasma inert gas phase condensation technique. These were used as Raman active substrates for Surface Enhanced Raman Scattering (SERS) studies of 19 standard L-amino acids adsorbed on the surface of Ag nanoclusters via Agsbnd N bonds. A detailed study of two essential aromatic amino acids viz. L-Phenylalanine and L-Tryptophan showed a correlation between the Raman intensity of the characteristic lines of phenol and indole side chains and their molar concentrations in the range 1 μM-1 mM. This indicates that Raman studies can be used for quantitative determination of the amino acids in proteins.

  12. Serum Fatty Acids Are Correlated with Inflammatory Cytokines in Ulcerative Colitis

    PubMed Central

    Wiese, Dawn M.; Horst, Sara N.; Brown, Caroline T.; Allaman, Margaret M.; Hodges, Mallary E.; Slaughter, James C.; Druce, Jennifer P.; Beaulieu, Dawn B.; Schwartz, David A.; Wilson, Keith T.; Coburn, Lori A.

    2016-01-01

    Background and Aims Ulcerative colitis (UC) is associated with increased dietary intake of fat and n-6 polyunsaturated fatty acids (PUFA). Modification of fat metabolism may alter inflammation and disease severity. Our aim was to assess differences in dietary and serum fatty acid levels between control and UC subjects and associations with disease activity and inflammatory cytokines. Methods Dietary histories, serum, and colonic tissue samples were prospectively collected from 137 UC subjects and 38 controls. Both histologic injury and the Mayo Disease Activity Index were assessed. Serum and tissue cytokines were measured by Luminex assay. Serum fatty acids were obtained by gas chromatography. Results UC subjects had increased total fat and oleic acid (OA) intake, but decreased arachidonic acid (AA) intake vs controls. In serum, there was less percent saturated fatty acid (SFA) and AA, with higher monounsaturated fatty acids (MUFA), linoleic acid, OA, eicosapentaenoic acid (EPA), and docosapentaenoic acid (DPA) in UC. Tissue cytokine levels were directly correlated with SFA and inversely correlated with PUFA, EPA, and DPA in UC subjects, but not controls. 5-aminosalicylic acid therapy blunted these associations. Conclusions In summary, we found differences in serum fatty acids in UC subjects that correlated with pro-inflammatory tissue cytokines. We propose that fatty acids may affect cytokine production and thus be immunomodulatory in UC. PMID:27227540

  13. Enhancing essential amino acids and health benefit components in grain crops for improved nutritional values.

    PubMed

    Wenefrida, Ida; Utomo, Herry S; Blanche, Sterling B; Linscombe, S D

    2009-01-01

    Improving essential amino acids or protein content, along with other phytonutrients in the food crops, will affect a great portion of the world population, especially in developing countries where rice grain is the main source of protein. Malnutrition, including deficiencies in protein/energy, iron/zinc, vitamin A, and iodine, causes a total 24,000 deaths per day worldwide. The problem is severe where rice is the major staple food. Protein deficiency involves both the quantity (amount) and quality (the content in essential amino acids) of the dietary protein. Various interventions, such as distribution, fortification, dietary diversification, and measures against infectious diseases, have been applied to reduce deficiency disorders. The problem, however, remains unsolved. Developing genetically novel lines with elevated content of essential amino acids together with other health benefit components becomes more feasible for the enhancement of breeding techniques, genomics, molecular manipulations, and genetic engineering. Advancement in basic genetic and genetic engineering has resulted in successful enrichment of some essential amino acids, such as lysine (Lys), tryptophan (Trp), and methionine (Met). Successful genetic enhancement has been largely restricted to the maize crop through enrichment of grain Lys and to some extends Trp. Since rice is the main source of calories and protein intake for billions of people, enhancing essential amino acids in rice represents a tremendous challenge. This paper will discuss and review the current status in basic genetics, molecular genetics, and genetic engineering associated with the enhancement of amino acids and other health benefit components in major grain crop improvement. Patents and future efforts associated with enhancing nutritional quality of the grain will also be reviewed as a concerted effort to solve the malnutrition problem and improve the quality of life worldwide.

  14. Betaine and Beet Molasses Enhance L-Lactic Acid Production by Bacillus coagulans

    PubMed Central

    Xu, Ke; Xu, Ping

    2014-01-01

    Lactic acid is an important chemical with various industrial applications, and it can be efficiently produced by fermentation, in which Bacillus coagulans strains present excellent performance. Betaine can promote lactic acid fermentation as an effective osmoprotectant. Here, positive effect of betaine on fermentation by B. coagulans is revealed. Betaine could enhance lactic acid production by protecting l-LDH activity and cell growth from osmotic inhibition, especially under high glucose concentrations and with poor organic nitrogen nutrients. The fermentation with 0.05 g/L betaine could produce 17.9% more lactic acid compared to the fermentation without betaine. Beet molasses, which is rich in sucrose and betaine, was utilized in a co-feeding fermentation and raised the productivity by 22%. The efficient lactic acid fermentation by B. coagulans is thus developed by using betaine and beet molasses. PMID:24956474

  15. Betaine and beet molasses enhance L-lactic acid production by Bacillus coagulans.

    PubMed

    Xu, Ke; Xu, Ping

    2014-01-01

    Lactic acid is an important chemical with various industrial applications, and it can be efficiently produced by fermentation, in which Bacillus coagulans strains present excellent performance. Betaine can promote lactic acid fermentation as an effective osmoprotectant. Here, positive effect of betaine on fermentation by B. coagulans is revealed. Betaine could enhance lactic acid production by protecting l-LDH activity and cell growth from osmotic inhibition, especially under high glucose concentrations and with poor organic nitrogen nutrients. The fermentation with 0.05 g/L betaine could produce 17.9% more lactic acid compared to the fermentation without betaine. Beet molasses, which is rich in sucrose and betaine, was utilized in a co-feeding fermentation and raised the productivity by 22%. The efficient lactic acid fermentation by B. coagulans is thus developed by using betaine and beet molasses. PMID:24956474

  16. A clinical trial of combined use of rosiglitazone and 5-aminosalicylate for ulcerative colitis

    PubMed Central

    Liang, Hong-Liang; Ouyang, Qin

    2008-01-01

    AIM: To investigate the therapeutic effects of the combined use of rosiglitazone and aminosalicylate on mild or moderately active ulcerative colitis (UC). METHODS: According to the national guideline for diagnosis and treatment of inflammatory bowel disease (IBD) in China, patients with mild or moderately active UC in our hospital were selected from July to November, 2004. Patients with infectious colitis, amoebiasis, or cardiac, renal or hepatic failure and those who had received corticosteroid or immunosuppressant treatment within the last month were excluded. Following a quasi-randomization principle, patients were allocated alternatively into the treatment group (TG) with rosiglitazone 4 mg/d plus 5-ASA 2 g/d daily or the control group (CG) with 5-ASA 2 g/d alone, respectively, for 4 wk. Clinical changes were evaluated by Mayo scoring system and histological changes by Truelove-Richards’ grading system at initial and final point of treatment. RESULTS: Forty-two patients completed the trial, 21 each in TG and CG. The Mayo scores in TG at initial and final points were 5.87 (range: 4.29-7.43) and 1.86 (range: 1.03-2.69) and those in CG were 6.05 (range: 4.97-7.13) and 2.57 (range: 1.92-3.22) respectively. The decrements of Mayo scores were 4.01 in TG and 3.48 in CG, with a remission rate of 71.4% in TG and 57.1% in CG, respectively. Along with the improvement of disease activity index (DAI), the histological grade improvement was more significant in TG than in CG (P < 0.05). CONCLUSION: Combined treatment with rosiglitazone and 5-ASA achieved better therapeutic effect than 5-ASA alone without any side effects. Rosiglitazone can alleviate colonic inflammation which hopefully becomes a novel agent for UC treatment. PMID:18176972

  17. Persistence to oral 5-aminosalicylate therapy for inflammatory bowel disease in Australia.

    PubMed

    Selinger, Christian P; Kemp, Andrew; Leong, Rupert Wl

    2014-03-01

    Aminosalicylate (5-ASA) is effective treatment for inflammatory bowel diseases (IBDs) but requires continuous maintenance therapy. This study determines persistence of 5-ASA in IBD using national population-based data for Australia from 2002 to 2011 with follow up for 36 months. Non-persistence was defined as failing to fill a prescription for 3 months. Of 12,592 patients those initiated on non-sulphasalazine 5-ASA (2917) had significantly higher persistence (P < 0.001) than those on sulphasalazine (9675). Persistence for sulphasalazine and non-sulphasalazine 5-ASA initiation was 22.3% and 28.5% at 12-months, and 11.9% and 16.2% at 24-months. Sulphasalazine poor persistence continued despite intra-class switch to another 5-ASA. Patients receiving immunomodulator co-therapy had higher persistence (P < 0.001). National population-based data identified persistence to 5-ASA to be low but significantly lower when sulphasalazine is the initial drug. Physicians should stress the importance of long-term 5-ASA therapy as overall drug efficacy especially the 5-ASA chemo-prophylactic benefits may be reduced by non-persistence.

  18. 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…

  19. ENHANCED DISEASE SUSCEPTIBILITY 1 and SALICYLIC ACID act redundantly to regulate resistance gene-mediated signaling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Resistance (R) protein–associated pathways are well known to participate in defense against a variety of microbial pathogens. Salicylic acid (SA) and its associated proteinaceous signaling components, including enhanced disease susceptibility 1 (EDS1), non–race-specific disease resistance 1 (NDR1), ...

  20. Enhanced lignin monomer production caused by cinnamic Acid and its hydroxylated derivatives inhibits soybean root growth.

    PubMed

    Lima, Rogério Barbosa; Salvador, Victor Hugo; dos Santos, Wanderley Dantas; Bubna, Gisele Adriana; Finger-Teixeira, Aline; Soares, Anderson Ricardo; Marchiosi, Rogério; Ferrarese, Maria de Lourdes Lucio; Ferrarese-Filho, Osvaldo

    2013-01-01

    Cinnamic acid and its hydroxylated derivatives (p-coumaric, caffeic, ferulic and sinapic acids) are known allelochemicals that affect the seed germination and root growth of many plant species. Recent studies have indicated that the reduction of root growth by these allelochemicals is associated with premature cell wall lignification. We hypothesized that an influx of these compounds into the phenylpropanoid pathway increases the lignin monomer content and reduces the root growth. To confirm this hypothesis, we evaluated the effects of cinnamic, p-coumaric, caffeic, ferulic and sinapic acids on soybean root growth, lignin and the composition of p-hydroxyphenyl (H), guaiacyl (G) and syringyl (S) monomers. To this end, three-day-old seedlings were cultivated in nutrient solution with or without allelochemical (or selective enzymatic inhibitors of the phenylpropanoid pathway) in a growth chamber for 24 h. In general, the results showed that 1) cinnamic, p-coumaric, caffeic and ferulic acids reduced root growth and increased lignin content; 2) cinnamic and p-coumaric acids increased p-hydroxyphenyl (H) monomer content, whereas p-coumaric, caffeic and ferulic acids increased guaiacyl (G) content, and sinapic acid increased sinapyl (S) content; 3) when applied in conjunction with piperonylic acid (PIP, an inhibitor of the cinnamate 4-hydroxylase, C4H), cinnamic acid reduced H, G and S contents; and 4) when applied in conjunction with 3,4-(methylenedioxy)cinnamic acid (MDCA, an inhibitor of the 4-coumarate:CoA ligase, 4CL), p-coumaric acid reduced H, G and S contents, whereas caffeic, ferulic and sinapic acids reduced G and S contents. These results confirm our hypothesis that exogenously applied allelochemicals are channeled into the phenylpropanoid pathway causing excessive production of lignin and its main monomers. By consequence, an enhanced stiffening of the cell wall restricts soybean root growth.

  1. Gallic Acid, the Active Ingredient of Terminalia bellirica, Enhances Adipocyte Differentiation and Adiponectin Secretion.

    PubMed

    Makihara, Hiroko; Koike, Yuka; Ohta, Masatomi; Horiguchi-Babamoto, Emi; Tsubata, Masahito; Kinoshita, Kaoru; Akase, Tomoko; Goshima, Yoshio; Aburada, Masaki; Shimada, Tsutomu

    2016-01-01

    Visceral obesity induces the onset of metabolic disorders such as insulin resistance and diabetes mellitus. Adipose tissue is considered as a potential pharmacological target for treating metabolic disorders. The fruit of Terminalia bellirica is extensively used in Ayurvedic medicine to treat patients with diseases such as diabetes mellitus. We previously investigated the effects of a hot water extract of T. bellirica fruit (TB) on obesity and insulin resistance in spontaneously obese type 2 diabetic mice. To determine the active ingredients of TB and their molecular mechanisms, we focused on adipocyte differentiation using mouse 3T3-L1 cells, which are widely used to study adipocyte physiology. We show here that TB enhanced the differentiation of 3T3-L1 cells to mature adipocytes and that one of the active main components was identified as gallic acid. Gallic acid (10-30 µM) enhanced the expression and secretion of adiponectin via adipocyte differentiation and also that of fatty acid binding protein-4, which is the target of peroxisome proliferator-activated receptor gamma (PPARγ), although it does not alter the expression of the upstream genes PPARγ and CCAAT enhancer binding protein alpha. In the PPARγ ligand assay, the binding of gallic acid to PPARγ was undetectable. These findings indicate that gallic acid mediates the therapeutic effects of TB on metabolic disorders by regulating adipocyte differentiation. Therefore, TB shows promise as a candidate for preventing and treating patients with metabolic syndrome. PMID:27374289

  2. Gallic Acid, the Active Ingredient of Terminalia bellirica, Enhances Adipocyte Differentiation and Adiponectin Secretion.

    PubMed

    Makihara, Hiroko; Koike, Yuka; Ohta, Masatomi; Horiguchi-Babamoto, Emi; Tsubata, Masahito; Kinoshita, Kaoru; Akase, Tomoko; Goshima, Yoshio; Aburada, Masaki; Shimada, Tsutomu

    2016-01-01

    Visceral obesity induces the onset of metabolic disorders such as insulin resistance and diabetes mellitus. Adipose tissue is considered as a potential pharmacological target for treating metabolic disorders. The fruit of Terminalia bellirica is extensively used in Ayurvedic medicine to treat patients with diseases such as diabetes mellitus. We previously investigated the effects of a hot water extract of T. bellirica fruit (TB) on obesity and insulin resistance in spontaneously obese type 2 diabetic mice. To determine the active ingredients of TB and their molecular mechanisms, we focused on adipocyte differentiation using mouse 3T3-L1 cells, which are widely used to study adipocyte physiology. We show here that TB enhanced the differentiation of 3T3-L1 cells to mature adipocytes and that one of the active main components was identified as gallic acid. Gallic acid (10-30 µM) enhanced the expression and secretion of adiponectin via adipocyte differentiation and also that of fatty acid binding protein-4, which is the target of peroxisome proliferator-activated receptor gamma (PPARγ), although it does not alter the expression of the upstream genes PPARγ and CCAAT enhancer binding protein alpha. In the PPARγ ligand assay, the binding of gallic acid to PPARγ was undetectable. These findings indicate that gallic acid mediates the therapeutic effects of TB on metabolic disorders by regulating adipocyte differentiation. Therefore, TB shows promise as a candidate for preventing and treating patients with metabolic syndrome.

  3. Enhancement of the Electrical Properties of CVD-Grown Graphene with Ascorbic Acid Treatment

    NASA Astrophysics Data System (ADS)

    Tang, Chunmiao; Chen, Zhiying; Zhang, Haoran; Zhang, Yaqian; Zhang, Yanhui; Sui, Yanping; Yu, Guanghui; Cao, Yijiang

    2016-02-01

    Ascorbic acid was used to modify to chemical vapor deposition (CVD)-grown graphene films transferred onto SiO2 substrate. Residual polymer (polymethyl methacrylate), Fe3+, Cl-, H2O, and O2 affected the electrical and thermal properties on graphene during the transfer or device fabrication processes. Exposure of transferred graphene to ascorbic acid resulted in significantly enhanced electrical properties with increased charge carrier mobility. All devices exhibited more than 30% improvement in room temperature carrier mobility in air. The carrier mobility of the treated graphene did not significantly decrease in 21 days. This result can be attributed to electron donation to graphene through the -OH functional group in ascorbic acid that is absorbed in graphene. This work provides a method to enhance the electrical properties of CVD-grown graphene.

  4. Iontophoretic enhancement of leuprolide acetate by fatty acids, limonene, and depilatory lotions through porcine epidermis.

    PubMed

    Rastogi, Sumeet K; Singh, Jagdish

    2004-11-01

    The effect of chemical enhancers (e.g., fatty acids, limonene, depilatory lotions) and iontophoresis was investigated on the in vitro permeability of leuprolide acetate through porcine epidermis. Franz diffusion cells and Scepter iontophoretic power source were used for the percutaneous absorption studies. Anodal iontophoresis was performed at 0.2 mA/cm2 current density. Fatty acids used were palmitic (C16:0), palmitoleic (C16:1), stearic (C18:0), oleic (C18:1), linoleic (C18:2), and linolenic (C18:3) acids. The passive and iontophoretic flux were significantly (p < 0.05) greater through fatty acids-treated porcine epidermis in comparison to the control (untreated epidermis) for leuprolide acetate. The passive and iontophoretic permeability of leuprolide acetate increased with increasing number of cis double bonds. Among the fatty acids tested, linolenic acid (C18:3) exhibited the maximum permeability of leuprolide acetate during passive (51.42 x 10(-4) cm/hr) and iontophoretic (318.98 x 10(-4) cm/hr) transport. The passive and iontophoretic flux of leuprolide acetate were significantly (p < 0.05) greater through the limonene and depilatory lotion treated epidermis in comparison to their respective control. In conclusion, iontophoresis in combination with chemical enhancers synergistically increased (p < 0.05) the in vitro permeability of leuprolide acetate through porcine epidermis.

  5. The Hip Functional Retrieval after Elective Surgery May Be Enhanced by Supplemented Essential Amino Acids

    PubMed Central

    Baldissarro, Eleonora; Aquilani, Roberto; Boschi, Federica; Baiardi, Paola; Iadarola, Paolo; Fumagalli, Marco; Pasini, Evasio; Verri, Manuela; Dossena, Maurizia; Gambino, Arianna; Cammisuli, Sharon; Viglio, Simona

    2016-01-01

    It is not known whether postsurgery systemic inflammation and plasma amino acid abnormalities are still present during rehabilitation of individuals after elective hip arthroplasty (EHA). Sixty subjects (36 females; age 66.58 ± 8.37 years) were randomized to receive 14-day oral EAAs (8 g/day) or a placebo (maltodextrin). At admission to and discharge from the rehabilitation center, serum C-reactive protein (CRP) and venous plasma amino acid concentrations were determined. Post-EHA hip function was evaluated by Harris hip score (HHS) test. Ten matched healthy subjects served as controls. At baseline, all patients had high CRP levels, considerable reduction in several amino acids, and severely reduced hip function (HHS 40.78 ± 2.70 scores). After treatment, inflammation decreased both in the EAA group and in the placebo group. Only EAA patients significantly improved their levels of glycine, alanine, tyrosine, and total amino acids. In addition, they enhanced the rate of hip function recovery (HHS) (from baseline 41.8 ± 1.15 to 76.37 ± 6.6 versus baseline 39.78 ± 4.89 to 70.0 ± 7.1 in placebo one; p = 0.006). The study documents the persistence of inflammation and plasma amino acid abnormalities in post-EHA rehabilitation phase. EAAs enhance hip function retrieval and improve plasma amino acid abnormalities. PMID:27110573

  6. Remediation of TCE-contaminated groundwater using acid/BOF slag enhanced chemical oxidation.

    PubMed

    Tsai, T T; Kao, C M; Wang, J Y

    2011-04-01

    The objective of this study was to evaluate the potential of applying acid/H(2)O(2)/basic oxygen furnace slag (BOF slag) and acid/S(2)O(8)(2-)/BOF slag systems to enhance the chemical oxidation of trichloroethylene (TCE)-contaminated groundwater. Results from the bench-scale study indicate that TCE oxidation via the Fenton-like oxidation process can be enhanced with the addition of BOF slag at low pH (pH=2-5.2) and neutral (pH=7.1) conditions. Because the BOF slag has iron abundant properties (14% of FeO and 6% of Fe(2)O(3)), it can be sustainably reused for the supplement of iron minerals during the Fenton-like or persulfate oxidation processes. Results indicate that higher TCE removal efficiency (84%) was obtained with the addition of inorganic acid for the activation of Fenton-like reaction compared with the experiments with organic acids addition (with efficiency of 10-15% lower) (BOF slag=10gL(-1); initial pH=5.2). This could be due to the fact that organic acids would compete with TCE for available oxidants. Results also indicate that the pH value had a linear correlation with the observed first-order decay constant of TCE, and thus, lower pH caused a higher TCE oxidation rate.

  7. Enhanced isomer purity of lactic acid from the non-sterile fermentation of kitchen wastes.

    PubMed

    Zhang, Bo; He, Pin-Jing; Ye, Ning-Fang; Shao, Li-Ming

    2008-03-01

    In order to improve the purity of lactic acid isomers, the effects of pH, temperature, fermentation time and their interactions on l(+) or d(-)-lactic acid production were evaluated during lactic acid fermentation of the non-sterile kitchen wastes. The results showed that l(+)-lactic acid was the main isomeric form. The isomer purity was much higher at acidic or alkalic pH (non-controlled pH, pH 5 and pH 8) than neutral pH (pH 6 and pH 7). Increasing the fermentation temperature from 35 degrees C to 45 degrees C at pH 7 enhanced the isomer purity from 60:40 to 83:17. The optimal fermentation time for the purity of lactic acid isomers was found to depend on the corresponding pH and temperature. From the response surface analysis, the optimized combination of pH and temperature could obviously increase the l(+)-isomer concentration. It is confirmed that the variation of the isomer purity with pH, temperature and fermentation time change resulted from the substitution of microbial community composition. The lactic acid bacteria and Clostridium sp. dominated the fermentation of non-sterile kitchen wastes, and the emergence and disappearance of lactic acid bacteria which produced l(+)-isomer and Clostridium sp. resulted in the variations of the isomer purity. PMID:17376675

  8. Coexpressing Escherichia coli cyclopropane synthase with Sterculia foetida Lysophosphatidic acid acyltransferase enhances cyclopropane fatty acid accumulation.

    PubMed

    Yu, Xiao-Hong; Prakash, Richa Rawat; Sweet, Marie; Shanklin, John

    2014-01-01

    Cyclopropane fatty acids (CPAs) are desirable as renewable chemical feedstocks for the production of paints, plastics, and lubricants. Toward our goal of creating a CPA-accumulating crop, we expressed nine higher plant cyclopropane synthase (CPS) enzymes in the seeds of fad2fae1 Arabidopsis (Arabidopsis thaliana) and observed accumulation of less than 1% CPA. Surprisingly, expression of the Escherichia coli CPS gene resulted in the accumulation of up to 9.1% CPA in the seed. Coexpression of a Sterculia foetida lysophosphatidic acid acyltransferase (SfLPAT) increases CPA accumulation up to 35% in individual T1 seeds. However, seeds with more than 9% CPA exhibit wrinkled seed morphology and reduced size and oil accumulation. Seeds with more than 11% CPA exhibit strongly decreased seed germination and establishment, and no seeds with CPA more than 15% germinated. That previous reports suggest that plant CPS prefers the stereospecific numbering (sn)-1 position whereas E. coli CPS acts on sn-2 of phospholipids prompted us to investigate the preferred positions of CPS on phosphatidylcholine (PC) and triacylglycerol. Unexpectedly, in planta, E. coli CPS acts primarily on the sn-1 position of PC; coexpression of SfLPAT results in the incorporation of CPA at the sn-2 position of lysophosphatidic acid. This enables a cycle that enriches CPA at both sn-1 and sn-2 positions of PC and results in increased accumulation of CPA. These data provide proof of principle that CPA can accumulate to high levels in transgenic seeds and sets the stage for the identification of factors that will facilitate the movement of CPA from PC into triacylglycerol to produce viable seeds with additional CPA accumulation. PMID:24204024

  9. Enhanced succinic acid production in Aspergillus saccharolyticus by heterologous expression of fumarate reductase from Trypanosoma brucei.

    PubMed

    Yang, Lei; Lübeck, Mette; Ahring, Birgitte K; Lübeck, Peter S

    2016-02-01

    Aspergillus saccharolyticus exhibits great potential as a cell factory for industrial production of dicarboxylic acids. In the analysis of the organic acid profile, A. saccharolyticus was cultivated in an acid production medium using two different pH conditions. The specific activities of the enzymes, pyruvate carboxylase (PYC), malate dehydrogenase (MDH), and fumarase (FUM), involved in the reductive tricarboxylic acid (rTCA) branch, were examined and compared in cells harvested from the acid production medium and a complete medium. The results showed that ambient pH had a significant impact on the pattern and the amount of organic acids produced by A. saccharolyticus. The wild-type strain produced higher amount of malic acid and succinic acid in the pH buffered condition (pH 6.5) compared with the pH non-buffered condition. The enzyme assays showed that the rTCA branch was active in the acid production medium as well as the complete medium, but the measured enzyme activities were different depending on the media. Furthermore, a soluble NADH-dependent fumarate reductase gene (frd) from Trypanosoma brucei was inserted and expressed in A. saccharolyticus. The expression of the frd gene led to an enhanced production of succinic acid in frd transformants compared with the wild-type in both pH buffered and pH non-buffered conditions with highest amount produced in the pH buffered condition (16.2 ± 0.5 g/L). This study demonstrates the feasibility of increasing succinic acid production through the cytosolic reductive pathway by genetic engineering in A. saccharolyticus.

  10. pH dependence of methyl phosphonic acid, dipicolinic acid, and cyanide by surface-enhanced Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Farquharson, Stuart; Gift, Alan; Maksymiuk, Paul; Inscore, Frank E.; Smith, Wayne W.

    2004-03-01

    U.S. and Coalition forces fighting terrorism in Afghanistan and Iraq must consider a wide range of attack scenarios in addition to car bombings. Among these is the intentional poisoning of water supplies to obstruct military operations. To counter such attacks, the military is developing portable analyzers that can identify and quantify potential chemical agents in water supplies at microgram per liter concentrations within 10 minutes. To aid this effort we have been investigating the value of a surface-enhanced Raman spectroscopy based portable analyzer. In particular we have been developing silver-doped sol-gels to generate SER spectra of chemical agents and their hydrolysis products. Here we present SER spectra of methyl phosphonic acid and cyanide as a function of pH, an important factor affecting quantitation measurements, which to our knowledge has not been examined. In addition, dipicolinic acid, a chemical signature associated with anthrax-causing spores, is also presented.

  11. Humic acids enhance the microbially mediated release of sedimentary ferrous iron.

    PubMed

    Chang, Chun-Han; Wei, Chia-Cheng; Lin, Li-Hung; Tu, Tzu-Hsuan; Liao, Vivian Hsiu-Chuan

    2016-03-01

    Iron (Fe) is an essential element for many organisms, but high concentrations of iron can be toxic. The complex relation between iron, arsenic (As), bacteria, and organic matter in sediments and groundwater is still an issue of environmental concern. The present study addresses the effects of humic acids and microorganisms on the mobilization of iron in sediments from an arsenic-affected area, and the microbial diversity was analyzed. The results showed that the addition of 50, 100, and 500 mg/L humic acids enhanced ferrous iron (Fe(II)) release in a time-dependent and dose-dependent fashion under anaerobic conditions. A significant increase in the soluble Fe(II) concentrations occurred in the aqueous phases of the samples during the first 2 weeks, and aqueous Fe(II) reached its maximum concentrations after 8 weeks at the following Fe(II) concentrations: 28.95 ± 1.16 mg/L (original non-sterilized sediments), 32.50 ± 0.71 mg/L (50 mg/L humic acid-amended, non-sterilized sediments), 37.50 ± 1.85 mg/L (100 mg/L humic acid-amended, non-sterilized sediments), and 39.00 ± 0.43 mg/L (500 mg/L humic acid-amended, non-sterilized sediments). These results suggest that humic acids can further enhance the microbially mediated release of sedimentary iron under anaerobic conditions. By contrast, very insignificant amounts of iron release were observed from sterilized sediments (the abiotic controls), even with the supplementation of humic acids under anaerobic incubation. In addition, the As(III) release was increased from 50 ± 10 μg/L (original non-sterilized sediments) to 110 ± 45 μg/L (100 mg/L humic acid-amended, non-sterilized sediments) after 8 weeks of anaerobic incubation. Furthermore, a microbial community analysis indicated that the predominant class was changed from Alphaproteobacteria to Deltaproteobacteria, and clearly increased populations of Geobacter sp., Paludibacter sp., and Methylophaga sp. were found after adding humic acids

  12. Enhanced rosmarinic acid production in cultured plants of two species of Mentha.

    PubMed

    Roy, Debleena; Mukhopadhyay, Sandip

    2012-11-01

    In the present investigation an attempt has been made to enhance rosmarinic acid level in plants, grown in vitro, of 2 species of Mentha in presence of 2 precursors in the nutrient media during culture. For in vitro culture establishment and shoot bud multiplication, MS basal media were used supplemented with different concentrations and combinations of different growth regulator like NAA (alpha-napthaleneacetic acid), BAP (6-benzylaminopurine). The medium containing NAA (0.25 mg/L) and BAP (2.5 mg/L) gave the highest potentiality of shoot formation (average 58.0 numbers of shoots) per explant for Mentha piperita L. and the medium containing BAP (2.0 mg/L) gave the highest potentiality of shoot (average 19.2 numbers of shoots) formation per explant for Mentha arvensis L. The complete plants were regenerated in above mentioned media after 8 weeks of subculture. For in vitro enhancement of rosmarinic acid production, the 2 precursors tyrosine (Tyr) and phenylalanine (Phe) were added in the nutrient media at different levels (0.5 mg/L to 15.0 mg/L). Tyrosine was found to be very effective for augmenting rosmarinic acid content in Mentha piperita L. It nearly increased the production up to 1.77 times. In case of Mentha arvensis L., phenylalanine significantly affected the production of rosmarinic acid and the production was nearly 2.03 times more than the control. No significant increase in biomass was observed after addition of these precursors indicating that the added amino acids acting as precursors for rosmarinic acid synthesis were readily utilized in producing rosmarinic acid without promoting growth. Total protein profile also revealed the presence of a specific band in polyacrylamide gel electrophoresis.

  13. Enhanced Extracorporeal CO2 Removal by Regional Blood Acidification: Effect of Infusion of Three Metabolizable Acids.

    PubMed

    Scaravilli, Vittorio; Kreyer, Stefan; Linden, Katharina; Belenkiy, Slava; Pesenti, Antonio; Zanella, Alberto; Cancio, Leopoldo C; Batchinsky, Andriy I

    2015-01-01

    Acidification of blood entering a membrane lung (ML) with lactic acid enhances CO2 removal (VCO2ML). We compared the effects of infusion of acetic, citric, and lactic acids on VCO2ML. Three sheep were connected to a custom-made circuit, consisting of a Hemolung device (Alung Technologies, Pittsburgh, PA), a hemofilter (NxStage, NxStage Medical, Lawrence, MA), and a peristaltic pump recirculating ultrafiltrate before the ML. Blood flow was set at 250 ml/min, gas flow (GF) at 10 L/min, and recirculating ultrafiltrate flow at 100 ml/min. Acetic (4.4 M), citric (0.4 M), or lactic (4.4 M) acids were infused in the ultrafiltrate at 1.5 mEq/min, for 2 hours each, in randomized fashion. VCO2ML was measured by the Hemolung built-in capnometer. Circuit and arterial blood gas samples were collected at baseline and during acid infusion. Hemodynamics and ventilation were monitored. Acetic, citric, or lactic acids similarly enhanced VCO2ML (+35%), from 37.4 ± 3.6 to 50.6 ± 7.4, 49.8 ± 5.6, and 52.0 ± 8.2 ml/min, respectively. Acids similarly decreased pH, increased pCO2, and reduced HCO3 of the post-acid extracorporeal blood sample. No significant effects on arterial gas values, ventilation, or hemodynamics were observed. In conclusion, it is possible to increase VCO2ML by more than one-third using any one of the three metabolizable acids.

  14. Novel dry powder inhaler formulation of glucagon with addition of citric acid for enhanced pulmonary delivery.

    PubMed

    Onoue, Satomi; Yamamoto, Kiyoshi; Kawabata, Yohei; Hirose, Mariko; Mizumoto, Takahiro; Yamada, Shizuo

    2009-12-01

    Glucagon, a gut hormone, is one of the key regulatory elements in glucose homeostasis, and is clinically used for treatment of hypoglycemia and premedication in peroral endoscopy. Dry powder inhaler (DPI) form of glucagon is believed to be a promising new dosage form, and the present study aimed to develop a novel glucagon-DPI using absorption enhancer for improved pharmacological effects. The cytotoxicity of citric and capric acids, the potential absorption enhancers, at 1 and 10 mM was assessed by monitoring extracellular LDH levels in rat alveolar L2 cells, and a concentration- and time-dependent release of LDH was observed in capric acid, but not in citric acid-treated cells. DPI form of glucagon containing citric acid was prepared with a jet mill, and laser diffraction and cascade impactor analyses of the newly developed glucagon-DPI suggested high dispersion and deposition in the respiratory organs with an emitted dose and fine particle fraction of 99.5 and 25%, respectively. Addition of citric acid in glucagon-DPI improved the dissolution behavior, and did not impair the solid-state stability of glucagon-DPI. Intratracheal administration of glucagon-DPI (50 microg-glucagon/kg body weight of rat) containing citric acid led to 2.9-fold more potent hyperglycemic effect in rats, as compared to inhaled glucagon-DPI without citric acid. Based on these physicochemical and pharmacological characterization, the dry powder inhaler of glucagon with addition of citric acid would be of use as an alternative to injection form.

  15. The enhancement of pipemidic acid permeation into the pig urinary bladder wall.

    PubMed

    Kerec, M; Svigelj, V; Bogataj, M; Mrhar, A

    2002-06-20

    The influence of interactions between polycarbophil and calcium on a model drug permeation into the pig urinary bladder wall was investigated. Pipemidic acid was used as a model drug. One percent w/v polycarbophil dispersion significantly increases the permeation of pipemidic acid into the urinary bladder wall. The enhanced absorption of pipemidic acid caused by polycarbophil is significantly less pronounced in polycarbophil dispersions containing calcium. The enhancement of pipemidic acid permeation into the urinary bladder wall could be due to the opening of tight junctions, which causes higher paracellular permeability. In the case of polycarbophil dispersion with calcium some carboxylic groups of polymer are already occupied with calcium, present in the dispersions. As a consequence extracellular calcium binds to polycarbophil in lower extent if compared with polycarbophil dispersion without calcium and transport is increased to a lesser degree. We concluded that the mechanism of drug absorption enhancement caused by polycarbophil could be similar for urinary bladder as described in the literature for intestinal mucosa.

  16. Mechanism for the Enhanced Excited-State Lewis Acidity of Methyl Viologen.

    PubMed

    Hohenstein, Edward G

    2016-02-17

    Aqueous solutions of methyl viologen (MV(2+)) exhibit anomalous fluorescence behavior. Although it has long fluorescence lifetimes in polar solvents such as acetonitrile, MV(2+) has a short fluorescence lifetime in water. Recent experiments by Kohler and co-workers (Henrich et al. J. Phys. Chem. B 2015, 119, 2737-2748) have implicated an excited-state acid/base reaction as the source of the nonradiative decay pathway. While many chemical species exhibit enhanced Brønsted acidity in their excited state, MV(2+) is the first example of a species with enhanced Lewis acidity. Using a complete active space configuration interaction (CASCI) approach, excited-state molecular dynamics simulations of aqueous MV(2+) are performed in order to test the hypothesis that MV(2+) acts as a Lewis photoacid and to elucidate a mechanism for this behavior. These simulations show that the Lewis acidity of MV(2+) is indeed enhanced by photoexcitation. On its S1 excited state, MV(2+) reacts with water to generate a hydronium ion approximately 1.5 ps after excitation. After the hydronium ion is produced, the corresponding hydroxide ion adds to MV(2+) to form a covalently bound photoproduct and, subsequently, evolves toward a conical intersection.

  17. Nanoparticle-enhanced fluorescence emission for non-separation assays of carbohydrates using a boronic acid-alizarin complex.

    PubMed

    Li, Qianjin; Kamra, Tripta; Ye, Lei

    2016-03-01

    Addition of crosslinked polymer nanoparticles into a solution of a 3-nitrophenylboronic acid-alizarin complex leads to significant enhancement of fluorescence emission. Using the nanoparticle-enhanced boronic acid-alizarin system has improved greatly the sensitivity and extended the dynamic range of separation-free fluorescence assays for carbohydrates.

  18. Radiation induces acid tolerance of Clostridium tyrobutyricum and enhances bioproduction of butyric acid through a metabolic switch

    PubMed Central

    2014-01-01

    Background Butyric acid as a renewable resource has become an increasingly attractive alternative to petroleum-based fuels. Clostridium tyrobutyricum ATCC 25755T is well documented as a fermentation strain for the production of acids. However, it has been reported that butyrate inhibits its growth, and the accumulation of acetate also inhibits biomass synthesis, making production of butyric acid from conventional fermentation processes economically challenging. The present study aimed to identify whether irradiation of C. tyrobutyricum cells makes them more tolerant to butyric acid inhibition and increases the production of butyrate compared with wild type. Results In this work, the fermentation kinetics of C. tyrobutyricum cultures after being classically adapted for growth at 3.6, 7.2 and 10.8 g·L-1 equivalents were studied. The results showed that, regardless of the irradiation used, there was a gradual inhibition of cell growth at butyric acid concentrations above 10.8 g·L-1, with no growth observed at butyric acid concentrations above 3.6 g·L-1 for the wild-type strain during the first 54 h of fermentation. The sodium dodecyl sulfate polyacrylamide gel electrophoresis also showed significantly different expression levels of proteins with molecular mass around the wild-type and irradiated strains. The results showed that the proportion of proteins with molecular weights of 85 and 106 kDa was much higher for the irradiated strains. The specific growth rate decreased by 50% (from 0.42 to 0.21 h-1) and the final concentration of butyrate increased by 68% (from 22.7 to 33.4 g·L-1) for the strain irradiated at 114 AMeV and 40 Gy compared with the wild-type strains. Conclusions This study demonstrates that butyric acid production from glucose can be significantly improved and enhanced by using 12C6+ heavy ion-irradiated C. tyrobutyricum. The approach is economical, making it competitive compared with similar fermentation processes. It may prove useful as

  19. Mechanism of action of 5-arninosalicylic acid

    PubMed Central

    Greenfield, S. M.; Thompson, R. P. H.

    1992-01-01

    5-Aminosalicylic Acid (5-ASA) has been used for over 50 years in the treatment of inflammatory bowel disease in the pro-drug form sulphasalazine (SASP). SASP is also used to treat rheumatoid arthritis. However whether the therapeutic properties of SASP are due to the intact molecule, the 5-ASA or sulphapyridine components is unknown. Several mechanisms of action have been proposed for 5-ASA and SASP including interference in the metabolism of arachidonic acid to prostaglandins and leukotrienes, scavenging,of reactive oxygen species, effects on leucocyte function and production of cytokines. However, it is unlikely that the anti-inflammatory properties of SASP and 5-ASA are due to several different properties but more likely that a single property of 5-ASA explains the theraapeutic effects of 5-ASA and SASP. Reactive oxygen species (ROS) are involved in the metabolism of prostaglandins and leukotrienes and can act as second messengers, and so the scavenging of ROS may be the single mechanism of action of 5-ASA that gives rise to its antiinflammatory effects in both inflammatory bowel disease and rheumatoid arthritis. PMID:18475455

  20. Maximizing the electromagnetic and chemical resonances of surface-enhanced Raman scattering for nucleic acids.

    PubMed

    Freeman, Lindsay M; Pang, Lin; Fainman, Yeshaiahu

    2014-08-26

    Although surface-enhanced Raman spectroscopy (SERS) has previously been performed with nucleic acids, the measured intensities for each nucleic acid have varied significantly depending on the SERS substrate and excitation wavelength. We have demonstrated that the charge-transfer (CT) mechanism, also known as the chemical enhancement of SERS, is responsible for the discrepancies previously reported in literature. The electronic states of cytosine and guanine attached to silver atoms are computationally calculated and experimentally measured to be in the visible range, which leads to a resonance Raman effect at the corresponding maximum wavelengths. The resulting SERS measurements are in good agreement with the simulated values, in which cytosine-silver shows stronger enhancement at 532 nm and guanine-silver shows stronger enhancement at 785 nm. An atomic layer of aluminum oxide is deposited on substrates to prevent charge-transfer, and corresponding measurements show weaker Raman signals caused by the suppression of the chemical resonance. These findings suggest the optimal SERS signal can be achieved by tuning the excitation wavelength to match both the electromagnetic and chemical resonances, paving the way for future single molecule detection of nucleic acids other than adenine.

  1. Enhanced Synthesis of Alkyl Amino Acids in Miller's 1958 H2S Experiment

    NASA Technical Reports Server (NTRS)

    Parker, Eric T.; Cleaves, H. James; Callahan, Michael P.; Dworkin, James P.; Glavin, Daniel P.; Lazcano, Antonio; Bada, Jeffrey L.

    2011-01-01

    Stanley Miller's 1958 H2S-containing experiment, which included a simulated prebiotic atmosphere of methane (CH4), ammonia (NH3), carbon dioxide (CO2), and hydrogen sulfide (H2S) produced several alkyl amino acids, including the alpha-, beta-, and gamma-isomers of aminobutyric acid (ABA) in greater relative yields than had previously been reported from his spark discharge experiments. In the presence of H2S, aspariic and glutamic acids could yield alkyl amino acids via the formation of thioimide intermediates. Radical chemistry initiated by passing H2S through a spark discharge could have also enhanced alkyl amino acid synthesis by generating alkyl radicals that can help form the aldehyde and ketone precursors to these amino acids. We propose mechanisms that may have influenced the synthesis of certain amino acids in localized environments rich in H2S and lightning discharges, similar to conditions near volcanic systems on the early Earth, thus contributing to the prebiotic chemical inventory of the primordial Earth.

  2. Ligand-enhanced electrokinetic remediation of metal-contaminated marine sediments with high acid buffering capacity.

    PubMed

    Masi, Matteo; Iannelli, Renato; Losito, Gabriella

    2016-06-01

    The suitability of electrokinetic remediation for removing heavy metals from dredged marine sediments with high acid buffering capacity was investigated. Laboratory-scale electrokinetic remediation experiments were carried out by applying two different voltage gradients to the sediment (0.5 and 0.8 V/cm) while circulating water or two different chelating agents at the electrode compartments. Tap water, 0.1 M citric acid and 0.1 M ethylenediaminetetraacetic acid (EDTA) solutions were used respectively. The investigated metals were Zn, Pb, V, Ni and Cu. In the unenhanced experiment, the acid front could not propagate due to the high acid buffering capacity of the sediments; the production of OH(-) ions at the cathode resulted in a high-pH environment causing the precipitation of CaCO3 and metal hydroxides. The use of citric acid prevented the formation of precipitates, but solubilisation and mobilisation of metal species were not sufficiently achieved. Metal removal was relevant when EDTA was used as the conditioning agent, and the electric potential was raised up to 0.8 V/cm. EDTA led to the formation of negatively charged complexes with metals which migrated towards the anode compartment by electromigration. This result shows that metal removal from sediments with high acid buffering capacity may be achieved by enhancing the electrokinetic process by EDTA addition when the acidification of the medium is not economically and/or environmentally sustainable. PMID:26490900

  3. Enhanced synthesis of alkyl amino acids in Miller's 1958 H2S experiment.

    PubMed

    Parker, Eric T; Cleaves, H James; Callahan, Michael P; Dworkin, Jason P; Glavin, Daniel P; Lazcano, Antonio; Bada, Jeffrey L

    2011-12-01

    Stanley Miller's 1958 H(2)S-containing experiment, which included a simulated prebiotic atmosphere of methane (CH(4)), ammonia (NH(3)), carbon dioxide (CO(2)), and hydrogen sulfide (H(2)S) produced several alkyl amino acids, including the α-, β-, and γ-isomers of aminobutyric acid (ABA) in greater relative yields than had previously been reported from his spark discharge experiments. In the presence of H(2)S, aspartic and glutamic acids could yield alkyl amino acids via the formation of thioimide intermediates. Radical chemistry initiated by passing H(2)S through a spark discharge could have also enhanced alkyl amino acid synthesis by generating alkyl radicals that can help form the aldehyde and ketone precursors to these amino acids. We propose mechanisms that may have influenced the synthesis of certain amino acids in localized environments rich in H(2)S and lightning discharges, similar to conditions near volcanic systems on the early Earth, thus contributing to the prebiotic chemical inventory of the primordial Earth. PMID:22139514

  4. Enhancing fluorescence intensity of Ellagic acid in Borax-HCl-CTAB micelles

    NASA Astrophysics Data System (ADS)

    Wang, Feng; Huang, Wei; Zhang, Shuai; Liu, Guokui; Li, Kexiang; Tang, Bo

    2011-03-01

    Ellagic acid (C 14H 6O 8), a naturally occurring phytochemical, found mainly in berries and some nuts, has anticarcinogenic and antioxidant properties. It is found that fluorescence of Ellagic acid (EA) is greatly enhanced by micelle of cetyltrimethylammonium bromide (CTAB) surfactant. Based on this effect, a sensitive proposed fluorimetric method was applied for the determination of Ellagic acid in aqueous solution. In the Borax-HCl buffer, the fluorescence intensity of Ellagic acid in the presence of CTAB is proportional to the concentration of Ellagic acid in range from 8.0 × 10 -10 to 4.0 × 10 -5 mol L -1; and the detection limits are 3.2 × 10 -10 mol L -1 and 5.9 × 10 -10 mol L -1 excited at 266 nm and 388 nm, respectively. The actual samples of pomegranate rinds are simply manipulated and satisfactorily determined. The interaction mechanism studies argue that the negative EA-Borax complex is formed and solubilized in the cationic surfactant CTAB micelle in this system. The fluorescence intensity of EA enhances because the CTAB micelle provides a hydrophobic microenvironment for EA-Borax complex, which can prevent collision with water molecules and decrease the energy loss of EA-Borax complex.

  5. Enhancing fluorescence intensity of Ellagic acid in Borax-HCl-CTAB micelles.

    PubMed

    Wang, Feng; Huang, Wei; Zhang, Shuai; Liu, Guokui; Li, Kexiang; Tang, Bo

    2011-03-01

    Ellagic acid (C(14)H(6)O(8)), a naturally occurring phytochemical, found mainly in berries and some nuts, has anticarcinogenic and antioxidant properties. It is found that fluorescence of Ellagic acid (EA) is greatly enhanced by micelle of cetyltrimethylammonium bromide (CTAB) surfactant. Based on this effect, a sensitive proposed fluorimetric method was applied for the determination of Ellagic acid in aqueous solution. In the Borax-HCl buffer, the fluorescence intensity of Ellagic acid in the presence of CTAB is proportional to the concentration of Ellagic acid in range from 8.0×10(-10) to 4.0×10(-5) mol L(-1); and the detection limits are 3.2×10(-10) mol L(-1) and 5.9×10(-10) mol L(-1) excited at 266 nm and 388 nm, respectively. The actual samples of pomegranate rinds are simply manipulated and satisfactorily determined. The interaction mechanism studies argue that the negative EA-Borax complex is formed and solubilized in the cationic surfactant CTAB micelle in this system. The fluorescence intensity of EA enhances because the CTAB micelle provides a hydrophobic microenvironment for EA-Borax complex, which can prevent collision with water molecules and decrease the energy loss of EA-Borax complex.

  6. Arabidopsis ENHANCED DISEASE SUSCEPTIBILITY1 promotes systemic acquired resistance via azelaic acid and its precursor 9-oxo nonanoic acid.

    PubMed

    Wittek, Finni; Hoffmann, Thomas; Kanawati, Basem; Bichlmeier, Marlies; Knappe, Claudia; Wenig, Marion; Schmitt-Kopplin, Philippe; Parker, Jane E; Schwab, Wilfried; Vlot, A Corina

    2014-11-01

    Systemic acquired resistance (SAR) is a form of inducible disease resistance that depends on salicylic acid and its upstream regulator ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1). Although local Arabidopsis thaliana defence responses activated by the Pseudomonas syringae effector protein AvrRpm1 are intact in eds1 mutant plants, SAR signal generation is abolished. Here, the SAR-specific phenotype of the eds1 mutant is utilized to identify metabolites that contribute to SAR. To this end, SAR bioassay-assisted fractionation of extracts from the wild type compared with eds1 mutant plants that conditionally express AvrRpm1 was performed. Using high-performance liquid chromatography followed by mass spectrometry, systemic immunity was associated with the accumulation of 60 metabolites, including the putative SAR signal azelaic acid (AzA) and its precursors 9-hydroperoxy octadecadienoic acid (9-HPOD) and 9-oxo nonanoic acid (ONA). Exogenous ONA induced SAR in systemic untreated leaves when applied at a 4-fold lower concentration than AzA. The data suggest that in planta oxidation of ONA to AzA might be partially responsible for this response and provide further evidence that AzA mobilizes Arabidopsis immunity in a concentration-dependent manner. The AzA fragmentation product pimelic acid did not induce SAR. The results link the C9 lipid peroxidation products ONA and AzA with systemic rather than local resistance and suggest that EDS1 directly or indirectly promotes the accumulation of ONA, AzA, or one or more of their common precursors possibly by activating one or more pathways that either result in the release of these compounds from galactolipids or promote lipid peroxidation.

  7. Morphology-dependent Electrochemical Enhancements of Porous Carbon as Sensitive Determination Platform for Ascorbic Acid, Dopamine and Uric Acid

    PubMed Central

    Cheng, Qin; Ji, Liudi; Wu, Kangbing; Zhang, Weikang

    2016-01-01

    Using starch as the carbon precursor and different-sized ZnO naoparticles as the hard template, a series of porous carbon materials for electrochemical sensing were prepared. Experiments of scanning electron microscopy, transmission electron microscopy and Nitrogen adsorption-desorption isotherms reveal that the particle size of ZnO has big impacts on the porous morphology and surface area of the resulting carbon materials. Through ultrasonic dispersion of porous carbon and subsequent solvent evaporation, different sensing interfaces were constructed on the surface of glassy carbon electrode (GCE). The electrochemical behaviors of ascorbic acid (AA), dopamine (DA) and uric acid (UA) were studied. On the surface of porous carbon materials, the accumulation efficiency and electron transfer ability of AA, DA and UA are improved, and consequently their oxidation signals enhance greatly. Moreover, the interface enhancement effects of porous carbon are also controlled by the particle size of hard template. The constructed porous carbon interface displays strong signal amplification ability and holds great promise in constructing a sensitive platform for the simultaneous determination of AA, DA and UA. PMID:26924080

  8. Morphology-dependent Electrochemical Enhancements of Porous Carbon as Sensitive Determination Platform for Ascorbic Acid, Dopamine and Uric Acid

    NASA Astrophysics Data System (ADS)

    Cheng, Qin; Ji, Liudi; Wu, Kangbing; Zhang, Weikang

    2016-02-01

    Using starch as the carbon precursor and different-sized ZnO naoparticles as the hard template, a series of porous carbon materials for electrochemical sensing were prepared. Experiments of scanning electron microscopy, transmission electron microscopy and Nitrogen adsorption-desorption isotherms reveal that the particle size of ZnO has big impacts on the porous morphology and surface area of the resulting carbon materials. Through ultrasonic dispersion of porous carbon and subsequent solvent evaporation, different sensing interfaces were constructed on the surface of glassy carbon electrode (GCE). The electrochemical behaviors of ascorbic acid (AA), dopamine (DA) and uric acid (UA) were studied. On the surface of porous carbon materials, the accumulation efficiency and electron transfer ability of AA, DA and UA are improved, and consequently their oxidation signals enhance greatly. Moreover, the interface enhancement effects of porous carbon are also controlled by the particle size of hard template. The constructed porous carbon interface displays strong signal amplification ability and holds great promise in constructing a sensitive platform for the simultaneous determination of AA, DA and UA.

  9. Enhanced level of n-3 fatty acid in membrane phospholipids induces lipid peroxidation in rats fed dietary docosahexaenoic acid oil.

    PubMed

    Song, J H; Miyazawa, T

    2001-03-01

    The effect of dietary docosahexaenoic acid (DHA, 22:6n-3) oil with different lipid types on lipid peroxidation was studied in rats. Each group of male Sprague-Dawley rats was pair fed 15% (w/w) of either DHA-triglycerides (DHA-TG), DHA-ethyl esters (DHA-EE) or DHA-phospholipids (DHA-PL) for up to 3 weeks. The palm oil (supplemented with 20% soybean oil) diet without DHA was fed as the control. Dietary DHA oils lowered plasma triglyceride concentrations in rats fed DHA-TG (by 30%), DHA-EE (by 45%) and DHA-PL (by 27%), compared to control. The incorporation of dietary DHA into plasma and liver phospholipids was more pronounced in the DHA-TG and DHA-EE group than in the DHA-PL group. However, DHA oil intake negatively influenced lipid peroxidation in both plasma and liver. Phospholipid peroxidation in plasma and liver was significantly higher than control in rats fed DHA-TG or DHA-EE, but not DHA-PL. These results are consistent with increased thiobarbituric acid reactive substances (TBARS) and decreased alpha-tocopherol levels in plasma and liver. In addition, liver microsomes from rats of each group were exposed to a mixture of chelated iron (Fe(3+)/ADP) and NADPH to determine the rate of peroxidative damage. During NADPH-dependent peroxidation of microsomes, the accumulation of phospholipid hydroperoxides, as well as TBARS, were elevated and alpha-tocopherol levels were significantly exhausted in DHA-TG and DHA-EE groups. During microsomal lipid peroxidation, there was a greater loss of n-3 fatty acids (mainly DHA) than of n-6 fatty acids, including arachidonic acid (20:4n-6). These results indicate that polyunsaturation of n-3 fatty acids is the most important target for lipid peroxidation. This suggests that the ingestion of large amounts of DHA oil enhances lipid peroxidation in the target membranes where greater amounts of n-3 fatty acids are incorporated, thereby increasing the peroxidizability and possibly accelerating the atherosclerotic process.

  10. Status of fatty acids as skin penetration enhancers-a review.

    PubMed

    Mittal, Ashu; Sara, U V S; Ali, Asgar; Aqil, Mohd

    2009-07-01

    Novel techniques for drug delivery have been investigated in human medicine in recent years. The transdermal route of drug delivery has attracted researchers due to many biomedical advantages associated with it. However, excellent impervious nature of skin is the greatest challenge that has to be overcome for successfully delivering drug molecules to the systemic circulation by this route. One long-standing approach for improving transdermal drug delivery uses penetration enhancers (also called sorption promoters or accelerants) that can reversibly compromise the skin's barrier function and consequently allow the entry of otherwise poorly penetrating molecules into the membrane and through to the systemic circulation. A large number of fatty acids have been used as permeation enhancers. They have proven to be effective and safe sorption promoters. This present review includes the classification, feasibility and application of fatty acids as sorption promoters for improved delivery of drug through skin. PMID:19604141

  11. Enhancement of taxol-induced apoptosis by inhibition of NF-κB with ursorlic acid

    NASA Astrophysics Data System (ADS)

    Li, Yunlong; Xing, Da

    2007-05-01

    Taxol is known to inhibit cell growth and triggers significant apoptosis in various cancer cells, and activation of proliferation factor NF-κB during Taxol-induced apoptosis is regarded as a main reason resulting in tumor cells resistance to Taxol. It has been found that ursorlic acid can inhibit the activation of NF-κB. In order to study whether ursorlic acid can enhance the Taxol-induced apoptosis, we use fluorescence resonance energy transfer (FRET) technique and probe SCAT3 to compare the difference of caspase-3 activation between Taxol alone and Taxol combined ursorlic acid. With laser scanning confocal microscopy, we find that ursorlic acid, a nontoxic food component, sensitizes ASTC-a-1 cells more efficiently to Taxol-induced apoptosis by advanced activation of caspase 3. The result also suggests that there would be a synergistic effect between Taxol and ursorlic acid, and the more detailed mechanism of synergistic effect needs to be clarified further, such as the correlations among NF-κB, Akt, caspase 8, which leads to the advanced activation of caspase 3 during combined treatment of Taxol and ursorlic acid. Moreover, this may be a new way to improve Taxol-dependent tumor therapy.

  12. Enhanced succinic acid production from corncob hydrolysate by microbial electrolysis cells.

    PubMed

    Zhao, Yan; Cao, Weijia; Wang, Zhen; Zhang, Bowen; Chen, Kequan; Ouyang, Pingkai

    2016-02-01

    In this study, Actinobacillus succinogenes NJ113 microbial electrolysis cells (MECs) were used to enhance the reducing power responsible for succinic acid production from corncob hydrolysate. During corncob hydrolysate fermentation, electric MECs resulted in a 1.31-fold increase in succinic acid production and a 1.33-fold increase in the reducing power compared with those in non-electric MECs. When the hydrolysate was detoxified by combining Ca(OH)2, NaOH, and activated carbon, succinic acid production increased from 3.47 to 6.95 g/l. Using a constant potential of -1.8 V further increased succinic acid production to 7.18 g/l. A total of 18.09 g/l of succinic acid and a yield of 0.60 g/g total sugar were obtained after a 60-h fermentation when NaOH was used as a pH regulator. The improved succinic acid yield from corncob hydrolysate fermentation using A. succinogenes NJ113 in electric MECs demonstrates the great potential of using biomass as a feedstock to cost-effectively produce succinate. PMID:26708482

  13. Surface-enhanced Raman scattering (SERS) spectroscopy technique for lactic acid in serum measurement

    NASA Astrophysics Data System (ADS)

    Chiang, Hui Hua Kenny; Hsu, Po Hsiang

    2005-08-01

    Highly sensitive measurement of biomolecules is very important in clinical diagnosis and biomedical sensing. Spectroscopic methods have played important roles in biomedical sensing system developments. Recent development in surface enhanced Raman scattering (SERS) method has greatly enhanced the weak Raman signals of biomolecules and has provided great potentials for real time measurement of biomolecules of body fluid. In addition, Raman measurement has the advantage of not requiring extrinsic fluorescent marker for labeling purpose. In this study, we have pioneered in the development of SERS spectroscopic measurement technique for serum lactic acid, which is one of the most important metabolic parameter in blood. We have fabricated Ag colloidal nanoparticles to enhance the weak Raman signal of lactic acid in serum. The diameter of the Ag nanoparticle is 20 nm, the nanoparticles concentration is 109particles/ml. We have observed the SERS characteristic peak of lactic acid at 1285~1480cm-1 under 632.8 nm HeNe laser excitation. We have demonstrated the measurement of the lactic acid in filtered serum in the physiological concentration range 5x10-3~22x10-3 mole/L, which is hundred times lower than the detectible range using traditional Raman approach. The serum samples with were measured in a specially designed reflector type sample holder to form a multiple reflection of excitation laser through the sample, between a reflector and a notch filter. In conclusion, this research demonstrates the feasibility of using Ag SERS technique for measuring the lactic acid at physical concentration and establishes the platform technique for human body fluid measurements.

  14. Fluorescence enhancement of glutaraldehyde functionalized polyaniline nanofibers in the presence of aromatic amino acids.

    PubMed

    Borah, Rajiv; Kumar, Ashok

    2016-04-01

    Polyaniline nanofibers (PNFs) synthesized by dilute polymerization method have been surface functionalized with glutaraldehyde at their N-terminals in Phosphate Buffered Saline (PBS) at P(H)=7.4 in order to achieve improved interaction of surface functionalized polyaniline nanofibers (SF-PNFs) with aromatic amino acids-Tyrosine, Tryptophan and Phenylalanine through incorporation of aldehyde (-CHO) and hydroxyl (-OH) functionalities. HRTEM reveals nanofibers of average diameter of 35.66 nm. FESEM depicts interconnected networks of nanofibers of polyaniline (PAni). UV-visible absorption and Fluorescence spectroscopy indicate that the PNFs and SF-PNFs are in emeraldine base (EB) form. FT-IR, (1)H NMR spectroscopy suggests covalent interactions of SF-PNFs with aromatic amino acids and possible reaction mechanisms have been proposed based on these results. Remarkable enhancement in fluorescence signals of SF-PNFs in the presence of aromatic amino acids has been observed and the apparent binding constant (KA) and the number of binding sites (n) have been calculated using fluorescence enhancement equation. The KA value is found to be highest for SF-PNFs+Tyrosine and n is two for all the polymer amino acid complexes, which are in agreement with the FT-IR and (1)H NMR results. Fluorescence resonance energy transfer (FRET) efficiency has been found to be highest for SF-PNFs+Tyrosine giving maximum fluorescence enhancement. The study of interaction mechanisms by means of an extremely sensitive technique like fluorescence using SF-PNFs as a substrate may provide a promising analytical tool for detection and monitoring any biochemical reactions involving these three aromatic amino acids.

  15. Enhanced Biocide Mitigation of Field Biofilm Consortia by a Mixture of D-Amino Acids.

    PubMed

    Li, Yingchao; Jia, Ru; Al-Mahamedh, Hussain H; Xu, Dake; Gu, Tingyue

    2016-01-01

    Microbiologically influenced corrosion (MIC) is a major problem in the oil and gas industry as well as in many other industries. Current treatment methods rely mostly on pigging and biocide dosing. Biocide resistance is a growing concern. Thus, it is desirable to use biocide enhancers to improve the efficacy of existing biocides. D-Amino acids are naturally occurring. Our previous work demonstrated that some D-amino acids are biocide enhancers. Under a biocide stress of 50 ppm (w/w) hydroxymethyl phosphonium sulfate (THPS) biocide, 1 ppm D-tyrosine and 100 ppm D-methionine used separately successfully mitigated the Desulfovibrio vulgaris biofilm on carbon steel coupons. The data reported in this work revealed that 50 ppm of an equimolar mixture of D-methionine, D-tyrosine, D-leucine, and D-tryptophan greatly enhanced 50 ppm THPS biocide treatment of two recalcitrant biofilm consortia containing sulfate reducing bacteria (SRB), nitrate reducing bacteria (NRB), and fermentative bacteria, etc., from oil-field operations. The data also indicated that individual D-amino acids were inadequate for the biofilm consortia. PMID:27379039

  16. Enhanced Biocide Mitigation of Field Biofilm Consortia by a Mixture of D-Amino Acids

    PubMed Central

    Li, Yingchao; Jia, Ru; Al-Mahamedh, Hussain H.; Xu, Dake; Gu, Tingyue

    2016-01-01

    Microbiologically influenced corrosion (MIC) is a major problem in the oil and gas industry as well as in many other industries. Current treatment methods rely mostly on pigging and biocide dosing. Biocide resistance is a growing concern. Thus, it is desirable to use biocide enhancers to improve the efficacy of existing biocides. D-Amino acids are naturally occurring. Our previous work demonstrated that some D-amino acids are biocide enhancers. Under a biocide stress of 50 ppm (w/w) hydroxymethyl phosphonium sulfate (THPS) biocide, 1 ppm D-tyrosine and 100 ppm D-methionine used separately successfully mitigated the Desulfovibrio vulgaris biofilm on carbon steel coupons. The data reported in this work revealed that 50 ppm of an equimolar mixture of D-methionine, D-tyrosine, D-leucine, and D-tryptophan greatly enhanced 50 ppm THPS biocide treatment of two recalcitrant biofilm consortia containing sulfate reducing bacteria (SRB), nitrate reducing bacteria (NRB), and fermentative bacteria, etc., from oil-field operations. The data also indicated that individual D-amino acids were inadequate for the biofilm consortia. PMID:27379039

  17. Enhanced Biocide Mitigation of Field Biofilm Consortia by a Mixture of D-Amino Acids.

    PubMed

    Li, Yingchao; Jia, Ru; Al-Mahamedh, Hussain H; Xu, Dake; Gu, Tingyue

    2016-01-01

    Microbiologically influenced corrosion (MIC) is a major problem in the oil and gas industry as well as in many other industries. Current treatment methods rely mostly on pigging and biocide dosing. Biocide resistance is a growing concern. Thus, it is desirable to use biocide enhancers to improve the efficacy of existing biocides. D-Amino acids are naturally occurring. Our previous work demonstrated that some D-amino acids are biocide enhancers. Under a biocide stress of 50 ppm (w/w) hydroxymethyl phosphonium sulfate (THPS) biocide, 1 ppm D-tyrosine and 100 ppm D-methionine used separately successfully mitigated the Desulfovibrio vulgaris biofilm on carbon steel coupons. The data reported in this work revealed that 50 ppm of an equimolar mixture of D-methionine, D-tyrosine, D-leucine, and D-tryptophan greatly enhanced 50 ppm THPS biocide treatment of two recalcitrant biofilm consortia containing sulfate reducing bacteria (SRB), nitrate reducing bacteria (NRB), and fermentative bacteria, etc., from oil-field operations. The data also indicated that individual D-amino acids were inadequate for the biofilm consortia.

