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Sample records for asymmetric arginine dimethylation

  1. Asymmetric Dimethyl Arginine in Hypothyroid Patients

    International Nuclear Information System (INIS)

    Abdel-Messeih, P.L.

    2012-01-01

    Thyroid diseases may lead to endothelial dysfunction, however, the mechanism underlying the endothelial dysfunction in thyroid disease is still not clear. Asymmetric dimethyl arginine (ADMA), a novel inhibitor of endothelial nitric oxide synthetase (eNOS), was reported to inhibit nitric oxide (NO) synthesis from L-arginine. The present study was carried out to investigate ADMA levels together with effects of dislipidemia in sub-clinical and overt hypothyroid females. There were significant increase in the levels of total cholesterol, low density lipoprotein-cholesterol (LDL-c), high density lipoprotein-cholesterol (HDL-c), thyroid stimulating hormone (TSH) and ADMA in hypothyroid females as compared to controls while the levels of NO and free T 4 were significantly decreased than controls. Sub-clinical hypothyroid females had significant high TSH, LDL-c and non-significantly high ADMA levels and total cholesterol as compared to controls while they had significant decrease in NO, HDL-c and non-significant decrease in free T 4 as compared to controls. There were significant negative correlations between NO and both ADMA (r 2 = 0.84) and free T 4 (r 2 = 0.95) in overt hypothyroid group while significant positive correlation (r 2 = 0.85) was detected between TSH and HDL-c in the same group. These results are highly suggestive that the decrease of nitric oxide secondary to accumulation of ADMA represent an important pathogenic factor together with dyslipidemia in endothelial dysfunction and increased cardiovascular risk especially in hypothyroid females

  2. Asymmetric Dimethyl Arginine in Hypothyroid Patients

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Messeih, P. L. [Health Radiation Research Department, National Centre for Radiation Research and Technology, Cairo (Egypt)

    2012-07-01

    Thyroid diseases may lead to endothelial dysfunction, however, the mechanism underlying the endothelial dysfunction in thyroid disease is still not clear. Asymmetric dimethyl arginine (ADMA), a novel inhibitor of endothelial nitric oxide synthetase (eNOS), was reported to inhibit nitric oxide (NO) synthesis from L-arginine. The present study was carried out to investigate ADMA levels together with effects of dislipidemia in sub-clinical and overt hypothyroid females. There were significant increase in the levels of total cholesterol, low density lipoprotein-cholesterol (LDL-c), high density lipoprotein-cholesterol (HDL-c), thyroid stimulating hormone (TSH) and ADMA in hypothyroid females as compared to controls while the levels of NO and free T{sub 4} were significantly decreased than controls. Sub-clinical hypothyroid females had significant high TSH, LDL-c and non-significantly high ADMA levels and total cholesterol as compared to controls while they had significant decrease in NO, HDL-c and non-significant decrease in free T{sub 4} as compared to controls. There were significant negative correlations between NO and both ADMA (r{sup 2} = 0.84) and free T{sub 4} (r{sup 2} = 0.95) in overt hypothyroid group while significant positive correlation (r{sup 2} = 0.85) was detected between TSH and HDL-c in the same group. These results are highly suggestive that the decrease of nitric oxide secondary to accumulation of ADMA represent an important pathogenic factor together with dyslipidemia in endothelial dysfunction and increased cardiovascular risk especially in hypothyroid females.

  3. Low plasma arginine:asymmetric dimethyl arginine ratios predict mortality after intracranial aneurysm rupture

    DEFF Research Database (Denmark)

    Staalsø, Jonatan Myrup; Bergström, Anita; Edsen, Troels

    2013-01-01

    Asymmetrical dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthases, predicts mortality in cardiovascular disease and has been linked to cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH). In this prospective study, we assessed whether circulating ADMA, arginine...

  4. Asymmetric Arginine dimethylation of Epstein-Barr virus nuclear antigen 2 promotes DNA targeting

    International Nuclear Information System (INIS)

    Gross, Henrik; Barth, Stephanie; Palermo, Richard D.; Mamiani, Alfredo; Hennard, Christine; Zimber-Strobl, Ursula; West, Michelle J.; Kremmer, Elisabeth; Graesser, Friedrich A.

    2010-01-01

    The Epstein-Barr virus (EBV) growth-transforms B-lymphocytes. The virus-encoded nuclear antigen 2 (EBNA2) is essential for transformation and activates gene expression by association with DNA-bound transcription factors such as RBPJκ (CSL/CBF1). We have previously shown that EBNA2 contains symmetrically dimethylated Arginine (sDMA) residues. Deletion of the RG-repeat results in a reduced ability of the virus to immortalise B-cells. We now show that the RG repeat also contains asymmetrically dimethylated Arginines (aDMA) but neither non-methylated (NMA) Arginines nor citrulline residues. We demonstrate that only aDMA-containing EBNA2 is found in a complex with DNA-bound RBPJκ in vitro and preferentially associates with the EBNA2-responsive EBV C, LMP1 and LMP2A promoters in vivo. Inhibition of methylation in EBV-infected cells results in reduced expression of the EBNA2-regulated viral gene LMP1, providing additional evidence that methylation is a prerequisite for DNA-binding by EBNA2 via association with the transcription factor RBPJκ.

  5. Asymmetric dimethyl-L-arginine (ADMA): a possible link between homocyst(e)ine and endothelial dysfunction.

    Science.gov (United States)

    Stühlinger, Markus C; Stanger, Olaf

    2005-02-01

    Hyperhomocyst(e)inemia is associated with an increased risk for atherosclerotic disease and venous thromboembolism. The impact of elevated plasma homocysteine levels seems to be clinically relevant, since the total cardiovascular risk of hyperhomocyst(e)inemia is comparable to the risk associated with hyperlipidemia or smoking. There is substantial evidence for impairment of endothelial function in human and animal models of atherosclerosis, occurring even before development of overt plaques. Interestingly endothelial dysfunction appears to be a sensitive indicator of the process of atherosclerotic lesion development and predicts future vascular events. NO is the most potent endogenous vasodilator known. It is released by the endothelium, and reduced NO bioavailability is responsible for impaired endothelium-dependent vasorelaxation in hyperhomocyst(e)inemia and other metabolic disorders associated with vascular disease. Substances leading to impaired endothelial function as a consequence of reduced NO generation are endogenous NO synthase inhibitors such as ADMA. Indeed there is accumulating evidence from animal and human studies that ADMA, endothelial function and homocyst(e)ine might be closely interrelated. Specifically elevations of ADMA associated with impaired endothelium-dependent relaxation were found in chronic hyperhomocyst(e)inemia, as well as after acute elevation of plasma homocyst(e)ine following oral methionine intake. The postulated mechanisms for ADMA accumulation are increased methylation of arginine residues within proteins, as well as reduced metabolism of ADMA by the enzyme DDAH, but they still need to be confirmed to be operative in vivo. Hyperhomocyst(e)inemia, as well as subsequent endothelial dysfunction can be successfully treated by application of folate and B vitamins. Since ADMA seems to play a central role in homocyst(e)ine-induced endothelial dysfunction, another way of preventing vascular disease in patients with elevated homocyst

  6. Effect of keto amino acids on asymmetric dimethyl arginine, muscle and fat tissue in chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Vladimir Teplan

    2012-06-01

    Full Text Available Levels of endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA are elevated in chronic kidney disease (CKD and may contribute to vascular complications. In this study we tested the hypothesis that elevated ADMA can be reduced in CKD patients by long-term administration of low-protein diet (LPD supplemented with keto amino acids (KA. In a long-term prospective double blind placebo controlled randomized trial, we evaluated a total of 120 CKD patients (62/58F aged 22-76 yrs with creatinine clearance 22-40mL/min/1.73m2 for a period of 36 months. All patients were on low-protein diet containing 0.6 protein/kg/IBW/day and 120-125/kJ/kg/IBW/day. LPD was randomly supplemented with KA at dosage of 100 mg/kg/IBW/day (61 patients, Group I while 59 patients (Group II received placebo. During the study period, glomerular filtration rate (GFR slightly decreased (Ccr from 34.2±11.6 to 29.9±9.2 mL/min and 33.5±11.6 to 22.2±10.4 mL/min in Group I and II, respectively; this however was more marked in Group II (p<0.01. Fat in muscle measured by MR spectroscopy (MRS, m.tibialis anterior significantly decreased in Group I and was linked to reduced volume of visceral fat measured by MRI (p<0.01. Reduction of fat in Group II was not significant. In Group I, there was a significant decrease in the plasma level of ADMA (from 2.4±0.4 to 1.2±0.3 μmol/L, p<0.01, but ADMA remained unchanged in Group II. A further remarkable finding was reduction in the plasma concentration of pentosidine (from 486±168 to 325±127 μg/L, p<0.01 and decrease of proteinuria (from 3.7±2.20 to 1.6±1.2 g/24hrs, p<0.01 in Group I. Plasma adiponectin (ADPN in Group I rose (p<0.01. Analysis of lipid spectrum revealed a mild yet significant decrease in total cholesterol and LPD-cholesterol (p<0.01, more pronounced in Group I. In Group I, there was a decrease in plasma triglycerides (from 3.8±1.5 down to 2.3±0.5 mmol/L, p<0.01, whereas glycated hemoglobin (HbAc1

  7. How does spa treatment affect cardiovascular function and vascular endothelium in patients with generalized osteoarthritis? A pilot study through plasma asymmetric di-methyl arginine (ADMA) and L-arginine/ADMA ratio

    Science.gov (United States)

    Karaarslan, Fatih; Ozkuk, Kagan; Seringec Karabulut, Serap; Bekpinar, Seldag; Karagulle, Mufit Zeki; Erdogan, Nergis

    2018-05-01

    The study aims to investigate the effect of spa treatment on vascular endothelium and clinical symptoms of generalized osteoarthritis. Forty generalized osteoarthritis (GOA) patients referred to a government spa hospital, and 40 GOA patients followed on university hospital locomotor system disease ambulatory clinics were included as study and control groups, respectively. Study group received spa treatment including thermal water baths, physical therapy modalities, and exercises. Control group was followed with home exercises for 15 days. Plasma ADMA, L-arginine, L-arginine/ADMA ratio, routine blood analyses, 6-min walking test, including fingertip O2 saturation, systolic/diastolic blood pressure, and pulse rate, were measured at the beginning and at the end of treatment. Groups were evaluated with VAS pain, patient, and physician global assessment; HAQ; and WOMAC at the beginning, at the end, and after 1 month of treatment. In study group, L-arginine and L-arginine/ADMA ratio showed statistically significant increase after treatment. Plasma ADMA levels did not change. There is no significant difference in intergroup comparison. Study group displayed statistically significant improvements in all clinical parameters. The study showed that spa treatment does not cause any harm to the vascular endothelium through ADMA. Significant increase in plasma L-arginine and L-arginine/ADMA ratio suggests that balneotherapy may play a preventive role on cardiovascular diseases. Balneotherapy provides meaningful improvements on clinical parameters of GOA.

  8. How does spa treatment affect cardiovascular function and vascular endothelium in patients with generalized osteoarthritis? A pilot study through plasma asymmetric di-methyl arginine (ADMA) and L-arginine/ADMA ratio

    Science.gov (United States)

    Karaarslan, Fatih; Ozkuk, Kagan; Seringec Karabulut, Serap; Bekpinar, Seldag; Karagulle, Mufit Zeki; Erdogan, Nergis

    2017-12-01

    The study aims to investigate the effect of spa treatment on vascular endothelium and clinical symptoms of generalized osteoarthritis. Forty generalized osteoarthritis (GOA) patients referred to a government spa hospital, and 40 GOA patients followed on university hospital locomotor system disease ambulatory clinics were included as study and control groups, respectively. Study group received spa treatment including thermal water baths, physical therapy modalities, and exercises. Control group was followed with home exercises for 15 days. Plasma ADMA, L-arginine, L-arginine/ADMA ratio, routine blood analyses, 6-min walking test, including fingertip O2 saturation, systolic/diastolic blood pressure, and pulse rate, were measured at the beginning and at the end of treatment. Groups were evaluated with VAS pain, patient, and physician global assessment; HAQ; and WOMAC at the beginning, at the end, and after 1 month of treatment. In study group, L-arginine and L-arginine/ADMA ratio showed statistically significant increase after treatment. Plasma ADMA levels did not change. There is no significant difference in intergroup comparison. Study group displayed statistically significant improvements in all clinical parameters. The study showed that spa treatment does not cause any harm to the vascular endothelium through ADMA. Significant increase in plasma L-arginine and L-arginine/ADMA ratio suggests that balneotherapy may play a preventive role on cardiovascular diseases. Balneotherapy provides meaningful improvements on clinical parameters of GOA.

  9. Organocatalytic asymmetric michael addition of aldehydes to beta-nitroacroleine dimethyl acetal.

    Science.gov (United States)

    Reyes, Efraim; Vicario, Jose L; Badía, Dolores; Carrillo, Luisa

    2006-12-21

    [Structure: see text] The organocatalytic asymmetric Michael addition of aldehydes to beta-nitroacroleine dimethyl acetal has been studied in detail. The reaction took place with excellent yields and high stereoselectivities when a chiral beta-amino alcohol such as L-prolinol was employed as the catalyst, leaving a formation of highly functionalized enantioenriched compounds containing two differentiated formyl groups together with a nitro moiety.

  10. Effect of methylation on the side-chain pKa value of arginine.

    Science.gov (United States)

    Evich, Marina; Stroeva, Ekaterina; Zheng, Yujun George; Germann, Markus W

    2016-02-01

    Arginine methylation is important in biological systems. Recent studies link the deregulation of protein arginine methyltransferases with certain cancers. To assess the impact of methylation on interaction with other biomolecules, the pKa values of methylated arginine variants were determined using NMR data. The pKa values of monomethylated, symmetrically dimethylated, and asymmetrically dimethylated arginine are similar to the unmodified arginine (14.2 ± 0.4). Although the pKa value has not been significantly affected by methylation, consequences of methylation include changes in charge distribution and steric effects, suggesting alternative mechanisms for recognition. © 2015 The Protein Society.

  11. An Arginine Finger Regulates the Sequential Action of Asymmetrical Hexameric ATPase in the Double-Stranded DNA Translocation Motor.

    Science.gov (United States)

    Zhao, Zhengyi; De-Donatis, Gian Marco; Schwartz, Chad; Fang, Huaming; Li, Jingyuan; Guo, Peixuan

    2016-10-01

    Biological motors are ubiquitous in living systems. Currently, how the motor components coordinate the unidirectional motion is elusive in most cases. Here, we report that the sequential action of the ATPase ring in the DNA packaging motor of bacteriophage ϕ29 is regulated by an arginine finger that extends from one ATPase subunit to the adjacent unit to promote noncovalent dimer formation. Mutation of the arginine finger resulted in the interruption of ATPase oligomerization, ATP binding/hydrolysis, and DNA translocation. Dimer formation reappeared when arginine mutants were mixed with other ATPase subunits that can offer the arginine to promote their interaction. Ultracentrifugation and virion assembly assays indicated that the ATPase was presenting as monomers and dimer mixtures. The isolated dimer alone was inactive in DNA translocation, but the addition of monomer could restore the activity, suggesting that the hexameric ATPase ring contained both dimer and monomers. Moreover, ATP binding or hydrolysis resulted in conformation and entropy changes of the ATPase with high or low DNA affinity. Taking these observations together, we concluded that the arginine finger regulates sequential action of the motor ATPase subunit by promoting the formation of the dimer inside the hexamer. The finding of asymmetrical hexameric organization is supported by structural evidence of many other ATPase systems showing the presence of one noncovalent dimer and four monomer subunits. All of these provide clues for why the asymmetrical hexameric ATPase gp16 of ϕ29 was previously reported as a pentameric configuration by cryo-electron microscopy (cryo-EM) since the contact by the arginine finger renders two adjacent ATPase subunits closer than other subunits. Thus, the asymmetrical hexamer would appear as a pentamer by cryo-EM, a technology that acquires the average of many images. Copyright © 2016 Zhao et al.

  12. Heat capacities and asymmetric criticality of the (liquid + liquid) coexistence curves for {dimethyl carbonate + n-undecane, or n-tridecane}

    International Nuclear Information System (INIS)

    Chen, Zhiyun; Shi, Aiqin; Liu, Shixia; Yin, Tianxiang; Shen, Weiguo

    2014-01-01

    Highlights: • Coexistence curves of dimethyl carbonate + n-undecane (or + n-tridecane) were measured. • Isobaric heat capacity per unit volume of critical binary solutions dimethyl carbonate + n-undecane (or + n-tridecane) were determined. • The critical exponent β are consistent with the 3D-Ising value. • The asymmetry of the coexistence curves were discussed by the complete scaling theory. - Abstract: The (liquid + liquid) coexistences and the critical behavior of isobaric heat capacity per unit volume for critical binary solutions {dimethyl carbonate + n-undecane, or n-tridecane} have been studied. The critical exponents β and α were deduced and found to be consistent with the 3D-Ising values. The critical amplitudes were determined and used to test the asymmetric criticality of coexistence curves. It was found that the heat capacity does play an important role in describing the asymmetric criticality of the coexistence curves

  13. Impaired endothelial function after aneurysmal subarachnoid haemorrhage correlates with arginine:asymmetric dimethylarginine ratio

    DEFF Research Database (Denmark)

    Bergström, A; Staalsø, J M; Romner, B

    2014-01-01

    BACKGROUND: Endothelial dysfunction might be involved in the development of cerebral vasospasm after aneurysmal subarachnoid haemorrhage (SAH). METHODS: This prospective observational study of 48 SAH subjects and 23 control subjects examined associations between reactive hyperaemia index (RHI....... Five consecutive measurements were obtained at days 0-2, 3-5, 6-8, 9-11, and 12-15. RESULTS: RHI was 1.67 (0.46) at days 0-2 after SAH but increased at days 3-15 to the same levels as in controls (P... and arginine:ADMA ratio (r=0.43, P

  14. PRMT1-mediated arginine methylation controls ATXN2L localization

    Energy Technology Data Exchange (ETDEWEB)

    Kaehler, Christian; Guenther, Anika; Uhlich, Anja; Krobitsch, Sylvia, E-mail: krobitsc@molgen.mpg.de

    2015-05-15

    Arginine methylation is a posttranslational modification that is of importance in diverse cellular processes. Recent proteomic mass spectrometry studies reported arginine methylation of ataxin-2-like (ATXN2L), the paralog of ataxin-2, a protein that is implicated in the neurodegenerative disorder spinocerebellar ataxia type 2. Here, we investigated the methylation state of ATXN2L and its significance for ATXN2L localization. We first confirmed that ATXN2L is asymmetrically dimethylated in vivo, and observed that the nuclear localization of ATXN2L is altered under methylation inhibition. We further discovered that ATXN2L associates with the protein arginine-N-methyltransferase 1 (PRMT1). Finally, we showed that neither mutation of the arginine–glycine-rich motifs of ATXN2L nor methylation inhibition alters ATXN2L localization to stress granules, suggesting that methylation of ATXN2L is probably not mandatory. - Highlights: • ATXN2L is asymmetrically dimethylated in vivo. • ATXN2L interacts with PRMT1 under normal and stress conditions. • PRMT1-mediated dimethylation of ATXN2L controls its nuclear localization. • ATXN2L localization to stress granules appears independent of its methylation state.

  15. Comparison of Three Sample Preparation Procedures for the Quantification of L-Arginine, Asymmetric Dimethylarginine, and Symmetric Dimethylarginine in Human Plasma Using HPLC-FLD

    DEFF Research Database (Denmark)

    Schou-Pedersen, Anne Marie Voigt; Lykkesfeldt, Jens

    2018-01-01

    Increased asymmetric dimethylarginine (ADMA) in human plasma has been associated with reduced generation of nitric oxide, leading to atherosclerotic diseases. ADMA may therefore be an important biomarker for cardiovascular disease. In the present study, three sample preparation techniques were co...... sample preparation of human plasma samples before HPLC-FLD in providing important information regarding elevated ADMA concentrations.......Increased asymmetric dimethylarginine (ADMA) in human plasma has been associated with reduced generation of nitric oxide, leading to atherosclerotic diseases. ADMA may therefore be an important biomarker for cardiovascular disease. In the present study, three sample preparation techniques were...... compared regarding the quantification of L-arginine and ADMA in human plasma: (A) protein precipitation (PP) based on aqueous trichloroacetic acid (TCA), (B) PP using a mixture of ammonia and acetonitrile, and (C) solid-phase extraction (SPE). The samples were analysed by using high-performance liquid...

  16. Comparison of Three Sample Preparation Procedures for the Quantification of L-Arginine, Asymmetric Dimethylarginine, and Symmetric Dimethylarginine in Human Plasma Using HPLC-FLD

    Science.gov (United States)

    Schou-Pedersen, Anne Marie Voigt

    2018-01-01

    Increased asymmetric dimethylarginine (ADMA) in human plasma has been associated with reduced generation of nitric oxide, leading to atherosclerotic diseases. ADMA may therefore be an important biomarker for cardiovascular disease. In the present study, three sample preparation techniques were compared regarding the quantification of L-arginine and ADMA in human plasma: (A) protein precipitation (PP) based on aqueous trichloroacetic acid (TCA), (B) PP using a mixture of ammonia and acetonitrile, and (C) solid-phase extraction (SPE). The samples were analysed by using high-performance liquid chromatography with fluorescence detection (HPLC-FLD). The analytical performance of (A) was comparable with that of (C), demonstrating recoveries of >90%, coefficient of variations (CVs, %) of 0.994), precision (sample preparation of human plasma samples before HPLC-FLD in providing important information regarding elevated ADMA concentrations. PMID:29484214

  17. Asymmetric dimethyl arginine induces pulmonary vascular dysfunction via activation of signal transducer and activator of transcription 3 and stabilization of hypoxia-inducible factor 1-alpha

    Czech Academy of Sciences Publication Activity Database

    Pekarová, Michaela; Koudelka, Adolf; Kolářová, Hana; Ambrožová, Gabriela; Klinke, A.; Černá, A.; Kadlec, J.; Trundová, Mária; Šindlerová, Lenka; Kuchta, R.; Kuchtová, Z.; Lojek, Antonín; Kubala, Lukáš

    2015-01-01

    Roč. 73, OCT 2015 (2015), s. 138-148 ISSN 1537-1891 R&D Projects: GA ČR(CZ) GP13-40882P; GA MŠk(CZ) EE2.3.30.0030 Grant - others:GAAV(CZ) M200041208 Institutional support: RVO:68081707 Keywords : NITRIC-OXIDE PRODUCTION * SMOOTH-MUSCLE-CELLS * ARTERIAL-HYPERTENSION Subject RIV: BO - Biophysics; EI - Biotechnology ; Bionics (BTO-N) Impact factor: 2.500, year: 2015

  18. The L-arginine/asymmetric dimethylarginine ratio is improved by anti-tumor necrosis factor-α therapy in inflammatory arthropathies. Associations with aortic stiffness.

    Science.gov (United States)

    Angel, Kristin; Provan, Sella Aarrestad; Mowinckel, Petter; Seljeflot, Ingebjørg; Kvien, Tore Kristian; Atar, Dan

    2012-11-01

    Anti-Tumor Necrosis Factor (TNF)-α therapy improves vascular pathology in inflammatory arthropathies such as rheumatoid arthritis, ankylosing spondylitis and psoriatic arthritis. The l-arginine/ADMA ratio is important for modulation of the nitric oxide synthase activity. We examined the effect of TNF-α antagonists on ADMA and l-arginine/ADMA, and associations between ADMA, L-arginine/ADMA, aortic stiffness and carotid intima media thickness (CIMT) in patients with inflammatory arthropathies. Forty-eight patients who started with anti-TNF-α therapy were compared with a non-treated group of 32 patients. Plasma ADMA and L-arginine were assessed at baseline, 3 and 12 months. In a subgroup of 55 patients, aortic pulse wave velocity (aPWV) was measured at baseline, 3 and 12 moths, and CIMT was examined at baseline and 12 months. Anti-TNF-α therapy increased the L-arginine/ADMA ratio (mean [SD]) in the treatment group compared to the control group after 3 months (12 [29] vs. -13 [20], P < 0.001) and 12 months (7 [27] vs. -8 [19], P = 0.008), but did not affect ADMA (3 months: 0.00 [0.09] μmol/L vs. 0.02 [0.07] μmol/L, P = 0.42, 12 months: 0.01 [0.08] μmol/L vs. 0.01 [0.09] μmol/L, P = 0.88). Baseline aPWV was associated with ADMA (P = 0.02) and L-arginine/ADMA (P = 0.02) in multiple regression analyses, and the L-arginine/ADMA ratio was continuously associated with aPWV after initiation of anti-TNF-α therapy (P = 0.03). ADMA and L-arginine/ADMA were not correlated with CIMT. Anti-TNF-α therapy improved the L-arginine/ADMA ratio in patients with inflammatory arthropathies. ADMA and the L-arginine/ADMA ratio were associated with aPWV, and might have a mechanistic role in the aortic stiffening observed in these patients. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  19. Effects of L-cysteine and N-acetyl-L-cysteine on 4-hydroxy-2, 5-dimethyl-3(2H)-furanone (furaneol), 5-(hydroxymethyl)furfural, and 5-methylfurfural formation and browning in buffer solutions containing either rhamnose or glucose and arginine.

    Science.gov (United States)

    Haleva-Toledo, E; Naim, M; Zehavi, U; Rouseff, R L

    1999-10-01

    Solutions of L-cysteine (Cys) and N-acetyl-L-cysteine (AcCys), containing glucose or rhamnose, with or without arginine, were buffered to pH 3, 5, and 7 and incubated at 70 degrees C for 48 h. Cys and AcCys inhibited the formation of (hydroxymethyl)furfural (HMF) from glucose and methylfurfural (MF) from rhamnose under acidic conditions. AcCys inhibited the accumulation of 4-hydroxy-2, 5-dimethyl- 3(2H)-furanone (DMHF, Furaneol) from rhamnose, but Cys, under our experimental conditions, enhanced Furaneol accumulation from rhamnose. Cys and AcCys reacted directly with Furaneol but not with HMF or MF. Both Cys and AcCys inhibited nonenzymatic browning at pH 7. At pH 3, however, Cys reacted with both glucose and rhamnose to produce unidentified compounds that increased the visible absorbency.

  20. Arginine, citrulline and nitric oxide metabolism in sepsis

    Science.gov (United States)

    Arginine has vasodilatory effects, via its conversion by nitric oxide (NO) synthase into NO, and immunomodulatory actions that play important roles in sepsis. Protein breakdown affects arginine availability, and the release of asymmetric dimethylarginine, an inhibitor of NO synthase, may therefore a...

  1. Histone H3 Methylated at Arginine 17 Is Essential for Reprogramming the Paternal Genome in Zygotes

    Directory of Open Access Journals (Sweden)

    Yuki Hatanaka

    2017-09-01

    Full Text Available At fertilization, the paternal genome undergoes extensive reprogramming through protamine-histone exchange and active DNA demethylation, but only a few maternal factors have been defined in these processes. We identified maternal Mettl23 as a protein arginine methyltransferase (PRMT, which most likely catalyzes the asymmetric dimethylation of histone H3R17 (H3R17me2a, as indicated by in vitro assays and treatment with TBBD, an H3R17 PRMT inhibitor. Maternal histone H3.3, which is essential for paternal nucleosomal assembly, is unable to be incorporated into the male pronucleus when it lacks R17me2a. Mettl23 interacts with Tet3, a 5mC-oxidizing enzyme responsible for active DNA demethylation, by binding to another maternal factor, GSE (gonad-specific expression. Depletion of Mettl23 from oocytes resulted in impaired accumulation of GSE, Tet3, and 5hmC in the male pronucleus, suggesting that Mettl23 may recruit GSE-Tet3 to chromatin. Our findings establish H3R17me2a and its catalyzing enzyme Mettl23 as key regulators of paternal genome reprogramming.

  2. The Arginine/ADMA Ratio Is Related to the Prevention of Atherosclerotic Plaques in Hypercholesterolemic Rabbits When Giving a Combined Therapy with Atorvastatine and Arginine

    Directory of Open Access Journals (Sweden)

    Saskia J. H. Brinkmann

    2015-05-01

    Full Text Available Supplementation with arginine in combination with atorvastatin is more efficient in reducing the size of an atherosclerotic plaque than treatment with a statin or arginine alone in homozygous Watanabe heritable hyperlipidemic (WHHL rabbits. We evaluated the mechanism behind this feature by exploring the role of the arginine/asymmetric dimethylarginine (ADMA ratio, which is the substrate and inhibitor of nitric oxide synthase (NOS and thereby nitric oxide (NO, respectively. Methods: Rabbits were fed either an arginine diet (group A, n = 9, standard rabbit chow plus atorvastatin (group S, n = 8, standard rabbit chow plus an arginine diet with atorvastatin (group SA, n = 8 or standard rabbit chow (group C, n = 9 as control. Blood was sampled and the aorta was harvested for topographic and histological analysis. Plasma levels of arginine, ADMA, cholesterol and nitric oxide were determined and the arginine/ADMA ratio was calculated. Results: The decrease in ADMA levels over time was significantly correlated to fewer aortic lesions in the distal aorta and total aorta. The arginine/ADMA ratio was correlated to cholesterol levels and decrease in cholesterol levels over time in the SA group. A lower arginine/ADMA ratio was significantly correlated to lower NO levels in the S and C group. Discussion: A balance between arginine and ADMA is an important indicator in the prevention of the development of atherosclerotic plaques.

  3. Karakteristik Membran Asimetris Polietersufone (PES dengan Pelarut Dimetil Formamide dan N-Metil-2-Pyrolidone - (Characteristic of Poliethersulfone (PES Asymmetric Membrane with Dimethyl Formamide and N-Methyl Pyrolidone as Solvent

    Directory of Open Access Journals (Sweden)

    Sri Mulyati

    2017-06-01

    Full Text Available Membrane that is generally used for separation process could be made using phase inversion technique. This research aims to create polyethersulfone (PES asymmetric membranes via phase inversion technique using solvent and Trans Membrane Pressure (TMP as variable. SEM analysis indicated that membranes had asymmetric structure that consits of two layers which denser skin layer on the top surface and the porous support on the bottom. PES/DMF membrane showed larger pore structure than PES/NMP. The permeability coefficients of both membranes were in the ultrafiltration range. The coefficient permeability (Lp of PES/DMF membrane was 35.769 L/m2.hour, much greater compared to PES/NMP membrane which was 15.364 L/m2.hour.bar. Molecular Weight Cut-Off (MWCO of PES/DMF membrane was 177 Kda, meanwhile PES/NMP was 186 Kda. Performances of the membranes were evaluated  using dextrane as feed solution. PES/DMF membrane resulted in an higher flux and lower rejection than PES/NMP.Keywords: asymmetric membrane, membrane performance, Molecular Weight Cut-Off (MWCO, morphology, permeability ABSTRAKMembran yang umumnya digunakan untuk proses pemisahan dapat dibuat menggunakan teknik inversi fasa. Penelitian ini bertujuan untuk mengetahui karakteristik membran asimetris polietersulfone (PES yang dibuat menggunakan teknik inversi fasa dengan variabel jenis pelarut dan Trans Membrane Pressure (TMP. Hasil analisis Scanning Electron Microscopy (SEM terhadap morfologi membran membuktikan bahwa membran yang dihasilkan merupakan membran asimetris yang terdiri dari dua lapisan yaitu bagian atas merupakan lapisan tipis dan lapisan bawah adalah lapisan berpori. Membran PES/DMF memiliki struktur pori yang lebih besar dibandingkan membran PES/NMP. Koefisien permeabilitas kedua membran yang dihasilkan berada dalam jangkauan ultrafiltrasi. Koefisien permeabilitas (Lp membran PES/DMF sebesar 35,769 L/m2.jam, nilai ini jauh lebih besar dibandingkan PES/NMP yaitu 15,364 L/m2.jam

  4. Online trapping and enrichment ultra performance liquid chromatography–tandem mass spectrometry method for sensitive measurement of “arginine-asymmetric dimethylarginine cycle” biomarkers in human exhaled breath condensate

    International Nuclear Information System (INIS)

    Di Gangi, Iole Maria; Pirillo, Paola; Carraro, Silvia; Gucciardi, Antonina; Naturale, Mauro; Baraldi, Eugenio; Giordano, Giuseppe

    2012-01-01

    Highlights: ► Simultaneous quantification of “arginine-ADMA cycle” metabolites developed in EBC. ► EBC is a non-invasive matrix highly useful in patients with respiratory diseases. ► Method, fast, precise and accurate, is suitable in the pediatric clinical studies. ► Sensitivity is increased using on-line trapping and enrichment-UPLC–MS/MS method. ► EBC measurements in asthmatic adolescents confirm that ADMA is increased in asthma. - Abstract: Background: Exhaled breath condensate (EBC) is a biofluid collected non invasively that, enabling the measurement of several biomarkers, has proven useful in the study of airway inflammatory diseases, including asthma, COPD and cystic fibrosis. To the best of our knowledge, there is no previous report of any analytical method to detect ADMA in EBC. Objectives: Aim of this work was to develop an online sample trapping and enrichment system, coupled with an UPLC–MS/MS method, for simultaneous quantification of seven metabolites related to “Arginine-ADMA cycle”, using the isotopic dilution. Methods: Butylated EBC samples were trapped in an online cartridge, washed before and after each injection with cleanup solution to remove matrix components and switched inline into the high pressure analytical column. Multiple reaction monitoring in positive mode was used for analyte quantification by tandem mass spectrometry. Results: Validation studies were performed in EBC to examine accuracy, precision and robustness of the method. For each compound, the calibration curves showed a coefficient of correlation (r 2 ) greater than 0.992. Accuracy (%Bias) was −1 ), measured in EBC samples of asthmatic adolescents are significantly increased (p < 0.0001) than in normal controls (0.0040 ± 0.0021 vs. 0.0012 ± 0.0005 and 0.0020 ± 0.0015 vs. 0.0002 ± 0.0001, respectively), as well the ADMA/Tyr (0.34 ± 0.09 vs. 0.12 ± 0.02, p < 0.0001) and the SDMA/Tyr ratio (0.10 ± 0.04 vs. 0.015 ± 0.004, p < 0.0001). Conclusions

  5. Online trapping and enrichment ultra performance liquid chromatography-tandem mass spectrometry method for sensitive measurement of 'arginine-asymmetric dimethylarginine cycle' biomarkers in human exhaled breath condensate

    Energy Technology Data Exchange (ETDEWEB)

    Di Gangi, Iole Maria, E-mail: giordano@pediatria.unipd.it [Chromatography and Mass Spectrometry Laboratory, Department of Women' s and Children' s Health, University of Padova (Italy); Pirillo, Paola [Chromatography and Mass Spectrometry Laboratory, Department of Women' s and Children' s Health, University of Padova (Italy); Carraro, Silvia [Unit of Allergy and Respiratory Diseases, Department of Women' s and Children' s Health, University of Padova (Italy); Gucciardi, Antonina; Naturale, Mauro [Chromatography and Mass Spectrometry Laboratory, Department of Women' s and Children' s Health, University of Padova (Italy); Baraldi, Eugenio [Unit of Allergy and Respiratory Diseases, Department of Women' s and Children' s Health, University of Padova (Italy); Giordano, Giuseppe [Chromatography and Mass Spectrometry Laboratory, Department of Women' s and Children' s Health, University of Padova (Italy)

    2012-11-19

    Highlights: Black-Right-Pointing-Pointer Simultaneous quantification of 'arginine-ADMA cycle' metabolites developed in EBC. Black-Right-Pointing-Pointer EBC is a non-invasive matrix highly useful in patients with respiratory diseases. Black-Right-Pointing-Pointer Method, fast, precise and accurate, is suitable in the pediatric clinical studies. Black-Right-Pointing-Pointer Sensitivity is increased using on-line trapping and enrichment-UPLC-MS/MS method. Black-Right-Pointing-Pointer EBC measurements in asthmatic adolescents confirm that ADMA is increased in asthma. - Abstract: Background: Exhaled breath condensate (EBC) is a biofluid collected non invasively that, enabling the measurement of several biomarkers, has proven useful in the study of airway inflammatory diseases, including asthma, COPD and cystic fibrosis. To the best of our knowledge, there is no previous report of any analytical method to detect ADMA in EBC. Objectives: Aim of this work was to develop an online sample trapping and enrichment system, coupled with an UPLC-MS/MS method, for simultaneous quantification of seven metabolites related to 'Arginine-ADMA cycle', using the isotopic dilution. Methods: Butylated EBC samples were trapped in an online cartridge, washed before and after each injection with cleanup solution to remove matrix components and switched inline into the high pressure analytical column. Multiple reaction monitoring in positive mode was used for analyte quantification by tandem mass spectrometry. Results: Validation studies were performed in EBC to examine accuracy, precision and robustness of the method. For each compound, the calibration curves showed a coefficient of correlation (r{sup 2}) greater than 0.992. Accuracy (%Bias) was <3% except for NMMA and H-Arg (<20%), intra- and inter-assay precision (expressed as CV%) were within {+-}20% and recovery ranged from 97.1 to 102.8% for all analytes. Inter-day variability analysis on 20 EBC of adult subjects did

  6. Restoration of impaired nitric oxide production in MELAS syndrome with citrulline and arginine supplementation.

    Science.gov (United States)

    El-Hattab, Ayman W; Hsu, Jean W; Emrick, Lisa T; Wong, Lee-Jun C; Craigen, William J; Jahoor, Farook; Scaglia, Fernando

    2012-04-01

    Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is one of the most common mitochondrial disorders. Although the pathogenesis of stroke-like episodes remains unclear, it has been suggested that mitochondrial proliferation may result in endothelial dysfunction and decreased nitric oxide (NO) availability leading to cerebral ischemic events. This study aimed to assess NO production in subjects with MELAS syndrome and the effect of the NO precursors arginine and citrulline. Using stable isotope infusion techniques, we assessed arginine, citrulline, and NO metabolism in control subjects and subjects with MELAS syndrome before and after arginine or citrulline supplementation. The results showed that subjects with MELAS had lower NO synthesis rate associated with reduced citrulline flux, de novo arginine synthesis rate, and plasma arginine and citrulline concentrations, and higher plasma asymmetric dimethylarginine (ADMA) concentration and arginine clearance. We conclude that the observed impaired NO production is due to multiple factors including elevated ADMA, higher arginine clearance, and, most importantly, decreased de novo arginine synthesis secondary to decreased citrulline availability. Arginine and, to a greater extent, citrulline supplementation increased the de novo arginine synthesis rate, the plasma concentrations and flux of arginine and citrulline, and NO production. De novo arginine synthesis increased markedly with citrulline supplementation, explaining the superior efficacy of citrulline in increasing NO production. The improvement in NO production with arginine or citrulline supplementation supports their use in MELAS and suggests that citrulline may have a better therapeutic effect than arginine. These findings can have a broader relevance for other disorders marked by perturbations in NO metabolism. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. The Ergogenic Potential of Arginine

    Directory of Open Access Journals (Sweden)

    La Bounty Paul M

    2004-12-01

    Full Text Available Abstract Arginine is a conditionally essential amino acid that is involved in protein synthesis, the detoxification of ammonia, and its conversion to glucose as well as being catabolized to produce energy. In addition to these physiological functions, arginine has been purported to have ergogenic potential. Athletes have taken arginine for three main reasons: 1 its role in the secretion of endogenous growth hormone; 2 its involvement in the synthesis of creatine; 3 its role in augmenting nitric oxide. These aspects of arginine supplementation will be discussed as well as a review of clinical investigations involving exercise performance and arginine ingestion.

  8. The Hydrophobic Region of the DmsA Twin-Arginine Leader Peptide Determines Specificity with Chaperone DmsD

    OpenAIRE

    Winstone, Tara M. L.; Tran, Vy A.; Turner, Raymond J.

    2013-01-01

    The system specific chaperone DmsD plays a role in the maturation of the catalytic subunit of dimethyl sulfoxide (DMSO) reductase, DmsA. Pre-DmsA contains a 45-amino acid twin-arginine leader peptide that is important for targeting and translocation of folded and cofactor-loaded DmsA by the twin-arginine translocase. DmsD has previously been shown to interact with the complete twin-arginine leader peptide of DmsA. In this study, isothermal titration calorimetry was used to investigate the the...

  9. PRMT5: A novel regulator of Hepatitis B virus replication and an arginine methylase of HBV core.

    Directory of Open Access Journals (Sweden)

    Barbora Lubyova

    Full Text Available In mammals, protein arginine methyltransferase 5, PRMT5, is the main type II enzyme responsible for the majority of symmetric dimethylarginine formation in polypeptides. Recent study reported that PRMT5 restricts Hepatitis B virus (HBV replication through epigenetic repression of HBV DNA transcription and interference with encapsidation of pregenomic RNA. Here we demonstrate that PRMT5 interacts with the HBV core (HBc protein and dimethylates arginine residues within the arginine-rich domain (ARD of the carboxyl-terminus. ARD consists of four arginine rich subdomains, ARDI, ARDII, ARDIII and ARDIV. Mutation analysis of ARDs revealed that arginine methylation of HBc required the wild-type status of both ARDI and ARDII. Mass spectrometry analysis of HBc identified multiple potential ubiquitination, methylation and phosphorylation sites, out of which lysine K7 and arginines R150 (within ARDI and R156 (outside ARDs were shown to be modified by ubiquitination and methylation, respectively. The HBc symmetric dimethylation appeared to be linked to serine phosphorylation and nuclear import of HBc protein. Conversely, the monomethylated HBc retained in the cytoplasm. Thus, overexpression of PRMT5 led to increased nuclear accumulation of HBc, and vice versa, down-regulation of PRMT5 resulted in reduced levels of HBc in nuclei of transfected cells. In summary, we identified PRMT5 as a potent controller of HBc cell trafficking and function and described two novel types of HBc post-translational modifications (PTMs, arginine methylation and ubiquitination.

  10. Systemic inflammation is linked to low arginine and high ADMA plasma levels resulting in an unfavourable NOS substrate-to-inhibitor ratio: the Hoorn Study

    NARCIS (Netherlands)

    van der Zwan, L.P.; Scheffer, P.G.; Dekker, J.M.; Stehouwer, C.D.A.; Heine, R.J.; Teerlink, T.

    2011-01-01

    Inflammation is associated with a reduced availability of NO in the vasculature. We investigated the possible involvement of altered levels of the substrate (arginine) and the inhibitor [ADMA (asymmetric ω-N

  11. Plasma L-arginine levels distinguish pulmonary arterial hypertension from left ventricular systolic dysfunction.

    Science.gov (United States)

    Sandqvist, Anna; Schneede, Jörn; Kylhammar, David; Henrohn, Dan; Lundgren, Jakob; Hedeland, Mikael; Bondesson, Ulf; Rådegran, Göran; Wikström, Gerhard

    2018-03-01

    Pulmonary arterial hypertension (PAH) is a life-threatening condition, characterized by an imbalance of vasoactive substances and remodeling of pulmonary vasculature. Nitric oxide, formed from L-arginine, is essential for homeostasis and smooth muscle cell relaxation in PAH. Our aim was to compare plasma concentrations of L-arginine, asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA) in PAH compared to left ventricular systolic dysfunction (LVSD) and healthy subjects. This was an observational, multicenter study comparing 21 patients with PAH to 14 patients with LVSD and 27 healthy subjects. Physical examinations were obtained and blood samples were collected. Plasma levels of ADMA, SDMA, L-arginine, L-ornithine, and L-citrulline were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Plasma levels of ADMA and SDMA were higher, whereas L-arginine and L-arginine/ADMA ratio were lower in PAH patients compared to healthy subjects (p L-arginine than patients with LVSD (p L-Arginine correlated to 6 min walking distance (6MWD) (r s  = 0.58, p = 0.006) and L-arginine/ADMA correlated to WHO functional class (r s  = -0.46, p = 0.043) in PAH. In conclusion, L-arginine levels were significantly lower in treatment naïve PAH patients compared to patients with LVSD. Furthermore, L-arginine correlated with 6MWD in PAH. L-arginine may provide useful information in differentiating PAH from LVSD.

  12. Dietary arginine and linear growth

    DEFF Research Database (Denmark)

    van Vught, Anneke J A H; Dagnelie, Pieter C; Arts, Ilja C W

    2013-01-01

    Child Intervention Study during 2001-2 (baseline), and at 3-year and 7-year follow-up, were used. Arginine intake was estimated via a 7 d precoded food diary at baseline and 3-year follow-up. Data were analysed in a multilevel structure in which children were embedded within schools. Random intercept......The amino acid arginine is a well-known growth hormone (GH) stimulator and GH is an important modulator of linear growth. The aim of the present study was to investigate the effect of dietary arginine on growth velocity in children between 7 and 13 years of age. Data from the Copenhagen School...... and slopes were defined to estimate the association between arginine intake and growth velocity, including the following covariates: sex; age; baseline height; energy intake; puberty stage at 7-year follow-up and intervention/control group. The association between arginine intake and growth velocity...

  13. Dimethyl N-cyanodithioiminocarbonate

    Directory of Open Access Journals (Sweden)

    Mouhamadou Birame Diop

    2016-03-01

    Full Text Available The title compound, C4H6N2S2, crystallizes with four independent molecules in the asymmetric unit. Two of the molecules are disordered about a pseudo twofold rotation axis. The mean values of the C—N bonds are 1.143 (5 Å for C[triple-bond]N, 1.302 (5 Å for C=N and 1.341 (5 Å for the C—N single bond. In the crystal, molecules are linked via C—H...N hydrogen bonds, forming slabs parallel to the bc plane.

  14. INF-β1b therapy modulates L-arginine and nitric oxide metabolism in patients with relapse remittent multiple sclerosis.

    Science.gov (United States)

    Stojanovic, Ivana; Vojinovic, Slobodan; Ljubisavljevic, Srdjan; Pavlovic, Radmila; Basic, Jelena; Pavlovic, Dusica; Ilic, Andjelka; Cvetkovic, Tatjana; Stukalov, Maja

    2012-12-15

    The scope of this study is the examination of NO(2)+NO(3), 3-nitrotyrosine (3-NT), S-nitrosothiols (RSNO), arginase activity and asymmetric (ADMA) and symmetric (SDMA) dimethyl-L-arginine concentrations in plasma of MS patients during interferon-β1b therapy. The study population included 15 (12 women, 3 men) untreated MS patients and 12 (10 women, 2 men) interferon-β1b treated MS patients with clinically definite relapsing MS (McDonalds criteria) for at least 1 year and a baseline EDSS score of 1.0 to 3.5 inclusive. Patients were treated with 250 μg IU interferon-β1b s.c. every second day during 30 months. The disease course was evaluated using correlations between baseline EDSS score and relapse rates in both groups. During interferon-β1b treatment, EDSS scores in treated patients were decreased compared to untreated ones - after 18 and 30 months (p<0.05). In interferon-β1b treated MS patients, NO(2)+NO(3), 3-NT and RSNO plasma concentrations were significantly lower (p<0.05), while arginase activity, ADMA and SDMA levels were significantly increased (p<0.05) during the therapy, compared to the baseline levels in treated patients. The investigated parameters may be the new biomarkers, providing information for the therapeutic approach and valuable in clinical monitoring. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Kidney Mass Reduction Leads to l-Arginine Metabolism-Dependent Blood Pressure Increase in Mice.

    Science.gov (United States)

    Pillai, Samyuktha Muralidharan; Seebeck, Petra; Fingerhut, Ralph; Huang, Ji; Ming, Xiu-Fen; Yang, Zhihong; Verrey, François

    2018-02-25

    Uninephrectomy (UNX) is performed for various reasons, including kidney cancer or donation. Kidneys being the main site of l-arginine production in the body, we tested whether UNX mediated kidney mass reduction impacts l-arginine metabolism and thereby nitric oxide production and blood pressure regulation in mice. In a first series of experiments, we observed a significant increase in arterial blood pressure 8 days post-UNX in female and not in male mice. Further experimental series were performed in female mice, and the blood pressure increase was confirmed by telemetry. l-citrulline, that is used in the kidney to produce l-arginine, was elevated post-UNX as was also asymmetric dimethylarginine, an inhibitor of nitric oxide synthase that competes with l-arginine and is a marker for renal failure. Interestingly, the UNX-induced blood pressure increase was prevented by supplementation of the diet with 5% of the l-arginine precursor, l-citrulline. Because l-arginine is metabolized in the kidney and other peripheral tissues by arginase-2, we tested whether the lack of this metabolic pathway also compensates for decreased l-arginine production in the kidney and/or for local nitric oxide synthase inhibition and consecutive blood pressure increase. Indeed, upon uninephrectomy, arginase-2 knockout mice (Arg-2 -/- ) neither displayed an increase in asymmetric dimethylarginine and l-citrulline plasma levels nor a significant increase in blood pressure. UNX leads to a small increase in blood pressure that is prevented by l-citrulline supplementation or arginase deficiency, 2 measures that appear to compensate for the impact of kidney mass reduction on l-arginine metabolism. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  16. Amniotic Fluid Arginine from Gestational Weeks 13 to 15 Is a Predictor of Birth Weight, Length, and Head Circumference

    Directory of Open Access Journals (Sweden)

    Astrid Bjørke-Jenssen

    2017-12-01

    Full Text Available Arginine is a constituent of proteins and a precursor for polyamines and nitric oxide, and is essential for placentation, angiogenesis, and growth. Maternal plasma arginine concentrations are found to be lower in pregnancies complicated by fetal growth restriction, and arginine supplementation in later pregnancy is reported to increase birth weight. We measured arginine and the metabolites asymmetric dimethylarginine (ADMA and symmetric dimethylarginine (SDMA in the amniotic fluid obtained in pregnancy weeks 13 to 15 from 363 pregnancies with a documented normal outcome and related the concentrations to birth weight, length, and head circumference. Arginine was higher in the amniotic fluid from female (mean 40.8 (SD 10.6 µmol/L compared to male fetuses (37.4 (SD 11.2 µmol/L, p = 0.003. Despite the gender difference, arginine in the amniotic fluid from gestational weeks 13–15 was the strongest predictor for birth weight, length, and head circumference. ADMA was a strong predictor for birth weight and length, SDMA for birth weight, while Arg/ADMA and Arg/SDMA only predicted head circumference in multiple linear regression models. Due to increased arginine demands, pregnancy is considered a state of relative arginine deficiency. Our findings reflect the importance of a good maternal arginine status in early pregnancy, an observation that should be evaluated in an intervention study.

  17. Asymmetric collider

    International Nuclear Information System (INIS)

    Bharadwaj, V.; Colestock, P.; Goderre, G.; Johnson, D.; Martin, P.; Holt, J.; Kaplan, D.

    1993-01-01

    The study of CP violation in beauty decay is one of the key challenges facing high energy physics. Much work has not yielded a definitive answer how this study might best be performed. However, one clear conclusion is that new accelerator facilities are needed. Proposals include experiments at asymmetric electron-positron colliders and in fixed-target and collider modes at LHC and SSC. Fixed-target and collider experiments at existing accelerators, while they might succeed in a first observation of the effect, will not be adequate to study it thoroughly. Giomataris has emphasized the potential of a new approach to the study of beauty CP violation: the asymmetric proton collider. Such a collider might be realized by the construction of a small storage ring intersecting an existing or soon-to-exist large synchrotron, or by arranging collisions between a large synchrotron and its injector. An experiment at such a collider can combine the advantages of fixed-target-like spectrometer geometry, facilitating triggering, particle identification and the instrumentation of a large acceptance, while the increased √s can provide a factor > 100 increase in beauty-production cross section compared to Tevatron or HERA fixed-target. Beams crossing at a non-zero angle can provide a small interaction region, permitting a first-level decay-vertex trigger to be implemented. To achieve large √s with a large Lorentz boost and high luminosity, the most favorable venue is the high-energy booster (HEB) at the SSC Laboratory, though the CERN SPS and Fermilab Tevatron are also worth considering

  18. Diabetic Retinopathy Is Associated With Elevated Serum Asymmetric and Symmetric Dimethylarginines

    OpenAIRE

    Abhary, Sotoodeh; Kasmeridis, Nicholas; Burdon, Kathryn P.; Kuot, Abraham; Whiting, Malcolm J.; Yew, Wai Ping; Petrovsky, Nikolai; Craig, Jamie E.

    2009-01-01

    OBJECTIVE Asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and l-arginine directly influence nitric oxide production. Our objective was to test whether serum ADMA, SDMA, or l-arginine levels correlate with diabetic retinopathy subtype or severity. RESEARCH DESIGN AND METHODS A total of 162 subjects with type 1 diabetes and 343 with type 2 diabetes, of whom 329 subjects had no diabetic retinopathy, 27 had nonproliferative diabetic retinopathy (NPDR), 101 had proliferative...

  19. L-Homoarginine and L-arginine are antagonistically related to blood pressure in an elderly population: the Hoorn study

    NARCIS (Netherlands)

    van der Zwan, L.P.; Davids, M.; Scheffer, P.G.; Dekker, J.M.; Stehouwer, C.D.A.; Teerlink, T.

    2013-01-01

    Objectives: Production of nitric oxide by the vascular endothelium is crucial for the maintenance of vascular tone, an important determinant of blood pressure. L-Arginine and its homolog L-homoarginine are competitive substrates of nitric oxide synthase (NOS), whereas asymmetric dimethylarginine

  20. Rmt1 catalyzes zinc-finger independent arginine methylation of ribosomal protein Rps2 in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Lipson, Rebecca S.; Webb, Kristofor J.; Clarke, Steven G.

    2010-01-01

    Rps2/rpS2 is a well conserved protein of the eukaryotic ribosomal small subunit. Rps2 has previously been shown to contain asymmetric dimethylarginine residues, the addition of which is catalyzed by zinc-finger-containing arginine methyltransferase 3 (Rmt3) in the fission yeast Schizosaccharomyces pombe and protein arginine methyltransferase 3 (PRMT3) in mammalian cells. Here, we demonstrate that despite the lack of a zinc-finger-containing homolog of Rmt3/PRMT3 in the budding yeast Saccharomyces cerevisiae, Rps2 is partially modified to generate asymmetric dimethylarginine and monomethylarginine residues. We find that this modification of Rps2 is dependent upon the major arginine methyltransferase 1 (Rmt1) in S. cerevisiae. These results are suggestive of a role for Rmt1 in modifying the function of Rps2 in a manner distinct from that occurring in S. pombe and mammalian cells.

  1. Dimethyl amiloride improves glucose homeostasis in mouse models of type 2 diabetes.

    Science.gov (United States)

    Gunawardana, Subhadra C; Head, W Steven; Piston, David W

    2008-06-01

    Dimethyl amiloride (DMA) enhances insulin secretion in the pancreatic beta-cell. DMA also enhances time-dependent potentiation (TDP) and enables TDP to occur in situations where it is normally absent. As we have demonstrated before, these effects are mediated in part through inhibition of neuronal nitric oxide synthase (nNOS), resulting in increased availability of arginine. Thus both DMA and arginine have the potential to correct the secretory defect in diabetes by enabling or enhancing TDP. In the current study we have demonstrated the ability of these agents to improve blood glucose homeostasis in three mouse models of type 2 diabetes. The pattern of TDP under different conditions indicates that inhibition of NOS is not the only mechanism through which DMA exerts its positive effects. Thus we also have explored another possible mechanism through which DMA enables/enhances TDP, via the activation of mitochondrial alpha-ketoglutarate dehydrogenase.

  2. Correlation of the L-Arginine Pathway with Thrombo-Inflammation May Contribute to the Outcome of Acute Ischemic Stroke

    DEFF Research Database (Denmark)

    Molnar, Tihamer; Pusch, Gabriella; Nagy, Lajos

    2016-01-01

    BACKGROUND: Immune responses contribute to secondary injury after acute ischemic stroke (AIS), and metabolites of the L-arginine pathway are associated with stroke outcome. Here, we analyzed the relationship of the L-arginine pathway with thrombo-inflammatory biomarkers in AIS and their additive...... and independent associations to outcome. METHODS: Serial changes in P-selectin, tPA, MCP-1, sCD40L, IL-6, IL-8, L-arginine, and asymmetric and symmetric dimethylarginine (ADMA, SDMA) were investigated in 55 patients with AIS and without infection within 6 and 72 hours after stroke onset. Outcomes were assessed...... as National Institutes of Health Stroke Scale (NIHSS) worsening by 24 hours, poststroke infection, and death by 1 month. RESULTS: Serum levels of L-arginine showed negative correlation, whereas ADMA and SDMA showed positive correlation with thrombo-inflammatory biomarkers in the hyperacute phase. Most...

  3. Arginine de novo and nitric oxide production in disease states

    OpenAIRE

    Luiking, Yvette C.; Ten Have, Gabriella A. M.; Wolfe, Robert R.; Deutz, Nicolaas E. P.

    2012-01-01

    Arginine is derived from dietary protein intake, body protein breakdown, or endogenous de novo arginine production. The latter may be linked to the availability of citrulline, which is the immediate precursor of arginine and limiting factor for de novo arginine production. Arginine metabolism is highly compartmentalized due to the expression of the enzymes involved in arginine metabolism in various organs. A small fraction of arginine enters the NO synthase (NOS) pathway. Tetrahydrobiopterin ...

  4. The Effect of Carbohydrates and Arginine on Arginine Metabolism by Excised Bean Leaves in the Dark

    Science.gov (United States)

    Stewart, Cecil R.

    1975-01-01

    The effect of carbohydrate on arginine utilization by excised bean (Phaseolus vulgaris L. var. Tendergreen) leaves in the dark was studied by adding arginine to leaves differing in carbohydrate levels, and measuring the arginine content of the leaves at intervals. In nonstarved leaves, the arginine content decreased steadily after vacuum infiltration of 10 mm arginine and was essentially completely utilized by 36 hours after infiltration. In starved leaves, the arginine content did not decrease except for a brief period of about 4 hours after infiltration. The distribution of 14C after adding 14C-arginine to starved and nonstarved leaves indicated that the presence of carbohydrates in the leaves stimulates the utilization of arginine for protein synthesis and conversion to other amino acids, organic acids, and CO2 (catabolism). Adding sucrose along with arginine to starved leaves stimulated this utilization of arginine for both protein synthesis and catabolism. This effect of sugar on catabolism is different than results of similar studies done previously with proline. Increasing the concentration of added arginine greatly increased arginine catabolism but had a relatively small effect on utilization of arginine for protein synthesis. This result is the same as similar results from adding different concentrations of proline to excised leaves. PMID:16659159

  5. L-arginine biosensors: A comprehensive review

    Directory of Open Access Journals (Sweden)

    Neelam Verma

    2017-12-01

    Full Text Available Arginine has been considered as the most potent nutraceutics discovered ever, due to its powerful healing property, and it's been known to scientists as the Miracle Molecule. Arginine detection in fermented food products is necessary because, high level of arginine in foods forms ethyl carbamate (EC during the fermentation process. Therefore, L-arginine detection in fermented food products is very important as a control measure for quality of fermented foods, food supplements and beverages including wine. In clinical analysis arginine detection is important due to their enormous inherent versatility in various metabolic pathways, topmost in the synthesis of Nitric oxide (NO and tumor growth. A number of methods are being used for arginine detection, but biosensors technique holds prime position due to rapid response, high sensitivity and high specificity. However, there are many problems still to be addressed, including selectivity, real time analysis and interference of urea presence in the sample. In the present review we aim to emphasize the significant role of arginine in human physiology and foods. A small attempt has been made to discuss the various techniques used for development of arginine biosensor and how these techniques affect their performance. The choice of transducers for arginine biosensor ranges from optical, pH sensing, ammonia gas sensing, ammonium ion-selective, conductometric and amperometric electrodes because ammonia is formed as a final product.

  6. Asymmetric Ashes

    Science.gov (United States)

    2006-11-01

    that oscillate in certain directions. Reflection or scattering of light favours certain orientations of the electric and magnetic fields over others. This is why polarising sunglasses can filter out the glint of sunlight reflected off a pond. When light scatters through the expanding debris of a supernova, it retains information about the orientation of the scattering layers. If the supernova is spherically symmetric, all orientations will be present equally and will average out, so there will be no net polarisation. If, however, the gas shell is not round, a slight net polarisation will be imprinted on the light. This is what broad-band polarimetry can accomplish. If additional spectral information is available ('spectro-polarimetry'), one can determine whether the asymmetry is in the continuum light or in some spectral lines. In the case of the Type Ia supernovae, the astronomers found that the continuum polarisation is very small so that the overall shape of the explosion is crudely spherical. But the much larger polarization in strongly blue-shifted spectral lines evidences the presence, in the outer regions, of fast moving clumps with peculiar chemical composition. "Our study reveals that explosions of Type Ia supernovae are really three-dimensional phenomena," says Dietrich Baade. "The outer regions of the blast cloud is asymmetric, with different materials found in 'clumps', while the inner regions are smooth." "This study was possible because polarimetry could unfold its full strength thanks to the light-collecting power of the Very Large Telescope and the very precise calibration of the FORS instrument," he adds. The research team first spotted this asymmetry in 2003, as part of the same observational campaign (ESO PR 23/03 and ESO PR Photo 26/05). The new, more extensive results show that the degree of polarisation and, hence, the asphericity, correlates with the intrinsic brightness of the explosion. The brighter the supernova, the smoother, or less clumpy

  7. Polymersomes with asymmetric membranes and self-assembled superstructures using pentablock quintopolymers resolved by electron tomography

    KAUST Repository

    Haataja, J. S.; Houbenov, N.; Aseyev, V.; Fragouli, P.; Iatrou, H.; Sougrat, Rachid; Hadjichristidis, Nikolaos; Ikkala, O.

    2018-01-01

    Polystyrene-block-poly(1,4-isoprene)-block-poly(dimethyl siloxane)-block-poly(tert-butyl methacrylate)-block-poly(2-vinyl pyridine), PS-b-PI-b-PDMS-b-PtBMA-b-P2VP, self-assembles in acetone into polymersomes with asymmetric (directional) PI

  8. Role of type II protein arginine methyltransferase 5 in the regulation of Circadian Per1 gene.

    Directory of Open Access Journals (Sweden)

    Jungtae Na

    Full Text Available Circadian clocks are the endogenous oscillators that regulate rhythmic physiological and behavioral changes to correspond to daily light-dark cycles. Molecular dissections have revealed that transcriptional feedback loops of the circadian clock genes drive the molecular oscillation, in which PER/CRY complexes inhibit the transcriptional activity of the CLOCK/BMAL1 heterodimer to constitute a negative feedback loop. In this study, we identified the type II protein arginine methyltransferase 5 (PRMT5 as an interacting molecule of CRY1. Although the Prmt5 gene was constitutively expressed, increased interaction of PRMT5 with CRY1 was observed when the Per1 gene was repressed both in synchronized mouse liver and NIH3T3 cells. Moreover, rhythmic recruitment of PRMT5 and CRY1 to the Per1 gene promoter was found to be associated with an increased level of histone H4R3 dimethylation and Per1 gene repression. Consistently, decreased histone H4R3 dimethylation and altered rhythmic Per1 gene expression were observed in Prmt5-depleted cells. Taken together, these findings provide an insight into the link between histone arginine methylation by PRMT5 and transcriptional regulation of the circadian Per1 gene.

  9. Crystal structures of hibiscus acid and hibiscus acid dimethyl ester isolated from Hibiscus sabdariffa (Malvaceae).

    Science.gov (United States)

    Zheoat, Ahmed M; Gray, Alexander I; Igoli, John O; Kennedy, Alan R; Ferro, Valerie A

    2017-09-01

    The biologically active title compounds have been isolated from Hibiscus sabdariffa plants, hibiscus acid as a dimethyl sulfoxide monosolvate [systematic name: (2 S ,3 R )-3-hy-droxy-5-oxo-2,3,4,5-tetra-hydro-furan-2,3-di-carb-oxy-lic acid dimethyl sulfoxide monosolvate], C 6 H 6 O 7 ·C 2 H 6 OS, (I), and hibiscus acid dimethyl ester [systematic name: dimethyl (2 S ,3 R )-3-hy-droxy-5-oxo-2,3,4,5-tetra-hydro-furan-2,3-di-carboxyl-ate], C 8 H 10 O 7 , (II). Compound (I) forms a layered structure with alternating layers of lactone and solvent mol-ecules, that include a two-dimensional hydrogen-bonding construct. Compound (II) has two crystallographically independent and conformationally similar mol-ecules per asymmetric unit and forms a one-dimensional hydrogen-bonding construct. The known absolute configuration for both compounds has been confirmed.

  10. DIVERSE POTENTIAL AND PHARMACOLOGICAL STUDIES OF ARGININE

    Directory of Open Access Journals (Sweden)

    Anju Meshram

    2015-09-01

    Full Text Available Arginine is metabolically flexible amino acid with major role in protein synthesis and detoxification of ammonia. It is involved in several metabolic pathways for the production of biologically active compounds such as creatine, nitric oxide, ornithine, glutamate, agmatine, citrulline and polyamines. Regarding this all, we review the crucial role of arginine in metabolism, diversified prospective uses and pharmacological applications. Arginine plays an important role in the treatment of tumorigenesis, asthama, gastric, erectile dysfunction, apoptosis, melanoma and congestive heart failure. Ability to produce nitric oxide offers various applications as in the prevention of age and hair loss. It serves as a precursor of creatine with ergogenic potential. The ability to increase endogenous growth hormone makes arginine a preferred supplement for the improvement of physical performance. In the present study details about the pharmacological applications of arginine based on modern scientific investigations have been discussed. There are immense properties hidden in arginine that need to be explored using the scientific investigations to make it beneficial for the medicine and human health. More research is needed to evaluate the role of arginine supplementation on exercise performance and training adaptations in healthy and diseased populations before taking any conclusions.

  11. Dimethyl sulfoxide complexing with iodine

    Energy Technology Data Exchange (ETDEWEB)

    Borovikov, Yu Ya; Serguchev, Yu A; Staninets, V I

    1986-01-01

    Dielectrometry, conductometry, IR-spectroscopy are used to study dimethyl sulfoxide complexing with iodine in binary system and in CCl/sub 4/, C/sub 6/H/sub 6/, C/sub 6/H/sub 5/Cl, C/sub 6/H/sub 5/CF/sub 3/, 1, 2-dichloroethane solutions. Complexes of 1:1 composition are formed in solutions, in the binary system of 2:1 and 2:2 composition. I/sub 2/ molecules add to oxygen atoms. In CCl/sub 4/ and in binary system gradual transformation of so called external charge transfer complexes (CTC-1) to internal ones (CTC-2) that are described by the 1st order reaction kinetic equations is observed. On dissolution of CTC of 2:2 composition they disproportionate into two CTC molecules 1:1. Enthalpy of forming CTC-1 1:1 is approximately 4 kcal/mol, CTC-2 1:1 - 8, CTC-1 2:1 - 8 kcal/mol.

  12. The L-arginine Pathway in Acute Ischemic Stroke and Severe Carotid Stenosis

    DEFF Research Database (Denmark)

    Molnar, Tihamer; Pusch, Gabriella; Papp, Viktoria

    2014-01-01

    BACKGROUND: Endothelial dysfunction is associated with increased levels of asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) resulting in a decreased production of nitric oxide, which regulates the vascular tone. METHODS: Patients with acute ischemic stroke (AIS, n = 55......) and asymptomatic significant carotid stenosis (AsCS, n = 44) were prospectively investigated. L-arginine, ADMA, SDMA, S100 B, and high-sensitivity C-reactive protein (hsCRP) were serially measured within 6 hours after the onset of stroke, at 24 and 72 poststroke hours. All markers were compared with healthy...... subjects (n = 45). The severity of AIS was daily assessed by National Institute of Health Stroke Scale scoring. RESULTS: Even within 6 hours after the onset of stroke, L-arginine, ADMA, and SDMA were significantly higher in patients with AIS compared with both AsCS and healthy subjects. S100 B reflecting...

  13. Arginine depletion by arginine deiminase does not affect whole protein metabolism or muscle fractional protein synthesis rate in mice

    Science.gov (United States)

    Due to the absolute need for arginine that certain cancer cells have, arginine depletion is a therapy in clinical trials to treat several types of cancers. Arginine is an amino acids utilized not only as a precursor for other important molecules, but also for protein synthesis. Because arginine depl...

