Science.gov

Sample records for acid loading concentration

  1. Citraturic response to oral citric acid load

    NASA Technical Reports Server (NTRS)

    Sakhaee, K.; Alpern, R.; Poindexter, J.; Pak, C. Y.

    1992-01-01

    It is possible that some orally administered citrate may appear in urine by escaping oxidation in vivo. To determine whether this mechanism contributes to the citraturic response to potassium citrate, we measured serum and urinary citrate for 4 hours after a single oral load of citric acid (40 mEq.) in 6 normal subjects. Since citric acid does not alter acid-base balance, the effect of absorbed citrate could be isolated from that of alkali load. Serum citrate concentration increased significantly (p less than 0.05) 30 minutes after a single oral dose of citric acid and remained significantly elevated for 3 hours after citric acid load. Commensurate with this change, urinary citrate excretion peaked at 2 hours and gradually decreased during the next 2 hours after citric acid load. In contrast, serum and urinary citrate remained unaltered following the control load (no drug). Differences of the citratemic and citraturic effects between phases were significant (p less than 0.05) at 2 and 3 hours. Urinary pH, carbon dioxide pressure, bicarbonate, total carbon dioxide and ammonium did not change at any time after citric acid load, and did not differ between the 2 phases. No significant difference was noted in serum electrolytes, arterialized venous pH and carbon dioxide pressure at any time after citric acid load and between the 2 phases. Thus, the citraturic and citratemic effects of oral citric acid are largely accountable by provision of absorbed citrate, which has escaped in vivo degradation.

  2. Acid loading test (pH)

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003615.htm Acid loading test (pH) To use the sharing features on this page, please enable JavaScript. The acid loading test (pH) measures the ability of the ...

  3. Acid loading test (pH)

    MedlinePlus

    The acid loading test (pH) measures the ability of the kidneys to send acid to the urine when there is too much acid in the ... Urine with a pH less than 5.3 is normal. Normal value ranges may vary slightly among different laboratories. Some labs use different ...

  4. Behavior of concentrically loaded CFT braces connections

    PubMed Central

    Hassan, Maha M.; Ramadan, Hazem M.; Abdel-Mooty, Mohammed N.; Mourad, Sherif A.

    2013-01-01

    Concrete filled tubes (CFTs) composite columns have many economical and esthetic advantages, but the behavior of their connections is complicated. Through this study, it is aimed to investigate the performance and behavior of different connection configurations between concrete filled steel tube columns and bracing diagonals through an experimental program. The study included 12 connection subassemblies consisting of a fixed length steel tube and gusset plate connected to the tube end with different details tested under half cyclic loading. A notable effect was observed on the behavior of the connections due to its detailing changes with respect to capacity, failure mode, ductility, and stress distribution. PMID:25685491

  5. Insulin-loaded alginic acid nanoparticles for sublingual delivery.

    PubMed

    Patil, Nilam H; Devarajan, Padma V

    2016-01-01

    Alginic acid nanoparticles (NPs) containing insulin, with nicotinamide as permeation enhancer were developed for sublingual delivery. The lower concentration of proteolytic enzymes, lower thickness and enhanced retention due to bioadhesive property, were relied on for enhanced insulin absorption. Insulin-loaded NPs were prepared by mild and aqueous based nanoprecipitation process. NPs were negatively charged and had a mean size of ∼200 nm with low dispersity index. Insulin loading capacities of >95% suggested a high association of insulin with alginic acid. Fourier Transform Infra-Red Spectroscopy (FTIR) spectra and DSC (Differential Scanning Calorimetry) thermogram of insulin-loaded NPs revealed the association of insulin with alginic acid. Circular dichroism (CD) spectra confirmed conformational stability, while HPLC analysis confirmed chemical stability of insulin in the NPs. Sublingually delivered NPs with nicotinamide exhibited high pharmacological availability (>100%) and bioavailability (>80%) at a dose of 5 IU/kg. The high absolute pharmacological availability of 20.2% and bioavailability of 24.1% in comparison with subcutaneous injection at 1 IU/kg, in the streptozotocin-induced diabetic rat model, suggest the insulin-loaded alginic acid NPs as a promising sublingual delivery system of insulin. PMID:24901208