  18. Enhanced charge transport in highly conducting PEDOT-PSS films after acid treatment

    NASA Astrophysics Data System (ADS)

    Shiva, V. Akshaya; Bhatia, Ravi; Menon, Reghu

    The high electrical conductivity, good stability, high strength, flexibility and good transparency of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS), make it useful for many applications including polymeric anodes for organic photovoltaics, light-emitting diodes, flexible electrodes, supercapacitors, electrochromic devices, field-effect transistors and antistatic-coatings. However, the electrical conductivity of PEDOT-PSS has to be increased significantly for replacement of indium tin oxide (ITO) as the transparent electrode in optoelectronic devices. The as prepared (pristine) PEDOT-PSS film prepared from the PEDOT-PSS aqueous solution usually has conductivity below 1Scm-1, remarkably lower than ITO. Significant conductivity enhancement has been observed on transparent and conductive PEDOT-PSS films after a treatment with inorganic acids. Our study investigates the charge transport in pristine and H2SO4, HNO3, HCl treated PEDOT-PSS films. We have treated the films with various concentrations of acids to probe the effect of the acid treatment on the conduction mechanism. The study includes the measurement of dc and electric field dependent conductivity of films in the temperature range of 4.2K-300K. We have also performed magneto-resistance measurements in the range of 0-5T. An enhancement by a factor of~103 has been observed in the room temperature conductivity. The detailed magneto-transport studies explain the various mechanisms for the conductivity enhancement observed.

  19. Enhanced amino acid utilization sustains growth of cells lacking Snf1/AMPK.

    PubMed

    Nicastro, Raffaele; Tripodi, Farida; Guzzi, Cinzia; Reghellin, Veronica; Khoomrung, Sakda; Capusoni, Claudia; Compagno, Concetta; Airoldi, Cristina; Nielsen, Jens; Alberghina, Lilia; Coccetti, Paola

    2015-07-01

    The metabolism of proliferating cells shows common features even in evolutionary distant organisms such as mammals and yeasts, for example the requirement for anabolic processes under tight control of signaling pathways. Analysis of the rewiring of metabolism, which occurs following the dysregulation of signaling pathways, provides new knowledge about the mechanisms underlying cell proliferation. The key energy regulator in yeast Snf1 and its mammalian ortholog AMPK have earlier been shown to have similar functions at glucose limited conditions and here we show that they also have analogies when grown with glucose excess. We show that loss of Snf1 in cells growing in 2% glucose induces an extensive transcriptional reprogramming, enhances glycolytic activity, fatty acid accumulation and reliance on amino acid utilization for growth. Strikingly, we demonstrate that Snf1/AMPK-deficient cells remodel their metabolism fueling mitochondria and show glucose and amino acids addiction, a typical hallmark of cancer cells.

  20. ENHANCED MOBILITY OF DENSE NONAQUEOUS-PHASE LIQUIDS (DNAPLs) USING DISSOLVED HUMIC ACIDS

    SciTech Connect

    EDWIN S. OLSON; JOHN R. GALLAGHER; MARC D. KURZ

    1998-10-01

    The specific objectives of this subtask are as follows: � Evaluate the suitability of using humic acids to enhance the solubility and mobility of DNAPL contaminants sorbed to soils. � Evaluate the toxicity and bioavailablity of the DNAPLs to biodegrading microorganisms. To meet the first objective, the Energy & Environmental Research Center (EERC) evaluated a set of humic acids (two) with different chemical compositions and polarities for the following: � Ability of the humates to mobilize/solubilize selected (three) DNAPLs � Mobilization/solubilization in batch soil�water experiments (one soil) � Removal rate via biotreatment with a well-established active microbial culture. The second objective was met by evaluating the inhibiting effects of a leonardite-derived humic acid on active microbial populations.

  1. α-Mangostin, a Natural Agent, Enhances the Response of NRAS Mutant Melanoma to Retinoic Acid

    PubMed Central

    Xia, Yun; Chen, Jing; Gong, Chongwen; Chen, Hongxiang; Sun, Jiaming

    2016-01-01

    Background The identification and use of novel compounds alone or in combination hold promise for the fight against NRAS mutant melanoma. Material/Methods We screened a kinase-specific inhibitor library through combining it with α-Mangostin in NRAS mutant melanoma cell line, and verified the enhancing effect of α-Mangostin through inhibition of the tumorigenesis pathway. Results Within the kinase inhibitors, retinoic acid showed a significant synergistic effect with α-Mangostin. α-Mangostin also can reverse the drug resistance of retinoic acid in RARa siRNA-transduced sk-mel-2 cells. Colony assay, TUNEL staining, and the expressions of several apoptosis-related genes revealed that α-Mangostin enhanced the effect of retinoic acid-induced apoptosis. The combination treatment resulted in marked induction of ROS generation and inhibition of the AKT/S6 pathway. Conclusions These results indicate that the combination of these novel natural agents with retinoid acid may be clinically effective in NRAS mutant melanoma. PMID:27104669

  2. Corn starch granules with enhanced load-carrying capacity via citric acid treatment.

    PubMed

    Kim, Jong-Yea; Huber, Kerry C

    2013-01-01

    This research investigated conditions by which maize starch granule porosity and load-carrying capacity (LCC) might be enhanced via treatment with varying citric acid concentrations (0.5-1.5 M), temperatures (40-60 °C), and lengths of treatment (1-8 h). At the lowest temperatures (40 and 50 °C), citric acid treatment induced minimal physicochemical changes to granules. In contrast, both aqueous and oil LCCs of starches treated at 60 °C (0.5 M citric acid, 2 h) were almost doubled (15.69 and 14.48 mL/10 g starch, respectively), recovering 92% of the granular starch after treatment. Such treatment increased starch hydration capacity (0.97-1.91) and reduced gelatinization enthalpy (10.6-7.4 J/g). More severe treatment conditions adversely impacted aqueous LCC (due to excessive granule swelling), but improved oil absorption. The basis for LCC enhancement by citric acid treatment was ascribed to leaching of starch material from granules and partial disruption of the granule crystalline structure, as opposed to starch hydrolysis or chemical substitution.

  3. Surface modification of activated carbon for enhanced adsorption of perfluoroalkyl acids from aqueous solutions.

    PubMed

    Zhi, Yue; Liu, Jinxia

    2016-02-01

    The objective of the research was to examine the effect of increasing carbon surface basicity on uptake of perfluorooctane sulfonic (PFOS) and carboxylic acids (PFOA) by activated carbon. Granular activated carbons made from coal, coconut shell, wood, and phenolic-polymer-based activated carbon fibers were modified through high-temperature and ammonia gas treatments to facilitate systematical evaluation of the impact of basicity of different origins. Comparison of adsorption isotherms and adsorption distribution coefficients showed that the ammonia gas treatment was more effective than the high-temperature treatment in enhancing surface basicity. The resultant higher point of zero charges and total basicity (measured by total HCl uptake) correlated with improved adsorption affinity for PFOS and PFOA. The effectiveness of surface modification to enhance adsorption varied with carbon raw material. Wood-based carbons and activated carbon fibers showed enhancement by one to three orders of magnitudes while other materials could experience reduction in adsorption towards either PFOS or PFOA.

  4. Surface modification of activated carbon for enhanced adsorption of perfluoroalkyl acids from aqueous solutions.

    PubMed

    Zhi, Yue; Liu, Jinxia

    2016-02-01

    The objective of the research was to examine the effect of increasing carbon surface basicity on uptake of perfluorooctane sulfonic (PFOS) and carboxylic acids (PFOA) by activated carbon. Granular activated carbons made from coal, coconut shell, wood, and phenolic-polymer-based activated carbon fibers were modified through high-temperature and ammonia gas treatments to facilitate systematical evaluation of the impact of basicity of different origins. Comparison of adsorption isotherms and adsorption distribution coefficients showed that the ammonia gas treatment was more effective than the high-temperature treatment in enhancing surface basicity. The resultant higher point of zero charges and total basicity (measured by total HCl uptake) correlated with improved adsorption affinity for PFOS and PFOA. The effectiveness of surface modification to enhance adsorption varied with carbon raw material. Wood-based carbons and activated carbon fibers showed enhancement by one to three orders of magnitudes while other materials could experience reduction in adsorption towards either PFOS or PFOA. PMID:26469934

  5. Acetate induced enhancement of photocatalytic hydrogen peroxide production from oxalic acid and dioxygen.

    PubMed

    Yamada, Yusuke; Nomura, Akifumi; Miyahigashi, Takamitsu; Ohkubo, Kei; Fukuzumi, Shunichi

    2013-05-01

    The addition of acetate ion to an O2-saturated mixed solution of acetonitrile and water containing oxalic acid as a reductant and 2-phenyl-4-(1-naphthyl)quinolinium ion (QuPh(+)-NA) as a photocatalyst dramatically enhanced the turnover number of hydrogen peroxide (H2O2) production. In this photocatalytic H2O2 production, a base is required to facilitate deprotonation of oxalic acid forming oxalate dianion, which acts as an actual electron donor, whereas a Brønsted acid is also necessary to protonate O2(•-) for production of H2O2 by disproportionation. The addition of acetate ion to a reaction solution facilitates both the deprotonation of oxalic acid and the protonation of O2(•-) owing to a pH buffer effect. The quantum yield of the photocatalytic H2O2 production under photoirradiation (λ = 334 nm) of an O2-saturated acetonitrile-water mixed solution containing acetate ion, oxalic acid and QuPh(+)-NA was determined to be as high as 0.34, which is more than double the quantum yield obtained by using oxalate salt as an electron donor without acetate ion (0.14). In addition, the turnover number of QuPh(+)-NA reached more than 340. The reaction mechanism and the effect of solvent composition on the photocatalytic H2O2 production were scrutinized by using nanosecond laser flash photolysis.

  6. Longitudinal-relaxation-enhanced NMR experiments for the study of nucleic acids in solution.

    PubMed

    Farjon, Jonathan; Boisbouvier, Jérôme; Schanda, Paul; Pardi, Arthur; Simorre, Jean-Pierre; Brutscher, Bernhard

    2009-06-24

    Atomic-resolution information on the structure and dynamics of nucleic acids is essential for a better understanding of the mechanistic basis of many cellular processes. NMR spectroscopy is a powerful method for studying the structure and dynamics of nucleic acids; however, solution NMR studies are currently limited to relatively small nucleic acids at high concentrations. Thus, technological and methodological improvements that increase the experimental sensitivity and spectral resolution of NMR spectroscopy are required for studies of larger nucleic acids or protein-nucleic acid complexes. Here we introduce a series of imino-proton-detected NMR experiments that yield an over 2-fold increase in sensitivity compared to conventional pulse schemes. These methods can be applied to the detection of base pair interactions, RNA-ligand titration experiments, measurement of residual dipolar (15)N-(1)H couplings, and direct measurements of conformational transitions. These NMR experiments employ longitudinal spin relaxation enhancement techniques that have proven useful in protein NMR spectroscopy. The performance of these new experiments is demonstrated for a 10 kDa TAR-TAR*(GA) RNA kissing complex and a 26 kDa tRNA.

  7. Enhanced antiamyloidal activity of hydroxy cinnamic acids by enzymatic esterification with alkyl alcohols.

    PubMed

    Kondo, Hazuki; Sugiyama, Haruka; Katayama, Shigeru; Nakamura, Soichiro

    2014-01-01

    Lipophilic derivatives of hydroxyl cinnamic acids (HCAs) including caffeic acid (CA), ferulic acid, sinapic acid (SA), and chlorogenic acid were synthesized by esterification with butanol, octanol, or hexadecanol catalyzed by the lipase from Candida antarctica to investigate the effect of lipophilicity on their antiamyloidal activity assessed by the inhibitory activities toward fibrillization of amyloid β (Aβ) peptide. Among them, CA showed the highest activity at 50 μM, reducing the amyloid fibril formation of Aβ to 34.4 ± 6.8%. The antiamyloidal effects of HCAs were enhanced by esterification with alkyl alcohols, and the longer alkyl chain tended to be more effective except for SA. Aβ fibril formation was suppressed by the hexadecyl ester of CA, which was reduced to 8.8 ± 2.3%. In contrast, those of octyl and butyl esters were 19.3 ± 2.3% and 41.6 ± 6.1%, respectively. These results show that lipophilicity plays an important role in the antiamyloidal activities of esterified phenolic compounds.

  8. Enhanced ethanol production from deacetylated yellow poplar acid hydrolysate by Pichia stipitis.

    PubMed

    Cho, Dae Haeng; Shin, Soo-Jeong; Bae, Yangwon; Park, Chulhwan; Kim, Yong Hwan

    2010-07-01

    In this study, alkaline-pretreatment for the extraction of acetic acid from xylan of hemicellulose was introduced prior to concentrated acid hydrolysis of yellow poplar wood meal. Ethanol fermentability in deacetylated yellow poplar hydrolysate (DYPH) by Pichia stipitis was also investigated. The alkali-pretreatment conditions were evaluated in terms of temperature, reaction time, and alkalinity. 94% of the acetyl group in xylan of the yellow poplar hemicellulose fraction was extracted using 0.5% sodium hydroxide solution at 60 degrees C for 60 min. The cell growth and ethanol production of P. stipitis was strongly affected by acetic acid, either in synthetic medium with 7.1g/l of acetic acid added or in yellow poplar hydrolysate (YPH) containing 7.1g/l of acetic acid. On the other hand, ethanol production in DYPH was slightly higher than that of the control although cell growth decreased by 34%. In the case of DYPH, the ethanol yield, volumetric ethanol productivity, and theoretical yield percentage was 0.48 g/g, 0.40 g/lh, and 93.2%, respectively. Thus, the alkaline-pretreatment method greatly enhanced the ethanol fermentability of yellow poplar hydrolysate. PMID:19959357

  9. Combined humic acid adsorption and enhanced Fenton processes for the treatment of naphthalene dye intermediate wastewater.

    PubMed

    Gu, Lin; Zhu, Nanwen; Wang, Liang; Bing, Xiaoxiao; Chen, Xiaoliang

    2011-12-30

    In this work, an humic acid adsorption with an enhanced Fenton oxidation was employed to treat the real effluent originating from the 1-diazo-2-naphthol-4-sulfonic acid (1,2,4-Acid) production plant. In a first step, humic acid with MgSO(4) was selected as adsorbent and precipitant for physicochemical pretreatment, the synergetic effect had led to 39% of COD removal and 89% of colour removal. A multi-staged Fenton oxidation process with inner circulation was introduced subsequently. The TOC, COD, 1,2,4-Acid, NH(4)(+)-N, SS and colour were reduced from 3024 mg/L, 12,780 mg/L, 9103 mg/L, 110 mg/L, 240 mg/L and 25,600 (multiple) to 46 mg/L, 210 mg/L, 21 mg/L, 16 mg/L, 3 mg/L and 25 through the combined process, respectively. Hydrogen peroxide consumed per kg COD had saved up to 36% when two-staged Fenton process with inner circulation (flow-back to influent ratio: 3) was applied. Influence of H(2)O(2) concentration, flow-back to influent ratio and staged Fenton mode were investigated in detail in order to find out the optimal operating parameters. The kinetics of 1,2,4-Acid degradation by two-staged Fenton process was investigated. The evolution of the main intermediates during the degradation process was conducted using the LC-(ESI)-TOF-MS technique, and the results showed a staged degradation pathway from the ring opening of naphthalene compounds to the formation of benzene compounds and carboxyl acids. The combined process had been proved effective in both technical and economic aspects.

  10. Enhanced undecylprodigiosin production from Serratia marcescens SS-1 by medium formulation and amino-acid supplementation.

    PubMed

    Wei, Yu-Hong; Yu, Wan-Ju; Chen, Wei-Chuan

    2005-10-01

    Serratia marcescens Simon Swift-1 (SS-1) was used to produce a prodigiosin-like pigment, undecylprodigiosin (UP), known to have antitumor activities and potential as an anticancer drug. Modified media containing components of Luria-Bertani (LB) broth and selected amino acids were used to improve UP production from S. marcescens SS-1. Optimal culture conditions (e.g., temperature, pH, agitation rate) for UP production were also identified. It was found that S. marcescens SS-1 was able to produce 690 mg l-1 of UP when it was grown with 5 g l-1 yeast extract alone (YE medium) under the optimal culture conditions of 30 degrees C, 200 rpm, and pH 8. The UP production of 690 mg l-1 is nearly 23-fold of that obtained from original LB medium. Addition of amino acids containing pyrrole-like structures further enhanced UP production. Nearly 2 and 1.4 g l-1 of UP was produced when the SS-1 strain was cultivated with YE medium supplemented with proline and histidine (5 g l-1), respectively. Moreover, the addition of aspartic acid (5 g l-1) also resulted in a high UP production of 1.4 g l-1. Optimal dosages of the three amino acids were subsequently determined and the highest UP production (2.5 g l-1) was achieved with the addition of 10 g l-1 of proline. This suggests that the supplementation of amino acids related to the formation of a UP precursor (e.g., pyrrolylpyrromethene) could enhance UP production by the SS-1 strain.

  11. Self-assembling micelle-like nanoparticles with detachable envelopes for enhanced delivery of nucleic acid therapeutics.

    PubMed

    Battogtokh, Gantumur; Ko, Young Tag

    2014-03-01

    In spite of the great potential of nucleic acids as therapeutic agents, the clinical application of nucleic acid therapeutics requires the development of effective systemic delivery strategies. In an effort to develop effective nucleic acid delivery systems suitable for clinical application, we previously reported a self-assembling micelle-like nanoparticle that was based on phospholipid-polyethylenimine conjugates, i.e., "micelle-like nanoparticles" (MNPs). In this study, we aimed to improve the system by enhancing the efficiency of intracellular delivery of the payload via pH-responsive detachment of the monolayer envelope and release of the nucleic acid therapeutics upon reaching the target tissues with an acidic pH, e.g., tumors. The acid-cleavable phospholipid-polyethylenimine conjugate was synthesized via hydrazone bond, and acid-cleavable MNPs were then prepared and characterized as before. We evaluated the acid-cleavable MNP construct for in vitro and in vivo nucleic acid delivery efficiency using cultured tumor cells and tumor-bearing mice. The acid-cleavable nanocarrier showed an enhanced cellular delivery at pH 6.5 as compared to pH 7.4, whereas the noncleavable nanocarrier did not show any differences. Tail vein injections also led to enhanced intracellular uptake of the acid-cleavable nanocarrier compared to the noncleavable nanocarrier into tumor cells of tumor-bearing mice although no significant difference was observed in total tumor accumulation.

  12. β-cyclocitral upregulates salicylic acid signalling to enhance excess light acclimation in Arabidopsis.

    PubMed

    Lv, Feifei; Zhou, Jun; Zeng, Lizhang; Xing, Da

    2015-08-01

    β-cyclocitral (β-CC), a volatile oxidized derivative of β-carotene, can upregulate the expression of defence genes to enhance excess light (EL) acclimation. However, the signalling cascades underlying this process remain unclear. In this study, salicylic acid (SA) is involved in alleviating damage to promote β-CC-enhanced EL acclimation. In early stages of EL illumination, β-CC pretreatment induced SA accumulation and impeded reactive oxygen species (ROS) production in the chloroplast. A comparative analysis of two SA synthesis pathways in Arabidopsis revealed that SA concentration mainly increased via the isochorismate synthase 1 (ICS1)-mediated isochorismate pathway, which depended on essential regulative function of enhanced disease susceptibility 1 (EDS1). Further results showed that, in the process of β-CC-enhanced EL acclimation, nuclear localization of nonexpressor of pathogenesis-related genes 1 (NPR1) was regulated by SA accumulation and NPR1 induced subsequent transcriptional reprogramming of gluthathione-S-transferase 5 (GST5) and GST13 implicated in detoxification. In summary, β-CC-induced SA synthesis contributes to EL acclimation response by decreasing ROS production in the chloroplast, promoting nuclear localization of NPR1, and upregulating GST transcriptional expression. This process is a possible molecular regulative mechanism of β-CC-enhanced EL acclimation.

  13. Mechanisms of enhanced total organic carbon elimination from oxalic acid solutions by electro-peroxone process.

    PubMed

    Wang, Huijiao; Yuan, Shi; Zhan, Juhong; Wang, Yujue; Yu, Gang; Deng, Shubo; Huang, Jun; Wang, Bin

    2015-09-01

    Electro-peroxone (E-peroxone) is a novel electrocatalytic ozonation process that combines ozonation and electrolysis process to enhance pollutant degradation during water and wastewater treatment. This enhancement has been mainly attributed to several mechanisms that increase O3 transformation to ·OH in the E-peroxone system, e.g., electro-generation of H2O2 from O2 at a carbon-based cathode and its subsequent peroxone reaction with O3 to ·OH, electro-reduction of O3 to ·OH at the cathode, and O3 decomposition to ·OH at high local pH near the cathode. To get more insight how these mechanisms contribute respectively to the enhancement, this study investigated total organic carbon (TOC) elimination from oxalic acid (OA) solutions by the E-peroxone process. Results show that the E-peroxone process significantly increased TOC elimination rate by 10.2-12.5 times compared with the linear addition of the individual rates of corresponding ozonation and electrolysis process. Kinetic analyses reveal that the electrochemically-driven peroxone reaction is the most important mechanism for the enhanced TOC elimination rate, while the other mechanisms contribute minor to the enhancement by a factor of 1.6-2.5. The results indicate that proper selection of electrodes that can effectively produce H2O2 at the cathode is critical to maximize TOC elimination in the E-peroxone process.

  14. Mechanisms of enhanced total organic carbon elimination from oxalic acid solutions by electro-peroxone process.

    PubMed

    Wang, Huijiao; Yuan, Shi; Zhan, Juhong; Wang, Yujue; Yu, Gang; Deng, Shubo; Huang, Jun; Wang, Bin

    2015-09-01

    Electro-peroxone (E-peroxone) is a novel electrocatalytic ozonation process that combines ozonation and electrolysis process to enhance pollutant degradation during water and wastewater treatment. This enhancement has been mainly attributed to several mechanisms that increase O3 transformation to ·OH in the E-peroxone system, e.g., electro-generation of H2O2 from O2 at a carbon-based cathode and its subsequent peroxone reaction with O3 to ·OH, electro-reduction of O3 to ·OH at the cathode, and O3 decomposition to ·OH at high local pH near the cathode. To get more insight how these mechanisms contribute respectively to the enhancement, this study investigated total organic carbon (TOC) elimination from oxalic acid (OA) solutions by the E-peroxone process. Results show that the E-peroxone process significantly increased TOC elimination rate by 10.2-12.5 times compared with the linear addition of the individual rates of corresponding ozonation and electrolysis process. Kinetic analyses reveal that the electrochemically-driven peroxone reaction is the most important mechanism for the enhanced TOC elimination rate, while the other mechanisms contribute minor to the enhancement by a factor of 1.6-2.5. The results indicate that proper selection of electrodes that can effectively produce H2O2 at the cathode is critical to maximize TOC elimination in the E-peroxone process. PMID:25989593

  15. Recent Advances in the Imaging Diagnosis of Hepatocellular Carcinoma: Value of Gadoxetic Acid-Enhanced MRI

    PubMed Central

    Joo, Ijin; Lee, Jeong Min

    2016-01-01

    Magnetic resonance imaging (MRI) using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DPTA), or gadoxetic acid for short, is a hepatocyte-specific contrast agent which is now increasingly used for the detection and characterization of focal hepatic lesions, particularly in patients at high-risk of developing hepatocellular carcinomas (HCC). In fact, several recent guidelines now recognize gadoxetic acid-enhanced MRI (Gd-EOB-MRI) as the primary diagnostic imaging modality for the noninvasive diagnosis of HCC, although it must be noted that several major guidelines still include only extracellular contrast media-enhanced computed tomography and MRI. The primary merits of Gd-EOB-MRI lie in the fact that it can provide not only dynamic imaging, but also hepatobiliary phase (HBP) imaging which can lead to high lesion-to-liver contrast and give additional information regarding hepatocyte uptake via organic anion transporting polypeptides. This, in turn, allows higher sensitivity in detecting small HCCs and helps provide additional information regarding the multistep process of hepatocarcinogenesis. Indeed, many recent studies have investigated the diagnostic value of Gd-EOB-MRI for early HCCs as well as its role as a potential imaging biomarker in predicting outcome. We herein review the recent advances in the imaging diagnosis of HCCs focusing on the applications of Gd-EOB-MRI and the challenging issues that remain. PMID:26989660

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

    PubMed Central

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

    2016-01-01

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

  17. Enhanced transformation of diphenylarsinic acid in soil under sulfate-reducing conditions.

    PubMed

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

    2012-11-30

    Diphenylarsinic acid (DPAA) is known to be the major contaminant in soils where diphenylchloroarsine and diphenylcyanoarsine were abandoned after World Wars I and II. In this study, experimental model studies were performed to elucidate key factors regulating the transformation of DPAA under anaerobic soil conditions. The elimination of DPAA in Gleysol soils (Qiqihar and Shindori soils) was more rapid than in Mollisol and Regosol soils (Heihe and Ikarashi soils, respectively) during a 5-week incubation. No clear relationship between decreasing rates of DPAA concentrations and soil Eh values was found. The Ikarashi soil showed the slowest decrease in DPAA concentrations among the four soils, but the transformation of DPAA was notably enhanced by addition of exogenous sulfate together with acetate, cellulose or rice straw. Addition of molybdate, a specific inhibitor of sulfate reduction, resulted in the stagnation of DPAA transformation, suggesting that indigenous sulfate reducers play a role in DPAA transformation under anaerobic conditions. Arsenate, phenylarsonic acid, phenylmethylarsinic acid, diphenylmethylarsine oxide and three unknown compounds were detected as metabolites of DPAA. This is the first study to reveal enhancement of DPAA transformation under sulfate-reducing conditions. PMID:23069334

  18. Biochar enhances Aspergillus niger rock phosphate solubilization by increasing organic acid production and alleviating fluoride toxicity.

    PubMed

    Mendes, Gilberto de Oliveira; Zafra, David Lopez; Vassilev, Nikolay Bojkov; Silva, Ivo Ribeiro; Ribeiro, José Ivo; Costa, Maurício Dutra

    2014-05-01

    During fungal rock phosphate (RP) solubilization, a significant quantity of fluoride (F(-)) is released together with phosphorus (P), strongly inhibiting the process. In the present study, the effect of two F(-) adsorbents [activated alumina (Al2O3) and biochar] on RP solubilization by Aspergillus niger was examined. Al2O3 adsorbed part of the F(-) released but also adsorbed soluble P, which makes it inappropriate for microbial RP solubilization systems. In contrast, biochar adsorbed only F(-) while enhancing phosphate solubilization 3-fold, leading to the accumulation of up to 160 mg of P per liter. By comparing the values of F(-) measured in solution at the end of incubation and those from a predictive model, it was estimated that up to 19 mg of F(-) per liter can be removed from solution by biochar when added at 3 g liter(-1) to the culture medium. Thus, biochar acted as an F(-) sink during RP solubilization and led to an F(-) concentration in solution that was less inhibitory to the process. In the presence of biochar, A. niger produced larger amounts of citric, gluconic, and oxalic acids, whether RP was present or not. Our results show that biochar enhances RP solubilization through two interrelated processes: partial removal of the released F(-) and increased organic acid production. Given the importance of organic acids for P solubilization and that most of the RPs contain high concentrations of F(-), the proposed solubilization system offers an important technological improvement for the microbial production of soluble P fertilizers from RP.

  19. Recent Advances in the Imaging Diagnosis of Hepatocellular Carcinoma: Value of Gadoxetic Acid-Enhanced MRI.

    PubMed

    Joo, Ijin; Lee, Jeong Min

    2016-02-01

    Magnetic resonance imaging (MRI) using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DPTA), or gadoxetic acid for short, is a hepatocyte-specific contrast agent which is now increasingly used for the detection and characterization of focal hepatic lesions, particularly in patients at high-risk of developing hepatocellular carcinomas (HCC). In fact, several recent guidelines now recognize gadoxetic acid-enhanced MRI (Gd-EOB-MRI) as the primary diagnostic imaging modality for the noninvasive diagnosis of HCC, although it must be noted that several major guidelines still include only extracellular contrast media-enhanced computed tomography and MRI. The primary merits of Gd-EOB-MRI lie in the fact that it can provide not only dynamic imaging, but also hepatobiliary phase (HBP) imaging which can lead to high lesion-to-liver contrast and give additional information regarding hepatocyte uptake via organic anion transporting polypeptides. This, in turn, allows higher sensitivity in detecting small HCCs and helps provide additional information regarding the multistep process of hepatocarcinogenesis. Indeed, many recent studies have investigated the diagnostic value of Gd-EOB-MRI for early HCCs as well as its role as a potential imaging biomarker in predicting outcome. We herein review the recent advances in the imaging diagnosis of HCCs focusing on the applications of Gd-EOB-MRI and the challenging issues that remain. PMID:26989660

  20. Enhanced succinic acid productivity by expression of mgtCB gene in Escherichia coli mutant.

    PubMed

    Wang, Jing; Yang, Le; Wang, Dan; Dong, Lichun; Chen, Rachel

    2016-04-01

    In this study, a novel engineering Escherichia coli strain (CBMG111) with the expression of mgtCB gene was constructed for the enhanced fermentative production of succinic acid by utilizing the synergetic effect of mgtC gene to improve the growth of strains at the environment of low Mg(2+) concentration and mgtB to enhance the transport of Mg(2+) into cells. After the effect of the expression of the individual genes (mgtA, mgtB, mgtC) on the growth of E. coli was clarified, the fermentative production of succinic acid by CBMG111 was studied with the low-price mixture of Mg(OH)2 and NH3·H2O as the alkaline neutralizer and the biomass hydrolysates as the carbon sources, which demonstrated that the expression of mgtCB gene can significantly increase the productivity of succinic acid (2.97 g L(-1) h(-1)) compared with that by using the engineering strain with the overexpression of mgtA gene. PMID:26711444

  1. Okadaic acid and trifluoperazine enhance Agrobacterium-mediated transformation in eastern white pine.

    PubMed

    Tang, Wei; Lin, Jinxing; Newton, Ronald J

    2007-05-01

    Mature zygotic embryos of recalcitrant Christmas tree species eastern white pine (Pinus strobus L.) were used as explants for Agrobacterium tumefaciens strain GV3101-mediated transformation using the uidA (beta-Glucuronidase) gene as a reporter. Influence of the time of sonication and the concentrations of protein phosphatase inhibitor (okadaic acid) and kinase inhibitor (trifluoperazine) on Agrobacterium-mediated transformation have been evaluated. A high transformation frequency was obtained after embryos were sonicated for 45-50 s, or treated with 1.5-2.0 microM okadaic acid or treated with 100-200 microM trifluoperazine, respectively. Protein phosphatase and kinase inhibitors enhance Agrobacterium-mediated transformation in eastern white pine. A 2-3.5-fold higher rate of hygromycin-resistant callus was obtained with an addition of 2 microM okadaic acid or 150 microM trifluoperazine or sonicated embryos for 45 s. Stable integration of the uidA gene in the plant genome of eastern white pine was confirmed by polymerase chain reaction (PCR), Southern and northern blot analyses. These results demonstrated that a stable and enhanced transformation system has been established in eastern white pine and this system would provide an opportunity to transfer economically important genes into this Christmas tree species.

  2. Enhanced thermal- and photo-stability of acid yellow 17 by incorporation into layered double hydroxides

    SciTech Connect

    Wang Qian; Feng Yongjun; Feng Junting; Li Dianqing

    2011-06-15

    2,5-dichloro-4-(5-hydroxy-3-methyl-4-(sulphophenylazo) pyrazol-1-yl) benzenesulphonate (DHSB) anions, namely acid yellow 17 anions, have been successfully intercalated into Zn-Al layered double hydroxides (LDH) to produce a novel organic-inorganic pigment by a simple method involving separate nucleation and aging steps (SNAS), and the dye-intercalated LDH was analyzed by various techniques, e.g., XRD, SEM, FT-IR, TG-DTA and ICP. The d-spacing of the prepared LDH is 2.09 nm. Furthermore, the incorporation of the DHSB aims to enhance the thermal- and photo-stability of the guest dye molecule, for example, the less color change after accelerated thermal- and photo-aging test. - Graphical abstract: Acid yellow anions were successfully assembled into ZnAl layered double hydroxides (LDH) to produce a novel organic-inorganic composite pigment by a simple method involving separate nucleation and aging steps (SNAS). Highlights: > Acid yellow 17 was directly intercalated into ZnAl-LDH to form a novel pigment. > The pigment was prepared by a method involving separate nucleation and aging steps. > The intercalation of dye anions enhances its thermal- and photo-stability.

  3. Mechanism for enhanced 5-aminolevulinic acid fluorescence in isocitrate dehydrogenase 1 mutant malignant gliomas

    PubMed Central

    Kim, Ji Young; Kim, Sung Kwon; Kim, Seung-Ki; Park, Sung-Hye; Kim, Hyeonjin; Lee, Se-Hoon; Choi, Seung Hong; Park, Sunghyouk; Park, Chul-Kee

    2015-01-01

    Fluorescence-guided surgery using 5-aminolevulinic acid (5-ALA) has become the main treatment modality in malignant gliomas. However unlike glioblastomas, there are inconsistent result about fluorescence status in WHO grade III gliomas. Here, we show that mutational status of IDH1 is linked to 5-ALA fluorescence. Using genetically engineered malignant glioma cells harboring wild type (U87MG-IDH1WT) or mutant (U87MG-IDH1R132H) IDH1, we demonstrated a lag in 5-ALA metabolism and accumulation of protoporphyrin IX (PpIX) in U87MG-IDH1R132H cells. Next, we used liquid chromatography–mass spectrometry (LC-MS) to screen for tricarboxylic acid (TCA) cycle-related metabolite changes caused by 5-ALA exposure. We observed low baseline levels of NADPH, an essential cofactor for the rate-limiting step of heme degradation, in U87MG-IDH1R132H cells. High levels of NADPH are required to metabolize excessive 5-ALA, giving a plausible reason for the temporarily enhanced 5-ALA fluorescence in mutant IDH1 cells. This hypothesis was supported by the results of metabolic screening in human malignant glioma samples. In conclusion, we have discovered a relationship between enhanced 5-ALA fluorescence and IDH1 mutations in WHO grade III gliomas. Low levels of NADPH in tumors with mutated IDH1 is responsible for the enhanced fluorescence. PMID:26008980

  4. Abscisic Acid Regulation of Root Hydraulic Conductivity and Aquaporin Gene Expression Is Crucial to the Plant Shoot Growth Enhancement Caused by Rhizosphere Humic Acids.

    PubMed

    Olaetxea, Maite; Mora, Verónica; Bacaicoa, Eva; Garnica, María; Fuentes, Marta; Casanova, Esther; Zamarreño, Angel M; Iriarte, Juan C; Etayo, David; Ederra, Iñigo; Gonzalo, Ramón; Baigorri, Roberto; García-Mina, Jose M

    2015-12-01

    The physiological and metabolic mechanisms behind the humic acid-mediated plant growth enhancement are discussed in detail. Experiments using cucumber (Cucumis sativus) plants show that the shoot growth enhancement caused by a structurally well-characterized humic acid with sedimentary origin is functionally associated with significant increases in abscisic acid (ABA) root concentration and root hydraulic conductivity. Complementary experiments involving a blocking agent of cell wall pores and water root transport (polyethylenglycol) show that increases in root hydraulic conductivity are essential in the shoot growth-promoting action of the model humic acid. Further experiments involving an inhibitor of ABA biosynthesis in root and shoot (fluridone) show that the humic acid-mediated enhancement of both root hydraulic conductivity and shoot growth depended on ABA signaling pathways. These experiments also show that a significant increase in the gene expression of the main root plasma membrane aquaporins is associated with the increase of root hydraulic conductivity caused by the model humic acid. Finally, experimental data suggest that all of these actions of model humic acid on root functionality, which are linked to its beneficial action on plant shoot growth, are likely related to the conformational structure of humic acid in solution and its interaction with the cell wall at the root surface.

  5. Adaptive enhancement of amino acid uptake and exodus by thymic lymphocytes: influence of pH.

    PubMed

    Peck, W A; Rockwell, L H; Lichtman, M A

    1976-11-01

    Entry of certain free amino acids (alpha aminoisobutyric acid (AIB), alanine and proline), but not of leucine into rat thymic lymphocytes increased progressively when the cells were incubated in amino acid deficient medium. Actinomycin D, cycloheximide, or a high concentration of AIB abolished the time-related increase in AIB accumulation, whereas exposure to a high concentration of leucine had no effect. This phenomenon could not be attributed to a progressive alteration in the nature of the incubation medium nor to reduced transinhibition of AIB uptake. The exodus of AIB also increased with time, but to a smaller degree than AIB entry. Initial rates of AIB entry and exodus increased with increases in the pH of the incubation medium over the range 6.5-8.0. The effects of pH on entry and exodus were time-related, increasing progressively oveb nullified the magnified time related increments in AIB transport caused by prolonged incubation at pH 8.0. The influence of a given pH on transport of AIB decreased rapidly when the cells were transferred to medium of another pH, but this tendency diminished the longer the cells were exposed to the initial pH. pH influenced the entry of alanine and proline in the same fashion as that of AIB, but did not affect leucine entry. These results indicate that thymic lymphocytes exhibit adaptive enhancement in the accumulation of free amino acids that are transported largley by the A or alanine-preferring system, and that the adaptive process involves both entry and exodus. Moreover, alterations in pH modify entry and exodus of these same amino acids, profoundly affect the magnitude of time-released increases, and may induce fundamental changes in the mechanism(s) serving amino acid transport.

  6. Enhancing the efficiency and regioselectivity of P450 oxidation catalysts by unnatural amino acid mutagenesis.

    PubMed

    Kolev, Joshua N; Zaengle, Jacqueline M; Ravikumar, Rajesh; Fasan, Rudi

    2014-05-01

    The development of effective strategies for modulating the reactivity and selectivity of cytochrome P450 enzymes represents a key step toward expediting the use of these biocatalysts for synthetic applications. We have investigated the potential of unnatural amino acid mutagenesis to aid efforts in this direction. Four unnatural amino acids with diverse aromatic side chains were incorporated at 11 active-site positions of a substrate-promiscuous CYP102A1 variant. The resulting "uP450s" were then tested for their catalytic activity and regioselectivity in the oxidation of two representative substrates: a small-molecule drug and a natural product. Large shifts in regioselectivity resulted from these single mutations, and in particular, for para-acetyl-Phe substitutions at positions close to the heme cofactor. Screening this mini library of uP450s enabled us to identify P450 catalysts for the selective hydroxylation of four aliphatic positions in the target substrates, including a C(sp(3))-H site not oxidized by the parent enzyme. Furthermore, we discovered a general activity-enhancing effect of active-site substitutions involving the unnatural amino acid para-amino-Phe, which resulted in P450 catalysts capable of supporting the highest total turnover number reported to date on a complex molecule (34,650). The functional changes induced by the unnatural amino acids could not be reproduced by any of the 20 natural amino acids. This study thus demonstrates that unnatural amino acid mutagenesis constitutes a promising new strategy for improving the catalytic activity and regioselectivity of P450 oxidation catalysts. PMID:24692265

  7. Enhancing the Efficiency and Regioselectivity of P450 Oxidation Catalysts via Unnatural Amino Acid Mutagenesis

    PubMed Central

    Kolev, Joshua N.; Zaengle, Jacqueline M.; Ravikumar, Rajesh

    2014-01-01

    The development of effective strategies for modulating the reactivity and selectivity of cytochrome P450 enzymes represents a key step toward expediting the use of these biocatalysts for synthetic applications. In this work, we investigated the potential of unnatural amino acid mutagenesis to aid efforts in this direction. To this end, four unnatural amino acids comprising a diverse set of aromatic side-chain groups were incorporated into eleven active site positions of a substrate-promiscuous CYP102A1 variant. The resulting ‘uP450s’ were then tested for their catalytic activity and regioselectivity in the oxidation of two representative substrates consisting of a small-molecule drug and a natural product. Large shifts in regioselectivity were obtained as a result of these single mutations and, in particular, via para-acetyl-Phe substitutions at positions in close proximity to the heme cofactor. Notably, screening of this mini library of uP450s enabled the rapid identification of P450 catalysts for the selective hydroxylation of four aliphatic positions in the target substrates, including a C(sp3)—H site not oxidized by the parent enzyme. Furthermore, our studies led to the discovery of a general activity-enhancing effect of active site substitutions involving the unnatural amino acid para-amino-Phe, resulting in P450 catalysts capable of supporting the highest total turnover number reported to date on a complex molecule (34,650 turnovers). The functional changes induced by the unnatural amino acids could not be recapitulated by any of the twenty natural amino acids. This study thus demonstrates that unnatural amino acid mutagenesis constitutes a promising, new strategy for improving the catalytic activity and regioselectivity of P450 oxidation catalysts. PMID:24692265

  8. Evaluation of hyper thermal acid hydrolysis of Kappaphycus alvarezii for enhanced bioethanol production.

    PubMed

    Ra, Chae Hun; Nguyen, Trung Hau; Jeong, Gwi-Taek; Kim, Sung-Koo

    2016-06-01

    Hyper thermal (HT) acid hydrolysis of Kappaphycus alvarezii, a red seaweed, was optimized to 12% (w/v) seaweed slurry content, 180mM H2SO4 at 140°C for 5min. The maximum monosaccharide concentration of 38.3g/L and 66.7% conversion from total fermentable monosaccharides of 57.6g/L with 120gdw/L K. alvarezii slurry were obtained from HT acid hydrolysis and enzymatic saccharification. HT acid hydrolysis at a severity factor of 0.78 efficiently converted the carbohydrates of seaweed to monosaccharides and produced a low concentration of inhibitory compounds. The levels of ethanol production by separate hydrolysis and fermentation with non-adapted and adapted Kluyveromyces marxianus to high concentration of galactose were 6.1g/L with ethanol yield (YEtOH) of 0.19 at 84h and 16.0g/L with YEtOH of 0.42 at 72h, respectively. Development of the HT acid hydrolysis process and adapted yeast could enhance the overall ethanol fermentation yields of K. alvarezii seaweed. PMID:26950757

  9. Enhanced fumaric acid production from brewery wastewater and insight into the morphology of Rhizopus oryzae 1526.

    PubMed

    Das, Ratul Kumar; Brar, Satinder Kaur

    2014-03-01

    The present work explores brewery wastewater as a novel substrate for fumaric acid production employing the filamentous fungal strain Rhizopus oryzae 1526 through submerged fermentation. The effects of different parameters such as substrate total solid concentrations, fermentation pH, incubation temperature, flask shaking speed, and inoculum size on the fungal morphologies were investigated. Different morphological forms (mycelium clumps, suspended mycelium, and solid/hairy pellets) of R. oryzae 1526 were obtained at different applied fermentation pH, incubation temperature, flask shaking speed, and inoculum size. Among all the obtained morphologies, pellet morphology was found to be the most favorable for enhanced production of fumaric acid for different studied parameters. Scanning electron microscopic investigation was done to reveal the detailed morphologies of the pellets formed under all optimized conditions. With all the optimized growth conditions (pH 6, 25 °C, 200 rpm, 5% (v/v) inoculum size, 25 g/L total solid concentration, and pellet diameter of 0.465 ± 0.04 mm), the highest concentration of fumaric acid achieved was 31.3 ± 2.77 g/L. The results demonstrated that brewery wastewater could be used as a good substrate for the fungal strain R. oryzae 1526 in submerged fermentation for the production of fumaric acid. PMID:24469587

  10. Enhancing proton conduction via doping of supramolecular liquid crystals (4-alkoxybenzoic acids) with imidazole

    NASA Astrophysics Data System (ADS)

    Liang, Ting; Wu, Yong; Tan, Shuai; Yang, Xiaohui; Wei, Bingzhuo

    2015-09-01

    Enhancing proton conduction via doping was first achieved in hydrogen-bonded liquid crystals consisting of benzoic acids. Supramolecular liquid crystals formed by pure 4-alkoxybenzoic acids (nAOBA, n = 8, 10, 12) exhibited the maximum proton conductivity of 5.0 × 10-8 S cm-1. Doping of nAOBA with 25 mol% imidazole (Im0.25) had little impact on mesomorphism but increased proton conductivities by at least 3 orders of magnitude. The liquid crystals formed by nAOBA-Im0.25 exhibited the maximum proton conductivity of 1.9 × 10-4 S cm-1. It was proposed that structure diffusion of imidazole bridged interdimer proton transfer to form continuous conducting pathways in mesomorphic nAOBA-Im0.25.

  11. Dithiol amino acids can structurally shape and enhance the ligand-binding properties of polypeptides

    NASA Astrophysics Data System (ADS)

    Chen, Shiyu; Gopalakrishnan, Ranganath; Schaer, Tifany; Marger, Fabrice; Hovius, Ruud; Bertrand, Daniel; Pojer, Florence; Heinis, Christian

    2014-11-01

    The disulfide bonds that form between two cysteine residues are important in defining and rigidifying the structures of proteins and peptides. In polypeptides containing multiple cysteine residues, disulfide isomerization can lead to multiple products with different biological activities. Here, we describe the development of a dithiol amino acid (Dtaa) that can form two disulfide bridges at a single amino acid site. Application of Dtaas to a serine protease inhibitor and a nicotinic acetylcholine receptor inhibitor that contain disulfide constraints enhanced their inhibitory activities 40- and 7.6-fold, respectively. X-ray crystallographic and NMR structure analysis show that the peptide ligands containing Dtaas have retained their native tertiary structures. We furthermore show that replacement of two cysteines by Dtaas can avoid the formation of disulfide bond isomers. With these properties, Dtaas are likely to have broad application in the rational design or directed evolution of peptides and proteins with high activity and stability.

  12. Histogram Analysis of Gadoxetic Acid-Enhanced MRI for Quantitative Hepatic Fibrosis Measurement

    PubMed Central

    Kim, Honsoul; Park, Seong Ho; Kim, Eun Kyung; Kim, Myeong-Jin; Park, Young Nyun; Park, Hae-Jeong; Choi, Jin-Young

    2014-01-01

    Purpose The diagnosis and monitoring of liver fibrosis is an important clinical issue; however, this is usually achieved by invasive methods such as biopsy. We aimed to determine whether histogram analysis of hepatobiliary phase images of gadoxetic acid-enhanced magnetic resonance imaging (MRI) can provide non-invasive quantitative measurement of liver fibrosis. Methods This retrospective study was approved by the institutional ethics committee, and a waiver of informed consent was obtained. Hepatobiliary phase images of preoperative gadoxetic acid-enhanced MRI studies of 105 patients (69 males, 36 females; age 56.1±12.2) with pathologically documented liver fibrosis grades were analyzed. Fibrosis staging was F0/F1/F2/F3/F4 (METAVIR system) for 11/20/13/15/46 patients, respectively. Four regions-of-interest (ROI, each about 2 cm2) were placed on predetermined locations of representative images. The measured signal intensity of pixels in each ROI was used to calculate corrected coefficient of variation (cCV), skewness, and kurtosis. An average value of each parameter was calculated for comparison. Statistical analysis was performed by ANOVA, receiver operating characteristic (ROC) curve analysis, and linear regression. Results The cCV showed statistically significant differences among pathological fibrosis grades (P<0.001) whereas skewness and kurtosis did not. Univariable linear regression analysis suggested cCV to be a meaningful parameter in predicting the fibrosis grade (P<0.001, β = 0.40 and standard error  = 0.06). For discriminating F0-3 from F4, the area under ROC score was 0.857, standard deviation 0.036, 95% confidence interval 0.785–0.928. Conclusion Histogram analysis of hepatobiliary phase images of gadoxetic acid-enhanced MRI can provide non-invasive quantitative measurements of hepatic fibrosis. PMID:25460180

  13. Lysophosphatidic acid enhances collagen deposition and matrix thickening in engineered tissue.

    PubMed

    Chabaud, Stéphane; Marcoux, Thomas-Louis; Deschênes-Rompré, Marie-Pier; Rousseau, Alexandre; Morissette, Amélie; Bouhout, Sara; Bernard, Geneviève; Bolduc, Stéphane

    2015-11-01

    The time needed to produce engineered tissue is critical. A self-assembly approach provided excellent results regarding biological functions and cell differentiation because it closely respected the microenvironment of cells. Nevertheless, the technique was time consuming for producing tissue equivalents with enough extracellular matrix to allow manipulations. Unlike L-arginine supplementation that only increased accumulation of collagen in cell culture supernatant in our model, addition of lysophosphatidic acid, a natural bioactive lipid, did not modify the amount of accumulated collagen in the cell culture supernatant; however, it enhanced the matrix deposition rate without inducing fibroblast hyperproliferation and tissue fibrosis.

  14. Thiolated Carboxymethyl-Hyaluronic-Acid-Based Biomaterials Enhance Wound Healing in Rats, Dogs, and Horses

    PubMed Central

    Yang, Guanghui; Prestwich, Glenn D.; Mann, Brenda K.

    2011-01-01

    The progression of wound healing is a complicated but well-known process involving many factors, yet there are few products on the market that enhance and accelerate wound healing. This is particularly problematic in veterinary medicine where multiple species must be treated and large animals heal slower, oftentimes with complicating factors such as the development of exuberant granulation tissue. In this study a crosslinked-hyaluronic-acid (HA-) based biomaterial was used to treat wounds on multiple species: rats, dogs, and horses. The base molecule, thiolated carboxymethyl HA, was first found to increase keratinocyte proliferation in vitro. Crosslinked gels and films were then both found to enhance the rate of wound healing in rats and resulted in thicker epidermis than untreated controls. Crosslinked films were used to treat wounds on forelimbs of dogs and horses. Although wounds healed slower compared to rats, the films again enhanced wound healing compared to untreated controls, both in terms of wound closure and quality of tissue. This study indicates that these crosslinked HA-based biomaterials enhance wound healing across multiple species and therefore may prove particularly useful in veterinary medicine. Reduced wound closure times and better quality of healed tissue would decrease risk of infection and pain associated with open wounds. PMID:23738117

  15. Comparative proteomic analysis of differentially expressed proteins in β-aminobutyric acid enhanced Arabidopsis thaliana tolerance to simulated acid rain.

    PubMed

    Liu, Tingwu; Jiang, Xinwu; Shi, Wuliang; Chen, Juan; Pei, Zhenming; Zheng, Hailei

    2011-05-01

    Acid rain is a worldwide environmental issue that has seriously destroyed forest ecosystems. As a highly effective and broad-spectrum plant resistance-inducing agent, β-aminobutyric acid could elevate the tolerance of Arabidopsis when subjected to simulated acid rain. Using comparative proteomic strategies, we analyzed 203 significantly varied proteins of which 175 proteins were identified responding to β-aminobutyric acid in the absence and presence of simulated acid rain. They could be divided into ten groups according to their biological functions. Among them, the majority was cell rescue, development and defense-related proteins, followed by transcription, protein synthesis, folding, modification and destination-associated proteins. Our conclusion is β-aminobutyric acid can lead to a large-scale primary metabolism change and simultaneously activate antioxidant system and salicylic acid, jasmonic acid, abscisic acid signaling pathways. In addition, β-aminobutyric acid can reinforce physical barriers to defend simulated acid rain stress.

  16. Using Laboratory Activities Enhanced with Concept Cartoons to Support Progression in Students' Understanding of Acid-Base Concepts

    ERIC Educational Resources Information Center

    Ozmen, Haluk; Demircioglu, Gokhan; Burhan, Yasemin; Naseriazar, Akbar; Demircioglu, Hulya

    2012-01-01

    The aim of this study is to examine the effectiveness of an intervention based on a series of laboratory activities enhanced with concept cartoons. The purpose of the intervention was to enhance students' understanding of acid-base chemistry for eight grade students' from two classes in a Turkish primary school. A pretest-posttest non-equivalent…

  17. Label-free direct surface-enhanced Raman scattering (SERS) of nucleic acids (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Guerrini, Luca; Morla-Folch, Judit; Gisbert-Quilis, Patricia; Xie, Hainan; Alvarez-Puebla, Ramon

    2016-03-01

    Recently, plasmonic-based biosensing has experienced an unprecedented level of attention, with a particular focus on the nucleic acid detection, offering efficient solutions to engineer simple, fast, highly sensitive sensing platforms while overcoming important limitations of PCR and microarray techniques. In the broad field of plasmonics, surface-enhanced Raman scattering (SERS) spectroscopy has arisen as a powerful analytical tool for detection and structural characterization of biomolecules. Today applications of SERS to nucleic acid analysis largely rely on indirect strategies, which have been demonstrated very effective for pure sensing purposes but completely dismiss the exquisite structural information provided by the direct acquisition of the biomolecular vibrational fingerprint. Contrarily, direct label-free SERS of nucleic acid shows an outstanding potential in terms of chemical-specific information which, however, remained largely unexpressed mainly because of the inherent poor spectral reproducibility and/or limited sensitivity. To address these limitations, we developed a fast and affordable high-throughput screening direct SERS method for gaining detailed genomic information on nucleic acids (DNA and RNA) and for the characterization and quantitative recognition of DNA interactions with exogenous agents. The simple strategy relies on the electrostatic adhesion of DNA/RNA onto positively-charged silver colloids that promotes the nanoparticle aggregation into stable clusters yielding intense and reproducible SERS spectra at picogram level (i.e. the analysis can be performed without the necessity of amplification steps thus providing realistic direct information of the nucleic acid in its native state). We anticipate this method to gain a vast impact and set of applications in different fields, including medical diagnostics, genomic screening, drug discovery, forensic science and even molecular electronics.

  18. Docosahexaenoic Acid Induces Oxidative DNA Damage and Apoptosis, and Enhances the Chemosensitivity of Cancer Cells.

    PubMed

    Song, Eun Ah; Kim, Hyeyoung

    2016-01-01

    The human diet contains low amounts of ω-3 polyunsaturated fatty acids (PUFAs) and high amounts of ω-6 PUFAs, which has been reported to contribute to the incidence of cancer. Epidemiological studies have shown that a high consumption of fish oil or ω-3 PUFAs reduced the risk of colon, pancreatic, and endometrial cancers. The ω-3 PUFA, docosahexaenoic acid (DHA), shows anticancer activity by inducing apoptosis of some human cancer cells without toxicity against normal cells. DHA induces oxidative stress and oxidative DNA adduct formation by depleting intracellular glutathione (GSH) and decreasing the mitochondrial function of cancer cells. Oxidative DNA damage and DNA strand breaks activate DNA damage responses to repair the damaged DNA. However, excessive DNA damage beyond the capacity of the DNA repair processes may initiate apoptotic signaling pathways and cell cycle arrest in cancer cells. DHA shows a variable inhibitory effect on cancer cell growth depending on the cells' molecular properties and degree of malignancy. It has been shown to affect DNA repair processes including DNA-dependent protein kinases and mismatch repair in cancer cells. Moreover, DHA enhanced the efficacy of anticancer drugs by increasing drug uptake and suppressing survival pathways in cancer cells. In this review, DHA-induced oxidative DNA damage, apoptotic signaling, and enhancement of chemosensitivity in cancer cells will be discussed based on recent studies. PMID:27527148

  19. Ultrasonic enhance acid hydrolysis selectivity of cellulose with HCl-FeCl3 as catalyst.

    PubMed

    Li, Jinbao; Zhang, Xiangrong; Zhang, Meiyun; Xiu, Huijuan; He, Hang

    2015-03-01

    The effect of ultrasonic pretreatment coupled with HCl-FeCl3 catalyst was evaluated to hydrolyze cellulose amorphous regions. The ultrasonic pretreatment leads to cavitation that affects the morphology and microstructure of fibers, enhancing the accessibility of chemical reagent to the loosened amorphous regions of cellulose. In this work, Fourier transform infrared spectroscopy (FTIR) was used to identify characteristic absorption bands of the constituents and the crystallinity was evaluated by the X-ray diffraction (XRD) technique. The results indicated that appropriate ultrasonic pretreatment assisted with FeCl3 can enhance the acid hydrolysis of amorphous regions of cellulose, thus improving the crystallinity of the remaining hydrocellulose. It was observed that sonication samples that were pretreated for 300 W and 20 min followed by acid hydrolysis had maximum of 78.9% crystallinity. The crystallinity was 9.2% higher than samples that were not subjected to ultrasound. In addition, the average fines length decreased from 49 μm to 37 μm. PMID:25498717

  20. Detection of amino acid neurotransmitters by surface enhanced Raman scattering and hollow core photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Tiwari, Vidhu S.; Khetani, Altaf; Monfared, Ali Momenpour T.; Smith, Brett; Anis, Hanan; Trudeau, Vance L.

    2012-03-01

    The present work explores the feasibility of using surface enhanced Raman scattering (SERS) for detecting the neurotransmitters such as glutamate (GLU) and gamma-amino butyric acid (GABA). These amino acid neurotransmitters that respectively mediate fast excitatory and inhibitory neurotransmission in the brain, are important for neuroendocrine control, and upsets in their synthesis are also linked to epilepsy. Our SERS-based detection scheme enabled the detection of low amounts of GLU (10-7 M) and GABA (10-4 M). It may complement existing techniques for characterizing such kinds of neurotransmitters that include high-performance liquid chromatography (HPLC) or mass spectrography (MS). This is mainly because SERS has other advantages such as ease of sample preparation, molecular specificity and sensitivity, thus making it potentially applicable to characterization of experimental brain extracts or clinical diagnostic samples of cerebrospinal fluid and saliva. Using hollow core photonic crystal fiber (HC-PCF) further enhanced the Raman signal relative to that in a standard cuvette providing sensitive detection of GLU and GABA in micro-litre volume of aqueous solutions.

  1. Enhanced esterification of oleic acid and methanol by deep eutectic solvent assisted Amberlyst heterogeneous catalyst.

    PubMed

    Pan, Ying; Alam, Md Asraful; Wang, Zhongming; Wu, Jingcheng; Zhang, Yi; Yuan, Zhenhong

    2016-11-01

    In present study, esterification of oleic acid with methanol using deep eutectic solvent (DES) assisted Amberlyst heterogeneous catalyst was investigated to produce biodiesel. Results showed that esterification efficiency was enhanced by the DES. The combined effect of DES on Amberlyst BD20 (BD20) is better than Amberlyst 15 (A-15) due to different structure. The optimal reaction conditions were 12:1M ratio of methanol to oleic acid, 20%(wt/wt) catalyst (BD20-DES (2:8) and A-15-DES (8:2)) at 85°C for 100min with agitating at 200rpm. The mechanism involved in catalysis and their capacity to reuse were studied. We proposed, Choline chloride-glycerol (Chcl-gly) DES could enhance the Amberlyst function due to the hydrogen bond effect on both DES and water. BD20 has fewer pores than A-15, have desirable performance in decreasing the inhibition the water during esterification of high FFA content and provide better performance in reuse.

  2. Amino acid conjugated self assembling molecules for enhancing surface wettability of fiber laser treated titanium surfaces

    NASA Astrophysics Data System (ADS)

    Akkan, Cagri K.; Hür, Deniz; Uzun, Lokman; Garipcan, Bora

    2016-03-01

    Surface wetting properties of implants are one of the most critical parameter, which determine the interaction of proteins and cells with the implant surface. In this regards, acid etching and sand blasting are the mostly used methods at surface modification of Titanium (Ti) for enhanced surface wettability. Besides, these kinds of modifications may cause a conflict whether the surface wettability is influenced by the process related surface contaminations or by the surface roughness. In contrast, lasers might be an option for the alteration of surface wetting properties via supporting micro and/or nano surface topographies while preventing surface chemical contaminations. In this work, we focused on two steps of surface processing approaches of Ti surface: physical and chemical modifications. Herein, we hierarchically structured Ti surfaces by using microsecond modulated pulsed fiber laser. Subsequently, laser structured and non-structured Ti surfaces were further modified with novel histidine and leucine Amino Acid conjugated Self-Assembled Molecules (His1-SAMs2 and Leu3-SAMs) to alter the surface wettability by introducing biologically hydrophilic and hydrophobic groups. Modification of Ti surfaces with His-SAMs and Leu-SAMs ended up with stable wetting properties when compared to non-modified surfaces after 7 days which may enhances the cell-surface interaction.

  3. Docosahexaenoic Acid Induces Oxidative DNA Damage and Apoptosis, and Enhances the Chemosensitivity of Cancer Cells

    PubMed Central

    Song, Eun Ah; Kim, Hyeyoung

    2016-01-01

    The human diet contains low amounts of ω-3 polyunsaturated fatty acids (PUFAs) and high amounts of ω-6 PUFAs, which has been reported to contribute to the incidence of cancer. Epidemiological studies have shown that a high consumption of fish oil or ω-3 PUFAs reduced the risk of colon, pancreatic, and endometrial cancers. The ω-3 PUFA, docosahexaenoic acid (DHA), shows anticancer activity by inducing apoptosis of some human cancer cells without toxicity against normal cells. DHA induces oxidative stress and oxidative DNA adduct formation by depleting intracellular glutathione (GSH) and decreasing the mitochondrial function of cancer cells. Oxidative DNA damage and DNA strand breaks activate DNA damage responses to repair the damaged DNA. However, excessive DNA damage beyond the capacity of the DNA repair processes may initiate apoptotic signaling pathways and cell cycle arrest in cancer cells. DHA shows a variable inhibitory effect on cancer cell growth depending on the cells’ molecular properties and degree of malignancy. It has been shown to affect DNA repair processes including DNA-dependent protein kinases and mismatch repair in cancer cells. Moreover, DHA enhanced the efficacy of anticancer drugs by increasing drug uptake and suppressing survival pathways in cancer cells. In this review, DHA-induced oxidative DNA damage, apoptotic signaling, and enhancement of chemosensitivity in cancer cells will be discussed based on recent studies. PMID:27527148

  4. Enhanced esterification of oleic acid and methanol by deep eutectic solvent assisted Amberlyst heterogeneous catalyst.

