WorldWideScience

Sample records for low-molecular-weight volatile hydrocarbons

  1. Production of low molecular weight hydrocarbons by volcanic eruptions on early Mars.

    Science.gov (United States)

    Segura, Antígona; Navarro-González, Rafael

    2005-10-01

    Methane and other larger hydrocarbons have been proposed as possible greenhouse gases on early Mars. In this work we explore if volcanic processes may have been a source for such molecules based on theoretical and experimental considerations. Geologic evidence and numerical simulations indicate that explosive volcanism was widely distributed throughout Mars. Volcanic lightning is typically produced in such explosive volcanism. Therefore this geologic setting was studied to determine if lightning could be a source for hydrocarbons in volcanic plumes. Volcanic lightning was simulated by focusing a high-energy infrared laser beam inside of a Pyrex reactor that contained the proposed volcanic gas mixture composed of 64% CH(4), 24% H(2), 10% H(2)O and 2% N(2), according to an accretion model and the nitrogen content measured in Martian meteorites. The analysis of products was performed by gas chromatography coupled to infrared and mass spectroscopy. Eleven hydrocarbons were identified among the products, of which acetylene (C(2)H(2)) was the most abundant. A thermochemical model was used to determine which hydrocarbons could arise only from volcanic heat. In this case, acetylene and ethylene are formed at magmatic temperatures. Our results indicate that explosive volcanism may have injected into the atmosphere of early Mars approximately 6 x 10(12) g yr(-1) of acetylene, and approximately 2 x 10(12) g yr(-1) of 1,3-butadiyne, both produced by volcanic lightning, approximately 5 x 10(11) g yr(-1) of ethylene produced by volcanic heat, and 10(13) g yr(-1) of methane.

  2. Analytical system for stable carbon isotope measurements of low molecular weight (C2-C6 hydrocarbons

    Directory of Open Access Journals (Sweden)

    T. Röckmann

    2011-06-01

    Full Text Available We present setup, testing and initial results from a new automated system for stable carbon isotope ratio measurements on C2 to C6 atmospheric hydrocarbons. The inlet system allows analysis of trace gases from air samples ranging from a few liters for urban samples and samples with high mixing ratios, to many tens of liters for samples from remote unpolluted regions with very low mixing ratios. The centerpiece of the sample preparation is the separation trap, which is used to separate CO2 and methane from the compounds of interest. The main features of the system are (i the capability to sample up to 300 l of air, (ii long term (since May 2009 operational δ13C accuracy levels in the range 0.3–0.8 ‰ (1-σ, and (iii detection limits of order 1.5–2.5 ngC (collected amount of substance for all reported compounds. The first application of this system was the analysis of 21 ambient air samples taken during 48 h in August 2009 in Utrecht, the Netherlands. Results obtained are generally in good agreement with those from similar urban ambient air studies. Short sample intervals allowed by the design of the instrument help to illustrate the complex diurnal behavior of hydrocarbons in an urban environment, where diverse sources, dynamical processes, and chemical reactions are present.

  3. Prediction of dioxin/furan incinerator emissions using low-molecular-weight volatile products of incomplete combustion.

    Science.gov (United States)

    Lemieux, P M; Lee, C W; Ryan, J V

    2000-12-01

    Emissions of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/Fs) from incinerators and other stationary combustion sources are of environmental concern because of the toxicity of certain PCDD/F congeners. Measurement of trace levels of PCDDs/Fs in combustor emissions is not a trivial matter. Development of one or more simple, easy-to-measure, reliable indicators of stack PCDD/F concentrations not only would enable incinerator operators to economically optimize system performance with respect to PCDD/F emissions, but could also provide a potential technique for demonstrating compliance status on a more frequent basis. This paper focuses on one approach to empirically estimate PCDD/F emissions using easy-to-measure volatile organic C2 chlorinated alkene precursors coupled with flue gas cleaning parameters. Three data sets from pilot-scale incineration experiments were examined for correlations between C2 chlorinated alkenes and PCDDs/Fs. Each data set contained one or more C2 chloroalkenes that were able to account for a statistically significant fraction of the variance in PCDD/F emissions. Variations in the vinyl chloride concentrations were able to account for the variations in the PCDD/F concentrations strongly in two of the three data sets and weakly in one of the data sets.

  4. Identification and Quantification of Oxidoselina-1,3,7(11-Trien-8-One and Cyanidin-3-Glucoside as One of the Major Volatile and Non-Volatile Low-Molecular-Weight Constituents in Pitanga Pulp.

    Directory of Open Access Journals (Sweden)

    Denise Josino Soares

    Full Text Available The pulp of pitanga (Eugenia uniflora L. is used to prepare pitanga juice. However, there are no reports on the identification and quantification of the main constituents in pitanga pulp. The aim of this study was to identify and quantify the major volatile and non-volatile low-molecular-weight constituents of the pulp. Isolation of volatile compounds was performed by solvent-assisted flavor evaporation technique. Characterization of the main volatile and non-volatile constituents was performed by GC-MS, LC-MS and NMR spectroscopy. For quantitative measurements, the main volatile compound needed to be isolated from pitanga pulp to obtain a commercially not available reference standard. Cyanidin-3-glucoside was determined as one of the most abundant non-volatile pulp compound yielding 53.8% of the sum of the intensities of all ions detected by LC-MS. Quantification of cyanidin-3-glucoside in pitanga pulp resulted in a concentration of 344 ± 66.4 μg/mL corresponding to 688 ± 133 μg/g dried pulp and 530 ± 102 μg/g fruit. For the volatile fraction, oxidoselina-1,3,7(11-trien-8-one was identified as the main volatile pulp constituent (27.7% of the sum of the intensities of all ions detected by GC-MS, reaching a concentration of 89.0 ± 16.9 μg/mL corresponding to 1.34 ± 0.25 μg/g fresh pulp and 1.03 ± 0.19 μg/g fruit. The results provide quantitative evidence for the occurrence of an anthocyanin and an oxygenated sesquiterpene as one of the major volatile and non-volatile low-molecular-weight compounds in pitanga pulp.

  5. Identification and Quantification of Oxidoselina-1,3,7(11)-Trien-8-One and Cyanidin-3-Glucoside as One of the Major Volatile and Non-Volatile Low-Molecular-Weight Constituents in Pitanga Pulp.

    Science.gov (United States)

    Josino Soares, Denise; Pignitter, Marc; Ehrnhöfer-Ressler, Miriam Margit; Walker, Jessica; Montenegro Brasil, Isabella; Somoza, Veronika

    2015-01-01

    The pulp of pitanga (Eugenia uniflora L.) is used to prepare pitanga juice. However, there are no reports on the identification and quantification of the main constituents in pitanga pulp. The aim of this study was to identify and quantify the major volatile and non-volatile low-molecular-weight constituents of the pulp. Isolation of volatile compounds was performed by solvent-assisted flavor evaporation technique. Characterization of the main volatile and non-volatile constituents was performed by GC-MS, LC-MS and NMR spectroscopy. For quantitative measurements, the main volatile compound needed to be isolated from pitanga pulp to obtain a commercially not available reference standard. Cyanidin-3-glucoside was determined as one of the most abundant non-volatile pulp compound yielding 53.8% of the sum of the intensities of all ions detected by LC-MS. Quantification of cyanidin-3-glucoside in pitanga pulp resulted in a concentration of 344 ± 66.4 μg/mL corresponding to 688 ± 133 μg/g dried pulp and 530 ± 102 μg/g fruit. For the volatile fraction, oxidoselina-1,3,7(11)-trien-8-one was identified as the main volatile pulp constituent (27.7% of the sum of the intensities of all ions detected by GC-MS), reaching a concentration of 89.0 ± 16.9 μg/mL corresponding to 1.34 ± 0.25 μg/g fresh pulp and 1.03 ± 0.19 μg/g fruit. The results provide quantitative evidence for the occurrence of an anthocyanin and an oxygenated sesquiterpene as one of the major volatile and non-volatile low-molecular-weight compounds in pitanga pulp.

  6. Investigation of Galactosylated Low Molecular Weight Chitosan ...

    African Journals Online (AJOL)

    was coupled with low molecular weight chitosan (LMWC) using carbodiimide chemistry. .... High molecular weight chitosan (minimum 85% ..... membrane permeability of drug and mutual repulsion ... coating thickness and the lower solubility of.

  7. Anticoagulant effect of low molecular weight heparin on central ...

    African Journals Online (AJOL)

    Purpose: To analyse the effect of low molecular weight heparin on venous catheters in haemodialysis patients. Methods: This study included 140 eligible patients who were randomly and evenly divided into two groups, viz, a study group that received low molecular weight heparin and a control group that received ...

  8. Clinical effects of low-molecular-weight heparin combined with ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research August 2016; 15 (8): 1787-1792 ... Keywords: Acute pancreatitis, Low-molecular-weight heparin, Multiple organ function syndrome,. APACHE II score ... mediators by lowering the expression of.

  9. In vitro anticoagulation monitoring of low-molecular-weight heparin

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-qi; SHI Xu-bo; YANG Jin-gang; HU Da-yi

    2009-01-01

    Background Although low-molecular-weight heparin has replaced unfractionated heparin to become the primary anticoagulation drug for treatment of acute coronary syndrome, there is no convenient bedside monitoring method. We explored the best laboratory monitoring method of low-molecular-weight heparins (enoxapadn, dalteparin, and nadroparin) by use of the Sonoclot coagulation analyzer to monitor the activated clotting time.Methods Atotal of 20 healthy volunteers were selected and 15 ml of fasting venous blood samples were collected and incubated. Four coagulants, kaolin, diatomite, glass bead, and magnetic stick, were used to determine the activated clotting time of the low-molecular-weight heparins at different in vitro anti-Xa factor concentrations. A correlation analysis was made to obtain the regression equation. The activated clotting time of the different low-molecular-weight heparins with the same anti-Xa factor concentration was monitored when the coagulant glass beads were applied. Results The activated clotting time measured using the glass beads, diatomite, kaolin, and magnetic stick showed a linear correlation with the concentration of nadroparin (r= 0.964, 0.966, 0.970, and 0.947, respectively). The regression equation showed that the linear slopes of different coagulants were significantly different (glass beads 230.03 s/IU,diatomite 89.91 s/IU, kaolin 50.87 s/IU, magnetic stick could not be calculated). When the concentration of the anti-Xa factor was the same for different low-molecular-weight heparins, the measured activated clotting time was different after the application of the glass bead coagulant.Conclusions The glass bead coagulant is most feasible for monitoring the in vitro anticoagulation activity of nadroparin.The different effects of different low-molecular-weight heparins on the activated clotting time may be related to the different anti-Ila activities.

  10. Low-molecular-weight chitosans: Preparation and characterization

    Czech Academy of Sciences Publication Activity Database

    Tishchenko, Galina; Šimůnek, Jiří; Brus, Jiří; Netopilík, Miloš; Pekárek, Michal; Walterová, Zuzana; Koppová, Ingrid; Lenfeld, Jiří

    2011-01-01

    Roč. 86, č. 2 (2011), s. 1077-1081 ISSN 0144-8617 R&D Projects: GA ČR(CZ) GA525/08/0803 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z50450515 Keywords : low-molecular-weight chitosans * chitooligosaccharides * oxidative depolymerization Subject RIV: ED - Physiology Impact factor: 3.628, year: 2011

  11. Clinical effects of low-molecular-weight heparin combined with ...

    African Journals Online (AJOL)

    Purpose: To explore the clinical effects of low-molecular-weight heparin (LMWH) combined with ulinastatin (UTI) in children with acute pancreatitis. Methods: In total, 560 patients with severe acute pancreatitis treated at Binzhou People's Hospital, Shandong, China, from April 2012 to June 2014 were enrolled in this study.

  12. Low molecular weight salts combined with fluorinated solvents for electrolytes

    Science.gov (United States)

    Tikhonov, Konstantin; Yip, Ka Ki; Lin, Tzu-Yuan; Lei, Norman; Guerrero-Zavala, Guillermo; Kwong, Kristie W.

    2015-11-10

    Provided are electrochemical cells and electrolytes used to build such cells. An electrolyte includes at least one salt having a molecular weight less than about 250. Such salts allow forming electrolytes with higher salt concentrations and ensure high conductivity and ion transport in these electrolytes. The low molecular weight salt may have a concentration of at least about 0.5M and may be combined with one or more other salts, such as linear and cyclic imide salts and/or methide salts. The concentration of these additional salts may be less than that of the low molecular weight salt, in some embodiments, twice less. The additional salts may have a molecular weight greater than about 250. The electrolyte may also include one or more fluorinated solvents and may be capable of maintaining single phase solutions at between about -30.degree. C. to about 80.degree. C.

  13. Physical Properties of Low-Molecular Weight Polydimethylsiloxane Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Christine Cardinal [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Graham, Alan [Univ. of Colorado, Denver, CO (United States); Nemer, Martin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Phinney, Leslie M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Garcia, Robert M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Soehnel, Melissa Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stirrup, Emily Kate [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-02-01

    Physical property measurements including viscosity, density, thermal conductivity, and heat capacity of low-molecular weight polydimethylsiloxane (PDMS) fluids were measured over a wide temperature range (-50°C to 150°C when possible). Properties of blends of 1 cSt and 20 cSt PDMS fluids were also investigated. Uncertainties in the measurements are cited. These measurements will provide greater fidelity predictions of environmental sensing device behavior in hot and cold environments.

  14. Prophylaxis of postoperative thromboembolism with low molecular weight heparins

    DEFF Research Database (Denmark)

    Jørgensen, L N; Wille-Jørgensen, P; Hauch, O

    1993-01-01

    To evaluate the thromboprophylactic use of low molecular weight heparins (LMWHs), publications from 27 orthopaedic trials and 35 studies of patients undergoing general or gynaecological surgery were scrutinized and subjected to a partial meta-analysis. In orthopaedic surgery, LMWHs were superior...... to placebo or dextran and at least as efficient as unfractionated heparin in the prevention of deep vein thrombosis (DVT). Compared with unfractionated heparin, one of the LMWH preparations significantly reduced the total incidence of DVT. The rate of non-fatal pulmonary embolism was 0.49 per cent...

  15. The effect of low molecular weight multifunctional additives on heavy oil viscosity

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, T.B.P.; Yarranton, H.W.; Larter, S.R. [Calgary Univ., AB (Canada)

    2010-07-01

    Crude oils contain many small multifunctional low molecular weight components that act as linking molecules between larger functionalized species. The linkage molecules have a significant impact on the flow properties of hydrocarbon systems. This study investigated the use of a low molecular weight multiheteroatom species (LMWMH) as a molecular Velcro linking high molecular weight components together. LMWMH species were added to Albertan bitumens and heavy oil, and their impact on viscosity was investigated. Results of the experimental studies were then compared with the effects of hydrocarbon solvents on similar samples. The LMWMH species included bifunctional species and analogous alkyl and aryl monoamines that acted as blocking molecules to hinder the association of larger petroleum species. Density and viscosity measurements were conducted. A correlation method was used to predict the viscosity of the solvent-diluted heavy oil and bitumen samples. The study showed that of the tested additives, only aniline demonstrated an additional viscosity-reducing effect. The aniline inhibited asphaltene association and is a promising candidate for enhanced in-situ bitumen viscosity reduction. 23 refs., 4 tabs.

  16. Alkyl cross-linked low molecular weight polypropyleneimine dendrimers as efficient gene delivery vectors

    Directory of Open Access Journals (Sweden)

    Faezeh Moghadam Ariaee

    2016-10-01

    Conclusion: Our results indicated that oligomerization of low molecular weight PPI (PPI G2-alkyl-PPI G2 conjugate could be an approach to increase the transfection efficiency and to lower the cytotoxicity of low molecular weight polycations.

  17. Recent developments in separation of low molecular weight heparin anticoagulants.

    Science.gov (United States)

    Sadowski, Radosław; Gadzała-Kopciuch, Renata; Buszewski, Bogusław

    2017-10-05

    The general function of anticoagulants is to prevent blood clotting and growing of the existing clots in blood vessels. In recent years, there has been a significant improvement in developing methods of prevention as well as pharmacologic and surgical treatment of thrombosis. For over the last two decades, low molecular weight heparins (LMWHs) have found their application in the antithrombotic diseases treatment. These types of drugs are widely used in clinical therapy. Despite the biological and medical importance of LMWHs, they have not been completely characterized in terms of their chemical structure. Due to both, the structural complexity of these anticoagulants and the presence of impurities, their structural characterization requires the employment of advanced analytical techniques. Since separation techniques play the key role in these endeavors, this review will focus on the presentation of recent developments in the separation of LMWH anticoagulants. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  18. Low-molecular-weight carbohydrates from red seaweeds

    International Nuclear Information System (INIS)

    Duarte, M.E.R.; Tischer, C.A.; Gorin, P.A.J.; Noseda, M.D.

    1997-01-01

    Red algae (Rhodophyta) produce, as their principal photosynthetic metabolites, low-molecular-weight carbohydrates and polyols. The former are heterosides consisting of galactose and glycerol and are produced by all the orders of Phodophyta except the ceramiales. They are named: floridoside [α-D-galactopyranosyl (1->2)-glycerol], isofloridoside D-form [α-D-galactopyranosyl-(1->)D-glycerol] and L-form [α-D-galactopyranosyl-(1->1)-L-glycerol] (Meng et al., 1987, Karsten et al., 1993). The Ceramiales synthesize the chemically related digeneaside [α-D-mannopyranosyl-(1->2)-L-glycerate] (Kirst, 1980). Some of the red seaweeds also produce polyols such as dulcitol and D-sorbitol (Karsten et al., 1992). (author)

  19. Low-molecular-weight carbohydrates from red seaweeds

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, M.E.R.; Tischer, C.A.; Gorin, P.A.J.; Noseda, M.D. [Parana Univ., Curitiba, PR (Brazil). Dept. de Bioquimica

    1997-12-31

    Red algae (Rhodophyta) produce, as their principal photosynthetic metabolites, low-molecular-weight carbohydrates and polyols. The former are heterosides consisting of galactose and glycerol and are produced by all the orders of Phodophyta except the ceramiales. They are named: floridoside [{alpha}-D-galactopyranosyl (1->2)-glycerol], isofloridoside D-form [{alpha}-D-galactopyranosyl-(1->)D-glycerol] and L-form [{alpha}-D-galactopyranosyl-(1->1)-L-glycerol] (Meng et al., 1987, Karsten et al., 1993). The Ceramiales synthesize the chemically related digeneaside [{alpha}-D-mannopyranosyl-(1->2)-L-glycerate] (Kirst, 1980). Some of the red seaweeds also produce polyols such as dulcitol and D-sorbitol (Karsten et al., 1992). (author) 4 refs., 8 figs., 1 tabs.

  20. Obstetric outcome with low molecular weight heparin therapy during pregnancy.

    LENUS (Irish Health Repository)

    Donnelly, J

    2012-01-01

    This was a prospective study of women attending a combined haematology\\/obstetric antenatal clinic in the National Maternity Hospital (2002-2008). Obstetric outcome in mothers treated with low molecular weight heparin (LMWH) was compared to the general obstetric population of 2006. There were 133 pregnancies in 105 women. 85 (63.9%) received prophylactic LMWH and 38 (28.6%) received therapeutic LMWH in pregnancy. 10 (7.5%) received postpartum prophylaxis only. The perinatal mortality rate was 7.6\\/1000 births. 14 (11.3%) women delivered preterm which is significantly higher than the hospital population rate (5.7%, p<0.05). Despite significantly higher labour induction rates (50% vs 29.2% p<0.01), there was no difference in CS rates compared to the general hospital population (15.4% vs 18.9%, NS). If carefully managed, these high-risk women can achieve similar vaginal delivery rates as the general obstetric population.

  1. Low-molecular-weight heparins: pharmacologic profile and product differentiation.

    Science.gov (United States)

    Fareed, J; Jeske, W; Hoppensteadt, D; Clarizio, R; Walenga, J M

    1998-09-10

    The interchangeability of low-molecular-weight heparins (LMWHs) has been the subject of discussion since these products were first introduced for the prophylaxis of deep vein thrombosis. Experimental evidence now exists to show that LMWHs differ from each other in a number of characteristics. Products have been differentiated on the basis of molecular weight and biologic properties, but only limited information derived from the clinical setting is available. Potency has been described on the basis of anti-Factor Xa activity, but at equivalent anti-Xa activities, the anti-Factor IIa activity of different products shows marked variations. At the relatively small doses used for the management of postsurgical deep vein thrombosis, the effect of these interproduct differences may be relatively minor, but as LMWHs are developed for therapeutic use at much higher doses, such differences may become clinically important. Variations in safety and efficacy reported in clinical trials of LMWHs may reflect the known differences in their molecular composition and pharmacologic properties.

  2. MALDI matrices for low molecular weight compounds: an endless story?

    Science.gov (United States)

    Calvano, Cosima Damiana; Monopoli, Antonio; Cataldi, Tommaso R I; Palmisano, Francesco

    2018-04-23

    Since its introduction in the 1980s, matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) has gained a prominent role in the analysis of high molecular weight biomolecules such as proteins, peptides, oligonucleotides, and polysaccharides. Its application to low molecular weight compounds has remained for long time challenging due to the spectral interferences produced by conventional organic matrices in the low m/z window. To overcome this problem, specific sample preparation such as analyte/matrix derivatization, addition of dopants, or sophisticated deposition technique especially useful for imaging experiments, have been proposed. Alternative approaches based on second generation (rationally designed) organic matrices, ionic liquids, and inorganic matrices, including metallic nanoparticles, have been the object of intense and continuous research efforts. Definite evidences are now provided that MALDI MS represents a powerful and invaluable analytical tool also for small molecules, including their quantification, thus opening new, exciting applications in metabolomics and imaging mass spectrometry. This review is intended to offer a concise critical overview of the most recent achievements about MALDI matrices capable of specifically address the challenging issue of small molecules analysis. Graphical abstract An ideal Book of matrices for MALDI MS of small molecules.

  3. Antiaging activity of low molecular weight peptide from Paphia undulate

    Science.gov (United States)

    Chen, Xin; Cai, Bingna; Chen, Hua; Pan, Jianyu; Chen, Deke; Sun, Huili

    2013-05-01

    Low molecular weight peptide (LMWP) was prepared from clam Paphia undulate and its antiaging effect on D-galactose-induced acute aging in rats, aged Kunming mice, ultraviolet-exposed rats, and thermally injured rats was investigated. P. undulate flesh was homogenized and digested using papain under optimal conditions, then subjected to Sephadex G-25 chromatography to isolate the LMWP. Administration of LMWP significantly reversed D-galactose-induced oxidative stress by increasing the activities of glutathione peroxidase (GPx) and catalase (CAT), and by decreasing the level of malondialdehyde (MDA). This process was accompanied by increased collagen synthesis. The LMWP prevented photoaging and promoted dermis recovery and remission of elastic fiber hyperplasia. Furthermore, treatment with the LMWP helped to regenerate elastic fibers and the collagen network, increased superoxide dismutase (SOD) in the serum and significantly decreased MDA. Thermal scald-induced inflammation and edema were also relieved by the LWMP, while wound healing in skin was promoted. These results suggest that the LMWP from P. undulate could serve as a new antiaging substance in cosmetics.

  4. The Effect of Low Molecular Weight Heparins on Fracture Healing.

    Science.gov (United States)

    Kapetanakis, Stylianos; Nastoulis, Evangelos; Demesticha, Theano; Demetriou, Thespis

    2015-01-01

    Venous Thromboembolism is a serious complication in the trauma patient. The most commonly studied and used anticoagulant treatment in prophylaxis of thrombosis is heparin. The prolonged use of unfractionated heparin has been connected with increased incidence of osteoporotic fractures. Low molecular-weight-heparins (LMWHs) have been the golden rule in antithrombotic therapy during the previous two decades as a way to overcome the major drawbacks of unfractioned heparin. However there are few studies reporting the effects of LMWHs on bone repair after fractures. This review presents the studies about the effects of LMWHs on bone biology (bone cells and bone metabolism) and underlying the mechanisms by which LMWHs may impair fracture healing process. The authors' research based on literature concluded that there are no facts and statistics for the role of LMWHs on fracture healing process in humans and the main body of evidence of their role comes from in vitro and animal studies. Further large clinical studies designed to compare different types of LMWHs, in different dosages and in different patient or animal models are needed for exploring the effects of LMWHs on fracture healing process.

  5. Intravitreal low molecular weight heparin in PVR surgery.

    Directory of Open Access Journals (Sweden)

    Kumar Atul

    2003-01-01

    Full Text Available Purpose: To evaluate the efficacy of low molecular weight heparin (LMWH in prevention of postoperative fibrin formation following vitreoretinal surgery with proliferative vitreoretinopathy (PVR. Material and Methods: Thirty consecutive patients of retinal detachment with advanced PVR were enrolled in the study. They were randomised to study and control groups (n = 15 each. Study group patients received vitreoretinal surgery with 5 IU/cc of LMWH in vitrectomy infusion fluid. The control group patients received vitroretinal surgery without heparin in the infusion fluid. Patients were followed up at 1 week, 1 month and 3 months after surgery. Postoperative bleeding, media clarity, best-corrected visual acuity and success of the surgery at the end of 3 months were compared between the two groups. Results: At each follow-up visit, the study group showed a better media clarity, which was statistically significant ( P = 0.0042. The study group had a 50% better chance of retinal reattachment compared to the control group. Five patients had intraoperative bleeding in the study group (33% compared to 3 patients in the control group (20%. Conclusion: Use of intravitreal LMWH prevents postoperative fibrin formation and is beneficial in repair of retinal detachments with PVR.

  6. Low molecular weight heparin versus unfractionated heparin in the initial treatment of venous thromboembolism

    NARCIS (Netherlands)

    Hettiarachchi, R. J.; Prins, M. H.; Lensing, A. W.; Buller, H. R.

    1998-01-01

    In this review, we analyze data from randomized trials in which low molecular weight heparin was compared with unfractionated heparin, both to estimate the treatment effect of low molecular weight heparin in the initial treatment of venous thromboembolism and to evaluate the effect of the varied

  7. Nitrogen mineralization in a simulated rhizosphere as influenced by low molecular weight organic substances

    OpenAIRE

    Begum, Shamim Ara; Kader, MD Abdul; Sleutel, Steven; De Neve, Stefaan

    2012-01-01

    Rhizodeposits consist of over 200 organic compounds, mainly low-molecular-weight organic substances (LMWOS) such as amino acids (AA), carbohydrates (CH) and carboxylic acids (CA), lipids and phenols. Those LMWOS influence nutrient turnover, particularly N turnover. However, the exact influence of these organic substances on nitrogen mineralization is yet unknown. Therefore, the stimulatory effects of low molecular weight organic substances on nitrogen mineralization in the rhizosphere of a si...

  8. Should Low Molecular Weight PSMA Targeted Ligands Get Bigger and Use Albumin Ligands for PSMA Targeting?

    OpenAIRE

    Huang, Steve S.; Heston, Warren D.W.

    2017-01-01

    Prostate Specific Membrane Antigen (PSMA) is strongly expressed in prostate cancer. Recently a number of low-molecular-weight inhibitors have demonstrated excellent PSMA targeting activity for both imaging as well as Lutecium-177 radiotherapy in human trials. The paper by Choy et al raises the question of whether we can further increase the effectiveness of PSMA targeted therapy by adding an albumin-binding entity to low-molecular-weight agents

  9. Low molecular weight compounds as effective dispersing agents in the formation of colloidal silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Natsuki, Jun; Natsuki, Toshiaki, E-mail: natsuki@shinshu-u.ac.jp; Abe, Takao [Shinshu University, Faculty of Textile Science and Technology (Japan)

    2013-03-15

    A convenient method to synthesize uniform, well-dispersed colloidal silver nanoparticles is described. Aldonic acid or {alpha}-hydroxy acid compounds of low molecular weight are used instead of polymeric compounds as dispersing agents to prepare silver nanoparticles. The size, conformation, and electrical conductivity of the silver nanoparticles, and the effect and function of the dispersing agents are investigated in detail. Using these low molecular weight compounds as dispersing agents, silver nanoparticles with a diameter of 10 nm or less and high electrical conductivity can be obtained. In addition, this procedure allows silver nanoparticles to be sintered at 150 Degree-Sign C, which is lower than that required for silver nanoparticle formulation using polymeric compounds (200 Degree-Sign C). The silver nanoparticles produced by this process can be used to prepare various inks and to manufacture electronic circuits. It is found that low molecular weight compounds are more effective dispersing agents than polymeric compounds in the formation of silver nanoparticles.

  10. Determination of low molecular weight thiols using monobromobimane fluorescent labeling and high-performance liquid chromatography

    Science.gov (United States)

    Fahey, Robert C.; Newton, Gerald L.

    1988-01-01

    Methods are described for the preparation and high-performance liquid chromatography (HPLC) analysis of monobromobimane derivatives of low molecular weight thiols in extracts of biological samples. Typical problems encountered in the development and application of these methods are discussed. Analysis of mung bean extract is used as an example.

  11. Low-molecular-weight heparin in the treatment of patients with venous thromboembolism

    NARCIS (Netherlands)

    tenCate, JW; Buller, HR; Gent, M; Hirsh, J; Prins, MH; Baildon, R; Lensing, AWA; Anderson, DR; vanBeek, EJR; Fiesinger, JN; Tijssen, JGP; vanBarneveld, A; Eimers, LT; Graafsma, YP; Hettiarachchi, R; Hutten, B; Redekop, K; Haley, S; LIberale, L; Finch, T; Whittaker, S; Wilkinson, L; Prandoni, P; Villalta, S; Girolami, B; Bagatella, P; Rossi, L; Girolami, A; Piovella, F; Barone, M; Beltrametti, C; Serafini, S; Siragusa, S; Ascari, E; Kovacs, MJ; Morrow, B; Kovacs, J; Kuijer, PMM; Koopman, MMW; Jagt, H; Weitz, J; Kearon, C; Biagioni, L; Haas, S; Lossner, F; Spengel, FA; Berger, M; Demers, C; Poulin, J; vanderMeer, J; Que, GTH; Smid, WM; Robinson, KS; Boyle, E; Leclerc, [No Value; StJacques, B; Finkenbine, S; Gallus, AS; Cohlan, D; Rich, C; Brandjes, DPM; Hoefnagel, CA; deRijk, M; Turkstra, F; Desjardins, L; CoteDesjardins, J; Couture, L; Ruel, M; Villenueve, J; Geerts, WH; Jay, RM; Code, EKI; Turpie, AGG; Johnson, J; Nguyen, P; Cusson, [No Value; Roy, S; Wells, PS; Bormanis, J; Goudie, D; Cruickshank, M; vonLewinski, M; Monreal, M; Sahuquillo, JC; Lafoz, E; Simonneau, G; Parent, F; Jagot, J; Douketis, JD; Kinnon, K; Ginsberg, JS; BrillEdwards, P; Donovan, D; Ockelford, PA; Kassis, J; Bornais, S; Planchon, B; ElKouri, D; Pistorius, MA; Escribano, M; Garrido, G; Chesterman, CN; Chong, BH; Pritchard, S; Cade, JF; Bynon, T; Stanford, J; Brien, WM; Palmer, B; Faivre, R; Petiteau, B; Manucci, PM; Moia, M; Bucciarelli, P

    1997-01-01

    Background Low-molecular-weight heparin is known to be safe and effective for the initial Treatment of patients with proximal deep-vein thrombosis. However, its application to patients with pulmonary embolism or previous episodes of thromboembolism has not been studied. Methods We randomly assigned

  12. Low-molecular-weight poly-carboxylate as crystal growth modifier in ...

    Indian Academy of Sciences (India)

    Biomineralization; growth modifier; amino acid; low-molecular-weight chiral poly- carboxylate; calcium ... They are also used as gravity sensors, for metal storage and .... The pH of the solutions was maintained at ~10⋅0 for different periods of ...

  13. A global survey of low-molecular weight carbohydrates in lentils

    Science.gov (United States)

    Lentils contain a range of low-molecular weight carbohydrates (LMWC); however, those have not been well characterized. The objectives of this study were to (1) determine the concentrations of LMWC in lentils grown in six locations, and (2) identify any genetic and environmental effects on those LMWC...

  14. Development of haplotype-specific molecular markers for the low-molecular-weight glutenin subunits

    Science.gov (United States)

    Low-molecular-weight glutenin subunits (LMW-GSs) are one of the major components of gluten and their allelic variation has been widely associated with numerous wheat end-use quality parameters. These proteins are encoded by multigene families located at the orthologous Glu-3 loci (Glu-A3, Glu-B3 and...

  15. Safety of low-molecular-weight heparin in pregnancy: a systematic review

    NARCIS (Netherlands)

    Sanson, B. J.; Lensing, A. W.; Prins, M. H.; Ginsberg, J. S.; Barkagan, Z. S.; Lavenne-Pardonge, E.; Brenner, B.; Dulitzky, M.; Nielsen, J. D.; Boda, Z.; Turi, S.; Mac Gillavry, M. R.; Hamulyák, K.; Theunissen, I. M.; Hunt, B. J.; Büller, H. R.

    1999-01-01

    Unfractionated heparin (UFH) remains the anticoagulant of choice during pregnancy. Low-molecular-weight heparins (LMWH) are an attractive alternative to UFH due to their logistic advantages and their association with a lower incidence of osteoporosis and HIT. We reviewed all published clinical

  16. Separation and analysis of low molecular weight plasticizers in poly(vinyl chloride) tubes

    DEFF Research Database (Denmark)

    Wang, Qian; Storm, Birgit Kjærside

    2005-01-01

    ) and thermogravimetric analysis (TGA), as well as by studying the extracted low molecular weight plasticizers by gas chromatography/mass spectroscopy (GC/MS) and GC. It was found that the simple room temperature extraction in chloroform showed the best separation of plasticizers from the PVC matrix. Close results...

  17. Venous thromboembolism in pregnancy: prophylaxis and treatment with low molecular weight heparin

    DEFF Research Database (Denmark)

    Andersen, Anita Sylvest; Berthelsen, Jørgen G; Bergholt, Thomas

    2010-01-01

    OBJECTIVE: To evaluate the safety of individually dosed low molecular weight heparin (LMWH) for prophylaxis and treatment of thromboembolic complications in pregnancy. DESIGN: Cohort study with a chronologic register-based control group. SETTING: Department of Obstetrics and Gynecology, Hillerød ...

  18. Venous thromboembolism in pregnancy: prophylaxis and treatment with low molecular weight heparin

    DEFF Research Database (Denmark)

    Andersen, Anita Sylvest; Berthelsen, Jørgen G.; Bergholt, Thomas

    2010-01-01

    OBJECTIVE: To evaluate the safety of individually dosed low molecular weight heparin (LMWH) for prophylaxis and treatment of thromboembolic complications in pregnancy. DESIGN: Cohort study with a chronologic register-based control group. SETTING: Department of Obstetrics and Gynecology, Hillerød...

  19. Low molecular weight chemical-induced occupational asthma : The focus on alveolar macrophages

    NARCIS (Netherlands)

    Valstar, Dingena Labine

    2004-01-01

    Asthma is a very common disorder and its prevalence has increased over the past two to three decades. The proportion of cases attributable to occupational exposure at the workplace is estimated at ~10% of adult-onset asthma. Most cases of occupational asthma are caused by low molecular weight

  20. Role of Laccase and Low Molecular Weight Metabolites from Trametes versicolor in Dye Decolorization

    Directory of Open Access Journals (Sweden)

    Diego Moldes

    2012-01-01

    Full Text Available The studies regarding decolorization of dyes by laccase may not only inform about the possible application of this enzyme for environmental purposes, but also may provide important information about its reaction mechanism and the influence of several factors that could be involved. In this paper, decolorization of crystal violet and phenol red was carried out with different fractions of extracellular liquids from Trametes versicolor cultures, in order to describe the role of laccase in this reaction. Moreover, the possible role of the low molecular weight metabolites (LMWMs also produced by the fungus was evaluated. The results confirm the existence of a nonenzymatic decolorization factor, since the nonprotein fraction of the extracellular liquids from cultures of T. versicolor has shown decolorization capability. Several experiments were performed in order to identify the main compounds related to this ability, which are probably low molecular weight peroxide compounds.

  1. Managing cancer-related venous thromboembolic disease: low-molecular-weight heparins and beyond.

    Science.gov (United States)

    O'Connell, Casey L; Liebman, Howard A

    2008-12-01

    Venous thromboembolism is a major contributor to the morbidity and mortality of patients with cancer. For patients undergoing cancer surgery, several trials support the safety and efficacy of unfractionated heparin and of low-molecular-weight heparin for the prevention of venous thromboembolism, while data regarding the efficacy and safety of these agents in the setting of medical hospitalization is less definitive and must be extracted from trials including noncancer patients with different thrombotic risk factors. Randomized clinical studies confirm that patients with cancer who develop venous thromboembolism have superior outcomes when treated with long-term low-molecular-weight heparin as compared with warfarin. Novel anticoagulants that are orally bioavailable and function by directly inhibiting factor Xa or thrombin are entering the market. To date, data regarding the efficacy and safety of these novel anticoagulants as venous thromboembolism prophylaxis and treatment in cancer patients are not available and must be extracted from larger trials with heterogeneous patient populations.

  2. Phosphorus release from phosphate rock and iron phosphate by low-molecular-weight organic acids.

    Science.gov (United States)

    Xu, Ren-kou; Zhu, Yong-guan; Chittleborough, David

    2004-01-01

    Low-molecular-weight(LMW) organic acids widely exist in soils, particularly in the rhizosphere. A series of batch experiments were carried out to investigate the phosphorus release from rock phosphate and iron phosphate by low-molecular-weight organic acids. Results showed that citric acid had the highest capacity to solubilize P from both rock and iron phosphate. P solubilization from rock phosphate and iron phosphate resulted in net proton consumption. P release from rock phosphate was positively correlated with the pKa values. P release from iron phosphate was positively correlated with Fe-organic acid stability constants except for aromatic acids, but was notcorrelated with pKa. Increase in the concentrations of organic acids enhanced P solubilization from both rock and iron phosphate almost linearly. Addition of phenolic compounds further increased the P release from iron phosphate. Initial solution pH had much more substantial effect on P release from rock phosphate than from iron phosphate.

  3. Preparation of the low molecular weight serum proteome for mass spectrometry analysis.

    Science.gov (United States)

    Waybright, Timothy J; Chan, King C; Veenstra, Timothy D; Xiao, Zhen

    2013-01-01

    The discovery of viable biomarkers or indicators of disease states is complicated by the inherent complexity of the chosen biological specimen. Every sample, whether it is serum, plasma, urine, tissue, cells, or a host of others, contains thousands of large and small components, each interacting in multiple ways. The need to concentrate on a group of these components to narrow the focus on a potential biomarker candidate becomes, out of necessity, a priority, especially in the search for immune-related low molecular weight serum biomarkers. One such method in the field of proteomics is to divide the sample proteome into groups based on the size of the protein, analyze each group, and mine the data for statistically significant items. This chapter details a portion of this method, concentrating on a method for fractionating and analyzing the low molecular weight proteome of human serum.

  4. Structure and allosteric effects of low-molecular-weight activators on the protein kinase PDK1

    DEFF Research Database (Denmark)

    Hindie, Valerie; Stroba, Adriana; Zhang, Hua

    2009-01-01

    -dependent activation of AGC kinases. The AGC kinase PDK1 is activated by the docking of a phosphorylated motif from substrates. Here we present the crystallography of PDK1 bound to a rationally developed low-molecular-weight activator and describe the conformational changes induced by small compounds in the crystal...... molecular details of the allosteric changes induced by small compounds that trigger the activation of PDK1 through mimicry of phosphorylation-dependent conformational changes....

  5. A low molecular weight urinary proteome profile of human kidney aging

    OpenAIRE

    Zürbig, Petra; Decramer, Stéphane; Dakna, Mohammed; Jantos, Justyna; Good, David M.; Coon, Joshua J.; Bandin, Flavio; Mischak, Harald; Bascands, Jean-Loup; Schanstra, Joost P

    2009-01-01

    Aging induces morphological changes of the kidney and reduces renal function. We analyzed the low molecular weight urinary proteome of 324 healthy individuals from 2-73 years of age to gain insight on renal aging in humans. We observed age-related modification of secretion of 325 out of 5000 urinary peptides. The majority of these changes was associated with renal development before and during puberty, while 49 peptides were related to aging in adults. Of these 49 peptides, the majority were ...

  6. Growth of thin films of low molecular weight proteins by matrix assisted pulsed laser evaporation (MAPLE)

    DEFF Research Database (Denmark)

    Matei, Andreea; Schou, Jørgen; Constantinescu, C.

    2011-01-01

    Thin films of lysozyme and myoglobin grown by matrix assisted pulsed laser evaporation (MAPLE) from a water ice matrix have been investigated. The deposition rate of these two low molecular weight proteins (lysozyme: 14307 amu and myoglobin: 17083 amu) exhibits a maximum of about 1–2 ng/cm2 per....... The results for lysozyme demonstrate that the fragmentation rate of the proteins during the MAPLE process is not influenced by the pH of the water solution prior to freezing....

  7. Study the Effect of Imposing Surfactants toward the Evaporation of Low Molecular Weight Alcohol

    OpenAIRE

    Mohammad , H.H.; Sharifuddin Md. , Zain; Rashid Atta , Khan; Khalisanni , Khalid

    2013-01-01

    International audience; In this paper, Reversed-Flow Gas Chromatography (RF-GC) is utilized to investigate the evaporation of low molecular weight alcohol. Evaporation rates as well as the diffusion rates of methanol are determined with a surfactant monolayer on the surface of the liquid; while nitrogen acts as carrier gas, at 313 K. The precision (>99.9%) and accuracy of this investigation demonstrates the potential of current methodologies for environmental impact studies; this is further v...

  8. Study the Effect of Imposing Surfactants toward the Evaporation of Low Molecular Weight Alcohol

    OpenAIRE

    H.H., Mohammad; Zain, Sharifuddin Mohd; Khan, Rashid Atta; Khalid, Khalisanni

    2017-01-01

    In this paper, Reversed-Flow Gas Chromatography (RF-GC) is utilized to investigate the evaporation of low molecular weight alcohol. Evaporation rates as well as the diffusion rates of methanol are determined with a surfactant monolayer on the surface of the liquid; while nitrogen acts as carrier gas, at 313 K. The precision (>99.9%) and accuracy of this investigation demonstrates the potential of current methodologies for environmental impact studies; this is further verified when the results...

  9. Bilateral rectal sheath hematomas after low-molecular weight heparin treatment in uremia.

    Science.gov (United States)

    Xu, Lu; Liu, Lei; Li, Xinjian

    2017-11-01

    Rectus sheath hematomas (RSHs) are uncommon. They are usually unilateral and rarely bilateral. In this paper, we report the first case of spontaneous bilateral RSHs in a uremic patient after the administration of the first dose of low-molecular weight heparin during hemodialysis. The most interesting aspect of this case is that the main symptom of RSH in our patient was urinary bladder irritation. We highlight the importance of the prompt diagnosis and management of this medical emergency.

  10. Update on the clinical use of the low-molecular-weight heparin, parnaparin

    Directory of Open Access Journals (Sweden)

    Giuseppe Camporese

    2009-09-01

    Full Text Available Giuseppe Camporese1, Enrico Bernardi2, Franco Noventa31Unit of Angiology and 3Department of Clinical and Experimental Medicine, Clinical Epidemiology Group, University Hospital of Padua, Italy; 2Department of Emergency and Accident Medicine, Hospital of Conegliano Veneto, ItalyAbstract: Parnaparin is a low-molecular-weight heparin that has widely shown its efficacy and safety in prevention of venous thromboembolism, in the treatment of chronic venous disorders, and in the treatment of venous and arterial (stable and unstable angina, acute ST-segment elevation myocardial infarction thrombosis. Parnaparin at the respective dosages of 3200, 4250, 6400, or 12800 IUaXa for a period ranging from 3 to 5 days to 6 months, is usually administered subcutaneously by means of once-daily regimen and is better tolerated than unfractionated heparin at the injection site. In the variety of commercially available low-molecular-weight heparins, parnaparin represents a useful therapeutic option, even though little evidence is available comparing the superiority or the equivalent efficacy and safety of parnaparin to that of the unfractionated heparin or placebo. This review summarizes the available literature on the use of parnaparin in different settings of cardiovascular diseases, including papers published during the past year and ongoing studies.Keywords: low-molecular-weight heparin, heparin, parnaparin, acute coronary syndromes, venous thromboembolism

  11. Western blotting of high and low molecular weight proteins using heat.

    Science.gov (United States)

    Kurien, Biji T; Scofield, R Hal

    2015-01-01

    A method for the electrophoretic transfer of high and low molecular weight proteins to nitrocellulose membranes following sodium dodecyl sulfate (SDS) polyacrylamide gel is described here. The transfer was performed with heated (70-75 °C) normal transfer buffer from which methanol had been omitted. Complete transfer of high and low molecular weight antigens (molecular weight protein standards, a purified protein, and proteins from a human tissue extract) could be carried out in 10 min for a 7 % (0.75 mm) SDS polyacrylamide gel. For 10 and 12.5 % gels (0.75 mm) the corresponding time was 15 min. A complete transfer could be carried out in 20 min for 7, 10, and 12.5 % gels (1.5 mm gels). The permeability of the gel is increased by heat, such that the proteins trapped in the polyacrylamide gel matrix can be easily transferred to the membrane. The heat mediated transfer method was compared with a conventional transfer protocol, under similar conditions. The conventional method transferred minimal low molecular weight proteins while retaining most of the high molecular weight proteins in the gel. In summary, this procedure is particularly useful for the transfer of high molecular weight proteins, very rapid, and avoids the use of methanol.

  12. Low molecular-weight phenols in Tannat wines made by alternative winemaking procedures.

    Science.gov (United States)

    Favre, Guzmán; Peña-Neira, Álvaro; Baldi, Cecilia; Hernández, Natalia; Traverso, Sofía; Gil, Graciela; González-Neves, Gustavo

    2014-09-01

    Low molecular weight phenols of Tannat red wines produced by Traditional Maceration (TM), Prefermentative Cold Maceration (PCM), Maceration Enzyme (ENZ) and grape-Seed Tannins additions (ST), were performed and discussed. Alternatives to TM increased wine phenolic contents but unequally, ST increased mainly smaller flavans-3-ol, PCM anthocyanins and ENZ proanthocyanidins (up to 2250 mg/L). However low molecular weight flavan-3-ols remained below 9 mg/L in all wines, showing that there is not necessarily a correspondence between wine richness in total tannins and flavan-3-ols contents at low molecular weight. PCM wines had particularly high concentrations of tyrosol and tryptophol, yeast metabolism derived compounds. The use of grape-seed enological tannins did not increase grape seed derived phenolic compounds such as gallic acid. Caftaric acid was found in concentrations much higher than those reported in other grape varieties. Wine phenolic content and composition was considerably affected by the winemaking procedures tested. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Cellular Viscosity in Prokaryotes and Thermal Stability of Low Molecular Weight Biomolecules.

    Science.gov (United States)

    Cuecas, Alba; Cruces, Jorge; Galisteo-López, Juan F; Peng, Xiaojun; Gonzalez, Juan M

    2016-08-23

    Some low molecular weight biomolecules, i.e., NAD(P)H, are unstable at high temperatures. The use of these biomolecules by thermophilic microorganisms has been scarcely analyzed. Herein, NADH stability has been studied at different temperatures and viscosities. NADH decay increased at increasing temperatures. At increasing viscosities, NADH decay rates decreased. Thus, maintaining relatively high cellular viscosity in cells could result in increased stability of low molecular weight biomolecules (i.e., NADH) at high temperatures, unlike what was previously deduced from studies in diluted water solutions. Cellular viscosity was determined using a fluorescent molecular rotor in various prokaryotes covering the range from 10 to 100°C. Some mesophiles showed the capability of changing cellular viscosity depending on growth temperature. Thermophiles and extreme thermophiles presented a relatively high cellular viscosity, suggesting this strategy as a reasonable mechanism to thrive under these high temperatures. Results substantiate the capability of thermophiles and extreme thermophiles (growth range 50-80°C) to stabilize and use generally considered unstable, universal low molecular weight biomolecules. In addition, this study represents a first report, to our knowledge, on cellular viscosity measurements in prokaryotes and it shows the dependency of prokaryotic cellular viscosity on species and growth temperature. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  14. Low molecular weight halogenated hydrocarbons (LMHHs) in Mediterranean sea water: Preliminary observations

    International Nuclear Information System (INIS)

    Elder, D.L.; Villeneuve, J.P.; Harvey, G.R.

    1976-01-01

    Halogenated organic compounds containing 1-3 carbon atoms are among the most extensively produced synthetic chemicals. Within this group of compounds are solvents such as chloroform, carbon tetrachloride, trichloroethane and the chlorofluoro carbons or freons which are used as refrigerants and aerosol sprays. Once produced many of these compounds are eventually released to the environment

  15. Radiation-induced volatile hydrocarbon production in platelets

    International Nuclear Information System (INIS)

    Radha, E.; Vaishnav, Y.N.; Kumar, K.S.; Weiss, J.F.

    1989-01-01

    Generation of volatile hydrocarbons (ethane, pentane) as a measure of lipid peroxidation was followed in preparations from platelet-rich plasma irradiated in vitro. The hydrocarbons in the headspace of sealed vials containing irradiated and nonirradiated washed platelets, platelet-rich plasma, or platelet-poor plasma increased with time. The major hydrocarbon, pentane, increased linearly and significantly with increasing log radiation dose, suggesting that reactive oxygen species induced by ionizing radiation result in lipid peroxidation. Measurements of lipid peroxidation products may give an indication of suboptimal quality of stored and/or irradiated platelets

  16. Modification of polyelectrolyte microcapsules into a container for the low molecular weight compounds

    Science.gov (United States)

    Goryacheva, O. A.; Gao, H.; Sukhorukov, G. B.

    2018-04-01

    Polyelectrolyte microcapsules are one of the most successful developments in the direction of target drug delivery. Nevertheless, to encapsulate low molecular weight compounds and to deliver the targeted drugs it is necessary to modify the surface of the microcapsules. Silica nanostructures obtained as result of hydrolysis of (3-Aminopropyl)- triethoxysilane (APTES) were used for the modification of the microcapsules. This material shows no toxic effect on cells and is capable of biodegradation. Amino-groups in the structure of APTES make it possible for further direct bioconjugation.

  17. Process for producing volatile hydrocarbons from hydrocarbonaceous solids

    Energy Technology Data Exchange (ETDEWEB)

    1949-02-03

    In a process for producing volatile hydrocarbons from hydrocarbonaceous solids, a hydrocarbonaceus solid is passed in subdivided state and in the form of a bed downwardly through an externally unheated distilling retort wherein the evolution of volatiles from the bed is effected while solid material comprising combustible heavy residue is discharged from the lower portion of the bed and retort, combustibles are burned from the discharged solid material. The admixture resultant combustion gases with the vapours evolved in the retort is prevented, and a stream of hydrocarbon fluid is heated by indirect heat exchange with hot combustion gases produced by burning to a high temperature and is introduced into the distilling retort and direct contact with bed, supplying heat to the latter for effecting the evolution of volatiles from the hydrocarbonaceous solid. The improvement consists of subjecting the volatile distillation products evolved and removed from the bed to a fractionation and separating selected relatively light and heavy hydrocarbon fractions from the distillation products, withdrawing at least one of the selected fractions from the prcess as a product heating at least one other of the selected fractions to high temperature by the indirect heat exchange with hot combustion gases, and introducing the thus heated hydrocarbon fraction into direct contact with the bed.

  18. Adsorption of volatile hydrocarbons in iron polysulfide chalcogels

    KAUST Repository

    Ahmed, Ejaz; Rothenberger, Alexander

    2014-01-01

    are found in micro (below 2 nm), meso (2-50 nm), and macro (above 50 nm) porous regions. These chalcogels possess optical bandgaps in the range of 1.55-2.70 eV. These aerogels have been studied for the adsorption of volatile hydrocarbons and gases. A much

  19. Analysis of sulfates on low molecular weight heparin using mass spectrometry: structural characterization of enoxaparin.

    Science.gov (United States)

    Gupta, Rohitesh; Ponnusamy, Moorthy P

    2018-05-21

    Structural characterization of Low Molecular Weight Heparin (LMWH) is critical to meet biosimilarity standards. In this context, the review focuses on structural analysis of labile sulfates attached to the side-groups of LMWH using mass spectrometry. A comprehensive review of this topic will help readers to identify key strategies for tackling the problem related to sulfate loss. At the same time, various mass spectrometry techniques are presented to facilitate compositional analysis of LMWH, mainly Enoxaparin. Areas covered: This review summarizes findings on mass spectrometry application for LMWH, including modulation of sulfates, using enzymology and sample preparation approaches. Furthermore, popular open-source software packages for automated spectral data interpretation are also discussed. Successful use of LC/MS can decipher structural composition for LMWH and help evaluate their sameness or biosimilarity with the innovator molecule. Overall, the literature has been searched using PubMed by typing various search queries such as "enoxaparin", "mass spectrometry", "low molecular weight heparin", "structural characterization", etc. Expert commentary: This section highlights clinically relevant areas that need improvement to achieve satisfactory commercialization of LMWHs. It also primarily emphasizes the advancements in instrumentation related to mass spectrometry, and discusses building automated software for data interpretation and analysis.

  20. 99m-Tc-aprotinin; a low molecular weight protein for the study of renal function

    International Nuclear Information System (INIS)

    Bianchi, C.; Donadio, C.; Tramonti, G.; Lorusso, P.; Bellitto, L.; Lunghi, F.

    1982-01-01

    Aprotinin (A), a low molecular weight polypeptide (6500 daltons), is a protease inhibitor which is electively accumulated in the kidney of animals. If labelled with Tcsup(99m), A is an excellent agent for renal imaging. Pharmacokinetics of A-Tcsup(99m) was studied in 53 renal patients with different degrees of renal impairment. In patients with normal or slightly impaired renal function the plasma cl of A-Tcsup(99m) was lower than the GFR (mean ratio plasma cl A-Tcsup(99m)/GFR = 0.68+-0.22 SD). In patients with renal failure, the plasma cl exceeded the GFR (mean ratio 3.35). The apparent distribution volume of A-Tcsup(99m) (percent of body weight) was 15.4+-2.5 SD. A-Tcsup(99m) was markedly and rapidly accumulated in the kidneys. In patients with unilateral kidney disease the accumulation curve of the affected kidney was flatter than that of the contralateral kidney. In 4 of these patients the functional difference between the two kidneys as given by renal accumulation of A-Tcsup(99m) (2 hrs after injection) was lower than that of GFR. Urinary excretion of radioactivity in the first 2 hrs after i.v. injection of A-Tcsup(99m) was negligible (2.4+-1.6 SD percent of the dose). Conclusions: Labelled aprotinin is promising for the study of renal handling of low molecular weight proteins and for the measurement of unilateral renal function. (Author)

  1. Low molecular weight chitosan conjugated with folate for siRNA delivery in vitro: optimization studies

    Science.gov (United States)

    Fernandes, Julio C; Qiu, Xingping; Winnik, Francoise M; Benderdour, Mohamed; Zhang, Xiaoling; Dai, Kerong; Shi, Qin

    2012-01-01

    The low transfection efficiency of chitosan is one of its drawbacks as a gene delivery carrier. Low molecular weight chitosan may help to form small-sized polymer-DNA or small interfering RNA (siRNA) complexes. Folate conjugation may improve gene transfection efficiency because of the promoted uptake of folate receptor-bearing cells. In the present study, chitosan was conjugated with folate and investigated for its efficacy as a delivery vector for siRNA in vitro. We demonstrate that the molecular weight of chitosan has a major influence on its biological and physicochemical properties, and very low molecular weight chitosan (below 10 kDa) has difficulty in forming stable complexes with siRNA. In this study, chitosan 25 kDa and 50 kDa completely absorbed siRNA and formed nanoparticles (≤220 nm) at a chitosan to siRNA weight ratio of 50:1. The introduction of a folate ligand onto chitosan decreased nanoparticle toxicity. Compared with chitosan-siRNA, folate-chitosan-siRNA nanoparticles improved gene silencing transfection efficiency. Therefore, folate-chitosan shows potential as a viable candidate vector for safe and efficient siRNA delivery. PMID:23209368

  2. Vitamin K antagonists or low-molecular-weight heparin for the long term treatment of symptomatic venous thromboembolism

    NARCIS (Netherlands)

    van der Heijden, J. F.; Hutten, B. A.; Büller, H. R.; Prins, M. H.

    2002-01-01

    BACKGROUND: People with venous thromboembolism are generally treated for five days with intravenous unfractionated heparin or subcutaneous low-molecular-weight heparin followed by three months of vitamin K antagonists treatment. Treatment with vitamin K antagonists requires regular laboratory

  3. Synthesis and characterization of sugar based low molecular weight gelators and the preparation of chiral sulfinamides

    Science.gov (United States)

    Mangunuru, Hari Prasad Reddy

    Low molecular weight gelators (LMWGs) have received considerable attention in the field of chemistry from last few decades. These compounds form self-assembled fibrous networks like micelles, cylindrical, sheets, fibers, layers and so on. The fibrous network entraps the solvent and forms gel, because of the self-assembly phenomenon and their demonstrated potential uses in a variety of areas, ranging from environmental to medicinal applications. Sugars are good starting materials to synthesize the new class of LMWG's, because these are different from some expensive materials, these are natural products. We have synthesized and characterized the LMGS's based on D-glucose and D-glucosamine. D-glucosamine is the versatile starting material to make different peptoids and triazoles. Several series of compounds were synthesized using compounds 1-3 as starting material and studied the gelation behavior all the compounds. We have studied the self-assembling properties of a new class of tripeptoids, synthesized by one-pot Ugi reaction from simple starting materials. Among the focused library of tripeptoids synthesized, we found that several efficient low molecular weight organogelators were obtained for aqueous DMSO and ethanol mixtures. We have also synthesized and characterized a series of monosaccharide triazole derivatives. These compounds were synthesized from N-acetyl glucosamine and D-glucose via a Cu(I) catalyzed azide/alkyne cycloaddition reaction (CuAAc). The compounds have been screened for their gelation properties and several efficient low molecular weight organo/hydro gelators were obtained, among these compounds, five per-acetyl glucosamine derivatives and one peracetyl glucose derivative were able to form gels in water. These new molecules are expected to be useful in drug delivery and tissue engineering.*. Asymmetric synthesis of chiral amines is a challenging in synthetic organic chemistry. The development of new catalysts for asymmetric organic

  4. Study of the emission of low molecular weight organic compounds of various plants

    International Nuclear Information System (INIS)

    Steinbrecher, R.; Stahl, K.; Slemr, J.; Hahn, J.

    1992-01-01

    Biogenic hydrocarbons are known to act as important precursors in tropospheric photochemical ozone formation. Large uncertainties exist about the composition of the mix of volatile organic compounds, emitted by various plant species and the respective emission rates. The emission and deposition behavior of wheat plants, as far as C 2 to C 9 hydrocarbons (NMHC), formaldehyde, and acetaldehyde are concerned, was studied both in the field (BIATEX experimental site, Manndorf, Bavaria) and in the laboratory. Vertical flux rates of the different compounds ranged from -4 to +4 nmol C m -2 surface area s -1 . Aldehydeemission showed a seasonal trend with high rates in spring and lower towards the end of the vegetation period. Ambient temperature appears to control only the flux of ethane, ethene, propane and propene, whereas acetaldehyde emission by wheat plants as well as by Norway spruce is controlled by light. Over a spruce canopy (BIATEX experimental site Schachtenau, Bayerischer Wald, national park, FRG) the 12 most abundant NMHC exhibited no distinct diurnal cycle, and only small differences in mixing ratios were detected between two heights (31 and 51 m) revealing that the impact of the canopy on the abundances of the non-terpenoid NMHCs present in the air above the canopy was small. Aldehyde mixing ratios above a spruce canopy, however, may significantly be influenced either by direct emission of aldehydes from spruce or by production of aldehydes during photochemical degradation of precursors. (orig.). 87 refs., 4 tabs., 25 figs [de

  5. ADME-Tox profiling of some low molecular weight water soluble chitosan derivatives

    Directory of Open Access Journals (Sweden)

    Adriana Isvoran

    2017-09-01

    Full Text Available Within this study we use a few computational tools for predicting absorption, distribution, metabolism, excretion and toxicity (ADME-Tox, pharmacokinetics profiles, toxic/adverse effects, carcinogenicity, cardiotoxicity and endocrine disruption of some of low molecular weight water soluble derivatives of chitosan that are used in wound healing. Investigated compounds do not possess drug-like properties, their pharmacokinetics profiles reveal poor gastrointestinal absorption and low skin penetration. Chitosan derivatives cannot pass the blood-brain barrier and they are not able to inhibit the enzymes of the cytochrome P450 that are involved in the metabolism of xenobiotics. They do not reflect carcinogenicity and cardiotoxicity and reveal only a low probability to be endocrine disruptors. The main side effects in humans of the investigated compounds are: weight loss, acidosis, gastrointestinal toxicity, respiratory failure. This information is especially important for professional exposure and accidental contamination with these compounds.

  6. Participation of Low Molecular Weight Electron Carriers in Oxidative Protein Folding

    Directory of Open Access Journals (Sweden)

    József Mandl

    2009-03-01

    Full Text Available Oxidative protein folding is mediated by a proteinaceous electron relay system, in which the concerted action of protein disulfide isomerase and Ero1 delivers the electrons from thiol groups to the final acceptor. Oxygen appears to be the final oxidant in aerobic living organisms, although the existence of alternative electron acceptors, e.g. fumarate or nitrate, cannot be excluded. Whilst the protein components of the system are well-known, less attention has been turned to the role of low molecular weight electron carriers in the process. The function of ascorbate, tocopherol and vitamin K has been raised recently. In vitro and in vivo evidence suggests that these redox-active compounds can contribute to the functioning of oxidative folding. This review focuses on the participation of small molecular weight redox compounds in oxidative protein folding.

  7. Low molecular weight polylactic acid as a matrix for the delayed release of pesticides.

    Science.gov (United States)

    Zhao, Jing; Wilkins, Richard M

    2005-05-18

    Low molecular weight polylactic acid (LMW PLA) was used as a matrix to formulate biodegradable matrix granules and films with bromacil using a melt process. The compatibility of the PLA with bromacil was evaluated. The release characteristics of the formulations were investigated in vitro. The degradation and erosion of the formulations were monitored by pH and gravimetric analysis during the course of release. Various granules and films had similar biphasic release patterns, a delayed release followed by an explosive release. The release rates were independent of bromacil content in the matrix, but varied with the geometry of matrices. The mechanisms of diffusion and erosion were involved in the release. The delayed release of the formulations was dominantly governed by the degradation and erosion of PLA. LMW PLA underwent bulk erosion. LMW PLA-based matrix formulations could thus be useful for the application of pesticides to sensitive targets such as seed treatment.

  8. Low molecular weight heparins in the prevention of deep-vein thrombosis in general surgery.

    Science.gov (United States)

    Breddin, H K

    1999-01-01

    Unfractionated heparin (UFH) was the established treatment in the early 1980s for the prophylaxis of venous thromboembolic disease (VTED) in patients undergoing general surgery. This was one of the earliest indications in which low molecular weight heparins (LMWHs) were tested, and about 40 trials have revealed that these agents are at least as effective and safe as UFH with a tendency of superiority when higher dosages are used. In most trials, the fibrinogen uptake test has been used to assess the frequency of deep vein thrombosis. LMWHs exhibit a number of improved features over UFH, including ease of administration and convenient once daily dosing, facilitating outpatient management. A still open question is the ideal time and dose of the first one or two injections of a LMWH. To determine the clinical relevance of product differentiation further, clinical trials, directly comparing different LMWHs, are required.

  9. Antioxidation activities of low-molecular-weight gelatin hydrolysate isolated from the sea cucumber Stichopus japonicus

    Science.gov (United States)

    Wang, Jingfeng; Wang, Yuming; Tang, Qingjuan; Wang, Yi; Chang, Yaoguang; Zhao, Qin; Xue, Changhu

    2010-03-01

    Gelatin extracted from the body wall of the sea cucumber ( Stichopus japonicus) was hydrolyzed with flavourzyme. Low-molecular-weight gelatin hydrolysate (LMW-GH) of 700-1700 Da was produced using an ultrafiltration membrane bioreactor system. Chemiluminescence analysis revealed that LMW-GH scavenges high free radicals in a concentration-dependent manner; IC50 value for superoxide and hydroxyl radicals was 442 and 285 μg mL-1, respectively. LMW-GH exhibited excellent inhibitory characteristics against melanin synthesis and tyrosinase activity in B16 cells. Furthermore, LMW-GH notably increased intracellular glutathione (GSH), which in turn suppressed melanogenesis. LMW-GH performs antioxidation activity, holding the potential of being used as a valuable ingredient in function foods, cosmetics and pharmaceuticals or nutriceuticals.

  10. Developing a Macroscopic Mechanistic Model for Low Molecular Weight Diffusion through Polymers in the Rubbery State

    DEFF Research Database (Denmark)

    Martinez-Lopez, Brais; Huguet, P.; Gontard, N.

    2016-01-01

    Raman microspectroscopy was used to determine the Fickian diffusivity of two families of low molecular weight molecules through amorphous polystyrene in the rubbery state. Different effects of the temperature on diffusivity for each of the families suggested that molecular mobility is controlled...... by both the volume and flexibility of the diffusing substance when the movement of polymer chains can generate stress induced deformation of molecules. The diffusing molecules were represented as Newtonian spring–bead systems, which allowed us to quantify their flexibility, in function of the vibration...... frequency of their bonds by reconstructing their theoretical spectra. Results showed that the use of molecular descriptors that take into account flexibility rather than the most stable conformation of the diffusing molecules may improve the description of the diffusion behavior caused by variations...

  11. Toxicological Evaluation of Low Molecular Weight Fucoidan in Vitro and in Vivo

    Directory of Open Access Journals (Sweden)

    Pai-An Hwang

    2016-06-01

    Full Text Available For a long time, fucoidan has been well known for its pharmacological activities, and recently low molecular weight fucoidan (LMF has been used in food supplements and pharmaceutical products. In the present study, LMF was extracted from Laminaria japonica by enzyme hydrolysis. The toxicity of LMF in mouse and rat models was determined by many methods, such as total arsenic content, bacterial reverse mutation assay, chromosome aberration assay, and in vivo micronucleus assay. The present findings showed that LMF at 5000 μg/mL exhibited no mutagenicity. It also produced no formatting disruption of red blood cells in vivo. At 2000 mg/kg BW/day there were no toxicological indications. LMF is expected to be used as a safe food supplement.

  12. Reversible Masking Using Low-Molecular-Weight Neutral Lipids to Achieve Optimal-Targeted Delivery

    Directory of Open Access Journals (Sweden)

    Nancy Smyth Templeton

    2012-01-01

    Full Text Available Intravenous injection of therapeutics is required to effectively treat or cure metastatic cancer, certain cardiovascular diseases, and other acquired or inherited diseases. Using this route of delivery allows potential uptake in all disease targets that are accessed by the bloodstream. However, normal tissues and organs also have the potential for uptake of therapeutic agents. Therefore, investigators have used targeted delivery to attempt delivery solely to the target cells; however, use of ligands on the surface of delivery vehicles to target specific cell surface receptors is not sufficient to avoid nonspecific uptake. PEGylation has been used for decades to try to avoid nonspecific uptake but suffers from many problems known as “The PEGylation Dilemma.” We have solved this dilemma by replacing PEGylation with reversible masking using low-molecular-weight neutral lipids in order to achieve optimal-targeted delivery solely to target cells. Our paper will focus on this topic.

  13. Determination of free inositols and other low molecular weight carbohydrates in vegetables.

    Science.gov (United States)

    Hernández-Hernández, Oswaldo; Ruiz-Aceituno, Laura; Sanz, María Luz; Martínez-Castro, Isabel

    2011-03-23

    Different low molecular weight carbohydrates including saccharides, polyalcohols, sugar acids, and glycosides have been identified and quantified in different edible vegetables from Asteraceae, Amarantaceae, Amarylidaceae, Brassicaceae, Dioscoreaceae, and Solanaceae families by gas chromatography-mass spectrometry. Apart from glucose, fructose, and sucrose, other saccharides such as sedoheptulose in chicory, spinach, cabbage, purple yam, eggplant, radish, and oak leaf lettuce, rutinose in eggplant skin, and a glycosyl-inositol in spinach have been identified. chiro-Inositol was found in all vegetables of the Asteraceae family (3.1-32.6 mg 100 g(-1)), whereas scyllo-inositol was detected in those of purple yam, eggplant, artichoke, chicory, escarole, and endive (traces-23.2 mg 100 g(-1)). α-Galactosides, kestose, glucaric acid, and glycosyl-glycerols were also identified and quantified in some of the analyzed vegetables. Considering the bioactivity of most of these compounds, mainly chicory leaves, artichokes, lettuces, and purple yam could constitute beneficial sources for human health.

  14. Prolonged thromboprophylaxis with low molecular weight heparin for abdominal or pelvic surgery

    DEFF Research Database (Denmark)

    Rasmussen, Morten Schnack; Jørgensen, Lars Nannestad; Wille-Jørgensen, Peer

    2009-01-01

    BACKGROUND: Major abdominal and pelvic surgery carries a high risk of venous thromboembolism (VTE). The efficacy of thromboprophylaxis with low-molecular weight heparin (LMWH) administered during the in-hospital period is well documented, but the optimal duration of thromboprophylaxis after surgery...... evaluating prolonged thromboprophylaxis with LMWH as compared to control or placebo. 133 studies were found in the searches, of which only 4 were found eligible for inclusion, and 129 were excluded. The incidence of overall VTE after major abdominal or pelvic surgery was 14.3% (95% confidence interval 11...... significant reduction of even the incidence of symptomatic VTE from 1.7% (95% CI 0.8% - 3.4%) in the control group to 0.2 % (95% CI 0.0% - 1.2%) in patients receiving prolonged thromboprophylaxis, Peto Odds ratio 0.22 (95% CI 0.06 -0.80), P = 0.02. The respective incidence of bleeding in the control and LMWH...

  15. Spontaneous Hemocholecyst in an End-Stage Renal Failure Patient on Low Molecular Weight Heparin Hemodialysis

    Directory of Open Access Journals (Sweden)

    Konstantinos Blouhos

    2012-01-01

    Full Text Available The present paper describes a case of spontaneous hemocholecyst in a patient with end-stage renal failure on low molecular weight heparin hemodialysis. The patient presented with acute right upper quadrant pain. An initial ultrasound scan demonstrated a distended gallbladder containing echogenic bile without stones. During hospitalization the patient became febrile, and jaundiced, developed leukocytosis, and had an elevation in serum bilirubin, transaminases, and alkaline phosphatase. A new ultrasound demonstrated a thick-walled gallbladder containing echogenic bile and pericholecystic fluid. MRI depicted a distended gallbladder containing material of mixed signal intensity and a normal biliary tract. Open cholecystectomy revealed a gallbladder filled with blood and clots, and transcystic common bile duct exploration flushed blood clots out of the bile duct. To our knowledge this is the second case of spontaneous hemocholecyst reported in the literature as a consequence of uremic bleeding and LMWH hemodialysis in the absence of other pathology.

  16. Effect of soil sieving on respiration induced by low-molecular-weight substrates

    Science.gov (United States)

    Datta, Rahul; Vranová, Valerie; Pavelka, Marian; Rejšek, Klement; Formánek, Pavel

    2014-03-01

    The mesh size of sieves has a significant impact upon soil disturbance, affecting pore structure, fungal hyphae, proportion of fungi to bacteria, and organic matter fractions. The effects are dependent upon soil type and plant coverage. Sieving through a 2 mm mesh increases mineralization of exogenously supplied carbohydrates and phenolics compared to a 5 mm mesh and the effect is significant (p<0.05), especially in organic horizons, due to increased microbial metabolism and alteration of other soil properties. Finer mesh size particularly increases arabinose, mannose, galactose, ferulic and pthalic acid metabolism, whereas maltose mineralization is less affected. Sieving through a 5 mm mesh size is suggested for all type of experiments where enhanced mineralization of low-molecular-weight organic compounds needs to be minimalized.

  17. Low Molecular Weight Norbornadiene Derivatives for Molecular Solar-Thermal Energy Storage.

    Science.gov (United States)

    Quant, Maria; Lennartson, Anders; Dreos, Ambra; Kuisma, Mikael; Erhart, Paul; Börjesson, Karl; Moth-Poulsen, Kasper

    2016-09-05

    Molecular solar-thermal energy storage systems are based on molecular switches that reversibly convert solar energy into chemical energy. Herein, we report the synthesis, characterization, and computational evaluation of a series of low molecular weight (193-260 g mol(-1) ) norbornadiene-quadricyclane systems. The molecules feature cyano acceptor and ethynyl-substituted aromatic donor groups, leading to a good match with solar irradiation, quantitative photo-thermal conversion between the norbornadiene and quadricyclane, as well as high energy storage densities (396-629 kJ kg(-1) ). The spectroscopic properties and energy storage capability have been further evaluated through density functional theory calculations, which indicate that the ethynyl moiety plays a critical role in obtaining the high oscillator strengths seen for these molecules. © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  18. Low Molecular Weight Chitosan–Insulin Polyelectrolyte Complex: Characterization and Stability Studies

    Directory of Open Access Journals (Sweden)

    Zakieh I. Al-Kurdi

    2015-03-01

    Full Text Available The aim of the work reported herein was to investigate the effect of various low molecular weight chitosans (LMWCs on the stability of insulin using USP HPLC methods. Insulin was found to be stable in a polyelectrolyte complex (PEC consisting of insulin and LMWC in the presence of a Tris-buffer at pH 6.5. In the presence of LMWC, the stability of insulin increased with decreasing molecular weight of LMWC; 13 kDa LMWC was the most efficient molecular weight for enhancing the physical and chemical stability of insulin. Solubilization of insulin-LMWC polyelectrolyte complex (I-LMWC PEC in a reverse micelle (RM system, administered to diabetic rats, results in an oral delivery system for insulin with acceptable bioactivity.

  19. Electrophoretic variation in low molecular weight lens crystallins from inbred strains of rats.

    Science.gov (United States)

    Donner, M E; Skow, L C; Kunz, H W; Gill, T J

    1985-10-01

    Analysis of rat lens soluble proteins by analytical isoelectric focusing detected two inherited electrophoretic differences in low molecular weight (LM) crystallins from inbred strains of rats (Rattus norvegicus). The polymorphic lens crystallins were shown to be similar to a genetically variant LM crystallin, LEN-1, previously described in mice (Mus musculus) and encoded on chromosome 1, at a locus linked to Pep-3 (dipeptidase). Linkage analysis demonstrated that the rat crystallin locus was loosely linked to Pep-3 at a recombination distance of 38 +/- 4.5 U. These data suggest the conservation of a large chromosomal region during the evolution of Rodentia and support the hypothesis that the gamma-crystallins are evolving more rapidly than alpha- or beta-crystallins.

  20. Calibration of low molecular weight polypeptides by sodium dodecylsulphate polyacrylamide gel electrophoresis

    International Nuclear Information System (INIS)

    Glyn, M.C.P.; Bull, J.; Wright, R.

    1982-01-01

    Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) is a technique commonly used in determining molecular weights of large proteins and peptides. This technique is used to analyse viral peptides, available in amounts too small to be monitored by an ultraviolet spectrophotometer. An experiment is described (with the limiting factor to use the SDS-PAGE technique), to determine the molecular weight peptides and the results are given to fit the linear relationship log M=4.286 - 0.42 V(e)/V(o). The results given by the SDS-PAGE system, described in the article, show that the experimental values describe a linear relationship with good resolution of low molecular weight peptides in the range 3 000 to 14 000 and that a partial cyanogen bromide digest of cytochrome c is suitable for calibration standards

  1. Calcium binding to low molecular weight compounds and health promoting products

    DEFF Research Database (Denmark)

    Vavrusova, Martina

    absorption. Therefore, calcium as an essential nutrient should not be underestimated in our diet. Milk and dairy products are good sources of bioavailable calcium due to specific protein binding. Other sources of calcium, apart from a balanced and healthy diet, are calcium supplements and calcium fortified...... food. Therefore, an understanding of the basic chemistry of calcium binding to low molecular weight compounds can contribute to a general knowledge about calcium bioavailability and also to product improvement. Calcium precipitation with palmitate was described by a first-order reaction for conditions...... of excess calcium in neutral aqueous solutions with a stoichiometry Ca:Pal lower than 1:2. Increasing pH during aging of the precipitate and solubility product determination lead to a suggestion of an initial precipitation of calcium hydroxy palmitate as a possible precursor phase. The binding of calcium...

  2. Characterization of Low-Molecular-Weight Heparins by Strong Anion-Exchange Chromatography.

    Science.gov (United States)

    Sadowski, Radosław; Gadzała-Kopciuch, Renata; Kowalkowski, Tomasz; Widomski, Paweł; Jujeczka, Ludwik; Buszewski, Bogusław

    2017-11-01

    Currently, detailed structural characterization of low-molecular-weight heparin (LMWH) products is an analytical subject of great interest. In this work, we carried out a comprehensive structural analysis of LMWHs and applied a modified pharmacopeial method, as well as methods developed by other researchers, to the analysis of novel biosimilar LMWH products; and, for the first time, compared the qualitative and quantitative composition of commercially available drugs (enoxaparin, nadroparin, and dalteparin). For this purpose, we used strong anion-exchange (SAX) chromatography with spectrophotometric detection because this method is more helpful, easier, and faster than other separation techniques for the detailed disaccharide analysis of new LMWH drugs. In addition, we subjected the obtained results to statistical analysis (factor analysis, t-test, and Newman-Keuls post hoc test).

  3. Low-molecular-weight cyclin E: the missing link between biology and clinical outcome

    International Nuclear Information System (INIS)

    Akli, Said; Keyomarsi, Khandan

    2004-01-01

    Cyclin E, a key mediator of transition during the G 1 /S cellular division phase, is deregulated in a wide variety of human cancers. Our group recently reported that overexpression and generation of low-molecular-weight (LMW) isoforms of cyclin E were associated with poor clinical outcome among breast cancer patients. However, the link between LMW cyclin E biology in mediating a tumorigenic phenotype and clinical outcome is unknown. To address this gap in knowledge, we assessed the role of LMW isoforms in breast cancer cells; we found that these forms of cyclin E induced genomic instability and resistance to p21, p27, and antiestrogens in breast cancer. These findings suggest that high levels of LMW isoforms of cyclin E not only can predict failure to endocrine therapy but also are true prognostic indicators because of their influence on cell proliferation and genetic instability

  4. Isolation of low-molecular-weight lead-binding protein from human erythrocytes

    International Nuclear Information System (INIS)

    Raghavan, S.R.V.; Gonick, H.C.

    1977-01-01

    In blood, lead is mainly associated with erythrocytes and only a very small amount is found in plasma. Previously it was thought that the lead was bound to the erythrocyte cell membrane but more recently it has been observed that lead is bound primarily to the cell contents, ostensibly hemoglobin. In examining the lead-binding properties of normal human erythrocytes and those of lead-exposed industrial workers, we have found that, whereas lead binds only to hemoglobin in normal erythrocytes, there is also appreciable binding of lead to a low-molecular weight-protein in erythrocytes from lead-exposed workers. The synthesis of this protein may be induced by lead exposure. The 10,000 molecular weight protein may act as a storage site and mechanism for segregating lead in a non-toxic form

  5. Impact of Low Molecular Weight Poly(3-hexylthiophene)s as Additives in Organic Photovoltaic Devices.

    Science.gov (United States)

    Seibers, Zach D; Le, Thinh P; Lee, Youngmin; Gomez, Enrique D; Kilbey, S Michael

    2018-01-24

    Despite tremendous progress in using additives to enhance the power conversion efficiency of organic photovoltaic devices, significant challenges remain in controlling the microstructure of the active layer, such as at internal donor-acceptor interfaces. Here, we demonstrate that the addition of low molecular weight poly(3-hexylthiophene)s (low-MW P3HT) to the P3HT/fullerene active layer increases device performance up to 36% over an unmodified control device. Low MW P3HT chains ranging in size from 1.6 to 8.0 kg/mol are blended with 77.5 kg/mol P3HT chains and [6,6]-phenyl C 61 butyric acid methyl ester (PCBM) fullerenes while keeping P3HT/PCBM ratio constant. Optimal photovoltaic device performance increases are obtained for each additive when incorporated into the bulk heterojunction blend at loading levels that are dependent upon additive MW. Small-angle X-ray scattering and energy-filtered transmission electron microscopy imaging reveal that domain sizes are approximately invariant at low loading levels of the low-MW P3HT additive, and wide-angle X-ray scattering suggests that P3HT crystallinity is unaffected by these additives. These results suggest that oligomeric P3HTs compatibilize donor-acceptor interfaces at low loading levels but coarsen domain structures at higher loading levels and they are consistent with recent simulations results. Although results are specific to the P3HT/PCBM system, the notion that low molecular weight additives can enhance photovoltaic device performance generally provides a new opportunity for improving device performance and operating lifetimes.