  14. Ecological Effect of Arginine on Oral Microbiota.

    Science.gov (United States)

    Zheng, Xin; He, Jinzhi; Wang, Lin; Zhou, Shuangshuang; Peng, Xian; Huang, Shi; Zheng, Liwei; Cheng, Lei; Hao, Yuqing; Li, Jiyao; Xu, Jian; Xu, Xin; Zhou, Xuedong

    2017-08-03

    Dental caries is closely associated with the microbial dybiosis between acidogenic/aciduric pathogens and alkali-generating commensal bacteria colonized in the oral cavity. Our recent studies have shown that arginine may represent a promising anti-caries agent by modulating microbial composition in an in vitro consortium. However, the effect of arginine on the oral microbiota has yet to be comprehensively delineated in either clinical cohort or in vitro biofilm models that better represent the microbial diversity of oral cavity. Here, by employing a clinical cohort and a saliva-derived biofilm model, we demonstrated that arginine treatment could favorably modulate the oral microbiota of caries-active individuals. Specifically, treatment with arginine-containing dentifrice normalized the oral microbiota of caries-active individuals similar to that of caries-free controls in terms of microbial structure, abundance of typical species, enzymatic activities of glycolysis and alkali-generation related enzymes and their corresponding transcripts. Moreover, we found that combinatory use of arginine with fluoride could better enrich alkali-generating Streptococcus sanguinis and suppress acidogenic/aciduric Streptococcus mutans, and thus significantly retard the demineralizing capability of saliva-derived oral biofilm. Hence, we propose that fluoride and arginine have a potential synergistic effect in maintaining an eco-friendly oral microbial equilibrium in favor of better caries management.

  15. THE ARGININE AND PREARGININE GROUPS IN EDESTIN.

    Science.gov (United States)

    Simms, H S

    1930-09-20

    The author corroborates the data of Schmidt showing that the dissociation index of the third group of arginine is pK(3)' = 12.5. New titration data of edestin have been obtained in very alkaline solutions and show that there is a corresponding group with a titration index of pG' = 12.0, but present in much less quantity than can account for the arginine found on hydrolysis. The data support the theory that the combination of strong base or strong acid with proteins is produced by the formation of salts with the "extra groups" of those trivalent amino acids which can be isolated from the protein, with the exception of arginine. Arginine contributes to the titration curve in much smaller amount than is found on hydrolysis. This deficiency in the arginine group may be accounted for by the basic group in proteins having a titration index of pG' = 3.8 to 4.6 (depending on the protein), which apparently yields arginine on hydrolysis, and may properly be called prearginine.

  16. Heterologous radioimmunoassay for arginine vasopressin

    International Nuclear Information System (INIS)

    Shimamoto, K.; Murase, T.; Yamaji, T.

    1976-01-01

    A sensitive and specific radioimmunoassay for arginine vasopressin (AVP) was developed utilizing the antisera against lysine vasopressin (LVP) in combination with a labeled AVP. The assay employs an acetone extraction procedure and detects as little as 0.8 pg. per millimeter of AVP in human plasma. In normal subjects, the mean (+- S.D.) plasma concentration of AVP was 4.9 +- 1.2 pg. per milliliter after fluid deprivation and 1.2 +- 0.4 pg. per milliliter after water loading. Plasma AVP levels correlated significantly with plasma osmolalities. In four patients with diabetes insipidus, plasma AVP concentrations ranged from less than 0.8 to 1.2 pg. per milliliter, whereas six patients with the syndrome of inappropriate ADH secretion showed plasma levels of AVP which correspond to those of the dehydrated state in normal subjects or greater, although plasma osmolalities were low in all cases. It was concluded that the present radioimmunoassay method for AVP provides a useful way of assessing neurohypophyseal function in man

  17. Injection characteristics of dimethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Glensvig, M.

    1996-09-01

    Dimethyl ether (DME) has proved to be a new ultra-clean alternative fuel for diesel engines. Engine tests have shown considerably lower NO{sub x} emissions, no particle emissions and lower noise compared to that obtained from normal diesel engine operation. DME also has demonstrated favorable response to Exhaust Gas Recirculation (EGR). The purpose of this investigation was to achieve a better understanding of the fundamental spray behavior of DME. Fundamental spray behaviour was characterized by fuel spray penetration and angle, atomization and droplet size and evaporation. The influence of fuel characteristics, nozzle geometry and ambient pressure on the DME and diesel spray behavior was investigated. Fuel was injected into an unheated injection chamber with a ambient pressure of 15 bar and 25 bar, respectively, giving a simplified simulation of the environment in an operating engine. Two nozzles were studied: a single hole nozzle and a pintle nozzle. A conventional fuel injection system was used for both nozzles. Injection parameters of RPM, throttle position, fuel line length and chamber environment were held constant for both nozzles. The sprays were visualized using schlieren and high speed photography. Results show that the general appearance of the DME spray is similar to that of diesel spray. The core of the DME spray seems less dense and the spray tip less sharp compared to diesel spray, indicating smaller droplets with a lower momentum in the core of the DME spray. Schlieren film shows that with both DME and diesel fuel, the spray tip only consists of liquid and that evaporation occurs after a brief time interval. Penetration of DME is about one third that of diesel using the pintle nozzle. Also, the spray angle is considerably larger for the DME spray compared to the diesel spray. A comparatively smaller difference in penetration is observed using the hole nozzle. Differences in penetration for the hole nozzle are within the limit of the penetration

  18. Ablation of arginase II spares arginine and abolishes the arginine requirement for growth in male mice

    Science.gov (United States)

    Arginine is considered a semi-essential amino acid in many species, including humans, because under certain conditions its demand exceeds endogenous production. Arginine availability, however, is not only determined by its production, but also by its disposal. Manipulation of disposal pathways has t...

  19. IMMUNOSUPPRESSIVE EFFECTS OF ARGININE DEIMINASE FROM STREPTOCOCCUS PYOGENES

    Directory of Open Access Journals (Sweden)

    E. A. Starikova

    2015-01-01

    Full Text Available Many pathogens use metabolic pathway of arginine for successful dissemination. Bacterial arginine deiminase hydrolyzes arginine to form one molecule of ammonia and two molecules of ATP. The activity of the enzyme contributes to the improvement of survival of pathogenic bacteria in conditions of low pH at the site of infection or in phagolysosome, as well as in anaerobic conditions, and also leads to deficiency of arginine. Metabolism of arginine plays an important role in regulating the functions of immune system cells in mammals. Arginine is a substrate of enzymes NOS and arginase. Arginine depletion, potentially contributs to immunosuppression. The review analyzed the literature data on the effect of streptococcal arginine deiminase on the metabolism of arginine eukaryotic cells, and discusses immunosuppressive action of the enzyme.

  20. Arginine Adjunctive Therapy in Active Tuberculosis

    Directory of Open Access Journals (Sweden)

    Aliasghar Farazi

    2015-01-01

    Full Text Available Background. Dietary supplementation has been used as a mechanism to augment the immune system. Adjunctive therapy with L-arginine has the potential to improve outcomes in active tuberculosis. Methods. In a randomized clinical trial 63 participants with smear-positive pulmonary tuberculosis in Markazi Province of Iran were given arginine or placebo for 4 weeks in addition to conventional chemotherapy. The final treatment success, sputum conversion, weight gain, and clinical symptoms after one and two months were considered as primary outcomes and secondary outcomes were ESR, CRP, and Hg. Data were collected and analyzed with SPSS software (ver. 18. Results. Arginine supplementation reduced constitutional symptoms (P=0.032 in patients with smear-positive TB at the end of the first month of treatment. Arginine treated patients had significantly increased BMI at the end of the first and second months of treatment (P=0.032 and P=0.04 and a reduced CRP at the end of the first month of treatment (P=0.03 versus placebo group. Conclusion. Arginine is useful as an adjunctive therapy in patients with active tuberculosis, in which the effects are more likely mediated by the increased production of nitric oxide and improved constitutional symptoms and weight gain. This trial is registered with Clinical Trials Registry of Iran: IRCT201211179855N2.

  1. Principles of asymmetric synthesis

    CERN Document Server

    Gawley, Robert E; Aube, Jeffrey

    2012-01-01

    The world is chiral. Most of the molecules in it are chiral, and asymmetric synthesis is an important means by which enantiopure chiral molecules may be obtained for study and sale. Using examples from the literature of asymmetric synthesis, this book presents a detailed analysis of the factors that govern stereoselectivity in organic reactions. After an explanation of the basic physical-organic principles governing stereoselective reactions, the authors provide a detailed, annotated glossary of stereochemical terms. A chapter on "Practical Aspects of Asymmetric Synthesis" provides a critical overview of the most common methods for the preparation of enantiomerically pure compounds, techniques for analysis of stereoisomers using chromatographic, spectroscopic, and chiroptical methods. The authors then present an overview of the most important methods in contemporary asymmetric synthesis organized by reaction type. Thus, there are four chapters on carbon-carbon bond forming reactions, one chapter on reductions...

  2. 21 CFR 172.133 - Dimethyl dicarbonate.

    Science.gov (United States)

    2010-04-01

    ... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... treatment, filtration, or other technologies prior to the use of dimethyl dicarbonate: (1) In wine, dealcoholized wine, and low alcohol wine in an amount not to exceed 200 parts per million. (2) In ready-to-drink...

  3. Inactivation of MXR1 Abolishes Formation of Dimethyl Sulfide from Dimethyl Sulfoxide in Saccharomyces cerevisiae

    OpenAIRE

    Hansen, Jørgen

    1999-01-01

    Dimethyl sulfide (DMS) is a sulfur compound of importance for the organoleptic properties of beer, especially some lager beers. Synthesis of DMS during beer production occurs partly during wort production and partly during fermentation. Methionine sulfoxide reductases are the enzymes responsible for reduction of oxidized cellular methionines. These enzymes have been suggested to be able to reduce dimethyl sulfoxide (DMSO) as well, with DMS as the product. A gene for an enzymatic activity lead...

  4. Effects of fetal exposure to high-fat diet or maternal hyperglycemia on L-arginine and nitric oxide metabolism in lung.

    Science.gov (United States)

    Grasemann, C; Herrmann, R; Starschinova, J; Gertsen, M; Palmert, M R; Grasemann, H

    2017-02-20

    Alterations in the L-arginine/nitric oxide (NO) metabolism contribute to diseases such as obesity, metabolic syndrome and airway dysfunction. The impact of early-life exposures on the L-arginine/NO metabolism in lung later in life is not well understood. The objective of this work was to study the effects of intrauterine exposures to maternal hyperglycemia and high-fat diet (HFD) on pulmonary L-arginine/NO metabolism in mice. We used two murine models of intrauterine exposures to maternal (a) hyperglycemia and (b) HFD to study the effects of these exposures on the L-arginine/NO metabolism in lung in normal chow-fed offspring. Both intrauterine exposures resulted in NO deficiency in the lung of the offspring at 6 weeks of age. However, each of the exposures leading to different metabolic phenotypes caused a distinct alteration in the L-arginine/NO metabolism. Maternal hyperglycemia leading to impaired glucose tolerance but no obesity in the offspring resulted in increased levels of asymmetric dimethylarginine and impairment of NO synthases. Although maternal HFD led to obesity without impairment in glucose tolerance in the offspring, it resulted in increased expression and activity of arginase in the lung of the normal chow-fed offspring. These data suggest that maternal hyperglycemia and HFD can cause alterations in the pulmonary L-arginine/NO metabolism in offspring.

  5. The do's and don'ts of arginine supplementation

    African Journals Online (AJOL)

    to meet the body's nutritional needs for energy, protein and micronutrients. ... inflammatory response syndrome (SIRS) and therefore the use of arginine in this ... smooth muscle cell proliferation12 and controlling vascular oxidative stress and the ... reduced arginine levels in sepsis that reflect the specific changes in arginine ...

  6. Modulators of arginine metabolism support cancer immunosurveillance

    Directory of Open Access Journals (Sweden)

    Freschi Massimo

    2009-01-01

    Full Text Available Abstract Background Tumor-associated accrual of myeloid derived suppressor cells (MDSC in the blood, lymphoid organs and tumor tissues may lead to perturbation of the arginine metabolism and impairment of the endogenous antitumor immunity. The objective of this study was to evaluate whether accumulation of MDSC occurred in Th2 prone BALB/c and Th1 biased C57BL/6 mice bearing the C26GM colon carcinoma and RMA T lymphoma, respectively, and to investigate whether N(G nitro-L-arginine methyl ester (L-NAME and sildenafil, both modulators of the arginine metabolism, restored antitumor immunity. Results We report here that MDSC accumulate in the spleen and blood of mice irrespective of the mouse and tumor model used. Treatment of tumor-bearing mice with either the phosphodiesterase-5 inhibitor sildenafil or the nitric-oxide synthase (NOS inhibitor L-NAME significantly restrained tumor growth and expanded the tumor-specific immune response. Conclusion Our data emphasize the role of MDSC in modulating the endogenous tumor-specific immune response and underline the anti-neoplastic therapeutic potential of arginine metabolism modulators.

  7. Altered brain arginine metabolism in schizophrenia.

    Science.gov (United States)

    Liu, P; Jing, Y; Collie, N D; Dean, B; Bilkey, D K; Zhang, H

    2016-08-16

    Previous research implicates altered metabolism of l-arginine, a versatile amino acid with a number of bioactive metabolites, in the pathogenesis of schizophrenia. The present study, for we believe the first time, systematically compared the metabolic profile of l-arginine in the frontal cortex (Brodmann's area 8) obtained post-mortem from schizophrenic individuals and age- and gender-matched non-psychiatric controls (n=20 per group). The enzyme assays revealed no change in total nitric oxide synthase (NOS) activity, but significantly increased arginase activity in the schizophrenia group. Western blot showed reduced endothelial NOS protein expression and increased arginase II protein level in the disease group. High-performance liquid chromatography and liquid chromatography/mass spectrometric assays confirmed significantly reduced levels of γ-aminobutyric acid (GABA), but increased agmatine concentration and glutamate/GABA ratio in the schizophrenia cases. Regression analysis indicated positive correlations between arginase activity and the age of disease onset and between l-ornithine level and the duration of illness. Moreover, cluster analyses revealed that l-arginine and its main metabolites l-citrulline, l-ornithine and agmatine formed distinct groups, which were altered in the schizophrenia group. The present study provides further evidence of altered brain arginine metabolism in schizophrenia, which enhances our understanding of the pathogenesis of schizophrenia and may lead to the future development of novel preventions and/or therapeutics for the disease.

  8. Modulation of Epstein–Barr Virus Nuclear Antigen 2-dependent transcription by protein arginine methyltransferase 5

    International Nuclear Information System (INIS)

    Liu, Cheng-Der; Cheng, Chi-Ping; Fang, Jia-Shih; Chen, Ling-Chih; Zhao, Bo; Kieff, Elliott; Peng, Chih-Wen

    2013-01-01

    Highlights: ► Catalytic active PRMT5 substantially binds to the EBNA2 RG domain. ► PRMT5 augments the EBNA2-dependent transcription. ► PRMT5 triggers the symmetric dimethylation of the EBNA2 RG domain. ► PRMT5 enhances the promoter occupancy of EBNA2 on its target promoters. -- Abstract: Epstein–Barr Virus Nuclear Antigen (EBNA) 2 features an Arginine–Glycine repeat (RG) domain at amino acid positions 335–360, which is a known target for protein arginine methyltransferaser 5 (PRMT5). In this study, we performed protein affinity pull-down assays to demonstrate that endogenous PRMT5 derived from lymphoblastoid cells specifically associated with the protein bait GST-E2 RG. Transfection of a plasmid expressing PRMT5 induced a 2.5- to 3-fold increase in EBNA2-dependent transcription of both the LMP1 promoter in AKATA cells, which contain the EBV genome endogenously, and a Cp-Luc reporter plasmid in BJAB cells, which are EBV negative. Furthermore, we showed that there was a 2-fold enrichment of EBNA2 occupancy in target promoters in the presence of exogenous PRMT5. Taken together, we show that PRMT5 triggers the symmetric dimethylation of EBNA2 RG domain to coordinate with EBNA2-mediated transcription. This modulation suggests that PRMT5 may play a role in latent EBV infection

  9. Modulation of Epstein–Barr Virus Nuclear Antigen 2-dependent transcription by protein arginine methyltransferase 5

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Cheng-Der; Cheng, Chi-Ping; Fang, Jia-Shih; Chen, Ling-Chih [Department of Life Sciences, Tzu-Chi University, 701 Chung-Yang Rd. Sec 3, Hualien 97004, Taiwan (China); Zhao, Bo; Kieff, Elliott [Department of Medicine and Microbiology and Molecular Genetics, Channing Laboratory, Brigham and Women’s Hospital and Harvard Medical School, 181 Longwood Ave., Boston 02115, MA (United States); Peng, Chih-Wen, E-mail: pengcw@mail.tcu.edu.tw [Department of Life Sciences, Tzu-Chi University, 701 Chung-Yang Rd. Sec 3, Hualien 97004, Taiwan (China)

    2013-01-18

    Highlights: ► Catalytic active PRMT5 substantially binds to the EBNA2 RG domain. ► PRMT5 augments the EBNA2-dependent transcription. ► PRMT5 triggers the symmetric dimethylation of the EBNA2 RG domain. ► PRMT5 enhances the promoter occupancy of EBNA2 on its target promoters. -- Abstract: Epstein–Barr Virus Nuclear Antigen (EBNA) 2 features an Arginine–Glycine repeat (RG) domain at amino acid positions 335–360, which is a known target for protein arginine methyltransferaser 5 (PRMT5). In this study, we performed protein affinity pull-down assays to demonstrate that endogenous PRMT5 derived from lymphoblastoid cells specifically associated with the protein bait GST-E2 RG. Transfection of a plasmid expressing PRMT5 induced a 2.5- to 3-fold increase in EBNA2-dependent transcription of both the LMP1 promoter in AKATA cells, which contain the EBV genome endogenously, and a Cp-Luc reporter plasmid in BJAB cells, which are EBV negative. Furthermore, we showed that there was a 2-fold enrichment of EBNA2 occupancy in target promoters in the presence of exogenous PRMT5. Taken together, we show that PRMT5 triggers the symmetric dimethylation of EBNA2 RG domain to coordinate with EBNA2-mediated transcription. This modulation suggests that PRMT5 may play a role in latent EBV infection.

  10. Quantifying social asymmetric structures.

    Science.gov (United States)

    Solanas, Antonio; Salafranca, Lluís; Riba, Carles; Sierra, Vicenta; Leiva, David

    2006-08-01

    Many social phenomena involve a set of dyadic relations among agents whose actions may be dependent. Although individualistic approaches have frequently been applied to analyze social processes, these are not generally concerned with dyadic relations, nor do they deal with dependency. This article describes a mathematical procedure for analyzing dyadic interactions in a social system. The proposed method consists mainly of decomposing asymmetric data into their symmetric and skew-symmetric parts. A quantification of skew symmetry for a social system can be obtained by dividing the norm of the skew-symmetric matrix by the norm of the asymmetric matrix. This calculation makes available to researchers a quantity related to the amount of dyadic reciprocity. With regard to agents, the procedure enables researchers to identify those whose behavior is asymmetric with respect to all agents. It is also possible to derive symmetric measurements among agents and to use multivariate statistical techniques.

  11. Asymmetrical field emitter

    Science.gov (United States)

    Fleming, J.G.; Smith, B.K.

    1995-10-10

    A method is disclosed for providing a field emitter with an asymmetrical emitter structure having a very sharp tip in close proximity to its gate. One preferred embodiment of the present invention includes an asymmetrical emitter and a gate. The emitter having a tip and a side is coupled to a substrate. The gate is connected to a step in the substrate. The step has a top surface and a side wall that is substantially parallel to the side of the emitter. The tip of the emitter is in close proximity to the gate. The emitter is at an emitter potential, and the gate is at a gate potential such that with the two potentials at appropriate values, electrons are emitted from the emitter. In one embodiment, the gate is separated from the emitter by an oxide layer, and the emitter is etched anisotropically to form its tip and its asymmetrical structure. 17 figs.

  12. Chiral PEPPSI Complexes: Synthesis, Characterization, and Application in Asymmetric Suzuki–Miyaura Coupling Reactions

    KAUST Repository

    Benhamou, Laure

    2014-01-13

    PEPPSI complexes incorporating chiral N-heterocyclic carbene (NHC) ligands based on 2,2-dimethyl-1-(o-substituted aryl)propan-1-amines were synthesized. Two complexes, with one saturated and one unsaturated NHC ligand, were structurally characterized. The chiral PEPPSI complexes were used in asymmetric Suzuki-Miyaura reactions, giving atropisomeric biaryl products in modest to good enantiomeric ratios. © 2013 American Chemical Society.

  13. Chiral PEPPSI Complexes: Synthesis, Characterization, and Application in Asymmetric Suzuki–Miyaura Coupling Reactions

    KAUST Repository

    Benhamou, Laure; Besnard, Cé line; Kü ndig, E. Peter

    2014-01-01

    PEPPSI complexes incorporating chiral N-heterocyclic carbene (NHC) ligands based on 2,2-dimethyl-1-(o-substituted aryl)propan-1-amines were synthesized. Two complexes, with one saturated and one unsaturated NHC ligand, were structurally characterized. The chiral PEPPSI complexes were used in asymmetric Suzuki-Miyaura reactions, giving atropisomeric biaryl products in modest to good enantiomeric ratios. © 2013 American Chemical Society.

  14. Asymmetric ion trap

    Science.gov (United States)

    Barlow, Stephan E.; Alexander, Michael L.; Follansbee, James C.

    1997-01-01

    An ion trap having two end cap electrodes disposed asymmetrically about a center of a ring electrode. The inner surface of the end cap electrodes are conformed to an asymmetric pair of equipotential lines of the harmonic formed by the application of voltages to the electrodes. The asymmetry of the end cap electrodes allows ejection of charged species through the closer of the two electrodes which in turn allows for simultaneously detecting anions and cations expelled from the ion trap through the use of two detectors charged with opposite polarity.

  15. Reaction of dimethyl hydrogen phosphite with acecyclone

    International Nuclear Information System (INIS)

    Arbuzov, B.A.; Fuzhenkova, A.V.; Tyryshkin, N.I.

    1987-01-01

    In the presence of bases acecyclone reacts with dimethyl hydrogen phosphite with the formation of gamma-keto phosphonates with conjugated and unconjugated structures, and also an enol phosphate, a product containing a bond between oxygen of the cyclone and phosphorus. In the absence of bases, as well as the beta-keto phosphonate, gamma-keto phosphonates of cis and trans structure are formed; they are products of the 1,4 addition of dimethyl hydrogen phosphite to the conjugated fragment C=C-C=O of the cyclone. The compositions of the reaction mixture were determined by IR and NMR spectroscopy and TLC. Full-scale analysis of chemical shifts and spin-spin coupling constants was performed

  16. (α,α-dimethyl)glycyl (dmg) PNAs

    Science.gov (United States)

    Gourishankar, Aland; Ganesh, Krishna N.

    2012-01-01

    The design and facile synthesis of sterically constrained new analogs of PNA having gem-dimethyl substitutions on glycine (dmg-PNA-T) is presented. The PNA oligomers [aminoethyl dimethylglycyl (aedmg) and aminopropyl dimethylglycyl (apdmg)] synthesized from the monomers 6 and 12) effected remarkable stabilization of homothyminePNA2:homoadenine DNA/RNA triplexes and mixed base sequence duplexes with target cDNA or RNA. They show a higher binding to DNA relative to that with isosequential RNA. This may be a structural consequence of the sterically rigid gem-dimethyl group, imposing a pre-organized conformation favorable for complex formation with cDNA. The results complement our previous work that had demonstrated that cyclohexanyl-PNAs favor binding with cRNA compared with cDNA and imply that the biophysical and structural properties of PNAs can be directed by introduction of the right rigidity in PNA backbone devoid of chirality. This approach of tweaking selectivity in binding of PNA constructs by installing gem-dimethyl substitution in PNA backbone can be extended to further fine-tuning by similar substitution in the aminoethyl segment as well either individually or in conjunction with present substitution. PMID:22679528

  17. Chemical modification of arginine residues in the lactose repressor

    International Nuclear Information System (INIS)

    Whitson, P.A.; Matthews, K.S.

    1987-01-01

    The lactose repressor protein was chemically modified with 2,3-butanedione and phenylglyoxal. Arginine reaction was quantitated by either amino aced analysis or incorporation of 14 C-labeled phenylglyoxal. Inducer binding activity was unaffected by the modification of arginine residues, while both operator and nonspecific DNA binding activities were diminished, although to differing degrees. The correlation of the decrease in DNA binding activities with the modification of ∼ 1-2 equiv of arginine per monomer suggests increased reactivity of a functionally essential residue(s). For both reagents, operator DNA binding activity was protected by the presence of calf thymus DNA, and the extent of reaction with phenylglyoxal was simultaneously diminished. This protection presumably results from steric restriction of reagent access to an arginine(s) that is (are) essential for DNA binding interactions. These experiments suggest that there is (are) an essential reactive arginine(s) critical for repressor binding to DNA

  18. How Is Nature Asymmetric?

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 6. How Is Nature Asymmetric? - Discrete Symmetries in Particle Physics and their Violation ... Indian Institute of Technology, Chennai. Aligarh Muslim University. University of Rajasthan, Jaipur. Indian Institute of Science, Bangalore 560012, India.

  19. Exploring asymmetric catalytic transformations

    NARCIS (Netherlands)

    Guduguntla, Sureshbabu

    2017-01-01

    In Chapter 2, we report a highly enantioselective synthesis of β-alkyl-substituted alcohols through a one-pot Cu- catalyzed asymmetric allylic alkylation with organolithium reagents followed by reductive ozonolysis. The synthesis of γ-alkyl-substituted alcohols was also achieved through Cu-catalyzed

  20. Synthesis of Dimethyl Glutarate from Cyclobutanone and Dimethyl Carbonate over Solid Base Catalysts

    International Nuclear Information System (INIS)

    Zhi, Chen; Dudu, Wu

    2012-01-01

    A facile route for the synthesis of dimethyl glutarate (DMG) from cyclobutanone and dimethyl carbonate (DMC) in the presence of solid base catalysts has been developed. It was found that the intermediate carbomethoxycyclobutanone (CMCB) was produced from cyclobutanone with DMC in the first step, and then CMCB was further converted to DMG by reacting with a methoxide group. The role of the basic catalysts can be mainly ascribed to the activation of cyclobutanone via the abstraction of a proton in the α-position by base sites, and solid bases with moderate strength, such as MgO, favor the formation of DMG

  1. Synthesis of Dimethyl Glutarate from Cyclobutanone and Dimethyl Carbonate over Solid Base Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Zhi, Chen; Dudu, Wu [Guangdong Medical College, Dongguan (China)

    2012-06-15

    A facile route for the synthesis of dimethyl glutarate (DMG) from cyclobutanone and dimethyl carbonate (DMC) in the presence of solid base catalysts has been developed. It was found that the intermediate carbomethoxycyclobutanone (CMCB) was produced from cyclobutanone with DMC in the first step, and then CMCB was further converted to DMG by reacting with a methoxide group. The role of the basic catalysts can be mainly ascribed to the activation of cyclobutanone via the abstraction of a proton in the {alpha}-position by base sites, and solid bases with moderate strength, such as MgO, favor the formation of DMG

  2. Preparation of arginine (guanide 14C)

    International Nuclear Information System (INIS)

    Pichat, L.; Baret, C.

    1960-01-01

    Reaction of anhydrous ammoniac at 800 deg. C on 14 CO 3 Ba gives rise to barium cyanamide 14 C with a yield of about 98 per cent. Addition on H 2 S on cyanamide 14 C leads to thiourea 14 C with a 85 per cent yield, which is quantitatively transformed into S-ethyl-isothiouronium iodide by treatment with methyl iodide. This 14 C-isothiouronium salt is used to introduce 14 C guanide group in α-N-tosyl-ornithine; tosyl group in α-N-tosyl-arginine thus obtained is then removed by hydrolysis with hydrochloric acid. Arginine is separated as flavianic acid salt and is purified on exchange resin Dowex-50. The overall yield based on 14 CO 3 Ba is 25 per cent. (author) [fr

  3. Effects of arginine on multimodal anion exchange chromatography.

    Science.gov (United States)

    Hirano, Atsushi; Arakawa, Tsutomu; Kameda, Tomoshi

    2015-12-01

    The effects of arginine on binding and elution properties of a multimodal anion exchanger, Capto adhere, were examined using bovine serum albumin (BSA) and a monoclonal antibody against interleukin-8 (mAb-IL8). Negatively charged BSA was bound to the positively charged Capto adhere and was readily eluted from the column with a stepwise or gradient elution using 1M NaCl at pH 7.0. For heat-treated BSA, small oligomers and remaining monomers were also eluted using a NaCl gradient, whereas larger oligomers required arginine for effective elution. The positively charged mAb-IL8 was bound to Capto adhere at pH 7.0. Arginine was also more effective for elution of the bound mAb-IL8 than was NaCl. The results imply that arginine interacts with the positively charged Capto adhere. The mechanism underlying the interactions of arginine with Capto adhere was examined by calculating the binding free energy between an arginine molecule and a Capto adhere ligand in water through molecular dynamics simulations. The overall affinity of arginine for Capto adhere is attributed to the hydrophobic and π-π interactions between an arginine side chain and the aromatic moiety of the ligand as well as hydrogen bonding between arginine and the ligand hydroxyl group, which may account for the characteristics of protein elution using arginine. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Expression, purification, crystallization and preliminary crystallographic study of isolated modules of the mouse coactivator-associated arginine methyltransferase 1

    Energy Technology Data Exchange (ETDEWEB)

    Troffer-Charlier, Nathalie; Cura, Vincent; Hassenboehler, Pierre; Moras, Dino; Cavarelli, Jean, E-mail: cava@igbmc.u-strasbg.fr [IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Département de Biologie et Génomique Structurales, 1 Rue Laurent Fries, Illkirch, F-67404 (France); INSERM, U596, Illkirch, F-67400 (France); CNRS, UMR7104, Illkirch, F-67400 (France); Université Louis Pasteur, Faculté des Sciences de la Vie, Strasbourg, F-67000 (France)

    2007-04-01

    Isolated modules of mouse coactivator-associated arginine methyltransferase 1 encompassing the protein arginine N-methyltransferase catalytic domain have been overexpressed, purified and crystallized. X-ray diffraction data have been collected and have enabled determination of the structures by multiple isomorphous replacement using anomalous scattering. Coactivator-associated arginine methyltransferase 1 (CARM1) plays a crucial role in gene expression as a coactivator of several nuclear hormone receptors and also of non-nuclear receptor systems. Its recruitment by the transcriptional machinery induces protein methylation, leading to chromatin remodelling and gene activation. CARM1{sub 28–507} and two structural states of CARM1{sub 140–480} were expressed, purified and crystallized. Crystals of CARM1{sub 28–507} belong to space group P6{sub 2}22, with unit-cell parameters a = b = 136.0, c = 125.3 Å; they diffract to beyond 2.5 Å resolution using synchrotron radiation and contain one monomer in the asymmetric unit. The structure of CARM1{sub 28–507} was solved by multiple isomorphous replacement and anomalous scattering methods. Crystals of apo CARM1{sub 140–480} belong to space group I222, with unit-cell parameters a = 74.6, b = 99.0, c = 207.4 Å; they diffract to beyond 2.7 Å resolution and contain two monomers in the asymmetric unit. Crystals of CARM1{sub 140–480} in complex with S-adenosyl-l-homocysteine belong to space P2{sub 1}2{sub 1}2, with unit-cell parameters a = 74.6, b = 98.65, c = 206.08 Å; they diffract to beyond 2.6 Å resolution and contain four monomers in the asymmetric unit. The structures of apo and holo CARM1{sub 140–480} were solved by molecular-replacement techniques from the structure of CARM1{sub 28–507}.

  5. Multipartite asymmetric quantum cloning

    International Nuclear Information System (INIS)

    Iblisdir, S.; Gisin, N.; Acin, A.; Cerf, N.J.; Filip, R.; Fiurasek, J.

    2005-01-01

    We investigate the optimal distribution of quantum information over multipartite systems in asymmetric settings. We introduce cloning transformations that take N identical replicas of a pure state in any dimension as input and yield a collection of clones with nonidentical fidelities. As an example, if the clones are partitioned into a set of M A clones with fidelity F A and another set of M B clones with fidelity F B , the trade-off between these fidelities is analyzed, and particular cases of optimal N→M A +M B cloning machines are exhibited. We also present an optimal 1→1+1+1 cloning machine, which is an example of a tripartite fully asymmetric cloner. Finally, it is shown how these cloning machines can be optically realized

  6. Asymmetric information and economics

    Science.gov (United States)

    Frieden, B. Roy; Hawkins, Raymond J.

    2010-01-01

    We present an expression of the economic concept of asymmetric information with which it is possible to derive the dynamical laws of an economy. To illustrate the utility of this approach we show how the assumption of optimal information flow leads to a general class of investment strategies including the well-known Q theory of Tobin. Novel consequences of this formalism include a natural definition of market efficiency and an uncertainty principle relating capital stock and investment flow.

  7. Determination of dimethyl selenide and dimethyl sulphide compounds causing off-flavours in bottled mineral waters.

    Science.gov (United States)

    Guadayol, Marta; Cortina, Montserrat; Guadayol, Josep M; Caixach, Josep

    2016-04-01

    Sales of bottled drinking water have shown a large growth during the last two decades due to the general belief that this kind of water is healthier, its flavour is better and its consumption risk is lower than that of tap water. Due to the previous points, consumers are more demanding with bottled mineral water, especially when dealing with its organoleptic properties, like taste and odour. This work studies the compounds that can generate obnoxious smells, and that consumers have described like swampy, rotten eggs, sulphurous, cooked vegetable or cabbage. Closed loop stripping analysis (CLSA) has been used as a pre-concentration method for the analysis of off-flavour compounds in water followed by identification and quantification by means of GC-MS. Several bottled water with the aforementioned smells showed the presence of volatile dimethyl selenides and dimethyl sulphides, whose concentrations ranged, respectively, from 4 to 20 ng/L and from 1 to 63 ng/L. The low odour threshold concentrations (OTCs) of both organic selenide and sulphide derivatives prove that several objectionable odours in bottled waters arise from them. Microbial loads inherent to water sources, along with some critical conditions in water processing, could contribute to the formation of these compounds. There are few studies about volatile organic compounds in bottled drinking water and, at the best of our knowledge, this is the first study reporting the presence of dimethyl selenides and dimethyl sulphides causing odour problems in bottled waters. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Delayed dermal burns caused by dimethyl acetylenedicarboxylate

    Energy Technology Data Exchange (ETDEWEB)

    Slovak, A J; Payne, A R

    1984-07-01

    A chemical operator handling dimethyl acetylenedicarboxylate (DMAD) developed delayed and pain-free burns on one of his feet 2 days after a supposed spillage of DMAD. The injuries were confirmed to be associated with DMAD by chemical analysis of the operator's safety boot and patch tests. DMAD easily penetrates some protective clothing and dilute solutions can still be hazardous: the toxic effect is compounded by being delayed and painless. The lachrymatory irritant properties of undiluted DMAD are not adequate warning of its presence or spillage in quantities sufficient to cause significant skin damage.

  9. Asymmetric Evolutionary Games

    Science.gov (United States)

    McAvoy, Alex; Hauert, Christoph

    2015-01-01

    Evolutionary game theory is a powerful framework for studying evolution in populations of interacting individuals. A common assumption in evolutionary game theory is that interactions are symmetric, which means that the players are distinguished by only their strategies. In nature, however, the microscopic interactions between players are nearly always asymmetric due to environmental effects, differing baseline characteristics, and other possible sources of heterogeneity. To model these phenomena, we introduce into evolutionary game theory two broad classes of asymmetric interactions: ecological and genotypic. Ecological asymmetry results from variation in the environments of the players, while genotypic asymmetry is a consequence of the players having differing baseline genotypes. We develop a theory of these forms of asymmetry for games in structured populations and use the classical social dilemmas, the Prisoner’s Dilemma and the Snowdrift Game, for illustrations. Interestingly, asymmetric games reveal essential differences between models of genetic evolution based on reproduction and models of cultural evolution based on imitation that are not apparent in symmetric games. PMID:26308326

  10. Transsulfuration pathway thiols and methylated arginines: the Hunter Community Study.

    Directory of Open Access Journals (Sweden)

    Arduino A Mangoni

    Full Text Available Serum homocysteine, when studied singly, has been reported to be positively associated both with the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine [ADMA, via inhibition of dimethylarginine dimethylaminohydrolase (DDAH activity] and with symmetric dimethylarginine (SDMA. We investigated combined associations between transsulfuration pathway thiols, including homocysteine, and serum ADMA and SDMA concentrations at population level.Data on clinical and demographic characteristics, medication exposure, C-reactive protein, serum ADMA and SDMA (LC-MS/MS, and thiols (homocysteine, cysteine, taurine, glutamylcysteine, total glutathione, and cysteinylglycine; capillary electrophoresis were collected from a sample of the Hunter Community Study on human ageing [n = 498, median age (IQR = 64 (60-70 years].REGRESSION ANALYSIS SHOWED THAT: a age (P = 0.001, gender (P = 0.03, lower estimated glomerular filtration rate (eGFR, P = 0.08, body mass index (P = 0.008, treatment with beta-blockers (P = 0.03, homocysteine (P = 0.02, and glutamylcysteine (P = 0.003 were independently associated with higher ADMA concentrations; and b age (P = 0.001, absence of diabetes (P = 0.001, lower body mass index (P = 0.01, lower eGFR (P<0.001, cysteine (P = 0.007, and glutamylcysteine (P < 0.001 were independently associated with higher SDMA concentrations. No significant associations were observed between methylated arginines and either glutathione or taurine concentrations.After adjusting for clinical, demographic, biochemical, and pharmacological confounders the combined assessment of transsulfuration pathway thiols shows that glutamylcysteine has the strongest and positive independent associations with ADMA and SDMA. Whether this reflects a direct effect of glutamylcysteine on DDAH activity (for ADMA and/or cationic amino acid transport requires further investigations.

  11. Footwear contact dermatitis from dimethyl fumarate.

    Science.gov (United States)

    Švecová, Danka; Šimaljakova, Maria; Doležalová, Anna

    2013-07-01

    Dimethyl fumarate (DMF) is an effective inhibitor of mold growth. In very low concentrations, DMF is a potent sensitizer that can cause severe allergic contact dermatitis (ACD). It has been identified as the agent responsible for furniture contact dermatitis in Europe. The aim of this study was to evaluate patients in Slovakia with footwear ACD associated with DMF, with regard to clinical manifestations, patch test results, and results of chemical analysis of their footwear. Nine patients with suspected footwear contact dermatitis underwent patch testing with the following allergens: samples of their own footwear, commercial DMF, the European baseline, shoe screening, textile and leather dye screening, and industrial biocides series. The results were recorded according to international guidelines. The content of DMF in footwear and anti-mold sachets was analyzed using gas chromatography and mass spectrometry. Acute ACD was observed in nine Caucasian female patients. All patients developed delayed sensitization, as demonstrated by positive patch testing using textile footwear lining. Seven patients were patch tested with 0.1% DMF, and all seven were positive. Chemical analysis of available footwear showed that DMF was present in very high concentrations (25-80 mg/Kg). Dimethyl fumarate is a new footwear allergen and was responsible for severe ACD in our patients. To avoid an increase in the number of cases, the already approved European preventive measures should be accepted and commonly employed. © 2013 The International Society of Dermatology.

  12. Iodine-Catalyzed Isomerization of Dimethyl Muconate

    Energy Technology Data Exchange (ETDEWEB)

    Settle, Amy E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Berstis, Laura R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhang, Shuting [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rorrer, Nicholas [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hu, Haiming [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Richards, Ryan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Beckham, Gregg T [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Crowley, Michael F [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vardon, Derek R [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-04-12

    cis,cis-Muconic acid is a platform biobased chemical that can be upgraded to drop-in commodity and novel monomers. Among the possible drop-in products, dimethyl terephthalate can be synthesized via esterification, isomerization, Diels-Alder cycloaddition, and dehydrogenation. The isomerization of cis,cis-dimethyl muconate (ccDMM) to the trans,trans-form (ttDMM) can be catalyzed by iodine; however, studies have yet to address (i) the mechanism and reaction barriers unique to DMM, and (ii) the influence of solvent, potential for catalyst recycle, and recovery of high-purity ttDMM. To address this gap, we apply a joint computational and experimental approach to investigate iodine-catalyzed isomerization of DMM. Density functional theory calculations identified unique regiochemical considerations due to the large number of halogen-diene coordination schemes. Both transition state theory and experiments estimate significant barrier reductions with photodissociated iodine. Solvent selection was critical for rapid kinetics, likely due to solvent complexation with iodine. Under select conditions, ttDMM yields of 95% were achieved in <1 h with methanol, followed by high purity recovery (>98%) with crystallization. Lastly, post-reaction iodine can be recovered and recycled with minimal loss of activity. Overall, these findings provide new insight into the mechanism and conditions necessary for DMM isomerization with iodine to advance the state-of-the-art for biobased chemicals.

  13. Dimethyl ether as a drift-chamber gas

    International Nuclear Information System (INIS)

    Bari, G.; Basile, M.; Bonvicini, G.; Cara Romeo, G.; Casaccia, R.; Cifarelli, L.; Cindolo, F.; Contin, A.; D'Ali, G.; Del Papa, C.; Focardi, S.; Iacobucci, G.; Maccarrone, G.; Massam, T.; Motta, F.; Nania, R.; Palmonari, F.; Prisco, G.; Sartorelli, G.; Susinno, G.; Votano, L.; Zichichi, A.; Istituto Nazionale di Fisica Nucleare, Bologna; European Organization for Nuclear Research, Geneva; Istituto Nazionale di Fisica Nucleare, Frascati; Michigan Univ., Ann Arbor; Palermo Univ.

    1986-01-01

    We have continued the testing of dimethyl ether as a drift-chamber gas in order to improve the understanding of its properties. In particular, we report on measurement accuracy, on systematic effects, and some preliminary data on the ageing of a detector filled with dimethyl ether. (orig.)

  14. Arginine (Di)methylated Human Leukocyte Antigen Class I Peptides Are Favorably Presented by HLA-B*07

    NARCIS (Netherlands)

    Marino, Fabio; Mommen, Geert P M; Jeko, Anita; Meiring, Hugo D; van Gaans-van den Brink, Jacqueline A M; Scheltema, Richard A; van Els, Cécile A C M; Heck, Albert J R

    Alterations in protein post-translational modification (PTM) are recognized hallmarks of diseases. These modifications potentially provide a unique source of disease-related human leukocyte antigen (HLA) class I-presented peptides that can elicit specific immune responses. While phosphorylated HLA

  15. Characterization of arginine decarboxylase from Dianthus caryophyllus.

    Science.gov (United States)

    Ha, Byung Hak; Cho, Ki Joon; Choi, Yu Jin; Park, Ky Young; Kim, Kyung Hyun

    2004-04-01

    Arginine decarboxylase (ADC, EC 4.1.1.9) is a key enzyme in the biosynthesis of polyamines in higher plants, whereas ornithine decarboxylase represents the sole pathway of polyamine biosynthesis in animals. Previously, we characterized a genomic clone from Dianthus caryophyllus, in which the deduced polypeptide of ADC was 725 amino acids with a molecular mass of 78 kDa. In the present study, the ADC gene was subcloned into the pGEX4T1 expression vector in combination with glutathione S-transferase (GST). The fusion protein GST-ADC was water-soluble and thus was purified by sequential GSTrap-arginine affinity chromatography. A thrombin-mediated on-column cleavage reaction was employed to release free ADC from GST. Hiload superdex gel filtration FPLC was then used to obtain a highly purified ADC. The identity of the ADC was confirmed by immunoblot analysis, and its specific activity with respect to (14)C-arginine decarboxylation reaction was determined to be 0.9 CO(2) pkat mg(-1) protein. K(m) and V(max) of the reaction between ADC and the substrate were 0.077 +/- 0.001 mM and 6.0 +/- 0.6 pkat mg(-1) protein, respectively. ADC activity was reduced by 70% in the presence of 0.1 mM Cu(2+) or CO(2+), but was only marginally affected by Mg(2+), or Ca(2+) at the same concentration. Moreover, spermine at 1 mM significantly reduced its activity by 30%.

  16. Weissella halotolerans W22 combines arginine deiminase and ornithine decarboxylation pathways and converts arginine to putrescine

    NARCIS (Netherlands)

    Pereira, C. I.; San Romao, M. V.; Lolkema, J. S.; Barreto Crespo, M. T.; Baretto Crespo, M.

    2009-01-01

    Aims: To demonstrate that the meat food strain Weissella halotolerans combines an ornithine decarboxylation pathway and an arginine deiminase (ADI) pathway and is able to produce putrescine, a biogenic amine. Evidence is shown that these two pathways produce a proton motive force (PMF). Methods and

  17. Asymmetric dimethylarginine in children with homocystinuria or phenylketonuria.

    Science.gov (United States)

    Kanzelmeyer, Nele; Tsikas, Dimitrios; Chobanyan-Jürgens, Kristine; Beckmann, Bibiana; Vaske, Bernhard; Illsinger, Sabine; Das, Anibh M; Lücke, Thomas

    2012-05-01

    Plasma concentration of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide (NO) synthesis from L-arginine and a cardiovascular risk factor, was found to be elevated in plasma of homocysteinemic adults. Enhanced cardiovascular risk due to homocystinuria and impaired renal function has been found in patients with phenylketonuria (PKU) on protein-restricted diet. However, it is still unknown whether ADMA synthesis is also elevated in children with homocystinuria due to cystathionine beta-synthase deficiency (classical homocystinuria), and whether ADMA may play a role in phenylketonuria in childhood. In the present study, we investigated the status of the L-arginine/NO pathway in six young patients with homocystinuria, in 52 young phenylketonuria patients on natural protein-restricted diet, and in age- and gender-matched healthy children serving as controls. ADMA in plasma and urine was determined by GC-MS/MS. The NO metabolites nitrate and nitrite in plasma and urine, and urinary dimethylamine (DMA), the dimethylarginine dimethylaminohydrolase (DDAH) metabolite of ADMA, were measured by GC-MS. Unlike urine ADMA excretion, plasma ADMA concentration in patients with homocystinuria was significantly higher than in controls (660±158 vs. 475±77 nM, P=0.035). DMA excretion rate was considerably higher in children with homocystinuria as compared to controls (62.2±24.5 vs. 6.5±2.9 μmol/mmol creatinine, P=0.068), indicating enhanced DDAH activity in this disease. In contrast and unexpectedly, phenylketonuria patients had significantly lower ADMA plasma concentrations compared to controls (512±136 vs. 585±125 nM, P=0.009). Phenylketonuria patients and controls had similar L-arginine/ADMA molar ratios in plasma. Urinary nitrite excretion was significantly higher in phenylketonuria as compared to healthy controls (1.7±1.7 vs. 0.7±1.2 μmol/mmol creatinine, P=0.003). Our study shows that the L-arginine/NO pathway is differently altered in children

  18. A glutamate/aspartate switch controls product specificity in a protein arginine methyltransferase

    Energy Technology Data Exchange (ETDEWEB)

    Debler, Erik W.; Jain, Kanishk; Warmack, Rebeccah A.; Feng, You; Clarke, Steven G.; Blobel, Günter; Stavropoulos, Pete

    2016-02-08

    Trypanosoma brucei PRMT7 (TbPRMT7) is a protein arginine methyltransferase (PRMT) that strictly monomethylates various substrates, thus classifying it as a type III PRMT. However, the molecular basis of its unique product specificity has remained elusive. Here, we present the structure of TbPRMT7 in complex with its cofactor product S-adenosyl-L-homocysteine (AdoHcy) at 2.8 Å resolution and identify a glutamate residue critical for its monomethylation behavior. TbPRMT7 comprises the conserved methyltransferase and β-barrel domains, an N-terminal extension, and a dimerization arm. The active site at the interface of the N-terminal extension, methyltransferase, and β-barrel domains is stabilized by the dimerization arm of the neighboring protomer, providing a structural basis for dimerization as a prerequisite for catalytic activity. Mutagenesis of active-site residues highlights the importance of Glu181, the second of the two invariant glutamate residues of the double E loop that coordinate the target arginine in substrate peptides/proteins and that increase its nucleophilicity. Strikingly, mutation of Glu181 to aspartate converts TbPRMT7 into a type I PRMT, producing asymmetric dimethylarginine (ADMA). Isothermal titration calorimetry (ITC) using a histone H4 peptide showed that the Glu181Asp mutant has markedly increased affinity for monomethylated peptide with respect to the WT, suggesting that the enlarged active site can favorably accommodate monomethylated peptide and provide sufficient space for ADMA formation. In conclusion, these findings yield valuable insights into the product specificity and the catalytic mechanism of protein arginine methyltransferases and have important implications for the rational (re)design of PRMTs.

  19. Selectivity control of carbonylation of methanol to dimethyl oxalate and dimethyl carbonate over gold anode by electrochemical potential.

    Science.gov (United States)

    Funakawa, Akiyasu; Yamanaka, Ichiro; Takenaka, Sakae; Otsuka, Kiyoshi

    2004-05-05

    New and unique electrocatalysis of gold for the carbonylation of methanol to dimethyl oxalate (DMO) and dimethyl carbonate (DMC) was found. The selectivity to DMO and DMC could be controlled over gold anode by electrochemical potential, as you like. Drastic changes of gold electrocatalysis was due to changes of the oxidation state of gold, Au0 or Au3+.

  20. Study on the synthesis of dimethyl 1,4-cyclohexanedicarboxylate by catalytic hydrogenation of dimethyl terephthalate

    Directory of Open Access Journals (Sweden)

    LI Yuanhua

    2016-12-01

    Full Text Available In the field of polymer industry,1,4-cyclohexanedimethanol (CHDM occupies an important position especially for the synthesis of highly valued polyester products.In industry,CHDM is prepared from dimethyl terephthalate (DMT through a two-step hydrogenation process Palladium supported on magnesium oxide (Pd/MgO was prepared by animpregnation method and was characterized by x-ray diffraction (XRD,transmission electron microscope (TEM and scan electron microscope (SEM.During the hydrogenation of DMT to synthesize dimethyl 1,4-cyclohexanedicarboxylate (DMCD,the as-prepared Pd/MgO was used as the catalyst with methyl acetate as the solvent.Under optimized reaction conditions (reaction temperature:180 ℃,reaction pressure:4.5 MPa,the conversion of DMT was 100% and the selectivity of DMCD was 99%.Such a catalyst shows a good potential in industrial applications.

  1. Asymmetric quantum cloning machines

    International Nuclear Information System (INIS)

    Cerf, N.J.

    1998-01-01

    A family of asymmetric cloning machines for quantum bits and N-dimensional quantum states is introduced. These machines produce two approximate copies of a single quantum state that emerge from two distinct channels. In particular, an asymmetric Pauli cloning machine is defined that makes two imperfect copies of a quantum bit, while the overall input-to-output operation for each copy is a Pauli channel. A no-cloning inequality is derived, characterizing the impossibility of copying imposed by quantum mechanics. If p and p ' are the probabilities of the depolarizing channels associated with the two outputs, the domain in (√p,√p ' )-space located inside a particular ellipse representing close-to-perfect cloning is forbidden. This ellipse tends to a circle when copying an N-dimensional state with N→∞, which has a simple semi-classical interpretation. The symmetric Pauli cloning machines are then used to provide an upper bound on the quantum capacity of the Pauli channel of probabilities p x , p y and p z . The capacity is proven to be vanishing if (√p x , √p y , √p z ) lies outside an ellipsoid whose pole coincides with the depolarizing channel that underlies the universal cloning machine. Finally, the tradeoff between the quality of the two copies is shown to result from a complementarity akin to Heisenberg uncertainty principle. (author)

  2. On the mechanism of arginine requirement for adenovirus synthesis

    International Nuclear Information System (INIS)

    Plaat, D.; Weber, J.

    1979-01-01

    The effects of arginine deprivation on the synthesis and processing of viral proteins and the assembly of incomplete and complete virions were studied during infection with human adenovirus type 2. Arginine deprivation greatly reduced the synthesis of all viral proteins, particularly the precursor to core protein VII. The inhibition was completely reversible by the addition of arginine to the medium. Arginine deprivation between 7 and 20 hours post-infection inhibited the processing of PVII to VII, suggesting that PVII is not cleaved autocatalytically. The assembly of incomplete virions was sensitive to arginine deprivation only prior to 20 hours, while the assembly of complete virions was dependent on the continuous presence of arginine. This observation supports the hypothesis that incomplete virions are precursors of complete virions. The experiments on the PVII-specific endoprotease activity showed that arginine deprivation caused only slight reduction in the in vitro activity, although no activity was observed in vivo. The present results lead to the hypothesis that arginine deficiency inhibits the synthesis of a functional protein essential for virion maturation, other than the synthesis of processing of PVII. (author)

  3. Chemical mechanisms of histone lysine and arginine modifications

    OpenAIRE

    Smith, Brian C.; Denu, John M.

    2008-01-01

    Histone lysine and arginine residues are subject to a wide array of post-translational modifications including methylation, citrullination, acetylation, ubiquitination, and sumoylation. The combinatorial action of these modifications regulates critical DNA processes including replication, repair, and transcription. In addition, enzymes that modify histone lysine and arginine residues have been correlated with a variety of human diseases including arthritis, cancer, heart disease, diabetes, an...

  4. Functional and neurochemical profile of place learning after L-nitro-arginine in the rat

    DEFF Research Database (Denmark)

    Mogensen, Jesper; Wörtwein, Gitta; Hasman, Andreas

    1995-01-01

    Neurobiology, nitrogenoxid (NO), place learning, rotte, L-Nitro-Arginin, funktionel genopretning......Neurobiology, nitrogenoxid (NO), place learning, rotte, L-Nitro-Arginin, funktionel genopretning...

  5. Protein arginine methyltransferase 5 functions as an epigenetic activator of the androgen receptor to promote prostate cancer cell growth.

    Science.gov (United States)

    Deng, X; Shao, G; Zhang, H-T; Li, C; Zhang, D; Cheng, L; Elzey, B D; Pili, R; Ratliff, T L; Huang, J; Hu, C-D

    2017-03-02

    Protein arginine methyltransferase 5 (PRMT5) is an emerging epigenetic enzyme that mainly represses transcription of target genes via symmetric dimethylation of arginine residues on histones H4R3, H3R8 and H2AR3. Accumulating evidence suggests that PRMT5 may function as an oncogene to drive cancer cell growth by epigenetic inactivation of several tumor suppressors. Here, we provide evidence that PRMT5 promotes prostate cancer cell growth by epigenetically activating transcription of the androgen receptor (AR) in prostate cancer cells. Knockdown of PRMT5 or inhibition of PRMT5 by a specific inhibitor reduces the expression of AR and suppresses the growth of multiple AR-positive, but not AR-negative, prostate cancer cells. Significantly, knockdown of PRMT5 in AR-positive LNCaP cells completely suppresses the growth of xenograft tumors in mice. Molecular analysis reveals that PRMT5 binds to the proximal promoter region of the AR gene and contributes mainly to the enriched symmetric dimethylation of H4R3 in the same region. Mechanistically, PRMT5 is recruited to the AR promoter by its interaction with Sp1, the major transcription factor responsible for AR transcription, and forms a complex with Brg1, an ATP-dependent chromatin remodeler, on the proximal promoter region of the AR gene. Furthermore, PRMT5 expression in prostate cancer tissues is significantly higher than that in benign prostatic hyperplasia tissues, and PRMT5 expression correlates positively with AR expression at both the protein and mRNA levels. Taken together, our results identify PRMT5 as a novel epigenetic activator of AR in prostate cancer. Given that inhibiting AR transcriptional activity or androgen synthesis remains the major mechanism of action for most existing anti-androgen agents, our findings also raise an interesting possibility that targeting PRMT5 may represent a novel approach for prostate cancer treatment by eliminating AR expression.

  6. Arginine affects appetite via nitric oxide in ducks.

    Science.gov (United States)

    Wang, C; Hou, S S; Huang, W; Xu, T S; Rong, G H; Xie, M

    2014-08-01

    The objective of the study was to investigate the mechanism by which arginine regulates feed intake in Pekin ducks. In experiment 1, one hundred forty-four 1-d-old male Pekin ducks were randomly allotted to 3 dietary treatments with 6 replicate pens of 8 birds per pen. Birds in each group were fed a corn-corn gluten meal diet containing 0.65, 0.95, and 1.45% arginine. Ducks fed the diet containing 0.65% arginine had lower feed intake and plasma nitric oxide level (P ducks were allotted to 1 of 2 treatments. After 2 h fasting, birds in the 2 groups were intraperitoneally administrated saline and l-NG-nitro-arginine methyl ester HCl (L-NAME) for 3 d, respectively. Feed intake (P study implied that arginine modifies feeding behavior possibly through controlling endogenous synthesis of nitric oxide in Pekin ducks. © Poultry Science Association Inc.

  7. Anti-aging effects of l-arginine

    Directory of Open Access Journals (Sweden)

    Mohamed Z. Gad

    2010-07-01

    Full Text Available l-Arginine is one of the most metabolically versatile amino acids. In addition to its role in the synthesis of nitric oxide, l-arginine serves as a precursor for the synthesis of polyamines, proline, glutamate, creatine, agmatine and urea. Several human and experimental animal studies have indicated that exogenous l-arginine intake has multiple beneficial pharmacological effects when taken in doses larger than normal dietary consumption. Such effects include reduction in the risk of vascular and heart diseases, reduction in erectile dysfunction, improvement in immune response and inhibition of gastric hyperacidity. This review summarises several positive studies and personal experiences of l-arginine. The demonstrated anti-aging benefits of l-arginine show greater potential than any pharmaceutical or nutraceutical agent ever previously discovered.

  8. Purification of free arginine from chickpea (Cicer arietinum) seeds.

    Science.gov (United States)

    Cortés-Giraldo, Isabel; Megías, Cristina; Alaiz, Manuel; Girón-Calle, Julio; Vioque, Javier

    2016-02-01

    Chickpea is a grain legume widely consumed in the Mediterranean region and other parts of the world. Chickpea seeds are rich in proteins but they also contain a substantial amount of free amino acids, especially arginine. Hence chickpea may represent a useful source of free amino acids for nutritional or pharmaceutical purposes. Arginine is receiving great attention in recent years because it is the substrate for the synthesis of nitric oxide, an important signaling molecule involved in numerous physiological and pathological processes in mammals. In this work we describe a simple procedure for the purification of arginine from chickpea seeds, using nanofiltration technology and an ion-exchange resin, Amberlite IR-120. Arginine was finally purified by precipitation or crystallization, yielding preparations with purities of 91% and 100%, respectively. Chickpea may represent an affordable green source of arginine, and a useful alternative to production by fermentation or protein hydrolysis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Protein arginine methyltransferase 5 promotes lung cancer metastasis via the epigenetic regulation of miR-99 family/FGFR3 signaling.

    Science.gov (United States)

    Jing, Pengyu; Zhao, Nan; Ye, Mingxiang; Zhang, Yong; Zhang, Zhipei; Sun, Jianyong; Wang, Zhengxin; Zhang, Jian; Gu, Zhongping

    2018-07-28

    Protein arginine methyltransferase 5 (PRMT5) functions as a tumor initiator to regulate several cancer progressions, such as proliferation and apoptosis, by catalyzing the symmetrical dimethylation (me2s) of arginine residues within targeted molecules. However, the exact role of PRMT5-mediated metastasis in lung cancer is not fully understood. Here, we illustrated its potential effects in lung cancer metastasis in vivo and vitro. PRMT5 was frequently overexpressed in lung tumors, and its expression was positively related to tumor stages, lymphatic metastasis and poor outcome. In this model, PRMT5 repressed the transcription of the miR-99 family by symmetrical dimethylation of histone H4R3, which increased FGFR3 expression and in turn activated Erk1/2 and Akt, leading to cell growth and metastasis in lung cancer. Furthermore, loss of PRMT5 exerted anti-metastasis effects on lung cancer progression by blocking histone-modification of miR-99 family. Overall, this study provides new insights into the PRMT5/miR-99 family/FGFR3 axis in regulating lung cancer progression and identifies PRMT5 as a promising prognostic biomarker and therapeutic target. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

  10. Protein arginine methyltransferase 5 regulates multiple signaling pathways to promote lung cancer cell proliferation

    International Nuclear Information System (INIS)

    Sheng, Xiumei; Wang, Zhengxin

    2016-01-01

    Protein arginine methyltransferase 5 (PRMT5) catalyzes the formation of symmetrical dimethylation of arginine residues in proteins. WD repeat domain 77 (WDR77), also known as p44, MEP50, or WD45, forms a stoichiometric complex with PRMT5. The PRMT5/p44 complex is required for cellular proliferation of lung and prostate epithelial cells during earlier stages of development and is re-activated during prostate and lung tumorigenesis. The molecular mechanisms by which PRMT5 and p44 promote cellular proliferation are unknown. Expression of PRMT5 and p44 in lung and prostate cancer cells was silenced and their target genes were identified. The regulation of target genes was validated in various cancer cells during lung development and tumorigenesis. Altered expression of target genes was achieved by ectopic cDNA expression and shRNA-mediated silencing. PRMT5 and p44 regulate expression of a specific set of genes encoding growth and anti-growth factors, including receptor tyrosine kinases and antiproliferative proteins. Genes whose expression was suppressed by PRMT5 and p44 encoded anti-growth factors and inhibited cell growth when ectopically expressed. In contrast, genes whose expression was enhanced by PRMT5 and p44 encoded growth factors and increased cell growth when expressed. Altered expression of target genes is associated with re-activation of PRMT5 and p44 during lung tumorigenesis. Our data provide the molecular basis by which PRMT5 and p44 regulate cell growth and lay a foundation for further investigation of their role in lung tumor initiation. The online version of this article (doi:10.1186/s12885-016-2632-3) contains supplementary material, which is available to authorized users

  11. Nitric Oxide Metabolites and Asymmetric Dimethylarginine Concentrations in Breast Milk

    Directory of Open Access Journals (Sweden)

    Hakan Öztürk

    2017-04-01

    Full Text Available Objective: Nitric oxide plays a preventive role in the development of necrotizing enterocolitis. Oral nitrite and nitrate intake has gained importance with the discovery of the conversion of nitrite to nitric oxide in acidic medium out of the synthesis of nitric oxide from L-arginine. Objective of this study was to examine the breast milk concentrations of nitric oxide and asymmetric dimethylarginine which is a competitive inhibitor of nitric oxide and to compare these concentrations in terms of gestational age and maturity of breast milk. Study Design: Forty-one women were included in the study. Milk samples were collected from 3 groups of mothers as term, late preterm and preterm on the postpartum days 3, 7 and 28. Results: When breast milk concentrations of nitric oxide were compared according to the postnatal day of the milk independently from gestational age; nitric oxide concentration was higher in the colostrum than in the transition milk and mature milk (p=0,035; p=0,001; respectively. For the comparison of asymmetric dimethylarginine concentrations among these groups and days; no statistically significant difference was observed in terms of gestational age and maturity of the milk (p=0.865, p=0.115; respectively. Conclusion: The highest nitric oxide concentration was found in the colostrum, suggesting that colostrum is a valuable food for newborns. Plasma concentrations of asymmetric dimethylarginine were negatively correlated with nitric oxide and did not show a correlation with breast milk, suggesting that asymmetric dimethylargininedoesn’t make nitric oxide inhibition in breast milk.

  12. Cinchona alkaloids in asymmetric organocatalysis

    NARCIS (Netherlands)

    Marcelli, T.; Hiemstra, H.

    2010-01-01

    This article reviews the applications of cinchona alkaloids as asymmetric catalysts. In the last few years, characterized by the resurgence of interest in asymmetric organocatalysis, cinchona derivatives have been shown to catalyze an outstanding array of chemical reactions, often with remarkable

  13. Alternative Asymmetric Stochastic Volatility Models

    NARCIS (Netherlands)

    M. Asai (Manabu); M.J. McAleer (Michael)

    2010-01-01

    textabstractThe stochastic volatility model usually incorporates asymmetric effects by introducing the negative correlation between the innovations in returns and volatility. In this paper, we propose a new asymmetric stochastic volatility model, based on the leverage and size effects. The model is

  14. Asymmetric Realized Volatility Risk

    Directory of Open Access Journals (Sweden)

    David E. Allen

    2014-06-01

    Full Text Available In this paper, we document that realized variation measures constructed from high-frequency returns reveal a large degree of volatility risk in stock and index returns, where we characterize volatility risk by the extent to which forecasting errors in realized volatility are substantive. Even though returns standardized by ex post quadratic variation measures are nearly Gaussian, this unpredictability brings considerably more uncertainty to the empirically relevant ex ante distribution of returns. Explicitly modeling this volatility risk is fundamental. We propose a dually asymmetric realized volatility model, which incorporates the fact that realized volatility series are systematically more volatile in high volatility periods. Returns in this framework display time varying volatility, skewness and kurtosis. We provide a detailed account of the empirical advantages of the model using data on the S&P 500 index and eight other indexes and stocks.

  15. Asymmetric Higgsino dark matter.

    Science.gov (United States)

    Blum, Kfir; Efrati, Aielet; Grossman, Yuval; Nir, Yosef; Riotto, Antonio

    2012-08-03

    In the supersymmetric framework, prior to the electroweak phase transition, the existence of a baryon asymmetry implies the existence of a Higgsino asymmetry. We investigate whether the Higgsino could be a viable asymmetric dark matter candidate. We find that this is indeed possible. Thus, supersymmetry can provide the observed dark matter abundance and, furthermore, relate it with the baryon asymmetry, in which case the puzzle of why the baryonic and dark matter mass densities are similar would be explained. To accomplish this task, two conditions are required. First, the gauginos, squarks, and sleptons must all be very heavy, such that the only electroweak-scale superpartners are the Higgsinos. With this spectrum, supersymmetry does not solve the fine-tuning problem. Second, the temperature of the electroweak phase transition must be low, in the (1-10) GeV range. This condition requires an extension of the minimal supersymmetric standard model.

  16. Asymmetric Organocatalytic Cycloadditions

    DEFF Research Database (Denmark)

    Mose, Rasmus

    2016-01-01

    has gained broad recognition as it has found several applications in academia and industry. The [4+2] cycloaddition has also been performed in an enantioselective aminocatalytic fashion which allows the generation of optically active products. In this thesis it is demonstrated how trienamines can......Since the onset of the new millennium the field of organocatalysis has undergone a great expansion led by investigations in the field of aminocatalysis. This thesis will address some recent developments in aminocatalyzed cycloadditions and provide a theoretical background hereto. Cycloadditions...... undergo cascade reactions with different electron deficient dienophiles in Diels Alder – nucleophilic ring closing reactions. This methodology opens up for the direct asymmetric formation of hydroisochromenes and hydroisoquinolines which may possess interesting biological activities. It is also...

  17. Sensitive radioimmunoassay for plasma arginine vasopressin

    International Nuclear Information System (INIS)

    Thibonnier, M.; Soto, M.E.; Corvol, P.; Milliez, P.; Marchetti, J.; Menard, J.

    1980-01-01

    Using an ion exchange resin, a sensitive radioimmunoassay for plasma arginine vasopressin (AVP) was developed. This assay was characterized by the absence of blank values, an excellent recovery rate, great sensitivity (0.1 pg of AVP was significantly detected) and reproducibility. In 8 normal men, plasma AVP after overnight dehydration was 1.57+-0.17 pg/ml, and dropped to 0.58+-0.11 pg/ml after 20 ml/kg oral water loading. Significant correlations between plasma AVP levels and plasma or urinary osmolality confirm the validity of this assay. In complete pituitary diabetes insipidus (n=4) plasma AVP was undetectable whereas it was frankly increased in Schwartz-Bartter syndrome (3 to 33 pg/ml, n=8) [fr

  18. Arginine and Polyamines Fate in Leishmania Infection

    Science.gov (United States)

    Muxel, Sandra M.; Aoki, Juliana I.; Fernandes, Juliane C. R.; Laranjeira-Silva, Maria F.; Zampieri, Ricardo A.; Acuña, Stephanie M.; Müller, Karl E.; Vanderlinde, Rubia H.; Floeter-Winter, Lucile M.