  6. Diffusion of sulfuric acid in concentrated solutions

    SciTech Connect

    Umino, S.; Newman, J. )

    1993-08-01

    Aqueous sulfuric acid is an economically important chemical reagent. It is one of the largest volume chemical commodities, finding uses in fertilizer production, petroleum refining, extraction of metals from their ores, production of inorganic pigments, pickling of iron and steel, synthesis of surface-active agents, and as a reactant in the lead-acid storage battery. The restricted diffusion method was used to measure the differential diffusion coefficient of sulfuric acid in water at 25 C for the concentration range from 0.3 to 7.5 molar. The concentration gradients of diffusing species were observed by Rayleigh interferometry. Experimental transport data are analyzed with concentrated solution theory of electrolytes in order to elucidate macroscopic transport characteristics of sulfuric acid in terms of specific binary interactions in solution. Results indicate that the transport properties of sulfuric acid are determined by the hydrogen ion-water molecule.

  7. DICARBOXYLIC ACID CONCENTRATION TRENDS AND SAMPLING ARTIFACTS

    EPA Science Inventory

    This abstract describes a slide presentation on results of dicarboxylic acid concentration trends and sampling artifacts to be presented at the 2006 International Aerosol Conference sponsored by the American Association for Aerosol Research in St. Paul, Minnesota on September 10-...

  8. INDOOR CONCENTRATION MODELING OF AEROSOL STRONG ACIDITY

    EPA Science Inventory

    A model for estimating indoor concentrations of acid aerosol was applied to data collected during the summer of 1989, in a densely populated location in New Jersey. he model, from a study of a semi-rural community in Pennsylvania, was used to estimate indoor concentrations of aer...

  9. Wind loading on solar concentrators: some general considerations

    SciTech Connect

    Roschke, E. J.

    1984-05-01

    A survey has been completed to examine the problems and complications arising from wind loading on solar concentrators. Wind loading is site specific and has an important bearing on the design, cost, performance, operation and maintenance, safety, survival, and replacement of solar collecting systems. Emphasis herein is on paraboloidal, two-axis tracking systems. Thermal receiver problems also are discussed. Wind characteristics are discussed from a general point of view; current methods for determining design wind speed are reviewed. Aerodynamic coefficients are defined and illustrative examples are presented. Wind tunnel testing is discussed, and environmental wind tunnels are reviewed; recent results on heliostat arrays are reviewed as well. Aeroelasticity in relation to structural design is discussed briefly. Wind loads, i.e., forces and moments, are proportional to the square of the mean wind velocity. Forces are proportional to the square of concentrator diameter, and moments are proportional to the cube of diameter. Thus, wind loads have an important bearing on size selection from both cost and performance standpoints. It is concluded that sufficient information exists so that reasonably accurate predictions of wind loading are possible for a given paraboloidal concentrator configuration, provided that reliable and relevant wind conditions are specified. Such predictions will be useful to the design engineer and to the systems engineer as well. Information is lacking, however, on wind effects in field arrays of paraboloidal concentrators. Wind tunnel tests have been performed on model heliostat arrays, but there are important aerodynamic differences between heliostats and paraboloidal dishes.

  10. Generation of hydroxyl radicals from metal-loaded humic acids

    SciTech Connect

    Paciolla, M.D.; Jansen, S.A.; Davies, G.