  6. The association of low-molecular-weight hydrophobic compounds with native casein micelles in bovine milk.

    Science.gov (United States)

    Cheema, M; Mohan, M S; Campagna, S R; Jurat-Fuentes, J L; Harte, F M

    2015-08-01

    The agreed biological function of the casein micelles in milk is to carry minerals (calcium, magnesium, and phosphorus) from mother to young along with amino acids for growth and development. Recently, native and modified casein micelles were used as encapsulating and delivery agents for various hydrophobic low-molecular-weight probes. The ability of modified casein micelles to bind certain probes may derive from the binding affinity of native casein micelles. Hence, a study with milk from single cows was conducted to further elucidate the association of hydrophobic molecules into native casein micelles and further understand their biological function. Hydrophobic and hydrophilic extraction followed by ultraperformance liquid chromatography-high resolution mass spectrometry analysis were performed over protein fractions obtained from size exclusion fractionation of raw skim milk. Hydrophobic compounds, including phosphatidylcholine, lyso-phosphatidylcholine, phosphatidylethanolamine, and sphingomyelin, showed strong association exclusively to casein micelles as compared with whey proteins, whereas hydrophilic compounds did not display any preference for their association among milk proteins. Further analysis using liquid chromatography-tandem mass spectrometry detected 42 compounds associated solely with the casein-micelles fraction. Mass fragments in tandem mass spectrometry identified 4 of these compounds as phosphatidylcholine with fatty acid composition of 16:0/18:1, 14:0/16:0, 16:0/16:0, and 18:1/18:0. These results support that transporting low-molecular-weight hydrophobic molecules is also a biological function of the casein micelles in milk. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  7. Measurement of low molecular weight silicon AMC to protect UV optics in photo-lithography environments

    Science.gov (United States)

    Lobert, Jürgen M.; Miller, Charles M.; Grayfer, Anatoly; Tivin, Anne M.

    2009-03-01

    A new analytical method for semiconductor-specific applications is presented for the accurate measurement of low molecular weight, silicon-containing, organic compounds TMS, HMDSO and D3. Low molecular weight / low boiling point silicon-containing compounds are not captured for extended periods of time by traditional chemical filters but have the same potential to degrade exposure tool optical surfaces as their high molecular weight counterparts. Likewise, we show that capturing these compounds on sample traps that are commonly used for organic AMC analysis does not work for various reasons. Using the analytical method described here, TMS, HMDSO and D3 can be measured artifact-free, with at least a 50:1 peak-to-noise ratio at the method detection limit, determined through the Hubaux-Vos method and satisfying a conservative 99% statistical confidence. Method detection limits for the compounds are 1-6 ppt in air. We present calibration curve, capacity, capture efficiency, break-through and repeatability data to demonstrate robustness of method. Seventy-one real-world samples from 26 projects taken in several fab environments show that TMS is found in concentrations 100 times higher than those of HMDSO and D3. All compounds are found in all environments in concentrations ranging from zero to 12 ppm, but most concentrations were below 50 ppb. All compounds are noticeably higher in litho-bays than in sub-fabs and we found all three compounds inside of two exposure tools, suggesting cleanroom and/or tool-internal contamination sources.

  8. Low-molecular weight heparin increases circulating sFlt-1 levels and enhances urinary elimination.

    Directory of Open Access Journals (Sweden)

    Henning Hagmann

    Full Text Available RATIONALE: Preeclampsia is a devastating medical complication of pregnancy which leads to maternal and fetal morbidity and mortality. While the etiology of preeclampsia is unclear, human and animal studies suggest that excessive circulating levels of soluble fms-like tyrosine-kinase-1 (sFlt-1, an alternatively spliced variant of VEGF-receptor1, contribute to the signs and symptoms of preeclampsia. Since sFlt-1 binds to heparin and heparan sulfate proteoglycans, we hypothesized that the anticoagulant heparin, which is often used in pregnancy, may interfere with the levels, distribution and elimination of sFlt-1 in vivo. OBJECTIVE: We systematically determined serum and urine levels of angiogenic factors in preeclamptic women before and after administration of low molecular weight heparin and further characterized the interaction with heparin in biochemical studies. METHODS AND RESULTS: Serum and urine samples were used to measure sFlt-1 levels before and after heparin administration. Serum levels of sFlt-1 increased by 25% after heparin administration in pregnant women. The magnitude of the increase in circulating sFlt-1 correlated with initial sFlt-1 serum levels. Urinary sFlt-1 levels were also elevated following heparin administration and levels of elimination were dependent on the underlying integrity of the glomerular filtration barrier. Biochemical binding studies employing cation exchange chromatography revealed that heparin bound sFlt-1 had decreased affinity to negatively charged surfaces when compared to sFlt-1 alone. CONCLUSION: Low molecular weight heparin administration increased circulating sFlt1 levels and enhanced renal elimination. We provide evidence that both effects may be due to heparin binding to sFlt1 and masking the positive charges on sFlt1 protein.

  9. Effects of low molecular weight organic acids on 137Cs release from contaminated soils

    International Nuclear Information System (INIS)

    Chiang, Po Neng; Wang, Ming Kuang; Huang, Pan Ming; Wang, Jeng Jong

    2011-01-01

    Radio pollutant removal is one of several priority restoration strategies for the environment. This study assessed the effect of low molecular weight organic acid on the lability and mechanisms for release of 137 Cs from contaminated soils. The amount of 137 Cs radioactivity released from contaminated soils reacting with 0.02 M low molecular weight organic acids (LMWOAs) specifically acetic, succinic, oxalic, tartaric, and citric acid over 48 h were 265, 370, 760, 850, and 1002 Bq kg -1 , respectively. The kinetic results indicate that 137 Cs exhibits a two-step parabolic diffusion equation and a good linear relationship, indicating that the parabolic diffusion equation describes the data quite well, as shown by low p and high r 2 values. The fast stage, which was found to occur within a short period of time (0.083-3 h), corresponds to the interaction of LMWOAs with the surface of clay minerals; meanwhile, during the slow stage, which occurs over a much longer time period (3-24 h), desorption primarily is attributed to inter-particle or intra-particle diffusion. After a fifth renewal of the LMWOAs, the total levels of 137 Cs radioactivity released by acetic, succinic, oxalic, tartaric, and citric acid were equivalent to 390, 520, 3949, 2061, and 4422 Bq kg -1 soil, respectively. H + can protonate the hydroxyl groups and oxygen atoms at the broken edges or surfaces of the minerals, thereby weakening Fe-O and Al-O bonds. After protonation of H + , organic ligands can attack the OH and OH 2 groups in the minerals easily, to form complexes with surface structure cations, such as Al and Fe. The amounts of 137 Cs released from contaminated soil treated with LMWOAs were substantially increased, indicating that the LMWOAs excreted by the roots of plants play a critical role in 137 Cs release.

  10. Holographic detection of hydrocarbon gases and other volatile organic compounds.

    Science.gov (United States)

    Martínez-Hurtado, J L; Davidson, C A B; Blyth, J; Lowe, C R

    2010-10-05

    There is a need to develop sensors for real-time monitoring of volatile organic compounds (VOCs) and hydrocarbon gases in both external and indoor environments, since these compounds are of growing concern in human health and welfare. Current measurement technology for VOCs requires sophisticated equipment and lacks the prospect for rapid real-time monitoring. Holographic sensors can give a direct reading of the analyte concentration as a color change. We report a technique for recording holographic sensors by laser ablation of silver particles formed in situ by diffusion. This technique allows a readily available hydrophobic silicone elastomer to be transformed into an effective sensor for hydrocarbon gases and other volatile compounds. The intermolecular interactions present between the polymer and molecules are used to predict the sensor performance. The hydrophobicity of this material allows the sensor to operate without interference from water and other atmospheric gases and thus makes the sensor suitable for biomedical, industrial, or environmental analysis.

  11. Natural elimination of volatile halogenated hydrocarbons from the environment

    Energy Technology Data Exchange (ETDEWEB)

    Harress, H.M.; Grathwohl, P.; Torunski, H.

    1987-01-01

    Recently carried out field investigations of groundwater contaminations with volatile halogenated hydrocarbons have shown evidence of natural elimination of these hazardous substances. This elimination effects is rare and observed in connection with special geological conditions. With regard to some contaminated sites, the following mechanisms for this behaviour are discussed: 1. Stripping by naturally ascending gases. 2. Sorption on soil organic matter. 3. Biodegradation. The so far compiled knowledge allowed to develop further research programmes, which are pursued in various projects.

  12. Practical Application of Aptamer-Based Biosensors in Detection of Low Molecular Weight Pollutants in Water Sources

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2018-02-01

    Full Text Available Water pollution has become one of the leading causes of human health problems. Low molecular weight pollutants, even at trace concentrations in water sources, have aroused global attention due to their toxicity after long-time exposure. There is an increased demand for appropriate methods to detect these pollutants in aquatic systems. Aptamers, single-stranded DNA or RNA, have high affinity and specificity to each of their target molecule, similar to antigen-antibody interaction. Aptamers can be selected using a method called Systematic Evolution of Ligands by EXponential enrichment (SELEX. Recent years we have witnessed great progress in developing aptamer selection and aptamer-based sensors for low molecular weight pollutants in water sources, such as tap water, seawater, lake water, river water, as well as wastewater and its effluents. This review provides an overview of aptamer-based methods as a novel approach for detecting low molecular weight pollutants in water sources.

  13. Surface engineering on mesoporous silica chips for enriching low molecular weight phosphorylated proteins

    Science.gov (United States)

    Hu, Ye; Peng, Yang; Lin, Kevin; Shen, Haifa; Brousseau, Louis C., III; Sakamoto, Jason; Sun, Tong; Ferrari, Mauro

    2011-02-01

    Phosphorylated peptides and proteins play an important role in normal cellular activities, e.g., gene expression, mitosis, differentiation, proliferation, and apoptosis, as well as tumor initiation, progression and metastasis. However, technical hurdles hinder the use of common fractionation methods to capture phosphopeptides from complex biological fluids such as human sera. Herein, we present the development of a dual strategy material that offers enhanced capture of low molecular weight phosphoproteins: mesoporous silica thin films with precisely engineered pore sizes that sterically select for molecular size combined with chemically selective surface modifications (i.e. Ga3+, Ti4+ and Zr4+) that target phosphoroproteins. These materials provide high reproducibility (CV = 18%) and increase the stability of the captured proteins by excluding degrading enzymes, such as trypsin. The chemical and physical properties of the composite mesoporous thin films were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy and ellipsometry. Using mass spectroscopy and biostatistics analysis, the enrichment efficiency of different metal ions immobilized on mesoporous silica chips was investigated. The novel technology reported provides a platform capable of efficiently profiling the serum proteome for biomarker discovery, forensic sampling, and routine diagnostic applications.Phosphorylated peptides and proteins play an important role in normal cellular activities, e.g., gene expression, mitosis, differentiation, proliferation, and apoptosis, as well as tumor initiation, progression and metastasis. However, technical hurdles hinder the use of common fractionation methods to capture phosphopeptides from complex biological fluids such as human sera. Herein, we present the development of a dual strategy material that offers enhanced capture of low molecular weight phosphoproteins: mesoporous

  14. Release of low molecular weight silicones and platinum from silicone breast implants.

    Science.gov (United States)

    Lykissa, E D; Kala, S V; Hurley, J B; Lebovitz, R M

    1997-12-01

    We have conducted a series of studies addressing the chemical composition of silicone gels from breast implants as well as the diffusion of low molecular weight silicones (LM-silicones) and heavy metals from intact implants into various surrounding media, namely, lipid-rich medium (soy oil), aqueous tissue culture medium (modified Dulbecco's medium, DMEM), or an emulsion consisting of DMEM plus 10% soy oil. LM-silicones in both implants and surrounding media were detected and quantitated using gas chromatography (GC) coupled with atomic emission (GC-AED) as well as mass spectrometric (GC/MS) detectors, which can detect silicones in the nanogram range. Platinum, a catalyst used in the preparation of silicone gels, was detected and quantitated using inductive argon-coupled plasma/mass spectrometry (ICP-MS), which can detect platinum in the parts per trillion range. Our results indicate that GC-detectable low molecular weight silicones contribute approximately 1-2% to the total gel mass and consist predominantly of cyclic and linear poly-(dimethylsiloxanes) ranging from 3 to 20 siloxane [(CH3)2-Si-O] units (molecular weight 200-1500). Platinum can be detected in implant gels at levels of approximately 700 micrograms/kg by ICP-MS. The major component of implant gels appears to be high molecular weight silicone polymers (HM-silicones) too large to be detected by GC. However, these HM-silicones can be converted almost quantitatively (80% by mass) to LM-silicones by heating implant gels at 150-180 degrees C for several hours. We also studied the rates at which LM-silicones and platinum leak through the intact implant outer shell into the surrounding media under a variety of conditions. Leakage of silicones was greatest when the surrounding medium was lipid-rich, and up to 10 mg/day LM-silicones was observed to diffuse into a lipid-rich medium per 250 g of implant at 37 degrees C. This rate of leakage was maintained over a 7-day experimental period. Similarly, platinum was

  15. Low molecular weight heparin for prevention of venous thromboembolism in patients with lower-leg immobilization.

    Science.gov (United States)

    Testroote, Mark; Stigter, Willem A H; Janssen, Loes; Janzing, Heinrich M J

    2014-04-25

    Immobilization of the lower leg is associated with venous thromboembolism (VTE). Low molecular weight heparin (LMWH) is an anticoagulant treatment which might be used in adult patients with lower-leg immobilization to prevent deep venous thrombosis (DVT) and its complications. This is an update of the review first published in 2008. To assess the effectiveness of low molecular weight heparin for the prevention of venous thromboembolism in patients with lower-leg immobilization in an ambulant setting. For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched June 2013) and CENTRAL (2013, Issue 5). Randomized controlled trials (RCTs) and controlled clinical trials (CCTs) that described thromboprophylaxis by means of LMWH compared with no prophylaxis or placebo in adult patients with lower-leg immobilization. Immobilization was by means of a plaster cast or brace. Two authors independently assessed trial quality and extracted data. The review authors contacted the trial authors for additional information if required. Statistical analysis was carried out using Review Manager (RevMan 5). We included six RCTs fulfilling the above criteria with a total of 1490 patients. We found an incidence of VTE ranging from 4.3% to 40% in patients who had a leg injury that had been immobilized in a plaster cast or a brace for at least one week and who received no prophylaxis, or placebo. This number was significantly lower in patients who received daily subcutaneous injections of LMWH during immobilization (event rates ranging from 0% to 37%; odds ratio (OR) 0.49; fixed 95% confidence interval (CI) 0.34 to 0.72; with minimal evidence of heterogeneity with an I(2) of 20%, P = 0. 29). Comparable results were seen in the following subcategories: operated patients, conservatively treated patients, patients with fractures, patients with soft-tissue injuries, patients with proximal thrombosis, patients with

  16. Partial characterization of a low molecular weight human collagen that undergoes alternative splicing

    International Nuclear Information System (INIS)

    Pihlajaniemi, T.; Myllylea, R.; Kurkinen, M.; Prockop, D.J.

    1987-01-01

    A cDNA library prepared from RNA isolated from a cultured human tumor cell line, HT-1080, was screened with a mouse cDNA clone coding for part of the -Gly-Xaa-Yaa-domain of the α2(IV) collagen chain. Four overlapping cDNA clones were characterized that coded for a low molecular weight human collagen. The cDNA clones did not, however, code for the short-chain collagens, types IX and X. The amino acid sequences derived from the clones resembled type IV collagen in that there were short interruptions in the repeating -Gly-Xaa-Yaa-sequence. The noncollagenous, carboxyl-terminal domain was, however, much shorter and contained only 18 amino acid residues. Interestingly, one of the cDNA clones contained an additional 36 nucleotides not found in an overlapping clone. The 36 nucleotides encoded four -Gly-Xaa-Yaa-repeats without changing the reading frame. Nuclease S1 mapping using a 32 P-labelled probe demonstrated that the different between the clones was due to existence of two different mRNAs. A synthetic 24-residue peptide corresponding to the last two -Gly-Xaa-Yaa-triplets and the entire carboxyl-terminal domain was used to generate polyclonal antibodies. Electrophoretic transfer blot analysis of HT-1080 cells and normal human skin fibroblasts identified two polypeptides, M/sub r/ 67,000 and M/sub r/ 62,000, that were sensitive to bacterial collagenase

  17. Peptide and low molecular weight proteins based kidney targeted drug delivery systems.

    Science.gov (United States)

    Xu, Pengfei; Zhang, Hailiang; Dang, Ruili; Jiang, Pei

    2018-05-30

    Renal disease is a worldwide public health problem, and unfortunately, the therapeutic index of regular drugs is limited. Thus, it is a great need to develop effective treatment strategies. Among the reported strategies, kidney-targeted drug delivery system is a promising method to increase renal efficacy and reduce extra-renal toxicity. In recent years, working as vehicles for targeted drug delivery, low molecular weight proteins (LMWP) and peptide have received immense attention due to their many advantages, such as selective accumulation in kidney, high drug loading capability, control over routes of biodegradation, convenience in modification at the amino terminus, and good biocompatibility. In this review, we describe the current LMWP and peptide carriers for kidney targeted drug delivery systems. In addition, we discuss different linking strategies between carriers and drugs. Furthermore, we briefly outline the current status and attempt to give an outlook on the further study. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  18. Circular dichroism studies of low molecular weight hydrogelators: The use of SRCD and addressing practical issues.

    Science.gov (United States)

    Sitsanidis, Efstratios D; Piras, Carmen C; Alexander, Bruce D; Siligardi, Giuliano; Jávorfi, Tamás; Hall, Andrew J; Edwards, Alison A

    2018-04-12

    Circular dichroism (CD) spectroscopy has been used extensively for the investigation of the conformation and configuration of chiral molecules, but its use for evaluating the mode of self-assembly in soft materials has been limited. Herein, we report a protocol for the study of such materials by electronic CD spectroscopy using commercial/benchtop instruments and synchrotron radiation (SR) using the B23 beamline available at Diamond Light Source. The use of the B23 beamtime for SRCD was advantageous because of the unique enhanced spatial resolution achieved because of its highly collimated and small beamlight cross section (ca. 250 μm) and higher photon flux in the far UV region (175-250 nm) enhancing the signal-to-noise ratio relative to benchtop CD instruments. A set of low molecular weight (LMW) hydrogelators, comprising two Fmoc-protected enantiomeric monosaccharides and one Fmoc dipeptide (Fmoc-FF), were studied. The research focused on the optimization of sample preparation and handling, which then enabled the characterization of sample conformational homogeneity and thermal stability. CD spectroscopy, in combination with other spectroscopic techniques and microscopy, will allow a better insight into the self-assembly of chiral building blocks into higher order structural architectures. © 2018 Wiley Periodicals, Inc.

  19. Ancient low-molecular-weight organic acids in permafrost fuel rapid carbon dioxide production upon thaw.

    Science.gov (United States)

    Drake, Travis W; Wickland, Kimberly P; Spencer, Robert G M; McKnight, Diane M; Striegl, Robert G

    2015-11-10

    Northern permafrost soils store a vast reservoir of carbon, nearly twice that of the present atmosphere. Current and projected climate warming threatens widespread thaw of these frozen, organic carbon (OC)-rich soils. Upon thaw, mobilized permafrost OC in dissolved and particulate forms can enter streams and rivers, which are important processors of OC and conduits for carbon dioxide (CO2) to the atmosphere. Here, we demonstrate that ancient dissolved organic carbon (DOC) leached from 35,800 y B.P. permafrost soils is rapidly mineralized to CO2. During 200-h experiments in a novel high-temporal-resolution bioreactor, DOC concentration decreased by an average of 53%, fueling a more than sevenfold increase in dissolved inorganic carbon (DIC) concentration. Eighty-seven percent of the DOC loss to microbial uptake was derived from the low-molecular-weight (LMW) organic acids acetate and butyrate. To our knowledge, our study is the first to directly quantify high CO2 production rates from permafrost-derived LMW DOC mineralization. The observed DOC loss rates are among the highest reported for permafrost carbon and demonstrate the potential importance of LMW DOC in driving the rapid metabolism of Pleistocene-age permafrost carbon upon thaw and the outgassing of CO2 to the atmosphere by soils and nearby inland waters.

  20. Disappearance of a low molecular weight heparin fraction (CY 216) differs from standard heparin in rabbits

    International Nuclear Information System (INIS)

    Boneu, B.; Buchanan, M.R.; Caranobe, C.; Gabaig, A.M.; Dupouy, D.; Sie, P.; Hirsh, J.

    1987-01-01

    In previous studies, we have reported that standard heparin (SH) was cleared by two mechanisms, a saturable mechanism which predominated at low doses (less than 100 anti-factor Xa U/kg) and a non-saturable mechanism which predominated at higher doses, when the first mechanism became saturated. In this study, we examined the importance of these two mechanisms in the disappearance of a low molecular weight heparin fraction (LMWH) (CY 216), by comparing the pharmacokinetics and the pharmacodynamics of a wide range of doses of SH and CY 216 (1.5 to 500 anti-factor Xa U/kg). Pharmacokinetics was measured as the disappearance of 125 I-radiolabelled SH or CY 216. Pharmacodynamics was measured as the disappearance of the anti-factor Xa activity of SH and CY 216. We found that the saturable mechanism contributed little to the disappearance of CY 216 and that it was cleared predominantly by the non-saturable mechanism at all doses tested. Thus, at low doses (less than 100 anti-factor Xa U/kg), SH was cleared more rapidly than CY 216, whereas at higher doses, CY 216 was cleared more rapidly than SH. We conclude that the mechanism of disappearance of LMWH's differ significantly from those of SH, and that this difference may explain the apparent prolonged anticoagulant activity of LMWH's within the therapeutic range doses

  1. Molecular imprinted polymer-coated optical fiber sensor for the identification of low molecular weight molecules.

    Science.gov (United States)

    Lépinay, Sandrine; Ianoul, Anatoli; Albert, Jacques

    2014-10-01

    A biomimetic optical probe for detecting low molecular weight molecules (maltol, 3-hydroxy-2-methyl-4H-pyran-4-one, molecular weight of 126.11 g/mol), was designed, fabricated, and characterized. The sensor couples a molecular imprinted polymer (MIP) and the Bragg grating refractometry technology into an optical fiber. The probe is fabricated first by inscribing tilted grating planes in the core of the fiber, and then by photopolymerization to immobilize a maltol imprinted MIP on the fiber cladding surface over the Bragg grating. The sensor response to the presence of maltol in different media is obtained by spectral interrogation of the fiber transmission signal. The results showed that the limit of detection of the sensor reached 1 ng/mL in pure water with a sensitivity of 6.3 × 10(8)pm/M. The selectivity of the sensor against other compounds and its reusability were also studied experimentally. Finally, the unambiguous detection of concentrations as little as 10nM of maltol in complex media (real food samples) by the MIP-coated tilted fiber Bragg grating sensor was demonstrated. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Comprehensive Analysis of Low-Molecular-Weight Human Plasma Proteome Using Top-Down Mass Spectrometry.

    Science.gov (United States)

    Cheon, Dong Huey; Nam, Eun Ji; Park, Kyu Hyung; Woo, Se Joon; Lee, Hye Jin; Kim, Hee Cheol; Yang, Eun Gyeong; Lee, Cheolju; Lee, Ji Eun

    2016-01-04

    While human plasma serves as a great source for disease diagnosis, low-molecular-weight (LMW) proteome (mass spectrometry to analyze the LMW proteoforms present in four types of human plasma samples pooled from three healthy controls (HCs) without immunoaffinity depletion and with depletion of the top two, six, and seven high-abundance proteins. The LMW proteoforms were first fractionated based on molecular weight using gel-eluted liquid fraction entrapment electrophoresis (GELFrEE). Then, the GELFrEE fractions containing up to 30 kDa were subjected to nanocapillary-LC-MS/MS, and the high-resolution MS and MS/MS data were processed using ProSightPC 3.0. As a result, a total of 442 LMW proteins and cleaved products, including those with post-translational modifications and single amino acid variations, were identified. From additional comparative analysis of plasma samples without immunoaffinity depletion between HCs and colorectal cancer (CRC) patients via top-down approach, tens of LMW proteoforms, including platelet factor 4, were found to show >1.5-fold changes between the plasma samples of HCs and CRC patients, and six of the LMW proteins were verified by Western blot analysis.

  3. Detection of Low Molecular Weight Adulterants in Beverages by Direct Analysis in Real Time Mass Spectrometry.

    Science.gov (United States)

    Sisco, Edward; Dake, Jeffrey

    2016-04-14

    Direct Analysis in Real Time Mass Spectrometry (DART-MS) has been used to detect the presence of non-narcotic adulterants in beverages. The non-narcotic adulterants that were examined in this work incorporated a number low molecular weight alcohols, acetone, ammonium hydroxide, and sodium hypochlorite. Analysis of the adulterants was completed by pipetting 1 µL deposits onto glass microcapillaries along with an appropriate dopant species followed by introduction into the DART gas stream. It was found that detection of these compounds in the complex matrices of common beverages (soda, energy drinks, etc.) was simplified through the use of a dopant species to allow for adduct formation with the desired compound(s) of interest. Other parameters that were investigated included DART gas stream temperature, in source collision induced dissociation, ion polarity, and DART needle voltage. Sensitivities of the technique were found to range from 0.001 % volume fraction to 0.1 % volume fraction, comparable to traditional analyses completed using headspace gas chromatography mass spectrometry (HS-GC/MS). Once a method was established using aqueous solutions, , fifteen beverages were spiked with each of the nine adulterants, to simulate real world detection, and in nearly all cases the adulterant could be detected either in pure form, or complexed with the added dopant species. This technique provides a rapid way to directly analyze beverages believed to be contaminated with non-narcotic adulterants at sensitivities similar to or exceeding those of traditional confirmatory analyses.

  4. Mapping of low molecular weight heparins using reversed phase ion pair liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Li, Daoyuan; Chi, Lequan; Jin, Lan; Xu, Xiaohui; Du, Xuzhao; Ji, Shengli; Chi, Lianli

    2014-01-01

    Low molecular weight heparins (LMWHs) are structurally complex, highly sulfated and negatively charged, linear carbohydrate polymers prepared by chemical or enzymatic depolymerization of heparin. They are widely used as anticoagulant drugs possessing better bioavailability, longer half-life, and lower side effects than heparin. Comprehensive structure characterization of LMWHs is important for drug quality assurance, generic drug application, and new drug research and development. However, fully characterization of all oligosaccharide chains in LMWHs is not feasible for current available analytical technologies due to their structure complexity and heterogeneity. Fingerprinting profiling is an efficient way for LMWHs' characterization and comparison. In this work, we present a simple, sensitive, and powerful analytical approach for structural characterization of LMWHs. Two different LMWHs, enoxaparin and nadroparin, were analyzed using reversed phase ion pair electrospray ionization mass spectrometry (RPIP-ESI-MS). More than 200 components were identified, including major structures, minor structures, and process related impurities. This approach is robust for high resolution and complementary fingerprinting analysis of LMWHs. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. High-affinity binding of two molecules of cysteine proteinases to low-molecular-weight kininogen.

    Science.gov (United States)

    Turk, B.; Stoka, V.; Björk, I.; Boudier, C.; Johansson, G.; Dolenc, I.; Colic, A.; Bieth, J. G.; Turk, V.

    1995-01-01

    Human low-molecular-weight kininogen (LK) was shown by fluorescence titration to bind two molecules of cathepsins L and S and papain with high affinity. By contrast, binding of a second molecule of cathepsin H was much weaker. The 2:1 binding stoichiometry was confirmed by titration monitored by loss of enzyme activity and by sedimentation velocity experiments. The kinetics of binding of cathepsins L and S and papain showed the two proteinase binding sites to have association rate constants kass,1 = 10.7-24.5 x 10(6) M-1 s-1 and kass,2 = 0.83-1.4 x 10(6) M-1 s-1. Comparison of these kinetic constants with previous data for intact LK and its separated domains indicate that the faster-binding site is also the tighter-binding site and is present on domain 3, whereas the slower-binding, lower-affinity site is on domain 2. These results also indicate that there is no appreciable steric hindrance for the binding of proteinases between the two binding sites or from the kininogen light chain. PMID:8528085

  6. Studies on Antiviral and Immuno-Regulation Activity of Low Molecular Weight Fucoidan from Laminaria japonica

    Science.gov (United States)

    Sun, Taohua; Zhang, Xinhui; Miao, Ying; Zhou, Yang; Shi, Jie; Yan, Meixing; Chen, Anjin

    2018-06-01

    The antiviral activity in vitro and in vivo and the effect of the immune system of two fucoidan fractions with low molecular weight and different sulfate content from Laminaria japonica (LMW fucoidans) were investigated in order to examine the possible mechanism. In vitro, I-type influenza virus, adenovirus and Parainfluenza virus I were used to infect Hep-2, Hela and MDCK cells, respectively. And 50% tissue culture infective dose was calculated to detect the antiviral activity of two LMW fucoidans. The results indicated that compared with the control group, 2 kinds of LMW fucoidans had remarkable antiviral activity in vitro in middle and high doses, while at low doses, the antiviral activity of 2 kinds of LMW fucoidans was not statistically different from that in the blank control group. And there was no statistically difference between two LMW fucoidans in antiviral activity. In vivo, LMW fucoidans could prolong the survival time of virus-infected mice, and could improve the lung index of virus-infected mice significantly, which have statistical differences with the control group significantly ( p 0.05). In this study, it was shown that both of two LMW fucoidans (LF1, LF2) could increase the thymus index, spleen index, phagocytic index, phagocytosis coefficient and half hemolysin value in middle and high doses, which suggested that LMW fucoidans could play an antiviral role by improving the quality of immune organs, improving immune cell phagocytosis and humoral immunity.

  7. [Impact of low-molecular-weight heparin practice guidelines in a geriatric hospital].

    Science.gov (United States)

    d'Arailh, Lydie; Gaubert-Dahan, Marie-Line; Muller, Florence; Lechowski, Laurent; Teillet, Laurent

    2011-06-01

    The purpose of this study was to assess the impact of good use of anticoagulants guidelines implementation on low molecular weight heparin (LMWH) prescription in a french geriatric hospital. This interventional "before and after" study was conduced by the same geriatrician on a d-day in 2006 and 2009. Guidelines for anticoagulant's prescription based on selected references in the literature was established by an expert's consensus and implemented in 2008. Data were collected in all departments at the Sainte-Perine geriatric hospital for each patient with an LMWH prescription. Assessment was based on quality judgment criteria (indication, dosage, treatment duration, biological monitoring of LMWH). Data were collected for 72 prescriptions prior to the guidelines implementation and for 54 after. Sex-ratio, mean age and percentage of LMWH prescription did not differ significantly between the two periods. There was a better conformity for LMWH dosage prescription (p = 0.002) and biological monitoring prescription (p = 0.036) after the guidelines implementation. Conformity of LMWH indication and treatment duration were improved but the difference remained not significant (respectively p = 0.49 and p = 0.80). Implementing guidelines for LMWH use in geriatrics can improve quality of prescription. The impact was effective but limited. These guidelines are now in general use in the Sainte-Perine hospital.

  8. [Effects of low molecular weight organic acids on redox reactions of mercury].

    Science.gov (United States)

    Zhao, Shi-Bo; Sun, Rong-Guo; Wang, Ding-Yong; Wang, Xiao-Wen; Zhang, Cheng

    2014-06-01

    To study the effects of the main component of vegetation root exudates-low molecular weight organic acids on the redox reactions of mercury, laboratory experiments were conducted to investigate the roles of tartaric, citric, and succinic acid in the redox reactions of mercury, and to analyze their interaction mechanism. The results indicated that tartaric acid significantly stimulated the mercury reduction reaction, while citric acid had inhibitory effect. Succinic acid improved the reduction rate at low concentration, and inhibited the reaction at high concentration. The mercury reduction rate by tartaric acid treatment was second-order with respect to Hg2+ concentration, ranging from 0.0014 L x (ng x min)(-1) to 0.005 6 L x (ng x min)(-1). All three organic acids showed a capacity for oxidating Hg(0) in the early stage, but the oxidized Hg(0) was subsequently reduced. The oxidation capacity of the three organic acids was in the order of citric acid > tartaric acid > succinic acid.

  9. Immune-enhancing activities of low molecular weight β-glucan depolymerized by gamma irradiation

    Science.gov (United States)

    Sung, Nak-Yun; Byun, Eui-Hong; Kwon, Sun-Kyu; Song, Beom-Seok; Choi, Jong-il; Kim, Jae-Hun; Byun, Myung-Woo; Yoo, Young-Choon; Kim, Mee-Ree; Lee, Ju-Woon

    2009-07-01

    β-glucans are structural cell wall polymers of many microorganisms and cereals which possess immunomodulatory properties and have been used in the food, cosmetic and medical industry. In our previous study, β-glucan was depolymerized by gamma irradiation and leads to improve the solubility and viscosity. This study was carried out to evaluate the functional properties, mainly immune-enhancing activities of low molecular weight β-glucan fragmented by gamma irradiation. The results showed that RAW 264.7 macrophage cell stimulation activities of irradiated β-glucan were higher than that of non-irradiated β-glucan. In addition, the oral administration of gamma-irradiated β-glucan significantly increased the proliferation and cytokine (IFN-γ and IL-2) release of spleen and Peyer's patch cells compared with non-irradiated β-glucan. In conclusion, gamma irradiation could be used as an effective method for the production of depolymerized β-glucan improved functional property such as immunomodulatory activity.

  10. Immune-enhancing activities of low molecular weight β-glucan depolymerized by gamma irradiation

    International Nuclear Information System (INIS)

    Sung, Nak-Yun; Byun, Eui-Hong; Kwon, Sun-Kyu; Song, Beom-Seok; Choi, Jong-il; Kim, Jae-Hun; Byun, Myung-Woo; Yoo, Young-Choon; Kim, Mee-Ree; Lee, Ju-Woon

    2009-01-01

    β-glucans are structural cell wall polymers of many microorganisms and cereals which possess immunomodulatory properties and have been used in the food, cosmetic and medical industry. In our previous study, β-glucan was depolymerized by gamma irradiation and leads to improve the solubility and viscosity. This study was carried out to evaluate the functional properties, mainly immune-enhancing activities of low molecular weight β-glucan fragmented by gamma irradiation. The results showed that RAW 264.7 macrophage cell stimulation activities of irradiated β-glucan were higher than that of non-irradiated β-glucan. In addition, the oral administration of gamma-irradiated β-glucan significantly increased the proliferation and cytokine (IFN-γ and IL-2) release of spleen and Peyer's patch cells compared with non-irradiated β-glucan. In conclusion, gamma irradiation could be used as an effective method for the production of depolymerized β-glucan improved functional property such as immunomodulatory activity.

  11. Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants.

    Science.gov (United States)

    Simal-Gándara, J; Sarria-Vidal, M; Koorevaar, A; Rijk, R

    2000-08-01

    The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick oriented PP) into the food stimulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.

  12. Crystal structure and putative substrate identification for the Entamoeba histolytica low molecular weight tyrosine phosphatase.

    Science.gov (United States)

    Linford, Alicia S; Jiang, Nona M; Edwards, Thomas E; Sherman, Nicholas E; Van Voorhis, Wesley C; Stewart, Lance J; Myler, Peter J; Staker, Bart L; Petri, William A

    2014-01-01

    Entamoeba histolytica is a eukaryotic intestinal parasite of humans, and is endemic in developing countries. We have characterized the E. histolytica putative low molecular weight protein tyrosine phosphatase (LMW-PTP). The structure for this amebic tyrosine phosphatase was solved, showing the ligand-induced conformational changes necessary for binding of substrate. In amebae, it was expressed at low but detectable levels as detected by immunoprecipitation followed by immunoblotting. A mutant LMW-PTP protein in which the catalytic cysteine in the active site was replaced with a serine lacked phosphatase activity, and was used to identify a number of trapped putative substrate proteins via mass spectrometry analysis. Seven of these putative substrate protein genes were cloned with an epitope tag and overexpressed in amebae. Five of these seven putative substrate proteins were demonstrated to interact specifically with the mutant LMW-PTP. This is the first biochemical study of a small tyrosine phosphatase in Entamoeba, and sets the stage for understanding its role in amebic biology and pathogenesis. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Patient compliance with extended low molecular weight heparin injections following hip and knee arthroplasty.

    Science.gov (United States)

    Deakin, Dan E; Mishreki, Andrew; Aslam, Nadim; Docker, Charles

    2010-01-01

    The use of extended duration thromboprophylaxis following hip and knee arthroplasty is becoming widespread. The aim of our study was to determine patient compliance with extended duration thromboprophylaxis using low molecular weight (LMWH) injections following hip and knee arthroplasty. 42 consecutive patients undergoing hip and knee arthroplasty were prospectively contacted during their fifth post operative week. A fully anonymised questionnaire was completed by each patient. All patients responded. One was excluded having been prescribed warfarin for pre existing atrial fibrillation. Twenty nine (71%) patients were discharged with the intention of self administering LMWH injections. Eight (20%) and four (9%) patients were discharged with the intention of administration by a relative or district nurse respectively. No patient required the person administering the injections to be changed after discharge from hospital. 90% (n=37) of patients reported not missing any doses. 10% (n=2) of patients missed one dose and 10% (n=2) missed two doses. Patient compliance with extended duration thromboprophylaxis using LMWH injections is extremely high. Oral thromboprophylaxis may be useful in the minority of patients requiring daily visits by a nurse to administer injections.

  14. Feline urine metabolomic signature: characterization of low-molecular-weight substances in urine from domestic cats.

    Science.gov (United States)

    Rivera-Vélez, Sol-Maiam; Villarino, Nicolas F

    2018-02-01

    Objectives This aim of this study was to characterize the composition and content of the feline urine metabolome. Methods Eight healthy domestic cats were acclimated at least 10 days before starting the study. Urine samples (~2 ml) were collected by ultrasound-guided cystocentesis. Samples were centrifuged at 1000 × g for 8 mins, and the supernatant was analyzed by gas chromatography/time-of-flight mass spectrometery. The urine metabolome was characterized using an untargeted metabolomics approach. Results Three hundred and eighteen metabolites were detected in the urine of the eight cats. These molecules are key components of at least 100 metabolic pathways. Feline urine appears to be dominated by carbohydrates, carbohydrate conjugates, organic acid and derivatives, and amino acids and analogs. The five most abundant molecules were phenaceturic acid, hippuric acid, pseudouridine phosphate and 3-(4-hydroxyphenyl) propionic acid. Conclusions and relevance This study is the first to characterize the feline urine metabolome. The results of this study revealed the presence of multiple low-molecular-weight substances that were not known to be present in feline urine. As expected, the origin of the metabolites detected in urine was diverse, including endogenous compounds and molecules biosynthesized by microbes. Also, the diet seemed to have had a relevant role on the urine metabolome. Further exploration of the urine metabolic phenotype will open a window for discovering unknown, or poorly understood, metabolic pathways. In turn, this will advance our understanding of feline biology and lead to new insights in feline physiology, nutrition and medicine.

  15. Trypanosoma equiperdum Low Molecular Weight Proteins As Candidates for Specific Serological Diagnosis of Dourine

    Directory of Open Access Journals (Sweden)

    Mirella Luciani

    2018-03-01

    Full Text Available The diagnosis of dourine can be difficult because the clinical signs of this disease in horses are similar to those of surra, caused by Trypanosoma evansi. Moreover, T. equiperdum and T. evansi are closely related and, so far, they cannot be distinguished using serological tests. In a previous work, the T. equiperdum protein pattern recognized by antibodies from dourine-infected horses and the humoral immune response kinetics were investigated by immunoblotting assay; a total of 20 sera from naturally and experimentally infected horses and from healthy animals were tested. Immunoblotting analysis showed that antibodies from infected horses specifically bind T. equiperdum low molecular weight proteins (from 16 to 35 kDa, which are not recognized by antibodies from uninfected horses. In this work, we tested other 615 sera (7 from naturally infected horses and 608 sera from healthy horses and donkeys: results confirmed the data obtained previously. In addition, six SDS-PAGE bands with molecular weight ranging from 10 to 37 kDa were analyzed by mass spectrometry, in order to identify immunogenic proteins that could be used as biomarkers for the diagnosis of dourine. A total of 167 proteins were identified. Among them, 37 were found unique for T. equiperdum. Twenty-four of them could represent possible candidate diagnostic antigens for the development of serological tests specific for T. equiperdum.

  16. Low Molecular Weight Fucoidan Inhibits Tumor Angiogenesis through Downregulation of HIF-1/VEGF Signaling under Hypoxia

    Directory of Open Access Journals (Sweden)

    Meng-Chuan Chen

    2015-07-01

    Full Text Available Activation of hypoxia-induced hypoxia-inducible factors-1 (HIF-1 plays a critical role in promoting tumor angiogenesis, growth and metastasis. Low molecular weight fucoidan (LMWF is prepared from brown algae, and exhibits anticancer activity. However, whether LMWF attenuates hypoxia-induced angiogenesis in bladder cancer cells and the molecular mechanisms involved remain unclear. This is the first study to demonstrate that LMWF can inhibit hypoxia-stimulated H2O2 formation, HIF-1 accumulation and transcriptional activity vascular endothelial growth factor (VEGF secretion, and the migration and invasion in hypoxic human bladder cancer cells (T24 cells. LMWF also downregulated hypoxia-activated phosphorylation of PI3K/AKT/mTOR/p70S6K/4EBP-1 signaling in T24 cells. Blocking PI3K/AKT or mTOR activity strongly diminished hypoxia-induced HIF-1α expression and VEGF secretion in T24 cells, supporting the involvement of PI3K/AKT/mTOR in the induction of HIF-1α and VEGF. Additionally, LMWF significantly attenuated angiogenesis in vitro and in vivo evidenced by reduction of tube formation of hypoxic human umbilical vascular endothelial cells and blood capillary generation in the tumor. Similarly, administration of LMWF also inhibited the HIF-1α and VEGF expression in vivo, accompanied by a reduction of tumor growth. In summary, under hypoxia conditions, the antiangiogenic activity of LMWF in bladder cancer may be associated with suppressing HIF-1/VEGF-regulated signaling pathway.

  17. Contribution of low molecular weight phenols to bitter taste and mouthfeel properties in red wines.

    Science.gov (United States)

    Gonzalo-Diago, Ana; Dizy, Marta; Fernández-Zurbano, Purificación

    2014-07-01

    The aim of this study was to explore the relationship between low molecular weight compounds present in wines and their sensory contribution. Six young red wines were fractionated by gel permeation chromatography and subsequently each fraction obtained was separated from sugars and acids by solid phase extraction. Wines and both fractions were in-mouth evaluated by a trained sensory panel and UPLC-MS analyses were performed. The lack of ethanol and proanthocyanidins greatly increased the acidity perceived. The elimination of organic acids enabled the description of the samples, which were evaluated as bitter, persistent and slightly astringent. Coutaric acid and quercetin-3-O-rutinoside appear to be relevant astringent compounds in the absence of proanthocyanidins. Bitter taste was highly correlated with the in-mouth persistence. A significant predictive model for bitter taste was built by means of PLSR. Further research must be carried out to validate the sensory contribution of the compounds involved in bitterness and astringency and to verify the sensory interactions observed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Use of low molecular weight Heparin for Hemodialysis: A short term study

    International Nuclear Information System (INIS)

    Al-Arrayed, S.; Seshadri, R.

    2002-01-01

    Although unfractionated heparin (UFH) is the anticoagulant commonly usedfor Hemodialysis (HD), low molecular weight heparin (LMWH) has been found tobe equally efficacious. The aim of this study was to explore the safety andefficacy of a single bolus dose of the LMWH, enoxaparin. Thirty-eightpatients on maintenance HD were randomly divided into two equal groups. Themean age and body-weight of the two were comparable. While one group received1 mg/kg body-weight (the manufacturer's recommended dose) of enoxaparin forthree dialysis sessions of three-hour duration each, the either groupreceived a fixed dose of 40 mg for the same number of dialysis. For the nextthree dialysis sessions, these doses were exchanged between the groups. Inall, total of 228 HD sessions were monitored for clotting of bloodlines/dialyzers and bleeding from vascular access and other sites. The rateof complications was compared with the historical data while UFH was beingused for the same patients. In general, enoxapirin was associated with fewerepisodes of bleeding and clotting. Our study confirms that LMWH is ofcomparable efficacy to UFH and probably a lesser than recommended dose isadequate for three-hour HD session. (author)

  19. Rapid Analysis of Apolar Low Molecular Weight Constituents in Wood Using High Pressure Liquid Chromatography with Evaporative Light Scattering Detection

    NARCIS (Netherlands)

    Claassen, F.W.; Haar, van de C.; Beek, van T.A.; Dorado, J.; Martinez-Inigo, M.; Sierra-Alvarez, R.

    2000-01-01

    A new high pressure liquid chromatographic method with evaporative light scattering detection was developed for the qualitative and quantitative analysis of apolar, low molecular weight constituents in wood. The wood extractives were obtained by means of a 6 h Soxhlet extraction with acetone. The

  20. Influence of low-molecular-weight glutenin subunit haplotypes on dough rheology and baking quality in elite common wheat varieties

    Science.gov (United States)

    The low molecular weight glutenin subunits (LMW-GSs) are a class of wheat seed storage proteins directly involved in the formation of gluten. Depending on the first amino acid residue of the mature proteins, the LMW-GSs are divided into methionine, serine or isoleucine type. These proteins are encod...

  1. Influence of Low Molecular Weight Organic Acids on Transport of Cadmium and Copper Ions across Model Phospholipid Membranes

    Czech Academy of Sciences Publication Activity Database

    Parisová, Martina; Navrátil, Tomáš; Šestáková, Ivana; Jaklová Dytrtová, Jana; Mareček, Vladimír

    2013-01-01

    Roč. 8, č. 1 (2013), s. 27-44 ISSN 1452-3981 R&D Projects: GA AV ČR IAA400400806 Institutional support: RVO:61388963 ; RVO:61388955 Keywords : cadmium * copper * low molecular weight organic acid Subject RIV: CG - Electrochemistry Impact factor: 1.956, year: 2013

  2. Vitamin K antagonists or low-molecular-weight heparin for the long term treatment of symptomatic venous thromboembolism

    NARCIS (Netherlands)

    van der Heijden, J. F.; Hutten, B. A.; Büller, H. R.; Prins, M. H.

    2000-01-01

    Patients who have had an episode of symptomatic venous thromboembolism are usually treated for at least five days with intravenous unfractionated heparin or subcutaneous low-molecular-weight heparin. Thereafter, they received a three month course of a vitamin K antagonist, with a dose adjusted to

  3. Low molecular weight heparin for prevention of venous thromboembolism in patients with lower-limb immobilization.

    Science.gov (United States)

    Zee, Aniek Ag; van Lieshout, Kelly; van der Heide, Maaike; Janssen, Loes; Janzing, Heinrich Mj

    2017-08-06

    Immobilization of the lower limb is a risk factor for venous thromboembolism (VTE). Low molecular weight heparins (LMWHs) are anticoagulants, which might be used in adult patients with lower-limb immobilization to prevent deep venous thrombosis (DVT) and its complications. This is an update of the review first published in 2008. To assess the effectiveness of low molecular weight heparin for the prevention of venous thromboembolism in patients with lower-limb immobilization in an ambulatory setting. For this update, the Cochrane Vascular Information Specialist searched the Specialised Register, CENTRAL, and three trials registers (April 2017). Randomized controlled trials (RCTs) and controlled clinical trials (CCTs) that described thromboprophylaxis by means of LMWH compared with no prophylaxis or placebo in adult patients with lower-limb immobilization. Immobilization was by means of a plaster cast or brace. Two review authors independently selected trials, assessed risk of bias and extracted data. The review authors contacted the trial authors for additional information if required. Statistical analysis was carried out using Review Manager 5. We included eight RCTs that fulfilled our criteria, with a total of 3680 participants. The quality of evidence, according GRADE, varied by outcome and ranged from low to moderate. We found an incidence of DVT ranging from 4.3% to 40% in patients who had a leg injury that had been immobilized in a plaster cast or a brace for at least one week, and who received no prophylaxis, or placebo. This number was significantly lower in patients who received daily subcutaneous injections of LMWH during immobilization, with event rates ranging from 0% to 37% (odds ratio (OR) 0.45, 95% confidence interval (CI) 0.33 to 0.61; with minimal evidence of heterogeneity: I² = 26%, P = 0.23; seven studies; 1676 participants, moderate-quality evidence). Comparable results were seen in the following groups of participants: patients with below

  4. Can thiolation render a low molecular weight polymer of just 20-kDa mucoadhesive?

    Science.gov (United States)

    Mahmood, Arshad; Bonengel, Sonja; Laffleur, Flavia; Ijaz, Muhammad; Idrees, Muneeb Ahmad; Hussain, Shah; Huck, Christian W; Matuszczak, Barbara; Bernkop-Schnürch, Andreas

    2016-01-01

    The objective was to investigate whether even low-molecular weight polymers (LMWPs) can be rendered mucoadhesive due to thiolation. Interceded by the double catalytic system carbodiimide/N-hydroxysuccinimide, cysteamine was covalently attached to a copolymer, poly(4-styrenesulfonic acid-co-maleic acid) (PSSA-MA) exhibiting a molecular weight of just 20 kDa. Depending on the amount of added N-hydroxysuccinimide and cysteamine, the resulting PSSA-MA-cysteamine (PC) conjugates exhibited increasing degree of thiolation, highest being "PC 2300" exhibiting 2300.16 ± 149.86 μmol thiol groups per gram of polymer (mean ± SD; n = 3). This newly developed thiolated polymer was evaluated regarding mucoadhesive, rheological and drug release properties as well from the toxicological point of view. Swelling behavior in 100 mM phosphate buffer pH 6.8 was improved up to 180-fold. Furthermore, due to thiolation, the mucoadhesive properties of the polymer were 240-fold improved. Rheological measurements of polymer/mucus mixtures confirmed results obtained by mucoadhesion studies. In comparison to unmodified polymer, PC 2300 showed 2.3-, 2.3- and 2.4-fold increase in dynamic viscosity, elastic modulus and viscous modulus, respectively. Sustained release of the model drug codeine HCl out of the thiomer was provided for 2.5 h (p polymer. Moreover, the thiomer was found non-toxic over Caco-2 cells for a period of 6- and 24-h exposure. Findings of the present study provide evidence that due to thiolation LMWPs can be rendered highly mucoadhesive as well as cohesive and that a controlled drug release out of such polymers can be provided.

  5. Effect of low molecular weight heparin (enoxaparin) on congenital cataract surgery.

    Science.gov (United States)

    Caça, Ihsan; Sahin, Alparslan; Cingü, Abdullah Kürsat; Ari, Seyhmus; Alakuş, Fuat; Cinar, Yasin

    2012-01-01

    To assess the efficacy of intracameral enoxaparin (a low-molecular-weight heparin) infusion, in variable doses on postoperative inflammatory response in congenital cataract surgery. It is a prospective, randomized controlled trial. Eighty eyes of 53 children with congenital cataract were enrolled in this study. Every eye had primary posterior capsulorrhexis and intraocular lens (IOL) implantation after lens aspiration. The eyes were divided into 4 equal groups. In group 1 balanced salt solution (BSS) without enoxaparin was used as an irrigation solution. Whereas in group 2, 3 and 4, 40mg, 20mg and 10mg enoxaparin in 500mL BSS was used respectively. The inflammatory response in the anterior chamber was compared among the groups with slit-lamp biomicroscopy. The mean follow-up period was (17.75±3.95) months in group 1, (18.00±5.15) months in group 2, (19.20±5.47) months in group 3 and (18.65±5.16) months in group 4. Mean number of inflammatory cells in the anterior chamber in group 1 was significantly higher than that of group 2, 3, 4 (P0.05). There were IOL precipitates in 4 eyes of group 1 and 2 eyes of group 4. IOL precipitate formation was significantly higher in group 1 than that of group 2 and 3 in which there was no IOL precipitate (P=0.048). There was IOL subluxation in only one eye of group 1, 3 and 4 while no subluxation was observed in group 2 (P>0.05). There was no statistically significant difference detected about IOL subluxation occurance in all 4 groups (P>0.05). Complications of cataract surgery in congenital cataract patients associated with postoperative inflammatory response found to be decreased with the use of enoxaparin in intraocular infusion solutions. Furthermore according to our results the anti-inflammatory effect of enoxaparin was dose dependant.

  6. Low Molecular Weight Heparin Improves Endothelial Function in Pregnant Women at High Risk of Preeclampsia.

    Science.gov (United States)

    McLaughlin, Kelsey; Baczyk, Dora; Potts, Audrey; Hladunewich, Michelle; Parker, John D; Kingdom, John C P

    2017-01-01

    Low molecular weight heparin (LMWH) has been investigated for the prevention of severe preeclampsia, although the mechanisms of action are unknown. The objective of this study was to investigate the cardiovascular effects of LMWH in pregnant women at high risk of preeclampsia. Pregnant women at high risk of preeclampsia (n=25) and low-risk pregnant controls (n=20) at 22 to 26 weeks' gestation underwent baseline cardiovascular assessments. High-risk women were then randomized to LMWH or saline placebo (30 mg IV bolus and 1 mg/kg subcutaneous dose). Cardiovascular function was assessed 1 and 3 hours post randomization. The in vitro endothelial effects of patient serum and exogenous LMWH on human umbilical venous endothelial cells were determined. High-risk women demonstrated a reduced cardiac output, high resistance hemodynamic profile with impaired radial artery flow-mediated dilation compared with controls. LMWH increased flow-mediated dilation in high-risk women 3 hours after randomization compared with baseline and increased plasma levels of placental growth factor, soluble fms-like tyrosine kinase-1, and myeloperoxidase. Serum from high-risk women impaired endothelial cell angiogenesis and increased PlGF-1 and PlGF-2 transcription compared with serum from low-risk controls. Coexposure of high-risk serum with LMWH improved the in vitro angiogenic response such that it was equivalent to that of low-risk serum and promoted placental growth factor secretion. LMWH improves maternal endothelial function in pregnant women at high risk of developing preeclampsia, possibly mediated through increased placental growth factor bioavailability. © 2016 American Heart Association, Inc.

  7. Aspirin and low-molecular weight heparin combination therapy effectively prevents recurrent miscarriage in hyperhomocysteinemic women.

    Directory of Open Access Journals (Sweden)

    Pratip Chakraborty

    Full Text Available The management of recurrent pregnancy loss (RPL still remains a great challenge, and women with polycystic ovarian syndrome (PCOS are at a greater risk for spontaneous abortion. Treatment with low-molecular-weight heparin (LMWH has become an accepted treatment option for women with RPL; however, the subgroup of women, who are likely to respond to LMWH, has not been precisely identified. The present study evaluated the efficacy of LMWH with reference to PCOS and associated metabolic phenotypes including hyperhomocysteinemia (HHcy, insulin resistance (IR and obesity. This prospective observational study was conducted at Institute of Reproductive Medicine, Kolkata, India. A total of 967 women with history of 2 or more consecutive first trimester abortions were screened and 336 were selected for the study. The selected patients were initially divided on the basis of presence or absence of PCOS, while subsequent stratification was based on HHcy, IR and/or obesity. The subjects had treatment with aspirin during one conception cycle and aspirin-LMWH combined anticoagulant therapy for the immediate next conception cycle, if the first treated cycle was unsuccessful. Pregnancy salvage was the sole outcome measure. The overall rate of pregnancy salvage following aspirin therapy was 43.15%, which was mostly represented by normohomocysteinemic women, while the salvage rate was lower in the HHcy populations irrespective of the presence or absence of PCOS, IR, or obesity. By contrast, aspirin-LMWH combined therapy could rescue 66.84% pregnancies in the aspirin-failed cases. Logistic regression analyses showed that HHcy remained a significant factor in predicting salvage rates in the PCOS, IR, and obese subpopulations controlled for other confounding factors. With regard to pregnancy salvage, combined anticoagulant therapy with aspirin and LMWH conferred added benefit to those with HHcy phenotype.

  8. The safety of low molecular-weight heparin after blunt liver and spleen injuries.

    Science.gov (United States)

    Rostas, Jack W; Manley, Justin; Gonzalez, Richard P; Brevard, Sidney B; Ahmed, Naveed; Frotan, Mohammad Amin; Mitchell, Ellen; Simmons, Jon D

    2015-07-01

    Anticoagulation is routinely administered to all trauma patients owing to the high incidence of venous thromboembolism (VTE). However, the timing of administration of anticoagulation is not clearly defined when patients have blunt spleen or liver injuries because of the perceived risk of hemorrhage with early administration. A retrospective chart review was performed of all blunt trauma patients who sustained blunt liver and/or spleen injuries during the 5-year period from 2007 to 2011. Data were collected for all patients managed with nonoperative therapy for these injuries while also receiving routine prophylactic anticoagulation with low molecular-weight heparin. Patients were categorized based on the initiation of enoxaparin therapy after injury: early (72 hours). Primary and secondary outcomes were designated as need for operative or radiologic intervention secondary to spleen or liver hemorrhage, number of transfusions, and incidence of VTE. Three hundred and twenty-eight patients were included. There were no enoxaparin-related hemorrhagic complications or hemorrhage necessitating operative intervention. Patients in the early, intermediate, and late groups received an average of .9, .93, and 1.55 units of blood, respectively. There was 1 pulmonary embolism in the early group, and there were 6 VTE complications in the late group (3 deep venous thromboses and 3 pulmonary embolisms). There are currently no standards for the initiation of prophylactic anticoagulation in trauma patients with blunt liver and spleen injuries. Early administration may be safe and reduce the incidence of thrombotic complications in patients with blunt spleen and liver injuries. Prospective studies in this area are warranted. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Physicochemical and immunologic characterization of low-molecular-weight allergoids of Dactylis glomerata pollen proteins.

    Science.gov (United States)

    Cirković, T D; Bukilica, M N; Gavrović, M D; Vujcić, Z M; Petrović, S; Jankov, R M

    1999-02-01

    Orchard grass (Dactylis glomerata) pollen proteins were chemically modified by means of acid anhydrides (maleic and succinic anhydride) to obtain low-molecular-weight allergoids. Chemical modification in both cases led to the replacement of one positive charge (epsilon amino group of Lys) by one negative charge, yielding proteins with changed physicochemical properties in comparison to the native orchard grass-pollen proteins. Physicochemical characterization of derivatives was done by gel chromatography, SDS-PAGE, and isoelectric focusing. To examine the IgE-binding properties of these derivatives, we carried out immunoblotting. To examine the ability of derivatives to induce IgG production, we immunized rabbits. Skin prick testing with the allergoids was performed on 15 individuals allergic to orchard grass pollens and on two healthy subjects. It was shown that the modified proteins retain their original molecular weights, but change pI to more acidic values. In the case of allergoids, a strong reduction in IgE binding was found. Immunization of rabbits with allergoids showed that the derivatives retain the ability to induce IgG production, and that the antisera obtained in such a way react to native (unmodified) extract. The ability of derivatives to induce allergic reaction was significantly reduced. The patients (86.6%) included in our study exhibited less than 50% of native extract response. Among them, 53.3% had no response to one or both allergoids. These modification procedures yield allergoids with a reduced allergenic activity and preserved immunogenic potential suitable for use in immunotherapy.

  10. Efficacy and safety of once daily low molecular weight heparin (tinzaparin sodium) in high risk pregnancy.

    LENUS (Irish Health Repository)

    Ní Ainle, Fionnuala

    2008-10-01

    Low molecular weight heparin (LMWH) is widely regarded as the anticoagulant treatment of choice for the prevention and treatment of venous thromboembolism during pregnancy. However, previous studies have demonstrated that the pharmacokinetic profiles of LMWH vary significantly with increasing gestation. Consequently, it remains unclear whether LMWH regimens recommended for use in nonpregnant individuals can be safely extrapolated to pregnant women. The aims of this study were to assess the safety and the efficacy of tinzaparin sodium (Innohep) administered only once daily during pregnancy. A systematic retrospective review identified a cohort of 37 high-risk pregnancies which had been managed using tinzaparin 175 IU\\/kg once daily. In 26 cases, the index pregnancy had been complicated by development of an acute venous thromboembolism (17 deep vein thrombosis and nine pulmonary embolism). For each individual, case notes were examined and data extracted using a predetermined questionnaire. No episodes of recurrent venous thromboembolism were identified amongst this cohort of pregnancies managed using once daily LMWH administration. However, two unusual thrombotic complications were observed, including a parietal infarct in one patient, and a postpartum cerebral venous thrombosis in another. Once daily tinzaparin was well tolerated, with no cases of heparin-induced thrombocytopaenia, symptomatic osteoporosis, or foetal malformations. Tinzaparin dose modification based upon peak anti-Xa levels occurred in 45% of the cases examined. The present study is the largest study to have examined the clinical efficacy of once daily LMWH for use in pregnant women at high risk of venous thromboembolism. Our data support the safety and efficacy of antenatal tinzaparin at a dose of 175 IU\\/kg. In order to determine whether this once daily regimen provides equivalent (or indeed greater) thromboprophylaxis to twice daily LMWH regimens during pregnancy will require highly powered

  11. Detoxification of Atrazine by Low Molecular Weight Thiols in Alfalfa (Medicago sativa).

    Science.gov (United States)

    Zhang, Jing Jing; Xu, Jiang Yan; Lu, Feng Fan; Jin, She Feng; Yang, Hong

    2017-10-16

    Low molecular weight (LMW) thiols in higher plants are a group of sulfur-rich nonprotein compounds and play primary and multiple roles in cellular redox homeostasis, enzyme activities, and xenobiotics detoxification. This study focused on identifying thiols-related protein genes from the legume alfalfa exposed to the herbicide atrazine (ATZ) residues in environment. Using high-throughput RNA-sequencing, a set of ATZ-responsive thiols-related protein genes highly up-regulated and differentially expressed in alfalfa was identified. Most of the differentially expressed genes (DEGs) were involved in regulation of biotic and abiotic stress responses. By analyzing the genes involved in thiols-mediated redox homeostasis, we found that many of them were thiols-synthetic enzymes such as γ-glutamylcysteine synthase (γECS), homoglutathione synthetase (hGSHS), and glutathione synthetase (GSHS). Using liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS), we further characterized a group of ATZ-thiols conjugates, which are the detoxified forms of ATZ in plants. Cysteine S-conjugate ATZ-HCl+Cys was the most important metabolite detected by MS. Several other ATZ-conjugates were also examined as ATZ-detoxified metabolites. Such results were validated by characterizing their analogs in rice. Our data showed that some conjugates under ATZ stress were detected in both plants, indicating that some detoxified mechanisms and pathways can be shared by the two plant species. Overall, these results indicate that LMW thiols play critical roles in detoxification of ATZ in the plants.

  12. Low molecular weight dextran provides similar optical coherence tomography coronary imaging compared to radiographic contrast media.

    Science.gov (United States)

    Frick, Kyle; Michael, Tesfaldet T; Alomar, Mohammed; Mohammed, Atif; Rangan, Bavana V; Abdullah, Shuaib; Grodin, Jerrold; Hastings, Jeffrey L; Banerjee, Subhash; Brilakis, Emmanouil S

    2014-11-01

    Optical coherence tomography (OCT) coronary imaging requires displacement of red blood cells from the vessel lumen. This is usually accomplished using radiographic contrast. Low molecular weight dextran has low cost and is safe in low volumes. In the present study, we compared dextran with contrast for coronary OCT imaging. Fifty-one vessels in 26 patients were sequentially imaged using manual injection of radiographic contrast (iodixanol) and dextran. OCT images were analyzed at 1 mm intervals to determine the image clarity (defined as a visible lumen border > 270°) and to measure the lumen area and lumen diameter. To correct for the refractive index of dextran, the dextran area measurements were multiplied by 1.117 and the dextran length measurements were multiplied by 1.057. A total of 3,418 cross-sections (1,709 with contrast and 1,709 with dextran) were analyzed. There were no complications related to OCT imaging or to contrast or dextran administration. Clear image segments were observed in 97.0% vs. 96.7% of the cross-sections obtained with contrast and dextran, respectively (P = 0.45). The mean lumen areas were also similar: 6.69 ± 1.95 mm(2) with iodixanol vs. 7.06 ± 2.06 mm(2) with dextran (correlation coefficient 0.984). The image quality and measurements during OCT image acquisition are similar for dextran and contrast. Dextran could be used instead of contrast for OCT imaging, especially in patients in whom contrast load minimization is desired. © 2013 Wiley Periodicals, Inc.

  13. Mechanistic investigation of Fe(III) oxide reduction by low molecular weight organic sulfur species

    Science.gov (United States)

    Eitel, Eryn M.; Taillefert, Martial

    2017-10-01

    Low molecular weight organic sulfur species, often referred to as thiols, are known to be ubiquitous in aquatic environments and represent important chemical reductants of Fe(III) oxides. Thiols are excellent electron shuttles used during dissimilatory iron reduction, and in this capacity could indirectly affect the redox state of sediments, release adsorbed contaminants via reductive dissolution, and influence the carbon cycle through alteration of bacterial respiration processes. Interestingly, the reduction of Fe(III) oxides by thiols has not been previously investigated in environmentally relevant conditions, likely due to analytical limitations associated with the detection of thiols and their oxidized products. In this study, a novel electrochemical method was developed to simultaneously determine thiol/disulfide pair concentrations in situ during the reduction of ferrihydrite in batch reactors. First order rate laws with respect to initial thiol concentration were confirmed for Fe(III) oxyhydroxide reduction by four common thiols: cysteine, homocysteine, cysteamine, and glutathione. Zero order was determined for both Fe(III) oxyhydroxide and proton concentration at circumneutral pH. A kinetic model detailing the molecular mechanism of the reaction was optimized with proposed intermediate surface structures. Although metal oxide overall reduction rate constants were inversely proportional to the complexity of the thiol structure, the extent of metal reduction increased with structure complexity, indicating that surface complexes play a significant role in the ability of these thiols to reduce iron. Taken together, these results demonstrate the importance of considering the molecular reaction mechanism at the iron oxide surface when investigating the potential for thiols to act as electron shuttles during dissimilatory iron reduction in natural environments.

  14. Auricularia auricular polysaccharide-low molecular weight chitosan polyelectrolyte complex nanoparticles: Preparation and characterization

    Directory of Open Access Journals (Sweden)

    Wei Xiong

    2016-06-01

    Full Text Available Novel polyelectrolyte complex nanoparticles (AAP/LCS NPs were prepared in this study and these were produced by mixing negatively charged auricularia auricular polysaccharide (AAP with positively charged low molecular weight chitosan (LCS in an aqueous medium. The AAP was extracted and purified from auricularia auricular, and then characterized by micrOTOF-Q mass spectrometry, UV/Vis spectrophotometry, moisture analyzer and SEM. The yield, moisture, and total sugar content of the AAP were 4.5%, 6.2% and 90.12% (w/w, respectively. The AAP sample was water-soluble and exhibited white flocculence. The characteristics of AAP/LCS NPs, such as the particle size, zeta potential, morphology, FT-IR spectra, DSC were investigated. The results obtained revealed that the AAP/LCS NPs had a spherical shape with a diameter of 223 nm and a smooth surface, and the results of the FT-IR spectra and DSC investigations indicated that there was an electrostatic interaction between the two polyelectrolyte polymers. Bovine serum albumin (BSA, pI = 4.8 and bovine hemoglobin (BHb, pI = 6.8 were used as model drugs to investigate the loading and release features of the AAP/LCS NPs. The results obtained showed that the AAP/LCS NPs had a higher entrapment efficiency (92.6% for BHb than for BSA (81.5%. The cumulative release of BSA and BHb from AAP/LCS NPs after 24 h in vitro was 95.4% and 91.9%, respectively. The in vitro release demonstrated that AAP/LCS NPs provided a sustained release matrix suitable for the delivery of protein drugs. These studies demonstrate that AAP/LCS NPs have a very promising potential as a delivery system for protein drugs.

  15. Adsorption of volatile hydrocarbons in iron polysulfide chalcogels

    KAUST Repository

    Ahmed, Ejaz

    2014-11-01

    We report the synthesis, characterization and possible applications of three new metal-chalcogenide aerogels KFe3Co3S 21, KFe3Y3S22 and KFe 3Eu3S22. Metal acetates react with the alkali metal polychalcogenides in formamide/water mixture to form extended polymeric frameworks that exhibit gelation phenomena. Amorphous aerogels obtained after supercritical CO2 drying have BET surface area from 461 to 573 m 2/g. Electron microscopy images and nitrogen adsorption measurements showed that pore sizes are found in micro (below 2 nm), meso (2-50 nm), and macro (above 50 nm) porous regions. These chalcogels possess optical bandgaps in the range of 1.55-2.70 eV. These aerogels have been studied for the adsorption of volatile hydrocarbons and gases. A much higher adsorption of toluene in comparison with cyclohexane and cyclopentane vapors have been observed. The adsorption capacities of the three volatile hydrocarbons are found in the following order: toluene > cyclohexane > cyclopentane. It has been observed that high selectivity in adsorption is feasible with high-surface-area metal chalcogenides. Similarly, almost an eight to ten times increase in adsorption selectivity towards CO2 over H2/CH4 was observed in the aerogels. Moreover, reversible ion-exchange properties for K+/Cs+ ions have also been demonstrated. © 2014 Elsevier Inc. All rights reserved.

  16. Marsh plant response to metals: Exudation of aliphatic low molecular weight organic acids (ALMWOAs)

    Science.gov (United States)

    Rocha, A. Cristina S.; Almeida, C. Marisa R.; Basto, M. Clara P.; Vasconcelos, M. Teresa S. D.

    2016-03-01

    Metal exposure is known to induce the production and secretion of substances, such as aliphatic low molecular weight organic acids (ALMWOAs), into the rhizosphere by plant roots. Knowledge on this matter is extensive for soil plants but still considerably scarce regarding marsh plants roots adapted to high salinity media. Phragmites australis and Halimione portulacoides, two marsh plants commonly distributed in European estuarine salt marshes, were used to assess the response of roots of both species, in terms of ALMWOAs exudation, to Cu, Ni and Cd exposure (isolated and in mixture since in natural environment, they are exposed to mixture of metals). As previous studies were carried out in unrealistic and synthetic media, here a more natural medium was selected. Therefore, in vitro experiments were carried out, with specimens of both marsh plants, and in freshwater contaminated with two different Cu, Ni and Cd concentrations (individual metal and in mixture). Both marsh plants were capable of liberating ALMWOAs into the surrounding medium. Oxalic, citric and maleic acids were found in P. australis root exudate solutions and oxalic and maleic acids in H. portulacoides root exudate solutions. ALMWOA liberation by both plants was plant species and metal-dependent. For instance, Cu affected the exudation of oxalic acid by H. portulacoides and of oxalic and citric acids by P. australis roots. In contrast, Ni and Cd did not stimulate any specific response. Regarding the combination of all metals, H. portulacoides showed a similar response to that observed for Cu individually. However, in the P. australis case, at high metal concentration mixture, a synergetic effect led to the increase of oxalic acid levels in root exudate solution and to a decrease of citric acid liberation. A correlation between ALMWOAs exudation and metal accumulation could not be established. P. australis and H. portulacoides are considered suitable metal phytoremediators of estuarine impacted areas

  17. Low molecular weight protein enrichment on mesoporous silica thin films for biomarker discovery.

    Science.gov (United States)

    Fan, Jia; Gallagher, James W; Wu, Hung-Jen; Landry, Matthew G; Sakamoto, Jason; Ferrari, Mauro; Hu, Ye

    2012-04-17

    The identification of circulating biomarkers holds great potential for non invasive approaches in early diagnosis and prognosis, as well as for the monitoring of therapeutic efficiency.(1-3) The circulating low molecular weight proteome (LMWP) composed of small proteins shed from tissues and cells or peptide fragments derived from the proteolytic degradation of larger proteins, has been associated with the pathological condition in patients and likely reflects the state of disease.(4,5) Despite these potential clinical applications, the use of Mass Spectrometry (MS) to profile the LMWP from biological fluids has proven to be very challenging due to the large dynamic range of protein and peptide concentrations in serum.(6) Without sample pre-treatment, some of the more highly abundant proteins obscure the detection of low-abundance species in serum/plasma. Current proteomic-based approaches, such as two-dimensional polyacrylamide gel-electrophoresis (2D-PAGE) and shotgun proteomics methods are labor-intensive, low throughput and offer limited suitability for clinical applications.(7-9) Therefore, a more effective strategy is needed to isolate LMWP from blood and allow the high throughput screening of clinical samples. Here, we present a fast, efficient and reliable multi-fractionation system based on mesoporous silica chips to specifically target and enrich LMWP.(10,11) Mesoporous silica (MPS) thin films with tunable features at the nanoscale were fabricated using the triblock copolymer template pathway. Using different polymer templates and polymer concentrations in the precursor solution, various pore size distributions, pore structures, connectivity and surface properties were determined and applied for selective recovery of low mass proteins. The selective parsing of the enriched peptides into different subclasses according to their physicochemical properties will enhance the efficiency of recovery and detection of low abundance species. In combination with mass

  18. Total protein, albumin and low-molecular-weight protein excretion in HIV-positive patients

    Directory of Open Access Journals (Sweden)

    Campbell Lucy J

    2012-08-01

    Full Text Available Abstract Background Chronic kidney disease is common in HIV positive patients and renal tubular dysfunction has been reported in those receiving combination antiretroviral therapy (cART. Tenofovir (TFV in particular has been linked to severe renal tubular disease as well as proximal tubular dysfunction. Markedly elevated urinary concentrations of retinal-binding protein (RBP have been reported in patients with severe renal tubular disease, and low-molecular-weight proteins (LMWP such as RBP may be useful in clinical practice to assess renal tubular function in patients receiving TFV. We analysed 3 LMWP as well as protein and albumin in the urine of a sample of HIV positive patients. Methods In a cross-sectional fashion, total protein, albumin, RBP, cystatin C, and neutrophil gelatinase-associated lipocalin (NGAL were quantified in random urine samples of 317 HIV positive outpatients and expressed as the ratio-to-creatinine (RBPCR, CCR and NGALCR. Exposure to cART was categorised as none, cART without TFV, and cART containing TFV and a non-nucleoside reverse-transcriptase-inhibitor (TFV/NNRTI or TFV and a protease-inhibitor (TFV/PI. Results Proteinuria was present in 10.4 % and microalbuminuria in 16.7 % of patients. Albumin accounted for approximately 10 % of total urinary protein. RBPCR was within the reference range in 95 % of patients while NGALCR was elevated in 67 % of patients. No overall differences in urine protein, albumin, and LMWP levels were observed among patients stratified by cART exposure, although a greater proportion of patients exposed to TFV/PI had RBPCR >38.8 μg/mmol (343 μg/g (p = 0.003. In multivariate analyses, black ethnicity (OR 0.43, 95 % CI 0.24, 0.77 and eGFR 2 (OR 3.54, 95 % CI 1.61, 7.80 were independently associated with upper quartile (UQ RBPCR. RBPCR correlated well to CCR (r2 = 0.71, but not to NGALCR, PCR or ACR. Conclusions In HIV positive patients, proteinuria was predominantly of

  19. Unfractionated heparin versus low molecular weight heparins for avoiding heparin-induced thrombocytopenia in postoperative patients.

    Science.gov (United States)

    Junqueira, Daniela R; Zorzela, Liliane M; Perini, Edson

    2017-04-21

    Heparin-induced thrombocytopenia (HIT) is an adverse drug reaction presenting as a prothrombotic disorder related to antibody-mediated platelet activation. It is a paradoxical immune reaction resulting in thrombin generation in vivo, which leads to a hypercoagulable state and the potential to initiate venous or arterial thrombosis. A number of factors are thought to influence the incidence of HIT including the type and preparation of heparin (unfractionated heparin (UFH) or low molecular weight heparin (LMWH)) and the heparin-exposed patient population, with the postoperative patient population at higher risk.Although LMWH has largely replaced UFH as a front-line therapy, there is evidence supporting a lack of superiority of LMWH compared with UFH regarding prevention of deep vein thrombosis and pulmonary embolism following surgery, and similar frequencies of bleeding have been described with LMWH and UFH. The decision as to which of these two preparations of heparin to use may thus be influenced by harmful effects such as HIT. We therefore sought to determine the relative impact of UFH and LMWH on HIT in postoperative patients receiving thromboembolism prophylaxis. This is an update of a review first published in 2012. The objective of this review was to compare the incidence of heparin-induced thrombocytopenia (HIT) and HIT complicated by venous thromboembolism in postoperative patients exposed to unfractionated heparin (UFH) versus low molecular weight heparin (LMWH). For this update, the Cochrane Vascular Information Specialist searched the Specialised Register (May 2016), CENTRAL (2016, Issue 4) and trials registries. The authors searched Lilacs (June 2016) and additional trials were sought from reference lists of relevant publications. We included randomised controlled trials (RCTs) in which participants were postoperative patients allocated to receive prophylaxis with UFH or LMWH, in a blinded or unblinded fashion. Studies were excluded if they did not use

  20. Effect of low molecular weight heparin in combined with Shuxuetong in preventing the post-traumatic deep venous thrombosis

    Directory of Open Access Journals (Sweden)

    Li-Mian Xu

    2016-05-01

    Full Text Available Objective: To observe the effect of low molecular weight heparin in combined with Shuxuetong in preventing the post-traumatic deep venous thrombosis (DVT. Methods: A total of 120 patients with post-traumatic DVT who were admitted in our hospital from February, 2014 to February, 2015 were included in the study and divided into the treatment group and the control group with 60 cases in each group according to different treatment protocols. The patients in the treatment group were given subcutaneous injection of low molecular weight heparin calcium and intravenous drip of Shuxuetong, while the patients in the control group were only given subcutaneous injection of low molecular weight heparin calcium. The changes of swelling degrees and coagulation indicators of the affected limb before and after treatment, and the clinical efficacy in the two groups were compared. Results: The total effective rate in the treatment group was significantly higher than that in the control group. The mean range of the perimeter 15cm above and below the bilateral knee joints after treatment in the treatment group was significantly lower than that in the control group. The shrinking rate of the mean range of the perimeter of the bilateral limbs in the treatment group was significantly higher than that in the control group. The comparison of PT, APTT, FIB, and INR before treatment between the two groups was not statistically significant. PT, APTT, and INR after treatment in the treatment group were significantly higher than those in the control group, while FIB was significantly lower than that in the control group. Conclusions: The low molecular weight heparin in combined with Shuxuetong can effectively prevent the post-traumatic DVT, with no requirement of monitoring of the bleeding tendency and safety.

  1. Mass Spectrometry Imaging of low Molecular Weight Compounds in Garlic (Allium sativum L.) with Gold Nanoparticle Enhanced Target.