    2018-01-01

    Leishmania is a protozoan parasite that alternates its life cycle between the sand fly and the mammalian host macrophages, involving several environmental changes. The parasite responds to these changes by promoting a rapid metabolic adaptation through cellular signaling modifications that lead to transcriptional and post-transcriptional gene expression regulation and morphological modifications. Molecular approaches such as gene expression regulation, next-generation sequencing (NGS), microRNA (miRNA) expression profiling, in cell Western blot analyses and enzymatic activity profiling, have been used to characterize the infection of murine BALB/c and C57BL/6 macrophages, as well as the human monocytic cell-lineage THP-1, with Leishmania amazonensis wild type (La-WT) or arginase knockout (La-arg-). These models are being used to elucidate physiological roles of arginine and polyamines pathways and the importance of arginase for the establishment of the infection. In this review, we will describe the main aspects of Leishmania-host interaction, focusing on the arginine and polyamines pathways and pointing to possible targets to be used for prognosis and/or in the control of the infection. The parasite enzymes, arginase and nitric oxide synthase-like, have essential roles in the parasite survival and in the maintenance of infection. On the other hand, in mammalian macrophages, defense mechanisms are activated inducing alterations in the mRNA, miRNA and enzymatic profiles that lead to the control of infection. Furthermore, the genetic background of both parasite and host are also important to define the fate of infection. PMID:29379478

  19. Combinatorial effects of arginine and fluoride on oral bacteria.

    Science.gov (United States)

    Zheng, X; Cheng, X; Wang, L; Qiu, W; Wang, S; Zhou, Y; Li, M; Li, Y; Cheng, L; Li, J; Zhou, X; Xu, X

    2015-02-01

    Dental caries is closely associated with the microbial disequilibrium between acidogenic/aciduric pathogens and alkali-generating commensal residents within the dental plaque. Fluoride is a widely used anticaries agent, which promotes tooth hard-tissue remineralization and suppresses bacterial activities. Recent clinical trials have shown that oral hygiene products containing both fluoride and arginine possess a greater anticaries effect compared with those containing fluoride alone, indicating synergy between fluoride and arginine in caries management. Here, we hypothesize that arginine may augment the ecological benefit of fluoride by enriching alkali-generating bacteria in the plaque biofilm and thus synergizes with fluoride in controlling dental caries. Specifically, we assessed the combinatory effects of NaF/arginine on planktonic and biofilm cultures of Streptococcus mutans, Streptococcus sanguinis, and Porphyromonas gingivalis with checkerboard microdilution assays. The optimal NaF/arginine combinations were selected, and their combinatory effects on microbial composition were further examined in single-, dual-, and 3-species biofilm using bacterial species-specific fluorescence in situ hybridization and quantitative polymerase chain reaction. We found that arginine synergized with fluoride in suppressing acidogenic S. mutans in both planktonic and biofilm cultures. In addition, the NaF/arginine combination synergistically reduced S. mutans but enriched S. sanguinis within the multispecies biofilms. More importantly, the optimal combination of NaF/arginine maintained a "streptococcal pressure" against the potential growth of oral anaerobe P. gingivalis within the alkalized biofilm. Taken together, we conclude that the combinatory application of fluoride and arginine has a potential synergistic effect in maintaining a healthy oral microbial equilibrium and thus represents a promising ecological approach to caries management. © International & American

  20. Arginine-aromatic interactions and their effects on arginine-induced solubilization of aromatic solutes and suppression of protein aggregation

    KAUST Repository

    Shah, Dhawal

    2011-09-21

    We examine the interaction of aromatic residues of proteins with arginine, an additive commonly used to suppress protein aggregation, using experiments and molecular dynamics simulations. An aromatic-rich peptide, FFYTP (a segment of insulin), and lysozyme and insulin are used as model systems. Mass spectrometry shows that arginine increases the solubility of FFYTP by binding to the peptide, with the simulations revealing the predominant association of arginine to be with the aromatic residues. The calculations further show a positive preferential interaction coefficient, Γ XP, contrary to conventional thinking that positive Γ XP\\'s indicate aggregation rather than suppression of aggregation. Simulations with lysozyme and insulin also show arginine\\'s preference for aromatic residues, in addition to acidic residues. We use these observations and earlier results reported by us and others to discuss the possible implications of arginine\\'s interactions with aromatic residues on the solubilization of aromatic moieties and proteins. Our results also highlight the fact that explanations based purely on Γ XP, which measures average affinity of an additive to a protein, could obscure or misinterpret the underlying molecular mechanisms behind additive-induced suppression of protein aggregation. © 2011 American Institute of Chemical Engineers (AIChE).

  1. Polymersomes with asymmetric membranes and self-assembled superstructures using pentablock quintopolymers resolved by electron tomography

    KAUST Repository

    Haataja, J. S.

    2018-01-09

    Polystyrene-block-poly(1,4-isoprene)-block-poly(dimethyl siloxane)-block-poly(tert-butyl methacrylate)-block-poly(2-vinyl pyridine), PS-b-PI-b-PDMS-b-PtBMA-b-P2VP, self-assembles in acetone into polymersomes with asymmetric (directional) PI-b-PDMS membranes. The polymersomes, in turn, self-assemble into superstructures. Analogically to supravesicular structures at a smaller length scale, we refer to them as suprapolymersome structures. Electron tomograms are shown to be invaluable in the structural assessment of such complex self-assemblies.

  2. Force on an Asymmetric Capacitor

    National Research Council Canada - National Science Library

    Bahder, Thomas

    2003-01-01

    .... At present, the physical basis for the Biefeld-Brown effect is not understood. The order of magnitude of the net force on the asymmetric capacitor is estimated assuming two different mechanisms of charge conduction between its electrodes...

  3. Asymmetric cation-binding catalysis

    DEFF Research Database (Denmark)

    Oliveira, Maria Teresa; Lee, Jiwoong

    2017-01-01

    The employment of metal salts is quite limited in asymmetric catalysis, although it would provide an additional arsenal of safe and inexpensive reagents to create molecular functions with high optical purity. Cation chelation by polyethers increases the salts' solubility in conventional organic...... solvents, thus increasing their applicability in synthesis. The expansion of this concept to chiral polyethers led to the emergence of asymmetric cation-binding catalysis, where chiral counter anions are generated from metal salts, particularly using BINOL-based polyethers. Alkali metal salts, namely KF...... highly enantioselective silylation reactions in polyether-generated chiral environments, and leading to a record-high turnover in asymmetric organocatalysis. This can lead to further applications by the asymmetric use of other inorganic salts in various organic transformations....

  4. Facilitation of peptide fibre formation by arginine-phosphate ...

    Indian Academy of Sciences (India)

    WINTEC

    Peptide; self-assembly; arginine; microscopy. ... The latter property, in particular, observed in .... this process repeated till the gummy compound be- ..... micrograph of Congo red-stained image of individual peptide fibre from aged solution of 4.

  5. Multicatalyst system in asymmetric catalysis

    CERN Document Server

    Zhou, Jian

    2014-01-01

    This book introduces multi-catalyst systems by describing their mechanism and advantages in asymmetric catalysis.  Helps organic chemists perform more efficient catalysis with step-by-step methods  Overviews new concepts and progress for greener and economic catalytic reactions  Covers topics of interest in asymmetric catalysis including bifunctional catalysis, cooperative catalysis, multimetallic catalysis, and novel tandem reactions   Has applications for pharmaceuticals, agrochemicals, materials, and flavour and fragrance

  6. Acellular matrix of bovine pericardium bound with L-arginine

    International Nuclear Information System (INIS)

    Kim, Hyo Joo; Bae, Jin Woo; Kim, Chun Ho; Lee, Jin Woo; Shin, Jung Woog; Park, Ki Dong

    2007-01-01

    Surface immobilization of bioactive molecules onto natural tissues has been interestingly studied for the development of new functional matrices for the replacement of lost or malfunctioning tissues. In this study, an acellular matrix of bovine pericardium (ABP) was chemically modified by the direct coupling of L-arginine after glutaraldehyde (GA) cross-linking. The effects of L-arginine coupling on durability and calcification were investigated and the biocompatibility was evaluated in vitro and in vivo. A four-step detergent and enzymatic extraction process has been utilized to remove cellular components from fresh bovine pericardium (BP). Microscopic observation confirmed that nearly all cellular constituents are removed. Thermal and mechanical properties showed that the durability of L-arginine-treated matrices increased as compared with control ABP and GA-treated ABP. Resistance to collagenase digestion revealed that modified matrices have greater resistance to enzyme digestion than control ABP and GA-treated ABP. The in vivo calcification study demonstrated much less calcium deposition on L-arginine-treated ABP than GA-treated one. In vitro cell viability results showed that ABP modified with L-arginine leads to a significant increase in attachment of human dermal fibroblasts. The obtained results attest to the usefulness of L-arginine-treated ABP matrices for cardiovascular bioprostheses

  7. Acellular matrix of bovine pericardium bound with L-arginine

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo Joo [Department of Molecular Science and Technology, Ajou University, Suwon 443-749 (Korea, Republic of); Bae, Jin Woo [Department of Molecular Science and Technology, Ajou University, Suwon 443-749 (Korea, Republic of); Kim, Chun Ho [Laboratory of Tissue Engineering, Korea Cancer Center Hospital, Seoul 139-240 (Korea, Republic of); Lee, Jin Woo [Department of Orthopaedic Surgery, College of Medicine, Yonsei University, Seoul 120-749 (Korea, Republic of); Shin, Jung Woog [Department of Biomedical Engineering, Inje University, Gimhae 621-749 (Korea, Republic of); Park, Ki Dong [Department of Molecular Science and Technology, Ajou University, Suwon 443-749 (Korea, Republic of)

    2007-09-15

    Surface immobilization of bioactive molecules onto natural tissues has been interestingly studied for the development of new functional matrices for the replacement of lost or malfunctioning tissues. In this study, an acellular matrix of bovine pericardium (ABP) was chemically modified by the direct coupling of L-arginine after glutaraldehyde (GA) cross-linking. The effects of L-arginine coupling on durability and calcification were investigated and the biocompatibility was evaluated in vitro and in vivo. A four-step detergent and enzymatic extraction process has been utilized to remove cellular components from fresh bovine pericardium (BP). Microscopic observation confirmed that nearly all cellular constituents are removed. Thermal and mechanical properties showed that the durability of L-arginine-treated matrices increased as compared with control ABP and GA-treated ABP. Resistance to collagenase digestion revealed that modified matrices have greater resistance to enzyme digestion than control ABP and GA-treated ABP. The in vivo calcification study demonstrated much less calcium deposition on L-arginine-treated ABP than GA-treated one. In vitro cell viability results showed that ABP modified with L-arginine leads to a significant increase in attachment of human dermal fibroblasts. The obtained results attest to the usefulness of L-arginine-treated ABP matrices for cardiovascular bioprostheses.

  8. Asymmetric Gepner models (revisited)

    Energy Technology Data Exchange (ETDEWEB)

    Gato-Rivera, B. [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands)] [Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain); Schellekens, A.N., E-mail: t58@nikhef.n [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands)] [Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain)] [IMAPP, Radboud Universiteit, Nijmegen (Netherlands)

    2010-12-11

    We reconsider a class of heterotic string theories studied in 1989, based on tensor products of N=2 minimal models with asymmetric simple current invariants. We extend this analysis from (2,2) and (1,2) spectra to (0,2) spectra with SO(10) broken to the Standard Model. In the latter case the spectrum must contain fractionally charged particles. We find that in nearly all cases at least some of them are massless. However, we identify a large subclass where the fractional charges are at worst half-integer, and often vector-like. The number of families is very often reduced in comparison to the 1989 results, but there are no new tensor combinations yielding three families. All tensor combinations turn out to fall into two classes: those where the number of families is always divisible by three, and those where it is never divisible by three. We find an empirical rule to determine the class, which appears to extend beyond minimal N=2 tensor products. We observe that distributions of physical quantities such as the number of families, singlets and mirrors have an interesting tendency towards smaller values as the gauge groups approaches the Standard Model. We compare our results with an analogous class of free fermionic models. This displays similar features, but with less resolution. Finally we present a complete scan of the three family models based on the triply-exceptional combination (1,16{sup *},16{sup *},16{sup *}) identified originally by Gepner. We find 1220 distinct three family spectra in this case, forming 610 mirror pairs. About half of them have the gauge group SU(3)xSU(2){sub L}xSU(2){sub R}xU(1){sup 5}, the theoretical minimum, and many others are trinification models.

  9. Radioimmunoassay of arginine vasopressin in human plasma

    International Nuclear Information System (INIS)

    Uhlich, E.; Weber, P.; Groeschel-Stewart, U.; Roeschlau, T.; Wuerzburg Univ.

    1975-01-01

    Antibodies for the radioimmunoassay of arginine vasopressin (AVP) described here were produced in rabbits using synthetic AVP coupled to rabbit γ-globulin with carbodiimide. In three out of six rabbits, significant antibody titres were obtained. Using the best antisera produced, 40% of labelled AVP was bound at a final dilution of 1 : 50,000. After iodination of synthetic AVP with 125 I using the chloramin-T method, a gel filtration on Sephadex G-25 was performed to purify the iodinated AVP. For separation of antibody bound and free hormone, a second antibody precipitation was used. There was no crossreactivity with oxytocin. AVP was extracted from plasma after ammoniumsulfate precipitation of the proteins by adsorption to Florisil. The recovery of AVP added to plasma in amounts of 5-25 pg/ml was 60 +- 15% (n = 6). The minimum amount of AVP detectable was 1 pg per ml plasma. The plasma level in normal adults under standard conditions was 3.4 +- 2.2 pg/ml. This is in agreement with data recently published by other researchers. The applicability and reproducibility was further tested in measurements of samples taken hourly during the entire day under water diuresis and after hormonal stimulation of AVP. (orig.) [de

  10. Arginine side chain interactions and the role of arginine as a gating charge carrier in voltage sensitive ion channels

    Science.gov (United States)

    Armstrong, Craig T.; Mason, Philip E.; Anderson, J. L. Ross; Dempsey, Christopher E.

    2016-02-01

    Gating charges in voltage-sensing domains (VSD) of voltage-sensitive ion channels and enzymes are carried on arginine side chains rather than lysine. This arginine preference may result from the unique hydration properties of the side chain guanidinium group which facilitates its movement through a hydrophobic plug that seals the center of the VSD, as suggested by molecular dynamics simulations. To test for side chain interactions implicit in this model we inspected interactions of the side chains of arginine and lysine with each of the 19 non-glycine amino acids in proteins in the protein data bank. The arginine guanidinium interacts with non-polar aromatic and aliphatic side chains above and below the guanidinium plane while hydrogen bonding with polar side chains is restricted to in-plane positions. In contrast, non-polar side chains interact largely with the aliphatic part of the lysine side chain. The hydration properties of arginine and lysine are strongly reflected in their respective interactions with non-polar and polar side chains as observed in protein structures and in molecular dynamics simulations, and likely underlie the preference for arginine as a mobile charge carrier in VSD.

  11. 1,5-Dimethyl-2-phenyl-1H-pyrazol-3(2H-one–4,4′-(propane-2,2-diylbis[1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H-one] (1/1

    Directory of Open Access Journals (Sweden)

    Krzysztof Lyczko

    2013-01-01

    Full Text Available The asymmetric unit of the title compound, C11H12N2O·C25H28N4O2, contains two different molecules. The smaller is known as antipyrine [systematic name: 1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H-one] and the larger is built up from two antypirine molecules which are connected through a C atom of the pyrazolone ring to a central propanyl part [systematic name: 4,4′-(propane-2,2-diylbis[1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H-one]. Intramolecular C—H...O hydrogen bonds occur in the latter molecule. In the crystal, C—H...O hydrogen bonds link the molecules into a two-dimensional network parallel to (001.

  12. The effect of arginine on oral biofilm communities.

    Science.gov (United States)

    Nascimento, M M; Browngardt, C; Xiaohui, X; Klepac-Ceraj, V; Paster, B J; Burne, R A

    2014-02-01

    Alkali production by oral bacteria via the arginine deiminase system (ADS) increases the pH of oral biofilms and reduces the risk for development of carious lesions. This study tested the hypothesis that increased availability of arginine in the oral environment through an exogenous source enhances the ADS activity levels in saliva and dental plaque. Saliva and supra-gingival plaque samples were collected from 19 caries-free (CF) individuals (DMFT = 0) and 19 caries-active (CA) individuals (DMFT ≥ 2) before and after treatment, which comprised the use of a fluoride-free toothpaste containing 1.5% arginine, or a regular fluoride-containing toothpaste twice daily for 4 weeks. ADS activity was measured by quantification of ammonia produced from arginine by oral samples at baseline, after washout period, 4 weeks of treatment, and 2 weeks post-treatment. Higher ADS activity levels were observed in plaque samples from CF compared to those of CA individuals (P = 0.048) at baseline. The use of the arginine toothpaste significantly increased ADS activity in plaque of CA individuals (P = 0.026). The plaque microbial profiles of CA treated with the arginine toothpaste showed a shift in bacterial composition to a healthier community, more similar to that of CF individuals. Thus, an anti-caries effect may be expected from arginine-containing formulations due in large part to the enhancement of ADS activity levels and potential favorable modification to the composition of the oral microbiome. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. L-Arginine Supplementation and Metabolism in Asthma

    Directory of Open Access Journals (Sweden)

    Angela Linderholm

    2011-01-01

    Full Text Available L-Arginine, the amino acid substrate for nitric oxide synthase, has been tested as a therapeutic intervention in a variety of chronic diseases and is commonly used as a nutritional supplement. In this study, we hypothesized that a subset of moderate to severe persistent asthma patients would benefit from supplementation with L-arginine by transiently increasing nitric oxide levels, resulting in bronchodilation and a reduction in inflammation. The pilot study consisted of a 3 month randomized, double-blind, placebo-controlled trial of L-arginine (0.05 g/kg twice daily in patients with moderate to severe asthma. We measured spirometry, exhaled breath nitric oxide, serum arginine metabolites, questionnaire scores, daily medication use and PEFR with the primary endpoint being the number of minor exacerbations at three months. Interim analysis of the 20 subjects showed no difference in the number of exacerbations, exhaled nitric oxide levels or lung function between groups, though participants in the L-arginine group had higher serum L-arginine at day 60 (2.0 ± 0.6 × 10−3 vs. 1.1 ± 0.2 × 10−3 µmol/L, p < 0.05, ornithine at day 30 (2.4 ± 0.9 vs. 1.2 ± 0.3 µmol/L serum, p < 0.05 and ADMA at day 30 (6.0 ± 1.5 × 10−1 vs. 2.6 ± 0.6 × 10−1 µmol/L serum, p < 0.05 on average compared to the placebo group. The study was terminated prematurely. Supplementing asthma subjects with L-arginine increases plasma levels; whether subgroups might benefit from such supplementation requires further study.

  14. Does asymmetric correlation affect portfolio optimization?

    Science.gov (United States)

    Fryd, Lukas

    2017-07-01

    The classical portfolio optimization problem does not assume asymmetric behavior of relationship among asset returns. The existence of asymmetric response in correlation on the bad news could be important information in portfolio optimization. The paper applies Dynamic conditional correlation model (DCC) and his asymmetric version (ADCC) to propose asymmetric behavior of conditional correlation. We analyse asymmetric correlation among S&P index, bonds index and spot gold price before mortgage crisis in 2008. We evaluate forecast ability of the models during and after mortgage crisis and demonstrate the impact of asymmetric correlation on the reduction of portfolio variance.

  15. Synthesis of dimethyl-1,1 guanylguanidine-{sup 14}C-2,4 (dimethyl-1-1 biguanide) hydrochloride; Synthese du chlorhydrate de dimethyl-1,1 guanylguanidine {sup 14}C-2,4 (dimethyl-1-1 biguanide)

    Energy Technology Data Exchange (ETDEWEB)

    Herbert, M; Pichat, L [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1961-07-01

    A description of the synthesis of dimethyl-1,1 guanylguanidine-{sup 14}C-2,4 hydrochloride passing through the {sup 14}C{sub 2} dicyandiamide. The overall yield with respect to Ba{sup 14}CO{sub 3} is 38 per cent. (author) [French] Description de la synthese du chlorhydrate de dimethyl-1,1 guanylguanidine {sup 14}C-2,4 par l'intermediaire de la dicyandiamide {sup 14}C{sub 2}. Le rendement global par rapport a {sup 14}CO{sub 3}Ba est de 38 pour cent. (auteur)

  16. Stable isotope dimethyl labelling for quantitative proteomics and beyond

    Science.gov (United States)

    Hsu, Jue-Liang; Chen, Shu-Hui

    2016-01-01

    Stable-isotope reductive dimethylation, a cost-effective, simple, robust, reliable and easy-to- multiplex labelling method, is widely applied to quantitative proteomics using liquid chromatography-mass spectrometry. This review focuses on biological applications of stable-isotope dimethyl labelling for a large-scale comparative analysis of protein expression and post-translational modifications based on its unique properties of the labelling chemistry. Some other applications of the labelling method for sample preparation and mass spectrometry-based protein identification and characterization are also summarized. This article is part of the themed issue ‘Quantitative mass spectrometry’. PMID:27644970

  17. Asymmetric Synthesis via Chiral Aziridines

    DEFF Research Database (Denmark)

    Tanner, David Ackland; Harden, Adrian; Wyatt, Paul

    1996-01-01

    A series of chiral bis(aziridines) has been synthesised and evaluated as chelating ligands for a variety of asymmetric transformations mediated by metals [Os (dihydroxylation), Pd (allylic alkylation) Cu (cyclopropanation and aziridination, Li (1,2-addition of organolithiums to imines)]. In the b......A series of chiral bis(aziridines) has been synthesised and evaluated as chelating ligands for a variety of asymmetric transformations mediated by metals [Os (dihydroxylation), Pd (allylic alkylation) Cu (cyclopropanation and aziridination, Li (1,2-addition of organolithiums to imines...

  18. Ideal 3D asymmetric concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Botella, Angel [Departamento Fisica Aplicada a los Recursos Naturales, Universidad Politecnica de Madrid, E.T.S.I. de Montes, Ciudad Universitaria s/n, 28040 Madrid (Spain); Fernandez-Balbuena, Antonio Alvarez; Vazquez, Daniel; Bernabeu, Eusebio [Departamento de Optica, Universidad Complutense de Madrid, Fac. CC. Fisicas, Ciudad Universitaria s/n, 28040 Madrid (Spain)

    2009-01-15

    Nonimaging optics is a field devoted to the design of optical components for applications such as solar concentration or illumination. In this field, many different techniques have been used for producing reflective and refractive optical devices, including reverse engineering techniques. In this paper we apply photometric field theory and elliptic ray bundles method to study 3D asymmetric - without rotational or translational symmetry - concentrators, which can be useful components for nontracking solar applications. We study the one-sheet hyperbolic concentrator and we demonstrate its behaviour as ideal 3D asymmetric concentrator. (author)

  19. Activities of arginine and ornithine decarboxylases in various plant species.

    Science.gov (United States)

    Birecka, H; Bitonti, A J; McCann, P P

    1985-10-01

    In extracts from the youngest leaves of Avena sativa, Hordeum vulgare, Zea Mays, Pisum sativum, Phaseolus vulgaris, Lactuca sativa, and four pyrrolizidine alkaloid-bearing species of Heliotropium, the activities of ornithine decarboxylase, close to V(max), ranged between traces and 1.5 nanomoles per hour per gram fresh weight when based on putrescine formed during incubation with labeled ornithine. The arginine decarboxylase activities in the same extracts ranged between 8 and 8000 nanomoles per hour per gram fresh weight being lowest in the borages and highest in oat and barley. alpha-Difluoromethylornithine and alpha-difluoromethylarginine inhibited ornithine and arginine decarboxylases, respectively, in all species. Agmatine, putrescine, spermidine, and spermine were found in all, diaminopropane in eight, and cadaverine in three species.No correlation was observed between arginine or ornithine decarboxylase level and the levels of total polyamines. The in vitro decarboxylase activities found in the borages cannot explain the high accumulation of putrescine-derived pyrrolizidines in their youngest leaves if the pyrrolizidines are produced in situ from arginine and/or ornithine as precursors; other possibilities are discussed.In assays of ornithine decarboxylase, an interference of decarboxylation not due to this enzyme was observed in extracts from all species. In arginine decarboxylase assays, the interfering decarboxylation as well as the interference of arginase were apparent in two species. Addition of aminoguanidine was needed to suppress oxidative degradation of putrescine and agmatine during incubation of extracts from pea, bean, lettuce, Heliotropium angiospermum, and Heliotropium indicum.

  20. Decryptification of Acid Phosphatase in Arthrospores of Geotrichum Species Treated with Dimethyl Sulfoxide and Acetone

    Science.gov (United States)

    Cotter, David A.; Martel, Anita J.; MacDonald, Paul

    1975-01-01

    Decryptification of acid phosphatase in Geotrichum sp. arthrospores was accomplished using acetone or dimethyl sulfoxide treatment. Both dimethyl sulfoxide and acetone irreversibly destroyed the integrity of the spore membranes without solubilizing acid phosphatase. PMID:1167386

  1. Synthesis and crystal structure of a new 2,6-dimethyl piperazine-1,4-diium perchlorate monohydrate: [C{sub 6}H{sub 16}N{sub 2}](ClO{sub 4}){sub 2} · H{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Mleh, C. Ben [Université de Carthage, Laboratoire de Chimie des Matériaux, Faculté des Sciences de Bizerte (Tunisia); Roisnel, T. [Université de Rennes I, Centre de Diffractométrie X, UMR 6226 CNRS, Unité Sciences Chimiques de Rennes (France); Marouani, H., E-mail: houda.marouani@fsb.rnu.tn [Université de Carthage, Laboratoire de Chimie des Matériaux, Faculté des Sciences de Bizerte (Tunisia)

    2017-03-15

    A proton transfer compound 2,6-dimethyl piperazine-1,4-diium perchlorate monohydrate was synthesized by slow evaporation at room temperature using 2,6-dimethyl piperazine as template. The asymmetric unit contains one organic dication, two crystal graphically independent perchlorate anions and one water molecule. Each organic entities is engaged in a large number of bifurcated and non-bifurcated N–H···O (O) and C–H···O hydrogen bonds with different species and enhanced the three dimensional supramolecular network. In addition, the diprotonated piperazine ring adopts a chair conformation with the methyl groups occupying equatorial positions.

  2. Gliclazide directly inhibits arginine-induced glucagon release

    DEFF Research Database (Denmark)

    Cejvan, Kenan; Coy, David H; Holst, Jens Juul

    2002-01-01

    Arginine-stimulated insulin and somatostatin release is enhanced by the sulfonylurea gliclazide. In contrast, gliclazide inhibits the glucagon response. The aim of the present study was to investigate whether this inhibition of glucagon release was mediated by a direct suppressive effect of glicl......Arginine-stimulated insulin and somatostatin release is enhanced by the sulfonylurea gliclazide. In contrast, gliclazide inhibits the glucagon response. The aim of the present study was to investigate whether this inhibition of glucagon release was mediated by a direct suppressive effect....... In islet perifusions with DC-41-33, arginine-induced glucagon release was inhibited by 66%. We therefore concluded that gliclazide inhibits glucagon release by a direct action on the pancreatic A cell....

  3. Mitochondria: role of citrulline and arginine supplementation in MELAS syndrome.

    Science.gov (United States)

    El-Hattab, Ayman W; Emrick, Lisa T; Chanprasert, Sirisak; Craigen, William J; Scaglia, Fernando

    2014-03-01

    Mitochondria are found in all nucleated human cells and generate most of the cellular energy. Mitochondrial disorders result from dysfunctional mitochondria that are unable to generate sufficient ATP to meet the energy needs of various organs. Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a frequent maternally inherited mitochondrial disorder. There is growing evidence that nitric oxide (NO) deficiency occurs in MELAS syndrome and results in impaired blood perfusion that contributes significantly to several complications including stroke-like episodes, myopathy, and lactic acidosis. Both arginine and citrulline act as NO precursors and their administration results in increased NO production and hence can potentially have therapeutic utility in MELAS syndrome. Citrulline raises NO production to a greater extent than arginine, therefore, citrulline may have a better therapeutic effect. Controlled studies assessing the effects of arginine or citrulline supplementation on different clinical aspects of MELAS syndrome are needed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Arginine-aromatic interactions and their effects on arginine-induced solubilization of aromatic solutes and suppression of protein aggregation

    KAUST Repository

    Shah, Dhawal; Li, Jianguo; Shaikh, Abdul Rajjak; Rajagopalan, Raj

    2011-01-01

    We examine the interaction of aromatic residues of proteins with arginine, an additive commonly used to suppress protein aggregation, using experiments and molecular dynamics simulations. An aromatic-rich peptide, FFYTP (a segment of insulin), and lysozyme and insulin are used as model systems. Mass spectrometry shows that arginine increases the solubility of FFYTP by binding to the peptide, with the simulations revealing the predominant association of arginine to be with the aromatic residues. The calculations further show a positive preferential interaction coefficient, Γ XP, contrary to conventional thinking that positive Γ XP's indicate aggregation rather than suppression of aggregation. Simulations with lysozyme and insulin also show arginine's preference for aromatic residues, in addition to acidic residues. We use these observations and earlier results reported by us and others to discuss the possible implications of arginine's interactions with aromatic residues on the solubilization of aromatic moieties and proteins. Our results also highlight the fact that explanations based purely on Γ XP, which measures average affinity of an additive to a protein, could obscure or misinterpret the underlying molecular mechanisms behind additive-induced suppression of protein aggregation. © 2011 American Institute of Chemical Engineers (AIChE).

  5. Crystallization and X-ray diffraction studies of arginine kinase from the white Pacific shrimp Litopenaeus vannamei

    International Nuclear Information System (INIS)

    Lopez-Zavala, Alonso A.; Sotelo-Mundo, Rogerio R.; Garcia-Orozco, Karina D.; Isac-Martinez, Felipe; Brieba, Luis G.; Rudiño-Piñera, Enrique

    2012-01-01

    The crystallization and preliminary X-ray diffraction analysis at 1.25 Å resolution of free-ligand arginine kinase from the Pacific whiteleg shrimp Litopenaeus vannamei are reported. Crystals belong to space group P2 1 2 1 2 1 , phases were determined by molecular replacement and refinement was performed with Phenix. Crystals of an unligated monomeric arginine kinase from the Pacific whiteleg shrimp Litopenaeus vannamei (LvAK) were successfully obtained using the microbatch method. Crystallization conditions and preliminary X-ray diffraction analysis to 1.25 Å resolution are reported. Data were collected at 100 K on NSLS beamline X6A. The crystals belonged to space group P2 1 2 1 2 1 , with unit-cell parameters a = 56.5, b = 70.2, c = 81.7 Å. One monomer per asymmetric unit was found, with a Matthews coefficient (V M ) of 2.05 Å 3 Da −1 and 40% solvent content. Initial phases were determined by molecular replacement using a homology model of LvAK as the search model. Refinement was performed with PHENIX, with final R work and R free values of 0.15 and 0.19, respectively. Biological analysis of the structure is currently in progress

  6. Asymmetric Penning trap coherent states

    International Nuclear Information System (INIS)

    Contreras-Astorga, Alonso; Fernandez, David J.

    2010-01-01

    By using a matrix technique, which allows to identify directly the ladder operators, the coherent states of the asymmetric Penning trap are derived as eigenstates of the appropriate annihilation operators. They are compared with those obtained through the displacement operator method.

  7. JET and COMPASS asymmetrical disruptions

    Czech Academy of Sciences Publication Activity Database

    Gerasimov, S.N.; Abreu, P.; Baruzzo, M.; Drozdov, V.; Dvornova, A.; Havlíček, Josef; Hender, T.C.; Hronová-Bilyková, Olena; Kruezi, U.; Li, X.; Markovič, Tomáš; Pánek, Radomír; Rubinacci, G.; Tsalas, M.; Ventre, S.; Villone, F.; Zakharov, L.E.

    2015-01-01

    Roč. 55, č. 11 (2015), s. 113006-113006 ISSN 0029-5515 R&D Projects: GA MŠk(CZ) LM2011021 Institutional support: RVO:61389021 Keywords : tokamak * asymmetrical disruption * JET * COMPASS Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 4.040, year: 2015

  8. Plasma glucagon responses to L-arginine in various diseases

    International Nuclear Information System (INIS)

    Morita, Nobuto; Hayakawa, Hiroyuki; Kawai, Kohzo; Noto, Yutaka; Ohno, Taro

    1978-01-01

    To clarify the mechanism of abnormal glucose metabolism in the secondary diabetes, we examined the dynamics of plasma glucagon levels in various diseases which may accompany glucose intolerance. Plasma glucagon responses to L-arginine were observed in 20 liver cirrhotics, 8 patients with chronic renal failure, 6 patients with chronic pancreatitis, 4 patients, with hyperthyroidism, 22 diabetics and 9 normal controls. Plasma glucagon levels were determined by the radioimmunoassay method of Unger using 125 I-glucagon and antiserum 30K which is specific for pancreatic glucagon. In the cirrhotics, the plasma glucagon responses to L-arginine were significantly higher than in normal controls. The patients whose BSP retention at 45 minutes were above 30% showed higher plasma glucagon responses than in the patients whose BSP retention at 45 minutes were below 30%, suggesting that the more severely the liver was damaged, the more the plasma glucagon levels were elevated. In the patients with chronic renal failure, the plasma glucagon responses to L-arginine were also significantly higher than in normal controls. These abnormal levels were not improved by a hemodialysis, although serum creatinine levels were fairly decreased. In the patients with chronic pancreatitis, the plasma glucagon responses to L-arginine were the same as those in normal controls. In the patients with hyperthyroidism the plasma glucagon responses to L-arginine seemed to be lower than normal controls. In the diabetics, the plasma glucagon responses to L-arginine were almost the same as in normal controls. However their glucagon levels seemed to be relatively high, considering the fact that diabetics had high blood glucose levels. (auth.)

  9. 40 CFR 721.6167 - Piperdinium, 1,1-dimethyl-, chloride.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Piperdinium, 1,1-dimethyl-, chloride... Substances § 721.6167 Piperdinium, 1,1-dimethyl-, chloride. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as piperdinium, 1,1-dimethyl-, chloride. (PMN...

  10. Recommended vapor pressures for thiophene, sulfolane, and dimethyl sulfoxide

    Czech Academy of Sciences Publication Activity Database

    Fulem, Michal; Růžička, K.; Růžička, M.

    2011-01-01

    Roč. 303, č. 2 (2011), s. 205-216 ISSN 0378-3812 Institutional research plan: CEZ:AV0Z10100521 Keywords : thiophene sulfolane * dimethyl sulfoxide * vapor pressure * heat capacity * vaporization enthalpy * recommended vapor pressure equation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.139, year: 2011

  11. Dimethyl ether in diesel engines - progress and perspectives

    DEFF Research Database (Denmark)

    Sorenson, Spencer C

    2001-01-01

    A review of recent developments related to the use of dimethyl ether (DME) in engines is presented Research work discussed is in the areas of engine performance and emissions, fuel injection systems, spray and ignition delay, and detailed chemical kinetic modeling. DME's properties and safety asp...

  12. Fixation of carbon dioxide into dimethyl carbonate over ...

    Science.gov (United States)

    A titanium-based zeolitic thiophene-benzimidazolate framework has been designed for the direct synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide. The developed catalyst activates carbon dioxide and delivers over 16% yield of DMC without the use of any dehydrating agent or requirement for azeotropic distillation. Prepared for submission to Nature Scientific reports.

  13. Arginine intake and risk of coronary heart disease mortality in elderly men

    NARCIS (Netherlands)

    Oomen, C.M.; Erk, van M.J.; Feskens, E.J.M.; Kok, F.J.; Kromhout, D.

    2000-01-01

    From experimental studies, the hypothesis is derived that the amino acid arginine, the precursor of NO, could restore the impaired endothelial function and increased platelet activation observed in atherosclerosis. We investigated whether dietary intake of arginine is associated with reduced

  14. Effects of dietary L-arginine on orthodontic tooth movement in rats

    African Journals Online (AJOL)

    Yomi

    2012-01-03

    Jan 3, 2012 ... arginine in drinking water six days before the insertion of springs to ... Key words: L-Arginine, dietary, orthodontic tooth movement, nitric oxide, root resorption, osteoclast, .... cAMP, interleukin 1-beta and neurotransmitters are.

  15. Identification of a Novel Protein Arginine Methyltransferase 5 Inhibitor in Non-small Cell Lung Cancer by Structure-Based Virtual Screening

    Directory of Open Access Journals (Sweden)

    Qianqian Wang

    2018-03-01

    Full Text Available Protein arginine methyltransferase 5 (PRMT5 is able to regulate gene transcription by catalyzing the symmetrical dimethylation of arginine residue of histone, which plays a key role in tumorigenesis. Many efforts have been taken in discovering small-molecular inhibitors against PRMT5, but very few were reported and most of them were SAM-competitive. EPZ015666 is a recently reported PRMT5 inhibitor with a new binding site, which is different from S-adenosylmethionine (SAM-binding pocket. This new binding site provides a new clue for the design and discovery of potent and specific PRMT5 inhibitors. In this study, the structure-based virtual screening targeting this site was firstly performed to identify potential PRMT5 inhibitors. Then, the bioactivity of the candidate compound was studied. MTT results showed that compound T1551 decreased cell viability of A549 and H460 non-small cell lung cancer cell lines. By inhibiting the methyltransferase activity of PRMT5, T1551 reduced the global level of H4R3 symmetric dimethylation (H4R3me2s. T1551 also downregulated the expression of oncogene FGFR3 and eIF4E, and disturbed the activation of related PI3K/AKT/mTOR and ERK signaling in A549 cell. Finally, we investigated the conformational spaces and identified collective motions important for description of T1551/PRMT5 complex by using molecular dynamics simulation and normal mode analysis methods. This study provides a novel non-SAM-competitive hit compound for developing small molecules targeting PRMT5 in non-small cell lung cancer.

  16. The role of arginine and the modified arginine deiminase enzyme ADI-PEG 20 in cancer therapy with special emphasis on Phase I/II clinical trials.

    Science.gov (United States)

    Synakiewicz, Anna; Stachowicz-Stencel, Teresa; Adamkiewicz-Drozynska, Elzbieta

    2014-11-01

    The metabolic differences between normal, healthy cells and neoplastic cells have been exploited by anticancer therapies targeting metabolic pathways. Various studies of malignant processes have demonstrated disturbances in both arginine synthesis and metabolism that enhance or inhibit tumor cell growth. Consequently, there has been an increased interest in the arginine-depleting enzyme arginine deiminase (ADI) as a potential antineoplastic therapy. This review summarizes the literature on the potential anti-cancer therapeutics arginine and ADI, an arginine-catabolizing enzyme. The authors searched the MEDLINE database PubMed using the key words: 'arginine, 'ADI', 'arginine in cancer' and 'ADI and cancer'. The authors evaluate prospective randomized studies on cancer patients between 2004 and 2013 as well as ongoing research found through the US National Institutes of Health trial database. The results of current studies are promising but do not give unequivocal answers and so it is impossible to recommend arginine or its enzyme ADI as a therapeutic. In the opinion of the authors, further identification of arginine-dependent malignant tumors and their metabolism should be investigated. Furthermore, the use of these chemicals, in combination with other chemotherapeutics drugs, should be investigated and indeed may improve the success of arginine-depleting enzymes such as pegylated ADI (ADI-PEG20).

  17. Effects of dimethyl fumarate on neuroprotection and immunomodulation

    Directory of Open Access Journals (Sweden)

    Albrecht Philipp

    2012-07-01

    Full Text Available Abstract Background Neuronal degeneration in multiple sclerosis has been linked to oxidative stress. Dimethyl fumarate is a promising novel oral therapeutic option shown to reduce disease activity and progression in patients with relapsing-remitting multiple sclerosis. These effects are presumed to originate from a combination of immunomodulatory and neuroprotective mechanisms. We aimed to clarify whether neuroprotective concentrations of dimethyl fumarate have immunomodulatory effects. Findings We determined time- and concentration-dependent effects of dimethyl fumarate and its metabolite monomethyl fumarate on viability in a model of endogenous neuronal oxidative stress and clarified the mechanism of action by quantitating cellular glutathione content and recycling, nuclear translocation of transcription factors, and the expression of antioxidant genes. We compared this with changes in the cytokine profiles released by stimulated splenocytes measured by ELISPOT technology and analyzed the interactions between neuronal and immune cells and neuronal function and viability in cell death assays and multi-electrode arrays. Our observations show that dimethyl fumarate causes short-lived oxidative stress, which leads to increased levels and nuclear localization of the transcription factor nuclear factor erythroid 2-related factor 2 and a subsequent increase in glutathione synthesis and recycling in neuronal cells. Concentrations that were cytoprotective in neuronal cells had no negative effects on viability of splenocytes but suppressed the production of proinflammatory cytokines in cultures from C57BL/6 and SJL mice and had no effects on neuronal activity in multi-electrode arrays. Conclusions These results suggest that immunomodulatory concentrations of dimethyl fumarate can reduce oxidative stress without altering neuronal network activity.

  18. Cyclodextrins in Asymmetric and Stereospecific Synthesis

    Directory of Open Access Journals (Sweden)

    Fliur Macaev

    2015-09-01

    Full Text Available Since their discovery, cyclodextrins have widely been used as green and easily available alternatives to promoters or catalysts of different chemical reactions in water. This review covers the research and application of cyclodextrins and their derivatives in asymmetric and stereospecific syntheses, with their division into three main groups: (1 cyclodextrins promoting asymmetric and stereospecific catalysis in water; (2 cyclodextrins’ complexes with transition metals as asymmetric and stereospecific catalysts; and (3 cyclodextrins’ non-metallic derivatives as asymmetric and stereospecific catalysts. The scope of this review is to systematize existing information on the contribution of cyclodextrins to asymmetric and stereospecific synthesis and, thus, to facilitate further development in this direction.

  19. Crystal structure of arginine methyltransferase 6 from Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Chongyuan Wang

    Full Text Available Arginine methylation plays vital roles in the cellular functions of the protozoan Trypanosoma brucei. The T. brucei arginine methyltransferase 6 (TbPRMT6 is a type I arginine methyltransferase homologous to human PRMT6. In this study, we report the crystal structures of apo-TbPRMT6 and its complex with the reaction product S-adenosyl-homocysteine (SAH. The structure of apo-TbPRMT6 displays several features that are different from those of type I PRMTs that were structurally characterized previously, including four stretches of insertion, the absence of strand β15, and a distinct dimerization arm. The comparison of the apo-TbPRMT6 and SAH-TbPRMT6 structures revealed the fine rearrangements in the active site upon SAH binding. The isothermal titration calorimetry results demonstrated that SAH binding greatly increases the affinity of TbPRMT6 to a substrate peptide derived from bovine histone H4. The western blotting and mass spectrometry results revealed that TbPRMT6 methylates bovine histone H4 tail at arginine 3 but cannot methylate several T. brucei histone tails. In summary, our results highlight the structural differences between TbPRMT6 and other type I PRMTs and reveal that the active site rearrangement upon SAH binding is important for the substrate binding of TbPRMT6.

  20. Arginine-dependent acid resistance in Salmonella enterica serovar Typhimurium

    NARCIS (Netherlands)

    Kieboom, J.; Abee, T.

    2006-01-01

    Salmonella enterica serovar Typhimurium does not survive a pH 2.5 acid challenge under conditions similar to those used for Escherichia coli (J. W. Foster, Nat. Rev. Microbiol. 2:898-907, 2004). Here, we provide evidence that S. enterica serovar Typhimurium can display arginine-dependent acid

  1. Soil CO2 evolution: Response from arginine additions

    Science.gov (United States)

    Short-term response of soil C mineralization following drying/rewetting has been proposed as an indicator of soil microbial activity. Houston Black clay was amended with four rates of arginine to vary microbial response and keep other soil properties constant. The evolution of CO2 during one and thr...

  2. Glutamine-enriched enteral diet increases renal arginine production

    NARCIS (Netherlands)

    Houdijk, A. P.; van Leeuwen, P. A.; Teerlink, T.; FLINKERBUSCH, E. L.; Boermeester, M. A.; Sauerwein, H. P.; Wesdorp, R. I.

    1994-01-01

    Arginine (Arg) is generated in the kidney by the conversion of circulating citrulline. The most important source for circulating citrulline is the metabolism of glutamine (Gln) by the gut. In this study, we investigated the influence of an enteral diet enriched with Gln on renal Arg synthesis in the

  3. Effect of iron, taurine and arginine on rat hepatic fibrosis

    International Nuclear Information System (INIS)

    Song Liangwen; Wang Dewen; Cui Xuemei

    1997-01-01

    Objective: The promotion role of iron on pathogenesis of hepatic fibrosis and the protective role of taurine and L-arginine against hepatic fibrosis were studied. Method: The model of rat radiation hepatic fibrosis was used. Experimental rats were divided into 0 Gy, 30 Gy, 30 Gy + iron, 30 Gy + taurine and 30 Gy + L-arginine groups. Serum iron, liver tissue hydroxyproline (Hyp) and malondialdehyde (MDA) were measured one and three months respectively after irradiation of hepatic tissue, production and distribution characteristics of hepatic tissue type I and III collagen were observed with a polarizing microscope. Results: Administration of iron agent could significantly increase hepatic tissue MDA content and serum iron concentration, one month after irradiation, hepatic tissue Hyp in 30 Gy + iron group began to increase, and collagen in hepatic tissue obviously increased. Taurine and L-arginine could reduce serum iron concentration and decrease production of hepatic fissure Hyp. Conclusion: Exogenous iron agent could promote early development of radiation hepatic fibrosis; taurine and arginine could diminish pathologic alteration of hepatic fibrosis to a certain extent

  4. Electron Jet of Asymmetric Reconnection

    Science.gov (United States)

    Khotyaintsev, Yu. V.; Graham, D. B.; Norgren, C.; Eriksson, E.; Li, W.; Johlander, A.; Vaivads, A.; Andre, M.; Pritchett, P. L.; Retino, A.; hide

    2016-01-01

    We present Magnetospheric Multiscale observations of an electron-scale current sheet and electron outflow jet for asymmetric reconnection with guide field at the subsolar magnetopause. The electron jet observed within the reconnection region has an electron Mach number of 0.35 and is associated with electron agyrotropy. The jet is unstable to an electrostatic instability which generates intense waves with E(sub parallel lines) amplitudes reaching up to 300 mV/m and potentials up to 20% of the electron thermal energy. We see evidence of interaction between the waves and the electron beam, leading to quick thermalization of the beam and stabilization of the instability. The wave phase speed is comparable to the ion thermal speed, suggesting that the instability is of Buneman type, and therefore introduces electron-ion drag and leads to braking of the electron flow. Our observations demonstrate that electrostatic turbulence plays an important role in the electron-scale physics of asymmetric reconnection.

  5. Stable walking with asymmetric legs

    International Nuclear Information System (INIS)

    Merker, Andreas; Rummel, Juergen; Seyfarth, Andre

    2011-01-01

    Asymmetric leg function is often an undesired side-effect in artificial legged systems and may reflect functional deficits or variations in the mechanical construction. It can also be found in legged locomotion in humans and animals such as after an accident or in specific gait patterns. So far, it is not clear to what extent differences in the leg function of contralateral limbs can be tolerated during walking or running. Here, we address this issue using a bipedal spring-mass model for simulating walking with compliant legs. With the help of the model, we show that considerable differences between contralateral legs can be tolerated and may even provide advantages to the robustness of the system dynamics. A better understanding of the mechanisms and potential benefits of asymmetric leg operation may help to guide the development of artificial limbs or the design novel therapeutic concepts and rehabilitation strategies.

  6. Variable angle asymmetric cut monochromator

    International Nuclear Information System (INIS)

    Smither, R.K.; Fernandez, P.B.

    1993-09-01

    A variable incident angle, asymmetric cut, double crystal monochromator was tested for use on beamlines at the Advanced Photon Source (APS). For both undulator and wiggler beams the monochromator can expand area of footprint of beam on surface of the crystals to 50 times the area of incident beam; this will reduce the slope errors by a factor of 2500. The asymmetric cut allows one to increase the acceptance angle for incident radiation and obtain a better match to the opening angle of the incident beam. This can increase intensity of the diffracted beam by a factor of 2 to 5 and can make the beam more monochromatic, as well. The monochromator consists of two matched, asymmetric cut (18 degrees), silicon crystals mounted so that they can be rotated about three independent axes. Rotation around the first axis controls the Bragg angle. The second rotation axis is perpendicular to the diffraction planes and controls the increase of the area of the footprint of the beam on the crystal surface. Rotation around the third axis controls the angle between the surface of the crystal and the wider, horizontal axis for the beam and can make the footprint a rectangle with a minimum. length for this area. The asymmetric cut is 18 degrees for the matched pair of crystals, which allows one to expand the footprint area by a factor of 50 for Bragg angles up to 19.15 degrees (6 keV for Si[111] planes). This monochromator, with proper cooling, will be useful for analyzing the high intensity x-ray beams produced by both undulators and wigglers at the APS

  7. Asymmetric information and bank runs

    OpenAIRE

    Gu, Chao

    2007-01-01

    It is known that sunspots can trigger panic-based bank runs and that the optimal banking contract can tolerate panic-based runs. The existing literature assumes that these sunspots are based on a publicly observed extrinsic randomizing device. In this paper, I extend the analysis of panic-based runs to include an asymmetric-information, extrinsic randomizing device. Depositors observe different, but correlated, signals on the stability of the bank. I find that if the signals that depositors o...

  8. Asymmetric information and macroeconomic dynamics

    Science.gov (United States)

    Hawkins, Raymond J.; Aoki, Masanao; Roy Frieden, B.

    2010-09-01

    We show how macroeconomic dynamics can be derived from asymmetric information. As an illustration of the utility of this approach we derive the equilibrium density, non-equilibrium densities and the equation of motion for the response to a demand shock for productivity in a simple economy. Novel consequences of this approach include a natural incorporation of time dependence into macroeconomics and a common information-theoretic basis for economics and other fields seeking to link micro-dynamics and macro-observables.

  9. Asymmetric Synthesis of Apratoxin E.

    Science.gov (United States)

    Mao, Zhuo-Ya; Si, Chang-Mei; Liu, Yi-Wen; Dong, Han-Qing; Wei, Bang-Guo; Lin, Guo-Qiang

    2016-10-21

    An efficient method for asymmetric synthesis of apratoxin E 2 is described in this report. The chiral lactone 8, recycled from the degradation of saponin glycosides, was utilized to prepare the non-peptide fragment 6. In addition to this "from nature to nature" strategy, olefin cross-metathesis (CM) was applied as an alternative approach for the formation of the double bond. Moreover, pentafluorophenyl diphenylphosphinate was found to be an efficient condensation reagent for the macrocyclization.

  10. Comprehensive asymmetric dark matter model

    OpenAIRE

    Lonsdale, Stephen J.; Volkas, Raymond R.

    2018-01-01

    Asymmetric dark matter (ADM) is motivated by the similar cosmological mass densities measured for ordinary and dark matter. We present a comprehensive theory for ADM that addresses the mass density similarity, going beyond the usual ADM explanations of similar number densities. It features an explicit matter-antimatter asymmetry generation mechanism, has one fully worked out thermal history and suggestions for other possibilities, and meets all phenomenological, cosmological and astrophysical...

  11. Analysis of an Alanine/Arginine Mixture by Using TLC/FTIR Technique

    Directory of Open Access Journals (Sweden)

    Jun Liu

    2014-01-01

    Full Text Available We applied TLC/FTIR coupled with mapping technique to analyze an alanine/arginine mixture. Narrow band TLC plates prepared by using AgI as a stationary phase were used to separate alanine and arginine. The distribution of alanine and arginine spots was manifested by a 3D chromatogram. Alanine and arginine can be successfully separated by the narrow band TLC plate. In addition, the FTIR spectra of the separated alanine and arginine spots on the narrow band TLC plate are roughly the same as the corresponding reference IR spectra.

  12. Effects of acute and chronic stress on the L-arginine nitric oxide pathway in black and white South Africans: the sympathetic activity and ambulatory blood pressure in Africans study.

    Science.gov (United States)

    Reimann, Manja; Hamer, Mark; Malan, Nicolaas T; Schlaich, Markus P; Lambert, Gavin W; Ziemssen, Tjalf; Boeger, Rainer H; Malan, Leoné

    2013-10-01

    This study investigated the impact of stress on effectors of the L-arginine/nitric oxide (NO) system including the endogenous inhibitor asymmetric dimethylarginine (ADMA). Black (n = 168) and white (n = 206) South African teachers were exposed to a mental and a physical stressor for 1 minute, respectively. Serum samples for determination of l-arginine, NO metabolites, ADMA, and symmetric dimethylarginine (SDMA) were obtained at rest and during stress exposure. Perception of task stressfulness was assessed on a 7-point Likert scale, and psychological distress was estimated by the General Health Questionnaire. Black South Africans exhibited higher resting levels of NO metabolites (adjusted mean [standard error of the mean] = 11.3 [1.3] versus 3.9 [1.1] μmol/l, p stress were evident for NO metabolites (blacks versus whites: 5.94 [1.55] versus -0.74 [1.25] μmol/l, p = .004) and SDMA (blacks versus whites: -0.02 [0.01] versus 0.02 [0.01] μmol/l, p = .004). Ethnicity-by-psychological distress interaction for stress responses was found for l-arginine/ADMA ratio (p = .027). The l-arginine/NO system is affected by psychosocial distress with higher susceptibility in black South Africans. This interaction may contribute to the higher cardiovascular disease risk in black South Africans.

  13. Polyfluorinated boron cluster based salts: A new electrolyte for application in nonaqueous asymmetric AC/Li{sub 4}Ti{sub 5}O{sub 12} supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Ionica-Bousquet, C.M.; Munoz-Rojas, D.; Palacin, M.R. [Institut de Ciencia de Materials de Barcelona, CSIC, Campus UAB, E-08193 Bellaterra (Spain); Casteel, W.J. Jr.; Pearlstein, R.M.; Kumar, G. Girish; Pez, G.P. [Air Products and Chemicals, Inc., 7201 Hamilton Blvd., Allentown, PA 18195 (United States)

    2011-02-01

    Solutions of novel fluorinated lithium dodecaborate (Li{sub 2}B{sub 12}F{sub x}H{sub 12-x}) salts have been evaluated as electrolytes in nonaqueous asymmetric supercapacitors with Li{sub 4}Ti{sub 5}O{sub 12} as negative electrode, and activated carbon (AC) as positive electrode. The results obtained with these new electrolytes were compared with those obtained with cells built using standard 1 M LiPF{sub 6} dissolved in ethylene carbonate and dimethyl carbonate (EC:DMC; 1:1, v/v) as electrolyte. The specific energy, rate capability, and cycling performances of nonaqueous asymmetric cells based on these new electrolyte salts were studied. Cells assembled using the new fluoroborate salts show excellent reversibility, coulombic efficiency, rate capability and improved cyclability when compared with the standard electrolyte. These features confirm the suitability of lithium-fluoro-borate based salts to be used in nonaqueous asymmetric supercapacitors. (author)

  14. Radioprotection by dimethyl sulfoxide on two biological system

    International Nuclear Information System (INIS)

    Bernardes, D.M.L.; Villavicencio, A.L.C.H.; Del Mastro, N.L.

    1990-01-01

    The effects of dimethyl sulfoxide treatment on two biological systems are examined: a) In vivo, the level of albinic mouse survive from IPEN, when irradiated with 9 Gy of 60 Co., 1 hour after the injection ip of DMSO 0,025M. b) In vivo, molecular level, when DMSO 1M, is added 10 min. before the irradiation with 25.000 Gy of 60 Co, from an aqueous solution of proteins from crystalline bovine. (C.G.C.) [pt

  15. In vivo whole body and organ arginine metabolism during endotoxemia (sepsis) is dependent on mouse strain and gender

    NARCIS (Netherlands)

    Luiking, Y. C.; Hallemeesch, M. M.; Vissers, Y. L. J.; Lamers, W. H.; Deutz, N. E. P.

    2004-01-01

    Arginine metabolism involves various organs such as the kidney, the intestines, and the liver, which act together in an interorgan axis. Major pathways for arginine production are protein breakdown and de novo arginine production from citrulline; disposal of arginine is mainly used for protein

  16. Diapause prevention effect of Bombyx mori by dimethyl sulfoxide.

    Directory of Open Access Journals (Sweden)

    Takayuki Yamamoto

    Full Text Available HCl treatment has been, for about 80 years, the primary method for the prevention of entry into embryonic diapauses of Bombyx mori. This is because no method is as effective as the HCl treatment. In this study, we discovered that dimethyl sulfoxide (DMSO prevented entry into the diapause of the silkworm, Bombyx mori. The effect of diapause prevention was 78% as a result of treatment with 100% DMSO concentration, and the effect was comparable to that of the HCl treatment. In contrast, in the case of non-diapause eggs, hatchability was decreased by DMSO in a concentration-dependent manner. The effect of DMSO was restricted within 24 hours after oviposition of diapause eggs, and the critical period was slightly shorter than the effective period of the HCl treatment. DMSO analogs, such as dimethyl formamide (DMF and dimethyl sulfide (DMS, did little preventive effect against the diapause. Furthermore, we also investigated the permeation effects of chemical compounds by DMSO. When treated with an inhibitor of protein kinase CK2 (CK2 dissolved in DMSO, the prevention rate of the diapause was less than 40%. This means that the inhibition effect by the CK2 inhibitor was the inhibition of embryonic development after diapause prevention by DMSO. These data suggest that DMSO has the effects of preventing from entering into the diapause and permeation of chemicals into diapause eggs.

  17. Fragrance material review on 2,2-dimethyl-3-phenylpropanol.

    Science.gov (United States)

    Scognamiglio, J; Jones, L; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 2,2-dimethyl-3-phenylpropanol when used as a fragrance ingredient is presented. 2,2-Dimethyl-3-phenylpropanol is a member of the fragrance structural group Aryl Alkyl Alcohols and is a primary alcohol. The AAAs are a structurally diverse class of fragrance ingredients that includes primary, secondary, and tertiary alkyl alcohols covalently bonded to an aryl (Ar) group, which may be either a substituted or unsubstituted benzene ring. The common structural element for the AAA fragrance ingredients is an alcohol group -C-(R1)(R2)OH and generically the AAA fragrances can be represented as an Ar-C-(R1)(R2)OH or Ar-Alkyl-C-(R1)(R2)OH group. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2,2-dimethyl-3-phenylpropanol were evaluated then summarized and includes physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, phototoxicity, and photoallergy data. A safety assessment of the entire Aryl Alkyl Alcohols will be published simultaneously with this document; please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all Aryl Alkyl Alcohols in fragrances. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Theoretical study about L-arginine complexes formation with thiotriazolin

    Directory of Open Access Journals (Sweden)

    L. I. Kucherenko

    2017-02-01

    Full Text Available Brain vascular diseases are one of the leading causes of morbidity, mortality and disability of population in the industrialized countries of the world. An important element of this problem’s solution is the creation of new highly effective and safe drugs, which would lead to mortality reduction, to increase in life expectancy and quality of life. Therefore it is interesting to create a new combined drug based on L-arginine and thiotriazolin. Purpose of the study: to consider the possible structure and energy characteristics of complexes formed by L-arginine, 3-methyl-1,2,4-triazolyl-5-thioacetate (MTTA and morpholine. Calculation method. The initial approximation to the complex geometry was obtained using molecular docking with the help of AutoDock Vina program. The obtained ternary complexes were pre-optimized by semi-empirical PM7 method with modeling the impact of the environment by COSMO method. The calculations were carried out using MOPAC2012 program. Then they were optimized by B97-D3/SVP + COSMO (Water dispersion-corrected DFT-D with geometrical spreading correction on insufficiency of gCP basis set. A more accurate calculation of the solvation energy was conducted by SMD. The calculations by density functional method were carried out using the ORCA 3.0.3 software. Energy complex formation in solution was calculated as the difference of the Gibbs free energy of the solvated complex and its individual components. Results. Quantum chemical calculations show, that thiotriazolin and L-arginine are able to form ternary complexes, where molecules are linked by multiple hydrogen bonds. The calculation data suggest, that studied complexes are thermodynamically unstable in solution. The energies of them are positive, but rather low despite charge gain of a number of intermolecular hydrogen bonds. Finding. Based on the results of the conducted quantum-chemical study of a three components system (MTTA, morpholine, and L-arginine it is possible

  19. Synthesis method of asymmetric gold particles.

    Science.gov (United States)

    Jun, Bong-Hyun; Murata, Michael; Hahm, Eunil; Lee, Luke P

    2017-06-07

    Asymmetric particles can exhibit unique properties. However, reported synthesis methods for asymmetric particles hinder their application because these methods have a limited scale and lack the ability to afford particles of varied shapes. Herein, we report a novel synthetic method which has the potential to produce large quantities of asymmetric particles. Asymmetric rose-shaped gold particles were fabricated as a proof of concept experiment. First, silica nanoparticles (NPs) were bound to a hydrophobic micro-sized polymer containing 2-chlorotritylchloride linkers (2-CTC resin). Then, half-planar gold particles with rose-shaped and polyhedral structures were prepared on the silica particles on the 2-CTC resin. Particle size was controlled by the concentration of the gold source. The asymmetric particles were easily cleaved from the resin without aggregation. We confirmed that gold was grown on the silica NPs. This facile method for synthesizing asymmetric particles has great potential for materials science.

  20. LG tools for asymmetric wargaming

    Science.gov (United States)

    Stilman, Boris; Yakhnis, Alex; Yakhnis, Vladimir

    2002-07-01

    Asymmetric operations represent conflict where one of the sides would apply military power to influence the political and civil environment, to facilitate diplomacy, and to interrupt specified illegal activities. This is a special type of conflict where the participants do not initiate full-scale war. Instead, the sides may be engaged in a limited open conflict or one or several sides may covertly engage another side using unconventional or less conventional methods of engagement. They may include peace operations, combating terrorism, counterdrug operations, arms control, support of insurgencies or counterinsurgencies, show of force. An asymmetric conflict can be represented as several concurrent interlinked games of various kinds: military, transportation, economic, political, etc. Thus, various actions of peace violators, terrorists, drug traffickers, etc., can be expressed via moves in different interlinked games. LG tools allow us to fully capture the specificity of asymmetric conflicts employing the major LG concept of hypergame. Hypergame allows modeling concurrent interlinked processes taking place in geographically remote locations at different levels of resolution and time scale. For example, it allows us to model an antiterrorist operation taking place simultaneously in a number of countries around the globe and involving wide range of entities from individuals to combat units to governments. Additionally, LG allows us to model all sides of the conflict at their level of sophistication. Intelligent stakeholders are represented by means of LG generated intelligent strategies. TO generate those strategies, in addition to its own mathematical intelligence, the LG algorithm may incorporate the intelligence of the top-level experts in the respective problem domains. LG models the individual differences between intelligent stakeholders. The LG tools make it possible to incorporate most of the known traits of a stakeholder, i.e., real personalities involved in

  1. Incompressibility of asymmetric nuclear matter

    International Nuclear Information System (INIS)

    Chen, Liewen; Cai, Baojun; Shen, Chun; Ko, Cheming; Xu, Jun; Li, Baoan

    2010-01-01

    Using an isospin- and momentum-dependent modified Gogny (MDI) interaction, the Skyrme-Hartree-Fock (SHF) approach, and a phenomenological modified Skyrme-like (MSL) model, we have studied the incompressibility K sat (δ) of isospin asymmetric nuclear matter at its saturation density. Our results show that in the expansion of K sat (δ) in powers of isospin asymmetry δ, i.e., K sat (δ) = K 0 + K sat,2 δ 2 + K sat,4 δ 4 + O(δ 6 ), the magnitude of the 4th-order K sat,4 parameter is generally small. The 2nd-order K sat,2 parameter thus essentially characterizes the isospin dependence of the incompressibility of asymmetric nuclear matter at saturation density. Furthermore, the K sat,2 can be expressed as K sat,2 = K sym – 6L – J 0 /K 0 L in terms of the slope parameter L and the curvature parameter K sym of the symmetry energy and the third-order derivative parameter J 0 of the energy of symmetric nuclear matter at saturation density, and we find the higher order J 0 contribution to K sat,2 generally cannot be neglected. Also, we have found a linear correlation between K sym and L as well as between J 0 /K 0 and K 0 . Using these correlations together with the empirical constraints on K 0 and L, the nuclear symmetry energy E sym (ρ0) at normal nuclear density, and the nucleon effective mass, we have obtained an estimated value of K sat,2 = -370 ± 120 MeV for the 2nd-order parameter in the isospin asymmetry expansion of the incompressibility of asymmetric nuclear matter at its saturation density. (author)

  2. Asymmetric effects in customer satisfaction

    DEFF Research Database (Denmark)

    Füller, Johann; Matzler, Kurt; Faullant, Rita

    2006-01-01

    The results of this study on customer satisfaction in snowboard areas show that the relationship between an attribute and overall satisfaction can indeed be asymmetric. A 30-item self-administered survey was completed by snowboarders (n=2526) in 51 areas in Austria, Germany, Switzerland and Italy....... Results show that waiting time is a dissatisfier; it has a significant impact on overall customer satisfaction in the low satisfaction condition and becomes insignificant in the high satisfaction situation. Restaurants and bars are hybrids, i.e. importance does not depend on performance. Slopes, fun...

  3. Asymmetric Formal Synthesis of Azadirachtin.

    Science.gov (United States)

    Mori, Naoki; Kitahara, Takeshi; Mori, Kenji; Watanabe, Hidenori

    2015-12-01

    An asymmetric formal synthesis of azadirachtin, a potent insect antifeedant, was accomplished in 30 steps to Ley's synthetic intermediate (longest linear sequence). The synthesis features: 1) rapid access to the optically active right-hand segment starting from the known 5-hydroxymethyl-2-cyclopentenone scaffold; 2) construction of the B and E rings by a key intramolecular tandem radical cyclization; 3) formation of the hemiacetal moiety in the C ring through the α-oxidation of the six-membered lactone followed by methanolysis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Spontaneous baryogenesis from asymmetric inflaton

    International Nuclear Information System (INIS)

    Takahashi, Fuminobu

    2015-10-01

    We propose a variant scenario of spontaneous baryogenesis from asymmetric inflaton based on current-current interactions between the inflaton and matter fields with a non-zero B-L charge. When the inflaton starts to oscillate around the minimum after inflation, it may lead to excitation of a CP-odd component, which induces an effective chemical potential for the B-L number through the current-current interactions. We study concrete inflation models and show that the spontaneous baryogenesis scenario can be naturally implemented in the chaotic inflation in supergravity.

  5. Combinatorial Effects of Arginine and Fluoride on Oral Bacteria

    OpenAIRE

    Zheng, X.; Cheng, X.; Wang, L.; Qiu, W.; Wang, S.; Zhou, Y.; Li, M.; Li, Y.; Cheng, L.; Li, J.; Zhou, X.; Xu, X.

    2015-01-01

    Dental caries is closely associated with the microbial disequilibrium between acidogenic/aciduric pathogens and alkali-generating commensal residents within the dental plaque. Fluoride is a widely used anticaries agent, which promotes tooth hard-tissue remineralization and suppresses bacterial activities. Recent clinical trials have shown that oral hygiene products containing both fluoride and arginine possess a greater anticaries effect compared with those containing fluoride alone, indicati...

  6. Primary assimilation process of triply (/sup 15/N, /sup 14/C and /sup 3/H) labeled arginine in the roots of arginine-fed barley

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Satoshi [Tokyo Univ. (Japan). Faculty of Agriculture

    1981-03-01

    To clarify the mechanism of arginine utilization in barley roots, triply labeled (ureido-/sup 15/N, ureido-/sup 14/C and 5-/sup 3/H) arginine was applied to plants precultured with arginine (Arg-plants). (5-/sup 3/H) Arginine was incorporated mainly into ornithine, suggesting that arginase contributes in the first step of arginine metabolism. The arginase activity in the tissues was greatly enhanced by continuous supply of arginine, whereas urease activity was not by the same treatment. The amount of /sup 14/CO/sub 2/ evolved from (ureido-/sup 14/C) arginine in the Arg-plants was several times higher than that in plants treated with NO/sub 3//sup -/(NO/sub 3/-plants), and most /sup 14/C-urea exogenously supplied to detached roots of Arg-plants was immediately decomposed to /sup 14/CO/sub 2/. The urea released from arginine by arginase was cleaved to /sup 15/NH/sub 4//sup +/ + /sup 14/CO/sub 2/ by urease. Most of the /sup 14/CO/sub 2/ was then lost from the root system. On the other hand, the released /sup 15/NH/sub 4//sup +/ was reassimilated into amino acids probably through the pathway of ammonia assimilation. Released (5-/sup 3/H) ornithine was metabolized dominantly to proline.