    PubMed

    Pan, Ying; Alam, Md Asraful; Wang, Zhongming; Wu, Jingcheng; Zhang, Yi; Yuan, Zhenhong

    2016-11-01

    In present study, esterification of oleic acid with methanol using deep eutectic solvent (DES) assisted Amberlyst heterogeneous catalyst was investigated to produce biodiesel. Results showed that esterification efficiency was enhanced by the DES. The combined effect of DES on Amberlyst BD20 (BD20) is better than Amberlyst 15 (A-15) due to different structure. The optimal reaction conditions were 12:1M ratio of methanol to oleic acid, 20%(wt/wt) catalyst (BD20-DES (2:8) and A-15-DES (8:2)) at 85°C for 100min with agitating at 200rpm. The mechanism involved in catalysis and their capacity to reuse were studied. We proposed, Choline chloride-glycerol (Chcl-gly) DES could enhance the Amberlyst function due to the hydrogen bond effect on both DES and water. BD20 has fewer pores than A-15, have desirable performance in decreasing the inhibition the water during esterification of high FFA content and provide better performance in reuse. PMID:27614157

  5. Transcriptome analysis of acetic-acid-treated yeast cells identifies a large set of genes whose overexpression or deletion enhances acetic acid tolerance.

    PubMed

    Lee, Yeji; Nasution, Olviyani; Choi, Eunyong; Choi, In-Geol; Kim, Wankee; Choi, Wonja

    2015-08-01

    Acetic acid inhibits the metabolic activities of Saccharomyces cerevisiae. Therefore, a better understanding of how S. cerevisiae cells acquire the tolerance to acetic acid is of importance to develop robust yeast strains to be used in industry. To do this, we examined the transcriptional changes that occur at 12 h post-exposure to acetic acid, revealing that 56 and 58 genes were upregulated and downregulated, respectively. Functional categorization of them revealed that 22 protein synthesis genes and 14 stress response genes constituted the largest portion of the upregulated and downregulated genes, respectively. To evaluate the association of the regulated genes with acetic acid tolerance, 3 upregulated genes (DBP2, ASC1, and GND1) were selected among 34 non-protein synthesis genes, and 54 viable mutants individually deleted for the downregulated genes were retrieved from the non-essential haploid deletion library. Strains overexpressing ASC1 and GND1 displayed enhanced tolerance to acetic acid, whereas a strain overexpressing DBP2 was sensitive. Fifty of 54 deletion mutants displayed enhanced acetic acid tolerance. Three chosen deletion mutants (hsps82Δ, ato2Δ, and ssa3Δ) were also tolerant to benzoic acid but not propionic and sorbic acids. Moreover, all those five (two overexpressing and three deleted) strains were more efficient in proton efflux and lower in membrane permeability and internal hydrogen peroxide content than controls. Individually or in combination, those physiological changes are likely to contribute at least in part to enhanced acetic acid tolerance. Overall, information of our transcriptional profile was very useful to identify molecular factors associated with acetic acid tolerance.

  6. Desire for penile girth enhancement and the effects of the self-injection of hyaluronic Acid gel.

    PubMed

    Coskuner, Enis Rauf; Canter, Halil Ibrahim

    2012-07-01

    Penile girth enhancement is a controversial subject but demands for enhancement are increasing steadily. Although various fillers have been widely used for soft tissue augmentation, there is no reliable material for this particular situation. Here we report a case of an acute hypersensitivity reaction in a man after his first self-injection of a filler material, which, he claimed, was hyaluronic acid gel for penile girth enhancement and glans penis augmentation. PMID:23112518

  7. Acidity enhancement of unsaturated bases of group 15 by association with borane and beryllium dihydride. Unexpected boron and beryllium Brønsted acids.

    PubMed

    Martín-Sómer, Ana; Mó, Otilia; Yáñez, Manuel; Guillemin, Jean-Claude

    2015-01-21

    The intrinsic acidity of CH2[double bond, length as m-dash]CHXH2, HC[triple bond, length as m-dash]CXH2 (X = N, P, As, Sb) derivatives and of their complexes with BeH2 and BH3 has been investigated by means of high-level density functional theory and molecular orbital ab initio calculations, using as a reference the ethyl saturated analogues. The acidity of the free systems steadily increases down the group for the three series of derivatives, ethyl, vinyl and ethynyl. The association with both beryllium dihydride and borane leads to a very significant acidity enhancement, being larger for BeH2 than for BH3 complexes. This acidity enhancement, for the unsaturated compounds, is accompanied by a change in the acidity trends down the group, which do not steadily decrease but present a minimum value for both the vinyl- and the ethynyl-phosphine. When the molecule acting as the Lewis acid is beryllium dihydride, the π-type complexes in which the BeH2 molecules interact with the double or triple bond are found, in some cases, to be more stable, in terms of free energies, than the conventional complexes in which the attachment takes place at the heteroatom, X. The most important finding, however, is that P, As, and Sb ethynyl complexes with BeH2 do not behave as P, As, or Sb Brønsted acids, but unexpectedly as Be acids.

  8. Hypotonic stimuli enhance proton-gated currents of acid-sensing ion channel-1b

    SciTech Connect

    Ugawa, Shinya Ishida, Yusuke; Ueda, Takashi; Yu, Yong; Shimada, Shoichi

    2008-03-14

    Acid-sensing ion channels (ASICs) are strong candidates for mammalian mechanoreceptors. We investigated whether mouse acid-sensing ion channel-1b (ASIC1b) is sensitive to mechanical stimuli using oocyte electrophysiology, because ASIC1b is located in the mechanosensory stereocilia of cochlear hair cells. Hypotonic stimuli that induced membrane stretch of oocytes evoked no significant current in ASIC1b-expressing oocytes at pH 7.5. However, acid (pH 4.0 or 5.0)-evoked currents in the oocytes were substantially enhanced by the hypotonicity, showing mechanosensitivity of ASIC1b and possible mechanogating of the channel in the presence of other components. Interestingly, the ASIC1b channel was permeable to K{sup +} (a principal charge carrier for cochlear sensory transduction) and the affinity of the channel for amiloride (IC{sub 50} (inhibition constant) = approximately 48.3 {mu}M) was quite similar to that described for the mouse hair cell mechanotransducer current. Taken together, these data raise the possibility that ASIC1b participates in cochlear mechanoelectrical transduction.

  9. Enhanced copper surface protection in aqueous solutions containing short-chain alkanoic acid potassium salts.

    PubMed

    Abelev, Esta; Starosvetsky, David; Ein-Eli, Yair

    2007-10-23

    The ability of dissolved potassium monocarboxylate salts to produce surface passivation and to inhibit aqueous corrosion of copper was studied. The electrochemical measurements indicate that the inhibiting efficiency of these compounds, with a general formula Cn-1H2n-1COOK or CnK (n=3...12), is dependent on the hydrocarbon chain length. The inhibiting efficiency was higher for a longer hydrocarbon chain of n-alkanoic acid. The degree of copper protection was found to increase with an increase in n-alkanoic acid potassium salt concentration; the optimum concentration of potassium dodecanoate (C12K) in sulfate solutions was found to be 0.07 M. The protective layers formed at the copper surface subsequent to exposure in various n-alkanoic acid potassium salt solutions were characterized by contact angle measurements, electrochemical impedance spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared reflection spectroscopy. Pronounced copper protection was attributed to the growth of a protective film on the copper surface, containing both copper oxides and copper carboxylate compounds. It is suggested that the organic molecules enhance copper protection by covering copper oxides with a thin and dense organic layer, which prevents water molecules or aggressive anions from interacting with the copper surface.

  10. Enhanced thermal tolerance in a mutant of Arabidopsis deficient in palmitic acid unsaturation

    SciTech Connect

    Kunst, L.; Somerville, C. ); Browse, J. )

    1989-09-01

    A mutant of Arabidopsis thaliana, deficient in the activity of a chloroplast {omega}9 fatty acid desaturase, accumulates high amounts of palmitic acid (16:0), and exhibits an overall reduction in the level of unsaturation of chloroplast lipids. Under standard conditions the altered membrane lipid composition had only minor effects on growth rate of the mutant, net photosynthetic CO{sub 2} fixation, photosynthetic electron transport, or chloroplast ultrastructure. Similarly, fluorescence polarization measurements indicated that the fluidity of the membranes was not significantly different in the mutant and the wild type. However, at temperatures above 28{degree}C, the mutant grew more rapidly than the wild type suggesting that the altered fatty acid composition enhanced the thermal tolerance of the mutant. Similarly, the chloroplast membranes of the mutant were more resistant than wild type to thermal inactivation of photosynthetic electron transport. These observations lend support to previous suggestions that chloroplast membrane lipid composition may be an important component of the thermal acclimation response observed in many plant species which are photosynthetically active during periods of seasonally variable temperature extremes.

  11. Freezing-Enhanced Dissolution of Iron Oxides: Effects of Inorganic Acid Anions.

    PubMed

    Jeong, Daun; Kim, Kitae; Min, Dae Wi; Choi, Wonyong

    2015-11-01

    Dissolution of iron from mineral dust particles greatly depends upon the type and amount of copresent inorganic anions. In this study, we investigated the roles of sulfate, chloride, nitrate, and perchlorate on the dissolution of maghemite and lepidocrocite in ice under both dark and UV irradiation and compared the results with those of their aqueous counterparts. After 96 h of reaction, the total dissolved iron in ice (pH 3 before freezing) was higher than that in the aqueous phase (pH 3) by 6-28 times and 10-20 times under dark and UV irradiation, respectively. Sulfuric acid was the most efficient in producing labile iron under dark condition, whereas hydrochloric acid induced the most dissolution of the total and ferrous iron in the presence of light. This ice-induced dissolution result was also confirmed with Arizona Test Dust (AZTD). In the freeze-thaw cycling test, the iron oxide samples containing chloride, nitrate, or perchlorate showed a similar extent of total dissolved iron after each cycling while the sulfate-containing sample rapidly lost its dissolution activity with repeating the cycle. This unique phenomenon observed in ice might be related to the freeze concentration of protons, iron oxides, and inorganic anions in the liquid-like ice grain boundary region. These results suggest that the ice-enhanced dissolution of iron oxides can be a potential source of bioavailable iron, and the acid anions critically influence this process.

  12. Growth suppression by ursodeoxycholic acid involves caveolin-1 enhanced degradation of EGFR

    PubMed Central

    Feldman, Rebecca; Martinez, Jesse D.

    2009-01-01

    Summary Ursodeoxycholic acid (UDCA) has been shown to prevent colon tumorigenesis in animal models and in humans. In vitro work indicates that this bile acid can suppress cell growth and mitogenic signaling suggesting that UDCA may be an anti-proliferative agent. However, the mechanism by which UDCA functions is unclear. Previously we showed that bile acids may alter cellular signaling by acting at the plasma membrane. Here we utilized EGFR as a model membrane receptor and examined the effects that UDCA has on its functioning. We found that UDCA promoted an interaction between EGFR and caveolin-1 and this interaction enhanced UDCA-mediated suppression of MAP kinase activity and cell growth . Importantly, UDCA treatment led to recruitment of the ubiquitin ligase, c-Cbl, to the membrane, ubiquitination of EGFR, and increased receptor degradation. Moreover, suppression of c-Cbl activity abrogated UDCA's growth suppression activities suggesting that receptor ubiquitination plays an important role in UDCA's biological activities. Taken together these results suggest that UDCA may act to suppress cell growth by inhibiting the mitogenic activity of receptor tyrosine kinases such as EGFR through increased receptor degradation. PMID:19446582

  13. Gold Nanoparticles Enhance the Anticancer Activity of Gallic Acid against Cholangiocarcinoma Cell Lines.

    PubMed

    Rattanata, Narintorn; Daduang, Sakda; Wongwattanakul, Molin; Leelayuwat, Chanvit; Limpaiboon, Temduang; Lekphrom, Ratsami; Sandee, Alisa; Boonsiri, Patcharee; Chio-Srichan, Sirinart; Daduang, Jureerut

    2015-01-01

    Gold nanoparticles (GNPs) were conjugated with gallic acid (GA) at various concentrations between 30 and 150 μM and characterized using transmission electron microscopy (TEM) and UV-Vis spectroscopy (UV-VIS). The anticancer activities of the gallic acid-stabilized gold nanoparticles against well-differentiated (M213) and moderately differentiated (M214) adenocarcinomas were then determined using a neutral red assay. The GA mechanism of action was evaluated using Fourier transform infrared (FTIR) microspectroscopy. Distinctive features of the FTIR spectra between the control and GA-treated cells were confirmed by principal component analysis (PCA). The surface plasmon resonance spectra of the GNPs had a maximum absorption at 520 nm, whereas GNPs-GA shifted the maximum absorption values. In an in vitro study, the complexed GNPs-GA had an increased ability to inhibit the proliferation of cancer cells that was statistically significant (P<0.0001) in both M213 and M214 cells compared to GA alone, indicating that the anticancer activity of GA can be improved by conjugation with GNPs. Moreover, PCA revealed that exposure of the tested cells to GA resulted in significant changes in their cell membrane lipids and fatty acids, which may enhance the efficacy of this anticancer activity regarding apoptosis pathways.

  14. Freezing-Enhanced Dissolution of Iron Oxides: Effects of Inorganic Acid Anions.

    PubMed

    Jeong, Daun; Kim, Kitae; Min, Dae Wi; Choi, Wonyong

    2015-11-01

    Dissolution of iron from mineral dust particles greatly depends upon the type and amount of copresent inorganic anions. In this study, we investigated the roles of sulfate, chloride, nitrate, and perchlorate on the dissolution of maghemite and lepidocrocite in ice under both dark and UV irradiation and compared the results with those of their aqueous counterparts. After 96 h of reaction, the total dissolved iron in ice (pH 3 before freezing) was higher than that in the aqueous phase (pH 3) by 6-28 times and 10-20 times under dark and UV irradiation, respectively. Sulfuric acid was the most efficient in producing labile iron under dark condition, whereas hydrochloric acid induced the most dissolution of the total and ferrous iron in the presence of light. This ice-induced dissolution result was also confirmed with Arizona Test Dust (AZTD). In the freeze-thaw cycling test, the iron oxide samples containing chloride, nitrate, or perchlorate showed a similar extent of total dissolved iron after each cycling while the sulfate-containing sample rapidly lost its dissolution activity with repeating the cycle. This unique phenomenon observed in ice might be related to the freeze concentration of protons, iron oxides, and inorganic anions in the liquid-like ice grain boundary region. These results suggest that the ice-enhanced dissolution of iron oxides can be a potential source of bioavailable iron, and the acid anions critically influence this process. PMID:26444653

  15. Facile plasma-enhanced deposition of ultrathin crosslinked amino acid films for conformal biometallization.

    PubMed

    Anderson, Kyle D; Slocik, Joseph M; McConney, Michael E; Enlow, Jesse O; Jakubiak, Rachel; Bunning, Timothy J; Naik, Rajesh R; Tsukruk, Vladimir V

    2009-03-01

    A novel method for the facile fabrication of conformal, ultrathin, and uniform synthetic amino acid coatings on a variety of practical surfaces by plasma-enhanced chemical vapor deposition is introduced. Tyrosine, which is utilized as an agent to reduce gold nanoparticles from solution, is sublimed into the plasma field and directly deposited on a variety of substrates to form a homogeneous, conformal, and robust polyamino acid coating in a one-step, solvent-free process. This approach is applicable to many practical surfaces and allows surface-induced biometallization while avoiding multiple wet-chemistry treatments that can damage many soft materials. Moreover, by placing a mask over the substrate during deposition, the tyrosine coating can be micropatterned. Upon its exposure to a solution of gold chloride, a network of gold nanoparticles forms on the surface, replicating the initial micropattern. This method of templated biometallization is adaptable to a variety of practical inorganic and organic substrates, such as silicon, glass, nitrocellulose, polystyrene, polydimethylsiloxane, polytetrafluoroethylene, polyethylene, and woven silk fibers. No special pretreatment is necessary, and the technique results in a rapid, conformal amino acid coating that can be utilized for further biometallization.

  16. Enhanced histamine release from lung mast cells of guinea pigs exposed to sulfuric acid aerosols

    SciTech Connect

    Fujimaki, Hidekazu ); Katayama, Noboru; Wakamori, Kazuo )

    1992-06-01

    To clarify the relationship between air pollution and mast cell response, the effects of sulfuric acid aerosols on histamine release from lung mast cells of guinea pigs were investigated. Guinea pigs were exposed to 0.3, 1.0 and 3.2 mg/m{sup 3} sulfuric acid (H{sub 2}SO{sub 4}) aerosols or 4 ppm nitrogen dioxide (NO{sub 2}) for 2 and 4 weeks. After the exposure, lung mast cell suspensions were isolated by collagenase treatment and antigen- or A23187-induced histamine release was measured. Antigen-induced histamine release from mast cells was significantly enhanced by the exposure to 1.0 and 3.2 mg/m{sup 3} H{sub 2}SO{sub 4} for 2 weeks, but exposure to H{sub 2}SO{sub 4} for 4 weeks did not show the enhancement of antigen-induced histamine release. A23187-induced histamine release was significantly enhanced by the exposure to 1.0 mg/m{sup 3} H{sub 2}SO{sub 4} or 4 ppm NO{sub 2} for 2 weeks, but suppression of histamine release from lung mast cells stimulated with A23187 was observed by the exposure to 3.2 mg/m{sup 3} H{sub 2}So{sub 4} for 4 weeks. The exposure to 0.3 mg/m{sup 3} H{sub 2}So{sub 4} showed no changes in antigen- and A23187-induced histamine release. The combination of 1.0 mg/m{sup 3} H{sub 2}So{sub 4} with 4 ppm NO{sub 2} for 2 weeks resulted in no changes in antigen- and A23187-induced histamine release. These results suggested that functional properties of lung mast cells may be altered by a low concentration of H{sub 2}So{sub 4} aerosol exposure.

  17. Resveratrol and P-glycoprotein Inhibitors Enhance the Anti-skin Cancer Effects of Ursolic Acid

    PubMed Central

    Junco, Jacob J.; Mancha, Anna; Malik, Gunjan; Wei, Sung-Jen; Kim, Dae Joon; Liang, Huiyun; Slaga, Thomas J.

    2013-01-01

    Ursolic acid (UA), present in apples, rosemary, and other sources, is known to inhibit tumor formation and tumor cell viability in multiple systems, including skin. However, various cancers are resistant to UA treatment. Herein, skin carcinoma cells (Ca3/7) as compared to skin papilloma cells (MT1/2) displayed more resistance to UA-induced cytotoxicity. Interestingly, Ca3/7 cells had elevated levels of P-glycoprotein (P-gp), an ATP-dependent efflux pump that mediates resistance to chemotherapy in pre-clinical and clinical settings, and not only accumulated less but also more rapidly expelled the P-gp substrate Rhodamine 123 (Rh123) indicating UA is transported by P-gp. To determine if P-gp inhibition can enhance UA-mediated cytotoxicity, cells were challenged with P-gp inhibitors verapamil (VRP) or cyclosporin A (CsA). Alternatively, cells were pre-treated with the natural compound resveratrol (RES), a known chemotherapy sensitizer. VRP and RES enhanced the effects of UA in both cell lines, while CsA only did so in Ca3/7 cells. Similarly, VRP inhibited Rh123 efflux in both lines, while CsA only inhibited Rh123 efflux in Ca3/7 cells. RES did not inhibit Rh123 efflux in either line, indicating the synergistic effects of RES and UA are not manifest by inhibition of P-gp-mediated efflux of UA. These results indicate that the anti-skin cancer effects of UA are enhanced with P-gp inhibitors. In addition, RES and UA interact synergistically, but not through inhibition of P-gp. Implications Resveratrol and/or p-glycoprotein inhibitors in combination with ursolic acid are an effective anti-skin cancer regimen. PMID:24072817

  18. Ethylene-Enhanced 1-Aminocyclopropane-1-carboxylic Acid Synthase Activity in Ripening Apples 1

    PubMed Central

    Bufler, Gebhard

    1984-01-01

    Apples (Malus sylvestris Mill, cv Golden Delicious) were treated before harvest with aminoethoxyvinylglycine (AVG). AVG is presumed to reversibly inhibit 1-aminocyclopropane-1-carboxylic acid (ACC) activity, but not the formation of ACC synthase. AVG treatment effectively blocked initiation of autocatalytic ethylene production and ripening of harvested apples. Exogenous ethylene induced extractable ACC synthase activity and ripening in AVG-treated apples. Removal of exogenous ethylene caused a rapid decline in ACC synthase activity and in CO2 production. The results with ripened, AVG-treated apples indicate (a) a dose-response relationship between ethylene and enhancement of ACC synthase activity with a half-maximal response at approximately 0.8 μl/l ethylene; (b) reversal of ethylene-enhanced ACC synthase activity by CO2; (c) enhancement of ACC synthase activity by the ethylene-activity analog propylene. Induction of ACC synthase activity, autocatalytic ethylene production, and ripening of preclimacteric apples not treated with AVG were delayed by 6 and 10% CO2, but not by 1.25% CO2. However, each of these CO2 concentrations reduced the rate of increase of ACC synthase activity. PMID:16663569

  19. Expression of Vitis amurensis NAC26 in Arabidopsis enhances drought tolerance by modulating jasmonic acid synthesis.

    PubMed

    Fang, Linchuan; Su, Lingye; Sun, Xiaoming; Li, Xinbo; Sun, Mengxiang; Karungo, Sospeter Karanja; Fang, Shuang; Chu, Jinfang; Li, Shaohua; Xin, Haiping

    2016-04-01

    The growth and fruit quality of grapevines are widely affected by abnormal climatic conditions such as water deficits, but many of the precise mechanisms by which grapevines respond to drought stress are still largely unknown. Here, we report that VaNAC26, a member of the NAC transcription factor family, was upregulated dramatically during cold, drought and salinity treatments in Vitis amurensis, a cold and drought-hardy wild Vitis species. Heterologous overexpression of VaNAC26 enhanced drought and salt tolerance in transgenic Arabidopsis. Higher activities of antioxidant enzymes and lower concentrations of H2O2 and O2 (-) were found in VaNAC26-OE lines than in wild type plants under drought stress. These results indicated that scavenging by reactive oxygen species (ROS) was enhanced by VaNAC26 in transgenic lines. Microarray-based transcriptome analysis revealed that genes related to jasmonic acid (JA) synthesis and signaling were upregulated in VaNAC26-OE lines under both normal and drought conditions. VaNAC26 showed a specific binding ability on the NAC recognition sequence (NACRS) motif, which broadly exists in the promoter regions of upregulated genes in transgenic lines. Endogenous JA content significantly increased in the VaNAC26-OE lines 2 and 3. Our data suggest that VaNAC26 responds to abiotic stresses and may enhance drought tolerance by transcriptional regulation of JA synthesis in Arabidopsis.

  20. Uric acid enhances the antitumor immunity of dendritic cell-based vaccine.

    PubMed

    Wang, Yihan; Ma, Xuelei; Su, Chao; Peng, Bin; Du, Jing; Jia, Hongyuan; Luo, Min; Fang, Chunju; Wei, Yuquan

    2015-01-01

    Uric acid (UA) released from dying cells has been recognized by the immune system as a danger signal. In response to UA, dendritic cells (DC) in the immune system mature and enhance the T cell response to foreign antigens. It is conceivable that the antitumor immunity of a tumor vaccine could be promoted by the administration of UA. To test this concept, we applied UA as an adjuvant to a DC-based vaccine, and discovered that the administration of UA as an adjuvant significantly enhanced the ability of the tumor lysate-pulsed DC vaccine in delaying the tumor growth. The antitumor activity was achieved with adoptively transferred lymphocytes, and both CD8(+) T cells and NK cells were required to achieve effective immunity. This resulted in an increased accumulation of activated CD8(+) T cells and an elevated production of IFN-γ. Collectively, our study shows that the administration of UA enhances the antitumor activity of tumor lysate-pulsed DC vaccine, thus providing the preclinical rationale for the application of UA in DC-based vaccine strategies.

  1. SV40 enhancer activation during retinoic acid-induced differentiation of F9 embryonal carcinoma cells.

    PubMed Central

    Sleigh, M J; Lockett, T J

    1985-01-01

    The transient expression vector pSV2CAT, which carries the bacterial chloramphenicol acetyl transferase (CAT) gene under the control of the SV40 early promoter, was used to transfect the murine embryonal carcinoma cell line F9 at various times during the retinoic acid-induced differentiation of these cells. Expression of the CAT gene under SV40 promoter control was found to increase markedly on F9 cell differentiation, measured relative to expression from the thymidine kinase promoter in the same cells. A series of constructs was prepared to identify the features of the SV40 early promoter required for transcription in differentiated and undifferentiated cells, as well as the factors limiting transcription in each case. The increased transcription seen on F9 cell differentiation was not observed when cells were transfected with molecules lacking a functional enhancer. It appears that as embryonal carcinoma cells differentiate, increased SV40 transcription results from enhancer sequence activation. In both differentiated and undifferentiated cell types the level of transcription was found to be limited by the availability and/or activity of cellular factors necessary for enhancer function. Images Fig. 1. PMID:3004973

  2. Expression of Vitis amurensis NAC26 in Arabidopsis enhances drought tolerance by modulating jasmonic acid synthesis

    PubMed Central

    Fang, Linchuan; Su, Lingye; Sun, Xiaoming; Li, Xinbo; Sun, Mengxiang; Karungo, Sospeter Karanja; Fang, Shuang; Chu, Jinfang; Li, Shaohua; Xin, Haiping

    2016-01-01

    The growth and fruit quality of grapevines are widely affected by abnormal climatic conditions such as water deficits, but many of the precise mechanisms by which grapevines respond to drought stress are still largely unknown. Here, we report that VaNAC26, a member of the NAC transcription factor family, was upregulated dramatically during cold, drought and salinity treatments in Vitis amurensis, a cold and drought-hardy wild Vitis species. Heterologous overexpression of VaNAC26 enhanced drought and salt tolerance in transgenic Arabidopsis. Higher activities of antioxidant enzymes and lower concentrations of H2O2 and O2 − were found in VaNAC26-OE lines than in wild type plants under drought stress. These results indicated that scavenging by reactive oxygen species (ROS) was enhanced by VaNAC26 in transgenic lines. Microarray-based transcriptome analysis revealed that genes related to jasmonic acid (JA) synthesis and signaling were upregulated in VaNAC26-OE lines under both normal and drought conditions. VaNAC26 showed a specific binding ability on the NAC recognition sequence (NACRS) motif, which broadly exists in the promoter regions of upregulated genes in transgenic lines. Endogenous JA content significantly increased in the VaNAC26-OE lines 2 and 3. Our data suggest that VaNAC26 responds to abiotic stresses and may enhance drought tolerance by transcriptional regulation of JA synthesis in Arabidopsis. PMID:27162276

  3. Enhancement of carvedilol solubility by solid dispersion technique using cyclodextrins, water soluble polymers and hydroxyl acid.

    PubMed

    Yuvaraja, K; Khanam, Jasmina

    2014-08-01

    Aim of the present work is to enhance aqueous solubility of carvedilol (CV) by solid dispersion technique using wide variety of carriers such as: β-cyclodextrin (βCD), hydroxypropyl-β-cyclodextrin (HPβCD), tartaric acid (TA), polyvinyl pyrrolidone K-30 (PVP K-30) and poloxamer-407 (PLX-407). Various products of 'CV-solid dispersion' had been studied extensively in various pH conditions to check enhancement of solubility and dissolution characteristics of carvedilol. Any physical change upon interaction between CV and carriers was confirmed by instrumental analysis: XRD, DSC, FTIR and SEM. Negative change of Gibb's free energy and complexation constants (Kc, 75-240M(-1), for cyclodextrins and 1111-20,365M(-1), for PVP K-30 and PLX-407) were the evidence of stable nature of the binding between CV and carriers. 'Solubility enhancement factor' of ionized-CV was found high enough (340 times) with HPβCD in presence of TA. TA increases the binding efficiency of cyclodextrin and changing the pH of microenvironment in dissolution medium. In addition, ionization process was used to increase the apparent intrinsic solubility of drug. In vitro, dissolution time of CV was remarkably reduced in the solid dispersion system compared to that of pure drug. This may be attributed to increased wettability, dispersing ability and transformation of crystalline state of drug to amorphous one.

  4. 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

  5. All-Trans-Retinoic Acid Enhances Mitochondrial Function in Models of Human Liver.

    PubMed

    Tripathy, Sasmita; Chapman, John D; Han, Chang Y; Hogarth, Cathryn A; Arnold, Samuel L M; Onken, Jennifer; Kent, Travis; Goodlett, David R; Isoherranen, Nina

    2016-05-01

    All-trans-retinoic acid (atRA) is the active metabolite of vitamin A. The liver is the main storage organ of vitamin A, but activation of the retinoic acid receptors (RARs) in mouse liver and in human liver cell lines has also been shown. AlthoughatRA treatment improves mitochondrial function in skeletal muscle in rodents, its role in modulating mitochondrial function in the liver is controversial, and little data are available regarding the human liver. The aim of this study was to determine whetheratRA regulates hepatic mitochondrial activity.atRA treatment increased the mRNA and protein expression of multiple components of mitochondrialβ-oxidation, tricarboxylic acid (TCA) cycle, and respiratory chain. Additionally,atRA increased mitochondrial biogenesis in human hepatocytes and in HepG2 cells with and without lipid loading based on peroxisome proliferator activated receptor gamma coactivator 1αand 1βand nuclear respiratory factor 1 mRNA and mitochondrial DNA quantification.atRA also increasedβ-oxidation and ATP production in HepG2 cells and in human hepatocytes. Knockdown studies of RARα, RARβ, and PPARδrevealed that the enhancement of mitochondrial biogenesis andβ-oxidation byatRA requires peroxisome proliferator activated receptor delta. In vivo in mice,atRA treatment increased mitochondrial biogenesis markers after an overnight fast. Inhibition ofatRA metabolism by talarozole, a cytochrome P450 (CYP) 26 specific inhibitor, increased the effects ofatRA on mitochondrial biogenesis markers in HepG2 cells and in vivo in mice. These studies show thatatRA regulates mitochondrial function and lipid metabolism and that increasingatRA concentrations in human liver via CYP26 inhibition may increase mitochondrial biogenesis and fatty acidβ-oxidation and provide therapeutic benefit in diseases associated with mitochondrial dysfunction. PMID:26921399

  6. Oxygen-enhanced biodegradation of phenoxy acids in ground water at contaminated sites.

    PubMed

    Tuxen, Nina; Reitzel, Lotte A; Albrechtsen, Hans-Jørgen; Bjerg, Poul L

    2006-01-01

    The effects of adding oxygen to anaerobic aquifer materials on biodegradation of phenoxy acid herbicides were studied by laboratory experiments with aquifer material from two contaminated sites (a former agricultural machinery service and an old landfill). At both sites, the primary pollutants were phenoxy acids and related chlorophenols. It was found that addition of oxygen enhanced degradation of the six original phenoxy acids and six original chlorophenols. Inverse modeling on 14C 4-chloro-2-methylphenoxypropanoic acid (MCPP) degradation curves revealed that increasing the oxygen concentrations from <0.3 mg/L up to 7 to 8 mg/L shortened the lag phases (from approximately 150 d to 5 to 25 d) and increased first-order degradation rate constants by 1 order of magnitude (from approximately 5 x 10(-2) d(-1) to up to 30 x 10(-2) d(-1)). Additionally, the degree of MCPP mineralization was increased (30% to 50% mineralized at low oxygen concentrations and 50% to 70% mineralized at high oxygen concentrations, based on 14CO2 recovery). These positive effects on degradation were observed even at relatively low oxygen concentrations (2 mg/L). Furthermore, effects related to the addition of oxygen on the general geochemistry were studied. An oxygen consumption of 2.2 to 2.6 mg O2/g dw was observed due to oxidation of solid organic matter and, to some extent (0.5% to 11% of the total oxygen consumption), water-soluble compounds such as Fe2+, dissolved Mn, nonvolatile organic carbon, and NH4+. Overall, the results suggest that stimulated biodegradation by addition of oxygen might be a feasible remediation technology at herbicide-contaminated sites, although oxygen consumption by the sediment could limit the applicability.

  7. Raman and surface-enhanced Raman spectroscopy of amino acids and nucleotide bases for target bacterial vibrational mode identification

    NASA Astrophysics Data System (ADS)

    Guicheteau, Jason; Argue, Leanne; Hyre, Aaron; Jacobson, Michele; Christesen, Steven D.

    2006-05-01

    Raman and surface-enhanced Raman spectroscopy (SERS) studies of bacteria have reported a wide range of vibrational mode assignments associated with biological material. We present Raman and SER spectra of the amino acids phenylalanine, tyrosine, tryptophan, glutamine, cysteine, alanine, proline, methionine, asparagine, threonine, valine, glycine, serine, leucine, isoleucine, aspartic acid and glutamic acid and the nucleic acid bases adenosine, guanosine, thymidine, and uridine to better characterize biological vibrational mode assignments for bacterial target identification. We also report spectra of the bacteria Bacillus globigii, Pantoea agglomerans, and Yersinia rhodei along with band assignments determined from the reference spectra obtained.

  8. Exogenous jasmonic acid can enhance tolerance of wheat seedlings to salt stress.

    PubMed

    Qiu, ZongBo; Guo, JunLi; Zhu, AiJing; Zhang, Liang; Zhang, ManMan

    2014-06-01

    Jasmonic acid (JA) is regarded as endogenous regulator that plays an important role in regulating stress responses, plant growth and development. To investigate the physiological mechanisms of salt stress mitigated by exogenous JA, foliar application of 2mM JA was done to wheat seedlings for 3days and then they were subjected to 150mM NaCl. Our results showed that 150mM NaCl treatment significantly decreased plant height, root length, shoot dry weight, root dry weight, the concentration of glutathione (GSH), chlorophyll b (Chl b) and carotenoid (Car), the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), enhanced the concentration of malondialdehyde (MDA), hydrogen peroxide (H2O2) and the rate of superoxide radical (O2•-) generation in the wheat seedlings when compared with the control. However, treatments with exogenous JA for 3 days significantly enhanced salt stress tolerance in wheat seedlings by decreasing the concentration of MDA and H2O2, the production rate of O2•- and increasing the transcript levels and activities of SOD, POD, CAT and APX and the contents of GSH, Chl b and Car, which, in turn, enhanced the growth of salt stressed seedlings. These results suggested that JA could effectively protect wheat seedlings from salt stress damage by enhancing activities of antioxidant enzymes and the concentration of antioxidative compounds to quench the excessive reactive oxygen species caused by salt stress and presented a practical implication for wheat cultivation in salt-affected soils.

  9. Lewis Acids as Activators in CBS-Catalysed Diels-Alder Reactions: Distortion Induced Lewis Acidity Enhancement of SnCl4.

    PubMed

    Nödling, Alexander R; Möckel, Robert; Tonner, Ralf; Hilt, Gerhard

    2016-09-01

    The effect of several Lewis acids on the CBS catalyst (named after Corey, Bakshi and Shibata) was investigated in this study. While (2) H NMR spectroscopic measurements served as gauge for the activation capability of the Lewis acids, in situ FT-IR spectroscopy was employed to assess the catalytic activity of the Lewis acid oxazaborolidine complexes. A correlation was found between the Δδ((2) H) values and rate constants kDA , which indicates a direct translation of Lewis acidity into reactivity of the Lewis acid-CBS complexes. Unexpectedly, a significant deviation was found for SnCl4 as Lewis acid. The SnCl4 -CBS adduct was much more reactive than the Δδ((2) H) values predicted and gave similar reaction rates to those observed for the prominent AlBr3 -CBS adduct. To rationalize these results, quantum mechanical calculations were performed. The frontier molecular orbital approach was applied and a good correlation between the LUMO energies of the Lewis acid-CBS-naphthoquinone adducts and kDA could be found. For the SnCl4 -CBS-naphthoquinone adduct an unusual distortion was observed leading to an enhanced Lewis acidity. Energy decomposition analysis with natural orbitals for chemical valence (EDA-NOCV) calculations revealed the relevant interactions and activation mode of SnCl4 as Lewis acid in Diels-Alder reactions. PMID:27492791

  10. Endoplasmic reticulum-located PDAT1-2 from castor bean enhances hydroxy fatty acid accumulation in transgenic plants.

    PubMed

    Kim, Hyun Uk; Lee, Kyeong-Ryeol; Go, Young Sam; Jung, Jin Hee; Suh, Mi-Chung; Kim, Jong Bum

    2011-06-01

    Ricinoleic acid (12-hydroxy-octadeca-9-enoic acid) is a major unusual fatty acid in castor oil. This hydroxy fatty acid is useful in industrial materials. This unusual fatty acid accumulates in triacylglycerol (TAG) in the seeds of the castor bean (Ricinus communis L.), even though it is synthesized in phospholipids, which indicates that the castor plant has an editing enzyme, which functions as a phospholipid:diacylglycerol acyltransferase (PDAT) that is specific to ricinoleic acid. Transgenic plants containing fatty acid Δ12-hydroxylase encoded by the castor bean FAH12 gene produce a limited amount of hydroxy fatty acid, a maximum of around 17% of TAGs present in Arabidopsis seeds, and this unusual fatty acid remains in phospholipids of cell membranes in seeds. Identification of ricinoleate-specific PDAT from castor bean and manipulation of the phospholipid editing system in transgenic plants will enhance accumulation of the hydroxy fatty acid in transgenic seeds. The castor plant has three PDAT genes; PDAT1-1 and PDAT2 are homologs of PDAT, which are commonly found in plants; however, PDAT1-2 is newly grouped as a castor bean-specific gene. PDAT1-2 is expressed in developing seeds and localized in the endoplasmic reticulum, similar to FAH12, indicating its involvement in conversion of ricinoleic acid into TAG. PDAT1-2 significantly enhances accumulation of total hydroxy fatty acid up to 25%, with a significant increase in castor-like oil, 2-OH TAG, in seeds of transgenic Arabidopsis, which is an identification of the key gene for oilseed engineering in production of unusual fatty acids.

  11. Structure-selective hot-spot Raman enhancement for direct identification and detection of trace penicilloic acid allergen in penicillin.

    PubMed

    Zhang, Liying; Jin, Yang; Mao, Hui; Zheng, Lei; Zhao, Jiawei; Peng, Yan; Du, Shuhu; Zhang, Zhongping

    2014-08-15

    Trace penicilloic acid allergen frequently leads to various fatal immune responses to many patients, but it is still a challenge to directly discriminate and detect its residue in penicillin by a chemosensing way. Here, we report that silver-coated gold nanoparticles (Au@Ag NPs) exhibit a structure-selective hot-spot Raman enhancement capability for direct identification and detection of trace penicilloic acid in penicillin. It has been demonstrated that penicilloic acid can very easily link Au@Ag NPs together by its two carboxyl groups, locating itself spontaneously at the interparticle of Au@Ag NPs to form strong Raman hot-spot. At the critical concentration inducing the nanoparticle aggregation, Raman-enhanced effect of penicilloic acid is ~60,000 folds higher than that of penicillin. In particular, the selective Raman enhancement to the two carboxyl groups makes the peak of carboxyl group at C6 of penicilloic acid appear as a new Raman signal due to the opening of β-lactam ring of penicillin. The surface-enhanced Raman scattering (SERS) nanoparticle sensor reaches a sensitive limit lower than the prescribed 1.0‰ penicilloic acid residue in penicillin. The novel strategy to examine allergen is more rapid, convenient and inexpensive than the conventional separation-based assay methods.

  12. Enhanced optoelectronic quality of perovskite thin films with hypophosphorous acid for planar heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Pathak, Sandeep; Sakai, Nobuya; Stergiopoulos, Thomas; Nayak, Pabitra K.; Noel, Nakita K.; Haghighirad, Amir A.; Burlakov, Victor M.; Dequilettes, Dane W.; Sadhanala, Aditya; Li, Wenzhe; Wang, Liduo; Ginger, David S.; Friend, Richard H.; Snaith, Henry J.

    2015-11-01

    Solution-processed metal halide perovskite semiconductors, such as CH3NH3PbI3, have exhibited remarkable performance in solar cells, despite having non-negligible density of defect states. A likely candidate is halide vacancies within the perovskite crystals, or the presence of metallic lead, both generated due to the imbalanced I/Pb stoichiometry which could evolve during crystallization. Herein, we show that the addition of hypophosphorous acid (HPA) in the precursor solution can significantly improve the film quality, both electronically and topologically, and enhance the photoluminescence intensity, which leads to more efficient and reproducible photovoltaic devices. We demonstrate that the HPA can reduce the oxidized I2 back into I-, and our results indicate that this facilitates an improved stoichiometry in the perovskite crystal and a reduced density of metallic lead.

  13. Hyaluronic acid grafted PLGA copolymer nanoparticles enhance the targeted delivery of Bromelain in Ehrlich's Ascites Carcinoma.

    PubMed

    Bhatnagar, Priyanka; Pant, Aditya Bhushan; Shukla, Yogeshwer; Panda, Amulya; Gupta, Kailash Chand

    2016-08-01

    Rapidly increasing malignant neoplastic disease demands immediate attention. Several dietary compounds have recently emerged as strong anti-cancerous agents. Among, Bromelain (BL), a protease from pineapple plant, was used to enhance its anti-cancerous efficacy using nanotechnology. In lieu of this, hyaluronic acid (HA) grafted PLGA copolymer, having tumor targeting ability, was developed. BL was encapsulated in copolymer to obtain BL-copolymer nanoparticles (NPs) that ranged between 140 to 281nm in size. NPs exhibited higher cellular uptake and cytotoxicity in cells with high CD44 expression as compared with non-targeted NPs. In vivo results on tumor bearing mice showed that NPs were efficient in suppressing the tumor growth. Hence, the formulation could be used as a self-targeting drug delivery cargo for the remission of cancer. PMID:27287553

  14. Copper catalysis for enhancement of cobalt leaching and acid utilization efficiency in microbial fuel cells.

    PubMed

    Liu, Yaxuan; Shen, Jingya; Huang, Liping; Wu, Dan

    2013-11-15

    Enhancement of both cobalt leaching from LiCoO2 and acid utilization efficiency (AUE) in microbial fuel cells (MFCs) was successfully achieved by the addition of Cu(II). A dosage of 10mg/L Cu(II) improved both cobalt leaching up to 308% and AUE of 171% compared to the controls with no presence of Cu(II). The apparent activation energy of cobalt leaching catalyzed by Cu(II) in MFCs was only 11.8 kJ/mol. These results demonstrate cobalt leaching in MFCs using Cu(II) as a catalyst may be an effective strategy for cobalt recovery and recycle of spent Li-ion batteries, and the evidence of influence factors including solid/liquid ratio, temperature, and pH and solution conductivity can contribute to improving understanding of and optimizing cobalt leaching catalyzed by Cu(II) in MFCs.

  15. Enhanced optoelectronic quality of perovskite thin films with hypophosphorous acid for planar heterojunction solar cells

    DOE PAGES

    Zhang, Wei; Pathak, Sandeep; Sakai, Nobuya; Stergiopoulos, Thomas; Nayak, Pabitra K.; Noel, Nakita K.; Haghighirad, Amir A.; Burlakov, Victor M.; deQuilettes, Dane W.; Sadhanala, Aditya; et al

    2015-11-30

    Solution-processed metal halide perovskite semiconductors, such as CH3NH3PbI3, have exhibited remarkable performance in solar cells, despite having non-negligible density of defect states. A likely candidate is halide vacancies within the perovskite crystals, or the presence of metallic lead, both generated due to the imbalanced I/Pb stoichiometry which could evolve during crystallization. Herein, we show that the addition of hypophosphorous acid (HPA) in the precursor solution can significantly improve the film quality, both electronically and topologically, and enhance the photoluminescence intensity, which leads to more efficient and reproducible photovoltaic devices. We demonstrate that the HPA can reduce the oxidized I2 backmore » into I-, and our results indicate that this facilitates an improved stoichiometry in the perovskite crystal and a reduced density of metallic lead.« less

  16. Copper catalysis for enhancement of cobalt leaching and acid utilization efficiency in microbial fuel cells.

    PubMed

    Liu, Yaxuan; Shen, Jingya; Huang, Liping; Wu, Dan

    2013-11-15

    Enhancement of both cobalt leaching from LiCoO2 and acid utilization efficiency (AUE) in microbial fuel cells (MFCs) was successfully achieved by the addition of Cu(II). A dosage of 10mg/L Cu(II) improved both cobalt leaching up to 308% and AUE of 171% compared to the controls with no presence of Cu(II). The apparent activation energy of cobalt leaching catalyzed by Cu(II) in MFCs was only 11.8 kJ/mol. These results demonstrate cobalt leaching in MFCs using Cu(II) as a catalyst may be an effective strategy for cobalt recovery and recycle of spent Li-ion batteries, and the evidence of influence factors including solid/liquid ratio, temperature, and pH and solution conductivity can contribute to improving understanding of and optimizing cobalt leaching catalyzed by Cu(II) in MFCs. PMID:24007993

  17. Aqueous solutions of acidic ionic liquids for enhanced stability of polyoxometalate-carbon supercapacitor electrodes

    NASA Astrophysics Data System (ADS)

    Hu, Chenchen; Zhao, Enbo; Nitta, Naoki; Magasinski, Alexandre; Berdichevsky, Gene; Yushin, Gleb

    2016-09-01

    Nanocomposites based on polyoxometalates (POMs) nanoconfined in microporous carbons have been synthesized and used as electrodes for supercapacitors. The addition of the pseudocapacitance from highly reversible redox reaction of POMs to the electric double-layer capacitance of carbon lead to an increase in specific capacitance of ∼90% at 1 mV s-1. However, high solubility of POM in traditional aqueous electrolytes leads to rapid capacity fading. Here we demonstrate that the use of aqueous solutions of protic ionic liquids (P-IL) as electrolyte instead of aqueous sulfuric acid solutions offers an opportunity to significantly improve POM cycling stability. Virtually no degradation in capacitance was observed in POM-based positive electrode after 10,000 cycles in an asymmetric capacitor with P-IL aqueous electrolyte. As such, POM-based carbon composites may now present a viable solution for enhancing energy density of electrical double layer capacitors (EDLC) based on pure carbon electrodes.

  18. Enhanced lymphocyte proliferation in patients with adrenoleukodystrophy treated with erucic acid (22:1)-rich triglycerides.

    PubMed

    Pour, R B; Stöckler-Ipsiroglu, S; Hunneman, D H; Gahr, M; Korenke, G C; Pabst, W; Hanefeld, F; Peters, A

    2000-03-01

    Lymphocytopenia and depression of natural killer cells have been observed in patients with adrenoleukodystrophy (ALD) treated with glycerol trioleate and glycerol trierucate ('Lorenzo's oil'). To investigate possible alterations of cellular immunoreactivity, we measured lymphocyte proliferation in response to mitogens (PHA, Con A, PWM, OKT3) in 27 patients on treatment and in 14 patients without treatment. In patients on treatment, lymphocyte proliferation in response to the mitogens PHA and Con A was significantly higher than in patients without treatment. Lymphocyte proliferation in patients without treatment was comparable to that of normal control lymphocytes. Additionally, we found increased concentrations of erucic acid, C22:1, in lymphocytes from patients with treatment. The enhanced proliferation of lymphocytes in response to mitogens is an indication of increased reactivity of cellular immunity to unspecific immunological stimuli. Long-term side-effects on cellular immunoreactivity have to be considered in ALD patients treated with Lorenzo's oil.

  19. Glucose-lowering effects of intestinal bile acid sequestration through enhancement of splanchnic glucose utilization.

    PubMed

    Prawitt, Janne; Caron, Sandrine; Staels, Bart

    2014-05-01

    Intestinal bile acid (BA) sequestration efficiently lowers plasma glucose concentrations in type 2 diabetes (T2D) patients. Because BAs act as signaling molecules via receptors, including the G protein-coupled receptor TGR5 and the nuclear receptor FXR (farnesoid X receptor), to regulate glucose homeostasis, BA sequestration, which interrupts the entero-hepatic circulation of BAs, constitutes a plausible action mechanism of BA sequestrants. An increase of intestinal L-cell glucagon-like peptide-1 (GLP-1) secretion upon TGR5 activation is the most commonly proposed mechanism, but recent studies also argue for a direct entero-hepatic action to enhance glucose utilization. We discuss here recent findings on the mechanisms of sequestrant-mediated glucose lowering via an increase of splanchnic glucose utilization through entero-hepatic FXR signaling.

  20. Enhanced optoelectronic quality of perovskite thin films with hypophosphorous acid for planar heterojunction solar cells

    PubMed Central

    Zhang, Wei; Pathak, Sandeep; Sakai, Nobuya; Stergiopoulos, Thomas; Nayak, Pabitra K.; Noel, Nakita K.; Haghighirad, Amir A.; Burlakov, Victor M.; deQuilettes, Dane W.; Sadhanala, Aditya; Li, Wenzhe; Wang, Liduo; Ginger, David S.; Friend, Richard H.; Snaith, Henry J.

    2015-01-01

    Solution-processed metal halide perovskite semiconductors, such as CH3NH3PbI3, have exhibited remarkable performance in solar cells, despite having non-negligible density of defect states. A likely candidate is halide vacancies within the perovskite crystals, or the presence of metallic lead, both generated due to the imbalanced I/Pb stoichiometry which could evolve during crystallization. Herein, we show that the addition of hypophosphorous acid (HPA) in the precursor solution can significantly improve the film quality, both electronically and topologically, and enhance the photoluminescence intensity, which leads to more efficient and reproducible photovoltaic devices. We demonstrate that the HPA can reduce the oxidized I2 back into I−, and our results indicate that this facilitates an improved stoichiometry in the perovskite crystal and a reduced density of metallic lead. PMID:26615763

  1. Enhanced optoelectronic quality of perovskite thin films with hypophosphorous acid for planar heterojunction solar cells.

    PubMed

    Zhang, Wei; Pathak, Sandeep; Sakai, Nobuya; Stergiopoulos, Thomas; Nayak, Pabitra K; Noel, Nakita K; Haghighirad, Amir A; Burlakov, Victor M; deQuilettes, Dane W; Sadhanala, Aditya; Li, Wenzhe; Wang, Liduo; Ginger, David S; Friend, Richard H; Snaith, Henry J

    2015-01-01

    Solution-processed metal halide perovskite semiconductors, such as CH3NH3PbI3, have exhibited remarkable performance in solar cells, despite having non-negligible density of defect states. A likely candidate is halide vacancies within the perovskite crystals, or the presence of metallic lead, both generated due to the imbalanced I/Pb stoichiometry which could evolve during crystallization. Herein, we show that the addition of hypophosphorous acid (HPA) in the precursor solution can significantly improve the film quality, both electronically and topologically, and enhance the photoluminescence intensity, which leads to more efficient and reproducible photovoltaic devices. We demonstrate that the HPA can reduce the oxidized I2 back into I(-), and our results indicate that this facilitates an improved stoichiometry in the perovskite crystal and a reduced density of metallic lead.

  2. Enhanced removal of 8-quinolinecarboxylic acid in an activated carbon cloth by electroadsorption in aqueous solution.

    PubMed

    López-Bernabeu, S; Ruiz-Rosas, R; Quijada, C; Montilla, F; Morallón, E

    2016-02-01

    The effect of the electrochemical treatment (potentiostatic treatment in a filter-press electrochemical cell) on the adsorption capacity of an activated carbon cloth (ACC) was analyzed in relation with the removal of 8-quinolinecarboxylic acid pollutant from water. The adsorption capacity of an ACC is quantitatively improved in the presence of an electric field (electroadsorption process) reaching values of 96% in comparison to 55% in absence of applied potential. In addition, the cathodic treatment results in higher removal efficiencies than the anodic treatment. The enhanced adsorption capacity has been proved to be irreversible, since the removed compound remains adsorbed after switching the applied potential. The kinetics of the adsorption processes is also improved by the presence of an applied potential. PMID:26433936

  3. Enhanced optoelectronic quality of perovskite thin films with hypophosphorous acid for planar heterojunction solar cells

    SciTech Connect

    Zhang, Wei; Pathak, Sandeep; Sakai, Nobuya; Stergiopoulos, Thomas; Nayak, Pabitra K.; Noel, Nakita K.; Haghighirad, Amir A.; Burlakov, Victor M.; deQuilettes, Dane W.; Sadhanala, Aditya; Li, Wenzhe; Wang, Liduo; Ginger, David S.; Friend, Richard H.; Snaith, Henry J.

    2015-11-30

    Solution-processed metal halide perovskite semiconductors, such as CH3NH3PbI3, have exhibited remarkable performance in solar cells, despite having non-negligible density of defect states. A likely candidate is halide vacancies within the perovskite crystals, or the presence of metallic lead, both generated due to the imbalanced I/Pb stoichiometry which could evolve during crystallization. Herein, we show that the addition of hypophosphorous acid (HPA) in the precursor solution can significantly improve the film quality, both electronically and topologically, and enhance the photoluminescence intensity, which leads to more efficient and reproducible photovoltaic devices. We demonstrate that the HPA can reduce the oxidized I2 back into I-, and our results indicate that this facilitates an improved stoichiometry in the perovskite crystal and a reduced density of metallic lead.

  4. Hyaluronic acid grafted PLGA copolymer nanoparticles enhance the targeted delivery of Bromelain in Ehrlich's Ascites Carcinoma.

    PubMed

    Bhatnagar, Priyanka; Pant, Aditya Bhushan; Shukla, Yogeshwer; Panda, Amulya; Gupta, Kailash Chand

    2016-08-01

    Rapidly increasing malignant neoplastic disease demands immediate attention. Several dietary compounds have recently emerged as strong anti-cancerous agents. Among, Bromelain (BL), a protease from pineapple plant, was used to enhance its anti-cancerous efficacy using nanotechnology. In lieu of this, hyaluronic acid (HA) grafted PLGA copolymer, having tumor targeting ability, was developed. BL was encapsulated in copolymer to obtain BL-copolymer nanoparticles (NPs) that ranged between 140 to 281nm in size. NPs exhibited higher cellular uptake and cytotoxicity in cells with high CD44 expression as compared with non-targeted NPs. In vivo results on tumor bearing mice showed that NPs were efficient in suppressing the tumor growth. Hence, the formulation could be used as a self-targeting drug delivery cargo for the remission of cancer.

  5. Enhanced removal of 8-quinolinecarboxylic acid in an activated carbon cloth by electroadsorption in aqueous solution.

    PubMed

    López-Bernabeu, S; Ruiz-Rosas, R; Quijada, C; Montilla, F; Morallón, E

    2016-02-01

    The effect of the electrochemical treatment (potentiostatic treatment in a filter-press electrochemical cell) on the adsorption capacity of an activated carbon cloth (ACC) was analyzed in relation with the removal of 8-quinolinecarboxylic acid pollutant from water. The adsorption capacity of an ACC is quantitatively improved in the presence of an electric field (electroadsorption process) reaching values of 96% in comparison to 55% in absence of applied potential. In addition, the cathodic treatment results in higher removal efficiencies than the anodic treatment. The enhanced adsorption capacity has been proved to be irreversible, since the removed compound remains adsorbed after switching the applied potential. The kinetics of the adsorption processes is also improved by the presence of an applied potential.

  6. Free nitrous acid pretreatment of wasted activated sludge to exploit internal carbon source for enhanced denitrification.

    PubMed

    Ma, Bin; Peng, Yongzhen; Wei, Yan; Li, Baikun; Bao, Peng; Wang, Yayi

    2015-03-01

    Using internal carbon source contained in waste activated sludge (WAS) is beneficial for nitrogen removal from wastewater with low carbon/nitrogen ratio, but it is usually limited by sludge disintegration. This study presented a novel strategy based on free nitrous acid (FNA) pretreatment to intensify the release of organic matters from WAS for enhanced denitrification. During FNA pretreatment, soluble chemical oxygen demand (SCOD) production kept increasing when FNA increased from 0 to 2.04 mg HNO2-N/L. Compared with untreated WAS, the internal carbon source production increased by 50% in a simultaneous fermentation and denitrification reactor fed with WAS pretreated by FNA for 24 h at 2.04 mg HNO2-N/L. This also increased denitrification efficiency by 76% and sludge reduction by 87.5%. More importantly, greenhouse gas nitrous oxide production in denitrification was alleviated since more electrons could be provided by FNA pretreated WAS.

  7. Transgenic expression of delta-6 and delta-15 fatty acid desaturases enhances omega-3 polyunsaturated fatty acid accumulation in Synechocystis sp. PCC6803

    PubMed Central

    2014-01-01

    Background Polyunsaturated fatty acids (PUFAs), which contain two or more double bonds in their backbone, are the focus of intensive global research, because of their nutritional value, medicinal applications, and potential use as biofuel. However, the ability to produce these economically important compounds is limited, because it is both expensive and technically challenging to separate omega-3 polyunsaturated fatty acids (ω-3 PUFAs) from natural oils. Although the biosynthetic pathways of some plant and microalgal ω-3 PUFAs have been deciphered, current understanding of the correlation between fatty acid desaturase content and fatty acid synthesis in Synechocystis sp. PCC6803 is incomplete. Results We constructed a series of homologous vectors for the endogenous and exogenous expression of Δ6 and Δ15 fatty acid desaturases under the control of the photosynthesis psbA2 promoter in transgenic Synechocystis sp. PCC6803. We generated six homologous recombinants, harboring various fatty acid desaturase genes from Synechocystis sp. PCC6803, Gibberella fujikuroi and Mortierella alpina. These lines produced up to 8.9 mg/l of α-linolenic acid (ALA) and 4.1 mg/l of stearidonic acid (SDA), which are more than six times the corresponding wild-type levels, at 20°C and 30°C. Thus, transgenic expression of Δ6 and Δ15 fatty acid desaturases enhances the accumulation of specific ω-3 PUFAs in Synechocystis sp. PCC6803. Conclusions In the blue-green alga Synechocystis sp. PCC6803, overexpression of endogenous and exogenous genes encoding PUFA desaturases markedly increased accumulation of ALA and SDA and decreased accumulation of linoleic acid and γ-linolenic acid. This study lays the foundation for increasing the fatty acid content of cyanobacteria and, ultimately, for producing nutritional and medicinal products with high levels of essential ω-3 PUFAs. PMID:24581179

  8. Response surface optimization of culture medium for enhanced docosahexaenoic acid production by a Malaysian thraustochytrid

    PubMed Central

    Manikan, Vidyah; Kalil, Mohd Sahaid; Hamid, Aidil Abdul

    2015-01-01

    Docosahexaenoic acid (DHA, C22:6n-3) plays a vital role in the enhancement of human health, particularly for cognitive, neurological, and visual functions. Marine microalgae, such as members of the genus Aurantiochytrium, are rich in DHA and represent a promising source of omega-3 fatty acids. In this study, levels of glucose, yeast extract, sodium glutamate and sea salt were optimized for enhanced lipid and DHA production by a Malaysian isolate of thraustochytrid, Aurantiochytrium sp. SW1, using response surface methodology (RSM). The optimized medium contained 60 g/L glucose, 2 g/L yeast extract, 24 g/L sodium glutamate and 6 g/L sea salt. This combination produced 17.8 g/L biomass containing 53.9% lipid (9.6 g/L) which contained 44.07% DHA (4.23 g/L). The optimized medium was used in a scale-up run, where a 5 L bench-top bioreactor was employed to verify the applicability of the medium at larger scale. This produced 24.46 g/L biomass containing 38.43% lipid (9.4 g/L), of which 47.87% was DHA (4.5 g/L). The total amount of DHA produced was 25% higher than that produced in the original medium prior to optimization. This result suggests that Aurantiochytrium sp. SW1 could be developed for industrial application as a commercial DHA-producing microorganism. PMID:25721623

  9. Omega-3 polyunsaturated fatty acids enhance cerebral angiogenesis and provide long-term protection after stroke

    PubMed Central

    Wang, Jiayin; Shi, Yejie; Zhang, Lili; Zhang, Feng; Hu, Xiaoming; Zhang, Wengting; Leak, Rehana K.; Gao, Yanqin; Chen, Ling; Chen, Jun

    2014-01-01

    Stroke is a devastating neurological disorder and one of the leading causes of death and serious disability. After cerebral ischemia, revascularization in the ischemic boundary zone provides nutritive blood flow as well as various growth factors to promote the survival and activity of neurons and neural progenitor cells. Enhancement of angiogenesis and the resulting improvement of cerebral microcirculation are key restorative mechanisms and represent an important therapeutic strategy for ischemic stroke. In the present study, we tested the hypothesis that post-stroke angiogenesis would be enhanced by omega-3 polyunsaturated fatty acids (n-3 PUFAs), a major component of dietary fish oil. To this end, we found that transgenic fat-1 mice that overproduce n-3 PUFAs exhibited long-term behavioral and histological protection against transient focal cerebral ischemia (tFCI). Importantly, fat-1 transgenic mice also exhibited robust improvements in revascularization and angiogenesis compared to wild type littermates, suggesting a potential role for n-3 fatty acids in post-stroke cerebrovascular remodeling. Mechanistically, n-3 PUFAs induced upregulation of angiopoietin 2 (Ang 2) in astrocytes after tFCI and stimulated extracellular Ang 2 release from cultured astrocytes after oxygen and glucose deprivation. Ang 2 facilitated endothelial proliferation and barrier formation in vitro by potentiating the effects of VEGF on phospholipase Cγ1 and Src signaling. Consistent with these findings, blockade of Src activity in post-stroke fat-1 mice impaired n-3 PUFA-induced angiogenesis and exacerbated long-term neurological outcomes. Taken together, our findings strongly suggest that n-3 PUFA supplementation is a potential angiogenic treatment capable of augmenting brain repair and improving long-term functional recovery after cerebral ischemia. PMID:24794156

  10. Enhanced 5-aminolevulinic acid-gold nanoparticle conjugate-based photodynamic therapy using pulse laser

    NASA Astrophysics Data System (ADS)

    Xu, Hao; Yao, Cuiping; Wang, Jing; Chang, Zhennan; Zhang, Zhenxi

    2016-02-01

    The low bioavailability is a crucial limitation for the application of 5-aminolevulinic acid (ALA) in theranostics. In this research, 5-aminolevulinic acid and gold nanoparticle conjugates (ALA-GNPs) were synthesized to improve the bioavailability of ALA and to investigate the impact of ALA photodynamic therapy (ALA-PDT) in Hela cells. A 532 nm pulse laser and light-emitting diode (central wavelengths 502 nm) were jointly used as light sources in PDT research. The results show a 532 nm pulse laser can control ALA release from ALA-GNPs by adjusting the pulse laser dose. This laser control release may be attributed to the heat generation from GNPs under pulse laser irradiation, which indicates accurately adjusting the pulse laser dose to control the drug release in the cell interior can be considered as a new cellular surgery modality. Furthermore, the PDT results in Hela cells indicate the enhancement of ALA release by pulse laser before PDT can promote the efficacy of cell eradication in the light-emitting diode PDT (LED-PDT). This laser mediated drug release system can provide a new online therapy approach in PDT and it can be utilized in the optical monitor technologies based individual theranostics.