    Science.gov (United States)

    Misiorek, Maria; Sekuła, Justyna; Ruman, Tomasz

    2017-11-01

    Garlic (Allium sativum) is the subject of many studies due to its numerous beneficial properties. Although compounds of garlic have been studied by various analytical methods, their tissue distributions are still unclear. Mass spectrometry imaging (MSI) appears to be a very powerful tool for the identification of the localisation of compounds within a garlic clove. Visualisation of the spatial distribution of garlic low-molecular weight compounds with nanoparticle-based MSI. Compounds occurring on the cross-section of sprouted garlic has been transferred to gold-nanoparticle enhanced target (AuNPET) by imprinting. The imprint was then subjected to MSI analysis. The results suggest that low molecular weight compounds, such as amino acids, dipeptides, fatty acids, organosulphur and organoselenium compounds are distributed within the garlic clove in a characteristic manner. It can be connected with their biological functions and metabolic properties in the plant. New methodology for the visualisation of low molecular weight compounds allowed a correlation to be made between their spatial distribution within a sprouted garlic clove and their biological function. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  2. Tailoring of the Nanotexture of Mesoporous Silica Films and their Functionalized Derivatives for Selectively Harvesting Low Molecular Weight Protein

    Science.gov (United States)

    Hu, Ye; Bouamrani, Ali; Tasciotti, Ennio; Li, Li; Liu, Xuewu; Ferrari, Mauro

    2010-01-01

    We present a fast, efficient and reliable system based on mesoporous silica chips to specifically fractionate and enrich the low molecular weight proteome. Mesoporous silica thin films with tunable features at the nanoscale were fabricated using the triblock copolymer template pathway. Using different templates and concentrations in the precursor solution, various pore size distributions, pore structures and connectivity were obtained and applied for selective recovery of low mass proteins. In combination with mass spectrometry and statistic analysis, we demonstrated the correlation between the nanophase characteristics of the mesoporous silica thin films and the specificity and efficacy of low mass proteome harvesting. In addition, to overcome the limitations of the pre-functionalization method in polymer selection, plasma ashing was used for the first time for the treatment of the mesoporous silica surface prior to chemical modification. Surface charge modifications by different functional groups resulted in a selective capture of the low molecular weight proteins from serum sample. In conclusion our study demonstrates that the ability to tune the physico-chemical properties of mesoporous silica surfaces, for a selective enrichment of the low molecular weight proteome from complex biological fluids, has the potential to promote proteomic biomarker discovery. PMID:20014864

  3. Deproteinization assessment using isotopically enriched compounds to trace the coprecipitation of low-molecular-weight selenium species with proteins.

    Science.gov (United States)

    Godin, Simon; Bouzas-Ramos, Diego; Fontagné-Dicharry, Stéphanie; Bouyssière, Brice; Bueno, Maïté

    2017-08-01

    Studies have shown that information related to the presence of low-molecular-weight metabolites is frequently lost after deproteinization of complex matrices, such as blood and plasma, during sample preparation. Therefore, the effect of several deproteinization reagents on low-molecular-weight selenium species has been compared by species-specific isotope labeling. Two isotopically enriched selenium tracers were used to mimic models of small inorganic anionic ( 77 Se-selenite) and organic zwitterionic ( 76 Se-selenomethionine) species. The results presented here show that the use of a methanol-acetonitrile-acetone (1:1:1 v/v/v) mixture provided approximately two times less tracer loss from plasma samples in comparison with the classic procedure using acetonitrile, which may not be optimal as it leads to important losses of low-molecular-weight selenium species. In addition, the possible interactions between selenium tracers and proteins were investigated, revealing that both coprecipitation phenomena and association with proteins were potentially responsible for selenite tracer losses during protein precipitation in blood samples. However, coprecipitation phenomena were found to be fully responsible for losses of both tracers observed in plasma samples and of the selenomethionine tracer in blood samples. This successfully applied strategy is anticipated to be useful for more extensive future studies in selenometabolomics. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Microbial utilization of low molecular weight organic substrates in soil depends on their carbon oxidation state

    Science.gov (United States)

    Gunina, Anna; Smith, Andrew; Jones, Davey; Kuzyakov, Yakov

    2017-04-01

    Removal of low molecular weight organic substances (LMWOS), originating from plants and microorganisms, from soil solution is regulated by microbial uptake. In addition to the concentration of LMWOS in soil solution, the chemical properties of each substance (e.g. C oxidation state, number of C atoms, number of -COOH groups) can affect their uptake and subsequent partitioning of C within the soil microbial community. The aim of this study was to trace the initial fate of three dominant classes of LMWOS in soil (sugars, carboxylic and amino acids), including their removal from solution and utilization by microorganisms, and to reveal the effect of substance chemical properties on these processes. Soil solution, spiked at natural abundance levels with 14C-labelled glucose, fructose, malate, succinate, formate, alanine or glycine, was added to the soil and 14C was traced in the dissolved organic carbon (DOC), CO2, cytosol and soil organic carbon (SOC) over 24 hours. The half-life time of all LMWOS in the DOC (T1 /2-solution) varied between 0.6-5.0 min showing extremely fast initial uptake of LMWOS. The T1 /2-solution of substances was dependent on C oxidation state, indicating that less oxidized organic substances (with C oxidation state "0") were retained longer in soil solution than oxidized substances. The LMWOS-C T1 /2-fast, characterizing the half-life time of 14C in the fast mineralization pool, ranged between 30 and 80 min, with the T1 /2-fast of carboxylic acids (malic acid) being the fastest and the T1 /2-fast of amino acids (glycine) being the slowest. An absence of correlation between T1 /2-fast and either C oxidation state, number of C atoms, or number of -COOH groups suggests that intercellular metabolic pathways are more important for LMWOS transformation in soil than their basic chemical properties. The CO2 release during LMWOS mineralization accounted for 20-90% of 14C applied. Mineralization of LMWOS was the least for sugars and the greatest for

  5. Microbial utilization of low molecular weight organics in soil depends on the substances properties

    Science.gov (United States)

    Gunina, Anna

    2016-04-01

    Utilization of low molecular weight organic substances (LMWOS) in soil is regulated by microbial uptake from solution and following incorporation of into specific cell cycles. Various chemical properties of LMWOS, namely oxidation state, number of carbon (C) atoms, number of carboxylic (-COOH) groups, can affect their uptake from soil solution and further microbial utilization. The aim of the study was to trace the initial fate (including the uptake from soil solution and utilization by microorganisms) of three main classes of LMWOS, having contrast properties - sugars, carboxylic and amino acids. Top 10 cm of mineral soil were collected under Silver birch stands within the Bangor DIVERSE experiment, UK. Soil solution was extracted by centrifugation at 4000 rpm during 15 min. Soil was spiked with 14C glucose or fructose; malic, succinic or formic acids; alanine or glycine. No additional non-labeled LMWOS were added. 14C was traced in the dissolved organic matter (DOM), CO2, cytosol and soil organic matter (SOM) during one day. To estimate half-life times (T1 /2)of LMWOS in soil solution and in SOM pools, the single and double first order kinetic equations were fitted to the uptake and mineralization dynamics, respectively. The LMWOS T1 /2in DOM pool varied between 0.6-5 min, with the highest T1 /2for sugars (3.7 min) and the lowest for carboxylic acids (0.6-1.4 min). Thus, initial uptake of LMWOS is not a limiting step of microbial utilization. The T1 /2 of carboxylic and amino acids in DOM were closely related with oxidation state, showing that reduced substances remain in soil solution longer, than oxidized. The initial T1 /2 of LMWOS in SOM ranged between 30-80 min, with the longest T1 /2 for amino acids (50-80 min) and the shortest for carboxylic acids (30-48 min). These T1 /2values were in one-two orders of magnitude higher than LMWOS T1 /2 in soil solution, pointing that LMWOS mineralization occur with a delay after the uptake. Absence of correlations between

  6. Functional Comparison for Lipid Metabolism and Intestinal and Fecal Microflora Enzyme Activities between Low Molecular Weight Chitosan and Chitosan Oligosaccharide in High-Fat-Diet-Fed Rats.

    Science.gov (United States)

    Chiu, Chen-Yuan; Feng, Shih-An; Liu, Shing-Hwa; Chiang, Meng-Tsan

    2017-07-24

    The present study investigated and compared the regulatory effects on the lipid-related metabolism and intestinal disaccharidase/fecal bacterial enzyme activities between low molecular weight chitosan and chitosan oligosaccharide in high-fat-diet-fed rats. Diet supplementation of low molecular weight chitosan showed greater efficiency than chitosan oligosaccharide in suppressing the increased weights in body and in liver and adipose tissues of high-fat-diet-fed rats. Supplementation of low molecular weight chitosan also showed a greater improvement than chitosan oligosaccharide in imbalance of plasma, hepatic, and fecal lipid profiles, and intestinal disaccharidase activities in high-fat-diet-fed rats. Moreover, both low molecular weight chitosan and chitosan oligosaccharide significantly decreased the fecal microflora mucinase and β-glucuronidase activities in high-fat-diet-fed rats. These results suggest that low molecular weight chitosan exerts a greater positive improvement than chitosan oligosaccharide in lipid metabolism and intestinal disaccharidase activity in high-fat-diet-induced obese rats.

  7. Low molecular weight thiols and thioredoxins are important players in Hg(II) resistance in Thermus thermophilus HB27.

    Science.gov (United States)

    Norambuena, J; Wang, Y; Hanson, T; Boyd, J M; Barkay, T

    2017-11-17

    Mercury (Hg), one of the most toxic and widely distributed heavy metals, has a high affinity for thiol groups. Thiol groups reduce and sequester Hg. Therefore, low molecular weight and protein thiols may be important cell components used in Hg resistance. To date, the role of low molecular weight thiols in Hg-detoxification remains understudied. The mercury resistance ( mer ) operon of Thermus thermophilus suggests an evolutionary link between Hg(II) resistance and low molecular weight thiol metabolism. This mer operon encodes for an enzyme involved in methionine biosynthesis, Oah. Challenge with Hg(II) resulted in increased expression of genes involved in the biosynthesis of multiple low molecular weight thiols (cysteine, homocysteine, and bacillithiol), as well as the thioredoxin system. Phenotypic analysis of gene replacement mutants indicated that Oah contributes to Hg resistance under sulfur limiting conditions, and strains lacking bacillithiol and/or thioredoxins are more sensitive to Hg(II) than the wild type. Growth in presence of either a thiol oxidizing agent or a thiol alkylating agent increased sensitivity to Hg(II). Furthermore, exposure to 3 μM Hg(II) consumed all intracellular reduced bacillithiol and cysteine. Database searches indicate that oah2 is present in all Thermus spp. mer operons. The presence of a thiol related gene was also detected in some alphaprotobacterial mer operons, in which a glutathione reductase gene was present, supporting the role of thiols in Hg(II) detoxification. These results have led to a working model in which LMW thiols act as Hg(II) buffering agents while Hg is reduced by MerA. Importance The survival of microorganisms in presence of toxic metals is central to life's sustainability. The affinity of thiol groups to toxic heavy metals drives microbe-metal interactions and modulate metal toxicity. Mercury detoxification ( mer ) genes likely originated early in microbial evolution among geothermal environments. Little is

  8. Measurement error potential and control when quantifying volatile hydrocarbon concentrations in soils

    International Nuclear Information System (INIS)

    Siegrist, R.L.

    1991-01-01

    Due to their widespread use throughout commerce and industry, volatile hydrocarbons such as toluene, trichloroethene, and 1, 1,1-trichloroethane routinely appears as principal pollutants in contamination of soil system hydrocarbons is necessary to confirm the presence of contamination and its nature and extent; to assess site risks and the need for cleanup; to evaluate remedial technologies; and to verify the performance of a selected alternative. Decisions regarding these issues have far-reaching impacts and, ideally, should be based on accurate measurements of soil hydrocarbon concentrations. Unfortunately, quantification of volatile hydrocarbons in soils is extremely difficult and there is normally little understanding of the accuracy and precision of these measurements. Rather, the assumptions often implicitly made that the hydrocarbon data are sufficiently accurate for the intended purpose. This appear presents a discussion of measurement error potential when quantifying volatile hydrocarbons in soils, and outlines some methods for understanding the managing these errors

  9. Low-molecular-weight organoiodine and organobromine compounds released by polar macroalgae--the influence of abiotic factors.

    Science.gov (United States)

    Laturnus, F; Giese, B; Wiencke, C; Adams, F C

    2000-01-01

    The influence of temperature, light, salinity and nutrient availability on the release of volatile halogenated hydrocarbons was investigated in the Antarctic red macroalgal species Gymnogongrus antarcticus Skottsberg. Compared to standard culture condition, an increase in the release rates of iodocompounds was generally found for the exposure of the alga to altered environmental conditions. Macroalgae exhibited higher release rates after adaptation for two months to the changed factors, than after short-term exposure. Monitoring the release rates during a 24 h incubation period (8.25 h light, 15.75 h darkness) showed that changes between light and dark periods had no influence on the release of volatile halocarbons. Compounds like bromoform and 1-iodobutane exhibited constant release rates during the 24 h period. The formation mechanisms and biological role of volatile organohalogens are discussed. Although marine macroalgae are not considered to be the major source of biogenically-produced volatile organohalogens, they contribute significantly to the bromine and iodine cycles in the environment. Under possible environmental changes like global warming and uncontrolled entrophication of the oceans their significance may be increase.

  10. Peptidylation for the determination of low-molecular-weight compounds by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

    Science.gov (United States)

    Tang, Feng; Cen, Si-Ying; He, Huan; Liu, Yi; Yuan, Bi-Feng; Feng, Yu-Qi

    2016-05-23

    Determination of low-molecular-weight compounds by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) has been a great challenge in the analytical research field. Here we developed a universal peptide-based derivatization (peptidylation) strategy for the sensitive analysis of low-molecular-weight compounds by MALDI-TOF-MS. Upon peptidylation, the molecular weights of target analytes increase, thus avoiding serious matrix ion interference in the low-molecular-weight region in MALDI-TOF-MS. Since peptides typically exhibit good signal response during MALDI-TOF-MS analysis, peptidylation endows high detection sensitivities of low-molecular-weight analytes. As a proof-of-concept, we analyzed low-molecular-weight compounds of aldehydes and thiols by the developed peptidylation strategy. Our results showed that aldehydes and thiols can be readily determined upon peptidylation, thus realizing the sensitive and efficient determination of low-molecular-weight compounds by MALDI-TOF-MS. Moreover, target analytes also can be unambiguously detected in biological samples using the peptidylation strategy. The established peptidylation strategy is a universal strategy and can be extended to the sensitive analysis of various low-molecular-weight compounds by MALDI-TOF-MS, which may be potentially used in areas such as metabolomics.

  11. Effect of adjuvant low-molecular-weight heparin therapy on placental hypoxia and cell apoptosis in puerperae with severe preeclampsia

    Directory of Open Access Journals (Sweden)

    Miao Zhou1

    2017-04-01

    Full Text Available Objective: To study the effect of adjuvant low-molecular-weight heparin therapy on placental hypoxia and cell apoptosis in puerperae with severe preeclampsia. Methods: A total of 94 puerperae with severe preeclampsia who received treatment and safely gave birth in our hospital between May 2014 and May 2016 were selected as the research subjects and randomly divided into the LMWH group who received low-molecular-weight heparin combined with conventional symptomatic treatment and the control group who received conventional symptomatic treatment. Before and after treatment, serum was collected respectively to determine the levels of placental hypoxia-related cytokines, and after delivery, the placentas were collected to detect oxidative stress indexes and cell apoptosis indexes. Results: After treatment, serum PLGF and PAPP-A levels of both groups were significantly higher than those before treatment while sFlt-1 and sEng levels were significantly lower than those before treatment, and after treatment, serum PLGF and PAPP-A levels of LMWH group were significantly higher than those of control group while sFlt-1 and sEng levels were significantly lower than those of control group; ROS and RNS levels as well as Fas, FasL, caspase-3 and caspase-8 protein expression in placenta tissue of LMWH group were significantly lower than those of control group while GPx-1, SOD-1 and Trx levels as well as Survivin, XIAP and Bcl-2 protein expression were significantly higher than those of control group. Conclusion: Adjuvant low-molecular-weight heparin therapy can relieve the placental hypoxia, improve oxidative stress reaction and inhibit cell apoptosis in puerperae with severe preeclampsia.

  12. Preparation of Low Molecular Weight Gelatin Using Microwave Discharge Electrodeless Lamp/TiO2 Photocatalyst Hybrid System.

    Science.gov (United States)

    Lee, Do-Jin; Kim, Hangun; Park, Young-Kwon; Kim, Byung Hoon; Lee, Heon; Jungf, Sana-Chul

    2016-02-01

    In this study, an MDEL/TiO2 photocatalyst hybrid system was applied to the production of low molecular weight gelatin. The molecular weight of produed gelatin decreased with increasing microwave intensity and increasing treatment time. The abscission of the chemical bonds between the con- stituents of gelatin by photocatalytic reaction did not alter the characteristics of gelatin. Formation of any by-products due to side reaction was not observed. It is suggested that gelatin was depolymerized by hydroxyl radicals produced during the MDEL/TiO2 photochemical reaction.

  13. Preparation of Low Molecular Weight Heparin by Microwave Discharge Electrodeless Lamp/TiO2 Photo-Catalytic Reaction.

    Science.gov (United States)

    Lee, Do-Jin; Kim, Byung Hoon; Kim, Sun-Jae; Kim, Jung-Sik; Lee, Heon; Jung, Sang-Chul

    2015-01-01

    An MDEL/TiO2 photo-catalyst hybrid system was applied, for the first time, for the production of low molecular weight heparin. The molecular weight of produed heparin decreased with increasing microwave intensity and treatment time. The abscission of the chemical bonds between the constituents of heparin by photo-catalytic reaction did not alter the characteristics of heparin. Formation of by-products due to side reaction was not observed. It is suggested that heparin was depolymerized by active oxygen radicals produced during the MDEL/TiO2 photo-chemical reaction.

  14. Characterization of dacC, which encodes a new low-molecular-weight penicillin-binding protein in Bacillus subtilis

    DEFF Research Database (Denmark)

    Pedersen, Lotte Bang; Murray, T; Popham, D L

    1998-01-01

    The pbp gene (renamed dacC), identified by the Bacillus subtilis genome sequencing project, encodes a putative 491-residue protein with sequence homology to low-molecular-weight penicillin-binding proteins. Use of a transcriptional dacC-lacZ fusion revealed that dacC expression (i) is initiated...... at the end of stationary phase; (ii) depends strongly on transcription factor sigmaH; and (iii) appears to be initiated from a promoter located immediately upstream of yoxA, a gene of unknown function located upstream of dacC on the B. subtilis chromosome. A B. subtilis dacC insertional mutant grew...

  15. Computer aided drug discovery of highly ligand efficient, low molecular weight imidazopyridine analogs as FLT3 inhibitors.

    Science.gov (United States)

    Frett, Brendan; McConnell, Nick; Smith, Catherine C; Wang, Yuanxiang; Shah, Neil P; Li, Hong-yu

    2015-04-13

    The FLT3 kinase represents an attractive target to effectively treat AML. Unfortunately, no FLT3 targeted therapeutic is currently approved. In line with our continued interests in treating kinase related disease for anti-FLT3 mutant activity, we utilized pioneering synthetic methodology in combination with computer aided drug discovery and identified low molecular weight, highly ligand efficient, FLT3 kinase inhibitors. Compounds were analyzed for biochemical inhibition, their ability to selectively inhibit cell proliferation, for FLT3 mutant activity, and preliminary aqueous solubility. Validated hits were discovered that can serve as starting platforms for lead candidates. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  16. Determination of Some Low Molecular Weight Carbohydrates in the Fruits of Wild Cherry Laurel (Laurocerasus officinalis Roem.) Using Gas Chromatography

    OpenAIRE

    AYAZ, F. Ahmet; KADIOĞLU, Asım; HAYIRLIOĞLU-AYAZ, Sema

    1998-01-01

    Some low-molecular-weight carbohydrates extracted with ethanol and water from the fruits of Laurocerasus officinalis Roem. ( Rosaceae), from two different regions in Trabzon, were analysed using gas chromatography. In one population, the analysis in the ethanol extraction showed the occurence of fructose, glucose, sorbitol and sucrose in concentrations (w/w) of 25.20; 23.00; 14.00 and 0.024 %, respectively. The same sugars, in the water extraction were found in concentrations (w/w) of 24.6...

  17. Preparation of Low Allergenic Protein Concentrated Natural Rubber Latex Using Suitable Low Molecular Weight Cellulose Derivatives Induced by Gamma Irradiation

    International Nuclear Information System (INIS)

    Siri-Upathum, Chyagrit; Boonyawat, Jariya

    2007-08-01

    Full text: Low molecular weight carboxy methyl cellulose (CMC), hydroxyl ethyl cellulose (HEC), hydroxyl propyl cellulose (HPC) and methyl cellulose (MC) prepared by radiation-induced degradation were added into diluted natural concentrated latex prior to centrifuge for a purpose of reducing allergenic rubber protein in the latex. Optimum molecular weight (Mv) of CMC and HEC for such a purpose was found to be 17-18 kDa which decreased allergenic rubber protein (14-94 kDa) to an undetectable amount as determined by SDS PAGE method

  18. The low molecular weight protein PsaI stabilizes the light-harvesting complex II docking site of photosystem I

    DEFF Research Database (Denmark)

    Plöchinger, Magdalena; Torabi, Salar; Rantala, Marjaana

    2016-01-01

    PsaI represents one of three low molecular weight peptides of PSI. Targeted inactivation of the plastid PsaI gene in Nicotiana tabacum has no measurable effect on photosynthetic electron transport around PSI or on accumulation of proteins involved in photosynthesis. Instead, the lack of Psa......I destabilizes the association of PsaL and PsaH to PSI, both forming the light-harvesting complex (LHC)II docking site of PSI. These alterations at the LHCII binding site surprisingly did not prevent state transition but led to an increased incidence of PSI-LHCII complexes, coinciding with an elevated...

  19. Effect of low-molecular-weight organic acids on photo-degradation of phenanthrene catalyzed by Fe(III)-smectite under visible light.

    Science.gov (United States)

    Jia, Hanzhong; Chen, Hongxia; Nulaji, Gulimire; Li, Xiyou; Wang, Chuanyi

    2015-11-01

    The photolysis of polycyclic aromatic hydrocarbons (PAHs) is potentially an important process for its transformation and fate on contaminated soil surfaces. In this study, phenanthrene is employed as a model to explore PAH photodegradation with the assistance of Fe(III)-smectite under visible-light while focusing on roles played by five low-molecular-weight organic acids (LMWOAs), i.e., malic acid, oxalic acid, citric acid, ethylenediaminetetraacetic acid (EDTA), and nitrilotriacetic acid. Our results show that oxalic acid is most effective in promoting the photodegradation of phenanthrene, while only a slight increase in the rate of phenanthrene photodegradation is observed in the presence of malic acid. Electron paramagnetic resonance experiments confirm the formation of CO2(-) radicals in the presence of malic and oxalic acid, which provides strong evidence for generating OH and subsequent photoreaction pathways. The presence of EDTA or nitrilotriacetic acid significantly inhibits both Fe(II) formation and phenanthrene photodegradation because these organic anions tend to chelate with Fe(III), leading to decreases in the electron-accepting potential of Fe(III)-smectite and a weakened interaction between phenanthrene and Fe(III)-smectite. These observations provide valuable insights into the transformation and fate of PAHs in the natural soil environment and demonstrate the potential for using some LMWOAs as additives for the remediation of contaminated soil. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Volatile Fuel Hydrocarbons and MTBE in the Environment

    Science.gov (United States)

    Cozzarelli, I. M.; Baehr, A. L.

    2003-12-01

    Petroleum hydrocarbons (hydrocarbons that result from petroleum products such as oil, gasoline, or diesel fuel) are among the most commonly occurring and widely distributed contaminants in the environment. Volatile hydrocarbons are the lighter fraction of the petroleum hydrocarbons and, together with fuel oxygenates, are most often released from crude oil and liquid petroleum products produced from crude oil. The demand for crude oil stems from the world's ever-growing energy need. From 1970 to 1999, primary energy production of the world grew by 76% (Energy Information Administration, 2001), with fossil fuels (crude oil, natural gas, and coal) accounting for ˜85% of all energy produced worldwide (Figure 1). World crude oil production reached a record 68 million barrels (bbl) per day (1.08×1010 L d-1) in 2000. The world's dependence on oil as an energy source clearly is identified as contributing to global warming and worsening air and water quality. (7K)Figure 1. World primary energy production by source from 1970 to 1999 (Energy Information Administration, 2001). Petroleum products are present in Earth's subsurface as solids, liquids, or gases. This chapter presents a summary of the environmental problems and issues related to the use of liquid petroleum, or oil. The focus is on the sources of volatile hydrocarbons and fuel oxygenates and the geochemical behavior of these compounds when they are released into the environment. Although oxygenates currently in commercial use include compounds other than methyl t-butyl ether (MTBE), such as ethanol (ETOH), most of the information presented here focuses on MTBE because of its widespread occurrence. The environmental impact of higher molecular weight hydrocarbons that also originate from petroleum products is described in (Chapter 9.13, Abrajano et al.).Crude oil occurs within the Earth and is a complex mixture of natural compounds composed largely of hydrocarbons containing only hydrogen and carbon atoms. The minor

  1. Evidence of low molecular weight components in the organic matrix of the reef building coral, Stylophora pistillata.

    Science.gov (United States)

    Puverel, S; Houlbrèque, F; Tambutté, E; Zoccola, D; Payan, P; Caminiti, N; Tambutté, S; Allemand, D

    2007-08-01

    Biominerals contain both inorganic and organic components. Organic components are collectively termed the organic matrix, and this matrix has been reported to play a crucial role in mineralization. Several matrix proteins have been characterized in vertebrates, but only a few in invertebrates, primarily in Molluscs and Echinoderms. Methods classically used to extract organic matrix proteins eliminate potential low molecular weight matrix components, since cut-offs ranging from 3.5 to 10 kDa are used to desalt matrix extracts. Consequently, the presence of such components remains unknown and these are never subjected to further analyses. In the present study, we have used microcolonies from the Scleractinian coral Stylophora pistillata to study newly synthesized matrix components by labelling them with 14C-labelled amino acids. Radioactive matrix components were investigated by a method in which both total organic matrix and fractions of matrix below and above 5 kDa were analyzed. Using this method and SDS-PAGE analyses, we were able to detect the presence of low molecular mass matrix components (weight molecules, these probably form the bulk of newly synthesized organic matrix components. Our results suggest that these low molecular weight components may be peptides, which can be involved in the regulation of coral skeleton mineralization.

  2. The polysaccharide and low molecular weight components of Opuntia ficus indica cladodes: Structure and skin repairing properties.

    Science.gov (United States)

    Di Lorenzo, Flaviana; Silipo, Alba; Molinaro, Antonio; Parrilli, Michelangelo; Schiraldi, Chiara; D'Agostino, Antonella; Izzo, Elisabetta; Rizza, Luisa; Bonina, Andrea; Bonina, Francesco; Lanzetta, Rosa

    2017-02-10

    The Opuntia ficus-indica multiple properties are reflected in the increasing interest of chemists in the identification of its natural components having pharmaceutical and/or cosmetical applications. Here we report the structural elucidation of Opuntia ficus-indica mucilage that highlighted the presence of components differing for their chemical nature and the molecular weight distribution. The high molecular weight components were identified as a linear galactan polymer and a highly branched xyloarabinan. The low molecular weight components were identified as lactic acid, D-mannitol, piscidic, eucomic and 2-hydroxy-4-(4'-hydroxyphenyl)-butanoic acids. A wound healing assay was performed in order to test the cicatrizing properties of the various components, highlighting the ability of these latter to fasten dermal regeneration using a simplified in vitro cellular model based on a scratched keratinocytes monolayer. The results showed that the whole Opuntia mucilage and the low molecular weight components are active in the wound repair. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Low molecular weight components in an aquatic humic substance as characterized by membrane dialysis and orbitrap mass spectrometry.

    Science.gov (United States)

    Remucal, Christina K; Cory, Rose M; Sander, Michael; McNeill, Kristopher

    2012-09-04

    Suwannee River fulvic acid (SRFA) was dialyzed through a 100-500 molecular weight cutoff dialysis membrane, and the dialysate and retentate were analyzed by UV-visible absorption and high-resolution Orbitrap mass spectrometry (MS). A significant fraction (36% based on dissolved organic carbon) of SRFA passed through the dialysis membrane. The fraction of SRFA in the dialysate had a different UV-visible absorption spectrum and was enriched in low molecular weight molecules with a more aliphatic composition relative to the initial SRFA solution. Comparison of the SRFA spectra collected by Orbitrap MS and Fourier transform ion cyclotron resonance MS (FT-ICR MS) demonstrated that the mass accuracy of the Orbitrap MS is sufficient for determination of unique molecular formulas of compounds with masses masses detected by Orbitrap MS were found in the 100-200 Da mass range. Many of these low molecular masses corresponded to molecular formulas of previously identified compounds in organic matter, lignin, and plants, and the use of the standard addition method provided an upper concentration estimate of selected target compounds in SRFA. Collectively, these results provide evidence that SRFA contains low molecular weight components that are present individually or in loosely bound assemblies.

  4. Photo-oxidation of 6-thioguanine by UVA: the formation of addition products with low molecular weight thiol compounds.

    Science.gov (United States)

    Ren, Xiaolin; Xu, Yao-Zhong; Karran, Peter

    2010-01-01

    The thiopurine, 6-thioguanine (6-TG) is present in the DNA of patients treated with the immunosuppressant and anticancer drugs azathioprine or mercaptopurine. The skin of these patients is selectively sensitive to UVA radiation-which comprises >90% of the UV light in incident sunlight-and they suffer high rates of skin cancer. UVA irradiation of DNA 6-TG produces DNA lesions that may contribute to the development of cancer. Antioxidants can protect 6-TG against UVA but 6-TG oxidation products may undergo further reactions. We characterize some of these reactions and show that addition products are formed between UVA-irradiated 6-TG and N-acetylcysteine and other low molecular weight thiol compounds including β-mercaptoethanol, cysteine and the cysteine-containing tripeptide glutathione (GSH). GSH is also adducted to 6-TG-containing oligodeoxynucleotides in an oxygen- and UVA-dependent nucleophilic displacement reaction that involves an intermediate oxidized 6-TG, guanine sulfonate (G(SO3) ). These photochemical reactions of 6-TG, particularly the formation of a covalent oligodeoxynucleotide-GSH complex, suggest that crosslinking of proteins or low molecular weight thiol compounds to DNA may be a previously unrecognized hazard in sunlight-exposed cells of thiopurine-treated patients. © 2010 The Authors. Journal Compilation. The American Society of Photobiology.

  5. Effect of low-molecular-weight beta-cyclodextrin polymer on release of drugs from mucoadhesive buccal film dosage forms.

    Science.gov (United States)

    Arakawa, Yotaro; Kawakami, Shigeru; Yamashita, Fumiyoshi; Hashida, Mitsuru

    2005-09-01

    We investigated the effect of low-molecular-weight beta-cyclodextrin (beta-CyD) polymer on in vitro release of two drugs with different lipophilicities (i.e., lidocaine and ketoprofen) from mucoadhesive buccal film dosage forms. When beta-CyD polymer was added to hydroxypropylcellulose (HPC) or polyvinylalcohol (PVA) film dosage forms, the release of lidocaine into artificial saliva (pH 5.7) was reduced by 40% of the control. In contrast, the release of ketoprofen from the polymer film was enhanced by addition of beta-CyD polymer to the vehicle. When lidocaine and ketoprofen was incubated with beta-CyD polymer in the artificial saliva, concentration of free lidocaine molecules decreased in a beta-CyD polymer concentration-dependent manner. The association constant with beta-CyD polymer was 6.9+/-0.6 and 520+/-90 M(-1) for lidocaine and ketoprofen, respectively. Retarded release of the hydrophilic lidocaine by beta-CyD polymer might be due to the decrease in thermodynamic activity by inclusion complex formation, whereas enhanced release of the lipophilic ketoprofen by the beta-CyD polymer might be due to prevention of recrystallization occurring after contacting the film with aqueous solution. Thus, effects of low-molecular-weight beta-CyD polymer to the drug release rate from film dosage forms would vary according to the strength of interaction with and the solubility of active ingredient.

  6. Low-Molecular-Weight Metabolites from Diatoms: Structures, Biological Roles and Biosynthesis

    Directory of Open Access Journals (Sweden)

    Valentin Stonik

    2015-06-01

    Full Text Available Diatoms are abundant and important biological components of the marine environment that biosynthesize diverse natural products. These microalgae are rich in various lipids, carotenoids, sterols and isoprenoids, some of them containing toxins and other metabolites. Several groups of diatom natural products have attracted great interest due to their potential practical application as energy sources (biofuel, valuable food constituents, and prospective materials for nanotechnology. In addition, hydrocarbons, which are used in climate reconstruction, polyamines which participate in biomineralization, new apoptotic agents against tumor cells, attractants and deterrents that regulate the biochemical communications between marine species in seawaters have also been isolated from diatoms. However, chemical studies on these microalgae are complicated by difficulties, connected with obtaining their biomass, and the influence of nutrients and contaminators in their environment as well as by seasonal and climatic factors on the biosynthesis of the corresponding natural products. Overall, the number of chemically studied diatoms is lower than that of other algae, but further studies, particularly those connected with improvements in the isolation and structure elucidation technique as well as the genomics of diatoms, promise both to increase the number of studied species with isolated biologically active natural products and to provide a clearer perception of their biosynthesis.

  7. Degradation of volatile hydrocarbons from steam-classified solid waste by a mixture of aromatic hydrocarbon-degrading bacteria.

    Science.gov (United States)

    Leahy, Joseph G; Tracy, Karen D; Eley, Michael H

    2003-03-01

    Steam classification is a process for treatment of solid waste that allows recovery of volatile organic compounds from the waste via steam condensate and off-gases. A mixed culture of aromatic hydrocarbon-degrading bacteria was used to degrade the contaminants in the condensate, which contained approx. 60 hydrocarbons, of which 38 were degraded within 4 d. Many of the hydrocarbons, including styrene, 1,2,4-trimethylbenzene, naphthalene, ethylbenzene, m-/p-xylene, chloroform, 1,3-dichloropropene, were completely or nearly completely degraded within one day, while trichloroethylene and 1,2,3-trichloropropane were degraded more slowly.

  8. Preparation of Low Molecular Weight Chitosan by Radiation and its Application for Plant Growth Promoter. Chapter 10

    Energy Technology Data Exchange (ETDEWEB)

    Darwis, D.; Puspitasari, T.; Iramani, D.; Susilowati, Sri; Pangerteni, D.S., E-mail: darmawan_p3tir@batan.go.id [National Nuclear Energy Agency, Centre for Application of Isotopes and Radiation Technology (Indonesia)

    2014-07-15

    Chitosan was prepared through the alkaline deacetylation of chitin from shrimp shell waste. Chitosan with a degree of deacetylation of about 70% was produced by hot alkaline deacetylation (DDA) at 90°C for 8 hours or at room temperature deacetylation for 7 days. Through these processes, chitosan with an average molecular weight (Mw) of 141 k Dalton was obtained. Low molecular weight chitosan, Mw 14 k Dalton called “Fitosan” was prepared by irradiating chitosan using gamma rays at a dose of 75 kGy. The results showed that gamma irradiation is an effective method of degrading chitosan by cleavages of glycosidic bond. To improve crop yields and suppress diseases due to virus, bacteria, and fungi, Fitosan was successfully applied to chili, potato, and soybean. Socio-economic impacts of the use of Fitosan on the plants include increased income and improvement of the welfare of farmers. (author)

  9. [Search for potential gastric cancer biomarkers using low molecular weight blood plasma proteome profiling by mass spectrometry].

    Science.gov (United States)

    Shevchenko, V E; Arnotskaia, N E; Ogorodnikova, E V; Davydov, M M; Ibraev, M A; Turkin, I N; Davydov, M I

    2014-01-01

    Gastric cancer, one of the most widespread malignant tumors, still lacks reliable serum/plasma biomarkers of its early detection. In this study we have developed, unified, and tested a new methodology for search of gastric cancer biomarkers based on profiling of low molecular weight proteome (LMWP) (1-17 kDa). This approach included three main components: sample pre-fractionation, matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS), data analysis by a bioinformatics software package. Applicability and perspectives of the developed approach for detection of potential gastric cancer markers during LMWP analysis have been demonstrated using 69 plasma samples from patients with gastric cancer (stages I-IV) and 238 control samples. The study revealed peptides/polypeptides, which may be potentially used for detection of this pathology.

  10. Approaches for the analysis of low molecular weight compounds with laser desorption/ionization techniques and mass spectrometry.

    Science.gov (United States)

    Bergman, Nina; Shevchenko, Denys; Bergquist, Jonas

    2014-01-01

    This review summarizes various approaches for the analysis of low molecular weight (LMW) compounds by different laser desorption/ionization mass spectrometry techniques (LDI-MS). It is common to use an agent to assist the ionization, and small molecules are normally difficult to analyze by, e.g., matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) using the common matrices available today, because the latter are generally small organic compounds themselves. This often results in severe suppression of analyte peaks, or interference of the matrix and analyte signals in the low mass region. However, intrinsic properties of several LDI techniques such as high sensitivity, low sample consumption, high tolerance towards salts and solid particles, and rapid analysis have stimulated scientists to develop methods to circumvent matrix-related issues in the analysis of LMW molecules. Recent developments within this field as well as historical considerations and future prospects are presented in this review.

  11. Biomimetic studies of wood decay: Simulating the effect of low molecular weight compounds and fungal enzymes

    DEFF Research Database (Denmark)

    Hastrup, Anne Christine Steenkjær; Howell, Caitlin; Jellison, Jody

    The effect of FeCl3 (Fe3+), hydrogen peroxide (H2O2), a low molecular weight compound (2,3- Dihydroxybenzoic acid), and oxalic acid on wood were tested in a study designed to mimic wood degradation by brown rot fungi. Previous studies suggest that these components are involved in the early stages...... 50 ml of 40 mM acetate buffer (pH 4.5), white pine wood powder and varying combinations of the chemicals previously mentioned. Changes in cellulose crystallinity were analyzed by X-ray diffraction using a ¿-2¿ scan. Findings suggest that iron, H2O2, chelators and oxalic acid may affect over all...

  12. Water extraction of coals - potential for estimating low molecular weight organic acids as carbon feedstock for the deep terrestrial biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Vieth, A.; Mangelsdorf, K.; Sykes, R.; Horsfield, B. [Geoforschungszentrum Potsdam, Potsdam (Germany)

    2008-08-15

    With the recent increasing interest in the deep biosphere, the question arises as to where the carbon sources that support deep microbial communities are derived from. Our research was focussed on the water-soluble, low molecular weight (LMW) organic acids that are potentially available from different sedimentary lithologies to serve as a carbon source to feed the deep biosphere. A series of Eocene-Pleistocene coals, mudstones and sandstones of varying rank (maturity) and total organic carbon (TOC) content from the Waikato Basin, New Zealand, has been Soxhlet-extracted using water. The combined concentration of recovered formate, acetate and oxalate range from 366 to 2499 {mu} g/g sediment and appear to be dependent on rank, organofacies and TOC. The yields indicate the potential of carbonaceous sediments to feed the local deep terrestrial biosphere over geological periods of time. The existence of living microbial organisms in the mudstones and sandstones was proved by the identification of intact phospholipids (PLs).

  13. In Vivo Anti-Cancer Mechanism of Low-Molecular-Weight Fucosylated Chondroitin Sulfate (LFCS) from Sea Cucumber Cucumaria frondosa.

    Science.gov (United States)

    Liu, Xiaoxiao; Liu, Yong; Hao, Jiejie; Zhao, Xiaoliang; Lang, Yinzhi; Fan, Fei; Cai, Chao; Li, Guoyun; Zhang, Lijuan; Yu, Guangli

    2016-05-12

    The low-molecular-weight fucosylated chondroitin sulfate (LFCS) was prepared from native fucosylated chondroitin sulfate (FCS), which was extracted and isolated from sea cucumber Cucumaria frondosa, and the anti-cancer mechanism of LFCS on mouse Lewis lung carcinoma (LLC) was investigated. The results showed that LFCS remarkably inhibited LLC growth and metastasis in a dose-dependent manner. LFCS induced cell cycle arrest by increasing p53/p21 expression and apoptosis through activation of caspase-3 activity in LLC cells. Meanwhile, LFCS suppressed the expression of vascular endothelial growth factor (VEGF), increased the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) and downregulated the matrix metalloproteinases (MMPs) level. Furthermore, LFCS significantly suppressed the activation of ERK1/2/p38 MAPK/NF-κB pathway, which played a prime role in expression of MMPs. All of these data indicate LFCS may be used as anti-cancer drug candidates and deserve further study.

  14. In Vivo Anti-Cancer Mechanism of Low-Molecular-Weight Fucosylated Chondroitin Sulfate (LFCS from Sea Cucumber Cucumaria frondosa

    Directory of Open Access Journals (Sweden)

    Xiaoxiao Liu

    2016-05-01

    Full Text Available The low-molecular-weight fucosylated chondroitin sulfate (LFCS was prepared from native fucosylated chondroitin sulfate (FCS, which was extracted and isolated from sea cucumber Cucumaria frondosa, and the anti-cancer mechanism of LFCS on mouse Lewis lung carcinoma (LLC was investigated. The results showed that LFCS remarkably inhibited LLC growth and metastasis in a dose-dependent manner. LFCS induced cell cycle arrest by increasing p53/p21 expression and apoptosis through activation of caspase-3 activity in LLC cells. Meanwhile, LFCS suppressed the expression of vascular endothelial growth factor (VEGF, increased the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1 and downregulated the matrix metalloproteinases (MMPs level. Furthermore, LFCS significantly suppressed the activation of ERK1/2/p38 MAPK/NF-κB pathway, which played a prime role in expression of MMPs. All of these data indicate LFCS may be used as anti-cancer drug candidates and deserve further study.

  15. Effects of low molecular weight fungal compounds on inflammatory gene transcription and expression in mouse alveolar macrophages.

    Science.gov (United States)

    Rand, Thomas G; Dipenta, J; Robbins, C; Miller, J D

    2011-04-25

    The inflammatory potential and molecular mechanisms underscoring inflammatory responses of lung cells to compounds from fungi that grow on damp building materials is poorly understood in vitro. In this study we evaluated the effect of pure fungal compounds on potentiating acute inflammatory response in primary mouse alveolar macrophages (AMs) and tested the hypothesis that AM responses to low molecular weight fungal compounds exhibit temporal and compound specificity that mimic that observed in the whole lung. Transcriptional responses of 13 inflammation/respiratory burst-associated genes (KC=Cxcl1, Cxcl2, Cxcl5, Cxcl10, Ccl3, Ccl112, Ccl20, IL-1β, Il-6, ifi27 Tnfα, iNOS and Blvrb) were evaluated in mouse AMs exposed to a 1ml (10(-8)mol) dose of either pure atranone C, brevianimide, cladosporin, curdlan, LPS, neoechinulin A & B, sterigmatocystin or TMC-120A for 2h, 4h and 12h PE using customized reverse transcription (RT)-PCR based arrays. Multianalyte ELISA was used to measure expression of 6 pro-inflammatory cytokines common to the transcriptional assays (Cxcl1, Cxcl10, Ccl3, IL1β, Ifn-λ and Tnf-α) to determine whether gene expression corresponded to the transcription data. Compared to controls, all of these compounds induced significant (≥2.5-fold or ≤-2.5-fold change at p≤0.05) time- and compound-specific transcriptional gene alterations in treatment AMs. The highest number of transcribed genes were in LPS treatment AMs at 12h PE (12/13) followed by neoechinulin B at 4h PE (11/13). Highest fold change values (>30) were associated with KC, Cxcl2, Cxcl5 and IL1β genes in cells exposed to LPS. Compound exposures also induced significant (p≤0.05) time- and compound-specific pro-inflammatory responses manifest as differentially elevated Cxcl1, Cxcl10, Ccl3, Ifn-λ and Tnf-α concentrations in culture supernatant of treatment AMs. Dissimilarity in transcriptional responses in AMs and our in vivo model of lung disease is likely attributable to whole lung

  16. Spatial distributions of and diurnal variations in low molecular weight carbonyl compounds in coastal seawater, and the controlling factors

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Kazuhiko, E-mail: takedaq@hiroshima-u.ac.jp [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Katoh, Shinya; Mitsui, Yumi; Nakano, Shinichi [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Nakatani, Nobutake [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Department of Environmental and Symbiotic Sciences, Rakuno Gakuen University, 582 Bunkyodai-Midorimachi, Ebetsu, Hokkaido 069-8501 (Japan); Sakugawa, Hiroshi [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan)

    2014-09-15

    We studied the spatial distributions of and the diurnal variations in four low molecular weight (LMW) carbonyl compounds, formaldehyde, acetaldehyde, propionaldehyde, and glyoxal, in coastal seawater. The samples were taken from the coastal areas of Hiroshima Bay, the Iyo Nada, and the Bungo Channel, western Japan. The formaldehyde, acetaldehyde, and glyoxal concentrations were higher in the northern part of Hiroshima Bay than at offshore sampling points in the Iyo Nada and the Bungo Channel. These three compounds were found at much higher concentrations in the surface water than in deeper water layers in Hiroshima Bay. It is noteworthy that propionaldehyde was not detected in any of the seawater samples, the concentrations present being lower than the detection limit (1 nanomole per liter (nM)) of the high performance liquid chromatography (HPLC) system we used. Photochemical and biological experiments were performed in the laboratory to help understand the characteristic distributions and fates of the LMW carbonyl compounds. The primary process controlling their fate in the coastal environment appears to be their biological consumption. The direct photo degradation of propionaldehyde, initiated by ultraviolet (UV) absorption, was observed, although formaldehyde and acetaldehyde were not degraded by UV irradiation. Our results suggest that the degradation of the LMW carbonyl compounds by photochemically formed hydroxyl radicals is relatively insignificant in the study area. Atmospheric deposition is a possible source of soluble carbonyl compounds in coastal surface seawater, but it may not influence the carbonyl concentrations in offshore waters. - Highlights: • Low molecular weight (LMW) carbonyl compounds in coastal seawater were determined. • Photochemical productions of LMW carbonyl compounds in seawater were observed. • LMW carbonyl compounds were largely consumed biologically. • Photochemical degradation was relatively insignificant in the study area.

  17. Spatial distributions of and diurnal variations in low molecular weight carbonyl compounds in coastal seawater, and the controlling factors

    International Nuclear Information System (INIS)

    Takeda, Kazuhiko; Katoh, Shinya; Mitsui, Yumi; Nakano, Shinichi; Nakatani, Nobutake; Sakugawa, Hiroshi

    2014-01-01

    We studied the spatial distributions of and the diurnal variations in four low molecular weight (LMW) carbonyl compounds, formaldehyde, acetaldehyde, propionaldehyde, and glyoxal, in coastal seawater. The samples were taken from the coastal areas of Hiroshima Bay, the Iyo Nada, and the Bungo Channel, western Japan. The formaldehyde, acetaldehyde, and glyoxal concentrations were higher in the northern part of Hiroshima Bay than at offshore sampling points in the Iyo Nada and the Bungo Channel. These three compounds were found at much higher concentrations in the surface water than in deeper water layers in Hiroshima Bay. It is noteworthy that propionaldehyde was not detected in any of the seawater samples, the concentrations present being lower than the detection limit (1 nanomole per liter (nM)) of the high performance liquid chromatography (HPLC) system we used. Photochemical and biological experiments were performed in the laboratory to help understand the characteristic distributions and fates of the LMW carbonyl compounds. The primary process controlling their fate in the coastal environment appears to be their biological consumption. The direct photo degradation of propionaldehyde, initiated by ultraviolet (UV) absorption, was observed, although formaldehyde and acetaldehyde were not degraded by UV irradiation. Our results suggest that the degradation of the LMW carbonyl compounds by photochemically formed hydroxyl radicals is relatively insignificant in the study area. Atmospheric deposition is a possible source of soluble carbonyl compounds in coastal surface seawater, but it may not influence the carbonyl concentrations in offshore waters. - Highlights: • Low molecular weight (LMW) carbonyl compounds in coastal seawater were determined. • Photochemical productions of LMW carbonyl compounds in seawater were observed. • LMW carbonyl compounds were largely consumed biologically. • Photochemical degradation was relatively insignificant in the study area

  18. Low-Molecular-Weight Chitosan Supplementation Increases the Population of Prevotella in the Cecal Contents of Weanling Pigs

    Directory of Open Access Journals (Sweden)

    Ting Yu

    2017-11-01

    Full Text Available Low-molecular-weight chitosan (LC promoted growth in weaned piglets as an alternative to feed-grade antibiotics. To investigate the influence of LC supplementation on piglets' gut microbiome and compare the differences in community composition between LC and antibiotics with ZnO addition, we assessed the cecal microbial community by 16S rRNA gene sequencing with three treatments consisting of basal diet (CTR group, basal diet with low-molecular-weight chitosan (LC group, and basal diet with antibiotic and ZnO (AZ group. LC decreased pH more than AZ did in the cecum (both compared to CTR. Beta diversity analysis showed that community structure was distinctly different among the CTR, LC, and AZ treatments, indicating that either LC or AZ treatment modulated the piglet microbiota. Bacteroidetes, Firmicutes, and Proteobacteria dominated the community [>98% of operational taxonomic units (OTUs] in piglet cecal contents. Compared to CTR, both LC, and AZ increased the relative abundance of Bacteroidetes while they decreased the count of Firmicutes and AZ decreased the population of Proteobacteria. In CTR the top four abundant genera were Prevotella (~10.4%, Succinivibrio (~6.2%, Lactobacillus (~5.6%, and Anaerovibrio (5.4%. Both LC and AZ increased the relative abundance of Prevotella but decreased the ratio of Lactobacillus when they compared with CTR. Moreover, LC increased the relative abundance of Succinivibrio and Anaerovibrio while AZ decreased them. The microbial function prediction showed LC enriched more pathways in the metabolism of cofactors and vitamins than CTR or AZ did. LC may potentially function as an alternative to feed-grade antibiotics in weaned piglets due to its beneficial regulation of the intestinal microbiome.

  19. Enhanced levels of atmospheric low-molecular weight monocarboxylic acids in gas and particulates over Mt. Tai, North China, during field burning of agricultural wastes

    Science.gov (United States)

    Mochizuki, Tomoki; Kawamura, Kimitaka; Nakamura, Shinnosuke; Kanaya, Yugo; Wang, Zifa

    2017-12-01

    To understand the source and atmospheric behaviour of low molecular weight monocarboxylic acids (monoacids), gaseous (G) and particulate (P) organic acids were collected at the summit of Mt. Tai in the North China Plain (NCP) during field burning of agricultural waste (wheat straw). Particulate organic acids were collected with neutral quartz filter whereas gaseous organic acids were collected with KOH-impregnated quartz filter. Normal (C1-C10), branched (iC4-iC6), hydroxy (lactic and glycolic), and aromatic (benzoic) monoacids were determined with a capillary gas chromatography employing p-bromophenacyl esters. We found acetic acid as the most abundant gas-phase species whereas formic acid is the dominant particle-phase species. Concentrations of formic (G/P 1 570/1 410 ng m-3) and acetic (3 960/1 120 ng m-3) acids significantly increased during the enhanced field burning of agricultural wastes. Concentrations of formic and acetic acids in daytime were found to increase in both G and P phases with those of K+, a field-burning tracer (r = 0.32-0.64). Primary emission and secondary formation of acetic acid is linked with field burning of agricultural wastes. In addition, we found that particle-phase fractions (Fp = P/(G + P)) of formic (0.50) and acetic (0.31) acids are significantly high, indicating that semi-volatile organic acids largely exist as particles. Field burning of agricultural wastes may play an important role in the formation of particulate monoacids in the NCP. High levels (917 ng m-3) of particle-phase lactic acid, which is characteristic of microorganisms, suggest that microbial activity associated with terrestrial ecosystem significantly contributes to the formation of organic aerosols.

  20. Preparation of Low Molecular Weight Chondroitin Sulfates, Screening of a High Anti-Complement Capacity of Low Molecular Weight Chondroitin Sulfate and Its Biological Activity Studies in Attenuating Osteoarthritis.

    Science.gov (United States)

    Li, Lian; Li, Yan; Feng, Danyang; Xu, Linghua; Yin, Fengxin; Zang, Hengchang; Liu, Chunhui; Wang, Fengshan

    2016-10-11

    Chondroitin sulfate (CS) plays important roles in the complement system. However, the CS structure is complicated due to different sources and the number and positions of sulfate groups. The objective of this study was to prepare different low molecular weight chondroitin sulfates (LMWCSs) and to investigate the biological activity in anti-complement capacity. A series of LMWCSs was prepared from different sources and characterized by ultraviolet-visible (UV) spectroscopy, high-performance liquid chromatography (HPLC), size exclusion chromatography-multiangle laser light scattering (SEC-MALLS) and nuclear magnetic resonance (NMR) spectroscopy. Hemolytic, anti-complement 3 deposition capacity and cell viability assays were carried out to investigate the biological activities in vitro. The results showed that LMWCS prepared from shark cartilage with the oxidative degradation method (LMWCS-S-O) had the best anti-complement capacity. LMWCS-S-O could inhibit the alternative pathway of the complement system and protect chondrocytes from cell death. The attenuating effect of LMWCS-S-O on Osteoarthritis (OA) was investigated by destabilization of the medial meniscus (DMM) model in vivo. Functional wind-up, histological and C5b-9 analyses were used to evaluate the treatment effect on the OA model. In vivo results showed that LMWCS-S-O could attenuate OA. LMWCS-S-O with a high content of ΔDi-2,6diS and ΔDi-6S could be used for attenuating OA through regulating the complement system.

  1. Preparation of Low Molecular Weight Chondroitin Sulfates, Screening of a High Anti-Complement Capacity of Low Molecular Weight Chondroitin Sulfate and Its Biological Activity Studies in Attenuating Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Lian Li

    2016-10-01

    Full Text Available Chondroitin sulfate (CS plays important roles in the complement system. However, the CS structure is complicated due to different sources and the number and positions of sulfate groups. The objective of this study was to prepare different low molecular weight chondroitin sulfates (LMWCSs and to investigate the biological activity in anti-complement capacity. A series of LMWCSs was prepared from different sources and characterized by ultraviolet-visible (UV spectroscopy, high-performance liquid chromatography (HPLC, size exclusion chromatography-multiangle laser light scattering (SEC-MALLS and nuclear magnetic resonance (NMR spectroscopy. Hemolytic, anti-complement 3 deposition capacity and cell viability assays were carried out to investigate the biological activities in vitro. The results showed that LMWCS prepared from shark cartilage with the oxidative degradation method (LMWCS-S-O had the best anti-complement capacity. LMWCS-S-O could inhibit the alternative pathway of the complement system and protect chondrocytes from cell death. The attenuating effect of LMWCS-S-O on Osteoarthritis (OA was investigated by destabilization of the medial meniscus (DMM model in vivo. Functional wind-up, histological and C5b-9 analyses were used to evaluate the treatment effect on the OA model. In vivo results showed that LMWCS-S-O could attenuate OA. LMWCS-S-O with a high content of ΔDi-2,6diS and ΔDi-6S could be used for attenuating OA through regulating the complement system.

  2. Characterization of low molecular weight fragments from gamma irradiated κ-carrageenan used as plant growth promoter

    Science.gov (United States)

    Abad, Lucille V.; Aurigue, Fernando B.; Relleve, Lorna S.; Montefalcon, Djowel Recto V.; Lopez, Girlie Eunice P.

    2016-01-01

    Radiation degraded κ-carrageenan (1% solution at absorbed doses of 20 kGy and 30 kGy) were tested for its plant growth promoter (PGP) effect on pechay plants under hydroponics condition. Results revealed that higher PGP effects were found in κ-carrageenan irradiated at an absorbed dose of 30 kGy. Mw of irradiated κ-carrageenan as measured by GPC were determined to be 7362 Da and 6762 Da for 20 kGy and 30 kGy, respectively. Fractionation of the irradiated κ-carrageenan (30 kGy) was done to separate different Mw fractions using Mw cut-off filters of 1 kDa, 3 kDa, and 5 kDa. The PGP effect of the different retentates showed that biological activity in plants followed the order of 5 kDa>3 kDa>1 kDa using hydroponics condition but the reverse was observed in the order of 1 kDa>3 kDa>5 kDa when absorbed in plants by foliar spraying. GPC chromatogram indicated at least three (3) low molecular weight (LMW) fragments from radiation modified κ-carrageenan solution with an Mw<2000 Da. A fragment has also been identified with an Mw of as low as 160 Da which was produced under acidic (un-neutralized) condition. This may be attributed to the formation of 5-hydroxymethylfurfural (5-HMF).

  3. Development and in vivo evaluation of an oral delivery system for low molecular weight heparin based on thiolated polycarbophil.

    Science.gov (United States)

    Kast, Constantia E; Guggi, Davide; Langoth, Nina; Bernkop-Schnürch, Andreas

    2003-06-01

    It was the purpose of this study to develop a new oral drug delivery system for low molecular weight heparin (LMWH) providing an improved bioavailability and a prolonged therapeutic effect. The permeation enhancing polycarbophil-cysteine conjugate (PCP-Cys) used in this study displayed 111.4 +/- 6.4 microM thiol groups per gram polymer. Permeation studies on freshly excised intestinal mucosa were performed in Ussing chambers demonstrating a 2-fold improved uptake of heparin as a result of the addition of 0.5% (w/v) PCP-Cys and the permeation mediator glutathione (GSH). Tablets containing PCP-Cys, GSH, and 279 IU of LMWH showed a sustained drug release over 4 h. To guarantee the swelling of the polymeric carrier matrix in the small intestine tablets were enteric coated. They were orally given to rats. For tablets being based on the thiomer/GSH system an absolute bioavailability of 19.9 +/- 9.3% (means +/- SD; n = 5) vs. intravenous injection could be achieved. whereas tablets comprising unmodified PCP did not lead to a significant (p < 0.01) heparin concentration in plasma. The permeation enhancing effect and subsequently a therapeutic heparin level was maintained for 24 h after a single dose. Because of the strong and prolonged lasting permeation enhancing effect of the thiomer/GSH system, the oral bioavailability of LMWH could be significantly improved. This new delivery system represents therefore a promising tool for the oral administration of heparin.

  4. Effects of low molecular weight hyaluronan combined with carprofen on canine osteoarthritis articular chondrocytes and cartilage explants in vitro.

    Science.gov (United States)

    Euppayo, Thippaporn; Siengdee, Puntita; Buddhachat, Kittisak; Pradit, Waranee; Viriyakhasem, Nawarat; Chomdej, Siriwadee; Ongchai, Siriwan; Harada, Yasuji; Nganvongpanit, Korakot

    2015-09-01

    Intra-articular injection with non-steroidal anti-inflammatory drugs (NSAIDs) is used to treat inflammatory joint disease, but the side effects of NSAIDs include chondrotoxicity. Hyaluronan has shown positive effects on chondrocytes by reducing apoptosis and increasing proteoglycan synthesis. The purposes of this study were to evaluate the effects of low molecular weight hyaluronan (low MW HA), carprofen 25 mg/ml, carprofen 12.5 mg/ml, and a combination of HA and carprofen on canine osteoarthritis (OA) articular chondrocytes and a cartilage explant model in terms of cell viability, extracellular matrix remaining, and gene expression after exposure. In chondrocyte culture, MTT assay was used to evaluate the chondrotoxicity of IC50 and IC80 of carprofen with HA. In cartilage explant culture, two kinds of extracellular matrix (uronic acid and collagen) remaining in cartilage were used to evaluate cartilage damage for 14 d after treatment. Expression of COL2A1, AGG, and MMP3 was used to evaluate the synthesis and degradation of the matrix for 7 d after treatment. In chondrocyte culture, low MW HA could preserve OA chondrocyte viability but could not reduce the chondrotoxicity level of carprofen (P carprofen caused less destruction of uronic acid and collagen structure when compared with the control (P carprofen resulted in higher COL2A1 and AGG expression levels than carprofen alone.

  5. The role of microbial low-molecular-weight autoregulatory factors (alkylhydroxybenzenes) in resistance of microorganisms to radiation

    Science.gov (United States)

    El-Registan, G. I.; Mulyukin, A. L.; Nikolaev, Yu. A.; Stepanenko, I. Yu.; Shanenko, E. A.; Strakhovskaya, M. G.; Revina, A. A.

    Low-molecular-weight cell-to-cell communication factors are produced by various pro- and eukaryotes and involved in autoregulation of the growth and development of microbial cultures. As for some bacterial and yeast species, these factors were identified as isomers and homologs of alkylhydroxybenzenes (AHBs). Depending on the concentration, they participate in controlling the transition to stationary phase, entering the resting state, and stress resistance of vegetative cells to gamma-irradiation, photooxidation (singlet oxygen), heat shock. Chemical analogs of microbial AHBs protected microbial cultures from stressful situations and prolonged starvation and exerted (1) the stabilizing activity toward biomacromolecules and supermolecular structures (cell membranes) and (2) the ability to scavenge active oxygen species. The stabilizing effect of AHBs as chemical chaperones resulted from their complex formation with protected macromolecules due to intermolecular hydrogen bonds, hydrophobic and electrostatic interactions and was demonstrated on models of individual enzymes (trypsin, amylase, etc.). The action of AHBs as active oxygen species scavengers was related to their oxidative conversion to water-insoluble polymeric products. Particularly, AHBs protected the yeast from the action of (a) active oxygen species formed during gamma-irradiation (50 krad, 196 rad/sec) or (b) singlet oxygen generated in cells photosensitized by chlorin e6 (10 mkg/L). It is important that microbial AHBs were not species-specific and defended cultured animal cells (ras-transformed fibroblasts) from the action of organic toxicants. The use of AHBs as protectants and adaptogens will be discussed as well as perspectives of further investigations.

  6. The role of microbial low-molecular-weight autoregulatory factors (alkylhydroxybenzenes) in resistance of microorganisms to radiation and heat shock

    Science.gov (United States)

    El-Registan, Galina I.; Mulyukin, Andrey L.; Nikolaev, Yuri A.; Stepanenko, Irina Yu.; Kozlova, Alla N.; Martirosova, Elena I.; Shanenko, Elena F.; Strakhovskaya, Marina G.; Revina, Aleksandra A.

    Low-molecular-weight cell-to-cell communication factors are produced by various pro- and eukaryotes and involved in autoregulation of the growth and development of microbial cultures. As for some bacterial and yeast species, these factors were identified as isomers and homologues of alkylhydroxybenzenes (AHB). Depending on the concentration, they participate in controlling the transition to stationary phase, entering the resting state, and stress resistance of vegetative cells to gamma-irradiation, photooxidation (singlet oxygen), and heat shock. Chemical analogues of microbial AHB protected microbial cultures from stressful situations and exerted (1) the stabilizing activity toward macromolecules and (2) the ability to scavenge active oxygen species. The stabilizing effect of AHBs resulted from their complex formation with protected macromolecules due to intermolecular hydrogen bonds, hydrophobic and electrostatic interactions and was demonstrated on models of individual enzymes (trypsin). Particularly, AHBs protected the yeast from the action of (a) active oxygen species formed during gamma-irradiation (500 Gy, 1.96 Gy/s) or (b) singlet oxygen generated in cells photosensitized by chlorin e 6 (10 μg/L). It is important that microbial AHBs were not species-specific and defended cultured microbial and animal cells from the action of organic toxicants. The use of AHBs as protectants and adaptogens is discussed as well as perspectives of further investigations.

  7. Effects of low molecular weight heparin on the polarization and cytokine profile of macrophages and T helper cells in vitro.

    Science.gov (United States)

    Bruno, Valentina; Svensson-Arvelund, Judit; Rubér, Marie; Berg, Göran; Piccione, Emilio; Jenmalm, Maria C; Ernerudh, Jan

    2018-03-08

    Low molecular weight heparin (LMWH) is widely used in recurrent miscarriage treatment. The anti-coagulant effects are established, while immunological effects are not fully known. Our aim was to assess LMWH effects on activation and polarization of central regulatory immune cells from healthy women, and on placenta tissues from women undergoing elective abortions. Isolated blood monocytes and T helper (Th) cells under different activation and polarizing conditions were cultured with or without LMWH. Flow cytometry showed that LMWH exposure induced increased expression of HLA-DR and CD206 in macrophages. This phenotype was associated with increased secretion of Th17-associated CCL20, and decreased secretion of CCL2 (M2-associated) and CCL22 (Th2), as measured by multiplex bead array. In accordance, LMWH exposure to Th cells reduced the proportion of CD25highFoxp3+ regulatory T-cells, intensified IFN-γ secretion and showed a tendency to increase the lymphoblast proportions. Collectively, a mainly pro-inflammatory effect was noted on two essential tolerance-promoting cells. Although the biological significancies of these in vitro findings are uncertain and need to be confirmed in vivo, they suggest the possibility that immunological effects of LMWH may be beneficial mainly at an earlier gestational age to provide an appropriate implantation process in women with recurrent miscarriage.

  8. In vitro fermentation and prebiotic potential of novel low molecular weight polysaccharides derived from agar and alginate seaweeds.

    Science.gov (United States)

    Ramnani, Priya; Chitarrari, Roberto; Tuohy, Kieran; Grant, John; Hotchkiss, Sarah; Philp, Kevin; Campbell, Ross; Gill, Chris; Rowland, Ian

    2012-02-01

    Fermentation properties and prebiotic potential of novel low molecular weight polysaccharides (LMWPs) derived from agar and alginate bearing seaweeds was investigated. Ten LMWPs were supplemented to pH, temperature controlled anaerobic batch cultures inoculated with human feces from three donors, in triplicate. Microbiota changes were monitored using Fluorescent in-situ hybridization and short chain fatty acids, the fermentation end products were analysed using gas chromatography. Of the ten LMWPs tested, Gelidium seaweed CC2253 of molecular weight 64.64 KDa showed a significant increase in bifidobacterial populations from log(10) 8.06 at 0 h to log(10) 8.55 at 24 h (p = 0.018). For total bacterial populations, alginate powder CC2238 produced a significant increase from log(10) 9.01 at 0 h to log(10) 9.58 at 24 h (p = 0.032). No changes were observed in the other bacterial groups tested viz. Bacteroides, Lactobacilli/Enterococci, Eubacterium rectale/Clostridium coccoides and Clostridium histolyticum. The polysaccharides also showed significant increases in total SCFA production, particularly acetic and propionic acids, indicating that they were readily fermented. In conclusion, some LMWPs derived from agar and alginate bearing seaweeds were fermented by gut bacteria and exhibited potential to be used a novel source of prebiotics. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Effects of proteins on absorption by the rat of iron from polymeric and low-molecular-weight iron species

    International Nuclear Information System (INIS)

    Berner, L.; Miller, D.

    1986-01-01

    To examine effects of proteins on Fe absorption from polymeric ferric hydroxides (polys) or low-molecular-weight complexes (LMW Fe), 2 studies were conducted. First, anemic rats were given 59 Fe-labeled polys or LMW Fe in the presence and absence of pepsin-digested soy protein isolate, casein, and BSA. The doses were introduced into ligated duodenal segments for 1 hr. Uptake into the carcass of 59 Fe from polys was doubled in the presence of BSA (7.8 vs 16.1%, p 59 Fe from LMW Fe was 7X greater than from polys; BSA and casein had no effect but soy depressed Fe uptake by almost 50% (57.4 vs 35.5%, p < .05). The second experiment repeated the first except that the proteins were not pepsin-digested and the doses were given by gastric intubation. All Fe, whether from polys or LMW Fe, was highly available (although in vitro digestions reveal that polys are not depolymerized to a large degree under simulated stomach conditions). Soy depressed Fe uptake from both sources (92.9 vs. 81.6%, LMW Fe and 85.4 vs 73.7%, polys) while casein and BSA had no effect. These results show: (1) BSA can depolymerize polys in the rat duodenum, thus enhancing absorption; (2) soy isolate generally depressed Fe uptake; and (3) the rat stomach appears to have an exceptional capacity for equalizing Fe sources

  10. Development of gel-filter method for high enrichment of low-molecular weight proteins from serum.

    Directory of Open Access Journals (Sweden)

    Lingsheng Chen

    Full Text Available The human serum proteome has been extensively screened for biomarkers. However, the large dynamic range of protein concentrations in serum and the presence of highly abundant and large molecular weight proteins, make identification and detection changes in the amount of low-molecular weight proteins (LMW, molecular weight ≤ 30kDa difficult. Here, we developed a gel-filter method including four layers of different concentration of tricine SDS-PAGE-based gels to block high-molecular weight proteins and enrich LMW proteins. By utilizing this method, we identified 1,576 proteins (n = 2 from 10 μL serum. Among them, 559 (n = 2 proteins belonged to LMW proteins. Furthermore, this gel-filter method could identify 67.4% and 39.8% more LMW proteins than that in representative methods of glycine SDS-PAGE and optimized-DS, respectively. By utilizing SILAC-AQUA approach with labeled recombinant protein as internal standard, the recovery rate for GST spiked in serum during the treatment of gel-filter, optimized-DS, and ProteoMiner was 33.1 ± 0.01%, 18.7 ± 0.01% and 9.6 ± 0.03%, respectively. These results demonstrate that the gel-filter method offers a rapid, highly reproducible and efficient approach for screening biomarkers from serum through proteomic analyses.

  11. Induction of ovulation by a potent, orally active, low molecular weight agonist (Org 43553) of the luteinizing hormone receptor.

    Science.gov (United States)

    van de Lagemaat, R; Timmers, C M; Kelder, J; van Koppen, C; Mosselman, S; Hanssen, R G J M

    2009-03-01

    In assisted reproductive technology, human chorionic gonadotrophin (hCG) is administered subcutaneously for the induction of oocyte maturation and ovulation. Our efforts to develop orally bioavailable luteinizing hormone (LH) receptor agonists have led to the discovery of Org 43553, a low molecular weight (LMW) LH receptor (LH-R) agonist. Org 43553 was tested in vitro and in vivo in pre-clinical pharmacological models to demonstrate efficacy and oral availability. Org 43553 is a potent stimulator of the human LH-R in vitro (EC(50) 3.7 nM). In primary mouse Leydig cells, Org 43553 stimulated testosterone production. Pharmacokinetic analyses showed high oral bioavailability in rats (79%) and dogs (44%) with a shorter half-life compared with hCG (3.4 versus 5.6 h in the rat). Ovulation induction by Org 43553 was demonstrated in immature mice as well as in cyclic rats after single-dose oral administration (50 mg/kg). The ovulated oocytes were of good quality as demonstrated by successful fertilization and implantation of normal embryos. In male rats, testosterone production was substantially induced after oral administration. Org 43553 is the first LMW LH-R mimetic with demonstrated in vivo efficacy upon oral administration and could therefore replace subcutaneously administered hCG. The elimination half-life of Org 43553 is substantially shorter than hCG, which could potentially represent a clinical benefit in reducing the risk of ovarian hyperstimulation syndrome (OHSS).

  12. Competitive displacement of sodium caseinate by low-molecular-weight emulsifiers and the effects on emulsion texture and rheology.

    Science.gov (United States)

    Munk, M B; Larsen, F H; van den Berg, F W J; Knudsen, J C; Andersen, M L

    2014-07-29

    Low-molecular-weight (LMW) emulsifiers are used to promote controlled destabilization in many dairy-type emulsions in order to obtain stable foams in whippable products. The relation between fat globule aggregation induced by three LMW emulsifiers, lactic acid ester of monoglyceride (LACTEM), saturated monoglyceride (GMS), and unsaturated monoglyceride (GMU) and their effect on interfacial protein displacement was investigated. It was found that protein displacement by LMW emulsifiers was not necessary for fat globule aggregation in emulsions, and conversely fat globule aggregation was not necessarily accompanied by protein displacement. The three LMW emulsifiers had very different effects on emulsions. LACTEM induced shear instability of emulsions, which was accompanied by protein displacement. High stability was characteristic for emulsions with GMS where protein was displaced from the interface. Emulsions containing GMU were semisolid, but only low concentrations of protein were detected in the separated serum phase. The effects of LACTEM, GMS, and GMU may be explained by three different mechanisms involving formation of interfacial α-gel, pickering stabilization and increased exposure of bound casein to the water phase. The latter may facilitate partial coalescence. Stabilizing hydrocolloids did not have any effect on the LMW emulsifiers' ability to induce protein displacement.

  13. Low-molecular-weight organic acids correlate with cultivar variation in ciprofloxacin accumulation in Brassica parachinensis L.

    Science.gov (United States)

    Zhao, Hai-Ming; Xiang, Lei; Wu, Xiao-Lian; Jiang, Yuan-Neng; Li, Hui; Li, Yan-Wen; Cai, Quan-Ying; Mo, Ce-Hui; Liu, Jie-Sheng; Wong, Ming-Hung

    2017-08-31

    To understand the mechanism controlling cultivar differences in the accumulation of ciprofloxacin (CIP) in Chinese flowering cabbage (Brassica parachinensis L.), low-molecular-weight organic acids (LMWOAs) secreted from the roots of high- and low-CIP cultivars (Sijiu and Cutai, respectively) and their effects on the bioavailability of CIP in soil were investigated. Significant differences in the content of LMWOAs (especially maleic acid) between the two cultivars played a key role in the variation in CIP accumulation. Based on the Freundlich sorption coefficient (K f ) and distribution coefficient (K d ), the presence of LMWOAs reduced the CIP sorption onto soil particles, and higher concentrations of LMWOAs led to less CIP sorption onto soil. On the other hand, LMWOAs enhanced CIP desorption by lowering the solution pH, which changed the surface charge of soil particles and the degree of CIP ionization. LMWOAs promoted CIP desorption from soil by breaking cation bridges and dissolving metal cations, particularly Cu 2+ . These results implied that the LMWOAs (mainly maleic acid) secreted from Sijiu inhibited CIP sorption onto soil and improved CIP desorption from soil to a greater extent than those secreted from Cutai, resulting in higher bioavailability of CIP and more uptake and accumulation of CIP in the former.

  14. Potential effects of a low-molecular-weight fucoidan extracted from brown algae on bone biomaterial osteoconductive properties.

    Science.gov (United States)

    Changotade, S Igondjo Tchen; Korb, G; Bassil, J; Barroukh, B; Willig, C; Colliec-Jouault, S; Durand, P; Godeau, G; Senni, K

    2008-12-01

    In this work, we first tested the influence of low-molecular-weight (LMW) fucoidan extracted from pheophicae cell wall on bidimensional cultured normal human osteoblasts' behaviors. Second, by impregnation procedure with LMW fucoidan of bone biomaterial (Lubboc), we explored in this bone extracellular matrix context its capabilities to support human osteoblastic behavior in 3D culture. In bidimensionnal cultures, we evidenced that LMW fucoidan promotes human osteoblast proliferation and collagen type I expression and favors precocious alkaline phosphatase activity. Furthermore, with LMW fucoidan, von Kossa's staining was positive at 30 days and positive only at 45 days in the absence of LMW fucoidan. In our three-dimensional culture models with the biomaterial pretreated with LMW fucoidan, osteoblasts promptly overgrew the pretreated biomaterial. We also evidenced that osteoblasts increased proliferation with pretreated biomaterial when compared with untreated biomaterial. Osteoblasts secreted osteocalcin and expressed BMP2 receptor on control material as well as with LMW fucoidan impregnated biomaterial. In conclusion, in our experimental conditions, LMW fucoidan stimulated expression of osteoblastic markers differentiation such as alkaline phosphatase activity, collagen type I expression, and mineral deposition; furthermore, cell proliferation was favored. These findings suggest that fucoidan could be clinically useful for bone regeneration and bone substitute design. (c) 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008.

  15. Differential Effects of Low-Molecular-Weight Organic Acids on the Mobilization of Soil-Borne Arsenic and Trace Metals.

    Science.gov (United States)

    Nworie, Obinna Elijah; Qin, Junhao; Lin, Chuxia

    2017-08-21

    A batch experiment was conducted to examine the effects of six low-molecular-weight organic acids on the mobilization of arsenic and trace metals from a range of contaminated soils. The results showed that the organic acids behaved differently when reacting with soil-borne As and trace metals. Oxalic acid and acetic acid had the strongest and weakest capacity to mobilize the investigated elements, respectively. The solubilisation of iron oxides by the organic acids appears to play a critical role in mobilizing other trace metals and As. Apart from acidification and complexation, reductive dissolution played a dominant role in the dissolution of iron oxides in the presence of oxalic acid, while acidification tended to be more important for dissolving iron oxides in the presence of other organic acids. The unique capacity of oxalic acid to solubilize iron oxides tended to affect the mobilization of other elements in different ways. For Cu, Mn, and Zn, acidification-driven mobilization was likely to be dominant while complexation might play a major role in Pb mobilization. The formation of soluble Fe and Pb oxalate complexes could effectively prevent arsenate or arsenite from combining with these metals to form solid phases of Fe or Pb arsenate or arsenite.

  16. Biochar immobilizes soil-borne arsenic but not cationic metals in the presence of low-molecular-weight organic acids.

    Science.gov (United States)

    Alozie, Nneka; Heaney, Natalie; Lin, Chuxia

    2018-07-15

    A batch experiment was conducted to examine the effects of biochar on the behaviour of soil-borne arsenic and metals that were mobilized by three low-molecular-weight organic acids. In the presence of citric acid, oxalic acid and malic acid at a molar concentration of 0.01M, the surface of biochar was protonated, which disfavours adsorption of the cationic metals released from the soil by organic acid-driven mobilization. In contrast, the oxyanionic As species were re-immobilized by the protonated biochar effectively. Biochar could also immobilize oxyanionic Cr species but not cationic Cr species. The addition of biochar increased the level of metals in the solution due to the release of the biochar-borne metals under attack by LMWOAs via cation exchange. Biochar could also have the potential to enhance reductive dissolution of iron and manganese oxides in the soil, leading to enhanced release of trace elements bound to these oxides. The findings obtained from this study have implications for evaluating the role of biochar in immobilizing trace elements in rhizosphere. Adsorption of cationic heavy metals on biochar in the presence of LMWOAs is unlikely to be a mechanism responsible for the impeded uptake of heavy metals by plants growing in heavy metal-contaminated soils. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Effects of EDTA and low molecular weight organic acids on soil solution properties of a heavy metal polluted soil.

    Science.gov (United States)

    Wu, L H; Luo, Y M; Christie, P; Wong, M H

    2003-02-01

    A pot experiment was conducted to study the effects of EDTA and low molecular weight organic acids (LMWOA) on the pH, total organic carbon (TOC) and heavy metals in the soil solution in the rhizosphere of Brassica juncea grown in a paddy soil contaminated with Cu, Zn, Pb and Cd. The results show that EDTA and LMWOA have no effect on the soil solution pH. EDTA addition significantly increased the TOC concentrations in the soil solution. The TOC concentrations in treatments with EDTA were significantly higher than those in treatments with LMWOA. Adding 3 mmol kg(-1) EDTA to the soil markedly increased the total concentrations of Cu, Zn, Pb and Cd in the soil solution. Compared to EDTA, LMWOA had a very small effect on the metal concentrations. Total concentrations in the soil solution followed the sequence: EDTA > citric acid (CA) approximately oxalic acid (OA) approximately malic acid (MA) for Cu and Pb; EDTA > MA > CA approximately OA for Zn; and EDTA > MA > CA > OA for Cd. The labile concentrations of Cu, Zn, Pb and Cd showed similar trends to the total concentrations.

  18. Effect of high and low molecular weight glutenin subunits, and subunits of gliadin on physicochemical parameters of different wheat genotypes

    Directory of Open Access Journals (Sweden)

    Mariana Souza Costa

    2013-02-01

    Full Text Available Identification of functional properties of wheat flour by specific tests allows genotypes with appropriate characteristics to be selected for specific industrial uses. The objective of wheat breeding programs is to improve the quality of germplasm bank in order to be able to develop wheat with suitable gluten strength and extensibility for bread making. The aim of this study was to evaluate 16 wheat genotypes by correlating both glutenin subunits of high and low molecular weight and gliadin subunits with the physicochemical characteristics of the grain. Protein content, sedimentation volume, sedimentation index, and falling number values were analyzed after the grains were milled. Hectoliter weight and mass of 1000 seeds were also determined. The glutenin and gliadin subunits were separated using polyacrylamide gel in the presence of sodium dodecyl sulfate. The data were evaluated using variance analysis, Pearson's correlation, principal component analysis, and cluster analysis. The IPR 85, IPR Catuara TM, T 091015, and T 091069 genotypes stood out from the others, which indicate their possibly superior grain quality with higher sedimentation volume, higher sedimentation index, and higher mass of 1000 seeds; these genotypes possessed the subunits 1 (Glu-A1, 5 + 10 (Glu-D1, c (Glu-A3, and b (Glu-B3, with exception of T 091069 genotype that possessed the g allele instead of b in the Glu-B3.