  7. Spray drying of poorly soluble drugs from aqueous arginine solution.

    Science.gov (United States)

    Ojarinta, Rami; Lerminiaux, Louise; Laitinen, Riikka

    2017-10-30

    Co-amorphous drug-amino acid mixtures have shown potential for improving the solid-state stability and dissolution behavior of amorphous drugs. In previous studies, however these mixtures have been produced mainly with small-scale preparation methods, or with methods that have required the use of organic solvents or other dissolution enhancers. In the present study, co-amorphous ibuprofen-arginine and indomethacin-arginine mixtures were spray dried from water. The mixtures were prepared at two drug-arginine molar ratios (1:1 and 1:2). The properties of the prepared mixtures were investigated with differential scanning calorimetry, X-ray powder diffractometry, Fourier-transform infrared spectroscopy and a 24h, non-sink, dissolution study. All mixtures exhibited a single glass transition temperature (T g ), evidence of the formation of homogenous single-phase systems. Fourier transform infrared spectroscopy revealed strong interactions (mainly salt formation) that account for the positive deviation between measured and estimated T g values. No crystallization was observed during a 1-year stability study in either 1:1 or 1:2 mixtures, but in the presence of moisture, handling difficulties were encountered. The formation of co-amorphous salts led to improved dissolution characteristics when compared to the corresponding physical mixtures or to pure crystalline drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. [l-arginine efficiency in MELAS syndrome. A case report].

    Science.gov (United States)

    Moutaouakil, F; El Otmani, H; Fadel, H; Sefrioui, F; Slassi, I

    2009-05-01

    Mitochondrial encephalomyopathy lactic acidosis and stoke-like episodes (MELAS) is a rare neurodegenerative disease caused by mutations of mitochondrial DNA. We report the case of a 12-year-old child with MELAS syndrome who presented with recurrent migraine-like headache and sudden blindness suggesting stroke-like episodes. Furthermore, he developed progressive muscular impairment with bilateral hearing loss. Serum lactate and pyruvate levels were elevated and the muscle biopsy showed an aspect of red-ragged fibers with Gomori trichrome. Brain imaging showed calcifications of basal ganglia on the CT scan and a parieto-occipital high signal on diffusion-weighted MRI. A genetic analysis was not performed but the presence of hearing loss in the patient's mother was suggestive of maternal transmission. Stroke-like episodes in the form of migraine-like headache and blindness were the patient's major complaint and did not improve despite analgesic drugs. After oral administration of l-arginine at the dose of 0.4mg/kg per day, stroke-like symptoms totally and rapidly disappeared. The efficiency of l-arginine in stroke-like episodes was initially reported then confirmed in a controlled study. The pathophysiology of stoke-like episodes and the mechanisms underlying the action of l-arginine are discussed.

  9. Dietary arginine depletion reduces depressive-like responses in male, but not female, mice.

    Science.gov (United States)

    Workman, Joanna L; Weber, Michael D; Nelson, Randy J

    2011-09-30

    Previous behavioral studies have manipulated nitric oxide (NO) production either by pharmacological inhibition of its synthetic enzyme, nitric oxide synthase (NOS), or by deletion of the genes that code for NOS. However manipulation of dietary intake of the NO precursor, L-arginine, has been understudied in regard to behavioral regulation. L-Arginine is a common amino acid present in many mammalian diets and is essential during development. In the brain L-arginine is converted into NO and citrulline by the enzyme, neuronal NOS (nNOS). In Experiment 1, paired mice were fed a diet comprised either of an L-arginine-depleted, L-arginine-supplemented, or standard level of L-arginine during pregnancy. Offspring were continuously fed the same diets and were tested in adulthood in elevated plus maze, forced swim, and resident-intruder aggression tests. L-Arginine depletion reduced depressive-like responses in male, but not female, mice and failed to significantly alter anxiety-like or aggressive behaviors. Arginine depletion throughout life reduced body mass overall and eliminated the sex difference in body mass. Additionally, arginine depletion significantly increased corticosterone concentrations, which negatively correlated with time spent floating. In Experiment 2, adult mice were fed arginine-defined diets two weeks prior to and during behavioral testing, and again tested in the aforementioned tests. Arginine depletion reduced depressive-like responses in the forced swim test, but did not alter behavior in the elevated plus maze or the resident intruder aggression test. Corticosterone concentrations were not altered by arginine diet manipulation in adulthood. These results indicate that arginine depletion throughout development, as well as during a discrete period during adulthood ameliorates depressive-like responses. These results may yield new insights into the etiology and sex differences of depression. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Predictive Potential of Twenty-Two Biochemical Biomarkers for Coronary Artery Disease in Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Edimar Cristiano Pereira

    2015-01-01

    Full Text Available We investigated the potential of a panel of 22 biomarkers to predict the presence of coronary artery disease (CAD in type 2 diabetes mellitus (DM2 patients. The study enrolled 96 DM2 patients with (n = 75 and without (n = 21 evidence of CAD. We assessed a biochemical profile that included 22 biomarkers: total cholesterol, LDL, HDL, LDL/HDL, triglycerides, glucose, glycated hemoglobin, fructosamine, homocysteine, cysteine, methionine, reduced glutathione, oxidized glutathione, reduced glutathione/oxidized glutathione, L-arginine, asymmetric dimethyl-L-arginine, symmetric dimethyl-L-arginine, asymmetric dimethyl-L-arginine/L-arginine, nitrate plus nitrite, S-nitrosothiols, nitrotyrosine, and n-acetyl-β-glucosaminidase. Prediction models were built using logistic regression models. We found that eight biomarkers (methionine, nitratate plus nitrite, n-acetyl-β-glucosaminidase, BMI, LDL, HDL, reduced glutathione, and L-arginine/asymmetric dimethyl-L-arginine along with gender and BMI were significantly associated with the odds of CAD in DM2. These preliminary findings support the notion that emerging biochemical markers might be used for CAD prediction in patients with DM2. Our findings warrant further investigation with large, well-designed studies.

  11. Field factors for asymmetric collimators

    International Nuclear Information System (INIS)

    Turner, J.R.; Butler, A.P.H.

    1996-01-01

    In recent years manufacturers have been supplying linear accelerators with either a single pair or a dual pair of collimators. The use of a model to relate off-axis field factors to on-axis field factors obviates the need for repeat measurements whenever the asymmetric collimators are employed. We have investigated the variation of collimator scatter Sc, with distance of the central ray x from the central axis for a variety of non square field sizes. Collimator scatter was measured by in-air measurements with a build-up cap. The Primaty-Off-Centre-Ratio (POCR) was measured in-air by scanning orthogonally across the beam with an ionization chamber. The result of the investigation is the useful prediction of off-axis field factors for a range of rectangular asymmetric fields using the simple product of the on-axis field factor and the POCR in air. The effect of asymmetry on the quality of the beam and hence the percent depth dose will be discussed. (author)

  12. Temporal variations in dimethylsulphoniopropionate and dimethyl sulphide in the Zuari estuary, Goa (India)

    Digital Repository Service at National Institute of Oceanography (India)

    Shenoy, D.M.; Patil, J.S.

    . F., & Wakeham, S. G. (1998). Temporal variability of dimethyl sulfide and dimethylsulfoniopropionate in the Sargasso Sea. DeepSeaRes.PartI, 45, 2085– 2104. DeSouza, M. P., & Yoch, D. C. (1996). Differential metabolism of dimethyl...) measurements and a procedure to predict sea surface DMS as a function of latitude, longitude, and month.GlobalBiogeochemicalCycles,13, 399–444. Kiene, R. P. (1990). Dimethyl sulfide production from dimethyl-sulfoniopropionate in coastal seawater samples...

  13. Asymmetric Frontal Brain Activity and Parental Rejection

    NARCIS (Netherlands)

    Huffmeijer, R.; Alink, L.R.A.; Tops, M.; Bakermans-Kranenburg, M.J.; van IJzendoorn, M.H.

    2013-01-01

    Asymmetric frontal brain activity has been widely implicated in reactions to emotional stimuli and is thought to reflect individual differences in approach-withdrawal motivation. Here, we investigate whether asymmetric frontal activity, as a measure of approach-withdrawal motivation, also predicts

  14. Worst Asymmetrical Short-Circuit Current

    DEFF Research Database (Denmark)

    Arana Aristi, Iván; Holmstrøm, O; Grastrup, L

    2010-01-01

    In a typical power plant, the production scenario and the short-circuit time were found for the worst asymmetrical short-circuit current. Then, a sensitivity analysis on the missing generator values was realized in order to minimize the uncertainty of the results. Afterward the worst asymmetrical...

  15. Mechanochemistry assisted asymmetric organocatalysis: A sustainable approach

    Directory of Open Access Journals (Sweden)

    Pankaj Chauhan

    2012-12-01

    Full Text Available Ball-milling and pestle and mortar grinding have emerged as powerful methods for the development of environmentally benign chemical transformations. Recently, the use of these mechanochemical techniques in asymmetric organocatalysis has increased. This review highlights the progress in asymmetric organocatalytic reactions assisted by mechanochemical techniques.

  16. Proteome-wide analysis of arginine monomethylation reveals widespread occurrence in human cells

    DEFF Research Database (Denmark)

    Larsen, Sara C; Sylvestersen, Kathrine B; Mund, Andreas

    2016-01-01

    to the frequency of somatic mutations at arginine methylation sites throughout the proteome, we observed that somatic mutations were common at arginine methylation sites in proteins involved in mRNA splicing. Furthermore, in HeLa and U2OS cells, we found that distinct arginine methyltransferases differentially...... kidney 293 cells, indicating that the occurrence of this modification is comparable to phosphorylation and ubiquitylation. A site-level conservation analysis revealed that arginine methylation sites are less evolutionarily conserved compared to arginines that were not identified as modified...... as coactivator-associated arginine methyltransferase 1 (CARM1)] or PRMT1 increased the RNA binding function of HNRNPUL1. High-content single-cell imaging additionally revealed that knocking down CARM1 promoted the nuclear accumulation of SRSF2, independent of cell cycle phase. Collectively, the presented human...

  17. Drosophila arginine methyltransferase 1 (DART1) is an ecdysone receptor co-repressor

    International Nuclear Information System (INIS)

    Kimura, Shuhei; Sawatsubashi, Shun; Ito, Saya; Kouzmenko, Alexander; Suzuki, Eriko; Zhao, Yue; Yamagata, Kaoru; Tanabe, Masahiko; Ueda, Takashi; Fujiyama, Sari; Murata, Takuya; Matsukawa, Hiroyuki; Takeyama, Ken-ichi; Yaegashi, Nobuo

    2008-01-01

    Histone arginine methylation is an epigenetic marker that regulates gene expression by defining the chromatin state. Arginine methyltransferases, therefore, serve as transcriptional co-regulators. However, unlike other transcriptional co-regulators, the physiological roles of arginine methyltransferases are poorly understood. Drosophila arginine methyltransferase 1 (DART1), the mammalian PRMT1 homologue, methylates the arginine residue of histone H4 (H4R3me2). Disruption of DART1 in Drosophila by imprecise P-element excision resulted in low viability during metamorphosis in the pupal stages. In the pupal stage, an ecdysone hormone signal is critical for developmental progression. DART1 interacted with the nuclear ecdysone receptor (EcR) in a ligand-dependent manner, and co-repressed EcR in intact flies. These findings suggest that DART1, a histone arginine methyltransferase, is a co-repressor of EcR that is indispensable for normal pupal development in the intact fly

  18. Dimethyl ether production from methanol and/or syngas

    Science.gov (United States)

    Dagle, Robert A; Wang, Yong; Baker, Eddie G; Hu, Jianli

    2015-02-17

    Disclosed are methods for producing dimethyl ether (DME) from methanol and for producing DME directly from syngas, such as syngas from biomass. Also disclosed are apparatus for DME production. The disclosed processes generally function at higher temperatures with lower contact times and at lower pressures than conventional processes so as to produce higher DME yields than do conventional processes. Certain embodiments of the processes are carried out in reactors providing greater surface to volume ratios than the presently used DME reactors. Certain embodiments of the processes are carried out in systems comprising multiple microchannel reactors.

  19. Performance of long straw tubes using dimethyl ether

    International Nuclear Information System (INIS)

    Benussi, L.; Bertani, M.; Bianco, S.; Fabbri, F.L.; Gianotti, P.; Giardoni, M.; Guaraldo, C.; Lanaro, A.; Lucherini, V.; Mecozzi, A.; Passamonti, L.; Russo, V.; Sarwar, S.

    1995-01-01

    A cylindrical tracking detector with an inner radius of one meter employing straw tubes is being envisaged for the FINUDA experiment aimed at hyper-nuclear physics at DAΦNE, the Frascati φ-factory. A prototype using several 10 mm and 20 mm diameter, two meter long aluminized mylar straws has been assembled and tested with a one GeV/c pion beam. While operating with dimethyl ether, gas gain, space resolution, and device systematics have been studied. A simple method of correction for systematics due to straw eccentricity has been developed and, once applied, a space resolution better than 40 μm can be reached. (orig.)

  20. Dimethyl (E-2-(N-phenylacetamidobut-2-enedioate

    Directory of Open Access Journals (Sweden)

    Ting Bin Wen

    2011-01-01

    Full Text Available The title compound, C14H15NO5, was obtained from the reaction of acetanilide with dimethyl acetylenedicarboxylate in the presence of potassium carbonate. The C=C double bond adopts an E configuration and the geometry around the amide N atom is almost planar rather than pyramidal (mean deviation of 0.0032 Å from the C3N plane. The packing of the molecules in the crystal structure is stabilized by intermolecular C—H...O hydrogen bonds.

  1. (2E-3-(3,5-Dimethyl-1-phenyl-1H-pyrazol-4-yl-1-(2,5-dimethyl-3-thienylprop-2-en-1-one

    Directory of Open Access Journals (Sweden)

    Salman A. Khan

    2010-04-01

    Full Text Available The title compound, (2E-3-(3,5-dimethyl-1-phenyl-1H-pyrazol-4-yl-1-(2,5-dimethyl-3-thienylprop-2-en-1-one (3 was synthesized in high yield by aldol condensation of 3-acetyl-2,5-dimethylthiophene and 3,5-dimethyl-1-phenylpyrazole-4-carboxaldehyde in ethanolic NaOH at room temperature. Its structure was fully characterized by elemental analysis, IR, 1H NMR, 13C NMR and EI-MS spectral analysis.

  2. Designing asymmetric multiferroics with strong magnetoelectric coupling

    Science.gov (United States)

    Lu, Xuezeng; Xiang, Hongjun; Rondinelli, James; Materials Theory; Design Group Team

    2015-03-01

    Multiferroics offer exciting opportunities for electric-field control of magnetism. Single-phase multiferroics suitable for such applications at room temperature need much more study. Here, we propose the concept of an alternative type of multiferroics, namely, the ``asymmetric multiferroic.'' In asymmetric multiferroics, two locally stable ferroelectric states are not symmetrically equivalent, leading to different magnetic properties between these two states. Furthermore, we predict from first principles that a Fe-Cr-Mo superlattice with the LiNbO3-type structure is such an asymmetric multiferroic. The strong ferrimagnetism, high ferroelectric polarization, and significant dependence of the magnetic transition temperature on polarization make this asymmetric multiferroic an ideal candidate for realizing electric-field control of magnetism at room temperature. Our study suggests that the asymmetric multiferroic may provide an alternative playground for voltage control of magnetism and find its applications in spintronics and quantum computing.

  3. Arginine does not exacerbate markers of inflammation in cocultures of human enterocytes and leukocytes

    DEFF Research Database (Denmark)

    Parlesak, Alexandr; Negrier, I.; Neveux, N.

    2007-01-01

    with arginine did not affect epithelial integrity, production of any of the cytokines investigated, or the amount of nitric oxide. The amino acid used primarily by nonstimulated intestinal epithelial cells cocultured with leukocytes was glutamine. Activation of IEC with bacteria significantly enhanced...... the catabolism of serine, asparagine, and lysine, and reduced glutamine catabolism. Addition of arginine increased ornithine formation and moderately reduced transepithelial transport of methionine and other amino acids. Hence, arginine supplementation does not interfere with inflammation-associated cross...

  4. Inhibition of protein aggregation: supramolecular assemblies of arginine hold the key.

    Directory of Open Access Journals (Sweden)

    Utpal Das

    Full Text Available BACKGROUND: Aggregation of unfolded proteins occurs mainly through the exposed hydrophobic surfaces. Any mechanism of inhibition of this aggregation should explain the prevention of these hydrophobic interactions. Though arginine is prevalently used as an aggregation suppressor, its mechanism of action is not clearly understood. We propose a mechanism based on the hydrophobic interactions of arginine. METHODOLOGY: We have analyzed arginine solution for its hydrotropic effect by pyrene solubility and the presence of hydrophobic environment by 1-anilino-8-naphthalene sulfonic acid fluorescence. Mass spectroscopic analyses show that arginine forms molecular clusters in the gas phase and the cluster composition is dependent on the solution conditions. Light scattering studies indicate that arginine exists as clusters in solution. In the presence of arginine, the reverse phase chromatographic elution profile of Alzheimer's amyloid beta 1-42 (Abeta(1-42 peptide is modified. Changes in the hydrodynamic volume of Abeta(1-42 in the presence of arginine measured by size exclusion chromatography show that arginine binds to Abeta(1-42. Arginine increases the solubility of Abeta(1-42 peptide in aqueous medium. It decreases the aggregation of Abeta(1-42 as observed by atomic force microscopy. CONCLUSIONS: Based on our experimental results we propose that molecular clusters of arginine in aqueous solutions display a hydrophobic surface by the alignment of its three methylene groups. The hydrophobic surfaces present on the proteins interact with the hydrophobic surface presented by the arginine clusters. The masking of hydrophobic surface inhibits protein-protein aggregation. This mechanism is also responsible for the hydrotropic effect of arginine on various compounds. It is also explained why other amino acids fail to inhibit the protein aggregation.

  5. Arginine Improves pH Homeostasis via Metabolism and Microbiome Modulation.

    Science.gov (United States)

    Agnello, M; Cen, L; Tran, N C; Shi, W; McLean, J S; He, X

    2017-07-01

    Dental caries can be described as a dysbiosis of the oral microbial community, in which acidogenic, aciduric, and acid-adapted bacterial species promote a pathogenic environment, leading to demineralization. Alkali generation by oral microbes, specifically via arginine catabolic pathways, is an essential factor in maintaining plaque pH homeostasis. There is evidence that the use of arginine in dentifrices helps protect against caries. The aim of the current study was to investigate the mechanistic and ecological effect of arginine treatment on the oral microbiome and its regulation of pH dynamics, using an in vitro multispecies oral biofilm model that was previously shown to be highly reflective of the in vivo oral microbiome. Pooled saliva from 6 healthy subjects was used to generate overnight biofilms, reflecting early stages of biofilm maturation. First, we investigated the uptake of arginine by the cells of the biofilm as well as the metabolites generated. We next explored the effect of arginine on pH dynamics by pretreating biofilms with 75 mM arginine, followed by the addition of sucrose (15 mM) after 0, 6, 20, or 48 h. pH was measured at each time point and biofilms were collected for 16S sequencing and targeted arginine quantification, and supernatants were prepared for metabolomic analysis. Treatment with only sucrose led to a sustained pH drop from 7 to 4.5, while biofilms treated with sucrose after 6, 20, or 48 h of preincubation with arginine exhibited a recovery to higher pH. Arginine was detected within the cells of the biofilms, indicating active uptake, and arginine catabolites citrulline, ornithine, and putrescine were detected in supernatants, indicating active metabolism. Sequencing analysis revealed a shift in the microbial community structure in arginine-treated biofilms as well as increased species diversity. Overall, we show that arginine improved pH homeostasis through a remodeling of the oral microbial community.

  6. Remission of diabetes mellitus in cats cannot be predicted by the arginine stimulation test

    OpenAIRE

    Tschuor, F

    2011-01-01

    Background: Responsiveness of β-cells to arginine persists the longest during diabetes progression, making the intravenous arginine stimulation test (IVAST) a useful tool to assess residual insulin and glucagon secretion. Hypothesis: Diabetic cats with and without remission will have different arginine-induced insulin or glucagon response. Animals: 17 cats with diabetes, 7 healthy cats. Methods: Response to IVAST was assessed by calculating insulin and glucagon area under the c...

  7. Inhibition of mammalian nitric oxide synthases by agmatine, an endogenous polyamine formed by decarboxylation of arginine.

    OpenAIRE

    Galea, E; Regunathan, S; Eliopoulos, V; Feinstein, D L; Reis, D J

    1996-01-01

    Agmatine, decarboxylated arginine, is a metabolic product of mammalian cells. Considering the close structural similarity between L-arginine and agmatine, we investigated the interaction of agmatine and nitric oxide synthases (NOSs), which use L-arginine to generate nitric oxide (NO) and citrulline. Brain, macrophages and endothelial cells were respectively used as sources for NOS isoforms I, II and III. Enzyme activity was measured by the production of nitrites or L-citrulline. Agmatine was ...

  8. The arginine-ornithine antiporter ArcD contributes to biological fitness of Streptococcus suis

    Directory of Open Access Journals (Sweden)

    Marcus eFulde

    2014-08-01

    Full Text Available The arginine-ornithine antiporter (ArcD is part of the Arginine Deiminase System (ADS, a catabolic, energy-providing pathway found in a variety of different bacterial species, including the porcine zoonotic pathogen Streptococcus suis. The ADS has recently been shown to play a role in the pathogenicity of S. suis, in particular in its survival in host cells. The contribution of arginine and arginine transport mediated by ArcD, however, has yet to be clarified. In the present study, we showed by experiments using [U-13C6]arginine as a tracer molecule that S. suis is auxotrophic for arginine and that bacterial growth depends on the uptake of extracellular arginine. To further study the role of ArcD in arginine metabolism, we generated an arcD-specific mutant strain and characterized its growth compared to the wild-type (WT strain, a virulent serotype 2 strain. The mutant strain showed a markedly reduced growth rate in chemically defined media supplemented with arginine when compared to the WT strain, indicating that ArcD promotes arginine uptake. To further evaluate the in vivo relevance of ArcD, we studied the intracellular bacterial survival of the arcD mutant strain in an epithelial cell culture infection model. The mutant strain was substantially attenuated, and its reduced intracellular survival rate correlated with a lower ability to neutralize the acidified environment. Based on these results, we propose that ArcD, by its function as an arginine-ornithine antiporter, is important for supplying arginine as substrate of the ADS and, thereby, contributes to biological fitness and virulence of S. suis in the host.

  9. A case of asymmetrical arthrogryposis

    International Nuclear Information System (INIS)

    Hageman, G.; Vette, J.K.; Willemse, J.

    1983-01-01

    Following the introduction of the conception that arthrogryposis is a symptom and not a clinical entity, a case of the very rare asymmetric form of neurogenic arthrogryposis is presented. The asymmetry of congenital contractures and weakness is associated with hemihypotrophy. The value of muscular CT-scanning prior to muscle biopsy is demonstrated. Muscular CT-scanning shows the extension of adipose tissue, which has replaced damaged muscles and therby indicates the exact site for muscle biopsy. Since orthopaedic treatment in arthrogryposis can be unrewarding due to severe muscular degeneration, preoperative scanning may provide additional important information on muscular function and thus be of benefit for surgery. The advantage of muscular CT-scanning in other forms of arthrogryposis requires further determination. The differential diagnosis with Werdnig-Hoffmann disease is discussed. (author)

  10. Comprehensive asymmetric dark matter model

    Science.gov (United States)

    Lonsdale, Stephen J.; Volkas, Raymond R.

    2018-05-01

    Asymmetric dark matter (ADM) is motivated by the similar cosmological mass densities measured for ordinary and dark matter. We present a comprehensive theory for ADM that addresses the mass density similarity, going beyond the usual ADM explanations of similar number densities. It features an explicit matter-antimatter asymmetry generation mechanism, has one fully worked out thermal history and suggestions for other possibilities, and meets all phenomenological, cosmological and astrophysical constraints. Importantly, it incorporates a deep reason for why the dark matter mass scale is related to the proton mass, a key consideration in ADM models. Our starting point is the idea of mirror matter, which offers an explanation for dark matter by duplicating the standard model with a dark sector related by a Z2 parity symmetry. However, the dark sector need not manifest as a symmetric copy of the standard model in the present day. By utilizing the mechanism of "asymmetric symmetry breaking" with two Higgs doublets in each sector, we develop a model of ADM where the mirror symmetry is spontaneously broken, leading to an electroweak scale in the dark sector that is significantly larger than that of the visible sector. The weak sensitivity of the ordinary and dark QCD confinement scales to their respective electroweak scales leads to the necessary connection between the dark matter and proton masses. The dark matter is composed of either dark neutrons or a mixture of dark neutrons and metastable dark hydrogen atoms. Lepton asymmetries are generated by the C P -violating decays of heavy Majorana neutrinos in both sectors. These are then converted by sphaleron processes to produce the observed ratio of visible to dark matter in the universe. The dynamics responsible for the kinetic decoupling of the two sectors emerges as an important issue that we only partially solve.

  11. Bioinformatic evaluation of L-arginine catabolic pathways in 24 cyanobacteria and transcriptional analysis of genes encoding enzymes of L-arginine catabolism in the cyanobacterium Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Pistorius Elfriede K

    2007-11-01

    Full Text Available Abstract Background So far very limited knowledge exists on L-arginine catabolism in cyanobacteria, although six major L-arginine-degrading pathways have been described for prokaryotes. Thus, we have performed a bioinformatic analysis of possible L-arginine-degrading pathways in cyanobacteria. Further, we chose Synechocystis sp. PCC 6803 for a more detailed bioinformatic analysis and for validation of the bioinformatic predictions on L-arginine catabolism with a transcript analysis. Results We have evaluated 24 cyanobacterial genomes of freshwater or marine strains for the presence of putative L-arginine-degrading enzymes. We identified an L-arginine decarboxylase pathway in all 24 strains. In addition, cyanobacteria have one or two further pathways representing either an arginase pathway or L-arginine deiminase pathway or an L-arginine oxidase/dehydrogenase pathway. An L-arginine amidinotransferase pathway as a major L-arginine-degrading pathway is not likely but can not be entirely excluded. A rather unusual finding was that the cyanobacterial L-arginine deiminases are substantially larger than the enzymes in non-photosynthetic bacteria and that they are membrane-bound. A more detailed bioinformatic analysis of Synechocystis sp. PCC 6803 revealed that three different L-arginine-degrading pathways may in principle be functional in this cyanobacterium. These are (i an L-arginine decarboxylase pathway, (ii an L-arginine deiminase pathway, and (iii an L-arginine oxidase/dehydrogenase pathway. A transcript analysis of cells grown either with nitrate or L-arginine as sole N-source and with an illumination of 50 μmol photons m-2 s-1 showed that the transcripts for the first enzyme(s of all three pathways were present, but that the transcript levels for the L-arginine deiminase and the L-arginine oxidase/dehydrogenase were substantially higher than that of the three isoenzymes of L-arginine decarboxylase. Conclusion The evaluation of 24

  12. Protein arginine methyltransferase 1 regulates herpes simplex virus replication through ICP27 RGG-box methylation

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Jungeun; Shin, Bongjin; Park, Eui-Soon; Yang, Sujeong; Choi, Seunga [Department of Microbiology, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejon 305-764 (Korea, Republic of); BK21 Bio Brain Center, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejon 305-764 (Korea, Republic of); Kang, Misun [Department of Microbiology, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejon 305-764 (Korea, Republic of); Rho, Jaerang, E-mail: jrrho@cnu.ac.kr [Department of Microbiology, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejon 305-764 (Korea, Republic of); BK21 Bio Brain Center, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejon 305-764 (Korea, Republic of); GRAST, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejon 305-764 (Korea, Republic of)

    2010-01-01

    Protein arginine methylation is involved in viral infection and replication through the modulation of diverse cellular processes including RNA metabolism, cytokine signaling, and subcellular localization. It has been suggested previously that the protein arginine methylation of the RGG-box of ICP27 is required for herpes simplex virus type-1 (HSV-1) viral replication and gene expression in vivo. However, a cellular mediator for this process has not yet been identified. In our current study, we show that the protein arginine methyltransferase 1 (PRMT1) is a cellular mediator of the arginine methylation of ICP27 RGG-box. We generated arginine substitution mutants in this domain and examined which arginine residues are required for methylation by PRMT1. R138, R148 and R150 were found to be the major sites of this methylation but additional arginine residues serving as minor methylation sites are still required to sustain the fully methylated form of ICP27 RGG. We also demonstrate that the nuclear foci-like structure formation, SRPK interactions, and RNA-binding activity of ICP27 are modulated by the arginine methylation of the ICP27 RGG-box. Furthermore, HSV-1 replication is inhibited by hypomethylation of this domain resulting from the use of general PRMT inhibitors or arginine mutations. Our data thus suggest that the PRMT1 plays a key role as a cellular regulator of HSV-1 replication through ICP27 RGG-box methylation.

  13. Synthesis of the arginine labelled by {sup 15}N on the amidine group; Synthese de l'arginine marquee par {sup 15}N dans le groupe amidine

    Energy Technology Data Exchange (ETDEWEB)

    Pichat, L; Clement, J [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

    1955-07-01

    For some biologic studies, it was necessarily to have (+) arginine marked by nitrogen 15 in the amidine group. This report describes the synthesis of the labelled arginine. The first step is the synthesis of the methyl-isourated hydro-chlorate, the intermediate reactive, from the ClNH{sub 4} isotope. The arginine is obtained from the ornithine which we previously blocked the amino group as cupric complex. The mean yield in arginine reaches 30%, based on the ammonium chloride uses. (M.B.) [French] Pour certaines etudes biologiques, il etait indispensable de disposer de (+) arginine marquee par l'azote 15 dans le groupement amidine. Ce rapport decrit la synthese de l'ariginine marquee. La premiere etape est la synthese du chlorhydrate de methylisouree, intermediaire reactif, a partir du ClNH{sub 4} isotopique. L'obtention de l'arginine est obtenue a partir de l'ornithine dont on a prealablement bloque le groupe amino sous forme de complexe cuivrique. Le rendement global moyen en arginine atteint 30 %, base sur le chlorure d'ammonium utilise. (M.B.)

  14. Entropy Generation Minimization in Dimethyl Ether Synthesis: A Case Study

    Science.gov (United States)

    Kingston, Diego; Razzitte, Adrián César

    2018-04-01

    Entropy generation minimization is a method that helps improve the efficiency of real processes and devices. In this article, we study the entropy production (due to chemical reactions, heat exchange and friction) in a conventional reactor that synthesizes dimethyl ether and minimize it by modifying different operating variables of the reactor, such as composition, temperature and pressure, while aiming at a fixed production of dimethyl ether. Our results indicate that it is possible to reduce the entropy production rate by nearly 70 % and that, by changing only the inlet composition, it is possible to cut it by nearly 40 %, though this comes at the expense of greater dissipation due to heat transfer. We also study the alternative of coupling the reactor with another, where dehydrogenation of methylcyclohexane takes place. In that case, entropy generation can be reduced by 54 %, when pressure, temperature and inlet molar flows are varied. These examples show that entropy generation analysis can be a valuable tool in engineering design and applications aiming at process intensification and efficient operation of plant equipment.

  15. L-Arginine Pathway in COPD Patients with Acute Exacerbation

    DEFF Research Database (Denmark)

    Ruzsics, Istvan; Nagy, Lajos; Keki, Sandor

    2016-01-01

    -performance liquid chromatography in venous blood samples and partial capillary oxygen pressure were prospectively investigated in 32 patients with COPD, 12 with AECOPD and 30 healthy subjects. RESULTS: Both ADMA and SDMA were significantly higher in AECOPD compared to stable COPD (p = 0.004 and p ....001, respectively). Oxygen content in capillaries correlated with serum ADMA concentration. However, the concentration of L-arginine was not different between AECOPD and stable COPD. Both ADMA and SDMA separated AECOPD with high sensitivity and specificity (AUC: 0.81, p = 0.001; AUC: 0.91, p

  16. Two Approaches to the Synthesis of Dimethyl Fumarate That Demonstrate Fundamental Principles of Organic Chemistry

    Science.gov (United States)

    Love, Brian E.; Bennett, Lisa J.

    2017-01-01

    Two experiments are described which lead to the preparation of dimethyl fumarate, a compound currently used in the treatment of multiple sclerosis. Preparation of a compound with "real-world" applications is believed to increase student interest in the experiment. One experiment involves the isomerization of dimethyl maleate to the…

  17. Efficient and Simple Synthesis of 6-Aryl-1,4-dimethyl-9H-carbazoles

    Directory of Open Access Journals (Sweden)

    Sylvain Rault

    2008-06-01

    Full Text Available A synthetic method for the preparation of 6-aryl-1,4-dimethyl-9H-carbazoles involving a palladium catalyzed coupling reaction of 1,4-dimethyl-9H-carbazole-6-boronic acids and (heteroaryl halides is described.

  18. Direct dimethyl ether fueling of a high temperature polymer fuel cell

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf; Vassiliev, Anton; Olsen, M.I.

    2012-01-01

    Direct dimethyl ether (DME) fuel cells suffer from poor DME–water miscibility and so far peak powers of only 20–40 mW cm−2 have been reported. Based on available literature on solubility of dimethyl ether (DME) in water at ambient pressure it was estimated that the maximum concentration of DME at...

  19. A novel preparation of methyl-β-cyclodextrin from dimethyl carbonate and β-cyclodextrin

    DEFF Research Database (Denmark)

    Gan, Yongjiang; Zhang, Yimin; Xiao, Chuanhao

    2011-01-01

    A novel green synthesis process about methyl-β-cyclodextrin has been investigated through the reaction between β-cyclodextrin and dimethyl carbonate by anhydrous potassium carbonate as catalyst in DMF. The influence of experimental factors including the molar ratio of dimethyl carbonate to β-cycl...

  20. The subcellular compartmentalization of arginine metabolizing enzymes and their role in endothelial dysfunction

    Directory of Open Access Journals (Sweden)

    Feng eChen

    2013-07-01

    Full Text Available The endothelial production of nitric oxide (NO mediates endothelium-dependent vasorelaxation and restrains vascular inflammation, smooth muscle proliferation and platelet aggregation. Impaired production of NO is a hallmark of endothelial dysfunction and promotes the development of cardiovascular disease. In endothelial cells, NO is generated by endothelial nitric oxide synthase (eNOS through the conversion of its substrate, L-arginine to L-citrulline. Reduced access to L-arginine has been proposed as a major mechanism underlying reduced eNOS activity and NO production in cardiovascular disease. The arginases (Arg1 and Arg2 metabolize L-arginine to generate L-ornithine and urea and increased expression of arginase has been proposed as a mechanism of reduced eNOS activity secondary to the depletion of L-arginine. Indeed, supplemental L-arginine and suppression of arginase activity has been shown to improve endothelium-dependent relaxation and ameliorate cardiovascular disease. However, L-arginine concentrations in endothelial cells remain sufficiently high to support NO synthesis suggesting additional mechanisms. The compartmentalization of intracellular L-arginine into poorly interchangeable pools has been proposed to allow for the local depletion of L-arginine. Indeed the subcellular location of L-arginine metabolizing enzymes plays important functional roles. In endothelial cells, eNOS is found in discrete intracellular locations and the capacity to generate NO is heavily influenced by its localtion. Arg1 and Arg2 also reside in different subcellular environments and are thought to differentially influence endothelial function. The plasma membrane solute transporter, CAT-1 and the arginine recycling enzyme, ASL, co-localize with eNOS and facilitate NO release. This review highlights the importance of the subcellular location of eNOS and arginine transporting and metabolizing enzymes to NO release and cardiovascular disease.

  1. Effects of arginine and phytogenic additive supplementation on performance and health of brown-egg layers

    Directory of Open Access Journals (Sweden)

    Vitor Barbosa Fascina

    Full Text Available ABSTRACT This study was performed to evaluate the effects of the association of different digestible arginine and phytogenic additive dietary levels on performance and health status of brown-egg layers. In this study, a total of 504 33-week-old Hisex Brown layers were distributed into a completely randomized experimental design to a 4 × 3 factorial arrangement (dietary digestible arginine levels: 880, 968, 1056, or 1144 mg/kg of feed × phytogenic additive levels: 0, 100, and 200 mg/kg of feed with six replicate cages of seven birds per cage. The phytogenic additive was composed of extracts of Baccharis dracunculifolia (40%, Astragalus membranaceus lipopolysaccharides (20%, cinnamon, and grape seed (20%. Feed intake was reduced when diets containing 1056 mg of arginine were supplemented with 100 or 200 mg phytogenic additive per kg. Feed conversion ratio was improved when diets were supplemented with 100 mg of phytogenic additive or with 1056 mg of arginine per kg of feed. Egg mass was increased when diets were supplemented with 1056 mg arginine per kg of feed. Arginine supplementation quadratically increased albumen percentage and reduced yolk percentage. Higher arginine and phytogenic additive levels reduced heterophyl:lymphocyte ratio and blood uric acid, total cholesterol, very-low density lipoprotein, and triglyceride levels. Dietary supplementation of 100 mg of phytogenic additive associated with high arginine levels increased nitric oxide production by peritoneal macrophages and 1056 mg of arginine increased antibodies titers against Newcastle disease virus. Blood and intestinal malonaldehyde levels were reduced when 200 mg of the phytogenic additive was added. Dietary supplementation of 968 mg of arginine or 100 mg of a phytogenic additive (40% Baccharis dracunculifolia, 20% Astragalus membranaceus, 20% cinnamon, and 20% grape seed extracts per kilogram of diet improves the feed conversion ratio and associated inclusion of 1144 mg of

  2. Chaos of several typical asymmetric systems

    International Nuclear Information System (INIS)

    Feng Jingjing; Zhang Qichang; Wang Wei

    2012-01-01

    The threshold for the onset of chaos in asymmetric nonlinear dynamic systems can be determined using an extended Padé method. In this paper, a double-well asymmetric potential system with damping under external periodic excitation is investigated, as well as an asymmetric triple-well potential system under external and parametric excitation. The integrals of Melnikov functions are established to demonstrate that the motion is chaotic. Threshold values are acquired when homoclinic and heteroclinic bifurcations occur. The results of analytical and numerical integration are compared to verify the effectiveness and feasibility of the analytical method.

  3. Modelling asymmetric growth in crowded plant communities

    DEFF Research Database (Denmark)

    Damgaard, Christian

    2010-01-01

    A class of models that may be used to quantify the effect of size-asymmetric competition in crowded plant communities by estimating a community specific degree of size-asymmetric growth for each species in the community is suggested. The model consists of two parts: an individual size......-asymmetric growth part, where growth is assumed to be proportional to a power function of the size of the individual, and a term that reduces the relative growth rate as a decreasing function of the individual plant size and the competitive interactions from other plants in the neighbourhood....

  4. Low-Temperature Oxidation of Dimethyl Ether to Polyoxymethylene Dimethyl Ethers over CNT-Supported Rhenium Catalyst

    Directory of Open Access Journals (Sweden)

    Qingde Zhang

    2016-03-01

    Full Text Available Due to its excellent conductivity, good thermal stability and large specific surface area, carbon nano-tubes (CNTs were selected as support to prepare a Re-based catalyst for dimethyl ether (DME direct oxidation to polyoxymethylene dimethyl ethers (DMMx. The catalyst performance was tested in a continuous flow type fixed-bed reactor. H3PW12O40 (PW12 was used to modify Re/CNTs to improve its activity and selectivity. The effects of PW12 content, reaction temperature, gas hourly space velocity (GHSV and reaction time on DME oxidation to DMMx were investigated. The results showed that modification of CNT-supported Re with 30% PW12 significantly increased the selectivity of DMM and DMM2 up to 59.0% from 6.6% with a DME conversion of 8.9%; besides that, there was no COx production observed in the reaction under the optimum conditions of 513 K and 1800 h−1. The techniques of XRD, BET, NH3-TPD, H2-TPR, XPS, TEM and SEM were used to characterize the structure, surface properties and morphology of the catalysts. The optimum amount of weak acid sites and redox sites promotes the synthesis of DMM and DMM2 from DME direct oxidation.

  5. Thermodynamics of Hydrogen Production from Dimethyl Ether Steam Reforming and Hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    T.A. Semelsberger

    2004-10-01

    The thermodynamic analyses of producing a hydrogen-rich fuel-cell feed from the process of dimethyl ether (DME) steam reforming were investigated as a function of steam-to-carbon ratio (0-4), temperature (100 C-600 C), pressure (1-5 atm), and product species: acetylene, ethanol, methanol, ethylene, methyl-ethyl ether, formaldehyde, formic acid, acetone, n-propanol, ethane and isopropyl alcohol. Results of the thermodynamic processing of dimethyl ether with steam indicate the complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide for temperatures greater than 200 C and steam-to-carbon ratios greater than 1.25 at atmospheric pressure (P = 1 atm). Increasing the operating pressure was observed to shift the equilibrium toward the reactants; increasing the pressure from 1 atm to 5 atm decreased the conversion of dimethyl ether from 99.5% to 76.2%. The order of thermodynamically stable products in decreasing mole fraction was methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol, methyl-ethyl ether and methanol--formaldehyde, formic acid, and acetylene were not observed. The optimal processing conditions for dimethyl ether steam reforming occurred at a steam-to-carbon ratio of 1.5, a pressure of 1 atm, and a temperature of 200 C. Modeling the thermodynamics of dimethyl ether hydrolysis (with methanol as the only product considered), the equilibrium conversion of dimethyl ether is limited. The equilibrium conversion was observed to increase with temperature and steam-to-carbon ratio, resulting in a maximum dimethyl ether conversion of approximately 68% at a steam-to-carbon ratio of 4.5 and a processing temperature of 600 C. Thermodynamically, dimethyl ether processed with steam can produce hydrogen-rich fuel-cell feeds--with hydrogen concentrations exceeding 70%. This substantiates dimethyl ether as a viable source of hydrogen for PEM fuel cells.

  6. Establishment of Dimethyl Labeling-based Quantitative Acetylproteomics in Arabidopsis.

    Science.gov (United States)

    Liu, Shichang; Yu, Fengchao; Yang, Zhu; Wang, Tingliang; Xiong, Hairong; Chang, Caren; Yu, Weichuan; Li, Ning

    2018-05-01

    Protein acetylation, one of many types of post-translational modifications (PTMs), is involved in a variety of biological and cellular processes. In the present study, we applied both C sCl d ensity g radient (CDG) centrifugation-based protein fractionation and a dimethyl-labeling-based 4C quantitative PTM proteomics workflow in the study of dynamic acetylproteomic changes in Arabidopsis. This workflow integrates the dimethyl c hemical labeling with c hromatography-based acetylpeptide separation and enrichment followed by mass spectrometry (MS) analysis, the extracted ion chromatogram (XIC) quantitation-based c omputational analysis of mass spectrometry data to measure dynamic changes of acetylpeptide level using an in-house software program, named S table isotope-based Qua ntitation- D imethyl labeling (SQUA-D), and finally the c onfirmation of ethylene hormone-regulated acetylation using immunoblot analysis. Eventually, using this proteomic approach, 7456 unambiguous acetylation sites were found from 2638 different acetylproteins, and 5250 acetylation sites, including 5233 sites on lysine side chain and 17 sites on protein N termini, were identified repetitively. Out of these repetitively discovered acetylation sites, 4228 sites on lysine side chain ( i.e. 80.5%) are novel. These acetylproteins are exemplified by the histone superfamily, ribosomal and heat shock proteins, and proteins related to stress/stimulus responses and energy metabolism. The novel acetylproteins enriched by the CDG centrifugation fractionation contain many cellular trafficking proteins, membrane-bound receptors, and receptor-like kinases, which are mostly involved in brassinosteroid, light, gravity, and development signaling. In addition, we identified 12 highly conserved acetylation site motifs within histones, P-glycoproteins, actin depolymerizing factors, ATPases, transcription factors, and receptor-like kinases. Using SQUA-D software, we have quantified 33 ethylene hormone-enhanced and

  7. Modeling of asymmetrical boost converters

    Directory of Open Access Journals (Sweden)

    Eliana Isabel Arango Zuluaga

    2014-01-01

    Full Text Available The asymmetrical interleaved dual boost (AIDB is a fifth-order DC/DC converter designed to interface photovoltaic (PV panels. The AIDB produces small current harmonics to the PV panels, reducing the power losses caused by the converter operation. Moreover, the AIDB provides a large voltage conversion ratio, which is required to step-up the PV voltage to the large dc-link voltage used in grid-connected inverters. To reject irradiance and load disturbances, the AIDB must be operated in a closed-loop and a dynamic model is required. Given that the AIDB converter operates in Discontinuous Conduction Mode (DCM, classical modeling approaches based on Continuous Conduction Mode (CCM are not valid. Moreover, classical DCM modeling techniques are not suitable for the AIDB converter. Therefore, this paper develops a novel mathematical model for the AIDB converter, which is suitable for control-pur-poses. The proposed model is based on the calculation of a diode current that is typically disregarded. Moreover, because the traditional correction to the second duty cycle reported in literature is not effective, a new equation is designed. The model accuracy is contrasted with circuital simulations in time and frequency domains, obtaining satisfactory results. Finally, the usefulness of the model in control applications is illustrated with an application example.

  8. Asymmetric Supercapacitor Electrodes and Devices.

    Science.gov (United States)

    Choudhary, Nitin; Li, Chao; Moore, Julian; Nagaiah, Narasimha; Zhai, Lei; Jung, Yeonwoong; Thomas, Jayan

    2017-06-01

    The world is recently witnessing an explosive development of novel electronic and optoelectronic devices that demand more-reliable power sources that combine higher energy density and longer-term durability. Supercapacitors have become one of the most promising energy-storage systems, as they present multifold advantages of high power density, fast charging-discharging, and long cyclic stability. However, the intrinsically low energy density inherent to traditional supercapacitors severely limits their widespread applications, triggering researchers to explore new types of supercapacitors with improved performance. Asymmetric supercapacitors (ASCs) assembled using two dissimilar electrode materials offer a distinct advantage of wide operational voltage window, and thereby significantly enhance the energy density. Recent progress made in the field of ASCs is critically reviewed, with the main focus on an extensive survey of the materials developed for ASC electrodes, as well as covering the progress made in the fabrication of ASC devices over the last few decades. Current challenges and a future outlook of the field of ASCs are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Bioinspired smart asymmetric nanochannel membranes.

    Science.gov (United States)

    Zhang, Zhen; Wen, Liping; Jiang, Lei

    2018-01-22

    Bioinspired smart asymmetric nanochannel membranes (BSANM) have been explored extensively to achieve the delicate ionic transport functions comparable to those of living organisms. The abiotic system exhibits superior stability and robustness, allowing for promising applications in many fields. In view of the abundance of research concerning BSANM in the past decade, herein, we present a systematic overview of the development of the state-of-the-art BSANM system. The discussion is focused on the construction methodologies based on raw materials with diverse dimensions (i.e. 0D, 1D, 2D, and bulk). A generic strategy for the design and construction of the BSANM system is proposed first and put into context with recent developments from homogeneous to heterogeneous nanochannel membranes. Then, the basic properties of the BSANM are introduced including selectivity, gating, and rectification, which are associated with the particular chemical and physical structures. Moreover, we summarized the practical applications of BSANM in energy conversion, biochemical sensing and other areas. In the end, some personal opinions on the future development of the BSANM are briefly illustrated. This review covers most of the related literature reported since 2010 and is intended to build up a broad and deep knowledge base that can provide a solid information source for the scientific community.

  10. Reflection asymmetric shapes in nuclei

    International Nuclear Information System (INIS)

    Ahmad, I.; Carpenter, M.P.; Emling, H.

    1989-01-01

    Experimental data show that there is no even-even nucleus with a reflection asymmetric shape in its ground state. Maximum octupole- octupole correlations occur in nuclei in the mass 224 (N∼134, Z∼88) region. Parity doublets, which are the characteristic signature of octupole deformation, have been observed in several odd mass Ra, Ac and Pa nuclei. Intertwined negative and positive parity levels have been observed in several even-even Ra and Th nuclei above spin ∼8ℎ. In both cases, the opposite parity states are connected by fast El transitions. In some medium-mass nuclei intertwined negative and positive parity levels have also been observed above spin ∼7ℎ. The nuclei which exhibit octupole deformation in this mass region are 144 Ba, 146 Ba and 146 Ce; 142 Ba, 148 Ce, 150 Ce and 142 Xe do not show these characteristics. No case of parity doublet has been observed in the mass 144 region. 32 refs., 16 figs., 1 tab

  11. Twin Higgs Asymmetric Dark Matter.

    Science.gov (United States)

    García García, Isabel; Lasenby, Robert; March-Russell, John

    2015-09-18

    We study asymmetric dark matter (ADM) in the context of the minimal (fraternal) twin Higgs solution to the little hierarchy problem, with a twin sector with gauged SU(3)^{'}×SU(2)^{'}, a twin Higgs doublet, and only third-generation twin fermions. Naturalness requires the QCD^{'} scale Λ_{QCD}^{'}≃0.5-20  GeV, and that t^{'} is heavy. We focus on the light b^{'} quark regime, m_{b^{'}}≲Λ_{QCD}^{'}, where QCD^{'} is characterized by a single scale Λ_{QCD}^{'} with no light pions. A twin baryon number asymmetry leads to a successful dark matter (DM) candidate: the spin-3/2 twin baryon, Δ^{'}∼b^{'}b^{'}b^{'}, with a dynamically determined mass (∼5Λ_{QCD}^{'}) in the preferred range for the DM-to-baryon ratio Ω_{DM}/Ω_{baryon}≃5. Gauging the U(1)^{'} group leads to twin atoms (Δ^{'}-τ^{'}[over ¯] bound states) that are successful ADM candidates in significant regions of parameter space, sometimes with observable changes to DM halo properties. Direct detection signatures satisfy current bounds, at times modified by dark form factors.

  12. Lift production through asymmetric flapping

    Science.gov (United States)

    Jalikop, Shreyas; Sreenivas, K. R.

    2009-11-01

    At present, there is a strong interest in developing Micro Air Vehicles (MAV) for applications like disaster management and aerial surveys. At these small length scales, the flight of insects and small birds suggests that unsteady aerodynamics of flapping wings can offer many advantages over fixed wing flight, such as hovering-flight, high maneuverability and high lift at large angles of attack. Various lift generating mechanims such as delayed stall, wake capture and wing rotation contribute towards our understanding of insect flight. We address the effect of asymmetric flapping of wings on lift production. By visualising the flow around a pair of rectangular wings flapping in a water tank and numerically computing the flow using a discrete vortex method, we demonstrate that net lift can be produced by introducing an asymmetry in the upstroke-to-downstroke velocity profile of the flapping wings. The competition between generation of upstroke and downstroke tip vortices appears to hold the key to understanding this lift generation mechanism.

  13. The Role of Protein Arginine Methyltransferases in Inflammatory Responses

    Directory of Open Access Journals (Sweden)

    Ji Hye Kim

    2016-01-01

    Full Text Available Protein arginine methyltransferases (PRMTs mediate the methylation of a number of protein substrates of arginine residues and serve critical functions in many cellular responses, including cancer development, progression, and aggressiveness, T-lymphocyte activation, and hepatic gluconeogenesis. There are nine members of the PRMT family, which are divided into 4 types (types I–IV. Although most PRMTs do not require posttranslational modification (PTM to be activated, fine-tuning modifications, such as interactions between cofactor proteins, subcellular compartmentalization, and regulation of RNA, via micro-RNAs, seem to be required. Inflammation is an essential defense reaction of the body to eliminate harmful stimuli, including damaged cells, irritants, or pathogens. However, chronic inflammation can eventually cause several types of diseases, including some cancers, atherosclerosis, rheumatoid arthritis, and periodontitis. Therefore, inflammation responses should be well modulated. In this review, we briefly discuss the role of PRMTs in the control of inflammation. More specifically, we review the roles of four PRMTs (CARM1, PRMT1, PRMT5, and PRMT6 in modulating inflammation responses, particularly in terms of modulating the transcriptional factors or cofactors related to inflammation. Based on the regulatory roles known so far, we propose that PRMTs should be considered one of the target molecule groups that modulate inflammatory responses.

  14. Agmatine: multifunctional arginine metabolite and magic bullet in clinical neuroscience?

    Science.gov (United States)

    Laube, Gregor; Bernstein, Hans-Gert

    2017-07-26

    Agmatine, the decarboxylation product of arginine, was largely neglected as an important player in mammalian metabolism until the mid-1990s, when it was re-discovered as an endogenous ligand of imidazoline and α 2 -adrenergic receptors. Since then, a wide variety of agmatine-mediated effects have been observed, and consequently agmatine has moved from a wallflower existence into the limelight of clinical neuroscience research. Despite this quantum jump in scientific interest, the understanding of the anabolism and catabolism of this amine is still vague. The purification and biochemical characterization of natural mammalian arginine decarboxylase and agmatinase still are open issues. Nevertheless, the agmatinergic system is currently one of the most promising candidates in order to pharmacologically interfere with some major diseases of the central nervous system, which are summarized in the present review. Particularly with respect to major depression, agmatine, its derivatives, and metabolizing enzymes show great promise for the development of an improved treatment of this common disease. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

  15. Arginine Vasotocin, the Social Neuropeptide of Amphibians and Reptiles.

    Science.gov (United States)

    Wilczynski, Walter; Quispe, Maricel; Muñoz, Matías I; Penna, Mario

    2017-01-01

    Arginine vasotocin (AVT) is the non-mammalian homolog of arginine vasopressin (AVP) and, like vasopressin, serves as an important modulator of social behavior in addition to its peripheral functions related to osmoregulation, reproductive physiology, and stress hormone release. In amphibians and reptiles, the neuroanatomical organization of brain AVT cells and fibers broadly resembles that seen in mammals and other taxa. Both parvocellular and magnocellular AVT-containing neurons are present in multiple populations located mainly in the basal forebrain from the accumbens-amygdala area to the preoptic area and hypothalamus, from which originate widespread fiber connections spanning the brain with a particularly heavy innervation of areas associated with social behavior and decision-making. As for mammalian AVP, AVT is present in greater amounts in males in many brain areas, and its presence varies seasonally, with hormonal state, and in males with differing social status. AVT's social influence is also conserved across herpetological taxa, with significant effects on social signaling and aggression, and, based on the very small number of studies investigating more complex social behaviors in amphibians and reptiles, AVT may also modulate parental care and social bonding when it is present in these vertebrates. Within this conserved pattern, however, both AVT anatomy and social behavior effects vary significantly across species. Accounting for this diversity represents a challenge to understanding the mechanisms by which AVT exerts its behavioral effects, as well are a potential tool for discerning the structure-function relationships underlying AVT's many effects on behavior.

  16. PRmePRed: A protein arginine methylation prediction tool.

    Directory of Open Access Journals (Sweden)

    Pawan Kumar

    Full Text Available Protein methylation is an important Post-Translational Modification (PTMs of proteins. Arginine methylation carries out and regulates several important biological functions, including gene regulation and signal transduction. Experimental identification of arginine methylation site is a daunting task as it is costly as well as time and labour intensive. Hence reliable prediction tools play an important task in rapid screening and identification of possible methylation sites in proteomes. Our preliminary assessment using the available prediction methods on collected data yielded unimpressive results. This motivated us to perform a comprehensive data analysis and appraisal of features relevant in the context of biological significance, that led to the development of a prediction tool PRmePRed with better performance. The PRmePRed perform reasonably well with an accuracy of 84.10%, 82.38% sensitivity, 83.77% specificity, and Matthew's correlation coefficient of 66.20% in 10-fold cross-validation. PRmePRed is freely available at http://bioinfo.icgeb.res.in/PRmePRed/.

  17. 1,3-Dimethyl-1H-indole-2-carbonitrile

    Directory of Open Access Journals (Sweden)

    Jiang-Sheng Li

    2009-08-01

    Full Text Available The title compound, C11H10N2, crystallizes with two molecules in the asymmetric unit, both of which are essentially planar (r.m.s. deviations = 0.014 and 0.016 Å. In the crystal, aromatic π–π stacking interactions occur [shortest centroid–centroid separation = 3.5569 (11 Å].

  18. Crystal structure of μ-oxalato-κ2O1:O2-bis[(dimethyl sulfoxide-κOtriphenyltin(IV

    Directory of Open Access Journals (Sweden)

    Serigne Fallou Pouye

    2017-07-01

    Full Text Available In the previously reported [C2O4(SnPh32] complex [Diop et al. (2003. Appl. Organomet. Chem. 17, 881–882.], the SnIV atoms are able to formally complete their coordination by addition of dimethyl sulfoxide (DMSO molecules provided by the reaction medium, affording the title complex, [Sn2(C6H56(C2O4(C2H6OS2]. The SnIV atoms are then pentacoordinated, with a common trans trigonal–bipyramidal arrangement. The asymmetric unit contains one half-molecule, which is completed by inversion symmetry in space group type C2/c. The inversion centre is placed at the mid-point of the central bis-monodentate oxalate dianion, C2O42−, which bridges the [(SnPh3(DMSO] moieties. The molecule crystallizes as a disordered system, with two phenyl rings disordered by rotation about their Sn—C bonds, while the DMSO molecule is split over two positions due to a tetrahedral inversion at the S atom. All disordered parts were refined with occupancies fixed of 0.5.

  19. The do's and don'ts of arginine supplementation | Chetty | South ...

    African Journals Online (AJOL)

    In the last three decades the nutritional and pharmacologic effects of arginine have been the subject of intense investigation. Taking into consideration the many benefits that have been demonstrated from arginine supplementation, the question remains: “Can we afford not to supplement with this immuno-nutrient”.

  20. Radioimmunoassay of [8-D-arginine] deamino-vasopressin (dDAVP)

    International Nuclear Information System (INIS)

    Slaninova, J.; Barth, T.

    1978-01-01

    Specific antibodies to [8-D-arginine] deamino-vasopressin (dDAVP) were prepared by immunizing pigs with the conjugate of [8-D-arginine] vasopressin (DVAP) and rabbit immunoglobulin. The specificity of the antibodies was studied by comparing their cross-reactivity with 20 analogues of neurohypophysial hormones. The sensitivity of the developed radioimmunoassay was 30 pg/ml. (authors)

  1. Multiple Arginine Residues Are Methylated in Drosophila Mre11 and Required for Survival Following Ionizing Radiation.

    Science.gov (United States)

    Yuan, Qing; Tian, Ran; Zhao, Haiying; Li, Lijuan; Bi, Xiaolin

    2018-05-31

    Mre11 is a key player for DNA double strand break repair. Previous studies have shown that mammalian Mre11 is methylated at multiple arginines in its C-terminal Glycine-Arginine-Rich motif (GAR) by protein arginine methyltransferase PRMT1. Here, we found that the Drosophila Mre11 is methylated at arginines 559, 563, 565, and 569 in the GAR motif by DART1, the Drosophila homolog of PRMT1. Mre11 interacts with DART1 in S2 cells, and this interaction does not require the GAR motif. Arginines methylated Mre11 localizes exclusively in the nucleus as soluble nuclear protein or chromatin-binding protein. To study the in vivo functions of methylation, we generated the single Arg-Ala and all Arginines mutated flies. We found these mutants were sensitive to ionizing radiation. Furthermore, Arg-Ala mutated flies had no irradiation induced G2/M checkpoint defect in wing disc and eye disc. Thus, we provided evidence that arginines in Drosophila Mre11 are methylated by DART1 methytransferase and flies loss of arginine methylation are sensitive to irradiation. Copyright © 2018 Yuan et al.

  2. L-arginine increases nitric oxide and attenuates pressor and heart ...

    African Journals Online (AJOL)

    olayemitoyin

    heart rate responses to change in posture in sickle cell anemia subjects. 1 .... the standing position and measurements made immediately. Arterial ... pressure was the difference between systolic and diastolic ... Table 3. Effect of L-Arginine Supplementation on Blood Pressure Parameters, Plasma L-Arginine and Nitric Oxide.

  3. Synthesis, characterization and behaviour of trans-bis (argininate) copper (II) to gamma radiation

    International Nuclear Information System (INIS)

    Pereira, A.B.

    1984-01-01

    The synthesis, the characterization and the behaviour to gamma radiation of trans-bis (argininate) copper (II) are presented. The synthesis is made from copper sulfate, sodium hydroxide and hydrochloride of L (+) arginine, in aqueous medium, and the characterization by infrared spectroscopy, visible and ultraviolet spectroscopy and elementary analysis. (C.G.C.)

  4. An efficient catalyst for asymmetric Reformatsky reaction

    Indian Academy of Sciences (India)

    rate enantioselectivity using N,N-dialkylnorephedrines as chiral ligands. ..... temperatures also, there was no product conversion. ... Optimization of reaction conditions for asymmetric Reformatsky reaction between benzaldehyde and α-.

  5. Asymmetric cryptography based on wavefront sensing.

    Science.gov (United States)

    Peng, Xiang; Wei, Hengzheng; Zhang, Peng

    2006-12-15

    A system of asymmetric cryptography based on wavefront sensing (ACWS) is proposed for the first time to our knowledge. One of the most significant features of the asymmetric cryptography is that a trapdoor one-way function is required and constructed by analogy to wavefront sensing, in which the public key may be derived from optical parameters, such as the wavelength or the focal length, while the private key may be obtained from a kind of regular point array. The ciphertext is generated by the encoded wavefront and represented with an irregular array. In such an ACWS system, the encryption key is not identical to the decryption key, which is another important feature of an asymmetric cryptographic system. The processes of asymmetric encryption and decryption are formulized mathematically and demonstrated with a set of numerical experiments.

  6. Asymmetrical Representation of Gender in Amharic1

    African Journals Online (AJOL)

    Administrator

    in its grammar. Gender representation in this language is asymmetrical heavily ..... In dictionaries where. Amharic appears either as the target or the source language, verbs are entered ...... The Dialects of Amharic Revisited. Semitica et.

  7. Beam-beam issues in asymmetric colliders

    International Nuclear Information System (INIS)

    Furman, M.A.

    1992-07-01

    We discuss generic beam-beam issues for proposed asymmetric e + - e - colliders. We illustrate the issues by choosing, as examples, the proposals by Cornell University (CESR-B), KEK, and SLAC/LBL/LLNL (PEP-II)

  8. Congenital asymmetric crying face: a case report

    Directory of Open Access Journals (Sweden)

    Semra Kara

    2011-12-01

    Full Text Available Congenital asymmetric crying face is an anomalia caused by unilateral absence or weakness of depressor anguli oris muscle The major finding of the disease is the absence or weakness in the outer and lower movement of the commissure during crying. The other expression muscles are normal and the face is symmetric at rest. The asymmetry in congenital asymmetric crying face is most evident during infancy but decreases by age. Congenital asymmetric crying face can be associated with cervicofacial, musclebone, respiratory, genitourinary and central nervous system anomalia. It is diagnosed by physical examination. This paper presents a six days old infant with Congenital asymmetric crying face and discusses the case in terms of diagnosis and disease features.

  9. Asymmetric total synthesis of cladosporin and isocladosporin.

    Science.gov (United States)

    Zheng, Huaiji; Zhao, Changgui; Fang, Bowen; Jing, Peng; Yang, Juan; Xie, Xingang; She, Xuegong

    2012-07-06

    The first asymmetric total syntheses of cladosporin and isocladosporin were accomplished in 8 steps with 8% overall yield and 10 steps with 26% overall yield, respectively. The relative configuration of isocladosporin was determined via this total synthesis.

  10. Magnetically Modified Asymmetric Supercapacitors, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project is for the development of an asymmetric supercapacitor that will have improved energy density and cycle life....

  11. The ArcD1 and ArcD2 arginine/ornithine exchangers encoded in the arginine deiminase (ADI) pathway gene cluster of Lactococcus lactis

    NARCIS (Netherlands)

    Noens, Elke E E; Kaczmarek, Michał B; Żygo, Monika; Lolkema, Juke S

    2015-01-01

    The arginine deiminase pathway (ADI) gene cluster in Lactococcus lactis contains two copies of a gene encoding an L-arginine/L-ornithine exchanger, the arcD1 and arcD2 genes. The physiological function of ArcD1 and ArcD2 was studied by deleting the two genes. Deletion of arcD1 resulted in loss of

  12. Cell surface binding and uptake of arginine- and lysine-rich penetratin peptides in absence and presence of proteoglycans

    KAUST Repository

    Å mand, Helene L.; Rydberg, Hanna A.; Fornander, Louise H.; Lincoln, Per; Nordé n, Bengt; Esbjö rner, Elin K.

    2012-01-01

    Cell surface proteoglycans (PGs) appear to promote uptake of arginine-rich cell-penetrating peptides (CPPs), but their exact functions are unclear. To address if there is specificity in the interactions of arginines and PGs leading to improved

  13. Impact of Secondary Interactions in Asymmetric Catalysis

    OpenAIRE

    Frölander, Anders

    2007-01-01

    This thesis deals with secondary interactions in asymmetric catalysis and their impact on the outcome of catalytic reactions. The first part revolves around the metal-catalyzed asymmetric allylic alkylation reaction and how interactions within the catalyst affect the stereochemistry. An OH–Pd hydrogen bond in Pd(0)–π-olefin complexes of hydroxy-containing oxazoline ligands was identified by density functional theory computations and helped to rationalize the contrasting results obtained emplo...

  14. Engineered Asymmetric Composite Membranes with Rectifying Properties.

    Science.gov (United States)

    Wen, Liping; Xiao, Kai; Sainath, Annadanam V Sesha; Komura, Motonori; Kong, Xiang-Yu; Xie, Ganhua; Zhang, Zhen; Tian, Ye; Iyoda, Tomokazu; Jiang, Lei

    2016-01-27

    Asymmetric composite membranes with rectifying properties are developed by grafting pH-stimulus-responsive materials onto the top layer of the composite structure, which is prepared by two novel block copolymers using a phase-separation technique. This engineered asymmetric composite membrane shows potential applications in sensors, filtration, and nanofluidic devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. The role of the arginine metabolome in pain: implications for sickle cell disease

    Directory of Open Access Journals (Sweden)

    Bakshi N

    2016-03-01

    Full Text Available Nitya Bakshi,1–2 Claudia R Morris3–6 1Division of Pediatric Hematology-Oncology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA; 2Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Atlanta, GA, USA; 3Division of Pediatric Emergency Medicine, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA; 4Department of Emergency Medicine, Emory University School of Medicine, Atlanta, GA, USA; 5Emory-Children’s Center for Cystic Fibrosis and Airways Disease Research, Emory University School of Medicine, Atlanta, GA, USA; 6Pediatric Emergency Medicine, Children’s Healthcare of Atlanta, Atlanta, GA, USA Abstract: Sickle cell disease (SCD is the most common hemoglobinopathy in the US, affecting approximately 100,000 individuals in the US and millions worldwide. Pain is the hallmark of SCD, and a subset of patients experience pain virtually all of the time. Of interest, the arginine metabolome is associated with several pain mechanisms highlighted in this review. Since SCD is an arginine deficiency syndrome, the contribution of the arginine metabolome to acute and chronic pain in SCD is a topic in need of further attention. Normal arginine metabolism is impaired in SCD through various mechanisms that contribute to endothelial dysfunction, vaso-occlusion, pulmonary complications, risk of leg ulcers, and early mortality. Arginine is a semiessential amino acid that serves as a substrate for protein synthesis and is the precursor to nitric oxide (NO, polyamines, proline, glutamate, creatine, and agmatine. Since arginine is involved in multiple metabolic processes, a deficiency of this amino acid has the potential to disrupt many cellular and organ functions. NO is a potent vasodilator that is depleted in SCD and may contribute to vaso-occlusive pain. As the obligate substrate for NO production, arginine also plays a mechanistic role in SCD-related pain, although its

  16. Changes in Dimethyl Sulfide Oceanic Distribution due to Climate Change

    Energy Technology Data Exchange (ETDEWEB)

    Cameron-Smith, P; Elliott, S; Maltrud, M; Erickson, D; Wingenter, O

    2011-02-16

    Dimethyl sulfide (DMS) is one of the major precursors for aerosols and cloud condensation nuclei in the marine boundary layer over much of the remote ocean. Here they report on coupled climate simulations with a state-of-the-art global ocean biogeochemical model for DMS distribution and fluxes using present-day and future atmospheric CO{sub 2} concentrations. They find changes in zonal averaged DMS flux to the atmosphere of over 150% in the Southern Ocean. This is due to concurrent sea ice changes and ocean ecosystem composition shifts caused by changes in temperature, mixing, nutrient, and light regimes. The largest changes occur in a region already sensitive to climate change, so any resultant local CLAW/Gaia feedback of DMS on clouds, and thus radiative forcing, will be particularly important. A comparison of these results to prior studies shows that increasing model complexity is associted with reduced DMS emissions at the equator and increased emissions at high latitudes.