  11. Phenylboronic acid-decorated gelatin nanoparticles for enhanced tumor targeting and penetration.

    PubMed

    Wang, Xin; Wei, Bing; Cheng, Xu; Wang, Jun; Tang, Rupei

    2016-09-23

    Phenylboronic acid-decorated nanoparticles (NPs) were prepared for tumor-targeted drug delivery. 3-carboxyphenylboronic acid (3-CPBA) was modified on the surface of conventional gelatin NPs (designated as NP1) to give tumor-targeting NPs (designated as NP2). The morphology and stability of NP1 and NP2 were then investigated using transmission electron microscopy, scanning electron microscopy, and dynamic light scattering. The results show that both NP1 and NP2 are spherical-like and kinetically stable under various conditions. Doxorubicin hydrochloride (DOX) was used as a model anticancer drug and was loaded into NP1 (NP1-DOX) and NP2 (NP2-DOX). The i n vitro cellular uptake and cytotoxicity of NP1-DOX and NP2-DOX were measured using SH-SY5Y cells, H22 cells, and HepG2 cells. Tumor penetration, accumulation, and antitumor activity were investigated using SH-SY5Y tumor-like spheroids and H22 tumor-bearing mice. All results demonstrated that the conjugation of 3-CPBA can efficiently enhance non-targeted NPs' tumor-homing activity, thus improving their tumor accumulation and antitumor effect. PMID:27514078

  12. Expression of rapeseed microsomal lysophosphatidic acid acyltransferase isozymes enhances seed oil content in Arabidopsis.

    PubMed

    Maisonneuve, Sylvie; Bessoule, Jean-Jacques; Lessire, René; Delseny, Michel; Roscoe, Thomas J

    2010-02-01

    In higher plants, lysophosphatidic acid acyltransferase (LPAAT), located in the cytoplasmic endomembrane compartment, plays an essential role in the synthesis of phosphatidic acid, a key intermediate in the biosynthesis of membrane phospholipids in all tissues and storage lipids in developing seeds. In order to assess the contribution of LPAATs to the synthesis of storage lipids, we have characterized two microsomal LPAAT isozymes, the products of homoeologous genes that are expressed in rapeseed (Brassica napus). DNA sequence homologies, complementation of a bacterial LPAAT-deficient mutant, and enzymatic properties confirmed that each of two cDNAs isolated from a Brassica napus immature embryo library encoded a functional LPAAT possessing the properties of a eukaryotic pathway enzyme. Analyses in planta revealed differences in the expression of the two genes, one of which was detected in all rapeseed tissues and during silique and seed development, whereas the expression of the second gene was restricted predominantly to siliques and developing seeds. Expression of each rapeseed LPAAT isozyme in Arabidopsis (Arabidopsis thaliana) resulted in the production of seeds characterized by a greater lipid content and seed mass. These results support the hypothesis that increasing the expression of glycerolipid acyltransferases in seeds leads to a greater flux of intermediates through the Kennedy pathway and results in enhanced triacylglycerol accumulation.

  13. Citric Acid Enhanced Copper Removal by a Novel Multi-amines Decorated Resin

    PubMed Central

    Ling, Chen; Liu, Fuqiang; Pei, Zhiguo; Zhang, Xiaopeng; Wei, Mengmeng; Zhang, Yanhong; Zheng, Lirong; Zhang, Jing; Li, Aimin; Xing, Baoshan

    2015-01-01

    Cu removal by a novel multi-amines decorated resin (PAMD) from wastewater in the absence or presence of citric acid (CA) was examined. Adsorption capacity of Cu onto PAMD markedly increased by 186% to 5.07 mmol/g in the presence of CA, up to 7 times of that onto four commercial resins under the same conditions. Preloaded and kinetic studies demonstrated adsorption of [Cu-CA] complex instead of CA site-bridging and variations of adsorbate species were qualitatively illustrated. The interaction configuration was further studied with ESI-MS, FTIR, XPS and XANES characterizations. The large enhancement of Cu adsorption in Cu-CA bi-solutes systems was attributed to mechanism change from single-site to dual-sites interaction in which cationic or neutral Cu species (Cu2+ and CuHL0) coordinated with neutral amine sites and anionic complex species (CuL− and Cu2L22−) directly interacted with protonated amine sites via electrostatic attraction, and the ratio of the two interactions was approximately 0.5 for the equimolar bi-solutes system. Moreover, commonly coexisting ions in wastewaters had no obvious effect on the superior performance of PAMD. Also, Cu and CA could be recovered completely with HCl. Therefore, PAMD has a great potential to efficiently remove heavy metal ions from wastewaters in the presence of organic acids. PMID:25962970

  14. Enhanced disease susceptibility 1 and salicylic acid act redundantly to regulate resistance gene-mediated signaling.

    PubMed

    Venugopal, Srivathsa C; Jeong, Rae-Dong; Mandal, Mihir K; Zhu, Shifeng; Chandra-Shekara, A C; Xia, Ye; Hersh, Matthew; Stromberg, Arnold J; Navarre, DuRoy; Kachroo, Aardra; Kachroo, Pradeep

    2009-07-01

    Resistance (R) protein-associated pathways are well known to participate in defense against a variety of microbial pathogens. Salicylic acid (SA) and its associated proteinaceous signaling components, including enhanced disease susceptibility 1 (EDS1), non-race-specific disease resistance 1 (NDR1), phytoalexin deficient 4 (PAD4), senescence associated gene 101 (SAG101), and EDS5, have been identified as components of resistance derived from many R proteins. Here, we show that EDS1 and SA fulfill redundant functions in defense signaling mediated by R proteins, which were thought to function independent of EDS1 and/or SA. Simultaneous mutations in EDS1 and the SA-synthesizing enzyme SID2 compromised hypersensitive response and/or resistance mediated by R proteins that contain coiled coil domains at their N-terminal ends. Furthermore, the expression of R genes and the associated defense signaling induced in response to a reduction in the level of oleic acid were also suppressed by compromising SA biosynthesis in the eds1 mutant background. The functional redundancy with SA was specific to EDS1. Results presented here redefine our understanding of the roles of EDS1 and SA in plant defense.

  15. Acidic phospholipids govern the enhanced activation of IgG-B cell receptor.

    PubMed

    Chen, Xiangjun; Pan, Weiling; Sui, Yinqiang; Li, Hua; Shi, Xiaoshan; Guo, Xingdong; Qi, Hai; Xu, Chenqi; Liu, Wanli

    2015-10-06

    B cells that express the isotype-switched IgG-B cell receptor (IgG-BCR) are one of the driving forces for antibody memory. To allow for a rapid memory IgG antibody response, IgG-BCR evolved into a highly effective signalling machine. Here, we report that the positively charged cytoplasmic domain of mIgG (mIgG-tail) specifically interacts with negatively charged acidic phospholipids. The key immunoglobulin tail tyrosine (ITT) in mIgG-tail is thus sequestered in the membrane hydrophobic core in quiescent B cells. Pre-disruption of such interaction leads to excessive recruitment of BCRs and inflated BCR signalling upon antigen stimulation, resulting in hyperproliferation of primary B cells. Physiologically, membrane-sequestered mIgG-tail can be released by antigen engagement or Ca(2+) mobilization in the initiation of B cell activation. Our studies suggest a novel regulatory mechanism for how dynamic association of mIgG-tail with acidic phospholipids governs the enhanced activation of IgG-BCR.

  16. Sensitive detection of nucleic acids with rolling circle amplification and surface-enhanced Raman scattering spectroscopy.

    PubMed

    Hu, Juan; Zhang, Chun-yang

    2010-11-01

    Detection of specific DNA sequences is important to molecular biology research and clinical diagnostics. To improve the sensitivity of surface-enhanced Raman scattering spectroscopy (SERS), a variety of signal amplification methods has been developed, including Raman-active-dye, polymerase chain reaction (PCR) technology, molecular beacon, SERS-active substrates, and SERS-tag. However, the combination of rolling circle amplification (RCA) with SERS for nucleic acid detection has not been reported. Herein, we describe a new approach for nucleic acid detection by the combination of RCA reaction with SERS. Because of the binding of abundance repeated sequences of RCA products with gold nanoparticle (Au NP) and Rox-modified detection probes, SERS signal is significantly amplified and the detection limit of 10.0 pM might be achieved. The sensitivity of RCA-based SERS has increased by as much as 3 orders of magnitude as compared to PCR-based SERS and is also comparable with or even exceeds that of both RCA-based electrochemical and RCA-based fluorescent methods. This RCA-based SERS might discriminate perfect matched target DNA from 1-base mismatched DNA with high selectivity. The high sensitivity and selectivity of RCA-based SERS makes it a potential tool for early diagnosis of gene-related disease and also offers a great promise for multiplexed assays with DNA microarrays.

  17. Phenylboronic acid-decorated gelatin nanoparticles for enhanced tumor targeting and penetration

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Wei, Bing; Cheng, Xu; Wang, Jun; Tang, Rupei

    2016-09-01

    Phenylboronic acid-decorated nanoparticles (NPs) were prepared for tumor-targeted drug delivery. 3-carboxyphenylboronic acid (3-CPBA) was modified on the surface of conventional gelatin NPs (designated as NP1) to give tumor-targeting NPs (designated as NP2). The morphology and stability of NP1 and NP2 were then investigated using transmission electron microscopy, scanning electron microscopy, and dynamic light scattering. The results show that both NP1 and NP2 are spherical-like and kinetically stable under various conditions. Doxorubicin hydrochloride (DOX) was used as a model anticancer drug and was loaded into NP1 (NP1-DOX) and NP2 (NP2-DOX). The i n vitro cellular uptake and cytotoxicity of NP1-DOX and NP2-DOX were measured using SH-SY5Y cells, H22 cells, and HepG2 cells. Tumor penetration, accumulation, and antitumor activity were investigated using SH-SY5Y tumor-like spheroids and H22 tumor-bearing mice. All results demonstrated that the conjugation of 3-CPBA can efficiently enhance non-targeted NPs’ tumor-homing activity, thus improving their tumor accumulation and antitumor effect.

  18. Enhancing the natural removal of As in a reactive fluvial confluence receiving acid drainage

    NASA Astrophysics Data System (ADS)

    Abarca, M. I.; Arce, G.; Montecinos, M.; Guerra, P. A.; Pasten, P.

    2014-12-01

    Fluvial confluences are natural reactors that can determine the fate of contaminants in watersheds receiving acid drainage. Hydrological, hydrodynamic and chemical factors determine distinct conditions for the formation of suspended particles of iron and aluminum oxyhydroxides. The chemical and physical properties of these particle assemblages (e.g. particle size, chemical composition) can vary according to inflow mixing ratios, hydrodynamic velocity profiles, and chemical composition of the flows mixing at the confluence. Due to their capacity to sorb metals, it is important to identify the optimal conditions for removing metals from the aqueous phase, particularly arsenic, a contaminant frequently found in acid drainage. We studied a river confluence in the Lluta watershed, located in the arid Chilean Altiplano. We performed field measurements and laboratory studies to find optimal mixing ratio for arsenic sorption onto oxyhydroxide particles at the confluence between the Azufre (pH=2, As=2 mg/L) and the Caracarani river (pH=8, As<0.1 mg/L). As the contribution of the acidic stream increased, the concentration of Fe and Al in the solid phase reached a peak at different pHs. Although the optimal pH for As sorption was ~3, the overall maximum removal of As at the confluence, ocurred for pH~4. This is produced because optimal As sorption does not occur necessarily for the highest concentrations of particles being formed. We propose that fluvial confluences could be engineered to enhance the natural attenuation of contaminants. An analogy between confluences and coagulation-flocculation-sedimentation drinking water plants could be used to engineer such intervention.Acknowledgements: Proyecto Fondecyt 1130936 and Proyecto CONICYT FONDAP 15110020

  19. Interleukin-1 family members are enhanced in psoriasis and suppressed by vitamin D and retinoic acid.

    PubMed

    Balato, Anna; Schiattarella, Maria; Lembo, Serena; Mattii, Martina; Prevete, Nella; Balato, Nicola; Ayala, Fabio

    2013-04-01

    Interleukin (IL)-1 family comprise 11 members that play an important role in immune regulation and inflammatory process. Retinoids exert complex effects on the immune system, having anti-inflammatory effects in chronic dermatological diseases. Vitamin D (vitD) and analogs have been shown to suppress TNF-α-induced IL-1α in human keratinocytes (KCs). In the present study, we investigated IL-1 family members in psoriasis and the effects of vitD and retinoic acid (RA) on these members. We analyzed IL-1 family members gene expression in psoriatic skin and in ex vivo skin organ culture exposed to TNF-α, IL-17 or broadband UVB; afterwards, treatment with vitD or RA was performed and IL-1 family members mRNA was evaluated. Similarly, KCs were stimulated with IL-17 and subsequently treated with vitD. IL-1 family members were enhanced in psoriatic skin and in ex vivo skin organ cultures after pro-inflammatory stimuli (TNF-α, IL-17 and UVB). RA and vitD were able to suppress this enhancement.

  20. Aminolevulinic Acid-Based Tumor Detection and Therapy: Molecular Mechanisms and Strategies for Enhancement

    PubMed Central

    Yang, Xue; Palasuberniam, Pratheeba; Kraus, Daniel; Chen, Bin

    2015-01-01

    Aminolevulinic acid (ALA) is the first metabolite in the heme biosynthesis pathway in humans. In addition to the end product heme, this pathway also produces other porphyrin metabolites. Protoporphyrin (PpIX) is one heme precursor porphyrin with good fluorescence and photosensitizing activity. Because tumors and other proliferating cells tend to exhibit a higher level of PpIX than normal cells after ALA incubation, ALA has been used as a prodrug to enable PpIX fluorescence detection and photodynamic therapy (PDT) of lesion tissues. Extensive studies have been carried out in the past twenty years to explore why some tumors exhibit elevated ALA-mediated PpIX and how to enhance PpIX levels to achieve better tumor detection and treatment. Here we would like to summarize previous research in order to stimulate future studies on these important topics. In this review, we focus on summarizing tumor-associated alterations in heme biosynthesis enzymes, mitochondrial functions and porphyrin transporters that contribute to ALA-PpIX increase in tumors. Mechanism-based therapeutic strategies for enhancing ALA-based modalities including iron chelators, differentiation agents and PpIX transporter inhibitors are also discussed. PMID:26516850

  1. Sildenafil enhances the peripheral antinociceptive effect of ellagic acid in the rat formalin test

    PubMed Central

    Mansouri, Mohammad Taghi; Naghizadeh, Bahareh; Ghorbanzadeh, Behnam

    2014-01-01

    Objective: Ellagic acid (EA), a major polyphenolic compound of pomegranate juice, produces antinociceptive effects, which are mediated through opioidergic and nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathways. The present study was conducted to elucidate the peripheral antinociceptive effect of EA alone and in combination with sildenafil in the rat formalin test. Materials and Methods: Pain was produced by intraplantar injection of formalin (2.5%) in rats and nociceptive behavior was measured as the number of flinches every 5 min in 60 min after injection. Results: Local administration of EA and sildenafil dose-dependently increased the nociception threshold in both phases of the test. Moreover, sub-effective doses of sildenafil (25 or 50 mcg/paw, i.p.) significantly and dose-dependently enhanced the antinociception induced by a sub-effective dose of EA (60 mcg/paw, i.pl.) in both phases of the test. The antinociception produced by these drugs alone, or in combination, was due to a peripheral site of action, since the administration in the contralateral paw was ineffective. Conclusion: Our results suggest that EA has local peripheral antinociceptive activity, and enhancement of this effect with sildenafil probably occurs through the inhibition of cGMP metabolism. PMID:25097278

  2. Selection of enhanced antimicrobial activity posing lactic acid bacteria characterised by (GTG)5-PCR fingerprinting.

    PubMed

    Šalomskienė, Joana; Abraitienė, Asta; Jonkuvienė, Dovilė; Mačionienė, Irena; Repečkienė, Jūratė

    2015-07-01

    The aim of the study was a detail evaluation of genetic diversity among the lactic acid bacteria (LAB) strains having an advantage of a starter culture in order to select genotypically diverse strains with enhanced antimicrobial effect on some harmfull and pathogenic microorganisms. Antimicrobial activity of LAB was performed by the agar well diffusion method and was examined against the reference strains and foodborne isolates of Bacillus cereus, Listeria monocytogenes, Escherichia coli, Staphylococcus aureus and Salmonella Typhimurium. Antifungal activity was tested against the foodborne isolates of Candida parapsilosis, Debaromyces hansenii, Kluyveromyces marxianus, Pichia guilliermondii, Yarowia lipolytica, Aspergillus brasiliensis, Aspergillus versicolor, Cladosporium herbarum, Penicillium chrysogenum and Scopulariopsis brevicaulis. A total 40 LAB strains representing Lactobacillus (23 strains), Lactococcus (13 strains) and Streptococcus spp. (4 strains) were characterised by repetitive sequence based polymerase chain reaction fingerprinting which generated highly discriminatory profiles, confirmed the identity and revealed high genotypic heterogeneity among the strains. Many of tested LAB demonstrated strong antimicrobial activity specialised against one or few indicator strains. Twelve LAB strains were superior in suppressing growth of the whole complex of pathogenic bacteria and fungi. These results demonstrated that separate taxonomic units offered different possibilities of selection for novel LAB strains could be used as starter cultures enhancing food preservation.

  3. Ultrasensitive electrochemical detection of nucleic acids by template enhanced hybridization followed with rolling circle amplification.

    PubMed

    Ji, Hanxu; Yan, Feng; Lei, Jianping; Ju, Huangxian

    2012-08-21

    An ultrasensitive protocol for electrochemical detection of DNA is designed with quantum dots (QDs) as a signal tag by combining the template enhanced hybridization process (TEHP) and rolling circle amplification (RCA). Upon the recognition of the molecular beacon (MB) to target DNA, the MB hybridizes with assistants and target DNA to form a ternary ''Y-junction''. The target DNA can be dissociated from the structure under the reaction of nicking endonuclease to initiate the next hybridization process. The template enhanced MB fragments further act as the primers of the RCA reaction to produce thousands of repeated oligonucleotide sequences, which can bind with oligonucleotide functionalized QDs. The attached signal tags can be easily read out by square-wave voltammetry after dissolving with acid. Because of the cascade signal amplification and the specific TEHP and RCA reaction, this newly designed protocol provides an ultrasensitive electrochemical detection of DNA down to the attomolar level (11 aM) with a linear range of 6 orders of magnitude (from 1 × 10(-17) to 1 × 10(-11) M) and can discriminate mismatched DNA from perfect matched target DNA with high selectivity. The high sensitivity and specificity make this method a great potential for early diagnosis in gene-related diseases.

  4. High orientation of long chain branched poly (lactic acid) with enhanced blood compatibility and bionic structure.

    PubMed

    Li, Zhengqiu; Ye, Lin; Zhao, Xiaowen; Coates, Phil; Caton-Rose, Fin; Martyn, Michasel

    2016-05-01

    Highly oriented poly (lactic acid) (PLA) with bionic microgrooves was fabricated through solid hot drawing technology for further improving the mechanical properties and blood biocompatibility of PLA. In order to enhance the melt strength and thus obtain high orientation degree, long chain branched PLA was prepared at first through a two-step ring-opening reaction during processing. Linear viscoelasticity combined with branch-on-branch model was used to predict probable compositions and chain topologies of the products, and it was found that the molecular weight of PLA increased and topological structures with star like chain with three arms and tree-like chain with two generations formed during reactive processing, and consequently draw ratio as high as1200% can be achieved during the subsequent hot stretching. With the increase of draw ratio, the tensile strength and orientation degree of PLA increased dramatically. Long chain branching and orientation could significantly enhance the blood compatibility of PLA by prolonging clotting time and decreasing platelet activation. Microgrooves can be observed on the surface of the oriented PLA which were similar to the intimal layer of blood vessel, and such bionic structure resulted from the formation of the oriented shish kebab-like crystals along the draw direction.

  5. Synergistic interactions between grafted hyaluronic acid and lubricin provide enhanced wear protection and lubrication.

    PubMed

    Das, Saurabh; Banquy, Xavier; Zappone, Bruno; Greene, George W; Jay, Gregory D; Israelachvili, Jacob N

    2013-05-13

    Normal (e.g., adhesion) and lateral (friction) forces were measured between physisorbed and chemically grafted layers of hyaluronic acid (HA), an anionic polyelectrolyte in the presence of lubricin (Lub), a mucinous glycoprotein, on mica surfaces using a surface forces apparatus (SFA). This work demonstrates that high friction coefficients between the surfaces do not necessarily correlate with surface damage and that chemically grafted HA acts synergistically with Lub to provide friction reduction and enhanced wear protection to the surfaces. Surface immobilization of HA by grafting is necessary for such wear protection. Increasing the concentration of Lub enhances the threshold load that a chemically grafted HA surface can be subjected to before the onset of wear. Addition of Lub does not have any beneficial effect if HA is physisorbed to the mica surfaces. Damage occurs at loads less than 1 mN regardless of the amount of Lub, indicating that the molecules in the bulk play little or no role in protecting the surfaces from damage. Lub penetrates into the chemically bound HA to form a visco-elastic gel that reduces the coefficient of friction as well as boosts the strength of the surface against abrasive wear (damage).

  6. Stable Ag@oxides nanoplates for surface-enhanced Raman spectroscopy of amino acids.

    PubMed

    Du, Peng; Ma, Lan; Cao, Yinghui; Li, Di; Liu, Zhenyu; Wang, Zhenxin; Sun, Zaicheng

    2014-06-11

    Surface enhancement Raman scattering (SERS) is a powerful technique for detecting low-concentration analytes (chemicals and biochemicals). Herein, a high-performance SERS biosensing system has been created by using highly stable Ag@oxides nanoplates as enhancers. The Ag nanoplates were stabilized by coating a uniform ultrathin layer of oxides (SiO2 or TiO2) on the Ag surface through a simple sol-gel route. The thin oxide layer allows the plasmonic property of the original Ag nanoplates to be retained while preventing their contact with external etchants. The oxides provide an excellent platform for binding all kinds of molecules that contain a COOH group in addition to a SH group. We demonstrate that Ag@oxides have high performance with respect to the typical SERS molecule 4-ATP, which contains a typical SH group. Ag@oxides also can be directly employed for the SERS detection of amino acids. The highly stable Ag@oxides nanoplates are believed to hold great promise for fabricating a wide range of biosensors for the detection of many other biomolecules and may also find many interesting opportunities in the fields of biological labeling and imaging.

  7. Sonodynamic therapy using 5-aminolevulinic acid enhances the efficacy of bleomycin.

    PubMed

    Osaki, Tomohiro; Ono, Misato; Uto, Yoshihiro; Ishizuka, Masahiro; Tanaka, Tohru; Yamanaka, Nobuyasu; Kurahashi, Tsukasa; Azuma, Kazuo; Murahata, Yusuke; Tsuka, Takeshi; Ito, Norihiko; Imagawa, Tomohiro; Okamoto, Yoshiharu

    2016-04-01

    Sonodynamic therapy (SDT) kills tumor cells through the synergistic effects of ultrasound and a sonosensitizer agent. We examined whether 5-aminolevulinic acid (5-ALA)-based SDT at 1 or 3 MHz could enhance the cytotoxicity of bleomycin (BLM) toward mouse mammary tumor cells both in vitro and in vivo. At 1 MHz, cell viability in the 5-ALA-based SDT group at 1, 2, and 3 W/cm(2) was 34.30%, 50.90%, and 60.16%, respectively. Cell viability in the 5-ALA-based SDT+BLM group at 1, 2, and 3 W/cm(2) was 0.09%, 0.32%, and 0.17%, respectively. In contrast, at 3 MHz, 5-ALA-based SDT+BLM did not show pronounced cytotoxicity. In the in vivo study, 5-ALA-based SDT+BLM was significantly more cytotoxic than 5-ALA-based SDT at 1 MHz and 3 MHz. These findings suggest that the mechanism of tumor shrinkage induced by 5-ALA-based SDT+BLM might involve not only direct cell killing, but also vascular shutdown. Thus, we show here that 5-ALA-based SDT enhances the efficacy of BLM both in vitro and in vivo. PMID:26799128

  8. Synaptic enhancement induced by gintonin via lysophosphatidic acid receptor activation in central synapses.

    PubMed

    Park, Hoyong; Kim, Sungmin; Rhee, Jeehae; Kim, Hyeon-Joong; Han, Jung-Soo; Nah, Seung-Yeol; Chung, ChiHye

    2015-03-01

    Lysophosphatidic acid (LPA) is one of the well-characterized, ubiquitous phospholipid molecules. LPA exerts its effect by activating G protein-coupled receptors known as LPA receptors (LPARs). So far, LPAR signaling has been critically implicated during early development stages, including the regulation of synapse formation and the morphology of cortical and hippocampal neurons. In adult brains, LPARs seem to participate in cognitive as well as emotional learning and memory. Recent studies using LPAR1-deficient mice reported impaired performances in a number of behavioral tasks, including the hippocampus-dependent spatial memory and fear conditioning tests. Nevertheless, the effect of LPAR activation in the synaptic transmission of central synapses after the completion of embryonic development has not been investigated. In this study, we took advantage of a novel extracellular agonist for LPARs called gintonin to activate LPARs in adult brain systems. Gintonin, a recently identified active ingredient in ginseng, has been shown to activate LPARs and mobilize Ca(2+) in an artificial cell system. We found that the activation of LPARs by application of gintonin acutely enhanced both excitatory and inhibitory transmission in central synapses, albeit through tentatively distinct mechanisms. Gintonin-mediated LPAR activation primarily resulted in synaptic enhancement and an increase in neuronal excitability in a phospholipase C-dependent manner. Our findings suggest that LPARs are able to directly potentiate synaptic transmission in central synapses when stimulated exogenously. Therefore, LPARs could serve as a useful target to modulate synaptic activity under pathological conditions, including neurodegenerative diseases.

  9. Free nitrous acid (FNA)-based pretreatment enhances methane production from waste activated sludge.

    PubMed

    Wang, Qilin; Ye, Liu; Jiang, Guangming; Jensen, Paul D; Batstone, Damien J; Yuan, Zhiguo

    2013-10-15

    Anaerobic digestion of waste activated sludge (WAS) is currently enjoying renewed interest due to the potential for methane production. However, methane production is often limited by the slow hydrolysis rate and/or poor methane potential of WAS. This study presents a novel pretreatment strategy based on free nitrous acid (FNA or HNO2) to enhance methane production from WAS. Pretreatment of WAS for 24 h at FNA concentrations up to 2.13 mg N/L substantially enhanced WAS solubilization, with the highest solubilization (0.16 mg chemical oxygen demand (COD)/mg volatile solids (VS), at 2.13 mg HNO2-N/L) being six times that without FNA pretreatment (0.025 mg COD/mg VS, at 0 mg HNO2-N/L). Biochemical methane potential tests demonstrated methane production increased with increased FNA concentration used in the pretreatment step. Model-based analysis indicated FNA pretreatment improved both hydrolysis rate and methane potential, with the highest improvement being approximately 50% (from 0.16 to 0.25 d(-1)) and 27% (from 201 to 255 L CH4/kg VS added), respectively, achieved at 1.78-2.13 mg HNO2-N/L. Further analysis indicated that increased hydrolysis rate and methane potential were related to an increase in rapidly biodegradable substrates, which increased with increased FNA dose, while the slowly biodegradable substrates remained relatively static.

  10. Microwave enhanced chemical reduction process for nitrite-containing wastewater treatment using sulfaminic acid.

    PubMed

    Li, Nan; Wang, Peng; Liu, Qingsong; Cao, Hailei

    2010-01-01

    High-concentration nitrite-containing wastewater that presents extreme toxicity to human health and organisms is difficult to be treated using traditional biological process. In this study, a novel microwave-enhanced chemical reduction process (MECRP) using sulfaminic acid (SA) was proposed as a new manner to treat such type of wastewater. Based on lab-scale experiments, it was shown that 75%-80% nitrite (NO2-) could be removed within time as short as 4 min under 50 W microwave irradiation in pH range 5-10 when molar ratio of SA to nitrite (SA/NO2-) was 0.8. Pilot-scale investigations demonstrated that MECRP was able to achieve nitrite and chemical oxygen demand (COD) removal with efficiency up to 80% and 20%, respectively under operating conditions of SA concentration 80 kg/m3, SA/NO2- ratio 0.8, microwave power 3.4 kW, and stirring time 3 min. Five-day biological oxygen demand (BOD5)/COD value of treated effluent after MECRP was increased from 0.05 to 0.36 (by 620%), which clearly suggested a considerable improvement of biodegradability for subsequent biological treatment. This study provided a demonstration of using microwave irradiation to enhance reaction between SA and nitrite in a short time, in which nitrite in wastewater was completely converted into nitrogen gas without leaving any sludge and secondary pollutants. PMID:20397387

  11. Potential use of ascorbic acid-based surfactants as skin penetration enhancers.

    PubMed

    Palma, S D; Maletto, B; Lo Nostro, P; Manzo, R H; Pistoresi-Palencia, M C; Allemandi, D A

    2006-08-01

    6-O-Ascorbic acid alkanoates (ASCn) are amphiphilic molecules having physical-chemical properties that depend on the alkyl chain length. The derivatives of low molecular weight (n < 11) have enough aqueous solubility to produce self-assemblies at room temperature ( approximately 25 degrees C), while those with longer alkyl chains possess a critical micellar temperature (CMT) higher than 30 degrees C. At higher temperatures (T degrees > CMT), ASCn aqueous suspensions turn into either micellar solutions or gel phases, depending on the length of the hydrophobic chain. On cooling, coagels are produced, which possess a lamellar structure that exhibit sharp X-ray diffraction patterns and optical birefringence. The semisolid consistency of such coagels is an interesting property to formulate dermatological pharmaceutical dosage forms able to solubilize and stabilize different drugs. The objective of the present study was the evaluation of the enhancing permeation effect of ASCn with different chain lengths and to correlate permeability changes with histological effects. With this purpose, ASCn coagels containing anthralin (antipsoriasic drug) or fluorescein isothiocyanate (FITC, hydrophobic fluorescent marker) were assayed on rat skin (ex vivo) and mice skin (in vivo), respectively. Also, histological studies were performed aimed at detecting some possible side effects of ASCn. No inflammatory cellular response was observed in the skin when ASCn coagels were applied, suggesting non-irritating properties. Light microscopy indicated slight disruption and fragmentation of stratum corneum. The penetration of ASCn through rat skin epidermis was very fast and quantitatively significant. The permeation of anthralin was significantly increased when the drug was vehiculized in ASCn coagels, compared to other pharmaceutical systems. The results indicated that ASC12 seems to have the highest enhancing effect on FITC permeation. ASC12 appears to be the compound that possesses the

  12. Enhanced skin regeneration by nanoegg formulation of all-trans retinoic acid.

    PubMed

    Yamaguchi, Y; Nakamura, N; Nagasawa, T; Kitagawa, A; Matsumoto, K; Soma, Y; Matsuda, T; Mizoguchi, M; Igarashi, R

    2006-02-01

    All-trans retinoic acid (atRA) which could smooth wrinkles and produce less pigmented skin after a few months of treatment has been studied in research into topical treatments for a potent inhibitor of new melanin production. However, the clinical responses of commercial atRA cream predominantly comprise severe inflammation. We report a novel nanotechnology "nanoegg" system giving improved effects of atRA self-assembly which were coated by CaCO3. Dorsal areas of hairless mouse and porcine skin were employed for administration of nanoegg ointment and commercial products. The mRNA for heparin-binding epidermal growth factor-like growth factor (HB-EGF) from tissues was measured by a real-time PCR method. All tissues were stained for detection of hyaluronate and the thickness of the epidermis. A clinical trial in humans was carried out at St. Marianna University in Japan. As a result, the irritation and inflammation associated with atRA molecules were substantially reduced. The physicochemical instability of atRA was also dramatically improved. Furthermore, nanoegg enhanced marked expression of mRNA for HB-EGF from keratinocytes, which is known as one of the markers of keratinocyte turnover. Also, production of hyaluronate was surprisingly in the intercellular spaces of the basal and spinous cell layers 2 days after treatment. Even at the low concentration of atRA in the nanoegg system, the proliferation and differentiation of keratinocyte was somewhat enhanced. A nanoegg may thus not only prevent adverse effects, but also markedly enhance the main effect.

  13. Bacterial inoculants of forage grasses that enhance degradation of 2-chlorobenzoic acid in soil

    SciTech Connect

    Siciliano, S.D.; Germida, J.J.

    1997-06-01

    Biological remediation of contaminated soil is an effective method of reducing risk to human and ecosystem health. Bacteria and plants might be used to enhance remediation of soil pollutants in situ. This study assessed the potential of bacteria, plants, and plant-bacteria associations to remediate 2-chlorobenzoic acid (2CBA) contaminated soil. Initially, grass viability was assessed in 2CBA-contaminated soil. Soil was contaminated with 2CBA, forage grasses were grown under growth chamber conditions for 42 or 60 d, and the 2CBA concentration in soil was determined by gas chromatography. Only five of 16 forage grasses grew in 2CBA-treated soil. Growth of Bromus inermis had no effect on 2CBA concentration, whereas Agropyron intermedium, B. biebersteinii, A. riparum, and Elymus dauricus decreased 2CBA relative to nonplanted control soil by 32 to 42%. The 12 bacteria isolates were screened for their ability to promote the germination of the five grasses in 2CBA-contaminated soil. Inoculation of A. riparum with Pseudomonas aeruginosa strain R75, a proven plant growth-promoting rhizobacterium, increased seed germination by 80% and disappearance of 2CBA by 20% relative to noninoculated plants. Inoculation of E. dauricus with a mixture of P. savastanoi strain CB35, a 2CBA-degrading bacterium, and P. aeruginosa strain R75 increased disappearance of 2CBA by 112% relative to noninoculated plants. No clear relationship between enhanced 2CBA disappearance and increased plant biomass was found. These results suggest that specific plant-microbial systems can be developed to enhance remediation of pollutants in soil.

  14. Elongation of very long-chain fatty acids is enhanced in X-linked adrenoleukodystrophy.

    PubMed

    Kemp, Stephan; Valianpour, Fredoen; Denis, Simone; Ofman, Rob; Sanders, Robert-Jan; Mooyer, Petra; Barth, Peter G; Wanders, Ronald J A

    2005-02-01

    X-linked adrenoleukodystrophy (X-ALD) is a progressive neurodegenerative disorder characterized by the accumulation of saturated and mono-unsaturated very long-chain fatty acids (VLCFA) and reduced peroxisomal VLCFA beta-oxidation activity. In this study, we investigated the role of VLCFA biosynthesis in X-ALD fibroblasts. Our data demonstrate that elongation of both saturated and mono-unsaturated VLCFAs is enhanced in fibroblasts from patients with peroxisomal beta-oxidation defects including X-ALD, and peroxisome biogenesis disorders. These data indicate that enhanced VLCFA elongation is a general phenomenon associated with an impairment in peroxisomal beta-oxidation, and not specific for X-ALD alone. Analysis of plasma samples from patients with X-ALD and different peroxisomal beta-oxidation deficiencies revealed increased concentrations of VLCFAs up to 32 carbons. We infer that enhanced elongation does not result from impaired peroxisomal beta-oxidation alone, but is due to the additional effect of unchecked chain elongation. We demonstrate that elongated VLCFAs are incorporated into complex lipids. The role of chain elongation was also studied retrospectively in samples from patients with X-ALD previously treated with "Lorenzo's oil." We found that the decrease in plasma C26:0 previously found is offset by the increase of mono-unsaturated VLCFAs, not measured previously during the trial. We conclude that evaluation of treatment protocols for disorders of peroxisomal beta-oxidation making use of plasma samples should include the measurement of saturated and unsaturated VLCFAs of chain lengths above 26 carbon atoms. We also conclude that chain elongation offers an interesting target to be studied as a possible mode of treatment for X-ALD and other peroxisomal beta-oxidation disorders.

  15. Gintonin enhances performance of mice in rotarod test: Involvement of lysophosphatidic acid receptors and catecholamine release.

    PubMed

    Lee, Byung-Hwan; Kim, Jisu; Lee, Ra Mi; Choi, Sun-Hye; Kim, Hyeon-Joong; Hwang, Sung-Hee; Lee, Myung Koo; Bae, Chun-Sik; Kim, Hyoung-Chun; Rhim, Hyewon; Lim, Kiwon; Nah, Seung-Yeol

    2016-01-26

    Ginseng has a long history of use as a tonic for restoration of vigor. One example of ginseng-derived tonic effect is that it can improve physical stamina under conditions of stress. However, the active ingredient and the underlying molecular mechanism responsible for the ergogenic effect are unknown. Recent studies show that ginseng contains a novel ingredient, gintonin, which consists of a unique class of herbal-medicine lysophosphatidic acids (LPAs). Gintonin activates G protein-coupled LPA receptors to produce a transient [Ca(2+)]i signal, which is coupled to diverse intra- and inter-cellular signal transduction pathways that stimulate hormone or neurotransmitter release. However, relatively little is known about how gintonin-mediated cellular modulation is linked to physical endurance. In the present study, systemic administration of gintonin, but not ginsenosides, in fasted mice increased blood glucose concentrations in a dose-dependent manner. Gintonin treatment elevated blood glucose to a maximum level after 30min. This elevation in blood glucose level could be abrogated by the LPA1/3 receptor antagonist, Ki16425, or the β-adrenergic receptor antagonist, propranolol. Furthermore, gintonin-dependent enhanced performance of fasted mice in rotarod test was likewise abrogated by Ki16425. Gintonin also elevated plasma epinephrine and norepinephrine concentrations. The present study shows that gintonin mediates catecholamine release through activation of the LPA receptor and that activation of the β-adrenergic receptor is coupled to liver glycogenolysis, thereby increasing the supply of glucose and enhancing performance in the rotarod test. Thus, gintonin acts via the LPA-catecholamine-glycogenolysis axis, representing a candidate mechanism that can explain how ginseng treatment enhances physical stamina. PMID:26706688

  16. Lactic acid fermentation as a tool to enhance the functional features of Echinacea spp

    PubMed Central

    2013-01-01

    Background Extracts and products (roots and/or aerial parts) from Echinacea ssp. represent a profitable market sector for herbal medicines thanks to different functional features. Alkamides and polyacetylenes, phenols like caffeic acid and its derivatives, polysaccharides and glycoproteins are the main bioactive compounds of Echinacea spp. This study aimed at investigating the capacity of selected lactic acid bacteria to enhance the antimicrobial, antioxidant and immune-modulatory features of E. purpurea with the prospect of its application as functional food, dietary supplement or pharmaceutical preparation. Results Echinacea purpurea suspension (5%, wt/vol) in distilled water, containing 0.4% (wt/vol) yeast extract, was fermented with Lactobacillus plantarum POM1, 1MR20 or C2, previously selected from plant materials. Chemically acidified suspension, without bacterial inoculum, was used as the control to investigate functional features. Echinacea suspension fermented with Lb. plantarum C2 exhibited a marked antimicrobial activity towards Gram-positive and -negative bacteria. Compared to control, the water-soluble extract from Echinacea suspension fermented with Lactobacillus plantarum 1MR20 showed twice time higher radical scavenging activity on DPPH. Almost the same was found for the inhibition of oleic acid peroxidation. The methanol extract from Echinacea suspension had inherent antioxidant features but the activity of extract from the sample fermented with strain 1MR20 was the highest. The antioxidant activities were confirmed on Balb 3T3 mouse fibroblasts. Lactobacillus plantarum C2 and 1MR20 were used in association to ferment Echinacea suspension, and the water-soluble extract was subjected to ultra-filtration and purification through RP-FPLC. The antioxidant activity was distributed in a large number of fractions and proportional to the peptide concentration. The antimicrobial activity was detected only in one fraction, further subjected to nano

  17. Enhanced antimicrobial effect of organic acid washing against foodborne pathogens on broccoli by vacuum impregnation.

    PubMed

    Kang, Jun-Won; Kang, Dong-Hyun

    2016-01-18

    This study was undertaken to evaluate the effect of vacuum impregnation applied to the washing process for removal of Salmonella Typhimurium and Listeria monocytogenes from broccoli surfaces. Broccoli was inoculated with the two foodborne pathogens and treated with simple dipping washing or with vacuum impregnation in 2% malic acid for 5, 10, 20, or 30 min. There were two methods of vacuum impregnation: continuous and intermittent. After 30 min of 101.3 kPa (=14.7 psi, simple dipping), 61.3 kPa (=8.9 psi), and 21.3 kPa (=3.1 psi) of continuous vacuum impregnation treatment, there were 1.6, 2.0, and 2.4 log 10 CFU/g reductions of S. Typhimurium and 1.5, 1.7, and 2.3 log 10 CFU/g reductions of L. monocytogenes, respectively. After 30 min of 101.3, 61.3, and 21.3 kPa of intermittent vacuum impregnation treatment, there were 1.5, 2.3, and 3.7 log 10 CFU/g reductions of S. Typhimurium and 1.6, 2.1, and 3.2 log 10 CFU/g reductions of L. monocytogenes, respectively. Scanning electron photomicrographs showed that bacteria tend to attach to or become entrapped in protective sites after simple wash processing (dipping). However, most bacteria were washed out of protective sites after intermittent treatment. Direct treatment of cell suspensions with vacuum impregnation showed that it had no inactivation capacity in itself since there were no significant differences (P ≥ 0.05) between the reduction rates of non- and vacuum impregnation treatment. These results demonstrate that the increased antimicrobial effect of vacuum impregnation can be attributed to increased accessibility of sanitizer and an enhanced washing effect in protected sites on produce. Color, texture and titratable acidity values of broccoli treated with intermittent vacuum impregnation in 2% malic acid for 30 min were not significantly (P ≥ 0.05) different from those of untreated samples even though a storage interval was needed for titratable acidity values to be reduced to levels comparable to those of

  18. DEPOSITION TANK CORROSION TESTING FOR ENHANCED CHEMICAL CLEANING POST OXALIC ACID DESTRUCTION

    SciTech Connect

    Mickalonis, J.

    2011-08-29

    An Enhanced Chemical Cleaning (ECC) process is being developed to aid in the high level waste tank closure at the Savannah River Site. The ECC process uses an advanced oxidation process (AOP) to destroy the oxalic acid that is used to remove residual sludge from a waste tank prior to closure. The AOP process treats the dissolved sludge with ozone to decompose the oxalic acid through reactions with hydroxyl radicals. The effluent from this oxalic acid decomposition is to be sent to a Type III waste tank and may be corrosive to these tanks. As part of the hazardous simulant testing that was conducted at the ECC vendor location, corrosion testing was conducted to determine the general corrosion rate for the deposition tank and to assess the susceptibility to localized corrosion, especially pitting. Both of these factors impact the calculation of hydrogen gas generation and the structural integrity of the tanks, which are considered safety class functions. The testing consisted of immersion and electrochemical testing of A537 carbon steel, the material of construction of Type III tanks, and 304L stainless steel, the material of construction for transfer piping. Tests were conducted in solutions removed from the destruction loop of the prototype ECC set up. Hazardous simulants, which were manufactured at SRNL, were used as representative sludges for F-area and H-area waste tanks. Oxalic acid concentrations of 1 and 2.5% were used to dissolve the sludge as a feed to the ECC process. Test solutions included the uninhibited effluent, as well as the effluent treated for corrosion control. The corrosion control options included mixing with an inhibited supernate and the addition of hydroxide. Evaporation of the uninhibited effluent was also tested since it may have a positive impact on reducing corrosion. All corrosion testing was conducted at 50 C. The uninhibited effluent was found to increase the corrosion rate by an order of magnitude from less than 1 mil per year (mpy

  19. Enhanced antimicrobial effect of organic acid washing against foodborne pathogens on broccoli by vacuum impregnation.

    PubMed

    Kang, Jun-Won; Kang, Dong-Hyun

    2016-01-18

    This study was undertaken to evaluate the effect of vacuum impregnation applied to the washing process for removal of Salmonella Typhimurium and Listeria monocytogenes from broccoli surfaces. Broccoli was inoculated with the two foodborne pathogens and treated with simple dipping washing or with vacuum impregnation in 2% malic acid for 5, 10, 20, or 30 min. There were two methods of vacuum impregnation: continuous and intermittent. After 30 min of 101.3 kPa (=14.7 psi, simple dipping), 61.3 kPa (=8.9 psi), and 21.3 kPa (=3.1 psi) of continuous vacuum impregnation treatment, there were 1.6, 2.0, and 2.4 log 10 CFU/g reductions of S. Typhimurium and 1.5, 1.7, and 2.3 log 10 CFU/g reductions of L. monocytogenes, respectively. After 30 min of 101.3, 61.3, and 21.3 kPa of intermittent vacuum impregnation treatment, there were 1.5, 2.3, and 3.7 log 10 CFU/g reductions of S. Typhimurium and 1.6, 2.1, and 3.2 log 10 CFU/g reductions of L. monocytogenes, respectively. Scanning electron photomicrographs showed that bacteria tend to attach to or become entrapped in protective sites after simple wash processing (dipping). However, most bacteria were washed out of protective sites after intermittent treatment. Direct treatment of cell suspensions with vacuum impregnation showed that it had no inactivation capacity in itself since there were no significant differences (P ≥ 0.05) between the reduction rates of non- and vacuum impregnation treatment. These results demonstrate that the increased antimicrobial effect of vacuum impregnation can be attributed to increased accessibility of sanitizer and an enhanced washing effect in protected sites on produce. Color, texture and titratable acidity values of broccoli treated with intermittent vacuum impregnation in 2% malic acid for 30 min were not significantly (P ≥ 0.05) different from those of untreated samples even though a storage interval was needed for titratable acidity values to be reduced to levels comparable to those of

  20. Enhanced absorption of n-3 fatty acids from emulsified compared with encapsulated fish oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have important nutrition and disease management properties. Presently fish oil (FO) supplementation relies on capsular triglyceride. Flavored emulsified lipid preparations may provide an improved approach to FO del...

  1. Alkyl polyglucose enhancing propionic acid enriched short-chain fatty acids production during anaerobic treatment of waste activated sludge and mechanisms.

    PubMed

    Luo, Jingyang; Feng, Leiyu; Chen, Yinguang; Sun, Han; Shen, Qiuting; Li, Xiang; Chen, Hong

    2015-04-15

    Adding alkyl polyglucose (APG) into an anaerobic treatment system of waste activated sludge (WAS) was reported to remarkably improve the production of short-chain fatty acids (SCFAs), especially propionic acid via simultaneously accelerating solubilization and hydrolysis, enhancing acidification, inhibiting methanogenesis and balancing carbon to nitrogen (C/N) ratio of substrate. Not only the production of SCFAs, especially propionic acid, was significantly improved by APG, but also the feasible operation time was shortened. The SCFAs yield at 0.3 g APG per gram of total suspended solids (TSS) within 4 d was 2988 ± 60 mg chemical oxygen demand (COD) per liter, much higher than that those from sole WAS or sole WAS plus sole APG. The corresponding yield of propionic acid was 1312 ± 25 mg COD/L, 7.9-fold of sole WAS. Mechanism investigation showed that during anaerobic treatment of WAS in the presence of APG both the solubilization and hydrolysis were accelerated and the acidification was enhanced, while the methanogenesis was inhibited. Moreover, the activities of key enzymes involved in WAS hydrolysis and acidification were improved through the adjustment of C/N ratio of substrates with APG. The abundance of microorganisms responsible for organic compounds hydrolysis and SCFAs production was also observed to be greatly enhanced with APG via 454 high-throughput pyrosequencing analysis.

  2. Enhancement of power production with tartaric acid doped polyaniline nanowire network modified anode in microbial fuel cells.

    PubMed

    Liao, Zhi-Hong; Sun, Jian-Zhong; Sun, De-Zhen; Si, Rong-Wei; Yong, Yang-Chun

    2015-09-01

    The feasibility to use tartaric acid doped PANI for MFC anode modification was determined. Uniform PANI nanowires doped with tartaric acid were synthesized and formed mesoporous networks on the carbon cloth surface. By using this tartaric acid doped PANI modified carbon cloth (PANI-TA) as the anode, the voltage output (435 ± 15 mV) and power output (490 ± 12 mW/m(2)) of MFC were enhanced by 1.6 times and 4.1 times compared to that of MFC with plain carbon cloth anode, respectively. Strikingly, the performance of PANI-TA MFC was superior to that of the MFCs with inorganic acids doped PNAI modified anode. These results substantiated that tartaric acid is a promising PANI dopant for MFC anode modification, and provided new opportunity for MFC performance improvement.

  3. Fortification of eggs with folic acid as a possible contribution to enhance the folic acid status of populations.

    PubMed

    Roth-Maier, Dora A; Böhmer, Barbara M

    2007-07-01

    The aim of the present study was to evaluate the enrichment of folic acid in eggs by supplementing hens' diet. Seventy-two hens (LSL) were assigned to 5 dietary groups and supplemented with 0, 0.5, 1.0, 2.0, and 4.0 mg folic acid/kg feed during an 8-week period. Eggs for folic acid analysis were collected in weeks 4 and 8 and analyzed by microbiological method using L. casei. The performance of the hens was not influenced by the supplementation. The content of folic acid in eggs increased significantly from 3.1 microg/g DM to 5.5 microg/g DM (week 4) and from 2.1 microg/g DM to 4.2 microg/g DM (week 8), respectively. One fortified egg can provide up to 76 microg folic acid. Additionally the intestinal availability of folic acid in eggs was determined in pigs as an animal model for human nutrition. Six pigs were fitted with ileorectal-anastomosis and received boiled eggs combined with a supplementary diet according to nutrient requirement. The metabolic trial ran for 12 days with a pre-period of 7 days and a collection period of 5 days. Feed and chyme were analyzed for folic acid as mentioned above. The availability of folate in eggs was determined as 68%, which means that one fortified egg provides up to 52 microg folate equivalent to 13% of the recommended daily intake.

  4. Zoledronic acid enhances Vδ2 T-lymphocyte antitumor response to human glioma cell lines.

    PubMed

    Cimini, E; Piacentini, P; Sacchi, A; Gioia, C; Leone, S; Lauro, G M; Martini, F; Agrati, C

    2011-01-01

    Glioblastoma multiforme (GBM), the most frequent and aggressive primary brain tumor in humans, responds modestly to treatment: most patients survive less than one year after diagnosis, despite both classical and innovative treatment approaches. A recent paper focused on γδ T-cell response in GBM patients, suggesting the application of an immunomodulating strategy based on γδ T-cells which is already in clinical trials for other tumors. Human Vγ2 T-cells recognize changes in the mevalonate metabolic pathway of transformed cells by activating cytotoxic response, and by cytokine and chemokine release. Interestingly, this activation may also be induced in vivo by drugs, such as zoledronic acid, that induce the accumulation of Vγ2 T-cell ligand Isopentenyl-pyrophosphate by blocking the farnesyl pyrophosphate synthase enzyme. The aim of our work is to confirm whether bisphosphonate treatment would make glioma cell lines more susceptible to lysis by in vitro expanded γδ T-cells, improving their antitumor activity. We expanded in vitro human Vγ2 T-cells by phosphoantigen stimulation and tested their activity against glioma cell lines. Co-culture with glioma cells induced Vγ2 T-cell differentiation in effector/memory cells, killing glioma cells by the release of perforin. Interestingly, glioma cells were directly affected by zoledronic acid; moreover, treatment increased their activating ability on Vγ2 T-cells, inducing an effective antitumor cytotoxic response. Taken together, our results show that aminobisphosphonate drugs may play a dual role against GBM, by directly affecting tumor cells, and by enhancing the antitumor response of Vγ2 T-cells. Our results confirm the practicability of this approach as a new immunotherapeutic strategy for GBM treatment.

  5. Phthalic acid esters found in municipal organic waste: enhanced anaerobic degradation under hyper-thermophilic conditions.

    PubMed

    Hartmann, H; Ahring, B K

    2003-01-01

    Contamination of the organic fraction of municipal solid waste (OFMSW) with xenobiotic compounds and their fate during anaerobic digestion was investigated. The phthalic acid ester di-(2-ethylhexyl)phthalate (DEHP) was identified as the main contaminant in OFMSW in concentrations more than half of the threshold value for the use as fertilizer on agricultural soil in Denmark. Analysis of DEHP in samples before and after large-scale anaerobic digesters revealed higher concentrations of DEHP per kg dry matter in the effluent than in the influent. The concentration of DEHP and DBP (dibutylphthalate) in OFMSW was monitored in the influent and effluent of anaerobic thermophilic (55 degrees C) and hyper-thermophilic (68 degrees C) laboratory-scale reactor systems. In the thermophilic reactors with a hydraulic retention time (HRT) of 15 days 38-70% of DBP was removed, but no consistent removal of DEHP was observed. However, after treatment of the effluent from the thermophilic reactor in a hyper-thermophilic digester (HRT: 5 days) 34-53% of the DEHP content was removed and the DBP removal was increased to further 62-74%. Removal rates (k(h)) of DEHP and DBP were found to be 0.11-0.32 d(-1) and 0.41-0.79 d(-1), which is much higher than in previous investigations. It can be concluded that the higher removal rates are due to the higher temperature and higher initial concentrations per kg dry matter. These results suggest that the limiting factor for DEHP degradation is the bioavailability, which is enhanced at higher temperature and higher degradation of solid organic matter, to which the highly hydrophobic DEHP is adsorbed. The investigated reactor configuration with a thermophilic and a hyper-thermophilic treatment is, therefore, a good option for combining high rate degradation of organic matter with high biogas yields and efficient reduction of the phthalic acid ester contamination.

  6. Ursolic acid regulates aging process through enhancing of metabolic sensor proteins level.

    PubMed

    Bahrami, Soroush Alaghehband; Bakhtiari, Nuredin

    2016-08-01

    We previously reported that Ursolic Acid (UA) ameliorates skeletal muscle performance through satellite cells proliferation and cellular energy status. In studying the potential role of the hypothalamus in aging, we developed a strategy to pursue UA effects on the hypothalamus anti-aging proteins such as; SIRT1, SIRT6, PGC-1β and α-Klotho. In this study, we used a model of aging animals (C57BL/6). UA dissolved in Corn oil (20mg/ml) and then administrated (200mg/Kg i.p injection) to mice, twice daily for 7days. After treatment times, the mice perfused and the hypothalamus isolated for preparing of tissue to Immunofluorescence microscopy. The data illustrated that UA significantly increased SIRT1 (∼3.5±0.3 folds) and SIRT-6 (∼1.5±0.2 folds) proteins overexpression (P<0.001). In addition, our results showed that UA enhanced α-Klotho (∼3.3±0.3) and PGC-1β (∼2.6±0.2 folds) proteins levels (P<0. 01). In this study, data were analyzed using SPSS 16 (ANOVA test). To the best of our knowledge, it seems that UA through enhancing of anti-aging biomarkers (SIRT1 and SIRT6) and PGC-1β in hypothalamus regulates aging-process and attenuates mitochondrial-related diseases. In regard to the key role of α-Klotho in aging, our data indicate that UA may be on the horizon to forestall diseases of aging. PMID:27470332

  7. Para-aminobenzoic acid (PABA) synthase enhances thermotolerance of mushroom Agaricus bisporus.

    PubMed

    Lu, Zhonglei; Kong, Xiangxiang; Lu, Zhaoming; Xiao, Meixiang; Chen, Meiyuan; Zhu, Liang; Shen, Yuemao; Hu, Xiangyang; Song, Siyang

    2014-01-01

    Most mushrooms are thermo-sensitive to temperatures over 23°C, which greatly restricts their agricultural cultivation. Understanding mushroom's innate heat-tolerance mechanisms may facilitate genetic improvements of their thermotolerance. Agaricus bisporus strain 02 is a relatively thermotolerant mushroom strain, while strain 8213 is quite thermo-sensitive. Here, we compared their responses at proteomic level to heat treatment at 33°C. We identified 73 proteins that are differentially expressed between 02 and 8213 or induced upon heat stress in strain 02 itself, 48 of which with a known identity. Among them, 4 proteins are constitutively more highly expressed in 02 than 8213; and they can be further upregulated in response to heat stress in 02, but not in 8213. One protein is encoded by the para-aminobenzoic acid (PABA) synthase gene Pabs, which has been shown to scavenge the reactive oxygen species in vitro. Pabs mRNA and its chemical product PABA show similar heat stress induction pattern as PABA synthase protein and are more abundant in 02, indicating transcriptional level upregulation of Pabs upon heat stress. A specific inhibitor of PABA synthesis impaired thermotolerance of 02, while exogenous PABA or transgenic overexpression of 02 derived PABA synthase enhanced thermotolerance of 8213. Furthermore, compared to 8213, 02 accumulated less H2O2 but more defense-related proteins (e.g., HSPs and Chitinase) under heat stress. Together, these results demonstrate a role of PABA in enhancing mushroom thermotolerance by removing H2O2 and elevating defense-related proteins. PMID:24614118

  8. Salicylic acid confers enhanced resistance to Glomerella leaf spot in apple.

    PubMed

    Zhang, Ying; Shi, Xiangpeng; Li, Baohua; Zhang, Qingming; Liang, Wenxing; Wang, Caixia

    2016-09-01

    Glomerella leaf spot (GLS) caused by Glomerella cingulata is a newly emergent disease that results in severe defoliation and fruit spots in apple. Currently, there are no effective means to control this disease except for the traditional fungicide sprays. Induced resistance by elicitors against pathogens infection is a widely accepted eco-friendly strategy. In the present study, we investigated whether exogenous application of salicylic acid (SA) could improve resistance to GLS in a highly susceptible apple cultivar (Malus domestica Borkh. cv. 'Gala') and the underlying mechanisms. The results showed that pretreatment with SA, at 0.1-1.0 mM, induced strong resistance against GLS in 'Gala' apple leaves, with SA treated leaves showing significant reduction in lesion numbers and disease index. Concurrent with the enhanced disease resistance, SA treatment markedly increased the total antioxidant capacity (T-AOC) and defence-related enzyme activities, including catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO). As expected, SA treatment also induced the expression levels of five pathogenesis-related (PR) genes including PR1, PR5, PR8, Chitinase and β-1,3-glucanase. Furthermore, the most pronounced and/or rapid increase was observed in leaves treated with SA and subsequently inoculated with G. cingulata compared to the treatment with SA or inoculation with the pathogen. Together, these results suggest that exogenous SA triggered increase in reactive oxygen species levels and the antioxidant system might be responsible for enhanced resistance against G. cingulata in 'Gala' apple leaves. PMID:27139585

  9. Para-aminobenzoic acid (PABA) synthase enhances thermotolerance of mushroom Agaricus bisporus.

    PubMed

    Lu, Zhonglei; Kong, Xiangxiang; Lu, Zhaoming; Xiao, Meixiang; Chen, Meiyuan; Zhu, Liang; Shen, Yuemao; Hu, Xiangyang; Song, Siyang

    2014-01-01

    Most mushrooms are thermo-sensitive to temperatures over 23°C, which greatly restricts their agricultural cultivation. Understanding mushroom's innate heat-tolerance mechanisms may facilitate genetic improvements of their thermotolerance. Agaricus bisporus strain 02 is a relatively thermotolerant mushroom strain, while strain 8213 is quite thermo-sensitive. Here, we compared their responses at proteomic level to heat treatment at 33°C. We identified 73 proteins that are differentially expressed between 02 and 8213 or induced upon heat stress in strain 02 itself, 48 of which with a known identity. Among them, 4 proteins are constitutively more highly expressed in 02 than 8213; and they can be further upregulated in response to heat stress in 02, but not in 8213. One protein is encoded by the para-aminobenzoic acid (PABA) synthase gene Pabs, which has been shown to scavenge the reactive oxygen species in vitro. Pabs mRNA and its chemical product PABA show similar heat stress induction pattern as PABA synthase protein and are more abundant in 02, indicating transcriptional level upregulation of Pabs upon heat stress. A specific inhibitor of PABA synthesis impaired thermotolerance of 02, while exogenous PABA or transgenic overexpression of 02 derived PABA synthase enhanced thermotolerance of 8213. Furthermore, compared to 8213, 02 accumulated less H2O2 but more defense-related proteins (e.g., HSPs and Chitinase) under heat stress. Together, these results demonstrate a role of PABA in enhancing mushroom thermotolerance by removing H2O2 and elevating defense-related proteins.

  10. Ursolic acid regulates aging process through enhancing of metabolic sensor proteins level.

    PubMed

    Bahrami, Soroush Alaghehband; Bakhtiari, Nuredin

    2016-08-01

    We previously reported that Ursolic Acid (UA) ameliorates skeletal muscle performance through satellite cells proliferation and cellular energy status. In studying the potential role of the hypothalamus in aging, we developed a strategy to pursue UA effects on the hypothalamus anti-aging proteins such as; SIRT1, SIRT6, PGC-1β and α-Klotho. In this study, we used a model of aging animals (C57BL/6). UA dissolved in Corn oil (20mg/ml) and then administrated (200mg/Kg i.p injection) to mice, twice daily for 7days. After treatment times, the mice perfused and the hypothalamus isolated for preparing of tissue to Immunofluorescence microscopy. The data illustrated that UA significantly increased SIRT1 (∼3.5±0.3 folds) and SIRT-6 (∼1.5±0.2 folds) proteins overexpression (P<0.001). In addition, our results showed that UA enhanced α-Klotho (∼3.3±0.3) and PGC-1β (∼2.6±0.2 folds) proteins levels (P<0. 01). In this study, data were analyzed using SPSS 16 (ANOVA test). To the best of our knowledge, it seems that UA through enhancing of anti-aging biomarkers (SIRT1 and SIRT6) and PGC-1β in hypothalamus regulates aging-process and attenuates mitochondrial-related diseases. In regard to the key role of α-Klotho in aging, our data indicate that UA may be on the horizon to forestall diseases of aging.