  19. Amphiphilic graft copolymer based on poly(styrene-co-maleic anhydride with low molecular weight polyethylenimine for efficient gene delivery

    Directory of Open Access Journals (Sweden)

    Duan XP

    2012-09-01

    Full Text Available Xiaopin Duan,1,2 Jisheng Xiao,2 Qi Yin,2 Zhiwen Zhang,2 Shirui Mao,1 Yaping Li21School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, 2Center of Pharmaceutics, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, ChinaBackground and methods: A new amphiphilic comb-shaped copolymer (SP was synthesized by conjugating poly(styrene-co-maleic anhydride with low molecular weight polyethyleneimine for gene delivery. Fourier transform infrared spectrum, 1H nuclear magnetic resonance, and gel permeation chromatography were used to characterize the graft copolymer.Results: The buffering capability of SP was similar to that of polyethyleneimine within the endosomal pH range. The copolymer could condense DNA effectively to form complexes with a positive charge (13–30 mV and a small particle size (130–200 nm at N/P ratios between 5 and 20, and protect DNA from degradation by DNase I. In addition, SP showed much lower cytotoxicity than polyethyleneimine 25,000. Importantly, the gene transfection activity and cellular uptake of SP-DNA complexes were all markedly higher than that of complexes of polyethyleneimine 25,000 and DNA in MCF-7 and MCF-7/ADR cell lines.Conclusion: This work highlights the promise of SP as a safe and efficient synthetic vector for DNA delivery.Keywords: poly(styrene-co-maleic anhydride, polyethylenimine, DNA, gene delivery

  20. Cloning and Characterization of Low-Molecular-Weight Glutenin Subunit Alleles from Chinese Wheat Landraces (Triticum aestivum L.

    Directory of Open Access Journals (Sweden)

    Hongqi Si

    2014-01-01

    Full Text Available Low-molecular-weight glutenin subunits (LMW-GS are of great importance in processing quality and participate in the formation of polymers in wheat. In this study, eight new LMW-GS alleles were isolated from Chinese wheat landraces (Triticum aestivum L. and designated as Glu-A3-1a, Glu-A3-1b, Glu-B3-1a, Glu-B3-1b, Glu-B3-1c, Glu-D3-1a, Glu-D3-1b, and Glu-D3-1c, which were located at the Glu-A3, Glu-B3, and Glu-D3 loci, respectively. Based on the proteins encoded, the number of deduced amino acids of Glu-B3 alleles was approximately 50 more than those of Glu-A3 and Glu-D3 alleles. The first cysteine of Glu-A3 and Glu-D3 alleles was located at the N-terminal domain, while that of Glu-B3 alleles was found in the repetitive domain, which may lead to the different functioning in forming disulfide bonds. All the eight genes were LMW-m types and the new allele of Glu-B3-1a which had nine cysteine residues may be the desirable LMW-GS gene for improving bread-making quality.

  1. Purification and partial characterization of low molecular weight vicilin-like glycoprotein from the seeds of Citrullus lanatus.

    Science.gov (United States)

    Yadav, Sushila; Tomar, Anil Kumar; Jithesh, O; Khan, Meraj Alam; Yadav, R N; Srinivasan, A; Singh, Tej P; Yadav, Savita

    2011-12-01

    The watermelon (Citrullus lanatus) seeds are highly nutritive and contain large amount of proteins and many beneficial minerals such as magnesium, calcium, potassium, iron, phosphorous, zinc etc. In various parts of the world, C. lanatus seed extracts are used to cure cancer, cardiovascular diseases, hypertension, and blood pressure. C. lanatus seed extracts are also used as home remedy for edema and urinary tract problems. In this study, we isolated protein fraction of C. lanatus seeds using various protein separation methods. We successfully purified a low molecular weight vicilin-like glycoprotein using chromatographic methods followed by SDS-PAGE and MALDI-TOF/MS identification. This is the first report of purification of a vicilin like polypeptide from C. lanatus seeds. In next step, we extracted mRNA from immature seeds and reverse transcribed it using suitable forward and reverse primers for purified glycoprotein. The PCR product was analysed on 1% agarose gel and was subsequently sequenced by Dideoxy DNA sequencing method. An amino acid translation of the gene is in agreement with amino acid sequences of the identified peptides.

  2. Effect of starch microspheres on the passage of labelled erythrocytes and a low molecular weight marker through the liver

    International Nuclear Information System (INIS)

    Starkhammar, H.; Haakansson, L.

    1987-01-01

    Degradable starch microspheres (DSM) injected intra-arterially together with cytostatic drugs increase the regional uptake of the drug and as a result reduce the systemic drug concentration. Previous studies have indicated that fixed doses of DSM result in different degrees of vascular occlusion and therefore variable systemic concentration of the co-injected drug. Continuous registration of the systemic concentration of 99 Tc m -hydroxymethylene diphosphonate ( 99 Tc m -HDP) co-injected intra-arterially with DSM was earlier used to monitor treatment sessions and to optimize the dose of microspheres. Further to investigate the mechanism of DSM-induced retention, the effect of DSM on the passage of this low molecular weight marker and of labelled erythrocytes (a marker confined to the blood vessels), was compared in 10 patients with liver metastases. DSM reduced the amount of 99 Tc m -HDP passing through the liver by 6 to 47% while the amount of erythrocytes eventually passing the liver was much less reduced (0-14%). The rate of passage, however, was significantly reduced for both labelled markers. These results indicate that substances retained by co-injection of DSM are not to a significant extent lodged within the blood vessels but diffuse into extra-vasal tissue compartments. (orig.)

  3. Mechanism study of endothelial protection and inhibits platelet activation of low molecular weight fucoidan from Laminaria japonica

    Science.gov (United States)

    Chen, Anjin; Zhang, Fang; Shi, Jie; Zhao, Xue; Yan, Meixing

    2016-10-01

    Several studies have indicated that fucoidan fractions with low molecular weight and different sulfate content from Laminaria japonica could inhibit the activation of platelets directly by reducing the platelet aggregation. To explore the direct effect of LMW fucoidan on the platelet system furthermore and examine the possible mechanism, the endothelial protection and inhibits platelet activation effects of two LMW fucoidan were investigated. In the present study, Endothelial injury model of rats was made by injection of adrenaline (0.4 mg kg-1) and human umbilical vein endothelial cells were cultured. vWF level was be investigated in vivo and in vitro as an important index of endothelial injury. LMW fucoidan could significantly reduce vWF level in vascular endothelial injury rats and also significantly reduce vWF level in vitro. The number of EMPs was be detected as another important index of endothelial injury. The results showed that LMW fucoidan reduced EMPs stimulated by tumor necrosis factor. In this study, it was found that by inhibiting platelet adhesion, LMW fucoidan played a role in anti-thrombosis and the specific mechanism of action is to inhibit the flow of extracellular Ca2+. All in a word, LMW fucoidan could inhibit the activation of platelets indirectly by reducing the concentration of EMPs and vWF, at the same time; LMW fucoidan inhibited the activation of platelets directly by inhibiting the flow of extracellular Ca2+.

  4. Anti-HCV effect of Lentinula edodes mycelia solid culture extracts and low-molecular-weight lignin.

    Science.gov (United States)

    Matsuhisa, Koji; Yamane, Seiji; Okamoto, Toru; Watari, Akihiro; Kondoh, Masuo; Matsuura, Yoshiharu; Yagi, Kiyohito

    2015-06-19

    Lentinula edodes mycelia solid culture extract (MSCE) contains several bioactive molecules, including some polyphenolic compounds, which exert immunomodulatory, antitumor, and hepatoprotective effects. In this study, we examined the anti-hepatitis C virus (HCV) activity of MSCE and low-molecular-weight lignin (LM-lignin), which is the active component responsible for the hepatoprotective effect of MSCE. Both MSCE and LM-lignin inhibited the entry of two HCV pseudovirus (HCVpv) types into Huh7.5.1 cells. LM-lignin inhibited HCVpv entry at a lower concentration than MSCE and inhibited the entry of HCV particles in cell culture (HCVcc). MSCE also inhibited HCV subgenome replication. LM-lignin had no effect on HCV replication, suggesting that MSCE contains additional active substances. We demonstrate here for the first time the anti-HCV effects of plant-derived LM-lignin and MSCE. The hepatoprotective effect of LM-lignin suggests that lignin derivatives, which can be produced in abundance from existing plant resources, may be effective in the treatment of HCV-related diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Impact of low molecular weight organic acids and dissolved organic matter on sorption and mobility of isoproturon in two soils.

    Science.gov (United States)

    Ding, Qing; Wu, Hai Lang; Xu, Yun; Guo, Li Juan; Liu, Kai; Gao, Hui Min; Yang, Hong

    2011-06-15

    Isoproturon is a selective herbicide belonging to the phenylurea family and widely used for pre- and post-emergence control of annual weeds. Soil amendments (e.g. organic compounds or dissolved organic matter) may affect environmental behavior and bioavailability of pesticides. However, whether the physiochemical process of isoproturon in soils is affected by organic amendments and how it is affected in different soil types are unknown. To evaluate the impact of low molecular weight organic acids (LMWOA) and dissolved organic matter (DOM) on sorption/desorption and mobility of isoproturon in soils, comprehensive analyses were performed using two distinct soil types (Eutric gleysols and Hap udic cambisols). Our analysis revealed that adsorption of isoproturon in Eutric gleysols was depressed, and desorption and mobility of isoproturon were promoted in the presence of DOM and LMWOA. However, the opposite result was observed with Hap udic cambisols, suggesting that the soil type affected predominantly the physiochemical process. We also characterized differential components of the soils using three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy and Fourier transform infrared (FT-IR) spectroscopy and show that the two soils displayed different intensity of absorption bands for several functional groups. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Hemorrhagic shock and surgical stress alter distribution of labile zinc within high- and low-molecular-weight plasma fractions.

    Science.gov (United States)

    Kelly, Edward; Mathew, Jeff; Kohler, Jonathan E; Blass, Amy L; Soybel, And David I

    2012-08-01

    Zinc ions (Zn) are essential for tissue repair following injury or stress. We hypothesize that during such stresses Zn is redistributed to labile pools in plasma components. Here we tested this hypothesis using a novel assay to monitor labile Zn in plasma in hemorrhagic shock. Adult rats in the shock group (S group) underwent hemorrhage and resuscitation. Blood samples were drawn at baseline and at 1, 4, and 24 h. The surgical control group (SC group) was anesthetized and instrumented, but not bled. Albumin, total Zn, and labile Zn levels were assayed in plasma. Binding capacity for Zn was assessed in high- and low-molecular-weight pools. Significant decreases in total Zn were observed by 24 h, in both S and SC groups. Albumin levels were significantly reduced in the S group at 1 and 4 h but restored at 24 h; significant changes were not observed in other groups. In whole plasma, labile Zn levels were stable initially in the S and SC groups, but declined at 24 h. In the high-molecular-weight pool, marked and significant impairment of binding was noted throughout all time periods following the shock period in the S group. Such changes were observed in the SC group of less intensity and duration. These experiments suggest that shock alters affinity of plasma proteins for Zn, promoting delivery to peripheral tissues during periods of increased Zn utilization.

  7. Transparent Low Molecular Weight Poly(Ethylene Glycol Diacrylate-Based Hydrogels as Film Media for Photoswitchable Drugs

    Directory of Open Access Journals (Sweden)

    Théophile Pelras

    2017-11-01

    Full Text Available Hydrogels have shown a great potential as materials for drug delivery systems thanks to their usually excellent bio-compatibility and their ability to trap water-soluble organic molecules in a porous network. In this study, poly(ethylene glycol-based hydrogels containing a model dye were synthesized by ultraviolet (UV-A photopolymerization of low-molecular weight macro-monomers and the material properties (dye release ability, transparency, morphology, and polymerization kinetics were studied. Real-time infrared measurements revealed that the photopolymerization of the materials was strongly limited when the dye was added to the uncured formulation. Consequently, the procedure was adapted to allow for the formation of sufficiently cured gels that are able to capture and later on to release dye molecules in phosphate-buffered saline solution within a few hours. Due to the transparency of the materials in the 400–800 nm range, the hydrogels are suitable for the loading and excitation of photoactive molecules. These can be uptaken by and released from the polymer matrix. Therefore, such materials may find applications as cheap and tailored materials in photodynamic therapy (i.e., light-induced treatment of skin infections by bacteria, fungi, and viruses using photoactive drugs.

  8. Amphiphilic graft copolymer based on poly(styrene-co-maleic anhydride) with low molecular weight polyethylenimine for efficient gene delivery

    Science.gov (United States)

    Duan, Xiaopin; Xiao, Jisheng; Yin, Qi; Zhang, Zhiwen; Mao, Shirui; Li, Yaping

    2012-01-01

    Background and methods A new amphiphilic comb-shaped copolymer (SP) was synthesized by conjugating poly(styrene-co-maleic anhydride) with low molecular weight polyethyleneimine for gene delivery. Fourier transform infrared spectrum, 1H nuclear magnetic resonance, and gel permeation chromatography were used to characterize the graft copolymer. Results The buffering capability of SP was similar to that of polyethyleneimine within the endosomal pH range. The copolymer could condense DNA effectively to form complexes with a positive charge (13–30 mV) and a small particle size (130–200 nm) at N/P ratios between 5 and 20, and protect DNA from degradation by DNase I. In addition, SP showed much lower cytotoxicity than polyethyleneimine 25,000. Importantly, the gene transfection activity and cellular uptake of SP-DNA complexes were all markedly higher than that of complexes of polyethyleneimine 25,000 and DNA in MCF-7 and MCF-7/ADR cell lines. Conclusion This work highlights the promise of SP as a safe and efficient synthetic vector for DNA delivery. PMID:23028224

  9. Growth of fungi on volatile aromatic hydrocarbons: environmental technology perspectives

    NARCIS (Netherlands)

    Prenafeta Boldú, F.X.

    2002-01-01

    The present study aimed the better understanding of the catabolism of monoaromatic hydrocarbons by fungi. This knowledge can be used to enhance the biodegradation of BTEX pollutants. Fungi with the capacity of using toluene as the sole source of carbon and energy were isolated by enriching

  10. Polycyclic aromatic hydrocarbons and volatile organic compounds in biochar and biochar-amended soil: A review

    Science.gov (United States)

    Residual pollutants including polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), and carbon(aceous) nanoparticles are inevitably generated during the pyrolysis of waste biomass, and remain on the solid co-product called biochar. Such pollutants could have adverse effects on ...

  11. Definition of the low molecular weight glutenin subunit gene family members in a set of standard bread wheat (Triticum aestivum L.) varieties

    Science.gov (United States)

    Low-molecular-weight glutenin subunits (LMW-GS) are a class of seed storage proteins that play a major role in the determination of the viscoelastic properties of wheat dough. Most of the LMW-GSs are encoded by a multi-gene family located on the short arms of the homoeologous group 1 chromosomes, at...

  12. Low-molecular-weight color pI markers to monitor on-line the peptide focusing process in OFFGEL fractionation

    Czech Academy of Sciences Publication Activity Database

    Michelland, S.; Bourgoin-Voillard, S.; Cunin, V.; Tollance, A.; Bertolino, P.; Šlais, Karel; Seve, M.

    2017-01-01

    Roč. 38, č. 16 (2017), s. 2034-2041 ISSN 0173-0835 Institutional support: RVO:68081715 Keywords : iTRAQ labeling * low- molecular -weight color pI markers * peptides OFFGEL fractionation Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 2.744, year: 2016

  13. Retardative chain transfer in free radical free-radical polymerisations of vinyl neo-decanoate in low molecular weight polyisoprene and toluene

    NARCIS (Netherlands)

    Monteiro, M.J.; Subramaniam, N.; Taylor, J.R.; Pham, B.T.T.; Tonge, M.P.; Gilbert, R.G.

    2001-01-01

    The kinetics of free-radical polymerisation of vinyl neo-decanoate (VneoD) and the molecular weight distributions (MWDs) of the polymers formed in the presence and absence of low molecular weight polyisoprene at 50°C under a variety of conditions were investigated. The bulk reaction was successfully

  14. Highly active, recyclable catalyst for the manufacture of viscous, low molecular weight, CO–ethene–propene-based polyketone, base component for a new class of resins

    NARCIS (Netherlands)

    Broekhuis, Antonius A.; Dirkzwager, Hendrik; Mul, Wilhelmus P.; Heeres, Hero J.; Linden, Adrianus J. van der; Orpen, A. Guy

    2002-01-01

    A highly active, recyclable homogeneous palladium(II) catalyst is described for the manufacture of viscous, low molecular weight CO–ethene–propene-based polyketone (Carilite Oligomer), used for the manufacture of a new class of resins (Carilite Resins). The catalyst is composed of palladium acetate,

  15. Low-molecular-weight color pI markers to monitor on-line the peptide focusing process in OFFGEL fractionation

    Czech Academy of Sciences Publication Activity Database

    Michelland, S.; Bourgoin-Voillard, S.; Cunin, V.; Tollance, A.; Bertolino, P.; Šlais, Karel; Seve, M.

    2017-01-01

    Roč. 38, č. 16 (2017), s. 2034-2041 ISSN 0173-0835 Institutional support: RVO:68081715 Keywords : iTRAQ labeling * low-molecular-weight color pI markers * peptides OFFGEL fractionation Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 2.744, year: 2016

  16. Incidence of postpartum haemorrhage in women receiving therapeutic doses of low-molecular-weight heparin: results of a retrospective cohort study

    NARCIS (Netherlands)

    Roshani, Sara; Cohn, Danny M.; Stehouwer, Alexander C.; Wolf, Hans; van der Post, Joris A. M.; Büller, Harry R.; Kamphuisen, Pieter W.; Middeldorp, Saskia

    2011-01-01

    Background Low-molecular-weight heparin (LMWH) is the drug of choice to prevent venous thrombosis in pregnancy, but the optimal dose for prevention while avoiding bleeding is unclear. This study investigated whether therapeutic doses of LMWH increase the incidence of postpartum haemorrhage (PPH) in

  17. Incidence of postpartum haemorrhage in women receiving therapeutic doses of low-molecular-weight heparin : results of a retrospective cohort study

    NARCIS (Netherlands)

    Roshani, Sara; Cohn, Danny M; Stehouwer, Alexander C; Wolf, Hans; van der Post, Joris A M; Büller, Harry R; Kamphuisen, Pieter W; Middeldorp, Saskia

    2011-01-01

    Background Low-molecular-weight heparin (LMWH) is the drug of choice to prevent venous thrombosis in pregnancy, but the optimal dose for prevention while avoiding bleeding is unclear. This study investigated whether therapeutic doses of LMWH increase the incidence of postpartum haemorrhage (PPH) in

  18. Low-molecular-weight carbohydrate Pentaisomaltose may replace dimethyl sulfoxide as a safer cryoprotectant for cryopreservation of peripheral blood stem cells

    DEFF Research Database (Denmark)

    Svalgaard, Jesper Dyrendom; Haastrup, Eva Kannik; Reckzeh, Kristian

    2016-01-01

    -related side effects, there is an increasing demand for DMSO-free alternatives. We therefore investigated whether Pentaisomaltose (PIM), a low-molecular-weight carbohydrate (1 kDa), can be used for cryopreservation of peripheral blood stem cells, more specifically hematopoietic progenitor cell apheresis (HPC...

  19. Low-molecular-weight heparin and aspirin in the prevention of recurrent early-onset pre-eclampsia in women with antiphospholipid antibodies : the FRUIT-RCT

    NARCIS (Netherlands)

    van Hoorn, Marion E.; Hague, William M.; Pampus , van Mariëlle G.; Bezemer, Dick; de Vries, Johanna I. P.

    Objective: To examine whether combined treatment with low-molecular-weight heparin (LMWH) and aspirin reduces recurrent hypertensive disorders of pregnancy (HD: pre-eclampsia, eclampsia or HELLP syndrome) in women with antiphospholipid antibodies (aPLA) and a previous delivery for HD and/or

  20. Quantification of low molecular weight selenium metabolites in human plasma after treatment with selenite in pharmacological doses by LC-ICP-MS

    DEFF Research Database (Denmark)

    Flouda, Konstantina; Dersch, Julie Maria; Gabel-Jensen, Charlotte

    2016-01-01

    The paper presents an analytical method for quantification of low molecular weight (LMW) selenium compounds in human plasma based on liquid chromatography inductively coupled plasma mass spectrometry (LC-ICP-MS) and post column isotope dilution-based quantification. Prior to analysis, samples were...

  1. Low molecular weight chitosan-coated silver nanoparticles are effective for the treatment of MRSA-infected wounds

    Directory of Open Access Journals (Sweden)

    Peng Y

    2017-01-01

    Full Text Available Yinbo Peng,1 Chenlu Song,1 Chuanfeng Yang,1 Qige Guo,1 Min Yao1,2 1Department of Burns and Plastic Surgery, Shanghai Ninth People’s Hospital, Institute of Traumatic Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China; 2Department of Dermatology, Wellman Center for Photomedicine, Harvard Medical School, Massachusetts General Hospital, Boston, MA, USA Abstract: Silver nanoparticles (AgNPs are being widely applied as topical wound materials; however, accumulated deposition of silver in the liver, spleen, and other main organs may lead to organ damage and dysfunction. We report here that low molecular weight chitosan-coated silver nanoparticles (LMWC-AgNPs are effective against methicillin-resistant Staphylococcus aureus (MRSA, have better biocompatibility, and have lower body absorption characteristics when compared with polyvinylpyrrolidone-coated silver nanoparticles (PVP-AgNPs and silver nanoparticles without surface stabilizer (uncoated-AgNPs in a dorsal MRSA wound infection mouse model. LMWC-AgNPs were synthesized by reducing silver nitrate with low molecular weight chitosan as a stabilizer and reducing agent, while PVP-AgNPs were synthesized using polyvinylpyrrolidone as a stabilizer and ethanol as a reducing agent. AgNPs with different surface stabilizers were identified by UV-visible absorption spectrometry, and particle size was determined by transmission electron microscopy. UV-visible absorption spectra of LMWC-AgNPs, PVP-AgNPs and uncoated-AgNPs were similar and their sizes were in the range of 10–30 nm. In vitro experiments showed that the three types of AgNPs had similar MRSA-killing effects, with obvious effect at 4 µg/mL and 100% effect at 8 µg/mL. Bacteriostatic annulus experiments also showed that all the three types of AgNPs had similar antibacterial inhibitory effect at 10 µg/mL. Cell counting kit-8 assay and Hoechst/propidium iodide (PI staining showed that LMWC-AgNPs were

  2. Physicochemical properties and ecotoxicological effects of yttrium oxide nanoparticles in aquatic media: Role of low molecular weight natural organic acids

    International Nuclear Information System (INIS)

    Zhang, Fan; Wang, Zhuang; Wang, Se; Fang, Hao; Chen, Mindong; Xu, Defu; Tang, Lili; Wang, Degao

    2016-01-01

    Understanding how engineered nanoparticles (ENPs) interact with natural organic acids is important to ecological risk assessment of ENPs, but this interaction remains poorly studied. Here, we investigate the dispersion stability, ion release, and toxicity of yttrium oxide nanoparticles (nY_2O_3) suspensions after exposure to two low molecular weight natural organic acids (LOAs), namely benzoic acid and gallic acid. We find that in the presence of LOAs the nY_2O_3 suspensions become more stable with surface zeta potential more positive or negative, accompanied by small agglomerated size. LOA interaction with nY_2O_3 is shown to promote the release of dissolved yttrium from the nanoparticles, depending on the concentrations of LOAs. Toxic effects of the nY_2O_3 suspensions incubated with LOAs on Scenedesmus obliquus as a function of their mixture levels show three types of signs: stimulation, inhibition, and alleviation. The mechanism of the effects of LOAs on the nY_2O_3 toxicity may be mainly associated with the degree of agglomeration, particle-induced oxidative stress, and dissolved yttrium. Our results stressed the importance of LOA impacts on the fate and toxicity of ENPs in the aquatic environment. - Highlights: • LOAs significantly increased aqueous stability of nY2O3 in a dose-dependent manner. • The presence of LOAs promoted dissolution of nY2O3 in a dose-dependent manner. • Toxicity of nY2O3 with LOAs to Scenedesmus obliquus varied with mixture levels. • Stimulation, inhibition, and alleviation effects of nY2O3 with LOAs were observed. • Mechanism may be driven by agglomeration, oxidative stress, and dissolved yttrium. - LOAs elevate the dispersion stability of nano-Y_2O_3, promote the release of dissolved yttrium, and alter the algal toxicity of nano-Y_2O_3.

  3. Bilayered near-infrared fluorescent nanoparticles based on low molecular weight PEI for tumor-targeted in vivo imaging

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hao; Li, Ke [Xi’an Jiaotong University, Key Laboratory of Biomedical Information Engineering of Education Ministry, School of Life Science and Technology (China); Xu, Liang [The University of Kansas, Department of Molecular Biosciences (United States); Wu, Daocheng, E-mail: wudaocheng@mail.xjtu.edu.cn [Xi’an Jiaotong University, Key Laboratory of Biomedical Information Engineering of Education Ministry, School of Life Science and Technology (China)

    2014-12-15

    To improve the tumor fluorescent imaging results in vivo, bilayered nanoparticles encapsulating a lipophilic near-infrared (NIR) fluorescent dye 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindotri-carbocyanine iodide (DiR) were prepared using low molecular weight stearic acid-grafted polyethyleneimine and hyaluronic acid (DiR-PgSHA nanoparticles), which were investigated as a novel NIR fluorescent nano-probe for in vivo tumor-targeted optical imaging. These nanoparticles were characterized by transmission electron microscopy (TEM), infrared (IR) spectra, UV-visual absorption, and fluorescent emission spectra. Their cytotoxicity in vitro and hepatotoxicity in vivo were tested by MTT assay and histological study, respectively. In vivo NIR fluorescence imaging of the DiR-PgSHA nanoparticles was performed using a Carestream imaging system. The DiR-PgSHA nanoparticles were sphere shaped with a diameter of approximately 50 nm according to the TEM images. The DiR-PgSHA nanoparticles had a low cytotoxicity in vitro according to the MTT assay and low hepatotoxicity in vivo as determined in histological studies. The fluorescent emission of DiR-PgSHA nanoparticles was stable in pH values of 5–9 in solution, with only slight blue-shifts of the emission maxima at the basic pH range. The DiR-PgSHA nanoparticles exhibited a substantial tumor-targeting ability in the optical imaging with the use of tumor-bearing mice. These results demonstrated that the DiR-PgSHA nanoparticle is an excellent biocompatible nano-probe for in vivo tumor-targeted NIR fluorescence imaging with a potential for clinical applications.

  4. Alternative CHCA-based matrices for the analysis of low molecular weight compounds by UV-MALDI-tandem mass spectrometry.

    Science.gov (United States)

    Porta, Tiffany; Grivet, Chantal; Knochenmuss, Richard; Varesio, Emmanuel; Hopfgartner, Gérard

    2011-02-01

    Analysis of low molecular weight compounds (LMWC) in complex matrices by vacuum matrix-assisted laser desorption/ionization (MALDI) often suffers from matrix interferences, which can severely degrade limits of quantitation. It is, therefore, useful to have available a range of suitable matrices, which exhibit complementary regions of interference. Two newly synthesized α-cyanocinnamic acid derivatives are reported here; (E)-2-cyano-3-(naphthalen-2-yl)acrylic acid (NpCCA) and (2E)-3-(anthracen-9-yl)-2-cyanoprop-2enoic acid (AnCCA). Along with the commonly used α-cyano-4-hydroxycinnamic acid (CHCA), and the recently developed 4-chloro-α-cyanocinnamic acid (Cl-CCA) matrices, these constitute a chemically similar series of matrices covering a range of molecular weights, and with correspondingly differing ranges of spectral interference. Their performance was compared by measuring the signal-to-noise ratios (S/N) of 47 analytes, mostly pharmaceuticals, with the different matrices using the selected reaction monitoring (SRM) mode on a triple quadrupole instrument equipped with a vacuum MALDI source. AnCCA, NpCCA and Cl-CCA were found to offer better signal-to-noise ratios in SRM mode than CHCA, but Cl-CCA yielded the best results for 60% of the compounds tested. To better understand the relative performance of this matrix series, the proton affinities (PAs) were measured using the kinetic method. Their relative values were: AnCCA > CHCA > NpCCA > Cl-CCA. This ordering is consistent with the performance data. The synthesis of the new matrices is straightforward and they provide (1) tunability of matrix background interfering ions and (2) enhanced analyte response for certain classes of compounds. Copyright © 2011 John Wiley & Sons, Ltd.

  5. Fragment profiling of low molecular weight heparins using reversed phase ion pair liquid chromatography-electrospray mass spectrometry.

    Science.gov (United States)

    Xu, Xiaohui; Li, Daoyuan; Chi, Lequan; Du, Xuzhao; Bai, Xue; Chi, Lianli

    2015-04-30

    Low molecular weight heparins (LMWHs) are linear and highly charged carbohydrate polymers prepared by chemical or enzymatic depolymerization of heparin. Compared to unfractionated heparin (UFH), LMWHs are prevalently used as clinical anticoagulant drugs due to their lower side effects and better bioavailability. The work presented herein provides a rapid and powerful fragment mapping method for structural characterization of LMWHs. The chain fragments of two types of LMWHs, enoxaparin and nadroparin, were generated by controlled enzymatic digestion with each of heparinase I (Hep I, Enzyme Commission (EC) # 4.2.2.7), heparinase II (Hep II, no EC # assigned) and heparinase III (Hep III, EC # 4.2.2.8). Reversed phase ion pair high performance liquid chromatography (RPIP-HPLC) coupled with electrospray ion trap time-of-flight mass spectrometry (ESI-IT-TOF-MS) was used to profile the oligosaccharide chains ranging from disaccharides to decasaccharides. A database containing all theoretical structural compositions was established to assist the mass spectra interpretation. The six digests derived by three enzymes from two types of LMWHs exhibited distinguishable fingerprinting patterns. And a total of 94 enoxaparin fragments and 109 nadroparin fragments were detected and identified. Besides the common LMWH oligosaccharides, many components containing characteristic LMWH structures such as saturated L-idopyranosuronic acid, 2,5-anhydro-D-mannitol, 1,6-anhydro-D-aminopyranose, as well as odd number oligosaccharides were also revealed. Quantitative comparison of major components derived from innovator and generic nadroparin products was presented. This approach to profile LMWHs' fragments offers a highly reproducible, high resolution and information-rich tool for evaluating the quality of this category of anticoagulant drugs or comparing structural similarities among samples from various sources. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Characterization of the Organic Component of Low-Molecular-Weight Chromium-Binding Substance and Its Binding of Chromium123

    Science.gov (United States)

    Chen, Yuan; Watson, Heather M.; Gao, Junjie; Sinha, Sarmistha Halder; Cassady, Carolyn J.; Vincent, John B.

    2011-01-01

    Chromium was proposed to be an essential element over 50 y ago and was shown to have therapeutic potential in treating the symptoms of type 2 diabetes; however, its mechanism of action at a molecular level is unknown. One chromium-binding biomolecule, low-molecular weight chromium-binding substance (LMWCr or chromodulin), has been found to be biologically active in in vitro assays and proposed as a potential candidate for the in vivo biologically active form of chromium. Characterization of the organic component of LMWCr has proven difficult. Treating bovine LMWCr with trifluoroacetic acid followed by purification on a graphite powder micro-column generates a heptapeptide fragment of LMWCr. The peptide sequence of the fragment was analyzed by MS and tandem MS (MS/MS and MS/MS/MS) using collision-induced dissociation and post-source decay. Two candidate sequences, pEEEEGDD and pEEEGEDD (where pE is pyroglutamate), were identified from the MS/MS experiments; additional tandem MS suggests the sequence is pEEEEGDD. The N-terminal glutamate residues explain the inability to sequence LMWCr by the Edman method. Langmuir isotherms and Hill plots were used to analyze the binding constants of chromic ions to synthetic peptides similar in composition to apoLMWCr. The sequence pEEEEGDD was found to bind 4 chromic ions per peptide with nearly identical cooperativity and binding constants to those of apoLMWCr. This work should lead to further studies elucidating or eliminating a potential role for LMWCr in treating the symptoms of type 2 diabetes and other conditions resulting from improper carbohydrate and lipid metabolism. PMID:21593351

  7. Efficacy and safety of rivaroxaban versus low-molecular-weight heparin therapy in patients with lower limb fractures.

    Science.gov (United States)

    Long, Anhua; Zhang, Lihai; Zhang, Yingze; Jiang, Baoguo; Mao, Zhi; Li, Hongda; Zhang, Shanbao; Xie, Zongyan; Tang, Peifu

    2014-10-01

    Thromboprophylaxis with rivaroxaban has proved effective and safe in patients undergoing hip and knee replacement surgery. As it is unclear whether it is also effective and safe in fracture patients, the aim of the present study was to evaluate the efficacy and safety of rivaroxaban in patients with lower limb fractures. We performed a retrospective cohort study of 2,050 consecutive patients treated for lower limb fractures at our trauma center, comparing rates of venous thromboembolism (VTE), bleeding and surgical complications, and the length of hospital stay for 608 patients who received rivaroxaban and 717 who received a low-molecular-weight heparin (LMWH). Rates of symptomatic VTE were 4.9 and 8.6% in the rivaroxaban and LMWH groups, respectively (p = 0.008), and distal VTE rates were 1.8 and 5.7%, respectively (p = 0.036). The incidence of major bleeding events in the rivaroxaban group was also lower than in the LMWH group (0.2 vs 0.6%), but the difference between the groups was not statistically significant. The mean length of hospital stay was significantly shorter in the rivaroxaban group (12.2 vs 13.1 days, respectively; p = 0.016). This retrospective cohort study is the first report documenting the efficacy and safety of rivaroxaban in patients with lower extremity fractures. In comparison with LMWH, rivaroxaban reduced the incidence of VTE by 45% without increasing the risk of bleeding. However, prospective, randomized controlled trials comparing rivaroxaban and LMWH are needed to confirm our findings.

  8. Intramolecular deactivation processes of electronically excited Lanthanide(III) complexes with organic acids of low molecular weight

    Science.gov (United States)

    Burek, Katja; Eidner, Sascha; Kuke, Stefanie; Kumke, Michael U.

    2018-02-01

    The luminescence of Lanthanide(III) complexes with different model ligands was studied under direct as well as sensitized excitation conditions. The research was performed in the context of studies dealing with deep-underground storages for high-level nuclear waste. Here, Lanthanide(III) ions served as natural analogues for Actinide(III) ions and the low-molecular weight organic ligands are present in clay minerals and furthermore, they were employed as proxies for building blocks of humic substances, which are important complexing molecules in the natural environment, e.g., in the far field of a repository site. Time-resolved luminescence spectroscopy was applied for a detailed characterization of Eu(III), Tb(III), Sm(III) and Dy(III) complexes in aqueous solutions. Based on the observed luminescence the ligands were tentatively divided into two groups (A, B). The luminescence of Lanthanide(III) complexes of group A was mainly influenced by an energy transfer to OH-vibrations. Lanthanide(III) complexes of group B showed ligand-related luminescence quenching, which was further investigated. To gain more information on the underlying quenching processes of group A and B ligands, measurements at different temperatures (77 K ≤ T ≤ 353 K) were performed and activation energies were determined based on an Arrhenius analysis. Moreover, the influence of the ionic strength between 0 M ≤ I ≤ 4 M on the Lanthanide(III) luminescence was monitored for different complexes, in order to evaluate the influence of specific conditions encountered in host rocks foreseen as potential repository sites.

  9. LMWOA (low molecular weight organic acid) exudation by salt marsh plants: Natural variation and response to Cu contamination

    Science.gov (United States)

    Mucha, Ana P.; Almeida, C. Marisa R.; Bordalo, Adriano A.; Vasconcelos, M. Teresa S. D.

    2010-06-01

    This work aimed to evaluate, in vitro, the capability of roots of two salt marsh plants to release low molecular weight organic acids (LMWOAs) and to ascertain whether Cu contamination would stimulate or not organic acids exudation. The sea rush Juncus maritimus and the sea-club rush Scirpus maritimus, both from the lower Douro river estuary (NW Portugal), were used. Plants were collected seasonally, four times a year in 2004, during low tide. After sampling, plant roots were washed for removal of adherent particles and immersed for 2 h in a solution that matched salinity (3) and pH (7.5) of the pore water from the same location to obtain plant exudates. In one of the seasons, similar experiments were carried out but spiking the solution with different amounts of Cu in order to embrace the range between 0 and 1600 nM. In the final solutions as well as in sediment pore water LMWOAs were determined by high performance liquid chromatography. Plants were able to release, in a short period of time, relatively high amounts of LMWOAs (oxalate, citrate, malate, malonate, and succinate). In the sediment pore water oxalate, succinate and acetate were also detected. Therefore, plant roots probably contributed to the presence of some of these organic compounds in pore water. Exudation differed between the plant species and also showed some seasonally variation, particularly for S. maritimus. The release of oxalate by J. maritimus increased with Cu increase in the media. However, exudation of the other LMWOAs did not seem to be stimulated by Cu contamination in the media. This fact is compatible with the existence of alternative internal mechanisms for Cu detoxification, as denoted by the fact that in media contaminated with Cu both plant species accumulated relatively high amounts (29-83%) of the initially dissolved Cu. This study expands our knowledge on the contribution of globally dominant salt marsh plants to the release of LMWOAs into the environment.

  10. Identification and analysis of low molecular weight dissolved organic carbon in subglacial basal ice ecosystems by ion chromatography

    Science.gov (United States)

    Lawson, E. C.; Wadham, J. L.; Lis, G. P.; Tranter, M.; Pickard, A. E.; Stibal, M.; Dewsbury, P.; Fitzsimons, S.

    2015-08-01

    Glacial runoff is an important source of dissolved organic carbon (DOC) for downstream heterotrophic activity, despite the low overall DOC concentrations. This is because of the abundance of bioavailable, low molecular weight (LMW) DOC species. However, the provenance and character of LMW-DOC is not fully understood. We investigated the abundance and composition of DOC in subglacial environments via a molecular level DOC analysis of basal ice, which forms by water/sediment freeze-on to the glacier sole. Spectrofluorometry and a novel ion chromatographic method, which has been little utilised in glacial science for LMW-DOC determinations, were employed to identify and quantify the major LMW fractions (free amino acids, carbohydrates and carboxylic acids) in basal ice from four glaciers, each with a different basal debris type. Basal ice from Joyce Glacier (Antarctica) was unique in that 98 % of the LMW-DOC was derived from the extremely diverse FAA pool, comprising 14 FAAs. LMW-DOC concentrations in basal ice were dependent on the bioavailability of the overridden organic carbon (OC), which in turn, was influenced by the type of overridden material. Mean LMW-DOC concentrations in basal ice from Russell Glacier (Greenland), Finsterwalderbreen (Svalbard) and Engabreen (Norway) were low (0-417 nM C), attributed to the relatively refractory nature of the OC in the overridden paleosols and bedrock. In contrast, mean LMW-DOC concentrations were an order of magnitude higher (4430 nM C) in basal ice from Joyce Glacier, a reflection of the high bioavailability of the overridden lacustrine material (>17 % of the sediment OC comprised extractable carbohydrates, a proxy for bioavailable OC). We find that the overridden material may act as a direct (via abiotic leaching) and indirect (via microbial cycling) source of DOC to the subglacial environment and provides a range of LMW-DOC compounds that may stimulate microbial activity in wet sediments in current subglacial

  11. Bilayered near-infrared fluorescent nanoparticles based on low molecular weight PEI for tumor-targeted in vivo imaging

    International Nuclear Information System (INIS)

    Liu, Hao; Li, Ke; Xu, Liang; Wu, Daocheng

    2014-01-01

    To improve the tumor fluorescent imaging results in vivo, bilayered nanoparticles encapsulating a lipophilic near-infrared (NIR) fluorescent dye 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindotri-carbocyanine iodide (DiR) were prepared using low molecular weight stearic acid-grafted polyethyleneimine and hyaluronic acid (DiR-PgSHA nanoparticles), which were investigated as a novel NIR fluorescent nano-probe for in vivo tumor-targeted optical imaging. These nanoparticles were characterized by transmission electron microscopy (TEM), infrared (IR) spectra, UV-visual absorption, and fluorescent emission spectra. Their cytotoxicity in vitro and hepatotoxicity in vivo were tested by MTT assay and histological study, respectively. In vivo NIR fluorescence imaging of the DiR-PgSHA nanoparticles was performed using a Carestream imaging system. The DiR-PgSHA nanoparticles were sphere shaped with a diameter of approximately 50 nm according to the TEM images. The DiR-PgSHA nanoparticles had a low cytotoxicity in vitro according to the MTT assay and low hepatotoxicity in vivo as determined in histological studies. The fluorescent emission of DiR-PgSHA nanoparticles was stable in pH values of 5–9 in solution, with only slight blue-shifts of the emission maxima at the basic pH range. The DiR-PgSHA nanoparticles exhibited a substantial tumor-targeting ability in the optical imaging with the use of tumor-bearing mice. These results demonstrated that the DiR-PgSHA nanoparticle is an excellent biocompatible nano-probe for in vivo tumor-targeted NIR fluorescence imaging with a potential for clinical applications

  12. The potential of flow-through microdialysis for probing low-molecular weight organic anions in rhizosphere soil solution.

    Science.gov (United States)

    Sulyok, Michael; Miró, Manuel; Stingeder, Gerhard; Koellensperger, Gunda

    2005-08-01

    In this paper, flow-through microdialysis is presented as a novel analytical tool for automatic sampling of low molecular weight organic anions (LMWOA), such as oxalate and citrate, in solid samples of environmental concern. The microsampling methodology involves the implantation of dedicated capillary-type probes offering unrivalled spatial resolution (ca. 200μm) in definite soil sites. These passive samplers are aimed at monitoring local processes, such as the release of organic acids occurring in the rhizosphere environment, in nearly real-time. The influence of chemical and physical variables (composition and flow rate of the perfusion liquid, ionic strength and pH of the outer medium and presence of metal ions therein) was assessed in vitro using liquid-phase assays. On the other hand, the resistance of the external solid medium to mass transfer, and the actual applicability of in vivo calibration methods were investigated using quartz sand as an inert model soil. Microdialysers furnished with 3cm long semipermeable tubular membranes were perfused with 0.01M NaNO 3 at a flow rate of 2.0μl/min, yielding dialysis recoveries ≥45% for both assayed LMWOAs in simulated background soil electrolyte solutions, and ≥24% in the interstitial liquid of complex solid samples. Full knowledge of the fate of LMWOAs in soils was obtained through the application of stimulus-response approaches that mimic the discrete exudation pulses of roots. Highly time-resolved microdialysates were used to discern readily available species such as free carboxylic anions and LMW metal-organic acid complexes from adsorbed, precipitated or mineralised analyte species in a variety of soil samples containing variable amounts of organic matter, exchangeable cations and different levels of metal pollution.

  13. Low-molecular-weight polysaccharides from Agaricus blazei Murrill modulate the Th1 response in cancer immunity

    Science.gov (United States)

    Jiang, Liyan; Yu, Zhipu; Lin, Yu; Cui, Liran; Yao, Shujuan; Lv, Liyan; Liu, Jicheng

    2018-01-01

    To assess the effect of low-molecular-weight polysaccharides from Agaricus blazei Murrill (ABP-AW1) as an immunoadjuvant therapy for type 1 T-helper (Th1) responses in tumorigenesis, C57BL/6 mice were inoculated subcutaneously with ovalbumin (E.G7-OVA). After 3, 10 and 17 days, the mice were immunized with PBS, OVA alone, or OVA and ABP-AW1, at low (50 µg), intermediate (100 µg) or high (200 µg) doses. Tumor growth was examined and compared among the groups, as were the following parameters: Splenocyte viability/proliferation, peripheral blood CD4+/CD8+ T cell ratio, serum OVA-specific IgG1 and IgG2b, secretion of interleukin (IL)-2 and interferon (IFN)-γ, and IFN-γ production on a single cell level from cultured splenocytes. Tumor growth in mice treated with OVA and ABP-AW1 (100 or 200 µg) was significantly slower, compared with in the other groups at the same time-points. OVA with 100 or 200 µg ABP-AW1 was associated with a higher number of total splenocytes, a higher ratio of peripheral blood CD4+/CD8+ T-lymphocytes, higher serum levels of OVA-specific Th1-type antibody IgG2b and greater secretion of the Th1 cytokines IL-1 and IFN-γ from splenocytes. ABP-AW1 is a promising immunoadjuvant therapy candidate, due to its ability to boost the Th1 immune response when co-administered with a cancer vaccine intended to inhibit cancer progression. PMID:29467867

  14. Water-soluble low-molecular-weight -(1, 3–1, 6 D-Glucan inhibit cedar pollinosis

    Directory of Open Access Journals (Sweden)

    Tomoko Jippo

    2015-02-01

    Full Text Available Background: The incidence of allergic diseases such as allergic rhinitis, atopic dermatitis, asthma, and food allergies has increased in several countries. Mast cells have critical roles in various biologic processes related to allergic diseases. Mast cells express the high-affinity receptor for immunoglobulin (Ig E on their surface. The interaction of multivalent antigens with surface-bound IgE causes the secretion of granule-stored mediators, as well as the de novosynthesis of cytokines. Those mediators and cytokines proceed the allergic diseases. We investigated the effects of water-soluble, low-molecular-weight -(1, 3–1, 6 D-glucan isolated from Aureobasidium pullulans 1A1 strain black yeast (LMW--glucan on mast cell-mediated anaphylactic reactions. We reported that LMW--glucan dose-dependently inhibited the degranulation of mast cells. Furthermore, we found that orally administered LMW--glucan inhibited the IgE-mediated passive cutaneous anaphylaxis (PCA reaction in mice. Here, we examined if LMW--glucan had effects on Japanese cedar pollinosis. Findings: In a clinical study, a randomized, single-blind, placebo-controlled, parallel group study in 65 subjects (aged 2262 was performed. This study was undertaken 3 weeks before and until the end of the cedar pollen season. During the study, all subjects consumed one bottle of placebo or LMW--glucan daily and all subjects were required to record allergic symptoms in a diary. The LMW--glucan group had a significantly lower prevalence of sneezing, nose-blowing, tears, and hindrance to the activities of daily living than the placebo group. Conclusions: These results suggested that LMW--glucan could be an effective treatment for allergic diseases

  15. Effects of cadmium amendments on low-molecular-weight organic acid exudates in rhizosphere soils of tobacco and sunflower.

    Science.gov (United States)

    Chiang, Po-Neng; Wang, Ming Kuang; Chiu, Chih Yu; Chou, Shu-Yen

    2006-10-01

    To recognize physiological response of plants to cadmium (Cd) toxicity in rhizosphere of plants, the pot experiments were employed to investigate how low-molecular-weight organic acids (LMWOAs) were exudated from tobacco and sunflower roots of Cd-amended soils. The aims of this study were to assess the effect of LMWOAs on uptake of Cd by tobacco and sunflower under pot experiments, thus comparing the ability of tobacco and sunflower for phytoremediation. Surface soils (0-20 cm) were collected from Taichung Experiment Station (TC) (silty loam). Cadmium chloride (CdCl(2)) was amended into TC soil, giving Cd concentrations of 1, 5, 10 mg kg(-1) soil. Soils with different concentrations of Cd were put into 12 cm (i.d.) pots for incubation, and then 2-week-old tobacco and sunflower seedlings were transplanted into the pots. Tobacco and sunflower were grown in greenhouse for 50 days, respectively. The rhizosphere and bulk soils, and fresh plant tissues were collected after harvest. The Cd concentrations in the plant and transfer factor values in the sunflower were higher than that in the tobacco. No LMWOAs were detected by gas chromatograph in bulk soils, and low amounts of LMWOAs were found in uncontaminated rhizosphere soils. Acetic, lactic, glycolic, malic, maleic, and succinic acids were found in the tobacco and sunflower rhizosphere soils. Concentrations of LMWOAs increased with increasing amendment of Cd concentrations in tobacco and sunflower rhizosphere soils. Correlation coefficient (r) of concentrations of Cd amendment versus LMWOAs exudates of tobacco and sunflower were 0.85 and 0.98, respectively. These results suggest that the different levels of LMWOAs present in the rhizosphere soil play an important role in the solubilization of Cd that bound with soil particle into soil solution and then uptake by plants.

  16. Natural Compounds Interacting with Nicotinic Acetylcholine Receptors: From Low-Molecular Weight Ones to Peptides and Proteins

    Directory of Open Access Journals (Sweden)

    Denis Kudryavtsev

    2015-05-01

    Full Text Available Nicotinic acetylcholine receptors (nAChRs fulfill a variety of functions making identification and analysis of nAChR subtypes a challenging task. Traditional instruments for nAChR research are d-tubocurarine, snake venom protein α-bungarotoxin (α-Bgt, and α-conotoxins, neurotoxic peptides from Conus snails. Various new compounds of different structural classes also interacting with nAChRs have been recently identified. Among the low-molecular weight compounds are alkaloids pibocin, varacin and makaluvamines C and G. 6-Bromohypaphorine from the mollusk Hermissenda crassicornis does not bind to Torpedo nAChR but behaves as an agonist on human α7 nAChR. To get more selective α-conotoxins, computer modeling of their complexes with acetylcholine-binding proteins and distinct nAChRs was used. Several novel three-finger neurotoxins targeting nAChRs were described and α-Bgt inhibition of GABA-A receptors was discovered. Information on the mechanisms of nAChR interactions with the three-finger proteins of the Ly6 family was found. Snake venom phospholipases A2 were recently found to inhibit different nAChR subtypes. Blocking of nAChRs in Lymnaea stagnalis neurons was shown for venom C-type lectin-like proteins, appearing to be the largest molecules capable to interact with the receptor. A huge nAChR molecule sensible to conformational rearrangements accommodates diverse binding sites recognizable by structurally very different compounds.

  17. Static liquid permeation cell method for determining the migration parameters of low molecular weight organic compounds in polyethylene terephthalate.

    Science.gov (United States)

    Song, Yoon S; Koontz, John L; Juskelis, Rima O; Zhao, Yang

    2013-01-01

    The migration of low molecular weight organic compounds through polyethylene terephthalate (PET) films was determined by using a custom permeation cell assembly. Fatty food simulant (Miglyol 812) was added to the receptor chamber, while the donor chamber was filled with 1% and 10% (v/v) migrant compounds spiked in simulant. The permeation cell was maintained at 40°C, 66°C, 100°C or 121°C for up to 25 days of polymer film exposure time. Migrants in Miglyol were directly quantified without a liquid-liquid extraction step by headspace-GC-MS analysis. Experimental diffusion coefficients (DP) of toluene, benzyl alcohol, ethyl butyrate and methyl salicylate through PET film were determined. Results from Limm's diffusion model showed that the predicted DP values for PET were all greater than the experimental values. DP values predicted by Piringer's diffusion model were also greater than those determined experimentally at 66°C, 100°C and 121°C. However, Piringer's model led to the underestimation of benzyl alcohol (Áp = 3.7) and methyl salicylate (Áp = 4.0) diffusion at 40°C with its revised "upper-bound" Áp value of 3.1 at temperatures below the glass transition temperature (Tg) of PET (<70°C). This implies that input parameters of Piringer's model may need to be revised to ensure a margin of safety for consumers. On the other hand, at temperatures greater than the Tg, both models appear too conservative and unrealistic. The highest estimated Áp value from Piringer's model was 2.6 for methyl salicylate, which was much lower than the "upper-bound" Áp value of 6.4 for PET. Therefore, it may be necessary further to refine "upper-bound" Áp values for PET such that Piringer's model does not significantly underestimate or overestimate the migration of organic compounds dependent upon the temperature condition of the food contact material.

  18. Hylan G-F 20 Versus Low Molecular Weight Hyaluronic Acids for Knee Osteoarthritis: A Meta-Analysis.

    Science.gov (United States)

    Zhao, Hongmou; Liu, Hongliang; Liang, Xiaojun; Li, Yi; Wang, Junhu; Liu, Cheng

    2016-10-01

    Hyaluronic acid injection has been reported to decrease pain compared with baseline levels in knee joint osteoarthritis. Hylan G-F 20 is distinguished from the other products by its chemical structure and relatively higher molecular weight. Many trials have compared hylan G-F 20 and low molecular weight hyaluronic acids (LMWHAs); however, their relative efficacy and safety are still debated. The aim was to compare the effectiveness and safety of intra-articular injection of hylan G-F 20 and LMWHA in the treatment of knee joint osteoarthritis. A comprehensive search of the literature up to February 2016 was performed; multiple databases were searched with 'Synvisc' or 'hylan' or 'hyaluronan' as free word terms. The pain-related outcomes and treatment-related adverse events from intent-to-treat analyzed studies were pooled for meta-analysis; other functional outcomes were included in the qualitative analysis. Twenty trials with a total of 3034 patients and 3153 knees were included, with a pooled dropout rate of 7.2 %. The pooled pain-related outcomes at 2 to 3 months reached a statistically significant difference in favor of hylan G-F 20 (I 2  = 88 %; random effects; P = 0.02), and the significance still existed with exclusion (in order to eliminate heterogeneity) of the three studies that most favored hylan G-F 20 (I 2  = 51 %; fixed effect; P = 0.03). No significant difference was reached for other group and subgroup analyses. No significant difference was reached in comparing the patients with treatment-related adverse events (seven trials; 2025 patients; P = 0.13) or the treatment-related adverse events (six trials; 1633 patients; P = 0.14). According to the current results, limited evidence showed a superior effect favoring hylan G-F 20 over LMWHA in the period from 2 to 3 months post-injection for pain-related outcomes. There was no evidence of increased risk of treatment-related adverse events for hylan G-F 20 injections.

  19. Subcutaneous Administration of Low-Molecular-Weight Heparin to Horses Inhibits Ex Vivo Equine Herpesvirus Type 1-Induced Platelet Activation

    Directory of Open Access Journals (Sweden)

    Tracy Stokol

    2018-05-01

    Full Text Available Equine herpesvirus type 1 (EHV-1 is a major cause of infectious respiratory disease, abortion and neurologic disease. Thrombosis in placental and spinal vessels and subsequent ischemic injury in EHV-1-infected horses manifests clinically as abortion and myeloencephalopathy. We have previously shown that addition of heparin anticoagulants to equine platelet-rich plasma (PRP can abolish ex vivo EHV-1-induced platelet activation. The goal of this study was to test whether platelets isolated from horses treated with unfractionated heparin (UFH or low-molecular-weight heparin (LMWH were resistant to ex vivo EHV-1-induced activation. In a masked, block-randomized placebo-controlled cross-over trial, 9 healthy adult horses received 4 subcutaneous injections at q. 12 h intervals of one of the following treatments: UFH (100 U/kg loading dose, 3 maintenance doses of 80 U/kg, 2 doses of LMWH (enoxaparin 80 U/kg 24 h apart with saline at the intervening 12 h intervals, or 4 doses of saline. Blood samples were collected before treatment and after 36 h, 40 h (4 h after the last injection and 60 h (24 h after the last injection. Two strains of EHV-1, Ab4 and RacL11, were added to PRP ex vivo and platelet membrane expression of P selectin was measured as a marker of platelet activation. Drug concentrations were monitored in a Factor Xa inhibition (anti-Xa bioassay. We found that LMWH, but not UFH, inhibited platelet activation induced by low concentrations (1 × 106 plaque forming units/mL of both EHV-1 strains at 40 h. At this time point, all horses had anti-Xa activities above 0.1 U/ml (range 0.15–0.48 U/ml with LMWH, but not UFH. By 60 h, a platelet inhibitory effect was no longer detected and anti-Xa activity had decreased (range 0.03 to 0.07 U/ml in LMWH-treated horses. Neither heparin inhibited platelet activation induced by high concentrations (5 × 106 plaque forming units/mL of the RacL11 strain. We found substantial between horse

  20. Renal Protective Effects of Low Molecular Weight of Inonotus obliquus Polysaccharide (LIOP on HFD/STZ-Induced Nephropathy in Mice

    Directory of Open Access Journals (Sweden)

    Yen-Jung Chou

    2016-09-01

    Full Text Available Diabetic nephropathy (DN is the leading cause of end-stage renal disease in diabetes mellitus. Oxidative stress, insulin resistance and pro-inflammatory cytokines have been shown to play an important role in pathogeneses of renal damage on type 2 diabetes mellitus (DM. Inonotus obliquus (IO is a white rot fungus that belongs to the family Hymenochaetaceae; it has been used as an edible mushroom and exhibits many biological activities including anti-tumor, anti-oxidant, anti-inflammatory and anti-hyperglycemic properties. Especially the water-soluble Inonotus obliquus polysaccharides (IOPs have been previously reported to significantly inhibit LPS-induced inflammatory cytokines in mice and protect from streptozotocin (STZ-induced diabetic rats. In order to identify the nephroprotective effects of low molecular weight of IOP fraction (LIOP, from the fruiting bodies of Inonotus obliquus, high-fat diet (HFD plus STZ-induced type 2-like diabetic nephropathy C57BL/6 mice were investigated in this study. Our data showed that eight weeks of administration of 10–100 kDa, LIOP (300 mg/kg had progressively increased their sensitivity to glucose (less insulin tolerance, reduced triglyceride levels, elevated the HDL/LDL ratio and decreased urinary albumin/creatinine ratio(ACR compared to the control group. By pathological and immunohistochemical examinations, it was indicated that LIOP can restore the integrity of the glomerular capsules and increase the numbers of glomerular mesangial cells, associated with decreased expression of TGF-β on renal cortex in mice. Consistently, three days of LIOP (100 μg/mL incubation also provided protection against STZ + AGEs-induced glucotoxicity in renal tubular cells (LLC-PK1, while the levels of NF-κB and TGF-β expression significantly decreased in a dose-dependent manner. Our findings demonstrate that LIOP treatment could ameliorate glucolipotoxicity-induced renal fibrosis, possibly partly via the inhibition of NF

  1. Low molecular weight heparin may benefit nephrotic remission in steroid‑sensitive nephrotic syndrome via inhibiting elastase.

    Science.gov (United States)

    Zhai, Songhui; Hu, Lijuan; Zhong, Lin; Tao, Yuhong; Wang, Zheng

    2017-12-01

    Low molecular weight heparin (LMWH) has a structure similar to heparan sulfate, which exerts anti‑inflammatory effects via inhibiting elastase (Ela) activity. Release of Ela along the glomerular capillary wall may induce glomerular injury and proteinuria. The present study aimed to investigate the influence of LMWH on steroid‑sensitive nephrotic syndrome (SSNS) and the potential underlying mechanism. A total of 40 SSNS patients and 20 healthy controls were recruited. SSNS patients were treated with LMWH and prednisone simultaneously (LMWH+pred group) or with prednisone alone (pred group). Proteinuria, urinary glycosaminoglycans (GAGs), serum Ela and urinary creatinine levels were measured. The nephrotic period of SSNS was 15.93±5.78 days. The nephrotic period of SSNS in LMWH+pred group was significantly reduced compared with the pred group (14.13±4.56 vs. 18.63±6.49 days; PEla levels (77.64±10.99 ng/l) were significantly greater in the nephrotic period of SSNS compared with the remission period (0.107±0.026 g/24 h, 1.53±0.27 mg/mmol Cr and 41.92±7.81 ng/l, respectively) and the healthy control group (0.098±0.027 g/24 h, 1.40±0.26 mg/mmol creatinine and 38.43±9.83 ng/l, respectively; PEla levels in the LMWH+pred group were significantly reduced compared with the pred group (P0.05). Positive correlations were revealed between urinary GAG excretion and proteinuria (r=0.877; PEla levels (r=0.844; PEla levels and urinary GAG excretion (r=0.881; PEla levels may induce proteinuria by degrading GAGs in the glomerular basement membrane in children with SSNS. LMWH may benefit nephrotic remission of SSNS via inhibiting Ela.

  2. Characterizing endogenous and oxidative low molecular weight flavor/aroma compounds in fresh squeezed/blended pomegranate juice.

    Science.gov (United States)

    Little published information exists regarding flavor and aroma compounds in pomegranate (Punica granatum) juices. Although, arils have fruity and sweet characteristics, we found no publications describing volatile and semi-volatile compounds responsible for their typical flavor. Only two reports w...

  3. Inkjet-printed gold nanoparticle surfaces for the detection of low molecular weight biomolecules by laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Marsico, Alyssa L M; Creran, Brian; Duncan, Bradley; Elci, S Gokhan; Jiang, Ying; Onasch, Timothy B; Wormhoudt, Joda; Rotello, Vincent M; Vachet, Richard W

    2015-11-01

    Effective detection of low molecular weight compounds in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is often hindered by matrix interferences in the low m/z region of the mass spectrum. Here, we show that monolayer-protected gold nanoparticles (AuNPs) can serve as alternate matrices for the very sensitive detection of low molecular weight compounds such as amino acids. Amino acids can be detected at low fmol levels with minimal interferences by properly choosing the AuNP deposition method, density, size, and monolayer surface chemistry. By inkjet-printing AuNPs at various densities, we find that AuNP clusters are essential for obtaining the greatest sensitivity. Graphical Abstract ᅟ.

  4. Nanotexture Optimization by Oxygen Plasma of Mesoporous Silica Thin Film for Enrichment of Low Molecular Weight Peptides Captured from Human Serum

    Science.gov (United States)

    Hu, Ye; Peng, Yang; Brousseau, Louis; Bouamrani, Ali; Liu, Xuewu; Ferrari, Mauro

    2010-01-01

    This study investigated the optimization of mesoporous silica thin films by nanotexturing using oxygen plasma versus thermal oxidation. Calcination in oxygen plasma provides superior control over pore formation with regard to the pore surface and higher fidelity to the structure of the polymer template. The resulting porous film offers an ideal substrate for the selective partitioning of peptides from complex mixtures. The improved chemico-physical characteristics of porous thin films (pore size distribution, nanostructure, surface properties and pore connectivity) were systematically characterized with XRD, Ellipsometry, FTIR, TEM and N2 adsorption/desorption. The enrichment of low molecular weight proteins captured from human serum on mesoporous silica thin films fabricated by both methodologies were investigated by comparison of their MALDI-TOF MS profiles. This novel on-chip fractionation technology offers advantages in recovering the low molecular weight peptides from human serum, which has been recognized as an informative resource for early diagnosis of cancer and other diseases. PMID:21179395

  5. Method and apparatus for removing volatile hydrocarbons from particulate soils

    International Nuclear Information System (INIS)

    Mendenhall, R.L.

    1992-01-01

    This patent describes an apparatus for heating solid particulate mineral compositions. It comprises: a counterflow ratable drum having a first end and an opposite second end, a first portion of the drum extending from the first end for a first length and having a first diameter along the first length, and a second portion of the drum secured to and extending from the first portion to the second end for a second length and having a second diameter along the second length, the second diameter being less than the first diameter, a burner adjacent the first end for introducing and directing hot gases of combustion into the first portion of the drum toward the second end, means for introducing particulate composition into the drum at the second end, means for directing the particulate composition along the drum from the second end toward the first end, and means for recovering composition at the first end, means for removing a gaseous mixture of organic volatiles, gases of combustion and fine particles of the particulate composition adjacent the second drum end, means for separating fine particles of the particulate composition from the gaseous mixture, and means for returning the separated fine particulate composition particles to the first portion of the drum

  6. Solubility of crystalline organic compounds in high and low molecular weight amorphous matrices above and below the glass transition by zero enthalpy extrapolation.

    Science.gov (United States)

    Amharar, Youness; Curtin, Vincent; Gallagher, Kieran H; Healy, Anne Marie

    2014-09-10

    Pharmaceutical applications which require knowledge of the solubility of a crystalline compound in an amorphous matrix are abundant in the literature. Several methods that allow the determination of such data have been reported, but so far have only been applicable to amorphous polymers above the glass transition of the resulting composites. The current work presents, for the first time, a reliable method for the determination of the solubility of crystalline pharmaceutical compounds in high and low molecular weight amorphous matrices at the glass transition and at room temperature (i.e. below the glass transition temperature), respectively. The solubilities of mannitol and indomethacin in polyvinyl pyrrolidone (PVP) K15 and PVP K25, respectively were measured at different temperatures. Mixtures of undissolved crystalline solute and saturated amorphous phase were obtained by annealing at a given temperature. The solubility at this temperature was then obtained by measuring the melting enthalpy of the crystalline phase, plotting it as a function of composition and extrapolating to zero enthalpy. This new method yielded results in accordance with the predictions reported in the literature. The method was also adapted for the measurement of the solubility of crystalline low molecular weight excipients in amorphous active pharmaceutical ingredients (APIs). The solubility of mannitol, glutaric acid and adipic acid in both indomethacin and sulfadimidine was experimentally determined and successfully compared with the difference between their respective calculated Hildebrand solubility parameters. As expected from the calculations, the dicarboxylic acids exhibited a high solubility in both amorphous indomethacin and sulfadimidine, whereas mannitol was almost insoluble in the same amorphous phases at room temperature. This work constitutes the first report of the methodology for determining an experimentally measured solubility for a low molecular weight crystalline solute

  7. On the determination of diffusivities of volatile hydrocarbons in semi-solid bitumen

    International Nuclear Information System (INIS)

    Tang, J. S.

    2001-01-01

    Carbon dioxide, supercritical ethane and propane have been considered as solvents to recover heavy oil. Given that mixing solvent with bitumen is one of the important parameters governing the performance of the solvent extraction processes, good understanding of solvent dispersion is essential for the proper design of the process. Produced bitumen can still contain some residual volatile hydrocarbons after gas flashing off a three-phase separator. When exposed to the air due to a spill or ruptured line, these residual hydrocarbons can escape and create air pollution problems. Consequently, knowledge of the diffusivities of volatile components in bitumen is needed to assess the extent of environmental damage that may result from bitumen spill or working loss of vapour to the atmosphere. This paper discusses the de-coupled transfer model developed by this author (and described in a paper in vol. 78 of this journal) and its limiting solution, and provides a re-intrepretation of the method by Fu and Phillips (1979) which in turn was based on the late-time limiting solution advanced by Tang and Zhang (2000). The analysis indicates that gas purging is a valid method for determining the diffusion coefficients of trace, volatile hydrocarbons in bitumen. However, the assumption of de-coupling may not be appropriate for large diffusion flux and slow gas flow. Furthermore, improper use of the limiting solution theory could lead to a 25 per cent error in calculating the diffusion coefficient. 14 refs., 2 tabs., 8 figs

  8. Enzymatic and acidic degradation of high molecular weight dextran into low molecular weight and its characterizations using novel Diffusion-ordered NMR spectroscopy.

    Science.gov (United States)

    Iqbal, Samina; Marchetti, Roberta; Aman, Afsheen; Silipo, Alba; Qader, Shah Ali Ul; Molinaro, Antonio

    2017-10-01

    Low molecular weight fractions were derived from native high molecular weight dextran produced by Leuconostoc mesenteroides KIBGE-IB26. Structural characterization of native and low molecular weight fractions obtained after acidic and enzymatic hydrolysis was done using FTIR and NMR spectroscopy. The molecular weight was estimated using Diffusion Ordered NMR spectroscopy. Native dextran (892kDa) is composed of α-(1→6) glycosidic linkage along with α-(1→3) branching. Major proportion of 528kDa dextran was obtained after prolong enzymatic hydrolysis however, an effective acidic treatment at pH-1.4 up to 02 and 04h of exposure resulted in the formation of 77kDa and 57kDa, respectively. The increment in pH from 1.4 to 1.8 lowered the hydrolysis efficiency and resulted in the formation of 270kDa dextran fraction. The results suggest that derived low molecular weight water soluble fractions can be utilized as a drug delivery carrier along with multiple application relating pharmaceutical industries. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. [Effects of low molecular weight heparin on the inflammatory response and vascular injury in rat after electric burn].

    Science.gov (United States)

    Jiang, Nanhong; Xie, Weiguo; Wang, Hui; Jin, Dongmei; Tan, Hong; Zhao, Chaoli

    2014-04-01

    To observe the effects of low molecular weight heparin (LMWH) on the inflammatory response and vascular injury in rat after electric burn. A homemade regulator and transformer apparatus was used to reproduce the model of electric burn (0.5 cm×0.5 cm in size) with depth from full-thickness to full-thickness skin plus muscle and bone on the middle of the inside of right hind limb in 60 Wistar rats. The open wounds were covered with 20 g/L sulfadiazine silver paste immediately after injury. The wound condition was observed every day. The injured rats were divided into group LMWH and control group (C) according to the random number table, with 30 rats in each group. Rats in group LMWH were given subcutaneous injection of LMWH (1 U/g) in abdominal wall, 2 times a day. No other treatment was given in rats in group C. On post burn day (PBD) 3, 5, and 10, 10 rats respectively of two groups were sacrificed. The damaged tissue of wound and that around the wound (1.0 cm×0.5 cm in size) were excised, and heart blood was obtained. The pathological changes and thrombosis in damaged tissue were observed with HE, Masson, and aldehyde fuchsin staining, and the thrombosis rate was calculated. Serum contents of TNF-α and endothelin-1 were determined with ELISA. The mRNA expression of TNF-α in damaged tissue was detected with RT-PCR. Data were processed with Levene homogeneity test, analysis of variance of factorial design, LSD- t test, SNK- q test, and Friedman M nonparametric test. (1) The injured limb of rats was obviously swollen after electric burn, which reached deeply to the muscle and bone. Compared with those of group C, the swelling of rats subsided slightly faster and the inflammatory response was lighter in group LMWH at each time point. (2) The necrosis of damaged tissue and profuse infiltration of inflammatory cells were observed. Dilatation of blood vessels, congestion and thrombosis, and swelling, necrosis, and desquamation of vascular endothelial cells were

  10. Enhancement of trophoblast differentiation and survival by low molecular weight heparin requires heparin-binding EGF-like growth factor.

    Science.gov (United States)

    Bolnick, Alan D; Bolnick, Jay M; Kohan-Ghadr, Hamid-Reza; Kilburn, Brian A; Pasalodos, Omar J; Singhal, Pankaj K; Dai, Jing; Diamond, Michael P; Armant, D Randall; Drewlo, Sascha

    2017-06-01

    Does low molecular weight heparin (LMWH) require heparin-binding epidermal growth factor (EGF)-like growth factor (HBEGF) signaling to induce extravillous trophoblast differentiation and decrease apoptosis during oxidative stress? LMWH increased HBEGF expression and secretion, and HBEGF signaling was required to stimulate trophoblast extravillous differentiation, increase invasion in vitro and reduce trophoblast apoptosis during oxidative stress. Abnormal trophoblast differentiation and survival contribute to placental insufficiency syndromes, including preeclampsia and intrauterine growth restriction. Preeclampsia often manifests as a pro-thrombotic state, with unsuccessful transformation of the spiral arteries that reduces oxygen supply and can produce placental infarction. LMWH improves placental function by increasing blood flow. Recent data suggest that the actions of LMWH transcend its anti-coagulative properties, but the molecular mechanism is unknown. There is evidence that LMWH alters the expression of human HBEGF in trophoblast cells, which regulates human trophoblast pathophysiology. HBEGF, itself, is capable of increasing trophoblast survival and invasiveness. First-trimester placental explants and the HTR-8/SVneo cell line, established using extravillous trophoblast outgrowths from first-trimester villous explants, were treated in vitro with LMWH to examine the effects on HBEGF signaling and trophoblast function under normal physiological and pathological conditions. A highly specific antagonist of HBEGF and other inhibitors of HBEGF downstream signaling were used to determine the relationship between LMWH treatment and HBEGF. Placental tissues (n = 5) were obtained with IRB approval and patient consent from first-trimester terminations. Placental explants and HTR-8/SVneo cells were cultured on plastic or Matrigel™ and treated with a therapeutic dose of LMWH (Enoxaparin; 10 IU/ml), with or without CRM197, pan Erb-B2 Receptor Tyrosine Kinase (ERBB

  11. Composition and functional analysis of low-molecular-weight glutenin alleles with Aroona near-isogenic lines of bread wheat

    Directory of Open Access Journals (Sweden)

    Zhang Xiaofei

    2012-12-01

    Full Text Available Abstract Background Low-molecular-weight glutenin subunits (LMW-GS strongly influence the bread-making quality of bread wheat. These proteins are encoded by a multi-gene family located at the Glu-A3, Glu-B3 and Glu-D3 loci on the short arms of homoeologous group 1 chromosomes, and show high allelic variation. To characterize the genetic and protein compositions of LMW-GS alleles, we investigated 16 Aroona near-isogenic lines (NILs using SDS-PAGE, 2D-PAGE and the LMW-GS gene marker system. Moreover, the composition of glutenin macro-polymers, dough properties and pan bread quality parameters were determined for functional analysis of LMW-GS alleles in the NILs. Results Using the LMW-GS gene marker system, 14–20 LMW-GS genes were identified in individual NILs. At the Glu-A3 locus, two m-type and 2–4 i-type genes were identified and their allelic variants showed high polymorphisms in length and nucleotide sequences. The Glu-A3d allele possessed three active genes, the highest number among Glu-A3 alleles. At the Glu-B3 locus, 2–3 m-type and 1–3 s-type genes were identified from individual NILs. Based on the different compositions of s-type genes, Glu-B3 alleles were divided into two groups, one containing Glu-B3a, B3b, B3f and B3g, and the other comprising Glu-B3c, B3d, B3h and B3i. Eight conserved genes were identified among Glu-D3 alleles, except for Glu-D3f. The protein products of the unique active genes in each NIL were detected using protein electrophoresis. Among Glu-3 alleles, the Glu-A3e genotype without i-type LMW-GS performed worst in almost all quality properties. Glu-B3b, B3g and B3i showed better quality parameters than the other Glu-B3 alleles, whereas the Glu-B3c allele containing s-type genes with low expression levels had an inferior effect on bread-making quality. Due to the conserved genes at Glu-D3 locus, Glu-D3 alleles showed no significant differences in effects on all quality parameters. Conclusions This work

  12. Utilization of low molecular weight organics by soil microorganisms: combination of 13C-labelling with PLFA analysis

    Science.gov (United States)

    Gunina, Anna; Dippold, Michaela; Kuzyakov, Yakov

    2014-05-01

    Microbial metabolisation is the main transformation pathway of low molecular weight organic substances (LMWOS), but detailed knowledge concerning the fate of LMWOS in soils is strongly limited. Considering that various LMWOS classes enter biochemical cycles at different steps, we hypothesise that the percentage of their LMWOS-Carbon (C) used for microbial biomass (MB) production and consequently medium-term stabilisation in soil is different. We traced the three main groups of LMWOS: amino acids, sugars and carboxylic acids, by uniformly labelled 13C-alanine, -glutamate, -glucose, -ribose, -acetate and -palmitate. Incorporation of 13C from these LMWOS into MB (fumigation-extraction method) and into phospholipid fatty acids (PLFAs) (Bligh-Dyer extraction, purification and GC-C-IRMS measurement) was investigated under field conditions 3 d and 10 d after LMWOS application. The activity of microbial utilization of LMWOS for cell membrane construction was estimated by replacement of PLFA-C with 13C. Decomposition of LMWOS-C comprised 20-65% of the total label, whereas incorporation of 13C into MB amounted to 20-50% of initially applied 13C on day three and was reduced to 5-30% on day 10. Incorporation of 13C-labelled LMWOS into MB followed the trend sugars > carboxylic acids > amino acids. Differences in microbial utilisation between LMWOS were observed mainly at day 10. Thus, instead of initial rapid uptake, further metabolism within microbial cells accounts for the individual fate of C from different LMWOS in soils. Incorporation of 13C from each LMWOS into each PLFA occurred, which reflects the ubiquitous ability of all functional microbial groups for LMWOS utilization. The preferential incorporation of palmitate can be attributed to its role as a direct precursor for many fatty acids (FAs) and PLFA formation. Higher incorporation of alanine and glucose compared to glutamate, ribose and acetate reflect the preferential use of glycolysis-derived substances in the FAs

  13. Biofuel components change the ecology of bacterial volatile petroleum hydrocarbon degradation in aerobic sandy soil

    International Nuclear Information System (INIS)

    Elazhari-Ali, Abdulmagid; Singh, Arvind K.; Davenport, Russell J.; Head, Ian M.; Werner, David

    2013-01-01

    We tested the hypothesis that the biodegradation of volatile petroleum hydrocarbons (VPHs) in aerobic sandy soil is affected by the blending with 10 percent ethanol (E10) or 20 percent biodiesel (B20). When inorganic nutrients were scarce, competition between biofuel and VPH degraders temporarily slowed monoaromatic hydrocarbon degradation. Ethanol had a bigger impact than biodiesel, reflecting the relative ease of ethanol compared to methyl ester biodegradation. Denaturing gradient gel electrophoresis (DGGE) of bacterial 16S rRNA genes revealed that each fuel mixture selected for a distinct bacterial community, each dominated by Pseudomonas spp. Despite lasting impacts on soil bacterial ecology, the overall effects on VHP biodegradation were minor, and average biomass yields were comparable between fuel types, ranging from 0.40 ± 0.16 to 0.51 ± 0.22 g of biomass carbon per gram of fuel carbon degraded. Inorganic nutrient availability had a greater impact on petroleum hydrocarbon biodegradation than fuel composition. Highlights: ► The effect of 10% ethanol or 20% biodiesel on the biodegradability of volatile petroleum hydrocarbons in soil was investigated. ► Competition for scarce inorganic nutrients between biofuel and VPH degraders slowed monoaromatic hydrocarbon degradation. ► Biofuel effects were transitional. ► Each fuel selected for a distinct predominant bacterial community. ► All bacterial communities were dominated by Pseudomonas spp. - Blending of petroleum with ethanol or biodiesel changes the fuel degrading soil bacterial community structure, but the long-term effects on fuel biodegradability are minor.

  14. Characterization of low molecular weight dissolved natural organic matter along the treatment trait of a waterworks using Fourier transform ion cyclotron resonance mass spectrometry.

    Science.gov (United States)

    Zhang, Haifeng; Zhang, Yahe; Shi, Quan; Ren, Shuoyi; Yu, Jianwei; Ji, Feng; Luo, Wenbin; Yang, Min

    2012-10-15

    Dissolved natural organic matter (DOM), particularly the low molecular weight DOM, can affect the performance of water treatment processes and serve as a main precursor of disinfection by-products (DBPs) during chlorination. In this study, electrospray ionization coupled to Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) was used to characterize the low molecular weight DOM along the treatment trait of a conventional drinking water treatment plant. The ESI FT-ICR MS data showed that various C, H, O-only class species were the major components in the source water. According to the van Krevelen diagram analysis, lignin- and tannin-like compounds were the most abundant components. Within an isobaric group, the DOM molecules with a high degree of oxidation (high O/C value) were preferentially removed during coagulation, while those with low degree of oxidation were found to be more reactive toward chlorine. In addition, 357 one-chlorine containing products and 199 two-chlorine containing products formed during chlorination were detected in the chlorination effluent sample at a high confidence level. The chlorinated products can be arranged into series, suggesting that they were originated from C, H, O-only precursor compounds, which were in series related by the replacement of CH(4) against oxygen. For the first time, this study explored the behavior of low molecular weight DOM along a drinking water treatment trait on the molecular level, and revealed the presence of abundant unknown chlorinated products, which are probably rich in carboxylic and phenolic groups, in drinking water. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Children with atopic dermatitis and frequent emollient use have increased urinary levels of low-molecular-weight phthalate metabolites and parabens

    DEFF Research Database (Denmark)

    Overgaard, L E K; Main, K M; Frederiksen, H

    2017-01-01

    BACKGROUND: Parabens may be added to cosmetic and personal care products for preservation purposes. Low-molecular weight (LMW) phthalate diesters function as plasticizers, fixatives or solvents in such products, but may also be found in small quantities as contaminants from plastic containers...... whether the difference is explained by increased use of the specific emollients that are used to treat pruritic and inflamed skin, and/or whether the impaired skin barrier allows chemicals to penetrate more easily. Moreover, the putative toxicological burden is unknown....

  16. AVE5026, a new hemisynthetic ultra-low-molecular-weight heparin for the prevention of venous thromboembolism in patients after total knee replacement surgery

    DEFF Research Database (Denmark)

    Lassen, Michael Rud; Dahl, O E; Mismetti, P

    2009-01-01

    BACKGROUND: AVE5026 is a new hemisynthetic ultra-low-molecular-weight heparin, with a novel anti-thrombotic profile resulting from high anti-factor (F)Xa activity and residual anti-FIIa activity. AVE5026 is in clinical development for venous thromboembolism (VTE) prevention, a frequent complication....... The primary safety outcome was the incidence of major bleeding. RESULTS: The primary efficacy outcome was assessed in 464 patients. There was a significant dose-response across the five AVE5026 groups for VTE prevention (Pincidence of VTE ranging from 5.3% to 44.1% compared with 35...

  17. New filter media development for effective control of trimethysilanol (TMS) and related low molecular weight silicon containing organic species in the photobay ambient

    Science.gov (United States)

    Grayfer, Anatoly; Belanger, Frank V.; Cate, Phillip; Ruede, David

    2007-03-01

    The authors present results of extensive studies on the chemical behavior of low molecular weight silicon-containing species (LMWS) and associated challenges of their analytical determination and control to prevent adverse influence on critical optical elements of exposure tools. In their paper the authors describe a non-traditional approach to the creation of a TMS gaseous source for filter media development and an engineering solution to the challenge of controlling LMWS - a solution that shows a significant advantage over currently existing approaches.