  17. Synthesis pf dimethyl carbonate in supercritical carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Ballivet-Tkatchenko, D.; Plasseraud, L. [Universite de Bourgogne-UFR Sciences et Techniques, Dijon (France). Lab. de Synthese et Electrosynthese Organometalliques]. E-mail: ballivet@u-bourgogne.fr; Ligabue, R.A. [Pontificia Univ. Catolica do Rio Grande do Sul, Porto Alegre, RS (Brazil). Dept. de Quimica Pura

    2006-01-15

    The reactivity of carbon dioxide with methanol to form dimethyl carbonate was studied in the presence of the n-butylmethoxytin compounds n-Bu{sub 3}SnOCH{sub 3}, n-Bu{sub 2}Sn(OCH{sub 3}){sub 2}, and [n-Bu{sub 2}(CH{sub 3}O)Sn]{sub 2}O. The reaction occurred under solventless conditions at 423 K and was produced by an increase in CO{sub 2} pressure. This beneficial effect is primarily attributed to phase behavior. The mass transfer under liquid-vapor biphasic conditions was not limiting when the system reached the supercritical state for a CO{sub 2} pressure higher than 16 MPa. Under these conditions, CO{sub 2} acted as a reactant and a solvent. (author)

  18. Adducts of rare earth tris-acetylacetonates with dimethyl sulfoxide

    International Nuclear Information System (INIS)

    Dzyubenko, N.G.; Kalenichenko, Yu.V.; Martynenko, L.I.

    1988-01-01

    Adducts of rare earth and yttrium (r.e.e., M) acetylacetonates with dimethyl sulfoxide (DMSO), MA 3 xnDMSO are synthesized. The acetylacetonates of light r.e.e. (M=La-Tb) are shown by different physico-chemical methods to form diadducts of the MA 3 x2DMSOxH 2 O composition, where A - -acetylacetonate-ion, and the acetyl-acetonates of heavy r.e.e. (M=Dy-Lu, Y)-monoadducts MA 3 xDMSO. The estimation of adduct thermal stability is carried out using the values of seeming activation energy of their thermal degradation. Monoadducts are shown to give volatile forms of rare earth acetylacetonates during heating in vacuum, and diadducts do not form volatile forms of acetylacetonates

  19. Fragmentation of dimethyl ether in femtosecond intense field

    Science.gov (United States)

    Zhu, Jingyi; Guo, Wei; Wang, Yanqiu; Wang, Li

    2006-08-01

    The fragmentation of dimethyl ether (DME) in intense femtosecond laser field has been studied at 810, 405 and 270 nm with intensities up to 2.48 × 10 15, 3.86 × 10 15 and 1.62 × 10 14 W/cm 2, respectively. At 405 nm, DME is possibly firstly ionized by multiphoton absorption, and then parent ion DME + dissociates into fragments via filed-induced dissociation. For 810 and 270 nm laser fields, DME firstly dissociates into CH 3O and CH 3 fragments and then these neutral fragments are ionized by field tunneling. Another possible way for DME to dissociate at 810 and 270 nm is that DME is ionized by intense field ejection of inner valance electron and then the excited DME + dissociates into fragment ions. Ultrafast rearrangement of DME or DME + in intense field may be responsible to the unpredictable fragment ions, CHO+/C2H5+andH2+.

  20. DFT Study of dimers of dimethyl sulfoxide in gas phase

    Directory of Open Access Journals (Sweden)

    Reza Fazaeli

    2014-10-01

    Full Text Available Density functional (DFT calculations at M05-2x/aug-cc-pVDZ level were used to analyze the interactions between dimethyl sulfoxide (DMSO dimers. The structures obtained have been ana-lyzed with the Atoms in Molecules (AIMs and Natural Bond Orbital (NBO methodologies. Four minima were located on the potential energy surface of the dimers. Three types of interac-tions are observed, CH•••O, CH•••S hydrogen bonds and orthogonal interaction between the lone pair of the oxygen with the electron-deficient region of the sulfur atom. Stabilization energies of dimers including BSSE and ZPE are in the range 27–40 kJmol-1. The most stable conformers of dimers at DFT level is cyclic structure with antiparallel orientation of S=O groups pairing with three C–H∙∙∙O and a S∙∙∙O interactions.

  1. Crystal structure of dichloridobis(dimethyl N-cyanodithioiminocarbonatecobalt(II

    Directory of Open Access Journals (Sweden)

    Mouhamadou Birame Diop

    2016-01-01

    Full Text Available The structure of the mononuclear title complex, [{(H3CS2C=NC[triple-bond] N}2CoCl2], consists of a CoII atom coordinated in a distorted tetrahedral manner by two Cl− ligands and the terminal N atoms of two dimethyl N-cyanodithioiminocarbonate ligands. The two organic ligands are almost coplanar, with a dihedral angle of 5.99 (6° between their least-squares planes. The crystal packing features pairs of inversion-related complexes that are held together through C—H...Cl and C—H...S interactions and π–π stacking [centroid-to-centroid distance = 3.515 (su? Å]. Additional C—H...Cl and C—H...S interactions, as well as Cl...S contacts < 3.6 Å, consolidate the crystal packing.

  2. Homogeneous Charge Compression Ignition Combustion of Dimethyl Ether

    DEFF Research Database (Denmark)

    Pedersen, Troels Dyhr

    This thesis is based on experimental and numerical studies on the use of dimethyl ether (DME) in the homogeneous charge compression ignition (HCCI) combustion process. The first paper in this thesis was published in 2007 and describes HCCI combustion of pure DME in a small diesel engine. The tests...... were designed to investigate the effect of engine speed, compression ratio and equivalence ratio on the combustion timing and the engine performance. It was found that the required compression ratio depended on the equivalence ratio used. A lower equivalence ratio requires a higher compression ratio...... before the fuel is burned completely, due to lower in-cylinder temperatures and lower reaction rates. The study provided some insight in the importance of operating at the correct compression ratio, as well as the operational limitations and emission characteristics of HCCI combustion. HCCI combustion...

  3. Direct dimethyl ether high temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Vassiliev, Anton; Jensen, Jens Oluf; Li, Qingfeng

    and suffers from low DME solubility in water. When the DME - water mixture is fed as vapour miscibility is no longer a problem. The increased temperature is more beneficial for the kinetics of the direct oxidation of DME than of methanol. The Open Circuit Voltage (OCV) with DME operation was 50 to 100 m......A high temperature polybenzimidazole (PBI) polymer fuel cell was fed with dimethyl ether (DME) and water vapour mixture on the anode at ambient pressure with air as oxidant. A peak power density of 79 mW/cm2 was achieved at 200°C. A conventional polymer based direct DME fuel cell is liquid fed......V higher than that of methanol, indicating less fuel crossover....

  4. Accumulation of Citrulline by Microbial Arginine Metabolism during Alcoholic Fermentation of Soy Sauce.

    Science.gov (United States)

    Fang, Fang; Zhang, Jiran; Zhou, Jingwen; Zhou, Zhaohui; Li, Tieqiao; Lu, Liling; Zeng, Weizhu; Du, Guocheng; Chen, Jian

    2018-03-07

    Citrulline, the major precursor of ethyl carbamate in soy sauce, is an intermediate catabolite of arginine produced by bacteria present in soy sauce moromi mash. Pediococcus acidilactici is responsible for the formation of citrulline during the lactic acid fermentation process of soy sauce. However, citrulline accumulation during the alcoholic fermentation process and the corresponding bacteria involved have not been identified. Salt-tolerant, arginine-utilizing bacteria were isolated from moromi mash during the alcoholic fermentation process. Under normal cultivation conditions, arginine utilization by these strains did not contribute to citrulline accumulation. However, the conversion of arginine to citrulline by these bacteria increased when cultivated during the alcoholic fermentation process. Additionally, the ethanol-enhanced solubility of free fatty acids in moromi mash stimulated the accumulation of citrulline. Staphylococcus exhibited the highest capability in the conversion of arginine to citrulline.

  5. The second case of a young man with L-arginine-induced acute pancreatitis.

    Science.gov (United States)

    Binet, Quentin; Dufour, Inès; Agneessens, Emmanuel; Debongnie, Jean-Claude; Aouattah, Tarik; Covas, Angélique; Coche, Jean-Charles; De Koninck, Xavier

    2018-04-21

    Dietary supplementation of arginine has been used by numerous world-class athletes and professional bodybuilders over the past 30 years. L-Arginine indeed enhances muscular power and general performance via maintaining ATP level. However, L-arginine is also known to induce acute pancreatitis in murine models. We report the case of young man presenting with upper abdominal pain and increased serum lipase levels. Contrast-enhanced computed tomography confirms a mild acute pancreatitis. Common etiologies have been ruled out and toxicological anamnestic screening reveals the intake of protein powder. This is, to the best of our knowledge, the second case in human of arginine-induced acute pancreatitis. This case report suggests that every patient presenting with acute pancreatitis without obvious etiology should be evaluated for the intake of toxics other than alcohol, including L-arginine.

  6. Potentiality of application of the conductometric L-arginine biosensors for the real sample analysis

    Directory of Open Access Journals (Sweden)

    Jaffrezic-Renault N.

    2012-12-01

    Full Text Available Aim. To determine an influence of serum components on the L-arginine biosensor sensitivity and to formulate practical recommendations for its reliable analysis. Methods. The L-arginine biosensor comprised arginase and urease co-immobilized by cross-linking. Results. The biosensor specificity was investigated based on a series of representative studies (namely, through urea determination in the serum; inhibitory effect studies of mercury ions; high temperature treatment of sensors; studying the biosensor sensitivity to the serum treated by enzymes, and selectivity studies. It was found that the response of the biosensor to the serum injections was determined by high sensitivity of the L-arginine biosensor toward not only to L-arginine but also toward two other basic amino acids (L-lysine and L-histidine. Conclusions. A detailed procedure of optimization of the conductometric biosensor for L-arginine determination in blood serum has been proposed.

  7. Effects of Aging and Tocotrienol-Rich Fraction Supplementation on Brain Arginine Metabolism in Rats

    Directory of Open Access Journals (Sweden)

    Musalmah Mazlan

    2017-01-01

    Full Text Available Accumulating evidence suggests that altered arginine metabolism is involved in the aging and neurodegenerative processes. This study sought to determine the effects of age and vitamin E supplementation in the form of tocotrienol-rich fraction (TRF on brain arginine metabolism. Male Wistar rats at ages of 3 and 21 months were supplemented with TRF orally for 3 months prior to the dissection of tissue from five brain regions. The tissue concentrations of L-arginine and its nine downstream metabolites were quantified using high-performance liquid chromatography and liquid chromatography tandem mass spectrometry. We found age-related alterations in L-arginine metabolites in the chemical- and region-specific manners. Moreover, TRF supplementation reversed age-associated changes in arginine metabolites in the entorhinal cortex and cerebellum. Multiple regression analysis revealed a number of significant neurochemical-behavioral correlations, indicating the beneficial effects of TRF supplementation on memory and motor function.

  8. DIMETHYL ETHER (DME)-FUELED SHUTTLE BUS DEMONSTRATION PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Elana M. Chapman; Shirish Bhide; Jennifer Stefanik; Andre L. Boehman; David Klinikowski

    2003-04-01

    The objectives of this research and demonstration program are to convert a campus shuttle bus to operation on dimethyl ether, a potential ultra-clean alternative diesel fuel. To accomplish this objective, this project includes laboratory evaluation of a fuel conversion strategy, as well as, field demonstration of the DME-fueled shuttle bus. Since DME is a fuel with no lubricity (i.e., it does not possess the lubricating quality of diesel fuel), conventional fuel delivery and fuel injection systems are not compatible with dimethyl ether. Therefore, to operate a diesel engine on DME one must develop a fuel-tolerant injection system, or find a way to provide the necessary lubricity to the DME. In this project, they have chosen the latter strategy in order to achieve the objective with minimal need to modify the engine. The strategy is to blend DME with diesel fuel, to obtain the necessary lubricity to protect the fuel injection system and to achieve low emissions. The laboratory studies have included work with a Navistar V-8 turbodiesel engine, demonstration of engine operation on DME-diesel blends and instrumentation for evaluating fuel properties. The field studies have involved performance, efficiency and emissions measurements with the Champion Motorcoach ''Defender'' shuttle bus which will be converted to DME-fueling. The results include baseline emissions, performance and combustion measurements on the Navistar engine for operation on a federal low sulfur diesel fuel (300 ppm S). Most recently, they have completed engine combustion studies on DME-diesel blends up to 30 wt% DME addition.

  9. L-arginine prevents xanthoma development and inhibits atherosclerosis in LDL receptor knockout mice.

    Science.gov (United States)

    Aji, W; Ravalli, S; Szabolcs, M; Jiang, X C; Sciacca, R R; Michler, R E; Cannon, P J

    1997-01-21

    The potential antiatherosclerotic actions of NO were investigated in four groups of mice (n = 10 per group) lacking functional LDL receptor genes, an animal model of familial hypercholesterolemia. Group 1 was fed a regular chow diet. Groups 2 through 4 were fed a 1.25% high-cholesterol diet. In addition, group 3 received supplemental L-arginine and group 4 received L-arginine and N omega-nitro-L-arginine (L-NA), an inhibitor of NO synthase (NOS). Animals were killed at 6 months; aortas were stained with oil red O for planimetry and with antibodies against constitutive and inducible NOSs. Plasma cholesterol was markedly increased in the animals receiving the high-cholesterol diet. Xanthomas appeared in all mice fed the high-cholesterol diet alone but not in those receiving L-arginine. Aortic atherosclerosis was present in all mice on the high-cholesterol diet. The mean atherosclerotic lesion area was reduced significantly (P < .01) in the cholesterol-fed mice given L-arginine compared with those receiving the high-cholesterol diet alone. The mean atherosclerotic lesion area was significantly larger (P < .01) in cholesterol-fed mice receiving L-arginine + L-NA than in those on the high-cholesterol diet alone. Within the atherosclerotic plaques, endothelial cells immunoreacted for endothelial cell NOS; macrophages, foam cells, and smooth muscle cells immunostained strongly for inducible NOS and nitrotyrosine residues. The data indicate that L-arginine prevents xanthoma formation and reduces atherosclerosis in LDL receptor knockout mice fed a high-cholesterol diet. The abrogation of the beneficial effects of L-arginine by L-NA suggests that the antiatherosclerotic actions of L-arginine are mediated by NOS. The data suggest that L-arginine may be beneficial in familial hypercholesterolemia.

  10. Stationary phase expression of the arginine biosynthetic operon argCBH in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Sun Yuan

    2006-02-01

    Full Text Available Abstract Background Arginine biosynthesis in Escherichia coli is elevated in response to nutrient limitation, stress or arginine restriction. Though control of the pathway in response to arginine limitation is largely modulated by the ArgR repressor, other factors may be involved in increased stationary phase and stress expression. Results In this study, we report that expression of the argCBH operon is induced in stationary phase cultures and is reduced in strains possessing a mutation in rpoS, which encodes an alternative sigma factor. Using strains carrying defined argR, and rpoS mutations, we evaluated the relative contributions of these two regulators to the expression of argH using operon-lacZ fusions. While ArgR was the main factor responsible for modulating expression of argCBH, RpoS was also required for full expression of this biosynthetic operon at low arginine concentrations (below 60 μM L-arginine, a level at which growth of an arginine auxotroph was limited by arginine. When the argCBH operon was fully de-repressed (arginine limited, levels of expression were only one third of those observed in ΔargR mutants, indicating that the argCBH operon is partially repressed by ArgR even in the absence of arginine. In addition, argCBH expression was 30-fold higher in ΔargR mutants relative to levels found in wild type, fully-repressed strains, and this expression was independent of RpoS. Conclusion The results of this study indicate that both derepression and positive control by RpoS are required for full control of arginine biosynthesis in stationary phase cultures of E. coli.

  11. Poly-L-arginine: Enhancing Cytotoxicity and Cellular Uptake of Doxorubicin and Necrotic Cell Death.

    Science.gov (United States)

    Movafegh, Bahareh; Jalal, Razieh; Mohammadi, Zobeideh; Aldaghi, Seyyede Araste

    2018-04-11

    Cell resistance to doxorubicin and its toxicity to healthy tissue reduce its efficiency. The use of cell penetrating peptides as drug delivery system along with doxorubicin is a strategy to reduce its side effects. In this study, the influence of poly-L-arginine on doxorubicin cytotoxicity, its cellular uptake and doxorubicin-induced apoptosis on human prostate cancer DU145 cells are assessed. The cytotoxicity of doxorubicin and poly-L-arginine, alone and in combination, in DU145 cells was evaluated at different exposure times using MTT assay. The influence of poly-L-arginine on doxorubicin delivery into cells was evaluated by fluorescence microscopy and ultraviolet spectroscopy. DAPI and ethidium bromide-acridine orange stainings, flow cytometry using annexin V/propidium iodide, western blot analysis with anti-p21 antibody and caspase-3 activity were used to examine the influence of poly-L-arginine on doxorubicin-induced cell death. Poly-L-arginine had no cytotoxicity at low concentrations and short exposure times. Poly-L-arginine increased the cytotoxic effect of doxorubicin in DU145 cells in a time-dependent manner. But no significant reduction was found in HFF cell viability. Poly-L-arginine seems to facilitate doxorubicin uptake and increase its intracellular concentration. 24 h combined treatment of cells with doxorubicin (0.5 μM) and poly-L-arginine (1 μg ml-1) caused a small increase in doxorubicin-induced apoptosis and significant elevated necrosis in DU145 cells as compared to each agent alone. Conlusion: Our results indicate that poly-L-arginine at lowest and highest concentrations act as proliferation-inducing and antiproliferative agents, respectively. Between these concentrations, poly-L-arginine increases the cellular uptake of doxorubicin and its cytotoxicity through induction of necrosis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  12. Altered Nitrogen Balance and Decreased Urea Excretion in Male Rats Fed Cafeteria Diet Are Related to Arginine Availability

    Directory of Open Access Journals (Sweden)

    David Sabater

    2014-01-01

    rats, but low arginine levels point to a block in the urea cycle between ornithine and arginine, thereby preventing the elimination of excess nitrogen as urea. The ultimate consequence of this paradoxical block in the urea cycle seems to be the limitation of arginine production and/or availability.

  13. Natural 4-Hydroxy-2,5-dimethyl-3(2H)-furanone (Furaneol®)

    OpenAIRE

    Wilfried Schwab

    2013-01-01

    4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF, furaneol®) and its methyl ether 2,5-dimethyl-4-methoxy-3(2H)-furanone (DMMF) are import aroma chemicals and are considered key flavor compounds in many fruit. Due to their attractive sensory properties they are highly appreciated by the food industry. In fruits 2,5-dimethyl-3(2H)-furanones are synthesized by a series of enzymatic steps whereas HDMF is also a product of the Maillard reaction. Numerous methods for the synthetic preparation of these c...

  14. Inclined asymmetric librations in exterior resonances

    Science.gov (United States)

    Voyatzis, G.; Tsiganis, K.; Antoniadou, K. I.

    2018-04-01

    Librational motion in Celestial Mechanics is generally associated with the existence of stable resonant configurations and signified by the existence of stable periodic solutions and oscillation of critical (resonant) angles. When such an oscillation takes place around a value different than 0 or π , the libration is called asymmetric. In the context of the planar circular restricted three-body problem, asymmetric librations have been identified for the exterior mean motion resonances (MMRs) 1:2, 1:3, etc., as well as for co-orbital motion (1:1). In exterior MMRs the massless body is the outer one. In this paper, we study asymmetric librations in the three-dimensional space. We employ the computational approach of Markellos (Mon Not R Astron Soc 184:273-281, https://doi.org/10.1093/mnras/184.2.273, 1978) and compute families of asymmetric periodic orbits and their stability. Stable asymmetric periodic orbits are surrounded in phase space by domains of initial conditions which correspond to stable evolution and librating resonant angles. Our computations were focused on the spatial circular restricted three-body model of the Sun-Neptune-TNO system (TNO = trans-Neptunian object). We compare our results with numerical integrations of observed TNOs, which reveal that some of them perform 1:2 resonant, inclined asymmetric librations. For the stable 1:2 TNO librators, we find that their libration seems to be related to the vertically stable planar asymmetric orbits of our model, rather than the three-dimensional ones found in the present study.

  15. Radioimmunoassay of arginine vasopressin (AVP) and clinical application

    International Nuclear Information System (INIS)

    Wagner, H.; Haeberle, M.; Franz, H.E.; Maier, V.

    1977-01-01

    The low circulating levels of vasopressin required an initial extraction procedure. The extraction method itself presented problems with the specificity and the reproducibility of the extracted hormone from serum. The presented paper describes the developement of a radioimmunoassay without an extraction procedure. The AVP was coupled with rabbit-albumin by gluteraldehyde condensation for the immunization of rabbits. Synthetic AVP was iodinated by the method of GREENWOOD and HUNTER (1963) and purified by the addition of Dowex. The antibody cannot differentiate between lysine- and arginine-, ornithine-, glycerine - vasopressin and oxytocin. 1 - 24 ACTH and gastrin did not crosscreact. Normal subjects were found to have 5.7 +- 4.4/uU/ml after a dehydration period of 12 hours. Subjects suffering from psychogenic polydipsia showed normal levels, however, different forms of stress yielded higher levels in normal subjects. In patients suffering from liver cirrhosis the values normalized when ascites was under control. (orig.) [de

  16. Characterization of casein and poly-l-arginine multilayer films

    Science.gov (United States)

    Szyk-Warszyńska, Lilianna; Kilan, Katarzyna; Socha, Robert P.

    2014-06-01

    Thin films containing casein appear to be a promising material for coatings used in the medical area to promote biomineralization. alfa- and beta-casein and poly-L-arginine multilayer films were formed by the layer-by layer technique and their thickness and mass were analyzed by ellipsometry and quartz crystal microbalance with dissipation monitoring (QCM-D). We investigated the effect of the type of casein used for the film formation and of the polyethyleneimine anchoring layer on the thickness and mass of adsorbed films. The analysis of the mass of films during their post-treatment with the solutions of various ionic strength and pH provided the information concerning films stability, while the XPS elemental analysis confirmed binding of calcium ions by the casein embedded in the multilayers.

  17. Microwave heating of arginine yields highly fluorescent nanoparticles

    International Nuclear Information System (INIS)

    Philippidis, Aggelos; Stefanakis, Dimitrios; Anglos, Demetrios; Ghanotakis, Demetrios

    2013-01-01

    Brightly fluorescent nanoparticles were produced via a single-step, single-precursor procedure based on microwave heating of an aqueous solution of the amino acid arginine. Key structural and optical properties of the resulting Arg nanoparticles, Arg-dots, are reported and discussed with emphasis on the pH dependence of their fluorescence emission. The surface of the Arg-dots was functionalised through coupling to folic acid, opening up ways for connecting fluorescent nanoparticles to cancer cells. The generality and versatility of the microwave heating procedure was further demonstrated by the synthesis of different types of carbon nanoparticles, such as CE-dots, that were produced by use of citric acid and ethanolamine as precursors and compared to the Arg-dots.

  18. Arginine Vasotocin, the Social Neuropeptide of Amphibians and Reptiles

    Science.gov (United States)

    Wilczynski, Walter; Quispe, Maricel; Muñoz, Matías I.; Penna, Mario

    2017-01-01

    Arginine vasotocin (AVT) is the non-mammalian homolog of arginine vasopressin (AVP) and, like vasopressin, serves as an important modulator of social behavior in addition to its peripheral functions related to osmoregulation, reproductive physiology, and stress hormone release. In amphibians and reptiles, the neuroanatomical organization of brain AVT cells and fibers broadly resembles that seen in mammals and other taxa. Both parvocellular and magnocellular AVT-containing neurons are present in multiple populations located mainly in the basal forebrain from the accumbens–amygdala area to the preoptic area and hypothalamus, from which originate widespread fiber connections spanning the brain with a particularly heavy innervation of areas associated with social behavior and decision-making. As for mammalian AVP, AVT is present in greater amounts in males in many brain areas, and its presence varies seasonally, with hormonal state, and in males with differing social status. AVT’s social influence is also conserved across herpetological taxa, with significant effects on social signaling and aggression, and, based on the very small number of studies investigating more complex social behaviors in amphibians and reptiles, AVT may also modulate parental care and social bonding when it is present in these vertebrates. Within this conserved pattern, however, both AVT anatomy and social behavior effects vary significantly across species. Accounting for this diversity represents a challenge to understanding the mechanisms by which AVT exerts its behavioral effects, as well are a potential tool for discerning the structure-function relationships underlying AVT’s many effects on behavior. PMID:28824546

  19. Arginine Vasotocin, the Social Neuropeptide of Amphibians and Reptiles

    Directory of Open Access Journals (Sweden)

    Walter Wilczynski

    2017-08-01

    Full Text Available Arginine vasotocin (AVT is the non-mammalian homolog of arginine vasopressin (AVP and, like vasopressin, serves as an important modulator of social behavior in addition to its peripheral functions related to osmoregulation, reproductive physiology, and stress hormone release. In amphibians and reptiles, the neuroanatomical organization of brain AVT cells and fibers broadly resembles that seen in mammals and other taxa. Both parvocellular and magnocellular AVT-containing neurons are present in multiple populations located mainly in the basal forebrain from the accumbens–amygdala area to the preoptic area and hypothalamus, from which originate widespread fiber connections spanning the brain with a particularly heavy innervation of areas associated with social behavior and decision-making. As for mammalian AVP, AVT is present in greater amounts in males in many brain areas, and its presence varies seasonally, with hormonal state, and in males with differing social status. AVT’s social influence is also conserved across herpetological taxa, with significant effects on social signaling and aggression, and, based on the very small number of studies investigating more complex social behaviors in amphibians and reptiles, AVT may also modulate parental care and social bonding when it is present in these vertebrates. Within this conserved pattern, however, both AVT anatomy and social behavior effects vary significantly across species. Accounting for this diversity represents a challenge to understanding the mechanisms by which AVT exerts its behavioral effects, as well are a potential tool for discerning the structure-function relationships underlying AVT’s many effects on behavior.

  20. Clinical Outcome And Arginine Serum of Acute Ischemic Stroke Patients Supplemented by Snakehead Fish Extract

    Science.gov (United States)

    Pudjonarko, Dwi; Retnaningsih; Abidin, Zainal

    2018-02-01

    Background: Levels of arginine associated with clinical outcome in acute ischemic stroke (AIS). Arginine is a protein needed to synthesis nitric oxide (NO), a potential vasodilator and antioxidant. Snakehead fish is a source of protein which has antioxidant activity. Snakehead fish contains mineral, vitamin, and amino acids. One of the amino acids that were found quite high in snakehead fish extract is arginine. The aim of this study was done to determine the effect of snakehead fish extracts (SFE) on serum arginin levels and clinical outcome of AIS patients. Methods: It was double-blind randomized pretest-posttest control group design, with. AIS patients were divided into two groups i.e. snakehead fish extracts (SFE) and control. SFE group were administered 15 grams SFE for 7 days . Arginine serum levels and clinical outcome (measured by National Institute of Health Stroke Scale = NIHSS) were measured before and after treatment, other related factors were also analyzed in Logistic regression. Results: A total of 42 subjects who were performed random allocation as SFE or control group. There was no differences in subject characteristics between the two groups. There was a differences Δ arginine serum levels between SFE and control (33.6±19.95 μmol/L 0.3±2.51 μmol/L pgender factor that affected on improvement of NIHSS (OR=7; p=0,01). Conclusion: There is Clinical outcome improvement and enhancement of arginine serum levels in AIS patient with snakehead fish extract supplementation.

  1. Arginine as an adjuvant to chemotherapy improves clinical outcome in active tuberculosis

    DEFF Research Database (Denmark)

    Schön, T; Elias, D; Moges, F

    2003-01-01

    , and clinical symptoms after week 8. Secondary outcomes were sedimentation rate and levels of NO metabolites, arginine, citrulline, and tumour necrosis factor-a. Compared with the human immunodeficiency virus (HIV)-/TB+ placebo group, the HIV-/TB+ patients in the arginine group showed significant improvement......, defined as increased weight gain, higher sputum conversion rate and faster reduction of symptoms, such as cough. The arginine level increased after week 2 in the HIV-/TB+ arginine group (100.2 microM (range 90.5-109.9) versus 142.1 microM (range 114.1-170.1)) compared with the HIV-/TB+ placebo group (105.......5 microM (range 93.7-117.3) versus 95.7 microM (range 82.4-108.9)). HIV seroprevalence was 52.5%. No clinical improvement or increase in serum arginine was detected in arginine supplemented HIV+/TB+ patients compared with placebo. Arginine is beneficial as an adjuvant treatment in human immunodeficiency...

  2. Quantitative phosphoproteomics reveals the role of protein arginine phosphorylation in the bacterial stress response.

    Science.gov (United States)

    Schmidt, Andreas; Trentini, Débora Broch; Spiess, Silvia; Fuhrmann, Jakob; Ammerer, Gustav; Mechtler, Karl; Clausen, Tim

    2014-02-01

    Arginine phosphorylation is an emerging protein modification implicated in the general stress response of Gram-positive bacteria. The modification is mediated by the arginine kinase McsB, which phosphorylates and inactivates the heat shock repressor CtsR. In this study, we developed a mass spectrometric approach accounting for the peculiar chemical properties of phosphoarginine. The improved methodology was used to analyze the dynamic changes in the Bacillus subtilis arginine phosphoproteome in response to different stress situations. Quantitative analysis showed that a B. subtilis mutant lacking the YwlE arginine phosphatase accumulated a strikingly large number of arginine phosphorylations (217 sites in 134 proteins), however only a minor fraction of these sites was increasingly modified during heat shock or oxidative stress. The main targets of McsB-mediated arginine phosphorylation comprise central factors of the stress response system including the CtsR and HrcA heat shock repressors, as well as major components of the protein quality control system such as the ClpCP protease and the GroEL chaperonine. These findings highlight the impact of arginine phosphorylation in orchestrating the bacterial stress response.

  3. Atmospherically Relevant Radicals Derived from the Oxidation of Dimethyl Sulfide.

    Science.gov (United States)

    Mardyukov, Artur; Schreiner, Peter R

    2018-02-20

    The large number and amounts of volatile organosulfur compounds emitted to the atmosphere and the enormous variety of their reactions in various oxidation states make experimental measurements of even a small fraction of them a daunting task. Dimethyl sulfide (DMS) is a product of biological processes involving marine phytoplankton, and it is estimated to account for approximately 60% of the total natural sulfur gases released to the atmosphere. Ocean-emitted DMS has been suggested to play a role in atmospheric aerosol formation and thereby cloud formation. The reaction of ·OH with DMS is known to proceed by two independent channels: abstraction and addition. The oxidation of DMS is believed to be initiated by the reaction with ·OH and NO 3 · radicals, which eventually leads to the formation of sulfuric acid (H 2 SO 4 ) and methanesulfonic acid (CH 3 SO 3 H). The reaction of DMS with NO 3 · appears to proceed exclusively by hydrogen abstraction. The oxidation of DMS consists of a complex sequence of reactions. Depending on the time of the day or altitude, it may take a variety of pathways. In general, however, the oxidation proceeds via chains of radical reactions. Dimethyl sulfoxide (DMSO) has been reported to be a major product of the addition channel. Dimethyl sulfone (DMSO 2 ), SO 2 , CH 3 SO 3 H, and methanesulfinic acid (CH 3 S(O)OH) have been observed as products of further oxidation of DMSO. Understanding the details of DMS oxidation requires in-depth knowledge of the elementary steps of this seemingly simple transformation, which in turn requires a combination of experimental and theoretical methods. The methylthiyl (CH 3 S·), methylsulfinyl (CH 3 SO·), methylsulfonyl (CH 3 SO 2 ·), and methylsulfonyloxyl (CH 3 SO 3 ·) radicals have been postulated as intermediates in the oxidation of DMS. Therefore, studying the chemistry of sulfur-containing free radicals in the laboratory also is the basis for understanding the mechanism of DMS oxidation in the

  4. Reversal modes in asymmetric Ni nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Leighton, B.; Pereira, A. [Departamento de Fisica, Universidad de Santiago de Chile (USACH), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Escrig, J., E-mail: jescrigm@gmail.com [Departamento de Fisica, Universidad de Santiago de Chile (USACH), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Avda. Ecuador 3493, 917-0124 Santiago (Chile)

    2012-11-15

    We have investigated the evolution of the magnetization reversal mechanism in asymmetric Ni nanowires as a function of their geometry. Circular nanowires are found to reverse their magnetization by the propagation of a vortex domain wall, while in very asymmetric nanowires the reversal is driven by the propagation of a transverse domain wall. The effect of shape asymmetry of the wire on coercivity and remanence is also studied. Angular dependence of the remanence and coercivity is also addressed. Tailoring the magnetization reversal mechanism in asymmetric nanowires can be useful for magnetic logic and race-track memory, both of which are based on the displacement of magnetic domain walls. Finally, an alternative method to detect the presence of magnetic drops is proposed. - Highlights: Black-Right-Pointing-Pointer Asymmetry strongly modifies the magnetic behavior of a wire. Black-Right-Pointing-Pointer Very asymmetric nanowires reverse their magnetization by a transverse domain wall. Black-Right-Pointing-Pointer An alternative method to detect the presence of magnetic drops is proposed. Black-Right-Pointing-Pointer Tailoring the reversal mode in asymmetric nanowires can be useful for potential applications.

  5. Hepatic adaptation compensates inactivation of intestinal arginine biosynthesis in suckling mice.

    Directory of Open Access Journals (Sweden)

    Vincent Marion

    Full Text Available Suckling mammals, including mice, differ from adults in the abundant expression of enzymes that synthesize arginine from citrulline in their enterocytes. To investigate the importance of the small-intestinal arginine synthesis for whole-body arginine production in suckling mice, we floxed exon 13 of the argininosuccinate synthetase (Ass gene, which codes for a key enzyme in arginine biosynthesis, and specifically and completely ablated Ass in enterocytes by crossing Ass (fl and Villin-Cre mice. Unexpectedly, Ass (fl/fl /VilCre (tg/- mice showed no developmental impairments. Amino-acid fluxes across the intestine, liver, and kidneys were calculated after determining the blood flow in the portal vein, and hepatic and renal arteries (86%, 14%, and 33%, respectively, of the transhepatic blood flow in 14-day-old mice. Relative to control mice, citrulline production in the splanchnic region of Ass (fl/fl /VilCre (tg/- mice doubled, while arginine production was abolished. Furthermore, the net production of arginine and most other amino acids in the liver of suckling control mice declined to naught or even changed to consumption in Ass (fl/fl /VilCre (tg/- mice, and had, thus, become remarkably similar to that of post-weaning wild-type mice, which no longer express arginine-biosynthesizing enzymes in their small intestine. The adaptive changes in liver function were accompanied by an increased expression of genes involved in arginine metabolism (Asl, Got1, Gpt2, Glud1, Arg1, and Arg2 and transport (Slc25a13, Slc25a15, and Slc3a2, whereas no such changes were found in the intestine. Our findings suggest that the genetic premature deletion of arginine synthesis in enterocytes causes a premature induction of the post-weaning pattern of amino-acid metabolism in the liver.

  6. Atropine and ODQ antagonize tetanic fade induced by L-arginine in cats

    Directory of Open Access Journals (Sweden)

    J.M. Cruciol-Souza

    1999-10-01

    Full Text Available Although it has been demonstrated that nitric oxide (NO released from sodium nitrite induces tetanic fade in the cat neuromuscular preparations, the effect of L-arginine on tetanic fade and its origin induced by NO have not been studied in these preparations. Furthermore, atropine reduces tetanic fade induced by several cholinergic and anticholinergic drugs in these preparations, whose mechanism is suggested to be mediated by the interaction of acetylcholine with inhibitory presynaptic muscarinic receptors. The present study was conducted in cats to determine the effects of L-arginine alone or after pretreatment with atropine or 1H-[1,2,4]oxadiazole [4,3-a]quinoxalin-1-one (ODQ on neuromuscular preparations indirectly stimulated at high frequency. Drugs were injected into the middle genicular artery. L-arginine (2 mg/kg and S-nitroso-N-acetylpenicillamine (SNAP; 16 µg/kg induced tetanic fade. The Nw-nitro-L-arginine (L-NOARG; 2 mg/kg alone did not produce any effect, but reduced the tetanic fade induced by L-arginine. D-arginine (2 mg/kg did not induce changes in tetanic fade. The tetanic fade induced by L-arginine or SNAP was reduced by previous injection of atropine (1.0 µg/kg or ODQ (15 µg/kg. ODQ alone did not change tetanic fade. The data suggest that the NO-synthase-GC pathway participates in the L-arginine-induced tetanic fade in cat neuromuscular preparations. The tetanic fade induced by L-arginine probably depends on the action of NO at the presynaptic level. NO may stimulate guanylate cyclase increasing acetylcholine release and thereby stimulating presynaptic muscarinic receptors.

  7. PRE-EXERCISE ARGININE SUPPLEMENTATION INCREASES TIME TO EXHAUSTION IN ELITE MALE WRESTLERS

    Directory of Open Access Journals (Sweden)

    H.U. Yavuz

    2014-08-01

    Full Text Available Dietary supplements containing arginine are among the most popular ergogenics intended to enhance strength, power and muscle recovery associated with both anaerobic and aerobic exercise. The aim of the present study was to evaluate the possible effect of pre-exercise acute intake of arginine on performance and exercise metabolism during incremental exhaustive exercise in elite male wrestlers. Nine volunteer elite male wrestlers (24.7±3.8 years participated in this study. The test-retest protocol was used on the same subjects. The study was conducted using a cross-over design. A single dose of arginine (1.5 g · 10 kg-1 body weight or placebo was given to the subjects after 12 hours fasting (during the night for both test and retest. Subjects were allowed to drink water but not allowed to eat anything between arginine or placebo ingestion and the exercise protocol. An incremental exercise protocol was applied and oxygen consumption was measured during the exercise. Heart rate and plasma lactate levels were measured during the exercise and recovery. Results showed that in the same working loads there was no significant difference for the mean lactate levels and no difference in maximum oxygen consumption (arginine 52.47±4.01 mL · kg-1 · min-1, placebo 52.07±5.21 mL · kg-1 · min-1 or in maximum heart rates (arginine 181.09±13.57 bpm, placebo 185.89±7.38 bpm between arginine and placebo trials. Time to exhaustion was longer with arginine supplementation (1386.8±69.8 s compared to placebo (1313±90.8 s (p<0.05. These results suggest that L-arginine supplementation can have beneficial effects on exercise performance in elite male wrestlers but cannot explain the metabolic pathways which are responsible from these effects.

  8. Alterations in plasma L-arginine and methylarginines in heart failure and after heart transplantation.

    Science.gov (United States)

    Lundgren, Jakob; Sandqvist, Anna; Hedeland, Mikael; Bondesson, Ulf; Wikström, Gerhard; Rådegran, Göran

    2018-04-12

    Endothelial function, including the nitric oxide (NO)-pathway, has previously been extensively investigated in heart failure (HF). In contrast, studies are lacking on the NO pathway after heart transplantation (HT). We therefore investigated substances in the NO pathway prior to and after HT in relation to hemodynamic parameters. 12 patients (median age 50.0 yrs, 2 females), heart transplanted between June 2012 and February 2014, evaluated at our hemodynamic lab, at rest, prior to HT, as well as four weeks and six months after HT were included. All patients had normal left ventricular function post-operatively and none had post-operative pulmonary hypertension or acute cellular rejection requiring therapy at the evaluations. Plasma concentrations of ADMA, SDMA, L-Arginine, L-Ornithine and L-Citrulline were analyzed at each evaluation. In comparison to controls, the plasma L-Arginine concentration was low and ADMA high in HF patients, resulting in low L-Arginine/ADMA-ratio pre-HT. Already four weeks after HT L-Arginine was normalized whereas ADMA remained high. Consequently the L-Arginine/ADMA-ratio improved, but did not normalize. The biomarkers remained unchanged at the six-month evaluation and the L-Arginine/ADMA-ratio correlated inversely to pulmonary vascular resistance (PVR) six months post-HT. Plasma L-Arginine concentrations normalize after HT. However, as ADMA is unchanged, the L-Arginine/ADMA-ratio remained low and correlated inversely to PVR. Together these findings suggest that (i) the L-Arginine/ADMA-ratio may be an indicator of pulmonary vascular tone after HT, and that (ii) NO-dependent endothelial function is partly restored after HT. Considering the good postoperative outcome, the biomarker levels may be considered "normal" after HT.

  9. Thermochemical study of 2,5-dimethyl-3-furancarboxylic acid, 4,5-dimethyl-2-furaldehyde, and 3-acetyl-2,5-dimethylfuran

    International Nuclear Information System (INIS)

    Ribeiro da Silva, Manuel A.V.; Amaral, Luisa M.P.F.

    2011-01-01

    The standard (p o = 0.1 MPa) molar enthalpies of formation, in the gaseous state, at T = 298.15 K, for 2,5-dimethyl-3-furancarboxylic acid, 3-acetyl-2,5-dimethylfuran, and 4,5-dimethyl-2-furaldehyde were derived from the values of the standard molar enthalpies of formation, in the condensed phase, and the standard molar enthalpies of phase transition from the condensed to the gaseous state. The values of the standard molar enthalpies of formation of the compounds in the condensed phases were calculated from the measurements of the standard massic energies of combustion obtained by static bomb combustion calorimetry. The enthalpies of vaporization/sublimation were measured by Calvet high temperature microcalorimetry. For 2,5-dimethyl-3-furancarboxylic acid the standard enthalpy of sublimation was also calculated, by the application of the Clausius-Clapeyron equation, to the temperature dependence of the vapor pressures measured by the Knudsen effusion technique. (table)

  10. cis-Bis(2,2′-bipyridine-κ2N,N′bis(dimethyl sulfoxide-κOzinc bis(tetraphenylborate dimethyl sulfoxide monosolvate

    Directory of Open Access Journals (Sweden)

    Stefania Tomyn

    2011-12-01

    Full Text Available In the mononuclear title complex, [Zn(C10H8N22(C2H6OS2](C24H20B2·C2H6OS, the ZnII ion is coordinated by four N atoms of two bidentate 2,2′-bipyridine molecules and by the O atoms of two cis-disposed dimethyl sulfoxide molecules in a distorted octahedral geometry. The S atom and the methyl groups of one of the coordinated dimethyl sulfoxide molecules are disordered in a 0.509 (2:0.491 (2 ratio. The crystal packing is stabilized by C—H...O hydrogen bonds between the dimethyl sulfoxide solvent molecules and tetraphenylborate anions.

  11. Indian women of childbearing age do not metabolically conserve arginine as do American and Jamaican women.

    Science.gov (United States)

    Kao, Christina C; Hsu, Jean W; Dwarkanath, Pratibha; Karnes, Jeffrey M; Baker, Tameka M; Bohren, Kurt M; Badaloo, Asha; Thame, Minerva M; Kurpad, Anura V; Jahoor, Farook

    2015-05-01

    In a previous study in pregnant American women, we reported that arginine flux and nitric oxide synthesis increased in trimester 2. More recently, we reported that Indian women do not increase arginine flux during pregnancy as their American or Jamaican counterparts do. The purpose of this study was to determine whether Indian women of childbearing age are producing less arginine and/or catabolizing more arginine and therefore have less available for anabolic pathways than do Jamaican and American women. Thirty healthy women aged 28.3 ± 0.8 y from the United States, India, and Jamaica (n = 10/group) were given 6 h primed, constant intravenous infusions of guanidino-¹⁵N₂-arginine, 5,5-²H₂-citrulline, ¹⁵N₂-ornithine, and ring-²H₅-phenylalanine, in addition to primed, oral doses of U-¹³C₆-arginine in both the fasting and postprandial states. An oral dose of deuterium oxide was also given to determine fat-free mass (FFM). Compared with American women, Indian and Jamaican women had greater ornithine fluxes (μmol · kg fat FFM⁻¹ · h⁻¹) in the fasting and postprandial states (27.3 ± 2.5 vs. 39.6 ± 3.7 and 37.2 ± 2.0, respectively, P = 0.01), indicating greater arginine catabolism. However, Jamaican women had a higher endogenous arginine flux than did Indian and American women in the fasting (66.1 ± 3.1 vs. 54.2 ± 3.1 and 56.1 ± 2.1, respectively, P = 0.01) and postprandial (53.8 ± 2.2 vs. 43.7 ± 4.9 and 42.8 ± 3.1, respectively, P = 0.06) states. As a consequence, Indian women had lower arginine bioavailability (μmol · kg FFM⁻¹ · h⁻¹) in the fasting state (42.0 ± 2.6) than did American (49.9 ± 1.3, P = 0.045) and Jamaican (55.5 ± 3.5, P = 0.004) women, as well as in the postprandial state (40.7 ± 3.5 vs. 51.8 ± 1.2 and 57.5 ± 3.2, respectively, P = 0.001). Compared with American and Jamaican women, Indian women of childbearing age have a decreased arginine supply because of increased arginine catabolism without an

  12. Rate Constants for the Reactions of Hydroxyl Radical with Several Alkanes, Cycloalkanes, and Dimethyl Ether

    Science.gov (United States)

    DeMore, W.; Bayes, K.

    1998-01-01

    Relative rate experiements were used to measure rate constants and temperature denpendencies of the reactions of OH with propane, n-butane, n-pentane, n-hexane, cyclopropane, cyclobutane, cyclopentane, and dimethyl ether.

  13. Crystal structures of hibiscus acid and hibiscus acid dimethyl ester isolated from Hibiscus sabdariffa (Malvaceae)

    OpenAIRE

    Zheoat, Ahmed M.; Gray, Alexander I.; Igoli, John O.; Kennedy, Alan R.; Ferro, Valerie A.

    2017-01-01

    The biologically active title compounds have been isolated from Hibiscus sabdariffa plants, hibiscus acid as a dimethyl sulfoxide monosolvate [systematic name: (2S,3R)-3-hy?droxy-5-oxo-2,3,4,5-tetra?hydro?furan-2,3-di?carb?oxy?lic acid dimethyl sulfoxide monosolvate], C6H6O7?C2H6OS, (I), and hibiscus acid dimethyl ester [systematic name: dimethyl (2S,3R)-3-hy?droxy-5-oxo-2,3,4,5-tetra?hydro?furan-2,3-di?carboxyl?ate], C8H10O7, (II). Compound (I) forms a layered structure with alternating laye...

  14. USE OF DIMETHYL FUMARATE IN THE TREATMENT OF MULTIPLE SCLEROSIS: CLINICAL AND ECONOMIC ANALYSIS

    Directory of Open Access Journals (Sweden)

    V. R. Mkrtchyan

    2016-01-01

    Full Text Available The paper presents a review of an update on the comparative pharmacoeconomic analysis of using dimethyl fumarate in the treatment of multiple sclerosis (MS in European countries. A pharmacoeconomic evaluation was made to study the use of first-line oral dimethyl fumarate versus another first-line oral teriflunomide in the treatment of MS in the Russian Federation (for 1 year and second-line natalizumab and fingolimod. Among first-line oral drugs, dimethyl fumarate was shown to be superior to teriflunomide in a cost-effectiveness ratio and to be slightly ahead of the MS-modifying drugs (MSMDs  and the second-line drugs natalizumab and fingolimod. According to clinical and economic indicators, dimethyl fumarate is the drug of choise among other MSMDs in the treatment of MS.

  15. Biosynthesis of glycerol carbonate from glycerol by lipase in dimethyl carbonate as the solvent.

    Science.gov (United States)

    Lee, Kyung Hwa; Park, Chang-Ho; Lee, Eun Yeol

    2010-11-01

    Glycerol carbonate was synthesized from renewable glycerol and dimethyl carbonate using lipase in solvent-free reaction system in which excess dimethyl carbonate played as the reaction medium. A variety of lipases have been tested for their abilities to catalyze transesterification reaction, and Candida antartica lipase B and Novozyme 435 exhibited higher catalytic activities. The silica-coated glycerol with a 1:1 ratio was supplied to prevent two-phase formation between hydrophobic dimethyl carbonate and hydrophilic glycerol. Glycerol carbonate was successfully synthesized with more than 90% conversion from dimethyl carbonate and glycerol with a molar ratio of 10 using Novozyme 435-catalyzed transesterification at 70 °C. The Novozyme 435 [5% (w/w) and 20% (w/w)] and silica gel were more than four times recycled with good stability in a repeated batch operation for the solvent-free synthesis of glycerol carbonate.

  16. Kinetics of periodate oxidation of tris -(4,4'-dimethyl-2,2'-bipyridine ...

    African Journals Online (AJOL)

    dimethyl-2,2'-bipyridine) iron(II) in acid medium was investigated. The complex undergoes extensive protonation in acid medium. Both protonated and the unprotonated species undergo electron transfer reaction with the active periodate species ...

  17. The stability study of myristyl dimethyl amine oxide as an amphoteric ...

    African Journals Online (AJOL)

    The stability study of myristyl dimethyl amine oxide as an amphoteric surfactant in strong oxidant media containing 5 % m/m sodium hypochlorite through measurement of decomposing rate using high performance liquid chromatography and two phase titration.

  18. Direct synthesis of dimethyl carbonate from CO2 and methanol over ...

    Indian Academy of Sciences (India)

    The direct synthesis of dimethyl carbonate (DMC) from carbon dioxide (CO2) and methanol is ... Zirconia and ceria-based catalysts were most effective ... construction of a validation plant for dialkyl carbonates .... (mmol of MeOH consumed/2).

  19. Fixation of carbon dioxide into dimethyl carbonate over titanium-based zeolitic thiophene-benzimidazolate framework

    Data.gov (United States)

    U.S. Environmental Protection Agency — A titanium-based zeolitic thiophene-benzimidazolate framework has been designed for the direct synthesis of dimethyl carbonate (DMC) from methanol and carbon...

  20. Modeling of a Reaction-Distillation-Recycle System to Produce Dimethyl Ether through Methanol Dehydration

    Science.gov (United States)

    Muharam, Y.; Zulkarnain, L. M.; Wirya, A. S.

    2018-03-01

    The increase in the dimethyl ether yield through methanol dehydration due to a recycle integration to a reaction-distillation system was studied in this research. A one-dimensional phenomenological model of a methanol dehydration reactor and a shortcut model of distillation columns were used to achieve the aim. Simulation results show that 10.7 moles/s of dimethyl ether is produced in a reaction-distillation system with the reactor length being 4 m, the reactor inlet pressure being 18 atm, the reactor inlet temperature being 533 K, the reactor inlet velocity being 0.408 m/s, and the distillation pressure being 8 atm. The methanol conversion is 90% and the dimethyl ether yield is 48%. The integration of the recycle stream to the system increases the dimethyl ether yield by 8%.

  1. Negative argininosuccinate synthetase expression in melanoma tumours may predict clinical benefit from arginine-depleting therapy with pegylated arginine deiminase

    Science.gov (United States)

    Feun, L G; Marini, A; Walker, G; Elgart, G; Moffat, F; Rodgers, S E; Wu, C J; You, M; Wangpaichitr, M; Kuo, M T; Sisson, W; Jungbluth, A A; Bomalaski, J; Savaraj, N

    2012-01-01

    Background: Arginine-depleting therapy with pegylated arginine deiminase (ADI-PEG20) was reported to have activity in advanced melanoma in early phase I–II trial, and clinical trials are currently underway in other cancers. However, the optimal patient population who benefit from this treatment is unknown. Methods: Advanced melanoma patients with accessible tumours had biopsy performed before the start of treatment with ADI-PEG20 and at the time of progression or relapse when amenable to determine whether argininosuccinate synthetase (ASS) expression in tumour was predictive of response to ADI-PEG20. Results: Twenty-seven of thirty-eight patients treated had melanoma tumours assessable for ASS staining before treatment. Clinical benefit rate (CBR) and longer time to progression were associated with negative expression of tumour ASS. Only 1 of 10 patients with ASS-positive tumours (ASS+) had stable disease, whereas 4 of 17 (24%) had partial response and 5 had stable disease, when ASS expression was negative (ASS−), giving CBR rates of 52.9 vs 10%, P=0.041. Two responding patients with negative ASS expression before therapy had rebiopsy after tumour progression and the ASS expression became positive. The survival of ASS− patients receiving at least four doses at 320 IU m−2 was significantly better than the ASS+ group at 26.5 vs 8.5 months, P=0.024. Conclusion: ADI-PEG20 is safe and the drug is only efficacious in melanoma patients whose tumour has negative ASS expression. Argininosuccinate synthetase tumour positivity is associated with drug resistance and tumour progression. PMID:22472884

  2. Renewable resource management under asymmetric information

    DEFF Research Database (Denmark)

    Jensen, Frank; Andersen, Peder; Nielsen, Max

    2013-01-01

    Asymmetric information between fishermen and the regulator is important within fisheries. The regulator may have less information about stock sizes, prices, costs, effort, productivity and catches than fishermen. With asymmetric information, a strong analytical tool is principal-agent analysis....... In this paper, we study asymmetric information about productivity within a principal-agent framework and a tax on fishing effort is considered. It is shown that a second best optimum can be achieved if the effort tax is designed such that low-productivity agents rent is exhausted, while high-productivity agents...... receive an information rent. The information rent is equivalent to the total incentive cost. The incentive costs arise as we want to reveal the agent's type....

  3. Asymmetric synthesis II more methods and applications

    CERN Document Server

    Christmann, Mathias

    2012-01-01

    After the overwhelming success of 'Asymmetric Synthesis - The Essentials', narrating the colorful history of asymmetric synthesis, this is the second edition with latest subjects and authors. While the aim of the first edition was mainly to honor the achievements of the pioneers in asymmetric syntheses, the aim of this new edition was bringing the current developments, especially from younger colleagues, to the attention of students. The format of the book remained unchanged, i.e. short conceptual overviews by young leaders in their field including a short biography of the authors. The growing multidisciplinary research within chemistry is reflected in the selection of topics including metal catalysis, organocatalysis, physical organic chemistry, analytical chemistry, and its applications in total synthesis. The prospective reader of this book is a graduate or undergraduate student of advanced organic chemistry as well as the industrial chemist who wants to get a brief update on the current developments in th...

  4. Thermochemical biorefinery based on dimethyl ether as intermediate: Technoeconomic assessment

    International Nuclear Information System (INIS)

    Haro, P.; Ollero, P.; Villanueva Perales, A.L.; Gómez-Barea, A.

    2013-01-01

    Highlights: ► A thermochemical biorefinery based on bio-DME as intermediate is studied. ► The assessed concepts (12) lead to multi-product generation (polygeneration). ► In all concepts DME is converted by carbonylation or hydrocarbonylation. ► Rates of return are similar to or higher than plants producing a single product. -- Abstract: Thermochemical biorefinery based on dimethyl ether (DME) as an intermediate is studied. DME is converted into methyl acetate, which can either be hydrogenated to ethanol or sold as a co-product. Considering this option together with a variety of technologies for syngas upgrading, 12 different process concepts are analyzed. The considered products are ethanol, methyl acetate, H 2 , DME and electricity. The assessment of each alternative includes biomass pretreatment, gasification, syngas clean-up and conditioning, DME synthesis and conversion, product separation, and heat and power integration. A plant size of 500 MW th processing poplar chips is taken as a basis. The resulting energy efficiency to products ranges from 34.9% to 50.2%. The largest internal rate of return (28.74%) corresponds to a concept which produces methyl acetate, DME and electricity (exported to grid). A sensitivity analysis with respect to total plant investment (TPI), total operation costs (TOC) and market price of products was carried out. The overall conclusion is that, despite its greater complexity, this kind of thermochemical biorefinery is more profitable than thermochemical bioprocesses oriented to a single product.

  5. Synthesis of dimethyl carbonate by oxidative carbonylation of methanol

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B.G.; Han, M.S.; Kim, H.S.; Ahn, B.S.; Park, K.Y.

    1999-07-01

    Dimethyl carbonate (DMC) synthesis reaction by oxidative carbonylation of methanol has been studied using vapor phase flow reaction system in the presence of Cu-based catalysts. A series of Cu-based catalysts were prepared by the conventional impregnation method using activated carbon (AC) as support. The effect of various promoters and reaction conditions on the catalytic reactivities was intensively evaluated in terms of methanol conversion and DMC selectivity. The morphological change of catalysts during the reaction was also compared by X-ray diffraction and SEM analysis. Regardless of catalyst compositions, the optimal reaction temperature for oxidative carbonylation of methanol was found to be around 120--130 C. The reaction rate was too slow below 100 C, while too many by-products were produced above 150 C. Among the various catalysts employed, CuCl{sub 2}/NaOH/AC catalyst with the mole ratio of OH/Cu = 0.5--1.0 has shown the best catalytic performance, which appears to have a strong relationship with the formation of intermediate species, Cu{sub 2}(OH){sub 3}Cl.

  6. Photoluminescence of 1,3-dimethyl pyrazoloquinoline derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Koscien, E. [1st Liceum, Sobieskiego 22, 42-700 Lubliniec (Poland); Gondek, E.; Pokladko, M. [Institute of Physics, Technical University of Krakow, Podhorazych 1, 30-084 Krakow (Poland); Jarosz, B. [Department of Chemistry, Hugon Kollotaj Agricultural University, Al. Mickiewicza 24/28, 30-059 Krakow (Poland); Vlokh, R.O. [Institute of Physical Optics, Dragomanova 23, 79005 Lviv (Ukraine); Kityk, A.V. [Department of Electrical Engineering, Czestochowa University of Technology, Al. Armii Krajowej 17, 42-200 Czestochowa (Poland)], E-mail: kityk@ap.univie.ac.at

    2009-04-15

    This paper presents absorption and photoluminescence of 6-F, 6-Br, 6-Cl, 7-TFM and 6-COOEt derivatives of 1,3-dimethyl-1H-Pyrazolo[3,4-b]quinoline (DMPQ). The measured absorption and emission spectra are compared with the quantum chemical calculations performed by means of the semi-empirical methods (AM1 or PM3) that are applied either to the equilibrium conformations in vacuo (T = 0 K) or combined with the molecular dynamics simulations (T = 300 K). The spectra calculated by the AM1 method appear to be for all dyes in practically excellent agreement with the measured ones. In particular, the position of the first absorption band is obtained with the accuracy up to a few nanometers, whereas the calculated photoluminescence spectra predict the positions of the emission maxima for a gas phase with the accuracy up to 10-18 nm. The photoemission spectra of DMPQ dyes are considerably less solvatochromic comparing to phenyl-containing pyrazoloquinoline derivatives. According to the quantum chemical analysis the reason for such behaviour lies in a local character of the electronic transitions of DMPQ dyes which are characterized by a relatively small difference between the excited state and ground state dipole moments. Importantly that the rotational dynamics of both methyl subunits does not change this situation.

  7. Penguins are attracted to dimethyl sulphide at sea.

    Science.gov (United States)

    Wright, Kyran L B; Pichegru, Lorien; Ryan, Peter G

    2011-08-01

    Breeding Spheniscus penguins are central place foragers that feed primarily on schooling pelagic fish. They are visual hunters, but it is unclear how they locate prey patches on a coarse scale. Many petrels and storm petrels (Procellariiformes), the penguins' closest relatives, use olfactory cues to locate prey concentrations at sea, but this has not been demonstrated for penguins. Procellariiforms are attracted to a variety of olfactory cues, including dimethyl sulphide (DMS), an organosulphur compound released when phytoplankton is grazed, as well as fish odorants such as cod liver oil. A recent study found that African penguins Spheniscus demersus react to DMS on land. We confirm this result and show that African penguins are also attracted by DMS at sea. DMS-scented oil slicks attracted 2-3 times more penguins than control slicks, whereas penguins showed no response to slicks containing cod liver oil. The number of penguins attracted to DMS increased for at least 30 min, suggesting penguins could travel up to 2 km to reach scent cues. Repeats of land-based trials confirmed previous results showing DMS sensitivity of penguins on land. Our results also support the hypothesis that African penguins use DMS as an olfactory cue to locate prey patches at sea from a distance, which is particularly important given their slow commuting speed relative to that of flying seabirds.

  8. Electrochemical degradation of dimethyl phthalate ester on a DSA® electrode

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Fernanda L.; Aquino, Jose M.; Miwa, Douglas W.; Motheo, Artur J. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Instituto de Quimica; Rodrigo, Manuel A., E-mail: artur@iqsc.usp.br [Department of Chemical Engineering, Faculty of Chemical Sciences and Technologies, Universidad de Castilla - La Mancha, Ciudad Real (Spain)

    2014-03-15

    The electrochemical degradation of dimethyl phthalate (DMP) using a one-compartment filter press flow cell and a commercial dimensionally stable anode (DSA®) is presented. The best electrolysis conditions were determined by the analysis of the influence of the nature and concentration of the support electrolyte, pH, current density and temperature. The abatement of DMP concentration and total organic carbon (TOC) removal were superior in the presence of NaCl, as well as the apparent first order kinetic constants. Using constant ionic strength at 0.15 mol dm{sup -3} by adding Na{sub 2}SO{sub 4}, DMP concentration decreases faster at relative low NaCl concentrations while the TOC removal after 1 h of electrolysis increases with NaCl concentration. The DMP removal was very similar for all the current densities investigated at acidic solutions. When electric energy saving is considered, since the electrochemical system was under mass transport conditions, the best operational option is to use low current density values. (author)

  9. Synthesis of dimethyl carbonate from urea and methanol

    Energy Technology Data Exchange (ETDEWEB)

    Polyakov, M.; Kalevaru, V.N.; Martin, A. [Rostock Univ. (Germany). Leibniz Institute for Catalysis; Mueller, K.; Arlt, W. [Erlangen-Nuernberg Univ. (Germany); Strautmann, J.; Kruse, D. [Evonik Industries AG, Marl (Germany). Creavis Technologies and Innovation

    2012-07-01

    Alcoholation of urea with methanol to produce dimethyl carbonate (DMC) is an interesting approach from both the ecological and economical points of view because the urea synthesis usually occurs by the direct use of carbon dioxide. Literature survey reveals that metal oxide catalysts for instance MgO, ZnO, etc. or polyphosphoric acids are mostly used as catalysts for this reaction. In this contribution, we describe the application of ZnO, MgO, CaO, TiO{sub 2}, ZrO{sub 2} or Al{sub 2}O{sub 3} catalysts for the above mentioned reaction. The catalytic activity of different metal oxides towards DMC synthesis was checked and additionally a comparison of achieved conversions with that of predictions made by thermodynamic calculations was also carried out. The achieved conversions are in good agreement with those of calculated ones. The test results reveal that the reaction pressure and temperature have a strong influence on the formation of DMC. Higher reaction pressure improved the yield of DMC. Among different catalysts investigated, ZnO displayed the best performance. The conversion of urea in most cases is close to 100 % and methyl carbamate MC is the major product of the reaction. A part of MC is subsequently converted to DMC, which however depends upon the reaction conditions applied and nature of catalyst used. From the best case, a DMC yield of ca. 8 % could be successfully achieved over ZnO catalyst. (orig.)

  10. Dimethyl sulfoxyde diethyl fumarate solution for high dose dosimetry

    International Nuclear Information System (INIS)

    Al-Kassiri, H.; Kattan, M.; Daher, Y.

    2007-06-01

    Dosimetric characterization of diethyl fumarate DEF in dimethyl sulfoxyde DMSO solution has been studied spectrophotometrically for possible application at high dose radiation dosimetry in the range (0-225 kGy). The absorption spectra of irradiated solution showed broad absorption bands between (325-400 nm) with a shoulder at 332 nm. The absorption increases as the dose is increased. Absorbance at 332 nm were measured and plotted against absorbed dose. Linear relationship and good response were found between absorbed dose and absorbance of 20% DEF concentration in the range (0-225 kGy) at the wave length, and linearity up to 250 kGy of absorbance at 332 nm .Good dose rate independence was observed in the range (14-33 kGy/h). The effect of post irradiation storage in darkness and indirect daylight conditions were not found to influence the absorption up to 700 h after irradiation. The effect of irradiation temperature within the range (0 to 60 centigrade degree) on the dosimetry performance was discussed.(author)

  11. Prediction of dimethyl disulfide levels from biosolids using statistical modeling.

    Science.gov (United States)

    Gabriel, Steven A; Vilalai, Sirapong; Arispe, Susanna; Kim, Hyunook; McConnell, Laura L; Torrents, Alba; Peot, Christopher; Ramirez, Mark

    2005-01-01

    Two statistical models were used to predict the concentration of dimethyl disulfide (DMDS) released from biosolids produced by an advanced wastewater treatment plant (WWTP) located in Washington, DC, USA. The plant concentrates sludge from primary sedimentation basins in gravity thickeners (GT) and sludge from secondary sedimentation basins in dissolved air flotation (DAF) thickeners. The thickened sludge is pumped into blending tanks and then fed into centrifuges for dewatering. The dewatered sludge is then conditioned with lime before trucking out from the plant. DMDS, along with other volatile sulfur and nitrogen-containing chemicals, is known to contribute to biosolids odors. These models identified oxidation/reduction potential (ORP) values of a GT and DAF, the amount of sludge dewatered by centrifuges, and the blend ratio between GT thickened sludge and DAF thickened sludge in blending tanks as control variables. The accuracy of the developed regression models was evaluated by checking the adjusted R2 of the regression as well as the signs of coefficients associated with each variable. In general, both models explained observed DMDS levels in sludge headspace samples. The adjusted R2 value of the regression models 1 and 2 were 0.79 and 0.77, respectively. Coefficients for each regression model also had the correct sign. Using the developed models, plant operators can adjust the controllable variables to proactively decrease this odorant. Therefore, these models are a useful tool in biosolids management at WWTPs.

  12. Biodegradation of Dimethyl Phthalate by Freshwater Unicellular Cyanobacteria.

    Science.gov (United States)

    Zhang, Xiaohui; Liu, Lincong; Zhang, Siping; Pan, Yan; Li, Jing; Pan, Hongwei; Xu, Shiguo; Luo, Feng

    2016-01-01

    The biodegradation characteristics of dimethyl phthalate (DMP) by three freshwater unicellular organisms were investigated in this study. The findings revealed that all the organisms were capable of metabolizing DMP; among them, Cyanothece sp. PCC7822 achieved the highest degradation efficiency. Lower concentration of DMP supported the growth of the Cyanobacteria; however, with the increase of DMP concentration growth of Cyanobacteria was inhibited remarkably. Phthalic acid (PA) was detected to be an intermediate degradation product of DMP and accumulated in the culture solution. The optimal initial pH value for the degradation was detected to be 9.0, which mitigated the decrease of pH resulting from the production of PA. The optimum temperature for DMP degradation of the three species of organisms is 30°C. After 72 hours' incubation, no more than 11.8% of the residual of DMP aggregated in Cyanobacteria cells while majority of DMP remained in the medium. Moreover, esterase was induced by DMP and the activity kept increasing during the degradation process. This suggested that esterase could assist in the degradation of DMP.

  13. Biodegradation of Dimethyl Phthalate by Freshwater Unicellular Cyanobacteria

    Science.gov (United States)

    Zhang, Xiaohui; Liu, Lincong; Zhang, Siping; Pan, Yan; Li, Jing; Pan, Hongwei

    2016-01-01

    The biodegradation characteristics of dimethyl phthalate (DMP) by three freshwater unicellular organisms were investigated in this study. The findings revealed that all the organisms were capable of metabolizing DMP; among them, Cyanothece sp. PCC7822 achieved the highest degradation efficiency. Lower concentration of DMP supported the growth of the Cyanobacteria; however, with the increase of DMP concentration growth of Cyanobacteria was inhibited remarkably. Phthalic acid (PA) was detected to be an intermediate degradation product of DMP and accumulated in the culture solution. The optimal initial pH value for the degradation was detected to be 9.0, which mitigated the decrease of pH resulting from the production of PA. The optimum temperature for DMP degradation of the three species of organisms is 30°C. After 72 hours' incubation, no more than 11.8% of the residual of DMP aggregated in Cyanobacteria cells while majority of DMP remained in the medium. Moreover, esterase was induced by DMP and the activity kept increasing during the degradation process. This suggested that esterase could assist in the degradation of DMP. PMID:28078293

  14. Examining Dimethyl Sulfide Emissions in California's San Joaquin Valley

    Science.gov (United States)

    Huber, D.; Hughes, S.; Blake, D. R.