  11. Enhanced ozonation of dichloroacetic acid in aqueous solution using nanometer ZnO powders.

    PubMed

    Zhai, Xu; Chen, Zhonglin; Zhao, Shuqing; Wang, He; Yang, Lei

    2010-01-01

    Nanometer zinc oxide (ZnO) powders were used as a catalyst to enhance the ozonation for the degradation of dichloroacetic acid (DCAA) in aqueous solution. The batch experiments were carried out to investigate the effects of key factors such as catalyst dosage, ozone dosage, solution pH and tert-butyl alcohol (t-BuOH) on the degradation efficiency of DCAA. Density functional theory (DFT) was adopted to explore the mechanism of generating hydroxyl radical (*OH) on the ZnO surface. The results showed that adsorption and ozonation processes were not effective for DCAA removal, and the addition of ZnO catalyst improved the degradation efficiency of DCAA during ozonation, which caused an increase of 22.8% for DCAA decomposition compared to the case of ozonation alone after 25 min. Under the same experimental conditions, the DCAA decomposition was enhanced by increasing catalyst dosage from 100 to 500 mg/L and ozone dosage from 0.83 to 3.2 mg/L. The catalytic ozonation process is more pronounced than the ozonation process alone at pH 3.93, 6.88, and 10. With increasing the concentration of t-BuOH from 10 to 200 mg/L, the degradation of DCAA was significantly inhibited in the process of catalytic ozonation, indicating that ZnO catalytic ozonation followed *OH reaction mechanism. Based on the experimental results and DFT analysis, it is deduced that the generation of *OH on the ZnO surface is ascribed to the adsorption of molecule ozone followed by the interaction of adsorbed ozone with active sites of the catalyst surface. It is also concluded that ZnO may be an effective catalyst for DCAA removal, which could promote the formation of *OH derived from the catalytic decomposition of ozone. PMID:21235181

  12. Hydrocaffeic acid-chitosan nanoparticles with enhanced stability, mucoadhesion and permeation properties.

    PubMed

    Soliman, Ghareb M; Zhang, Yu Ling; Merle, Geraldine; Cerruti, Marta; Barralet, Jake

    2014-11-01

    Catechol-containing molecules, such as hydrocaffeic acid (HCA) have been shown to increase the mucoadhesion of several polymers. We report here a simple and bioinspired approach to enhance chitosan (CS) mucoadhesion and stabilize it in nanoparticulate form by preparing HCA-CS conjugates. HCA-CS conjugates containing 6 and 15mol% HCA were synthesized and characterized by FT-IR, (1)H NMR and UV-vis spectrophotometry. HCA-CS nanoparticles prepared by ionic gelation with sodium tripolyphosphate (TPP) ranged in size between 100 and 250nm depending on the polymer and TPP/CS weight ratio. In contrast to CS nanoparticles, which aggregate at pH>6.5, HCA-CS nanoparticles did not show any sign of aggregation or precipitation over the 4-10 pH range and maintain their size. Unexpectedly, HCA-CS nanoparticles also maintained their size and polydispersity index at pH 7.4 and NaCl concentrations of up to 500mM. Partial oxidation of HCA resulted in nanoparticle cross-linking and improved stability at pH<4. HCA-CS mucoadhesion to rabbit small intestine was 6 times higher than unmodified CS. CS and HCA-CS nanoparticles were able to induce reversible tight junction opening in Caco-2 cell monolayers. Tight junction opening facilitated the permeability of a model hydrophilic molecule, fluorescein isothiocyanate-labeled dextran (FD4) and was 3 times higher in the cells treated with HCA-CS 15% nanoparticles compared to control groups. HCA-CS conjugates were found to be excellent candidates for stable nanodelivery systems with enhanced oral absorption of hydrophilic molecules.

  13. Integrated phospholipidomics and transcriptomics analysis of Saccharomyces cerevisiae with enhanced tolerance to a mixture of acetic acid, furfural, and phenol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A mixture of acetic acid, furfural and phenol (AFP), three representative lignocellulose derived inhibitors, significantly inhibited the growth and bioethanol production of Saccharomyces cerevisiae. In order to uncover mechanisms behind the enhanced tolerance of an inhibitor-tolerant S.cerevisiae s...

  14. Electrophilic acid gas-reactive fluid, proppant, and process for enhanced fracturing and recovery of energy producing materials

    DOEpatents

    Fernandez, Carlos A.; Heldebrant, David J.; Bonneville, Alain H. R.; Jung, Hun Bok; Carroll, Kenneth

    2016-09-20

    An electrophilic acid gas-reactive fracturing and recovery fluid, proppant, and process are detailed. The fluid expands in volume to provide rapid and controlled increases in pressure that enhances fracturing in subterranean bedrock for recovery of energy-producing materials. Proppants stabilize openings in fractures and fissures following fracturing.

  15. A combined physiological and proteomic approach to reveal lactic-acid-induced alterations in Lactobacillus casei Zhang and its mutant with enhanced lactic acid tolerance.

    PubMed

    Wu, Chongde; Zhang, Juan; Chen, Wei; Wang, Miao; Du, Guocheng; Chen, Jian

    2012-01-01

    Lactobacillus casei has traditionally been recognized as a probiotic and frequently used as an adjunct culture in fermented dairy products, where acid stress is an environmental condition commonly encountered. In the present study, we carried out a comparative physiological and proteomic study to investigate lactic-acid-induced alterations in Lactobacillus casei Zhang (WT) and its acid-resistant mutant. Analysis of the physiological data showed that the mutant exhibited 33.8% higher glucose phosphoenolpyruvate:sugar phosphotransferase system activity and lower glycolytic pH compared with the WT under acidic conditions. In addition, significant differences were detected in both cells during acid stress between intracellular physiological state, including intracellular pH, H(+)-ATPase activity, and intracellular ATP pool. Comparison of the proteomic data based on 2D-DIGE and i-TRAQ indicated that acid stress invoked a global change in both strains. The mutant protected the cells against acid damage by regulating the expression of key proteins involved in cellular metabolism, DNA replication, RNA synthesis, translation, and some chaperones. Proteome results were validated by Lactobacillus casei displaying higher intracellular aspartate and arginine levels, and the survival at pH 3.3 was improved 1.36- and 2.10-fold by the addition of 50-mM aspartate and arginine, respectively. To our knowledge, this is the first demonstration that aspartate may be involved in acid tolerance in Lactobacillus casei. Results presented here may help us understand acid resistance mechanisms and help formulate new strategies to enhance the industrial applications of this species. PMID:22159611

  16. Acetic acid enhances endurance capacity of exercise-trained mice by increasing skeletal muscle oxidative properties.

    PubMed

    Pan, Jeong Hoon; Kim, Jun Ho; Kim, Hyung Min; Lee, Eui Seop; Shin, Dong-Hoon; Kim, Seongpil; Shin, Minkyeong; Kim, Sang Ho; Lee, Jin Hyup; Kim, Young Jun

    2015-01-01

    Acetic acid has been shown to promote glycogen replenishment in skeletal muscle during exercise training. In this study, we investigated the effects of acetic acid on endurance capacity and muscle oxidative metabolism in the exercise training using in vivo mice model. In exercised mice, acetic acid induced a significant increase in endurance capacity accompanying a reduction in visceral adipose depots. Serum levels of non-esterified fatty acid and urea nitrogen were significantly lower in acetic acid-fed mice in the exercised mice. Importantly, in the mice, acetic acid significantly increased the muscle expression of key enzymes involved in fatty acid oxidation and glycolytic-to-oxidative fiber-type transformation. Taken together, these findings suggest that acetic acid improves endurance exercise capacity by promoting muscle oxidative properties, in part through the AMPK-mediated fatty acid oxidation and provide an important basis for the application of acetic acid as a major component of novel ergogenic aids.

  17. Enhancement of radiotherapy by ceria nanoparticles modified with neogambogic acid in breast cancer cells

    PubMed Central

    Chen, Feng; Zhang, Xiao Hong; Hu, Xiao Dan; Zhang, Wei; Lou, Zhi Chao; Xie, Li Hua; Liu, Pei Dang; Zhang, Hai Qian

    2015-01-01

    Radiotherapy is one of the main strategies for cancer treatment but has significant challenges, such as cancer cell resistance and radiation damage to normal tissue. Radiosensitizers that selectively increase the susceptibility of cancer cells to radiation can enhance the effectiveness of radiotherapy. We report here the development of a novel radiosensitizer consisting of monodispersed ceria nanoparticles (CNPs) covered with the anticancer drug neogambogic acid (NGA-CNPs). These were used in conjunction with radiation in MCF-7 breast cancer cells, and the efficacy and mechanisms of action of this combined treatment approach were evaluated. NGA-CNPs potentiated the toxic effects of radiation, leading to a higher rate of cell death than either treatment used alone and inducing the activation of autophagy and cell cycle arrest at the G2/M phase, while pretreatment with NGA or CNPs did not improve the rate of radiation-induced cancer cells death. However, NGA-CNPs decreased both endogenous and radiation-induced reactive oxygen species formation, unlike other nanomaterials. These results suggest that the adjunctive use of NGA-CNPs can increase the effectiveness of radiotherapy in breast cancer treatment by lowering the radiation doses required to kill cancer cells and thereby minimizing collateral damage to healthy adjacent tissue. PMID:26316742

  18. Activation of ethylenediaminetetraacetic acid by a 940 nm diode laser for enhanced removal of smear layer.

    PubMed

    Lagemann, Manfred; George, Roy; Chai, Lei; Walsh, Laurence J

    2014-08-01

    Laser enhancement of ethylenediaminetetraacetic acid with cetrimide (EDTAC) has previously been shown to increase removal of smear layer, for middle-infrared erbium lasers. This study evaluated the efficiency of EDTAC activation using a near-infrared-pulsed 940 nm laser delivered by plain fibre tips into 15% EDTAC or 3% hydrogen peroxide. Root canals in 4 groups of 10 single roots were prepared using rotary files, with controls for the presence and absence of smear layer. After laser treatment (80 mJ pulse(-1) , 50 Hz, 6 cycles of 10 s), roots were split and the apical, middle and coronal thirds of the canal were examined using scanning electron microscopy, with the area of dentine tubules determined by a validated quantitative image analysis method. Lasing EDTAC considerably improved smear layer removal, while lasing into peroxide gave minimal smear layer removal. The laser protocol used was more effective for smear layer removal than the 'gold standard' protocol using EDTAC with sodium hypochlorite (NaOCl). In addition, lasers may also provide a benefit through photothermal disinfection. Further research is needed to optimise irrigant activation protocols using near-infrared diode lasers of other wavelengths.

  19. Enhancement of ganoderic acid production by constitutively expressing Vitreoscilla hemoglobin gene in Ganoderma lucidum.

    PubMed

    Li, Huan-Jun; He, Yi-Long; Zhang, De-Huai; Yue, Tong-Hui; Jiang, Lu-Xi; Li, Na; Xu, Jun-Wei

    2016-06-10

    The Vitreoscilla hemoglobin (VHb) gene was expressed in Ganoderma lucidum to enhance antitumor ganoderic acid (GA) production. The effects of VHb expression on the accumulation of GAs and lanosterol (intermediate) and the transcription of GA biosynthesis genes were also investigated. In VHb-expressing G. lucidum, the maximum concentrations of four individual GAs (GA-S, GA-T, GA-Mk and GA-Me) were 19.1±1.8, 34.6±2.1, 191.5±13.1 and 45.2±2.8μg/100mg dry weight, respectively, which were 1.4-, 2.2, 1.9- and 2.0-fold higher than those obtained in the wild-type strain. Moreover, the maximum lanosterol concentration in the strain expressing VHb was 1.28-fold lower than that in the wild-type strain. The transcription levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase, squalene synthase, and lanosterol synthase genes were up-regulated by 1.6-, 1.5-, and 1.6-fold, respectively, in the strain expressing VHb. This work is beneficial in developing an efficient fermentation process for the hyperproduction of GAs. PMID:27080449

  20. 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

  1. Alkyl hydroperoxide reductase enhances the growth of Leuconostoc mesenteroides lactic acid bacteria at low temperatures.

    PubMed

    Goto, Seitaro; Kawamoto, Jun; Sato, Satoshi B; Iki, Takashi; Watanabe, Itaru; Kudo, Kazuyuki; Esaki, Nobuyoshi; Kurihara, Tatsuo

    2015-01-01

    Lactic acid bacteria (LAB) can cause deterioration of food quality even at low temperatures. In this study, we investigated the cold-adaptation mechanism of a novel food spoilage LAB, Leuconostoc mesenteroides NH04 (NH04). L. mesenteroides was isolated from several spoiled cooked meat products at a high frequency in our factories. NH04 grew rapidly at low temperatures within the shelf-life period and resulted in heavy financial losses. NH04 grew more rapidly than related strains such as Leuconostoc mesenteroides NBRC3832 (NBRC3832) at 10°C. Proteome analysis of NH04 demonstrated that this strain produces a homolog of alkyl hydroperoxide reductase--AhpC--the expression of which can be induced at low temperatures. The expression level of AhpC in NH04 was approximately 6-fold higher than that in NBRC3832, which was grown under the same conditions. Although AhpC is known to have an anti-oxidative role in various bacteria by catalyzing the reduction of alkyl hydroperoxide and hydrogen peroxide, the involvement of AhpC in cold adaptation of food spoilage bacteria was unclear. We introduced an expression plasmid containing ahpC into NBRC3832, which grows slower than NH04 at 10°C, and found that expression of AhpC enhanced growth. These results demonstrated that AhpC, which likely increases anti-oxidative capacity of LAB, plays an important role in their rapid growth at low temperatures.

  2. Enhancement of Polyribosome Formation and RNA Synthesis of Gibberellic Acid in Wounded Potato Tuber Tissue 1

    PubMed Central

    Wielgat, Bernard; Kahl, Günter

    1979-01-01

    As part of a more detailed study on plant tumorigenesis, the action of gibberellic acid (GA3) in wounded potato tuber tissues as a model system has been evaluated. GA3 stimulates total RNA synthesis in wounded tissues, the optimal concentration being 0.1 micromolar. The responsiveness of the tissue toward the hormone develops with time after wounding. Whereas freshly wounded tissue does not respond at all to the hormone, it becomes competent after about 6 hours, the competence being maximal after 1 day of wound healing. GA3 enhances the formation of polyribosomes in wounded tissues and stimulates the synthesis of both ribosomal RNAs, transfer RNAs, 5S RNA, and a fraction, which in sucrose density gradients sediments between 18S rRNA and 5S RNA. This fraction contains presumptive mRNA. The hormone, then, is somehow recognized by wounded potato tissue in a time-specific way; the signal is transferred to the genome and triggers the synthesis of various RNA species. PMID:16661070

  3. Photoluminescence Enhancement and Structure Repairing of Monolayer MoSe2 by Hydrohalic Acid Treatment.

    PubMed

    Han, Hau-Vei; Lu, Ang-Yu; Lu, Li-Syuan; Huang, Jing-Kai; Li, Henan; Hsu, Chang-Lung; Lin, Yung-Chang; Chiu, Ming-Hui; Suenaga, Kazu; Chu, Chih-Wei; Kuo, Hao-Chung; Chang, Wen-Hao; Li, Lain-Jong; Shi, Yumeng

    2016-01-26

    Atomically thin two-dimensional transition-metal dichalcogenides (TMDCs) have attracted much attention recently due to their unique electronic and optical properties for future optoelectronic devices. The chemical vapor deposition (CVD) method is able to generate TMDCs layers with a scalable size and a controllable thickness. However, the TMDC monolayers grown by CVD may incorporate structural defects, and it is fundamentally important to understand the relation between photoluminescence and structural defects. In this report, point defects (Se vacancies) and oxidized Se defects in CVD-grown MoSe2 monolayers are identified by transmission electron microscopy and X-ray photoelectron spectroscopy. These defects can significantly trap free charge carriers and localize excitons, leading to the smearing of free band-to-band exciton emission. Here, we report that the simple hydrohalic acid treatment (such as HBr) is able to efficiently suppress the trap-state emission and promote the neutral exciton and trion emission in defective MoSe2 monolayers through the p-doping process, where the overall photoluminescence intensity at room temperature can be enhanced by a factor of 30. We show that HBr treatment is able to activate distinctive trion and free exciton emissions even from highly defective MoSe2 layers. Our results suggest that the HBr treatment not only reduces the n-doping in MoSe2 but also reduces the structural defects. The results provide further insights of the control and tailoring the exciton emission from CVD-grown monolayer TMDCs. PMID:26716765

  4. Enhancement of flux pinning in a MgB2 superconductor doped with tartaric acid

    NASA Astrophysics Data System (ADS)

    Hossain, M. S. A.; Kim, J. H.; Wang, X. L.; Xu, X.; Peleckis, G.; Dou, S. X.

    2007-01-01

    The synthesis and characterization of a carbon (C) doped polycrystalline MgB2 superconductor is reported with tartaric acid (C4H6O6) used as the C source. The amount of C4H6O6 is varied between 5 and 30 wt%. Relationships between microstructures, critical current density (Jc), critical temperature (Tc), upper critical field (Hc2), and irreversibility field (Hirr) for MgB2 doped with 0-30 wt% C4H6O6 are systematically studied. A reduction in Tc from 37.65 to 34.45 K and in lattice parameter a due to the C substitution occurs with C4H6O6 doping. Jc, Hc2, and Hirr are significantly enhanced with an increasing amount of C4H6O6. All the samples exhibit a Jc above 104 A cm-2 at 5 K and 8 T. This value is higher than for un-doped MgB2 by a factor of 6. The significant improvement in the superconducting properties is attributed to the lattice distortion due to the C substitution for boron, with the C coming from the C4H6O6. These findings suggest that C4H6O6 is a promising C source for MgB2 with excellent Jc properties under high field.

  5. Ultraviolet Light Enhances the Bovine Serum Albumin Fixation for Acid Fast Bacilli Stain

    PubMed Central

    Lai, Pei-Yin; Lee, Shih-Yi; Chou, Yu-Ching; Fu, Yung-Chieh; Wu, Chen-Cheng; Chiueh, Tzong-Shi

    2014-01-01

    The use of a liquid culture system such as MGIT broth has greatly improved the sensitivity of isolating mycobacteria in clinical laboratories. Microscopic visualization of acid fast bacilli (AFB) in the culture positive MGIT broth remains the first routine step for rapidly indicating the presence of mycobacteria. We modified an ultraviolet (UV) light fixation process to increase AFB cells adherence to the slide. The retained haze proportion of a 1-cm circle marked area on the smear slide was quantified after the staining procedure indicating the adherence degree of AFB cells. More AFB cells were preserved on the slide after exposure to UV light of either germicidal lamp or UV crosslinker in a time-dependent manner. We demonstrated both the bovine serum albumin (BSA) in MGIT media and UV light exposure were required for enhancing fixation of AFB cells. While applying to AFB stains for 302 AFB positive MGIT broths in clinics, more AFB cells were retained and observed on smear slides prepared by the modified fixation procedure rather than by the conventional method. The modified fixation procedure was thus recommended for improving the sensitivity of microscopic diagnosis of AFB cells in culture positive MGIT broth. PMID:24586725

  6. Protic acid resin enhanced 1-butyl-3-methylimidazolium chloride pretreatment of Arundo donax Linn.

    PubMed

    You, Tingting; Zhang, Liming; Zhou, Sukun; Xu, Feng

    2014-09-01

    To improve the cellulose digestibility of energy crop Arudo donax Linn. with cost-efficient, a novel pretreatment of protic acid resin Amberlyst 35DRY catalyzed inexpensive ionic liquid (IL) 1-butyl-3-methylimidazolium chloride ([C4mim]Cl) was developed in this work. The pretreatment was performed at 160°C with [C4mim]Cl for 1.5h, followed by Amberlyst 35DRY catalyzed at 90°C for 1h. The IL-Amberlyst pretreatment was demonstrated to be effective, evidenced by the reduction in cellulose crystallinity (31.4%) and increased porosity caused by extensive swelling the undissolved biomass and partial depolymerization of the longer cellulose chain of the dissolved biomass by Amberlyst. Consequently, a higher glucose yield (92.8%) was obtained than for the single [C4mim]Cl pretreatment (42.8%) at an enzyme loading of 20 FPU/g substrate. Overall, the enhanced pretreatment was competitive by using inexpensive and recyclable IL-Amberlyst 35DRY pretreated system with shorter processing time and reduced enzyme usage. PMID:25001325

  7. Lignan enhancement in hairy root cultures of Linum album using coniferaldehyde and methylenedioxycinnamic acid.

    PubMed

    Ahmadian Chashmi, Najmeh; Sharifi, Mohsen; Behmanesh, Mehrdad

    2016-07-01

    Feeding experiments with hairy root cultures of Linum album have established that the extracellular coniferaldehyde is a good precursor for production of two lignans: lariciresinol (LARI) and pinoresinol (PINO). The accumulation of the LARI, PINO, and podophyllotoxin (PTOX) in hairy roots were enhanced about 14.8-, 8.7-, and 1.5-fold (107.61, 8.7 and 6.42 µg g(-1) Fresh Wight), respectively, by the addition of coniferaldehyde (2 mM) to the culture media (after 24 hr). This result was correlated with an increase pinoresinol/lariciresinol reductase (PLR) expression gene and cinnamyl alcohol dehydrogenase (CAD) activity in the fed hairy roots. Adding 3,4-(methylendioxy)cinnamic acid (MDCA) precursor did not influence on the lignans accumulation, but the lignin content of the hairy roots was increased. Moreover, the expression genes of phenylalanine ammonialyase (PAL), CAD, and cinnamoyl-CoA reductase (CCR) were influenced after feeding hairy roots with MDCA.

  8. Poly(propylacrylic acid) enhances cationic lipid mediated delivery of antisense oligonucleotides

    PubMed Central

    Lee, Li Kim; Williams, Charity L.; Devore, David; Roth, Charles M.

    2008-01-01

    The use of antisense oligodeoxynucleotides (ODNs) to inhibit the expression of specific mRNA targets represents a powerful technology for control of gene expression. Cationic lipids and polymers are frequently used to improve the delivery of ODNs to cells, but the resulting complexes often aggregate, bind to serum components, and are trafficked poorly within cells. We show that the addition of a synthetic, pH-sensitive, membrane-disrupting polyanion, poly(propylacrylic acid) (PPAA), improves the in vitro efficiency of the cationic lipid, DOTAP, with regard to oligonucleotide delivery and antisense activity. In characterization studies, ODN complexation with DOTAP/ODN was maintained even when substantial amounts of PPAA were added. The formulation also exhibited partial protection of phosphodiester oligonucleotides against enzymatic digestion. In Chinese hamster ovary (CHO) cells, incorporation of PPAA in DOTAP/ODN complexes improved two- to threefold the cellular uptake of fluorescently tagged oligonucleotides. DOTAP/ODN complexes containing PPAA also maintained high levels of uptake into cells upon exposure to serum. Addition of PPAA to DOTAP/ODN complexes enhanced the antisense activity (using GFP as the target) over a range of PPAA concentrations in both serum-free, and to a lesser extent, serum-containing media. Thus, PPAA is a useful adjunct that improves the lipid-mediated delivery of oligonucleotides. PMID:16677032

  9. Enhanced formic acid electro-oxidation reaction on ternary Pd-Ir-Cu/C catalyst

    NASA Astrophysics Data System (ADS)

    Chen, Jinwei; Zhang, Jie; Jiang, Yiwu; Yang, Liu; Zhong, Jing; Wang, Gang; Wang, Ruilin

    2015-12-01

    Aim to further reduce the cost of Pd-Ir for formic acid electro-oxidation (FAEO), the Cu was used to construct a ternary metallic alloy catalyst. The prepared catalysts are characterized using XRD, TGA, EDX, TEM, XPS, CO-stripping, cyclic voltammetry and chronoamperometry. It is found that the Pd18Ir1Cu6 nanoparticles with a mean size of 3.3 nm are highly dispersed on carbon support. Componential distributions on catalyst are consistent with initial contents. Electrochemical measurements show that the PdIrCu/C catalyst exhibits the highest activity for FAEO. The mass activity of Pd in Pd18Ir1Cu6/C at 0.16 V (vs. SCE) is about 1.47, 1.62 and 2.08 times as high as that of Pd18Cu6/C, Pd18Ir1/C and Pd/C, respectively. The activity enhancement of PdIrCu/C should be attributed to the weakened CO adsorption strength and the removal of adsorbed intermediates at lower potential with the addition of Cu and Ir.

  10. Optimization of thermal-dilute sulfuric acid pretreatment for enhancement of methane production from cassava residues.

    PubMed

    Zhang, Qinghua; Tang, Lei; Zhang, Jianhua; Mao, Zhonggui; Jiang, Li

    2011-02-01

    In this study, the pretreatment of cassava residues by thermal-dilute sulfuric acid (TDSA) hydrolysis was investigated by means of a statistically designed set of experiments. A three-factor central composite design (CCD) was employed to identify the optimum pretreatment condition of cassava residues for methane production. The individual and interactive effects of temperature, H(2)SO(4) concentration and reaction time on increase of methane yield (IMY) were evaluated by applying response surface methodology (RSM). After optimization, the resulting optimum pretreatment condition was 157.84°C, utilizing 2.99% (w/w TS) H(2)SO(4) for 20.15 min, where the maximum methane yield (248 mL/g VS) was 56.96% higher than the control (158 mL/g VS), which was very close to the predict value 56.53%. These results indicate the model obtained through RSM analysis is suit to predict the optimum pretreatment condition and there is great potential of using TDSA pretreatment of cassava residues to enhance methane yield.

  11. Transgenic overproduction of omega-3 polyunsaturated fatty acids provides neuroprotection and enhances endogenous neurogenesis after stroke.

    PubMed

    Hu, X; Zhang, F; Leak, R K; Zhang, W; Iwai, M; Stetler, R A; Dai, Y; Zhao, A; Gao, Y; Chen, J

    2013-11-01

    Strokes are devastating as there are no current therapies to prevent the long term neurological deficits that they cause. Soon after ischemic stroke, there is proliferation and differentiation of neural stem/progenitor cells as an important mechanism for neuronal restoration. However, endogenous neurogenesis by itself is insufficient for effective brain repair after stroke as most newborn neurons do not survive. One fascinating strategy for stroke treatment would thus be maintaining the survival and/or promoting the differentiation of endogenous neural stem/progenitor cells. Using transgenic (Tg) mice over-expressing the C. elegans fat-1 gene encoding an enzyme that converts endogenous omega-6 to omega-3 polyunsaturated fatty acids (n-3 PUFAs), we showed that fat-1 Tg mice with chronically elevated brain levels of n-3 PUFAs exhibited less brain damage and significantly improved long-term neurological performance compared to wild type littermates. Importantly, post-stroke neurogenesis occurred more robustly in fat-1 Tg mice after focal ischemia. This was manifested by enhanced neural stem cell proliferation/differentiation and increased migration of neuroblasts to the ischemic sites where neuroblasts matured into resident neurons. Moreover, these neurogenic effects were accompanied by significantly increased oligodendrogenesis. Our results suggest that n-3 PUFA supplementation is a potential neurogenic and oligodendrogenic treatment to naturally improve post-stroke brain repair and long-term functional recovery. PMID:23971733

  12. Microinjection of valproic acid into the ventrolateral orbital cortex enhances stress-related memory formation.

    PubMed

    Zhao, Yan; Xing, Bo; Dang, Yong-hui; Qu, Chao-ling; Zhu, Feng; Yan, Chun-xia

    2013-01-01

    There is collecting evidence suggesting that the process of chromatin remodeling such as changes in histone acetylation contribute to the formation of stress-related memory. Recently, the ventrolateral orbital cortex (VLO), a major subdivision of orbitofrontal cortex (OFC), was shown to be involved in antidepressant-like actions through epigenetic mechanisms. Here, we further investigated the effects of the histone deacetylase inhibitor (HDACi) valproic acid (VPA) on stress-related memory formation and the underlying molecular mechanisms by using the traditional two-day forced swimming test (FST). The results showed that VPA significantly increased the immobility time on day 2 when infused into the VLO before the initial forced swim stress on day 1. The learned immobility response to the stress was associated with increased phosphorylation of extracellular signal-regulated kinase (ERK) in VLO and hippocampus on the first day. The levels of phosphorylated ERK (phospho-ERK) in VLO and hippocampus were significantly decreased when retested 24 h later. The pretreatment with intra-VLO VPA infusion further reduced the activation of ERK on day 2 and day 7 compared with the saline controls. Moreover, the VPA infusion pretreatment also induced a significantly decreased BDNF level in the VLO on day 2, whereas no change was detected in the hippocampus. These findings suggest that VPA enhance the memories of emotionally stressful events and the ERK activity is implicated in stimulating adaptive and mnemonic processes in case the event would recur.

  13. Magnetic microparticles post-synthetically coated by hyaluronic acid as an enhanced carrier for microfluidic bioanalysis.

    PubMed

    Holubova, Lucie; Knotek, Petr; Palarcik, Jiri; Cadkova, Michaela; Belina, Petr; Vlcek, Milan; Korecka, Lucie; Bilkova, Zuzana

    2014-11-01

    Iron oxide based particles functionalized by bioactive molecules have been utilized extensively in biotechnology and biomedicine. Despite their already proven advantages, instability under changing reaction conditions, non-specific sorption of biomolecules on the particles' surfaces, and iron oxide leakage from the naked particles can greatly limit their application. As confirmed many times, surface treatment with an appropriate stabilizer helps to minimize these disadvantages. In this work, we describe enhanced post-synthetic surface modification of superparamagnetic microparticles varying in materials and size using hyaluronic acid (HA) in various chain lengths. Scanning electron microscopy, atomic force microscopy, phase analysis light scattering and laser diffraction are the methods used for characterization of HA-coated particles. The zeta potential and thickness of HA-layer of HA-coated Dynabeads M270 Amine were -50 mV and 85 nm, respectively, and of HA-coated p(GMA-MOEAA)-NH2 were -38 mV and 140 nm, respectively. The electrochemical analysis confirmed the zero leakage of magnetic material and no reactivity of particles with hydrogen peroxide. The rate of non-specific sorption of bovine serum albumin was reduced up to 50% of the naked ones. The coating efficiency and suitability of biopolymer-based microparticles for magnetically active microfluidic devices were confirmed. PMID:25280714

  14. Starter cultures and cattle feed manipulation enhance conjugated linoleic acid concentrations in Cheddar cheese.

    PubMed

    Mohan, M S; Anand, S; Kalscheur, K F; Hassan, A N; Hippen, A R

    2013-04-01

    Conjugated linoleic acid (CLA) is a fatty acid (FA) that provides several health benefits to humans. The feeding of fish oil-supplemented diets to dairy cows has been extensively studied as a means to improve the CLA content in milk. Several studies have also been conducted on the ability of many microorganisms to produce CLA by utilizing substrates containing linoleic acid. In the present study, the dietary manipulated milk was used in combination with the CLA-producing culture to manufacture Cheddar cheese. The two diets fed to cattle were control and treatment diets to obtain control and treatment milk, respectively. The treatment diet containing fish oil (0.75% of dry matter) was fed to 32 dairy cows grouped in a pen for 18 d to increase the total CLA content in milk. Treatment milk had a CLA content of 1.60 g/100g of FA compared with 0.58 g/100g of FA in control milk obtained by feeding the control diet. A 2 × 2 factorial design with 3 replicates was used to test the combined effect of the CLA-producing starter culture of Lactococcus lactis (CI4b) versus a commercial CLA nonproducing cheese starter as the control culture, and type of milk (control vs. treatment milk) on CLA content in Cheddar cheese. Chemical composition (moisture, salt, fat, and protein) was not affected by the type of culture used. However, the age of the cheese affected the sensory properties and microbiological counts in the different treatments. Ripening with the CI4b culture was found to be effective in further enhancing the CLA content. The CI4b cheeses made from control milk and treatment milk contained 1.09 and 2.41 (±0.18) g of total CLA/100g of FA after 1 mo of ripening, which increased to 1.44 and 2.61 (±0.18) g of total CLA/100g of FA after 6 mo of ripening, respectively. The use of treatment milk resulted in an increase in the CLA isomers (trans-7,cis-9+cis-9,trans-11, trans-9,cis-11+cis-10,trans-12, trans-10,cis-12, cis-9,cis-11, trans-11,cis-13, cis-11,cis-13, trans-11,trans

  15. Starter cultures and cattle feed manipulation enhance conjugated linoleic acid concentrations in Cheddar cheese.

    PubMed

    Mohan, M S; Anand, S; Kalscheur, K F; Hassan, A N; Hippen, A R

    2013-04-01

    Conjugated linoleic acid (CLA) is a fatty acid (FA) that provides several health benefits to humans. The feeding of fish oil-supplemented diets to dairy cows has been extensively studied as a means to improve the CLA content in milk. Several studies have also been conducted on the ability of many microorganisms to produce CLA by utilizing substrates containing linoleic acid. In the present study, the dietary manipulated milk was used in combination with the CLA-producing culture to manufacture Cheddar cheese. The two diets fed to cattle were control and treatment diets to obtain control and treatment milk, respectively. The treatment diet containing fish oil (0.75% of dry matter) was fed to 32 dairy cows grouped in a pen for 18 d to increase the total CLA content in milk. Treatment milk had a CLA content of 1.60 g/100g of FA compared with 0.58 g/100g of FA in control milk obtained by feeding the control diet. A 2 × 2 factorial design with 3 replicates was used to test the combined effect of the CLA-producing starter culture of Lactococcus lactis (CI4b) versus a commercial CLA nonproducing cheese starter as the control culture, and type of milk (control vs. treatment milk) on CLA content in Cheddar cheese. Chemical composition (moisture, salt, fat, and protein) was not affected by the type of culture used. However, the age of the cheese affected the sensory properties and microbiological counts in the different treatments. Ripening with the CI4b culture was found to be effective in further enhancing the CLA content. The CI4b cheeses made from control milk and treatment milk contained 1.09 and 2.41 (±0.18) g of total CLA/100g of FA after 1 mo of ripening, which increased to 1.44 and 2.61 (±0.18) g of total CLA/100g of FA after 6 mo of ripening, respectively. The use of treatment milk resulted in an increase in the CLA isomers (trans-7,cis-9+cis-9,trans-11, trans-9,cis-11+cis-10,trans-12, trans-10,cis-12, cis-9,cis-11, trans-11,cis-13, cis-11,cis-13, trans-11,trans

  16. Enhancement of renal excretion of uric acid during long-term thiazide therapy.

    PubMed

    Pak, C Y; Tolentino, R; Stewart, A; Galosy, R A

    1978-11-01

    The effect of thiazide (hydrochlorothiazide 100 mg per day orally in two divided doses for up to 3 years) on uric acid metabolism was examined in 21 patients with renal stones suffering from renal hypercalciuria or absorptive hypercalciuria. Serum concentration of uric acid increased during thiazide therapy in every patient. In 12 of 21 patients, there was a transient or persistent rise in urinary uric acid of more than 50 mg per day during treatment. The mean urinary uric acid produced by thiazide was positively correlated with the change in the renal clearance of uric acid. Thus, an increase in urinary uric acid was often associated with a rise in uric acid clearance. The results suggest that thiazide may either increase the production of uric acid or decrease the extrarenal disposal of uric acid, in some patients.

  17. Water-enhanced solubility of carboxylic acids in organic solvents and its applications to extraction processes

    SciTech Connect

    Starr, J.N.; King, C.J.

    1991-11-01

    The solubilities of carboxylic acids in certain organic solvents increase remarkably with an increasing amount of water in the organic phase. This phenomenon leads to a novel extract regeneration process in which the co-extracted water is selectively removed from an extract, and the carboxylic acid precipitates. This approach is potentially advantageous compared to other regeneration processes because it removes a minor component of the extract in order to achieve a large recovery of acid from the extract. Carboxylic acids of interest include adipic acid, fumaric acid, and succinic acid because of their low to moderate solubilities in organic solvents. Solvents were screened for an increase in acid solubility with increased water concentration in the organic phase. Most Lewis-base solvents were found to exhibit this increased solubility phenomena. Solvents that have a carbonyl functional group showed a very large increase in acid solubility. 71 refs., 52 figs., 38 tabs.

  18. Ethylene-enhanced catabolism of ( sup 14 C)indole-3-acetic acid to indole-3-carboxylic acid in citrus leaf tissues. [Citrus sinensis

    SciTech Connect

    Sagee, O.; Riov, J.; Goren, J. )

    1990-01-01

    Exogenous ({sup 14}C)indole-3-acetic acid (IAA) is conjugated in citrus (Citrus sinensis) leaf tissues to one major substance which has been identified as indole-3-acetylaspartic acid (IAAsp). Ethylene pretreatment enhanced the catabolism of ({sup 14}C)IAA to indole-3-carboxylic acid (ICA), which accumulated as glucose esters (ICGlu). Increased formation of ICGlu by ethylene was accompanied by a concomitant decrease in IAAsp formation. IAAsp and ICGlu were identified by combined gas chromatography-mass spectrometry. Formation of ICGlu was dependent on the concentration of ethylene and the duration of the ethylene pretreatment. It is suggested that the catabolism of IAA to ICA may be one of the mechanisms by which ethylene endogenous IAA levels.

  19. Mutations in a delta9-Stearoyl-ACP-Desaturase Gene Are Associated with Enhanced Stearic Acid Levels in Soybean Seeds

    SciTech Connect

    Zhang, P.; Shanklin, J.; Burton, J. W.; Upchurch, R. G.; Whittle, E.; Dewey, R. E.

    2008-11-01

    Stearic acid (18:0) is typically a minor component of soybean [Glycine max (L.) Merr.] oil, accounting for only 2 to 4% of the total fatty acid content. Increasing stearic acid levels of soybean oil would lead to enhanced oxidative stability, potentially reducing the need for hydrogenation, a process leading to the formation of undesirable trans fatty acids. Although mutagenesis strategies have been successful in developing soybean germplasm with elevated 18:0 levels in the seed oil, the specific gene mutations responsible for this phenotype were not known. We report a newly identified soybean gene, designated SACPD-C, that encodes a unique isoform of {Delta}{sup 9}-stearoyl-ACP-desaturase, the enzyme responsible for converting stearic acid to oleic acid (18:1). High levels of SACPD-C transcript were only detected in developing seed tissue, suggesting that the encoded desaturase functions to enhance oleic acid biosynthetic capacity as the immature seed is actively engaged in triacylglycerol production and storage. The participation of SACPD-C in storage triacylglycerol synthesis is further supported by the observation of mutations in this gene in two independent sources of elevated 18:0 soybean germplasm, A6 (30% 18:0) and FAM94-41 (9% 18:0). A molecular marker diagnostic for the FAM94-41 SACPD-C gene mutation strictly associates with the elevated 18:0 phenotype in a segregating population, and could thus serve as a useful tool in the development of cultivars with oils possessing enhanced oxidative stability.

  20. Do fish oil omega-3 fatty acids enhance antioxidant capacity and mitochondrial fatty acid oxidation in human atrial myocardium via PPARγ activation?

    PubMed

    Anderson, Ethan J; Thayne, Kathleen A; Harris, Mitchel; Shaikh, Saame Raza; Darden, Timothy M; Lark, Daniel S; Williams, John Mark; Chitwood, W Randolph; Kypson, Alan P; Rodriguez, Evelio

    2014-09-10

    Abstract Studies in experimental models suggest that n-3 polyunsaturated fatty acids (PUFAs) improve metabolic and anti-inflammatory/antioxidant capacity of the heart, although the mechanisms are unclear and translational evidence is lacking. In this study, patients ingested a moderately high dose of n-3 PUFAs (3.4 g/day eicosapentaenoic (EPA) and doxosahexaenoic acid (DHA) ethyl-esters) for a period of 2-3 weeks before having elective cardiac surgery. Blood was obtained before treatment and at the time of surgery, and myocardial tissue from the right atrium was also dissected during surgery. Blood EPA levels increased and myocardial tissue EPA and DHA levels were significantly higher in n-3 PUFA-treated patients compared with untreated, standard-of-care control patients. Interestingly, n-3 PUFA patients had greater nuclear transactivation of peroxisome proliferator-activated receptor-γ (PPARγ), fatty acid metabolic gene expression, and enhanced mitochondrial respiration supported by palmitoyl-carnitine in the atrial myocardium, despite no difference in mitochondrial content. Myocardial tissue from n-3 PUFA patients also displayed greater expression and activity of key antioxidant/anti-inflammatory enzymes. These findings lead to our hypothesis that PPARγ activation is a mechanism by which fish oil n-3 PUFAs enhance mitochondrial fatty acid oxidation and antioxidant capacity in human atrial myocardium, and that this preoperative therapeutic regimen may be optimal for mitigating oxidative/inflammatory stress associated with cardiac surgery.

  1. Do Fish Oil Omega-3 Fatty Acids Enhance Antioxidant Capacity and Mitochondrial Fatty Acid Oxidation in Human Atrial Myocardium via PPARγ Activation?

    PubMed Central

    Thayne, Kathleen A.; Harris, Mitchel; Shaikh, Saame Raza; Darden, Timothy M.; Lark, Daniel S.; Williams, John Mark; Chitwood, W. Randolph; Kypson, Alan P.; Rodriguez, Evelio

    2014-01-01

    Abstract Studies in experimental models suggest that n-3 polyunsaturated fatty acids (PUFAs) improve metabolic and anti-inflammatory/antioxidant capacity of the heart, although the mechanisms are unclear and translational evidence is lacking. In this study, patients ingested a moderately high dose of n-3 PUFAs (3.4 g/day eicosapentaenoic (EPA) and doxosahexaenoic acid (DHA) ethyl-esters) for a period of 2–3 weeks before having elective cardiac surgery. Blood was obtained before treatment and at the time of surgery, and myocardial tissue from the right atrium was also dissected during surgery. Blood EPA levels increased and myocardial tissue EPA and DHA levels were significantly higher in n-3 PUFA-treated patients compared with untreated, standard-of-care control patients. Interestingly, n-3 PUFA patients had greater nuclear transactivation of peroxisome proliferator-activated receptor-γ (PPARγ), fatty acid metabolic gene expression, and enhanced mitochondrial respiration supported by palmitoyl-carnitine in the atrial myocardium, despite no difference in mitochondrial content. Myocardial tissue from n-3 PUFA patients also displayed greater expression and activity of key antioxidant/anti-inflammatory enzymes. These findings lead to our hypothesis that PPARγ activation is a mechanism by which fish oil n-3 PUFAs enhance mitochondrial fatty acid oxidation and antioxidant capacity in human atrial myocardium, and that this preoperative therapeutic regimen may be optimal for mitigating oxidative/inflammatory stress associated with cardiac surgery. Antioxid. Redox Signal. 21, 1156–1163. PMID:24597798

  2. Enhancement of caffeic acid phenethyl ester on all-trans retinoic acid-induced differentiation in human leukemia HL-60 cells

    SciTech Connect

    Kuo, H.-C.; Kuo, W.-H.; Lee, Y.-J.; Wang, C.-J.; Tseng, T.-H. . E-mail: tht@csmu.edu.tw

    2006-10-01

    All-trans retinoic acid (ATRA) induces complete remission in a high proportion of patients with acute promyelocytic leukemia (APL); however, the response is sometimes very slow. Furthermore, relapse and resistance to treatment often occur despite continued treatment with ATRA. Thereafter, combination treatment strategies have been suggested to circumvent these problems. The present study demonstrates that caffeic acid phenethyl ester (CAPE), a major component of honeybee propolis, enhanced ATRA-induced granulocytic differentiation in HL-60, a human promyelocytic cell line. The differentiation was assessed by Wright-Giemsa stain, nitroblue tetrazolium reduction, and membrane differentiation marker CD11b. In addition, CAPE enhanced ATRA-induced cell cycle arrest at the G1 phase by decreasing the association of cdk2-cyclin E complex. Finally, it was demonstrated that CAPE promoted the ATRA-mediated nuclear transcription activation of RAR{alpha} assessed by EMSA assay and enhanced the expression of target genes including RAR{alpha}, C/EBP{epsilon}, and p21 protein resulting in the differentiation development of leukemia. It is suggested that CAPE possesses the potential to enhance the efficiency of ATRA in the differentiation therapy of APL.

  3. Interaction of anthranilic acid with silver nanoparticles: A Raman, surface-enhanced Raman scattering and density functional theoretical study

    NASA Astrophysics Data System (ADS)

    Chadha, Ridhima; Maiti, Nandita; Kapoor, Sudhir

    2014-11-01

    Raman and surface-enhanced Raman scattering (SERS) studies of anthranilic acid have been investigated in solid, aqueous solution and on silver colloid. Anthranilic acid plays a key role in the brain in the production of quinolinic acid which is a powerful excitant and convulsant substance. Due to its medicinal importance, the surface adsorption properties of anthranilic acid have been studied. The experimental Raman and SERS data is supported with DFT calculations using B3LYP functional with aug-cc-pvdz and LANL2DZ basis sets. The comparison of experimental and theoretical results infers that anthranilate is chemisorbed to the silver surface directly through the carboxylate group with a perpendicular orientation. The time-dependent SERS spectrum of anthranilate showed no observable change indicating no structural transformation with time. The SERS spectrum recorded at different excitation wavelengths helped in understanding the origin of the SERS mechanism.

  4. Enhanced fatty acid accumulation in Isochrysis galbana by inhibition of the mitochondrial alternative oxidase pathway under nitrogen deprivation.

    PubMed

    Zhang, Litao; Liu, Jianguo

    2016-07-01

    The purpose of this study was to clarify the interrelation between the mitochondrial alternative oxidase (AOX) pathway and fatty acid accumulation in marine microalga Isochrysis galbana. Under normal conditions, the activity of the AOX pathway was maintained at a low level in I. galbana. Compared with the normal condition, nitrogen deprivation significantly increased the AOX pathway activity and fatty acid accumulation. Under nitrogen deprivation, the inhibition of the AOX pathway by salicylhydroxamic acid caused the accumulation of reducing equivalents and the over-reduction of chloroplasts in I. galbana cells, leading to a decrease in the photosynthetic O2 evolution rate. The over-production of reducing equivalents due to the inhibition of the AOX pathway under nitrogen deprivation further enhanced the accumulation of fatty acids in I. galbana cells.

  5. Humic acid enhanced remediation of an emplaced diesel source in groundwater. 1. Laboratory-based pilot scale test.

    PubMed

    Van Stempvoort, D R; Lesage, S; Novakowski, K S; Millar, K; Brown, S; Lawrence, J R

    2002-02-01

    The enhanced solubility of petroleum-derived compounds in humic acid solutions is the basis for a new groundwater remediation technology. In this unique pilot-scale test, a stationary contaminant source consisting of diesel fuel was placed below the water table in a model sand aquifer (1.2 x 5.5 x 1.8-m deep) and flushed with water at a flow rate of 2 cm/h over 5 years. At 51 days, laboratory grade humic acid was added to the water and maintained at a level of approximately 0.8 g/l. The addition of humic acid had only a small impact on the aqueous transport of the BTEX components, which were rapidly dissolved from the diesel, but had a large effect on the flushing of PAHs, including methylated naphthalenes (MNs). Binding to aqueous humic acid enhanced the solubilization of MNs two- to tenfold. During aqueous transport, biodegradation of the BTEX and PAHs occurred, limiting the lateral and longitudinal extent of the diesel contaminant plume in the model aquifer. It appears that through enhanced solubilization, the overall biodegradation rate of the MNs was increased. As the various MNs were depleted from the diesel source, the MN plume shrank and then disappeared.

  6. Culturing oil sands microbes as mixed species communities enhances ex situ model naphthenic acid degradation.

    PubMed

    Demeter, Marc A; Lemire, Joseph A; Yue, Gordon; Ceri, Howard; Turner, Raymond J

    2015-01-01

    Oil sands surface mining for bitumen results in the formation of oil sands process water (OSPW), containing acutely toxic naphthenic acids (NAs). Potential exists for OSPW toxicity to be mitigated by aerobic degradation of the NAs by microorganisms indigenous to the oil sands tailings ponds, the success of which is dependent on the methods used to exploit the metabolisms of the environmental microbial community. Having hypothesized that the xenobiotic tolerant biofilm mode-of-life may represent a feasible way to harness environmental microbes for ex situ treatment of OSPW NAs, we aerobically grew OSPW microbes as single and mixed species biofilm and planktonic cultures under various conditions for the purpose of assaying their ability to tolerate and degrade NAs. The NAs evaluated were a diverse mixture of eight commercially available model compounds. Confocal microscopy confirmed the ability of mixed and single species OSPW cultures to grow as biofilms in the presence of the NAs evaluated. qPCR enumeration demonstrated that the addition of supplemental nutrients at concentrations of 1 g L(-1) resulted in a more numerous population than 0.001 g L(-1) supplementation by approximately 1 order of magnitude. GC-FID analysis revealed that mixed species cultures (regardless of the mode of growth) are the most effective at degrading the NAs tested. All constituent NAs evaluated were degraded below detectable limits with the exception of 1-adamantane carboxylic acid (ACA); subsequent experimentation with ACA as the sole NA also failed to exhibit degradation of this compound. Single species cultures degraded select few NA compounds. The degradation trends highlighted many structure-persistence relationships among the eight NAs tested, demonstrating the effect of side chain configuration and alkyl branching on compound recalcitrance. Of all the isolates, the Rhodococcus spp. degraded the greatest number of NA compounds, although still less than the mixed species cultures

  7. Culturing oil sands microbes as mixed species communities enhances ex situ model naphthenic acid degradation

    PubMed Central

    Demeter, Marc A.; Lemire, Joseph A.; Yue, Gordon; Ceri, Howard; Turner, Raymond J.

    2015-01-01

    Oil sands surface mining for bitumen results in the formation of oil sands process water (OSPW), containing acutely toxic naphthenic acids (NAs). Potential exists for OSPW toxicity to be mitigated by aerobic degradation of the NAs by microorganisms indigenous to the oil sands tailings ponds, the success of which is dependent on the methods used to exploit the metabolisms of the environmental microbial community. Having hypothesized that the xenobiotic tolerant biofilm mode-of-life may represent a feasible way to harness environmental microbes for ex situ treatment of OSPW NAs, we aerobically grew OSPW microbes as single and mixed species biofilm and planktonic cultures under various conditions for the purpose of assaying their ability to tolerate and degrade NAs. The NAs evaluated were a diverse mixture of eight commercially available model compounds. Confocal microscopy confirmed the ability of mixed and single species OSPW cultures to grow as biofilms in the presence of the NAs evaluated. qPCR enumeration demonstrated that the addition of supplemental nutrients at concentrations of 1 g L-1 resulted in a more numerous population than 0.001 g L-1 supplementation by approximately 1 order of magnitude. GC-FID analysis revealed that mixed species cultures (regardless of the mode of growth) are the most effective at degrading the NAs tested. All constituent NAs evaluated were degraded below detectable limits with the exception of 1-adamantane carboxylic acid (ACA); subsequent experimentation with ACA as the sole NA also failed to exhibit degradation of this compound. Single species cultures degraded select few NA compounds. The degradation trends highlighted many structure-persistence relationships among the eight NAs tested, demonstrating the effect of side chain configuration and alkyl branching on compound recalcitrance. Of all the isolates, the Rhodococcus spp. degraded the greatest number of NA compounds, although still less than the mixed species cultures

  8. An enhanced procedure for measuring organic acids and methyl esters in PM2.5

    NASA Astrophysics Data System (ADS)

    Liu, F.; Duan, F. K.; He, K. B.; Ma, Y. L.; Rahn, K. A.; Zhang, Q.

    2015-11-01

    A solid-phase extraction (SPE) pretreatment procedure allowing organic acids to be separated from methyl esters in fine aerosol has been developed. The procedure first separates the organic acids from fatty acid methyl esters (FAMEs) and other nonacid organic compounds by aminopropyl-based SPE cartridge and then quantifies them by gas chromatography/mass spectrometry. The procedure prevents the fatty acids and dimethyl phthalate from being overestimated, and so allows us to accurately quantify the C4-C11 dicarboxylic acids (DCAs) and the C8-C30 monocarboxylic acids (MCAs). Results for the extraction of DCAs, MCAs, and AMAs in eluate and FAMEs in effluate by SAX and NH2 SPE cartridges exhibited that the NH2 SPE cartridge gave higher extraction efficiency than the SAX cartridge. The recoveries of analytes ranged from 67.5 to 111.3 %, and the RSD ranged from 0.7 to 10.9 %. The resulting correlations between the aliphatic acids and FAMEs suggest that the FAMEs had sources similar to those of the carboxylic acids, or were formed by esterifying carboxylic acids, or that aliphatic acids were formed by hydrolyzing FAMEs. Through extraction and cleanup using this procedure, 17 aromatic acids in eluate were identified and quantified by gas chromatography/tandem mass spectrometry, including five polycyclic aromatic hydrocarbon (PAH): acids 2-naphthoic, biphenyl-4-carboxylic, 9-oxo-9H-fluorene-1-carboxylic, biphenyl-4,4´-dicarboxylic, and phenanthrene-1-carboxylic acid, plus 1,8-naphthalic anhydride. Correlations between the PAH acids and the dicarboxylic and aromatic acids suggested that the first three acids and 1,8-naphthalic anhydride were secondary atmospheric photochemistry products and the last two mainly primary.

  9. Enhanced mobilization of arsenic and heavy metals from mine tailings by humic acid.

    PubMed

    Wang, Suiling; Mulligan, Catherine N

    2009-01-01

    Arsenic and heavy metal mobilization from mine tailings is an issue of concern as it might pose potential groundwater or ecological risks. Increasing attention recently has been focused on the effects of natural organic matter on the mobility behavior of the toxicants in the environment. Column experiments were carried out in this research study to evaluate the feasibility of using humic acid (HA) to mobilize arsenic and heavy metals (i.e., Cu, Pb and Zn) from an oxidized Pb-Zn mine tailings sample collected from Bathurst, New Brunswick, Canada. Capillary electrophoresis analyses indicated that arsenate [As(V)] was the only extractable arsenic species in the mine tailings and the addition of HA at pH 11 did not incur the oxidation-reduction or methylation reactions of arsenic. A 0.1% HA solution with an initial pH adjusted to 11 was selected as the flushing solution, while distilled water (initial pH adjusted to 11) was used as the control to account for the mobilization of arsenic and the heavy metals by physical mixing and the effect of pH. It was found that the HA could significantly enhance the mobilization of arsenic and heavy metals simultaneously from the mine tailings. After a 70-pore-volume-flushing, the mobilization of arsenic, copper, lead and zinc reached 97, 35, 838 and 224 mg kg(-1), respectively. The mobilization of arsenic and the heavy metals was found to be positively correlated with the mobilization of Fe in the presence of the HA. Moreover, the mobilization of arsenic was also correlated well with that of the heavy metals. The mobilization of co-existing metals to some extent might enhance arsenic mobilization in the presence of the HA by helping incorporate it into soluble aqueous organic complexes through metal-bridging mechanisms. Use of HA in arsenic and heavy metal remediation may be developed as an environmentally benign and possible effective remedial option to reduce and avoid further contamination.

  10. Optimization of date syrup for enhancement of the production of citric acid using immobilized cells of Aspergillus niger

    PubMed Central

    Mostafa, Yasser S.; Alamri, Saad A.

    2012-01-01

    Date syrup as an economical source of carbohydrates and immobilized Aspergillus niger J4, which was entrapped in calcium alginate pellets, were employed for enhancing the production of citric acid. Maximum production was achieved by pre-treating date syrup with 1.5% tricalcium phosphate to remove heavy metals. The production of citric acid using a pretreated medium was 38.87% higher than an untreated one that consumed sugar. The appropriate presence of nitrogen, phosphate and magnesium appeared to be important in order for citric acid to accumulate. The production of citric acid and the consumed sugar was higher when using 0.1% ammonium nitrate as the best source of nitrogen. The production of citric acid increased significantly when 0.1 g/l of KH2PO4 was added to the medium of date syrup. The addition of magnesium sulfate at the rate of 0.20 g/l had a stimulating effect on the production of citric acid. Maximum production of citric acid was obtained when calcium chloride was absent. One of the most important benefits of immobilized cells is their ability and stability to produce citric acid under a repeated batch culture. Over four repeated batches, the production of citric acid production was maintained for 24 days when each cycle continued for 144 h. The results obtained in the repeated batch cultivation using date syrup confirmed that date syrup could be used as a medium for the industrial production of citric acid. PMID:23961184

  11. Optimization of date syrup for enhancement of the production of citric acid using immobilized cells of Aspergillus niger.

    PubMed

    Mostafa, Yasser S; Alamri, Saad A

    2012-04-01

    Date syrup as an economical source of carbohydrates and immobilized Aspergillus niger J4, which was entrapped in calcium alginate pellets, were employed for enhancing the production of citric acid. Maximum production was achieved by pre-treating date syrup with 1.5% tricalcium phosphate to remove heavy metals. The production of citric acid using a pretreated medium was 38.87% higher than an untreated one that consumed sugar. The appropriate presence of nitrogen, phosphate and magnesium appeared to be important in order for citric acid to accumulate. The production of citric acid and the consumed sugar was higher when using 0.1% ammonium nitrate as the best source of nitrogen. The production of citric acid increased significantly when 0.1 g/l of KH2PO4 was added to the medium of date syrup. The addition of magnesium sulfate at the rate of 0.20 g/l had a stimulating effect on the production of citric acid. Maximum production of citric acid was obtained when calcium chloride was absent. One of the most important benefits of immobilized cells is their ability and stability to produce citric acid under a repeated batch culture. Over four repeated batches, the production of citric acid production was maintained for 24 days when each cycle continued for 144 h. The results obtained in the repeated batch cultivation using date syrup confirmed that date syrup could be used as a medium for the industrial production of citric acid.

  12. Fed-batch fermentation for enhanced lactic acid production from glucose/xylose mixture without carbon catabolite repression.

    PubMed

    Abdel-Rahman, Mohamed Ali; Xiao, Yaotian; Tashiro, Yukihiro; Wang, Ying; Zendo, Takeshi; Sakai, Kenji; Sonomoto, Kenji

    2015-02-01

    There has been tremendous growth in the production of optically pure l-lactic acid from lignocellulose-derived sugars. In this study, Enterococcus mundtii QU 25 was used to ferment a glucose/xylose mixture to l-lactic acid. Maintenance of the xylose concentration at greater than 10 g/L achieved homo-lactic acid fermentation and reduced the formation of byproducts. Furthermore, carbon catabolite repression (CCR) was avoided by maintaining the glucose concentration below 25 g/L; therefore, initial concentrations of 25 g/L glucose and 50 g/L xylose were selected. Supplementation with 5 g/L yeast extract enhanced the maximum xylose consumption rate and consequently increased lactic acid production and productivity. Finally, a 129 g/L lactic acid without byproducts was obtained with a maximum lactic acid productivity of 5.60 g/(L·h) in fed-batch fermentation with feeding a glucose/xylose mixture using ammonium hydroxide as the neutralizing agent. These results indicate a potential for lactic acid production from glucose and xylose as the main components of lignocellulosic biomasses.

  13. 10E,12Z-conjugated linoleic acid impairs adipocyte triglyceride storage by enhancing fatty acid oxidation, lipolysis, and mitochondrial reactive oxygen species

    PubMed Central

    den Hartigh, Laura J.; Han, Chang Yeop; Wang, Shari; Omer, Mohamed; Chait, Alan

    2013-01-01

    Conjugated linoleic acid (CLA) is a naturally occurring dietary trans fatty acid found in food from ruminant sources. One specific CLA isomer, 10E,12Z-CLA, has been associated with health benefits, such as reduced adiposity, while simultaneously promoting deleterious effects, such as systemic inflammation, insulin resistance, and dyslipidemia. The precise mechanisms by which 10E,12Z-CLA exerts these effects remain unknown. Despite potential health consequences, CLA continues to be advertised as a natural weight loss supplement, warranting further studies on its effects on lipid metabolism. We hypothesized that 10E,12Z-CLA impairs lipid storage in adipose tissue by altering the lipid metabolism of white adipocytes. We demonstrate that 10E,12Z-CLA reduced triglyceride storage due to enhanced fatty acid oxidation and lipolysis, coupled with diminished glucose uptake and utilization in cultured adipocytes. This switch to lipid utilization was accompanied by a potent proinflammatory response, including the generation of cytokines, monocyte chemotactic factors, and mitochondrial superoxide. Disrupting fatty acid oxidation restored glucose utilization and attenuated the inflammatory response to 10E,12Z-CLA, suggesting that fatty acid oxidation is critical in promoting this phenotype. With further investigation into the biochemical pathways involved in adipocyte responses to 10E,12Z-CLA, we can discern more information about its safety and efficacy in promoting weight loss. PMID:23956445

  14. Free fatty acid receptor 1 (FFAR1/GPR40) signaling affects insulin secretion by enhancing mitochondrial respiration during palmitate exposure.

    PubMed

    Kristinsson, Hjalti; Bergsten, Peter; Sargsyan, Ernest

    2015-12-01

    Fatty acids affect insulin secretion via metabolism and FFAR1-mediated signaling. Recent reports indicate that these two pathways act synergistically. Still it remains unclear how they interrelate. Taking into account the key role of mitochondria in insulin secretion, we attempted to dissect the metabolic and FFAR1-mediated effects of fatty acids on mitochondrial function. One-hour culture of MIN6 cells with palmitate significantly enhanced mitochondrial respiration. Antagonism or silencing of FFAR1 prevented the palmitate-induced rise in respiration. On the other hand, in the absence of extracellular palmitate FFAR1 agonists caused a modest increase in respiration. Using an agonist of the M3 muscarinic acetylcholine receptor and PKC inhibitor we found that in the presence of the fatty acid mitochondrial respiration is regulated via Gαq protein-coupled receptor signaling. The increase in respiration in palmitate-treated cells was largely due to increased glucose utilization and oxidation. However, glucose utilization was not dependent on FFAR1 signaling. Collectively, these results indicate that mitochondrial respiration in palmitate-treated cells is enhanced via combined action of intracellular metabolism of the fatty acid and the Gαq-coupled FFAR1 signaling. Long-term palmitate exposure reduced ATP-coupling efficiency of mitochondria and deteriorated insulin secretion. The presence of the FFAR1 antagonist during culture did not improve ATP-coupling efficiency, however, it resulted in enhanced mitochondrial respiration and improved insulin secretion after culture. Taken together, our study demonstrates that during palmitate exposure, integrated actions of fatty acid metabolism and fatty acid-induced FFAR1 signaling on mitochondrial respiration underlie the synergistic action of the two pathways on insulin secretion.

  15. Phytotoxicity of citric acid and Tween® 80 for potential use as soil amendments in enhanced phytoremediation.

    PubMed

    Agnello, A C; Huguenot, D; van Hullebusch, E D; Esposito, G

    2015-01-01

    Enhanced phytoremediation adding biodegradable amendments like low molecular weight organic acids and surfactants is an interesting area of current research to overcome the limitation that represents low bioavailability of pollutants in soils. However, prior to their use in assisted phytoremediation, it is necessary to test if amendments per se exert any toxic effect to plants and to optimize their application mode. In this context, the present study assessed the effects of citric acid and Tween® 80 (polyethylene glycol sorbitan monooleate) on the development of alfalfa (Medicago sativa) plants, as influenced by their concentration and frequency of application, in order to evaluate the feasibility for their future use in enhanced phytoremediation of multi-contaminated soils. The results showed that citric acid negatively affected plant germination, while it did not have any significant effect on biomass or chlorophyll content. In turn, Tween® 80 did not affect plant germination and showed a trend to increase biomass, as well as it did not have any significant effect on chlorophyll levels. M. sativa appeared to tolerate citric acid and Tween® 80 at the tested concentrations, applied weekly. Consequently, citric acid and Tween® 80 could potentially be utilized to assist phytoremediation of contaminated soils vegetated with M. sativa.