  18. Distribution of nonionic organic compounds (highly volatile chlorinated hydrocarbons) in the unsaturated zone

    Energy Technology Data Exchange (ETDEWEB)

    Grathwohl, P.

    1988-01-01

    Nonpolar pollutants, e.g. highly volatile chlorinated hydrocarbons (HVCH) are more or less equally distributed among all three soil phases (solids, water, air) in the unsaturated zone. The sorption of HVCH on soil solids depends on the amount and type of organic matter in the soil. For wet material an additional sorption on mineral surfaces can be neglected, since all possible sites for sorption are occupied by water. Provided the partition-coefficients or sorption-constants are known the contamination of the whole system can be evaluated from the pollutant concentration in the soil air; in addition it is possible to estimate a groundwater risk.

  19. Thermal Inactivation Kinetics and Secondary Structure Change of a Low Molecular Weight Halostable Exoglucanase from a Marine Aspergillus niger at High Salinities.

    Science.gov (United States)

    Xue, Dong-Sheng; Liang, Long-Yuan; Lin, Dong-Qiang; Yao, Shan-Jing

    2017-11-01

    Two kinds of exoglucanase were purified from a marine Aspergillus niger. Catalytic ability of halophilic exoglucanase with a lower molecular weight and secondary structure change was analyzed at different salinities. Activity of the low molecular weight exoglucanase in 10% NaCl solution (w/v) was 1.69-fold higher of that in NaCl-free solution. Half-life time in 10% NaCl solution (w/v) was over 1.27-fold longer of that in NaCl-free solution. Free energy change of the low molecular weight exoglucanase denaturation, △G, in 10% NaCl solution (w/v) was 0.54 kJ/mol more than that in NaCl-free solution. Melt point in 10% NaCl solution (w/v), 52.01 °C, was 4.21 °C higher than that in NaCl-free solution, 47.80 °C. K m value, 0.179 mg/ml in 10% NaCl solution (w/v) was less 0.044 mg/ml than that, 0.224 mg/ml, in NaCl-free solution. High salinity made content of α-helix increased. Secondary structure change caused by high salinities improved exoglucanase thermostability and catalysis activity. The halophilic exoglucanase from a marine A. niger was valuable for hydrolyzing cellulose at high salinities.

  20. Analysis of iminosugars and other low molecular weight carbohydrates in Aglaonema sp. extracts by hydrophilic interaction liquid chromatography coupled to mass spectrometry.

    Science.gov (United States)

    Rodríguez-Sánchez, S; García-Sarrió, M J; Quintanilla-López, J E; Soria, A C; Sanz, M L

    2015-12-04

    A method by hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry (HILIC-MS(2)) has been successfully developed for the simultaneous analysis of bioactive iminosugars and other low molecular weight carbohydrates in Aglaonema leaf extracts. Among other experimental chromatographic conditions, mobile phase eluents, additives and column temperature were evaluated in terms of retention time, resolution, peak width and symmetry provided for target carbohydrates. In general, narrow peaks (wh: 0.2-0.6min) with good symmetry (As: 0.9-1.3) and excellent resolution (Rs>1.8) were obtained for iminosugars using an acetonitrile:water gradient with 5mM ammonium acetate in both eluents at 55°C. Tandem mass spectra were used to confirm the presence of previously detected iminosugars in Aglaonema extracts and to tentatively identify for the first time others such as miglitol isomer, glycosyl-miglitol isomers and glycosyl-DMDP isomers. Concentration of total iminosugars varied from 1.35 to 2.84mgg(-1) in the extracts of the different Aglaonema samples analyzed. To the best of our knowledge, this is the first time that a HILIC-MS(2) method has been proposed for the simultaneous analysis of iminosugars and other low molecular weight carbohydrates of Aglaonema sp. extracts. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Crystallization and preliminary X-ray characterization of a thermostable low-molecular-weight 1,4-β-d-glucan glucohydrolase from an alkalothermophilic Thermomonospora sp

    International Nuclear Information System (INIS)

    Manikandan, K.; Jagtap, S.; Rao, M.; Ramakumar, S.

    2006-01-01

    A low-molecular-weight cellulase from an alkalothermophilic Thermomonospora sp. has been crystallized. A diffraction data set has been collected to 2.3 Å resolution. Cellulases catalyze the hydrolysis of β-1,4-glycosidic linkages within cellulose, the most abundant organic polymer on earth. The cellulase (TSC; EC 3.2.1.4) from an alkalothermophilic Thermomonospora sp. has a low molecular weight of 14.2 kDa. It is optimally active at 323 K and stable over the wide pH range of 5–9. Moreover, it has bifunctional activity against cellulose and xylan polymers. In this study, TSC was purified from the native source and crystallized by the hanging-drop vapour-diffusion method. The crystals belong to the orthorhombic space group P2 1 2 1 2 1 , with unit-cell parameters a = 49.9, b = 79.5, c = 99.7 Å, and diffract to better than 2.3 Å resolution

  2. Crystallization and preliminary X-ray characterization of a thermostable low-molecular-weight 1,4-β-d-glucan glucohydrolase from an alkalothermophilic Thermomonospora sp

    Energy Technology Data Exchange (ETDEWEB)

    Manikandan, K. [Department of Physics, Indian Institute of Science, Bangalore 560 012 (India); Jagtap, S.; Rao, M. [Division of Biochemical Sciences, National Chemical Laboratory, Pune 411 008 (India); Ramakumar, S., E-mail: ramak@physics.iisc.ernet.in [Department of Physics, Indian Institute of Science, Bangalore 560 012 (India); Bioinformatics Centre, Indian Institute of Science, Bangalore 560 012 (India)

    2006-04-01

    A low-molecular-weight cellulase from an alkalothermophilic Thermomonospora sp. has been crystallized. A diffraction data set has been collected to 2.3 Å resolution. Cellulases catalyze the hydrolysis of β-1,4-glycosidic linkages within cellulose, the most abundant organic polymer on earth. The cellulase (TSC; EC 3.2.1.4) from an alkalothermophilic Thermomonospora sp. has a low molecular weight of 14.2 kDa. It is optimally active at 323 K and stable over the wide pH range of 5–9. Moreover, it has bifunctional activity against cellulose and xylan polymers. In this study, TSC was purified from the native source and crystallized by the hanging-drop vapour-diffusion method. The crystals belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 49.9, b = 79.5, c = 99.7 Å, and diffract to better than 2.3 Å resolution.

  3. Ferric reductase activity of low molecular weight human milk fraction is associated with enhanced iron solubility and uptake in Caco-2 cells.

    Science.gov (United States)

    Pullakhandam, Raghu; Nair, Madhavan Krishnapillai; Kasula, Sunanda; Kilari, Sreenivasulu; Thippande, Tippeswamy Gowda

    2008-09-19

    It is known that the fractional absorption of extrinsic iron from human milk is higher in infants and adults. A low molecular weight milk fraction has been proposed to increase the bioavailability of iron from human milk. Nevertheless, the mechanisms remained elusive. Here in we demonstrate ferric reductase activity (Km7.73x10(-6)M) in low molecular weight human milk fraction (10kF, filtrate derived from ultra filtration of milk whey through 10kDa cutoff membrane), which increased ferric iron solubility and iron uptake in Caco-2 cells. The 10kF fraction was as effective as ascorbic acid (1:20 iron to ascorbic acid) in increasing the ferric iron solubility and uptake in Caco-2 cells. Further, gel filtration chromatography on peptide column led to co-elution of ferric reductase and iron solubilization activities at an apparent molecular mass of iron in Caco-2 cells. Thus, it is concluded that human milk possesses ferric reductase activity and is associated with ferric iron solubilization and enhanced absorption.

  4. Determination of volatile organic hydrocarbons in water samples by solid-phase dynamic extraction.

    Science.gov (United States)

    Jochmann, Maik A; Yuan, Xue; Schmidt, Torsten C

    2007-03-01

    In the present study a headspace solid-phase dynamic extraction method coupled to gas chromatography-mass spectrometry (HS-SPDE-GC/MS) for the trace determination of volatile halogenated hydrocarbons and benzene from groundwater samples was developed and evaluated. As target compounds, benzene as well as 11 chlorinated and brominated hydrocarbons (vinyl chloride, dichloromethane, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, carbon tetrachloride, chloroform, trichloroethylene, tetrachloroethylene, bromoform) of environmental and toxicological concern were included in this study. The analytes were extracted using a SPDE needle device, coated with a poly(dimethylsiloxane) with 10% embedded activated carbon phase (50-microm film thickness and 56-mm film length) and were analyzed by GC/MS in full-scan mode. Parameters that affect the extraction yield such as extraction and desorption temperature, salting-out, extraction and desorption flow rate, extraction volume and desorption volume, the number of extraction cycles, and the pre-desorption time have been evaluated and optimized. The linearity of the HS-SPDE-GC/MS method was established over several orders of magnitude. Method detection limits (MDLs) for the compounds investigated ranged between 12 ng/L for cis-dichloroethylene and trans-dichloroethylene and 870 ng/L for vinyl chloride. The method was thoroughly validated, and the precision at two concentration levels (0.1 mg/L and a concentration 5 times above the MDL) was between 3.1 and 16% for the analytes investigated. SPDE provides high sensitivity, short sample preparation and extraction times and a high sample throughput because of full automation. Finally, the applicability to real environmental samples is shown exemplarily for various groundwater samples from a former waste-oil recycling facility. Groundwater from the site showed a complex contamination with chlorinated volatile organic compounds and aromatic hydrocarbons.

  5. Determination of volatile organic hydrocarbons in water samples by solid-phase dynamic extraction

    Energy Technology Data Exchange (ETDEWEB)

    Jochmann, Maik A.; Schmidt, Torsten C. [Eberhard-Karls-Universitaet Tuebingen, Center for Applied Geoscience (ZAG), Tuebingen (Germany); Chair of Instrumental Analysis, University Duisburg-Essen, Duisburg (Germany); Yuan, Xue [Eberhard-Karls-Universitaet Tuebingen, Center for Applied Geoscience (ZAG), Tuebingen (Germany)

    2007-03-15

    In the present study a headspace solid-phase dynamic extraction method coupled to gas chromatography-mass spectrometry (HS-SPDE-GC/MS) for the trace determination of volatile halogenated hydrocarbons and benzene from groundwater samples was developed and evaluated. As target compounds, benzene as well as 11 chlorinated and brominated hydrocarbons (vinyl chloride, dichloromethane, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, carbon tetrachloride, chloroform, trichloroethylene, tetrachloroethylene, bromoform) of environmental and toxicological concern were included in this study. The analytes were extracted using a SPDE needle device, coated with a poly(dimethylsiloxane) with 10% embedded activated carbon phase (50-{mu}m film thickness and 56-mm film length) and were analyzed by GC/MS in full-scan mode. Parameters that affect the extraction yield such as extraction and desorption temperature, salting-out, extraction and desorption flow rate, extraction volume and desorption volume, the number of extraction cycles, and the pre-desorption time have been evaluated and optimized. The linearity of the HS-SPDE-GC/MS method was established over several orders of magnitude. Method detection limits (MDLs) for the compounds investigated ranged between 12 ng/L for cis-dichloroethylene and trans-dichloroethylene and 870 ng/L for vinyl chloride. The method was thoroughly validated, and the precision at two concentration levels (0.1 mg/L and a concentration 5 times above the MDL) was between 3.1 and 16% for the analytes investigated. SPDE provides high sensitivity, short sample preparation and extraction times and a high sample throughput because of full automation. Finally, the applicability to real environmental samples is shown exemplarily for various groundwater samples from a former waste-oil recycling facility. Groundwater from the site showed a complex contamination with chlorinated volatile organic compounds and aromatic hydrocarbons. (orig.)

  6. Methodology for the detection of contamination by hydrocarbons and further soil sampling for volatile and semi-volatile organic enrichment in former petrol stations, SE Spain

    Directory of Open Access Journals (Sweden)

    Rosa María Rosales Aranda

    2012-01-01

    Full Text Available The optimal detection and quantification of contamination plumes in soil and groundwater by petroleum organic compounds, gasoline and diesel, is critical for the reclamation of hydrocarbons contaminated soil at petrol stations. Through this study it has been achieved a sampling stage optimization in these scenarios by means of the location of potential contamination areas before sampling with the application of the 2D electrical resistivity tomography method, a geophysical non destructive technique based on resistivity measurements in soils. After the detection of hydrocarbons contaminated areas, boreholes with continuous coring were performed in a petrol station located in Murcia Region (Spain. The drillholes reached depths down to 10 m and soil samples were taken from each meter of the drilling. The optimization in the soil samples handling and storage, for both volatile and semi-volatile organic compounds determinations, was achieved by designing a soil sampler to minimize volatilization losses and in order to avoid the manual contact with the environmental samples during the sampling. The preservation of soil samples was performed according to Europe regulations and US Environmental Protection Agency recommendations into two kinds of glass vials. Moreover, it has been taken into account the determination techniques to quantify the hydrocarbon pollution based on Gas Chromatography with different detectors and headspace technique to reach a liquid-gas equilibrium for volatile analyses.

  7. Successful Treatment of Dental Infection-Induced Chronic Cavernous Sinus Thrombophlebitis With Antibiotics and Low-Molecular-Weight Heparin: Two Case Reports.

    Science.gov (United States)

    Li, Yuan; Zheng, Bo; Chen, Kangning; Gui, Li

    2015-08-01

    Two patients developed cavernous sinus thrombophlebitis from a tooth infection. A 36-year-old man experienced a severe headache with bilateral third and sixth cranial nerve palsies after extraction of his left upper third molar. Another 53-year-old diabetic man developed fever, headache, and bilateral complete ophthalmoplegia after a tooth infection. The brain magnetic resonance imaging scans of both patients showed bilateral cavernous sinus partial thrombosis. Broad-spectrum antibiotics plus low-molecular-weight heparin successfully resolved all symptoms. Both patients recovered fully without any recurrence at the 3-month follow-up visit. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  8. A novel procedure to detect low molecular weight compounds released by alkaline ester cleavage from low maturity coals to assess its feedstock for deep microbial life

    DEFF Research Database (Denmark)

    Glombitza, Clemens; Mangelsdorf, Kai; Horsfield, Brian

    2009-01-01

    and South Island of New Zealand (NZ) were examined to assess the amount of bound LMW organic acids. Formate, acetate and oxalate were detected in significant amounts whereas the amounts of these compounds decrease with increasing maturity of the coal sample. This decrease of LMW organic acids mainly...... for the investigation of low molecular weight (LMW) organic acids linked to the kerogen matrix is presented. These LMW organic acids form a potential feedstock for deep microbial populations. Twelve coal samples of different maturity (vitrinite reflectance (R0) of 0.28–0.80%) from several coal mines on the North...... and generation rates of LMW organic acids indicate that the NZ coals investigated exhibit the potential to feed deep terrestrial microbial life with appropriate substrates over geological time spans....

  9. Effects of low-molecular-weight organic acids on the acute lethality, accumulation, and enzyme activity of cadmium in Eisenia fetida in a simulated soil solution.

    Science.gov (United States)

    Liu, Hai-Long; Wang, Yu-Jun; Xuan, Liang; Dang, Fei; Zhou, Dong-Mei

    2017-04-01

    In the present study, the effects of low-molecular-weight organic acids (LMWOAs) on the toxicity of cadmium (Cd) to Eisenia fetida were investigated in a simulated soil solution. The LMWOAs protected E. fetida from Cd toxicity, as indicated by the increased median lethal concentration (LC50) values and the increased activity of superoxide dismutase. In addition, Cd concentrations in E. fetida decreased dramatically in the presence of LMWOAs. These results were likely because of the complexation between Cd and LMWOAs, which decreased the bioavailability and consequential toxicity of Cd to E. fetida. Notably, LMWOAs reduced Cd toxicity in decreasing order (ethylenediamine tetraacetic acid [EDTA] > citric acid > oxalic acid > malic acid > acetic acid), which was consistent with the decreasing complexation constants between LMWOAs and Cd. These results advance our understanding of the interactions between Cd and LMWOAs in soil. Environ Toxicol Chem 2017;36:1005-1011. © 2016 SETAC. © 2016 SETAC.

  10. Low-molecular weight fractions of Japanese soy sauce act as a RAGE antagonist via inhibition of RAGE trafficking to lipid rafts.

    Science.gov (United States)

    Munesue, Seiichi; Yamamoto, Yasuhiko; Urushihara, Ryouta; Inomata, Kouhei; Saito, Hidehito; Motoyoshi, So; Watanabe, Takuo; Yonekura, Hideto; Yamamoto, Hiroshi

    2013-12-01

    Advanced glycation end-products (AGE) have been implicated in aging and the pathogenesis of diabetic complications, inflammation, Alzheimer's disease, and cancer. AGE engage the cell surface receptor for AGE (RAGE), which in turn elicits intracellular signaling, leading to activation of NF-κB to cause deterioration of tissue homeostasis. AGE are not only formed within our bodies but are also derived from foods, endowing them with flavor. In the present study, we assessed the agonistic/antagonistic effects of food-derived AGE on RAGE signaling in a reporter assay system and found that low-molecular weight AGE can antagonize the action of AGE-BSA. Foods tested were Japanese soy sauce, coffee, cola, and red wine, all of which showed fluorescence characteristics of AGE. Soy sauce and coffee contained N(ε)-carboxymethyl-lysine (CML). Soy sauce, coffee, and red wine inhibited the RAGE ligand-induced activation of NF-κB, whereas cola had no effect on the ligand induction of NF-κB. The liquids were then fractionated into high-molecular weight (HMW) fractions and low-molecular weight (LMW) fractions. Soy sauce-, coffee-, and red wine-derived LMW fractions consistently inhibited the RAGE ligand induction of NF-κB, whereas the HMW fractions of these foods activated RAGE signaling. Using the LMW fraction of soy sauce as a model food-derived RAGE antagonist, we performed a plate-binding assay and found that the soy sauce LMW fractions competitively inhibited AGE-RAGE association. Further, this fraction significantly reduced AGE-dependent monocyte chemoattractant protein-1 (MCP-1) secretion from murine peritoneal macrophages. The LMF from soy sauce suppressed the AGE-induced RAGE trafficking to lipid rafts. These results indicate that small components in some, if not all, foods antagonize RAGE signaling and could exhibit beneficial effects on RAGE-related diseases.

  11. Determination of low-molecular-weight dicarboxylic acids in atmospheric aerosols by injection-port derivatization and gas chromatography-mass spectrometry

    Science.gov (United States)

    Ding, W.; Hsu, C.

    2008-12-01

    Currently, the investigations on aerosol water-soluble organic compounds (WSOCs) formed by burning biomass have become increasingly concerned with the role of these compounds in atmospheric chemistry and their effect on climate, because they have great potential to influence cloud formation, precipitation, and climate on both global and regional scales. Of these compounds, low-molecular weight (LMW) dicarboxylic acids (from C2 to C10) have attracted the most interest because of their properties as specific tracers for the burning of biomass. In this study, a modified injection-port derivatization and gas chromatography - mass spectrometry method was developed and evaluated for rapid determination of LMW dicarboxylic acids in atmospheric aerosol samples. The parameters related to the derivatization process (i.e., type of ion-pair reagent, injection-port temperature and concentration of ion-pair reagent) were optimized. Tetrabutylammonium hydroxide (TBA-OH) dissolved in methanol used as the ion-pair solution gave excellent yield for di-butyl ester low-molecular weight derivatives. Solid-phase extraction method instead of rotary evaporation was used to concentrate analytes from filter extracts. The recovery from filter extracts ranged from 67 to 86% with relative standard deviation (RSD) less than 13%. The concentrations of dicarboxylated C2, C3, C4, C5 and C6-C10 in atmospheric aerosols ranged from 91-240 ng/m3, 11-56 ng/m3, 12-49 ng/m3, 8-35 ng/m3 and n.d. to 17 ng/m3, respectively. Oxalic (C2) acid was the dominant dicarboxylic acids detected in aerosol samples. The total concentrations of the LMW dicarboxylic acids (from C2 to C10) correspond to 2.2 to 2.6% of the total aerosol mass.

  12. The effects of dietary kefir and low molecular weight sodium alginate on serum immune parameters, resistance against Streptococcus agalactiae and growth performance in Nile tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Van Doan, Hien; Hoseinifar, Seyed Hossein; Tapingkae, Wanaporn; Khamtavee, Pimporn

    2017-03-01

    The present study evaluates the effects of dietary kefir and low molecular weight sodium alginate (LWMSA) (singular or combined) on non-specific immune response, disease resistance and growth performance of Nile tilapia (Oreochromis niloticus). Fish with average weight of 18.60 ± 0.04 g were supplied and randomly stocked in sixteen glass tanks (150 L) at density of 20 fish per tank. Fish were fed experimental diets as follows: 0 g kg -1 LMWSA (Control, Diet 1), 10 g kg -1 LMWSA (Diet 2), 40 g kg -1 kefir (Diet 3), and 10 g kg -1 LMWSA + 40 g kg -1 kefir (Diet 4) for 50 days. At the end of the feeding trial, serum lysozyme (SL), phagocytosis (PI), respiratory burst (RB), and alternative complement (ACH50) activities as well as growth performance were measured. Singular and combined administration of kefir and low molecular weight sodium alginate (LMWSA) significantly increased serum SL, PI, RB, and ACH50 activities compared control group (P < 0.05); the highest innate immune responses were observed in fish fed combinational diet (kefir + LMWSA) (P < 0.05). The results of experimental challenge revealed significantly higher resistance against Streptococcus agalactiae in fish fed supplemented diets and the highest post challenge survival rate was observed in synbiotic diet (P < 0.05). Similar results obtained in case of growth parameters. Feeding on supplemented diet significantly improved SGR and FCR and the highest growth parameters was observed in fish fed synbiotic diet (P < 0.05). These finding revealed that combined administration of dietary kefir and LMWSA can be considered for improving immune response, disease resistance and growth performance of Nile tilapia. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. A low molecular weight zinc{sup 2+}-dipicolylamine-based probe detects apoptosis during tumour treatment better than an annexin V-based probe

    Energy Technology Data Exchange (ETDEWEB)

    Palmowski, Karin [RWTH-Aachen University, Department of Experimental Molecular Imaging, Aachen (Germany); University of Heidelberg, Department of Pneumology, Thoraxklinik Heidelberg, Heidelberg (Germany); Rix, Anne; Lederle, Wiltrud; Kiessling, Fabian [RWTH-Aachen University, Department of Experimental Molecular Imaging, Aachen (Germany); Behrendt, Florian F. [RWTH-Aachen University, Department of Nuclear Medicine, Aachen (Germany); Mottaghy, Felix M. [RWTH-Aachen University, Department of Nuclear Medicine, Aachen (Germany); Maastricht University Medical Center, Department of Nuclear Medicine, Maastricht (Netherlands); Gray, Brian D. [Molecular Targeting Technologies, Inc., West Chester, PA (United States); Pak, Koon Y. [University Medical Center Heidelberg, Academic Radiology Baden-Baden, Diagnostic and Interventional Radiology, Heidelberg (Germany); Palmowski, Moritz [RWTH-Aachen University, Department of Experimental Molecular Imaging, Aachen (Germany); RWTH-Aachen University, Department of Nuclear Medicine, Aachen (Germany); University Medical Center Heidelberg, Academic Radiology Baden-Baden, Diagnostic and Interventional Radiology, Heidelberg (Germany)

    2014-02-15

    Molecular imaging of apoptosis is frequently discussed for monitoring cancer therapies. Here, we compare the low molecular weight phosphatidylserine-targeting ligand zinc{sup 2+}-dipicolylamine (Zn{sup 2+}-DPA) with the established but reasonably larger protein annexin V. Molecular apoptosis imaging with the fluorescently labelled probes annexin V (750 nm, 36 kDa) and Zn{sup 2+}-DPA (794 nm, 1.84 kDa) was performed in tumour-bearing mice (A431). Three animal groups were investigated: untreated controls and treated tumours after 1 or 4 days of anti-angiogenic therapy (SU11248). Additionally, μPET with {sup 18} F-FDG was performed. Imaging data were displayed as tumour-to-muscle ratio (TMR) and validated by quantitative immunohistochemistry. Compared with untreated control tumours, TUNEL staining indicated significant apoptosis after 1 day (P < 0.05) and 4 days (P < 0.01) of treatment. Concordantly, Zn{sup 2+}-DPA uptake increased significantly after 1 day (P < 0.05) and 4 days (P < 0.01). Surprisingly, annexin V failed to detect significant differences between control and treated animals. Contrary to the increasing uptake of Zn{sup 2+}-DPA, {sup 18} F-FDG tumour uptake decreased significantly at days 1 (P < 0.05) and 4 (P < 0.01). Increase in apoptosis during anti-angiogenic therapy was detected significantly better with the low molecular weight probe Zn{sup 2+}-DPA than with the annexin V-based probe. Additionally, significant treatment effects were detectable as early using Zn{sup 2+}-DPA as with measurements of the glucose metabolism using {sup 18} F-FDG. (orig.)

  14. Enhancing the intestinal absorption of low molecular weight chondroitin sulfate by conjugation with α-linolenic acid and the transport mechanism of the conjugates.

    Science.gov (United States)

    Xiao, Yuliang; Li, Pingli; Cheng, Yanna; Zhang, Xinke; Sheng, Juzheng; Wang, Decai; Li, Juan; Zhang, Qian; Zhong, Chuanqing; Cao, Rui; Wang, Fengshan

    2014-04-25

    The purpose of this report was to demonstrate the effect of amphiphilic polysaccharides-based self-assembling micelles on enhancing the oral absorption of low molecular weight chondroitin sulfate (LMCS) in vitro and in vivo, and identify the transepithelial transport mechanism of LMCS micelles across the intestinal barrier. α-Linolenic acid-low molecular weight chondroitin sulfate polymers(α-LNA-LMCS) were successfully synthesized, and characterized by FTIR, (1)HNMR, TGA/DSC, TEM, laser light scattering and zeta potential. The significant oral absorption enhancement and elimination half-life (t₁/₂) extension of LNA-LMCS2 in rats were evidenced by intragastric administration in comparison with CS and LMCS. Caco-2 transport studies demonstrated that the apparent permeability coefficient (Papp) of LNA-LMCS2 was significantly higher than that of CS and LMCS (p<0.001), and no significant effects on the overall integrity of the monolayer were observed during the transport process. In addition, α-LNA-LMCS micelles accumulated around the cell membrane and intercellular space observed by confocal laser scanning microscope (CLSM). Furthermore, evident alterations in the F-actin cytoskeleton were detected by CLSM observation following the treatment of the cell monolayers with α-LNA-LMCS micelles, which further certified the capacity of α-LNA-LMCS micelles to open the intercellular tight junctions rather than disrupt the overall integrity of the monolayer. Therefore, LNA-LMCS2 with low cytotoxicity and high bioavailability might be a promising substitute for CS in clinical use, such as treating osteoarthritis, atherosclerosis, etc. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Safety and Efficacy of Bridging With Low-Molecular-Weight Heparin During Temporary Interruptions of Warfarin: A Register-Based Cohort Study.

    Science.gov (United States)

    Sjögren, Vilhelm; Grzymala-Lubanski, Bartosz; Renlund, Henrik; Svensson, Peter J; Själander, Anders

    2017-11-01

    Low-molecular-weight heparin (LMWH) is often recommended as a bridging therapy during temporary interruptions in warfarin treatment, despite lack of evidence. The aim of this study was to see whether we could find benefit from LMWH bridging. We studied all planned interruptions of warfarin within the Swedish anticoagulation register Auricula during 2006 to 2011. Low-molecular-weight heparin bridging was compared to nonbridging (control) after propensity score matching. Complications were identified in national clinical registers for 30 days following warfarin cessation, and defined as all-cause mortality, bleeding (intracranial, gastrointestinal, or other), or thrombosis (ischemic stroke or systemic embolism, venous thromboembolism, or myocardial infarction) that was fatal or required hospital care. Of the 14 556 identified warfarin interruptions, 12 659 with a known medical background had a mean age of 69 years, 61% were males, mean CHADS 2 (1 point for each of congestive heart failure, hypertension, age ≥75 years, diabetes, and 2 points for stroke or transient ischemic attack) score was 1.7, and CHA 2 DS 2 -VASc score was 3.4. The total number of LMWH bridgings was 7021. Major indications for anticoagulation were mechanical heart valve prostheses 4331, atrial fibrillation 1097, and venous thromboembolism 1331. Bridging patients had a higher rate of thrombotic events overall. Total risk of any complication did not differ significantly between bridging (1.5%) and nonbridging (1.2%). Regardless of indication for warfarin treatment, we found no benefit from bridging. The type of procedure prompting bridging was not known, and the likely reason for the observed higher risk of thrombosis with LMWH bridging is that low-risk procedures more often meant no bridging. Results from randomized trials are needed, especially for patients with mechanical heart valves.

  16. A single center retrospective cohort study comparing low-molecular-weight heparins to direct oral anticoagulants for the treatment of venous thromboembolism in patients with cancer - A real world experience.

    Science.gov (United States)

    Phelps, Megan K; Wiczer, Tracy E; Erdeljac, H Paige; Van Deusen, Kelsey R; Porter, Kyle; Philips, Gary; Wang, Tzu-Fei

    2018-01-01

    Introduction Low-molecular-weight heparins are the standard treatment for cancer-associated thrombosis. Recently, direct oral anticoagulants are a new option for thrombosis treatment; however, data supporting the use of direct oral anticoagulants for cancer-associated thrombosis are limited. Objectives The primary objective of this study was to determine the rate of recurrent cancer-associated thrombosis and major bleeding within 6 months of starting either low-molecular-weight heparin or direct oral anticoagulant for treatment of cancer-associated thrombosis. Secondary objectives were to determine the rates of clinically relevant-non-major bleeding and all-cause mortality. Patients/methods This is a retrospective cohort study including adults with cancer-associated thrombosis treated with low-molecular-weight heparin or direct oral anticoagulant between 2010 and 2016 at the Ohio State University. Medical records were reviewed for 6 months after initiation of anticoagulation or until the occurrence of recurrent cancer-associated thrombosis, major bleeding, cessation of anticoagulation of interest, or death, whichever occurred first. Results Four hundred and eighty patients were included (290 low-molecular-weight heparin and 190 direct oral anticoagulant). Patients treated with direct oral anticoagulant were found to carry "lower risk" features including cancer with lower VTE risk and lower rate of metastatic disease. After adjustment for baseline differences, there was no significant difference in the rate of recurrent cancer-associated thrombosis (7.2% low-molecular-weight heparin vs 6.3% direct oral anticoagulant, p = 0.71) or major bleeding (7.6% low-molecular-weight heparin vs 2.6% direct oral anticoagulant, p = 0.08). Conclusions Our study demonstrates that in a select population of cancer patients with VTE, direct oral anticoagulant use can be as effective and safe compared to the standard therapy with low-molecular-weight heparin.

  17. Synthetic crystalline ferroborosilicate compositions, the preparation thereof and their use in the conversion of synthesis gas to low molecular weight hydrocarbons

    International Nuclear Information System (INIS)

    Hinnenkamp, J.A.; Walatka, V.V.

    1987-01-01

    A method for the conversion of synthesis gas is described comprising: contacting synthesis gas which comprises hydrogen and carbon monoxide with a catalytically effective amount of a crystalline ferroborosilicate composition, under conversion conditions effective to provide ethane selectivity of at least 40%. The borosilicate composition is represented in terms of mole ratios as follows: (0.2 to 15) M/sub 2/m/O:(0.2 to 10) Z/sub 2/ O /sub 3/: (5 to 1000) SiO/sub 2/: Fe/sub 2/n/O: (0 to 2000) H/sub 2/O wherein M comprises a cation of a quaternary ammonium, metal, ammonium, hydrogen and mixtures thereof, m is the valence of the cation, n is the valence of the iron cation, and Z is boron. The composition contains ion-exchanged palladium or palladium impregnated onto the composition

  18. Petroleum environmental research forum field study on biofilters for control of volatile hydrocarbons

    International Nuclear Information System (INIS)

    Leson, G.; Smith, B.J.

    1997-01-01

    A field study on the treatment of volatile petroleum hydrocarbons (PHC) by biofiltration was conducted by the Petroleum Environmental Research Forum (PERF) between 1992 and 1994. Its objective was to assess the technical, regulatory, and economic feasibility of biofiltration for off-gases from petroleum processing and soil remediation equipment. It involved three small-scale biofilters provided by US vendors, treating off-gas from two soil vapor extraction sites and a source of refinery wastewater. Comprehensive monitoring of biofilter operating parameters and performance was conducted. Typically more than 95% of aromatic compounds such as benzene, and odorous reduced sulfur compounds can be removed at residence times of one minute or less, while removal of more than 70% of light aliphatics will require residence times of several minutes, and will thus require correspondingly large filter volumes and higher capital expenditure. The high percentage removal of aromatic hazardous air pollutants (HAP) and odors can generally be accomplished at comparatively short residence times while the need for high-percentage removal, particular of light aliphatics ( 5 ) will generally render biofiltration noncompetitive. Finally, a preliminary economic comparison of biofilters and established control technologies suggested that biofiltration may, for a representative design case involving off-gas from a refinery wastewater treatment operation, offer considerable savings in total cost of air pollution control for petroleum hydrocarbon streams if regulations require the control of aromatic HAP or odors

  19. Distribution of volatile liquid hydrocarbons in the vicinity of power/desalination plants in Kuwait

    International Nuclear Information System (INIS)

    Saeed, T.; Khordagui, H; AI-Bloushi, A.

    1999-01-01

    Volatile liquid hydrocarbons (VLHs) represent some 40% of crude oil and are considered to be the most toxic compounds of petroleum other than the carcinogenic polycyclic aromatic hydrocarbons. The distribution of these compounds in Kuwait's coastal waters in the vicinity and at the inlets of power plants was assessed. About 200 samples were collected from selected sampling stations over the four seasons. The VLHs in the samples were concentrated using Grob's closed-loop technique and analysed by GC using FID and confirmed by GC/MS. The results showed that VLHs were ubiquitous in the coastal water of Kuwait. The detected levels (ranged from 307 to 7882 ng/l in Kuwait Bay and from 331 to 5017 ng/l in the south) were comparable to the levels found in other parts of the world and were not alarming. However, the spotty higher levels encountered gave reason for some concern. Benzenoids (originating from petroleum) predominated, representing roughly 70% of the total VLHs. The levels were relatively low at the intake of the power plant located in the Kuwait Bay (annual average 677 ng/l) while higher levels (annual average 3006 ng/l) were encountered at the intake of the plant located at the south of oil the loading terminals and refineries. (author)

  20. Concentrations of cyclic volatile methylsiloxanes in European cosmetics and personal care products: Prerequisite for human and environmental exposure assessment

    NARCIS (Netherlands)

    Dudzina, T.; Goetz, N. von; Bogdal, C.; Biesterbos, J.W.H.; Hungerbuhler, K.

    2014-01-01

    Low molecular weight cyclic volatile methylsiloxanes (cVMSs) are widely employed as emollients and carrier solvents in personal care formulations in order to acquire desired performance benefits owing to their distinctive physicochemical properties. Under current European legislation cosmetic

  1. Feasibility study for application of the marine coral powder as a novel adsorbent for Volatile Organic Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Alireza Mashkoori

    2015-06-01

    Full Text Available The marine coral has a porous outer surface and it has served in the processes such as water treatment systems, removal of carbon dioxide and adsorption of arsenic. Based on the need for cheap and efficient adsorbents, in sampling, the aim of this study, comparison of the efficiency of marine coral powder and activated charcoal in adsorption of volatile organic hydrocarbons was considered. In this experimental research, a certain concentrations of 8 volatile organic hydrocarbons: (para-Xylene, Chloroform, Carbon tetrachloride, tert-Butanol, Pyridine, Acetone, Ethyl acetate and Diethyl ether was injected into dynamic atmospheric chamber in the NTP (Normal Temperature and Pressure conditions. Air sampling was performed with the tube containing marine coral powder as well as the tube of activated charcoal, based on the standard method of NIOSH (National Institute of Occupational Safety and Health and in the same laboratory conditions. Then samples were injected into the gas Chromatograph apparatus and analytical comparison has been done between the amount of adsorption of hydrocarbons by activated charcoal and coral powder-test and Mann-Whitney were done with SPSS V.20.Findings showed that there was a significant difference between the amount of adsorption of Para-Xylene, carbon tetrachloride, tert-Butanol, Pyridine, acetone and Ethyl acetate hydrocarbons by activated charcoal and coral powder (P<0.05(. The amount of hydrocarbons adsorption by activated charcoal was, more than coral powder significantly (P<0.001. Based on the present research, in sampling of used hydrocarbons, the marine coral powder was less efficient than the activated charcoal, and it is recommended that more works be designed about other techniques such as coating of the marine coral powder in order to the improvement of adsorption capacity for volatile organic hydrocarbons.

  2. Low Molecular Weight pDMAEMA-block-pHEMA Block-Copolymers Synthesized via RAFT-Polymerization: Potential Non-Viral Gene Delivery Agents?

    Directory of Open Access Journals (Sweden)

    Thomas Kissel

    2011-03-01

    Full Text Available The aim of this study was to investigate non-viral pDNA carriers based on diblock-copolymers consisting of poly(2-(dimethyl aminoethyl methacrylate (pDMAEMA and poly(2-hydroxyethyl methacrylate (pHEMA. Specifically the block-lengths and molecular weights were varied to determine the minimal requirements for transfection. Such vectors should allow better transfection at acceptable toxicity levels and the entire diblock-copolymer should be suitable for renal clearance. For this purpose, a library of linear poly(2-(dimethyl aminoethyl methacrylate-block-poly(2-hydroxyl methacrylate (pDMAEMA-block-pHEMA copolymers was synthesized via RAFT (reversible addition-fragmentation chain transfer polymerization in a molecular weight (Mw range of 17–35.7 kDa and analyzed using 1H and 13C NMR (nuclear magnetic resonance, ATR (attenuated total reflectance, GPC (gel permeation chromatography and DSC (differential scanning calorimetry. Copolymers possessing short pDMAEMA-polycation chains were 1.4–9.7 times less toxic in vitro than polyethylenimine (PEI 25 kDa, and complexed DNA into polyplexes of 100–170 nm, favorable for cellular uptake. The DNA-binding affinity and polyplex stability against competing polyanions was comparable with PEI 25 kDa. The zeta-potential of polyplexes of pDMAEMA-grafted copolymers remained positive (+15–30 mV. In comparison with earlier reported low molecular weight homo pDMAEMA vectors, these diblock-copolymers showed enhanced transfection efficacy under in vitro conditions due to their lower cytotoxicity, efficient cellular uptake and DNA packaging. The homo pDMAEMA115 (18.3 kDa self-assembled with DNA into small positively charged polyplexes, but was not able to transfect cells. The grafting of 6 and 57 repeating units of pHEMA (0.8 and 7.4 kDa to pDMAEMA115 increased the transfection efficacy significantly, implying a crucial impact of pHEMA on vector-cell interactions. The intracellular trafficking, in vivo transfection

  3. Major bleeding risks of different low-molecular-weight heparin agents: a cohort study in 12 934 patients treated for acute venous thrombosis.

    Science.gov (United States)

    van Rein, N; Biedermann, J S; van der Meer, F J M; Cannegieter, S C; Wiersma, N; Vermaas, H W; Reitsma, P H; Kruip, M J H A; Lijfering, W M

    2017-07-01

    Essentials Low-molecular-weight-heparins (LMWH) kinetics differ which may result in different bleeding risks. A cohort of 12 934 venous thrombosis patients on LMWH was followed until major bleeding. The absolute major bleeding risk was low among patients registered at the anticoagulation clinic. Once-daily dosing was associated with a lower bleeding risk as compared with twice-daily. Background Low-molecular-weight heparins (LMWHs) are considered members of a class of drugs with similar anticoagulant properties. However, pharmacodynamics and pharmacokinetics between LMWHs differ, which may result in different bleeding risks. As these agents are used by many patients, small differences may lead to a large effect on numbers of major bleeding events. Objectives To determine major bleeding risks for different LMWH agents and dosing schedules. Methods A cohort of acute venous thrombosis patients from four anticoagulation clinics who used an LMWH and a vitamin K antagonist were followed until they ceased LMWH treatment or until major bleeding. Exposures were classified according to different types of LMWHs and for b.i.d. and o.d. use. Cumulative incidences for major bleeding per 1000 patients and risk ratios were calculated and adjusted for study center. Results The study comprised 12 934 patients with a mean age of 59 years; 6218 (48%) were men. The cumulative incidence of major bleeding was 2.5 per 1000 patients (95% confidence interval [CI], 1.7-3.5). Enoxaparin b.i.d. or o.d. was associated with a relative bleeding risk of 1.7 (95% CI, 0.2-17.5) compared with nadroparin o.d. In addition, a nadroparin b.i.d. dosing schedule was associated with a 2.0-fold increased major bleeding risk (95% CI, 0.8-5.1) as compared with a nadroparin o.d. dosing schedule. Conclusions Absolute major bleeding rates were low for all LMWH agents and dosing schedules in a large unselected cohort. Nevertheless, twice-daily dosing with nadroparin appeared to be associated with an increased

  4. Efficacy and safety of total dose infusion of low molecular weight iron dextran in the treatment of iron deficiency anemia during pregnancy

    International Nuclear Information System (INIS)

    Ayub, R.; Tariq, N.; Iqbal, M.; Jafery, T.

    2008-01-01

    To determine the efficacy and safety of Total Dose Infusion (TDI) of low molecular weight iron dextran for the treatment of iron deficiency anemia compared to oral iron replacement during pregnancy through improvement in hemoglobin (Hb) after intervention. Non-randomized control trial. A group of 100 pregnant women with gestational age greater than 12 weeks with confirmed diagnosis of iron deficiency anemia attending the antenatal clinics were enrolled in this study. Total dose iron infusion of low molecular iron dextran was given to these patients after calculating iron deficit, in a monitored in-patient setting. Control comprised of a second group of 50 pregnant females matched for age, parity and baseline hemoglobin, tolerant to oral iron supplementation (ferrous sulphate 200 mg three times a day) attending the antenatal clinics during the same period. Post-treatment hemoglobin levels of study group as well as the oral control group were determined between 3 to 4 weeks. In the intervention group, mean pre-infusion hemoglobin level was 8.57 +- 0.9 gm/dl (range 5-10.5 gm/dl) and mean post-infusion Hb was 11.0 +- 1.1 (range 8.4-14.3 gm/dl). In control group, mean pre-oral intake Hb level was 9.5 +- 0.9 gm/dl (range 7-10.5 gm/dl) and mean post-oral intake Hb was 10.2 +- 1.2 gm/dl (range 6.4-12.8 gm/dl). Mean increase of Hb in intervention group was 2.43 gm/dl (95% CI 2.4 - 3.8) and for controls it was 0.7 gm/dl (95% CI 0.6-2.3). Flushing and palpitations were observed in 4% of interventional group patients and none in the control group. No significant adverse reactions were observed in either group. We conclude that the total parenteral iron replacement with low molecular weight iron dextran is an effective and safe method for the treatment of iron deficiency anemia in a selected group of pregnant women. (author)

  5. A novel tyrosine-modified low molecular weight polyethylenimine (P10Y) for efficient siRNA delivery in vitro and in vivo.

    Science.gov (United States)

    Ewe, Alexander; Przybylski, Susanne; Burkhardt, Jana; Janke, Andreas; Appelhans, Dietmar; Aigner, Achim

    2016-05-28

    The delivery of nucleic acids, particularly of small RNA molecules like siRNAs for the induction of RNA interference (RNAi), still represents a major hurdle with regard to their application in vivo. Possible therapeutic applications thus rely on the development of efficient non-viral gene delivery vectors. While low molecular weight polyethylenimines (PEIs) have been successfully explored, the introduction of chemical modifications offers an avenue towards the development of more efficient vectors. In this paper, we describe the synthesis of a novel tyrosine-modified low-molecular weight polyethylenimine (P10Y) for efficient siRNA complexation and delivery. The comparison with the respective parent PEI reveals that knockdown efficacies are considerably enhanced by the tyrosine modification, as determined in different reporter cell lines, without appreciable cytotoxicity. We furthermore identify optimal conditions for complex preparation as well as for storing or lyophilization of the complexes without loss of biological activity. Beyond reporter cell lines, P10Y/siRNA complexes mediate the efficient knockdown of endogenous target genes and, upon knockdown of the anti-apoptotic oncogene survivin, tumor cell inhibitory effects in different carcinoma cell lines. Pushing the system further towards its therapeutic in vivo application, we demonstrate in mice the delivery of intact siRNAs and distinct biodistribution profiles upon systemic (intravenous or intraperitoneal) injection. No adverse effects (hepatotoxicity, immunostimulation/alterations in immunophenotype, weight loss) are observed. More importantly, profound tumor-inhibitory effects in a melanoma xenograft mouse model are observed upon systemic application of P10Y/siRNA complexes for survivin knockdown, indicating the therapeutic efficacy of P10Y/siRNA complexes. Taken together, we (i) establish tyrosine-modified PEI (P10Y) as efficient platform for siRNA delivery in vitro and in vivo, (ii) identify optimal

  6. Impact of mixed low-molecular-weight organic acids on uranium accumulation and distribution in a variant of mustard (Brassica juncea var. tumida)

    International Nuclear Information System (INIS)

    Fangfang Qi; Dingna Wang; Lijian Ma; Yongdong Jin; Liang Du; Dong Zhang; Chuanqin Xia; Sichuan University, Chengdu

    2014-01-01

    The impact of a mixture of low-molecular-weight organic acids (LMWOAs) composed of CA/MA/OA/LA with a molar ratio of 2.5:2.31:1.15:0.044 on uranium (U) accumulation and distribution in mustard (Brassica juncea var. tumida) was studied in this paper in order to understand the mechanism of rhizosphere-exudation assisted phytoremediation by hydroponic and pot culture experiments. The impact of the mixture of LWMOAs (Mix) on U accumulation showed that in hydroponic conditions Mix could enhance U translocation from root-to-shoot in mustard, but inhibit U uptake in root. In pot experiments, Mix enhanced both root and shoot U accumulation in mustard. The time-dependent kinetics of U uptake in mustard on Mix treatment showed that U content in plant shoots and roots increased with time increasing, and the steady state conditions were obtained at the 8th and 5th day with the U content of 1,528 and 2,300 mg/kg, respectively. Transmission electron microscope and energy dispersive X-ray spectrometry analysis for mustard roots showed that U was mainly observed on cell membrane of mustard roots on Mix treatment. This study would provide new insights for the mixture of LWMOAs-assisted phytoremediation of U-contaminated soil. (author)

  7. [Long-term treatment with a low-molecular-weight heparin administered subcutaneously compared with a vitamin K antagonist: subanalysis of patients with cancer].

    Science.gov (United States)

    Romera-Villegas, Antonio; Martí Mestre, Xavier; Vila Coll, Ramón; Colomé Nafría, Esteve

    2015-01-01

    We performed a subanalysis of cancer patients enrolled in a clinical trial that compared long-term (6 months) treatment with a low-molecular-weight heparin (LMWH) administered subcutaneously or with acenocoumarol. The subanalysis assessed whether the characteristics of the tumor had an influence on the clinical response. A randomized open trial included 69 patients with cancer and symptomatic proximal deep vein thrombosis of the lower limbs. The tumor characteristics and treatment type were recorded. The main assessment criterion was the 12-month incidence of recurrent symptomatic venous thromboembolism (VTE). Sixty-one patients (88.4%) were analyzed. At the time of inclusion, the cancer characteristics and treatment were comparable between the 2 groups. Over the course of 12 months, the recurrent VTE was significantly greater in the elderly patients (71.5 ± 6.4 vs. 62.0 ± 15.1; p=.006). The logistic regression analysis showed no association between VTE recurrence and the location or extent of the tumor. However, the use of thrombogenic chemotherapy (p=.045) was independently associated with VTE recurrence, and longterm treatment with tinzaparin was almost a protective factor (p=.15). In this small sample, we observed an association between thrombogenic chemotherapy and recurrent VTE. The tendency towards a reduction in VTE recurrence at 12 months in patients with cancer in the LMWH group could be attributed to the effect of the full LMWH dosage. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

  8. A low molecular weight zinc2+-dipicolylamine-based probe detects apoptosis during tumour treatment better than an annexin V-based probe

    International Nuclear Information System (INIS)

    Palmowski, Karin; Rix, Anne; Lederle, Wiltrud; Kiessling, Fabian; Behrendt, Florian F.; Mottaghy, Felix M.; Gray, Brian D.; Pak, Koon Y.; Palmowski, Moritz

    2014-01-01

    Molecular imaging of apoptosis is frequently discussed for monitoring cancer therapies. Here, we compare the low molecular weight phosphatidylserine-targeting ligand zinc 2+ -dipicolylamine (Zn 2+ -DPA) with the established but reasonably larger protein annexin V. Molecular apoptosis imaging with the fluorescently labelled probes annexin V (750 nm, 36 kDa) and Zn 2+ -DPA (794 nm, 1.84 kDa) was performed in tumour-bearing mice (A431). Three animal groups were investigated: untreated controls and treated tumours after 1 or 4 days of anti-angiogenic therapy (SU11248). Additionally, μPET with 18 F-FDG was performed. Imaging data were displayed as tumour-to-muscle ratio (TMR) and validated by quantitative immunohistochemistry. Compared with untreated control tumours, TUNEL staining indicated significant apoptosis after 1 day (P 2+ -DPA uptake increased significantly after 1 day (P 2+ -DPA, 18 F-FDG tumour uptake decreased significantly at days 1 (P 2+ -DPA than with the annexin V-based probe. Additionally, significant treatment effects were detectable as early using Zn 2+ -DPA as with measurements of the glucose metabolism using 18 F-FDG. (orig.)

  9. Effects of Low-Molecular-Weight Fucoidan and High Stability Fucoxanthin on Glucose Homeostasis, Lipid Metabolism, and Liver Function in a Mouse Model of Type II Diabetes

    Directory of Open Access Journals (Sweden)

    Hong-Ting Victor Lin

    2017-04-01

    Full Text Available The combined effects of low-molecular-weight fucoidan (LMF and fucoxanthin (Fx in terms of antihyperglycemic, antihyperlipidemic, and hepatoprotective activities were investigated in a mouse model of type II diabetes. The intake of LMF, Fx, and LMF + Fx lowered the blood sugar and fasting blood sugar levels, and increased serum adiponectin levels. The significant decrease in urinary sugar was only observed in LMF + Fx supplementation. LMF and Fx had ameliorating effects on the hepatic tissue of db/db mice by increasing hepatic glycogen and antioxidative enzymes, and LMF was more effective than Fx at improving hepatic glucose metabolism. As for glucose and lipid metabolism in the adipose tissue, the expression of insulin receptor substrate (IRS-1, glucose transporter (GLUT, peroxisome proliferator-activated receptor gamma (PPARγ, and uncoupling protein (UCP-1 mRNAs in the adipose tissue of diabetic mice was significantly upregulated by Fx and LMF + Fx, and levels of inflammatory adipocytokines, such as adiponectin, tumor necrosis factor-α (TNF-α, and interleukin-6 (IL-6, were significantly modulated only by LMF + Fx supplementation. The efficacy of LMF + Fx supplementation on the decrease in urinary sugar and on glucose and lipid metabolism in the white adipose tissue of db/db mice was better than that of Fx or LMF alone, indicating the occurrence of a synergistic effect of LMF and Fx.

  10. Cyclodextrin-supported organic matrix for application of MALDI-MS for forensics. Soft-ionization to obtain protonated molecules of low molecular weight compounds

    Energy Technology Data Exchange (ETDEWEB)

    Yonezawa, Tetsu, E-mail: tetsu@eng.hokudai.ac.jp [Division of Materials Science and Engineering, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan); Department of Chemistry, School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Asano, Takashi [Division of Materials Science and Engineering, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan); Criminal Investigation Laboratory, Metropolitan Police Department, 2-1-1 Kasumigaseki, Chiyoda-ku, Tokyo 100-8929 (Japan); Fujino, Tatsuya [Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan); Nishihara, Hiroshi [Department of Chemistry, School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2013-06-20

    Highlights: ► MALDI-MS applications for drug identification in forensic science is investigated. ► Cyclodextrin-supported organic matrices strongly suppress the obstacle peaks of organic matrix compounds. ► Cyclodextrin-supported organic matrices also suppress the alkali adducted molecule peaks. ► Sugar units of cyclodextrins work for this specific features. - Abstract: A mass measurement technique for detecting low-molecular-weight drugs with a cyclodextrin-supported organic matrix was investigated. By using cyclodextrin-supported 2,4,6-trihydroxyacetophenone (THAP), the matrix-related peaks of drugs were suppressed. The peaks of protonated molecules of the sample and THAP were mainly observed, and small fragments were detected in a few cases. Despite the Na{sup +} and K{sup +} peaks were observed in the spectrum, Na{sup +} or K{sup +} adduct sample molecules were undetected, owing to the sugar units of cyclodextrin. The advantages of MALDI-MS with cyclodextrin-supported matrices as an analytical tool for forensic samples are discussed. The suppression of alkali adducted molecules and desorption process are also discussed.

  11. Influence of mineral characteristics on the retention of low molecular weight organic compounds: a batch sorption-desorption and ATR-FTIR study.

    Science.gov (United States)

    Yeasmin, Sabina; Singh, Balwant; Kookana, Rai S; Farrell, Mark; Sparks, Donald L; Johnston, Cliff T

    2014-10-15

    Batch experiments were conducted to evaluate the sorption-desorption behaviour of (14)C-labelled carboxylic acids (citric and oxalic) and amino acids (glutamic, alanine, phenylalanine and lysine) on pure minerals (kaolinite, illite, montmorillonite, ferrihydrite and goethite). The sorption experiments were complemented by ATR-FTIR spectroscopy to gain possible mechanistic insight into the organic acids-mineral interactions. In terms of charge, the organic solutes ranged from strongly negative (i.e., citric) to positively charged solutes (i.e., lysine); similarly the mineral phases also ranged from positively to negatively charged surfaces. In general, sorption of anionic carboxylic and glutamic acids was higher compared to the other compounds (except lysine). Cationic lysine showed a stronger affinity to permanently charged phyllosilicates than Fe oxides. The sorption of alanine and phenylalanine was consistently low for all minerals, with relatively higher sorption and lower desorption of phenylalanine than alanine. Overall, the role of carboxylic functional groups for the sorption and retention of these carboxylic and amino acids on Fe oxides (and kaolinite) and of amino group on 2:1 phyllosilicates was noticeable. Mineral properties (surface chemistry, specific surface area), chemistry of the organic compounds (pKa value, functional groups) and the equilibrium pH of the system together controlled the differences in sorption-desorption patterns. The results of this study aid to understand the effects of mineralogical and chemical factors that affect naturally occurring low molecular weight organic compounds sorption under field conditions. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Single-Handed Helical Polybissilsesquioxane Nanotubes and Mesoporous Nanofibers Prepared by an External Templating Approach Using Low-Molecular-Weight Gelators

    Directory of Open Access Journals (Sweden)

    Jing Hu

    2017-01-01

    Full Text Available Chiral low-molecular-weight gelators (LMWGs derived from amino acids can self-assemble into helical fibers and twisted/coiled nanoribbons by H-bonding and π–π interaction. Silica nanotubes with single-handed helices have been prepared using chiral LMWGs through sol–gel transcription. Molecular-scale chirality exists at the inner surfaces. Here, we discuss single-handed helical aromatic ring-bridged polybissilsesquioxane nanotubes and mesoporous nanofibers prepared using chiral LMWGs. This review aims at describing the formation mechanisms of the helical nanostructures, the origination of optical activity, and the applications for other helical nanomaterial preparation, mainly based on our group’s results. The morphology and handedness can be controlled by changing the chirality and kinds of LMWGs and tuning the reaction conditions. The aromatic rings arrange in a partially crystalline structure. The optical activity of the polybissilsesquioxane nanotubes and mesoporous nanofibers originates from chiral defects, including stacking and twisting of aromatic groups, on the inner surfaces. They can be used as the starting materials for preparation of silica, silicon, carbonaceous, silica/carbon, and silicon carbide nanotubes.

  13. Evaluation of different hydrophilic stationary phases for the simultaneous determination of iminosugars and other low molecular weight carbohydrates in vegetable extracts by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Rodríguez-Sánchez, S; Quintanilla-López, J E; Soria, A C; Sanz, M L

    2014-11-01

    Iminosugars are considered potential drug candidates for the treatment of several diseases, mainly as a result of their α-glycosidase inhibition properties. A method by hydrophilic interaction liquid chromatography tandem mass spectrometry has been optimized for the first time for the simultaneous determination of complex mixtures of bioactive iminosugars and other low molecular weight carbohydrates (LMWC) in vegetable extracts. Three hydrophilic stationary phases (sulfoalkylbetaine zwitterionic, polyhydroxyethyl aspartamide and ethylene bridge hybrid (BEH) with trifunctionally bonded amide) were compared under both basic and acidic conditions. The best sensitivity (limits of detection between 0.025 and 0.28ngmL -1 ) and overall chromatographic performance in terms of resolution, peak width and analysis time were obtained with the BEH amide column using 0.1% ammonium hydroxide as a mobile phase additive. The optimized method was applied to the analysis of extracts of hyacinth bulbs, buckwheat seeds and mulberry leaves. Iminosugar and other LMWC structures were tentatively assigned by their high resolution daughter ions mass spectra. Several iminosugars such as glycosyl-fagomine in mulberry extract were also described for the first time. Among the extracts analysed, mulberry showed the widest diversity of iminosugars, whereas the highest content of them was found in hyacinth bulb (2.5mgg -1 ) followed by mulberry (1.95 mgg -1 ). Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Characterization of product-related low molecular weight impurities in therapeutic monoclonal antibodies using hydrophilic interaction chromatography coupled with mass spectrometry.

    Science.gov (United States)

    Wang, Shunhai; Liu, Anita P; Yan, Yuetian; Daly, Thomas J; Li, Ning

    2018-05-30

    Traditional SDS-PAGE method and its modern equivalent CE-SDS method are both widely applied to assess the purity of therapeutic monoclonal antibody (mAb) drug products. However, structural identification of low molecular weight (LMW) impurities using those methods has been challenging and largely based on empirical knowledges. In this paper, we present that hydrophilic interaction chromatography (HILIC) coupled with mass spectrometry analysis is a novel and orthogonal method to characterize such LMW impurities present within a purified mAb drug product sample. We show here that after removal of N-linked glycans, the HILIC method separates mAb-related LMW impurities with a size-based elution order. The subsequent mass measurement from a high-resolution accurate mass spectrometer provides direct and unambiguous identification of a variety of low-abundance LMW impurities within a single LC-MS analysis. Free light chain, half antibody, H2L species (antibody possessing a single light chain) and protein backbone-truncated species can all be confidently identified and elucidated in great detail, including the truncation sites and associated post-translational modifications. It is worth noting that this study provides the first example where the H2L species can be directly detected in a mAb drug product sample by intact mass analysis without prior enrichment. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Low-molecular weight protein profiling of genetically modified maize using fast liquid chromatography electrospray ionization and time-of-flight mass spectrometry.

    Science.gov (United States)

    Koc, Anna; Cañuelo, Ana; Garcia-Reyes, Juan F; Molina-Diaz, Antonio; Trojanowicz, Marek

    2012-06-01

    In this work, the use of liquid chromatography coupled to electrospray time-of-flight mass spectrometry (LC-TOFMS) has been evaluated for the profiling of relatively low-molecular weight protein species in both genetically modified (GM) and non-GM maize. The proposed approach consisted of a straightforward sample fractionation with different water and ethanol-based buffer solutions followed by separation and detection of the protein species using liquid chromatography with a small particle size (1.8 μm) C(18) column and electrospray-time-of-flight mass spectrometry detection in the positive ionization mode. The fractionation of maize reference material containing different content of transgenic material (from 0 to 5% GM) led to five different fractions (albumins, globulins, zeins, zein-like glutelins, and glutelins), all of them containing different protein species (from 2 to 52 different species in each fraction). Some relevant differences in the quantity and types of protein species were observed in the different fractions of the reference material (with different GM contents) tested, thus revealing the potential use of the proposed approach for fast protein profiling and to detect tentative GMO markers in maize. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Profiling analysis of low molecular weight heparins by multiple heart-cutting two dimensional chromatography with quadruple time-of-flight mass spectrometry.

    Science.gov (United States)

    Ouyang, Yilan; Zeng, Yangyang; Rong, Yinxiu; Song, Yue; Shi, Lv; Chen, Bo; Yang, Xinlei; Xu, Naiyu; Linhardt, Robert J; Zhang, Zhenqing

    2015-09-01

    Low molecular weight heparins (LMWHs) are polydisperse and microheterogenous mixtures of polysaccharides used as anticoagulant drugs. Profiling analysis is important for obtaining deeper insights into the structure of LMWHs. Previous oligosaccharide mapping methods are relatively low resolution and are unable to show an entire picture of the structural complexity of LMWHs. In the current study a profiling method was developed relying on multiple heart-cutting, two-dimensional, ultrahigh performance liquid chromatography with quadruple time-of-flight mass spectrometry. This represents an efficient, automated, and robust approach for profiling LMWHs. Using size-exclusion chromatography and ion-pairing reversed-phase chromatography in a two-dimensional separation, LMW components of different sizes and LMW components of the same size but with different charges and polarities can be resolved, providing a more complete picture of a LMWH. Structural information on each component was then obtained with quadrupole time-of-flight mass spectrometry. More than 80 and 120 oligosaccharides were observed and unambiguously assigned from the LMWHs, nadroparin and enoxaparin, respectively. This method might be useful for quality control of LMWHs and as a powerful tool for heparin-related glycomics.

  17. Determination of low-molecular-weight dicarboxylic acids in atmospheric aerosols by injection-port derivatization and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Hsu, Ching-Lin; Ding, Wang-Hsien

    2009-12-15

    A rapid and environmental-friendly injection-port derivatization with gas chromatography-mass spectrometry (GC-MS) method was developed to determine selected low-molecular weight (LMW) dicarboxylic acids (from C2 to C10) in atmospheric aerosol samples. The parameters related to the derivatization process (i.e., type of ion-pair reagent, injection-port temperature and concentration of ion-pair reagent) were optimized. Tetrabutylammonium hydroxide (TBA-OH) 20 mM in methanol gave excellent yield for di-butyl ester dicarboxylate derivatives at injection-port temperature at 300 degrees C. Solid-phase extraction (SPE) method instead of rotary evaporation was used to concentrate analytes from filter extracts. The recovery from filter extracts ranged from 78 to 95% with relative standard deviation (RSD) less than 12%. Limits of quantitation (LOQs) ranged from 25 to 250 pg/m(3). The concentrations of di-carboxylated C2-C5 and total C6-C10 in particles of atmospheric aerosols ranged from 91.9 to 240, 11.3 to 56.7, 9.2 to 49.2, 8.7 to 35.3 and n.d. to 37.8 ng/m(3), respectively. Oxalic acid (C2) was the dominant LMW-dicarboxylic acids detected in aerosol samples. The quantitative results were comparable to the results obtained by the off-line derivatization.

  18. Content of selected elements and low-molecular-weight organic acids in fruiting bodies of edible mushroom Boletus badius (Fr.) Fr. from unpolluted and polluted areas.

    Science.gov (United States)

    Mleczek, Mirosław; Magdziak, Zuzanna; Gąsecka, Monika; Niedzielski, Przemysław; Kalač, Pavel; Siwulski, Marek; Rzymski, Piotr; Zalicka, Sylwia; Sobieralski, Krzysztof

    2016-10-01

    The aim of the study was to (i) investigate the potential of edible mushroom Boletus badius (Fr.) Fr. to accumulate 53 elements from unpolluted acidic sandy soil and polluted alkaline flotation tailing sites in Poland, (ii) to estimate the low-molecular-weight organic acid (LMWOA) profile and contents in fruit bodies, and finally (iii) to explore the possible relationship between elements and LMWOA content in mushrooms. The content of most elements in fruiting bodies collected from the flotation tailings was significantly higher than in mushrooms from the unpolluted soils. The occurrence of elements determined in fruiting bodies of B. badius has been varied (from 0.01 mg kg -1 for Eu, Lu, and Te up to 18,932 mg kg -1 for K). The results established the high importance of element contents in substrate. Among ten organic acids, nine have been found in wide range: from below 0.01 mg kg -1 for fumaric acid to 14.8 mg g -1 for lactic acid. Lactic and succinic acids were dominant in both areas, and citric acid was also in high content in polluted area. The correlation between element contents and the individual and total content of LMWOAs was confirmed.

  19. Low-molecular-weight fucoidan and high-stability fucoxanthin from brown seaweed exert prebiotics and anti-inflammatory activities in Caco-2 cells

    Directory of Open Access Journals (Sweden)

    Pai-An Hwang

    2016-08-01

    Full Text Available Background: The aim of this study is to investigate the anti-inflammatory effects of low-molecular-weight fucoidan (LMF and high-stability fucoxanthin (HS-Fucox in a lipopolysaccharide-induced inflammatory Caco-2 cell line co-culture with B. lactis. Methods: We used various methods such as transepithelial resistance (TER assay, cytokine secretion assay, and tight junction protein mRNA expression assay to examine LMF and HS-Fucox anti-inflammatory properties. Results: LMF and HS-Fucox activated probiotic growth and reduced the inflammation of the intestinal epithelial cells. Moreover, the combination of LMFHS-Fucox dramatically enhanced the intestinal epithelial barrier and immune function against the lipopolysaccharide effect by inhibiting IL-1β and TNF-α and promoting IL-10 and IFN-γ. Conclusion: These findings suggested that LMF and HS-Fucox, alone or in combination, could be the potential natural compounds to enhance the immune system and have an anti-inflammatory effect on the intestinal cells.

  20. Comparison of synthetic chelators and low molecular weight organic acids in enhancing phytoextraction of heavy metals by two ecotypes of Sedum alfredii Hance.

    Science.gov (United States)

    Liu, Dan; Islam, Ejazul; Li, Tingqiang; Yang, Xiaoe; Jin, Xiaofen; Mahmood, Qaisar

    2008-05-01

    Lab scale and pot experiments were conducted to compare the effects of synthetic chelators and low molecular weight organic acids (LMWOA) on the phytoextraction of multi-contaminated soils by two ecotypes of Sedum alfredii Hance. Through lab scale experiments, the treatment dosage of 5 and 10 mM for synthetic chelators and LMWOA, respectively, and the treatment time of 10 days were selected for pot experiment. In pot experiment, the hyperaccumulating ecotype (HE) was found more tolerant to the metal toxicity compared with the non-hyperaccumulating ecotype (NHE). EDTA for Pb, EDDS for Cu, and DTPA for Cu and Cd were found more effective to enhance heavy metal accumulation in the shoots of S. alfredii Hance. Compared with synthetic chelators, the phytoextraction ability of LMWOA was lesser. Considering the strong post-harvest effects of synthetic chelators, it is suggested that higher dosage of LMWOA could be practiced during phytoextraction, and some additional measures could also be taken to lower the potential environmental risks of synthetic chelators in the future studies.

  1. Improving the mining soil quality for a vegetation cover after addition of sewage sludges: inorganic ions and low-molecular-weight organic acids in the soil solution.

    Science.gov (United States)

    Peña, Aránzazu; Mingorance, Mª Dolores; Guzmán-Carrizosa, Ignacio; Fernández-Espinosa, Antonio J

    2015-03-01

    We assessed the effects of applying stabilized sewage sludge (SSL) and composted sewage sludge (CLV), at 5 and 10% to an acid mining soil. Limed soil (NCL) amended or not with SSL and CLV was incubated for 47 days. We studied the cations and organic and inorganic anions in the soil solution by means of ion chromatography. Liming led to big increases in Ca(2+) and SO4(2-) and to significant decreases in K(+), Mg(2+), NH4(+) and NO3(-). Addition of both organic amendments increased some cations (NH4(+), K(+), Mg(2+), Na(+)) and anions (Cl(-), NO3(-) only with CLV and PO4(3-) only with SSL) and provided a greater amount of low-molecular-weight organic acids (LMWOAs) (SSL more than CLV). Incubation led to decreases in all cations, particularly remarkable for Ca(2+) and Mg(2+) in SSL-10. A decrease in NH4(+) was associated with variations in NO2(-) and NO3(-) resulting from nitrification reactions. During incubation the LMWOAs content tended to decrease similarly to the cations, especially in SSL-10. Chemometric tools revealed a clear discrimination between SSL, CLV and NCL. Furthermore, treatment effects depended upon dose, mainly in SSL. Amendment nature and dose affect the quality of a mining soil and improve conditions for plant establishment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Simultaneous determination of low-molecular-weight organic acids and chlorinated acid herbicides in environmental water by a portable CE system with contactless conductivity detection.

    Science.gov (United States)

    Xu, Yan; Wang, Weilong; Li, Sam Fong Yau

    2007-05-01

    This report describes a method to simultaneously determine 11 low-molecular-weight (LMW) organic acids and 16 chlorinated acid herbicides within a single run by a portable CE system with contactless conductivity detection (CCD) in a poly(vinyl alcohol) (PVA)-coated capillary. Under the optimized condition, the LODs of CE-CCD ranged from 0.056 to 0.270 ppm, which were better than for indirect UV (IUV) detection of the 11 LMW organic acids or UV detection of the 16 chlorinated acid herbicides. Combined with an on-line field-amplified sample stacking (FASS) procedure, sensitivity enhancement of 632- to 1078-fold was achieved, with satisfactory reproducibility (RSDs of migration times less than 2.2%, and RSDs of peak areas less than 5.1%). The FASS-CE-CCD method was successfully applied to determine the two groups of acidic pollutants in two kinds of environmental water samples. The portable CE-CCD system shows advantages such as simplicity, cost effectiveness, and miniaturization. Therefore, the method presented in this report has great potential for onsite analysis of various pollutants at the trace level.

  3. Relationship between the ability of oral streptococci to interact with platelet glycoprotein Ibalpha and with the salivary low-molecular-weight mucin, MG2.

    Science.gov (United States)

    Plummer, Christopher; Douglas, Charles William Ian

    2006-12-01

    The oral streptococci Streptococcus sanguinis, Streptococcus gordonii and Streptococcus oralis are common aetiological agents of infective endocarditis, and their ability to adhere to and induce the aggregation of platelets is thought to be a virulence trait. The platelet glycoprotein GPIbalpha has been implicated as the adhesion receptor for S. sanguinis and S. gordonii, but it is not known if this is the case for S. oralis and other species. The aim of this study was to determine the GPIbalpha-interactive capability of a range of oral streptococci and to determine the relationship between this capability and their ability to interact with the salivary constituents that they would encounter in their normal habitat. All platelet-adhesive S. sanguinis strains and most S. gordonii strains adhered in a GPIbalpha-dependent manner, but strains of S. oralis, Streptococcus cristatus, Streptococcus parasanguinis and Streptococcus mitis had no direct affinity for platelets. Those strains that were able to bind GPIbalpha also bound to the low-molecular-weight submandibular salivary mucin, MG2, and this interaction was sialic acid-dependent. The data suggest that S. sanguinis and S. gordonii may be efficient colonizers of platelet vegetations because of their adaptation to recognize sialylated salivary mucins. In contrast, S. oralis does not interact with platelets and so is likely to colonize vegetations through an as yet unidentified mechanism.

  4. Mucoadhesive properties of low molecular weight chitosan- or glycol chitosan- and corresponding thiomer-coated poly(isobutylcyanoacrylate) core-shell nanoparticles.

    Science.gov (United States)

    Palazzo, Claudio; Trapani, Giuseppe; Ponchel, Gilles; Trapani, Adriana; Vauthier, Christine

    2017-08-01

    The aim of the present work was to evaluate the mucoadhesive properties of poly(isobutyl cyanoacrylate) (PIBCA) nanoparticles (NPs) coated with Low Molecular Weight (LMW) chitosan (CS)- and glycol chitosan (GCS)-based thiomers as well as with the corresponding LMW unmodified polysaccharides. For this purpose, all the CS- and GCS-based thiomers were prepared under simple and mild conditions starting from the LMW unmodified polymers CS and GCS. The resulting NPs were of spherical shape with diameters ranging from 400 to 600nm and 187 to 309nm, for CS- and GCS-based NPs, respectively. The mucoadhesive characteristics of these core shell NPs were studied in Ussing chambers measuring the percentage of NPs stuck on the mucosal of fresh intestinal tissue after 2h of incubation. Moreover, incubation of nanoparticle formulations with the intestinal tissue induced changes in transmucosal electrical resistance which were measured to gain information into the opening of tight junctions and to control the integrity of the mucosa. Thus, it was found that PIBCA NPs coated with the GCS-Glutathione conjugate (GCGPIBCA NPs) possessed the most favorable mucoadhesive performances. Moreover, both GCGPIBCA- and GCS-N-acetyl-cysteine (GCNPIBCA)-core-shell NPs might induced an enlargement of the epithelial cell tight junctions. In conclusion, coating of PIBCA NPs with GCS-based thiomers may be useful for improving the mucoadhesive and permeation properties of these nanocarriers. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2011-01-01

    A hydroponic experiment in a phytotron was performed to investigate the effect of two different Ca/Mg ratios (4:1 and 1:10) and trace element ions (Cd, Cu, Pb and Zn) in solution on the efficiency of low molecular weight organic acid (LMWOA) formation in Salix viminalis rhizosphere. Depending on the Ca/Mg ratio and presence of selected trace elements at 0.5mM concentration, the amount and kind of LMWOAs in the rhizosphere were significantly affected. In physiological 4:1 Ca/Mg ratio the following complex of acids was observed: malonic (Pb, Zn), citric, lactic, maleic and succinic (Zn) acids. Under 1:10 Ca/Mg ratio, citric (Cd, Zn), maleic and succinic (Cd, Cu, Pb, Zn) acids were seen. Additionally, high accumulation of zinc and copper in all systems was observed, with the exception of those where one of the metals was at higher concentration. Summing up, the results indicate a significant role of LMWOAs in Salix phytoremediation abilities. Both effects can be modulated depending on the mutual Ca/Mg ratio. Copyright © 2010 Elsevier Inc. All rights reserved.

  6. Cyclodextrin-supported organic matrix for application of MALDI-MS for forensics. Soft-ionization to obtain protonated molecules of low molecular weight compounds

    International Nuclear Information System (INIS)

    Yonezawa, Tetsu; Asano, Takashi; Fujino, Tatsuya; Nishihara, Hiroshi

    2013-01-01

    Highlights: ► MALDI-MS applications for drug identification in forensic science is investigated. ► Cyclodextrin-supported organic matrices strongly suppress the obstacle peaks of organic matrix compounds. ► Cyclodextrin-supported organic matrices also suppress the alkali adducted molecule peaks. ► Sugar units of cyclodextrins work for this specific features. - Abstract: A mass measurement technique for detecting low-molecular-weight drugs with a cyclodextrin-supported organic matrix was investigated. By using cyclodextrin-supported 2,4,6-trihydroxyacetophenone (THAP), the matrix-related peaks of drugs were suppressed. The peaks of protonated molecules of the sample and THAP were mainly observed, and small fragments were detected in a few cases. Despite the Na + and K + peaks were observed in the spectrum, Na + or K + adduct sample molecules were undetected, owing to the sugar units of cyclodextrin. The advantages of MALDI-MS with cyclodextrin-supported matrices as an analytical tool for forensic samples are discussed. The suppression of alkali adducted molecules and desorption process are also discussed

  7. Structural Characterization and Antioxidative Activity of Low-Molecular-Weights Beta-1,3-Glucan from the Residue of Extracted Ganoderma lucidum Fruiting Bodies

    Directory of Open Access Journals (Sweden)

    Pai-Feng Kao

    2012-01-01

    Full Text Available The major cell wall constituent of Ganoderma lucidum (G. lucidum is β-1,3-glucan. This study examined the polysaccharide from the residues of alkaline-extracted fruiting bodies using high-performance anion-exchange chromatography (HPAEC, and it employed nuclear magnetic resonance (NMR and mass spectrometry (MS to confirm the structures. We have successfully isolated low-molecular-weight β-1,3-glucan (LMG, in high yields, from the waste residue of extracted fruiting bodies of G. lucidum. The 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide (MTT assay evaluated the capability of LMG to suppress H2O2-induced cell death in RAW264.7 cells, identifying that LMG protected cells from H2O2-induced damage. LMG treatment decreased H2O2-induced intracellular reactive oxygen species (ROS production. LMG also influenced sphingomyelinase (SMase activity, stimulated by cell death to induce ceramide formation, and then increase cell ROS production. Estimation of the activities of neutral and acid SMases in vitro showed that LMG suppressed the activities of both neutral and acid SMases in a concentration-dependent manner. These results suggest that LMG, a water-soluble β-1,3-glucan recycled from extracted residue of G. lucidum, possesses antioxidant capability against H2O2-induced cell death by attenuating intracellular ROS and inhibiting SMase activity.

  8. The competing effects of microbially derived polymeric and low molecular-weight substances on the dispersibility of CeO2 nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Yuriko; Ochiai, Asumi; Kawamoto, Keisuke; Takeda, Ayaka; Ichiyoshi, Kenta; Ohnuki, Toshihiko; Hochella, Michael F.; Utsunomiya, Satoshi

    2018-02-26

    To understand the competing effects of the components in extracellular substances (ES), polymeric substances (PS) and low-molecular-weight small substances (SS) <1 kDa derived from microorganisms, on the colloidal stability of cerium dioxide nanoparticles (CeNPs), we investigated their adsorption to sparingly soluble CeNPs at room temperature at pH 6.0. The ES was extracted from the fungus S. cerevisiae. The polypeptides and phosphates in all components preferentially adsorbed onto the CeNPs. The zeta potentials of ES + CeNPs, PS + CeNPs, and SS + CeNPs overlapped on the plot of PS itself, indicating the surface charge of the polymeric substances controls the zeta potentials. The sizes of the CeNP aggregates, 100–1300 nm, were constrained by the zeta potentials. The steric barrier derived from the polymers, even in SS, enhanced the CeNP dispersibility at pH 1.5–10. Consequently, the PS and SS had similar effects on modifying the CeNP surfaces. The adsorption of ES, which contains PS + SS, can suppress the aggregation of CeNPs over a wider pH range than that for PS only. The present study addresses the non-negligible effects of small-sized molecules derived from microbial activity on the migration of CeNP in aquatic environments, especially where bacterial consortia prevail.

  9. FERMENTATION BY Lactobacillus paracasei OF GALACTOOLIGOSACCHARIDES AND LOW-MOLECULAR-WEIGHT CARBOHYDRATES EXTRACTED FROM SQUASH (Curcubita maxima AND LUPIN (Lupinus albus SEEDS

    Directory of Open Access Journals (Sweden)

    María I. Palacio

    2014-02-01

    Full Text Available The in vitro prebiotic activity of galactooligosaccharides (GOS and low-molecular-weight carbohydrates (LMWC extracted from lupin and squash seeds on the growth of Lactobacillus paracasei BGP1 was studied. To this end, the change in cell density after 24 h of L. paracasei growth on 1% (w/v glucose, 1% (w/v raffinose, 1% (w/v commercial inulin GR, 1% (w/v lupin extract, and 1% (w/v squash extract relative to the change in cell density of a mixture of enteric strains under the same culture conditions were evaluated. Additionally, the principal components of GOS and LMWC in the extracts were identified using Thin Layer Chromatography. The highest prebiotic activity score was for L. paracasei grown on squash extract (0.55±0.03, followed by lupin extract (0.49±0.02, inulin (0.38±0.05 and raffinose (0.37±0.05. These results will contribute to selecting plant species as potential sources of prebiotic ingredients for the development of functional foods.