    2017-12-01

    Dimethyl Sulfide (DMS) is a sulfur-containing compound that leads to the formation of aerosols which can lead to the formation of haze and fog. Whole air samples were collected on board the NASA C-23 Sherpa aircraft during the 2017 Student Airborne Research Program (SARP) over dairies and agricultural fields in the San Joaquin Valley. Analysis of the samples indicate average DMS concentrations of 23 ± 9 pptv, with a maximum concentration of 49 pptv. When compared with DMS concentrations from previous SARP missions (2009-2016), 2017 by far had the highest frequency of elevated DMS in this region. For this study, agricultural productivity of this region was analyzed to determine whether land use could be contributing to the elevated DMS. Top down and bottom up analysis of agriculture and dairies were used to determine emission rates of DMS in the San Joaquin Valley. Correlations to methane and ethanol were used to determine that DMS emissions were strongly linked to dairies, and resulted in R2 values of 0.61 and 0.43, respectively. These values indicate a strong correlation between dairies and DMS emissions. Combined with NOAA HySPLIT back trajectory data and analysis of ground air samples, results suggest that the contribution of dairies to annual DMS emissions in the San Joaquin Valley exceeds those from corn and alfalfa production.

  15. Metformin (dimethyl-biguanide induced DNA damage in mammalian cells

    Directory of Open Access Journals (Sweden)

    Rubem R. Amador

    2012-01-01

    Full Text Available Metformin (dimethyl-biguanide is an insulin-sensitizing agent that lowers fasting plasma-insulin concentration, wherefore it's wide use for patients with a variety of insulin-resistant and prediabetic states, including impaired glucose tolerance. During pregnancy it is a further resource for reducing first-trimester pregnancy loss in women with the polycystic ovary syndrome. We tested metformin genotoxicity in cells of Chinese hamster ovary, CHO-K1 (chromosome aberrations; comet assays and in mice (micronucleus assays. Concentrations of 114.4 µg/mL and 572 µg/mL were used in in vitro tests, and 95.4 mg/kg, 190.8 mg/kg and 333.9 mg/kg in assaying. Although the in vitro tests revealed no chromosome aberrations in metaphase cells, DNA damage was detected by comet assaying after 24 h of incubation at both concentrations. The frequency of DNA damage was higher at concentrations of 114.4 µg/mL. Furthermore, although mortality was not observed in in vitro tests, the highest dose of metformin suppressed bone marrow cells. However, no statistically significant differences were noted in micronuclei frequencies between treatments. In vitro results indicate that chronic metformin exposure may be potentially genotoxic. Thus, pregnant woman undergoing treatment with metformin should be properly evaluated beforehand, as regards vulnerability to DNA damage.

  16. Asymmetric acoustic transmission in multiple frequency bands

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hong-xiang, E-mail: jsdxshx@ujs.edu.cn [Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013 (China); Laboratory of Modern Acoustics, Institute of Acoustics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190 (China); Yuan, Shou-qi, E-mail: Shouqiy@ujs.edu.cn [Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013 (China); Zhang, Shu-yi [Laboratory of Modern Acoustics, Institute of Acoustics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)

    2015-11-23

    We report both experimentally and numerically that the multi-band device of the asymmetric acoustic transmission is realized by placing two periodic gratings with different periods on both sides of two brass plates immersed in water. The asymmetric acoustic transmission can exist in four frequency bands below 1500 kHz, which arises from the interaction between various diffractions from the two gratings and Lamb modes in the brass plates immersed in water. The results indicate that the device has the advantages of multiple band, broader bandwidth, and simpler structure. Our finding should have great potential applications in ultrasonic devices.

  17. Asymmetric acoustic transmission in multiple frequency bands

    International Nuclear Information System (INIS)

    Sun, Hong-xiang; Yuan, Shou-qi; Zhang, Shu-yi

    2015-01-01

    We report both experimentally and numerically that the multi-band device of the asymmetric acoustic transmission is realized by placing two periodic gratings with different periods on both sides of two brass plates immersed in water. The asymmetric acoustic transmission can exist in four frequency bands below 1500 kHz, which arises from the interaction between various diffractions from the two gratings and Lamb modes in the brass plates immersed in water. The results indicate that the device has the advantages of multiple band, broader bandwidth, and simpler structure. Our finding should have great potential applications in ultrasonic devices

  18. A highly sensitive and selective dimethyl ether sensor based on cataluminescence.

    Science.gov (United States)

    Zhang, Runkun; Cao, Xiaoan; Liu, Yonghui; Peng, Yan

    2010-07-15

    A sensor for detecting dimethyl ether was designed based on the cataluminescence phenomenon when dimethyl ether vapors were passing through the surface of the ceramic heater. The proposed sensor showed high sensitivity and selectivity to dimethyl ether at an optimal temperature of 279 degrees C. Quantitative analysis were performed at a wavelength of 425 nm, the flow rate of carrier air is around 300 mL/min. The linear range of the cataluminescence intensity versus concentration of dimethyl ether is 100-6.0x10(3) ppm with a detection limit of 80 ppm. The sensor response time is 2.5 s. Under the optimized conditions, none or only very low levels of interference were observed while the foreign substances such as benzene, formaldehyde, ammonia, methanol, ethanol, acetaldehyde, acetic acid, acrolein, isopropyl ether, ethyl acetate, glycol ether and 2-methoxyethanol were passing through the sensor. Since the sensor does not need to prepare and fix up the granular catalyst, the simple technology reduces cost, improves stability and extends life span. The method can be applied to facilitate detection of dimethyl ether in the air. The possible mechanism of cataluminescence from the oxidation of dimethyl ether on the surface of ceramic heater was discussed based on the reaction products. Copyright 2010 Elsevier B.V. All rights reserved.

  19. Management Strategies to Facilitate Optimal Outcomes for Patients Treated with Delayed-release Dimethyl Fumarate.

    Science.gov (United States)

    Mayer, Lori; Fink, Mary Kay; Sammarco, Carrie; Laing, Lisa

    2018-04-01

    Delayed-release dimethyl fumarate is an oral disease-modifying therapy that has demonstrated significant efficacy in adults with relapsing-remitting multiple sclerosis. Incidences of flushing and gastrointestinal adverse events are common in the first month after delayed-release dimethyl fumarate initiation. Our objective was to propose mitigation strategies for adverse events related to initiation of delayed-release dimethyl fumarate in the treatment of patients with multiple sclerosis. Studies of individually developed mitigation strategies and chart reviews were evaluated. Those results, as well as mitigation protocols developed at multiple sclerosis care centers, are summarized. Key steps to optimize the effectiveness of delayed-release dimethyl fumarate treatment include education prior to and at the time of delayed-release dimethyl fumarate initiation, initiation dose protocol gradually increasing to maintenance dose, dietary suggestions for co-administration with food, gastrointestinal symptom management with over-the-counter medications, flushing symptom management with aspirin, and temporary dose reduction. Using the available evidence from clinical trials and evaluations of post-marketing studies, these strategies to manage gastrointestinal and flushing symptoms can be effective and helpful to the patient when initiating delayed-release dimethyl fumarate.

  20. Asymmetric Dimethylarginine Plasma Levels and Endothelial Function in Newly Diagnosed Type 2 Diabetic Patients

    Directory of Open Access Journals (Sweden)

    Francesco Perticone

    2012-10-01

    Full Text Available It is now well established that major risk factors for cardiovascular diseases (CVD impact upon endothelial function by decreasing nitric oxide (NO bioavailability. Asymmetric dimethylarginine (ADMA, an endogenous analog of l-arginine, is able to inhibit the activity of endothelial-NO synthase, promoting endothelial dysfunction. Type 2 diabetes (T2D is characterized by a reduced endothelium-dependent vasodilation and increased ADMA levels and ADMA is strongly associated with micro- and macrovascular diabetic complications. However, there are not a lot of data about the role of ADMA on endothelial function in newly diagnosed T2D patients without cardiovascular (CV complications. For this aim, we have enrolled forty-five newly diagnosed T2D patients, evaluated by a oral glucose tolerance test, and thirty normal subjects. Endothelium-dependent and -independent vasodilatation was investigated by intra-arterial infusion of increasing doses of acetylcholine (ACh and sodium nitroprusside. ADMA was measured by high-performance liquid chromatography and insulin resistance (IR by HOMA. Newly diagnosed T2D patients showed higher ADMA and l-arginine mean values in comparison with normal subjects and a significantly reduced ACh-stimulated forearm blood flow (FBF. In T2D patients FBF was significantly and inversely correlated with ADMA (r = −0.524, p < 0.0001 and in a multivariate regression analysis, ADMA resulted the stronger predictor of FBF, explaining the 27.5% of variability (p < 0.0001. In conclusion, ADMA was strongly related to endothelial dysfunction also in patients with newly diagnosed T2D, without clinically manifest vascular complications. This field is of great interest for understanding the mechanisms underlying the pathogenesis of diabetic disease and its CV complications.

  1. Oral L-Arginine Stimulates GLP-1 Secretion to Improve Glucose Tolerance in Male Mice

    DEFF Research Database (Denmark)

    Clemmensen, Christoffer; Smajilovic, Sanela; Smith, Eric P

    2013-01-01

    Pharmacological and surgical interventions that increase glucagon-like peptide 1 (GLP-1) action are effective to improve glucose homeostasis in type 2 diabetes mellitus. In light of this, nutritional strategies to enhance postprandial GLP-1 secretion, particularly in the context of diet......-induced obesity, may provide an alternative therapeutic approach. Importantly, recent evidence suggests the amino acid l-arginine, a well-known insulin secretagogue, can also stimulate release of GLP-1 from isolated rat intestine. Here we tested the hypothesis that oral l-arginine acts as a GLP-1 secretagogue...... in vivo, to augment postprandial insulin secretion and improve glucose tolerance. To test this, we administered l-arginine or vehicle by oral gavage, immediately prior to an oral glucose tolerance test in lean and diet-induced obese mice. In both lean and obese mice oral l-arginine increased plasma GLP-1...

  2. Endothelial arginine resynthesis contributes to the maintenance of vasomotor function in male diabetic mice

    DEFF Research Database (Denmark)

    Chennupati, Ramesh; Meens, Merlijn J P M T; Marion, Vincent

    2014-01-01

    AIM: Argininosuccinate synthetase (ASS) is essential for recycling L-citrulline, the by-product of NO synthase (NOS), to the NOS substrate L-arginine. Here, we assessed whether disturbed arginine resynthesis modulates endothelium-dependent vasodilatation in normal and diabetic male mice. METHODS...... of endothelial citrulline recycling to arginine did not affect blood pressure and systemic arterial vasomotor responses in healthy mice. EDNO-mediated vasodilatation was significantly more impaired in diabetic Ass-KOTie2 than in control mice demonstrating that endothelial arginine recycling becomes a limiting...... responses were studied in isolated saphenous arteries of 12- and 34-week-old Ass-KOTie2 and control animals. At the age of 10 weeks, diabetes was induced in control and Ass-KOTie2 mice by streptozotocin injections. Vasomotor responses of diabetic animals were studied 10 weeks later. MAP was similar...

  3. Improved method and its clinical application of a radioimmunoassay of arginine vasopressin in human serum

    International Nuclear Information System (INIS)

    Wagner, H.; Maier, V.; Franz, H.W.; Ulm Univ.; Ulm Univ.

    1977-01-01

    A sensitive and specific double-antibody radioimmunoassay for measuring circulating levels of arginine vasopressin in human serum is described. It is possible to detect arginine vasopressin levels of 1 μU/ml serum without extraction procedure. Normal subjects were found to have 5.7 +- 4.4 μU/ml after a dehydration period of 12 hours. Water loading diminished arginine vasopressin concentrations while dehydration incrased it. Application of furosemide over a period of 14 days brought forth constant but not significant decreases. Subjects suffering from psychogenic polydipsia showed normal levels in spite of drinking 8-12 liters of water per day. Patients suffering from liver cirrhosis with ascites showed significantly higher arginine vasopressin levels, approaching normal values when ascites was under control. (orig.) [de

  4. Synthesis, characterization and properties of L-arginine-passivated silver nanocolloids

    International Nuclear Information System (INIS)

    Sunatkari, A. L.; Talwatkar, S. S.; Tamgadge, Y. S.; Muley, G. G.

    2016-01-01

    We investigate the effect of L-arginine-surface passivation on localised surface plasmon resonance (LSPR), size and stability of colloidal Silver Nanoparticles (AgNPs) synthesized by chemical reduction method. The surface Plasmon resonance absorption peak of AgNPs shows blue shift with the increase in L-arginine concentration. Transmission electron microscopy (TEM) analysis confirmed that the average size of AgNPs reduces from 10 nm to 6 nm as the concentration of L-Arginine increased from 1 to 5 mM. The X-ray diffraction study (XRD) confirmed the formation face-centred cubic (fcc) structured AgNPs. FT-IR studies revealed strong bonding between L-arginine functional groups and AgNPs.

  5. Synthesis, characterization and properties of L-arginine-passivated silver nanocolloids

    Energy Technology Data Exchange (ETDEWEB)

    Sunatkari, A. L., E-mail: ashok.sunatkari@rediffmail.com [Department of Physics, Siddhartha College of Arts, Science and Commerce, Fort, Mumbai-400001, India. Email: ashok.sunatkari@rediffmail.com (India); Talwatkar, S. S. [Department of Physics, N.G. Aacharya and D.K. Maratha College of Arts, Science and Commerce, Chembur, Mumbai-400071, India. Email: swarna-81@rediffmail.com (India); Tamgadge, Y. S. [Department of Physics, Mahatma Phule Arts, Commerce & S.R.C. Science College, Warud-444906, India. Email: ystamgadge@gmail.com (India); Muley, G. G., E-mail: gajananggm@yahoo.co.in [Department of Physics, Sant Gadge Baba Amravati University, Amravati-444602 India. Email: gajananggm@yahoo.co.in (India)

    2016-05-06

    We investigate the effect of L-arginine-surface passivation on localised surface plasmon resonance (LSPR), size and stability of colloidal Silver Nanoparticles (AgNPs) synthesized by chemical reduction method. The surface Plasmon resonance absorption peak of AgNPs shows blue shift with the increase in L-arginine concentration. Transmission electron microscopy (TEM) analysis confirmed that the average size of AgNPs reduces from 10 nm to 6 nm as the concentration of L-Arginine increased from 1 to 5 mM. The X-ray diffraction study (XRD) confirmed the formation face-centred cubic (fcc) structured AgNPs. FT-IR studies revealed strong bonding between L-arginine functional groups and AgNPs.

  6. Improved method and its clinical application of a radioimmunoassay of arginine vasopressin in human serum

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, H; Maier, V; Franz, H W [Ulm Univ. (Germany, F.R.). Abt. Endokrinologie und Stoffwechsel; Ulm Univ. (Germany, F.R.). Zentrum fuer Innere Medizin und Kinderheilkunde; Ulm Univ. (Germany, F.R.). Sektion Nephrologie)

    1977-05-01

    A sensitive and specific double-antibody radioimmunoassay for measuring circulating levels of arginine vasopressin in human serum is described. It is possible to detect arginine vasopressin levels of 1 ..mu..U/ml serum without extraction procedure. Normal subjects were found to have 5.7 +- 4.4 ..mu..U/ml after a dehydration period of 12 hours. Water loading diminished arginine vasopressin concentrations while dehydration incrased it. Application of furosemide over a period of 14 days brought forth constant but not significant decreases. Subjects suffering from psychogenic polydipsia showed normal levels in spite of drinking 8-12 liters of water per day. Patients suffering from liver cirrhosis with ascites showed significantly higher arginine vasopressin levels, approaching normal values when ascites was under control.

  7. The effect of citrulline and arginine supplementation on lactic acidemia in MELAS syndrome☆

    Science.gov (United States)

    El-Hattab, Ayman W.; Emrick, Lisa T.; Williamson, Kaitlin C.; Craigen, William J.; Scaglia, Fernando

    2013-01-01

    Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a mitochondrial disorder in which nitric oxide (NO) deficiency may play a role in the pathogenesis of several complications including stroke-like episodes and lactic acidosis. Supplementing the NO precursors arginine and citrulline restores NO production in MELAS syndrome. In this study we evaluated the effect of arginine or citrulline on lactic acidemia in adults with MELAS syndrome. Plasma lactate decreased significantly after citrulline supplementation, whereas the effect of arginine supplementation did not reach statistical significance. These results support the potential therapeutic utility of arginine and citrulline in MELAS syndrome and suggest that citrulline supplementation may be more efficacious. However, therapeutic efficacy of these compounds should be further evaluated in clinical trials. PMID:25411654

  8. The effect of citrulline and arginine supplementation on lactic acidemia in MELAS syndrome.

    Science.gov (United States)

    El-Hattab, Ayman W; Emrick, Lisa T; Williamson, Kaitlin C; Craigen, William J; Scaglia, Fernando

    2013-12-01

    Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a mitochondrial disorder in which nitric oxide (NO) deficiency may play a role in the pathogenesis of several complications including stroke-like episodes and lactic acidosis. Supplementing the NO precursors arginine and citrulline restores NO production in MELAS syndrome. In this study we evaluated the effect of arginine or citrulline on lactic acidemia in adults with MELAS syndrome. Plasma lactate decreased significantly after citrulline supplementation, whereas the effect of arginine supplementation did not reach statistical significance. These results support the potential therapeutic utility of arginine and citrulline in MELAS syndrome and suggest that citrulline supplementation may be more efficacious. However, therapeutic efficacy of these compounds should be further evaluated in clinical trials.

  9. The effects of L-arginine, D-arginine, L-name and methylene blue on channa striatus-induced peripheral antinociception in mice.

    Science.gov (United States)

    Zakaria, Zainul Amiruddin; Sulaiman, Mohd Rosian; Somchit, Muhammad Nazrul; Jais, Abdul Manan Mat; Ali, Daud Israf

    2005-08-03

    To determine the involvement of nitric oxide/cyclic guanosine monophosphate (NO/cGMP) pathway in aqueous supernatant of haruan (Channa striatus) fillet (ASH) antinociception using the acetic acid-induced abdominal constriction test. The ASH was prepared by soaking fresh haruan fillet in chloroform:methanol (CM) (2/1 (v/v)) for 72 h followed by evaporation of the upper layer supernatant to remove any solvent residues. The supernatant was then subjected to a freeze-drying process (48 h) followed by doses preparation. Subcutaneous (SC) administration of ASH alone (0.170, 0.426 and 1.704 mg/kg) exhibited a dose-dependent antinociception. On the other hand, 20 mg/kg (SC) of L-arginine and MB exhibited a significant nociception and antinociception, while D-arginine and L-NAME did not produce any effect at all. Pre-treatment with L-arginine was found to significantly reverse the three respective doses of ASH antinociception; pre-treatment with D-arginine did not produce any significant change in the ASH activity; pre-treatment with L-NAME only significantly increased the 0.170 and 0.426 mg/kg ASH antinociception; and pre-treatment with MB significantly enhanced the respective doses of ASH antinociception, respectively. Furthermore, co-treatment with L-NAME significantly enhanced the L-arginine reversal effect on 0.426 mg/kg ASH antinociception. In addition, MB significantly reversed the L-arginine nociception on 0.426 mg/kg ASH. These finding suggest ASH antinociception involves the nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) pathway. The presence of NO was found to reverse ASH antinociceptive activity while blocking of cGMP system enhanced it.

  10. Plasma l-citrulline concentrations in l-arginine-supplemented healthy dogs.

    Science.gov (United States)

    Flynn, K M; Kellihan, H B; Trepanier, L A

    2017-08-01

    To determine whether oral l-arginine increases plasma [l-citrulline] in dogs. Eleven healthy staff-owned dogs were used in this study. Dogs (n = 3) were given l-arginine (50mg/kg PO q8h) for 7 days, and plasma [l-arginine] and [l-citrulline] were analyzed by high performance liquid chromatography at baseline (BL), steady state trough, and 0.5, 1, 1.5, 2, 4, 6, and 8 h after final dosing on day 7. Eleven dogs were then treated with 100mg/kg l-arginine PO q8h for 7 days, and [l-arginine] and [l-citrulline] were measured at BL, steady state trough, and at peak 4 hrs after dosing (T4 hrs). - Plasma [l-arginine] and [l-citrulline] peaked at T4 hrs on the 50mg/kg dosage. Target outcome, modeled after human study results, of a doubling of [l-arginine] and a 25-30% increase in [l-citrulline] from BL were not reached. After the 100mg/kg dosage, plasma [l-arginine] increased from a BL median of 160.1 μM (range, 100.2-231.4 μM) to a peak of 417.4 μM (206.5-807.3 μM) at T4 hrs, and plasma [l-citrulline] increased from a BL median of 87.8 μM (59.1-117.1 μM) to peak of 102.2 μM (47.4-192.6 μM) at T4 hrs. Ten of eleven dogs showed a doubling of plasma [l-arginine] and 4/11 dogs achieved 25-30% or greater increases in plasma [l-citrulline]. No adverse effects on heart rate or blood pressure were noted. - Oral l-arginine dosage of 100mg/kg q8h doubles plasma [l-arginine] in healthy dogs, but conversion to l-citrulline is quite variable. Further evaluation of this dosage regimen in dogs with pulmonary hypertension is warranted. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Arginine metabolism by macrophages promotes cardiac and muscle fibrosis in mdx muscular dystrophy.

    Directory of Open Access Journals (Sweden)

    Michelle Wehling-Henricks

    2010-05-01

    Full Text Available Duchenne muscular dystrophy (DMD is the most common, lethal disease of childhood. One of 3500 new-born males suffers from this universally-lethal disease. Other than the use of corticosteroids, little is available to affect the relentless progress of the disease, leading many families to use dietary supplements in hopes of reducing the progression or severity of muscle wasting. Arginine is commonly used as a dietary supplement and its use has been reported to have beneficial effects following short-term administration to mdx mice, a genetic model of DMD. However, the long-term effects of arginine supplementation are unknown. This lack of knowledge about the long-term effects of increased arginine metabolism is important because elevated arginine metabolism can increase tissue fibrosis, and increased fibrosis of skeletal muscles and the heart is an important and potentially life-threatening feature of DMD.We use both genetic and nutritional manipulations to test whether changes in arginase metabolism promote fibrosis and increase pathology in mdx mice. Our findings show that fibrotic lesions in mdx muscle are enriched with arginase-2-expressing macrophages and that muscle macrophages stimulated with cytokines that activate the M2 phenotype show elevated arginase activity and expression. We generated a line of arginase-2-null mutant mdx mice and found that the mutation reduced fibrosis in muscles of 18-month-old mdx mice, and reduced kyphosis that is attributable to muscle fibrosis. We also observed that dietary supplementation with arginine for 17-months increased mdx muscle fibrosis. In contrast, arginine-2 mutation did not reduce cardiac fibrosis or affect cardiac function assessed by echocardiography, although 17-months of dietary supplementation with arginine increased cardiac fibrosis. Long-term arginine treatments did not decrease matrix metalloproteinase-2 or -9 or increase the expression of utrophin, which have been reported as beneficial

  12. Research

    African Journals Online (AJOL)

    abp

    2017-09-27

    Sep 27, 2017 ... protein, carotid intima -media thickness and asymmetric dimethyl arginine have been .... with LVH had a higher body mass index (27.3 vs 26.3, p=0.04) and were slightly .... adversely impacts cardiovascular morbidity and mortality in CKD patients [2-4]. ... conceptualized and designed the study. Yaw Ampem ...

  13. L-ARGININE PREVENTS METABOLIC EFFECTS OF HIGH GLUCOSE IN DIABETIC MICE

    OpenAIRE

    West, Matthew B.; Ramana, Kota V.; Kaiserova, Karin; Srivastava, Satish K.; Bhatnagar, Aruni

    2008-01-01

    We tested the hypothesis that activation of the polyol pathway and protein kinase C (PKC) during diabetes is due to loss of NO. Our results show that after 4 weeks of streptozotocin-induced diabetes, treatment with L-arginine restored NO levels and prevented tissue accumulation of sorbitol in mice, which was accompanied by an increase in glutathiolation of aldose reductase. L-arginine treatment decreased superoxide generation in the aorta, total PKC activity and PKC-βII phosphorylation in the...

  14. Standards vs. labels with imperfect competition and asymmetric information

    DEFF Research Database (Denmark)

    Baltzer, Kenneth Thomas

    2012-01-01

    I demonstrate that providing information about product quality is not necessarily the best way to address asymmetric information problems when markets are imperfectly competitive. In a vertical differentiation model I show that a Minimum Quality Standard, which retains asymmetric information...

  15. Standards vs. labels with imperfect competition and asymmetric information

    DEFF Research Database (Denmark)

    Baltzer, Kenneth Thomas

    I demonstrate that providing information about product quality is not necessarily the best way to address asymmetric information problems when markets are imperfectly competitive. In a vertical dierentiation model I show that a Minimum Quality Standard, which retains asymmetric information...

  16. Vortex Dynamics of Asymmetric Heave Plates

    Science.gov (United States)

    Rusch, Curtis; Maurer, Benjamin; Polagye, Brian

    2017-11-01

    Heave plates can be used to provide reaction forces for wave energy converters, which harness the power in ocean surface waves to produce electricity. Heave plate inertia includes both the static mass of the heave plate, as well as the ``added mass'' of surrounding water accelerated with the object. Heave plate geometries may be symmetric or asymmetric, with interest in asymmetric designs driven by the resulting hydrodynamic asymmetry. Limited flow visualization has been previously conducted on symmetric heave plates, but flow visualization of asymmetric designs is needed to understand the origin of observed hydrodynamic asymmetries and their dependence on the Keulegan-Carpenter number. For example, it is hypothesized that the time-varying added mass of asymmetric heave plates is caused by vortex shedding, which is related to oscillation amplitude. Here, using direct flow visualization, we explore the relationship between vortex dynamics and time-varying added mass and drag. These results suggest potential pathways for more advanced heave plate designs that can exploit vortex formation and shedding to achieve more favorable hydrodynamic properties for wave energy converters.

  17. Asymmetric hindwing foldings in rove beetles.

    Science.gov (United States)

    Saito, Kazuya; Yamamoto, Shuhei; Maruyama, Munetoshi; Okabe, Yoji

    2014-11-18

    Foldable wings of insects are the ultimate deployable structures and have attracted the interest of aerospace engineering scientists as well as entomologists. Rove beetles are known to fold their wings in the most sophisticated ways that have right-left asymmetric patterns. However, the specific folding process and the reason for this asymmetry remain unclear. This study reveals how these asymmetric patterns emerge as a result of the folding process of rove beetles. A high-speed camera was used to reveal the details of the wing-folding movement. The results show that these characteristic asymmetrical patterns emerge as a result of simultaneous folding of overlapped wings. The revealed folding mechanisms can achieve not only highly compact wing storage but also immediate deployment. In addition, the right and left crease patterns are interchangeable, and thus each wing internalizes two crease patterns and can be folded in two different ways. This two-way folding gives freedom of choice for the folding direction to a rove beetle. The use of asymmetric patterns and the capability of two-way folding are unique features not found in artificial structures. These features have great potential to extend the design possibilities for all deployable structures, from space structures to articles of daily use.

  18. Mixed gas plasticization phenomena in asymmetric membranes

    NARCIS (Netherlands)

    Visser, Tymen

    2006-01-01

    This thesis describes the thorough investigation of mixed gas transport behavior of asymmetric membranes in the separation of feed streams containing plasticizing gases in order to gain more insights into the complicated behavior of plasticization. To successfully employ gas separation membranes in

  19. Asymmetric conditional volatility in international stock markets

    Science.gov (United States)

    Ferreira, Nuno B.; Menezes, Rui; Mendes, Diana A.

    2007-08-01

    Recent studies show that a negative shock in stock prices will generate more volatility than a positive shock of similar magnitude. The aim of this paper is to appraise the hypothesis under which the conditional mean and the conditional variance of stock returns are asymmetric functions of past information. We compare the results for the Portuguese Stock Market Index PSI 20 with six other Stock Market Indices, namely the SP 500, FTSE 100, DAX 30, CAC 40, ASE 20, and IBEX 35. In order to assess asymmetric volatility we use autoregressive conditional heteroskedasticity specifications known as TARCH and EGARCH. We also test for asymmetry after controlling for the effect of macroeconomic factors on stock market returns using TAR and M-TAR specifications within a VAR framework. Our results show that the conditional variance is an asymmetric function of past innovations raising proportionately more during market declines, a phenomenon known as the leverage effect. However, when we control for the effect of changes in macroeconomic variables, we find no significant evidence of asymmetric behaviour of the stock market returns. There are some signs that the Portuguese Stock Market tends to show somewhat less market efficiency than other markets since the effect of the shocks appear to take a longer time to dissipate.

  20. MHD stability of vertically asymmetric tokamak equilibria

    International Nuclear Information System (INIS)

    Dalhed, H.E.; Grimm, R.C.; Johnson, J.L.

    1981-03-01

    The ideal MHD stability properties of a special class of vertically asymmetric tokamak equilibria are examined. The calculations confirm that no major new physical effects are introduced and the modifications can be understood by conventional arguments. The results indicate that significant departures from up-down symmetry can be tolerated before the reduction in β becomes important for reactor operation

  1. Catalytic asymmetric synthesis of the alkaloid (+)-myrtine

    NARCIS (Netherlands)

    Pizzuti, Maria Gabriefla; Minnaard, Adriaan J.; Feringa, Ben L.

    2008-01-01

    A new protocol for the asymmetric synthesis of trans-2,6-disubstituted-4-piperidones has been developed using a catalytic enantioselective conjugate addition reaction in combination with a diastereoselective lithiation-substitution sequence; an efficient synthesis of (+)-myrtine has been achieved

  2. Asymmetric Aminalization via Cation-Binding Catalysis

    DEFF Research Database (Denmark)

    Park, Sang Yeon; Liu, Yidong; Oh, Joong Suk

    2018-01-01

    Asymmetric cation-binding catalysis, in principle, can generate "chiral" anionic nucleophiles, where the counter cations are coordinated within chiral environments. Nitrogen-nucleophiles are intrinsically basic, therefore, its use as nucleophiles is often challenging and limiting the scope of the...

  3. Volume inequalities for asymmetric Wulff shapes

    OpenAIRE

    Schuster, Franz E.; Weberndorfer, Manuel

    2012-01-01

    Sharp reverse affine isoperimetric inequalities for asymmetric Wulff shapes and their polars are established, along with the characterization of all extremals. These new inequalities have as special cases previously obtained simplex inequalities by Ball, Barthe and Lutwak, Yang, and Zhang. In particular, they provide the solution to a problem by Zhang.

  4. Quantum optics of lossy asymmetric beam splitters

    NARCIS (Netherlands)

    Uppu, Ravitej; Wolterink, Tom; Tentrup, Tristan Bernhard Horst; Pinkse, Pepijn Willemszoon Harry

    2016-01-01

    We theoretically investigate quantum interference of two single photons at a lossy asymmetric beam splitter, the most general passive 2×2 optical circuit. The losses in the circuit result in a non-unitary scattering matrix with a non-trivial set of constraints on the elements of the scattering

  5. Motion in an Asymmetric Double Well

    OpenAIRE

    Brizard, Alain J.; Westland, Melissa C.

    2016-01-01

    The problem of the motion of a particle in an asymmetric double well is solved explicitly in terms of the Weierstrass and Jacobi elliptic functions. While the solution of the orbital motion is expressed simply in terms of the Weierstrass elliptic function, the period of oscillation is more directly expressed in terms of periods of the Jacobi elliptic functions.

  6. Asymmetric output profile of Xe Laser

    NARCIS (Netherlands)

    Blok, F.J.; Rubin, P.L.; Verschuur, Jeroen W.J.; Witteman, W.J.

    2001-01-01

    A new set of asymmetric modes was recently revealed in a Xe slab laser with pronounced lens effects originating from gas heating in the discharge. The appearance of these modes is a threshold effect. Their domain of existence in the Xe laser is discussed. It is shown that mode competition can result

  7. Computing modal dispersion characteristics of radially Asymmetric ...

    African Journals Online (AJOL)

    We developed a matrix theory that applies to with non-circular/circular but concentric layers fibers. And we compute the dispersion characteristics of radially unconventional fiber, known as Asymmetric Bragg fiber. An attempt has been made to determine how the modal characteristics change as circular Bragg fiber is ...

  8. Seasonally asymmetric enhancement of northern vegetation productivity

    Science.gov (United States)

    Park, T.; Myneni, R.

    2017-12-01

    Multiple evidences of widespread greening and increasing terrestrial carbon uptake have been documented. In particular, enhanced gross productivity of northern vegetation has been a critical role leading to observed carbon uptake trend. However, seasonal photosynthetic activity and its contribution to observed annual carbon uptake trend and interannual variability are not well understood. Here, we introduce a multiple-source of datasets including ground, atmospheric and satellite observations, and multiple process-based global vegetation models to understand how seasonal variation of land surface vegetation controls a large-scale carbon exchange. Our analysis clearly shows a seasonally asymmetric enhancement of northern vegetation productivity in growing season during last decades. Particularly, increasing gross productivity in late spring and early summer is obvious and dominant driver explaining observed trend and variability. We observe more asymmetric productivity enhancement in warmer region and this spatially varying asymmetricity in northern vegetation are likely explained by canopy development rate, thermal and light availability. These results imply that continued warming may facilitate amplifying asymmetric vegetation activity and cause these trends to become more pervasive, in turn warming induced regime shift in northern land.

  9. tlpA gene expression is required for arginine and bicarbonate chemotaxis in Helicobacter pylori.

    Science.gov (United States)

    Cerda, Oscar A; Núñez-Villena, Felipe; Soto, Sarita E; Ugalde, José Manuel; López-Solís, Remigio; Toledo, Héctor

    2011-01-01

    About half of the human population is infected with Helicobacter pylori, a bacterium causing gastritis, peptic ulcer and progression to gastric cancer. Chemotaxis and flagellar motility are required for colonization and persistence of H. pylori in the gastric mucus layer. It is not completely clear which chemical gradients are used by H. pylori to maintain its position. TlpA, a chemotaxis receptor for arginine/ bicarbonate, has been identified. This study aimed to find out whether tlpA gene expression is required for the chemotactic response to arginine/bicarbonate. Wild-type motile H. pylori ATCC 700392 and H. pylori ATCC 43504, a strain having an interrupted tlpA gene, were used. Also, a tlpA-knockout mutant of H. pylori 700392 (H. pylori 700-tlpA::cat) was produced by homologous recombination. Expression of tlpA was assessed by a Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) assay. Chemotaxis was measured as a Relative Chemotaxis Response (RCR) by a modified capillary assay. H. pylori 700392 presented chemotaxis to arginine and sodium bicarbonate. H. pylori 700-tlpA::cat showed neither tlpA gene expression nor chemotaxis towards arginine and bicarbonate. Besides confirming that TlpA is a chemotactic receptor for arginine/bicarbonate in H. pylori, this study showed that tlpA gene expression is required for arginine/bicarbonate chemotaxis.

  10. The role of arginine metabolic pathway during embryogenesis and germination in maritime pine (Pinus pinaster Ait.).

    Science.gov (United States)

    Llebrés, María-Teresa; Pascual, María-Belén; Debille, Sandrine; Trontin, Jean-François; Harvengt, Luc; Avila, Concepción; Cánovas, Francisco M

    2018-03-01

    Vegetative propagation through somatic embryogenesis is critical in conifer biotechnology towards multivarietal forestry that uses elite varieties to cope with environmental and socio-economic issues. An important and still sub-optimal process during in vitro maturation of somatic embryos (SE) is the biosynthesis and deposition of storage proteins, which are rich in amino acids with high nitrogen (N) content, such as arginine. Mobilization of these N-rich proteins is essential for the germination and production of vigorous somatic seedlings. Somatic embryos accumulate lower levels of N reserves than zygotic embryos (ZE) at a similar stage of development. To understand the molecular basis for this difference, the arginine metabolic pathway has been characterized in maritime pine (Pinus pinaster Ait.). The genes involved in arginine metabolism have been identified and GFP-fusion constructs were used to locate the enzymes in different cellular compartments and clarify their metabolic roles during embryogenesis and germination. Analysis of gene expression during somatic embryo maturation revealed high levels of transcripts for genes involved in the biosynthesis and metabolic utilization of arginine. By contrast, enhanced expression levels were only observed during the last stages of maturation and germination of ZE, consistent with the adequate accumulation and mobilization of protein reserves. These results suggest that arginine metabolism is unbalanced in SE (simultaneous biosynthesis and degradation of arginine) and could explain the lower accumulation of storage proteins observed during the late stages of somatic embryogenesis.

  11. Arginine- and Polyamine-Induced Lactic Acid Resistance in Neisseria gonorrhoeae.

    Directory of Open Access Journals (Sweden)

    Zheng Gong

    Full Text Available Microbe-derived lactic acid protects women from pathogens in their genital tract. The purpose of this study was to determine lactic acid susceptibility of Neisseria gonorrhoeae, and identify potential acid resistance mechanisms present in this pathogen. Tested in vitro, lactic acid killed all 10 gonococcal strains analyzed in a low pH-dependent manner. Full inactivation occurred at pH 4.5. At low pH, lactic acid treatment resulted in the entry of the DNA-binding fluorochrome propidium iodide into the microbial cells, suggesting that hydrogen ions from lactic acid compromise the integrity of the bacterial cell wall/membrane. Most likely, hydrogen ions also inactivate intracellular proteins since arginine rendered significant protection against lactic acid presumably through action of the gonococcal arginine decarboxylase, an enzyme located in the bacterial cytoplasm. Surprisingly, arginine also lessened lactic acid-mediated cell wall/membrane disruption. This effect is probably mediated by agmatine, a triamine product of arginine decarboxylase, since agmatine demonstrated a stronger protective effect on GC than arginine at equal molar concentration. In addition to agmatine, diamines cadaverine and putrescine, which are generated by bacterial vaginosis-associated microbes, also induced significant resistance to lactic acid-mediated GC killing and cell wall/membrane disruption. These findings suggest that the arginine-rich semen protects gonococci through both neutralization-dependent and independent mechanisms, whereas polyamine-induced acid resistance contributes to the increased risk of gonorrhea in women with bacterial vaginosis.

  12. tlpA gene expression is required for arginine and bicarbonate chemotaxis in Helicobacter pylori

    Directory of Open Access Journals (Sweden)

    Oscar A Cerda

    2011-01-01

    Full Text Available About half of the human population is infected with Helicobacter pylori, a bacterium causing gastritis, peptic ulcer and progression to gastric cancer. Chemotaxis and flagellar motility are required for colonization and persistence of H. pylori in the gastric mucus layer. It is not completely clear which chemical gradients are used by H. pylori to maintain its position. TlpA, a chemotaxis receptor for arginine/ bicarbonate, has been identified. This study aimed to find out whether tlpA gene expression is required for the chemotactic response to arginine/bicarbonate. Wild-type motile H. pylori ATCC 700392 and H. pylori ATCC 43504, a strain having an interrupted tlpA gene, were used. Also, a tlpA-knockout mutant of H. pylori 700392 (H. pylori 700-tlpA::cat was produced by homologous recombination. Expression of tlpA was assessed by a Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR assay. Chemotaxis was measured as a Relative Chemotaxis Response (RCR by a modified capillary assay. H. pylori 700392 presented chemotaxis to arginine and sodium bicarbonate. H. pylori 700-tlpA::cat showed neither tlpA gene expression nor chemotaxis towards arginine and bicarbonate. Besides confirming that TlpA is a chemotactic receptor for arginine/bicarbonate in H. pylori, this study showed that tlpA gene expression is required for arginine/bicarbonate chemotaxis.

  13. Charge Asymmetric Cosmic Rays as a probe of Flavor Violating Asymmetric Dark Matter

    DEFF Research Database (Denmark)

    Masina, Isabella; Sannino, Francesco

    2011-01-01

    The recently introduced cosmic sum rules combine the data from PAMELA and Fermi-LAT cosmic ray experiments in a way that permits to neatly investigate whether the experimentally observed lepton excesses violate charge symmetry. One can in a simple way determine universal properties of the unknown...... component of the cosmic rays. Here we attribute a potential charge asymmetry to the dark sector. In particular we provide models of asymmetric dark matter able to produce charge asymmetric cosmic rays. We consider spin zero, spin one and spin one-half decaying dark matter candidates. We show that lepton...... flavor violation and asymmetric dark matter are both required to have a charge asymmetry in the cosmic ray lepton excesses. Therefore, an experimental evidence of charge asymmetry in the cosmic ray lepton excesses implies that dark matter is asymmetric....

  14. DIMETHYL ETHER (DME)-FUELED SHUTTLE BUS DEMONSTRATION PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Elana M. Chapman; Shirish Bhide; Jennifer Stefanik; Howard Glunt; Andre L. Boehman; Allen Homan; David Klinikowski

    2003-04-01

    The objectives of this research and demonstration program are to convert a campus shuttle bus to operation on dimethyl ether, a potential ultra-clean alternative diesel fuel. To accomplish this objective, this project includes laboratory evaluation of a fuel conversion strategy, as well as, field demonstration of the DME-fueled shuttle bus. Since DME is a fuel with no lubricity (i.e., it does not possess the lubricating quality of diesel fuel), conventional fuel delivery and fuel injection systems are not compatible with dimethyl ether. Therefore, to operate a diesel engine on DME one must develop a fuel-tolerant injection system, or find a way to provide the necessary lubricity to the DME. In this project, they have chosen the latter strategy in order to achieve the objective with minimal need to modify the engine. Their strategy is to blend DME with diesel fuel, to obtain the necessary lubricity to protect the fuel injection system and to achieve low emissions. The bulk of the efforts over the past year were focused on the conversion of the campus shuttle bus. This process, started in August 2001, took until April 2002 to complete. The process culminated in an event to celebrate the launching of the shuttle bus on DME-diesel operation on April 19, 2002. The design of the system on the shuttle bus was patterned after the system developed in the engine laboratory, but also was subjected to a rigorous failure modes effects analysis (FMEA, referred to by Air Products as a ''HAZOP'' analysis) with help from Dr. James Hansel of Air Products. The result of this FMEA was the addition of layers of redundancy and over-pressure protection to the system on the shuttle bus. The system became operational in February 2002. Preliminary emissions tests and basic operation of the shuttle bus took place at the Pennsylvania Transportation Institute's test track facility near the University Park airport. After modification and optimization of the system on

  15. L-arginine:glycine amidinotransferase deficiency protects from metabolic syndrome.

    Science.gov (United States)

    Choe, Chi-un; Nabuurs, Christine; Stockebrand, Malte C; Neu, Axel; Nunes, Patricia; Morellini, Fabio; Sauter, Kathrin; Schillemeit, Stefan; Hermans-Borgmeyer, Irm; Marescau, Bart; Heerschap, Arend; Isbrandt, Dirk

    2013-01-01

    Phosphorylated creatine (Cr) serves as an energy buffer for ATP replenishment in organs with highly fluctuating energy demand. The central role of Cr in the brain and muscle is emphasized by severe neurometabolic disorders caused by Cr deficiency. Common symptoms of inborn errors of creatine synthesis or distribution include mental retardation and muscular weakness. Human mutations in l-arginine:glycine amidinotransferase (AGAT), the first enzyme of Cr synthesis, lead to severely reduced Cr and guanidinoacetate (GuA) levels. Here, we report the generation and metabolic characterization of AGAT-deficient mice that are devoid of Cr and its precursor GuA. AGAT-deficient mice exhibited decreased fat deposition, attenuated gluconeogenesis, reduced cholesterol levels and enhanced glucose tolerance. Furthermore, Cr deficiency completely protected from the development of metabolic syndrome caused by diet-induced obesity. Biochemical analyses revealed the chronic Cr-dependent activation of AMP-activated protein kinase (AMPK), which stimulates catabolic pathways in metabolically relevant tissues such as the brain, skeletal muscle, adipose tissue and liver, suggesting a mechanism underlying the metabolic phenotype. In summary, our results show marked metabolic effects of Cr deficiency via the chronic activation of AMPK in a first animal model of AGAT deficiency. In addition to insights into metabolic changes in Cr deficiency syndromes, our genetic model reveals a novel mechanism as a potential treatment option for obesity and type 2 diabetes mellitus.

  16. Deceleration of arginine kinase refolding by induced helical structures.

    Science.gov (United States)

    Li, Hai-Long; Zhou, Sheng-Mei; Park, Daeui; Jeong, Hyoung Oh; Chung, Hae Young; Yang, Jun-Mo; Meng, Fan-Guo; Hu, Wei-Jiang

    2012-04-01

    Arginine kinase (AK) is a key metabolic enzyme for keeping energy balance in invertebrates. Therefore, regulation of the enzymatic activity and the folding studies of AK from the various invertebrates have been the focus of investigation. We studied the effects of helical structures by using hexafluoroisopropanol (HFIP) on AK folding. Folding kinetic studies showed that the folding rates of the urea-denatured AKs were significantly decelerated after being induced in various concentrations of HFIP. AK lost its activity completely at concentrations greater than 60%. The results indicated that the HFIP-induced helical structures in the denatured state play a negative role in protein folding, and the helical structures induced in 5% (v/v) HFIP act as the most effective barrier against AK taking its native structure. The computational docking simulations (binding energies for -2.19 kcal/mol for AutoDock4.2 and -20.47 kcal/mol for Dock6.3) suggested that HFIP interacts with the several important residues that are predicted by both programs. The excessively pre-organized helical structures not only hampered the folding process, but also ultimately brought about changes in the three-dimensional conformation and biological function of AK.

  17. Effects of arginine vasopressin on musical working memory.

    Science.gov (United States)

    Granot, Roni Y; Uzefovsky, Florina; Bogopolsky, Helena; Ebstein, Richard P

    2013-01-01

    Previous genetic studies showed an association between variations in the gene coding for the 1a receptor of the neuro-hormone arginine vasopressin (AVP) and musical working memory (WM). The current study set out to test the influence of intranasal administration (INA) of AVP on musical as compared to verbal WM using a double blind crossover (AVP-placebo) design. Two groups of 25 males were exposed to 20 IU of AVP in one session, and 20 IU of saline water (placebo) in a second session, 1 week apart. In each session subjects completed the tonal subtest from Gordon's "Musical Aptitude Profile," the interval subtest from the "Montreal Battery for Evaluation of Amusias (MBEA)," and the forward and backward digit span tests. Scores in the digit span tests were not influenced by AVP. In contrast, in the music tests there was an AVP effect. In the MBEA test, scores for the group receiving placebo in the first session (PV) were higher than for the group receiving vasopressin in the first session (VP) (p music test these scores were significantly correlated with memory scores. Together the results reflect a complex interaction between AVP, musical memory, arousal, and contextual effects such as session, and base levels of memory. The results are interpreted in light of music's universal use as a means to modulate arousal on the one hand, and AVP's influence on mood, arousal, and social interactions on the other.

  18. Autoignited lifted flames of dimethyl ether in heated coflow air

    KAUST Repository

    Al-Noman, Saeed M.

    2018-05-16

    Autoignited lifted flames of dimethyl ether (DME) in laminar nonpremixed jets with high-temperature coflow air have been studied experimentally. When the initial temperature was elevated to over 860 K, an autoignition occurred without requiring an external ignition source. A planar laser-induced fluorescence (PLIF) technique for formaldehyde (CH2O) visualized qualitatively the zone of low temperature kinetics in a premixed flame. Two flame configurations were investigated; (1) autoignited lifted flames with tribrachial edge having three distinct branches of a lean and a rich premixed flame wings with a trailing diffusion flame and (2) autoignited lifted flames with mild combustion when the fuel was highly diluted. For the autoignited tribrachial edge flames at critical autoignition conditions, exhibiting repetitive extinction and re-ignition phenomena near a blowout condition, the characteristic flow time (liftoff height scaled with jet velocity) was correlated with the square of the ignition delay time of the stoichiometric mixture. The liftoff heights were also correlated as a function of jet velocity times the square of ignition delay time. Formaldehydes were observed between the fuel nozzle and the lifted flame edge, emphasizing a low-temperature kinetics for autoignited lifted flames, while for a non-autoignited lifted flame, formaldehydes were observed near a thin luminous flame zone.For the autoignited lifted flames with mild combustion, especially at a high temperature, a unique non-monotonic liftoff height behavior was observed; decreasing and then increasing liftoff height with jet velocity. This behavior was similar to the binary mixture fuels of CH4/H2 and CO/H2 observed previously. A transient homogeneous autoignition analysis suggested that such decreasing behavior with jet velocity can be attributed to partial oxidation characteristics of DME in producing appreciable amounts of CH4/CO/H2 ahead of the edge flame region.

  19. Lanthanide extraction with 2,5-dimethyl-2-hydroxyhexanoic acid

    International Nuclear Information System (INIS)

    Miller, J.H.

    1977-12-01

    This research is concerned with the solvent extraction into chloroform of the lanthanides, using 2,5-dimethyl-2-hydroxyhexanoic acid (DMHHA). This acid is the first α-hydroxy aliphatic acid to be studied as an extracting agent for the lanthanides. The chloroform-water DMHHA partition constant was determined to be 1.0 (at 0.1 M ionic strength and 25 0 C). The acid dimerizes in chloroform with a constant of 56. The light lanthanides can be extracted into chloroform by forming complexes with the DMHHA anions. The extracted metal species is highly aggregated. This extraction has a solubility limit which increases with the addition of unionized acid. The resultant extract is also highly aggregated. At unionized acid-to-metal ratios greater than one, extractions first occur followed by the slow precipitation of the lanthanide. At the tracer level, neodymium is extracted primarily as NdA 3 (HA) 5 and (NdA 3 ) 2 (HA)/sub q/. Very small amounts of (NdA 3 ) 2 and other metal aggregates are also present. The heavy lanthanides do not extract from solutions of DMHHA and its potassium salt, but form aqueous emulsions and precipitates. In the presence of the organic soluble tetrabutylammonium ion the heavy lanthanides can be extracted, presumably as ion pairs. The stability constants of the light lanthanides and DMHHA were determined. The separation factors obtained from DMHHA extractions of the light lanthanides were also investigated and found to be comparable to those obtained employing normal aliphatic carboxylic acid

  20. Autoignited lifted flames of dimethyl ether in heated coflow air

    KAUST Repository

    Al-Noman, Saeed M.; Choi, Byung Chul; Chung, Suk-Ho

    2018-01-01

    Autoignited lifted flames of dimethyl ether (DME) in laminar nonpremixed jets with high-temperature coflow air have been studied experimentally. When the initial temperature was elevated to over 860 K, an autoignition occurred without requiring an external ignition source. A planar laser-induced fluorescence (PLIF) technique for formaldehyde (CH2O) visualized qualitatively the zone of low temperature kinetics in a premixed flame. Two flame configurations were investigated; (1) autoignited lifted flames with tribrachial edge having three distinct branches of a lean and a rich premixed flame wings with a trailing diffusion flame and (2) autoignited lifted flames with mild combustion when the fuel was highly diluted. For the autoignited tribrachial edge flames at critical autoignition conditions, exhibiting repetitive extinction and re-ignition phenomena near a blowout condition, the characteristic flow time (liftoff height scaled with jet velocity) was correlated with the square of the ignition delay time of the stoichiometric mixture. The liftoff heights were also correlated as a function of jet velocity times the square of ignition delay time. Formaldehydes were observed between the fuel nozzle and the lifted flame edge, emphasizing a low-temperature kinetics for autoignited lifted flames, while for a non-autoignited lifted flame, formaldehydes were observed near a thin luminous flame zone.For the autoignited lifted flames with mild combustion, especially at a high temperature, a unique non-monotonic liftoff height behavior was observed; decreasing and then increasing liftoff height with jet velocity. This behavior was similar to the binary mixture fuels of CH4/H2 and CO/H2 observed previously. A transient homogeneous autoignition analysis suggested that such decreasing behavior with jet velocity can be attributed to partial oxidation characteristics of DME in producing appreciable amounts of CH4/CO/H2 ahead of the edge flame region.

  1. L-arginine and Arginase Products Potentiate Dexmedetomidine-induced Contractions in the Rat Aorta.

    Science.gov (United States)

    Wong, Emily S W; Man, Ricky Y K; Ng, Kwok F J; Leung, Susan W S; Vanhoutte, Paul M

    2018-03-01

    The α2-adrenergic sedative/anesthetic agent dexmedetomidine exerts biphasic effects on isolated arteries, causing endothelium-dependent relaxations at concentrations at or below 30 nM, followed by contractions at higher concentrations. L-arginine is a common substrate of endothelial nitric oxide synthase and arginases. This study was designed to investigate the role of L-arginine in modulating the overall vascular response to dexmedetomidine. Isometric tension was measured in isolated aortic rings of Sprague Dawley rats. Cumulative concentrations of dexmedetomidine (10 nM to 10 μM) were added to quiescent rings (with and without endothelium) after previous incubation with vehicle, N-nitro-L-arginine methyl ester hydrochloride (L-NAME; nitric oxide synthase inhibitor), prazosin (α1-adrenergic antagonist), rauwolscine (α2-adrenergic antagonist), L-arginine, (S)-(2-boronethyl)-L-cysteine hydrochloride (arginase inhibitor), N-hydroxy-L-arginine (arginase inhibitor), urea and/or ornithine. In some preparations, immunofluorescent staining, immunoblotting, or measurement of urea content were performed. Dexmedetomidine did not contract control rings with endothelium but evoked concentration-dependent increases in tension in such rings treated with L-NAME (Emax 50 ± 4%) or after endothelium-removal (Emax 74 ± 5%; N = 7 to 12). Exogenous L-arginine augmented the dexmedetomidine-induced contractions in the presence of L-NAME (Emax 75 ± 3%). This potentiation was abolished by (S)-(2-boronethyl)-L-cysteine hydrochloride (Emax 16 ± 4%) and N-hydroxy-L-arginine (Emax 18 ± 4%). Either urea or ornithine, the downstream arginase products, had a similar potentiating effect as L-arginine. Immunoassay measurements demonstrated an upregulation of arginase I by L-arginine treatment in the presence of L-NAME (N = 4). These results suggest that when vascular nitric oxide homeostasis is impaired, the potentiation of the vasoconstrictor effect of

  2. Growth and dielectric, mechanical, thermal and etching studies of an organic nonlinear optical L-arginine trifluoroacetate (LATF) single crystal

    International Nuclear Information System (INIS)

    Arjunan, S.; Mohan Kumar, R.; Mohan, R.; Jayavel, R.

    2008-01-01

    L-arginine trifluoroacetate, an organic nonlinear optical material, has been synthesized from aqueous solution. Bulk single crystal of dimension 57 mm x 5 mm x 3 mm has been grown by temperature lowering technique. Powder X-ray diffraction studies confirmed the monoclinic structure of the grown L-arginine trifluoroacetate crystal. Linear optical property of the grown crystal has been studied by UV-vis spectrum. Dielectric response of the L-arginine trifluoroacetate crystal was analysed for different frequencies and temperatures in detail. Microhardness study on the sample reveals that the crystal possesses relatively higher hardness compared to many organic crystals. Thermal analyses confirmed that the L-arginine trifluoroacetate material is thermally stable upto 212 deg. C. The etching studies have been performed to assess the perfection of the L-arginine trifluoroacetate crystal. Kurtz powder second harmonic generation test confirms the nonlinear optical properties of the as-grown L-arginine trifluoroacetate crystal

  3. Intracellular L-arginine concentration does not determine NO production in endothelial cells: Implications on the 'L-arginine paradox'

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Soyoung; Mohan, Srinidi [Department of Pharmaceutical Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14260 (United States); Fung, Ho-Leung, E-mail: hlfung@buffalo.edu [Department of Pharmaceutical Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14260 (United States)

    2011-11-04

    Highlights: Black-Right-Pointing-Pointer Our findings provide a possible solution to the 'L-arginine paradox'. Black-Right-Pointing-Pointer Extracellular L-arginine concentration is the major determinant of NO production. Black-Right-Pointing-Pointer Cellular L-arginine action is limited by cellular ARG transport, not the K{sub m} of NOS. Black-Right-Pointing-Pointer We explain how L-arginine supplementation can work to increase endothelial function. -- Abstract: We examined the relative contributory roles of extracellular vs. intracellular L-arginine (ARG) toward cellular activation of endothelial nitric oxide synthase (eNOS) in human endothelial cells. EA.hy926 human endothelial cells were incubated with different concentrations of {sup 15}N{sub 4}-ARG, ARG, or L-arginine ethyl ester (ARG-EE) for 2 h. To modulate ARG transport, siRNA for ARG transporter (CAT-1) vs. sham siRNA were transfected into cells. ARG transport activity was assessed by cellular fluxes of ARG, {sup 15}N{sub 4}-ARG, dimethylarginines, and L-citrulline by an LC-MS/MS assay. eNOS activity was determined by nitrite/nitrate accumulation, either via a fluorometric assay or by{sup 15}N-nitrite or estimated {sup 15}N{sub 3}-citrulline concentrations when {sup 15}N{sub 4}-ARG was used to challenge the cells. We found that ARG-EE incubation increased cellular ARG concentration but no increase in nitrite/nitrate was observed, while ARG incubation increased both cellular ARG concentration and nitrite accumulation. Cellular nitrite/nitrate production did not correlate with cellular total ARG concentration. Reduced {sup 15}N{sub 4}-ARG cellular uptake in CAT-1 siRNA transfected cells vs. control was accompanied by reduced eNOS activity, as determined by {sup 15}N-nitrite, total nitrite and {sup 15}N{sub 3}-citrulline formation. Our data suggest that extracellular ARG, not intracellular ARG, is the major determinant of NO production in endothelial cells. It is likely that once transported inside

  4. Intracellular L-arginine concentration does not determine NO production in endothelial cells: Implications on the “L-arginine paradox”

    International Nuclear Information System (INIS)

    Shin, Soyoung; Mohan, Srinidi; Fung, Ho-Leung

    2011-01-01

    Highlights: ► Our findings provide a possible solution to the “L-arginine paradox”. ► Extracellular L-arginine concentration is the major determinant of NO production. ► Cellular L-arginine action is limited by cellular ARG transport, not the K m of NOS. ► We explain how L-arginine supplementation can work to increase endothelial function. -- Abstract: We examined the relative contributory roles of extracellular vs. intracellular L-arginine (ARG) toward cellular activation of endothelial nitric oxide synthase (eNOS) in human endothelial cells. EA.hy926 human endothelial cells were incubated with different concentrations of 15 N 4 -ARG, ARG, or L-arginine ethyl ester (ARG-EE) for 2 h. To modulate ARG transport, siRNA for ARG transporter (CAT-1) vs. sham siRNA were transfected into cells. ARG transport activity was assessed by cellular fluxes of ARG, 15 N 4 -ARG, dimethylarginines, and L-citrulline by an LC–MS/MS assay. eNOS activity was determined by nitrite/nitrate accumulation, either via a fluorometric assay or by 15 N-nitrite or estimated 15 N 3 -citrulline concentrations when 15 N 4 -ARG was used to challenge the cells. We found that ARG-EE incubation increased cellular ARG concentration but no increase in nitrite/nitrate was observed, while ARG incubation increased both cellular ARG concentration and nitrite accumulation. Cellular nitrite/nitrate production did not correlate with cellular total ARG concentration. Reduced 15 N 4 -ARG cellular uptake in CAT-1 siRNA transfected cells vs. control was accompanied by reduced eNOS activity, as determined by 15 N-nitrite, total nitrite and 15 N 3 -citrulline formation. Our data suggest that extracellular ARG, not intracellular ARG, is the major determinant of NO production in endothelial cells. It is likely that once transported inside the cell, ARG can no longer gain access to the membrane-bound eNOS. These observations indicate that the “L-arginine paradox” should not consider intracellular ARG

  5. A role for PPARα in the regulation of arginine metabolism and nitric oxide synthesis.

    Science.gov (United States)

    Guelzim, Najoua; Mariotti, François; Martin, Pascal G P; Lasserre, Frédéric; Pineau, Thierry; Hermier, Dominique

    2011-10-01

    The pleiotropic effects of PPARα may include the regulation of amino acid metabolism. Nitric oxide (NO) is a key player in vascular homeostasis. NO synthesis may be jeopardized by a differential channeling of arginine toward urea (via arginase) versus NO (via NO synthase, NOS). This was studied in wild-type (WT) and PPARα-null (KO) mice fed diets containing either saturated fatty acids (COCO diet) or 18:3 n-3 (LIN diet). Metabolic markers of arginine metabolism were assayed in urine and plasma. mRNA levels of arginases and NOS were determined in liver. Whole-body NO synthesis and the conversion of systemic arginine into urea were assessed by using (15)N(2)-guanido-arginine and measuring urinary (15)NO(3) and [(15)N]-urea. PPARα deficiency resulted in a markedly lower whole-body NO synthesis, whereas the conversion of systemic arginine into urea remained unaffected. PPARα deficiency also increased plasma arginine and decreased citrulline concentration in plasma. These changes could not be ascribed to a direct effect on hepatic target genes, since NOS mRNA levels were unaffected, and arginase mRNA levels decreased in KO mice. Despite the low level in the diet, the nature of the fatty acids modulated some effects of PPARα deficiency, including plasma arginine and urea, which increased more in KO mice fed the LIN diet than in those fed the COCO diet. In conclusion, PPARα is largely involved in normal whole-body NO synthesis. This warrants further study on the potential of PPARα activation to maintain NO synthesis in the initiation of the metabolic syndrome.

  6. Expression pattern of a nuclear encoded mitochondrial arginine-ornithine translocator gene from Arabidopsis

    Directory of Open Access Journals (Sweden)

    Schneider Anja

    2003-01-01

    Full Text Available Abstract Background Arginine and citrulline serve as nitrogen storage forms, but are also involved in biosynthetic and catabolic pathways. Metabolism of arginine, citrulline and ornithine is distributed between mitochondria and cytosol. For the shuttle of intermediates between cytosol and mitochondria transporters present on the inner mitochondrial membrane are required. Yeast contains a mitochondrial translocator for ornithine and arginine, Ort1p/Arg11p. Ort1p/Arg11p is a member of the mitochondrial carrier family (MCF essential for ornithine export from mitochondria. The yeast arg11 mutant, which is deficient in Ort1p/Arg11p grows poorly on media lacking arginine. Results High-level expression of a nuclear encoded Arabidopsis thaliana homolog (AtmBAC2 of Ort1p/Arg11p was able to suppress the growth deficiency of arg11. RT-PCR analysis demonstrated expression of AtmBAC2 in all tissues with highest levels in flowers. Promoter-GUS fusions showed preferential expression in flowers, i.e. pollen, in the vasculature of siliques and in aborted seeds. Variable expression was observed in leaf vasculature. Induction of the promoter was not observed during the first two weeks in seedlings grown on media containing NH4NO3, arginine or ornithine as sole nitrogen sources. Conclusion AtmBAC2 was isolated as a mitochondrial transporter for arginine in Arabidopsis. The absence of expression in developing seeds and in cotyledons of seedlings indicates that other transporters are responsible for storage and mobilization of arginine in seeds.

  7. Effects of Arginine Vasopressin on musical short-term memory

    Directory of Open Access Journals (Sweden)

    Roni Y. Granot

    2013-10-01

    Full Text Available Previous genetic studies showed an association between variations in the gene coding for the 1a receptor of the neuro-hormone arginine vasopressin (AVP and musical working memory (WM. The current study set out to test the influence of intranasal administration (INA of AVP on musical as compared to verbal WM using a double blind crossover (AVP – placebo design. Two groups of 25 males were exposed to 20 IU of AVP in one session, and 20 IU of saline water (placebo in a second session, one week apart. In each session subjects completed the tonal subtest from Gordon's Musical Aptitude Profile, the interval subtest from the Montreal Battery for Evaluation of Amusias (MBEA, and the forward and backward digit span tests. Scores in the digit span tests were not influenced by AVP. In contrast, in the music tests there was an AVP effect. In the MBEA test, scores for the group receiving placebo in the first session (PV were higher than for the group receiving vasopressin in the first session (VP (p < .05 with no main Session effect nor Group * Session interaction. In the Gordon test there was a main Session effect (p < .05 with scores higher in the second as compared to the first session, a marginal main Group effect (p = .093 and a marginal Group X Session interaction (p = 0.88. In addition we found that the group that received AVP in the first session scored higher on scales indicative of happiness, and alertness on the Positive and Negative Affect Scale, (PANAS. Only in this group and only in the music test these scores were significantly correlated with memory scores. Together the results reflect a complex interaction between AVP, musical memory, arousal, and contextual effects such as session, and base levels of memory. The results are interpreted in light of music's universal use as a means to modulate arousal on the one hand, and AVP's influence on mood, arousal, and social interactions on the other.

  8. Pra Desain Pabrik Dimethyl Ether (DME dari Gas Alam

    Directory of Open Access Journals (Sweden)

    Ajeng Puspitasari Yudiputri

    2014-09-01

    Full Text Available Berdasarkan data PT Pertamina (Persero, total konsumsi LPG 2008 mencapai 1,85 juta ton dan 600.000 ton di antaranya untuk program konversi. Pada 2009 kebutuhan LPG akan meningkat menjadi 3,67 juta ton dan 2 juta ton di antaranya untuk program konversi sampai akhir tahun. Namun, sumber pasokan LPG dari dalam negeri diperkirakan tidak akan beranjak dari angka 1,8 juta ton per tahun dalam beberapa tahun mendatang. Sehingga, Indonesia harus menutup kebutuhan dengan mengimpor LPG dalam jumlah cukup besar. Maka dari itu dibutuhkan bahan bakar gas lain yang mampu mengatasi permasalahan yang ditimbulkan tersebut. Dimethyl Ether (DME merupakan senyawa ether yang paling sederhana dengan rumus kimia CH3OCH3. Produksi DME dapat dihasilkan melalui sintesis gas alam. DME berbentuk gas yang tidak berwarna pada suhu ambien, zat kimia yang stabil, dengan titik didih -25,1oC. Tekanan uap DME sekitar 0,6 Mpa pada 25oC dan dapat dicairkan seperti halnya LPG. Viskositas DME 0,12-0,15 kg/ms, setara dengan viskositas propana dan butane (konstituen utama LPG, sehingga infrastruktur untuk LPG dapat juga digunakan untuk DME. Berdasarkan data Departemen ESDM pada Januari 2012, total cadangan gas alam Indonesia tercatat mencapai 150,70 Trillion Square Cubic Feet (TSCF. Berdasarkan jumlah tersebut, sebanyak 103,35 TSCF merupakan gas alam terbukti, sementara 47,35 TSCF sisanya masih belum terbukti. Berdasarkan hal tersebut, diketahui bahwa senyawa DME merupakan senyawa yang sesuai untuk bahan substitusi LPG. Dan ditinjau dari analisa ekonomi, didapatkan besar Investasi : $ 636,447,074.69 ; Internal Rate of Return\t: 20.51%; POT: 4.13 tahun; BEP : 37.36 %; dan NPV 10 year : $ 518,848,692. Dari ketiga parameter sensitifitas yaitu fluktuasi biaya investasi, harga bahan baku, dan harga jual dari produk, terlihat bahwa ketiganya tidak memberikan pengaruh yang cukup signifikan terhadap kenaikan atau penurunan nilai IRR pabrik. Sehingga pabrik DME dari Gas Alam ini layak untuk

  9. DIMETHYL ETHER (DME)-FUELED SHUTTLE BUS DEMONSTRATION PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Elana M. Chapman; Shirish Bhide; Jennifer Stefanik; Howard Glunt; Andre L. Boehman; Allen Homan; David Klinikowski

    2003-04-01

    The objectives of this research and demonstration program are to convert a campus shuttle bus to operation on dimethyl ether, a potential ultra-clean alternative diesel fuel. To accomplish this objective, this project includes laboratory evaluation of a fuel conversion strategy, as well as, field demonstration of the DME-fueled shuttle bus. Since DME is a fuel with no lubricity (i.e., it does not possess the lubricating quality of diesel fuel), conventional fuel delivery and fuel injection systems are not compatible with dimethylether. Therefore, to operate a diesel engine on DME one must develop a fuel-tolerant injection system, or find a way to provide the necessary lubricity to the DME. In this project, they have chosen the latter strategy in order to achieve the objective with minimal need to modify the engine. The strategy is to blend DME with diesel fuel, to obtain the necessary lubricity to protect the fuel injection system and to achieve low emissions. The bulk of the efforts over the past year were focused on the conversion of the campus shuttle bus. This process, started in August 2001, took until April 2002 to complete. The process culminated in an event to celebrate the launching of the shuttle bus on DME-diesel operation on April 19, 2002. The design of the system on the shuttle bus was patterned after the system developed in the engine laboratory, but also was subjected to a rigorous failure modes effects analysis with help from Dr. James Hansel of Air Products. The result of this FMEA was the addition of layers of redundancy and over-pressure protection to the system on the shuttle bus. The system became operation in February 2002. Preliminary emissions tests and basic operation of the shuttle bus took place at the Pennsylvania Transportation institute's test track facility near the University Park airport. After modification and optimization of the system on the bus, operation on the campus shuttle route began in early June 2002. However, the

  10. Asymmetric and Symmetric Dimethylarginines are Markers of Delayed Cerebral Ischemia and Neurological Outcome in Patients with Subarachnoid Hemorrhage.