    1999-06-01

    Humic acids (HAs) are naturally occurring biopolymers that are ubiquitous in the environment. They are most commonly found in the soil, drinking water, and a variety of plants. Pharmacological and therapeutic studies involving humic acids have been reported to some extent. However, when certain transition metals are bound to humic acids, e.g., iron and copper, they can be harmful to biological organisms. For this study, humic acids were extracted from German, Irish, and New Hampshire soils that were selectively chosen because of their reich abundance in humic material. Each sample was treated at room temperature with 0.1 M ferric and cupric solutions for 48 h. The amount of iron and copper adsorbed by humic acid was accurately quantitated using atomic absorption spectroscopy. The authors further demonstrate that these metal-loaded humic acids can produce deleterious oxidizing species such as the hydroxyl radical (HO*) through the metal-driven Fenton reaction. Electron paramagnetic resonance (EPR) employing spin trapping techniques with 5,5-dimethylpyrroline N-oxide (DMPO) is used to confirm the generation of hydroxyl radicals. The DMPO-OH adduct with hyperfine splitting constants A{sub N} = A{sub H} = 14.9 G is observed upon the addition of exogenous hydrogen peroxide. The concentration of hydroxyl radical was determined using 4-hydroxytempo (TEMPO-OH) as a spin standard. The presence of another oxidizing species, Fe{double_bond}O{sup 2+}, is also proposed in the absence of hydrogen peroxide.

  11. The effects of load drop, uniform load and concentrated loads on waste tanks

    SciTech Connect

    Marusich, R.M., Westinghouse Hanford

    1996-09-06

    This document provides the supporting calculations performed by others specifically for the TWRS FSAR and more detailed summaries of the important references issued in the past regarding the effects of various loads.

  12. The effects of load drop, uniform load and concentrated loads on waste tanks

    SciTech Connect

    Marusich, R.M.

    1996-09-27

    This document provides the supporting calculations performed by others specifically for the TWRS FSAR and more detailed summaries of the important references issued in the past regarding the effects of various loads.

  13. Status of Lake Erie phosphorus loads and concentrations

    EPA Science Inventory

    Under the Great Lakes Water Quality Protocol of 2012, nutrient loading and nutrient concentrations for open and nearshore waters must be re-evaluated for Substance Objectives that are consistent with overall Ecosystem Objectives. One of the primary driving nutrients of interest ...

  14. Indoor concentration modeling of aerosol strong acidity

    SciTech Connect

    Zelenka, M.; Waldman, J.; Suh, H.; Koutrakis, P.

    1993-01-01

    A model for estimating indoor concentrations of acid aerosol was applied to data collected during the summer of 1989, in a densely populated location in New Jersey. The model, from a study of a semi-rural community in Pennsylvania, was used to estimate indoor concentrations of aerosol strong acidity (H+) at an elderly care residence in suburban New Jersey. The purpose of the present work is to assess the applicability of the model for predicting H+ exposures in a suburban environment and to evaluate the models performance for daytime and nighttime periods. Indoor and outdoor samples were taken at an elderly care home between June 20 and July 30, 1989. The indoor and outdoor monitoring schedule collected two 12-h samples per day. Samples were taken with the Indoor Denuder Sampler (IDS). Samples were analyzed for indoor and outdoor concentrations of aerosol strong acidity (H+), ammonia (NH3), and anion determination. The model generally underestimated the indoor H+ concentration. Slight improvement was seen in the model estimate of H+ for the nighttime period (7:00 pm to 7:00 am, local time). The model applied to the site in New Jersey did not predict the indoor H+ concentrations as well as it did for the experiment from which it was developed.

  15. [Plasma amino acid concentrations in aggressive dogs].