  10. Effects of low-molecular-weight-chitosan on the adenine-induced chronic renal failure rats in vitro and in vivo

    Science.gov (United States)

    Zhi, Xuan; Han, Baoqin; Sui, Xianxian; Hu, Rui; Liu, Wanshun

    2015-02-01

    The effects of low-molecular-weight-chitosan (LMWC) on chronic renal failure (CRF) rats induced by adenine were investigated in vivo and in vitro. Chitosan were hydrolyzed using chitosanase at pH 6-7 and 37° for 24 h to obtain LMWC. In vitro, the effect of LMWC on the proliferation of renal tubular epithelial cells (RTEC) showed that it had no cytotoxic effect and could promote cell growth. For the in vivo experiment, chronic renal failure rats induced by adenine were randomly divided into control group, Niaoduqing group, and high-, medium- and low-dose LMWC groups. For each group, we detected serum creatinine (SCR), blood urea nitrogen (BUN), and total superoxide dismutase (T-SOD), glutathione oxidase (GSH-Px) activities of renal tissue, and obtained the ratio of kidney weight/body weight, pathological changes of kidney. The levels of serum SCR, BUN were higher in the adenine-induced rats than those in the control group, indicating that the rat chronic renal failure model worked successfully. The results after treatment showed that LMWC could reduce the SCR and BUN levels and enhance the activities/levels of T-SOD and GSH-PX in kidney compared to control group. Histopathological examination revealed that adenine-induced renal alterations were restored by LMWC at three tested dosages, especially at the low dosage of 100 mg kg-1 d-1.

  11. Toxicity assessment of volatile organic compounds and polycyclic aromatic hydrocarbons in motorcycle exhaust

    International Nuclear Information System (INIS)

    Chang, C.-T.; Chen, B.-Y.

    2008-01-01

    This study investigates the toxicity of various pollutant species from motorcycle exhaust via dose-response analysis and margin of safety using Escherichia coli DH5α. The toxicity evaluation of the major components of motorcycle exhaust volatile organic compounds (VOCs), collected with impinger, and polycyclic aromatic hydrocarbons (PAHs), collected with filter and XAD-2, is essential to determine emission standards for motorcycles. The toxicity of benzene (B), toluene (T), ethyl benzene (E) and xylene (X) was selected for comparison as standard VOCs emitted from motorcycles. In addition, three types of reformulated gasoline (high oxygenate and high benzene content (No. 1), low oxygen and high benzene (No. 2), and low oxygen and low benzene (No. 3) were prepared to reveal combined toxicity of individual compositions. Motorcycle exhaust is significantly more toxic than BTEX due to the highly toxic VOCs generated from incomplete combustion. Overall toxicity evaluation showed that the toxicity, indicated as EC 50 , was approximately as follows: PAHs > two-stroke engines > four-stroke engines > BTEX

  12. Toxicity assessment of volatile organic compounds and polycyclic aromatic hydrocarbons in motorcycle exhaust.

    Science.gov (United States)

    Chang, Chang-Tang; Chen, Bor-Yann

    2008-05-30

    This study investigates the toxicity of various pollutant species from motorcycle exhaust via dose-response analysis and margin of safety using Escherichia coli DH5 alpha. The toxicity evaluation of the major components of motorcycle exhaust volatile organic compounds (VOCs), collected with impinger, and polycyclic aromatic hydrocarbons (PAHs), collected with filter and XAD-2, is essential to determine emission standards for motorcycles. The toxicity of benzene (B), toluene (T), ethyl benzene (E) and xylene (X) was selected for comparison as standard VOCs emitted from motorcycles. In addition, three types of reformulated gasoline (high oxygenate and high benzene content (No. 1), low oxygen and high benzene (No. 2), and low oxygen and low benzene (No. 3) were prepared to reveal combined toxicity of individual compositions. Motorcycle exhaust is significantly more toxic than BTEX due to the highly toxic VOCs generated from incomplete combustion. Overall toxicity evaluation showed that the toxicity, indicated as EC50, was approximately as follows: PAHs>two-stroke engines>four-stroke engines>BTEX.

  13. Volatile Short-chain Chlorinated Hydrocarbons in the Groundwater of the City of Zagreb

    Directory of Open Access Journals (Sweden)

    Marijanović-Rajčić, M.

    2008-01-01

    Full Text Available The aim of the study was to assess the quality of the groundwater sampled from private wells and the public water-supply system in terms of estimating the contamination caused by short-chain chlorinated hydrocarbons, as well as to estimate the exposure of the citizens dwelling in different suburbs to these pollutants of their drinking water (Fig. 1. The aim of the study was also to determine which suburb is supplied through the public water-supply system with water originating from the Sašnak spring that is contaminated with volatile chlorinated short-chain hydrocarbons.Drinking water samples were taken from 3 private wells and 1 public water-supply system situated in 3 Zagreb suburbs - Pešćenica, Trnje, and Trešnjevka. The sampling was carried out during 2003 and was undertaken on a seasonal basis. Short-chain chlorinated hydrocarbons - 1,1,1-trichloroethane, carbon tetrachloride, 1,1,2-trichloroethene and 1,1,2,2-tetrachloroethene - were determined by gas chromatography, following "liquid-liquid extraction" in pentane. For that purpose, we applied the gas chromatograph equipped with an electron-capture detector, thermo-programmable operations, and a suitable capillary column. The technique applied was that of split-injection.The groundwater of the City of Zagreb was found to be contaminated with volatile chlorinated hydrocarbons. The concentration level of 1,1,1-trichloroethane, determined in most of the samples, was found to be low (Fig. 2. On the other hand, 1,1,2-trichloroethene was present in all samples in concentrations of about 1 µg l-1- (Fig. 3. Only the drinking water samples taken from private wells in the suburb of Trnje contained somewhat higher mass concentrations of 1,1,1-trichloroethane, with the peak value of 19.03 µg l-1, measured in the winter season. In the samples taken from private wells in Trnje, the mass concentrations of 1,1,2,2-tetrachloroethene rangedfrom 15.30 µg l-1 to 18.65 µg l-1, as measured in autumn

  14. pH-responsive thiolated chitosan nanoparticles for oral low-molecular weight heparin delivery: in vitro and in vivo evaluation.

    Science.gov (United States)

    Fan, Bo; Xing, Yang; Zheng, Ying; Sun, Chuan; Liang, Guixian

    2016-01-01

    The aim of present study was to investigate a pH-responsive and mucoadhesive nanoparticle system for oral bioavailability enhancement of low-molecular weight heparin (LMWH). The thioglycolic acid (TGA) was first covalently attached to chitosan (CS) with 396.97 ± 54.54 μmol thiol groups per gram of polymer and then the nanoparticles were prepared with thiolated chitosan (TCS) and pH-sensitive polymer hydroxypropyl methylcellulose phthalate (HPMCP) by ionic cross-linking method. The obtained nanoparticles were characterized for the shape, particle size, zeta potential, drug entrapment efficiency and loading capacity. In vitro results revealed the acid stability of pH-responsive nanoparticles, which had a significant control over LMWH release and could effectively protect entrapped drugs in simulated gastric conditions. By the attachment of the thiol ligand, an improvement of permeation-enhancing effect on freshly excised carp intestine (1.86-fold improvement) could be found. The mucoadhesive properties were evaluated using fluorescently labeled TCS or CS nanoparticles. As compared with the controls, a significant improvement of mucoadhesion on rat intestinal mucosa was observed in TCS/HPMCP nanoparticles via confocal laser scanning microscopy. The activated partial thromboplastin time (APTT) was significantly prolonged and an increase in the oral bioavailability of LMWH was turned out to be pronounced after oral delivered LMWH-loaded TCS/HPMCP nanoparticles in rats, which suggested enhanced anticoagulant effects and improved absorption of LMWH. In conclusion, pH-responsive TCS/HPMCP nanoparticles hold promise for oral delivery of LMWH.

  15. Low-Molecular Weight Polyethylenimine Modified with Pluronic 123 and RGD- or Chimeric RGD-NLS Peptide: Characteristics and Transfection Efficacy of Their Complexes with Plasmid DNA

    Directory of Open Access Journals (Sweden)

    Jing Hu

    2016-05-01

    Full Text Available To solve the problem of transfection efficiency vs. cytotoxicity and tumor-targeting ability when polyethylenimine (PEI was used as a nonviral gene delivery vector, new degradable PEI polymers were synthesized via cross-linking low-molecular-weight PEI with Pluronic P123 and then further coupled with a targeting peptide R4 (RGD and a bifunctional R11 (RGD-NLS, which were termed as P123-PEI-R4 and P123-PEI-R11, respectively. Agarose gel electrophoresis showed that both P123-PEI-R4 and P123-PEI-R11 efficaciously condense plasmid DNA at a polymer-to-pDNA w/w ratio of 3.0 and 0.4, respectively. The polyplexes were stable in the presence of serum and could protect plasmid DNA against DNaseI. They had uniform spherical nanoparticles with appropriate sizes around 100–280 nm and zeta-potentials about +40 mV. Furthermore, in vitro experiments showed that these polyplexes had lower cytotoxicity at any concentration compared with PEI 25 kDa, thus giving promise to high transfection efficiency as compared with another P123-PEI derivate conjugated with trifunctional peptide RGD-TAT-NLS (P123-PEI-R18. More importantly, compared with the other polymers, P123-PEI-R11 showed the highest transfection efficiency with relatively lower cytotoxicity at any concentration, indicating that the new synthetic polymer P123-PEI-R11 could be used as a safe and efficient gene deliver vector.

  16. Global Liver Gene Expression Analysis on a Murine Metabolic Syndrome Model Treated by Low-molecular-weight Lychee Fruit Polyphenol (Oligonol®).

    Science.gov (United States)

    Uchiyama, Hironobu; Uehara, Kaori; Nagashima, Takayuki; Nakata, Akifumi; Sato, Keisuke; Mihara, Yoshihiro; Komatsu, Ken-Ich; Takanari, Jun; Shimizu, Shigeomi; Wakame, Koji

    2016-07-01

    Oligonol® (OLG) is a low-molecular-weight lychee fruit polyphenol mainly containing catechin-type monomers and oligomers of proanthocyanidins. Dietary OLG supplementation reportedly improves lipid metabolism disorder and lowers the visceral fat level in animal and human studies. Thus, we investigated the mechanism behind the protective and beneficial effects of OLG on a Western diet (WD)-induced metabolic syndrome (MetS) of a murine model. Using the C57BL/6J mouse for the MetS model, mice were divided into three groups: control (normal diet: ND), Western diet (WD) and WD + 0.5% OLG (OLG) groups. The WD group was fed a high-calorie (high fructose plus high fat) diet for 12 weeks to develop MetS. At week 12, all mice were sacrificed and the blood and liver were obtained for histological and biological examinations and RNA sequencing (RNA-Seq). Body weight, liver weight, plasma triglycerides (TG), total cholesterol (T-Cho) and alanine aminotransferase (ATS) levels of both OLG groups were significantly lower than those of the WD group. On histological examination of the liver, the area of fatty deposits was shown to be suppressed by OLG administration. Expression gene analysis in the liver of WD- versus OLG-fed mice by RNA-Seq showed that 464/45,706 genes exhibited a significant change of expression (corrected p-value metabolism-related genes Lpin1, Adig and Cidea were regulated by OLG administration. OLG may function to suppress MetS and the progression of geriatric diseases in WD-fed mice by regulating the expression of lipid metabolism, inflammation and tumor-related genes in the liver. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  17. Electrophoretic extraction of low molecular weight cationic analytes from sodium dodecyl sulfate containing sample matrices for their direct electrospray ionization mass spectrometry.

    Science.gov (United States)

    Kinde, Tristan F; Lopez, Thomas D; Dutta, Debashis

    2015-03-03

    While the use of sodium dodecyl sulfate (SDS) in separation buffers allows efficient analysis of complex mixtures, its presence in the sample matrix is known to severely interfere with the mass-spectrometric characterization of analyte molecules. In this article, we report a microfluidic device that addresses this analytical challenge by enabling inline electrospray ionization mass spectrometry (ESI-MS) of low molecular weight cationic samples prepared in SDS containing matrices. The functionality of this device relies on the continuous extraction of analyte molecules into an SDS-free solvent stream based on the free-flow zone electrophoresis (FFZE) technique prior to their ESI-MS analysis. The reported extraction was accomplished in our current work in a glass channel with microelectrodes fabricated along its sidewalls to realize the desired electric field. Our experiments show that a key challenge to successfully operating such a device is to suppress the electroosmotically driven fluid circulations generated in its extraction channel that otherwise tend to vigorously mix the liquid streams flowing through this duct. A new coating medium, N-(2-triethoxysilylpropyl) formamide, recently demonstrated by our laboratory to nearly eliminate electroosmotic flow in glass microchannels was employed to address this issue. Applying this surface modifier, we were able to efficiently extract two different peptides, human angiotensin I and MRFA, individually from an SDS containing matrix using the FFZE method and detect them at concentrations down to 3.7 and 6.3 μg/mL, respectively, in samples containing as much as 10 mM SDS. Notice that in addition to greatly reducing the amount of SDS entering the MS instrument, the reported approach allows rapid solvent exchange for facilitating efficient analyte ionization desired in ESI-MS analysis.

  18. Organic solvent and temperature-enhanced ion chromatography-high resolution mass spectrometry for the determination of low molecular weight organic and inorganic anions

    International Nuclear Information System (INIS)

    Gilchrist, Elizabeth S.; Nesterenko, Pavel N.; Smith, Norman W.; Barron, Leon P.

    2015-01-01

    Highlights: • IC selectivity at high contents of organic solvent in eluent and elevated temperature is studied. • Solvent-enhanced IC coupled to high resolution MS is beneficial for sensitive detection of ions. • The first application of IC-HRMS to the detection of low explosives in fingermarks is shown. - Abstract: There has recently been increased interest in coupling ion chromatography (IC) to high resolution mass spectrometry (HRMS) to enable highly sensitive and selective analysis. Herein, the first comprehensive study focusing on the direct coupling of suppressed IC to HRMS without the need for post-suppressor organic solvent modification is presented. Chromatographic selectivity and added HRMS sensitivity offered by organic solvent-modified IC eluents on a modern hyper-crosslinked polymeric anion-exchange resin (IonPac AS18) are shown using isocratic eluents containing 5–50 mM hydroxide with 0–80% methanol or acetonitrile for a range of low molecular weight anions (<165 Da). Comprehensive experiments on IC thermodynamics over a temperature range between 20–45 °C with the eluent containing up to 60% of acetonitrile or methanol revealed markedly different retention behaviour and selectivity for the selected analytes on the same polymer based ion-exchange resin. Optimised sensitivity with HRMS was achieved with as low as 30–40% organic eluent content. Analytical performance characteristics are presented and compared with other IC-MS based works. This study also presents the first application of IC-HRMS to forensic detection of trace low-order anionic explosive residues in latent human fingermarks

  19. Low-molecular-weight color pI markers to monitor on-line the peptide focusing process in OFFGEL fractionation.

    Science.gov (United States)

    Michelland, Sylvie; Bourgoin-Voillard, Sandrine; Cunin, Valérie; Tollance, Axel; Bertolino, Pascal; Slais, Karel; Seve, Michel

    2017-08-01

    High-throughput mass spectrometry-based proteomic analysis requires peptide fractionation to simplify complex biological samples and increase proteome coverage. OFFGEL fractionation technology became a common method to separate peptides or proteins using isoelectric focusing in an immobilized pH gradient. However, the OFFGEL focusing process may be further optimized and controlled in terms of separation time and pI resolution. Here we evaluated OFFGEL technology to separate peptides from different samples in the presence of low-molecular-weight (LMW) color pI markers to visualize the focusing process. LMW color pI markers covering a large pH range were added to the peptide mixture before OFFGEL fractionation using a 24-wells device encompassing the pH range 3-10. We also explored the impact of LMW color pI markers on peptide fractionation labeled previously for iTRAQ. Then, fractionated peptides were separated by RP_HPLC prior to MS analysis using MALDI-TOF/TOF mass spectrometry in MS and MS/MS modes. Here we report the performance of the peptide focusing process in the presence of LMW color pI markers as on-line trackers during the OFFGEL process and the possibility to use them as pI controls for peptide focusing. This method improves the workflow for peptide fractionation in a bottom-up proteomic approach with or without iTRAQ labeling. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. [Chromatographic mass spectrometric determination of low-molecular-weight aromatic compounds of microbial origin in the serum from patients with sepsis].

    Science.gov (United States)

    Beloborodova, N V; Arkhipova, A S; Beloborodov, D M; Boĭko, N B; Mel'ko, A I; Olenin, A Iu

    2006-02-01

    The investigation quantitatively determined the content of low-molecular-weight aromatic compounds of microbial origin in the sera of 34 individuals by chromatographic mass spectrometry. An "Agilent Technogies 6890N" gas chromatograph with a 5973 mass selective detector was applied; chromatographic separation of components was effected on an Hp-5MS quartz capillary column. Aromatic small molecules originating from microbes (SMOM) were determined in the sera of 7 patients with sepsis. The diagnosis of sepsis was documented by the presence of the systemic inflammation syndrome and by that of bacteriemia and/or artificial ventilation-associated pneumonia along with the level of procalcitonin of higher than 10 ng/ml. The levels of aromatic SMOM were compared in 10 healthy donors, 8 preoperative cardiosurgical patients, and 9 patients with different abnormalities without sepsis treated in an intensive care unit (ICU). Serum phenylacetic and 3-phenylpropionic acids were found to be prevalent in the healthy donors and postoperative cardiosurgical patients. In ICU patients with different complications without sepsis, more than half the compounds under study were undetectable, the others were found in very low concentrations, which may be accounted for by antibiotic therapy. At the same time, almost the whole spectrum of the test compounds (other than 3-phenylpropionic acid) with the highest concentrations of 3-phenyllactic, p-hydroxyphenylacetic, 3-(p-hydroxyphenyl)lactic and 2-hydroxybutanic acids, was detectable in septic patients receiving a more intensive therapy. The differences were statistically significant (by the Mann-Whitney U-test; p < 0.05). By taking into account the potentially high biological activity of the test compounds, studies are to be continued in this area.

  1. Effects of low molecular weight organic acids on the immobilization of aqueous Pb(II) using phosphate rock and different crystallized hydroxyapatite.

    Science.gov (United States)

    Wei, Wei; Cui, Jing; Wei, Zhenggui

    2014-06-01

    Understanding the effects of low molecular weight organic acids (LMWOAs) on the transformation of Pb(II) to geochemically stable pyromorphite (PY) by apatite materials (AMs), has considerable benefits for risk assessment and remediation strategies for contaminated water and soil. In this study, we systematically investigated the immobilization of Pb(II) from aqueous solution by natural phosphate rock (PR) and different crystallized hydroxyapatite (HAp) in the absence and presence of LMWOAs (oxalic, malic and citric acids). The results indicated that the effectiveness of PR and HAp in immobilizing Pb(II) followed in descending order by HAp2 (the poorly crystallized HAp), HAp1 (the well crystallized HAp) and PR, regardlessof the presence of LMWOAs. The presence of malic and citric acids significantly decreased the immobilizationefficiency of Pb(II) by HAp1 and PR, clarifying the lower adsorption affinities of Pb(II)-organic acid complexes on HAp1 and PR rather than Pb(II) ion. On thecontrary, oxalic acid could markedly enhance the removal of Pb(II) from aqueous solution by HAp1 and PR through the formation of lead oxalate, which was confirmed by FT-IR and XRDanalysis. Results also showed that LMWOAs had little promoting or inhibiting effect on the immobilization of Pb(II) by HAp2. This study suggested that the ubiquity of LMWOAs in natural environments could retard the transformation efficiency of Pb(II) to PY by AMs, especiallyin thepresenceof oxalic acid, and the poorly crystallized HAp2 had great potential to remediate Pb(II)-contaminated water and soil due to its insusceptibility to LMWOAs. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Laccase-Catalyzed Synthesis of Low-Molecular-Weight Lignin-Like Oligomers and their Application as UV-Blocking Materials.

    Science.gov (United States)

    Lim, Jieyan; Sana, Barindra; Krishnan, Ranganathan; Seayad, Jayasree; Ghadessy, Farid J; Jana, Satyasankar; Ramalingam, Balamurugan

    2018-02-02

    The laccase-catalyzed oxidative polymerization of monomeric and dimeric lignin model compounds was carried out with oxygen as the oxidant in aqueous medium. The oligomers were characterized by using gel permeation chromatography (GPC) and matrix-assisted laser desorption ionization time-of-flight mass spectroscopy (MALDI-TOF MS) analysis. Oxidative polymerization led to the formation of oligomeric species with a number-average molecular weight (M n ) that ranged from 700 to 2300 Da with a low polydispersity index. Spectroscopic analysis provided insight into the possible modes of linkages present in the oligomers, and the oligomerization is likely to proceed through the formation of C-C linkages between phenolic aromatic rings. The oligomers were found to show good UV light absorption characteristics with high molar extinction coefficient (5000-38 000 m -1  cm -1 ) in the UV spectral region. The oligomers were blended independently with polyvinyl chloride (PVC) by using solution blending to evaluate the compatibility and UV protection ability of the oligomers. The UV/Vis transmittance spectra of the oligomer-embedded PVC films indicated that these lignin-like oligomers possessed a notable ability to block UV light. In particular, oligomers obtained from vanillyl alcohol and the dimeric lignin model were found to show good photostability in accelerated UV weathering experiments. The UV-blocking characteristics and photostability were finally compared with the commercial low-molecular-weight UV stabilizer 2,4-dihydroxybenzophenone. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Study of the Efficacy, Safety and Tolerability of Low-Molecular-Weight Heparin vs. Unfractionated Heparin as Bridging Therapy in Patients with Embolic Stroke due to Atrial Fibrillation.

    Science.gov (United States)

    Feiz, Farnia; Sedghi, Reyhane; Salehi, Alireza; Hatam, Nahid; Bahmei, Jamshid; Borhani-Haghighi, Afshin

    2016-06-01

    Anticoagulation with adjusted dose warfarin is a well-accepted treatment for the prevention of recurrent stroke in patients with atrial fibrillation. Meanwhile, using bridging therapy with heparin or heparinoids before warfarin for initiation of anticoagulation is a matter of debate. We compared safety, efficacy, and tolerability of low-molecular-weight heparin (LMWH) and unfractionated heparin (UFH) as a bridging method in patients with recent ischemic stroke due to atrial fibrillation. This study was a randomized single-blind controlled trial in patients with acute ischemic stroke due to atrial fibrillation who were eligible for receiving warfarin and were randomly treated with 60 milligrams (mg) of LMWH (enoxaparin) subcutaneously every 12 h, or 1000 units/h of continuous intravenous heparin. The primary efficacy endpoints were recurrence of new ischemic stroke, myocardial infarction and/or death. The primary safety endpoint was central nervous system and/or systemic bleeding. Seventy-four subjects were recruited. Baseline demographic and clinical characteristics of two groups were matched. Composite endpoint outcome of new ischemic stroke, myocardial infarction, and/or death in follow-up period was seen in 10 subjects (27.03%) in UFH group and in four subjects (10.81%) in LMWH group (p value: 0.136). All hemorrhages and symptomatic central nervous system (CNS) hemorrhages in follow-up period were in 7 (18.9%) and 4 (10.8%) patients in UFH group, in 5 (13.5%), and 3 (8.1%) patients in LMWH group (p values: 0.754 and 0.751), respectively. Drop out and major adverse-effects such as heparin-induced thrombocytopenia and drug hypersensitivity were not seen in any patient. Enoxaparin can be a safe and efficient alternative for UFH as bridging therapy.

  4. High Molecular Weight Glucan of the Culinary Medicinal Mushroom Agaricus bisporus is an α-Glucan that Forms Complexes with Low Molecular Weight Galactan

    Directory of Open Access Journals (Sweden)

    Harry J. Wichers

    2010-08-01

    Full Text Available An a-glucan was isolated from the culinary medicinal mushroom A. bisporus by hot water extraction, ethanol precipitation and DEAE-cellulose chromatography. The resulting material showed a single HMW peak excluded from a Sephadex G50 column that could completely be degraded by α-amylase treatment. After heating in 1% SDS a small additional peak of low MW eluted from the G50 column. The monosaccharide composition of the main peak was evaluated by HPLC, and was found to consist of a majority of glucose (97.6%, and a minor proportion of galactose (2.4%. Methylation analysis and degradation by a-amylase indicated the presence of an a-glucan with a main chain consisting of (1®4-linked units, substituted at O-6 by α-D-glucopyranose single-units in the relation 1:8. Mono- (13C-, 1H-NMR and bidimensional [1H (obs.,13C-HSQC] spectroscopy analysis confirmed the a-configuration of the Glcp residues by low frequency resonances of C-1 at d 100.6, 100.2, and 98.8 ppm and H-1 high field ones at d 5.06, 5.11, and 4.74 ppm. The DEPT-13C-NMR allowed assigning the non-substituted and O-substituted –CH2 signals at d 60.3/60.8 and 66.2 ppm, respectively. Other assignments were attributed to C-2, C-3, C-4, C-5 and C-6 of the non-reducing ends at d 71.8; 72.8; 70.0; 71.3 and 60.3/60.8 ppm, respectively. The minor proportion of galactose that was demonstrated was probably derived from a complex between the a-glucan and a low molecular weight galactan.

  5. Combined administration of low molecular weight sodium alginate boosted immunomodulatory, disease resistance and growth enhancing effects of Lactobacillus plantarum in Nile tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Van Doan, Hien; Hoseinifar, Seyed Hossein; Tapingkae, Wanaporn; Tongsiri, Sudaporn; Khamtavee, Pimporn

    2016-11-01

    The present study investigates the effects of combined or singular administration of low molecular weight sodium alginate (LWMSA) and Lactobacillus plantarum on innate immune response, disease resistance and growth performance of Nile tilapia (Oreochromis niloticus). Three hundred and twenty fish were supplied and randomly stocked in sixteen glass tanks (150 L) assigned to four treatments as follows: 0 g kg -1 LMWSA (Control, Diet 1), 10 g kg -1 LMWSA (Diet 2), 10 8  CFU g -1 L. plantarum (Diet 3), and 10 g kg -1 LMWSA + 10 8  CFU g -1 L. plantarum (Diet 4). Following 30 and 60 days of the feeding trial, serum lysozyme, phagocytosis, respiratory burst and alternative complement activities as well as growth performance parameters (specific growth rate, feed conversion ratio) were measured. Serum lysozyme, phagocytosis, respiratory burst, and alternative complement activities of fish were significantly stimulated by both LMWSA and L. plantarum diets, however, the highest innate immune response were observed in fish fed synbiotic diet. At the end of the experiment, eight fish per replication were randomly selected for a challenge test against Streptococcus agalactiae. The survival rate of the fish fed supplemented diets was significantly greater than the control treatment and the highest post challenge survival rate was observed in synbiotic diet. Furthermore, SGR and FCR were significantly improved in fish fed supplemented diets after 60 days and the highest growth performance was observed in fish fed synbiotic diet. These results suggest combined LMWSA and L. plantarum can be considered as a promising immunostimulant and growth enhancer in Nile tilapia diet. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Organic solvent and temperature-enhanced ion chromatography-high resolution mass spectrometry for the determination of low molecular weight organic and inorganic anions

    Energy Technology Data Exchange (ETDEWEB)

    Gilchrist, Elizabeth S. [Analytical & Environmental Science Division, Department of Forensic & Analytical Science, King’s College London, 150 Stamford Street, London, SE1 9NH (United Kingdom); Nesterenko, Pavel N. [Australian Centre for Research on Separation Science, School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart 7001 (Australia); Smith, Norman W. [Analytical & Environmental Science Division, Department of Forensic & Analytical Science, King’s College London, 150 Stamford Street, London, SE1 9NH (United Kingdom); Barron, Leon P., E-mail: leon.barron@kcl.ac.uk [Analytical & Environmental Science Division, Department of Forensic & Analytical Science, King’s College London, 150 Stamford Street, London, SE1 9NH (United Kingdom)

    2015-03-20

    Highlights: • IC selectivity at high contents of organic solvent in eluent and elevated temperature is studied. • Solvent-enhanced IC coupled to high resolution MS is beneficial for sensitive detection of ions. • The first application of IC-HRMS to the detection of low explosives in fingermarks is shown. - Abstract: There has recently been increased interest in coupling ion chromatography (IC) to high resolution mass spectrometry (HRMS) to enable highly sensitive and selective analysis. Herein, the first comprehensive study focusing on the direct coupling of suppressed IC to HRMS without the need for post-suppressor organic solvent modification is presented. Chromatographic selectivity and added HRMS sensitivity offered by organic solvent-modified IC eluents on a modern hyper-crosslinked polymeric anion-exchange resin (IonPac AS18) are shown using isocratic eluents containing 5–50 mM hydroxide with 0–80% methanol or acetonitrile for a range of low molecular weight anions (<165 Da). Comprehensive experiments on IC thermodynamics over a temperature range between 20–45 °C with the eluent containing up to 60% of acetonitrile or methanol revealed markedly different retention behaviour and selectivity for the selected analytes on the same polymer based ion-exchange resin. Optimised sensitivity with HRMS was achieved with as low as 30–40% organic eluent content. Analytical performance characteristics are presented and compared with other IC-MS based works. This study also presents the first application of IC-HRMS to forensic detection of trace low-order anionic explosive residues in latent human fingermarks.

  7. Aging impacts of low molecular weight organic acids (LMWOAs) on furfural production residue-derived biochars: Porosity, functional properties, and inorganic minerals.

    Science.gov (United States)

    Liu, Guocheng; Chen, Lei; Jiang, Zhixiang; Zheng, Hao; Dai, Yanhui; Luo, Xianxiang; Wang, Zhenyu

    2017-12-31

    The aging of biochar by low molecular weight organic acids (LMWOAs), which are typical root-derived exudates, is not well understood. Three LMWOAs (ethanoic, malic, and citric acids) were employed to investigate their aging impacts on the biochars from furfural production residues at 300-600°C (BC300-600). The LMWOAs created abundant macropores in BC300, whereas they significantly increased the mesoporosity and surface area of BC600 by 13.5-27.0% and 44.6-61.5%, respectively. After LMWOA aging, the content of C and H of the biochars increased from 51.3-60.2% and 1.87-3.45% to 56.8-69.9% and 2.06-4.45%, respectively, but the O content decreased from 13.8-24.8% to 7.82-19.4% (except BC300). For carbon fraction in the biochars, the LMWOAs barely altered the bulk and surface functional properties during short-term aging. The LMWOAs facilitated the dissolution of minerals (e.g., K 2 Mg(PO 3 ) 4 , AlPO 4 , and Pb 2 P 2 O 7 ) and correspondingly promoted the release of not only plant nutrients (K + , Ca 2+ , Mg 2+ , Fe 3+ , PO 4 3- , and SO 4 2- ) but also toxic metals (Al 3+ and Pb 2+ ). This research provided systematic insights on the responses of biochar properties to LMWOAs and presented direct evidence for acid activation of inorganic minerals in the biochars by LMWOAs, which could enhance the understanding of environmental behaviors of biochars in rhizosphere soils. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Development of a new marker system for identifying the complex members of the low-molecular-weight glutenin subunit gene family in bread wheat (Triticum aestivum L.).

    Science.gov (United States)

    Zhang, Xiaofei; Liu, Dongcheng; Yang, Wenlong; Liu, Kunfan; Sun, Jiazhu; Guo, Xiaoli; Li, Yiwen; Wang, Daowen; Ling, Hongqing; Zhang, Aimin

    2011-05-01

    Low-molecular-weight glutenin subunits (LMW-GSs) play an important role in determining the bread-making quality of bread wheat. However, LMW-GSs display high polymorphic protein complexes encoded by multiple genes, and elucidating the complex LMW-GS gene family in bread wheat remains challenging. In the present study, using conventional polymerase chain reaction (PCR) with conserved primers and high-resolution capillary electrophoresis, we developed a new molecular marker system for identifying LMW-GS gene family members. Based on sequence alignment of 13 LMW-GS genes previously identified in the Chinese bread wheat variety Xiaoyan 54 and other genes available in GenBank, PCR primers were developed and assigned to conserved sequences spanning the length polymorphism regions of LMW-GS genes. After PCR amplification, 17 DNA fragments in Xiaoyan 54 were detected using capillary electrophoresis. In total, 13 fragments were identical to previously identified LMW-GS genes, and the other 4 were derived from unique LMW-GS genes by sequencing. This marker system was also used to identify LMW-GS genes in Chinese Spring and its group 1 nulli-tetrasomic lines. Among the 17 detected DNA fragments, 4 were located on chromosome 1A, 5 on 1B, and 8 on 1D. The results suggest that this marker system is useful for large-scale identification of LMW-GS genes in bread wheat varieties, and for the selection of desirable LMW-GS genes to improve the bread-making quality in wheat molecular breeding programmes.

  9. PCR-based isolation and identification of full-length low-molecular-weight glutenin subunit genes in bread wheat (Triticum aestivum L.).

    Science.gov (United States)

    Zhang, Xiaofei; Liu, Dongcheng; Jiang, Wei; Guo, Xiaoli; Yang, Wenlong; Sun, Jiazhu; Ling, Hongqing; Zhang, Aimin

    2011-12-01

    Low-molecular-weight glutenin subunits (LMW-GSs) are encoded by a multi-gene family and are essential for determining the quality of wheat flour products, such as bread and noodles. However, the exact role or contribution of individual LMW-GS genes to wheat quality remains unclear. This is, at least in part, due to the difficulty in characterizing complete sequences of all LMW-GS gene family members in bread wheat. To identify full-length LMW-GS genes, a polymerase chain reaction (PCR)-based method was established, consisting of newly designed conserved primers and the previously developed LMW-GS gene molecular marker system. Using the PCR-based method, 17 LMW-GS genes were identified and characterized in Xiaoyan 54, of which 12 contained full-length sequences. Sequence alignments showed that 13 LMW-GS genes were identical to those found in Xiaoyan 54 using the genomic DNA library screening, and the other four full-length LMW-GS genes were first isolated from Xiaoyan 54. In Chinese Spring, 16 unique LMW-GS genes were isolated, and 13 of them contained full-length coding sequences. Additionally, 16 and 17 LMW-GS genes in Dongnong 101 and Lvhan 328 (chosen from the micro-core collections of Chinese germplasm), respectively, were also identified. Sequence alignments revealed that at least 15 LMW-GS genes were common in the four wheat varieties, and allelic variants of each gene shared high sequence identities (>95%) but exhibited length polymorphism in repetitive regions. This study provides a PCR-based method for efficiently identifying LMW-GS genes in bread wheat, which will improve the characterization of complex members of the LMW-GS gene family and facilitate the understanding of their contributions to wheat quality.

  10. Molecular Weight Dependent Glucose Lowering Effect of Low Molecular Weight Chitosan Oligosaccharide (GO2KA1 on Postprandial Blood Glucose Level in SD Rats Model

    Directory of Open Access Journals (Sweden)

    Emmanouil Apostolidis

    2013-07-01

    Full Text Available This research investigated the effect of enzymatically digested low molecular weight (MW chitosan oligosaccharide on type 2 diabetes prevention. Three different chitosan oligosaccharide samples with varying MW were evaluated in vitro for inhibition of rat small intestinal α-glucosidase and porcine pancreatic α-amylase (GO2KA1; 10,000 Da. The in vitro results showed that all tested samples had similar rat α-glucosidase inhibitory and porcine α-amylase inhibitory activity. Based on these observations, we decided to further investigate the effect of all three samples at a dose of 0.1 g/kg, on reducing postprandial blood glucose levels in Sprague-Dawley (SD rat model after sucrose loading test. In the animal trial, all tested samples had postprandial blood glucose reduction effect, when compared to control, however GO2KA1 supplementation had the strongest effect. The glucose peak (Cmax for GO2KA1 and control was 152 mg/dL and 193 mg/dL, respectively. The area under the blood glucose-time curve (AUC for GO2KA1 and control was 262 h mg/dL and 305 h mg/dL, respectively. Furthermore, the time of peak plasma concentration of blood glucose (Tmax for GO2KA1 was significantly delayed (0.9 h compared to control (0.5 h. These results suggest that GO2KA1 could have a beneficial effect for blood glucose management relevant to diabetes prevention in normal and pre-diabetic individuals. The suggested mechanism of action is via inhibition of the carbohydrate hydrolysis enzyme α-glucosidase and since GO2KA1 (MW < 1000 Da had higher in vivo effect, we hypothesize that it is more readily absorbed and might exert further biological effect once it is absorbed in the blood stream, relevant to blood glucose management.

  11. Low-molecular-weight glutenin subunits from the 1U genome of Aegilops umbellulata confer superior dough rheological properties and improve breadmaking quality of bread wheat.

    Science.gov (United States)

    Wang, Jian; Wang, Chang; Zhen, Shoumin; Li, Xiaohui; Yan, Yueming

    2018-04-01

    Wheat-related genomes may carry new glutenin genes with the potential for quality improvement of breadmaking. In this study, we estimated the gluten quality properties of the wheat line CNU609 derived from crossing between Chinese Spring (CS, Triticum aestivum L., 2n = 6x = 42, AABBDD) and the wheat Aegilops umbellulata (2n = 2x = 14, UU) 1U(1B) substitution line, and investigated the function of 1U-encoded low-molecular-weight glutenin subunits (LMW-GS). The main quality parameters of CNU609 were significantly improved due to introgression of the 1U genome, including dough development time, stability time, farinograph quality number, gluten index, loaf size and inner structure. Glutenin analysis showed that CNU609 and CS had the same high-molecular-weight glutenin subunit (HMW-GS) composition, but CNU609 carried eight specific 1U genome-encoded LMW-GS. The introgression of the 1U-encoded LMW-GS led to more and larger protein body formation in the CNU609 endosperm. Two new LMW-m type genes from the 1U genome, designated Glu-U3a and Glu-U3b, were cloned and characterized. Secondary structure prediction implied that both Glu-U3a and Glu-U3b encode subunits with high α-helix and β-strand content that could benefit the formation of superior gluten structure. Our results indicate that the 1U genome has superior LMW-GS that can be used as new gene resources for wheat gluten quality improvement. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. Biomedical Application of Low Molecular Weight Heparin/Protamine Nano/Micro Particles as Cell- and Growth Factor-Carriers and Coating Matrix

    Directory of Open Access Journals (Sweden)

    Masayuki Ishihara

    2015-05-01

    Full Text Available Low molecular weight heparin (LMWH/protamine (P nano/micro particles (N/MPs (LMWH/P N/MPs were applied as carriers for heparin-binding growth factors (GFs and for adhesive cells including adipose-derived stromal cells (ADSCs and bone marrow-derived mesenchymal stem cells (BMSCs. A mixture of LMWH and P yields a dispersion of N/MPs (100 nm–3 μm in diameter. LMWH/P N/MPs can be immobilized onto cell surfaces or extracellular matrix, control the release, activate GFs and protect various GFs. Furthermore, LMWH/P N/MPs can also bind to adhesive cell surfaces, inducing cells and LMWH/P N/MPs-aggregate formation. Those aggregates substantially promoted cellular viability, and induced vascularization and fibrous tissue formation in vivo. The LMWH/P N/MPs, in combination with ADSCs or BMSCs, are effective cell-carriers and are potential promising novel therapeutic agents for inducing vascularization and fibrous tissue formation in ischemic disease by transplantation of the ADSCs and LMWH/P N/MPs-aggregates. LMWH/P N/MPs can also bind to tissue culture plates and adsorb exogenous GFs or GFs from those cells. The LMWH/P N/MPs-coated matrix in the presence of GFs may provide novel biomaterials that can control cellular activity such as growth and differentiation. Furthermore, three-dimensional (3D cultures of cells including ADSCs and BMSCs using plasma-medium gel with LMWH/P N/MPs exhibited efficient cell proliferation. Thus, LMWH/P N/MPs are an adequate carrier both for GFs and for stromal cells such as ADSCs and BMSCs, and are a functional coating matrix for their cultures.

  13. Use of Residual Biomass from the Textile Industry as Carbon Source for Production of a Low-Molecular-Weight Xylanase from Aspergillus oryzae

    Directory of Open Access Journals (Sweden)

    Gilvan Caetano Duarte

    2012-10-01

    Full Text Available Pretreated dirty cotton residue (PDCR from the textile industry was used as an alternative carbon source for the submerged cultivation of Aspergillus oryzae and the production of xylanases. The filtered culture supernatant was fractionated by ultrafiltration followed by three chromatographic steps, which resulted in the isolation of a homogeneous low-molecular-weight xylanase (Xyl-O1 with a mass of 21.5 kDa as determined by sodium dodecyl sulfate-polyacrilamide gel electrophoresis (SDS-PAGE co-polymerized with 0.1% oat spelt xylan. Enzyme catalysis was the most efficient at 50 °C and pH 6.0. The Km values (mg·mL−1 for the soluble fraction of oat spelt and birchwood xylans were 10.05 and 3.34, respectively. Xyl-O1 was more stable in the presence of 5,5-dithio-bis-(2-nitrobenzoic acid (DTNB, 1,4-dithiothreitol (DTT, l-cysteine or β-mercaptoethanol, which increased the rate of catalysis by 40%, 14%, 40% or 37%, respectively. The enzyme stability was improved at pH 7.0 in the presence of 20 mM l-cysteine, with the retention of nearly 100% of the activity after 6 h at 50 °C. Xyl-O1 catalyzed the cleavage of internal β-1,4 linkages of the soluble substrates containing d-xylose residues, with a maximum efficiency of 33% for the hydrolysis of birchwood xylan after 12 h of incubation. Identification of the hydrolysis products by high-performance anion exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD indicated the predominance of the hydrolysis products X2-X6 during the first 12 h of incubation and the accumulation of higher xylooligomers after the elution of the last xylooligomer standard, xylohexaose.

  14. Air-dust-borne associations of phototrophic and hydrocarbon-utilizing microorganisms: promising consortia in volatile hydrocarbon bioremediation.

    Science.gov (United States)

    Al-Bader, Dhia; Eliyas, Mohamed; Rayan, Rihab; Radwan, Samir

    2012-11-01

    Aquatic and terrestrial associations of phototrophic and heterotrophic microorganisms active in hydrocarbon bioremediation have been described earlier. The question arises: do similar consortia also occur in the atmosphere? Dust samples at the height of 15 m were collected from Kuwait City air, and analyzed microbiologically for phototrophic and heterotrophic hydrocarbon-utilizing microorganisms, which were subsequently characterized according to their 16S rRNA gene sequences. The hydrocarbon utilization potential of the heterotrophs alone, and in association with the phototrophic partners, was measured quantitatively. The chlorophyte Gloeotila sp. and the two cyanobacteria Nostoc commune and Leptolyngbya thermalis were found associated with dust, and (for comparison) the cynobacteria Leptolyngbya sp. and Acaryochloris sp. were isolated from coastal water. All phototrophic cultures harbored oil vapor-utilizing bacteria in the magnitude of 10(5) g(-1). Each phototrophic culture had its unique oil-utilizing bacteria; however, the bacterial composition in Leptolyngbya cultures from air and water was similar. The hydrocarbon-utilizing bacteria were affiliated with Acinetobacter sp., Aeromonas caviae, Alcanivorax jadensis, Bacillus asahii, Bacillus pumilus, Marinobacter aquaeolei, Paenibacillus sp., and Stenotrophomonas maltophilia. The nonaxenic cultures, when used as inocula in batch cultures, attenuated crude oil in light and dark, and in the presence of antibiotics and absence of nitrogenous compounds. Aqueous and diethyl ether extracts from the phototrophic cultures enhanced the growth of the pertinent oil-utilizing bacteria in batch cultures, with oil vapor as a sole carbon source. It was concluded that the airborne microbial associations may be effective in bioremediating atmospheric hydrocarbon pollutants in situ. Like the aquatic and terrestrial habitats, the atmosphere contains dust-borne associations of phototrophic and heterotrophic hydrocarbon

  15. Synthesis and Characterization of Quaternary Metal Chalcogenide Aerogels for Gas Separation and Volatile Hydrocarbon Adsorption

    KAUST Repository

    Edhaim, Fatimah A.

    2017-11-01

    In this dissertation, the metathesis route of metal chalcogenide aerogel synthesis was expanded by conducting systematic studies between polysulfide building blocks and the 1st-row transition metal linkers. Resulting materials were screened as sorbents for selective gas separation and volatile organic compounds adsorption. They showed preferential adsorption of polarizable gases (CO2) and organic compounds (toluene). Ion exchange and heavy metal remediation properties have also been demonstrated. The effect of the presence of different counter-ion within chalcogel frameworks on the adsorption capacity of the chalcogels was studied on AFe3Zn3S17 (A= K, Na, and Rb) chalcogels. The highest adsorption capacity toward hydrocarbons and gases was observed on Rb based chalcogels. Adopting a new building block [BiTe3]3- with the 1st-row transition metal ions results in the formation of three high BET surface area chalcogels, KCrBiTe3, KZnBiTe3, and KFeBiTe3. The resulting chalcogels showed preferential adsorption of toluene vapor, and remarkable selectivity of CO2, indicating the potential future use of chalcogels in adsorption-based gas or hydrocarbon separation processes. The synthesis and characterization of the rare earth chalcogels NaYSnS4, NaGdSnS4, and NaTbSnS4 are also reported. Rare earth metal ions react with the thiostannate clusters in formamide solution forming extended polymeric networks by gelation. Obtained chalcogels have high BET surface areas, and showed notable adsorption capacity toward CO2 and toluene vapor. These chalcogels have also been engaged in the absorption of different organic molecules. The results reveal the ability of the chalcogels to distinguish among organic molecules on their electronic structures; hence, they could be used as sensors. Furthermore, the synthesis of metal chalcogenide aerogels Co0.5Sb0.33MoS4 and Co0.5Y0.33MoS4 by the sol-gel method is reported. In this system, the building blocks [MoS4]2- chelated with Co2+ and (Sb3

  16. Site-specific probabilistic ecological risk assessment of a volatile chlorinated hydrocarbon-contaminated tidal estuary.

    Science.gov (United States)

    Hunt, James; Birch, Gavin; Warne, Michael St J

    2010-05-01

    Groundwater contaminated with volatile chlorinated hydrocarbons (VCHs) was identified as discharging to Penrhyn Estuary, an intertidal embayment of Botany Bay, New South Wales, Australia. A screening-level hazard assessment of surface water in Penrhyn Estuary identified an unacceptable hazard to marine organisms posed by VCHs. Given the limitations of hazard assessments, the present study conducted a higher-tier, quantitative probabilistic risk assessment using the joint probability curve (JPC) method that accounted for variability in exposure and toxicity profiles to quantify risk (delta). Risk was assessed for 24 scenarios, including four areas of the estuary based on three exposure scenarios (low tide, high tide, and both low and high tides) and two toxicity scenarios (chronic no-observed-effect concentrations [NOEC] and 50% effect concentrations [EC50]). Risk (delta) was greater at low tide than at high tide and varied throughout the tidal cycle. Spatial distributions of risk in the estuary were similar using both NOEC and EC50 data. The exposure scenario including data combined from both tides was considered the most accurate representation of the ecological risk in the estuary. When assessing risk using data across both tides, the greatest risk was identified in the Springvale tributary (delta=25%)-closest to the source area-followed by the inner estuary (delta=4%) and the Floodvale tributary (delta=2%), with the lowest risk in the outer estuary (delta=0.1%), farthest from the source area. Going from the screening level ecological risk assessment (ERA) to the probabilistic ERA changed the risk from unacceptable to acceptable in 50% of exposure scenarios in two of the four areas within the estuary. The probabilistic ERA provided a more realistic assessment of risk than the screening-level hazard assessment. Copyright (c) 2010 SETAC.

  17. Extended thromboprophylaxis with low-molecular-weight heparins after hospital discharge in high-risk surgical and medical patients: a review.

    Science.gov (United States)

    Huo, Michael H; Muntz, James

    2009-06-01

    Prophylaxis against venous thromboembolism (VTE) is routinely administered during the hospital stay in at-risk surgical and medical patients. However, in high-risk groups, the risk of deep-vein thrombosis or pulmonary embolism may persist for several weeks after discharge. The standard duration of thromboprophylaxis (6-14 days) may not provide adequate protection against such events. This article reviews published data on the efficacy and safety profile of extended-duration thromboprophylaxis in patients at high risk for VTE, the potential cost-effectiveness of such treatment, and practical aspects of ensuring an effective transition from the inpatient to the outpatient setting. MEDLINE and the Cochrane Database of Systematic Reviews were searched through January 2009 for relevant English-language reports of clinical trials, abstracts, and case reports. The search terms included, but were not limited to, venous thromboembolism, pulmonary embolism, anticoagulation, thromboprophylaxis, prolonged duration, and extended duration. The reference lists of the identified articles were reviewed for additional relevant publications. Congress Web sites were also consulted. The principal criteria for inclusion of a study were that it have a prospective, randomized design and include a control group. Case series and retrospective analyses were excluded. Studies have found that extended-duration thromboprophylaxis (28-45 days) with low-molecular-weight heparins (LMWHs) can reduce the risk of VTE in high-risk patients. In separate meta-analyses, extended-duration thromboprophylaxis with LMWH was associated with significant reductions in the likelihood of symptomatic VTE compared with standard-duration thromboprophylaxis in patients undergoing major orthopedic surgery (odds ratio [OR] = 0.38; 95% CI, 0.24-0.61) or major abdominal or pelvic surgery (Peto OR = 0.22; 95% CI, 0.06-0.80). There was large heterogeneity in the reported rates of major and minor bleeding. The occurrence of

  18. Methylmercury production in soil in the water-level-fluctuating zone of the Three Gorges Reservoir, China: The key role of low-molecular-weight organic acids.

    Science.gov (United States)

    Yin, Deliang; Wang, Yongmin; Jiang, Tao; Qin, Caiqing; Xiang, Yuping; Chen, Qiuyu; Xue, Jinping; Wang, Dingyong

    2018-04-01

    As important parts of dissolved organic matter, low-molecular-weight organic acids (LMWOAs) typically play important roles in desorbing Hg(II) from the soil solid-phase, which may directly or indirectly impact methylmercury (MeHg) production. However, the mechanism of these processes remains unclear. To better understand the effects of LMWOAs on Hg methylation in the soil, a field study was conducted to investigate the distribution of LMWOAs and their relationship with soil MeHg in a seasonally inundated area in the Three Gorges Reservoir (TGR), China. Meanwhile, laboratory simulation experiments were performed to determine the potential mechanism of LMWOAs in Hg methylation. The field investigation detected considerable amounts of LMWOAs in soil, among which tartaric acid and oxalic acid were dominant components. Among which, tartaric acid and oxalic acid were dominant components. Also, a seasonally and spatially heterogeneous distribution of LMWOAs in soil was observed. Notably, a significant positive relationship was found between MeHg concentrations and LMWOA pools in soil (r = 0.969, p < .01), implying that LMWOAs could promote soil MeHg production. The simulation experiments confirmed that the MeHg levels in soil were largely elevated with the addition of LMWOAs, which occurred mainly in oxygen-deficient environment and was mediated by biotic factors. The soluble Hg-LMWOA complexes, which were formed by the enhanced desorption of Hg(II) from solid-phase, were mostly responsible for the elevated MeHg production in soil. Moreover, those LMWOAs with more carboxylic groups were believed to enhance the net production of MeHg. The generated MeHg in sediment could diffuse into the overlying water, which thus poses a potential threat to the aquatic food web. Therefore, the enhanced Hg methylation caused by LMWOAs should be given more attention, especially in a seasonally inundated ecosystem, where the MeHg exposure is usually related to fishery activities

  19. [Effect of Low Molecular Weight Heparin Calcium Combined Compound Danshen Injection on Perinatal Outcomes of Nephrotic Syndrome Patients with Early Onset Severe Pre-eclampsia].

    Science.gov (United States)

    Tong, Chong-xin; Xing, Xiao-fen; Qiao, Shu-hua; Liu, Lin; Shan, Ling

    2015-08-01

    To observe the effect of low molecular weight heparin calcium (LMWHC) combined Compound Danshen Injection (DI) on nephrotic syndrome patients with early onset severe preeclampsia. Totally 80 nephrotic syndrome patients with early onset severe pre-eclampsia were randomly assigned to four groups voluntarily, i.e., Group A (22 cases, treated by magnesium sulfate), B (19 cases, treated by magnesium sulfate plus LMWHC), C (21 cases, magnesium sulfate plus DI), D (18 cases, magnesium sulfate plus LMWHC and DI). Umbilical arterial S/D ratios, amniotic fluid index (AFI), prolonged gestational age, placenta weight, neonatal weight, and Apgar score were compared among the four groups. Compared with before treatment in the same group, umbilical arterial S/D ratios decreased in the four groups (P <0. 05). AFI decreased in Group A, while it increased in Group B, C, and D (P<0. 05). Compared with Group A at the same time point, umbilical arterial S/D ratios decreased, and AFI increased in Group B, C, and D (P <0. 01 , P <0. 05). Prolonged gestational age and neonatal weight were increased in Group B, C, and D (P <0. 01, P <0. 05). Placenta weight were increased in Group B and D (P <0. 05). Apgar scores at 1 and 5 min were improved in Group D (P <0. 05). Compared with Group B and C at the same time point, umbilical arterial S/D ratios decreased, and AFI increased in Group D (P<0. 05). Compared with Group B, prolonged gestational age and placenta weight were decreased in Group C, but prolonged gestational age and placenta weight were increased in Group D (P <0.05). Compared with Group C, prolonged gestational age, placenta weight, and neonatal weight were increased in Group D (P <0. 05). Treatment of nephrotic syndrome patients with early onset severe pre-eclampsia by LMWHC combined DI could prolong gestational ages, obviously improve prenatal outcomes, with better effect obtained than using any of them alone.

  20. Angiogenic Factor Profiles in Pregnant Women With a History of Early-Onset Severe Preeclampsia Receiving Low-Molecular-Weight Heparin Prophylaxis.

    Science.gov (United States)

    Lecarpentier, Edouard; Gris, Jean Christophe; Cochery-Nouvellon, Eva; Mercier, Erick; Touboul, Cyril; Thadhani, Ravi; Karumanchi, S Ananth; Haddad, Bassam

    2018-01-01

    To evaluate whether daily low-molecular-weight (LMW) heparin prophylaxis during pregnancy alters profile of circulating angiogenic factors that have been linked with the pathogenesis of preeclampsia and fetal growth restriction. This is a planned ancillary study of the Heparin-Preeclampsia trial, a randomized trial in pregnant women with a history of severe early-onset preeclampsia (less than 34 weeks of gestation). In the parent study, all women were treated with aspirin and then randomized to receive LMW heparin or aspirin alone. In this study, we measured serum levels of circulating angiogenic factors (soluble fms-like tyrosine kinase-1, placental growth factor, and soluble endoglin by immunoassay) at the following gestational windows: 10-13 6/7 weeks, 14-17 6/7 weeks, 18-21 6/7 weeks, 22-25 6/7 weeks, 26-29 6/7 weeks, 30-33 6/7 weeks, and 34-37 6/7 weeks. Samples were available from 185 patients: LMW heparin+aspirin (n=92) and aspirin alone (n=93). The two groups had comparable baseline characteristics and had similar adverse composite outcomes (35/92 [38.0%] compared with 36/93 [38.7%]; P=.92). There were no significant differences in serum levels of soluble fms-like tyrosine kinase-1, placental growth factor, and soluble endoglin in the participants who received LMW heparin and aspirin compared with those who received aspirin alone regardless of gestational age period. Finally, women who developed an adverse composite outcome at less than 34 weeks of gestation demonstrated significant alterations in serum angiogenic profile as early as 10-13 6/7 weeks that was most dramatic 6-8 weeks preceding delivery. Prophylactic LMW heparin therapy when beginning from before 14 weeks of gestation with aspirin during pregnancy is not associated with an improved angiogenic profile. This may provide a molecular explanation for the lack of clinical benefit noted in recent trials. ClinicalTrials.gov, NCT00986765.

  1. The influence of a residual group in low-molecular-weight allergoids of Artemisia vulgaris pollen on their allergenicity, IgE- and IgG-binding properties.

    Science.gov (United States)

    Cirković, T; Gavrović-Jankulović, M; Prisić, S; Jankov, R M; Burazer, L; Vucković, O; Sporcić, Z; Paranos, S

    2002-11-01

    Reaction of epsilon-amino groups of lysine with potassium cyanate, maleic, or succinic anhydride leads to allergoids of low molecular weight. No study has been performed to compare their properties and investigate the influence of a residual group on allergenicity and human IgE- and IgG-binding of these derivatives. Allergoids of a pollen extract of Artemisia vulgaris were obtained by means of potassium cyanate, and succinic and maleic anhydride. Biochemical properties were investigated by determination of amino groups, enzyme activity, isoelectric focusing IEF and SDS-PAGE. IgE- and IgG-binding was determined using immunoblots and ELISA inhibition. Allergenicity was investigated by skin prick tests (SPT) on a group of 52 patients, of which 6 were control subjects, 30 were patients with no previous immunotherapy (IT), and 16 were patients undergoing immunotherapy. The same degree of amino-group modification (more than 85%), residual enzyme activity (less then 15%), IEF, and SDS-PAGE pattern were noted. In the immunoblots of IgE-binding, there was more pronounced reduction in the succinyl and maleyl derivatives than in the carbamyl one. IgG-binding was less affected by carbamylation than by acid anhydride modification. The SPT showed that the succinylated derivative had the most reduced allergenicity (98% showed a reduced wheal diameter when tested with the succinyl derivative, 87% with the maleyl allergoid, and 83% with the carbamyl allergoid). The most significant difference among allergoids could be seen in the group of patients with high skin reactivity (83% of patients showed no reaction to the succinyl derivative when compared to the value of 28% for the carbamyl derivative or 22% for the maleyl derivative). According to our results, all three modification procedures yielded allergoids with a similar extent of modification. No single biochemical parameter investigated in the study could predict the degree of reduced allergenicity in vivo. The most reduced

  2. Low Molecular Weight Glucosamine/L-lactide Copolymers as Potential Carriers for the Development of a Sustained Rifampicin Release System: Mycobacterium Smegmatis as a Tuberculosis Model

    Science.gov (United States)

    Ragusa, Jorge Alejandro

    Tuberculosis, a highly contagious disease, ranks as the second leading cause of death from an infectious disease, and remains a major global health problem. In 2013, 9 million new cases were diagnosed and 1.5 million people died worldwide from tuberculosis. This dissertation aims at developing a new, ultrafine particle-based efficient antibiotic delivery system for the treatment of tuberculosis. The carrier material to make the rifampicin (RIF)-loaded particles is a low molecular weight star-shaped polymer produced from glucosamine (molecular core building unit) and L-lactide (GluN-LLA). Stable particles with a very high 50% drug loading capacity were made via electrohydrodynamic atomization. Prolonged release (>14 days) of RIF from these particles is demonstrated. Drug release data fits the Korsmeyer-Peppas equation, which suggests the occurrence of a modified diffusion-controlled RIF release mechanism, and is also supported by differential scanning calorimetry and drug leaching tests. Cytotoxicity tests on Mycobacterium smegmatis showed that antibiotic-free GluN-LLA and polylactides (PLA) (reference material) particles did not show any significant anti-bacterial activity. The minimum inhibitory concentration and minimum bactericidal concentration values obtained for RIF-loaded particles showed 2- to 4-fold improvements in the anti-bacterial activity relative to the free drug. Cytotoxicity tests on macrophages indicated an increment in cell death as particle dose increased, but was not significantly affected by material type or particle size. Confocal microscopy was used to track internalization and localization of particles in the macrophages. GluN-LLA particles led to higher uptakes than the PLA particles. In addition, after phagocytosis, the GluN-LLA particles stayed in the cytoplasm and the particles showed a favorable long term drug release effect in killing intracellular bacteria compared to free RIF. The studies presented and discussed in this dissertation

  3. Monitoring low molecular weight heparins at therapeutic levels: dose-responses of, and correlations and differences between aPTT, anti-factor Xa and thrombin generation assays.

    Directory of Open Access Journals (Sweden)

    Owain Thomas

    Full Text Available Low molecular weight heparins (LMWH's are used to prevent and treat thrombosis. Tests for monitoring LMWH's include anti-factor Xa (anti-FXa, activated partial thromboplastin time (aPTT and thrombin generation. Anti-FXa is the current gold standard despite LMWH's varying affinities for FXa and thrombin.To examine the effects of two different LMWH's on the results of 4 different aPTT-tests, anti-FXa activity and thrombin generation and to assess the tests' concordance.Enoxaparin and tinzaparin were added ex-vivo in concentrations of 0.0, 0.5, 1.0 and 1.5 anti-FXa international units (IU/mL, to blood from 10 volunteers. aPTT was measured using two whole blood methods (Free oscillation rheometry (FOR and Hemochron Jr (HCJ and an optical plasma method using two different reagents (ActinFSL and PTT-Automat. Anti-FXa activity was quantified using a chromogenic assay. Thrombin generation (Endogenous Thrombin Potential, ETP was measured on a Ceveron Alpha instrument using the TGA RB and more tissue-factor rich TGA RC reagents.Methods' mean aPTT at 1.0 IU/mL LMWH varied between 54s (SD 11 and 69s (SD 14 for enoxaparin and between 101s (SD 21 and 140s (SD 28 for tinzaparin. ActinFSL gave significantly shorter aPTT results. aPTT and anti-FXa generally correlated well. ETP as measured with the TGA RC reagent but not the TGA RB reagent showed an inverse exponential relationship to the concentration of LMWH. The HCJ-aPTT results had the weakest correlation to anti-FXa and thrombin generation (Rs0.62-0.87, whereas the other aPTT methods had similar correlation coefficients (Rs0.80-0.92.aPTT displays a linear dose-response to LMWH. There is variation between aPTT assays. Tinzaparin increases aPTT and decreases thrombin generation more than enoxaparin at any given level of anti-FXa activity, casting doubt on anti-FXa's present gold standard status. Thrombin generation with tissue factor-rich activator is a promising method for monitoring LMWH's.

  4. Low-Molecular-Weight Iron Chelates May Be an Alternative to Gadolinium-based Contrast Agents for T1-weighted Contrast-enhanced MR Imaging.

    Science.gov (United States)

    Boehm-Sturm, Philipp; Haeckel, Akvile; Hauptmann, Ralf; Mueller, Susanne; Kuhl, Christiane K; Schellenberger, Eyk A

    2018-02-01

    Purpose To synthesize two low-molecular-weight iron chelates and compare their T1 contrast effects with those of a commercial gadolinium-based contrast agent for their applicability in dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging. Materials and Methods The animal experiments were approved by the local ethics committee. Two previously described iron (Fe) chelates of pentetic acid (Fe-DTPA) and of trans-cyclohexane diamine tetraacetic acid (Fe-tCDTA) were synthesized with stability constants several orders of magnitude higher than those of gadolinium-based contrast agents. The T1 contrast effects of the two chelates were compared with those of gadopentetate dimeglumine in blood serum phantoms at 1.5 T, 3 T, and 7 T. For in vivo studies, a human breast cancer cell line (MDA-231) was implanted in five mice per group. The dynamic contrast effects of the chelates were compared by performing DCE MR imaging with intravenous application of Fe-DTPA or Fe-tCDTA on day 1 and DCE MR imaging in the same tumors with gadopentetate dimeglumine on day 2. Quantitative DCE maps were generated with software and were compared by means of a one-tailed Pearson correlation test. Results Relaxivities in serum (0.94 T at room temperature) of Fe-tCDTA (r1 = 2.2 mmol -1 · sec -1 , r2 = 2.5 mmol -1 · sec -1 ) and Fe-DTPA (r1 = 0.9 mmol -1 · sec -1 , r2 = 0.9 mmol -1 · sec -1 ) were approximately twofold and fivefold lower, respectively, compared with those of gadopentetate dimeglumine (r1 = 4.1 mmol -1 · sec -1 , r2 = 4.8 mmol -1 · sec -1 ). Used at moderately higher concentrations, however, iron chelates generated similar contrast effects at T1-weighted MR imaging in vitro in serum, in vivo in blood, and for DCE MR imaging of breast cancer xenografts. The volume transfer constant values for Fe-DTPA and Fe-tCDTA in the same tumors correlated well with those observed for gadopentetate dimeglumine (Fe-tCDTA Pearson R, 0.99; P = .0003; Fe-DTPA Pearson R, 0.97; P

  5. Effect of volatile hydrocarbon fractions on mobility and earthworm uptake of polycyclic aromatic hydrocarbons from soils and soil/lampblack mixtures.

    Science.gov (United States)

    Bogan, Bill W; Beardsley, Kate E; Sullivan, Wendy R; Hayes, Thomas D; Soni, Bhupendra K

    2005-01-01

    Studies were conducted to examine the mobility and bioavailability to earthworms (Eisenia fetida) of priority pollutant polycyclic aromatic hydrocarbons (PAH) in a suite of 11 soils and soil/lampblack mixtures obtained from former manufactured-gas plant sites. Contaminant mobility was assessed using XAD4 resins encapsulated in dialysis tubing, which were exposed to slurried soils for 15 d. These experiments showed that mobility of PAH in the different soils strongly correlated to the levels of volatile hydrocarbons (namely, gasoline- and diesel-range organics [GRO and DRO]) that existed in the soils as co-contaminants. Actual PAH bioavailability (as measured by earthworm PAH concentrations) also appeared to depend on GRO + DRO levels, although this was most evident at high levels of these contaminants. These findings are discussed in view of the effects of dieselrange organics on oil viscosity, assuming that the hydrocarbon contaminants in these soils exist in the form of distinct adsorbed oil phases. This study, therefore, extends correlations between carrier-oil viscosity and dissolved solute bioavailability, previously observed in a number of other in vitro and whole-organism tests (and in bacterial mutagenicity studies in soil), to multicellular organisms inhabiting contaminated-soil systems.

  6. 低分子肝素治疗不稳定型心绞痛疗效观察%Low Molecular Weight Heparin in the Treatment of Unstable Angina Efficacy Observation

    Institute of Scientific and Technical Information of China (English)

    仁青措

    2013-01-01

    Objective: unstable angina pectoris (UAP) is a syndrome of coronary heart disease after transmural myocardial infarction, clinical treatment and prognosis is poor. Ef ect of low molecular weight heparin in treatment of UAP significantly, which has important clinical significance for improving the prognosis of. Methods: on the basis of conventional therapy plus low molecular weight heparin subcutaneous injection and oral administration of low-dose aspirin. Results:low molecular weight heparin plus aspirin in the treatment of UAP, frequency of angina pectoris at ack reduced, prolong the interval of electrocardiogram and dynamic electrocardiogram, myocardial ischemia significantly improved.%稳定型心绞痛(UAP)是冠心病中仅次于透壁性心肌梗死的综合征,临床治疗及预后较差。低分子肝素治疗UAP疗效显著,对改善预后有重要临床意义。常规治疗基础上+低分子肝素皮下注射+口服小剂量阿司匹林。低分子肝素+阿司匹林治疗UAP后,心绞痛发作频率减少,间隔时间延长,心电图及动态心电图心肌缺血明显改善。

  7. Use of an exchange method to estimate the association and dissociation rate constants of cadmium complexes formed with low-molecular-weight organic acids commonly exuded by plant roots.

    Science.gov (United States)

    Schneider, André; Nguyen, Christophe

    2011-01-01

    Organic acids released from plant roots can form complexes with cadmium (Cd) in the soil solution and influence metal bioavailability not only due to the nature and concentration of the complexes but also due to their lability. The lability of a complex influences its ability to buffer changes in the concentration of free ions (Cd); it depends on the association (, m mol s) and dissociation (, s) rate constants. A resin exchange method was used to estimate and (m mol s), which is the conditional estimate of depending on the calcium (Ca) concentration in solution. The constants were estimated for oxalate, citrate, and malate, three low-molecular-weight organic acids commonly exuded by plant roots and expected to strongly influence Cd uptake by plants. For all three organic acids, the and estimates were around 2.5 10 m mol s and 1.3 × 10 s, respectively. Based on the literature, these values indicate that the Cd- low-molecular-weight organic acids complexes formed between Cd and low-molecular-weight organic acids may be less labile than complexes formed with soil soluble organic matter but more labile than those formed with aminopolycarboxylic chelates. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  8. Production of hydroxyl radicals from abiotic oxidation of pyrite by oxygen under circumneutral conditions in the presence of low-molecular-weight organic acids

    Science.gov (United States)

    Zhang, Peng; Yuan, Songhu

    2017-12-01

    Besides acidic environments, pyrite oxidation also occurs in circumneutral environments, such as well-buffered marine and estuarine sediments and salt marshes where low-molecular-weight organic acids (LMWOAs) (e.g., citrate and oxalate) prevail. However, the production of hydroxyl radicals (radOH) from pyrite oxidation by oxygen (O2) in these circumneutral environments is poorly understood. In this study, radOH production was measured during the abiotic oxidation of pyrite by O2 under circumneutral conditions. A pyrite suspension (50 g/L pyrite) that was buffered at pH 6-8 was exposed to air for oxygenation in the dark. Benzoate (20 mM) was added into the suspension to trap radOH. At pH 7, the cumulative radOH reached 7.5 μM within 420 min in the absence of LMWOAs, whereas it increased to 14.8, 12 and 11.2 μM in the presence of 1 mM ethylenediaminotetraacetate, citrate and oxalate, respectively. When the citrate concentration, which serves as a LMWOAs model, was increased from 0.5 to 5 mM, the cumulative radOH increased from 10.3 to 27.3 μM within 420 min at pH 7. With the decrease in pH from 8 to 6, the cumulative radOH increased from 2.1 to 23.3 μM in the absence of LMWOAs, but it increased from 8.8 to 134.9 μM in the presence of 3 mM citrate. The presence of LMWOAs enhanced the radOH production from pyrite oxidation under circumneutral conditions. In the absence of LMOWAs, radOH is produced mostly from the oxidation of adsorbed Fe(II) by O2. In the presence of citrate, radOH production is attributed mainly to the oxidation of Fe(II)-citrate- by O2 and secondarily to the oxidation of H2O on surface-sulfur defects. The acceleration of pyrite oxidation by Fe(III)-citrate increases radOH production. Fe(II)-citrate- is generated mainly from the complexation of adsorbed Fe(II) by citrate and the reduction of Fe(III)-citrate, and the generation is suppressed by the oxidation of adsorbed Fe(II). Fe(III)-citrate is generated predominantly from Fe

  9. Exploring the relationship between polycyclic aromatic hydrocarbons and sedimentary organic carbon in three Chinese lakes

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Fengchang; Xu, Libin; Liao, Haiqing; Zhao, Xiaoli [Chinese Research Academy of Environmental Sciences, Beijing (China). State Key Lab. of Environmental Criteria and Risk Assessment; Sun, Yongge [Zhejiang Univ., Hangzhou (China). Inst. of Environmental and Biogeochemistry; Guo, Jianyang [Chinese Academy of Sciences, Guiyang (China). State Key Lab. of Environmental Geochemistry

    2012-05-15

    Purpose: Previous studies have shown a positive correlation between concentrations of polycyclic aromatic hydrocarbons (PAHs) and total organic carbon (TOC) in lake sediments. However, with respect to the complex organic matter in recent sediments, it is still unclear which part of TOC plays a key role in controlling PAHs distributions in natural sediments. The aim of this study was to examine the relationships between PAHs and TOC components of different origins in lake sediments. Materials and methods: Sediment cores from three Chinese lakes with different trophic conditions - Lakes Bosten, Dianchi, and Poyang - were collected using a piston core sampler. The cores were sectioned into 1- or 2-cm intervals immediately after collection and transported on ice to the laboratory where they were stored at -20 C. The subsamples were freeze-dried and ground with a mortar and pestle for analyses. PAHs were analyzed by GC-MS and TOC was determined with a PE elemental analyzer after the removal of carbonates. Rock-Eval 6 pyrolysis technique was used to deconvolute the TOC in the sediments into free and volatile hydrocarbons (S1), kerogen-derived hydrocarbons (S2), and residual carbon (RC); S2 was further separated into thermal less stable macromolecular organic matter (S2a) and high molecular weight kerogens (S2b). Results and discussion: Positive correlations between TOC and PAHs were observed in these lakes. Results show that the more labile, minor components of TOC (S1 and S2a) played a more important role in controlling PAH distributions than the major components of TOC (S2b and RC), probably due to the different accessibilities of the organic components. The algae-derived organic carbon had a greater influence on the distribution of low molecular weight PAHs than that of high molecular weight PAHs in sediments. This suggests that PAHs scavenging in the water column by algae is mainly targeted at low molecular weight PAHs, and that preferential scavenging of low

  10. Volatile hydrocarbon profile of Iberian dry-cured hams. A possible tool for authentication of hams according to the fattening diet.

    Science.gov (United States)

    Narváez-Rivas, Mónica; Vicario, Isabel M; Alcalde, M Jesús; León-Camacho, Manuel

    2010-06-15

    The aims of this work were to carry out a comprehensive study of the volatile hydrocarbons of 34 Iberian dry-cured hams and to evaluate the efficiency of these compounds for discriminating hams according to the fattening system: "Montanera" (B) and "Cebo" (C). The samples of hams were obtained by mincing the semimembranosus and semitendinosus muscles from slices of dry-cured ham. The analyses were carried out by gas chromatography-mass spectrometry with a polar capillary column and after a previous extraction by Purge and Trap method. Forty-three volatile hydrocarbons were identified, 26 of them for the first time in Iberian dry-cured ham. Only five compounds showed significant differences between the two types of hams. Among the 33 volatile hydrocarbons, 22 of them allowed a complete discrimination of the two groups of hams according the fattening system.

  11. Quantitative evaluation of volatile hydrocarbons in post-mortem blood in forensic autopsy cases of fire-related deaths.

    Science.gov (United States)

    Yonemitsu, Kosei; Sasao, Ako; Oshima, Toru; Mimasaka, Sohtaro; Ohtsu, Yuki; Nishitani, Yoko

    2012-04-10

    Volatile hydrocarbons in post-mortem blood from victims of fires were analyzed quantitatively by headspace gas chromatography mass spectrometry. The benzene and styrene concentrations in the blood were positively correlated with the carboxyhemoglobin (CO-Hb) concentration, which is evidence that the deceased inhaled the hydrocarbons and carbon monoxide simultaneously. By contrast, the concentrations of toluene and CO-Hb in the blood were not significantly correlated. This lack of correlation could be explained by two different sources of toluene, with low blood concentrations of toluene arising when the deceased inhaled smoke and high blood concentrations of toluene arising when the deceased inhaled petroleum vapor or other unknown vapors. The quantity of soot deposited in the respiratory tract was classified into four grades (-, 1+, 2+, 3+). The mean CO-Hb concentration in the 1+ soot group was significantly lower than those in the 2+ (ptypes of smoke produced by different materials. For example, petroleum combustion with a limited supply of oxygen, like in a compartment fire, may produce a large volume of dense black smoke that contains a large quantity of soot. Soot deposits in the airways and the blood CO-Hb concentration are basic and essential autopsy findings that are used to investigate fire-related deaths. The quantitative GC-MS analysis of blood volatile hydrocarbons can provide additional useful information on the cause of the fire and the circumstances surrounding the death. In combination, these three findings are useful for the reconstruction of cases. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  12. Discriminative stimulus effects of inhaled 1,1,1-trichloroethane in mice: comparison to other hydrocarbon vapors and volatile anesthetics.

    Science.gov (United States)

    Shelton, Keith L

    2009-04-01

    Because the toxicity of many inhalants precludes evaluation in humans, drug discrimination, an animal model of subjective effects, can be used to gain insights on their poorly understood abuse-related effects. The purpose of the present study was to train a prototypic inhalant that has known abuse liability, 1,1,1-trichloroethane (TCE), as a discriminative stimulus in mice, and compare it to other classes of inhalants. Eight B6SJLF1/J mice were trained to discriminate 10 min of exposure to 12,000 ppm inhaled TCE vapor from air and seven mice were trained to discriminate 4,000 ppm TCE from air. Tests were then conducted to characterize the discriminative stimulus of TCE and to compare it to representative aromatic and chlorinated hydrocarbon vapors, volatile halogenated anesthetics as well as an odorant compound. Only the 12,000 ppm TCE versus the air discrimination group exhibited sufficient discrimination accuracy for substitution testing. TCE vapor concentration- and exposure time-dependently substituted for the 12,000 ppm TCE vapor training stimulus. Full substitution was produced by trichloroethylene, toluene, enflurane, and sevoflurane. Varying degrees of partial substitution were produced by the other volatile test compounds. The odorant, 2-butanol, did not produce any substitution for TCE. The discriminative stimulus effects of TCE are shared fully or partially by chlorinated and aromatic hydrocarbons as well as by halogenated volatile anesthetics. However, these compounds can be differentiated from TCE both quantitatively and qualitatively. It appears that the degree of similarity is not solely a function of chemical classification but may also be dependent upon the neurochemical effects of the individual compounds.

  13. Synthesis and Characterization of Quaternary Metal Chalcogenide Aerogels for Gas Separation and Volatile Hydrocarbon Adsorption

    KAUST Repository

    Edhaim, Fatimah A.

    2017-01-01

    as sorbents for selective gas separation and volatile organic compounds adsorption. They showed preferential adsorption of polarizable gases (CO2) and organic compounds (toluene). Ion exchange and heavy metal remediation properties have also been demonstrated

  14. Investigation of non-volatile additives on the process of distillation of hydrocarbon mixtures

    Directory of Open Access Journals (Sweden)

    М.Б. Степанов

    2009-02-01

    Full Text Available  The given results of researches of influence of nonvolatile additives on processes of distillation of individual hydrocarbons and their mixes, including petroleum and mineral oil. With the help of the developed computer system of the continuous control of distillation it is shown, that at the presence of small amounts of the additive decrease of temperature of the beginning of boiling of hydrocarbons is observed, their speeds of banish and exits of light fuel mineral oil grow during initial oil refining

  15. Gas sealing efficiency of cap rocks. Pt. 1: Experimental investigations in pelitic sediment rocks. - Pt. 2: Geochemical investigations on redistribution of volatile hydrocarbons in the overburden of natural gas reservoirs; Gas sealing efficiency of cap rocks. T. 1: Experimentelle Untersuchungen in pelitischen Sedimentgesteinen. - T.2: Geochemische Untersuchungen zur Umverteilung leichtfluechtiger Kohlenwasserstoffe in den Deckschichten von Erdgaslagerstaetten. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Leythaeuser; Konstanty, J.; Pankalla, F.; Schwark, L.; Krooss, B.M.; Ehrlich, R.; Schloemer, S.

    1997-09-01

    New methods and concepts for the assessment of sealing properties of cap rocks above natural gas reservoirs and of the migration behaviour of low molecular-weight hydrocarbons in sedimentary basins were developed and tested. The experimental work comprised the systematic assesment of gas transport parameters on representative samples of pelitic rocks at elevated pressure and temperature conditions, and the characterization of their sealing efficiency as cap rocks overlying hydrocarbon accumulations. Geochemical case histories were carried out to analyse the distribution of low molecular-weight hydrocarbons in the overburden of known natural gas reservoirs in NW Germany. The results were interpreted with respect to the sealing efficiency of individual cap rock lithologies and the type and extent of gas losses. (orig.) [Deutsch] Zur Beurteilung der Abdichtungseigenschaften von Caprocks ueber Gaslagerstaetten und des Migrationsverhaltens niedrigmolekularer Kohlenwasserstoffe in Sedimentbecken wurden neue Methoden und Konzepte entwickelt und angewendet. In experimentellen Arbeiten erfolgte die systematische Bestimmung von Gas-Transportparametern an repraesentativen Proben pelitischer Gesteine unter erhoehten Druck- und Temperaturbedingungen und die Charakterisierung ihrer Abdichtungseffizienz als Deckschicht ueber Kohlenwasserstofflagerstaetten. In geochemischen Fallstudien wurde die Verteilung niedrigmolekularer Kohlenwasserstoffe in den Deckschichten ueber bekannten Erdgaslagerstaetten in NW-Deutschland analysiert und im Hinblick auf die Abdichtungseffizienz einzelner Caprock-Lithologien bzw. Art und Ausmass von Gasverlusten interpretiert. (orig.)

  16. Fates, Budgets, and Health Implications of Macondo Spill Volatile Hydrocarbons in the Ocean and Atmosphere of the Gulf of Mexico

    Science.gov (United States)

    Leifer, I.; Barletta, B.; Blake, D. R.; Blake, N. J.; Bradley, E. S.; Meinardi, S.; Lehr, B.; Luyendyk, B. P.; Roberts, D. A.; Rowland, F. S.

    2010-12-01

    The Macondo Oil Spill released unprecedented oil and gas to the ocean, estimated at 63000 bbl/day, which dispersed and dissolved during rise (Technical Flow Rate Team Report, 2010); yet, most of the oil reached the sea surface as oil slicks that then evolved due to weathering and dispersant application (Mass Balance Report, 2010). Remote sensing (near infrared imaging spectrometry) allowed quantification of thick surface oil, values of which were incorporated into an overall oil budget calculation. Remote sensing data, atmospheric samples, and numerical modeling, strongly suggest significant volatile loss during rise, yet measured atmospheric concentrations were high. Scaling atmospheric measurements to the total oil spill implies very high, extensive, and persistent levels of atmospheric petroleum hydrocarbon exposure with strong health implications to on-site workers and to coastal residents from wind advection.