    Science.gov (United States)

    Appel, Daniel; Seeberger, Miriam; Schwedhelm, Edzard; Czorlich, Patrick; Goetz, Alwin E; Böger, Rainer H; Hannemann, Juliane

    2018-03-20

    Delayed cerebral ischemia (DCI) is the major cause of lethality and neuronal damage in patients who survived the primary subarachnoid hemorrhage (SAH). Asymmetric and symmetric dimethylarginines (ADMA and SDMA) inhibit nitric oxide production from L-arginine via distinct mechanisms. Elevated ADMA levels are associated with vasospasm after SAH. We aimed to study the time course of ADMA and SDMA in plasma and ventricular cerebrospinal fluid (CSF) and their associations with DCI and outcome. We measured ADMA and SDMA in 34 SAH patients with an external ventricular drain at admission and on days 3, 6, 8, 12, and 15 and followed them up for clinical status and neurological outcome until 30 days post-discharge. DCI was defined as the appearance of new infarctions on cerebral computed tomography or magnetic resonance imaging. ADMA and SDMA plasma concentrations did not differ significantly at baseline between patients who suffered DCI (N = 14; 41%) and not; however, plasma ADMA reached a peak on days 8 and 15 after hemorrhage in patients with DCI (0.81-0.91 µmol/l). Baseline plasma L-arginine/ADMA ratio was significantly lower in patients with DCI (57.1 [34.3; 70.8] vs. 68.7 [55.7; 96.2]; p < 0.05). ADMA and SDMA concentrations in CSF were significantly higher in patients with DCI than without. In multivariable-adjusted linear regression models, CSF ADMA was negatively associated with the incidence of DCI (OR 0.03 [0.02-0.70]; p = 0.04), whereas CSF SDMA on the day of hemorrhage predicted poor neurological outcome until 30 days after discharge (OR 22.4 [1.21-416.02]; p = 0.04). Our study shows that ADMA and the L-arginine/ADMA ratio are associated with the incidence of DCI after SAH. By contrast, SDMA was associated with initial neuronal damage and poor neurological outcome after SAH. These data support the hypothesis that ADMA and L-arginine affect the pathophysiology of cerebral ischemia after SAH, while SDMA is a biomarker of neurological outcome after SAH.

  11. Direct catalytic asymmetric aldol-Tishchenko reaction.

    Science.gov (United States)

    Gnanadesikan, Vijay; Horiuchi, Yoshihiro; Ohshima, Takashi; Shibasaki, Masakatsu

    2004-06-30

    A direct catalytic asymmetric aldol reaction of propionate equivalent was achieved via the aldol-Tishchenko reaction. Coupling an irreversible Tishchenko reaction to a reversible aldol reaction overcame the retro-aldol reaction problem and thereby afforded the products in high enantio and diastereoselectivity using 10 mol % of the asymmetric catalyst. A variety of ketones and aldehydes, including propyl and butyl ketones, were coupled efficiently, yielding the corresponding aldol-Tishchenko products in up to 96% yield and 95% ee. Diastereoselectivity was generally below the detection limit of 1H NMR (>98:2). Preliminary studies performed to clarify the mechanism revealed that the aldol products were racemic with no diastereoselectivity. On the other hand, the Tishchenko products were obtained in a highly enantiocontrolled manner.

  12. Brownian Motion of Asymmetric Boomerang Colloidal Particles

    Science.gov (United States)

    Chakrabarty, Ayan; Konya, Andrew; Wang, Feng; Selinger, Jonathan; Sun, Kai; Wei, Qi-Huo

    2014-03-01

    We used video microscopy and single particle tracking to study the diffusion and local behaviors of asymmetric boomerang particles in a quasi-two dimensional geometry. The motion is biased towards the center of hydrodynamic stress (CoH) and the mean square displacements of the particles are linear at short and long times with different diffusion coefficients and in the crossover regime it is sub-diffusive. Our model based on Langevin theory shows that these behaviors arise from the non-coincidence of the CoH with the center of the body. Since asymmetric boomerangs represent a class of rigid bodies of more generals shape, therefore our findings are generic and true for any non-skewed particle in two dimensions. Both experimental and theoretical results will be discussed.

  13. Dynamics of asymmetric kinetic Ising systems revisited

    International Nuclear Information System (INIS)

    Huang, Haiping; Kabashima, Yoshiyuki

    2014-01-01

    The dynamics of an asymmetric kinetic Ising model is studied. Two schemes for improving the existing mean-field description are proposed. In the first scheme, we derive the formulas for instantaneous magnetization, equal-time correlation, and time-delayed correlation, considering the correlation between different local fields. To derive the time-delayed correlation, we emphasize that the small-correlation assumption adopted in previous work (Mézard and Sakellariou, 2011 J. Stat. Mech. L07001) is in fact not required. To confirm the prediction efficiency of our method, we perform extensive simulations on single instances with either temporally constant external driving fields or sinusoidal external fields. In the second scheme, we develop an improved mean-field theory for instantaneous magnetization prediction utilizing the notion of the cavity system in conjunction with a perturbative expansion approach. Its efficiency is numerically confirmed by comparison with the existing mean-field theory when partially asymmetric couplings are present. (paper)

  14. Bianisotropic metamaterials based on twisted asymmetric crosses

    International Nuclear Information System (INIS)

    Reyes-Avendaño, J A; Sampedro, M P; Juárez-Ruiz, E; Pérez-Rodríguez, F

    2014-01-01

    The effective bianisotropic response of 3D periodic metal-dielectric structures, composed of crosses with asymmetrically-cut wires, is investigated within a general homogenization theory using the Fourier formalism and the form-factor division approach. It is found that the frequency dependence of the effective permittivity for a system of periodically-repeated layers of metal crosses exhibits two strong resonances, whose separation is due to the cross asymmetry. Besides, bianisotropic metamaterials, having a base of four twisted asymmetric crosses, are proposed. The designed metamaterials possess negative refractive index at frequencies determined by the cross asymmetry, the gap between the arms of adjacent crosses lying on the same plane, and the type of Bravais lattice. (papers)

  15. Improved DFIG Capability during Asymmetrical Grid Faults

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede

    2015-01-01

    In the wind power application, different asymmetrical types of the grid fault can be categorized after the Y/d transformer, and the positive and negative components of a single-phase fault, phase-to-phase fault, and two-phase fault can be summarized. Due to the newly introduced negative and even...... the natural component of the Doubly-Fed Induction Generator (DFIG) stator flux during the fault period, their effects on the rotor voltage can be investigated. It is concluded that the phase-to-phase fault has the worst scenario due to its highest introduction of the negative stator flux. Afterwards......, the capability of a 2 MW DFIG to ride through asymmetrical grid faults can be estimated at the existing design of the power electronics converter. Finally, a control scheme aimed to improve the DFIG capability is proposed and the simulation results validate its feasibility....

  16. Deprivation of L-Arginine Induces Oxidative Stress Mediated Apoptosis in Leishmania donovani Promastigotes: Contribution of the Polyamine Pathway

    Science.gov (United States)

    Mandal, Abhishek; Das, Sushmita; Roy, Saptarshi; Ghosh, Ayan Kumar; Sardar, Abul Hasan; Verma, Sudha; Saini, Savita; Singh, Ruby; Abhishek, Kumar; Kumar, Ajay; Mandal, Chitra; Das, Pradeep

    2016-01-01

    The growth and survival of intracellular parasites depends on the availability of extracellular nutrients. Deprivation of nutrients viz glucose or amino acid alters redox balance in mammalian cells as well as some lower organisms. To further understand the relationship, the mechanistic role of L-arginine in regulation of redox mediated survival of Leishmania donovani promastigotes was investigated. L-arginine deprivation from the culture medium was found to inhibit cell growth, reduce proliferation and increase L-arginine uptake. Relative expression of enzymes, involved in L-arginine metabolism, which leads to polyamine and trypanothione biosynthesis, were downregulated causing decreased production of polyamines in L-arginine deprived parasites and cell death. The resultant increase in reactive oxygen species (ROS), due to L-arginine deprivation, correlated with increased NADP+/NADPH ratio, decreased superoxide dismutase (SOD) level, increased lipid peroxidation and reduced thiol content. A deficiency of L-arginine triggered phosphatidyl serine externalization, a change in mitochondrial membrane potential, release of intracellular calcium and cytochrome-c. This finally led to DNA damage in Leishmania promastigotes. In summary, the growth and survival of Leishmania depends on the availability of extracellular L-arginine. In its absence the parasite undergoes ROS mediated, caspase-independent apoptosis-like cell death. Therefore, L-arginine metabolism pathway could be a probable target for controlling the growth of Leishmania parasites and disease pathogenesis. PMID:26808657

  17. Asymmetric volatility connectedness on the forex market

    Czech Academy of Sciences Publication Activity Database

    Baruník, Jozef; Kočenda, Evžen; Vácha, Lukáš

    2017-01-01

    Roč. 77, č. 1 (2017), s. 39-56 ISSN 0261-5606 R&D Projects: GA ČR(CZ) GA16-14179S Institutional support: RVO:67985556 Keywords : volatility * connectedness * asymmetric effects Subject RIV: AH - Economics OBOR OECD: Finance Impact factor: 1.853, year: 2016 http://library.utia.cas.cz/separaty/2017/E/barunik-0478477.pdf

  18. Magnetic properties of strongly asymmetric nuclear matter

    International Nuclear Information System (INIS)

    Kutschera, M.; Wojcik, W.

    1988-01-01

    We investigate stability of neutron matter containing a small proton admixture with respect to spin fluctuations. We establish conditions under which strongly asymmetric nuclear matter could acquire a permanent magnetization. It is shown that if the protons are localized, the system becomes unstable to spin fluctuations for arbitrarily weak proton-neutron spin interactions. For non-localized protons there exists a threshold value of the spin interaction above which the system can develop a spontaneous polarization. 12 refs., 2 figs. (author)

  19. Isospin dependent properties of asymmetric nuclear matter

    OpenAIRE

    Chowdhury, P. Roy; Basu, D. N.; Samanta, C.

    2009-01-01

    The density dependence of nuclear symmetry energy is determined from a systematic study of the isospin dependent bulk properties of asymmetric nuclear matter using the isoscalar and the isovector components of density dependent M3Y interaction. The incompressibility $K_\\infty$ for the symmetric nuclear matter, the isospin dependent part $K_{asy}$ of the isobaric incompressibility and the slope $L$ are all in excellent agreement with the constraints recently extracted from measured isotopic de...

  20. Asymmetric flow events in a VEER 1000

    International Nuclear Information System (INIS)

    Horak, W.C.; Kennett, R.J.; Shier, W.; Guppy, J.G.

    1992-07-01

    This paper describes the simulation of asymmetric loss of flow events in Russian designed VVER-1000 reactors using the RETRAN-02 Mod4 computer code. VVER-1000 reactors have significant differences from United States pressurized water reactors including multi-level emergency response systems and plant operation at reduced power levels with one or more main circulation pumps inoperable. The results of these simulations are compared to similar analyses done by the designers for the Rovno plant

  1. Two particle states in an asymmetric box

    OpenAIRE

    Li, Xin; Liu, Chuan

    2004-01-01

    The exact two-particle energy eigenstates in an asymmetric rectangular box with periodic boundary conditions in all three directions are studied. Their relation with the elastic scattering phases of the two particles in the continuum are obtained. These results can be viewed as a generalization of the corresponding formulae in a cubic box obtained by L\\"uscher before. In particular, the s-wave scattering length is related to the energy shift in the finite box. Possible applications of these f...

  2. Symmetric vs. asymmetric punishment regimes for bribery

    OpenAIRE

    Engel, Christoph; Goerg, Sebastian J.; Yu, Gaoneng

    2012-01-01

    In major legal orders such as UK, the U.S., Germany, and France, bribers and recipients face equally severe criminal sanctions. In contrast, countries like China, Russia, and Japan treat the briber more mildly. Given these differences between symmetric and asymmetric punishment regimes for bribery, one may wonder which punishment strategy is more effective in curbing corruption. For this purpose, we designed and ran a lab experiment in Bonn (Germany) and Shanghai (China) with exactly the same...

  3. Predicting tensorial electrophoretic effects in asymmetric colloids

    Science.gov (United States)

    Mowitz, Aaron J.; Witten, T. A.

    2017-12-01

    We formulate a numerical method for predicting the tensorial linear response of a rigid, asymmetrically charged body to an applied electric field. This prediction requires calculating the response of the fluid to the Stokes drag forces on the moving body and on the countercharges near its surface. To determine the fluid's motion, we represent both the body and the countercharges using many point sources of drag known as Stokeslets. Finding the correct flow field amounts to finding the set of drag forces on the Stokeslets that is consistent with the relative velocities experienced by each Stokeslet. The method rigorously satisfies the condition that the object moves with no transfer of momentum to the fluid. We demonstrate that a sphere represented by 1999 well-separated Stokeslets on its surface produces flow and drag force like a solid sphere to 1% accuracy. We show that a uniformly charged sphere with 3998 body and countercharge Stokeslets obeys the Smoluchowski prediction [F. Morrison, J. Colloid Interface Sci. 34, 210 (1970), 10.1016/0021-9797(70)90171-2] for electrophoretic mobility when the countercharges lie close to the sphere. Spheres with dipolar and quadrupolar charge distributions rotate and translate as predicted analytically to 4% accuracy or better. We describe how the method can treat general asymmetric shapes and charge distributions. This method offers promise as a way to characterize and manipulate asymmetrically charged colloid-scale objects from biology (e.g., viruses) and technology (e.g., self-assembled clusters).

  4. Asymmetric threat data mining and knowledge discovery

    Science.gov (United States)

    Gilmore, John F.; Pagels, Michael A.; Palk, Justin

    2001-03-01

    Asymmetric threats differ from the conventional force-on- force military encounters that the Defense Department has historically been trained to engage. Terrorism by its nature is now an operational activity that is neither easily detected or countered as its very existence depends on small covert attacks exploiting the element of surprise. But terrorism does have defined forms, motivations, tactics and organizational structure. Exploiting a terrorism taxonomy provides the opportunity to discover and assess knowledge of terrorist operations. This paper describes the Asymmetric Threat Terrorist Assessment, Countering, and Knowledge (ATTACK) system. ATTACK has been developed to (a) data mine open source intelligence (OSINT) information from web-based newspaper sources, video news web casts, and actual terrorist web sites, (b) evaluate this information against a terrorism taxonomy, (c) exploit country/region specific social, economic, political, and religious knowledge, and (d) discover and predict potential terrorist activities and association links. Details of the asymmetric threat structure and the ATTACK system architecture are presented with results of an actual terrorist data mining and knowledge discovery test case shown.

  5. Diagnostic implications of asymmetrical mammographic patterns

    International Nuclear Information System (INIS)

    Asenjo, M.; Ania, B.J.

    1997-01-01

    To analyze the effect of asymmetrical mammographic patterns of the diagnosis of breast cancer. In a series of 6, 476 patients referred to a Breast Imaging Diagnosis Unit, we excluded males, women with previous breast surgery, and cases in which mammography was not performed, which left 5,203 women included. Each breast was classified according to one of four patterns of mammographic parenchymal density. Asymmetry was considered to exist when a patient's breasts had different patterns. Breast cancer was confirmed histologically in 282 (5.4%) women. The mammographic pattern was asymmetrical in 8% of the women with cancer and in 2% of the women without cancer (p<0.001). Fine-needle aspiration biopsy was performed in 78% and 96% (p=0.04), respectively, of the women with and without mammographic asymmetry who had neoplasms, and in 33% and 22% (p=0.02), respectively, of the women with and without mammographic asymmetry who did not have neoplasms. Asymmetrical mammographic pattern was four times more frequent in the women with breast cancer. This asymmetry decreased the frequency of needle biopsy in women with cancer, but increased the frequency of needle biopsy in women without cancer. (Author) 11 refs

  6. Hadron scattering in an asymmetric box

    International Nuclear Information System (INIS)

    Li Xin; Chen Ying; Meng Guozhan; Feng Xu; Gong Ming; He Song; Li Gang; Liu Chuan; Liu Yubin; Ma Jianping; Meng Xiangfei; Shen Yan; Zhang Jianbo

    2007-01-01

    We propose to study hadron-hadron scattering using lattice QCD in an asymmetric box which allows one to access more non-degenerate low-momentum modes for a given volume. The conventional Luescher's formula applicable in a symmetric box is modified accordingly. To illustrate the feasibility of this approach, pion-pion elastic scattering phase shifts in the I = 2, J = 0 channel are calculated within quenched approximation using improved gauge and Wilson fermion actions on anisotropic lattices in an asymmetric box. After the chiral and continuum extrapolation, we find that our quenched results for the scattering phase shifts in this channel are consistent with the experimental data when the three-momentum of the pion is below 300MeV. Agreement is also found when compared with previous theoretical results from lattice and other means. Moreover, with the usage of asymmetric volume, we are able to compute the scattering phases in the low-momentum range (pion three momentum less than about 350MeV in the center of mass frame) for over a dozen values of the pion three-momenta, much more than using the conventional symmetric box with comparable volume

  7. Simulation of Phenix EOL Asymmetric Test

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Kwi Seok; Lee, Kwi Lim; Choi, Chi Woong; Kang, Seok Hun; Chang, Won Pyo; Jeong, Hae Yong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    The asymmetric test of End-Of-Life (EOL) tests on the Phenix plant was used for the evaluation of the MARS-LMR in the Generation IV frame as a part of the code validation. The purpose of the test is to evaluate the ability of the system code to describe asymmetric situations and to identify important phenomena during asymmetrical transient such as a three dimensional effect, buoyancy influence, and thermal stratification in the hot and cold pools. 3-dimensional sodium coolant mixing in the pools has different characteristics from the one dimensional full instantaneous mixing. The velocities and temperatures at the core outlet level differ at each sub-assembly and the temperature in the center of the hot pool may be high because the driver fuels are located at the center region. The temperatures in the hot pool are not the same in the radial and axial locations due to the buoyancy effect. The temperatures in the cold pool also differ along with the elevations and azimuthal directions due to the outlet location of IHX and the thermal stratification

  8. Flatfish: an asymmetric perspective on metamorphosis.

    Science.gov (United States)

    Schreiber, Alexander M

    2013-01-01

    The most asymmetrically shaped and behaviorally lateralized of all the vertebrates, the flatfishes are an endless source of fascination to all fortunate enough to study them. Although all vertebrates undergo left-right asymmetric internal organ placement during embryogenesis, flatfish are unusual in that they experience an additional period of postembryonic asymmetric remodeling during metamorphosis, and thus deviate from a bilaterally symmetrical body plan more than other vertebrates. As with amphibian metamorphosis, all the developmental programs of flatfish metamorphosis are ultimately under the control of thyroid hormone. At least one gene pathway involved in embryonic organ lateralization (nodal-lefty-pitx2) is re-expressed in the larval stage during flatfish metamorphosis. Aspects of modern flatfish ontogeny, such as the gradual translocation of one eye to the opposite side of the head and the appearance of key neurocranial elements during metamorphosis, seem to elegantly recapitulate flatfish phylogeny. This chapter highlights the current state of knowledge of the developmental biology of flatfish metamorphosis with emphases on the genetic, morphological, behavioral, and evolutionary origins of flatfish asymmetry. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Natural 4-hydroxy-2,5-dimethyl-3(2H)-furanone (Furaneol®).

    Science.gov (United States)

    Schwab, Wilfried

    2013-06-13

    4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF, furaneol®) and its methyl ether 2,5-dimethyl-4-methoxy-3(2H)-furanone (DMMF) are import aroma chemicals and are considered key flavor compounds in many fruit. Due to their attractive sensory properties they are highly appreciated by the food industry. In fruits 2,5-dimethyl-3(2H)-furanones are synthesized by a series of enzymatic steps whereas HDMF is also a product of the Maillard reaction. Numerous methods for the synthetic preparation of these compounds have been published and are applied by industry, but for the development of a biotechnological process the knowledge and availability of biosynthetic enzymes are required. During the last years substantial progress has been made in the elucidation of the biological pathway leading to HDMF and DMMF. This review summarizes the latest advances in this field.

  10. Gas chromatographic--mass spectrometric quantitation of 16, 16-dimethyl-trans-delta 2-PGE1

    Energy Technology Data Exchange (ETDEWEB)

    Dimov, V.; Green, K.; Bygdeman, M.; Konishi, Y.; Imaki, K.; Hayashi, M.

    1983-02-01

    Di-deuterated and di-tritiated 16,16-dimethyl-trans-delta 2-PGE1 has been synthesized and used for development of a GC-MS method for quantitation of corresponding unlabelled drug in patient plasma. Although these carrier/internal standard molecules only contain 2 deuterium atoms the lower limit of detection at each injection is as low as about 40 pg. The maximum plasma levels of this drug following administration of vaginal suppositories used in clinical studies (1 mg 16,16-dimethyl-trans-delta 2-PGE1 methyl ester in 0.8 g Witepsol S-52) were 100-350 pg/ml i.e. in the same order of magnitude as earlier seen for 16,16-dimethyl-PGE2.

  11. Gas chromatographic--mass spectrometric quantitation of 16, 16-dimethyl-trans-delta 2-PGE1

    International Nuclear Information System (INIS)

    Dimov, V.; Green, K.; Bygdeman, M.; Konishi, Y.; Imaki, K.; Hayashi, M.

    1983-01-01

    Di-deuterated and di-tritiated 16,16-dimethyl-trans-delta 2-PGE1 has been synthesized and used for development of a GC-MS method for quantitation of corresponding unlabelled drug in patient plasma. Although these carrier/internal standard molecules only contain 2 deuterium atoms the lower limit of detection at each injection is as low as about 40 pg. The maximum plasma levels of this drug following administration of vaginal suppositories used in clinical studies (1 mg 16,16-dimethyl-trans-delta 2-PGE1 methyl ester in 0.8 g Witepsol S-52) were 100-350 pg/ml i.e. in the same order of magnitude as earlier seen for 16,16-dimethyl-PGE2

  12. Natural 4-Hydroxy-2,5-dimethyl-3(2H-furanone (Furaneol®

    Directory of Open Access Journals (Sweden)

    Wilfried Schwab

    2013-06-01

    Full Text Available 4-Hydroxy-2,5-dimethyl-3(2H-furanone (HDMF, furaneol® and its methyl ether 2,5-dimethyl-4-methoxy-3(2H-furanone (DMMF are import aroma chemicals and are considered key flavor compounds in many fruit. Due to their attractive sensory properties they are highly appreciated by the food industry. In fruits 2,5-dimethyl-3(2H-furanones are synthesized by a series of enzymatic steps whereas HDMF is also a product of the Maillard reaction. Numerous methods for the synthetic preparation of these compounds have been published and are applied by industry, but for the development of a biotechnological process the knowledge and availability of biosynthetic enzymes are required. During the last years substantial progress has been made in the elucidation of the biological pathway leading to HDMF and DMMF. This review summarizes the latest advances in this field.

  13. Synthesis, crystal structure, and spectra of 3,3- dimethyl-1-N-(1'-phenyl-2',3'-dimethyl-5'-oxo-3'- pyrazolin-4'-yl)imino-1,2,3,4-tetrahydroisoquinoline

    International Nuclear Information System (INIS)

    Sokol, V.I.; Ryabov, M.A.; Merkur'eva, N.Yu.; Davydov, V.V.; Zaitsev, B.E.; Shklyaev, Yu.V.; Sergienko, V.S.; Zaitsev, B.E.

    1996-01-01

    The synthesis and the crystal and molecular structure of 3,3-dimethyl-1-N-(1'-phenyl-2',3'- dimethyl-5'-oxo-3'-pyrazolin-4'-yl)imino-1,2,3,4-tetrahydroisoquinoline are reported. As is evidenced by the 1H NMR, IR, and electron spectra, the tautomeric form of the compounds observed in the crystal is also retained in solutions

  14. EVALUATION OF ANTIOXIDANT ACTIVITY OF SOME IMINES DERIVATIVES OF L-ARGININE.

    Science.gov (United States)

    Iacob, Andreea-Teodora; Drăgan, Maria; Constantin, Sandra; Lupaşcu, Florentina; Confederat, Luminiţa; Buron, F; Routier, S; Profire, Lenuţa

    2016-01-01

    L-Arginine is an a-amino acid which plays important roles in different diseases or processes, such as Alzheimer disease, inflammatory process, healing and tissue regeneration and it also could be useful as an anti-atherosclerotic agent. Considering the large amount of studies on the beneficial effects of different antioxidants, this paper is focused on the evaluation of the antioxidant potential of some imine derivatives, synthesized by the authors and described in a previous article. The evaluation of the antioxidant power was performed using phosphomolydenum-reducing antioxidant power (PRAP) and ferric reducing antioxidant power (FRAP) assays, tests described in the literature and which are used with some minor modifications. It was found that most of the imine derivatives are more active than the L-Arginine in the PPAP and FRAP assays. The most active derivative was the compound obtained by condensation of L-arginine with 2,3-dihydroxybenzaldehyde (2k) and 2-nitrobenzaldehyde (2g). Following the described protocol, some imine derivatives of L-arginine were evaluated in terms of antioxidant potential using in vitro methods. The most favorable influence was obtained by the aromatic substitution with nitro and hydroxyl, the corresponding derivatives being the most active derivatives compared to L-arginine.

  15. The impact of arginine-modified chitosan-DNA nanoparticles on the function of macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Liu Lanxia; Bai Yuanyuan; Song Chunni; Zhu Dunwan; Song Liping; Zhang Hailing; Dong Xia; Leng Xigang, E-mail: lengxg@bme.org.c [Tianjin Key Laboratory of Biomedical Materials, Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Laboratory of Bioengineering (China)

    2010-06-15

    It has been demonstrated that incorporation of arginine moieties into chitosan significantly elevates the transgenic efficacy of the chitosan. However, little is known about the impact of arginine-modified chitosan on the function of macrophages, which play a vitally important role in the inflammatory response of the body to foreign substances, especially particulate substances. This study was designed to investigate the impact of arginine-modified chitosan/DNA nanoparticles on the function of the murine macrophage through observation of phagocytic activity and production of pro-inflammatory cytokines (IL-1{beta}, IL-6, IL-10, IL-12, and TNF-{alpha}). Results showed that both chitosan/DNA nanoparticles and arginine-modified chitosan/DNA nanoparticles, containing 20 {mu}g/mL DNA, were internalized by almost all the macrophages in contact. This led to no significant changes, compared to the non-exposure group, in production of cytokines and phagocytic activity of the macrophages 24 h post co-incubation, whereas exposure to LPS induced obviously elevated cytokine production and phagocytic activity, suggesting that incorporation of arginine moieties into chitosan does not have a negative impact on the function of the macrophages.

  16. Activities of Arginine and Ornithine Decarboxylases in Various Plant Species 1

    Science.gov (United States)

    Birecka, Helena; Bitonti, Alan J.; McCann, Peter P.

    1985-01-01

    In extracts from the youngest leaves of Avena sativa, Hordeum vulgare, Zea Mays, Pisum sativum, Phaseolus vulgaris, Lactuca sativa, and four pyrrolizidine alkaloid-bearing species of Heliotropium, the activities of ornithine decarboxylase, close to Vmax, ranged between traces and 1.5 nanomoles per hour per gram fresh weight when based on putrescine formed during incubation with labeled ornithine. The arginine decarboxylase activities in the same extracts ranged between 8 and 8000 nanomoles per hour per gram fresh weight being lowest in the borages and highest in oat and barley. α-Difluoromethylornithine and α-difluoromethylarginine inhibited ornithine and arginine decarboxylases, respectively, in all species. Agmatine, putrescine, spermidine, and spermine were found in all, diaminopropane in eight, and cadaverine in three species. No correlation was observed between arginine or ornithine decarboxylase level and the levels of total polyamines. The in vitro decarboxylase activities found in the borages cannot explain the high accumulation of putrescine-derived pyrrolizidines in their youngest leaves if the pyrrolizidines are produced in situ from arginine and/or ornithine as precursors; other possibilities are discussed. In assays of ornithine decarboxylase, an interference of decarboxylation not due to this enzyme was observed in extracts from all species. In arginine decarboxylase assays, the interfering decarboxylation as well as the interference of arginase were apparent in two species. Addition of aminoguanidine was needed to suppress oxidative degradation of putrescine and agmatine during incubation of extracts from pea, bean, lettuce, Heliotropium angiospermum, and Heliotropium indicum. PMID:16664442

  17. Short Arginine Motifs Drive Protein Stickiness in the Escherichia coli Cytoplasm.

    Science.gov (United States)

    Kyne, Ciara; Crowley, Peter B

    2017-09-19

    Although essential to numerous biotech applications, knowledge of molecular recognition by arginine-rich motifs in live cells remains limited. 1 H, 15 N HSQC and 19 F NMR spectroscopies were used to investigate the effects of C-terminal -GR n (n = 1-5) motifs on GB1 interactions in Escherichia coli cells and cell extracts. While the "biologically inert" GB1 yields high-quality in-cell spectra, the -GR n fusions with n = 4 or 5 were undetectable. This result suggests that a tetra-arginine motif is sufficient to drive interactions between a test protein and macromolecules in the E. coli cytoplasm. The inclusion of a 12 residue flexible linker between GB1 and the -GR 5 motif did not improve detection of the "inert" domain. In contrast, all of the constructs were detectable in cell lysates and extracts, suggesting that the arginine-mediated complexes were weak. Together these data reveal the significance of weak interactions between short arginine-rich motifs and the E. coli cytoplasm and demonstrate the potential of such motifs to modify protein interactions in living cells. These interactions must be considered in the design of (in vivo) nanoscale assemblies that rely on arginine-rich sequences.

  18. Apple snack enriched with L-arginine using vacuum impregnation/ohmic heating technology.

    Science.gov (United States)

    Moreno, Jorge; Echeverria, Julian; Silva, Andrea; Escudero, Andrea; Petzold, Guillermo; Mella, Karla; Escudero, Carlos

    2017-07-01

    Modern life has created a high demand for functional food, and in this context, emerging technologies such as vacuum impregnation and ohmic heating have been applied to generate functional foods. The aim of this research was to enrich the content of the semi-essential amino acid L-arginine in apple cubes using vacuum impregnation, conventional heating, and ohmic heating. Additionally, combined vacuum impregnation/conventional heating and vacuum impregnation/ohmic heating treatments were evaluated. The above treatments were applied at 30, 40 and 50  ℃ and combined with air-drying at 40 ℃ in order to obtain an apple snack rich in L-arginine. Both the impregnation kinetics of L-arginine and sample color were evaluated. The impregnated samples created using vacuum impregnation/ohmic heating at 50 ℃ presented a high content of L-arginine, an effect attributed primarily to electropermeabilization. Overall, vacuum impregnation/ohmic heating treatment at 50 ℃, followed by drying at 40 ℃, was the best process for obtaining an apple snack rich in L-arginine.

  19. L-Arginine metabolism in cardiovascular and renal tissue from hyper- and hypothyroid rats.

    Science.gov (United States)

    Rodríguez-Gómez, Isabel; Moliz, Juan N; Quesada, Andrés; Montoro-Molina, Sebastian; Vargas-Tendero, Pablo; Osuna, Antonio; Wangensteen, Rosemary; Vargas, Félix

    2016-03-01

    This study assessed the effects of thyroid hormones on the enzymes involved in l-arginine metabolism and the metabolites generated by the different metabolic pathways. Compounds of l-arginine metabolism were measured in the kidney, heart, aorta, and liver of euthyroid, hyperthyroid, and hypothyroid rats after 6 weeks of treatment. Enzymes studied were NOS isoforms (neuronal [nNOS], inducible [iNOS], and endothelial [eNOS]), arginases I and II, ornithine decarboxylase (ODC), ornithine aminotransferase (OAT), and l-arginine decarboxylase (ADC). Metabolites studied were l-arginine, l-citrulline, spermidine, spermine, and l-proline. Kidney heart and aorta levels of eNOS and iNOS were augmented and reduced (P hyperthyroid rats and was decreased in kidney and aorta of hypothyroid rats (P hyperthyroid rats and remained unchanged in all organs of hypothyroid rats. The substrate for these enzymes, l-arginine, was reduced (P hyperthyroid rats. Levels of ODC and spermidine, its product, were increased and decreased (P metabolic pathways. The changes recorded in the abundance of eNOS, arginases I and II, and ADC protein in renal and cardiovascular tissues may play a role in the hemodynamic and renal manifestations observed in thyroid disorders. Furthermore, the changes in ODC and spermidine might contribute to the changes in cardiac and renal mass observed in thyroid disorders. © 2015 by the Society for Experimental Biology and Medicine.

  20. A UV-induced mutation in neurospora that affects translational regulation in response to arginine

    International Nuclear Information System (INIS)

    Freitag, M.; Dighde, N.; Sachs, M.S.

    1996-01-01

    The Neurospora crassa arg-2 gene encodes the small subunit of arginine-specific carbamoyl phosphate synthetase. The levels of arg-2 mRNA and mRNA translation are negatively regulated by arginine. An upstream open reading frame (uORF) in the transcript's 5' region has been implicated in arginine-specific control. An arg-2-hph fusion gene encoding hygromycin phosphotransferase conferred arginine-regulated resistance to hygromycin when introduced into N. crassa. We used an arg-2-hph strain to select for UV-induced mutants that grew in the presence of hygromycin and arginine, and we isolated 46 mutants that had either of two phenotypes. One phenotype indicated altered expression of both arg-2-hph and arg-2 genes; the other, altered expression of arg-2-hph but not arg-2. One of the latter mutations, which was genetically closely linked to arg-2-hph, was recovered from the 5' region of the arg-2-hph gene using PCR Sequence analyses and transformation experiments revealed a mutation at uORF codon 12 (Asp to Asn) that abrogated negative regulation. Examination of the distribution of ribosomes on arg-2-hph transcripts showed that loss of regulation had a translational component, indicating the uORF sequence was important for Arg-specific translational control. Comparisons with other uORFs suggest common elements in translational control mechanisms

  1. Asymmetric synthesis of a potent, aminopiperidine-fused imidazopyridine dipeptidyl peptidase IV inhibitor.

    Science.gov (United States)

    Xu, Feng; Corley, Edward; Zacuto, Michael; Conlon, David A; Pipik, Brenda; Humphrey, Guy; Murry, Jerry; Tschaen, David

    2010-03-05

    A practical asymmetric synthesis of a novel aminopiperidine-fused imidazopyridine dipeptidyl peptidase IV (DPP-4) inhibitor 1 has been developed. Application of a unique three-component cascade coupling with chiral nitro diester 7, which is easily accessed via a highly enantioselective Michael addition of dimethyl malonate to a nitrostyrene, allows for the assembly of the functionalized piperidinone skeleton in one pot. Through a base-catalyzed, dynamic crystallization-driven process, the cis-piperidionone 16a is epimerized to the desired trans isomer 16b, which is directly crystallized from the crude reaction stream in high yield and purity. Isomerization of the allylamide 16b in the presence of RhCl(3) is achieved without any epimerization of the acid/base labile stereogenic center adjacent to the nitro group on the piperidinone ring, while the undesired enamine intermediate is consumed to <0.5% by utilizing a trace amount of HCl generated from RhCl(3). The amino lactam 4, obtained through hydrogenation and hydrolysis, is isolated as its crystalline pTSA salt from the reaction solution directly, as such intramolecular transamidation has been dramatically suppressed via kinetic control. Finally, a Cu(I) catalyzed coupling-cyclization allows for the formation of the tricyclic structure of the potent DPP-4 inhibitor 1. The synthesis, which is suitable for large scale preparation, is accomplished in 23% overall yield.

  2. Variability in abundance and fluxes of dimethyl sulphide in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Shenoy, D.M.; DileepKumar, M.

    , 285-300 pp. Dacey, J.W.H. and S.G. Wakeham, 1986. Oceanic dimethyl sulfide: production during zooplankton grazing on phytoplankton. Science, 233, 1314-1316. Dickson, D.M., R.G. Wyn Jones and J. Davenport, 1980. Study-state osmotic adaptation.... Seasonal and short-term variability in dimethyl sulfide, sulfur dioxide and biogenic sulfur and sea salt aerosol particles in the arctic marine boundary layer during summer and autumn. Tellus, 48B, 272-299. Liss P.S., G. Malin and S.M. Turner, 1993...

  3. Multicomponent synthesis of 4,4-dimethyl sterol analogues and their effect on eukaryotic cells.

    Science.gov (United States)

    Alonso, Fernando; Cirigliano, Adriana M; Dávola, María Eugenia; Cabrera, Gabriela M; García Liñares, Guadalupe E; Labriola, Carlos; Barquero, Andrea A; Ramírez, Javier A

    2014-06-01

    Most sterols, such as cholesterol and ergosterol, become functional only after the removal of the two methyl groups at C-4 from their biosynthetic precursors. Nevertheless, some findings suggest that 4,4-dimethyl sterols might be involved in specific physiological processes. In this paper we present the synthesis of a collection of analogues of 4,4-dimethyl sterols with a diamide side chain and a preliminary analysis of their in vitro activity on selected biological systems. The key step for the synthesis involves an Ugi condensation, a versatile multicomponent reaction. Some of the new compounds showed antifungal and cytotoxic activity. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Theoretical and Experimental Studies of N,N-Dimethyl-N'-Picryl-4,4'-Stilbenediamine.

    Science.gov (United States)

    Papper, Vladislav; Wu, Yuanyuan; Kharlanov, Vladimir; Sukharaharja, Ayrine; Steele, Terry W J; Marks, Robert S

    2018-01-01

    N,N-dimethyl-N'-picryl-4,4'-stilbenediamine (DMPSDA) was prepared, purified and crystallised in a form of black lustrous crystals, and its absorption and fluorescence spectra were recorded in cyclohexane, acetonitrile and dimethyl sulfoxide. Non-emissive intramolecular charge transfer state (ICT) was clearly observed in this molecule in all three solvents. Theoretical calculations demonstrating a betaine electronic structure of the trinitrophenyl group in the ground state of the molecule and a charge transfer nature of the long wavelength transition S 0  → S 1 supported the experimental observations of the ICT formation in the molecule.

  5. trans-Dichlorido­bis(3,4-dimethyl­pyridine)platinum(II)

    Science.gov (United States)

    Chernyshev, Alexander N.; Bokach, Nadezhda A.; Izotova, Youlia A.; Haukka, Matti

    2009-01-01

    In the title compound, trans-[PtCl2(C7H9N)2], the PtII atom is located on an inversion center and is coordinated by two 3,4-dimethyl­pyridine ligands and two chloride ligands, resulting in a typical slightly distorted square-planar geometry. The crystallographic inversion centre forces the value of the C—N—N—C torsion angle to be linear and the 3,4-dimethyl-pyridine ligands to be coplanar. PMID:21581530

  6. Effect of L-arginine on the growth of Plasmodium falciparum and immune modulation of host cells.

    Science.gov (United States)

    Awasthi, Vikky; Chauhan, Rubika; Chattopadhyay, Debprasad; Das, Jyoti

    2017-01-01

    Malaria is a life-threatening disease caused by Plasmodium parasites. The life-cycle of Plasmodium species involves several stages both in mosquito and the vertebrate host. In the erythrocytic stage, Plasmodium resides inside the red blood cells (RBCs), where it meets most of its nutritional requirement by degrad- ing host's haemoglobin. L-arginine is required for growth and division of cells. The present study was aimed to demonstrate the effect of supplementation of different concentrations of L-arginine and L-citrulline on the growth of parasite, and effect of the culture supernatant on the host's peripheral blood mononuclear cells (PBMCs). To examine the effect of supplementation of L-arginine and L-citrulline, Plasmodium falciparum (3D7 strain) was cultured in RPMI 1640, L-arginine deficient RPMI 1640, and in different concentrations of L-arginine, and L-citrulline supplemented in arginine deficient RPMI 1640 medium. To have a holistic view of in vivo cell activation, the PBMCs isolated from healthy human host were cultured in the supernatant collected from P. falciparum culture. Growth of the parasite was greatly enhanced in L-arginine supplemented media and was found to be concentration dependent. However, parasite growth was compromised in L-citrulline supplemented and L-arginine deficient media. The supernatant collected from L-arginine supplemented parasite media (sArg) showed increased FOXP3 and interleukin-10 (IL-10) expression as compared to the supernatant collected from L-citrulline supple- mented parasite media (sCit). The in vitro culture results showed, decreased parasite growth, and decreased expression of programmed cell death-1 (PD-1) (a coinhibitory molecule) and IL-10 in the L-citrulline supplemented media as compared to L-arginine supplemented media. Hence, it was concluded that L-citrulline supplementation would be a better alternative than L-arginine to inhibit the parasite growth.

  7. Measurement of (vapor + liquid) equilibrium for the systems {methanol + dimethyl carbonate} and {methanol + dimethyl carbonate + tetramethylammonium bicarbonate} at p = (34.43, 67.74) kPa

    International Nuclear Information System (INIS)

    Yang Changsheng; Zeng Hao; Yin Xia; Ma Shengyong; Sun Feizhong; Li Yafei; Li Jiao

    2012-01-01

    Highlights: ► VLE data for the binary system and the ternary system were measured. ► Methanol, dimethyl carbonate, and tetramethylammonium bicarbonate were studied. ► Isobaric experimental data were measured at p = (34.43, 67.74) kPa. ► VLE data of binary system were correlated with the Wilson, NRTL, and UNIQUAC models. ► The salt effect of TMAB on the VLE of {methanol + DMC} system was investigated. - Abstract: Isobaric (vapor + liquid) equilibrium (VLE) data for the binary system (methanol + dimethyl carbonate) and the ternary system (methanol + dimethyl carbonate + tetramethylammonium bicarbonate) have been measured at p = (34.43, 67.74) kPa using a modified Rose–Williams still. The experimental data for the binary system were well correlated by Wilson, NRTL, and UNIQUAC activity-coefficient models at the two reduced pressures. All the experimental results of the binary system passed the thermodynamic consistency test by the area test of Redlich–Kister and the point test of Van Ness et al. The experimental results of ternary system show that the salt tetramethylammonium bicarbonate has a salting-in effect on methanol. And this effect enhances when the salt concentration increases.

  8. Artifact suppression in electron paramagnetic resonance imaging of 14N- and 15N-labeled nitroxyl radicals with asymmetric absorption spectra

    Science.gov (United States)

    Takahashi, Wataru; Miyake, Yusuke; Hirata, Hiroshi

    2014-10-01

    This article describes an improved method for suppressing image artifacts in the visualization of 14N- and 15N-labeled nitroxyl radicals in a single image scan using electron paramagnetic resonance (EPR). The purpose of this work was to solve the problem of asymmetric EPR absorption spectra in spectral processing. A hybrid function of Gaussian and Lorentzian lineshapes was used to perform spectral line-fitting to successfully separate the two kinds of nitroxyl radicals. This approach can process the asymmetric EPR absorption spectra of the nitroxyl radicals being measured, and can suppress image artifacts due to spectral asymmetry. With this improved visualization method and a 750-MHz continuous-wave EPR imager, a temporal change in the distributions of a two-phase paraffin oil and water/glycerin solution system was visualized using lipophilic and hydrophilic nitroxyl radicals, i.e., 2-(14-carboxytetradecyl)-2-ethyl-4,4-dimethyl-3-oxazolidinyloxy (16-DOXYL stearic acid) and 4-hydroxyl-2,2,6,6-tetramethylpiperidine-d17-1-15N-1-oxyl (TEMPOL-d17-15N). The results of the two-phase separation experiment verified that reasonable artifact suppression could be achieved by the present method that deals with asymmetric absorption spectra in the EPR imaging of 14N- and 15N-labeled nitroxyl radicals.

  9. Competitive metabolism of L-arginine: arginase as a therapeutic target in asthma☆

    Science.gov (United States)

    Bratt, Jennifer M.; Zeki, Amir A.; Last, Jerold A.; Kenyon, Nicholas J.

    2011-01-01

    Exhaled breath nitric oxide (NO) is an accepted asthma biomarker. Lung concentrations of NO and its amino acid precursor, L-arginine, are regulated by the relative expressions of the NO synthase (NOS) and arginase isoforms. Increased expression of arginase I and NOS2 occurs in murine models of allergic asthma and in biopsies of asthmatic airways. Although clinical trials involving the inhibition of NO-producing enzymes have shown mixed results, small molecule arginase inhibitors have shown potential as a therapeutic intervention in animal and cell culture models. Their transition to clinical trials is hampered by concerns regarding their safety and potential toxicity. In this review, we discuss the paradigm of arginase and NOS competition for their substrate L-arginine in the asthmatic airway. We address the functional role of L-arginine in inflammation and the potential role of arginase inhibitors as therapeutics. PMID:23554705

  10. l-arginine and l-NMMA for assessing cerebral endothelial dysfunction in ischaemic cerebrovascular disease

    DEFF Research Database (Denmark)

    Karlsson, William K; Sørensen, Caspar G; Kruuse, Christina

    2017-01-01

    Endothelial dysfunction (ED), in particular cerebral ED, may be an essential biomarker for ischaemic cerebrovascular disease. However, there is no consensus on methods to best estimate cerebral ED. In this systematic review, we evaluate the use of l-arginine and NG -monomethyl-l-arginine (l......-NMMA) for assessment of cerebral ED. A systematic search of PubMed, EMBASE and the Cochrane Library was done. We included studies investigating cerebrovascular response to l-arginine or l-NMMA in human subjects with vascular risk factors or ischaemic cerebrovascular disease. Seven studies (315 subjects) were eligible...... cerebrovascular disease. Inconsistencies in results were most likely due to variations in methods and included subject populations. In order to use cerebral ED as a prognostic marker, further studies are required to evaluate the association to cerebrovascular disease....

  11. Action of arginine for protection of ulcerative colitis by dextran sodium sulphate (DSS)

    International Nuclear Information System (INIS)

    Andrade, Maria Emilia Rabelo

    2016-01-01

    Recent studies have demonstrated the benefits of immunomodulators, such as arginine, in the regulation of inflammatory responses and trophism of the intestinal mucosa. The aim of this study was to evaluate the possible mechanisms action of arginine (pretreatment or treatment) in experimental model of ulcerative colitis induced by dextran sodium sulfate (DSS). C57BL/6 mice were randomized into 5 groups: Control group (C): standard diet and water; Arginine group (ARG): diet supplementation with arginine and water; Colitis group (COL): standard diet and DSS solution; Pretreated group (PT): diet supplementation with arginine before and during colitis induction; Treated group (T): diet supplementation with arginine during colitis induction. Colitis was induced by administration of 1.5% DSS for 5 days. After this, all the mice were euthanized and blood, organs and intestinal fluid were collected for carrying out analyzes. Parameters such as intestinal permeability (IP), bacterial translocation (BT), histological analysis (histological score, morphometric analysis, collagen and mucins stain), nitrate and nitrite, cytokines and chemokines, secretory immunoglobulin A (sIgA), inflammatory infiltrate and oxidative stress were performed. The ARG group did not show difference compared to group C in the investigated parameters (C vs ARG: p> 0.05). The COL group showed increased IP (C vs COL: p < 0.05) and BT (C vs COL: p <0.05). In the histological analysis, the COL group showed severe inflammation and reduction the crypts length. In addition, in the group COL observed increase infiltration of eosinophils, neutrophils and macrophages in the colon, increase cytokine IL-17 and chemokine KC in serum and oxidative stress in the colon (COL vs C: p <0.05). In the arginine-supplemented groups (PT and T) was observed decrease IP and BT to blood, liver and lung (PT and T vs Col: p <0.05). Histological analysis showed that the arginine (PT and T) preserved the intestinal mucosa and crypts

  12. Temporal Lob Epilepsi'sinde L-Arginine ve CaEDTA'nın Etkileri

    OpenAIRE

    NOYAN, Behzat

    2005-01-01

    Bu çalışmada, bir nitrik oksit (NO-) prekürsörü olan L-Arginine ve bir ekstrasellüler çinko şelatörü olan CaEDTA'nın pilokarpine HCl ile oluşturulan kısa süreli epileptik nöbet üzerine etkileri araştırıldı. Deney, nöbet kontrol (serum fizyolojik 10 µl, i.c.v., ve sonra 380 mg/kg pilokarpine HCl i.p.), L-Arginine (150 µg/10 µl, i.c.v.), CaEDTA (100 mM, 10 µl, i.c.v.), L-Arginine+CaEDTA olmak üzere 4 gruptan oluştu. Enjeksiyonlardan sonra iki saat boyunca nöbet davranışları gözlemlenen ...

  13. Sided functions of an arginine-agmatine antiporter oriented in liposomes.

    Science.gov (United States)

    Tsai, Ming-Feng; Fang, Yiling; Miller, Christopher

    2012-02-28

    The arginine-dependent extreme acid resistance system helps enteric bacteria survive the harsh gastric environment. At the center of this multiprotein system is an arginine-agmatine antiporter, AdiC. To maintain cytoplasmic pH, AdiC imports arginine and exports its decarboxylated product, agmatine, resulting in a net extrusion of one "virtual proton" in each turnover. The random orientation of AdiC in reconstituted liposomes throws up an obstacle to quantifying its transport mechanism. To overcome this problem, we introduced a mutation, S26C, near the substrate-binding site. This mutant exhibits substrate recognition and pH-dependent activity similar to those of the wild-type protein but loses function completely upon reaction with thiol reagents. The membrane-impermeant MTSES reagent can then be used as a cleanly sided inhibitor to silence those S26C-AdiC proteins whose extracellular portion projects from the external side of the liposome. Alternatively, the membrane-permeant MTSEA and membrane-impermeant reducing reagent, TCEP, can be used together to inhibit proteins in the opposite orientation. This approach allows steady-state kinetic analysis of AdiC in a sided fashion. Arginine and agmatine have similar Michaelis-Menten parameters for both sides of the protein, while the extracellular side selects arginine over argininamide, a mimic of the carboxylate-protonated form of arginine, more effectively than does the cytoplasmic side. Moreover, the two sides of AdiC have different pH sensitivities. AdiC activity increases to a plateau at pH 4 as the extracellular side is acidified, while the cytoplasmic side shows an optimal pH of 5.5, with further acidification inhibiting transport. This oriented system allows more precise analysis of AdiC-mediated substrate transport than has been previously available and permits comparison to the situation experienced by the bacterial membrane under acid stress.

  14. The Metabolic Conversion of Arginine in the Rumen Wall and its Importance in Ruminant Nitrogen Metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Harmeyer, J.; Kurelec, B.; Hill, H. [Department of Physiology, School of Veterinary Medicine, Hanover, Federal Republic of Germany (Germany)

    1968-07-01

    The functions of arginase and urease of the rumen wall were investigated in vitro and in vivo. Surviving ruminal mucosae of cattle were incubated for four hours. {sup 14}C-arginine-HCl, uniformly labelled, was added to the serosal side at a concentration of 10 pmol/mi. About 25% of the added arginine was used during the incubation by the ruminal tissue. In comparison with controls an increased amount of {sup 14}C-omithine, urea, and ammonia were formed in the mucosa and appeared on both sides. The increase was due to arginase and urease functions. It was estimated that about 50% of the urea formed by arginine breakdown were present at the mucosa side, mainly in the form of ammonia. Of the omithine simultaneously formed, 85% remained on the serosa side. Remarkable individual variations of omithine and urea formation were found from animal to animal. The in-vivo experiments were performed using goats with catheters placed in the right ruminal artery and vein. We injected 90 {mu}Ci of {sup 14}C-arginine into the ruminal artery. When 80 g of soluble starch were added to the rumen the activity and concentration of ornithine increased in the ruminal venous blood showing an arterial-venous difference. The radioactivity of urea in blood taken from the ruminal vein and the carotid artery did not show any difference. When starch was omitted from the rumen a comparable difference of omithine concentration was not found. It is assumed that the enzymes arginase and urease of the rumen wall are involved in nitrogen recycling processes. Blood arginine may be hydrolysed in the rumen wall forming urea and ornithine. Urea formed by arginine breakdown may be split to CO{sub 2} and ammonia. The experiments produced evidence that the ammonia formed preferably enters the rumen content. The nitrogen transfer through the rumen wall may be affected by varying activities of arginase. (author)

  15. Supplementation with rumen-protected L-arginine-HCl increased fertility in sheep with synchronized estrus.

    Science.gov (United States)

    de Chávez, Julio Agustín Ruiz; Guzmán, Adrian; Zamora-Gutiérrez, Diana; Mendoza, Germán David; Melgoza, Luz María; Montes, Sergio; Rosales-Torres, Ana María

    2015-08-01

    The aim of the present study was to evaluate the effects of L-arginine-HCl supplementation on ovulation rate, fertility, prolificacy, and serum VEGF concentrations in ewes with synchronized oestrus. Thirty Suffolk ewes with a mean body weight of 45 ± 3 kg and a mean body condition score (BCS) of 2.4 ± 0.28 were synchronized for estrus presentation with a progestin-containing sponge (20 mg Chronogest® CR) for 9 days plus PGF2-α (Lutalyse; Pfizer, USA) on day 7 after the insertion of the sponge. The ewes were divided into two groups; i.e., a control group (n = 15) that was fed on the native pasture (basal diet) and an L-arginine-HCl group (n = 15) that received 7.8 g of rumen-protected L-arginine-HCl from day 5 of the sponge insertion until day 25 after mating plus the basal diet. The L-arginine-HCl was administered daily via an esophageal probe between days 5 and 9 of the synchronization protocol and every third day subsequently. Blood samples were drawn from the jugular vein every 6 days throughout the entire experimental period. The results revealed that the L-arginine-HCl supplementation increased fertility during the synchronized estrus (P = 0.05). However, no effects were observed on the final BCS (P = 0.78), estrus presentation (P = 0.33), multiple ovulations (P = 0.24), prolificacy (P = 0.63), or serum VEGF concentration. In conclusion, L-arginine-HCl supplementation during the period used in this study increased fertility in sheep with synchronized estrus possibly due to improved embryo-fetal survival during early pregnancy.

  16. L-arginine fails to prevent ventricular remodeling and heart failure in the spontaneously hypertensive rat.

    Science.gov (United States)

    Brooks, Wesley W; Conrad, Chester H; Robinson, Kathleen G; Colucci, Wilson S; Bing, Oscar H L

    2009-02-01

    The effects of long-term oral administration of L-arginine, a substrate for nitric oxide (NO) production, on left ventricular (LV) remodeling, myocardial function and the prevention of heart failure (HF) was compared to the angiotensin-converting enzyme (ACE) inhibitor captopril in a rat model of hypertensive HF (aged spontaneously hypertensive rat (SHR)). SHRs and age-matched normotensive Wistar-Kyoto (WKY) rats were assigned to either no treatment, treatment with L-arginine (7.5 g/l in drinking water) or captopril (1 g/l in drinking water) beginning at 14 months of age, a time when SHRs exhibit stable compensated hypertrophy with no hemodynamic impairment; animals were studied at 23 months of age or at the time of HF. In untreated SHR, relative to WKY, there was significant LV hypertrophy, myocardial fibrosis, and isolated LV muscle performance and response to isoproterenol (ISO) were depressed; and, 7 of 10 SHRs developed HF. Captopril administration to six SHRs attenuated hypertrophy and prevented impaired inotropic responsiveness to ISO, contractile dysfunction, fibrosis, increased passive stiffness, and HF. In contrast, L-arginine administration to SHR increased LV hypertrophy and myocardial fibrosis while cardiac performance was depressed; and 7 of 9 SHRs developed HF. In WKY, L-arginine treatment but not captopril resulted in increased LV weight and the contractile response to ISO was blunted. Neither L-arginine nor captopril treatment of WKY changed fibrosis and HF did not occur. These data demonstrate that in contrast to captopril, long-term treatment with L-arginine exacerbates age-related cardiac hypertrophy, fibrosis, and did not prevent contractile dysfunction or the development of HF in aging SHR.

  17. Excess L-arginine restores endothelium-dependent relaxation impaired by monocrotaline pyrrole

    International Nuclear Information System (INIS)

    Cheng Wei; Oike, Masahiro; Hirakawa, Masakazu; Ohnaka, Keizo; Koyama, Tetsuya; Ito, Yushi

    2005-01-01

    The pyrrolizidine alkaloid plant toxin monocrotaline pyrrole (MCTP) causes pulmonary hypertension in experimental animals. The present study aimed to examine the effects of MCTP on the endothelium-dependent relaxation. We constructed an in vitro disease model of pulmonary hypertension by overlaying MCTP-treated bovine pulmonary artery endothelial cells (CPAEs) onto pulmonary artery smooth muscle cell-embedded collagen gel lattice. Acetylcholine (Ach) induced a relaxation of the control CPAEs-overlaid gels that were pre-contracted with noradrenaline, and the relaxation was inhibited by L-NAME, an inhibitor of NO synthase (NOS). In contrast, when MCTP-treated CPAEs were overlaid, the pre-contracted gels did not show a relaxation in response to Ach in the presence of 0.5 mM L-arginine. Expression of endothelial NOS protein, Ach-induced Ca 2+ transients and cellular uptake of L-[ 3 H]arginine were significantly smaller in MCTP-treated CPAEs than in control cells, indicating that these changes were responsible for the impaired NO production in MCTP-treated CPAEs. Since cellular uptake of L-[ 3 H]arginine linearly increased according to its extracellular concentration, we hypothesized that the excess concentration of extracellular L-arginine might restore NO production in MCTP-treated CPAEs. As expected, in the presence of 10 mM L-arginine, Ach showed a relaxation of the MCTP-treated CPAEs-overlaid gels. These results indicate that the impaired NO production in damaged endothelial cells can be reversed by supplying excess L-arginine

  18. Developmental changes of l-arginine transport at the blood-brain barrier in rats.

    Science.gov (United States)

    Tachikawa, Masanori; Hirose, Shirou; Akanuma, Shin-Ichi; Matsuyama, Ryo; Hosoya, Ken-Ichi

    2018-05-01

    l-Arginine is required for regulating synapse formation/patterning and angiogenesis in the developing brain. We hypothesized that this requirement would be met by increased transporter-mediated supply across the blood-brain barrier (BBB). Thus, the purpose of this work was to test the idea that elevation of blood-to-brain l-arginine transport across the BBB in the postnatal period coincides with up-regulation of cationic acid transporter 1 (CAT1) expression in developing brain capillaries. We found that the apparent brain-to-plasma concentration ratio (Kp, app) of l-arginine after intravenous administration during the first and second postnatal weeks was 2-fold greater than that at the adult stage. Kp, app of l-serine was also increased at the first postnatal week. In contrast, Kp, app of d-mannitol, a passively BBB-permeable molecule, did not change, indicating that increased transport of l-arginine and l-serine is not due to BBB immaturity. Double immunohistochemical staining of CAT1 and a marker protein, glucose transporter 1, revealed that CAT1 was localized on both luminal and abluminal membranes of brain capillary endothelial cells during the developmental and adult stages. A dramatic increase in CAT1 expression in the brain was seen at postnatal day 7 (P7) and day 14 (P14) and the expression subsequently decreased as the brain matured. In accordance with this, intense immunostaining of CAT1 was observed in brain capillaries at P7 and P14. These findings strongly support our hypothesis and suggest that the supply of blood-born l-arginine to the brain via CAT1 at the BBB plays a key role in meeting the elevated demand for l-arginine in postnatal brain. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Antioxidant properties of dimethyl sulfoxide and its viability as a solvent in the evaluation of neuroprotective antioxidants.

    Science.gov (United States)

    Sanmartín-Suárez, Carolina; Soto-Otero, Ramón; Sánchez-Sellero, Inés; Méndez-Álvarez, Estefanía

    2011-01-01

    Dimethyl sulfoxide is an amphiphilic compound whose miscibility with water and its ability to dissolve lipophilic compounds make it an appreciated solvent in biomedical research. However, its reported antioxidant properties raise doubts about its use as a solvent in evaluating new antioxidants. The goal of this investigation was to evaluate its antioxidant properties and carry out a comparative study on the antioxidant properties of some known neuroprotective antioxidants in the presence and absence of dimethyl sulfoxide. The antioxidant properties of dimethyl sulfoxide were studied in rat brain homogenates by determining its ability to reduce both lipid peroxidation (TBARS formation) and protein oxidation (increase in protein carbonyl content and decrease in free thiol content) induced by ferrous chloride/hydrogen peroxide. Its ability to reduce the production of hydroxyl radicals by 6-hydroxydopamine autoxidation was also estimated. The same study was also performed with three known antioxidants (α-phenyl-N-tert-butylnitrone; 2-methyl-2-nitrosopropane; 5,5-dimethyl-1-pyrroline N-oxide) in the presence and absence of dimethyl sulfoxide. Our results showed that dimethyl sulfoxide is able to reduce both lipid peroxidation and protein carbonyl formation induced by ferrous chloride/hydrogen peroxide in rat brain homogenates. It can also reduce the production of hydroxyl radicals during 6-hydroxydopamine autoxidation. However, it increases the oxidation of protein thiol groups caused by ferrous chloride/hydrogen peroxide in rat brain homogenate. Despite the here reported antioxidant and pro-oxidant properties of dimethyl sulfoxide, the results obtained with α-phenyl-N-tert-butylnitrone, 2-methyl-2-nitrosopropane, and 5,5-dimethyl-1-pyrroline N-oxide corroborate the antioxidant properties attributed to these compounds and support the potential use of dimethyl sulfoxide as a solvent in the study of the antioxidant properties of lipophilic compounds. Dimethyl sulfoxide

  20. Efficacy L-Arginine In Patients With Nonalcoholic Steatohepatitis Associated With Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Oleksandr Fediv

    2015-01-01

    Full Text Available Abstract Background and Purpose Recent research in the field of hematology indicate that among the many pathogenic mechanisms of development and progression of nonalcoholic steatohepatitis NASH which occurs on the background of the metabolic syndrome an important role is played by endothelial dysfunction and violations of haemocoagulation. The aim of this research was to study the effectiveness of L-arginine as it corrects endothelial dysfunction and disorders of homeostasis haemocoagulation link in patients with NASH associated with the metabolic syndrome. Subjects and Methods 128 patients with nonalcoholic steatohepatitis associated with metabolic syndrome were examined. Some patients 63 persons received standard treatment according to national guidelines. To another group 65 patients on the background of basic therapy L-arginine hydrochloride followed by transition to oral form of L-arginine aspartate was administered. Blood levels of stable nitrogen monoxide metabolites nitrites nitrates endothelin-1 and plasma recalcification time prothrombin time thrombin time activated partial thromboplastin time fibrinogen plasma level activity of antithrombin III and coagulation factor XIII potential activity of plasminogen plasma fibrinolytic blood activity were studied. Results Originally significantly increased levels of endothelin-1 decreased after the therapy in all studied groups but more noticeable changes in the group with L-arginine appointment were observed p0.05. In the studied groups normalization of stable nitrogen monoxide metabolites after treatment was also noticed. Significant p0.05 increase in all haemocoagulation time characteristics and activities of antithrombin-III and factor XIII was found. The positive effect of L-arginine on blood fibrinolytic activity was noted. Discussion and Conclusion Combined therapy of nonalcoholic steatohepatitis associated with metabolic syndrome with a differentiated degreeal L-arginine assignment by

  1. Arginine vasopressin stimulates phosphoinositide turnover in an enriched rat Leydig cell preparation

    DEFF Research Database (Denmark)

    Nielsen, J.R.; Hansen, Harald S.; Jensen, B.

    1989-01-01

    An enriched rat Leydig cell preparation was preincubated with [C]arachidonic acid. Stimulation of the cells with arginine vasopressin (AVP) (1 µM) for 2 min caused a significant increase in labelled phosphatidic acid and a significant fall in radioactivity in phosphatidylinositol and phosphatidyl......An enriched rat Leydig cell preparation was preincubated with [C]arachidonic acid. Stimulation of the cells with arginine vasopressin (AVP) (1 µM) for 2 min caused a significant increase in labelled phosphatidic acid and a significant fall in radioactivity in phosphatidylinositol...

  2. Arginine as an adjuvant to chemotherapy improves clinical outcome in active tuberculosis

    DEFF Research Database (Denmark)

    Schön, T; Elias, D; Moges, F

    2003-01-01

    Nitric oxide (NO) is involved in the host defence against tuberculosis (TB). Patients with TB exhibit increased catabolism and reduced energy intake. Thus the hypothesis for this study was that restoring a relative deficiency in the amino acid arginine, the substrate for mycobactericidal NO produ......Nitric oxide (NO) is involved in the host defence against tuberculosis (TB). Patients with TB exhibit increased catabolism and reduced energy intake. Thus the hypothesis for this study was that restoring a relative deficiency in the amino acid arginine, the substrate for mycobactericidal...... virus-negative patients with active tuberculosis, most likely mediated by increased production of nitric oxide....

  3. NOS3 is involved in the increased protein and arginine metabolic response in muscle during early endotoxemia in mice

    NARCIS (Netherlands)

    Luiking, Yvette C.; Hallemeesch, Marcella M.; Lamers, Wouter H.; Deutz, Nicolaas E. P.

    2005-01-01

    Sepsis is a severe catabolic condition. The loss of skeletal muscle protein mass is characterized by enhanced release of the amino acids glutamine and arginine, which (in)directly affects interorgan arginine and the related nitric oxide (NO) synthesis. To establish whether changes in muscle amino

  4. Functional variation in the arginine vasopressin 2 receptor as a modifier of human plasma von Willebrand factor levels

    DEFF Research Database (Denmark)

    Nossent, Anne Yaël; Robben, J H; Deen, P M T

    2010-01-01

    SUMMARY OBJECTIVES: Stimulation of arginine vasopressin 2 receptor (V2R) with arginine vasopressin (AVP) results in a rise in von Willebrand factor (VWF) and factor VIII plasma levels. We hypothesized that gain-of-function variations in the V2R gene (AVPR2) would lead to higher plasma levels of V...

  5. L-arginine enhances cell proliferation and reduces apoptosis in human endometrial RL95-2 cells

    Science.gov (United States)

    L-arginine is considered to be one of the most versatile amino acids due to the fact that it serves as a precursor for many important molecules in cellular physiology. When supplemented in the diet, L-arginine can increase the number of implantation sites in mice and rats, suggesting an effect at th...

  6. Heritability and genetic variance for citrulline, arginine and lycopene content in a diverse set of watermelon cultigens

    Science.gov (United States)

    Citrulline, arginine, and lycopene are naturally occurring compounds found in watermelon, Citrullus lanatus (Thumb) Matsum & Nakai, with beneficial effects on plant growth and human health. This study evaluated seven commercial cultivars and one breeding line for citrulline, arginine, and lycopene c...

  7. Arginine promotes Proteus mirabilis motility and fitness by contributing to conservation of the proton gradient and proton motive force.

    Science.gov (United States)

    Armbruster, Chelsie E; Hodges, Steven A; Smith, Sara N; Alteri, Christopher J; Mobley, Harry L T

    2014-10-01

    Swarming contributes to Proteus mirabilis pathogenicity by facilitating access to the catheterized urinary tract. We previously demonstrated that 0.1-20 mmol/L arginine promotes swarming on normally nonpermissive media and that putrescine biosynthesis is required for arginine-induced swarming. We also previously determined that arginine-induced swarming is pH dependent, indicating that the external proton concentration is critical for arginine-dependent effects on swarming. In this study, we utilized survival at pH 5 and motility as surrogates for measuring changes in the proton gradient (ΔpH) and proton motive force (μH(+) ) in response to arginine. We determined that arginine primarily contributes to ΔpH (and therefore μH(+) ) through the action of arginine decarboxylase (speA), independent of the role of this enzyme in putrescine biosynthesis. In addition to being required for motility, speA also contributed to fitness during infection. In conclusion, consumption of intracellular protons via arginine decarboxylase is one mechanism used by P. mirabilis to conserve ΔpH and μH(+) for motility. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  8. L-arginine supplementation enhances exhaled NO, breath condensate VEGF, and headache at 4,342 m.