    PubMed

    Juhr, Norbert-Christian; Brand, Ulrike; Riedel, Eberhard

    2005-01-01

    Following the hypothesis that metabolic screens may be useful tools in the diagnosis of canine aggression we have investigated the blood plasma amino acid levels of dogs which have been found aggressive (N = 10) against dogs or men in comparison to non-aggressive dogs (N = 10). In summary, the aggressive dogs showed elevated plasma concentrations of the neurophysiological active aromatic amino acids tryptophan (46/171 micromol/l, p < 0,001), tyrosine (38/67 micromol/l, p < 0.01) and histidine (74/91 micromol/l, p < 0.01) and lower lysine concentrations (175/151 micromol/l, p < 0.05), which seems to point to a stress situation of these dogs. The nitrogen metabolism is impaired in the urea-cycle in the conversion of ornithine (17/34 micromol/l, p < 0.01) to citrulline (64/47 micromol/l). Higher levels of branched chain amino acids, especially leucine (122/150 micromol/l, p < 0.01), mainly metabolized in muscles, and isoleucin (60/71 micromol/l, p < 0.05) show a high energy potential. The acidose-stimulator methionine (48/78 micromol/l, p < 0.01) proved elevated. The results show that the changed behavior in the aggressive dogs is also reflected in their free amino acid plasma concentrations, independent of the question whether these data are the cause or the result of the aggressivity. PMID:15803756

  16. Nutrient and Mercury Concentrations and Loads in Tahoe Basin Snowpack

    NASA Astrophysics Data System (ADS)

    Pearson, C.; Obrist, D.; Schumer, R.

    2013-12-01

    Approximately seventy percent of Lake Tahoe Basin precipitation falls as snow during the winter and spring. During snowpack storage, chemicals that accumulate throughout the season through wet and dry deposition are subject to transformations and emissions that affect the end-of-season chemical load in runoff and infiltrating groundwater. This study describes dynamics of nitrogen (N), phosphorus (P), and mercury (Hg) concentrations and loads in Tahoe Basin snowpack to fill a gap in the watershed's nutrient and pollutant mass balance. Bi-weekly snowpack cores and storm-based surface samples were collected at seven sites along two elevation gradients in the Tahoe Basin during the 2012 and 2013 snow years. Snowpack N content is controlled largely by deposition of nitrate (NO3-) and total ammonia nitrogen (TAN: NH3 + NH4+). NO3- deposition is linked with snow accumulation and snowpack concentrations are consistent throughout the sampling seasons. NO3- snowpack concentrations have no discernible spatial pattern and are likely driven by NOx emissions from out-of-basin sources. Unlike NO3-, TAN deposition is associated with dry deposition and concentrations increase towards the end of winter. This late season influx of TAN is likely connected with increased vertical mixing of the boundary layer and the onset of agricultural activity in the San Joaquin Valley. P deposition is strongly correlated with both longitude and elevation. These spatial patterns of P loading are consistent with particulate-bound dry deposition, originating mainly from in-basin urban sources. Lastly, Hg deposition shows little spatial or temporal variability throughout the Basin. This pattern is consistent with out-of-basin sourcing, likely from global background atmospheric concentrations. Hg speciation shows a post-depositional shift from dissolved to particulate phase as the dominant form. This shift is consistent photochemical induced gaseous emission of dissolved Hg and preferential retention of

  17. Novel fenofibric acid-loaded controlled release pellet bioequivalent to choline fenofibrate-loaded commercial product in beagle dogs.

    PubMed

    Kim, Kyung Soo; Jin, Sung Giu; Mustapha, Omer; Yousaf, Abid Mehmood; Kim, Dong Wuk; Kim, Young Hun; Kim, Jong Oh; Yong, Chul Soon; Woo, Jong Soo; Choi, Han-Gon