  17. Detection of volatile hydrocarbons and 2-dodecyl-cyclobutanone in irradiated Camembert. Nachweise von fluechtigen Kohlenwasserstoffen und 2-Dodecylcyclobutanon in bestrahltem Camembert

    Energy Technology Data Exchange (ETDEWEB)

    Spiegelberg, A. (Fachgebiet Lebensmittelbestrahlung, Bundesgesundheitsamt, Berlin (Germany)); Estendorfer, S. (Landesuntersuchungsamt fuer das Gesundheitswesen Suedbayern, Oberschleissheim (Germany)); Schulzki, G. (Fachgebiet Lebensmittelbestrahlung, Bundesgesundheitsamt, Berlin (Germany)); Helle, N. (Fachgebiet Lebensmittelbestrahlung, Bundesgesundheitsamt, Berlin (Germany)); Boegl, K.W. (Fachgebietsgruppe Lebensmittel- und Arzneimittelbestrahlung, Alternativverfahren, Bundesgesundheitsamt, Berlin (Germany)); Schreiber, G.A. (Fachgebiet Lebensmittelbestrahlung, Bundesgesundheitsamt, Berlin (Germany))

    1993-09-01

    The same methods which are used to detect radiation treatment of meat - the detection of volatile hydrocarbons and 2-alkylcyclobutanones - were successfully applied to identify irradiated Camembert (0.5 until 3 kGy) in examinations performed independently by the ''Landesuntersuchungsamt fuer das Gesundheitswesen Suedbayern'' (LUA) and by the Federal Health Office (BGA). (orig.)

  18. AVE5026, a new hemisynthetic ultra-low-molecular-weight heparin for the prevention of venous thromboembolism in patients after total knee replacement surgery--TREK: a dose-ranging study

    DEFF Research Database (Denmark)

    Lassen, M R; Dahl, O E; Mismetti, P

    2009-01-01

    BACKGROUND: AVE5026 is a new hemisynthetic ultra-low-molecular-weight heparin, with a novel anti-thrombotic profile resulting from high anti-factor (F)Xa activity and residual anti-FIIa activity. AVE5026 is in clinical development for venous thromboembolism (VTE) prevention, a frequent complication....... The primary safety outcome was the incidence of major bleeding. RESULTS: The primary efficacy outcome was assessed in 464 patients. There was a significant dose-response across the five AVE5026 groups for VTE prevention (Pincidence of VTE ranging from 5.3% to 44.1% compared with 35...

  19. Characterization of selected volatile organic compounds, polycyclic aromatic hydrocarbons and carbonyl compounds at a roadside monitoring station

    Science.gov (United States)

    Ho, K. F.; Lee, S. C.; Chiu, Gloria M. Y.

    Volatile organic compounds (VOCs), PAHs and carbonyl compounds are the major toxic components in Hong Kong. Emissions from motor vehicles have been one of the primary pollution sources in the metropolitan areas throughout Hong Kong for a long time. A 1-yr monitoring program for VOCs, PAHs and carbonyl compounds had been performed at a roadside urban station at Hong Kong Polytechnic University in order to determine the variations and correlations of each selected species (VOCs, PAHs and carbonyl compounds). This study is aimed to analyze toxic volatile organic compounds (benzene, toluene, ethylbenzene and xylene), two carbonyl compounds (formaldehyde, acetaldehyde), and selective polycyclic aromatic hydrocarbons. The monitoring program started from 16 April 1999 to 30 March 2000. Ambient VOC concentrations, many of which originate from the same sources as particulate PAHs and carbonyls compounds, show significant quantities of benzene, toluene and xylenes. Correlations and multivariate analysis of selected gaseous and particulate phase organic pollutants were performed. Source identification by principle component analysis and hierarchical cluster analysis allowed the identification of four sources (factors) for the roadside monitoring station. Factor 1 represents the effect of diesel vehicle exhaust. Factor 2 shows the contribution of aromatic compounds. Factor 3 explains photochemical products—formaldehyde and acetaldehyde. Factor 4 explains the effect of gasoline vehicle exhaust.

  20. Hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    1927-02-22

    Coal tar, mineral oils, bitumens, coal extraction products, hydrogenation products of coal, oil schists can be atomized and heated with steam to decompose pyrogenetically and form gases rich in olefins which may be heated with or without pressure and with or without catalysts to produce liquid hydrocarbons of low boiling point, some of which may be aromatic. The apparatus should be lined with copper, silica, or ferrosilicon to prevent contact of the bases with iron which causes deposition of soot. Catalysts used may be metal oxides, silica, graphite, active charcoal, mica, pumice, porcelain, barium carbonate, copper, silver, gold, chromium, boron, or their compounds. At temperatures from 300 to 400/sup 0/C, olefins are produced. At higher temperatures, naphthenes and benzene hydrocarbons are produced.

  1. Volatility

    Directory of Open Access Journals (Sweden)

    María Sánchez

    2016-11-01

    Full Text Available The action consists of moving with small kicks a tin of cola refresh -without Brand-from a point of the city up to other one. During the path I avoid bollards, the slope differences between sidewalks, pedestrians, parked motorcycles, etc. Volatility wants to say exactly that the money is getting lost. That the money is losing by gentlemen and by ladies who are neither financial sharks, nor big businessmen… or similarly, but ingenuous people, as you or as me, who walk down the street.

  2. Volatile Short-chain Chlorinated Hydrocarbons in the Groundwater of the City of Zagreb

    OpenAIRE

    Marijanović-Rajčić, M.; Senta, A.

    2008-01-01

    The aim of the study was to assess the quality of the groundwater sampled from private wells and the public water-supply system in terms of estimating the contamination caused by short-chain chlorinated hydrocarbons, as well as to estimate the exposure of the citizens dwelling in different suburbs to these pollutants of their drinking water (Fig. 1). The aim of the study was also to determine which suburb is supplied through the public water-supply system with water originating from the Sašna...

  3. In situ vadose zone bioremediation of soil contaminated with nonvolatile hydrocarbons

    International Nuclear Information System (INIS)

    Hogg, D.S.; Burden, R.J.; Riddell, P.J.

    1992-01-01

    In situ bioremediation has been successfully carried out on petroleum hydrocarbon-contaminated soil at a decommissioned bulk storage terminal in New Zealand. The site soils were contaminated mainly with diesel fuel and spent oil at concentrations ranging up to 95,000 mg/kg of total recoverable petroleum hydrocarbons. The in situ remediation system combines an enhanced bioremediation with vapor extraction and is installed almost entirely below grade, thereby allowing above ground activities to continue unimpeded. Laboratory-scale feasibility testing indicated that although appreciable volatilization of low molecular weight components would occur initially, biodegradation would be the primary mechanism by which contaminated soil would be remediated. During the remedial design phase, preliminary field testing was conducted to evaluate the optimum spacing for extraction wells and inlet vents. A pilot-scale system was installed in a 15-m by 35-m area of the site in June 1989 and operated for approximately 1 year. Soil monitoring performed approximately every 3 months indicated an overall reduction in soil petroleum hydrocarbon concentrations of 87% for the period from June 1989 to May 1991

  4. Volatile Hydrocarbon Analysis in Blood by Headspace Solid-Phase Microextraction: The Interpretation of VHC Patterns in Fire-Related Incidents.

    Science.gov (United States)

    Waters, Brian; Hara, Kenji; Ikematsu, Natsuki; Takayama, Mio; Kashiwagi, Masayuki; Matsusue, Aya; Kubo, Shin-Ichi

    2017-05-01

    A headspace solid-phase microextraction (HS-SPME) technique was used to quantitate the concentration of volatile hydrocarbons from the blood of cadavers by cryogenic gas chromatography-mass spectroscopy. A total of 24 compounds including aromatic and aliphatic volatile hydrocarbons were analyzed by this method. The analytes in the headspace of 0.1 g of blood mixed with 1.0 mL of distilled water plus 1 µL of an internal standard solution were adsorbed onto a 100-µm polydimethylsiloxane fiber at 0°C for 15 min, and measured using a GC-MS full scan method. The limit of quantitation for the analytes ranged from 6.8 to 10 ng per 1 g of blood. This method was applied to actual autopsy cases to quantitate the level of volatile hydrocarbons (VHCs) in the blood of cadavers who died in fire-related incidents. The patterns of the VHCs revealed the presence or absence of accelerants. Petroleum-based fuels such as gasoline and kerosene were differentiated. The detection of C8-C13 aliphatic hydrocarbons indicated the presence of kerosene; the detection of C3 alkylbenzenes in the absence of C8-C13 aliphatic hydrocarbons was indicative of gasoline; and elevated levels of styrene or benzene in the absence of C3/C4 alkylbenzenes and aliphatic hydrocarbons indicated a normal construction fire. This sensitive HS-SPME method could help aid the investigation of fire-related deaths by providing a simple pattern to use for the interpretation of VHCs in human blood. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Comprehensive speciation of low-molecular weight selenium metabolites in mustard seeds using HPLC-electrospray linear trap/Orbitrap tandem mass spectrometry.

    Science.gov (United States)

    Ouerdane, Laurent; Aureli, Federica; Flis, Paulina; Bierla, Katarzyna; Preud'homme, Hugues; Cubadda, Francesco; Szpunar, Joanna

    2013-09-01

    An analytical methodology based on high-resolution high mass accuracy electrospray ionization (ESI) tandem MS assisted by Se-specific detection using inductively coupled plasma mass spectrometry (ICP MS) was developed for speciation of selenium (Se) in seeds of black mustard (Brassica nigra) grown on Se-rich soil. Size-exclusion LC-ICP MS allowed the determination of the Se distribution according to the molecular mass and the control of the species stability during extraction. The optimization of hydrophilic interaction of LC and cation-exchange HPLC resulted in analytical conditions making it possible to detect and characterize over 30 Se species using ESI MS, including a number of minor (<0.5%) metabolites. Selenoglucosinolates were found to be the most important class of species accounting for at least 15% of the total Se present and over 50% of all the metabolites. They were found particularly unstable during aqueous extraction leading to the loss of Se by volatilization as methylselenonitriles and methylselenoisothiocyanates identified using gas chromatography (GC) with the parallel ICP MS and atmospheric pressure chemical ionization (APCI) MS/MS detection. However, selenoglucosinolates could be efficiently recovered by extraction with 70% methanol. Other classes of identified species included selenoamino acids, selenosugars, selenosinapine and selenourea derivatives. The three types of reactions leading to the formation of selenometabolites were: the Se-S substitution in the metabolic pathway, oxidative reactions of -SeH groups with endogenous biomolecules, and chemical reactions, e.g., esterification, of Se-containing molecules and other biomolecules through functional groups not involving Se.

  6. Near infra-red chemical species tomography of sprays of volatile hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Hindle, F.P.; Carey, S.J.; Ozanyan, K.B.; McCann, H. [Dept. of Electrical Engineering and Electronics, UMIST, Manchester (United Kingdom); Winterbone, D.E.; Clough, E. [Dept. of Mechanical, Aerospace and Mfg. Engineering, UMIST, Manchester (United Kingdom)

    2002-08-01

    We report an All-Opto-Electronic tomography system that is sensitive to hydrocarbon vapour distribution, or liquid spray distribution, with temporal resolution of over 3000 frames per second. A tomography system comprising 32 channels has been built and tested. For chemical sensitivity to saturated hydrocarbons, we exploit the principle of Near Infra-Red (NIR) absorption at 1700 nm relative to a reference wavelength, using laser diode sources whose technology is based on that of the communications industry. Images are obtained from a laboratory set-up incorporating both gaseous injection and a liquid Gasoline Direct Injection (GDI) system. The performance of a prototype system on a running GDI engine is reported. The difficulty in performing concentration measurements of the gaseous fuel within the liquid spray region is shown, and means to improve this performance are discussed. However, it has been found possible to image the liquid spray cone using attenuation of the reference beam. These images correlate well with other techniques [1]. (orig.) [German] Wir berichten ueber ein optoelektronisches Tomographiesystem zur Bestimmung der Verteilung von Kohlenwasserstoffdaempfen oder von Spraypartikeln, das eine hohe zeitliche Aufloesung von 3000 Aufnahmen pro Sekunde liefert. Ein System mit 32 Kanaelen wurde gebaut und getestet. Um Empfindichkeit auf gesaettigte Kohlenwasserstoffdaempfe zu erzielen, wurde die Absorption im Nahen Infrarot (NIR) bei 1700 nm, bezogen auf die bei einer Referenzwellen-laenge, genutzt. Laserdioden, deren Technologien auch in der Kommunikationstechnik Verwendung finden, kamen zum Einsatz. Von einem Laboraufbau wurden Bilder aufgenommen sowohl bei Injektion von Gas als auch bei Direkteinspritzung fluessigen Brennstoffs (GDI). Wir berichten ueber die Ergebnisse mit dem Prototyp-Messsystem an einem GDI-Motor. Es werden die Schwierigkeiten gezeigt, Messungen der Gaskonzentration innerhalb eines Spraypartikelbereichs durchzufuehren, und

  7. Occupational exposure to gases, polycyclic aromatic hydrocarbons and volatile organic compounds in biomass-fired power plants.

    Science.gov (United States)

    Jumpponen, M; Rönkkömäki, H; Pasanen, P; Laitinen, J

    2013-01-01

    The combustion of fuels produces air pollutants in the form of gases, organic compounds, and particulate matter. However, although the environmental aspect of these agents has been examined, workers' exposure to them is still a neglected issue. The purpose of this study was to measure maintenance and ash removal workers' multiple exposures to gases, volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) during their work tasks in biomass-fired power plants. Our hygienic measurements revealed that carbon monoxide, nitric oxide, ammonia and sulfur dioxide were the most common gases that the workers were exposed to during their tasks. Their average concentrations were 0.45 ppm, 0.06 ppm, 0.11 ppm and 0.42 ppm, respectively. Phenanthrene and naphthalene were the most prominent PAHs. At the same sampling points, the most commonly found VOCs were aromatic and aliphatic hydrocarbons and turpentines. The calculated total PAH concentrations were less than 7% of benzo[a]pyrene's eight-hour occupational exposure limit, and the total VOC concentrations were below the Finnish reference value for the normal industrial level in all measured work tasks. The most evident health effect caused by multiple exposures to gases was upper respiratory track irritation, followed by the disruption of oxygen transport, and finally central nervous system disorders. We recommend powered air respirators with ABEK+P3 cartridges and carbon monoxide gas detectors as the minimum requirement for those working inside biomass-fired power plant boilers, and compressed air breathing apparatus as the best form of protection. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Volatilization of polycyclic aromatic hydrocarbons from coal-tar-sealed pavement.

    Science.gov (United States)

    Van Metre, Peter C; Majewski, Michael S; Mahler, Barbara J; Foreman, William T; Braun, Christopher L; Wilson, Jennifer T; Burbank, Teresa L

    2012-06-01

    Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, are a potential source of volatile PAHs to the atmosphere. An initial assessment of volatilization of PAHs from coal-tar-sealed pavement is presented here in which we measured summertime gas-phase PAH concentrations 0.03 m and 1.28 m above the pavement surface of seven sealed (six with coal-tar-based sealant and one with asphalt-based sealant) and three unsealed (two asphalt and one concrete) parking lots in central Texas. PAHs also were measured in parking lot dust. The geometric mean concentration of the sum of eight frequently detected PAHs (ΣPAH(8)) in the 0.03-m samples above sealed lots (1320 ng m(-3)) during the hottest part of the day was 20 times greater than that above unsealed lots (66.5 ng m(-3)). The geometric mean concentration in the 1.28-m samples above sealed lots (138 ng m(-3)) was five times greater than above unsealed lots (26.0 ng m(-3)). Estimated PAH flux from the sealed lots was 60 times greater than that from unsealed lots (geometric means of 88 and 1.4 μg m(-2) h(-1), respectively). Although the data set presented here is small, the much higher estimated fluxes from sealed pavement than from unsealed pavement indicate that coal-tar-based sealants are emitting PAHs to urban air at high rates compared to other paved surfaces. Published by Elsevier Ltd.

  9. Volatilization of polycyclic aromatic hydrocarbons from coal-tar-sealed pavement

    Science.gov (United States)

    Van Metre, Peter C.; Majewski, Michael S.; Mahler, Barbara J.; Foreman, William T.; Braun, Christopher L.; Wilson, Jennifer T.; Burbank, Teresa L.

    2012-01-01

    Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, are a potential source of volatile PAHs to the atmosphere. An initial assessment of volatilization of PAHs from coal-tar-sealed pavement is presented here in which we measured summertime gas-phase PAH concentrations 0.03 m and 1.28 m above the pavement surface of seven sealed (six with coal-tar-based sealant and one with asphalt-based sealant) and three unsealed (two asphalt and one concrete) parking lots in central Texas. PAHs also were measured in parking lot dust. The geometric mean concentration of the sum of eight frequently detected PAHs (ΣPAH8) in the 0.03-m samples above sealed lots (1320 ng m-3) during the hottest part of the day was 20 times greater than that above unsealed lots (66.5 ng m-3). The geometric mean concentration in the 1.28-m samples above sealed lots (138 ng m-3) was five times greater than above unsealed lots (26.0 ng m-3). Estimated PAH flux from the sealed lots was 60 times greater than that from unsealed lots (geometric means of 88 and 1.4 μg m-2 h-1, respectively). Although the data set presented here is small, the much higher estimated fluxes from sealed pavement than from unsealed pavement indicate that coal-tar-based sealants are emitting PAHs to urban air at high rates compared to other paved surfaces.

  10. The pollution characteristics of odor, volatile organochlorinated compounds and polycyclic aromatic hydrocarbons emitted from plastic waste recycling plants.

    Science.gov (United States)

    Tsai, Chung-Jung; Chen, Mei-Lien; Chang, Keng-Fu; Chang, Fu-Kuei; Mao, I-Fang

    2009-02-01

    Plastic waste treatment trends toward recycling in many countries; however, the melting process in the facilities which adopt material recycling method for treating plastic waste may emit toxicants and cause sensory annoyance. The objectives of this study were to analyze the pollution characteristics of the emissions from the plastic waste recycling plants, particularly in harmful volatile organochlorinated compounds, polycyclic aromatic hydrocarbons (PAHs), odor levels and critical odorants. Ten large recycling plants were selected for analysis of odor concentration (OC), volatile organic compounds (VOCs) and PAHs inside and outside the plants using olfactometry, gas chromatography-mass spectrometry and high performance liquid chromatography-fluorescence detector, respectively. The olfactometric results showed that the melting processes used for treating polyethylene/polypropylene (PE/PP) and polyvinyl chloride (PVC) plastic waste significantly produced malodor, and the odor levels at downwind boundaries were 100-229 OC, which all exceeded Taiwan's EPA standard of 50 OC. Toluene, ethylbenzene, 4-methyl-2-pentanone, methyl methacrylate and acrolein accounted for most odors compared to numerous VOCs. Sixteen organochlorinated compounds were measured in the ambient air emitted from the PVC plastic waste recycling plant and total concentrations were 245-553 microg m(-3); most were vinyl chloride, chloroform and trichloroethylene. Concentrations of PAHs inside the PE/PP plant were 8.97-252.16 ng m(-3), in which the maximum level were 20-fold higher than the levels detected from boundaries. Most of these recycling plants simply used filter to treat the melting fumes, and this could not efficiently eliminate the gaseous compounds and malodor. Improved exhaust air pollution control were strongly recommended in these industries.

  11. Oligonol, a low-molecular-weight polyphenol derived from lychee fruit, attenuates diabetes-induced renal damage through the advanced glycation end product-related pathway in db/db mice.

    Science.gov (United States)

    Park, Chan Hum; Yokozawa, Takako; Noh, Jeong Sook

    2014-08-01

    This study was conducted to examine whether oligonol, a low-molecular-weight polyphenol derived from lychee fruit, has an ameliorative effect on diabetes-induced alterations, such as advanced glycation end product (AGE) formation or apoptosis in the kidneys of db/db mice with type 2 diabetes. Oligonol [10 or 20 mg/(kg body weight · d), orally] was administered every day for 8 wk to prediabetic db/db mice, and its effect was compared with vehicle-treated db/db and normal control mice (m/m). The administration of oligonol decreased the elevated renal glucose concentrations and reactive oxygen species in db/db mice (P factor-α (P related variables, representing renoprotective effects against the development of diabetic complications in db/db mice with type 2 diabetes. © 2014 American Society for Nutrition.

  12. Preferential adsorption of volatile hydrocarbons on high surface area chalcogels KMBiTe 3 (M = Cr, Zn, Fe)

    KAUST Repository

    Edhaim, Fatimah

    2017-12-21

    Three chalcogels KCrBiTe3, KZnBiTe3, and KFeBiTe3 were synthesized by the sol–gel metathesis route. K+ and the transition metal cations Cr2+, Zn2+ or Fe2+ connect [BiTe3]3− anions to form amorphous black compounds. Supercritical drying of the black gels produced porous materials with BET surface areas of 230 m2/g (KCrBiTe3), 450 m2/g (KZnBiTe3) and 514 m2/g (KFeBiTe3). The adsorption properties of the resulting chalcogenide aerogels or chalcogels have been studied using volatile organic hydrocarbons (VOCs) and gases as adsorptives. The results show preferential adsorption of toluene vapor over cyclohexane vapor. The adsorption capacity toward toluene is 5.02 mmol/g for KCrBiTe3, 5.58 mmol/g for KZnBiTe3 and 7.89 mmol/g for KFeBiTe3. Preferential adsorption of CO2 over CH4 or H2 was observed for the chalcogels: KCrBiTe3 (CO2/H2: 175, CO2/CH4: 50), KZnBiTe3 (CO2/H2: 180 and CO2/CH4: 60) and KFeBiTe3 (CO2/H2: 225 and CO2/CH4: 65).

  13. In vitro and in vivo siRNA delivery to hepatocyte utilizing ternary complexation of lactosylated dendrimer/cyclodextrin conjugates, siRNA and low-molecular-weight sacran.

    Science.gov (United States)

    Hayashi, Yuya; Higashi, Taishi; Motoyama, Keiichi; Jono, Hirofumi; Ando, Yukio; Arima, Hidetoshi

    2018-02-01

    In this study, we newly developed the ternary complexes consisting of lactosylated dendrimer (generation 3)/α-cyclodextrin conjugate (Lac-α-CDE), siRNA and the anionic polysaccharide sacrans, and evaluated their utility as siRNA transfer carriers. Three kinds of the low-molecular-weight sacrans, i.e. sacran (100) (Mw 44,889Da), sacran (1000) (Mw 943,692Da) and sacran (10,000) (Mw 1,488,281Da) were used. Lac-α-CDE/siRNA/sacran ternary complexes were prepared by adding the low-molecular-weight sacrans to the Lac-α-CDE/siRNA binary complex solution. Cellular uptake of the ternary complex with sacran (100) was higher than that of the binary complex or the other ternary complexes with sacran (1000) and sacran (10,000) in HepG2 cells. Additionally, the ternary complex possessed high serum resistance and endosomal escaping ability in HepG2 cells. High liver levels of siRNA and Lac-α-CDE were observed after the intravenous administration of the ternary complex rather than that of the binary complex. Moreover, intravenous administration of the ternary complex (siRNA 5mg/kg) induced the significant RNAi effect in the liver of mice with negligible change of blood chemistry values. Therefore, a ternary complexation of the Lac-α-CDE/siRNA binary complex with sacran is useful as a hepatocyte-specific siRNA delivery system. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Low-molecular-weight heparinoid compared with warfarin for prophylaxis of deep-vein thrombosis in patients who are operated on for fracture of the hip. A prospective, randomized trial

    International Nuclear Information System (INIS)

    Gerhart, T.N.; Yett, H.S.; Robertson, L.K.; Lee, M.A.; Smith, M.; Salzman, E.W.

    1991-01-01

    In a randomized, prospective trial, a low-molecular-weight heparinoid (Org 10172 [Lomoparan]) was compared with warfarin for efficacy and safety in preventing deep-vein thrombosis in 263 patients who had an operatively treated fracture of the hip. One group of patients received Org 10172 in a dose of 750 units subcutaneously every twelve hours until the ninth postoperative day; on the seventh postoperative day, warfarin was added to the regimen. The other group received only warfarin. Both drugs were begun preoperatively, immediately after the admission evaluation. In the patients who received warfarin, the desired prothrombin time was one and one-half times the control level. Deep-vein thrombosis was detected by 125 I-fibrinogen scanning and impedance plethysmography and was confirmed by phlebography and compression ultrasonography. Deep-vein thrombosis was found in nine (7 per cent) of the 132 patients who received Org 10172 and in twenty-eight (21 per cent) of the 131 patients who received warfarin (p less than 0.001). Adverse reactions were not significantly different in the two groups. Major bleeding complications occurred in eight patients in the Org-10172 group, only four of whom were receiving the drug at the time of bleeding, and in five patients who were receiving warfarin (not significant). There was no difference in intraoperative loss of blood or in requirements for transfusion. We concluded that the low-molecular-weight heparinoid Org 10172 is a safe, convenient, effective antithrombotic agent for the prevention of venous thrombosis after an operation for fracture of the hip

  15. The analysis of semi-volatile and non-volatile petroleum hydrocarbons in a soil/sediment matrix by capillary column gas chromatography/flame ionization detection (GC/FID)

    International Nuclear Information System (INIS)

    George, J.E. III; Thoma, J.J.; Hastings, M.

    1990-01-01

    A comprehensive analysis for semi-volatile and non-volatile fractions of petroleum hydrocarbons can be achieved by a solvent extraction/concentration techniques that will effectively extract these high molecular weight fractions from a soil matrix. The prepared extract is then injected directly into a gas chromatograph equipped with a capillary column and flame ionization detector. This technique applies to the following types of commercially available petroleum hydrocarbons: Diesel Nos. 2,4,5, and 6, fuel oils and several grades of lubrication oil. The identification of a particular petroleum hydrocarbon is determined visually by comparison of the samples with known hydrocarbon standards. Accurate quantitation of the chromatograms is possible by using peak area summation and the presence of an internal standard. The practical quantitation limit for the method is 10 mg/Kg for most fuel types. This paper presents a method for determining the concentration of these fuel types in soil. Data will be presented only on 10W40 lubrication oil in terms of method validation, calibration, percent recovery, and method detection limits. A discussion of the quatitation techniques used will also be included

  16. Volatile halogenated hydrocarbons over the western Pacific between 43° and 4°N

    Science.gov (United States)

    Quack, Birgit; Suess, Erwin

    1999-01-01

    A spectrum of halogenated hydrocarbon compounds in marine air masses were surveyed over an area in the western Pacific between 43°N, 150°E and 4°N, 113°E in September 1994. The ship's track between northern Japan and Singapore traversed three climatic zones of the northern hemisphere. Recently polluted air, clean marine air derived from the central Pacific Ocean from different latitudes, and marine air from the Indonesian archipelago were collected. Tetrachloroethene and trichloroethene of anthropogenic origin, brominated halocarbons as tribromomethane, dibromochloromethane and bromodichloromethane of anthropogenic and natural sources, and other trace gases were measured in the air samples. Very sparse data on the distribution of these compounds exist for the western Pacific atmosphere. The distribution patterns of the compounds were related to synoptic-scale meteorology, spatial conditions, and origin of the air masses. Anthropogenic and natural sources for both chlorinated and brominated substances were identified. Tetrachloroethene and trichloroethene concentrations and their ratios identify anthropogenic sources. Their mixing ratios were quite low compared to previously published data. They are in agreement with expected low concentrations of photochemically active substances during autumn, with an overall decrease in concentrations toward lower latitudes, and with a decrease of emissions during recent years. Strong evidence for a natural source of trichloroethene was discovered in the tropical region. The concentrations of naturally released brominated species were high compared to other measurements over the Pacific. Gradients toward the coasts and elevated concentrations in air masses influenced by coastal emissions point to significant coastal sources of these compounds. The trace gas composition of anthropogenic and natural compounds clearly identified the air masses which were traversed during the cruise.

  17. A high volume sampling system for isotope determination of volatile halocarbons and hydrocarbons

    Directory of Open Access Journals (Sweden)

    E. Bahlmann

    2011-10-01

    Full Text Available The isotopic composition of volatile organic compounds (VOCs can provide valuable information on their sources and fate not deducible from mixing ratios alone. In particular the reported carbon stable isotope ratios of chloromethane and bromomethane from different sources cover a δ13C-range of almost 100‰ making isotope ratios a very promising tool for studying the biogeochemistry of these compounds. So far, the determination of the isotopic composition of C1 and C2 halocarbons others than chloromethane is hampered by their low mixing ratios.

    In order to determine the carbon isotopic composition of C1 and C2 halocarbons with mixing ratios as low as 1 pptv (i a field suitable cryogenic high volume sampling system and (ii a chromatographic set up for processing these samples have been developed and validated. The sampling system was tested at two different sampling sites, an urban and a coastal location in Northern Germany. The average δ13C-values for bromomethane at the urban site were −42.9 ± 1.1‰ and agreed well with previously published results. But at the coastal site bromomethane was substantially enriched in 13C by almost 10‰. Less pronounced differences were observed for chlorodifluoromethane, 1,1,1-trichloroethane and chloromethane. We suggest that these differences are related to the turnover of these compounds in ocean surface waters. Furthermore we report first carbon isotope ratios for iodomethane (−40.4‰ to −79.8‰, bromoform (−13.8‰ to 22.9‰, and other halocarbons.

  18. Comparison of atmosphere/aquatic environment concentration ratio of volatile chlorinated hydrocarbons between temperate regions and Antarctica.

    Science.gov (United States)

    Zoccolillo, Lelio; Amendola, Luca; Insogna, Susanna

    2009-09-01

    For the purpose of understanding the transport and deposition mechanisms and the air-water distribution of some volatile chlorinated hydrocarbons (VCHCs), their atmosphere/aquatic environment concentration ratio was evaluated. In addition, for the purpose of differentiating VCHC behaviour in a temperate climate from its behaviour in a polar climate, the atmosphere/aquatic environment concentration ratio evaluated in matrices from temperate zones was compared with the concentration ratio evaluated in Antarctic matrices. In order to perform air samplings also at rigid Antarctic temperatures, the sampling apparatus, consisting of a diaphragm pump and canisters, was suitably modified. Chloroform, 1,1,1-trichloroethane, tetrachloromethane, 1,1,2-trichloroethylene and tetrachloroethylene were measured in air, water and snow using specific techniques composed of a purpose-made cryofocusing-trap-injector (for air samples) and a modified purge-and-trap injector (for aqueous samples) coupled to a gas chromatograph with mass spectrometric detection operating in selected ion monitoring mode. The VCHCs were retrieved in all the investigated matrices, both Italian and Antarctic, with concentrations varying from tens to thousands of ng m(-3) in air and from digits to hundreds of ng kg(-1) in water and snow. The atmosphere/aquatic environment concentration ratios were always found to be lower than 1. In particular, the Italian air/water concentration ratios were smaller than the Antarctic ones, by reason of the higher atmospheric photochemical activity in temperate zones. On the other hand, the Antarctic air/snow concentration ratios proved to be largely in favour of snow with respect to the Italian ratios, thus corroborating the hypothesis of a more efficient VCHC deposition mechanism and accumulation on Antarctic snow.

  19. Investigation of Galactosylated Low Molecular Weight Chitosan ...

    African Journals Online (AJOL)

    Gal-LMWC(s)-coated liposomes exhibited a maximum of 65 % in vitro drug release in 24 h in a sustained fashion. The 50 % inhibitory concentration (IC50) values for liposomal formulations and drug solution were 2.81 and 5.98 μg/ml, respectively. Conclusion: Gal-LMWC (s) coated liposomes containing DOX that ...

  20. Ternary complexes of folate-PEG-appended dendrimer (G4)/α-cyclodextrin conjugate, siRNA and low-molecular-weight polysaccharide sacran as a novel tumor-selective siRNA delivery system.

    Science.gov (United States)

    Ohyama, Ayumu; Higashi, Taishi; Motoyama, Keiichi; Arima, Hidetoshi

    2017-06-01

    We previously developed a tumor-selective siRNA carrier by preparing polyamidoamine dendrimer (generation 4, G4) conjugates with α-cyclodextrin and folate-polyethylene glycol (Fol-PαC (G4)). In the present study, we developed ternary complexes of Fol-PαC (G4)/siRNA with low-molecular-weight-sacrans to achieve more effective siRNA transfer activity. Among the different molecular-weight sacrans, i.e. sacran 100, 1000 and 10,000 (MW 44,889Da, 943,692Da and 1,488,281Da, respectively), sacran 100 significantly increased the cellular uptake and the RNAi effects of Fol-PαC (G4)/siRNA binary complex with negligible cytotoxicity in KB cells (folate receptor-α positive cells). In addition, the ζ-potential and particle size of Fol-PαC (G4)/siRNA complex were decreased by the ternary complexation with sacran 100. Importantly, the in vivo RNAi effect of the ternary complex after the intravenous administration to tumor-bearing BALB/c mice was significantly higher than that of the binary complex. In conclusion, Fol-PαC (G4)/siRNA/sacran 100 ternary complex has a potential as a novel tumor-selective siRNA delivery system. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. The potential of mycelium and culture broth of Lignosus rhinocerotis as substitutes for the naturally occurring sclerotium with regard to antioxidant capacity, cytotoxic effect, and low-molecular-weight chemical constituents.

    Directory of Open Access Journals (Sweden)

    Beng Fye Lau

    Full Text Available Previous studies on the nutritional and nutraceutical properties of Lignosus rhinocerotis focused mainly on the sclerotium; however, the supply of wild sclerotium is limited. In this investigation, the antioxidant capacity and cytotoxic effect of L. rhinocerotis cultured under different conditions of liquid fermentation (shaken and static were compared to the sclerotium produced by solid-substrate fermentation. Aqueous methanol extracts of the mycelium (LR-MH, LR-MT and culture broth (LR-BH, LR-BT demonstrated either higher or comparable antioxidant capacities to the sclerotium extract (LR-SC based on their radical scavenging abilities, reducing properties, metal chelating activities, and inhibitory effects on lipid peroxidation. All extracts exerted low cytotoxicity (IC50>200 µg/ml, 72 h against selected mammalian cell lines. Several low-molecular-weight compounds, including sugars, fatty acids, methyl esters, sterols, amides, amino acids, phenolics, and triterpenoids, were identified using GC-MS and UHPLC-ESI-MS/MS. The presence of proteins (<40 kDa in the extracts was confirmed by SDS-PAGE and SELDI-TOF-MS. Principal component analysis revealed that the chemical profiles of the mycelial extracts under shaken and static conditions were distinct from those of the sclerotium. Results from bioactivity evaluation and chemical profiling showed that L. rhinocerotis from liquid fermentation merits consideration as an alternative source of functional ingredients and potential substitute for the sclerotium.

  2. Qualitative and quantitative analysis of heparin and low molecular weight heparins using size exclusion chromatography with multiple angle laser scattering/refractive index and inductively coupled plasma/mass spectrometry detectors.

    Science.gov (United States)

    Ouyang, Yilan; Zeng, Yangyang; Yi, Lin; Tang, Hong; Li, Duxin; Linhardt, Robert J; Zhang, Zhenqing

    2017-11-03

    Heparin, a highly sulfated glycosaminoglycan, has been used as a clinical anticoagulant over 80 years. Low molecular weight heparins (LMWHs), heparins partially depolymerized using different processes, are widely used as clinical anticoagulants. Qualitative molecular weight (MW) and quantitative mass content analysis are two important factors that contribute to LMWH quality control. Size exclusion chromatography (SEC), relying on multiple angle laser scattering (MALS)/refractive index (RI) detectors, has been developed for accurate analysis of heparin MW in the absence of standards. However, the cations, which ion-pair with the anionic polysaccharide chains of heparin and LMWHs, had not been considered in previous reports. In this study, SEC with MALS/RI and inductively coupled plasma/mass spectrometry detectors were used in a comprehensive analytical approach taking both anionic polysaccharide and ion-paired cations heparin products. This approach was also applied to quantitative analysis of heparin and LMWHs. Full profiles of MWs and mass recoveries for three commercial heparin/LMWH products, heparin sodium, enoxaparin sodium and nadroparin calcium, were obtained and all showed higher MWs than previously reported. This important improvement more precisely characterized the MW properties of heparin/LMWHs and potentially many other anionic polysaccharides. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Method for simultaneous imaging of endogenous low molecular weight metabolites in mouse brain using TiO2 nanoparticles in nanoparticle-assisted laser desorption/ionization-imaging mass spectrometry.

    Science.gov (United States)

    Shrivas, Kamlesh; Hayasaka, Takahiro; Sugiura, Yuki; Setou, Mitsutoshi

    2011-10-01

    We report the detection of a group of endogenous low molecular weight metabolites (LMWM) in mouse brain (80-500 Da) using TiO(2) nanoparticles (NPs) in nanoparticle-assisted laser desorption/ionization-imaging mass spectrometry (Nano-PALDI-IMS) without any washing and separation step prior to MS analysis. The identification of metabolites using TiO(2) NPs was compared with a conventional organic matrix 2,5-dihydroxybenzoic acid (DHB) where signals of 179 molecules were specific to TiO(2) NPs, 4 were specific to DHB, and 21 were common to both TiO(2) NPs and DHB. The use of TiO(2) NPs enabled the detection of a higher number of LMWM as compared to DHB and gold NPs as a matrix. This approach is a simple, inexpensive, washing, and separation free for imaging and identification of LMWM in mouse brain. We believe that the biochemical information from distinct regions of the brain using a Nano-PALDI-IMS will be helpful in elucidating the imbalances linked with diseases in biomedical samples.

  4. Seasonal variations of low molecular weight hydroxy-dicarboxylic acids and oxaloacetic acid in remote marine aerosols from Chichijima Island in the western North Pacific (December 2010-November 2011)

    Science.gov (United States)

    Gowda, Divyavani; Kawamura, Kimitaka

    2018-05-01

    Concentrations of homologous hydroxy-dicarboxylic acids (diacids) (hC3-hC6) and keto-diacid (oxaloacetic acid) were measured in the atmospheric aerosols collected at Chichijima Island (27.04° N, 142.13° E) in the western North Pacific from December 2010 to November 2011. The monthly averaged concentrations of hydroxy-diacids and oxaloacetic acid were significantly higher in spring followed by winter and autumn. Molecular distributions of hydroxy-diacids demonstrated that malic acid was the most abundant species in all four seasons, followed by tartronic acid in winter and spring and 3- and 2-hydroxyglutaric acids in summer and autumn. Hydroxy-diacids and keto-diacid maximized in spring and winter when air masses originated from the Asian continent with westerly winds. The concentrations of total hydroxy-diacids and oxaloacetic acid ranged from 0.1 to 27.3 ng m-3 and Asia to remote Chichijima Island followed by photochemical processing of organic aerosols. Seasonal molecular distribution of hydroxy-diacids and oxaloacetic acid was found to be dependent on the source strengths and plausible photochemical processing to form smaller diacids. Moderate to strong correlations among hydroxy-diacids, oxaloacetic acid and low molecular weight (LMW) diacids suggest that hydroxy-diacids and oxaloacetic acid are the intermediates in the photochemical oxidation of LMW diacid. Hence, photochemical formation of the most abundant LMW diacids, i.e., oxalic acid, could be produced from hydroxy- and keto-diacid as intermediates.

  5. Atomic resolution crystal structure of VcLMWPTP-1 from Vibrio cholerae O395: Insights into a novel mode of dimerization in the low molecular weight protein tyrosine phosphatase family

    Energy Technology Data Exchange (ETDEWEB)

    Nath, Seema; Banerjee, Ramanuj; Sen, Udayaditya, E-mail: udayaditya.sen@saha.ac.in

    2014-07-18

    Highlights: • VcLMWPTP-1 forms dimer in solution. • The dimer is catalytically active unlike other reported dimeric LMWPTPs. • The formation of extended dimeric surface excludes the active site pocket. • The surface bears closer resemblance to eukaryotic LMWPTPs. - Abstract: Low molecular weight protein tyrosine phosphatase (LMWPTP) is a group of phosphotyrosine phosphatase ubiquitously found in a wide range of organisms ranging from bacteria to mammals. Dimerization in the LMWPTP family has been reported earlier which follows a common mechanism involving active site residues leading to an enzymatically inactive species. Here we report a novel form of dimerization in a LMWPTP from Vibrio cholera 0395 (VcLMWPTP-1). Studies in solution reveal the existence of the dimer in solution while kinetic study depicts the active form of the enzyme. This indicates that the mode of dimerization in VcLMWPTP-1 is different from others where active site residues are not involved in the process. A high resolution (1.45 Å) crystal structure of VcLMWPTP-1 confirms a different mode of dimerization where the active site is catalytically accessible as evident by a tightly bound substrate mimicking ligand, MOPS at the active site pocket. Although being a member of a prokaryotic protein family, VcLMWPTP-1 structure resembles very closely to LMWPTP from a eukaryote, Entamoeba histolytica. It also delineates the diverse surface properties around the active site of the enzyme.

  6. 1,3:2,4-Dibenzylidene-D-sorbitol (DBS) and its derivatives--efficient, versatile and industrially-relevant low-molecular-weight gelators with over 100 years of history and a bright future.

    Science.gov (United States)

    Okesola, Babatunde O; Vieira, Vânia M P; Cornwell, Daniel J; Whitelaw, Nicole K; Smith, David K

    2015-06-28

    Dibenzylidene-D-sorbitol (DBS) has been a well-known low-molecular-weight gelator of organic solvents for over 100 years. As such, it constitutes a very early example of a supramolecular gel--a research field which has recently developed into one of intense interest. The ability of DBS to self-assemble into sample-spanning networks in numerous solvents is predicated upon its 'butterfly-like' structure, whereby the benzylidene groups constitute the 'wings' and the sorbitol backbone the 'body'--the two parts representing the molecular recognition motifs underpinning its gelation mechanism, with the nature of solvent playing a key role in controlling the precise assembly mode. This gelator has found widespread applications in areas as diverse as personal care products and polymer nucleation/clarification, and has considerable potential in applications such as dental composites, energy technology and liquid crystalline materials. Some derivatives of DBS have also been reported which offer the potential to expand the scope and range of applications of this family of gelators and endow the nansocale network with additional functionality. This review aims to explain current trends in DBS research, and provide insight into how by combining a long history of application, with modern methods of derivatisation and analysis, the future for this family of gelators is bright, with an increasing number of high-tech applications, from environmental remediation to tissue engineering, being within reach.

  7. Evidence of a local negative role for cocaine and amphetamine regulated transcript (CART, inhibins and low molecular weight insulin like growth factor binding proteins in regulation of granulosa cell estradiol production during follicular waves in cattle

    Directory of Open Access Journals (Sweden)

    Ireland James J

    2006-04-01

    Full Text Available Abstract The ability of ovarian follicles to produce large amounts of estradiol is a hallmark of follicle health status. Estradiol producing capacity is lost in ovarian follicles before morphological signs of atresia. A prominent wave like pattern of growth of antral follicles is characteristic of monotocous species such as cattle, horses and humans. While our knowledge of the role of pituitary gonadotropins in support of antral follicle growth and development is well established, the intrinsic factors that suppress estradiol production and may help promote atresia during follicular waves are not well understood. Numerous growth factors and cytokines have been reported to suppress granulosa cell estradiol production in vitro, but the association of expression of many such factors in vivo with follicle health status and their physiological significance are not clear. The purpose of this review is to discuss the in vivo and in vitro evidence supporting a local physiological role for cocaine and amphetamine regulated transcript, inhibins and low molecular weight insulin like growth factor binding proteins in negative regulation of granulosa cell estradiol production, with emphasis on evidence from the bovine model system.

  8. Emissions of volatile hydrocarbons (VOC) during drying of sawdust; Utslaepp av laettflyktiga kolvaeten vid torkning av biobraenslen

    Energy Technology Data Exchange (ETDEWEB)

    Granstroem, Karin

    2001-08-01

    In the project 'Emissions of volatile hydrocarbons (VOC) during drying of sawdust' the identity, amount and composition of monoterpenes found in the drying medium of a fluidized bed drier drying sawdust from Norwegian spruce and Scotch pine has been determined. The energy efficiency of the drier has also been measured. The aim of this project was to reduce both emissions and energy required for drying, to minimize environmental and health hazards, and make drying more competitive. This would help our primary target group - small scale saw mills - to make use of the sawdust produced as a by- product by making pellets and briquettes. If the VOC remains in the sawdust its energy content will improve and therefore also its value as a fuel. The sawdust was dried to different moisture levels in a spouted bed drier at atmospheric pressure, using either recirculating or not recirculating drying medium with temperatures 140, 170 or 200 deg C. The emissions of VOC were measured using a flame ionization detector (FID) and the nature of the emissions analyzed with a gas chromatograph with mass spectrometric detector (GC-MS). The GC-MS data is reported as emitted substance per oven dry weight (odw). Experiments show that terpenes do not leave the sawdust in great amounts until it is dried to a moisture content (water/total weight) below 10%. When sawdust is dried to a predetermined moisture level, the terpene emissions increase when warmer incoming drying medium is used. The monoterpenes found in greatest amount are a-pinene, b-pinene, 3-carene, limonene and myrcene. y-terpinene was detected in emissions from pine but not from spruce. The relative amounts of different monoterpenes did not vary significantly with post-drying moisture content, but drying medium of higher temperature caused an increase in the relative amount of less volatile monoterpenes. The FID data is reported as concentration of VOC in the drying medium, and as weight VOC per odw. The concentration

  9. Analysis of the differentially expressed low molecular weight peptides in human serum via an N-terminal isotope labeling technique combining nano-liquid chromatography/matrix-assisted laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Leng, Jiapeng; Zhu, Dong; Wu, Duojiao; Zhu, Tongyu; Zhao, Ningwei; Guo, Yinlong

    2012-11-15

    Peptidomics analysis of human serum is challenging due to the low abundance of serum peptides and interference from the complex matrix. This study analyzed the differentially expressed (DE) low molecular weight peptides in human serum integrating a DMPITC-based N-terminal isotope labeling technique with nano-liquid chromatography and matrix-assisted laser desorption/ionization mass spectrometry (nano-LC/MALDI-MS). The workflow introduced a [d(6)]-4,6-dimethoxypyrimidine-2-isothiocyanate (DMPITC)-labeled mixture of aliquots from test samples as the internal standard. The spiked [d(0)]-DMPITC-labeled samples were separated by nano-LC then spotted on the MALDI target. Both quantitative and qualitative studies for serum peptides were achieved based on the isotope-labeled peaks. The DMPITC labeling technique combined with nano-LC/MALDI-MS not only minimized the errors in peptide quantitation, but also allowed convenient recognition of the labeled peptides due to the 6 Da mass difference. The data showed that the entire research procedure as well as the subsequent data analysis method were effective, reproducible, and sensitive for the analysis of DE serum peptides. This study successfully established a research model for DE serum peptides using DMPITC-based N-terminal isotope labeling and nano-LC/MALDI-MS. Application of the DMPITC-based N-terminal labeling technique is expected to provide a promising tool for the investigation of peptides in vivo, especially for the analysis of DE peptides under different biological conditions. Copyright © 2012 John Wiley & Sons, Ltd.

  10. An open-label randomized controlled trial of low molecular weight heparin compared to heparin and coumadin for the treatment of venous thromboembolic events in children: the REVIVE trial.

    Science.gov (United States)

    Massicotte, Patricia; Julian, Jim A; Gent, Michael; Shields, Karen; Marzinotto, Velma; Szechtman, Barbara; Andrew, Maureen

    2003-01-25

    Venous thromboembolic events (VTE) are serious complications in children and for which the standard of care, unfractionated heparin followed by oral anticoagulation (UFH/OA), is problematic. The objective of REVIVE was to compare the efficacy and safety of a low molecular weight heparin (reviparin-sodium) to UFH/OA for the treatment of VTE in children. This multicenter, open-label study, with blinded central outcome adjudication, randomized patients with objectively confirmed VTE to receive either reviparin-sodium or UFH/OA. Dose adjustments were made using nomograms. The efficacy outcome was based on recurrent VTE and death due to VTE during the 3-month treatment period. The safety outcomes were major bleeding, minor bleeding and death. Due to slow patient accrual, REVIVE was closed prematurely. At 3 months, with reviparin-sodium, 2/36 patients (5.6%) had recurrent VTE or death compared to 4/40 patients (10.0%) receiving UFH/OA (odds ratio=0.53; 95% CI=(0.05, 4.00); Fisher's exact test: 2P=0.677). There were 7 major bleeds, 2/36 (5.6%) in the reviparin-sodium group and 5/40 (12.5%) in UFH/OA group (odds ratio=0.41; 95% confidence interval 0.04, 2.76); Fisher's exact test: P=0.435). There were 5 deaths during the study period, 1 (2.8%) in the reviparin-sodium group and 4 (10.0%) in the UFH/OA group. All five deaths were unrelated to VTE but one was due to an intracranial hemorrhage in the UFH/OA group. Although limited by small sample size, REVIVE provides valuable information on the incidence of recurrent VTE, major bleeding and problematic issues associated with therapy of VTE in children.

  11. Low-concentration tailing and subsequent quicklime-enhanced remediation of volatile chlorinated hydrocarbon-contaminated soils by mechanical soil aeration.

    Science.gov (United States)

    Ma, Yan; Du, Xiaoming; Shi, Yi; Xu, Zhu; Fang, Jidun; Li, Zheng; Li, Fasheng

    2015-02-01

    Mechanical soil aeration has long been regarded as an effective ex-situ remediation technique and as suitable for remediation of large-scale sites contaminated by volatile organic compounds (VOCs) at low cost. However, it has been reported that the removal efficiency of VOCs from soil is relatively low in the late stages of remediation, in association with tailing. Tailing may extend the remediation time required; moreover, it typically results in the presence of contaminants residues at levels far exceeding regulations. In this context, the present study aimed to discuss the tailing that occurs during the process of remediation of soils contaminated artificially with volatile chlorinated hydrocarbons (VCHs) and to assess possible quicklime-enhanced removal mechanisms. The results revealed the following conclusions. First, temperature and aeration rate can be important controls on both the timing of appearance of tailing and the levels of residual contaminants. Furthermore, the addition of quicklime to soil during tailing can reduce the residual concentrations rapidly to below the remedial target values required for site remediation. Finally, mechanical soil aeration can be enhanced using quicklime, which can improve the volatilization of VCHs via increasing soil temperature, reducing soil moisture, and enhancing soil permeability. Our findings give a basic understanding to the elimination of the tailing in the application of mechanical soil aeration, particularly for VOCs-contaminated soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Quicklime-induced changes of soil properties: Implications for enhanced remediation of volatile chlorinated hydrocarbon contaminated soils via mechanical soil aeration.

    Science.gov (United States)

    Ma, Yan; Dong, Binbin; He, Xiaosong; Shi, Yi; Xu, Mingyue; He, Xuwen; Du, Xiaoming; Li, Fasheng

    2017-04-01

    Mechanical soil aeration is used for soil remediation at sites contaminated by volatile organic compounds. However, the effectiveness of the method is limited by low soil temperature, high soil moisture, and high soil viscosity. Combined with mechanical soil aeration, quicklime has a practical application value related to reinforcement remediation and to its action in the remediation of soil contaminated with volatile organic compounds. In this study, the target pollutant was trichloroethylene, which is a volatile chlorinated hydrocarbon pollutant commonly found in contaminated soils. A restoration experiment was carried out, using a set of mechanical soil-aeration simulation tests, by adding quicklime (mass ratios of 3, 10, and 20%) to the contaminated soil. The results clearly indicate that quicklime changed the physical properties of the soil, which affected the environmental behaviour of trichloroethylene in the soil. The addition of CaO increased soil temperature and reduced soil moisture to improve the mass transfer of trichloroethylene. In addition, it improved the macroporous cumulative pore volume and average pore size, which increased soil permeability. As soil pH increased, the clay mineral content in the soils decreased, the cation exchange capacity and the redox potential decreased, and the removal of trichloroethylene from the soil was enhanced to a certain extent. After the addition of quicklime, the functional group COO of soil organic matter could interact with calcium ions, which increased soil polarity and promoted the removal of trichloroethylene. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Treatability of volatile chlorinated hydrocarbon-contaminated soils of different textures along a vertical profile by mechanical soil aeration: A laboratory test.

    Science.gov (United States)

    Ma, Yan; Shi, Yi; Hou, Deyi; Zhang, Xi; Chen, Jiaqi; Wang, Zhifen; Xu, Zhu; Li, Fasheng; Du, Xiaoming

    2017-04-01

    Mechanical soil aeration is a simple, effective, and low-cost soil remediation technology that is suitable for sites contaminated with volatile chlorinated hydrocarbons (VCHs). Conventionally, this technique is used to treat the mixed soil of a site without considering the diversity and treatability of different soils within the site. A laboratory test was conducted to evaluate the effectiveness of mechanical soil aeration for remediating soils of different textures (silty, clayey, and sandy soils) along a vertical profile at an abandoned chloro-alkali chemical site in China. The collected soils were artificially contaminated with chloroform (TCM) and trichloroethylene (TCE). Mechanical soil aeration was effective for remediating VCHs (removal efficiency >98%). The volatilization process was described by an exponential kinetic function. In the early stage of treatment (0-7hr), rapid contaminant volatilization followed a pseudo-first order kinetic model. VCH concentrations decreased to low levels and showed a tailing phenomenon with very slow contaminant release after 8hr. Compared with silty and sandy soils, clayey soil has high organic-matter content, a large specific surface area, a high clay fraction, and a complex pore structure. These characteristics substantially influenced the removal process, making it less efficient, more time consuming, and consequently more expensive. Our findings provide a potential basis for optimizing soil remediation strategy in a cost-effective manner. Copyright © 2016. Published by Elsevier B.V.

  14. Identification of Low Molecular Weight Glutenin Alleles by Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF-MS) in Common Wheat (Triticum aestivum L.)

    Science.gov (United States)

    Islam, Shahidul; Applebee, Marie; Appels, Rudi; Yan, Yueming; Ma, Wujun

    2015-01-01

    Low molecular weight glutenin subunits (LMW-GS) play an important role in determining dough properties and breadmaking quality. However, resolution of the currently used methodologies for analyzing LMW-GS is rather low which prevents an efficient use of genetic variations associated with these alleles in wheat breeding. The aim of the current study is to evaluate and develop a rapid, simple, and accurate method to differentiate LMW-GS alleles using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. A set of standard single LMW-GS allele lines as well as a suite of well documented wheat cultivars were collected from France, CIMMYT, and Canada. Method development and optimization were focused on protein extraction procedures and MALDI-TOF instrument settings to generate reproducible diagnostic spectrum peak profiles for each of the known wheat LMW-GS allele. Results revealed a total of 48 unique allele combinations among the studied genotypes. Characteristic MALDI-TOF peak patterns were obtained for 17 common LMW-GS alleles, including 5 (b, a or c, d, e, f), 7 (a, b, c, d or i, f, g, h) and 5 (a, b, c, d, f) patterns or alleles for the Glu-A3, Glu-B3, and Glu-D3 loci, respectively. In addition, some reproducible MALDI-TOF peak patterns were also obtained that did not match with any known alleles. The results demonstrated a high resolution and throughput nature of MALDI-TOF technology in analyzing LMW-GS alleles, which is suitable for application in wheat breeding programs in processing a large number of wheat lines with high accuracy in limited time. It also suggested that the variation of LMW-GS alleles is more abundant than what has been defined by the current nomenclature system that is mainly based on SDS-PAGE system. The MALDI-TOF technology is useful to differentiate these variations. An international joint effort may be needed to assign allele symbols to these newly identified alleles and determine their effects on end

  15. (67/68)Ga-labeling agent that liberates (67/68)Ga-NOTA-methionine by lysosomal proteolysis of parental low molecular weight polypeptides to reduce renal radioactivity levels.

    Science.gov (United States)

    Uehara, Tomoya; Rokugawa, Takemi; Kinoshita, Mai; Nemoto, Souki; Fransisco Lazaro, Guerra Gomez; Hanaoka, Hirofumi; Arano, Yasushi

    2014-11-19

    The renal localization of gallium-67 or gallium-68 ((67/68)Ga)-labeled low molecular weight (LMW) probes such as peptides and antibody fragments constitutes a problem in targeted imaging. Wu et al. previously showed that (67)Ga-labeled S-2-(4-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid (SCN-Bz-NOTA)-conjugated methionine ((67)Ga-NOTA-Met) was rapidly excreted from the kidney in urine following lysosomal proteolysis of the parental (67)Ga-NOTA-Bz-SCN-disulfide-stabilized Fv fragment (Bioconjugate Chem., (1997) 8, 365-369). In the present study, a new (67/68)Ga-labeling reagent for LMW probes that liberates (67/68)Ga-NOTA-Met was designed, synthesized, and evaluated using longer-lived (67)Ga in order to reduce renal radioactivity levels. We employed a methionine-isoleucine (MI) dipeptide bond as the cleavable linkage. The amine residue of MI was coupled with SCN-Bz-NOTA for (67)Ga-labeling, while the carboxylic acid residue of MI was derivatized to maleimide for antibody conjugation in order to synthesize NOTA-MI-Mal. A Fab fragment of the anti-Her2 antibody was thiolated with iminothiolane, and NOTA-MI-Mal was conjugated with the antibody fragment by maleimide-thiol chemistry. The Fab fragment was also conjugated with SCN-Bz-NOTA (NOTA-Fab) for comparison. (67)Ga-NOTA-MI-Fab was obtained at radiochemical yields of over 95% and was stable in murine serum for 24 h. In the biodistribution study using normal mice, (67)Ga-NOTA-MI-Fab registered significantly lower renal radioactivity levels from 1 to 6 h postinjection than those of (67)Ga-NOTA-Fab. An analysis of urine samples obtained 6 h after the injection of (67)Ga-NOTA-MI-Fab showed that the majority of radioactivity was excreted as (67)Ga-NOTA-Met. In the biodistribution study using tumor-bearing mice, the tumor to kidney ratios of (67)Ga-NOTA-MI-Fab were 4 times higher (6 h postinjection) than those of (67)Ga-NOTA-Fab. Although further studies including the structure of radiometabolites and

  16. Determination of the Molecular Weight of Low-Molecular-Weight Heparins by Using High-Pressure Size Exclusion Chromatography on Line with a Triple Detector Array and Conventional Methods

    Directory of Open Access Journals (Sweden)

    Antonella Bisio

    2015-03-01

    Full Text Available The evaluation of weight average molecular weight (Mw and molecular weight distribution represents one of the most controversial aspects concerning the characterization of low molecular weight heparins (LMWHs. As the most commonly used method for the measurement of such parameters is high performance size exclusion chromatography (HP-SEC, the soundness of results mainly depends on the appropriate calibration of the chromatographic columns used. With the aim of meeting the requirement of proper Mw standards for LMWHs, in the present work the determination of molecular weight parameters (Mw and Mn by HP-SEC combined with a triple detector array (TDA was performed. The HP-SEC/TDA technique permits the evaluation of polymeric samples by exploiting the combined and simultaneous action of three on-line detectors: light scattering detectors (LALLS/RALLS; refractometer and viscometer. Three commercial LMWH samples, enoxaparin, tinzaparin and dalteparin, a γ-ray depolymerized heparin (γ-Hep and its chromatographic fractions, and a synthetic pentasaccharide were analysed by HP-SEC/TDA. The same samples were analysed also with a conventional HP-SEC method employing refractive index (RI and UV detectors and two different chromatographic column set, silica gel and polymeric gel columns. In both chromatographic systems, two different calibration curves were built up by using (i γ-Hep chromatographic fractions and the corresponding Mw parameters obtained via HP-SEC/TDA; (ii the whole γ-Hep preparation with broad Mw dispersion and the corresponding cumulative distribution function calculated via HP-SEC/TDA. In addition, also a chromatographic column calibration according to European Pharmacopoeia indication was built up. By comparing all the obtained results, some important differences among Mw and size distribution values of the three LMWHs were found with the five different calibration methods and with HP-SEC/TDA method. In particular, the detection of

  17. Selective adsorption of volatile hydrocarbons and gases in high surface area chalcogels containing [ES3]3- anions (E = As, Sb)

    KAUST Repository

    Ahmed, Ejaz; Khanderi, Jayaprakash; Anjum, Dalaver H.; Rothenberger, Alexander

    2014-01-01

    We describe the sol-gel synthesis of the two new chalcogels KFeSbS3 and NaFeAsS3, which demonstrate excellent adsorption selectivity for volatile hydrocarbons and gases. These predominantly mesoporous materials have been synthesized by reacting Fe(OAc)2 with K3SbS3 or Na3AsS3 in a formamide/water mixture at room temperature. Aerogels obtained after supercritical drying have BET surface areas of 636 m2/g and 505 m2/g for KFeSbS3 and NaFeAsS3, respectively, with pore sizes in the micro- (below 2 nm), meso- (2-50 nm), and macro- (above 50 nm) regions.

  18. Selective adsorption of volatile hydrocarbons and gases in high surface area chalcogels containing [ES3]3- anions (E = As, Sb)

    KAUST Repository

    Ahmed, Ejaz

    2014-11-25

    We describe the sol-gel synthesis of the two new chalcogels KFeSbS3 and NaFeAsS3, which demonstrate excellent adsorption selectivity for volatile hydrocarbons and gases. These predominantly mesoporous materials have been synthesized by reacting Fe(OAc)2 with K3SbS3 or Na3AsS3 in a formamide/water mixture at room temperature. Aerogels obtained after supercritical drying have BET surface areas of 636 m2/g and 505 m2/g for KFeSbS3 and NaFeAsS3, respectively, with pore sizes in the micro- (below 2 nm), meso- (2-50 nm), and macro- (above 50 nm) regions.

  19. A passive air sampler for characterizing the vertical concentration profile of gaseous phase polycyclic aromatic hydrocarbons in near soil surface air

    International Nuclear Information System (INIS)

    Zhang Yuzhong; Deng Shuxing; Liu Yanan; Shen Guofeng; Li Xiqing; Cao Jun; Wang Xilong; Reid, Brian; Tao Shu

    2011-01-01

    Air-soil exchange is an important process governing the fate of polycyclic aromatic hydrocarbons (PAHs). A novel passive air sampler was designed and tested for measuring the vertical concentration profile of 4 low molecular weight PAHs in gaseous phase (PAH LMW4 ) in near soil surface air. Air at various heights from 5 to 520 mm above the ground was sampled by polyurethane foam disks held in down-faced cartridges. The samplers were tested at three sites: A: an extremely contaminated site, B: a site near A, and C: a background site on a university campus. Vertical concentration gradients were revealed for PAH LMW4 within a thin layer close to soil surface at the three sites. PAH concentrations either decreased (Site A) or increased (Sites B and C) with height, suggesting either deposition to or evaporation from soils. The sampler is a useful tool for investigating air-soil exchange of gaseous phase semi-volatile organic chemicals. - Research highlights: → Design, field test and calibration of the novel passive air sampler, PAS-V-I. → Vertical concentration gradients of PAH LMW4 within a thin layer close to soil. → Comparison of results between PAS-V-I measurement and fugacity approach. → Potential application of PAS-V-I and further modifications. - A novel passive sampling device was developed and tested for measuring vertical concentration profile of gaseous phase polycyclic aromatic hydrocarbons in near soil surface air.

  20. Polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) mitigation in the pyrolysis process of waste tires using CO₂ as a reaction medium.

    Science.gov (United States)

    Kwon, Eilhann E; Oh, Jeong-Ik; Kim, Ki-Hyun

    2015-09-01

    Our work reported the CO2-assisted mitigation of PAHs and VOCs in the thermo-chemical process (i.e., pyrolysis). To investigate the pyrolysis of used tires to recover energy and chemical products, the experiments were conducted using a laboratory-scale batch-type reactor. In particular, to examine the influence of the CO2 in pyrolysis of a tire, the pyrolytic products including C1-5-hydrocarbons (HCs), volatile organic carbons (VOCs), and polycyclic aromatic hydrocarbons (PAHs) were evaluated qualitatively by gas chromatography (GC) with mass spectroscopy (MS) as well as with a thermal conductivity detector (TCD). The mass balance of the pyrolytic products under various pyrolytic conditions was established on the basis of their weight fractions of the pyrolytic products. Our experimental work experimentally validated that the amount of gaseous pyrolytic products increased when using CO2 as a pyrolysis medium, while substantially altering the production of pyrolytic oil in absolute content (7.3-17.2%) and in relative composition (including PAHs and VOCs). Thus, the co-feeding of CO2 in the pyrolysis process can be considered an environmentally benign and energy efficient process. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Water-Sediment Partition of Polycyclic Aromatic Hydrocarbons (PAHs) in Nansi Lake

    Science.gov (United States)

    Zhang, Guizhai; Diao, Youjiang

    2018-06-01

    Based on field data of polycyclic aromatic hydrocarbons (PAHs) in water and sediment in Nansi Lake. The concentrations and the partitioning characteristic of PAHs in the water and sediment were studied. The lgKd of high molecular weight PAHs were higher than the low molecular weight PAHs. The most of PAHs Kd values were negligible correlated with TOC, soluble salt, clay and pH of the sediment in Nansi Lake.

  2. Influence of Low Molecular Weight Polymers on the Rheology of Bentonite Suspensions Influence de polymères de faible masse moléculaire sur la rhéologie de suspensions de bentonite

    Directory of Open Access Journals (Sweden)

    Rossi S.

    2006-12-01

    Full Text Available In this communication we demonstrate how relatively low molecular weight synthetic polymers significantly alter the rheological properties of Bentonite/water suspensions depending upon the polymer dosage and/or degree of surface coverage on the clay particle. The behaviour of two types of nonionic polymers are reported; a series of nonylphenol poly(propylene oxide poly(ethylene oxide polymers with varying EO chain length and a series consisting of an ABA block copolymer of poly(propylene oxide-poly(ethylene oxide with varying EO chain length. Adsorption isotherms of dilute clay suspensions showed a higher uptake of the lowest molecular weight polymer (in µmol/m² for each series. The adsorbed amount G increases in the order NPE > PEO > PE. The oscillatory shear and steady state shear stress-shear rate measurements of concentrated clay suspensions (3-6% w/v facilitate the interpretation of the particle-particle interactions. The yield stress, plastic viscosity and elastic modulus showed a maximum at about 50% surface coverage by the NPE polymers, and a subsequent decrease due to stabilisation of the suspension. For the PE polymers these parameters continously decreased as the surface of the clay particle was covered. Scaling of the elastic modulus with increasing clay content allows the determination of the exponent n from a power-law fit G = Kon which qualitatively describes the degree of dispersion for the different polymers. Preliminary results of the effect of temperature and pressure on Bentonite/polymer suspensions are also presented. Dans cette communication, nous démontrons comment les polymères synthétiques de masse moléculaire relativement faible modifient notablement les propriétés rhéologiques de suspensions de bentonite dans l'eau en fonction de polymère et/ou du degré de couverture superficielle de la particule d'argile. Les comportements de deux types de polymères non ioniques sont décrits: une série de polymères

  3. Similar PAH fate in anaerobic digesters inoculated with three microbial communities accumulating either volatile fatty acids or methane.

    Directory of Open Access Journals (Sweden)

    Florence Braun

    Full Text Available Urban sludge produced on wastewater treatment plants are often contaminated by organic pollutants such as polycyclic aromatic hydrocarbons (PAH. Their removal under methanogenic conditions was already reported, but the factors influencing this removal remain unclear. Here, we determined the influence of microbial communities on PAH removal under controlled physico-chemical conditions. Twelve mesophilic anaerobic digesters were inoculated with three microbial communities extracted from ecosystems with contrasting pollution histories: a PAH contaminated soil, a PCB contaminated sediment and a low contaminated anaerobic sludge. These anaerobic digesters were operated during 100 days in continuous mode. A sterilised activated sludge, spiked with 13 PAH at concentrations usually encountered in full-scale wastewater treatment plants, was used as substrate. The dry matter and volatile solid degradation, the biogas production rate and composition, the volatile fatty acids (VFA production and the PAH removals were monitored. Bacterial and archaeal communities were compared in abundance (qPCR, in community structure (SSCP fingerprinting and in dominant microbial species (454-pyrosequencing. The bioreactors inoculated with the community extracted from low contaminated anaerobic sludge showed the greater methane production. The PAH removals ranged from 10% to 30%, respectively, for high and low molecular weight PAH, whatever the inoculums tested, and were highly correlated with the dry matter and volatile solid removals. The microbial community structure and diversity differed with the inoculum source; this difference was maintained after the 100 days of digestion. However, the PAH removal was not correlated to these diverse structures and diversities. We hence obtained three functional stable consortia with two contrasted metabolic activities, and three different pictures of microbial diversity, but similar PAH and matter removals. These results confirm

  4. Similar PAH fate in anaerobic digesters inoculated with three microbial communities accumulating either volatile fatty acids or methane.

    Science.gov (United States)

    Braun, Florence; Hamelin, Jérôme; Bonnafous, Anaïs; Delgenès, Nadine; Steyer, Jean-Philippe; Patureau, Dominique

    2015-01-01

    Urban sludge produced on wastewater treatment plants are often contaminated by organic pollutants such as polycyclic aromatic hydrocarbons (PAH). Their removal under methanogenic conditions was already reported, but the factors influencing this removal remain unclear. Here, we determined the influence of microbial communities on PAH removal under controlled physico-chemical conditions. Twelve mesophilic anaerobic digesters were inoculated with three microbial communities extracted from ecosystems with contrasting pollution histories: a PAH contaminated soil, a PCB contaminated sediment and a low contaminated anaerobic sludge. These anaerobic digesters were operated during 100 days in continuous mode. A sterilised activated sludge, spiked with 13 PAH at concentrations usually encountered in full-scale wastewater treatment plants, was used as substrate. The dry matter and volatile solid degradation, the biogas production rate and composition, the volatile fatty acids (VFA) production and the PAH removals were monitored. Bacterial and archaeal communities were compared in abundance (qPCR), in community structure (SSCP fingerprinting) and in dominant microbial species (454-pyrosequencing). The bioreactors inoculated with the community extracted from low contaminated anaerobic sludge showed the greater methane production. The PAH removals ranged from 10% to 30%, respectively, for high and low molecular weight PAH, whatever the inoculums tested, and were highly correlated with the dry matter and volatile solid removals. The microbial community structure and diversity differed with the inoculum source; this difference was maintained after the 100 days of digestion. However, the PAH removal was not correlated to these diverse structures and diversities. We hence obtained three functional stable consortia with two contrasted metabolic activities, and three different pictures of microbial diversity, but similar PAH and matter removals. These results confirm that PAH removal

  5. Distilling hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Bataafsche, N V; de Brey, J H.C.

    1918-10-30

    Hydrocarbons containing a very volatile constituent and less volatile constituents, such as casing-head gases, still gases from the distillation of crude petroleum and bituminous shale are separated into their constituents by rectification under pressure; a pressure of 20 atmospheres and limiting temperatures of 150/sup 0/C and 40/sup 0/C are mentioned as suitable. The mixture may be subjected to a preliminary treatment consisting in heating to a temperature below the maximum rectification temperature at a pressure greater than that proposed to be used in the rectification.

  6. Hydrocarbon pollution from marinas in estuarine sediments

    Science.gov (United States)

    Voudrias, Evangelos A.; Smith, Craig L.

    1986-03-01

    A measure of the impact of marinas on three Eastern Virginia estuarine creeks was obtained by a study of hydrocarbons in their sediments. Two of the creeks support considerable marine activity, including pleasure boat marinas, boat repair facilities, and commercial fishing operations. The third creek, which served as a control, is seldom used by boats, and is surrounded by marsh and woodland. Sediments from the creeks with marinas contained significantly higher levels of both aromatic and aliphatic hydrocarbons than did the control. Differences in the concentrations of certain oil-pollution indicators, such as the 17α,21β-hopane homologs and phytane, and low molecular weight aromatic hydrocarbons, are indicative of light petroleum fractions. Most of the aromatic hydrocarbons from all creeks, however, appear to have a pyrogenic origin. Although hydrocarbons from three probable origins (petroleum, pyrogenesis, and recent biosynthesis) were detected in all locations, the petroleum-derived and pyrogenic hydrocarbons were of only minor importance relative to the biogenic hydrocarbons in the control creek.

  7. A Survey of 42 Semi-Volatile Organic Contaminants in Groundwater along the Grand Canal from Hangzhou to Beijing, East China

    Directory of Open Access Journals (Sweden)

    Xiaojie Li

    2015-12-01

    Full Text Available The status of organic pollution in groundwater in eastern China along the Grand Canal from Hangzhou to Beijing was evaluated. Forty-two semi-volatile organic contaminants were analyzed, including 16 polycyclic aromatic hydrocarbons (PAHs, seven polychlorinated biphenyls (PCBs, 12 organochlorine pesticides (OCPs and seven organophosphorus pesticides (OPPs. Among the detected contaminants, PAHs were the most widespread compounds. One PCB and six OCPs were detected in the groundwater samples, but none of the target OPPs was detected. The total concentration of the 16 PAHs ranged from 0.21 to 1006 ng/L, among which phenanthrene (271 ng/L and fluoranthene (233 ng/L were present at very high concentrations and naphthalene (32 positive detections in 50 samples and fluorene (28 detections in 50 samples were the most frequently detected. Benzo[a]pyrene equivalents indicated a high environmental risk related to PAHs in a few groundwater samples. To identify the possible sources of PAHs, three concentration ratios, low molecular weight PAHs/high molecular weight PAHs, anthracene/(anthracene + phenanthrene and fluoranthene/(fluoranthene + pyrene, were determined, that indicated that the PAHs mainly originated from mixed sources: pyrolytic and petrogenic sources with different ratios at different sites.

  8. A passive air sampler for characterizing the vertical concentration profile of gaseous phase polycyclic aromatic hydrocarbons in near soil surface air.

    Science.gov (United States)

    Zhang, Yuzhong; Deng, Shuxing; Liu, Yanan; Shen, Guofeng; Li, Xiqing; Cao, Jun; Wang, Xilong; Reid, Brian; Tao, Shu

    2011-03-01

    Air-soil exchange is an important process governing the fate of polycyclic aromatic hydrocarbons (PAHs). A novel passive air sampler was designed and tested for measuring the vertical concentration profile of 4 low molecular weight PAHs in gaseous phase (PAH(LMW4)) in near soil surface air. Air at various heights from 5 to 520 mm above the ground was sampled by polyurethane foam disks held in down-faced cartridges. The samplers were tested at three sites: A: an extremely contaminated site, B: a site near A, and C: a background site on a university campus. Vertical concentration gradients were revealed for PAH(LMW4) within a thin layer close to soil surface at the three sites. PAH concentrations either decreased (Site A) or increased (Sites B and C) with height, suggesting either deposition to or evaporation from soils. The sampler is a useful tool for investigating air-soil exchange of gaseous phase semi-volatile organic chemicals. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Hydrocarbons and air pollution

    International Nuclear Information System (INIS)

    Herz, O.

    1992-01-01

    This paper shows the influence of hydrocarbons vapors, emitted by transports or by volatile solvents using, on air pollution. Hydrocarbons are the principal precursors of photochemical pollution. After a brief introduction on atmospheric chemistry and photochemical reactions, the author describes the french prevention program against hydrocarbons emissions. In the last chapter, informations on international or european community programs for photochemical pollution study are given. 5 figs., 10 tabs

  10. Determination of volatile polycyclic aromatic hydrocarbons in waters using headspace solid-phase microextraction with a benzyl-functionalized crosslinked polymeric ionic liquid coating.

    Science.gov (United States)

    Merdivan, Melek; Pino, Verónica; Anderson, Jared L

    2017-08-01

    A benzyl-functionalized crosslinked polymeric ionic liquid (PIL), produced through the co-polymerization of the 1-vinylbenzyl-3-hexadecylimidazolium bis[(trifluoromethyl)sulfonyl]imide (VBHDIM-NTf 2 ) ionic liquid (IL) monomer and 1,12-di(3-vinylbenzylimidazolium)dodecane bis[(trifluoromethyl)sulfonyl]imide ((DVBIM) 2 C 12- 2NTf 2 ) IL crosslinker, was successfully used as a sorbent coating in headspace solid-phase microextraction (SPME) coupled to gas chromatography (GC) with flame-ionization detection (FID) to determine seven volatile polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. Optimum extraction conditions for the PAHs when using the novel sorbent include an extraction temperature of 50°C, an ionic strength content adjusted with 30% (w/v) NaCl in the aqueous sample, and an extraction time of 60 min. The extraction performance of the crosslinked PIL fiber was compared to the SPME commercial coating polydimethylsiloxane fiber. The calibration ranges of the studied PAHs were linear in the range of 0.02-20 µg L -1 for the crosslinked PIL fiber. The accuracy of the proposed method was demonstrated by examining the spiked recoveries of seven PAHs which produced values ranging from 67.2% to 130% (for river- and seawater samples), and precision values lower than 9.4% for a spiked level of 1 µg L -1 , and detection limits between 0.01 and 0.04 µg L -1 , which supports the sensitivity of the method using GC-FID.

  11. Isolation of microorganisms with capability to degrade polycyclic aromatic hydrocarbons (PATH )

    International Nuclear Information System (INIS)

    Vargas, M.C; Ramirez, N.E; Rueda, S.M; Sanchez, F.N

    1996-01-01

    This paper summarizes a work conducted on the isolation of microorganisms of contaminated sediments with a high percentage of hydrocarbons aromatic polynuclear (Polynuclear Aromatic Hydrocarbons, PAHS) The methodology involved two selection systems called fast route and slow route in which exposure periods and contaminant concentrations are the key determinants. The microorganisms isolated through the slow route system are more likely to be successful in degrading high molecular weight PAH'S. The six strains obtained through the fast route system were able to grow on low molecular weight PAH's showing preference towards the first four compounds of the sixteen demanded by the EPA (Environmental Protection Agency)

  12. Emissions of volatile organic compounds (VOCs) from the food and drink industries of the European community

    Science.gov (United States)

    Passant, Neil R.; Richardson, Stephen J.; Swannell, Richard P. J.; Gibson, N.; Woodfield, M. J.; van der Lugt, Jan Pieter; Wolsink, Johan H.; Hesselink, Paul G. M.

    Estimates were made of the amounts of volatile organic compounds (VOCs) released into the atmosphere as a result of the industrial manufacture and processing of food and drink in the European Community. The estimates were based on a review of literature sources, industrial and government contacts and recent measurements. Data were found on seven food manufacturing sectors (baking, vegetable oil extraction, solid fat processing, animal rendering, fish meal processing, coffee production and sugar beet processing) and three drink manufacturing sectors (brewing, spirit production and wine making). The principle of a data quality label is advocated to illustrate the authors' confidence in the data, and to highlight areas for further research. Emissions of ethanol from bread baking and spirit maturation were found to be the principle sources. However, significant losses of hexane and large quantities of an ill-defined mixture of partially oxidized hydrocarbons were noted principally from seed oil extraction and the drying of plant material, respectively. This latter mixture included low molecular weight aldehydes, carboxylic acids, ketones, amines and esters. However, the precise composition of many emissions were found to be poorly understood. The total emission from the food and drink industry in the EC was calculated as 260 kt yr -1. However, many processes within the target industry were found to be completely uncharacterized and therefore not included in the overall estimate (e.g. soft drink manufacture, production of animal food, flavourings, vinegar, tea, crisps and other fried snacks). Moreover, the use of data quality labels illustrated the fact that many of our estimates were based on limited data. Hence, further emissions monitoring is recommended from identified sources (e.g. processing of sugar beet, solid fat and fish meal) and from uncharacterized sources.

  13. Exposure to polycyclic aromatic hydrocarbons and volatile organic compounds among recently pregnant rural Guatemalan women cooking and heating with solid fuels.