  16. Phytotoxicity of citric acid and Tween® 80 for potential use as soil amendments in enhanced phytoremediation.

    PubMed

    Agnello, A C; Huguenot, D; van Hullebusch, E D; Esposito, G

    2015-01-01

    Enhanced phytoremediation adding biodegradable amendments like low molecular weight organic acids and surfactants is an interesting area of current research to overcome the limitation that represents low bioavailability of pollutants in soils. However, prior to their use in assisted phytoremediation, it is necessary to test if amendments per se exert any toxic effect to plants and to optimize their application mode. In this context, the present study assessed the effects of citric acid and Tween® 80 (polyethylene glycol sorbitan monooleate) on the development of alfalfa (Medicago sativa) plants, as influenced by their concentration and frequency of application, in order to evaluate the feasibility for their future use in enhanced phytoremediation of multi-contaminated soils. The results showed that citric acid negatively affected plant germination, while it did not have any significant effect on biomass or chlorophyll content. In turn, Tween® 80 did not affect plant germination and showed a trend to increase biomass, as well as it did not have any significant effect on chlorophyll levels. M. sativa appeared to tolerate citric acid and Tween® 80 at the tested concentrations, applied weekly. Consequently, citric acid and Tween® 80 could potentially be utilized to assist phytoremediation of contaminated soils vegetated with M. sativa. PMID:25976880

  17. Ascorbic acid enhanced activation of oxygen by ferrous iron: A case of aerobic degradation of rhodamine B.

    PubMed

    Hou, Xiaojing; Shen, Wenjuan; Huang, Xiaopeng; Ai, Zhihui; Zhang, Lizhi

    2016-05-01

    Molecular oxygen activation by ferrous ions (Fe(II)) in aqueous solution could generate reactive oxygen species (ROS) with high oxidation potential via reaction between Fe(II) and oxygen molecules (Fe(II)/air), however, ROS yielded in the Fe(II)/air process is insufficient for removal of organic pollutants due to the irreversible ferric ions (Fe(III)) accumulation. In this study, we demonstrate that ascorbic acid (AA) could enhance ROS generation via oxygen activation by ferrous irons (AA/Fe(II)/air) and thus improve the degradation of rhodamine (RhB) significantly. It was found that the first-order aerobic degradation rate of RhB in the AA/Fe(II)/air process in the presence of ascorbic acid is more than 4 times that of the Fe(II)/Air system without adding ascorbic acid. The presence of ascorbic acid could relieve the accumulation of Fe(III) by reductive accelerating the Fe(III)/Fe(II) cycles, as well as lower the redox potential of Fe(III)/Fe(II) through chelating effect, leading to enhanced ROS generation for promoting RhB degradation. This study not only sheds light on the effect of ascorbic acid on aerobic Fe(II) oxidation, but also provides a green method for effective remediation of organic pollutants.

  18. Enhanced adsorption of acidic gases (CO2, NO2 and SO2) on light metal decorated graphene oxide.

    PubMed

    Chen, Chi; Xu, Kui; Ji, Xiao; Miao, Ling; Jiang, Jianjun

    2014-06-14

    The adsorption of several acidic gases (CO2, NO2 and SO2) on light metal (Li, Al) decorated graphene oxide (GO) is theoretically studied, based on the first-principles calculations. Configuration relaxation, binding energy and charge transfer are carried out to discuss the acidic gas adsorption ability of light metal decorated GO. It is found out that Li, Al could be anchored stably by hydroxyl and epoxy groups on GO, and then a strong adsorption of CO2, NO2 and SO2 will occur above these light metals. In contrast to Ti, Li decorated GO exhibits a comparable adsorption ability of acidic gases, but a much smaller interaction with O2 about 2.85-3.98 eV lower in binding energy; and Al decorated GO displays much higher binding energy of all acidic gases with an enhancement of about 0.59-2.29 eV. The results of enhanced acidic gas adsorption ability and a reduced interference by O2 imply that Li, Al decorated GO may be useful and promising for collection and filtration of exhaust gases.

  19. Enhancement of skin wound healing with decellularized scaffolds loaded with hyaluronic acid and epidermal growth factor.

    PubMed

    Su, Zhongchun; Ma, Huan; Wu, Zhengzheng; Zeng, Huilan; Li, Zhizhong; Wang, Yuechun; Liu, Gexiu; Xu, Bin; Lin, Yongliang; Zhang, Peng; Wei, Xing

    2014-11-01

    Current therapy for skin wound healing still relies on skin transplantation. Many studies were done to try to find out ways to replace skin transplantation, but there is still no effective alternative therapy. In this study, decellularized scaffolds were prepared from pig peritoneum by a series of physical and chemical treatments, and scaffolds loaded with hyaluronic acid (HA) and epidermal growth factor (EGF) were tested for their effect on wound healing. MTT assay showed that EGF increased NIH3T3 cell viability and confirmed that EGF used in this study was biologically active in vitro. Scanning electron microscope (SEM) showed that HA stably attached to scaffolds even after soaking in PBS for 48 h. ELISA assay showed that HA increased the adsorption of EGF to scaffolds and sustained the release of EGF from scaffolds. Animal study showed that the wounds covered with scaffolds containing HA and EGF recovered best among all 4 groups and had wound healing rates of 49.86%, 70.94% and 87.41% respectively for days 10, 15 and 20 post-surgery compared to scaffolds alone with wound healing rates of 29.26%, 42.80% and 70.14%. In addition, the wounds covered with scaffolds containing EGF alone were smaller than no EGF scaffolds on days 10, 15 and 20 post-surgery. Hematoxylin-Eosin (HE) staining confirmed these results by showing that on days 10, 15 and 20 post-surgery, the thicker epidermis and dermis layers were observed in the wounds covered with scaffolds containing HA and EGF than scaffolds alone. In addition, the thicker epidermis and dermis layers were also observed in the wounds covered with scaffolds containing EGF than scaffolds alone. Skin appendages were observed on day 20 only in the wound covered with scaffolds containing HA and EGF. These results demonstrate that the scaffolds containing HA and EGF can enhance wound healing.

  20. Disinfection efficiency of peracetic acid, UV and ozone after enhanced primary treatment of municipal wastewater.

    PubMed

    Gehr, Ronald; Wagner, Monika; Veerasubramanian, Priya; Payment, Pierre

    2003-11-01

    The City of Montreal Wastewater Treatment Plant uses enhanced physicochemical processes (ferric and/or alum coagulation) for suspended solids and phosphorus removal. The objective of this study was to assess the ability of peracetic acid (PAA), UV, or ozone to inactivate the indicator organisms fecal coliforms, Enterococci, MS-2 coliphage, or Clostridium perfringens in the effluent from this plant. PAA doses to reach the target fecal coliform level of 9000 CFU/100mL exceeded 6 mg/L; similar results were obtained for enterococci, and no inactivation of Clostridium perfringens was observed. However a 1-log reduction of MS-2 occurred at PAA doses of 1.5 mg/L and higher. It was expected that this effluent would have a high ozone demand, and would require relatively high UV fluences, because of relatively high effluent COD, iron and suspended solids concentrations, and low UV transmittance. This was confirmed herein. For UV, the inactivation curve for fecal coliforms showed the typical two-stage shape, with the target of 1000 CFU/100 mL (to account for photoreactivation) occurring in the asymptote zone at fluences >20 mJ/cm(2). In contrast, inactivation curves for MS-2 and Clostridium perfringens were linear. Clostridium perfringens was the most resistant organism. For ozone, inactivation was already observed before any residuals could be measured. The transferred ozone doses to reach target fecal coliform levels ( approximately 2-log reduction) were 30-50 mg/L. MS-2 was less resistant, but Clostridium perfringens was more resistant than fecal coliforms. The different behaviour of the four indicator organisms studied, depending on the disinfectant, suggests that a single indicator organism might not be appropriate. The required dose of any of the disinfectants is unlikely to be economically viable, and upstream changes to the plant will be needed. PMID:14568042

  1. Disinfection efficiency of peracetic acid, UV and ozone after enhanced primary treatment of municipal wastewater.

    PubMed

    Gehr, Ronald; Wagner, Monika; Veerasubramanian, Priya; Payment, Pierre

    2003-11-01

    The City of Montreal Wastewater Treatment Plant uses enhanced physicochemical processes (ferric and/or alum coagulation) for suspended solids and phosphorus removal. The objective of this study was to assess the ability of peracetic acid (PAA), UV, or ozone to inactivate the indicator organisms fecal coliforms, Enterococci, MS-2 coliphage, or Clostridium perfringens in the effluent from this plant. PAA doses to reach the target fecal coliform level of 9000 CFU/100mL exceeded 6 mg/L; similar results were obtained for enterococci, and no inactivation of Clostridium perfringens was observed. However a 1-log reduction of MS-2 occurred at PAA doses of 1.5 mg/L and higher. It was expected that this effluent would have a high ozone demand, and would require relatively high UV fluences, because of relatively high effluent COD, iron and suspended solids concentrations, and low UV transmittance. This was confirmed herein. For UV, the inactivation curve for fecal coliforms showed the typical two-stage shape, with the target of 1000 CFU/100 mL (to account for photoreactivation) occurring in the asymptote zone at fluences >20 mJ/cm(2). In contrast, inactivation curves for MS-2 and Clostridium perfringens were linear. Clostridium perfringens was the most resistant organism. For ozone, inactivation was already observed before any residuals could be measured. The transferred ozone doses to reach target fecal coliform levels ( approximately 2-log reduction) were 30-50 mg/L. MS-2 was less resistant, but Clostridium perfringens was more resistant than fecal coliforms. The different behaviour of the four indicator organisms studied, depending on the disinfectant, suggests that a single indicator organism might not be appropriate. The required dose of any of the disinfectants is unlikely to be economically viable, and upstream changes to the plant will be needed.

  2. Stability and solubility enhancement of ellagic acid in cellulose ester solid dispersions.

    PubMed

    Li, Bin; Harich, Kim; Wegiel, Lindsay; Taylor, Lynne S; Edgar, Kevin J

    2013-02-15

    Structurally varied, carboxyl-containing cellulose derivatives were evaluated for their ability to form amorphous solid dispersions (ASD) with ellagic acid (EA), in order to improve the solubility of this high-melting, poorly bioavailable, but highly bioactive natural flavonoid compound. ASDs of EA with carboxymethylcellulose acetate butyrate (CMCAB), cellulose acetate adipate propionate (CAAdP), and hydroxypropylmethylcellulose acetate succinate (HPMCAS) were prepared, and EA dissolution from these ASDs was compared with that from pure crystalline EA and from EA/poly(vinylpyrrolidinone) (PVP) solid dispersions (SD). Polymer/drug mixtures were characterized by powder X-ray diffraction (XRPD), modulated differential scanning calorimetry (MDSC), nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FT-IR). The XRPD and FT-IR results indicated that EA was amorphous in solid dispersions with EA concentration up to 25 wt%. The stability against crystallization and solution concentrations of EA from these solid dispersions were significantly higher than those observed for physical mixtures and pure crystalline EA. HPMCAS stabilized EA most effectively, among the polymers tested, against both chemical degradation and recrystallization. The relative ability to solubilize EA from ASDs at pH 6.8 was PVP>HPMCAS>CMCAB. EA dissolves from ASD in PVP quickly and completely (maximum 92%) at pH 6.8, but EA is also released from PVP at pH 1.2, and then crystallizes rapidly. Therefore PVP is not a practical candidate for EA ASD. In contrast, the cellulose derivative ASDs show very slow EA release at pH 1.2 (<4%) and faster but still incomplete drug release at pH 6.8 (maximum 35% for HPMCAS SD). The pH-triggered drug release from HPMCAS ASD makes HPMCAS a practical choice for EA solubility enhancement. PMID:23399175

  3. 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

  4. 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.

  5. 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

  6. SAR studies of 3-arylpropionic acids as potent and selective agonists of sphingosine-1-phosphate receptor-1 (S1P1) with enhanced pharmacokinetic properties.

    PubMed

    Yan, Lin; Huo, Pei; Hale, Jeffrey J; Mills, Sander G; Hajdu, Richard; Keohane, Carol A; Rosenbach, Mark J; Milligan, James A; Shei, Gan-Ju; Chrebet, Gary; Bergstrom, James; Card, Deborah; Mandala, Suzanne M

    2007-02-01

    Structure-activity relationship (SAR) studies of 3-arylpropionic acids-a class of novel S1P(1) selective agonists-by introducing substitution to the propionic acid chain and replacing the adjacent phenyl ring with pyridine led to a series of modified 3-arylpropionic acids with enhanced half-life in rat. These analogs (e.g., cyclopropanecarboxylic acids) exhibited longer half-life in rat than did unmodified 3-arylpropionic acids. This result suggests that metabolic oxidation at the propionic acid chain, particularly at the C3 benzylic position of 3-arylpropionic acids, is probably responsible for their short half-life in rodent.

  7. Surface-enhanced Raman spectroscopy for the in-vitro and ex-vivo detection of excitatory amino acids

    NASA Astrophysics Data System (ADS)

    O'Neal, D. P.; Motamedi, Massoud; Chen, Jefferson; Cote, Gerard L.

    1999-04-01

    Traditionally methods for the detection of excitatory amino acids, which have been linked to secondary injury following head trauma, can be excessively time consuming clinically. A near real-time measurement system could provide clinical information in anticipation of pharmaceutical intervention for head injured patients. Our studies have shown that surface-enhanced Raman spectroscopy (SERS) with silver colloids has the ability to measure physiological concentrations of in vitro excitatory amino acids using short scan times. Employing a damage model for ischemia, preliminary ex vivo rat extracellular grain fluid analysis shows an intriguing correlation between SERS spectral features and expected Glutamate concentration fluctuations following head injuries.

  8. Pretreatment of corn stover with diluted acetic acid for enhancement of acidogenic fermentation.

    PubMed

    Zhao, Xu; Wang, Lijuan; Lu, Xuebin; Zhang, Shuting

    2014-04-01

    A Box-Behnken design of response surface method was used to optimize acetic acid-catalyzed hydrothermal pretreatment of corn stover, in respect to acid concentration (0.05-0.25%), treatment time (5-15 min) and reaction temperature (180-210°C). Acidogenic fermentations with different initial pH and hydrolyzates were also measured to evaluate the optimal pretreatment conditions for maximizing acid production. The results showed that pretreatment with 0.25% acetic acid at 191°C for 7.74 min was found to be the most optimal condition for pretreatment of corn stover under which the production of acids can reach the highest level. Acidogenic fermentation with the hydrolyzate of pretreatment at the optimal condition at the initial pH=5 was shown to be butyric acid type fermentation, producing 21.84 g acetic acid, 7.246 g propionic acid, 9.170 butyric acid and 1.035 g isovaleric acid from 100g of corn stover in 900 g of water containing 2.25 g acetic acid.

  9. Enhanced absorption of bumetanide from suppositories containing weak acids in rabbits.

    PubMed

    Yagi, N; Kenmotsu, H; Shimode, Y; Oda, K; Sekikawa, H; Takada, M

    1993-03-01

    The in vitro release of bumetanide from macrogol suppositories with and without weak acids (citric acid and tartaric acid) was studied. The release of bumetanide was not affected when weak acids were added to the suppositories. The in vivo rectal absorption of bumetanide from the suppositories was evaluated in rabbits. The bioavailability (absolute), expressed as the ratio of the area under the plasma concentration-time curve (AUC) following oral administration of bumetanide, was 39% that of intravenous administration. The value in bumetanide following rectal administration of the suppositories without weak acids was 32%. Each absolute bioavailability following rectal administration of the suppositories with 5% citric acid and 5% tartaric acid was 52% and 42%, respectively. These values were significantly larger than those of rectal administration of the suppositories without weak acids. Particularly, the bioavailability following rectal administration of the suppositories containing citric acid was significantly different from even those of oral administration. The absorption rate constants of bumetanide from the suppositories with weak acids were significantly larger than those following oral administration. These results indicated the possibilities of the rectal route of administration of drugs which are weak organic acids and show low or variable bioavailability following oral administration. PMID:8364470

  10. On the mechanism of enhanced ATP formation in hypoxic myocardium caused by glutamic acid.

    PubMed

    Pisarenko, O I; Solomatina, E S; Ivanov, V E; Studneva, I M; Kapelko, V I; Smirnov, V N

    1985-01-01

    The effect of glutamic acid on the cardiac contractile function and sources of anaerobic ATP formation in hypoxic myocardium was studied in isovolumic rat hearts. The presence of glutamic acid (5 mM) in the perfusate significantly diminished an increment in diastolic pressure caused by 60 min hypoxia, and facilitated its complete recovery during 30 min reoxygenation. This effect was combined with the maintenance of a higher ATP level during hypoxia and reoxygenation. The total content of lactate in the heart-perfusate system rose exactly as during hypoxia without glutamic acid, while pyruvate content decreased due to increased alanine formation. Restoration of tissue content of glutamate and aspartate in the presence of exogenous glutamic acid was accompanied by a more than 2-fold increase in succinate formation, the end-product of the Krebs' cycle under anaerobic conditions. The products of glutamic acid transamination with oxaloacetic acid, aspartic and alpha-ketoglutaric acids (5mM each), induced the same functional and metabolic alterations as glutamic acid. Amino-oxyacetic acid, a tramsaminase inhibitor, eliminated the effects caused by glutamic acid. Moreover, the inhibition of transamination was accompanied by a decreased succinate and alanine synthesis as well as insignificantly increased lactate formation compared to hypoxia without additives. The results suggest that the beneficial effect of glutamic acid is due to the activation of anaerobic ATP formation in the mitochondria rather than stimulation of glycolysis.

  11. Enhanced ethylene emissions from red and Norway spruce exposed to acidic mists

    SciTech Connect

    Chen, Yimin; Wellburn, A.R. )

    1989-09-01

    Acidic cloudwater is believed to cause needle injury and to decrease winter hardiness in conifers. During simulations of these adverse conditions, rates of ethylene emissions from and levels of 1-aminocyclopropane-1-carboxylic acid (ACC) in both red and Norway spruce needles increased as a result of treatment with acidic mists but amounts of 1-malonyl(amino)cyclopropane-1-carboxylic acid remained unchanged. However, release of significant quantities of ethylene by another mechanism independent of ACC was also detected from brown needles. Application of exogenous plant growth regulators such as auxin, kinetic, abscisic acid and gibberellic acid (each 0.1 millimolar) had no obvious effects on the rates of basal or stress ethylene production from Norway spruce needles. The kinetics of ethylene formation by acidic mist-stressed needles suggest that there is no active inhibitive mechanism in spruce to prevent stress ethylene being released once ACC has been formed.

  12. Dynamic characterization of hydrophobic and hydrophilic solutes in oleic-acid enhanced transdermal delivery using two-photon fluorescence microscopy

    SciTech Connect

    Tseng, Te-Yu; Yang, Chiu-Sheng; Chen, Yang-Fang; Tsai, Tsung-Hua; Dong, Chen-Yuan

    2014-10-20

    In this letter, we propose an efficient methodology of investigating dynamic properties of sulforhodamine B and rhodamine B hexyl ester molecules transporting across ex-vivo human stratum corneum with and without oleic acid enhancement. Three-dimensional, time-lapse fluorescence images of the stratum corneum can be obtained using two-photon fluorescence microscopy. Furthermore, temporal quantifications of transport enhancements in diffusion parameters can be achieved with the use of Fick's second law. Dynamic characterization of solutes transporting across the stratum corneum is an effective method for understanding transient phenomena in transdermal delivery of probe molecules, leading to improved delivery strategies of molecular species for therapeutic purposes.

  13. Electrochemical formation of hydroxide for enhancing carbon dioxide and acid gas uptake by a solution

    DOEpatents

    Rau, Gregory Hudson

    2012-05-15

    A system is described for forming metal hydroxide from a metal carbonate utilizing a water electrolysis cell having an acid-producing anode and a hydroxyl-producing cathode immersed in a water solution of sufficient ionic content to allow an electric current to pass between the hydroxyl-producing cathode and the acid-producing anode. A metal carbonate, in particular water-insoluble calcium carbonate or magnesium carbonate, is placed in close proximity to the acid-producing anode. A direct current electrical voltage is provided across the acid-producing anode and the hydroxyl-producing cathode sufficient to generate acid at the acid-producing anode and hydroxyl ions at the hydroxyl-producing cathode. The acid dissolves at least part of the metal carbonate into metal and carbonate ions allowing the metal ions to travel toward the hydroxyl-producing cathode and to combine with the hydroxyl ions to form the metal hydroxide. The carbonate ions travel toward the acid-producing anode and form carbonic acid and/or water and carbon dioxide. Among other uses, the metal hydroxide formed can be employed to absorb acid gases such as carbon dioxide from a gas mixture. The invention can also generate hydrogen and oxidative gases such as oxygen or chlorine.

  14. Scalable preparation of alginate templated-layered double hydroxide mesoporous composites with enhanced surface areas and surface acidities.

    PubMed

    Zhao, Lina; Xu, Ting; Lei, Xiaodong; Xu, Sailong; Zhang, Fazhi

    2011-04-01

    Layered double hydroxides (LDHs), also known as hydrotalcite-like layered clays, have previously been investigated as a potential solid alkaline catalyst. A necessary calcinations/rehydration procedure, however, is utilized to enhance surface area and catalytic activity of LDHs involved. Here we report on a scalable preparation of sodium alginate-templated MgAI-LDH (LDH/SA) mesoporous composites with high surface area and surface acidity. The powdery LDH/SA mesoporous composites are prepared using alginate as template by a scalable method of separate nucleation and aging steps (SNAS). Comparison with the pristine MgAl-LDH shows that the obtained LDH/SA composites exhibit the greatly enhanced surface area and surface activity of surface acid sites at the elevated high temperatures which have scarcely been reported previously. Our results may allow designing a variety of mesoporous LDH-containing composites with potential applications in specific catalysis and purification processes.

  15. Surface plasmon resonance-enhanced fluorescence implementation of a single-step competition assay: demonstration of fatty acid measurement using an anti-fatty acid monoclonal antibody and a Cy5-labeled fatty acid.

    PubMed

    Vareiro, Margarida M L M; Tranchant, Isabelle; Maplin, Sandra; Zak, Kris; Gani, M M; Slevin, Christopher J; Hailes, Helen C; Tabor, Alethea B; Cameron, Petra J; Jenkins, A Toby A; Williams, David E

    2008-06-15

    The development of a single-step, separation-free method for measurement of low concentrations of fatty acid using a surface plasmon resonance-enhanced fluorescence competition assay with a surface-bound antibody is described. The assay behavior was unexpectedly complex. A nonlinear coverage-dependent self-quenching of emission from surface-bound fluorescent label was deduced from the response kinetics and attributed to a surface plasmon-mediated energy transfer between adsorbed fluorophores, modified by the effects of plasmon interference. Principles of assay design to avoid complications from such effects are discussed. An anti-fatty acid mouse monoclonal antibody reacting to the alkyl chain was prepared and supported on a gold chip at a spacing appropriate for surface-plasmon field-enhanced fluorescence spectroscopy (SPEFS), by applying successively a self-assembled biotinylated monolayer, then streptavidin, then biotinylated protein A, and then the antibody, which was crosslinked to the protein A. Synthesis of a fluorescently (Cy5) tagged C-11 fatty acid is reported. SPEFS was used to follow the kinetics of the binding of the labeled fatty acid to the antibody, and to implement a competition assay with free fatty acid (undecanoic acid), sensitive at the 1 microM scale, a sensitivity limit caused by the low affinity of antibodies for free fatty acids, rather than the SPEFS technique itself. Free fatty acid concentration in human serum is in the range 0.1-1mM, suggesting that this measurement approach could be applied in a clinical diagnostic context. Finally, a predictive, theoretical model of fatty acid binding was developed that accounted for the observed "overshoot" kinetics.

  16. Enhanced phenylpyruvic acid production with Proteus vulgaris in fed-batch and continuous fermentation.

    PubMed

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

    2016-01-01

    Phenylpyruvic acid is a deaminated form of phenylalanine and is used in various areas such as development of cheese and wine flavors, diagnosis of phenylketonuria, and to decrease excessive nitrogen accumulation in the manure of farm animals. However, reported phenylpyruvic acid fermentation studies in the literature have been usually performed at shake-flask scale with low production. In this study, phenylpyruvic acid production was evaluated in bench-top bioreactors by conducting fed-batch and continuous fermentation for the first time. As a result, maximum phenylpyruvic acid concentrations increased from 1350 mg/L (batch fermentation) to 2958 mg/L utilizing fed-batch fermentation. Furthermore, phenylpyruvic acid productivity was increased from 48 mg/L/hr (batch fermentation) to 104 and 259 mg/L/hr by conducting fed-batch and continuous fermentation, respectively. Overall, this study demonstrated that fed-batch and continuous fermentation significantly improved phenylpyruvic acid production in bench-scale bioreactor production.

  17. Oleic acid enhances G protein coupled receptor 43 expression in bovine intramuscular adipocytes but not in subcutaneous adipocytes.

    PubMed

    Chung, K Y; Smith, S B; Choi, S H; Johnson, B J

    2016-05-01

    We hypothesized that fatty acids would differentially affect G protein coupled receptor (GPR) 43 mRNA expression and GPR43 protein concentrations in bovine intramuscular (IM) and subcutaneous (SC) adipocytes. The GPR43 protein was detected in bovine liver, pancreas, and semimembranosus (MUS) muscle in samples taken at slaughter. Similarly, GPR43 protein levels were similar in IM adipose tissue and SM muscle but was barely detectable in SC adipose tissue. Primary cultures of IM and SC stromal vascular cells were isolated from bovine adipose tissues. Oleic acid (100 μ) stimulated PPARγ gene expression and decreased stearoyl-CoA desaturase (SCD) gene expression but had no effect on GPR43 gene expression, which was readily detectable in both IM and SC adipocytes. Differentiation cocktail (Diff; 10 μ insulin, 4 μ dexamethasone, and 10 μ ciglitizone) stimulated CCAAT/enhancer-binding protein β (C/EBPβ) and PPARγ gene expression in SC but not IM adipocytes, but Diff increased SCD gene expression in both cell types. Linoleic acid (10 µ) increased PPARγ gene expression relative to Diff cocktail in SC adipocytes, whereas linoleic acid and α-linolenic decreased SCD gene expression relative to control adipocytes and adipocytes incubated with Diff ( < 0.05). Increasing concentrations of oleic acid (1, 10, 100, and 500 μM) increased GPR43 protein and mRNA expression in IM but not SC adipocytes. These data indicated that oleic acid alters mRNA and protein concentrations of GPR43 in bovine IM adipocytes. PMID:27285685

  18. Enhancement of L-lactic acid production in Lactobacillus casei from Jerusalem artichoke tubers by kinetic optimization and citrate metabolism.

    PubMed

    Ge, Xiang-Yang; Qian, He; Zhang, Wei-Guo

    2010-01-01

    Efficient L-lactic acid production from Jerusalem artichoke tubers by Lactobacillus casei G-02 using simultaneous saccharification and fermentation (SSF) in fed-batch culture is demonstrated. The kinetic analysis in the SSF signified that the inulinase activity was subjected to product inhibition, while the fermentation activity of G-02 was subjected to substrate inhibition. It was also found that the intracellularly NOX activity was enhanced by the citrate metabolism, which increased the carbon flux of Embden-Meyerhof-Parnas (EMP) pathway dramatically, and resulted more ATP production. As a result, when the SSF was carried out at 40 degrees after the initial hydrolysis of 1 h with supplemented sodium citrate of 10g/L, L-lactic acid concentration of 141.5 g/L was obtained in 30 h with a volumetric productivity of 4.7 g/L/h. The conversion efficiency and product yield were 93.6% of the theoretical lactic acid yield and 52.4 g lactic acid/100 g Jerusalem artichoke flour, respectively. Such a high concentration of lactic acid with high productivity from Jerusalem artichoke has not been reported previously, and hence G-02 could be a potential candidate for economical production of L-lactic acid from Jerusalem artichoke at a commercial scale.

  19. Enhancement of L-lactic acid production in Lactobacillus casei from Jerusalem artichoke tubers by kinetic optimization and citrate metabolism.

    PubMed

    Ge, Xiang-Yang; Qian, He; Zhang, Wei-Guo

    2010-01-01

    Efficient L-lactic acid production from Jerusalem artichoke tubers by Lactobacillus casei G-02 using simultaneous saccharification and fermentation (SSF) in fed-batch culture is demonstrated. The kinetic analysis in the SSF signified that the inulinase activity was subjected to product inhibition, while the fermentation activity of G-02 was subjected to substrate inhibition. It was also found that the intracellularly NOX activity was enhanced by the citrate metabolism, which increased the carbon flux of Embden-Meyerhof-Parnas (EMP) pathway dramatically, and resulted more ATP production. As a result, when the SSF was carried out at 40 degrees after the initial hydrolysis of 1 h with supplemented sodium citrate of 10g/L, L-lactic acid concentration of 141.5 g/L was obtained in 30 h with a volumetric productivity of 4.7 g/L/h. The conversion efficiency and product yield were 93.6% of the theoretical lactic acid yield and 52.4 g lactic acid/100 g Jerusalem artichoke flour, respectively. Such a high concentration of lactic acid with high productivity from Jerusalem artichoke has not been reported previously, and hence G-02 could be a potential candidate for economical production of L-lactic acid from Jerusalem artichoke at a commercial scale. PMID:20134240

  20. Coexpressing Escherichia coli Cyclopropane Synthase with Sterculia foetida Lysophosphatidic Acid Acyltransferase Enhances Cyclopropane Fatty Acid Accumulation1[W][OPEN

    PubMed Central

    Yu, Xiao-Hong; Prakash, Richa Rawat; Sweet, Marie; Shanklin, John

    2014-01-01

    Cyclopropane fatty acids (CPAs) are desirable as renewable chemical feedstocks for the production of paints, plastics, and lubricants. Toward our goal of creating a CPA-accumulating crop, we expressed nine higher plant cyclopropane synthase (CPS) enzymes in the seeds of fad2fae1 Arabidopsis (Arabidopsis thaliana) and observed accumulation of less than 1% CPA. Surprisingly, expression of the Escherichia coli CPS gene resulted in the accumulation of up to 9.1% CPA in the seed. Coexpression of a Sterculia foetida lysophosphatidic acid acyltransferase (SfLPAT) increases CPA accumulation up to 35% in individual T1 seeds. However, seeds with more than 9% CPA exhibit wrinkled seed morphology and reduced size and oil accumulation. Seeds with more than 11% CPA exhibit strongly decreased seed germination and establishment, and no seeds with CPA more than 15% germinated. That previous reports suggest that plant CPS prefers the stereospecific numbering (sn)-1 position whereas E. coli CPS acts on sn-2 of phospholipids prompted us to investigate the preferred positions of CPS on phosphatidylcholine (PC) and triacylglycerol. Unexpectedly, in planta, E. coli CPS acts primarily on the sn-1 position of PC; coexpression of SfLPAT results in the incorporation of CPA at the sn-2 position of lysophosphatidic acid. This enables a cycle that enriches CPA at both sn-1 and sn-2 positions of PC and results in increased accumulation of CPA. These data provide proof of principle that CPA can accumulate to high levels in transgenic seeds and sets the stage for the identification of factors that will facilitate the movement of CPA from PC into triacylglycerol to produce viable seeds with additional CPA accumulation. PMID:24204024

  1. Enhancing effect of 4-hydroxy-3-nitrophenylacetic acid on transcription of the ice nucleation-active gene of Xanthomonas campestris.

    PubMed

    Watanabe, M; Watanabe, J; Michigami, Y

    1994-12-01

    Cultivation of an ice nucleation-active strain of Xanthomonas campestris in the presence (1 ppm) of 4-hydroxy-3-nitrophenylacetic acid resulted in enhancement of its ice-nucleation activity. Both the ice-nucleation-active protein, InaX, and its mRNA were effectively expressed in the bacterial cells cultured in the presence of this compound. This indicates that this compound stimulated the biosynthesis of the ice-nucleation-active protein. PMID:7765721

  2. Postharvest treatments with salicylic acid, acetylsalicylic acid or oxalic acid delayed ripening and enhanced bioactive compounds and antioxidant capacity in sweet cherry.

    PubMed

    Valero, Daniel; Díaz-Mula, Huertas M; Zapata, Pedro Javier; Castillo, Salvador; Guillén, Fabián; Martínez-Romero, Domingo; Serrano, María

    2011-05-25

    Sweet cherry cultivars ('Cristalina' and 'Prime Giant') harvested at commercial ripening stage were treated with salicylic acid (SA), acetylsalicylic acid (ASA) or oxalic acid (OA) at 1 mM and then stored for 20 days under cold temperature. Results showed that all treatments delayed the postharvest ripening process, manifested by lower acidity, color changes and firmness losses, and maintained quality attributes for longer periods than controls. In addition, total phenolics, anthocyanins and antioxidant activity increased in untreated fruit during the first 10 days of storage and then decreased, while in fruits of all treatments, these parameters increased continuously during storage without significant differences among treatments. Thus, postharvest treatments with natural compounds, such as SA, ASA or OA, could be innovative tools to extend the storability of sweet cherry with higher content of bioactive compounds and antioxidant activity as compared with control fruits. PMID:21506518

  3. Postharvest treatments with salicylic acid, acetylsalicylic acid or oxalic acid delayed ripening and enhanced bioactive compounds and antioxidant capacity in sweet cherry.

    PubMed

    Valero, Daniel; Díaz-Mula, Huertas M; Zapata, Pedro Javier; Castillo, Salvador; Guillén, Fabián; Martínez-Romero, Domingo; Serrano, María

    2011-05-25

    Sweet cherry cultivars ('Cristalina' and 'Prime Giant') harvested at commercial ripening stage were treated with salicylic acid (SA), acetylsalicylic acid (ASA) or oxalic acid (OA) at 1 mM and then stored for 20 days under cold temperature. Results showed that all treatments delayed the postharvest ripening process, manifested by lower acidity, color changes and firmness losses, and maintained quality attributes for longer periods than controls. In addition, total phenolics, anthocyanins and antioxidant activity increased in untreated fruit during the first 10 days of storage and then decreased, while in fruits of all treatments, these parameters increased continuously during storage without significant differences among treatments. Thus, postharvest treatments with natural compounds, such as SA, ASA or OA, could be innovative tools to extend the storability of sweet cherry with higher content of bioactive compounds and antioxidant activity as compared with control fruits.

  4. Surface-enhanced Raman spectroscopy of amino acids adsorbed on an electrochemically prepared silver surface

    NASA Astrophysics Data System (ADS)

    Stewart, S.; Fredericks, P. M.

    1999-07-01

    An electrochemically roughened silver surface, in conjunction with a Raman microprobe spectrometer, was used to obtain SER spectra of a suite of 19 L-amino acids. The spectra obtained were very different from previously reported SER spectra obtained from silver hydrosols of amino acids. Analysis of the spectra showed that adsorption of all amino acids was via the ionised carboxylate group, and that the side chain of most of the molecules was also in close proximity to the surface. The spectra also indicated that, in contrast, the amine terminus was protonated and relatively far from the surface. Sulfur-containing amino acids also interacted with the silver surface through their sulfur atoms.

  5. Bone growth enhancement in vivo on press-fit titanium alloy implants with acid etched microtexture.

    PubMed

    Daugaard, Henrik; Elmengaard, Brian; Bechtold, Joan E; Soballe, Kjeld

    2008-11-01

    Early bone ongrowth secures long-term fixation of primary implants inserted without cement. Implant surfaces roughened with a texture on the micrometer scale are known to be osseoconductive. The aim of this study was to evaluate the bone formation at the surface of acid etched implants modified on the micro-scale. We compared implants with a nonparticulate texture made by chemical milling (hydrofluoric acid, nitric acid) (control) with implants that had a dual acid etched (hydrofluoric acid, hydrochloric acid) microtexture surface superimposed on the primary chemically milled texture. We used an experimental joint replacement model with cylindrical titanium implants (Ti-6Al-4V) inserted paired and press-fit in cancellous tibia metaphyseal bone of eight canines for 4 weeks and evaluated by histomorphometric quantification. A significant twofold median increase was seen for bone ongrowth on the acid etched surface [median, 36.1% (interquartile range, 24.3-44.6%)] compared to the control [18.4% (15.6-20.4%)]. The percentage of fibrous tissue at the implant surface and adjacent bone was significantly less for dual acid textured implants compared with control implants. These results show that secondary roughening of titanium alloy implant surface by dual acid etching increases bone formation at the implant bone interface. PMID:18186059

  6. Electrochemical formation of hydroxide for enhancing carbon dioxide and acid gas uptake by a solution

    DOEpatents

    Rau, Gregory Hudson

    2014-07-01

    A system for forming metal hydroxide from a metal carbonate utilizes a water electrolysis cell having an acid-producing anode and a hydroxyl-producing cathode immersed in a water solution of sufficient ionic content to allow an electric current to pass between the hydroxyl-producing cathode and the acid-producing anode. A metal carbonate is placed in close proximity to the acid-producing anode. A direct current electrical voltage is provided across the acid-producing anode and the hydroxyl-producing cathode sufficient to generate acid at the acid-producing anode and hydroxyl ions at the hydroxyl-producing cathode. The acid dissolves at least part of the metal carbonate into metal and carbonate ions allowing the metal ions to travel toward the hydroxyl-producing cathode and to combine with the hydroxyl ions to form the metal hydroxide. The carbonate ions travel toward the acid-producing anode and form carbonic acid and/or water and carbon dioxide.

  7. Bone growth enhancement in vivo on press-fit titanium alloy implants with acid etched microtexture

    PubMed Central

    Daugaard, Henrik; Elmengaard, Brian; Bechtold, Joan E.; Soballe, Kjeld

    2013-01-01

    Early bone ongrowth secures long-term fixation of primary implants inserted without cement. Implant surfaces roughened with a texture on the micrometer scale are known to be osseoconductive. The aim of this study was to evaluate the bone formation at the surface of acid etched implants modified on the micro-scale. We compared implants with a nonparticulate texture made by chemical milling (hydrofluoric acid, nitric acid) (control) with implants that had a dual acid etched (hydrofluoric acid, hydrochloric acid) microtexture surface superimposed on the primary chemically milled texture. We used an experimental joint replacement model with cylindrical titanium implants (Ti-6Al-4V) inserted paired and press-fit in cancellous tibia metaphyseal bone of eight canines for 4 weeks and evaluated by histomorphometric quantification. A significant twofold median increase was seen for bone ongrowth on the acid etched surface [median, 36.1% (interquartile range, 24.3–44.6%)] compared to the control [18.4% (15.6–20.4%)]. The percentage of fibrous tissue at the implant surface and adjacent bone was significantly less for dual acid textured implants compared with control implants. These results show that secondary roughening of titanium alloy implant surface by dual acid etching increases bone formation at the implant bone interface. PMID:18186059

  8. The vitamin-like dietary supplement para-aminobenzoic acid enhances the antitumor activity of ionizing radiation

    SciTech Connect

    Xavier, Sandhya; MacDonald, Shannon; Roth, Jennifer; Caunt, Maresa; Akalu, Abebe; Morais, Danielle; Buckley, Michael T.; Liebes, Leonard; Formenti, Silvia C.; Brooks, Peter C. . E-mail: peter.brooks@med.nyu.edu

    2006-06-01

    Purpose: To determine whether para-aminobenzoic acid (PABA) alters the sensitivity of tumor cells to ionizing radiation in vitro and in vivo. Methods and Materials: Cellular proliferation was assessed by WST-1 assays. The effects of PABA and radiation on tumor growth were examined with chick embryo and murine models. Real-time reverse transcriptase-polymerase chain reaction and Western blotting were used to quantify p21{sup CIP1} and CDC25A levels. Results: Para-aminobenzoic acid enhanced (by 50%) the growth inhibitory activity of radiation on B16F10 cells, whereas it had no effect on melanocytes. Para-aminobenzoic acid enhanced (50-80%) the antitumor activity of radiation on B16F10 and 4T1 tumors in vivo. The combination of PABA and radiation therapy increased tumor apoptosis. Treatment of tumor cells with PABA increased expression of CDC25A and decreased levels of p21{sup CIP1}. Conclusions: Our findings suggest that PABA might represent a compound capable of enhancing the antitumor activity of ionizing radiation by a mechanism involving altered expression of proteins known to regulate cell cycle arrest.

  9. A comparison of water solubility enhancements of organic solutes by aquatic humic materials and commercial humic acids

    USGS Publications Warehouse

    Chlou, C.T.; Kile, D.E.; Brinton, T.I.; Malcolm, R.L.; Leenheer, J.A.; MacCarthy, P.

    1987-01-01

    Water solubility enhancements of 1,1-bis(p-chloro-phenyl)-2,2,2-trichloroethane (p,p???-DDT), 2,4,5,2???,5???-pentachlorobiphenyl (2,4,5,2???,5???-PCB), and 2,4,4???-tri-chlorobiphenyl (2,4,4???-PCB) by dissolved organic matter have been studied with the following samples: (1) acidic water samples from the Suwannee River, Georgia, and the Sopchoppy River, Florida; (2) a humic extract of a nearly neutral pH water from the Calcasieu River, Louisiana; (3) commercial humic acids from the Aldrich Chemical Co. and Fluka-Tridom Chemical Corp. The calculated partition coefficients on a dissolved organic carbon basis (Kdoc) for organic solutes with water samples and aquatic humic extracts from this and earlier studies indicate that the enhancement effect varies with the molecular composition of the aquatic humic materials. The Kdoc values with water and aquatic humic samples are, however, far less than the observed Kdoc values obtained with the two commercial samples, by factors of about 4-20. In view of this finding, one should be cautious in interpreting the effects of the dissolved organic matter on solubility enhancement of organic solutes on the basis of the use of commercial humic acids.

  10. Enhanced production of short-chain fatty acid from food waste stimulated by alkyl polyglycosides and its mechanism.

    PubMed

    Zhao, Jianwei; Yang, Qi; Li, Xiaoming; Wang, Dongbo; Luo, Kun; Zhong, Yu; Xu, Qiuxiang; Zeng, Guangming

    2015-12-01

    Short-chain fatty acids (SCFAs) are the valuable products derived from the anaerobic fermentation of organic solid waste. However, SCFAs yield was limited by the worse solubilization and hydrolysis of particulate organic matter, and rapid consumption of organic acid by methanogens. In this study, an efficient and green strategy, i.e. adding biosurfactant alkyl polyglycosides (APG) into anaerobic fermentation system, was applied to enhance SCFAs production from food waste. Experimental results showed that APG not only greatly improved SCFAs production but also shortened the fermentation time for the maximum SCFAs accumulation. The SCFAs yield at optimal APG dosage 0.2g/g TS (total solid) reached 37.2g/L, which was 3.1-fold of that in blank. Meanwhile, the time to accumulate the maximum SCFAs in the presence of APG was shortened from day 14 to day 6. The activities of key enzymes such as hydrolytic and acid-forming enzymes were greatly promoted due to the presence of APG. These results demonstrated that the enhanced mechanism of SCFAs production should be attributed to the acceleration of solubilization and hydrolysis, enhancement of acidification and inhibition of methanogenesis by APG. PMID:26342451

  11. Enhanced production of short-chain fatty acid from food waste stimulated by alkyl polyglycosides and its mechanism.

    PubMed

    Zhao, Jianwei; Yang, Qi; Li, Xiaoming; Wang, Dongbo; Luo, Kun; Zhong, Yu; Xu, Qiuxiang; Zeng, Guangming

    2015-12-01

    Short-chain fatty acids (SCFAs) are the valuable products derived from the anaerobic fermentation of organic solid waste. However, SCFAs yield was limited by the worse solubilization and hydrolysis of particulate organic matter, and rapid consumption of organic acid by methanogens. In this study, an efficient and green strategy, i.e. adding biosurfactant alkyl polyglycosides (APG) into anaerobic fermentation system, was applied to enhance SCFAs production from food waste. Experimental results showed that APG not only greatly improved SCFAs production but also shortened the fermentation time for the maximum SCFAs accumulation. The SCFAs yield at optimal APG dosage 0.2g/g TS (total solid) reached 37.2g/L, which was 3.1-fold of that in blank. Meanwhile, the time to accumulate the maximum SCFAs in the presence of APG was shortened from day 14 to day 6. The activities of key enzymes such as hydrolytic and acid-forming enzymes were greatly promoted due to the presence of APG. These results demonstrated that the enhanced mechanism of SCFAs production should be attributed to the acceleration of solubilization and hydrolysis, enhancement of acidification and inhibition of methanogenesis by APG.

  12. Modulation of fatty acid metabolism and tricarboxylic acid cycle to enhance the lipstatin production through medium engineering in Streptomyces toxytricini.

    PubMed

    Kumar, Punit; Dubey, Kashyap Kumar

    2016-08-01

    This work investigated the potential of medium engineering to obtain maximum biomass, non-conventional carbon sources for lipstatin production and modulation of tricarboxylic acid (TCA) cycle to promote lipstatin synthesis. It was found that 2:3 carbon and nitrogen ratio, produced maximum biomass of 7.9g/L in growth medium and 6.6g/L in pre-seed medium. Among the studied non-conventional carbon sources i.e., soya flour 40g/L and sesame oil 30mL/L were found producing 1109.37mg/L (1.24-fold of control) and 1196.75mg/L (1.34-fold of control) lipstatin respectively. Supplementation of TCA cycle intermediates revealed that NADH and succinic acid showed lipstatin production to 1132.99mg/L and 1171.10mg/L respectively. Experimental outcome was validated in 7L bioreactor and produced 2242.63mg/L lipstatin which was ∼14% higher than shake flask. PMID:26897471

  13. Enhanced enzymatic hydrolysis of poplar bark by combined use of gamma ray and dilute acid for bioethanol production

    NASA Astrophysics Data System (ADS)

    Chung, Byung Yeoup; Lee, Jae Taek; Bai, Hyoung-Woo; Kim, Ung-Jin; Bae, Hyeun-Jong; Gon Wi, Seung; Cho, Jae-Young

    2012-08-01

    Pretreatment of poplar bark with a combination of sulfuric acid (3%, w/w, H2SO4) and gamma irradiation (0-1000 kGy) was performed in an attempt to enhance enzymatic hydrolysis for bioethanol production. The yields of reducing sugar were slightly increased with an increasing irradiation dose, ranging from 35.4% to 51.5%, with a 56.1% reducing sugar yield observed after dilute acid pretreatment. These results clearly showed that soluble sugars were released faster and to a greater extent in dilute acid-pretreated poplar bark than in gamma irradiation-pretreated bark. When combined pretreatment was carried out, a drastic increase in reducing sugar yield (83.1%) was found compared with individual pretreatment, indicating the possibility of increasing the convertibility of poplar bark following combined pretreatment. These findings are likely associated with cellulose crystallinity, lignin modification, and removal of hemicelluloses.

  14. Vortex flux pinning mechanism and enhancement of in-field Jc in succinic acid doped MgB2

    NASA Astrophysics Data System (ADS)

    Ghorbani, S. R.; Darini, M.; Wang, X. L.; Hossain, M. S. A.; Dou, S. X.

    2013-08-01

    The field dependence of the resistivity and the critical current density, Jc(B), of MgB2 doped with 10 wt% wet and dry succinic acid have been investigated by magnetic measurements. The dry succinic acid significantly enhanced the upper critical field, the irreversibility field, and the Jc(B) compared to the wet succinic acid doped MgB2 and the pure MgB2. The field dependence of Jc(B) was analyzed within the collective pinning model. The observed temperature dependence of the crossover field, Bsb(T), from the single vortex to the small vortex bundle pinning regime shows that flux pinning arising from variation in the critical temperature, δTc, is the dominant mechanism for the wet sample over the whole studied temperature range, while there is a competition between δTc pinning and the pinning from variation in the mean free path, δl, for the dry sample.

  15. Epibrassinolide induces changes in indole-3-acetic acid, abscisic acid and polyamine concentrations and enhances antioxidant potential of radish seedlings under copper stress.

    PubMed

    Choudhary, Sikander Pal; Bhardwaj, Renu; Gupta, Bishan Datt; Dutt, Prabhu; Gupta, Rajinder Kumar; Biondi, Stefania; Kanwar, Mukesh

    2010-11-01

    In the present study, the effects of epibrassinolide (EBL) on indole-3-acetic acid (IAA), abscisic acid (ABA) and polyamine (PA) tissue concentrations and antioxidant potential of 7-day-old Raphanus sativus L. cv. 'Pusa chetki' seedlings grown under Cu stress were investigated. EBL treatment alone or in combination with Cu enhanced free and bound IAA titers when compared with the metal alone. Modest increases in free and bound ABA contents were observed for EBL treatment alone. However, the combination of EBL with Cu caused major increases in both forms of ABA, over Cu alone. Among the PAs analyzed, only putrescine and cadaverine concentrations were enhanced by EBL treatment alone. By contrast, a significant decline in putrescine and spermine contents was found in seedlings treated with EBL plus Cu. EBL treatments alone or in combination with Cu enhanced activities of guaiacol peroxidase (EC1.11.1.7), catalase (EC 1.11.1.6), superoxide dismutase (EC 1.15.1.1) and glutathione reductase (EC 1.6.4.2) and protein contents in comparison with metal and control treatments. A major decrease in malondialdehyde content was also recorded for EBL treatments with or without Cu. An increase in phytochelatin content was also observed in seedlings treated with EBL alone or in combination with Cu. Major improvement in radical scavenging activities, as attested by the antioxidant activity assay using DPPH (1,1-diphenylpicrylhydrazyl), and elevated deoxyribose and reducing powers, along with increased contents of ascorbic acid, total phenols and proline, also suggest a major influence of EBL application in mitigating copper-induced oxidative stress in radish seedlings.

  16. Glucuronic acid and the ethanol metabolite ethyl-glucuronide cause Toll-like receptor 4 activation and enhanced pain

    PubMed Central

    Lewis, Susannah S.; Hutchinson, Mark R.; Zhang, Yingning; Hund, Dana K.; Maier, Steven F.; Rice, Kenner C.; Watkins, Linda R.

    2013-01-01

    We have previously observed that the non-opioid morphine metabolite, morphine-3-glucuronide, enhances pain via a toll-like receptor 4 (TLR4) dependent mechanism. The present studies were undertaken to determine whether TLR4-dependent pain enhancement generalizes to other classes of glucuronide metabolites. In silico modeling predicted that glucuronic acid alone and ethyl glucuronide, a minor but long-lasting ethanol metabolite, would dock to the same MD-2 portion of the TLR4 receptor complex previously characterized as the docking site for morphine-3-glucuronide. Glucuronic acid, ethyl glucuronide and ethanol all caused an increase in TLR4-dependent reporter protein expression in a cell line transfected with TLR4 and associated co-signaling molecules. Glucuronic acid-, ethyl glucuronide-, and ethanol-induced increases in TLR4 signaling were blocked by the TLR4 antagonists LPS-RS and (+)-naloxone. Glucuronic acid and ethyl glucuronide both caused allodynia following intrathecal injection in rats, which was blocked by intrathecal co-administration of the TLR4 antagonist LPS-RS. The finding that ethyl glucuronide can cause TLR4-dependent pain could have implications for human conditions such as hangover headache and alcohol withdrawal hyperalgesia, as well as suggesting that other classes of glucuronide metabolites could have similar effects. PMID:23348028

  17. Humic acid enhanced remediation of an emplaced diesel source in groundwater. 2. Numerical model development and application.

    PubMed

    Molson, J W; Frind, E O; Van Stempvoort, D R; Lesage, S

    2002-02-01

    A pilot scale experiment for humic acid-enhanced remediation of diesel fuel, described in Part 1 of this series, is numerically simulated in three dimensions. Groundwater flow, enhanced solubilization of the diesel source, and reactive transport of the dissolved contaminants and humic acid carrier are solved with a finite element Galerkin approach. The model (BIONAPL) is calibrated by comparing observed and simulated concentrations of seven diesel fuel components (BTEX and methyl-, dimethyl- and trimethylnaphthalene) over a 1500-day monitoring period. Data from supporting bench scale tests were used to estimate contaminant-carrier binding coefficients and to simulate two-site sorption of the carrier to the aquifer sand. The model accurately reproduced the humic acid-induced 10-fold increase in apparent solubility of trimethylnaphthalene. Solubility increases on the order of 2-5 were simulated for methylnaphthalene and dimethylnaphthalene, respectively. Under the experimental and simulated conditions, the residual 500-ml diesel source was almost completely dissolved and degraded within 5 years. Without humic acid flushing, the simulations show complete source dissolution would take about six times longer.

  18. Enhanced D-lactic acid production from renewable resources using engineered Lactobacillus plantarum.

    PubMed

    Zhang, Yixing; Vadlani, Praveen V; Kumar, Amit; Hardwidge, Philip R; Govind, Revathi; Tanaka, Tsutomu; Kondo, Akihiko

    2016-01-01

    D-lactic acid is used as a monomer in the production of poly-D-lactic acid (PDLA), which is used to form heat-resistant stereocomplex poly-lactic acid. To produce cost-effective D-lactic acid by using all sugars derived from biomass efficiently, xylose-assimilating genes encoding xylose isomerase and xylulokinase were cloned into an L-lactate-deficient strain, Lactobacillus plantarum. The resulting recombinant strain, namely L. plantarum NCIMB 8826 ∆ldhL1-pLEM-xylAB, was able to produce D-lactic acid (at optical purity >99 %) from xylose at a yield of 0.53 g g(-1). Simultaneous utilization of glucose and xylose to produce D-lactic acid was also achieved by this strain, and 47.2 g L(-1) of D-lactic acid was produced from 37.5 g L(-1) glucose and 19.7 g L(-1) xylose. Corn stover and soybean meal extract (SBME) were evaluated as cost-effective medium components for D-lactic acid production. Optimization of medium composition using response surface methodology resulted in 30 % reduction in enzyme loading and 70 % reduction in peptone concentration. In addition, we successfully demonstrated D-lactic acid fermentation from corn stover and SBME in a fed-batch fermentation, which yielded 61.4 g L(-1) D-lactic acid with an overall yield of 0.77 g g(-1). All these approaches are geared to attaining high D-lactic acid production from biomass sugars to produce low-cost, highly thermostable biodegradable plastics.

  19. Inulin Derivatives Obtained Via Enhanced Microwave Synthesis for Nucleic Acid Based Drug Delivery.

    PubMed

    Sardo, Carla; Craparo, Emanuela Fabiola; Fiorica, Calogero; Giammona, Gaetano; Cavallaro, Gennara

    2015-01-01

    A new class of therapeutic agents with a high potential for the treatment of different socially relevant human diseases is represented by Nucleic Acid Based Drugs (NABD), including small interfering RNAs (siRNA), decoy oligodeoxynucleotides (decoy ODN) and antisense oligonucleotides (ASOs). Although NABD can be engineered to be specifically directed against virtually any target, their susceptibility to nuclease degradation and the difficulty of delivery into target tissues severely limit their use in clinical practice and require the development of an appropriate nanostructured delivery system. For delivery of NABD, Inulin (Inu), a natural, water soluble and biocompatible polysaccharide, was derivatized by Spermine (Spm), a flexible molecule with four amine groups that, having pKa values in the range between 8-11, is mainly in the protonated form at pH 7.4. The synthesis of related copolymers (Inu-Spm) was performed by a two step reaction, using a method termed Enhanced Microwave Synthesis (EMS) which has the advantage, compared to conventional microwave reaction, that high amount of energy can be applied to the reaction system, by administering microwave irradiation and simultaneously controlling the temperature in the reaction vessel with cooled air. The synthesized inulin derivatives were characterized by FT-IR spectra and (1)H-NMR. INU-Spm derivatives with a degree of derivatization of about 14 % mol/mol were obtained. These polycations were tested to evaluate their ability to form non covalent complexes with genetic material (polyplexes). Agarose gel retardation assays showed that the obtained copolymers are able to electrostatically interact with DNA duplex to form polyplexes at different c/p weight ratios. Moreover, light scattering studies, performed to analyze size and z-potential of polyplexes, evidenced that copolymers are able to interact with genetic material leading to the formation of nanoscaled systems. In addition, biocompatibility of polyplexes

  20. Enhancing Phospholipid Fatty Acid Profiling of Soil Bacterial Communities via Substrate- Specific 13C-labelling

    NASA Astrophysics Data System (ADS)

    Evershed, R. P.; Maxfield, P. J.; Bingham, E. M.; Dildar, N.; Brennand, E. L.; Hornibrook, E.

    2008-12-01

    A range of culture-independent methods, has recently emerged to study environmental microorganisms in situ[1]. One such method is phospholipid fatty acid (PLFA) analysis, wherein these ubiquitous membrane lipids provide a powerful tool for the study of unculturable soil microorganisms. PLFA analyses have been used to investigate the impacts of a wide range of environmental factors on the soil microbial community. An acknowledged shortcoming of the PLFAs approach is the lack the chemotaxonoic specificity, which restricts the ability of the method to probe the activities of specific functional groups of the microbial community selectively. However, the selectivity of PLFAs analyses can be enhanced by incubating soils with 13C- labelled substrates followed by gas chromatography-combustion-isotope ratio mass spectrometry to reveal the specific PLFAs incorporating the 13C-label. The application of this approach will be demonstrated through our recent work on methanotrophic bacteria in soils. We applied this approach initially to mineral soils[2] and then extended chemotaxonomic assessments by using a combination of 13C-labelled PLFAs and hopanoids [3]. We have used this approach to explore the properties of high affinity methanotrophs in a range of environments, investigating the relationship between methane oxidation rates and the nature and magnitude of the methanotrophic community for the first time[4,5] More recently we extended the technique using a novel time series 13C-labelling of PLFAs[6] to estimate the rate and progression of 13C- label incorporation and turnover of methanotrophic populations. This modified approach has been used to investigate the impacts of various environmental variables, e.g. soil type, vegetation cover and land use, on the methanotrophic biomass[7.8]. The unique nature of the 13CH4 as a gaseous substate/carbon source means that can be readily introduced into soils via a specific subset of the soil microbial biomass, thereby offering many

  1. Host-derived extracellular nucleic acids enhance innate immune responses, induce coagulation, and prolong survival upon infection in insects.

    PubMed

    Altincicek, Boran; Stötzel, Sabine; Wygrecka, Malgorzata; Preissner, Klaus T; Vilcinskas, Andreas

    2008-08-15

    Extracellular nucleic acids play important roles in human immunity and hemostasis by inducing IFN production, entrapping pathogens in neutrophil extracellular traps, and providing procoagulant cofactor templates for induced contact activation during mammalian blood clotting. In this study, we investigated the functions of extracellular RNA and DNA in innate immunity and hemolymph coagulation in insects using the greater wax moth Galleria mellonella a reliable model host for many insect and human pathogens. We determined that coinjection of purified Galleria-derived nucleic acids with heat-killed bacteria synergistically increases systemic expression of antimicrobial peptides and leads to the depletion of immune-competent hemocytes indicating cellular immune stimulation. These activities were abolished when nucleic acids had been degraded by nucleic acid hydrolyzing enzymes prior to injection. Furthermore, we found that nucleic acids induce insect hemolymph coagulation in a similar way as LPS. Proteomic analyses revealed specific RNA-binding proteins in the hemolymph, including apolipoproteins, as potential mediators of the immune response and hemolymph clotting. Microscopic ex vivo analyses of Galleria hemolymph clotting reactions revealed that oenocytoids (5-10% of total hemocytes) represent a source of endogenously derived extracellular nucleic acids. Finally, using the entomopathogenic bacterium Photorhabdus luminescens as an infective agent and Galleria caterpillars as hosts, we demonstrated that injection of purified nucleic acids along with P. luminescens significantly prolongs survival of infected larvae. Our results lend some credit to our hypothesis that host-derived nucleic acids have independently been co-opted in innate immunity of both mammals and insects, but exert comparable roles in entrapping pathogens and enhancing innate immune responses. PMID:18684961

  2. Quantifying solubility enhancement due to particle size reduction and crystal habit modification: case study of acetyl salicylic acid.

    PubMed

    Hammond, Robert B; Pencheva, Klimentina; Roberts, Kevin J; Auffret, Tony

    2007-08-01

    The poor solubility of potential drug molecules is a significant problem in the design of pharmaceutical formulations. It is well known, however, that the solubility of crystalline materials is enhanced when the particle size is reduced to submicron levels and this factor can be expected to enhance drug product bioavailability. Direct estimation of solubility enhancement, as calculated via the Gibbs-Thompson relationship, demands reasonably accurate values for the particle/solution interfacial tension and, in particular, its anisotropy with respect to the crystal product's habit and morphology. In this article, an improved, more molecule-centered, approach is presented towards the calculation of solubility enhancement factors in which molecular modeling techniques are applied, and the effects associated with both crystal habit modification and solvent choice are examined. A case study for facetted, acetyl salicylic acid (aspirin) crystals in equilibrium with saturated aqueous ethanol solution reveals that their solubility will be enhanced in the range (7-58%) for a crystal size of 0.02 microm, with significantly higher enhancement for crystal morphologies in which the hydrophobic crystal faces are more predominant than the hydrophilic faces and for solvents in which the solubility is smaller.

  3. Assessment of crude glycerol for Enhanced Biological Phosphorus Removal: Stability and role of long chain fatty acids.

    PubMed

    Tayà, Carlota; Guerrero, Javier; Suárez-Ojeda, María Eugenia; Guisasola, Albert; Baeza, Juan Antonio

    2015-12-01

    Enhanced Biological Phosphorus Removal (EBPR) of urban wastewaters is usually limited by the available carbon source required by Polyphosphate Accumulating Organisms (PAO). External carbon sources as volatile fatty acids (VFA) or other pure organic compounds have been tested at lab scale demonstrating its ability to enhance PAO activity, but the application of this strategy at full-scale WWTPs is not cost-effective. The utilization of industrial by-products with some of these organic compounds provides lower cost, but it has the possible drawback of having inhibitory or toxic compounds to PAO. This study is focused on the utilization of crude glycerol, the industrial by-product generated in the biodiesel production, as a possible carbon source to enhance EBPR in carbon-limited urban wastewaters. Crude glycerol has non-negligible content of other organic compounds as methanol, salts, VFA and long chain fatty acids (LCFA). VFA and methanol have been demonstrated to enhance PAO activity, but there is no previous study about the effect of LCFA on PAO. This work presents the operation of an EBPR SBR system using crude glycerol as sole carbon source, studying also its long-term stability. The effect of LCFA is evaluated at short and long-term operation, demonstrating for the first time EBPR activity with LCFA as sole carbon source and its long-term failure due to the increased hydrophobicity of the sludge. PMID:26092200

  4. Assessment of crude glycerol for Enhanced Biological Phosphorus Removal: Stability and role of long chain fatty acids.

    PubMed

    Tayà, Carlota; Guerrero, Javier; Suárez-Ojeda, María Eugenia; Guisasola, Albert; Baeza, Juan Antonio

    2015-12-01

    Enhanced Biological Phosphorus Removal (EBPR) of urban wastewaters is usually limited by the available carbon source required by Polyphosphate Accumulating Organisms (PAO). External carbon sources as volatile fatty acids (VFA) or other pure organic compounds have been tested at lab scale demonstrating its ability to enhance PAO activity, but the application of this strategy at full-scale WWTPs is not cost-effective. The utilization of industrial by-products with some of these organic compounds provides lower cost, but it has the possible drawback of having inhibitory or toxic compounds to PAO. This study is focused on the utilization of crude glycerol, the industrial by-product generated in the biodiesel production, as a possible carbon source to enhance EBPR in carbon-limited urban wastewaters. Crude glycerol has non-negligible content of other organic compounds as methanol, salts, VFA and long chain fatty acids (LCFA). VFA and methanol have been demonstrated to enhance PAO activity, but there is no previous study about the effect of LCFA on PAO. This work presents the operation of an EBPR SBR system using crude glycerol as sole carbon source, studying also its long-term stability. The effect of LCFA is evaluated at short and long-term operation, demonstrating for the first time EBPR activity with LCFA as sole carbon source and its long-term failure due to the increased hydrophobicity of the sludge.

  5. Caffeic acid production enhancement by engineering a phenylalanine over-producing Escherichia coli strain.

    PubMed

    Huang, Qin; Lin, Yuheng; Yan, Yajun

    2013-12-01

    Caffeic acid is a plant-specific phenylpropanoic acid with multiple health-improving effects reported, and its therapeutic derivatives have also been studied throughout the last decade. To meet its market need and achieve high-level production, microbial production of caffeic acid approaches have been developed in metabolically engineered Escherichia coli. In our previous work, we have established the first artificial pathway that realized de novo production of caffeic acid using E. coli endogenous 4-hydroxyphenylacetate 3-hydroxylase (4HP3H). In this work, we exploited the catalytic potential of 4HPA3H in the whole-cell bioconversion study and produced 3.82 g/L (461.12 mg/L/OD) caffeic acid from p-coumaric acid, a direct precursor. We further engineered a phenylalanine over-producer into a tyrosine over-producer and then introduced the artificial pathway. After adjusting the expression strategy and optimizing the inoculants timing, de novo production of caffeic acid reached 766.68 mg/L. Both results from the direct precursor and simple carbon sources represent the highest titers of caffeic acid from microbial production so far.