    2015-07-25

    The objective of this study was to develop a novel fenofibric acid-loaded controlled release pellet showing enhanced, or equivalent to, bioavailability compared with two commercially available products containing fenofibrate or choline fenofibrate. The effect of solubilizing agents on drug solubility and the impact of fillers on core properties were investigated. Among them, magnesium carbonate most improved drug solubility, and κ-carrageenan provided the best spherical cores. The fenofibric acid-loaded pellet was prepared with magnesium carbonate and κ-carrageenan employing the extrusion/spheronizing technique followed by coating with ethylcellulose. Furthermore, dissolution and pharmacokinetic study in beagle dogs were performed compared to the fenofibrate-loaded commercial tablet (FCT) and choline fenofibrate-loaded commercial mini-tablet (CFCM). This fenofibric acid-loaded pellet showed controlled release of the drug in phosphate buffer (pH 6.8) and 0.025 M sodium laurylsulfate within 4h. Furthermore, this pellet and CFCM exhibited similar dissolution profiles. Plasma concentrations greater than 1,000 ng/ml were maintained from 30 min to 8h, suggesting a sustained release pattern. Also, the fenofibric acid-loaded pellet gave significantly higher AUC and Cmax values than FCT, indicating that it improved the bioavailability of fenofibrate due to enhanced solubility and sustained release. In addition, this pellet and CFCM were not significantly different in terms of pharmacokinetic parameters including AUC, Cmax and Tmax. Thus, this pellet was bioequivalent to CFCM in beagle dogs. In conclusion, this fenofibric acid-loaded controlled release pellet would be a potential alternative to the choline fenofibrate-loaded commercial product. PMID:26024820

  18. Wind loading on solar concentrators: Some general considerations

    NASA Technical Reports Server (NTRS)

    Roschke, E. J.

    1984-01-01

    A survey was completed to examine the problems and complications arising from wind loading on solar concentrators. Wind loading is site specific and has an important bearing on the design, cost, performance, operation and maintenance, safety, survival, and replacement of solar collecting systems. Emphasis herein is on paraboloidal, two-axis tracking systems. Thermal receiver problems also are discussed. Wind characteristics are discussed from a general point of view. Current methods for determining design wind speed are reviewed. Aerodynamic coefficients are defined and illustrative examples are presented. Wind tunnel testing is discussed, and environmental wind tunnels are reviewed. Recent results on heliostat arrays are reviewed as well. Aeroelasticity in relation to structural design is discussed briefly.

  19. Elastic Stability of Concentric Tube Robots Subject to External Loads.

    PubMed

    Ha, Junhyoung; Park, Frank C; Dupont, Pierre E

    2016-06-01

    Concentric tube robots, which are comprised of precurved elastic tubes that are concentrically arranged, are being developed for many medical interventions. The shape of the robot is determined by the rotation and translation of the tubes relative to each other, and also by any external forces applied by the environment. As the tubes rotate and translate relative to each other, elastic potential energy caused by tube bending and twisting can accumulate; if a configuration is not locally elastically stable, then a dangerous snapping motion may occur as energy is suddenly released. External loads on the robot also influence elastic stability. In this paper, we provide a second-order sufficient condition, and also a separate necessary condition, for elastic stability. Using methods of optimal control theory, we show that these conditions apply to general concentric tube robot designs subject to arbitrary conservative external loads. They can be used to assess the stability of candidate robot configurations. Our results are validated via comparison with other known stability criteria, and their utility is demonstrated by an application to stable path planning. PMID:26441407

  20. Recovery levels after eccentric and concentric loading in maximal force

    PubMed Central

    Örer, Gamze Erikoğlu; Güzel, Nevin Atalay; Arslan, Erşan

    2016-01-01

    [Purpose] The aim of this study was to compare the differences in recovery periods after maximal concentric and eccentric exercises. [Subjects and Methods] Twenty-two participants voluntarily participated and were divided into two groups: the athlete and sedentary groups. An incremental treadmill running test was performed until exhaustion. During the subsequent passive recovery session, heart rate and venous blood lactate level were determined every 3 minutes until the venous blood lactate level reached 2 mmol/l. The same test protocol was implemented 15 days later. [Results] Both groups showed significantly shorter running durations in concentric exercise, while significant differences were found between the athlete and sedentary groups in terms of venous blood lactate level responses. In addition, there were significant differences between the athlete and sedentary groups in terms of running duration and heart rate in concentric and eccentric exercises. [Conclusion] The present study revealed no difference between the athlete and sedentary groups in terms of recovery durations after eccentric and concentric loadings, although the athletes demonstrated faster recovery in terms of HR compared with the sedentary group. It was thought that concentric exercises cause greater physiological responses. PMID:27390407

  1. Recovery of boric acid from evaporator concentrates

    SciTech Connect

    Chrubasik, A.; Hennecke, A.; Chechelnitzky, G.M.; Kremnev, V.A.; Sinjawski, P.N.; Tevestchenko, L.J.