    Science.gov (United States)

    Weinstein, John R; Asteria-Peñaloza, Renée; Diaz-Artiga, Anaité; Davila, Gilberto; Hammond, S Katharine; Ryde, Ian T; Meyer, Joel N; Benowitz, Neal; Thompson, Lisa M

    2017-06-01

    Household air pollution is a major contributor to death and disability worldwide. Over 95% of rural Guatemalan households use woodstoves for cooking or heating. Woodsmoke contains carcinogenic or fetotoxic polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs). Increased PAHs and VOCs have been shown to increase levels of oxidative stress. We examined PAH and VOC exposures among recently pregnant rural Guatemalan women exposed to woodsmoke and compared exposures to levels seen occupationally or among smokers. Urine was collected from 23 women who were 3 months post-partum three times over 72h: morning (fasting), after lunch, and following dinner or use of wood-fired traditional sauna baths (samples=68). Creatinine-adjusted urinary concentrations of metabolites of four PAHs and eight VOCs were analyzed by liquid chromatography-mass spectrometry. Creatinine-adjusted urinary biomarkers of oxidative stress, 8-isoprostane and 8-OHdG, were analyzed using enzyme-linked immunosorbent assays (ELISA). Long-term (pregnancy through 3 months prenatal) exposure to particulate matter and airborne PAHs were measured. Women using wood-fueled chimney stoves are exposed to high levels of particulate matter (median 48h PM 2.5 105.7μg/m 3 ; inter-quartile range (IQR): 77.6-130.4). Urinary PAH and VOC metabolites were significantly associated with woodsmoke exposures: 2-naphthol (median (IQR) in ng/mg creatinine: 295.9 (74.4-430.9) after sauna versus 23.9 (17.1-49.5) fasting; and acrolein: 571.7 (429.3-1040.7) after sauna versus 268.0 (178.3-398.6) fasting. Urinary PAH (total PAH: ρ=0.89, p0.85) or PAH and VOC biomarkers (ρ=-0.20 to 0.38, p>0.07). Urinary metabolite concentrations were significantly greater than those of heavy smokers (mean cigarettes/day=18) across all PAHs. In 15 (65%) women, maximum 1-hydroxypyrene concentrations exceeded the occupational exposure limit of coke-oven workers. The high concentrations of urinary PAH and VOC metabolites among

  14. Multivariate analysis of effects of diurnal temperature and seasonal humidity variations by tropical savanna climate on the emissions of anthropogenic volatile organic compounds.

    Science.gov (United States)

    Liu, Chih-Chung; Chen, Wei-Hsiang; Yuan, Chung-Shin; Lin, Chitsan

    2014-02-01

    Volatile organic compounds (VOCs), particularly those from anthropogenic sources, have been of substantial concern. In this study, the influences of diurnal temperature and seasonal humidity variations by tropical savanna climate on the distributions of VOCs from stationary industrial sources were investigated by analyzing the concentrations during the daytime and nighttime in the dry and wet seasons and assessing the results by principal component analysis (PCA) and cluster analysis. Kaohsiung City in Southern Taiwan, known for its severe VOC pollution, was chosen as the location to be examined. In the results, the VOC concentrations were lower during the daytime and in the wet season, possibly attributed to the stronger photochemical reactions and increasing inhibition of VOC emissions and transports by elevating humidity levels. Certain compounds became appreciably more important at higher humidity, as these compounds were saturated hydrocarbons with relatively low molecular weights. The influence of diurnal temperature variation on VOC distribution behaviors seemed to be less important than and interacted with that of seasonal humidity variation. Heavier aromatic hydrocarbons with more complex structures and some aliphatic compounds were found to be the main species accounting for the maximum variances of the data observed at high humidity, and the distinct grouping of compounds implied a pronounced inherent characteristic of each cluster in the observed VOC distributions. Under the influence of diurnal temperature variation, selected VOCs that may have stronger photochemical resistances and/or longer lifetimes in the atmosphere were clustered with each other in the cluster analysis, whereas the other groups might consist of compounds with different levels of vulnerability to sunlight or high temperatures. These findings prove the complications in the current knowledge regarding the VOC contaminations and providing insight for managing the adverse impacts of

  15. Seasonal atmospheric deposition and air-sea gas exchange of polycyclic aromatic hydrocarbons over the Yangtze River Estuary, East China Sea: Implications for source-sink processes

    Science.gov (United States)

    Jiang, Yuqing; Lin, Tian; Wu, Zilan; Li, Yuanyuan; Li, Zhongxia; Guo, Zhigang; Yao, Xiaohong

    2018-04-01

    In this work, air samples and surface seawater samples covering four seasons from March 2014 to January 2015 were collected from a background receptor site in the YRE to explore the seasonal fluxes of air-sea gas exchange and dry and wet deposition of 15 polycyclic aromatic hydrocarbons (PAHs) and their source-sink processes at the air-sea interface. The average dry and wet deposition fluxes of 15 PAHs were estimated as 879 ± 1393 ng m-2 d-1 and 755 ± 545 ng m-2 d-1, respectively. Gaseous PAH release from seawater to the atmosphere averaged 3114 ± 1999 ng m-2 d-1 in a year round. The air-sea gas exchange of PAHs was the dominant process at the air-sea interface in the YRE as the magnitude of volatilization flux of PAHs exceeded that of total dry and wet deposition. The gas PAH exchange flux was dominated by three-ring PAHs, with the highest value in summer and lowest in winter, indicating a marked seasonal variation owing to differences in Henry's law constants associated with temperature, as well as wind speed and gaseous-dissolved gradient among seasons. Based on the simplified mass balance estimation, a net 11 tons y-1 of PAHs (mainly three-ring PAHs) were volatilized from seawater to the atmosphere in a ∼20,000 km2 area in the YRE. Other than the year-round Yangtze River input and ocean ship emissions, the selective release of low-molecular-weight PAHs from bottom sediments in winter due to resuspension triggered by the East Asian winter monsoon is another potential source of PAHs. This work suggests that the source-sink processes of PAHs at the air-sea interface in the YRE play a crucial role in regional cycling of PAHs.

  16. Site profiles of low-volatile chlorinated hydrocarbons - cause-oriented monitoring in aquatic media. Vol.2. Low-volatile chlorinated hydrocarbons in surface water, sediments, suspended matter and fish of the Elbe river and its tributaries; Standortprofile schwerfluechtiger chlorierter Kohlenwasserstoffe (SCKW) - ursachenorientiertes Monitoring in aquatischen Medien. Bd. 2. SCKW in Oberflaechenwasser, Sediment, Schwebstoffen und Fischen aus der Elbe und Nebenfluessen

    Energy Technology Data Exchange (ETDEWEB)

    Heinisch, E.; Kettrup, A.; Gebefuegi, I.; Martens, D.; Bergheim, W.; Wenzel, S.

    2001-07-01

    Evaluating the primary data from ARGE ELBE, LAU Halle/Saale and the Environmental Specimen Banking (Umweltprobenbank) as well from publications from the Czech Republic (CHMU) the concentrations of the following low volatile chlorinated hydrocarbons were established for surface water, sediment, breams and eels from the rivers Elbe, Schwarze Elster, Mulde and Saale partly from 1989 till 1999: DDT and its metabolites DDE and DDD, partly as 2,4'- and 4,4' isomers; HCH ({alpha}-, {beta}-, {gamma}- and {delta} isomers); chlorinated benzenes with 1-6 Cl atoms and octachlorostyrene. The data evaluated were drawn up into tables - comprehensive in a separate supplement, in short versions within the text - and consolidated into graphs. Aim of the paper was a cause-oriented monitoring. The by far most important emission sources, found from the distance and time profiles as well as from special assessments of the substance patterns, were chemical plants. (orig.) [German] Durch Auswertung von Primaerdaten der ARGE ELBE, des LAU Halle/Saale und der Umweltprobenbank sowie von Publikationen aus Tschechien (CHMU) wurden fuer Oberflaechenwasser, Sediment, Brassen/Bleien und Aale aus der Elbe, Schwarzen Elster, Mulde und Saale fuer die Jahre von z.T. 1989 bis 1999 die Konzentrationen der folgenden schwerfluechtigen Kohlenwasserstoffe (SCKW) ermittelt: DDT und seine Metabolite DDE und DDD, z.T. als 2,4'- und 4,4'-Isomere; HCH ({alpha}-, {beta}-, {gamma}- und {delta}-Isomere); chlorierte Benzole mit 1-6 Cl-Atomen und Octachlorstyrol. Die ausgewerteten Daten wurden zu Tabellen - ausfuehrlich in einem gesonderten Tabellenanhang und verkuerzt im Textteil - zusammengestellt sowie zu Grafiken verdichtet. Ziel der Arbeit war ein ursachenorientiertes Monitoring. Als mit Abstand wesentlichste Emissionsquellen konnten anhand von Streckenprofilen und Zeitrastern sowie durch spezielle Auswertungen der Stoffmusterverteilungen Chemibetriebe ermittelt werden. (orig.)

  17. Characterization of low-molecular-weight glutenin subunit genes of ...

    Indian Academy of Sciences (India)

    2015-09-16

    Sep 16, 2015 ... 4Ministry of Education, Key Laboratory for Crop Genetic Resources and Improvement in Southwest China, ... gene mining have also been conducted in Aegilops genus, ... sites and pair-wise deletion for gaps/missing data.

  18. Extraction of low molecular weight RNA from Citrus trifolita tissues ...

    African Journals Online (AJOL)

    Jane

    2010-12-20

    Dec 20, 2010 ... A critical prerequisite in miRNA studies is acquisition of high quality LMW RNA. LMW RNA is ..... air-dried for a few minutes and then exposed to BIOMAX X-ray film for 48 h using an .... Approaches to microRNA discovery. Nat.

  19. Extraction of low molecular weight RNA from Citrus trifolita tissues ...

    African Journals Online (AJOL)

    We employed a simple and quick method involving trizol for total RNA extraction from citrus tissues, then generation of LMW RNA using 4M LiCl, which have been successfully utilized in studies in our laboratory. Compared with traditional methods, this method is less expensive and produced high RNA yields while avoiding ...

  20. Low molecular weight squash trypsin inhibitors from Sechium edule seeds.

    Science.gov (United States)

    Laure, Hélen J; Faça, Vítor M; Izumi, Clarice; Padovan, Júlio C; Greene, Lewis J

    2006-02-01

    Nine chromatographic components containing trypsin inhibitor activity were isolated from Sechium edule seeds by acetone fractionation, gel filtration, affinity chromatography and RP-HPLC in an overall yield of 46% of activity and 0.05% of protein. The components obtained with highest yield of total activity and highest specific activity were sequenced by Edman degradation and their molecular masses determined by mass spectrometry. The inhibitors contained 31, 32 and 27 residues per molecule and their sequences were: SETI-IIa, EDRKCPKILMRCKRDSDCLAKCTCQESGYCG; SETI-IIb, EEDRKCPKILMRCKRDSDCLAKCTCQESGYCG and SETI-V, CPRILMKCKLDTDCFPTCTCRPSGFCG. SETI-IIa and SETI-IIb, which differed by an amino-terminal E in the IIb form, were not separable under the conditions employed. The sequences are consistent with consensus sequences obtained from 37 other inhibitors: CPriI1meCk_DSDCla_C_C_G_CG, where capital letters are invariant amino acid residues and lower case letters are the most preserved in this position. SETI-II and SETI-V form complexes with trypsin with a 1:1 stoichiometry and have dissociation constants of 5.4x10(-11)M and 1.1x10(-9)M, respectively.

  1. Preventive role of low-molecular-weight heparin in unexplained ...

    African Journals Online (AJOL)

    Hospital, Islamabad, during April 2013 to January 2014, who had a history of ... 2 Department of Obstetrics and Gynecology, Alnafees Medical College, ISRA University, Islamabad, Pakistan ..... Terminology for pregnancy loss prior to viability:.

  2. Anticoagulant effect of low molecular weight heparin on central ...

    African Journals Online (AJOL)

    Results: No significant difference in general characteristics or the incidence of tube occlusion was detected ... position adjustment, the reverse connection of .... and the incidence of fibrin shells was highest in the control group (11.40 %; Table 3). Table 1: Occurrence of tube occlusion (N = 70). Variable. Tube occlusion.

  3. Low molecular weight block copolymers as plasticizers for polystyrene

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Karsten; Nielsen, Charlotte Juel; Hvilsted, Søren

    2005-01-01

    /mol and minimum polystyrene content of 50 w/w%, which by us is predicted as the limits for solubility of polystyrene-b-alkyl in polystyrene. DSC showed polystyrene was plasticized, as seen by a reduction in glass transition temperature, by block copolymers consisting of a polystyrene block with molecular weight...... of approximately 1 kg/mol and an alkyl block with a molecular weight of approximately of 0.3 kg/mol. The efficiency of the block copolymers as plasticizers increases with decreasing molecular weight and polystyrene content. In addition, polystyrene-b-alkyl is found to be an efficient plasticizer also...... for polystyrene-b-polyisoprene-b-polystyrene (SIS) block copolymers. The end use properties of SIS plasticized with polystyrene-b-alkyl, measured as tensile strength, is higher than for SIS plasticized with dioctyl adipate. The polystyrene-b-polybutadiene-b-polystyrene and polystyrene-bpoly(propylene glycol...

  4. Effects of low-molecular weight alcohols on bacterial viability

    Directory of Open Access Journals (Sweden)

    Man Adrian

    2017-10-01

    Full Text Available Alcohol based solutions are among the most convenient and wide spread aid in the prevention of nosocomial infections. The current study followed the efficacy of several types and isomers of alcohols on different bacterial species. Seven alcohols (ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl alcohol, and ethylene glycol were used to evaluate their minimal inhibitory and bactericidal effects by microdilution method on bacteria that express many phenotypical characteristics: different cell-wall structure (Gram positive/negative bacteria, capsule production (Klebsiella pneumoniae, antibiotic resistance (MRSA vs MSSA or high environmental adaptability (Pseudomonas aeruginosa. Results: The best inhibitory effect was noticed for n-propyl, followed by iso-propyl, n-butyl, and iso-butyl alcohols with equal values. Ethylene glycol was the most inefficient alcohol on all bacteria. In K. pneumoniae and P. aeruginosa, the bactericidal concentrations were higher than the inhibitory one, and to a level similar to that encountered for most of the Gram-positive bacteria. Among Gram-positive cocci, E. faecalis presented the lowest susceptibility to alcohols. Conclusions: All alcohols presented good effect on bacteria, even in low concentrations. Compared to ethanol as standard, there are better alternatives that can be used as antimicrobials, namely longer-chain alcohols such as propyl or butyric alcohols and their iso- isomers. Ethylene glycol should be avoided, due to its toxicity hazard and low antimicrobial efficacy. Bacterial phenotype (highly adaptable bacteria, biofilm formation and structure (cell wall structure, presence of capsule may drastically affect the responsiveness to the antimicrobial activity of alcohols, leading to higher bactericidal than inhibitory concentrations.

  5. Practical γ-Ray Level for Low Molecular Weight Chitosan

    International Nuclear Information System (INIS)

    Yoksan, Rangrong; Chirachanchai, Suwabun; Biramontri, Siriratana

    2003-06-01

    The present work proposes a practical level of γ-Ray to lower the molecular weigh of chitosan irradiated in solid state and water. The molecular weight reduction is up to 80% at γ-ray amount of 50 kGy. The same level of reduction can be achieved by only 20 kGy in the presence of initiator (K 2 S 2 O 8 or H 2 O 2 ). The structure is significantly changed in the case of chitosan-acetic acid solution or chitosan dispersed in water with 2% aq. K 2 S 2 O 8 solution

  6. Low-molecular-weight heparins allow selected outpatient treatment ...

    African Journals Online (AJOL)

    tor a I. 3. LMWHs may also cause fewer haemorrhagic complications as a result of their less pronounced effect on platelet and vascular endothelial function. These characteristics result in a longer half-life, better bio- availability, and more predictable anticoagulant activity.3.' The LMWHs can therefore be administered ...

  7. Extraction of low molecular weight RNA from Citrus trifolita tissues ...

    African Journals Online (AJOL)

    Jane

    2010-12-20

    Dec 20, 2010 ... many biological and metabolic processes, including tissue ... water before getting LMW RNA. ... 1 cm) were collected from five-year-old trifoliate orange (C. ... using 700 µl 75% ethanol and total RNA was precipitated by.

  8. Characterization of low-molecular-weight glutenin subunit genes of ...

    Indian Academy of Sciences (India)

    Supplementary data, J. Genet. 94, 497–501. Table 2. LMW-GS genes obtained in this study. Species. Accession no. Clone. Length (bp). Sequence similarity. Ae. bicornis. CIae 47. Sb47-1. 1053. EU189089 96% T. aestivum. (SbSb). Sb47-2. 1053. EU189089 96% T. aestivum. Sb47-3. 1053. EU305550 97% Ae. longissima.

  9. Polycyclic aromatic hydrocarbons in surface soil across the Tibetan Plateau: Spatial distribution, source and air–soil exchange

    International Nuclear Information System (INIS)

    Wang, Chuanfei; Wang, Xiaoping; Gong, Ping; Yao, Tandong

    2014-01-01

    There are limited data on polycyclic aromatic hydrocarbons (PAHs) in both the atmosphere and soil of the Tibetan Plateau (TP). Concentrations of PAHs were therefore measured in 13 XAD resin-based passive air samplers and 41 surface (0–5 cm) soil samples across the TP. The average concentration of atmospheric PAHs was 5.55 ng/m 3 , which was lower than that reported for other background areas, but higher than the Arctic. Concentrations in the soils fell in a wide range from 5.54 to 389 ng/g, with an average of 59.9 ng/g. Elevation was found to play an important role in determining the spatial distribution of soil PAHs. The air–soil exchange state showed that the soils of the TP will likely remain as a sink for high molecular weight PAHs, but may become a potential “secondary source” for low molecular weight PAHs. Highlights: • The levels of PAHs in air and soil of the Tibetan Plateau were relatively lower than other background region of world. • The soil PAHs concentration decreased with the increase of elevation. • The Tibetan Plateau will likely remain as a sink for high molecular weight PAHs. • The Tibetan Plateau may become a potential “secondary source” for low molecular weight PAHs. -- The Tibetan soil will likely remain as a sink for high molecular weight PAHs, but may become a potential “secondary source” for low molecular weight PAHs

  10. Recovering hydrocarbons with surfactants from lignin

    Energy Technology Data Exchange (ETDEWEB)

    Naae, D.G.; Whittington, L.E.; Ledoux, W.A.; Debons, F.E.

    1988-11-29

    This patent describes a method of recovering hydrocarbons from an underground hydrocarbon formation penetrated by at least one injection well and at least one production well, which comprises: injecting into the formation through an injection well a surfactant slug comprising about 0.1% to about 10% by weight of surfactants produced from lignin, the surfactants produced by placing lignin in contact with water, converting the lignin into low molecular weight lignin phenols by reducing the lignin in the presence of a reducing agent of carbon monoxide or hydrogen creating a reduction reaction mixture comprising oil soluble lignin phenols, the reduction occurring at a temperature greater than about 200/sup 0/C and a pressure greater than about 100 psi, recovering the oil soluble lignin phenols from the reduction mixture, and converting the lignin phenols into lignin surfactants by a reaction selected from the group consisting of alkoxylation, sulfonation, sulfation, aklylation, sulfomethylation, and alkoxysulfation; injecting into the formation through the injection well a drive fluid to push the surfactant slug towards a production well; and recovering hydrocarbons at the production well.

  11. Nonvolatile, semivolatile, or volatile: redefining volatile for volatile organic compounds.

    Science.gov (United States)

    Võ, Uyên-Uyén T; Morris, Michael P

    2014-06-01

    Although widely used in air quality regulatory frameworks, the term "volatile organic compound" (VOC) is poorly defined. Numerous standardized tests are currently used in regulations to determine VOC content (and thus volatility), but in many cases the tests do not agree with each other, nor do they always accurately represent actual evaporation rates under ambient conditions. The parameters (time, temperature, reference material, column polarity, etc.) used in the definitions and the associated test methods were created without a significant evaluation of volatilization characteristics in real world settings. Not only do these differences lead to varying VOC content results, but occasionally they conflict with one another. An ambient evaporation study of selected compounds and a few formulated products was conducted and the results were compared to several current VOC test methodologies: SCAQMD Method 313 (M313), ASTM Standard Test Method E 1868-10 (E1868), and US. EPA Reference Method 24 (M24). The ambient evaporation study showed a definite distinction between nonvolatile, semivolatile, and volatile compounds. Some low vapor pressure (LVP) solvents, currently considered exempt as VOCs by some methods, volatilize at ambient conditions nearly as rapidly as the traditional high-volatility solvents they are meant to replace. Conversely, bio-based and heavy hydrocarbons did not readily volatilize, though they often are calculated as VOCs in some traditional test methods. The study suggests that regulatory standards should be reevaluated to more accurately reflect real-world emission from the use of VOC containing products. The definition of VOC in current test methods may lead to regulations that exclude otherwise viable alternatives or allow substitutions of chemicals that may limit the environmental benefits sought in the regulation. A study was conducted to examine volatility of several compounds and a few formulated products under several current VOC test

  12. Sources and mass inventory of sedimentary polycyclic aromatic hydrocarbons in the Gulf of Thailand: Implications for pathways and energy structure in SE Asia.

    Science.gov (United States)

    Hu, Limin; Shi, Xuefa; Qiao, Shuqing; Lin, Tian; Li, Yuanyuan; Bai, Yazhi; Wu, Bin; Liu, Shengfa; Kornkanitnan, Narumol; Khokiattiwong, Somkiat

    2017-01-01

    Surface sediments obtained from a matrix of 92 sample sites in the Gulf of Thailand (GOT) were analyzed for a comprehensive study of the distribution, sources, and mass inventory of polycyclic aromatic hydrocarbons (PAHs) to assess their input pathways and impacts of the regional land-based energy structure on the deposition of PAHs on the adjacent continental margins. The concentration of 16 PAHs in the GOT ranged from 2.6 to 78.1ng/g (dry weight), and the mean concentration was 19.4±15.1ng/g. The spatial distribution pattern of 16 PAH was generally consistent with that of sediment grain size, suggesting the influence of regional hydrodynamic conditions. Correlation and principal component analysis of the PAHs indicated that direct land-based inputs were dominantly responsible for the occurrence of PAHs in the upper GOT and the low molecular weight (LMW) PAHs in the coastal region could be from petrogenic sources. A positive matrix factorization (PMF) model apportioned five contributors: petroleum residues (~44%), biomass burning (~13%), vehicular emissions (~11%), coal combustion (~6%), and air-water exchange (~25%). Gas absorption may be a significant external input pathway for the volatile PAHs in the open GOT, which further implies that atmospheric loading could be important for the sink of PAHs in the open sea of the Southeast Asia (SE Asia). The different PAH source patterns obtained and a significant disparity of PAH mass inventory in the sediments along the East and Southeast Asia continental margins can be ascribed mainly to different land-based PAH emission features under the varied regional energy structure in addition to the depositional environment and climatic conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Analysis of hydrocarbons generated in coalbeds

    Science.gov (United States)

    Butala, Steven John M.

    This dissertation describes kinetic calculations using literature data to predict formation rates and product yields of oil and gas at typical low-temperature conditions in coalbeds. These data indicate that gas formation rates from hydrocarbon thermolysis are too low to have generated commercial quantities of natural gas, assuming bulk first-order kinetics. Acid-mineral-catalyzed cracking, transition-metal-catalyzed hydrogenolysis of liquid hydrocarbons, and catalyzed CO2 hydrogenation form gas at high rates. The gaseous product compositions for these reactions are nearly the same as those for typical natural coalbed gases, while those from thermal and catalytic cracking are more representative of atypical coalbed gases. Three Argonne Premium Coals (Upper-Freeport, Pittsburgh #8 and Lewiston-Stockton) were extracted with benzene in both Soxhlet and elevated pressure extraction (EPE) systems. The extracts were compared on the basis of dry mass yield and hydrocarbon profiles obtained by gas chromatography/mass spectrometry. The dry mass yields for the Upper-Freeport coal gave consistent results by both methods, while the yields from the Pittsburgh #8 and Lewiston-Stockton coals were greater by the EPE method. EPE required ˜90 vol. % less solvent compared to Soxhlet extraction. Single-ion-chromatograms of the Soxhlet extracts all exhibited bimodal distributions, while those of the EPE extracts did not. Hydrocarbons analyzed from Greater Green River Basin samples indicate that the natural oils in the basin originated from the coal seams. Analysis of artificially produced oil indicates that hydrous pyrolysis mimics generation of C15+ n-alkanes, but significant variations were found in the branched alkane, low-molecular-weight n-alkanes, and high-molecular-weight aromatic hydrocarbon distributions.

  14. Risk of human exposure to polycyclic aromatic hydrocarbons: A case study in Beijing, China

    International Nuclear Information System (INIS)

    Yu, Yanxin; Li, Qi; Wang, Hui; Wang, Bin; Wang, Xilong; Ren, Aiguo; Tao, Shu

    2015-01-01

    Polycyclic aromatic hydrocarbons (PAHs) can cause adverse effects on human health. The relative contributions of their two major intake routes (diet and inhalation) to population PAH exposure are still unclear. We modeled the contributions of diet and inhalation to the overall PAH exposure of the population of Beijing in China, and assessed their human incremental lifetime cancer risks (ILCR) using a Mont Carlo simulation approach. The results showed that diet accounted for about 85% of low-molecular-weight PAH (L-PAH) exposure, while inhalation accounted for approximately 57% of high-molecular-weight PAH (H-PAH) exposure of the Beijing population. Meat and cereals were the main contributors to dietary PAH exposure. Both gaseous- and particulate-phase PAHs contributed to L-PAH exposure through inhalation, whereas exposure to H-PAHs was mostly from the particulate-phase. To reduce the cancer incidence of the Beijing population, more attention should be given to inhaled particulate-phase PAHs with considerable carcinogenic potential. - Highlights: • We modeled the contributions of diet and inhalation to population PAH exposure. • Diet contributed 85% of population exposure to low molecular-weight PAHs. • Inhalation contributed 57% of population exposure to high molecular-weight PAHs. • The PAH exposure level with body-weight adjustment decreased with age increasing. • The population cancer risk of PAH exposure is lower than the serious risk level. - The exposure of the Beijing population to carcinogenic polycyclic aromatic hydrocarbons was mainly from inhaled particulate matter

  15. A headspace solid-phase microextraction procedure coupled with gas chromatography-mass spectrometry for the analysis of volatile polycyclic aromatic hydrocarbons in milk samples

    Energy Technology Data Exchange (ETDEWEB)

    Aguinaga, N.; Campillo, N.; Vinas, P.; Hernandez-Cordoba, M. [University of Murcia, Department of Analytical Chemistry, Faculty of Chemistry, Murcia (Spain)

    2008-06-15

    A sensitive and solvent-free method for the determination of ten polycyclic aromatic hydrocarbons, namely, naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene and chrysene, with up to four aromatic rings, in milk samples using headspace solid-phase microextraction and gas chromatography-mass spectrometry detection has been developed. A polydimethylsiloxane-divinylbenzene fiber was chosen and used at 75 C for 60 min. Detection limits ranging from 0.2 to 5 ng L{sup -1} were attained at a signal-to-noise ratio of 3, depending on the compound and the milk sample under analysis. The proposed method was applied to ten different milk samples and the presence of six of the analytes studied in a skimmed milk with vegetal fiber sample was confirmed. The reliability of the procedure was verified by analyzing two different certified reference materials and by recovery studies. (orig.)

  16. Field desorption mass spectroscopy monitoring of changes in hydrocarbon type composition during petroleum biodegradation

    International Nuclear Information System (INIS)

    Huesemann, M.H.

    1995-01-01

    A comprehensive petroleum hydrocarbon characterization procedure involving group type separation, boiling point distribution, and hydrocarbon typing by field desorption mass spectroscopy (FDMS) has been developed to quantify changes in hydrocarbon type composition during bioremediation of petroleum-contaminated soils. FDMS is able to quantify the concentration of hundreds of specific hydrocarbon types based on their respective hydrogen deficiency (z-number) and molecular weight (carbon number). Analytical results from two bioremediation experiments involving soil contaminated with crude oil and motor oil indicate that alkanes and two-ring saturates (naphthenes) were readily biodegradable. In addition, low-molecular-weight hydrocarbons generally were biodegraded to a larger extent than those of high molecular weight. More importantly, it was found that the extent of biodegradation of specific hydrocarbon types was comparable between treatments and appeared to be unaffected by the petroleum contaminant source, soil type, or experimental conditions. It was therefore concluded that in these studies the extent of total petroleum hydrocarbon (TPH) biodegradation is primarily affected by the molecular composition of the petroleum hydrocarbons present in the contaminated soil

  17. Estudo experimental dos efeitos da heparina de baixo peso molecular (Enoxaparina na formação de calo ósseo em fêmures de ratos The effects of low-molecular-weight heparin (Enoxaparin on bony callus formation in rats' femurs - an experimental study

    Directory of Open Access Journals (Sweden)

    Salim Mussi Filho

    2006-01-01

    Full Text Available O tromboembolismo venoso é uma complicação grave que pode ocorrer após fraturas. O tratamento anticoagulante mais utilizado é com a heparina de baixo peso molecular (HBPM. Existem estudos que mostram que essa droga pode interferir no metabolismo ósseo. Com o objetivo de avaliar a influência da HBPM no processo de formação de calo ósseo, realizamos um estudo experimental em ratos. A amostra constituiu-se de 22 ratos de linhagem Wistar, machos, que foram submetidos à fratura diafisária de seus fêmures direitos. Foram divididos em dois grupos de 11. No grupo controle, os animais recebiam soro fisiológico e no grupo de estudo, recebiam HBPM, enoxaparina, diariamente, por 28 dias. Após este período os ratos foram submetidos à eutanásia e os fêmures foram avaliados. No estudo macroscópico foi constatada consolidação em 11 animais (100% que não receberam enoxaparina, e, em dez animais (90,9% que receberam a droga em estudo. No estudo histológico foi constatada a formação de calo ósseo em todos os fêmures. Concluiu-se neste experimento que a enoxaparina não altera o processo de consolidação óssea em fêmures de ratos Wistar.Venous thromboembolism is a serious complication that may follow fractures. The most commonly used anticoagulant treatment is low-molecular-weight heparin (LMWH. There are some studies showing that this drug may interfere on bone metabolism. With the objective of evaluating the LMWH influence on the process of bony callus formation, we conducted an experimental study on rats. Sample was constituted of 22 Wistar male rats, which were submitted to diaphyseal fracture on their right femurs. They were divided into two groups of 11 subjects each. In the control group, the animals received saline solution and in the study group, they received LMWH - enoxaparin - in a daily basis, during 28 days. After that period, the rats were submitted to euthanasia for femur assessment purposes. At the macroscopic study

  18. The effect of prophylactic dose of a low molecular weight heparin on skin wound healing of rats Efeito da dose profilática de heparina de baixo peso molecular na cicatrização de feridas na pele de ratos

    Directory of Open Access Journals (Sweden)

    Ozdamar Fuad Oken

    2009-12-01

    Full Text Available PURPOSE: To investigate the effect of prophylactic dose of a low molecular weight heparin, enoxaparin, on skin wound healing of rats. METHODS: Forty rats were used for the study. Rats were randomly assigned to two equal groups. Experimental group received prophylactic dose of enoxaparin. Physiologic saline was administered to the control group. Parameters of wound healing of experimental and control groups were compared. For comparison of the groups in terms of fibrosis, vascularization, inflammation, epithelization, and tensile strength test (Newton. Mann-Whitney-U test was used because variables were categorical data (fibrosis, vascularization, inflammation and epithelization. Differences between groups were analyzed with independent samples t-test (tensile strength. Significance was set at pOBJETIVO: Investigar o efeito de dose profilática da heparina de baixo peso molecular, enoxaparina, na cicatrização de feridas na pele de ratos. MÉTODOS: Quarenta ratos foram utilizados para o estudo. Ratos foram distribuídos aleatoriamente a dois grupos iguais. O grupo experimental recebeu profilática de enoxaparina. Solução salina fisiologica foi administrada ao grupo controle. Foram comparados parâmetros de cicatrização dos grupos experimental e controle.Os grupos foram comparados em termos de fibrose, vascularização, inflamação, epitelização e força tensil (teste de Newton. Foi realizado o teste de Mann-Whitney-U para variáveis com dados categóricos (fibrose, cicatrização, inflamação e epitelização. Diferenças entre os grupos foram analisadas como amostras independentes pelo t-teste (força tensil. Significância foi fixada para p < 0,05. RESULTADOS: A ferida do grupo experimental apresentou força tensil diminuída significativamente (p < 0,001, o exame histopatológico revelou um significativo (p < 0,001 retardo na epitelização e diminuição na fibrose, cicatrização, inflamação (p < 0,001 no grupo experimental

  19. Trace determination of volatile polycyclic aromatic hydrocarbons in natural waters by magnetic ionic liquid-based stir bar dispersive liquid microextraction.

    Science.gov (United States)

    Benedé, Juan L; Anderson, Jared L; Chisvert, Alberto

    2018-01-01

    In this work, a novel hybrid approach called stir bar dispersive liquid microextraction (SBDLME) that combines the advantages of stir bar sorptive extraction (SBSE) and dispersive liquid-liquid microextraction (DLLME) has been employed for the accurate and sensitive determination of ten polycyclic aromatic hydrocarbons (PAHs) in natural water samples. The extraction is carried out using a neodymium stir bar magnetically coated with a magnetic ionic liquid (MIL) as extraction device, in such a way that the MIL is dispersed into the solution at high stirring rates. Once the stirring is ceased, the MIL is magnetically retrieved onto the stir bar, and subsequently subjected to thermal desorption (TD) coupled to a gas chromatography-mass spectrometry (GC-MS) system. The main parameters involved in TD, as well as in the extraction step affecting the extraction efficiency (i.e., MIL amount, extraction time and ionic strength) were evaluated. Under the optimized conditions, the method was successfully validated showing good linearity, limits of detection and quantification in the low ng L -1 level, good intra- and inter-day repeatability (RSD < 13%) and good enrichment factors (18 - 717). This sensitive analytical method was applied to the determination of trace amounts of PAHs in three natural water samples (river, tap and rainwater) with satisfactory relative recovery values (84-115%), highlighting that the matrices under consideration do not affect the extraction process. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. HP-SPME of volatile polycyclic aromatic hydrocarbons from water using multiwalled carbon nanotubes coated on a steel fiber through electrophoretic deposition

    Energy Technology Data Exchange (ETDEWEB)

    Maghsoudi, S.; Noroozian, E. [Shahid Bahonar Univ., Kerman (Iran, Islamic Republic of). Dept. of Chemistry

    2012-08-15

    A headspace solid-phase microextraction (SPME) method using a stainless steel wire electrophoretically coated with dodecylsulfate modified multiwalled carbon nanotubes was used for the gas chromatographic (GC) determination of polycyclic aromatic hydrocarbons (PAHs) in aqueous samples. Electrophoretic deposition was easily carried out from an aqueous sodium dodecylsulfate medium. The effects of various parameters on the efficiency of SPME process, such as extraction time, extraction temperature, ionic strength, desorption time, and desorption temperature were studied. Under optimized conditions, the detection limits for the various PAHs studied varied from 0.03 to 0.07 ng mL{sup -1}. The inter-day and intra-day relative standard deviations at a 10 ng mL{sup -1} concentration level (n = 7) using a single-fiber were from 5.5 to 9.7 and 4.1 to 8.5 %, respectively. The fiber-to-fiber RSD% (n = 3) was between 7.3 and 11.1 %. The linear ranges were between 0.1 and 100 ng mL{sup -1}. The method was successfully applied to the analysis of a real sample with the recoveries from 88 to 105 % for 5 ng mL{sup -1} and 89 to 101 % for 0.5 ng mL{sup -1} samples. (orig.)

  1. Stable Carbon Isotope Fractionation during Bacterial Acetylene Fermentation: Potential for Life Detection in Hydrocarbon-Rich Volatiles of Icy Planet(oid)s.

    Science.gov (United States)

    Miller, Laurence G; Baesman, Shaun M; Oremland, Ronald S

    2015-11-01

    We report the first study of stable carbon isotope fractionation during microbial fermentation of acetylene (C2H2) in sediments, sediment enrichments, and bacterial cultures. Kinetic isotope effects (KIEs) averaged 3.7 ± 0.5‰ for slurries prepared with sediment collected at an intertidal mudflat in San Francisco Bay and 2.7 ± 0.2‰ for a pure culture of Pelobacter sp. isolated from these sediments. A similar KIE of 1.8 ± 0.7‰ was obtained for methanogenic enrichments derived from sediment collected at freshwater Searsville Lake, California. However, C2H2 uptake by a highly enriched mixed culture (strain SV7) obtained from Searsville Lake sediments resulted in a larger KIE of 9.0 ± 0.7‰. These are modest KIEs when compared with fractionation observed during oxidation of C1 compounds such as methane and methyl halides but are comparable to results obtained with other C2 compounds. These observations may be useful in distinguishing biologically active processes operating at distant locales in the Solar System where C2H2 is present. These locales include the surface of Saturn's largest moon Titan and the vaporous water- and hydrocarbon-rich jets emanating from Enceladus. Acetylene-Fermentation-Isotope fractionation-Enceladus-Life detection.

  2. Aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Roder, M.

    1985-01-01

    Papers dealing with radiolysis of aromatic hydrocarbons of different composition (from benzene to terphenyls and hydrocarbons with condensed rings) as well as their mixtures (with alkanes, alkenes, other aromatic hydrocarbons) are reviewed. High radiation stability of aromatic hydrocarbons in condensed phases associated with peculiarities of molecular structure of compounds is underlined. Mechanisms of radiolytic processes, vaues of product yields are considered

  3. Process for treating hydrocarbons, etc

    Energy Technology Data Exchange (ETDEWEB)

    1933-09-15

    A process is described for treating simultaneously bituminous substances and hydrocarbon oils for the production of low-boiling hydrocarbons and volatilization of the bituminous substances, characterized by the fact that it consists of heating a current of charge constituted by a mixture of the bituminous substances and hydrocarbon oils, to a high temperature, passing the heated current into a zone of extended reaction where the vapors are separated from the liquid or solid residue to favor transformation of the liquid hydrocarbons and volatilization of the bituminous substances, owing to the utilization of a heating agent carried to a high temperature being brought in contact with the heated charge in order to communicate its heat to the charge, while this later presents itself as relatively fine pellet or in the condition of distinct particles, particularly separated from one another.

  4. Ácidos orgânicos de baixo peso molecular e ácidos húmicos e alterações em algumas propriedades físicas e químicas de Latossolos, Plintossolo e Neossolo Quartzarênico Low molecular weight organic and humic acids and effects on physical and chemical properties of Oxisols and related soils

    Directory of Open Access Journals (Sweden)

    Marcelo Metri Corrêa

    2008-02-01

    longa, podendo-se estabelecer a seguinte ordem, de acordo com seu efeito: ácido cítrico > ácido oxálico > ácidos húmicos. O conteúdo de argila dispersa em água mostrou ser o principal fator responsável pelo aumento da resistência à penetração.The organic acids from the organic matter decomposition, root exudation and microbial activity, play an important role on physical and chemical soil conditions. However their efficiency is conditioned to the quality and kind of organic acids and interactions with the soil mineral surface. The aim of this study was to evaluate the effect of humic and organic acids of high and low molecular weight on the physical and chemical properties of B horizons of four Oxisols and one Plinthustult, and a C horizon of Quartzipsamment. A completely randomized 6x3x5 factorial design (soils x organic acids x dose was used, with 3 replications. The following organic acid rates were applied: 0, 1, 3, 9 and 18 mM citric and oxalic acid and 0.0; 2.0; 4.0; 6.0 and 10.0 g kg-1 humic acids. The experimental units consisted of 25 cm³ of air-dried fine-earth fraction in PVC cylinders (2.0 cm height and 4.0 cm diameter, subjected to moistening and drying cycles in an isothermal chamber at 30 °C, for three days, in seven cycles. The water dispersible clay, penetration resistance and ammonium oxalate-extracted Fe and Al were determined. The contents of water dispersible clay were variable, related to the rate and type of organic acids, and also to soil texture and mineralogy. Thus, the dispersion resistance of the goethitic was higher than of the hematitic soils, which was in turn higher than of the gibbsitic soils. Moreover, organic acids of low molecular weight resulted in higher dispersion and penetration resistance than those of high molecular weight, in the following sequence: citric acid ³ oxalic acid > humic acid. The content of water dispersible clay proved to be an important factor in the increase of penetration resistance.

  5. Gas chromatographic analysis of volatile hydrocarbons to detect irradiated chicken, pork and beef - an intercomparison study. A report in English and German

    Energy Technology Data Exchange (ETDEWEB)

    Schreiber, G.A.; Schulzki, G.; Spiegelberg, A.; Helle, N.; Adam, S.T.; Ammon, J.; Baumann, P.; Brockmann, R.; Baenziger, U.; Delincee, H.; Droz, C.; Estendorfer, S.; Gemperle, C.; Grabowski, H.U. von; Kaenzig, A.; Kroells, W.; Matter, L.; Metschies, M.; Mildau, G.; Pfordt, J.; Plaga-Lodde, A.; Punkert, M.; Roennefahrt, B.; Ruge, W.; Stemmer, H.; Vater, N.; Wilmers, K.; Boegl, K.W.

    1993-12-31

    This report provides a detailed description of an inter-laboratory study to detect irradiation treatment of chicken carcasses, pork and beef using a method suitable for routine application. The 17 participating laboratories determined the quantity of four different radiation-induced hydrocarbons (1-tetradecene, pentadecane, 1,7-hexadecadiene, 8-heptadecene) in coded samples approx. 3 and 6 months after irradiation. The quantities detected were used to identify the samples as irradiated or non-irradiated. The samples of each type of meat to be examined had been supplied by two different producers. The dose range that was tested (approx. 0.6 to 7.5 kGy) included commercially used doses (approx. 1 to 5 kGy). The method employed enable 98.3% of a total of 864 samples to be correctly identified as irradiated or non-irradiated. This result is remarkable: Although the marker concentrations in the various samples showed a clear dose dependency, the variation was quite marked. The high rate of correct identifications could be achieved by defining a sample only as irradiated if certain quantities of at least 3 of the radiolytic products to be determined had been found. A similar identification rate was achieved if quantification of markers was omitted to identify a sample only as irradiated when all the expected radiolysis products could be clearly detected. For all three types of meat, no significant differences in marker yields could be shown for the products of the respective two producers. Also, in none of the types of meat, any significant difference could be revealed for the quantiatitive results achieved three and six months after irradiation. These results show that irradiation of chicken carcasses, pork and beef in the commerically used dose range can be clearly detected throughout the entire period in which products are normally stored and that the method described is suitable for routine analyses in food control laboratories. (orig.)

  6. Gas chromatographic analysis of volatile hydrocarbons to detect irradiated chicken, pork and beef - an intercomparison study. A report in English and German

    International Nuclear Information System (INIS)

    Schreiber, G.A.; Schulzki, G.; Spiegelberg, A.; Helle, N.; Adam, S.T.; Ammon, J.; Baumann, P.; Brockmann, R.; Baenziger, U.; Delincee, H.; Droz, C.; Estendorfer, S.; Gemperle, C.; Grabowski, H.U. von; Kaenzig, A.; Kroells, W.; Matter, L.; Metschies, M.; Mildau, G.; Pfordt, J.; Plaga-Lodde, A.; Punkert, M.; Roennefahrt, B.; Ruge, W.; Stemmer, H.; Vater, N.; Wilmers, K.; Boegl, K.W.

    1993-01-01

    This report provides a detailed description of an inter-laboratory study to detect irradiation treatment of chicken carcasses, pork and beef using a method suitable for routine application. The 17 participating laboratories determined the quantity of four different radiation-induced hydrocarbons (1-tetradecene, pentadecane, 1,7-hexadecadiene, 8-heptadecene) in coded samples approx. 3 and 6 months after irradiation. The quantities detected were used to identify the samples as irradiated or non-irradiated. The samples of each type of meat to be examined had been supplied by two different producers. The dose range that was tested (approx. 0.6 to 7.5 kGy) included commercially used doses (approx. 1 to 5 kGy). The method employed enable 98.3% of a total of 864 samples to be correctly identified as irradiated or non-irradiated. This result is remarkable: Although the marker concentrations in the various samples showed a clear dose dependency, the variation was quite marked. The high rate of correct identifications could be achieved by defining a sample only as irradiated if certain quantities of at least 3 of the radiolytic products to be determined had been found. A similar identification rate was achieved if quantification of markers was omitted to identify a sample only as irradiated when all the expected radiolysis products could be clearly detected. For all three types of meat, no significant differences in marker yields could be shown for the products of the respective two producers. Also, in none of the types of meat, any significant difference could be revealed for the quantiatitive results achieved three and six months after irradiation. These results show that irradiation of chicken carcasses, pork and beef in the commerically used dose range can be clearly detected throughout the entire period in which products are normally stored and that the method described is suitable for routine analyses in food control laboratories. (orig.)

  7. Rare Earth Chalcogels NaLnSnS4 (Ln = Y, Gd, Tb) for Selective Adsorption of Volatile Hydrocarbons and Gases

    KAUST Repository

    Edhaim, Fatimah

    2017-06-28

    The synthesis and characterization of the rare earth chalcogenide aerogels NaYSnS4, NaGdSnS4, and NaTbSnS4 is reported. Rare earth metal ions like Y3+, Gd3+, and Tb3+ react with the chalcogenide clusters [SnS4]4– in aqueous formamide solution forming extended polymeric networks by gelation. Aerogels obtained after supercritical drying have BET surface areas of 649 m2·g–1 (NaYSnS4), 479 m2·g–1 (NaGdSnS4), and 354 m2·g–1 (NaTbSnS4). Electron microscopy and physisorption studies reveal that the new materials have pores in the macro (above 50 nm) and meso (2–50 nm) regions. These aerogels show higher adsorption of toluene vapor over cyclohexane vapor and CO2 over CH4 or H2. The notable adsorption capacity for toluene (NaYSnS4: 1108 mg·g–1; NaGdSnS4: 921 mg·g–1; and NaTbSnS4: 645 mg·g–1) and high selectivity for gases (CO2/H2: 172 and CO2/CH4: 50 for NaYSnS4, CO2/H2: 155 and CO2/CH4: 37 for NaGdSnS4, and CO2/H2: 75 and CO2/CH4: 28 for NaTbSnS4) indicate potential future use of chalcogels in adsorption-based gas or hydrocarbon separation processes.

  8. Studies on the production of hydrocarbon mixtures from waste methyl ethyl ketone

    International Nuclear Information System (INIS)

    Kokitkar, P.B.; Roth, O.B.; Debelak, K.A.

    1992-01-01

    Large quantities of waste solvents are generated annually around the world in a large number of diverse industries, the paints and plastics industry being the largest consumer. The management of these waste solvents is becoming more and more difficult due to stricter environmental regulations by the EPA. The paint and allied products industry is expected to shift its solvent use from aliphatics and aromatics to oxygenated solvents to meet emissions and disposal standards. Many researchers have studied the dehydration reactions of oxygenated solvents to produce dehydration. However, most researchers have obtained only low molecular weight compounds (C 3 - C 4 hydrocarbons) from C 1 - C 4 alcohols and ketones. The kinetics of this class of reactions are not available in the open literature. The objective of this paper is to investigate the thermodynamic feasibility of this class of reactions and to compare the hydrocarbon products obtained using methylethyl ketone with regular unleaded gasoline

  9. A statistical approach to the interpretation of aliphatic hydrocarbon distributions in marine sediments

    Science.gov (United States)

    Rapp, J.B.

    1991-01-01

    Q-mode factor analysis was used to quantitate the distribution of the major aliphatic hydrocarbon (n-alkanes, pristane, phytane) systems in sediments from a variety of marine environments. The compositions of the pure end members of the systems were obtained from factor scores and the distribution of the systems within each sample was obtained from factor loadings. All the data, from the diverse environments sampled (estuarine (San Francisco Bay), fresh-water (San Francisco Peninsula), polar-marine (Antarctica) and geothermal-marine (Gorda Ridge) sediments), were reduced to three major systems: a terrestrial system (mostly high molecular weight aliphatics with odd-numbered-carbon predominance), a mature system (mostly low molecular weight aliphatics without predominance) and a system containing mostly high molecular weight aliphatics with even-numbered-carbon predominance. With this statistical approach, it is possible to assign the percentage contribution from various sources to the observed distribution of aliphatic hydrocarbons in each sediment sample. ?? 1991.

  10. Rare earth chalcogels NaLnSnS{sub 4} (Ln = Y, Gd, Tb) for selective adsorption of volatile hydrocarbons and gases

    Energy Technology Data Exchange (ETDEWEB)

    Edhaim, Fatimah; Rothenberger, Alexander [Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal (Saudi Arabia)

    2017-08-16

    The synthesis and characterization of the rare earth chalcogenide aerogels NaYSnS{sub 4}, NaGdSnS{sub 4}, and NaTbSnS{sub 4} is reported. Rare earth metal ions like Y{sup 3+}, Gd{sup 3+}, and Tb{sup 3+} react with the chalcogenide clusters [SnS{sub 4}]{sup 4-} in aqueous formamide solution forming extended polymeric networks by gelation. Aerogels obtained after supercritical drying have BET surface areas of 649 m{sup 2}.g{sup -1} (NaYSnS{sub 4}), 479 m{sup 2}.g{sup -1} (NaGdSnS{sub 4}), and 354 m{sup 2}.g{sup -1} (NaTbSnS{sub 4}). Electron microscopy and physisorption studies reveal that the new materials have pores in the macro (above 50 nm) and meso (2-50 nm) regions. These aerogels show higher adsorption of toluene vapor over cyclohexane vapor and CO{sub 2} over CH{sub 4} or H{sub 2}. The notable adsorption capacity for toluene (NaYSnS{sub 4}: 1108 mg.g{sup -1}; NaGdSnS{sub 4}: 921 mg.g{sup -1}; and NaTbSnS4: 645 mg.g{sup -1}) and high selectivity for gases (CO{sub 2}/H{sub 2}: 172 and CO{sub 2}/CH{sub 4}: 50 for NaYSnS{sub 4}, CO{sub 2}/H{sub 2}: 155 and CO{sub 2}/CH{sub 4}: 37 for NaGdSnS{sub 4}, and CO{sub 2}/H{sub 2}: 75 and CO{sub 2}/CH{sub 4}: 28 for NaTbSnS{sub 4}) indicate potential future use of chalcogels in adsorption-based gas or hydrocarbon separation processes. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Effect of high and low molecular weight glutenin subunits, and subunits of gliadin on physicochemical parameters of different wheat genotypes Efeito das subunidades de glutenina de alto e baixo peso molecular e das subunidades de gliadina sobre os parâmetros físico-químicos de diferentes genótipos de trigo

    Directory of Open Access Journals (Sweden)

    Mariana Souza Costa

    2013-02-01

    Full Text Available Identification of functional properties of wheat flour by specific tests allows genotypes with appropriate characteristics to be selected for specific industrial uses. The objective of wheat breeding programs is to improve the quality of germplasm bank in order to be able to develop wheat with suitable gluten strength and extensibility for bread making. The aim of this study was to evaluate 16 wheat genotypes by correlating both glutenin subunits of high and low molecular weight and gliadin subunits with the physicochemical characteristics of the grain. Protein content, sedimentation volume, sedimentation index, and falling number values were analyzed after the grains were milled. Hectoliter weight and mass of 1000 seeds were also determined. The glutenin and gliadin subunits were separated using polyacrylamide gel in the presence of sodium dodecyl sulfate. The data were evaluated using variance analysis, Pearson's correlation, principal component analysis, and cluster analysis. The IPR 85, IPR Catuara TM, T 091015, and T 091069 genotypes stood out from the others, which indicate their possibly superior grain quality with higher sedimentation volume, higher sedimentation index, and higher mass of 1000 seeds; these genotypes possessed the subunits 1 (Glu-A1, 5 + 10 (Glu-D1, c (Glu-A3, and b (Glu-B3, with exception of T 091069 genotype that possessed the g allele instead of b in the Glu-B3.A identificação das propriedades funcionais de farinhas de trigo através de testes específicos possibilita selecionar genótipos de trigo com características adequadas a cada uso industrial. O principal objetivo dos programas de melhoramento genético é melhorar a qualidade do banco de germoplasma para que seja possível desenvolver trigos com força de glúten e extensibilidade adequadas para produção de produtos panificáveis. O objetivo deste estudo foi avaliar 16 genótipos de trigo correlacionando as subunidades de gluteninas de alto e baixo peso

  12. Volatility Discovery

    DEFF Research Database (Denmark)

    Dias, Gustavo Fruet; Scherrer, Cristina; Papailias, Fotis

    The price discovery literature investigates how homogenous securities traded on different markets incorporate information into prices. We take this literature one step further and investigate how these markets contribute to stochastic volatility (volatility discovery). We formally show...... that the realized measures from homogenous securities share a fractional stochastic trend, which is a combination of the price and volatility discovery measures. Furthermore, we show that volatility discovery is associated with the way that market participants process information arrival (market sensitivity......). Finally, we compute volatility discovery for 30 actively traded stocks in the U.S. and report that Nyse and Arca dominate Nasdaq....

  13. Seasonal atmospheric deposition and air-sea gaseous exchange of polycyclic aromatic hydrocarbons over the Yangtze River Estuary, East China Sea: Implication for the source-sink processes

    Science.gov (United States)

    Jiang, Y.; Guo, Z.

    2017-12-01

    As the home of the largest port in the world, the Yangtze River Estuary (YRE) in the East China Sea (ECS) is adjacent to the largest economic zone in China with more than 10% of Chinese population and provides one-fifth of national GDP. The YRE is under the path of contaminated East Asian continental outflow. These make the YRE unique for the pollutant biogeochemical cycling in the world. In this work, 94 pairs of air samples and 20 surface seawater samples covering four seasons were collected from a remote receptor site in the YRE from March 2014 to January 2015, in order to explore the seasonal fluxes of air-sea gaseous exchange and atmospheric dry and wet deposition of 15 polycyclic aromatic hydrocarbons (PAHs) and their source-sink processes at the air-sea interface. The average dry and wet deposition fluxes of 15 PAHs were estimated as 879 ± 1393 ng m-2 d-1 and 755 ± 545 ng m-2 d-1, respectively. The gaseous PAHs were released from seawater to atmosphere during the whole year with an average of 3039 ± 2030 ng m-2 d-1. The gaseous exchange of PAHs was referred as the dominant process at the air-sea interface in the YRE as the magnitude of volatilization flux of PAHs exceeded that of the total dry and wet deposition. The gaseous PAH exchange flux was dominated by 3-ring PAHs, with the highest value in summer while lowest in winter, depicting a strong seasonal variation due to temperature, wind speed and air-sea concentration gradient difference among seasons. Based on the simplified mass balance estimation, net 9.6 tons/y of PAHs was volatilized from seawater to atmosphere with an area of approximately 20000 km2 in the YRE. Apart from Yangtze River input and ocean ship emissions in the entire year, the selective release of low molecular weight PAHs from sediments in winter due to re-suspension triggered by the East Asian winter monsoon could be another possible source for dissolved PAHs. This work suggests that the source-sink processes of PAHs at air

  14. Virtual volatility

    Science.gov (United States)

    Silva, A. Christian; Prange, Richard E.

    2007-03-01

    We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation strategy.

  15. Iodine volatility

    International Nuclear Information System (INIS)

    Beahm, E.C.; Shockley, W.E.

    1984-01-01

    The ultimate aim of this program is to couple experimental aqueous iodine volatilities to a fission product release model. Iodine partition coefficients, for inorganic iodine, have been measured during hydrolysis and radiolysis. The hydrolysis experiments have illustrated the importance of reaction time on iodine volatility. However, radiolysis effects can override hydrolysis in determining iodine volatility. In addition, silver metal in radiolysis samples can react to form silver iodide accompanied by a decrease in iodine volatility. Experimental data are now being coupled to an iodine transport and release model that was developed in the Federal Republic of Germany

  16. Metabolic activation of volatile organic compounds and polycyclic aromatic hydrocarbons coated onto airborne PM{sub 2.5} in isolated human alveolar macrophages; Etude de l'activation metabolique des composes organiques volatils et des hydrocarbures aromatiques polycycliques d'un aerosol anthropogenique par des macrophages alveolaires humains en culture primaire

    Energy Technology Data Exchange (ETDEWEB)

    Saint-Georges, F.; Mulliez, P. [Hopital Saint Philibert - GHICL-FLM, Service de Pneumologie, 59 - Lomme (France); Saint-Georges, F.; Abbas, I.; Garcon, G.; Billet, S.; Verdin, A.; Shirali, P. [LCE-EA2598, Lab. de Recherche en toxicologie Industrielle et Environnementale - ULCO-MREI, 59 - Dunkerque (France); Gosset, P. [Hopital Saint Vincent, Laboratoire d' Anatomie et de Cytologie Pathologiques - GHICL-FLM, 59 - Lille (France); Courcot, D. [LCE-EA2598, Lab. de Catalyse et Environnement - ULCO-MREI, 59 - Dunkerque (France)

    2009-01-15

    To contribute to improve the knowledge of the underlying mechanisms of action involved in air pollution Particulate Matter (PM)-induced cytotoxicity, we were interested in the metabolic activation of Volatile Organic Compounds (VOC) and/or Polycyclic Aromatic Hydrocarbons (PAH)-coated onto Dunkerque City's PM{sub 2.5} in human Alveolar Macrophages (AM) isolated from Bronchoalveolar Lavage Fluid (BALF). This in vitro cell lung model is very close to the normal in vivo situation, notably in the characteristics that AM display in terms of gene expression of phase I and phase II-metabolizing enzymes. The bronchoscopic examinations and BAL procedures were carried out without any complications. The exposure of AM, during 24, 48 or 72 h, to increasing concentrations of the collected aerosol induced significant variations of the activities of the extracellular lactate dehydrogenase and the mitochondrial dehydrogenase. The lethal concentrations at 10% and 50% were 14.93 and 74.63 {mu}g/mL for AM, respectively, and indicated the relatively higher sensibility of such target lung cells. VOC and/or PAH-coated at low levels onto the surface of the particulate fraction significantly induced gene expression of cytochrome P450 (GYP) 1A1, CYP2E1, NADPH Quinone oxido-reductase (NQO)-1) and Glutathione S-Transferase (GST)P1 and M3, versus controls, suggesting thereby the formation of biologically reactive metabolites. Moreover, these results suggested the role of physical vector of carbonaceous core of PM, which can, therefore, increase both the penetration and the retention of attached-VOC into the cells, thereby enabling them to exert a more durable induction. Hence, we concluded that the metabolic activation of the very low doses of VOC and/or PAH-coated onto Dunkerque City's PM{sub 2.5} is one of the underlying mechanisms of action closely involved in its cytotoxicity in isolated human AM in culture. (author)

  17. 29 CFR 1910.1002 - Coal tar pitch volatiles; interpretation of term.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 6 2010-07-01 2010-07-01 false Coal tar pitch volatiles; interpretation of term. 1910.1002... Hazardous Substances § 1910.1002 Coal tar pitch volatiles; interpretation of term. As used in § 1910.1000 (Table Z-1), coal tar pitch volatiles include the fused polycyclic hydrocarbons which volatilize from the...

  18. Biodegradation of dicyclopentadiene by a mini-consortium isolated from hydrocarbon contaminated soil

    International Nuclear Information System (INIS)

    Shen, Y.; Stehmeier, L.; Voordouw, G.

    1997-01-01

    Thirty-five bacterial species were isolated from soil contaminated by low molecular weight hydrocarbons (C5+). All species were identified by gene sequencing. The isolated genomic DNAs from these bacteria were spotted on a master filter in denatured form. They were then hybridized with total community DNAs isolated from soil exposed to dicyclopentadiene (DCPD) in order to determine the effect of DCPD on the soil microbial community by comparison with an untreated control group. Incubation of soil with DCPD enriched a Sphingomonas sp. while incubation with DCPD in the absence of soil gave enrichment of a Pseudomonas sp. These results indicate that identification of bacterial isolates with DCPD degrading potential is possible and that such organisms can be isolated from C5+ contaminated sites. However, the possibility of removing DCPD contamination in soil by bioremediation is not yet proven.10 refs., 2 tabs., 2 figs

  19. Petroleum hydrocarbons

    International Nuclear Information System (INIS)

    Farrington, J.W.; Teal, J.M.; Parker, P.L.

    1976-01-01

    Methods for analysis of petroleum hydrocarbons in marine samples are presented. Types of hydrocarbons present and their origins are discussed. Principles and methods of analysis are outlined. Infrared spectrometry, uv spectrometry, gas chromatography, mass spectroscopy, and carbon 14 measurements are described

  20. Unstable volatility

    DEFF Research Database (Denmark)

    Casas, Isabel; Gijbels, Irène

    2012-01-01

    The objective of this paper is to introduce the break-preserving local linear (BPLL) estimator for the estimation of unstable volatility functions for independent and asymptotically independent processes. Breaks in the structure of the conditional mean and/or the volatility functions are common...... in Finance. Nonparametric estimators are well suited for these events due to the flexibility of their functional form and their good asymptotic properties. However, the local polynomial kernel estimators are not consistent at points where the volatility function has a break. The estimator presented...

  1. Chasing volatility

    DEFF Research Database (Denmark)

    Caporin, Massimiliano; Rossi, Eduardo; Santucci de Magistris, Paolo

    The realized volatility of financial returns is characterized by persistence and occurrence of unpreditable large increments. To capture those features, we introduce the Multiplicative Error Model with jumps (MEM-J). When a jump component is included in the multiplicative specification, the condi......The realized volatility of financial returns is characterized by persistence and occurrence of unpreditable large increments. To capture those features, we introduce the Multiplicative Error Model with jumps (MEM-J). When a jump component is included in the multiplicative specification...... estimate alternative specifications of the model using a set of daily bipower measures for 7 stock indexes and 16 individual NYSE stocks. The estimates of the jump component confirm that the probability of jumps dramatically increases during the financial crisis. Compared to other realized volatility...... models, the introduction of the jump component provides a sensible improvement in the fit, as well as for in-sample and out-of-sample volatility tail forecasts....

  2. The polycyclic aromatic hydrocarbon degradation potential of Gulf of Mexico coastal microbial communities after the Deepwater Horizon oil spill

    Directory of Open Access Journals (Sweden)

    Anthony D. Kappell

    2014-05-01

    Full Text Available The Deepwater Horizon (DWH blowout resulted in oil transport, including polycyclic aromatic hydrocarbons (PAHs to the Gulf of Mexico shoreline. The microbial communities of these shorelines are thought to be responsible for the intrinsic degradation of PAHs. To investigate the Gulf Coast beach microbial community response to hydrocarbon exposure, we examined the functional gene diversity, bacterial community composition, and PAH degradation capacity of a heavily oiled and non-oiled beach following the oil exposure. With a non-expression functional gene microarray targeting 539 gene families, we detected 28,748 coding sequences. Of these sequences, 10% were uniquely associated with the severely oil-contaminated beach and 6.0% with the non-oiled beach. There was little variation in the functional genes detected between the two beaches; however the relative abundance of functional genes involved in oil degradation pathways, including PAHs, were greater in the oiled beach. The microbial PAH degradation potentials of both beaches, were tested in mesocosms. Mesocosms were constructed in glass columns using sands with native microbial communities, circulated with artificial sea water and challenged with a mixture of PAHs. The low-molecular weight PAHs, fluorene and naphthalene, showed rapid depletion in all mesocosms while the high-molecular weight benzo[α]pyrene was not degraded by either microbial community. Both the heavily oiled and the non-impacted coastal communities showed little variation in their biodegradation ability for low molecular weight PAHs. Massively-parallel sequencing of 16S rRNA genes from mesocosm DNA showed that known PAH degraders and genera frequently associated with oil hydrocarbon degradation represented a major portion of the bacterial community. The observed similar response by microbial communities from beaches with a different recent history of oil exposure suggests that Gulf Coast beach communities are primed for PAH

  3. The hydrogen concentration as parameter to identify natural attenuation processes of volatile chlorinated hydrocarbons in ground water; Die Wasserstoffkonzentration als Parameter zur Identifizierung des natuerlichen Abbaus von leichtfluechtigen Chlorkohlenwasserstoffen (LCKW) im Grundwasser

    Energy Technology Data Exchange (ETDEWEB)

    Alter, M.D.

    2006-06-15

    In this study, the hydrogen concentration as parameter to identify natural attenuation processes of volatile chlorinated hydrocarbons was investigated. The currently accepted and recommended bubble strip method for hydrogen sampling was optimized, and a storage method for hydrogen samples was developed. Furthermore batch experiments with a dechlorinating mixed culture and pure cultures were carried out to study H{sub 2}-concentrations of competing redox processes. The extraction of hydrogen from ground water was optimized by a reduced inlet diameter of the usually applied gas sampling bulbs, allowing a maximal turbulent ow and gas transfer. With a gas volume of 10 ml and flow rates of 50 to 140 ml/min, the course of extraction almost followed the theoretical course of equilibration. At flow rates > 100 ml/min a equilibrium of 98% was achieved within 20 min. Until recently it was generally accepted that hydrogen samples can be stored only for 2 hours and therefore have to be analyzed immediately in the eld. Here, it was shown that eld samples can be stored for 1-3 days until analysis. For the dechlorination of tetrachloroethene (PCE), a hydrogen threshold concentration of 1-2 nM was found with the dechlorinating mixed culture as well as with a pure culture of Sulfurospirillum multivorans in combination with another pure culture Methanosarcina mazei. No dechlorination was detectable below this concentration. With the dechlorinating mixed culture, this finding is valid for all successive dechlorination steps until ethene. The hydrogen threshold concentration for denitrification were below the detection limit of 0,2 nM with the dechlorinating mixed culture. A threshold concentration of 3,1-3,5 nM was found for sulphate reduction and a threshold of 7-9 nM H{sub 2} for hydrogenotrophic methanogenesis. This implies that the natural dechlorination at contaminated sites is preferred to competing processes like sulphate reduction and methanogenesis. The threshold

  4. Biomimicry of volatile-based microbial control for managing emerging fungal pathogens.

    Science.gov (United States)

    Gabriel, K T; Joseph Sexton, D; Cornelison, C T

    2018-05-01

    Volatile organic compounds (VOCs) are known to be produced by a wide range of micro-organisms and for a number of purposes. Volatile-based microbial inhibition in environments such as soil is well-founded, with numerous antimicrobial VOCs having been identified. Inhibitory VOCs are of interest as microbial control agents, as low concentrations of gaseous VOCs can elicit significant antimicrobial effects. Volatile organic compounds are organic chemicals typically characterized as having low molecular weight, low solubility in water, and high vapour pressure. Consequently, VOCs readily evaporate to the gaseous phase at standard temperature and pressure. This contact-independent antagonism presents unique advantages over traditional, contact-dependent microbial control methods, including increased surface exposure and reduced environmental persistence. This approach has been the focus of our recent research, with positive results suggesting it may be particularly promising for the management of emerging fungal pathogens, such as the causative agents of white-nose syndrome of bats and snake fungal disease, which are difficult or impossible to treat using traditional approaches. Here, we review the history of volatile-based microbial control, discuss recent progress in formulations that mimic naturally antagonistic VOCs, outline the development of a novel treatment device, and highlight areas where further work is needed to successfully deploy VOCs against existing and emerging fungal pathogens. © 2017 The Society for Applied Microbiology.

  5. Trichoderma volatiles effecting Arabidopsis: from inhibition to protection against phytopathogenic fungi

    Directory of Open Access Journals (Sweden)

    Metwaly eRamadan

    2015-09-01

    Full Text Available Trichoderma species are present in many ecosystems and some strains have the ability to reduce the severity of plant diseases by activating various defence pathways via specific biologically active signaling molecules. Hence we investigated the effects of low molecular weight volatile compounds of Trichoderma asperellum IsmT5 on Arabidopsis thaliana. During co-cultivation of T. asperellum IsmT5 without physical contact to A. thaliana we observed smaller but vital and robust plants. The exposed plants exhibit increased trichome numbers, accumulation of defence-related compounds such as H2O2, anthocyanin, camalexin, and increased expression of defence related genes. We conclude that A. thaliana perceives the Trichoderma volatiles as stress compounds and subsequently initiates multilayered adaptations including activation of signaling cascades to withstand this environmental influence.The prominent headspace volatile of T. asperellum IsmT5 was identified to be 6-pentyl-α-pyrone, which was solely applied to A. thaliana to verify the growth and defence reactions. Most noticeable is that A. thaliana preexposed to 6PP showed significantly reduced symptoms when challenged with Botrytis cinerea and Alternaria brassicicola, indicating that defence-activated plants subsequently became more resistant to pathogen attack. Together, these results support that products that are based on Trichoderma volatiles have the potential being a useful biocontrol agent in agriculture.

  6. Volatility in energy prices

    International Nuclear Information System (INIS)

    Duffie, D.

    1999-01-01

    This chapter with 58 references reviews the modelling and empirical behaviour of volatility in energy prices. Constant volatility and stochastic volatility are discussed. Markovian models of stochastic volatility are described and the different classes of Markovian stochastic volatility model are examined including auto-regressive volatility, option implied and forecasted volatility, Garch volatility, Egarch volatility, multivariate Garch volatility, and stochastic volatility and dynamic hedging policies. Other volatility models and option hedging are considered. The performance of several stochastic volatility models as applied to heating oil, light oil, natural gas, electricity and light crude oil are compared

  7. Bioaugmentation and biostimulation as strategies for the bioremediation of a burned woodland soil contaminated by toxic hydrocarbons: a comparative study.

    Science.gov (United States)

    Andreolli, Marco; Lampis, Silvia; Brignoli, Pierlorenzo; Vallini, Giovanni

    2015-04-15

    In this work, the natural attenuation strategy (no soil amendments done) was compared with two different bioremediation approaches, namely bioaugmentation through soil inoculation with a suspension of Trichoderma sp. mycelium and biostimulation by soil addition with a microbial growth promoting formulation, in order to verify the effectiveness of these methods in terms of degradation efficiency towards toxic hydrocarbons, with particular attention to the high molecular weight (HMW) fraction, in a forest area impacted by recent wildfire in Northern Italy. The area under investigation, divided into three parcels, was monitored to figure out the dynamics of decay in soil concentration of C₁₂₋₄₀ hydrocarbons (including isoalkanes, cycloalkanes, alkyl-benzenes and alkyl-naphthalenes besides PAHs) and low molecular weight (LMW) PAHs, following the adoption of the foregoing different remediation strategies. Soil hydrocarbonoclastic potential was even checked by characterizing the autochthonous microbial cenoses. Field experiments proved that the best performance in the abatement of HMW hydrocarbons was reached 60 days after soil treatment through the biostimulation protocol, when about 70% of the initial concentration of HMW hydrocarbons was depleted. Within the same time, about 55% degradation was obtained with the bioaugmentation protocol, whilst natural attenuation allowed only a 45% removal of the starting C12-40 hydrocarbon fraction. Therefore, biostimulation seems to significantly reduce the time required for the remediation, most likely because of the enhancement of microbial degradation through the improvement of nutrient balance in the burned soil. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Stochastic volatility of volatility in continuous time

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole; Veraart, Almut

    This paper introduces the concept of stochastic volatility of volatility in continuous time and, hence, extends standard stochastic volatility (SV) models to allow for an additional source of randomness associated with greater variability in the data. We discuss how stochastic volatility...... of volatility can be defined both non-parametrically, where we link it to the quadratic variation of the stochastic variance process, and parametrically, where we propose two new SV models which allow for stochastic volatility of volatility. In addition, we show that volatility of volatility can be estimated...

  9. Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG) Field Demonstration Report: IRP Site 4, POL Area, Springfield ANG Base, Springfield, Ohio

    National Research Council Canada - National Science Library

    Reed, Dennis

    2003-01-01

    ...) methodology to compare the approaches. Soil core composites were analyzed for trichloroethylene, gasoline-range organics, volatile petroleum hydrocarbons, benzene, toluene, ethylbenzene, and xylenes...

  10. Purifying hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Demoulins, H D; Garner, F H

    1923-02-07

    Hydrocarbon distillates, including natural gases and vapors produced by cracking hydrocarbon oils, are desulfurized etc. by treating the vapor with an aqueous alkaline solution of an oxidizing agent. The hydrocarbons may be previously purified by sulfuric acid. In examples aqueous solutions of sodium or calcium hydrochlorite containing 1.5 to 5.0 grams per liter of available chlorine and sufficient alkali to give an excess of 0.1 percent in the spent reagent are preheated to the temperature of the vapor, and either sprayed or atomized into the vapors near the outlet of the dephlegmator or fractionating tower, or passed in countercurrent to the vapors through one or a series of scrubbers.

  11. Purifying hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Dunstan, A E

    1918-06-03

    Ligroin, kerosene, and other distillates from petroleum and shale oil, are purified by treatment with a solution of a hypochlorite containing an excess of alkali. The hydrocarbon may be poured into brine, the mixture stirred, and an electric current passed through. Heat may be applied.

  12. Contamination of rivers in Tianjin, China by polycyclic aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Shi, Z.; Tao, S.; Pan, B.; Fan, W.; He, X.C.; Zuo, Q.; Wu, S.P.; Li, B.G.; Cao, J.; Liu, W.X.; Xu, F.L.; Wang, X.J.; Shen, W.R.; Wong, P.K.

    2005-01-01

    Tianjin urban/industrial complex is highly polluted by some persistent organic pollutants. In this study, the levels of 16 priority polycyclic aromatic hydrocarbons (PAHs) were tested in sediment, water, and suspended particulate matter (SPM) samples in 10 rivers in Tianjin. The total concentration of 16 PAHs varied from 0.787 to 1943 μg/g dry weight in sediment, from 45.81 to 1272 ng/L in water, and from 0.938 to 64.2 μg/g dry weight in SPM. The levels of PAHs in these media are high in comparison with values reported from other river and marine systems. Variability of total concentrations of PAHs in sediment, water, and SPM from nine different rivers is consistent with each other. No obvious trends of total PAHs concentration variations were found between upstream and downstream sediment, water, and SPM samples for most rivers, which indicate local inputs and disturbances along these rivers. The spatial distributions of three-phase PAHs are very similar to each other, and they are also similar to those found in topsoil. However, their chemical profiles are significantly different from that of topsoil. The change of profiles is consistent with the different aqueous transport capability of 16 PAHs. Low molecular weight PAHs predomination suggests a relatively recent local source and coal combustion source of PAHs in the study area. - Coal combustion is suggested as a recent local source of PAHs in this area

  13. Volatiles from solids

    Energy Technology Data Exchange (ETDEWEB)

    Loughrey, C T

    1939-08-24

    To remove volatiles from solids, such as oil shale, gases, and/or vapours are passed through a mass of the materials, the vapours and gases separated, and the vapours condensed. The volatile-containing solid materials are fed to a retort, and a shaft is driven to rotate an impeller so as to displace the liquid and create a vortex tube, which draws in gas from the atmosphere through an intake, twyer, interstices in the material in the retort, a conduit, chamber, tubes, another chamber and cylinder. This gas is carried outwardly and upwardly by the vortices in the liquid and is carried to discharge through three conduits. The vapours entrained by the gas are part condensed in the liquid and the remainder directed to a condenser. Steam may be delivered to the twyer through a nozzle of a pipe, with or without air, and combustible hydrocarbon fuel may be fed through the burner nozzle or solid fuel may be directed from feeder and combusted in the twyer.

  14. GOM Deepwater Horizon Oil Spill: A Time Series Analysis of Variations in Spilled Hydrocarbons

    Science.gov (United States)

    Palomo, C. M.; Yan, B.

    2013-12-01

    An estimated amount of 210 million gallons of crude oil was released into the Gulf of Mexico (GOM) from April 20th to July 15th 2010 during the Deepwater Horizon oil rig explosion. The spill caused a tremendous financial, ecological, environmental and health impact and continues to affect the GOM today. Variations in hydrocarbons including alkanes, hopanes and poly-cyclic aromatic hydrocarbons (PAHs) can be analyzed to better understand the oil spill and assist in oil source identification. Twenty-one sediment samples*, two tar ball samples and one surface water oil sample were obtained from distinct locations in the GOM and within varying time frames from May to December 2010. Each sample was extracted through the ASE 200 solvent extractor, concentrated down under nitrogen gas, purified through an alumina column, concentrated down again with nitrogen gas and analyzed via GC X GC-TOF MS. Forty-one different hydrocarbons were quantified in each sample. Various hydrocarbon 'fingerprints,' such as parental :alkylate PAH ratios, high molecular weight PAHs: low molecular weight alkane ratios, and carbon preference index were calculated. The initial objective of this project was to identify the relative hydrocarbon contributions of petrogenic sources and combustion sources. Based on the calculated ratios, it is evident that the sediment core taken in October of 2010 was greatly affected by combustion sources. Following the first month of the spill, oil in the gulf was burned in attempts to contain the spill. Combustion related sources have quicker sedimentation rates, and hydrocarbons from a combustion source essentially move into deeper depths quicker than those from a petrogenic source, as was observed in analyses of the October 2010 sediment. *Of the twenty-one sediment samples prepared, nine were quantified for this project.

  15. Relationships between volatile compounds and sensory characteristics in virgin olive oil by analytical and chemometric approaches.

    Science.gov (United States)

    Procida, Giuseppe; Cichelli, Angelo; Lagazio, Corrado; Conte, Lanfranco S

    2016-01-15

    The volatile fraction of virgin olive oil is characterised by low molecular weight compounds that vaporise at room temperature. In order to obtain an aroma profile similar to natural olfactory perception, the composition of the volatile compounds was determined by applying dynamic headspace gas chromatography, performed at room temperature, with a cryogenic trap directly connected to a gas chromatograph-mass spectrometer system. Samples were also evaluated according to European Union and International Olive Council official methods for sensory evaluation. In this paper, the composition of the volatile fraction of 25 extra virgin olive oils from different regions of Italy was analysed and some preliminary considerations on relationships between chemical composition of volatile fraction and sensory characteristics are reported. Forty-two compounds were identified by means of the particular analytical technique used. All the analysed samples, classified as extra virgin by the panel test, never present peaks whose magnitude is important enough in defected oils. The study was focused on the evaluation of volatile compounds responsible for the positive impact on olive odour properties ('green-fruity' and 'sweet') and olfactory perception. Chemometric evaluation of data, obtained through headspace analysis and the panel test evaluation, showed a correlation between chemical compounds and sensory properties. On the basis of the results, the positive attributes of virgin olive oil are divided into two separated groups: sweet types or green types. Sixteen volatile compounds with known positive impact on odour properties were extracted and identified. In particular, eight compounds seem correlated with sweet properties whereas the green sensation appears to be correlated with eight other different substances. The content of the compounds at six carbon atoms proves to be very important in defining positive attributes of extra virgin olive oils and sensory evaluation. © 2015

  16. Pricing Volatility Referenced Assets

    Directory of Open Access Journals (Sweden)

    Alan De Genaro Dario

    2006-12-01

    Full Text Available Volatility swaps are contingent claims on future realized volatility. Variance swaps are similar instruments on future realized variance, the square of future realized volatility. Unlike a plain vanilla option, whose volatility exposure is contaminated by its asset price dependence, volatility and variance swaps provide a pure exposure to volatility alone. This article discusses the risk-neutral valuation of volatility and variance swaps based on the framework outlined in the Heston (1993 stochastic volatility model. Additionally, the Heston (1993 model is calibrated for foreign currency options traded at BMF and its parameters are used to price swaps on volatility and variance of the BRL / USD exchange rate.

  17. Cracking hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Forwood, G F; Lane, M; Taplay, J G

    1921-10-07

    In cracking and hydrogenating hydrocarbon oils by passing their vapors together with steam over heated carbon derived from shale, wood, peat or other vegetable or animal matter, the gases from the condenser are freed from sulfuretted hydrogen, and preferably also from carbon dioxide, and passed together with oil vapors and steam through the retort. Carbon dioxide may be removed by passage through slaked lime, and sulfuretted hydrogen by means of hydrated oxide of iron. Vapors from high-boiling oils and those from low-boiling oils are passed alternately through the retort, so that carbon deposited from the high-boiling oils is used up during treatment of low-boiling oils.

  18. Halogenated hydrocarbons - an environmental problem

    Energy Technology Data Exchange (ETDEWEB)

    Schoeler, H F; Thofern, E

    1984-01-01

    The paper provides a survey of the incidence of highly volatile halogenated hydrocarbons in ground, surface and drinking water as well as in the snows of Western Germany. Almost the entire production of chlorinated solvents is released into the environment. The absorption media are mostly soil, water and atmosphere. Whereas in the atmosphere elimination reactions take place, solvents that have passed the soil get into the ground water owing to their persistence and can cause considerable pollutions of drinking water. Moreover haloforms may occur in drinking water, which are produced during chlorine disinfection of pre-treated water.

  19. Antifungal activity of low molecular weight chitosan produced from non-traditional marine resources

    Directory of Open Access Journals (Sweden)

    Francisco Pire