    Science.gov (United States)

    Mansoor, Jim K; Morrissey, Brian M; Walby, William F; Yoneda, Ken Y; Juarez, Maya; Kajekar, Radhika; Severinghaus, John W; Eldridge, Marlowe W; Schelegle, Edward S

    2005-01-01

    We examined the effect of dietary supplementation with L-arginine on breath condensate VEGF, exhaled nitric oxide (NO), plasma erythropoietin, symptoms of acute mountain sickness, and respiratory related sensations at 4,342 m through the course of 24 h in seven healthy male subjects. Serum L-arginine levels increased in treated subjects at time 0, 8, and 24 h compared with placebo, indicating the effectiveness of our treatment. L-arginine had no significant effect on overall Lake Louise scores compared with placebo. However, there was a significant increase in headache within the L-arginine treatment group at 12 h compared with time 0, a change not seen in the placebo condition between these two time points. There was a trend (p = 0.087) toward greater exhaled NO and significant increases in breath condensate VEGF with L-arginine treatment, but no L-arginine effect on serum EPO. These results suggest that L-arginine supplementation increases HIF-1 stabilization in the lung, possibly through a NO-dependent pathway. In total, our observations indicate that L-arginine supplementation is not beneficial in the prophylactic treatment of AMS.

  9. Vibrational study, crystal structure and quantum calculations of 2,2'-azobipyridine and 4,4'-dimethyl-3,3'-dinitro-2,2'-azobipyridine

    International Nuclear Information System (INIS)

    Kucharska, E.; Hanuza, J.; Waskowska, A.; Talik, Z.

    2004-01-01

    Synthesis of 2,2'-azobipyridine and 4,4'-dimethyl-3,3'-dinitro-2,2'-azobipyridine is described. The X-ray structure of the later compound is reported and discussed in terms of its molecular structure with a particular attention to the conformation of the azo-bond and intermolecular C-H?O bonds. The crystal is monoclinic, space group P2 1 /c, with the unit cell parameters a = 12.388(2), b = 14.983(3), c 7.370(1) A, and β = 102.49(3) deg . The asymmetric unit consists of two 3-nitro-4-methyl-pyridine units linked by the -N=N- diazene bond. The pyridine rings are planar. The methyl carbon and the N atom of the nitro groups, substituted to the ring, are lying approximately in the plane. In the crystal structure the molecules are arranged in dimers due to the hydrogen bonding between the methyl group and the oxygen of the nitro group of the molecule related by a centre of symmetry. Fourier transform IR and Raman spectra of this compound have been measured and compared to the spectra of 2,2'-azobipyridine. The 6-31G basis set with the B3LYP and MPW1PW31 functionals have been used to discuss the structure and dynamics of the compounds studied

  10. Observation of asymmetric electromagnetic field profiles in chiral metamaterials

    Science.gov (United States)

    Hisamoto, Nobuyuki; Ueda, Tetsuya; Sawada, Kei; Tomita, Satoshi

    2018-02-01

    We experimentally observe asymmetric electromagnetic field profiles along two-dimensional chiral metamaterials. The asymmetric field profiles depending on the chirality and the operation frequency have been reproduced well by the numerical simulation. Around a chiral meta-atom, distribution of a Poynting vector is found to be shifted asymmetrically. These results are explained in terms of an analogy with the side-jump mechanism in the electronic anomalous Hall systems.

  11. Asymmetric forecasting and commitment policy in a robust control problem

    OpenAIRE

    Taro Ikeda

    2013-01-01

    This paper provides a piece of results regarding asymmetric forecasting and commitment monetary policy with a robust control algorithm. Previous studies provide no clarification of the connection between asymmetric preference and robust commitment policy. Three results emerge from general equilibrium modeling with asymmetric preference: (i) the condition for system stability implies an average inflation bias with respect to asymmetry (ii) the effect of asymmetry can be mitigated if policy mak...

  12. The human neonatal small intestine has the potential for arginine synthesis; developmental changes in the expression of arginine-synthesizing and -catabolizing enzymes

    Directory of Open Access Journals (Sweden)

    Ruijter Jan M

    2008-11-01

    Full Text Available Abstract Background Milk contains too little arginine for normal growth, but its precursors proline and glutamine are abundant; the small intestine of rodents and piglets produces arginine from proline during the suckling period; and parenterally fed premature human neonates frequently suffer from hypoargininemia. These findings raise the question whether the neonatal human small intestine also expresses the enzymes that enable the synthesis of arginine from proline and/or glutamine. Carbamoylphosphate synthetase (CPS, ornithine aminotransferase (OAT, argininosuccinate synthetase (ASS, arginase-1 (ARG1, arginase-2 (ARG2, and nitric-oxide synthase (NOS were visualized by semiquantitative immunohistochemistry in 89 small-intestinal specimens. Results Between 23 weeks of gestation and 3 years after birth, CPS- and ASS-protein content in enterocytes was high and then declined to reach adult levels at 5 years. OAT levels declined more gradually, whereas ARG-1 was not expressed. ARG-2 expression increased neonatally to adult levels. Neurons in the enteric plexus strongly expressed ASS, OAT, NOS1 and ARG2, while varicose nerve fibers in the circular layer of the muscularis propria stained for ASS and NOS1 only. The endothelium of small arterioles expressed ASS and NOS3, while their smooth-muscle layer expressed OAT and ARG2. Conclusion The human small intestine acquires the potential to produce arginine well before fetuses become viable outside the uterus. The perinatal human intestine therefore resembles that of rodents and pigs. Enteral ASS behaves as a typical suckling enzyme because its expression all but disappears in the putative weaning period of human infants.

  13. Ketene as a Reaction Intermediate in the Carbonylation of Dimethyl Ether to Methyl Acetate over Mordenite

    DEFF Research Database (Denmark)

    Rasmussen, Dominik Bjørn; Christensen, Jakob Munkholt; Temel, Burcin

    2015-01-01

    Unprecedented insight into the carbonylation of dimethyl ether over Mordenite is provided through the identification of ketene (CH2CO) as a reaction intermediate. The formation of ketene is predicted by detailed DFT calculations and verified experimentally by the observation of doubly deuterated ...

  14. Enthalpies of potassium iodide dissolution in dimethyl acetamide mixtures with water

    International Nuclear Information System (INIS)

    Privalova, N.M.; Gritsenko, S.I.; Vorob'ev, A.F.

    1986-01-01

    Enthalpies of potassium iodide dissolution in mixed dimethyl acetamide - water solvent at 298.15 K in the whole range of dimethyl acetamide compositions are measured by the calorimetric method. From the plots of KI dissolution enthalpy dependence and dependence of experimental ΔH p∞ 0 value deviations from calculational ones on solvent composition, as well as from the results of calculation of solvate shell composition of potassium iodide ions in the mixed solvent, it is obvious that in the region of 0-15 mol% concentrations of dimethyl acetamide insufficient enrichment of solvate ion shells by dimethyl acetamide (DMAA) occurs, in the region of 15-40 mol% DMAA compositions enrichment of solvate shells of ions by water occurs, in the region of 40-100 mol% DMAA enrichment of solvate ion shells by the organic component in comparison with mixture compostion occurs. Maximum enrichment of solvate ion shells by mixture components in three above mentioned regions of the mixed solvent occurs at 10, 30 and 80 mol% DMAA concentrations

  15. Thermodynamicy of Catalytic Formation of Dimethyl Ether from Methanol in Acidic Zeolites

    Czech Academy of Sciences Publication Activity Database

    Hyťha, Marek; Štich, I.; Gale, J. D.; Terakura, K.; Payne, M.

    2001-01-01

    Roč. 7, č. 12 (2001), s. 2521-2527 ISSN 0947-6539 Institutional research plan: CEZ:AV0Z1010914 Keywords : dimethyl ether * formation * theoretical study Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.614, year: 2001

  16. 5,5-Dimethyl-2-methylseleno-1,3,2-dioxaphosphorinan-2-one

    Directory of Open Access Journals (Sweden)

    Grzegorz Cholewinski

    2010-04-01

    Full Text Available The title compound, C6H13O3PSe, was obtained in the reaction of 5,5-dimethyl-2-oxo-2-seleno-1,3,2-dioxaphosphorinane potassium salt with methyl iodide. The selenomethyl group is in the axial position in relation to the six-membered dioxaphosphorinane ring.

  17. On-board conversion of methanol to dimethyl ether as an alternative diesel fuel

    Energy Technology Data Exchange (ETDEWEB)

    Armbruster, H; Heinzelmann, G; Struis, R; Stucki, S [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The catalytic dehydration of methanol to dimethyl ether was investigated for application on-board a methanol fuelled vehicle. Several catalysts have been tested in a fixed bed reactor. Our approach is to develop a small and efficient reactor converting liquid MeOH under pressure and at low reaction temperatures. (author) 2 figs., 5 refs.

  18. Structural and spectroscopic studies of 2,9-dimethyl-1,10 ...

    African Journals Online (AJOL)

    The crystal structures of the pronated ligand, 2,9-dimethyl-1,10-phenanthrolinium (DPH) cation with selected counter anions (chloride (1), triflate (2), and gold dicyanide (3)) are reported. The role of a hydrogen bond interaction in influencing the solid state p-p stacking found in all three compounds has been investigated.

  19. On the Origin of Microheterogeneity : A Mass Spectrometric Study of Dimethyl Sulfoxide-Water Binary Mixture

    NARCIS (Netherlands)

    Shin, Dong Nam; Wijnen, Jan W.; Engberts, Jan B.F.N.; Wakisaka, Akihiro

    2001-01-01

    We have studied the microscopic solvent structure of dimethyl sulfoxide-water mixtures and its influence on the solvation structure of solute from a clustering point of View, by means of a specially designed mass spectrometric system. It was observed that the propensity to the cluster formation is

  20. Electrochemical stability and transformations of fluorinated poly(2,6-dimethyl-1,4-phenylene oxide)

    NARCIS (Netherlands)

    Pud, A.A.; Rogalsky, S.P.; Ghapoval, G.S.; Kharitonov, A.P.; Kemperman, Antonius J.B.

    2000-01-01

    Fluorination of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) leads to narrowing of its window of electrochemical stability in a cathodic range of potentials. It is found this is connected with appearance of both perfluorinated and incompletely fluorinated units in the polymer. The former units are

  1. The industrial production of dimethyl carbonate from methanol and carbon dioxide

    NARCIS (Netherlands)

    De Groot, Frank F T; Lammerink, Roy R G J; Heidemann, Casper; Van Der Werff, Michiel P M; Garcia, Taiga Cafiero; Van Der Ham, Louis A G J; Van Den Berg, Henk

    2014-01-01

    This work discusses the design of a dimethyl carbonate (DMC) production plant based on methanol and CO2 as feed materials, which are a cheap and environment-friendly feedstock. DMC is a good alternative for methyl-tert-butyl ether (MTBE) as a fuel oxygenating agent, due to its low toxicity and fast

  2. Controls of dimethyl sulphide in the Bay of Bengal during BOBMEX-Pilot cruise 1998

    Digital Repository Service at National Institute of Oceanography (India)

    Shenoy, D.M.; DileepKumar, M.; Sarma, V.V.S.S

    The air-sea exchange is one of the main mechanisms maintaining the abundances of trace gases in the atmosphere. Some of these, such as carbon dioxide and dimethyl sulphide (DMS), will have a bearing on the atmospheric heat budget. While the former...

  3. Volatile Organic Sulfur Compounds of Environmental Interest: Dimethyl Sulfide and Methanethiol

    Science.gov (United States)

    Chasteen, Thomas G.; Bentley, Ronald

    2004-01-01

    Volatile organic sulfur compounds (VOSCs) have been assigned environmental roles in global warming, acid precipitation, and cloud formation where two important members dimethyl sulfide (CH3)2 S, DMS, and methanethiol, CH3SH, MT, of VOSC group are involved.

  4. Boltorn-Modified Poly(2,6-dimethyl-1,4,phenylene oxide) Gas Separation Membranes

    NARCIS (Netherlands)

    Sterescu, D.M.; Stamatialis, Dimitrios; Mendes, Eduardo; Kruse, Jan; Rätzke, Klaus; Faupel, Franz; Wessling, Matthias

    2007-01-01

    This paper describes the preparation, characterization and the permeation properties of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) dense polymer films containing aliphatic hyperbranched polyesters, Boltorn (H20, H30, and H40). The Boltorn are dispersed in PPO at various concentrations. The gas

  5. Asymmetric acoustic transmission in graded beam

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Li, E-mail: lj94172350@hotmail.com [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Wu, Jiu Hui, E-mail: ejhwu@mail.xjtu.edu.cn [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Guan, Dong; Lu, Kuan [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Gao, Nansha [School of Marine Science and Technology, Northwestern Polytechnical University, Xi’an, Shaanxi 710072 (China); Songhua, Cao [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China)

    2016-12-01

    We demonstrate the dynamic effective material parameters and vibration performance of a graded beam. The structure of the beam was composed of several unit cells with different fill factors. The dispersion relations and energy band structures of each unit cell were calculated using the finite element method (FEM). The dynamic effective material parameters in each unit cell of the graded beam were determined by the dispersion relations and energy band structures. Longitudinal wave propagation was investigated using a numerical method and FEM. The results show that the graded beam allows asymmetric acoustic transmission over a wide range of frequencies.

  6. OFFICER AND COMMANDER IN ASYMMETRIC WARFARE OPERATIONS

    Directory of Open Access Journals (Sweden)

    Giuseppe CAFORIO

    2013-01-01

    Full Text Available Starting from the data of a field research conducted among soldiers with asymmetric warfare experiences from nine different countries, the author seeks to identify and shed light on the various problems that officers with command responsibilities had to face during their missions. A picture emerges of feelings and experiences relating to their first impression upon arriving in the theatre, relations with local armed forces, relations with the local population and local authorities, relations with NGOs, relations with other armies, the impact of the rules of engagement (ROEs, training and education, and operational experiences. The paper ends with a discussion of the lessons learned.

  7. Nanotribology of Symmetric and Asymmetric Liquid Lubricants

    Directory of Open Access Journals (Sweden)

    Shinji Yamada

    2010-03-01

    Full Text Available When liquid molecules are confined in a narrow gap between smooth surfaces, their dynamic properties are completely different from those of the bulk. The molecular motions are highly restricted and the system exhibits solid-like responses when sheared slowly. This solidification behavior is very dependent on the molecular geometry (shape of liquids because the solidification is induced by the packing of molecules into ordered structures in confinement. This paper reviews the measurements of confined structures and friction of symmetric and asymmetric liquid lubricants using the surface forces apparatus. The results show subtle and complex friction mechanisms at the molecular scale.

  8. Asymmetric Total Synthesis of Ieodomycin B

    Directory of Open Access Journals (Sweden)

    Shuangjie Lin

    2017-01-01

    Full Text Available Ieodomycin B, which shows in vitro antimicrobial activity, was isolated from a marine Bacillus species. A novel asymmetric total synthetic approach to ieodomycin B using commercially available geraniol was achieved. The approach involves the generation of 1,3-trans-dihydroxyl at C-3 and C-5 positions via a Crimmins-modified Evans aldol reaction and a chelation-controlled Mukaiyama aldol reaction of a p-methoxybenzyl-protected aldehyde, as well as the generation of a lactone ring in a deprotection–lactonization one-pot reaction.

  9. The Asymmetric Effects of Investor Sentiment

    DEFF Research Database (Denmark)

    Lutz, Chandler

    2016-01-01

    We use the returns on lottery-like stocks and a dynamic factor model to construct a novel index of investor sentiment. This new measure is highly correlated with other behavioral indicators, but more closely tracks speculative episodes. Our main new finding is that the effects of sentiment...... are asymmetric: During peak-to-trough periods of investor sentiment (sentiment contractions), high sentiment predicts low future returns for the cross section of speculative stocks and for the market overall, whereas the relationship between sentiment and future returns is positive but relatively weak during...... trough-to-peak episodes (sentiment expansions). Overall, these results match theories and anecdotal accounts of investor sentiment....

  10. On asymmetric causal relationships in Petropolitics

    Directory of Open Access Journals (Sweden)

    Balan Feyza

    2016-01-01

    Full Text Available The aim of this paper is to examine whether the First Law of Petropolitics denominated by Friedman in 2006 is valid for OPEC countries. To do this, this paper analyses the relationship between political risk and oil supply by applying the asymmetric panel causality test suggested by Hatemi-J (2011 to these countries for the period 1984-2014. The results show that the First Law of Petropolitics is valid for Angola, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, and the UAE, given that positive oil supply shocks significantly lead to negative political stability shocks, and negative oil supply shocks significantly lead to positive shocks in political stability.

  11. Asymmetric nuclear matter and neutron star properties

    International Nuclear Information System (INIS)

    Engvik, L.; Hjorth-Jensen, M.; Osnes, E.; Bao, G.; Oestgaard, E.

    1994-06-01

    Properties of neutron stars such as mass and radius, using a relativistic Dirac-Brueckner-Hartree-Fock approach, are calculated. Modern meson-exchange potential models are used to evaluate the G-matrix for asymmetric nuclear matter. For pure neutron matter the maximum mass is found to be M max ∼ 2.4M for a radius R ∼ 12 km. With a proton fraction of 30% the result is M max ∼ 2.1M for a radius R ∼ 10.5 km, close to the experimental values. The implications are discussed. 20 refs., 3 figs

  12. Two particle states in an asymmetric box

    International Nuclear Information System (INIS)

    Li Xin; Liu Chuan

    2004-01-01

    The exact two-particle energy eigenstates in an asymmetric rectangular box with periodic boundary conditions in all three directions are studied. Their relation with the elastic scattering phases of the two particles in the continuum are obtained. These results can be viewed as a generalization of the corresponding formulae in a cubic box obtained by Luescher before. In particular, the s-wave scattering length is related to the energy shift in the finite box. Possible applications of these formulae are also discussed

  13. Asymmetrical Capacitors for Propulsion and the ISR Asymmetrical Capacitator Thruster, Experimental Results and Improved Designs

    Science.gov (United States)

    Canning, Francis; Winet, Ed; Ice, Bob; Melcher, Cory; Pesavento, Phil; Holmes, Alan; Butler, Carey; Cole, John; Campbell, Jonathan

    2004-01-01

    The outline of this viewgraph presentation on asymmetrical capacitor thruster development includes: 1) Test apparatus; 2) Devices tested; 3) Circuits used; 4) Data collected (Time averaged, Time resolved); 5) Patterns observed; 6) Force calculation; 7) Electrostatic modeling; 8) Understand it all.

  14. Chiral ferrocenes in asymmetric catalysis: synthesis and applications

    National Research Council Canada - National Science Library

    Dai, Li-Xin; Hou, Xue-Long

    2010-01-01

    .... It provides a thorough overview of the synthesis and characterization of different types of chiral ferrocene ligands, their application to various catalytic asymmetric reactions, and versatile chiral...

  15. The Effects of Pretreatment with Various Doses of L-Arginine on Cisplatin-Induced Nephropathy of Male Rats

    Directory of Open Access Journals (Sweden)

    B Rasoulian

    2016-09-01

    Full Text Available Introduction: Cisplatin is a widely used anti-cancer drug, which its application is limited by nephrotoxicity. In this study, the effect of pretreatment with different l-arginine doses on Cisplatin-induced renal functional injury was investigated. Methods: 63 male rats were divided into 7 groups: In groups 3, 4, 5 and 6, 60 min before the Cisplatin injection (5mg/kg; L-Arginine with doses of 50,100,200 or 400mg/kg was injected, respectively. In group7, normal saline was injected before Cisplatin administration. In groups 1 and 2, normal saline was injected instead of Cisplatin. In group 2, 60min before normal saline injection, 400mg/kg L-Arginine was administered and in group1, instead of L-arginine, normal saline was injected too. Injections were intraperitoneal. 72h after Cisplatin injection, blood sampling and plasma separation were done. Urine sample was collected 24 hours before blood sampling by metabolic cage. The mean of plasma urea and creatinine levels and creatinine clearance (ml/day.kg and fractional excretion of Na (FENa, % were compared among different groups as renal functional parameters. Results: In comparison to group 7, L-arginine injection in a dose of 400mg/kg led to significant amelioration of all parameters. 200 mg/kg L-arginine administration led to significant decrease in plasma urea level and FENa. 100mg/kg L-arginine caused significant improvement in fractional excretion of sodium. L-arginine injection with 50mg/kg dose, significantly ameliorate all renal function tests instead of creatinine clearance. Conclusion: Pretreatment with L-arginine administration with 400 or 50 mg/kg doses, respectively, had the highest effect on reducing Cisplatin-induced nephropathy. L-arginine injection with intermediate doses i.e. 200 or 100 mg/kg had less effect in reducing Cisplatin-induced nephropathy and it needs more investigations.

  16. Impaired nitric oxide production in children with MELAS syndrome and the effect of arginine and citrulline supplementation.

    Science.gov (United States)

    El-Hattab, Ayman W; Emrick, Lisa T; Hsu, Jean W; Chanprasert, Sirisak; Almannai, Mohammed; Craigen, William J; Jahoor, Farook; Scaglia, Fernando

    2016-04-01

    Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is one of the most frequent maternally inherited mitochondrial disorders. The pathogenesis of this syndrome is not fully understood and believed to result from several interacting mechanisms including impaired mitochondrial energy production, microvasculature angiopathy, and nitric oxide (NO) deficiency. NO deficiency in MELAS syndrome is likely to be multifactorial in origin with the decreased availability of the NO precursors, arginine and citrulline, playing a major role. In this study we used stable isotope infusion techniques to assess NO production in children with MELAS syndrome and healthy pediatric controls. We also assessed the effect of oral arginine and citrulline supplementations on NO production in children with MELAS syndrome. When compared to control subjects, children with MELAS syndrome were found to have lower NO production, arginine flux, plasma arginine, and citrulline flux. In children with MELAS syndrome, arginine supplementation resulted in increased NO production, arginine flux, and arginine concentration. Citrulline supplementation resulted in a greater increase of these parameters. Additionally, citrulline supplementation was associated with a robust increase in citrulline concentration and flux and de novo arginine synthesis rate. The greater effect of citrulline in increasing NO production is due to its greater ability to increase arginine availability particularly in the intracellular compartment in which NO synthesis takes place. This study, which is the first one to assess NO metabolism in children with mitochondrial diseases, adds more evidence to the notion that NO deficiency occurs in MELAS syndrome, suggests a better effect for citrulline because of its greater role as NO precursor, and indicates that impaired NO production occurs in children as well as adults with MELAS syndrome. Thus, the initiation of treatment with NO precursors may be

  17. Role of the L-citrulline/L-arginine cycle in iNANC nerve-mediated nitric oxide production and airway smooth muscle relaxation in allergic asthma

    NARCIS (Netherlands)

    Maarsingh, Ham; Leusink, John; Zaagsma, Johan; Meurs, Herman

    2006-01-01

    Nitric oxide synthase (NOS) converts L-arginine into nitric oxide (NO) and L-Citrulline. In NO-producing cells, L-citrulline can be recycled to L-arginine in a two-step reaction involving argininosuccinate synthase (ASS) and -lyase (ASL). In guinea pig trachea, L-arginine is a limiting factor in

  18. [Asymmetric hypertrophy of the masticatory muscles].

    Science.gov (United States)

    Arzul, L; Corre, P; Khonsari, R H; Mercier, J-M; Piot, B

    2012-06-01

    Hypertrophy of the masticatory muscles most commonly affects the masseter. Less common cases of isolated or associated temporalis hypertrophy are also reported. Parafunctional habits, and more precisely bruxism, can favor the onset of the hypertrophy. This condition is generally idiopathic and can require both medical and/or surgical management. A 29-year-old patient was referred to our department for an asymmetric swelling of the masticatory muscles. Physical examination revealed a bilateral hypertrophy of the masticatory muscles, predominantly affecting the right temporalis and the left masseter. Major bruxism was assessed by premature dental wearing. The additional examinations confirmed the isolated muscle hypertrophy. Benign asymmetric hypertrophy of the masticatory muscles promoted by bruxism was diagnosed. Treatment with injections of type A botulinum toxin was conducted in association with a splint and relaxation. Its effectiveness has been observed at six months. Few cases of unilateral or bilateral temporalis hypertrophy have been reported, added to the more common isolated masseter muscles hypertrophy. The diagnosis requires to rule out secondary hypertrophies and tumors using Magnetic Resonance Imaging. The condition is thought to be favoured by parafunctional habits such as bruxism. The conservative treatment consists in reducing the volume of the masticatory muscles using intramuscular injections of type A botulinum toxin. Other potential conservative treatments are wearing splints and muscle relaxant drugs. Surgical procedures aiming to reduce the muscle volume and/or the bone volume (mandibular gonioplasty) can be proposed. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  19. Asymmetric Uncertainty Expression for High Gradient Aerodynamics

    Science.gov (United States)

    Pinier, Jeremy T

    2012-01-01

    When the physics of the flow around an aircraft changes very abruptly either in time or space (e.g., flow separation/reattachment, boundary layer transition, unsteadiness, shocks, etc), the measurements that are performed in a simulated environment like a wind tunnel test or a computational simulation will most likely incorrectly predict the exact location of where (or when) the change in physics happens. There are many reasons for this, includ- ing the error introduced by simulating a real system at a smaller scale and at non-ideal conditions, or the error due to turbulence models in a computational simulation. The un- certainty analysis principles that have been developed and are being implemented today do not fully account for uncertainty in the knowledge of the location of abrupt physics changes or sharp gradients, leading to a potentially underestimated uncertainty in those areas. To address this problem, a new asymmetric aerodynamic uncertainty expression containing an extra term to account for a phase-uncertainty, the magnitude of which is emphasized in the high-gradient aerodynamic regions is proposed in this paper. Additionally, based on previous work, a method for dispersing aerodynamic data within asymmetric uncer- tainty bounds in a more realistic way has been developed for use within Monte Carlo-type analyses.

  20. D mesons in asymmetric nuclear matter

    International Nuclear Information System (INIS)

    Mishra, Amruta; Mazumdar, Arindam

    2009-01-01

    We calculate the in-medium D and D meson masses in isospin-asymmetric nuclear matter in an effective chiral model. The D and D mass modifications arising from their interactions with the nucleons and the scalar mesons in the effective hadronic model are seen to be appreciable at high densities and have a strong isospin dependence. These mass modifications can open the channels of the decay of the charmonium states (Ψ ' ,χ c ,J/Ψ) to DD pairs in dense hadronic matter. The isospin asymmetry in the doublet D=(D 0 ,D + ) is seen to be particularly appreciable at high densities and should show in observables such as their production and flow in asymmetric heavy-ion collisions in the compressed baryonic matter experiments in the future facility of FAIR, GSI. The results of the present work are compared to calculations of the D(D) in-medium masses in the literature using the QCD sum rule approach, quark meson coupling model, and coupled channel approach as well as to those from studies of quarkonium dissociation using heavy-quark potentials from lattice QCD at finite temperatures

  1. On the Collisionless Asymmetric Magnetic Reconnection Rate

    Science.gov (United States)

    Liu, Yi-Hsin; Hesse, M.; Cassak, P. A.; Shay, M. A.; Wang, S.; Chen, L.-J.

    2018-04-01

    A prediction of the steady state reconnection electric field in asymmetric reconnection is obtained by maximizing the reconnection rate as a function of the opening angle made by the upstream magnetic field on the weak magnetic field (magnetosheath) side. The prediction is within a factor of 2 of the widely examined asymmetric reconnection model (Cassak & Shay, 2007, https://doi.org/10.1063/1.2795630) in the collisionless limit, and they scale the same over a wide parameter regime. The previous model had the effective aspect ratio of the diffusion region as a free parameter, which simulations and observations suggest is on the order of 0.1, but the present model has no free parameters. In conjunction with the symmetric case (Liu et al., 2017, https://doi.org/10.1103/PhysRevLett.118.085101), this work further suggests that this nearly universal number 0.1, essentially the normalized fast-reconnection rate, is a geometrical factor arising from maximizing the reconnection rate within magnetohydrodynamic-scale constraints.

  2. Evolutionary stability in the asymmetric volunteer's dilemma.

    Directory of Open Access Journals (Sweden)

    Jun-Zhou He

    Full Text Available It is often assumed that in public goods games, contributors are either strong or weak players and each individual has an equal probability of exhibiting cooperation. It is difficult to explain why the public good is produced by strong individuals in some cooperation systems, and by weak individuals in others. Viewing the asymmetric volunteer's dilemma game as an evolutionary game, we find that whether the strong or the weak players produce the public good depends on the initial condition (i.e., phenotype or initial strategy of individuals. These different evolutionarily stable strategies (ESS associated with different initial conditions, can be interpreted as the production modes of public goods of different cooperation systems. A further analysis revealed that the strong player adopts a pure strategy but mixed strategies for the weak players to produce the public good, and that the probability of volunteering by weak players decreases with increasing group size or decreasing cost-benefit ratio. Our model shows that the defection probability of a "strong" player is greater than the "weak" players in the model of Diekmann (1993. This contradicts Selten's (1980 model that public goods can only be produced by a strong player, is not an evolutionarily stable strategy, and will therefore disappear over evolutionary time. Our public good model with ESS has thus extended previous interpretations that the public good can only be produced by strong players in an asymmetric game.

  3. An asymmetric B factory based on PEP

    Energy Technology Data Exchange (ETDEWEB)

    1991-02-01

    In this report we describe a design for a high-luminosity Asymmetric B Factory to be built in the PEP tunnel on the SLAC site. This proposal, a collaborative effort SLAC, LBL, and LLNL, is the culmination of more than two years of effort aimed at the design and construction of an asymmetric e{sup +}e{sup {minus}} collider capable of achieving a luminosity of L = 3 {times} 10{sup 33} cm{sup {minus}2} s{sup {minus}1}. The configuration adopted utilizes two storage rings, and electron ring operating at 9 GeV and a positron ring at 3.1 GeV, each with a circumference of 2200 m. The high-energy ring is an upgrade of the PEP storage ring at SLAC; all PEP magnets and most power supplies will be reused. The upgrade consists primarily of replacing the PEP vacuum chamber and RF system with newly designed versions optimized for the high-current environment of the B Factory. The low-energy ring will be newly constructed and will be situated atop the high-energy ring in the PEP tunnel. Utilities already installed in the PEP tunnel are largely sufficient to operate the two B Factory storage rings.

  4. An asymmetric B factory based on PEP

    International Nuclear Information System (INIS)

    1991-02-01

    In this report we describe a design for a high-luminosity Asymmetric B Factory to be built in the PEP tunnel on the SLAC site. This proposal, a collaborative effort SLAC, LBL, and LLNL, is the culmination of more than two years of effort aimed at the design and construction of an asymmetric e + e - collider capable of achieving a luminosity of L = 3 x 10 33 cm -2 s -1 . The configuration adopted utilizes two storage rings, and electron ring operating at 9 GeV and a positron ring at 3.1 GeV, each with a circumference of 2200 m. The high-energy ring is an upgrade of the PEP storage ring at SLAC; all PEP magnets and most power supplies will be reused. The upgrade consists primarily of replacing the PEP vacuum chamber and RF system with newly designed versions optimized for the high-current environment of the B Factory. The low-energy ring will be newly constructed and will be situated atop the high-energy ring in the PEP tunnel. Utilities already installed in the PEP tunnel are largely sufficient to operate the two B Factory storage rings

  5. Particle identification at an asymmetric B Factory

    International Nuclear Information System (INIS)

    Coyle, P.; Eigen, G.; Hitlin, D.; Oddone, P.; Ratcliff, B.; Roe, N.; Va'vra, J.; Ypsilantis, T.

    1991-09-01

    Particle identification systems are an important component of any detector at a high-luminosity, asymmetric B Factory. In particular, excellent hadron identification is required to probe CP violation in B 0 decays to CP eigenstates. The particle identification systems discussed below also provide help in separating leptons from hadrons at low momenta. We begin this chapter with a discussion of the physics motivation for providing particle identification, the inherent limitations due to interactions and decays in flight, and the requirements for hermiticity and angular coverage. A special feature of an asymmetric B Factory is the resulting asymmetry in the momentum distribution as a function of polar angle; this will also be quantified and discussed. In the next section the three primary candidates, time-of-flight (TOF), energy loss (dE/dx), and Cerenkov counters, both ring-imaging and threshold, will be briefly described and evaluated. Following this, one of the candidates, a long-drift Cerenkov ring-imaging device, is described in detail to provide a reference design. Design considerations for a fast RICH are then described. A detailed discussion of aerogel threshold counter designs and associated R ampersand D conclude the chapter. 56 refs., 64 figs., 13 tabs

  6. Arginine and vitamin E improve the immune response after a Salmonella challenge in broiler chicks

    Science.gov (United States)

    Two experiments were conducted to evaluate the effects of arginine (ARG), vitamin E (VE), and mannanoligosaccharide (MOS) on the immune response and clearance of Salmonella in broiler chickens. In each experiment, chicks were randomly distributed into 4 groups: antibiotic-free diet (negative contro...

  7. Structural alterations in rat myocardium induced by chronic l-arginine and l-NAME supplementation

    Directory of Open Access Journals (Sweden)

    Amal Abdussalam Ali A. Hmaid

    2018-03-01

    Full Text Available Structural changes affecting cardiomyocyte function may contribute to the pathophysiological remodeling underlying cardiac function impairment. Recent reports have shown that endogenous nitric oxide (NO plays an important role in this process. In order to examine the role of NO in cardiomyocyte remodeling, male rats were acclimated to room temperature (22 ± 1 °C or cold (4 ± 1 °C and treated with 2.25% l-arginine·HCl or 0.01% l-NAME (Nω-nitro-l-arginine methyl ester·HCl for 45 days. Untreated groups served as controls. Right heart ventricles were routinely prepared for light microscopic examination. Stereological estimations of volume densities of cardiomyocytes, surrounding blood vessels and connective tissue, as well as the morphometric measurements of cardiomyocyte diameters were performed. Tissue sections were also analyzed for structural alterations. We observed that both l-arginine and l-NAME supplementation induced cardiomyocyte hypertrophy, regardless of ambient temperature. However, cardiomyocyte hypertrophy was associated with fibrosis and extra collagen deposition only in the l-NAME treated group. Taken together, our results suggest that NO has a modulatory role in right heart ventricle remodeling by coordinating hypertrophy of cardiomyocytes and fibrous tissue preventing cardiac fibrosis. Keywords: Cardiomyocyte, Cardiac hypertrophy, l-Arginine, l-NAME, Myocardium

  8. Thermal, FT–IR and SHG efficiency studies of L-arginine doped KDP ...

    Indian Academy of Sciences (India)

    TECS

    popular due to their applications in frequency converters, electro-optic switching and .... parameters of dehydration process of pure and L-arginine doped KDP crystals were ... action, R a gas constant, and a the heating rate in deg.C.min. –1.

  9. Calcium alpha-ketoglutarate administration to malnourished hemodialysis patients improves plasma arginine concentrations.

    Science.gov (United States)

    Riedel, E; Hampl, H; Steudle, V; Nündel, M

    1996-01-01

    Calcium alpha-ketoglutarate administration to 24 malnourished hemodialysis patients for 1 year leads to a significant increase in plasma concentrations of L-arginine from 53.6 +/- 18.3 (compared to a healthy control group: 87.5 +/- 27.3) to 71.1 +/- 15.9 mumol/l (p calcium alpha-ketoglutarate administration.

  10. Serum Stabilities of Short Tryptophan-and Arginine-Rich Antimicrobial Peptide Analogs

    NARCIS (Netherlands)

    Nguyen, L.T.; Chau, J.K.; Perry, N.A.; de Boer, L.; Zaat, S.A.J.; Vogel, H.J.

    2010-01-01

    Background: Several short antimicrobial peptides that are rich in tryptophan and arginine residues were designed with a series of simple modifications such as end capping and cyclization. The two sets of hexapeptides are based on the Trp- and Arg-rich primary sequences from the "antimicrobial

  11. Effect of in ovo injection with L-arginine on productive and ...

    African Journals Online (AJOL)

    p2492989

    Significant decreases were recorded in blood serum cholesterol, total lipids ... 2% and 3% arginine, resulted in a significant improvement in the productive ... Various factors play important roles in birds in influencing hatchability efficiency and growth ... in the yolk sac may not be sufficient to supply in the maintenance energy.

  12. Friend of Prmt1, a novel chromatin target of protein arginine methyltransferases

    NARCIS (Netherlands)

    T.B. van Dijk (Thamar); N. Gillemans (Nynke); C. Stein (Claudia); P. Fanis (Pavlos); J.A.A. Demmers (Jeroen); M.P.C. van de Corput (Mariëtte); J. Essers (Jeroen); F.G. Grosveld (Frank); U.M. Bauer (Uta-Maria); J.N.J. Philipsen (Sjaak)

    2010-01-01

    textabstractWe describe the isolation and characterization of Friend of Prmt1 (Fop), a novel chromatin target of protein arginine methyltransferases. Human Fop is encoded by C1orf77, a gene of previously unknown function. We show that Fop is tightly associated with chromatin, and that it is modified

  13. Allevation of Oxidative Damages Induced by Salinity in Cress (Lepidium sativum by Pretreating with Arginine

    Directory of Open Access Journals (Sweden)

    E Asadi karam

    2015-05-01

    Full Text Available Salinity is one of the main stresses that have negative effectcs on seedling growth, and plant production. It inhibits growth of plants through disturbance of the balance between production of ROS and antioxidant defense mechanism which results in oxidative stress. Because, arginine is a vital regulator of physiological and developmental processes the effect of different concentrations of arginine pretreatment of the plant on alleviation of oxidative stress induced by salt 50 and 100Mm NaCl was investigated. Arginine pretreatment increased chlorophyll a, b, carotenoid and seedling growth under salinity condition. Results also showed that salt stress increased proline, protein, H2O2, soluble sugar and the activity of ascorbate peroxidase, guaiacol peroxidase and catalase. Pretreatment of plants with Arg reduced proline, soluble sugar, H2O2 and antioxidant enzymes activity content significantly. The conclusion is that in garden cress plants, pretreatment with concentration of 5 µM and 10 μM arginine may protect cress under salinity stress, probably through the contracting with ROS and or induction of anti-oxidative enzymes

  14. Conformationally Constrained Peptidomimetics as Inhibitors of the Protein Arginine Methyl Transferases

    DEFF Research Database (Denmark)

    Knuhtsen, Astrid; Legrand, Baptiste; Van der Poorten, Olivier

    2016-01-01

    Protein arginine N-methyl transferases (PRMTs) belong to a family of enzymes that modulate the epigenetic code through modifications of histones. In the present study, peptides emerging from a phage display screening were modified in the search for PRMT inhibitors through substitution with non-pr...

  15. Gas-phase salt bridge interactions between glutamic acid and arginine

    NARCIS (Netherlands)

    Jaeqx, S.; Oomens, J.; Rijs, A.M.

    2013-01-01

    The gas-phase side chain-side chain (SC-SC) interaction and possible proton transfer between glutamic acid (Glu) and arginine (Arg) residues are studied under low-temperature conditions in an overall neutral peptide. Conformation-specific IR spectra, obtained with the free electron laser FELIX, in

  16. Arginine-vasopressin stimulates the formation of phosphatidic acid in rat Leydig cells

    DEFF Research Database (Denmark)

    Nielsen, J.R.; Hansen, Harald S.; Jensen, B.

    1987-01-01

    Arginine-vasopressin (AVP) stimulated the formation of labelled phosphatidic acid (PA) in [C]arachidonic acid-prelabelled rat Leydig cells. After addition of 10 M AVP [C]arachidonoylphosphatidic acid reached a maximum within 2 min. The increase was dose-dependent (10-10 M). No change in labelling...

  17. Arginine metabolism is altered in adults with A-B + ketosis-prone diabetes

    Science.gov (United States)

    A-B + ketosis-prone diabetes (KPD) is a subset of type 2 diabetes in which patients have severe but reversible B cell dysfunction of unknown etiology. Plasma metabolomic analysis indicates that abnormal arginine metabolism may be involved. The objective of this study was to determine the relation be...

  18. Evidence for arginine as the endogenous precursor of necines in heliotropium.

    Science.gov (United States)

    Birecka, H; Birecki, M; Frohlich, M W

    1987-05-01

    In pyrrolizidine alkaloid-bearing Heliotropium angiospermum and H. indicum shoots exposed, in the light, to (14)C-labeled CO(2) for 44 hours, the incorporation of (14)C into 1,2-epoxy-1-hydroxymethylpyrrolizidine and retronecine amounted to 0.23 and 0.15%, respectively, of the total carbon assimilated. Treatment of the shoots with alpha-dl-difluoromethylornithine, the specific ornithine decarboxylase inhibitor, at 1 to 2 millimolar had no effect on (14)C incorporation into the necines. In contrast, alpha-dl-difluoromethylarginine, the specific arginine decarboxylase inhibitor, prevented the incorporation of (14)C into the necines of both species; the inhibitor did not affect the absolute incorporation of (14)C from exogenous [1,4-(14)C] putrescine in either species. Thus, arginine is the only apparent endogenous precursor of the putrescine channeled into pyrrolizidines, at least in these two Heliotropium species that exhibited a relatively much higher in vitro activity of arginine decarboxylase than of ornithine decarboxylase. However, within 28 hours after administration, not only exogenous l-[5-(14)C]arginine, but also exogenous l-[5-(14)C]ornithine exhibited significant incorporation of their label into the necines, incorporation that could be partially prevented by both inhibitors. Neither inhibitor affected the rates of (14)C-labeled CO(2) assimilation, transformation of labeled assimilates into ethanol-insoluble compounds, or the very high degree of conversion of the introduced amino acids into other compounds. Methodology related to alkaloid biosynthetic studies is discussed.

  19. Evidence for Arginine as the Endogenous Precursor of Necines in Heliotropium1

    Science.gov (United States)

    Birecka, Helena; Birecki, Mieczyslaw; Frohlich, M. W.

    1987-01-01

    In pyrrolizidine alkaloid-bearing Heliotropium angiospermum and H. indicum shoots exposed, in the light, to 14C-labeled CO2 for 44 hours, the incorporation of 14C into 1,2-epoxy-1-hydroxymethylpyrrolizidine and retronecine amounted to 0.23 and 0.15%, respectively, of the total carbon assimilated. Treatment of the shoots with α-dl-difluoromethylornithine, the specific ornithine decarboxylase inhibitor, at 1 to 2 millimolar had no effect on 14C incorporation into the necines. In contrast, α-dl-difluoromethylarginine, the specific arginine decarboxylase inhibitor, prevented the incorporation of 14C into the necines of both species; the inhibitor did not affect the absolute incorporation of 14C from exogenous [1,4-14C] putrescine in either species. Thus, arginine is the only apparent endogenous precursor of the putrescine channeled into pyrrolizidines, at least in these two Heliotropium species that exhibited a relatively much higher in vitro activity of arginine decarboxylase than of ornithine decarboxylase. However, within 28 hours after administration, not only exogenous l-[5-14C]arginine, but also exogenous l-[5-14C]ornithine exhibited significant incorporation of their label into the necines, incorporation that could be partially prevented by both inhibitors. Neither inhibitor affected the rates of 14C-labeled CO2 assimilation, transformation of labeled assimilates into ethanol-insoluble compounds, or the very high degree of conversion of the introduced amino acids into other compounds. Methodology related to alkaloid biosynthetic studies is discussed. PMID:16665402

  20. Diurnal changes in polyamine content, arginine and ornithine decarboxylase, and diamine oxidase in tobacco leaves

    Czech Academy of Sciences Publication Activity Database

    Gemperlová, Lenka; Nováková, Marie; Vaňková, Radomíra; Eder, Josef; Cvikrová, Milena

    2006-01-01

    Roč. 57, č. 6 (2006), s. 1413-1421 ISSN 0022-0957 R&D Projects: GA ČR GA206/03/0369 Institutional research plan: CEZ:AV0Z50380511 Keywords : Arginine decarboxylase * diamine oxidase * ornithine decarboxylase Subject RIV: ED - Physiology Impact factor: 3.630, year: 2006

  1. Erythrocytes L-arginine y+ transporter inhibition by N-ethylmaleimide in ice-bath.

    Science.gov (United States)

    Pinheiro da Costa, Bartira Ercília; de Almeida, Priscilla Barcellos; Conceição, Ioná Rosine; Antonello, Ivan Carlos Ferreira; d'Avila, Domingos O; Poli-de-Figueiredo, Carlos Eduardo

    2010-11-01

    Erythrocytes L: -arginine uptake is conveyed by y+ and y+L membrane transport systems. Pre-incubation with N-ethylmaleimide for 10 min at 37°C inhibits the y+ system. The aim of this study was to determine the ideal pre-incubation temperature in evaluating y+ and y+L systems. Cells were pre-incubated with or without N-ethylmaleimide for 10 min at 4°C and 37°C. L: -Arginine uptake was quantified by radioisotope and standard erythrocytes membrane flux methodology. Results demonstrate that erythrocytes L: -arginine content is depleted by pre-incubation at 37°C for 10 min, thus changing the V (max) measurement. The inhibitory effect of N-ethylmaleimide pre-incubation was temperature independent and already complete after 1 min of incubation. No significant difference in kinetic parameters was detected between cells pre-incubated at 37°C or 4°C, under zero-trans conditions. In conclusion, we suggest that measurement of erythrocytes L: -arginine uptake by y+ and y+L systems could be carried out without N-ethylmaleimide pre-incubation at 37°C.

  2. Mutations in protein N-arginine methyltransferases are not the cause of FTLD-FUS

    NARCIS (Netherlands)

    Ravenscroft, T.A.; Baker, M.C.; Rutherford, N.J.; Neumann, M.; Mackenzie, I.R.; Josephs, K.A.; Boeve, B.F.; Petersen, R.; Halliday, G.M.; Kril, J.; van Swieten, J.C.; Seeley, W.W.; Dickson, D.W.; Rademakers, R.

    2013-01-01

    The nuclear protein fused in sarcoma (FUS) is found in cytoplasmic inclusions in a subset of patients with the neurodegenerative disorder frontotemporal lobar degeneration (FTLD-FUS). FUS contains a methylated arginine-glycine-glycine domain that is required for transport into the nucleus. Recent

  3. Feed supplementation with arginine and zinc on antioxidant status and inflammatory response in challenged weanling piglets

    Directory of Open Access Journals (Sweden)

    Nadia Bergeron

    2017-09-01

    Full Text Available Although supplementing the diet with zinc oxide and arginine is known to improve growth in weanling piglets, the mechanism of action is not well understood. We measured the antioxidant status and inflammatory response in 48 weanling castrated male piglets fed diets supplemented with or without zinc oxide (2,500 mg Zn oxide per kg and arginine (1% starting at the age of 20 days. The animals were injected with lipopolysaccharide (100 μg/kg on day 5. Half of them received another injection on day 12. Blood samples were taken just before and 6, 24 and 48 h after injection and the mucosa lining the ileum was recovered following euthanizing on days 7 and 14. Zinc supplementation increased reduced and total glutathione (GSH (reduced and total during days 5 to 7 and arginine decreased oxidized GSH measured on days 5 and 12 and the ratio of total antioxidant capacity to total oxidative status during days 12 to 14. Zinc decreased plasma malondialdehyde measured on days 5 and 12 and serum haptoglobin measured on day 12 and increased both metallothionein-1 expression and total antioxidant capacity measured in the ileal mucosa on day 14. Tumour necrosis factor α concentration decreased from days 5 to 12 (all effects were significant at P < 0.05. This study shows that the zinc supplement reduced lipid oxidation and lipopolysaccharide-induced inflammation during the post-weaning period, while the arginine supplementation had only a limited effect.

  4. The Effect of Pumpkin ( Cucurbita pepo L) Seeds and L-Arginine ...

    African Journals Online (AJOL)

    The present study aimed to examine the effect of pumpkin (Cucurbita pepo L.) seeds supplementation on androgenic diet-induced atherosclerosis. Rat were divided into two main groups , normal control and atherogenic control rats , each group composed of three subgroups one of them supplemented with 2% arginine in ...

  5. Preparation of Simvastatin Hydrogel through Arginine Addition for Drug Delivery System

    Directory of Open Access Journals (Sweden)

    Rosyida Niswati Fathmah

    2018-01-01

    Full Text Available Simvastatin is a lipid lowering agent which has been used recently as drug delivery system for stimulating bone regeneration. Because of low therapeutic efficacy and bioavailability, it is necessary to deliver simvastatin by local administration e.g. by hydrogel system. However, simvastatin has very poor solubility which restricts to prepare hydrogel formulation. The aim of this study is to improve solubility of simvastatin with arginine as co-solvent for developing a controlled released drug delivery system by loading simvastatin into gelatin hydrogel. The solubility study was performed by addition of an excess mass of simvastatin into the specified molar solutions of the arginine. All conical flasks were placed in a mechanical water bath shaker at the temperature of 25, 40, and 50 °C and shaken for a maximum period of 72 hours. The drug concentration was analyzed by UV/Visible spectroscopy at 238 nm. The hydrogel was prepared by a dehydrothermal method. The results showed that simvastatin solubility increases with increasing arginine concentrations and temperature. Characterizations showed a successful preparation of simvastatin-loaded gelatin hydrogel. The arginine simvastatin hydrogel and the gelatin hydrogel (as a blank exhibited a comparable swelling index (ca. 6.5. Furthermore, microparticles of the material show a narrow particle size distribution in the range between 150-250 μm.

  6. L-Arginine deficiency causes airway hyperresponsiveness after the late asthmatic reaction

    NARCIS (Netherlands)

    Maarsingh, H.; Bossenga, B. E.; Bos, I. S. T.; Volders, H. H.; Zaagsma, J.; Meurs, H.

    Peroxynitrite has been shown to be crucially involved in airway hyperresponsiveness (AHR) after the late asthmatic reaction (LAR). Peroxynitrite production may result from simultaneous synthesis of nitric oxide (NO) and superoxide by inducible NO-synthase (iNOS) at low L-arginine concentrations.

  7. Periodical low eggshell temperatures during incubation and post hatch dietary arginine supplementation

    NARCIS (Netherlands)

    Afsarian, O.; Shahir, M.H.; Akhlaghi, A.; Lotfolahian, H.; Hoseini, A.; Lourens, A.

    2016-01-01

    An experiment was conducted to evaluate the effects of a periodically low eggshell temperature exposure during incubation and dietary supplementation of arginine on performance, ascites incidence, and cold tolerance acquisition in broilers. A total of 2,400 hatching eggs were randomly assigned to

  8. Nutritional supplementation with arginine protects radiation-induced effects: an experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Flavia Cristina Morone, E-mail: fcmorone@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Campos-Silva, Pamella; Souza, Diogo Benchimol de; Costa, Waldemar Silva; Sampaio, Francisco Jose Barcellos [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil)

    2016-10-15

    Purpose: To investigate the protective effect of L-arginine on the prostate (nonneoplasic) of rats with radiation-induced injury. Methods: Twenty-nine Wistar rats, male adult, allocated into three groups: Control group (C) was not exposed to irradiation (n=10); Radiated group (R) had undergone pelvic irradiation (n=10); Supplemented and radiated group (R+S) had undergone pelvic irradiation plus L-arginine supplementation (n=9). The animals were observed for signs of toxicity. After euthanization, the prostate was dissected under magnification and stained by hematoxylin and eosin to study acinar structures and stained with Picrosirius red for collagen analysis. Results: After radiation exposure, all animals presented diarrhea, but supplementation with L-arginine reduced this effect. The weight gain in the R+S group was significantly higher than in the C and R groups. In the R+S group the collagen density and the prostate acinar area was similar to the R and C groups. Epithelial height was significantly reduced in group R compared with group C (p<0.0001). When comparing the group R+S with R, a statistical difference was observed to be present (p<0.0001). Conclusions: Pelvic radiation promotes systemic effects and some structural modifications in the ventral prostate of rats. These modifications can be prevented by oral supplementation with L-arginine. (author)

  9. l-Arginine Pathway Metabolites Predict Need for Intra-operative Shunt During Carotid Endarterectomy

    DEFF Research Database (Denmark)

    Szabo, P; Lantos, J; Nagy, L

    2016-01-01

    lactate levels were increased during reperfusion (p = .02). The median pre-operative concentration of l-arginine was lower in patients requiring an intra-operative shunt than in patients without need of shunt (median: 30.3 μmol/L [interquartile range 24.4-34.4 μmol/L] vs. 57.6 μmol/L [interquartile range...

  10. Growth and characterization of pure and doped NLO L-arginine ...

    Indian Academy of Sciences (India)

    Administrator

    NLO; SHG; solution growth; LAA. 1. Introduction. L-arginine phosphate monohydrate (LAP) was first repor- ted by Xu et al (1983) as a promising nonlinear optical. (NLO) material. LAP is nearly three times more nonlinear than KDP. Monaco et al (1987) reported the formation of. LAP and its chemical analogs from the strongly ...

  11. Asymmetric dimethylarginine (ADMA) elevation and arginase up-regulation contribute to endothelial dysfunction related to insulin resistance in rats and morbidly obese humans.

    Science.gov (United States)

    El Assar, Mariam; Angulo, Javier; Santos-Ruiz, Marta; Ruiz de Adana, Juan Carlos; Pindado, María Luz; Sánchez-Ferrer, Alberto; Hernández, Alberto; Rodríguez-Mañas, Leocadio

    2016-06-01

    The presence of insulin resistance (IR) is determinant for endothelial dysfunction associated with obesity. Although recent studies have implicated the involvement of mitochondrial superoxide and inflammation in the defective nitric oxide (NO)-mediated responses and subsequent endothelial dysfunction in IR, other mechanisms could compromise this pathway. In the present study, we assessed the role of asymmetric dimethylarginine (ADMA) and arginase with respect to IR-induced impairment of endothelium-dependent vasodilatation in human morbid obesity and in a non-obese rat model of IR. We show that both increased ADMA and up-regulated arginase are determinant factors in the alteration of the l-arginine/NO pathway associated with IR in both models and also that acute treatment of arteries with arginase inhibitor or with l-arginine significantly alleviate endothelial dysfunction. These results help to expand our knowledge regarding the mechanisms of endothelial dysfunction that are related to obesity and IR and establish potential therapeutic targets for intervention. Insulin resistance (IR) is determinant for endothelial dysfunction in human obesity. Although we have previously reported the involvement of mitochondrial superoxide and inflammation, other mechanisms could compromise NO-mediated responses in IR. We evaluated the role of the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA) and arginase with respect to IR-induced impairment of l-arginine/NO-mediated vasodilatation in human morbid obesity and in a non-obese rat model of IR. Bradykinin-induced vasodilatation was evaluated in microarteries derived from insulin-resistant morbidly obese (IR-MO) and non-insulin-resistant MO (NIR-MO) subjects. Defective endothelial vasodilatation in IR-MO was improved by l-arginine supplementation. Increased levels of ADMA were detected in serum and adipose tissue from IR-MO. Serum ADMA positively correlated with IR score and negatively with pD2 for bradykinin. Gene

  12. Asymmetric dimethylarginine (ADMA) elevation and arginase up‐regulation contribute to endothelial dysfunction related to insulin resistance in rats and morbidly obese humans

    Science.gov (United States)

    El Assar, Mariam; Angulo, Javier; Santos‐Ruiz, Marta; Ruiz de Adana, Juan Carlos; Pindado, María Luz; Sánchez‐Ferrer, Alberto; Hernández, Alberto

    2016-01-01

    Key points The presence of insulin resistance (IR) is determinant for endothelial dysfunction associated with obesity.Although recent studies have implicated the involvement of mitochondrial superoxide and inflammation in the defective nitric oxide (NO)‐mediated responses and subsequent endothelial dysfunction in IR, other mechanisms could compromise this pathway.In the present study, we assessed the role of asymmetric dimethylarginine (ADMA) and arginase with respect to IR‐induced impairment of endothelium‐dependent vasodilatation in human morbid obesity and in a non‐obese rat model of IR.We show that both increased ADMA and up‐regulated arginase are determinant factors in the alteration of the l‐arginine/NO pathway associated with IR in both models and also that acute treatment of arteries with arginase inhibitor or with l‐arginine significantly alleviate endothelial dysfunction.These results help to expand our knowledge regarding the mechanisms of endothelial dysfunction that are related to obesity and IR and establish potential therapeutic targets for intervention. Abstract Insulin resistance (IR) is determinant for endothelial dysfunction in human obesity. Although we have previously reported the involvement of mitochondrial superoxide and inflammation, other mechanisms could compromise NO‐mediated responses in IR. We evaluated the role of the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA) and arginase with respect to IR‐induced impairment of l‐arginine/NO‐mediated vasodilatation in human morbid obesity and in a non‐obese rat model of IR. Bradykinin‐induced vasodilatation was evaluated in microarteries derived from insulin‐resistant morbidly obese (IR‐MO) and non‐insulin‐resistant MO (NIR‐MO) subjects. Defective endothelial vasodilatation in IR‐MO was improved by l‐arginine supplementation. Increased levels of ADMA were detected in serum and adipose tissue from IR‐MO. Serum ADMA positively correlated with

  13. Preferential Solvation of an Asymmetric Redox Molecule

    Energy Technology Data Exchange (ETDEWEB)

    Han, Kee Sung; Rajput, Nav Nidhi; Vijayakumar, M.; Wei, Xiaoliang; Wang, Wei; Hu, Jian Z.; Persson, Kristin A.; Mueller, Karl T.

    2016-12-15

    The fundamental correlations between inter-molecular interactions, solvation structure and functionality of electrolytes are in many cases unknown, particularly for multi-component liquid systems. In this work, we explore such correlations by investigating the complex interplay between solubility and solvation structure for the electrolyte system comprising N-(ferrocenylmethyl)-N,N-dimethyl-N-ethylammonium bistrifluoromethylsulfonimide (Fc1N112-TFSI) dissolved in a ternary carbonate solvent mixture using combined NMR relaxation and computational analyses. Probing the evolution of the solvent-solvent, ion-solvent and ion-ion interactions with an increase in solute concentration provides a molecular level understanding of the solubility limit of the Fc1N112-TFSI system. An increase in solute con-centration leads to pronounced Fc1N112-TFSI contact-ion pair formation by diminishing solvent-solvent and ion-solvent type interactions. At the solubility limit, the precipitation of solute is initiated through agglomeration of contact-ion pairs due to overlapping solvation shells.

  14. Supplementation with apple enriched with L-arginine may improve metabolic control and survival rate in alloxan-induced diabetic rats.

    Science.gov (United States)

    Escudero, Andrea; Petzold, Guillermo; Moreno, Jorge; Gonzalez, Marcelo; Junod, Julio; Aguayo, Claudio; Acurio, Jesenia; Escudero, Carlos

    2013-01-01

    Supplementation with L-arginine or fresh food with high content of this amino acid is associated with favorable effects in the metabolic control of diabetes. We aimed to determine whether supplementation with apples enriched with L-arginine offer additional benefits compared to L-arginine by itself in a preclinical study of diabetes. This study combines food-engineer technologies with in vivo and in vitro analysis. In vitro experiments show that cells derived from non-diabetic animals and exposed to high glucose (25 mM, 12 H) and cells isolated from alloxan-induced diabetic animals exhibited a reduction (∼50%) in the L-arginine uptake. This effect was reverted by L-arginine pretreatment (12 H) in both the normal and diabetes-derived cells. In preclinical studies, normoglycemic (n = 25) and diabetic groups (n = 50) were divided into subgroups that received either L-arginine (375 mg/kg per 10 days) or apple enriched with L-arginine or vehicle (control). In a preliminary analysis, supplementation with L-arginine by itself (50%) or apple enriched with L-arginine (100%) improve survival rate in the diabetic group compared to control (0%) at the end of the follow up (17 days). This phenomenon was associated with a partial but sustained high plasma level of L-arginine, as well as plasma concentration of nitrites and insulin in the L-arginine or apple + L-arginine groups after supplementation. Apple + L-arginine supplementation in diabetic animals induced the highest and longest effects in the level of these three markers among the studied groups. Therefore, apple enriched by L-arginine offers more benefits than L-arginine by itself in this preclinical study. Copyright © 2013 International Union of Biochemistry and Molecular Biology, Inc.

  15. L-arginine and glycine supplementation in the repair of the irradiated colonic wall of rats.

    Science.gov (United States)

    de Aguiar Picanço, Etiene; Lopes-Paulo, Francisco; Marques, Ruy G; Diestel, Cristina F; Caetano, Carlos Eduardo R; de Souza, Mônica Vieira Mano; Moscoso, Gabriela Mendes; Pazos, Helena Maria F

    2011-05-01

    Radiotherapy is widely used for cancer treatment but has harmful effects. This study aimed to assess the effects of L-arginine and glycine supplementation on the colon wall of rats submitted to abdominal irradiation. Forty male Wistar rats were randomly divided into four groups: I-healthy, II-irradiated with no amino acid supplementation, III-irradiated and supplemented with L-arginine, and IV-irradiated and supplemented with glycine. The animals received supplementation for 14 days, with irradiation being applied on the eighth day of the experiment. All animals underwent laparotomy on the 15th day for resection of a colonic segment for stereologic analysis. Parametric and nonparametric tests were used for statistical analysis, with the level of significance set at p ≤0.05. Stereologic analysis showed that irradiation induced a reduction of the total volume of the colon wall of group II and III animals compared to healthy controls, but not of group IV animals supplemented with glycine. The mucosal layer of the irradiated animals of all groups was reduced compared to healthy group I animals, but supplementation with L-arginine and glycine was effective in maintaining the epithelial surface of the mucosal layer. The present results suggest that glycine supplementation had a superior effect on the irradiated colon wall compared to L-arginine supplementation since it was able to maintain the thickness of the wall and the epithelial surface of the mucosa, whereas L-arginine maintained the partial volume of the epithelium and the epithelial surface, but not the total volume of the intestinal wall.

  16. The effect of L-Arginine on the brain tissue of stressed rats

    Directory of Open Access Journals (Sweden)

    Batoul Ebadi

    2010-01-01

    Full Text Available Introduction: This study was conducted to determine the possible beneficial results of L-arginine on prefrontal cortex of rats which impressed by immobilization stress to define the synchronous impression of stress and nitric oxide (NO on evolution of prefrontal cortex of rats after birth. Methods: Forty-eight one month, male Wistar rats were divided into two groups: stressed and non-stressed. L-Arginine (200 mg/kg as a NO synthase (NOS inducer and L-NAME (2O mg/kg were injected intraperitonealy (IP and 7- nitroindazde (25 mg/kg as non-specific was injected subcutaneously (S.C. for 4 weeks. The kind of stress was immobilization for 4 weeks, every other day. The brain was removed after this period and each brain divided into two parts in a coronal section manner. Anterior part used for histological studies with H&E staining and posterior part used for measurement of NO production using spectrophotometer at 540 nm wavelengh. Results: Statistical analysis of microscopic and light microscopic finding showed that thickness of prefrontal cortex and NO production were significantly decreased in stressed rats and especially in groups which received 7- nitroindazole and L-NAME and L-arginine could reverse these results. Discussion: According to this research, we could say that L-arginine decreases the cortical damages in stressed rats and 7-nitroindazole and L-NAME increase this damage in non-stressed group. Although in non stressed groups, L-arginine, L-NAME and 7- nitroindazole were all non-protective and damaging.

  17. The effect of L-Arginine on the brain tissue of stressed rats

    Directory of Open Access Journals (Sweden)

    Batoul Ebadi

    2010-01-01

    Full Text Available   Abstract  Introduction: This study was conducted to determine the possible beneficial results of L-arginine on prefrontal cortex of rats which impressed by immobilization stress to define the synchronous impression of stress and nitric oxide (NO on evolution of prefrontal cortex of rats after birth. Methods: Forty-eight one month, male Wistar rats were divided into two groups: stressed and non-stressed. L-Arginine (200 mg/kg as a NO synthase (NOS inducer and L-NAME (2O mg/kg were injected intraperitonealy (IP and 7- nitroindazde (25 mg/kg as non-specific was injected subcutaneously (S.C. for 4 weeks. The kind of stress was immobilization for 4 weeks, every other day. The brain was removed after this period and each brain divided into two parts in a coronal section manner. Anterior part used for histological studies with H&E staining and posterior part used for measurement of NO production using spectrophotometer at 540 nm wavelengh. Results: Statistical analysis of microscopic and light microscopic finding showed that thickness of prefrontal cortex and NO production were significantly decreased in stressed rats and especially in groups which received 7- nitroindazole and L-NAME and L-arginine could reverse these results. Discussion: According to this research, we could say that L-arginine decreases the cortical damages in stressed rats and 7-nitroindazole and L-NAME increase this damage in non-stressed group. Although in non stressed groups, L-arginine, L-NAME and 7- nitroindazole were all non-protective and damaging.

  18. EFFECTS OF ARGININE AND VITAMIN E SUPPLEMENTED DIETS ON THE IMMUNOLOGICAL RESPONSE OF BROILERS CHICKENS

    Directory of Open Access Journals (Sweden)

    David Jesús Chan Diaz

    2012-08-01

    Full Text Available In order to evaluate the effect of arginine and vitamin E supplementation in broiler chicken diets on the immune response during post-vaccine stress, a trial was conducted with 700 chicks (1 day-old which were distributed into 28 floor-pens and fed one of four dietary treatments (with 7 replicates randomly assigned: T1 = control diet (1.31 % of arginine and 10 IU of vitamin E/kg of feed; T2 = T1 + 0.3 % of arginine; T3 = T1 + 70 IU of vitamin E; T4 = T1 + 0.3 % of arginine + 70 IU of vitamin E. At 12 days of age, all birds were vaccinated against Newcastle disease virus (ND, infectious bronchitis, avian influenza (AI and fowl pox. The traits evaluated were: post-vaccine reaction at days 14, 16, 18, 21 and 23; antibody titers against ND and AI, and relative lymphoid organs weight at days 11, 19 and 26; and the performance were recorded weekly. Chickens fed T2, T4 (at day 16, and T3 (at day 21 had lesser (p≤0.05 post-vaccine reaction than birds fed T1. The antibody titers against ND (at day 11 was higher (p≤0.05 in chickens fed T4 (3.1, T3 (2.7 and T2 (2.7 compared to T1 (1.6; meanwhile, for AI titers no differences were found. There were no differences, neither for immune organs weight, nor for performance. In conclusion, arginine and vitamin E supplementation in broiler chicken diets reduced the post-vaccine stress and improved the immune response without affecting the performance.

  19. Endothelial arginine resynthesis contributes to the maintenance of vasomotor function in male diabetic mice.

    Directory of Open Access Journals (Sweden)

    Ramesh Chennupati

    Full Text Available Argininosuccinate synthetase (ASS is essential for recycling L-citrulline, the by-product of NO synthase (NOS, to the NOS substrate L-arginine. Here, we assessed whether disturbed arginine resynthesis modulates endothelium-dependent vasodilatation in normal and diabetic male mice.Endothelium-selective Ass-deficient mice (Assfl/fl/Tie2Cretg/- = Ass-KOTie2 were generated by crossing Assfl/fl mice ( = control with Tie2Cre mice. Gene ablation in endothelial cells was confirmed by immunohistochemistry. Blood pressure (MAP was recorded in 34-week-old male mice. Vasomotor responses were studied in isolated saphenous arteries of 12- and 34-week-old Ass-KOTie2 and control animals. At the age of 10 weeks, diabetes was induced in control and Ass-KOTie2 mice by streptozotocin injections. Vasomotor responses of diabetic animals were studied 10 weeks later. MAP was similar in control and Ass-KOTie2 mice. Depletion of circulating L-arginine by arginase 1 infusion or inhibition of NOS activity with L-NAME resulted in an increased MAP (10 and 30 mmHg, respectively in control and Ass-KOTie2 mice. Optimal arterial diameter, contractile responses to phenylephrine, and relaxing responses to acetylcholine and sodium nitroprusside were similar in healthy control and Ass-KOTie2 mice. However, in diabetic Ass-KOTie2 mice, relaxation responses to acetylcholine and endothelium-derived NO (EDNO were significantly reduced when compared to diabetic control mice.Absence of endothelial citrulline recycling to arginine did not affect blood pressure and systemic arterial vasomotor responses in healthy mice. EDNO-mediated vasodilatation was significantly more impaired in diabetic Ass-KOTie2 than in control mice demonstrating that endothelial arginine recycling becomes a limiting endothelial function in diabetes.

  20. Ultrathin-skinned asymmetric membranes by immiscible solvents treatment

    Science.gov (United States)

    Friesen, Dwayne T.; Babcock, Walter C.

    1989-01-01

    Improved semipermeable asymmetric fluid separation membranes useful in gas, vapor and liquid separations are disclosed. The membranes are prepared by substantially filling the pores of asymmetric cellulosic semipermeable membranes having a finely porous layer on one side thereof with a water immiscible organic liquid, followed by contacting the finely porous layer with water.