    1995-12-31

    The process is based on such characteristic properties of boric acid and borates as: solubility depending on pH-value; and high ion-exchange resin capacity for borates and its regeneration by means of ammonia solution. On the basis of laboratory investigations a pilot plant BOR 100 was built 1993. The operation of the pilot plant started at the beginning of 1994. After the functional test and start up in the first half year 1994 the treatment of few batches of original evaporator concentrates was performed.

  2. Micelles Protect and Concentrate Activated Acetic Acid

    NASA Astrophysics Data System (ADS)

    Todd, Zoe; House, C.

    2014-01-01

    As more and more exoplanets are discovered and the habitability of such planets is considered, one can turn to searching for the origin of life on Earth in order to better understand what makes a habitable planet. Activated acetic acid, or methyl thioacetate, has been proposed to be central to the origin of life on Earth, and also as an important energy currency molecule in early cellular evolution. We have investigated the hydrolysis of methyl thioacetate under various conditions. Its uncatalyzed rate of hydrolysis is about three orders of magnitude faster (K = 0.00663 s^-1; 100°C, pH 7.5, concentration = 0.33mM) than published rates for its catalyzed production making it unlikely to accumulate under prebiotic conditions. However, we also observed that methyl thioacetate was protected from hydrolysis when inside its own hydrophobic droplets. We found that methyl thioacetate protection from hydrolysis was also possible in droplets of hexane and in the membranes of nonanoic acid micelles. Thus, the hydrophobic regions of prebiotic micelles and early cell membranes could have offered a refuge for this energetic molecule increasing its lifetime in close proximity to the reactions for which it would be needed. Methyl thioacetate could thus be important for the origin of life on Earth and perhaps for better understanding the potential habitability of other planets.

  3. Hyperammonemia Associated with Valproic Acid Concentrations

    PubMed Central

    Alvariza, Silvana; Magallanes, Laura

    2014-01-01

    Valproic acid, a branched short-chain fatty acid, has numerous action mechanisms which turn it into a broad spectrum anticonvulsant drug and make its use possible in some other pathologies such as bipolar disorder. It is extensively metabolized in liver, representing β-oxidation in the mitochondria one of its main metabolic route (40%). Carnitine is responsible for its entry into the mitochondria as any other fatty acid. Long-term high-dose VPA therapy or acute VPA overdose induces carnitine depletion, resulting in high levels of ammonia in blood. As a high correlation between salivary valproic acid levels and plasma ultrafiltrate levels was found in humans, saliva becomes a promising monitoring fluid in order to study valproic acid pharmacokinetics and its toxic effect. Extended-release (twice daily) formulations of valproic acid or carnitine supplementation are the proposed two therapeutic strategies in order to reverse hyperammonemia. PMID:24868521

  4. Particle Concentration and Yield Stress of Biomass Slurries During Enzymatic Hydrolysis at High-Solids Loadings

    SciTech Connect

    Roche, C. M.; Dibble, C. J.; Knutsen, J. S.; Stickel, J. J.; Liberatore, M. W.

    2009-01-01

    Effective and efficient breakdown of lignocellulosic biomass remains a primary barrier for its use as a feedstock for renewable transportation fuels. A more detailed understanding of the material properties of biomass slurries during conversion is needed to design cost-effective conversion processes. A series of enzymatic saccharification experiments were performed with dilute acid pretreated corn stover at initial insoluble solids loadings of 20% by mass, during which the concentration of particulate solids and the rheological property yield stress ({tau}{sub y}) of the slurries were measured. The saccharified stover liquefies to the point of being pourable ({tau}{sub y} {le} 10 Pa) at a total biomass conversion of about 40%, after roughly 2 days of saccharification for a moderate loading of enzyme. Mass balance and semi-empirical relationships are developed to connect the progress of enzymatic hydrolysis with particle concentration and yield stress. The experimental data show good agreement with the proposed relationships. The predictive models developed here are based on established physical principles and should be applicable to the saccharification of other biomass systems. The concepts presented, especially the ability to predict yield stress from extent of conversion, will be helpful in the design and optimization of enzymatic hydrolysis processes that operate at high-solids loadings.