  6. Enhanced antimicrobial activity of monoglyceride of 7,10-dihydroxy-8(E)-octadecenoic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Structural modification of lipids via chemical reaction or microbial bioconversion can change their properties or even create novel functionalities. Enzymatic oxidation of lipids can lead to formation of oxylipin such as hydroxy fatty acids. One of the multi-hydroxy fatty acids, 7,10-dihydroxy-8(E)-...

  7. Thermochemical pretreatments for enhancing succinic acid production from industrial hemp (Cannabis sativa L.).

    PubMed

    Gunnarsson, Ingólfur B; Kuglarz, Mariusz; Karakashev, Dimitar; Angelidaki, Irini

    2015-04-01

    The aim of this study was to develop an efficient thermochemical method for treatment of industrial hemp biomass, in order to increase its bioconversion to succinic acid. Industrial hemp was subjected to various thermochemical pretreatments using 0-3% H2SO4, NaOH or H2O2 at 121-180°C prior to enzymatic hydrolysis. The influence of the different pretreatments on hydrolysis and succinic acid production by Actinobacillus succinogenes 130Z was investigated in batch mode, using anaerobic bottles and bioreactors. Enzymatic hydrolysis and fermentation of hemp material pretreated with 3% H2O2 resulted in the highest overall sugar yield (73.5%), maximum succinic acid titer (21.9 g L(-1)), as well as the highest succinic acid yield (83%). Results obtained clearly demonstrated the impact of different pretreatments on the bioconversion efficiency of industrial hemp into succinic acid.

  8. Enhanced stereocomplex formation of poly(L-lactic acid) and poly(D-lactic acid) in the presence of stereoblock poly(lactic acid).

    PubMed

    Fukushima, Kazuki; Chang, Yoon-Hee; Kimura, Yoshiharu

    2007-06-01

    Stereoblock poly(lactic acid) (sb-PLA) is incorporated into a 1:1 polymer blend system of poly(L-lactic acid) (PLLA) and poly(D-lactic acid) (PDLA) that has a high molecular weight to study its addition effect on the stereocomplex (sc) formation of PLLA and PDLA. The ternary polymer blend films are first prepared by casting polymer solutions of sb-PLA, PLLA, and PDLA with different compositions. Upon increasing the content of sb-PLA in the blend films the sc crystallization is driven to a higher degree, while the formation of homo-chiral (hc) crystals is decreased. Lowering the molecular weight of the incorporated sb-PLA effectively increases the sc formation. Consequently, it is revealed that sb-PLA can work as a compatibilizer to improve the poor sc formation in the polymer blend of PLLA and PDLA. PMID:17541929

  9. Acid-cleavable ketal containing poly(β-amino ester) for enhanced siRNA delivery.

    PubMed

    Guk, Kyeonghye; Lim, Hyungsuk; Kim, Byungkuk; Hong, Minsung; Khang, Gilson; Lee, Dongwon

    2013-09-10

    The safe and effective intracellular delivery of nucleic acids remains the most challenging obstacle to the broad application of gene therapy in clinic. Endosomal escape of nucleic acids is also a major barrier for efficient gene delivery. Ketal linkage is known to readily cleave at the acidic pH of endosomal compartments. Here, we report ketal containing poly(β-amino ester) (KPAE) as an acid-cleavable non-viral siRNA delivery system. KPAE efficiently condensed siRNA into nanocomplexes with a diameter of ≈ 150 nm, which are stable under neutral conditions but rapidly dissociate to release siRNA at acidic pH. KPAE had a buffering capacity due to the presence of secondary amines in its backbone, confirmed by acid-base titration. Moreover, the studies of confocal fluorescence imaging using calcein and LysoTracker Red revealed that KPAE disrupted endosomes by colloid osmotic mechanism and "proton sponge" effects. Cell culture studies demonstrated that KPAE can deliver tumor necrosis factor-α (TNF-α) siRNA to lipopolysaccharide (LPS)-stimulated macrophages and significantly inhibit the expression of TNF-α. The results demonstrate that acid-cleavable KPAE has great potential as gene delivery systems based on its excellent biocompatibility, pH sensitivity and high gene delivery efficiency.

  10. Mechanism for enhanced degradation of clofibric acid in aqueous by catalytic ozonation over MnOx/SBA-15.

    PubMed

    Sun, Qiangqiang; Wang, Yu; Li, Laisheng; Bing, Jishuai; Wang, Yingxin; Yan, Huihua

    2015-04-01

    Comparative experiments were conducted to investigate the catalytic ability of MnO(x)/SBA-15 for the ozonation of clofibric acid (CA) and its reaction mechanism. Compared with ozonation alone, the degradation of CA was barely enhanced, while the removal of TOC was significantly improved by catalytic ozonation (O3/MnO(x)/SBA-15). Adsorption of CA and its intermediates by MnO(x)/SBA-15 was proved unimportant in O3/MnO(x)/SBA-15 due to the insignificant adsorption of CA and little TOC variation after ceasing ozone in stopped-flow experiment. The more remarkably inhibition effect of sodium bisulfite (NaHSO3) on the removal of TOC in catalytic ozonation than in ozonation alone elucidated that MnO(x)/SBA-15 facilitated the generation of hydroxyl radicals (OH), which was further verified by electron spin-resonance spectroscopy (ESR). Highly dispersed MnO(x) on SBA-15 were believed to be the main active component in MnO(x)/SBA-15. Some intermediates were indentified and different degradation routes of CA were proposed in both ozonation alone and catalytic ozonation. The amounts of small molecular carboxylic acids (i.e., formic acid (FA), acetic acid (AA) and oxalic acid (OA)) generated in catalytic ozonation were lower than in ozonation alone, resulting from the generation of more OH.

  11. Enhanced bio-decolorization of 1-amino-4-bromoanthraquinone-2-sulfonic acid by Sphingomonas xenophaga with nutrient amendment.

    PubMed

    Lu, Hong; Guan, Xiaofan; Wang, Jing; Zhou, Jiti; Zhang, Haikun

    2015-01-01

    Bacterial decolorization of anthraquinone dye intermediates is a slow process under aerobic conditions. To speed up the process, in the present study, effects of various nutrients on 1-amino-4-bromoanthraquinone-2-sulfonic acid (ABAS) decolorization by Sphingomonas xenophaga QYY were investigated. The results showed that peptone, yeast extract and casamino acid amendments promoted ABAS bio-decolorization. In particular, the addition of peptone and casamino acids could improve the decolorization activity of strain QYY. Further experiments showed that l-proline had a more significant accelerating effect on ABAS decolorization compared with other amino acids. l-Proline not only supported cell growth, but also significantly increased the decolorization activity of strain QYY. Membrane proteins of strain QYY exhibited ABAS decolorization activities in the presence of l-proline or reduced nicotinamide adenine dinucleotide, while this behavior was not observed in the presence of other amino acids. Moreover, the positive correlation between l-proline concentration and the decolorization activity of membrane proteins was observed, indicating that l-proline plays an important role in ABAS decolorization. The above findings provide us not only a novel insight into bacterial ABAS decolorization, but also an l-proline-supplemented bioaugmentation strategy for enhancing ABAS bio-decolorization.

  12. Synergistic transcriptional enhancement does not depend on the number of acidic activation domains bound to the promoter.

    PubMed Central

    Oliviero, S; Struhl, K

    1991-01-01

    Many eukaryotic transcriptional activator proteins contain a DNA-binding domain that interacts with specific promoter sequences and an acidic activation region that is required to stimulate transcription. Transcriptional enhancement by such activator proteins is often synergistic and promiscuous; promoters containing multiple binding sites for an individual protein or even for unrelated proteins can be 10-100 times more active than promoters with single sites. It has been suggested that such synergy reflects a nonlinear response of the basic transcription machinery to the number and/or quality of acidic activation regions. Here, we determine the transcriptional activity of Jun-Fos heterodimers containing one or two GCN4 acidic activation regions on promoters containing one or two Ap-1 target sites. Surprisingly, heterodimers with one or two acidic regions activate transcription with similar efficiency and are equally synergistic (10- to 15-fold) on promoters containing two target sites. Thus, transcriptional synergy does not depend on the number of acidic activation regions but rather on the number of proteins bound to the promoter. This suggests that synergy is mediated either by cooperative DNA binding or by alternative mechanisms in which the DNA-binding domain plays a more direct role in transcription (e.g., changes in DNA structure, nucleosome displacement, or direct interactions with the transcriptional machinery). Images PMID:1898773

  13. Enhanced biological phosphorus removal driven by short-chain fatty acids produced from waste activated sludge alkaline fermentation.

    PubMed

    Tong, Juan; Chen, Yinguang

    2007-10-15

    This paper examines the feasibility of using alkaline fermentative short-chain fatty acids (SCFAs) as the carbon sources of enhanced biological phosphorus removal (EBPR) microorganisms. First, the released phosphorus was recovered from the SCFA-containing alkaline fermentation liquid by the formation of struvite precipitation, and 92.8% of the soluble ortho-phosphorus (SOP) could be recovered under conditions of Mg/P = 1.8 (mol/mol), pH 10.0, and a reaction time of 2 min. One reason for a Mg addition required in this study that was higher than the theoretical value was thatthe organic compounds consumed Mg. Then, two sequencing batch reactors (SBRs) were operated, respectively, with acetic acid and alkaline fermentative SCFAs as the carbon source of EBPR. The transformations of SOP, polyhydroxyalkanoates (PHAs), and glycogen and the removal of phosphorus were compared between two SBRs. It was observed that the phosphorus removal efficiency was around 98% with the fermentative SCFAs, and about 71% with acetic acid, although the former showed much lower transformations of both PHAs and glycogen. The reasons that fermentative SCFAs caused much higher SOP removal than acetic acid were due to less PHAs used for glycogen synthesis and a higher PHA utilization efficiency for SOP uptake. Finally, the toxicity of fermentation liquid to EBPR microorganisms was examined, and no inhibitory effect was observed. It can be concluded from this studythatthe SCFAs from alkaline fermentation of waste activated sludge were a superior carbon source for EBPR microorganisms than pure acetic acid.

  14. Ascorbic acid supplementation enhances recovery from ethanol induced inhibition of Leydig cell steroidogenesis than abstention in male guinea pigs.

    PubMed

    Radhakrishnakartha, Harikrishnan; Appu, Abhilash Puthuvelvippel; Indira, Madambath

    2014-01-15

    The impact of ascorbic acid supplementation against ethanol induced Leydig cell toxicity was studied in guinea pigs. Male guinea pigs were exposed to ethanol (4g/kgb.wt.) for 90 days. After 90 days, ethanol administration was completely stopped and animals in the ethanol group were divided into abstention group and ascorbic acid supplemented group (25mg/100gb.wt.) and those in control group were maintained as control and control+ascorbic acid group. Ethanol administration reduced the serum testosterone and LH (luteinising hormone) levels and elevated estradiol levels. Cholesterol levels in Leydig cell were increased whereas the mRNA and protein expressions of StAR (steroidogenic acute regulatory) protein, cytochrome P450scc (cytochrome p450side chain cleavage enzyme), 3β-HSD (3β-hydroxysteroid dehydrogenase), 17β-HSD (17β-hydroxysteroid dehydrogenase) and LH receptor were drastically reduced. Administration of ascorbic acid resulted in alteration of all these parameters indicating enhanced recovery from ethanol induced inhibition of Leydig cell steroidogenesis. Although abstention could also reduce the inhibition of steroidogenesis, this was lesser in comparison with ascorbic acid supplemented group.

  15. Structural and dynamic changes associated with beneficial engineered single-amino-acid deletion mutations in enhanced green fluorescent protein

    SciTech Connect

    Arpino, James A. J.; Rizkallah, Pierre J.; Jones, D. Dafydd

    2014-08-01

    The beneficial engineered single-amino-acid deletion variants EGFP{sup D190Δ} and EGFP{sup A227Δ} have been studied. Single-amino-acid deletions are a common part of the natural evolutionary landscape but are rarely sampled during protein engineering owing to limited and prejudiced molecular understanding of mutations that shorten the protein backbone. Single-amino-acid deletion variants of enhanced green fluorescent protein (EGFP) have been identified by directed evolution with the beneficial effect of imparting increased cellular fluorescence. Biophysical characterization revealed that increased functional protein production and not changes to the fluorescence parameters was the mechanism that was likely to be responsible. The structure EGFP{sup D190Δ} containing a deletion within a loop revealed propagated changes only after the deleted residue. The structure of EGFP{sup A227Δ} revealed that a ‘flipping’ mechanism was used to adjust for residue deletion at the end of a β-strand, with amino acids C-terminal to the deletion site repositioning to take the place of the deleted amino acid. In both variants new networks of short-range and long-range interactions are generated while maintaining the integrity of the hydrophobic core. Both deletion variants also displayed significant local and long-range changes in dynamics, as evident by changes in B factors compared with EGFP. Rather than being detrimental, deletion mutations can introduce beneficial structural effects through altering core protein properties, folding and dynamics, as well as function.

  16. Silica Gel for Enhanced Activity and Hypochlorite Protection of Cyanuric Acid Hydrolase in Recombinant Escherichia coli

    PubMed Central

    Radian, Adi; Aukema, Kelly G.; Aksan, Alptekin

    2015-01-01

    ABSTRACT Chlorinated isocyanuric acids are widely used water disinfectants that generate hypochlorite, but with repeated application, they build up cyanuric acid (CYA) that must be removed to maintain disinfection. 3-Aminopropyltriethoxysilane (APTES)-treated Escherichia coli cells expressing cyanuric acid hydrolase (CAH) from Moorella thermoacetica exhibited significantly high CYA degradation rates and provided protection against enzyme inactivation by hypochlorite (chlorine). APTES coating or encapsulation of cells had two benefits: (i) overcoming diffusion limitations imposed by the cell wall and (ii) protecting against hypochlorite inactivation of CAH activity. Cells encapsulated in APTES gels degraded CYA three times faster than nonfunctionalized tetraethoxysilane (TEOS) gels, and cells coated with APTES degraded CYA at a rate of 29 µmol/min per mg of CAH protein, similar to the rate with purified enzyme. UV spectroscopy, fluorescence spectroscopy, and scanning electron microscopy showed that the higher rates were due to APTES increasing membrane permeability and enhancing cyanuric acid diffusion into the cytoplasm to reach the CAH enzyme. Purified CAH enzyme was shown to be rapidly inactivated by hypochlorite. APTES aggregates surrounding cells protected via the amine groups reacting with hypochlorite as shown by pH changes, zeta potential measurements, and infrared spectroscopy. APTES-encapsulated E. coli cells expressing CAH degraded cyanuric acid at high rates in the presence of 1 to 10 ppm hypochlorite, showing effectiveness under swimming pool conditions. In contrast, CAH activity in TEOS gels or free cells was completely inactivated by hypochlorite. These studies show that commercially available silica materials can selectively enhance, protect, and immobilize whole-cell biocatalysts for specialized applications. PMID:26530383

  17. Water-enhanced solubility of carboxylic acids in organic solvents and its application to extraction processes

    SciTech Connect

    Starr, J.N. ); King, C.J. )

    1992-11-01

    This paper reports on solubilities of carboxylic acids in certain organic solvents which increase sharply as the concentration of water in the solvent increases. This phenomenon leads to a method of regeneration for solvent-extraction processes whereby coextracted water is selectively removed from the extract, such as by stripping, thereby precipitating the acid. The removal of a minor constituent to cause precipitation reduces energy consumption, in contrast with bulk removal of solvent. Solubilities of fumaric acid were measured in a number of organic solvents, with varying amounts of water in the organic phase. Cyclohexanone and methylcyclohexanone were chosen as solvents for which detailed solid-liquid and liquid-liquid equilibria were measured for adipic, fumaric, and succinic acids in the presence of varying concentrations of water, at both 25 and 45[degrees]C. Batch precipitation experiments were performed to demonstrate the processing concept and determine the relative volatility of water to solvent in the presence of carbon.

  18. Amino acids assisted hydrothermal synthesis of hierarchically structured ZnO with enhanced photocatalytic activities

    NASA Astrophysics Data System (ADS)

    Guo, Yanxia; Lin, Siwen; Li, Xuan; Liu, Yuping

    2016-10-01

    Novel hierarchically structured ZnO, including rose-like, dandelion-like and flower-like, have been synthesized through a simple hydrothermal process using different amino acids (glutamine, histidine and glycine) as structure-directing agents and urea as deposition agent, followed by subsequent calcination. Amino acids played a crucial role in the formation of hierarchically structured ZnO, and different amino acids could induce different exquisite shapes and assembly ways, as well as more oxygen defects. The prepared hierarchically structured ZnO exhibited excellent photocatalytic activities for the photodegradation of Rhodamine B, which was associated with their special hierarchical structures, large BET surface area and the existence of more oxygen defects. Amino acid-assisted growth mechanism of hierarchically structured ZnO was also discussed.

  19. Enhanced bioconversion of ethylene glycol to glycolic acid by a newly isolated Burkholderia sp. EG13.

    PubMed

    Gao, Xiaoxin; Ma, Zhengfei; Yang, Limin; Ma, Jiangquan

    2014-10-01

    Burkholderia sp. EG13 with high ethylene glycol-oxidizing activity was isolated from soil, which could be used for the synthesis of glycolic acid from the oxidation of ethylene glycol. Using the resting cells of Burkholderia sp. EG13 as biocatalysts, the optimum reaction temperature and pH were 30 °C and 6.0, respectively. After 24 h of biotransformation, the yield of glycolic acid from 200 mM ethylene glycol was 98.8 %. Furthermore, an integrated bioprocess for the production of glycolic acid which involved in situ product removal (ISPR) was investigated. Using fed-batch method with ISPR, a total of 793 mM glycolic acid has been accumulated in the reaction mixture after the 4th feed.

  20. Enhancement of L(+)-Lactic Acid Production of Immobilized Rhizopus Oryzae Implanted by Ion Beams

    NASA Astrophysics Data System (ADS)

    Fan, Yonghong; Yang, Yingge; Zheng, Zhiming; Li, Wen; Wang, Peng; Yao, Liming; Yu, Zengliang

    2008-02-01

    Immobilized Rhizopus oryzae culturing may be a solution to the inhibited production of L(+)-lactic acid in submerged fermentation, which is caused by aggregated mycelia floc. In the present study, a R. oryzae mutant (RL6041) with a 90% conversion rate of glucose into L-lactic acid was obtained by N+ implantation under the optimized conditions of a beam energy of 15 keV and a dose of 2.6 × 1015 ions/cm2. Using polyurethane foam as the immobilization matrix, the optimal L-lactic acid production conditions were determined as 4 mm polyurethane foam, 150 r/min, 50 g/L ~ 80 g/L of initial glucose, 38°C and pH 6.0. 15-cycle repeated productions of L-lactic acid by immobilized RL6041 were performed under the optimized culturing conditions and over 80% of the glucose was converted into L-lactic acid in 30 hours on average. The results show that immobilized RL6041 is a promising candidate for continuous L-lactic acid production.

  1. Caproic acid grafted chitosan cationic nanocomplexes for enhanced gene delivery: effect of degree of substitution.

    PubMed

    Layek, Buddhadev; Singh, Jagdish

    2013-04-15

    This work was designed to investigate the effect of the degree of substitutions of caproic acid on plasmid DNA (pDNA) binding, cellular uptake, biocompatibility, and transfection efficiency of caproic acid grafted chitosan (CGC). The CGC with three substitution degrees (CGC-5, CGC-15, and CGC-25) were synthesized by coupling caproic acid with chitosan. Chemical characterization of graft polymers was performed using FTIR, NMR, and elemental analysis. The CGC polymers showed good pDNA condensing capacity and efficient protection of pDNA from DNase I. The nanosized CGC/pDNA polyplexes exhibited well-defined spherical shapes and stability in serum. Isothermal titration calorimetry demonstrated reduction in CGC-pDNA binding constant with increase in the degree of caproic acid substitution. Caproic acid substitution resulted in 2-7-fold higher cellular uptake in HEK 293 cells mainly via the clathrin-mediated pathway without affecting biocompatibility. In vitro transfection study suggested a dependence of transfection efficiency on the variability of caproic acid substitution. The CGC-15 polymer exhibited 31-fold and 1.33-fold higher gene expression compared to chitosan and the marketed non-viral vector FuGENEHD, respectively. These finding suggests that the CGC-15 graft polymer is a promising non-viral gene delivery vector due to its superior transfection efficiency and biocompatibility.

  2. Sebum Free Fatty Acids Enhance the Innate Immune Defense of Human Sebocytes by Upregulating β-Defensin-2 Expression

    PubMed Central

    Nakatsuji, Teruaki; Kao, Mandy C.; Zhang, Liangfang; Zouboulis, Christos C.; Gallo, Richard L; Huang, Chun-Ming

    2011-01-01

    Various sebum free fatty acids (FFAs) have shown antibacterial activity against a broad range of Gram-positive bacteria, resulting in the suggestion that they are accountable, at least partially, for the direct antimicrobial activity of the skin surface. In this study, we examined the effects of sebum FFAs on the antimicrobial peptide (AMP)-mediated innate immune defense of human sebocytes. Incubation of lauric acid, palmitic acid, or oleic acid (OA) with human sebocytes dramatically enhanced their expression of human β-defensin (hBD)-2, one of the predominant AMPs found in the skin, whereas remarkable increases in hBD-1, hBD-3, and human cathelicidin LL-37 were not observed. Secreted hBD-2 was detectable by western blotting in the supernatant of sebocyte culture incubated with each FFA, but not with a vehicle control. The supernatant of FFA-incubated sebocyte culture showed antimicrobial activity against Propionibacterium acnes, whereas the enhanced antimicrobial activity of human sebocytes was neutralized by anti-hBD-2 IgG. In addition, the FFA-induced hBD-2 expression was suppressed by blocking the cluster of differentiation (CD)36 fatty acid translocase on the surface of sebocytes with anti-human CD36 IgG or blocking the NF-κB signaling pathway with BMS-345541, a highly selective inhibitor of inhibitory κB kinase. These data suggest that sebum FFAs upregulate the expression of hBD-2 in human sebocytes, which may enhance the disinfecting activity of the human sebaceous gland. The FFA-induced upregulation of hBD-2 is facilitated by CD36-mediated FFA uptake and NF-κB-mediated transactivation. The upregulation of mouse β-defensin 4, a mouse ortholog for hBD-2, was also observed in the hair follicle sebaceous glands of mouse ear skin after an epicutaneous application of OA, the most hBD-2-inducible FFA tested. This report highlights the potential of using FFAs as a multifunctional antimicrobial therapy agent for acne vulgaris treatment; FFAs may provide direct

  3. TRIP6 Enhances Lysophosphatidic Acid-induced Cell Migration by Interacting with the Lysophosphatidic Acid 2 Receptor*

    PubMed Central

    Xu, Jun; Lai, Yun-Ju; Lin, Weei-Chin; Lin, Fang-Tsyr

    2014-01-01

    Lysophosphatidic acid (LPA) induces actin rearrangement, focal adhesion assembly, and cell migration through the activation of small G protein Rho and its downstream effectors. These diverse cellular responses are mediated by its associated G protein-coupled receptors. However, the mechanisms and specificity by which these LPA receptors mediate LPA actions are still poorly understood. Here we show that LPA stimulation promotes the interaction of the LPA2 receptor with a focal adhesion molecule, TRIP6 (thyroid receptor interacting protein 6)/ZRP-1 (zyxin-related protein 1). TRIP6 directly binds to the carboxyl-terminal tail of the LPA2 receptor through its LIM domains. LPA-dependent recruitment of TRIP6 to the plasma membrane promotes its targeting to focal adhesions and co-localization with actin stress fibers. In addition, TRIP6 associates with the components of focal complexes including paxillin, focal adhesion kinase, c-Src, and p130cas in an agonist-dependent manner. Overexpression of TRIP6 augments LPA-induced cell migration; in contrast, suppression of endogenous TRIP6 expression by a TRIP6-specific small interfering RNA reduces it in SKOV3 ovarian cancer cells. Strikingly, the association with TRIP6 is specific to the LPA2 receptor but not LPA1 or LPA3 receptor, indicating a specific role for TRIP6 in regulating LPA2 receptor-mediated signaling. Taken together, our results suggest that TRIP6 functions at a point of convergence between the activated LPA2 receptor and downstream signals involved in cell adhesion and migration. PMID:14688263

  4. Thyroid hormone responsive protein Spot14 enhances catalysis of fatty acid synthase in lactating mammary epithelium[S

    PubMed Central

    Rudolph, Michael C.; Wellberg, Elizabeth A.; Lewis, Andrew S.; Terrell, Kristina L.; Merz, Andrea L.; Maluf, N. Karl; Serkova, Natalie J.; Anderson, Steven M.

    2014-01-01

    Thyroid hormone responsive protein Spot 14 has been consistently associated with de novo fatty acid synthesis activity in multiple tissues, including the lactating mammary gland, which synthesizes large quantities of medium chain fatty acids (MCFAs) exclusively via FASN. However, the molecular function of Spot14 remains undefined during lactation. Spot14-null mice produce milk deficient in total triglyceride and de novo MCFA that does not sustain optimal neonatal growth. The lactation defect was rescued by provision of a high fat diet to the lactating dam. Transgenic mice overexpressing Spot14 in mammary epithelium produced total milk fat equivalent to controls, but with significantly greater MCFA. Spot14-null dams have no diminution of metabolic gene expression, enzyme protein levels, or intermediate metabolites that accounts for impaired de novo MCFA. When [13C] fatty acid products were quantified in vitro using crude cytosolic lysates, native FASN activity was 1.6-fold greater in control relative to Spot14-null lysates, and add back of Spot14 partially restored activity. Recombinant FASN catalysis increased 1.4-fold and C = 14:0 yield was enhanced 4-fold in vitro following addition of Spot14. These findings implicate Spot14 as a direct protein enhancer of FASN catalysis in the mammary gland during lactation when maximal MCFA production is needed. PMID:24771867

  5. Fatty Acid Synthase as a Factor Required for Exercise-Induced Cognitive Enhancement and Dentate Gyrus Cellular Proliferation

    PubMed Central

    Chorna, Nataliya E.; Santos-Soto, Iván J.; Carballeira, Nestor M.; Morales, Joan L.; de la Nuez, Janneliz; Cátala-Valentin, Alma; Chornyy, Anatoliy P.; Vázquez-Montes, Adrinel; De Ortiz, Sandra Peña

    2013-01-01

    Voluntary running is a robust inducer of adult hippocampal neurogenesis. Given that fatty acid synthase (FASN), the key enzyme for de novo fatty acid biosynthesis, is critically involved in proliferation of embryonic and adult neural stem cells, we hypothesized that FASN could mediate both exercise-induced cell proliferation in the subgranular zone (SGZ) of the dentate gyrus (DG) and enhancement of spatial learning and memory. In 20 week-old male mice, voluntary running-induced hippocampal-specific upregulation of FASN was accompanied also by hippocampal-specific accumulation of palmitate and stearate saturated fatty acids. In experiments addressing the functional role of FASN in our experimental model, chronic intracerebroventricular (i.c.v.) microinfusions of C75, an irreversible FASN inhibitor, and significantly impaired exercise-mediated improvements in spatial learning and memory in the Barnes maze. Unlike the vehicle-injected mice, the C75 group adopted a non-spatial serial escape strategy and displayed delayed escape latencies during acquisition and memory tests. Furthermore, pharmacologic blockade of FASN function with C75 resulted in a significant reduction, compared to vehicle treated controls, of the number of proliferative cells in the DG of running mice as measured by immunoreactive to Ki-67 in the SGZ. Taken together, our data suggest that FASN plays an important role in exercise-mediated cognitive enhancement, which might be associated to its role in modulating exercise-induced stimulation of neurogenesis. PMID:24223732

  6. Fatty acid synthase as a factor required for exercise-induced cognitive enhancement and dentate gyrus cellular proliferation.

    PubMed

    Chorna, Nataliya E; Santos-Soto, Iván J; Carballeira, Nestor M; Morales, Joan L; de la Nuez, Janneliz; Cátala-Valentin, Alma; Chornyy, Anatoliy P; Vázquez-Montes, Adrinel; De Ortiz, Sandra Peña

    2013-01-01

    Voluntary running is a robust inducer of adult hippocampal neurogenesis. Given that fatty acid synthase (FASN), the key enzyme for de novo fatty acid biosynthesis, is critically involved in proliferation of embryonic and adult neural stem cells, we hypothesized that FASN could mediate both exercise-induced cell proliferation in the subgranular zone (SGZ) of the dentate gyrus (DG) and enhancement of spatial learning and memory. In 20 week-old male mice, voluntary running-induced hippocampal-specific upregulation of FASN was accompanied also by hippocampal-specific accumulation of palmitate and stearate saturated fatty acids. In experiments addressing the functional role of FASN in our experimental model, chronic intracerebroventricular (i.c.v.) microinfusions of C75, an irreversible FASN inhibitor, and significantly impaired exercise-mediated improvements in spatial learning and memory in the Barnes maze. Unlike the vehicle-injected mice, the C75 group adopted a non-spatial serial escape strategy and displayed delayed escape latencies during acquisition and memory tests. Furthermore, pharmacologic blockade of FASN function with C75 resulted in a significant reduction, compared to vehicle treated controls, of the number of proliferative cells in the DG of running mice as measured by immunoreactive to Ki-67 in the SGZ. Taken together, our data suggest that FASN plays an important role in exercise-mediated cognitive enhancement, which might be associated to its role in modulating exercise-induced stimulation of neurogenesis.

  7. Comparison of hot hydroxylamine hydrochloride and oxalic acid leaching of stream sediment and coated rock samples as anomaly enhancement techniques

    USGS Publications Warehouse

    Filipek, L.H.; Chao, T.T.; Theobald, P.K.

    1982-01-01

    A hot hydroxylamine hydrochloride (H-Hxl) extraction in 25% acetic acid is compared with the commonly used oxalic acid extraction as a method of anomaly enhancement for Cu and Zn in samples from two very different metal deposits and climatic environments. Results obtained on minus-80-mesh stream sediments from an area near the Magruder massive sulfide deposit in Lincoln County, Georgia, where the climate is humid subtropical, indicate that H-Hxl enhances the anomaly for Cu by a factor of 2 and for Zn by a factor of 1.5, compared to the oxalic method. Analyses of Fe oxide-coated rock samples from outcrops overlying the North Silver Bell porphyry copper deposit near Tucson, Arizona, where the climate is semi-arid to arid, indicate that both techniques effectively outline the zones of hydrothermal alteration. The H-Hxl extraction can also perform well in high-carbonate or high-clay environments, where other workers have suggested that oxalic acid is not very effective. Therefore, the H-Hxl method is recommended for general exploration use. ?? 1982.

  8. Surface functionalization of titanium substrates with chitosan-lauric acid conjugate to enhance osteoblasts functions and inhibit bacteria adhesion.

    PubMed

    Zhao, Lu; Hu, Yan; Xu, Dawei; Cai, Kaiyong

    2014-07-01

    Orthopedic implants failures are generally related to poor osseointegration and/or bacterial infection in clinical application. Surface functionalization of an implant is one promising alternative for enhancing osseointegration and/or reducing bacterial infection, thus ensuring the long term survival of the implant. In this study, titanium (Ti) substrates were surface functionalized with a polydopamine (PDOP) film as an intermediate layer for post-immobilization of chitosan-lauric acid (Chi-LA) conjugate. Chi-LA conjugate was synthesized and characterized by Fourier transform infrared spectroscopy (FTIR) and hydrogen proton nuclear magnetic resonance (NMR) spectrometer, respectively. Lauric acid (LA), a natural saturated fatty acid, was used mainly due to its good antibacterial property. Scanning electron microscopy (SEM) and water contact angle measurements were employed to detect the morphology changes and surface wettability of Ti substrates. The results suggested that Chi-LA conjugate was successfully immobilized onto the surfaces of Ti substrates. In vitro tests confirmed that the cell adhesion, cell viability, intracellular alkaline phosphatase activity and mineralization capacity of osteoblasts were remarkably improved when cultured onto Chi-LA surface functionalized Ti substrates. Antibacterial assay against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) showed that the Chi-LA modified Ti substrates efficiently inhibited the adhesion and growth of bacteria. Overall, this study developed a promising approach to fabricate functional Ti-based orthopedic implants, which could enhance the biological functions of osteoblasts and concurrently reduce bacteria adhesion. PMID:24880988

  9. Promoting extracellular matrix remodeling via ascorbic acid enhances the survival of primary ovarian follicles encapsulated in alginate hydrogels.

    PubMed

    Tagler, David; Makanji, Yogeshwar; Tu, Tao; Bernabé, Beatriz Peñalver; Lee, Raymond; Zhu, Jie; Kniazeva, Ekaterina; Hornick, Jessica E; Woodruff, Teresa K; Shea, Lonnie D

    2014-07-01

    The in vitro growth of ovarian follicles is an emerging technology for fertility preservation. Various strategies support the culture of secondary and multilayer follicles from various species including mice, non-human primate, and human; however, the culture of early stage (primary and primordial) follicles, which are more abundant in the ovary and survive cryopreservation, has been limited. Hydrogel-encapsulating follicle culture systems that employed feeder cells, such as mouse embryonic fibroblasts (MEFs), stimulated the growth of primary follicles (70-80 µm); yet, survival was low and smaller follicles (<70 µm) rapidly lost structure and degenerated. These morphologic changes were associated with a breakdown of the follicular basement membrane; hence, this study investigated ascorbic acid based on its role in extracellular matrix (ECM) deposition/remodeling for other applications. The selection of ascorbic acid was further supported by a microarray analysis that suggested a decrease in mRNA levels of enzymes within the ascorbate pathway between primordial, primary, and secondary follicles. The supplementation of ascorbic acid (50 µg/mL) significantly enhanced the survival of primary follicles (<80 µm) cultured in alginate hydrogels, which coincided with improved structural integrity. Follicles developed antral cavities and increased to diameters exceeding 250 µm. Consistent with improved structural integrity, the gene/protein expression of ECM and cell adhesion molecules was significantly changed. This research supports the notion that modifying the culture environment (medium components) can substantially enhance the survival and growth of early stage follicles.

  10. Enhanced Bio-hydrogen Production from Protein Wastewater by Altering Protein Structure and Amino Acids Acidification Type

    NASA Astrophysics Data System (ADS)

    Xiao, Naidong; Chen, Yinguang; Chen, Aihui; Feng, Leiyu

    2014-02-01

    Enhanced bio-hydrogen production from protein wastewater by altering protein structure and amino acids acidification type via pH control was investigated. The hydrogen production reached 205.2 mL/g-protein when protein wastewater was pretreated at pH 12 and then fermented at pH 10. The mechanism studies showed that pH 12 pretreatment significantly enhanced protein bio-hydrolysis during the subsequent fermentation stage as it caused the unfolding of protein, damaged the protein hydrogen bonding networks, and destroyed the disulfide bridges, which increased the susceptibility of protein to protease. Moreover, pH 10 fermentation produced more acetic but less propionic acid during the anaerobic fermentation of amino acids, which was consistent with the theory of fermentation type affecting hydrogen production. Further analyses of the critical enzymes, genes, and microorganisms indicated that the activity and abundance of hydrogen producing bacteria in the pH 10 fermentation reactor were greater than those in the control.

  11. Citric acid enhances the phytoextraction of manganese and plant growth by alleviating the ultrastructural damages in Juncus effusus L.

    PubMed

    Najeeb, U; Xu, L; Ali, Shafaqat; Jilani, Ghulam; Gong, H J; Shen, W Q; Zhou, W J

    2009-10-30

    Chelate-assisted phytoextraction by high biomass producing plant species enhances the removal of heavy metals from polluted environments. In this regard, Juncus effusus a wetland plant has great potential. This study evaluated the effects of elevated levels of manganese (Mn) on the vegetative growth, Mn uptake and antioxidant enzymes in J. effusus. We also studied the role of citric acid and EDTA on improving metal accumulation, plant growth and Mn toxicity stress alleviation. Three-week-old plantlets of J. effusus were subjected to various treatments in the hydroponics as: Mn (50, 100 and 500 microM) alone, Mn (500 microM) + citric acid (5 mM), and Mn (500 microM) + EDTA (5 mM). After 2 weeks of treatment, higher Mn concentrations significantly reduced the plant biomass and height. Both citric acid and EDTA restored the plant height as it was reduced at the highest Mn level. Only the citric acid (but not EDTA) was able to recover the plant biomass weight, which was also obvious from the microscopic visualization of mesophyll cells. There was a concentration dependent increase in Mn uptake in J. effusus plants, and relatively more deposition in roots compared to aerial parts. Although both EDTA and citric acid caused significant increase in Mn accumulation; however, the Mn translocation was enhanced markedly by EDTA. Elevated levels of Mn augmented the oxidative stress, which was evident from changes in the activities of antioxidative enzymes in plant shoots. Raised levels of lipid peroxidation and variable changes in the activities of antioxidant enzymes were recorded under Mn stress. Electron microscopic images revealed several modifications in the plants at cellular and sub-cellular level due to the oxidative damage induced by Mn. Changes in cell shape and size, chloroplast swelling, increased number of plastoglobuli and disruption of thylakoid were noticed. However, these plants showed a high degree of tolerance against Mn toxicity stress, and it removed

  12. Use of bacterial extracts to enhance amino acid breakdown in dry fermented sausages.

    PubMed

    Herranz, B; Fernández, M; de la Hoz, L; Ordóñez, J A

    2006-02-01

    The effect of the intracellular cell-free extracts (ICFEs) of two bacterial strains (Lactobacillus sakei GO and Bacillus pumilus) on the amino acid catabolism and the sensory properties of dry fermented sausages, was investigated. Extracts were added to sausages alone or in combination with a protease, papain. Amino acid breakdown was monitored by the changes in free amino acids, ammonia and amine content during the ripening process. A 15% decrease in the content of free amino acids was observed in sausages added with the ICFE from L. sakei GO. Furthermore, the extract of L. sakei GO significantly reduced (54-68%) the content of the amino acids considered as precursors of the typical ripened flavour, i.e., valine, leucine and isoleucine. Chemical changes were not reflected in a significant improvement of the sensory quality of sausages added with the ICFEs. The potential use of the bacterial ICFEs studied in the present work for the manufacture of dry fermented sausages, and its comparison with the use of fungal extracts, are discussed. PMID:22061560

  13. Enhancing the catalytic repertoire of nucleic acids: a systematic study of linker length and rigidity

    PubMed Central

    Lee, Sarah E.; Sidorov, Alexander; Gourlain, Thierry; Mignet, Nathalie; Thorpe, Simon J.; Brazier, John A.; Dickman, Mark J.; Hornby, David P.; Grasby, Jane A.; Williams, David M.

    2001-01-01

    The incorporation of potentially catalytic groups in DNA is of interest for the in vitro selection of novel deoxyribozymes. A series of 10 C5-modified analogues of 2′-deoxyuridine triphosphate have been synthesised that possess side chains of differing flexibility and bearing a primary amino or imidazole functionality. For each series of nucleotide analogues differing degrees of flexibility of the C5 side chain was achieved through the use of alkynyl, alkenyl and alkyl moieties. The imidazole function was conjugated to these C5-amino-modified nucleotides using either imidazole 4-acetic acid or imidazole 4-acrylic acid (urocanic acid). The substrate properties of the nucleotides (fully replacing dTTP) with Taq polymerase during PCR have been investigated in order to evaluate their potential applications for in vitro selection experiments. 5-(3-Aminopropynyl)dUTP and 5-(E-3-aminopropenyl)dUTP and their imidazole 4-acetic acid- and urocanic acid-modified conjugates were found to be substrates. In contrast, C5-amino-modified dUTPs with alkane or Z-alkene linkers and their corresponding conjugates were not substrates. The incorporation of these analogues during PCR has been confirmed by inhibition of restriction enzyme digestion using XbaI and by mass spectrometry of the PCR products. PMID:11266559

  14. Comparative proteomic analysis of engineered Saccharomyces cerevisiae with enhanced free fatty acid accumulation.

    PubMed

    Chen, Liwei; Lee, Jaslyn Jie Lin; Zhang, Jianhua; Chen, Wei Ning

    2016-02-01

    The engineered Saccharomyces cerevisiae strain △faa1△faa4 [Acot5s] was demonstrated to accumulate more free fatty acids (FFA) previously. Here, comparative proteomic analysis was performed to get a global overview of metabolic regulation in the strain. Over 500 proteins were identified, and 82 of those proteins were found to change significantly in the engineered strains. Proteins involved in glycolysis, acetate metabolism, fatty acid synthesis, TCA cycle, glyoxylate cycle, the pentose phosphate pathway, respiration, transportation, and stress response were found to be upregulated in △faa1△faa4 [Acot5s] as compared to the wild type. On the other hand, proteins involved in glycerol, ethanol, ergosterol, and cell wall synthesis were downregulated. Taken together with our metabolite analysis, our results showed that the disruption of Faa1 and Faa4 and expression of Acot5s in the engineered strain △faa1△faa4 [Acot5s] not only relieved the feedback inhibition of fatty acyl-CoAs on fatty acid synthesis, but also caused a major metabolic rearrangement. The rearrangement redirected carbon flux toward the pathways which generate the essential substrates and cofactors for fatty acid synthesis, such as acetyl-CoA, ATP, and NADPH. Therefore, our results help shed light on the mechanism for the increased production of fatty acids in the engineered strains, which is useful in providing information for future studies in biofuel production.

  15. Selectivity enhancement of Arsenazo(III) reagent towards heavier lanthanides using polyaminocarboxylic acids: A spectrophotometric study

    NASA Astrophysics Data System (ADS)

    Matharu, Komal; Mittal, Susheel K.; Ashok Kumar, S. K.; Sahoo, Suban K.

    2015-06-01

    A new study has been conducted to quantify lanthanide(III) ions using Arsenazo III-polyaminocarboxylic acid (PACA) system. The study disclosed two different analytically important information: (i) λmax of lanthanide-Arsenazo III complexes for lighter lanthanides like Ce(III) and Nd(III) did not shift from its original position on addition of PACA and (ii) for heavier lanthanides like Dy(III), Tm(III) and Lu(III) a new λmax at 538 nm was observed, while wavelengths at 610 nm and 654 nm were disappeared in presence of ethylenediaminetertracetic acid (EDTA) and trans-1,2-Diaminocyclohexane-N,N,N‧,N‧-tetraacetic acid (DCTA), further the intensity of peak decreased with increase in lanthanide(III) ion concentration. Effect of ethylene glycol-bis(2-aminoethylether)-N,N,N‧,N‧-tetraacetic acid (EGTA) and N-(2-hydroxyethyl) ethylenediamine-N,N‧,N‧-triacetic acid (EDTA-OH) on Arsenzo(III)-Ln(III) complex is very weak and there is no analytically importance of such interaction. Moreover, this work confirms that Nd(III) and heavy lanthanides can be successfully determined with high accuracy in the working range of concentration of these metal ions.

  16. Enhancing aptamer function and stability via in vitro selection using modified nucleic acids.

    PubMed

    Meek, Kirsten N; Rangel, Alexandra E; Heemstra, Jennifer M

    2016-08-15

    Nucleic acid aptamers have emerged as a promising alternative to antibodies for use as recognition elements in therapeutics, bioimaging, and analytical applications. A key benefit that aptamers possess relative to antibodies is their ability to be chemically synthesized. This advantage, coupled with the broad range of modified nucleotide building blocks that can be constructed using chemical synthesis, has enabled the discovery and development of modified aptamers having extraordinary affinity, specificity, and biostability. Early efforts to generate modified aptamers focused on selection of a native DNA or RNA aptamer, followed by post-selection trial-and-error testing of modifications. However, recent advances in polymerase engineering and templated nucleic acid synthesis have enabled the direct selection of aptamers having modified backbones and nucleobases. This review will discuss these technological advances and highlight the improvements in aptamer function that have been realized through in vitro selection of non-natural nucleic acids.

  17. Enhancing aptamer function and stability via in vitro selection using modified nucleic acids.

    PubMed

    Meek, Kirsten N; Rangel, Alexandra E; Heemstra, Jennifer M

    2016-08-15

    Nucleic acid aptamers have emerged as a promising alternative to antibodies for use as recognition elements in therapeutics, bioimaging, and analytical applications. A key benefit that aptamers possess relative to antibodies is their ability to be chemically synthesized. This advantage, coupled with the broad range of modified nucleotide building blocks that can be constructed using chemical synthesis, has enabled the discovery and development of modified aptamers having extraordinary affinity, specificity, and biostability. Early efforts to generate modified aptamers focused on selection of a native DNA or RNA aptamer, followed by post-selection trial-and-error testing of modifications. However, recent advances in polymerase engineering and templated nucleic acid synthesis have enabled the direct selection of aptamers having modified backbones and nucleobases. This review will discuss these technological advances and highlight the improvements in aptamer function that have been realized through in vitro selection of non-natural nucleic acids. PMID:27012179

  18. Economically enhanced succinic acid fermentation from cassava bagasse hydrolysate using Corynebacterium glutamicum immobilized in porous polyurethane filler.

    PubMed

    Shi, Xinchi; Chen, Yong; Ren, Hengfei; Liu, Dong; Zhao, Ting; Zhao, Nan; Ying, Hanjie

    2014-12-01

    An immobilized fermentation system, using cassava bagasse hydrolysate (CBH) and mixed alkalis, was developed to achieve economical succinic acid production by Corynebacterium glutamicum. The C. glutamicum strains were immobilized in porous polyurethane filler (PPF). CBH was used efficiently as a carbon source instead of more expensive glucose. Moreover, as a novel method for regulating pH, the easily decomposing NaHCO3 was replaced by mixed alkalis (NaOH and Mg(OH)2) for succinic acid production by C. glutamicum. Using CBH and mixed alkalis in the immobilized batch fermentation system, succinic acid productivity of 0.42gL(-1)h(-1) was obtained from 35gL(-1) glucose of CBH, which is similar to that obtained with conventional free-cell fermentation with glucose and NaHCO3. In repeated batch fermentation, an average of 22.5gL(-1) succinic acid could be obtained from each batch, which demonstrated the enhanced stability of the immobilized C. glutamicum cells.

  19. Effective Enhancement of Hypoglycemic Effect of Insulin by Liver-Targeted Nanoparticles Containing Cholic Acid-Modified Chitosan Derivative.

    PubMed

    Zhang, Zhe; Cai, Huanxin; Liu, Zhijia; Yao, Ping

    2016-07-01

    Liver is responsible for the balance of blood glucose level. In this study, cholic acid and N-(2-hydroxy)-propyl-3-trimethylammonium chloride modified chitosan (HTCC-CA) was used as a liver-targeted vehicle for insulin delivery. A novel approach was developed to effectively load insulin by mixing insulin and HTCC-CA in 50% ethanol and water mixed solvent at pH 2 and then dialysis against pH 7.4 phosphate buffer subsequently against water. The insulin-loaded HTCC-CA nanoparticles have an average diameter of 86 nm and insulin loading efficiency of 98.7%. Due to random distribution of the hydrophobic cholic acid groups in HTCC-CA, some of the cholic acid groups located on the nanoparticle surface. Compared with free insulin, the nanoparticles increased in vitro cellular uptake of insulin to 466%, and the nanoparticles accumulated in liver for more time after subcutaneous injection into mice. The therapy for diabetic rats displayed that the nanoparticles increased the pharmacological bioavailability of insulin to 475% relative to free insulin, and the nanoparticles could maintain the hypoglycemic effect for more than 24 h. This study demonstrates that the nanoparticles with cholic acid groups on their surface possess liver-targeted property and biocompatible insulin-loaded HTCC-CA nanoparticles can effectively enhance the hypoglycemic effect of insulin. PMID:27266268

  20. Enhanced Photocatalytic Performance of ZnS for Reversible Amination of α-oxo Acids by Hydrothermal Treatment

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Li, Qiliang; Liu, Xiaoyang; Yang, Yanqiang; Su, Wenhui

    2012-08-01

    To understand how life could have originated on early Earth, it is essential to know what biomolecules and metabolic pathways are shared by extant organisms and what organic compounds and their chemical reaction channels were likely to have been primordially available during the initial phase of the formation of prebiotic metabolism. In a previous study, we demonstrated for the first time the reversible amination of α-oxo acids on the surface of photo-illuminated ZnS. The sulfide mineral is a typical component at the periphery of submarine hydrothermal vents which has been frequently argued as a very attractive venue for the origin of life. In this work, in order to simulate more closely the precipitation environments of ZnS in the vent systems, we treated newly-precipitated ZnS with hydrothermal conditions and found that its photocatalytic power was significantly enhanced because the relative crystallinity of the treated sample was markedly increased with increasing temperature. Since the reported experimental conditions are believed to have been prevalent in shallow-water hydrothermal vents of early Earth and the reversible amination of α-oxo acids is a key metabolic pathway in all extant life forms, the results of this work provide a prototypical model of the prebiotic amino acid redox metabolism. The amino acid dehydrogenase-like chemistry on photo-irradiated ZnS surfaces may advance our understanding of the establishment of archaic non-enzymatic metabolic systems.

  1. Al-Fe interactions and growth enhancement in Melastoma malabathricum and Miscanthus sinensis dominating acid sulphate soils.

    PubMed

    Watanabe, Toshihiro; Jansen, Steven; Osaki, Mitsuru

    2006-12-01

    Plants growing in acid sulphate soils are subject to high levels of Al availability, which may have effects on the growth and distribution of these species. Although Fe availability is also high in acid sulphate soils, little is known about the effect of Fe on the growth of native plants in these soils. Two species dominating this soil type in Asia, viz. Melastoma malabathricum and Miscanthus sinensis were grown hydroponically in a nutrient solution with different concentrations of Al and Fe. Melastoma malabathricum is found to be sensitive to Fe (40 and 100 microm). Application of 500 microm Al, however, completely ameliorates Fe toxicity and is associated with a decrease of Fe concentration in shoots and roots. The primary reason for the Al-induced growth enhancement of M. malabathricum is considered to be the Al-induced reduction of toxic Fe accumulation in roots and shoots. Therefore, Al is nearly essential for M. malabathricum when growing in acid sulphate soils. In contrast, application of both Fe and Al does not reduce the growth of M. sinensis, and Al application does not result in lower shoot concentrations of Fe, suggesting that this grass species has developed different mechanisms for adaptation to acid sulphate soils. PMID:17081246

  2. Enhanced photocatalytic performance of ZnS for reversible amination of α-oxo acids by hydrothermal treatment.

    PubMed

    Wang, Wei; Li, Qiliang; Liu, Xiaoyang; Yang, Yanqiang; Su, Wenhui

    2012-08-01

    To understand how life could have originated on early Earth, it is essential to know what biomolecules and metabolic pathways are shared by extant organisms and what organic compounds and their chemical reaction channels were likely to have been primordially available during the initial phase of the formation of prebiotic metabolism. In a previous study, we demonstrated for the first time the reversible amination of α-oxo acids on the surface of photo-illuminated ZnS. The sulfide mineral is a typical component at the periphery of submarine hydrothermal vents which has been frequently argued as a very attractive venue for the origin of life. In this work, in order to simulate more closely the precipitation environments of ZnS in the vent systems, we treated newly-precipitated ZnS with hydrothermal conditions and found that its photocatalytic power was significantly enhanced because the relative crystallinity of the treated sample was markedly increased with increasing temperature. Since the reported experimental conditions are believed to have been prevalent in shallow-water hydrothermal vents of early Earth and the reversible amination of α-oxo acids is a key metabolic pathway in all extant life forms, the results of this work provide a prototypical model of the prebiotic amino acid redox metabolism. The amino acid dehydrogenase-like chemistry on photo-irradiated ZnS surfaces may advance our understanding of the establishment of archaic non-enzymatic metabolic systems.

  3. Al-Fe interactions and growth enhancement in Melastoma malabathricum and Miscanthus sinensis dominating acid sulphate soils.

    PubMed

    Watanabe, Toshihiro; Jansen, Steven; Osaki, Mitsuru

    2006-12-01

    Plants growing in acid sulphate soils are subject to high levels of Al availability, which may have effects on the growth and distribution of these species. Although Fe availability is also high in acid sulphate soils, little is known about the effect of Fe on the growth of native plants in these soils. Two species dominating this soil type in Asia, viz. Melastoma malabathricum and Miscanthus sinensis were grown hydroponically in a nutrient solution with different concentrations of Al and Fe. Melastoma malabathricum is found to be sensitive to Fe (40 and 100 microm). Application of 500 microm Al, however, completely ameliorates Fe toxicity and is associated with a decrease of Fe concentration in shoots and roots. The primary reason for the Al-induced growth enhancement of M. malabathricum is considered to be the Al-induced reduction of toxic Fe accumulation in roots and shoots. Therefore, Al is nearly essential for M. malabathricum when growing in acid sulphate soils. In contrast, application of both Fe and Al does not reduce the growth of M. sinensis, and Al application does not result in lower shoot concentrations of Fe, suggesting that this grass species has developed different mechanisms for adaptation to acid sulphate soils.

  4. Estrogen Enhances the Expression of the Polyunsaturated Fatty Acid Elongase Elovl2 via ERα in Breast Cancer Cells

    PubMed Central

    González-Bengtsson, Amanda; Asadi, Abolfazl; Gao, Hui; Dahlman-Wright, Karin

    2016-01-01

    Endocrine therapy is the first-line targeted adjuvant therapy for hormone-sensitive breast cancer. In view of the potential anticancer property of the omega-3 polyunsaturated fatty acid docosahexaenoic acid (DHA) together with chemotherapy in estrogen receptor alpha (ERα) positive mammary tumors, we have explored the regulation by estradiol of the fatty acid desaturation and elongation enzymes involved in DHA synthesis in the human breast cancer cell line MCF7, which expresses ERα but not ERβ. We demonstrate a robust up-regulation in the expression of the fatty acid elongases Elovl2 and Elovl5 upon estradiol stimulation in MCF7 cells, which was sustained for more than 24 hours. Exposure with the ER inhibitor tamoxifen abolished specifically the Elovl2 but not the Elovl5 expression. Similarly, knock-down of ERα eliminated almost fully the Elovl2 but not the Elovl5 expression. Furthermore, ERα binds to one specific ERE within the Elovl2 enhancer in a ligand dependent manner. The involvement of ERα in the control of especially Elovl2, which plays a crucial role in DHA synthesis, may have potential implications in the treatment of breast cancer. PMID:27788154

  5. Lignin extraction distinctively enhances biomass enzymatic saccharification in hemicelluloses-rich Miscanthus species under various alkali and acid pretreatments.

    PubMed

    Si, Shengli; Chen, Yan; Fan, Chunfen; Hu, Huizhen; Li, Ying; Huang, Jiangfeng; Liao, Haofeng; Hao, Bo; Li, Qing; Peng, Liangcai; Tu, Yuanyuan

    2015-05-01

    In this study, one- and two-step pretreatments with alkali and acid were performed in the three Miscanthus species that exhibit distinct hemicelluloses levels. As a result, one-step with 4% NaOH or two-step with 2% NaOH and 1% H2SO4 was examined to be optimal for high biomass saccharification, indicating that alkali was the main effecter of pretreatments. Notably, both one- and two-step pretreatments largely enhanced biomass digestibility distinctive in hemicelluloses-rich samples by effectively co-extracting hemicelluloses and lignin. However, correlation analysis further indicated that the effective lignin extraction, other than the hemicelluloses removals, predominately determined biomass saccharification under various alkali and acid pretreatments, leading to a significant alteration of cellulose crystallinity. Hence, this study has suggested the potential approaches in bioenergy crop breeding and biomass process technology.

  6. Novel hydrogels of chitosan and poly(vinyl alcohol)-g-glycolic acid copolymer with enhanced rheological properties.

    PubMed

    Lejardi, A; Hernández, R; Criado, M; Santos, Jose I; Etxeberria, A; Sarasua, J R; Mijangos, C

    2014-03-15

    Poly(vinyl alcohol) (PVA) has been grafted with glycolic acid (GL), a biodegradable hydroxyl acid to yield modified poly(vinyl alcohol) (PVAGL). The formation of hydrogels at pH = 6.8 and physiological temperature through blending chitosan (CS) and PVAGL at different concentrations has been investigated. FTIR, DOSY NMR and oscillatory rheology measurements have been carried out on CS/PVAGL hydrogels and the results have been compared to those obtained for CS/PVA hydrogels prepared under the same conditions. The experimental results point to an increase in the number of interactions between chitosan and PVAGL in polymer hydrogels prepared with modified PVA. The resulting materials with enhanced elastic properties and thixotropic behavior are potential candidates to be employed as injectable materials for biomedical applications.

  7. Beneficial effects of folic acid on enhancement of memory and antioxidant status in aged rat brain.

    PubMed

    Singh, Rashmi; Kanwar, Shalinder S; Sood, Pooja K; Nehru, Bimla

    2011-01-01

    As our population ages, diseases affecting memory and daily functioning will affect an increasing number of individuals, their families and the healthcare system. Therefore, there is a need to study and evaluate effects of certain conditions for anti-aging of the brain. Nutrient supplementation can modify the brain function. The chemistry and function of both the developing and the mature brain are influenced by diet (Fernstrom, Am J Clinical Nutrition 71:1669S-1673S, 2000). Clinical, biochemical, and pathological aspects have shown a correlation between mental symptoms, especially depression and cognitive decline, with high incidence of folate deficiency (Bottiglieri et al., J Neurol Neurosurg Psychiatry 69:562, 2000). In the present study, consequences of folic acid supplementation on brain dysfunction as a result of aging were studied in cerebral cortex, mid brain, and cerebellar regions of rat brain. This study was carried out on 6-, 11-, and 16-month-old rats, which received folic acid at a dose of 5 mg/kg body weight/day for a period of 8 weeks. Respective control groups of the same age groups were also taken. At the end of the treatment duration, behavioral studies were performed and later the animals were killed for various biochemical and histological investigations. Results indicated significant improvement in memory as assessed by active avoidance, passive avoidance, and plus maze tests in the folic acid supplemented aged animals. Significant improvement was also seen in the cellular protective mechanisms where by the activity of superoxide dismutase and catalase enzymes increased in folic acid supplemented group and so was the glutathione content. Increased lipid peroxidation content, a marker of aging, was also found to be decreased during folic acid supplementation in all the three regions of brain in our study. Thus, it can be concluded that folic acid helps in improving the memory status by reducing oxidative stress and maintaining the integrity of

  8. Inhibition of Fatty Acid Oxidation Modulates Immunosuppressive Functions of Myeloid-Derived Suppressor Cells and Enhances Cancer Therapies.

    PubMed

    Hossain, Fokhrul; Al-Khami, Amir A; Wyczechowska, Dorota; Hernandez, Claudia; Zheng, Liqin; Reiss, Krzystoff; Valle, Luis Del; Trillo-Tinoco, Jimena; Maj, Tomasz; Zou, Weiping; Rodriguez, Paulo C; Ochoa, Augusto C

    2015-11-01

    Myeloid-derived suppressor cells (MDSC) promote tumor growth by inhibiting T-cell immunity and promoting malignant cell proliferation and migration. The therapeutic potential of blocking MDSC in tumors has been limited by their heterogeneity, plasticity, and resistance to various chemotherapy agents. Recent studies have highlighted the role of energy metabolic pathways in the differentiation and function of immune cells; however, the metabolic characteristics regulating MDSC remain unclear. We aimed to determine the energy metabolic pathway(s) used by MDSC, establish its impact on their immunosuppressive function, and test whether its inhibition blocks MDSC and enhances antitumor therapies. Using several murine tumor models, we found that tumor-infiltrating MDSC (T-MDSC) increased fatty acid uptake and activated fatty acid oxidation (FAO). This was accompanied by an increased mitochondrial mass, upregulation of key FAO enzymes, and increased oxygen consumption rate. Pharmacologic inhibition of FAO blocked immune inhibitory pathways and functions in T-MDSC and decreased their production of inhibitory cytokines. FAO inhibition alone significantly delayed tumor growth in a T-cell-dependent manner and enhanced the antitumor effect of adoptive T-cell therapy. Furthermore, FAO inhibition combined with low-dose chemotherapy completely inhibited T-MDSC immunosuppressive effects and induced a significant antitumor effect. Interestingly, a similar increase in fatty acid uptake and expression of FAO-related enzymes was found in human MDSC in peripheral blood and tumors. These results support the possibility of testing FAO inhibition as a novel approach to block MDSC and enhance various cancer therapies.

  9. Inhibition of Fatty Acid Oxidation Modulates Immunosuppressive Functions of Myeloid-Derived Suppressor Cells and Enhances Cancer Therapies

    PubMed Central

    Hossain, Fokhrul; Al-Khami, Amir A.; Wyczechowska, Dorota; Hernandez, Claudia; Zheng, Liqin; Reiss, Krzystoff; Del Valle, Luis; Trillo-Tinoco, Jimena; Maj, Tomasz; Zou, Weiping; Rodriguez, Paulo C.; Ochoa, Augusto C.

    2015-01-01

    Myeloid-derived suppressor cells (MDSC) promote tumor growth by inhibiting T-cell immunity and promoting malignant cell proliferation and migration. The therapeutic potential of blocking MDSCs in tumors has been limited by their heterogeneity, plasticity, and resistance to various chemotherapy agents. Recent studies have highlighted the role of energy metabolic pathways in the differentiation and function of immune cells; however, the metabolic characteristics regulating MDSCs remain unclear. We aimed to determine the energy metabolic pathway(s) used by MDSCs, establish its impact on their immunosuppressive function, and test whether its inhibition blocks MDSCs and enhances antitumor therapies. Using several murine tumor models, we found that tumor-infiltrating MDSCs (T-MDSC) increased fatty acid uptake and activated fatty acid oxidation (FAO). This was accompanied by an increased mitochondrial mass, upregulation of key FAO enzymes, and increased oxygen consumption rate. Pharmacologic inhibition of FAO blocked immune inhibitory pathways and functions in T-MDSCs and decreased their production of inhibitory cytokines. FAO inhibition alone significantly delayed tumor growth in a T cell-dependent manner and enhanced the antitumor effect of adoptive T-cell therapy. Furthermore, FAO inhibition combined with low-dose chemotherapy completely inhibited T-MDSCs immunosuppressive effects and induced a significant antitumor effect. Interestingly, a similar increase in fatty acid uptake and expression of FAO-related enzymes was found in human MDSCs in peripheral blood and tumors. These results support the possibility of testing FAO inhibition as a novel approach to block MDSCs and enhance various cancer therapies. PMID:26025381

  10. Reversal learning enhanced by lysergic acid diethylamide (LSD): concomitant rise in brain 5-hydroxytryptamine levels.