  5. DICARBOXYLIC ACID CONCENTRATION TRENDS AND SAMPLING ARTIFACTS

    EPA Science Inventory

    Dicarboxylic acids associated with airborne particulate matter were measured during a summer period in Philadelphia that included multiple air pollution episodes. Samples were collected for two ten hour periods each day using a high volume sampler with two quartz fiber filters in...

  6. Solubility series of methanofullerenes in concentrated sulfuric acid

    NASA Astrophysics Data System (ADS)

    Biglova, Yu. N.; Kolesov, S. V.; Biglova, R. Z.; Kraikin, V. A.

    2015-12-01

    A spectroscopic study of the dissolution of C60 and its monosubstituted derivatives methanofullerenes in 98% sulfuric acid revealed that methanofullerenes dissolved in sulfuric acid much better than the starting C60. A solubility series of functionalized fullerenes was obtained, which did not change during the extraction of methanofullerenes with sulfuric acid from benzene solutions. An effective methods was developed for separating methanofullerenes, which is based on the difference between the solubilities of the starting and functionalized fullerenes in concentrated sulfuric acid.

  7. Antimicrobial activity of curcumin-loaded myristic acid microemulsions against Staphylococcus epidermidis.

    PubMed

    Liu, Chi-Hsien; Huang, Hsin-Ying

    2012-01-01

    The bactericidal properties of myristic acid and curcumin were revealed in a number of studies. However, whether curcumin-loaded myristic acid microemulsions can be used to inhibit Staphylococcus epidermidis, which causes nosocomial infections, has not been reported. Our aim was to develop curcumin-loaded myristic acid microemulsions to inhibit S. epidermidis on the skin. The interfacial tension, size distribution, and viscosity data of the microemulsions were characterized to elucidate the physicochemical properties of the curcumin microemulsions. Curcumin distribution in neonate pig skin was visualized using confocal laser scanning microscopy. Dermal curcumin accumulation (326 µg/g skin) and transdermal curcumin penetration (87 µg/cm(2)/d) were obtained with the microemulsions developed herein. Curcumin at the concentration of 0.86 µg/mL in the myristic acid microemulsion could inhibit 50% of the bacterial growth, which was 12 times more effective than curcumin dissolved in dimethyl sulfoxide (DMSO). The cocktail combination of myristic acid and curcumin in the microemulsion carrier synergistically inhibited the growth of S. epidermidis. The results we obtained highlight the potential of using curcumin-loaded microemulsions as an alternative treatment for S. epidermidis-associated diseases and acne vulgaris. PMID:22976319

  8. Ocular acid burn due to 20% concentrated salicylic acid.

    PubMed

    Shazly, Tarek A

    2011-03-01

    This is a case report of severe conjunctival and corneal epithelial defects resulting from accidental exposure to salicylic acid that was mistakenly used instead of artificial tears (eye drops). The patient was treated with tobramycin 0.3%-dexamethasone 1% 3 times a day, cyclopentolate 1% twice a day, and artificial tears 6 times a day and underwent daily examinations until the corneal and conjunctival epithelial defects resolved. The corneal and conjunctival epithelial defects slowly resolved over 14 days. Visual acuity improved to its preinjury level of 20/40 in the affected eye. No residual corneal scarring was evident. Slowly resolving corneal and conjunctival epithelial defects can occur from direct contact with salicylic acid; therefore, this medication should be packaged and labeled differently from eye drops. PMID:20954793