    PubMed

    King, A R; Martin, I L; Melville, K A

    1974-11-01

    1 Small doses of lysergic acid diethylamide (LSD) (12.5-50 mug/kg) consistently facilitated learning of a brightness discrimination reversal.2 2-Bromo-lysergic acid diethylamide (BOL-148), a structural analogue of LSD, with similar peripheral anti-5-hydroxytrypamine activity but no psychotomimetic properties, had no effect in this learning situation at a similar dose (25 mug/kg).3 LSD, but not BOL-148, caused a small but significant increase in brain 5-hydroxytryptamine levels, but had no effect on the levels of catecholamines in the brain at 25 mug/kg.

  11. Multi-walled carbon nanotubes in aqueous phytic acid for enhancing biosensor

    NASA Astrophysics Data System (ADS)

    Guo, Xiaoyu; Miao, Yun; Ye, Pingping; Wen, Ying; Yang, Haifeng

    2014-04-01

    The poor dispersion of carbon based nanomaterials without strong acid pretreatment in aqueous solution is a fundamental problem, limiting its applications in biology-related fields. A good dispersion of multi-walled carbon nanotubes (MWCNTs) in water was realized by 50 wt.% phytic acid (PA) solution. As an application case, the PA-MWCNTs dispersion in aqueous solution was used for the immobilization of horseradish peroxidase (HRP) and its direct electrochemistry was realized. The constructed biosensor has a sound limit of detection, wide linear range, and high affinity for hydrogen peroxide (H2O2) as well as being free from interference of co-existing electro-active species.

  12. Genetic engineering to contain the Vitreoscilla hemoglobin gene enhances degradation of benzoic acid by Xanthomonas maltophilia

    SciTech Connect

    Liu, S.C.; Webster, D.A.; Wei, M.L.; Stark, B.C.

    1996-01-05

    Xanthomonas maltophilia was transformed with the gene encoding Vitreoscilla (bacterial) hemoglobin, vgb, and the growth of the engineered strain was compared with that of the untransformed strain using benzoic acid as the sole carbon source. In general, growth of the engineered strain was greater than that of the untransformed strain; this was true for experiments using both overnight cultures and log phase cells as inocula, but particularly for the latter. In both cases the engineered strain was also more efficiency than the untransformed strain in converting benzoic acid into biomass.

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

    PubMed Central

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

    2012-01-01

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

  14. Knockdown of Nuclear-Located Enhancer RNAs and Long ncRNAs Using Locked Nucleic Acid GapmeRs.

    PubMed

    Roux, Benoit T; Lindsay, Mark A; Heward, James A

    2017-01-01

    The human genome is widely transcribed outside of protein-coding genes, producing thousands of noncoding RNAs from different subfamilies including enhancer RNAs. Functional studies to determine the role of individual genes are challenging with noncoding RNAs appearing to be more difficult to knockdown than mRNAs. One factor that may have hindered progress is that the majority of noncoding RNAs are thought to be located within the nucleus, where the efficiency of traditional RNA interference techniques is debatable. Here we present an alternative RNA interference technique utilizing Locked Nucleic Acids, which is able to efficiently knockdown noncoding RNAs irrespective of intracellular location. PMID:27662866

  15. Enhancements in hepatobiliary imaging: the spectrum of gadolinium-ethoxybenzyl diethylenetriaminepentaacetic acid usages in hepatobiliary magnetic resonance imaging.

    PubMed

    Channual, Stephanie; Pahwa, Anokh; Lu, David S; Raman, Steven S

    2016-09-01

    Gadolinium-ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) is a unique hepatocyte-specific contrast agent approved for clinical use in the United States in 2008. Gd-EOB-DTPA-enhanced MR has shown to improve detection and characterization of hepatic lesions. Gd-EOB-DTPA is now being routinely used in daily clinical practice worldwide. Therefore, it is important for radiologists to be familiar with the potential uses and pitfalls of Gd-EOB-DTPA, which extends beyond the assessment of focal hepatic lesions. The purpose of this article is to review the various usages of Gd-EOB-DTPA in hepatobiliary MR imaging. PMID:27225503

  16. Study on the fluorescence enhancement in Lanthanum(III)-carminic acid-cetyltrimethylammonium bromide system and its analytical application.

    PubMed

    Wang, Feng; Huang, Wei; Li, Kexiang; Li, Aihua; Gao, Wei; Tang, Bo

    2011-09-01

    A fluorescent enhancement system carminic acid (CA)-La3+-CTAB is found and based on this finding a new fluorimetric method for the determination of CA is developed. Under optimized conditions, the enhanced intensities of fluorescence are quantitatively in proportion to the concentrations of CA in the range of 0.01231-12.31 μg mL(-1). The detection limit is 10.92 ng mL(-1). Compared with other methods that have been reported to determine CA, this method has high sensitivity, stability and wide linear range. In addition, the luminescence mechanism indicates that the complex of La3+-CA (1:2) forms and solubilizes in CTAB micelle. PMID:21703912

  17. Study on the fluorescence enhancement in Lanthanum(III)-carminic acid-cetyltrimethylammonium bromide system and its analytical application

    NASA Astrophysics Data System (ADS)

    Wang, Feng; Huang, Wei; Li, Kexiang; Li, Aihua; Gao, Wei; Tang, Bo

    2011-09-01

    A fluorescent enhancement system carminic acid (CA)-La 3+-CTAB is found and based on this finding a new fluorimetric method for the determination of CA is developed. Under optimized conditions, the enhanced intensities of fluorescence are quantitatively in proportion to the concentrations of CA in the range of 0.01231-12.31 μg mL -1. The detection limit is 10.92 ng mL -1. Compared with other methods that have been reported to determine CA, this method has high sensitivity, stability and wide linear range. In addition, the luminescence mechanism indicates that the complex of La 3+-CA (1:2) forms and solubilizes in CTAB micelle.

  18. Ascorbic Acid Enhances the Accumulation of Polycyclic Aromatic Hydrocarbons (PAHs) in Roots of Tall Fescue (Festuca arundinacea Schreb.)

    PubMed Central

    Gao, Yanzheng; Li, Hui; Gong, Shuaishuai

    2012-01-01

    Plant contamination by polycyclic aromatic hydrocarbons (PAHs) is crucial to food safety and human health. Enzyme inhibitors are commonly utilized in agriculture to control plant metabolism of organic components. This study revealed that the enzyme inhibitor ascorbic acid (AA) significantly reduced the activities of peroxidase (POD) and polyphenol oxidase (PPO), thus enhancing the potential risks of PAH contamination in tall fescue (Festuca arundinacea Schreb.). POD and PPO enzymes in vitro effectively decomposed naphthalene (NAP), phenanthrene (PHE) and anthracene (ANT). The presence of AA reduced POD and PPO activities in plants, and thus was likely responsible for enhanced PAH accumulation in tall fescue. This conclusion is supported by the significantly enhanced uptake of PHE in plants in the presence of AA, and the positive correlation between enzyme inhibition efficiencies and the rates of metabolism of PHE in tall fescue roots. This study provides a new perspective, that the common application of enzyme inhibitors in agricultural production could increase the accumulation of organic contaminants in plants, hence enhancing risks to food safety and quality. PMID:23185628

  19. Surface enhanced Raman scattering of amino acids assisted by gold nanoparticles and Gd(3+) ions.

    PubMed

    López-Neira, Juan Pablo; Galicia-Hernández, José Mario; Reyes-Coronado, Alejandro; Pérez, Elías; Castillo-Rivera, Francisco

    2015-05-01

    The surface enhanced raman scattering (SERS) signal from the l-tyrosine (tyr) molecule adsorbed on gold nanoparticles (Au-tyr) is compared with the SERS signal assisted by the presence of gadolinium ions (Gd(3+)) coordinated with the Au-tyr system. An enhancement factor of the SERS signal in the presence of Gd(3+) ions was ∼5 times higher than that produced by l-tyrosine adsorbed on gold nanoparticles. The enhancement of the SERS signal can be attributed to a corresponding increase in the local electric field due to the presence of Gd(3+) ions in the vicinity of a gold dimer configuration. This scenario was confirmed by solving numerically Maxwell equations, showing an increase of 1 order of magnitude in the local electric scattered field when the Gd(3+) ion is located in between a gold dimer compared with naked gold nanoparticles.

  20. Enhanced pinocembrin production in Escherichia coli by regulating cinnamic acid metabolism

    NASA Astrophysics Data System (ADS)

    Cao, Weijia; Ma, Weichao; Wang, Xin; Zhang, Bowen; Cao, Xun; Chen, Kequan; Li, Yan; Ouyang, Pingkai

    2016-09-01

    Microbial biosynthesis of pinocembrin is of great interest in the area of drug research and human healthcare. Here we found that the accumulation of the pathway intermediate cinnamic acid adversely affected pinocembrin production. Hence, a stepwise metabolic engineering strategy was carried out aimed at eliminating this pathway bottleneck and increasing pinocembrin production. The screening of gene source and the optimization of gene expression was first employed to regulate the synthetic pathway of cinnamic acid, which showed a 3.53-fold increase in pinocembrin production (7.76 mg/L) occurred with the alleviation of cinnamic acid accumulation in the engineered E. coli. Then, the downstream pathway that consuming cinnamic acid was optimized by the site-directed mutagenesis of chalcone synthase and cofactor engineering. S165M mutant of chalcone synthase could efficiently improve the pinocembrin production, and allowed the product titer of pinocembrin increased to 40.05 mg/L coupled with the malonyl-CoA engineering. With a two-phase pH fermentation strategy, the cultivation of the optimized strain resulted in a final pinocembrin titer of 67.81 mg/L. The results and engineering strategies demonstrated here would hold promise for the titer improvement of other flavonoids.

  1. Bacterial fatty acids enhance recovery from the dauer larva in Caenorhabditis elegans.

    PubMed

    Kaul, Tiffany K; Reis Rodrigues, Pedro; Ogungbe, Ifedayo V; Kapahi, Pankaj; Gill, Matthew S

    2014-01-01

    The dauer larva is a specialized dispersal stage in the nematode Caenorhabditis elegans that allows the animal to survive starvation for an extended period of time. The dauer does not feed, but uses chemosensation to identify new food sources and to determine whether to resume reproductive growth. Bacteria produce food signals that promote recovery of the dauer larva, but the chemical identities of these signals remain poorly defined. We find that bacterial fatty acids in the environment augment recovery from the dauer stage under permissive conditions. The effect of increased fatty acids on different dauer constitutive mutants indicates a role for insulin peptide secretion in coordinating recovery from the dauer stage in response to fatty acids. These data suggest that worms can sense the presence of fatty acids in the environment and that elevated levels can promote recovery from dauer arrest. This may be important in the natural environment where the dauer larva needs to determine whether the environment is appropriate to support reproductive growth following dauer exit. PMID:24475206

  2. An enhanced system for unnatural amino acid mutagenesis in E. coli.

    PubMed

    Young, Travis S; Ahmad, Insha; Yin, Jun A; Schultz, Peter G

    2010-01-15

    We report a new vector, pEVOL, for the incorporation of unnatural amino acids into proteins in Escherichia coli using evolved Methanocaldococcus jannaschii aminoacyl-tRNA synthetase(s) (aaRS)/suppressor tRNA pairs. This new system affords higher yields of mutant proteins through the use of both constitutive and inducible promoters to drive the transcription of two copies of the M. jannaschii aaRS gene. Yields were further increased by coupling the dual-aaRS promoter system with a newly optimized suppressor tRNA(CUA)(opt) in a single-vector construct. The optimized suppressor tRNA(CUA)(opt) afforded increased plasmid stability compared with previously reported vectors for unnatural amino acid mutagenesis. To demonstrate the utility of this new system, we introduced 14 mutant aaRS into pEVOL and compared their ability to insert unnatural amino acids in response to three independent amber nonsense codons in sperm whale myoglobin or green fluorescent protein. When cultured in rich media in shake flasks, pEVOL was capable of producing more than 100 mg/L mutant GroEL protein. The versatility, increased yields, and increased stability of the pEVOL vector will further facilitate the expression of proteins with unnatural amino acids. PMID:19852970

  3. Enhancing polysaccharide-mediated delivery of nucleic acids through functionalization with secondary and tertiary amines.

    PubMed

    Ghosn, Bilal; Kasturi, Sudhir Pai; Roy, Krishnendu

    2008-01-01

    Chitosan is a polysaccharide that has generated significant interest as a non-viral gene delivery vehicle due to its cationic and biocompatible characteristics. However, transfection efficiency of chitosan is significantly lower compared to other cationic gene delivery agents, e.g. polyethyleneimine (PEI), dendrimers or cationic lipids. This is primarily attributed to its minimal solubility and low buffering capacity at physiological pH leading to poor endosomal escape of the gene carrier and inefficient cytoplasmic decoupling of the complexed nucleic acid. Here we have developed an imidazole acetic acid (IAA)-modified chitosan to introduce secondary and tertiary amines to the polymer in order to improve its endosomal buffering and solubility. The modified polymer was characterized by ninhydrin and (1)H NMR assays for degree of modification, while buffering and solubility were analyzed by acid titration. Nanocomplex formation, studied at various polymer-nucleic acid ratios, showed an increase in particle zeta potential for chitosan-IAA, as well as an increase in the effective diameter. Up to 100-fold increase in transfection efficiency of pDNA was seen for chitosan-IAA as compared to native chitosan, nearly matching that of PEI. In addition, transfection of siRNA by the modified polymers showed efficient gene knockdown equivalent to commercially available siPORT Amines. Collectively, these results demonstrate the potential of the imidazole-grafted chitosan as a biocompatible and effective delivery vehicle for both pDNA and siRNA.

  4. Engineering Clostridium beijerinckii with the Cbei_4693 gene knockout for enhanced ferulic acid tolerance.

    PubMed

    Liu, Jun; Guo, Ting; Shen, Xiaoning; Xu, Jiahui; Wang, Junzhi; Wang, Yanyan; Liu, Dong; Niu, Huanqing; Liang, Lei; Ying, Hanjie

    2016-07-10

    A mutant strain of Clostridium beijerinckii NCIMB 8052, C. beijerinckii M11, which exhibited ferulic acid tolerance up to 0.9g/L, was generated using atmospheric pressure glow discharge and high-throughput screening. Comparative genomic analysis revealed that this strain harbored a mutation of the Cbei_4693 gene, which encodes a hypothetical protein suspected to be an NADPH-dependent FMN reductase. After disrupting the Cbei_4693 gene in C. beijerinckii NCIMB 8052 using the ClosTron group II intron-based gene inactivation system, we obtained the Cbei_4693 gene inactivated mutant strain, C. beijerinckii 4693::int. Compared with C. beijerinckii NCIMB 8052, 6.23g/L of butanol was produced in P2 medium containing 0.5g/L of ferulic acid by 4693::int, and the ferulic acid tolerance was also significantly increased up to 0.8g/L. These data showed, for the first time, that the Cbei_4693 gene plays an important role in regulating ferulic acid tolerance in ABE fermentation by C. beijerinckii. PMID:27164255

  5. Solute-enhanced production of gamma-valerolactone (GVL) from aqueous solutions of levulinic acid

    DOEpatents

    Dumesic, James A; Wettstein, Stephanie G; Alonso, David Martin; Gurbuz, Elif Ispir

    2015-02-24

    A method to produce levulinic acid (LA) and gamma-valerolactone (GVL) from biomass-derived cellulose or lignocellulose by selective extraction of LA using GVL and optionally converting the LA so isolated into GVL, with no purifications steps required to yield the GVL.

  6. Enhanced pinocembrin production in Escherichia coli by regulating cinnamic acid metabolism.

    PubMed

    Cao, Weijia; Ma, Weichao; Wang, Xin; Zhang, Bowen; Cao, Xun; Chen, Kequan; Li, Yan; Ouyang, Pingkai

    2016-09-02

    Microbial biosynthesis of pinocembrin is of great interest in the area of drug research and human healthcare. Here we found that the accumulation of the pathway intermediate cinnamic acid adversely affected pinocembrin production. Hence, a stepwise metabolic engineering strategy was carried out aimed at eliminating this pathway bottleneck and increasing pinocembrin production. The screening of gene source and the optimization of gene expression was first employed to regulate the synthetic pathway of cinnamic acid, which showed a 3.53-fold increase in pinocembrin production (7.76 mg/L) occurred with the alleviation of cinnamic acid accumulation in the engineered E. coli. Then, the downstream pathway that consuming cinnamic acid was optimized by the site-directed mutagenesis of chalcone synthase and cofactor engineering. S165M mutant of chalcone synthase could efficiently improve the pinocembrin production, and allowed the product titer of pinocembrin increased to 40.05 mg/L coupled with the malonyl-CoA engineering. With a two-phase pH fermentation strategy, the cultivation of the optimized strain resulted in a final pinocembrin titer of 67.81 mg/L. The results and engineering strategies demonstrated here would hold promise for the titer improvement of other flavonoids.

  7. Enhance nisin yield via improving acid-tolerant capability of Lactococcus lactis F44

    PubMed Central

    Zhang, Jian; Caiyin, Qinggele; Feng, Wenjing; Zhao, Xiuli; Qiao, Bin; Zhao, Guangrong; Qiao, Jianjun

    2016-01-01

    Traditionally, nisin was produced industrially by using Lactococcus lactis in the neutral fermentation process. However, nisin showed higher activity in the acidic environment. How to balance the pH value for bacterial normal growth and nisin activity might be the key problem. In this study, 17 acid-tolerant genes and 6 lactic acid synthetic genes were introduced in L. lactis F44, respectively. Comparing to the 2810 IU/mL nisin yield of the original strain F44, the nisin titer of the engineered strains over-expressing hdeAB, ldh and murG, increased to 3850, 3979 and 4377 IU/mL, respectively. These engineered strains showed more stable intracellular pH value during the fermentation process. Improvement of lactate production could partly provide the extra energy for the expression of acid tolerance genes during growth. Co-overexpression of hdeAB, murG, and ldh(Z) in strain F44 resulted in the nisin titer of 4913 IU/mL. The engineered strain (ABGL) could grow on plates with pH 4.2, comparing to the surviving pH 4.6 of strain F44. The fed-batch fermentation showed nisin titer of the co-expression L. lactis strain could reach 5563 IU/mL with lower pH condition and longer cultivation time. This work provides a novel strategy of constructing robust strains for use in industry process. PMID:27306587

  8. Enhanced pinocembrin production in Escherichia coli by regulating cinnamic acid metabolism

    PubMed Central

    Cao, Weijia; Ma, Weichao; Wang, Xin; Zhang, Bowen; Cao, Xun; Chen, Kequan; Li, Yan; Ouyang, Pingkai

    2016-01-01

    Microbial biosynthesis of pinocembrin is of great interest in the area of drug research and human healthcare. Here we found that the accumulation of the pathway intermediate cinnamic acid adversely affected pinocembrin production. Hence, a stepwise metabolic engineering strategy was carried out aimed at eliminating this pathway bottleneck and increasing pinocembrin production. The screening of gene source and the optimization of gene expression was first employed to regulate the synthetic pathway of cinnamic acid, which showed a 3.53-fold increase in pinocembrin production (7.76 mg/L) occurred with the alleviation of cinnamic acid accumulation in the engineered E. coli. Then, the downstream pathway that consuming cinnamic acid was optimized by the site-directed mutagenesis of chalcone synthase and cofactor engineering. S165M mutant of chalcone synthase could efficiently improve the pinocembrin production, and allowed the product titer of pinocembrin increased to 40.05 mg/L coupled with the malonyl-CoA engineering. With a two-phase pH fermentation strategy, the cultivation of the optimized strain resulted in a final pinocembrin titer of 67.81 mg/L. The results and engineering strategies demonstrated here would hold promise for the titer improvement of other flavonoids. PMID:27586788

  9. Surfactant enhanced disinfection of the human norovirus surrogate, tulane virus with organic acids and surfactant

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Human infection with foodborne viruses can occur following consumption of contaminated food, person-to-person body contact, or release of aerosols. Combinatorial treatments of surfactants and organic acids may have synergistic or additive mechanisms to inactivate foodborne viruses and prevent outbr...

  10. Localized Pd Overgrowth on Cubic Pt Nanocrystals for Enhanced Electrocatalytic Oxidation of Formic Acid

    SciTech Connect

    Lee, H.; Habas, S.E.; Somorjai, G.A.; Yang, P.

    2008-03-20

    Binary Pt/Pd nanoparticles were synthesized by localized overgrowth of Pd on cubic Pt seeds for the investigation of electrocatalytic formic acid oxidation. The binary particles exhibited much less self-poisoning and a lower activation energy relative to Pt nanocubes, consistent with the single crystal study.

  11. Water Soluble Usnic Acid-Polyacrylamide Complexes with Enhanced Antimicrobial Activity against Staphylococcus epidermidis

    PubMed Central

    Francolini, Iolanda; Taresco, Vincenzo; Crisante, Fernanda; Martinelli, Andrea; D’Ilario, Lucio; Piozzi, Antonella

    2013-01-01

    Usnic acid, a potent antimicrobial and anticancer agent, poorly soluble in water, was complexed to novel antimicrobial polyacrylamides by establishment of strong acidic-base interactions. Thermal and spectroscopic analysis evidenced a molecular dispersion of the drug in the polymers and a complete drug/polymer miscibility for all the tested compositions. The polymer/drug complexes promptly dissolved in water and possessed a greater antimicrobial activity against Staphylococcus epidermidis than both the free drug and the polymer alone. The best results were obtained with the complex based on the lowest molecular weight polymer and containing a low drug content. Such a complex showed a larger inhibition zone of bacterial growth and a lower minimum inhibitory concentration (MIC) with respect to usnic acid alone. This improved killing effect is presumably due to the reduced size of the complexes that allows an efficient cellular uptake of the antimicrobial complexes. The killing effect extent seems to be not significantly dependent on usnic acid content in the samples. PMID:23549269

  12. Enhanced pinocembrin production in Escherichia coli by regulating cinnamic acid metabolism.

    PubMed

    Cao, Weijia; Ma, Weichao; Wang, Xin; Zhang, Bowen; Cao, Xun; Chen, Kequan; Li, Yan; Ouyang, Pingkai

    2016-01-01

    Microbial biosynthesis of pinocembrin is of great interest in the area of drug research and human healthcare. Here we found that the accumulation of the pathway intermediate cinnamic acid adversely affected pinocembrin production. Hence, a stepwise metabolic engineering strategy was carried out aimed at eliminating this pathway bottleneck and increasing pinocembrin production. The screening of gene source and the optimization of gene expression was first employed to regulate the synthetic pathway of cinnamic acid, which showed a 3.53-fold increase in pinocembrin production (7.76 mg/L) occurred with the alleviation of cinnamic acid accumulation in the engineered E. coli. Then, the downstream pathway that consuming cinnamic acid was optimized by the site-directed mutagenesis of chalcone synthase and cofactor engineering. S165M mutant of chalcone synthase could efficiently improve the pinocembrin production, and allowed the product titer of pinocembrin increased to 40.05 mg/L coupled with the malonyl-CoA engineering. With a two-phase pH fermentation strategy, the cultivation of the optimized strain resulted in a final pinocembrin titer of 67.81 mg/L. The results and engineering strategies demonstrated here would hold promise for the titer improvement of other flavonoids. PMID:27586788

  13. Humic acids enhanced removal of aromatic hydrocarbons from contaminated aquifers: developing a sustainable technology.

    PubMed

    Lesage, S; Brown, S; Millar, K; Novakowski, K

    2001-09-01

    Contamination by gasoline and diesel fuels is a threat to groundwater resources. Polynuclear aromatic hydrocarbons (PAHs) which can represent up to 60% of volume in diesel fuels are of particular concern because many of them are carcinogenic and they are persistent, especially in oxygen-limited environment. Despite the development of alternative approaches, pump and treat continues to be the leading technology for the remediation of groundwater contaminated by gasoline and diesel fuels. The efficiency of this technology is however limited by the low solubility of the aromatic hydrocarbons. The objective of this study was to investigate the influence of humic acids on the removal of aromatic hydrocarbons from petroleum products in groundwater aquifers and to evaluate the potential use of humic acids, as a cost effective additive, in groundwater and soil remediation. In order to prove the feasibility of using humic acid in the field, a pilot scale experiment was conducted in a model aquifer with a very dense monitoring network, providing controlled conditions only possible in a semi-artificial system. In addition, different sources of humic acids were compared with surfactants for their ability to bind PAHs.

  14. Activation of peroxisome proliferator-activated receptor-{alpha} enhances fatty acid oxidation in human adipocytes

    SciTech Connect

    Lee, Joo-Young; Hashizaki, Hikari; Goto, Tsuyoshi; Sakamoto, Tomoya; Takahashi, Nobuyuki; Kawada, Teruo

    2011-04-22

    Highlights: {yields} PPAR{alpha} activation increased mRNA expression levels of adipocyte differentiation marker genes and GPDH activity in human adipocytes. {yields} PPAR{alpha} activation also increased insulin-dependent glucose uptake in human adipocytes. {yields} PPAR{alpha} activation did not affect lipid accumulation in human adipocytes. {yields} PPAR{alpha} activation increased fatty acid oxidation through induction of fatty acid oxidation-related genes in human adipocytes. -- Abstract: Peroxisome proliferator-activated receptor-{alpha} (PPAR{alpha}) is a key regulator for maintaining whole-body energy balance. However, the physiological functions of PPAR{alpha} in adipocytes have been unclarified. We examined the functions of PPAR{alpha} using human multipotent adipose tissue-derived stem cells as a human adipocyte model. Activation of PPAR{alpha} by GW7647, a potent PPAR{alpha} agonist, increased the mRNA expression levels of adipocyte differentiation marker genes such as PPAR{gamma}, adipocyte-specific fatty acid-binding protein, and lipoprotein lipase and increased both GPDH activity and insulin-dependent glucose uptake level. The findings indicate that PPAR{alpha} activation stimulates adipocyte differentiation. However, lipid accumulation was not changed, which is usually observed when PPAR{gamma} is activated. On the other hand, PPAR{alpha} activation by GW7647 treatment induced the mRNA expression of fatty acid oxidation-related genes such as CPT-1B and AOX in a PPAR{alpha}-dependent manner. Moreover, PPAR{alpha} activation increased the production of CO{sub 2} and acid soluble metabolites, which are products of fatty acid oxidation, and increased oxygen consumption rate in human adipocytes. The data indicate that activation of PPAR{alpha} stimulates both adipocyte differentiation and fatty acid oxidation in human adipocytes, suggesting that PPAR{alpha} agonists could improve insulin resistance without lipid accumulation in adipocytes. The expected

  15. Differential stimulation of luminol-enhanced chemiluminescence (CL) and arachidonic acid metabolism in rat peritoneal neutrophils

    SciTech Connect

    Sturm, R.J.; Adams, L.M.; Cullinan, C.A.; Berkenkopf, J.W.; Weichman, B.M.

    1986-03-05

    Phorbol 12-myristate, 13-acetate (PMA) induced the production of radical oxygen species (ROS) from rat peritoneal neutrophils as assessed by CL. ROS generation occurred in a time- (maximum at 13.5 min) and dose- (concentration range of 1.7-498 nM) related fashion. However, 166 nM PMA did not induce either cyclooxygenase (CO) or lipoxygenase (LPO) product formation by 20 min post-stimulation. Conversely, A23187, at concentrations between 0.1 and 10 ..mu..M, stimulated both pathways of arachidonic acid metabolism, but had little or no effect upon ROS production. When suboptimal concentrations of PMA (5.5 nM) and A23187 (0.1-1 ..mu..M) were coincubated with the neutrophils, a synergistic ROS response was elicited. However, arachidonic acid metabolism in the presence of PMA was unchanged relative to A12187 alone. Nordihydroguaiaretic acid (NDGA) inhibited both PMA-induced CL (IC/sub 50/ = 0.9 ..mu..M) and A23187-induced arachidonic acid metabolism (IC/sub 50/ = 1.7 ..mu..M and 6.0 ..mu..M for LPO and CO, respectively). The mixed LPO-CO inhibitor, BW755C, behaved in a qualitatively similar manner to NDGA, whereas the CO inhibitors, indomethacin, piroxicam and naproxen had no inhibitory effect on ROS generation at concentrations as high as 100 ..mu..M. These results suggest that NDGA and BW755C may inhibit CL and arachidonic acid metabolism by distinct mechanisms in rat neutrophils.

  16. Enhanced Enzymatic Preparation of Biodiesel Using Ricinoleic Acid as Acyl Donor: Optimization Using Response Surface Methodology.

    PubMed

    Wang, Ping; Sun, Shangde

    2016-09-01

    Castor oil methyl ester is a kind of biodiesel from castor oil. However, in those previous methods for biodiesel preparation using castor oil as feedstock, glycerol was the main by-product, which had a strong blocking effect on the immobilized enzyme activity and affected the mass transfer of reaction system. For avoiding the negative effect of glycerol on the enzymatic esterification, biodiesel was prepared using ricinoleic acid (RA) as acyl donor. Enzyme screening was also studied, and the effects of reaction temperature, molar ratio of ricinoleic acid and methanol, enzyme load, and reaction time, on the preparation of castor methyl ester were also evaluated. Response surface methodology (RSM) was used to optimize the interaction effect of reaction variables (reaction temperature (30-70°C), enzyme load (2-7%; relative to the weight of total substrates), molar ratio of methanol to ricinoleic acid (2:1-10:1), and reaction time (0.5-2.5 h)) on the acid value (AV) and the degree of esterification (DE). Validation of the RSM model was verified by the good agreement between the experimental and the predicted values of AV and DE. The optimum preparation conditions were as follows: reaction temperature, 48.2°C; enzyme load, 5.8%; molar ratio of methanol to ricinoleic acid, 5.56:1; reaction time, 2.36 h. Under these conditions, the AV and DE of the esterification reaction are 10.36±1.05 mgKOH/g and 94.03±0.60%, respectively. The relationship between initial reaction rate and temperature was also established, and the activation energy (Ea) of the enzymatic esterification is 33.87 KJ/mol. PMID:27477073

  17. Enhanced activity of carvacrol against biofilm of Staphylococcus aureus and Staphylococcus epidermidis in an acidic environment.

    PubMed

    Nostro, Antonia; Cellini, Luigina; Zimbalatti, Vincenzo; Blanco, Anna Rita; Marino, Andreana; Pizzimenti, Francesco; Di Giulio, Mara; Bisignano, Giuseppe

    2012-12-01

    Carvacrol is an antimicrobial monoterpenic phenol which occurs in many plant essential oils. The aim of this study was to investigate its activity at acidic pH on staphylococcal forming and yet established biofilms, with particular focus to improve its effectiveness on Staphylococcus epidermidis biofilm. The results showed that the subinhibitory doses (1/2, 1/4 and 1/8 MIC) of carvacrol determined a higher reduction of S. epidermidis biofilm formation than that observed at neutral pH. A potentiated inhibitory effect was also observed on established biofilm, carvacrol caused either a strong reduction of biomass (>50%) and bacteria attached to polystyrene (>7 log units). The images of scanning electron microscopy and the gas-chromatographic analysis support these results. The development of acidic formulations containing carvacrol could be an important tool to control the staphylococcal biofilm in the medical and food environment.

  18. Enhanced Oxygen Reduction Activity In Acid By Tin-Oxide Supported Au Nanoparticle Catalysts

    SciTech Connect

    Baker,W.; Pietron, J.; Teliska, M.; Bouwman, P.; Ramaker, D.; Swider-Lyons, K.

    2006-01-01

    Gold nanoparticles supported on hydrous tin-oxide (Au-SnO{sub x}) are active for the four-electron oxygen reduction reaction in an acid electrolyte. The unique electrocatalytic of the Au-SnO is confirmed by the low amount of peroxide detected with rotating ring-disk electrode voltammetry and Koutecky-Levich analysis. In comparison, 10 wt % Au supported on Vulcan carbon and SnO{sub x} catalysts both produce significant peroxide in the acid electrolyte, indicating only a two-electron reduction reaction. Characterization of the Au-SnO{sub x} catalyst reveals a high-surface area, amorphous support with 1.7 nm gold metal particles. The high catalytic activity of the Au-SnO is attributed to metal support interactions. The results demonstrate a possible path to non-Pt catalysts for proton exchange membrane fuel cell cathodes.

  19. Organo-Lewis acids of enhanced utility, uses thereof, and products based thereon

    DOEpatents

    Marks, Tobin J.; Chen, You-Xian

    2001-01-01

    The organo-Lewis acids are novel triarylboranes which are highly fluorinated. Triarylboranes of one such type contain at least one ring substituent other than fluorine. These organoboranes have a Lewis acid strength essentially equal to or greater than that of the corresponding organoborane in which the substituent is replaced by fluorine, or have greater solubility in organic solvents. Another type of new organoboranes have 1-3 perfluorinated fused ring groups and 2-0 perfluorophenyl groups. When used as a cocatalyst in the formation of novel catalytic complexes with d- or f-block metal compounds having at least one leaving group such as a methyl group, these triorganoboranes, because of their ligand abstracting properties, produce corresponding anions which are capable of only weakly, if at all, coordinating to the metal center, and thus do not interfere in various polymerization processes such as are described.

  20. Organo-Lewis acids of enhanced utility, uses thereof, and products based thereon

    DOEpatents

    Marks, Tobin J.; Chen, You-Xian

    2002-01-01

    The organo-Lewis acids are novel triarylboranes which are are highly fluorinated. Triarylboranes of one such type contain at least one ring substituent other than fluorine. These organoboranes have a Lewis acid strength essentially equal to or greater than that of the corresponding organoborane in which the substituent is replaced by fluorine, or have greater solubility in organic solvents. Another type of new organoboranes have 1-3 perfluorinated fused ring groups and 2-0 perfluorophenyl groups. When used as a cocatalyst in the formation of novel catalytic complexes with d- or f-block metal compounds having at least one leaving group such as a methyl group, these triorganoboranes, because of their ligand abstracting properties, produce corresponding anions which are capable of only weakly, if at all, coordinating to the metal center, and thus do not interfere in various polymerization processes such as are described.

  1. Aminolevulinic Acid-Photodynamic Therapy Combined with Topically Applied Vascular Disrupting Agent Vadimezan Led to Enhanced Antitumor Responses

    PubMed Central

    Marrero, Allison; Becker, Theresa; Sunar, Ulas; Morgan, Janet; Bellnier, David

    2011-01-01

    The tumor-vascular disrupting agent (VDA) vadimezan (5,6-dimethylxanthenone-4-acetic acid, DMXAA) has been shown to potentiate the antitumor activity of photodynamic therapy (PDT) using systemically administered photosensitizers. Here, we characterized the response of subcutaneous syngeneic Colon26 murine colon adenocarcinoma tumors to PDT using the locally applied photosensitizer precursor aminolevulinic acid (ALA) in combination with a topical formulation of vadimezan. Diffuse correlation spectroscopy (DCS), a non-invasive method for monitoring blood flow, was utilized to determine tumor vascular response to treatment. Additionally, correlative CD31-immunohistochemistry to visualize endothelial damage, ELISA assays to measure induction of tumor necrosis factor-alpha (TNF-α) and tumor weight measurements were also examined in separate animals. In our previous work, DCS revealed a selective decrease in tumor blood flow over time following topical vadimezan. ALA-PDT treatment also induced a decrease in tumor blood flow. The onset of blood flow reduction was rapid in tumors treated with both ALA-PDT and vadimezan. CD31-immunostaining of tumor sections confirmed vascular damage following topical application of vadimezan. Tumor weight measurements revealed enhanced tumor growth inhibition with combination treatment compared to ALA-PDT or vadimezan treatment alone. In conclusion, vadimezan as a topical agent enhances treatment efficacy when combined with ALA-PDT. This combination could be useful in clinical applications. PMID:21575001

  2. Arbuscular mycorrhiza increase artemisinin accumulation in Artemisia annua by higher expression of key biosynthesis genes via enhanced jasmonic acid levels.

    PubMed

    Mandal, Shantanu; Upadhyay, Shivangi; Wajid, Saima; Ram, Mauji; Jain, Dharam Chand; Singh, Ved Pal; Abdin, Malik Zainul; Kapoor, Rupam

    2015-07-01

    It is becoming increasingly evident that the formation of arbuscular mycorrhiza (AM) enhances secondary metabolite production in shoots. Despite mounting evidence, relatively little is known about the underlying mechanisms. This study suggests that increase in artemisinin concentration in Artemisia annua colonized by Rhizophagus intraradices is due to altered trichome density as well as transcriptional patterns that are mediated via enhanced jasmonic acid (JA) levels. Mycorrhizal (M) plants had higher JA levels in leaf tissue that may be due to induction of an allene oxidase synthase gene (AOS), encoding one of the key enzymes for JA production. Non-mycorrhizal (NM) plants were exogenously supplied with a range of methyl jasmonic acid concentrations. When leaves of NM and M plants with similar levels of endogenous JA were compared, these matched closely in terms of shoot trichome density, artemisinin concentration, and transcript profile of artemisinin biosynthesis genes. Mycorrhization increased artemisinin levels by increasing glandular trichome density and transcriptional activation of artemisinin biosynthesis genes. Transcriptional analysis of some rate-limiting enzymes of mevalonate and methyl erythritol phosphate (MEP) pathways revealed that AM increases isoprenoids by induction of the MEP pathway. A decline in artemisinin concentration in shoots of NM and M plants treated with ibuprofen (an inhibitor of JA biosynthesis) further confirmed the implication of JA in the mechanism of artemisinin production.

  3. Enhancement of the inducible NO synthase activation by retinoic acid is mimicked by RARalpha agonist in vivo.

    PubMed

    Seguin-Devaux, Carole; Devaux, Yvan; Latger-Cannard, Véronique; Grosjean, Sandrine; Rochette-Egly, Cécile; Zannad, Faiez; Meistelman, Claude; Mertes, Paul-Michel; Longrois, Dan

    2002-09-01

    We have previously shown that all-trans retinoic acid (atRA), the active metabolite of vitamin A, enhances the activation of the inducible nitric oxide synthase (NOS II) pathway, a component of innate immunity, in rats in vivo. We investigated the relative contribution of retinoic acid receptor-alpha (RARalpha) and retinoid X receptors (RXRs) to NOS II activation triggered by LPS. Five-day supplementation with 10 mg/kg of either atRA or the RARalpha selective agonist Ro-40-6055, but not with 10 mg/kg of the pan-RXR agonist Ro-25-7386, enhanced the LPS-induced NOS II mRNA, protein expression in liver, and plasma nitrite/nitrate concentration. Both atRA and the RARalpha agonist (but not the RXR agonist) increased the number of peripheral T helper lymphocytes and plasma interferon-gamma concentration. Synergism between retinoids and LPS on NOS II activation within an organ coincided with synergism on interferon regulatory factor-1 mRNA expression but not with the level of expression of the RARalpha protein. These results suggest that, in vivo, atRA activates NOS II through RARalpha and contributes to characterizing the complex effect of retinoids on the host inflammatory/immune response.

  4. Enhancement of root hydraulic conductivity by methyl jasmonate and the role of calcium and abscisic acid in this process.

    PubMed

    Sánchez-Romera, Beatriz; Ruiz-Lozano, Juan Manuel; Li, Guowei; Luu, Doan-Trung; Martínez-Ballesta, Maria del Carmen; Carvajal, Micaela; Zamarreño, Angel María; García-Mina, Jose María; Maurel, Christophe; Aroca, Ricardo

    2014-04-01

    The role of jasmonic acid in the induction of stomatal closure is well known. However, its role in regulating root hydraulic conductivity (L) has not yet been explored. The objectives of the present research were to evaluate how JA regulates L and how calcium and abscisic acid (ABA) could be involved in such regulation. We found that exogenous methyl jasmonate (MeJA) increased L of Phaseolus vulgaris, Solanum lycopersicum and Arabidopsis thaliana roots. Tomato plants defective in JA biosynthesis had lower values of L than wild-type plants, and that L was restored by addition of MeJA. The increase of L by MeJA was accompanied by an increase of the phosphorylation state of the aquaporin PIP2. We observed that MeJA addition increased the concentration of cytosolic calcium and that calcium channel blockers inhibited the rise of L caused by MeJA. Treatment with fluoridone, an inhibitor of ABA biosynthesis, partially inhibited the increase of L caused by MeJA, and tomato plants defective in ABA biosynthesis increased their L after application of MeJA. It is concluded that JA enhances L and that this enhancement is linked to calcium and ABA dependent and independent signalling pathways. PMID:24131347

  5. Dietary histidine increases mouse skin urocanic acid levels and enhances UVB-induced immune suppression of contact hypersensitivity.

    PubMed

    Reilly, S K; De Fabo, E C

    1991-04-01

    Urocanic Acid (UCA) exists in mammalian skin primarily as the trans isomer and is photoisomerized to cis UCA upon UVB absorption. Our previous studies indicated that the photoisomerization of UCA is the initiating event in UBV-induced suppression of cell-mediated immunity (tUCA----cUCA----immune suppression). The purpose of this study was to verify the role of UCA in UV-induced immune suppression of contact hypersensitivity (CHS) in BALB/c mice. Since UCA is a metabolite of the amino acid L-histidine, we reasoned that increased dietary levels of histidine should raise skin tUCA levels. If skin tUCA is the UVB photoreceptor for immune suppression, this increase should enhance UV-induced suppression of CHS. HPLC analysis of skin from BALB/c mice given a histidine-rich diet (10%) showed that the total amount of UCA is significantly higher in these animals than in mice fed a normal diet. Further, levels of suppression of CHS of 3% and 49% in control fed mice, induced by 4.8 and 7.2 kJ/m2 UVB were significantly increased to 21% and 71% respectively in histidine-fed animals at these same UVB doses. These findings provide additional support for the UCA model for immune suppression, and provide the first evidence that UV-induced immune suppression can be enhanced by a dietary component, L-histidine. PMID:1857737

  6. A 70% Ethanol Extract of Mistletoe Rich in Betulin, Betulinic Acid, and Oleanolic Acid Potentiated β-Cell Function and Mass and Enhanced Hepatic Insulin Sensitivity

    PubMed Central

    Ko, Byoung-Seob; Kang, Suna; Moon, Bo Reum; Ryuk, Jin Ah; Park, Sunmin

    2016-01-01

    We investigated that the long-term consumption of the water (KME-W) and 70% ethanol (KME-E) mistletoe extracts had antidiabetic activities in partial pancreatectomized (Px) rats. Px rats were provided with a high-fat diet containing 0.6% KME-E, 0.6% KME-W, and 0.6% dextrin (control) for 8 weeks. As normal-control, Sham-operated rats were provided with 0.6% dextrin. In cell-based studies, the effects of its main terpenoids (betulin, betulinic acid, and oleanolic acid) on glucose metabolism were measured. Both KME-W and KME-E decreased epididymal fat mass by increasing fat oxidation in diabetic rats. KME-E but not KME-W exhibited greater potentiation of first-phase insulin secretion than the Px-control in a hyperglycemic clamp. KME-E also made β-cell mass greater than the control by increasing β-cell proliferation and decreasing its apoptosis. In a euglycemic-hyperinsulinemic clamp, whole-body glucose infusion rate and hepatic glucose output increased with potentiating hepatic insulin signaling in the following order: Px-control, KME-W, KME-E, and normal-control. Betulin potentiated insulin-stimulated glucose uptake via increased PPAR-γ activity and insulin signaling in 3T3-L1 adipocytes, whereas oleanolic acid enhanced glucose-stimulated insulin secretion and cell proliferation in insulinoma cells. In conclusion, KME-E prevented the deterioration of glucose metabolism in diabetic rats more effectively than KME-W and KME-E can be a better therapeutic agent for type 2 diabetes than KME-W. PMID:26884795

  7. Enhancing the performance of lead-acid batteries with carbon - In pursuit of an understanding

    NASA Astrophysics Data System (ADS)

    Moseley, Patrick T.; Rand, David A. J.; Peters, Ken

    2015-11-01

    The inherently poor dynamic charge-acceptance of the lead-acid battery can be greatly improved by the incorporation of additional carbon to the negative plate. An analysis is undertaken of the various ways by which the carbon may be introduced, and of the proposed mechanisms whereby its presence proves to be beneficial. It is intended that such an investigation should provide a guide to the selection of the optimum carbon inventory.

  8. Enhancement of lipid production and fatty acid profiling in Chlamydomonas reinhardtii, CC1010 for biodiesel production.

    PubMed

    Karpagam, R; Preeti, R; Ashokkumar, B; Varalakshmi, P

    2015-11-01

    Lipid from microalgae is one of the putative oil resources to facilitate the biodiesel production during this era of energy dissipation and environmental pollution. In this study, the key parameters such as biomass productivity, lipid productivity and lipid content were evaluated at the early stationary phase of Chlamydomonas reinhardtii, CC1010 cultivated in nutrient starved (nitrogen, phosphorous), glucose (0.05%, 0.1%, 0.15% and 0.2%) and vitamin B12 supplementation (0.001%, 0.002% and 0.003%) in Tris-Acetate-Phosphate (TAP) medium. The lipid content in nitrogen starved media was 61% which is 2.34 folds higher than nutrient sufficient TAP medium. Glucose supplementation has lead to proportional increase in biomass productivity with the increasing concentration of glucose whereas vitamin B12 supplementations had not shown any influence in lipid and biomass production. Further, fatty acid methyl ester (FAME) profiling of C. reinhardtii, CC 1010 has revealed more than 80% of total SFA (saturated fatty acid) and MUFA (mono unsaturated fatty acid) content. Quality checking parameters of biodiesel like cetane number, saponification value, iodine number and degree of unsaturation were analyzed and the biodiesel fuel properties were found to be appropriate as per the international standards, EN 14214 and ASTM D6751. Conclusively, among all the treatments, nitrogen starvation with 0.1% glucose supplementation had yielded high lipid content in C. reinhardtii, CC 1010.

  9. Enhanced sidewall functionalization of single-wall carbon nanotubes using nitric acid.

    PubMed

    Tobias, Gerard; Shao, Lidong; Ballesteros, Belin; Green, Malcolm L H

    2009-10-01

    When a sample of as-made single-walled carbon nanotubes (SWNTs) is treated with nitric acid, oxidation debris are formed due to the functionalization (mainly carboxylation) of the amorphous carbon present in the sample and a continuous coating along the carbon nanotube walls is created preventing the sidewall functionalization of the SWNTs. This oxidation debris can be easily removed by an aqueous base wash leaving behind a sample with a low degree of functionality. After removal of the amorphous carbon (by steam purification) from a sample of as-made SWNTs, the resulting purified SWNTs are readily carboxylated on the walls by nitric acid treatment. The use of steam for the purification of SWNTs samples allows the removal of the amorphous carbon and graphitic layers coating the metal particles present in the sample without altering the tubular structure of the SWNTs. The exposed metal particles can then be easily removed by an acid wash. Comparison between the steam treatment and molten sodium hydroxide treatment is made.

  10. The cell transmembrane pH gradient in tumors enhances cytotoxicity of specific weak acid chemotherapeutics.

    PubMed

    Kozin, S V; Shkarin, P; Gerweck, L E

    2001-06-15

    The extracellular pH is lower in tumor than in normal tissue, whereas their intracellular pH is similar. In this study, we show that the tumor-specific pH gradient may be exploited for the treatment of cancer by weak acid chemotherapeutics. i.v.-injected glucose substantially decreased the electrode estimated extracellular pH in a xenografted human tumor while its intracellular pH, evaluated by (31)P magnetic resonance spectroscopy, remained virtually unchanged. The resulting increase in the average cell pH gradient caused a parallel increase in tumor growth delay by the weak acid chlorambucil (CHL). Regardless of glucose administration, the effect of CHL was significantly greater in tumors preirradiated with a large dose of ionizing radiation. This suggests that CHL was especially pronounced in radioresistant hypoxic cells possessing a larger transmembrane pH gradient. These results indicate that the naturally occurring cell pH gradient difference between tumor and normal tissue is a major and exploitable determinant of the uptake of weak acids in the complex tumor microenvironment. The use of such drugs may be especially effective in combination with radiation.

  11. Enhancement of catalysis and functional expression of a bacterial laccase by single amino acid replacement.

    PubMed

    Nasoohi, Nikoo; Khajeh, Khosro; Mohammadian, Mahdi; Ranjbar, Bijan

    2013-09-01

    Structure-function relationships underlying laccases properties are very limited that makes these enzymes interesting for protein engineering approaches. Therefore in the current study, a thermostable laccase that was isolated from Bacillus sp. HR03 with the ability of bilirubin oxidation besides its laccase and tyrosinase activity is used. The extensive application of this enzyme is limited by its low expression level in Escherichia coli. Based on sequence alignments and structural studies, three single amino acid substitutions, D500G, D500E, D500S and a glycine insertion, are introduced using site-directed mutagenesis to evaluate the role of Asp(500) located in the C-terminal segment close to the T1 copper center. Substitution of aspartic acid with less sterically hindered, conserved residue such as glycine increase kcat (2.3 fold) and total activity (7.3 fold) which is accompanied by a significant increase in the expression level up to 3 fold. Biochemical characterization and structural studies using far-UV CD and fluorescence spectroscopy reveal the importance of C-terminal copper-binding loop in the laccase functional expression and catalytic efficiency. Kinetic characterization of the purified mutants toward 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), syringaldazine (SGZ) and bilirubin, shows that substrate specificity is left unchanged. PMID:23707861

  12. Traumatic Acid Reduces Oxidative Stress and Enhances Collagen Biosynthesis in Cultured Human Skin Fibroblasts.

    PubMed

    Jabłońska-Trypuć, Agata; Pankiewicz, Walentyn; Czerpak, Romuald

    2016-09-01

    Traumatic acid (TA) is a plant hormone (cytokinin) that in terms of chemical structure belongs to the group of fatty acids derivatives. It was isolated from Phaseolus vulgaris. TA activity and its influence on human cells and organism has not previously been the subject of research. The aim of this study was to examine the effects of TA on collagen content and basic oxidative stress parameters, such as antioxidative enzyme activity, reduced glutathione, thiol group content, and lipid peroxidation in physiological conditions. The results show a stimulatory effect of TA on tested parameters. TA caused a decrease in membrane phospholipid peroxidation and exhibited protective properties against ROS production. It also increases protein and collagen biosynthesis and its secretion into the culture medium. The present findings reveal that TA exhibits multiple and complex activity in fibroblast cells in vitro. TA, with its activity similar to unsaturated fatty acids, shows antioxidant and stimulatory effects on collagen biosynthesis. It is a potentially powerful agent with applications in the treatment of many skin diseases connected with oxidative stress and collagen biosynthesis disorders. PMID:27423205

  13. PEGylated bile acids for use in drug delivery systems: enhanced solubility and bioavailability of itraconazole.

    PubMed

    Le Dévédec, Frantz; Strandman, Satu; Hildgen, Patrice; Leclair, Grégoire; Zhu, X X

    2013-08-01

    Itraconazole is a drug of choice for the treatment of severe fungal infections and parasitic diseases, but its use is limited by its low water solubility and varying bioavailability. New self-emulsifying drug delivery systems (SEDDS) based on PEGylated bile acids (BA-PEGs) were designed and prepared, where the number and length of PEG arms were varied to optimize the loading of itraconazole in the final drug formulation. The use of both BA-PEGs and oleic acid improved the solubilization and absorption of the drug, which was in a glassy state in the SEDDS prepared with the melting method. High loading efficiencies of itraconazole (up to 20%) and stable liquid formulations were obtained at neutral pH, and full dispersion of itraconazole was reached in 2 h in simulated intestinal fluid (pH 6.8). Aqueous emulsions consisting of spherical micelles with mean hydrodynamic diameters (Dh) of ca. 75-220 nm, as verified by transmission electron microscopy and dynamic light scattering, are expected to improve the intestinal absorption of the drug. The new SEDDS showed good cytocompatibility by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays of BA-PEGs with Caco-2 and RAW 264.2 cells, and a low degree of hemolysis of human erythrocytes. The SEDDS based on PEGylated bile acids provide a controlled release system with significant improvement of the bioavailability of itraconazole in rats, as demonstrated by the pharmacokinetic studies.

  14. Tipepidine enhances the antinociceptive-like action of carbamazepine in the acetic acid writhing test.

    PubMed

    Kawaura, Kazuaki; Miki, Risa; Urashima, Yuri; Honda, Sokichi; Shehata, Ahmed M; Soeda, Fumio; Shirasaki, Tetsuya; Takahama, Kazuo

    2011-01-25

    Several antidepressants have been used to treat severe pain in clinics. Recently, we reported that the centrally acting non-narcotic antitussive (cough suppressant drug), tipepidine produces an antidepressant-like effect in the forced swimming test, although the mechanism of action appears to be quite different from that of known antidepressants. In the present study, we investigated whether a combination of tipepidine and carbamazepine acts synergistically to induce an antinociceptive effect in the acetic acid-induced writhing test in mice. Prior to studying the combination of tipepidine and carbamazepine, the analgesic action of tipepidine alone was also examined in mice. Tipepidine at 5-40mg/kg i.p. significantly reduced the number of writhes induced by acetic acid in mice. Carbamazepine at 20mg/kg i.p. also significantly reduced the writhing reaction. Furthermore, co-administration of carbamazepine (5 and 10mg/kg, i.p.) and tipepidine (2.5mg/kg i.p.) significantly decreased the number of writhes induced by acetic acid. This finding suggests that a combination of carbamazepine and tipepidine may be a new strategy for the treatment of neuropathic pain such as what occurs in trigeminal neuralgia, because the use of carbamazepine is often limited by its adverse effects and by reduction of its analgesic efficacy by microsomal enzyme induction. PMID:21114989

  15. Enhanced production of poly-γ-glutamic acid by a newly-isolated Bacillus subtilis.

    PubMed

    Ju, Wan-Taek; Song, Yong-Su; Jung, Woo-Jin; Park, Ro-Dong

    2014-11-01

    Application of poly-gamma-glutamic acid (γ-PGA), an unusual macromolecular anionic polypeptide, is limited due to the high cost associated with its low productivity. Screening bacterial strains to find a more efficient producer is one approach to overcome this limitation. Strain MJ80 was isolated as a γ-PGA producer among 1,500 bacterial colonies obtained from soil samples. It was identified as Bacillus subtilis, based on the biochemical and morphological properties and 16S rDNA gene sequencing. It produced γ-PGA from both glutamic acid and soybean powder, identifying it as a facultative glutamic acid-metabolizing bacterium. After optimization of its culture conditions, B. subtilis MJ80 showed γ-PGA productivity of 75.5 and 68.7 g/l in 3 and 300 l jar fermenters for 3 days cultivation, respectively, the highest productivity reported to date, suggesting MJ80 to be a promising strain for γ-PGA production.

  16. Enhancement of lipid production and fatty acid profiling in Chlamydomonas reinhardtii, CC1010 for biodiesel production.

    PubMed

    Karpagam, R; Preeti, R; Ashokkumar, B; Varalakshmi, P

    2015-11-01

    Lipid from microalgae is one of the putative oil resources to facilitate the biodiesel production during this era of energy dissipation and environmental pollution. In this study, the key parameters such as biomass productivity, lipid productivity and lipid content were evaluated at the early stationary phase of Chlamydomonas reinhardtii, CC1010 cultivated in nutrient starved (nitrogen, phosphorous), glucose (0.05%, 0.1%, 0.15% and 0.2%) and vitamin B12 supplementation (0.001%, 0.002% and 0.003%) in Tris-Acetate-Phosphate (TAP) medium. The lipid content in nitrogen starved media was 61% which is 2.34 folds higher than nutrient sufficient TAP medium. Glucose supplementation has lead to proportional increase in biomass productivity with the increasing concentration of glucose whereas vitamin B12 supplementations had not shown any influence in lipid and biomass production. Further, fatty acid methyl ester (FAME) profiling of C. reinhardtii, CC 1010 has revealed more than 80% of total SFA (saturated fatty acid) and MUFA (mono unsaturated fatty acid) content. Quality checking parameters of biodiesel like cetane number, saponification value, iodine number and degree of unsaturation were analyzed and the biodiesel fuel properties were found to be appropriate as per the international standards, EN 14214 and ASTM D6751. Conclusively, among all the treatments, nitrogen starvation with 0.1% glucose supplementation had yielded high lipid content in C. reinhardtii, CC 1010. PMID:25838071

  17. Helically agitated mixing in dry dilute acid pretreatment enhances the bioconversion of corn stover into ethanol

    PubMed Central

    2014-01-01

    Background Dry dilute acid pretreatment at extremely high solids loading of lignocellulose materials demonstrated promising advantages of no waste water generation, less sugar loss, and low steam consumption while maintaining high hydrolysis yield. However, the routine pretreatment reactor without mixing apparatus was found not suitable for dry pretreatment operation because of poor mixing and mass transfer. In this study, helically agitated mixing was introduced into the dry dilute acid pretreatment of corn stover and its effect on pretreatment efficiency, inhibitor generation, sugar production, and bioconversion efficiency through simultaneous saccharification and ethanol fermentation (SSF) were evaluated. Results The overall cellulose conversion taking account of cellulose loss in pretreatment was used to evaluate the efficiency of pretreatment. The two-phase computational fluid dynamics (CFD) model on dry pretreatment was established and applied to analyze the mixing mechanism. The results showed that the pretreatment efficiency was significantly improved and the inhibitor generation was reduced by the helically agitated mixing, compared to the dry pretreatment without mixing: the ethanol titer and yield from cellulose in the SSF reached 56.20 g/L and 69.43% at the 30% solids loading and 15 FPU/DM cellulase dosage, respectively, corresponding to a 26.5% increase in ethanol titer and 17.2% increase in ethanol yield at the same fermentation conditions. Conclusions The advantage of helically agitated mixing may provide a prototype of dry dilute acid pretreatment processing for future commercial-scale production of cellulosic ethanol. PMID:24387051

  18. Enhanced capacity of chitosan for transition-metal ions in sulphate-sulphuric acid solutions.

    PubMed

    Muzzarelli, R A; Rocchetti, R

    1974-11-01

    Batch measurements have shown that the collection yields of chitosan for chromium(III), iron(III), nickel, copper(II), zinc and mercury(II) from sulphuric acid solutions are higher when the solutions contain ammonium sulphate, or when chitosan conditioned in ammonium sulphate is used, particularly at pH 3.0 and 5.0. The contrary is verified for the oxy-anions vanadate, chromate and molybdate. Manganese is never collected. At pH 1.0 no collection occurs. A procedure for recycling chromatographic columns includes fixation of Cu or Ni from a sulphate solution at pH 3-5 on sulphate-conditioned chitosan, and elution with 0.1M sulphuric acid/0.1M ammonium sulphate at pH 1.0; the presence of sulphate in the eluent obviates the detrimental effect of sulphuric acid on the next cycle. Sulphate is the favoured counter-ion of the chelated cations and its action produces shorter chromatographic bands. The interaction of sulphate with chitosan is discussed in terms of crystallinity and steric distribution of the protonated amino-groups in the polymer. Data on the new diethylaminohydroxypropylcellulose are included. PMID:18961577

  19. Early endosseous integration enhanced by dual acid etching of titanium: a torque removal study in the rabbit.

    PubMed

    Klokkevold, P R; Johnson, P; Dadgostari, S; Caputo, A; Davies, J E; Nishimura, R D

    2001-08-01

    Textured implant surfaces are thought to enhance endosseous integration. Torque removal forces have been used as a biomechanical measure of anchorage, or endosseous integration, in which the greater forces required to remove implants may be interpreted as an increase in the strength of bony integration. The purpose of this study was to compare the torque resistance to removal of screw-shaped titanium implants having a dual acid-etched surface (Osseotite) with implants having either a machined surface, or a titanium plasma spray surface that exhibited a significantly more complex surface topography. Three custom screw-shaped implant types - machined, dual acid-etched (DAE), and titanium plasma sprayed (TPS) - were used in this study. Each implant surface was characterized by scanning electron microscopy and optical profilometry. One DAE implant was placed into each distal femur of eighteen adult New Zealand White rabbits along with one of the other implant types. Thus, each rabbit received two DAE implants and one each of the machined, or TPS, implants. All implants measured 3.25 mm in diameter x 4.00 mm in length without holes, grooves or slots to resist rotation. Eighteen rabbits were used for reverse torque measurements. Groups of six rabbits were sacrificed following one, two and three month healing periods. Implants were removed by reverse torque rotation with a digital torque-measuring device. Three implants with the machined surface preparation failed to achieve endosseous integration. All other implants were anchored by bone. Mean torque values for machined, DAE and TPS implants at one, two and three months were 6.00+/-0.64 N-cm, 9.07+/-0.67 N-cm and 6.73+/-0.95 N-cm; 21.86+/-1.37 N-cm, 27.63+/-3.41 N-cm and 27.40+/-3.89 N-cm; and 27.48+/-1.61 N-cm, 44.28+/-4.53 N-cm and 59.23+/-3.88 N-cm, respectively. Clearly, at the earliest time point the stability of DAE implants was comparable to that of TPS implants, while that of the machined implants was an order of

  20. A pH dependent Raman and surface enhanced Raman spectroscopic studies of citrazinic acid aided by theoretical calculations

    NASA Astrophysics Data System (ADS)

    Sarkar, Sougata; Chowdhury, Joydeep; Dutta, Soumen; Pal, Tarasankar

    2016-12-01

    A pH dependent normal Raman scattering (NRS) and surface enhanced Raman scattering (SERS) spectral patterns of citrazinic acid (CZA), a biologically important molecule, have been investigated. The acid, with different pKa values (~ 4 and ~ 11) for the two different functional groups (-COOH and -OH groups), shows interesting range of color changes (yellow at pH ~ 14 and brown at pH ~ 2) with the variation in solution pH. Thus, depending upon the pH of the medium, CZA molecule can exist in various protonated and/or deprotonated forms. Here we have prescribed the existence different possible forms of CZA at different pH (Forms "C", "H" and "Dprot" at pH ~ 14 and Forms "A", "D", and "P" at pH ~ 2 respectively). The NRS spectra of these solutions and their respective SERS spectra over gold nanoparticles were recorded. The spectra clearly differ in their spectral profiles. For example the SERS spectra recorded with the CZA solution at pH ~ 2 shows blue shift for different bands compared to its NRS window e.g. 406 to 450 cm- 1, 616 to 632 cm- 1, 1332 to 1343 cm- 1 etc. Again, the most enhanced peak at ~ 1548 cm- 1 in NRS while in the SERS window this appears at ~ 1580 cm- 1. Similar observation was also made for CZA at pH ~ 14. For example, the 423 cm- 1 band in the NRS profile experience a blue shift and appears at ~ 447 cm- 1 in the SERS spectrum as well as other bands at ~ 850, ~ 1067 and ~ 1214 cm- 1 in the SERS window are markedly enhanced. It is also worth noting that the SERS spectra at the different pH also differ from each other. These spectral differences indicate the existence of various adsorptive forms of the CZA molecule depending upon the pH of the solution. Therefore based on the experimental findings we propose different possible molecular forms of CZA at different pH (acidic and alkaline) conditions. For example forms 'A', 'D' and 'P' existing in acidic pH (pH ~ 2) and three other deprotonated forms 'C', 'H' and 'Dprot' in alkaline pH (pH ~ 14). The DFT

  1. A pH dependent Raman and surface enhanced Raman spectroscopic studies of citrazinic acid aided by theoretical calculations.

    PubMed

    Sarkar, Sougata; Chowdhury, Joydeep; Dutta, Soumen; Pal, Tarasankar

    2016-12-01

    A pH dependent normal Raman scattering (NRS) and surface enhanced Raman scattering (SERS) spectral patterns of citrazinic acid (CZA), a biologically important molecule, have been investigated. The acid, with different pKa values (~4 and ~11) for the two different functional groups (-COOH and -OH groups), shows interes