  9. Highly accurate boronimeter assay of concentrated boric acid solutions

    SciTech Connect

    Ball, R.M. )

    1992-01-01

    The Random-Walk Boronimeter has successfully been used as an on-line indicator of boric acid concentration in an operating commercial pressurized water reactor. The principle has been adapted for measurement of discrete samples to high accuracy and to concentrations up to 6000 ppm natural boron in light water. Boric acid concentration in an aqueous solution is a necessary measurement in many nuclear power plants, particularly those that use boric acid dissolved in the reactor coolant as a reactivity control system. Other nuclear plants use a high-concentration boric acid solution as a backup shutdown system. Such a shutdown system depends on rapid injection of the solution and frequent surveillance of the fluid to ensure the presence of the neutron absorber. The two methods typically used to measure boric acid are the chemical and the physical methods. The chemical method uses titration to determine the ionic concentration of the BO[sub 3] ions and infers the boron concentration. The physical method uses the attenuation of neutrons by the solution and infers the boron concentration from the neutron absorption properties. This paper describes the Random-Walk Boronimeter configured to measure discrete samples to high accuracy and high concentration.

  10. Heart Rate Response and Lactic Acid Concentration in Squash Players.

    ERIC Educational Resources Information Center

    Beaudin, Paula; And Others

    1978-01-01

    It was concluded that playing squash is an activity that results in heart rate responses of sufficient intensity to elicit aerobic training effects without producing high lactic acid concentration in the blood. (MM)

  11. Pictorial Analogies XI: Concentrations and Acidity of Solutions.

    ERIC Educational Resources Information Center

    Fortman, John J.

    1994-01-01

    Presents pictorial analogies of several concepts relating to solutions for chemistry students. These include concentration of solution, strength of solution, supersaturated solution, and conjugate acid-base pairs. Among the examples are comparison of acid strength to percentage of strong soldiers or making supersaturated solution analogous to a…

  12. A Novel Preparation Method for 5-Aminosalicylic Acid Loaded Eudragit S100 Nanoparticles

    PubMed Central

    Hu, Daode; Liu, Liang; Chen, Wenjuan; Li, Sining; Zhao, Yaping

    2012-01-01

    In this study, solution enhanced dispersion by supercritical fluids (SEDS) technique was applied for the preparation of 5-aminosalicylic acid (5-ASA) loaded Eudragit S100 (EU S100) nanoparticles. The effects of various process variables including pressure, temperature, 5-ASA concentration and solution flow rate on morphology, particle size, 5-ASA loading and entrapment efficiency of nanoparticles were investigated. Under the appropriate conditions, drug-loaded nanoparticles exhibited a spherical shape and small particle size with narrow particle size distribution. In addition, the nanoparticles prepared were characterized by X-ray diffraction, Differential scanning calorimetry and Fourier transform infrared spectroscopy analyses. The results showed that 5-ASA was imbedded into EU S100 in an amorphous state after SEDS processing and the SEDS process did not induce degradation of 5-ASA. PMID:22754377

  13. Concentrations of acidic antiinflammatory drugs in gastric mucosa.

    PubMed

    Frey, H H; El-Sayed, M A

    1977-12-01

    In rats, the concentrations of the acidic antiinflammatory drugs salicylic acid, acetylsalicylic acid, phenylbutazone, flufenamic acid and indomethacin in the glandular portion of the gastric mucosa were determined 30 and 60 min after oral or subcutaneous administration. In another series of experiments, solutions of the drugs were introduced into the ligated stomach and the concentrations in the mucosa and in the contents of the stomach were determined after 60 min. The ratio between the concentrations in the musoca and those in serum or gastric contents were much lower than expected according to the distribution by passive non-ionic diffusion. This apparent discrepancy may be explained as a result of a drug-induced damage to the mucosal cell allowing free diffusion of ionized drug across the cell membrane. PMID:603322

  14. Transdermal iontophoresis of flufenamic acid loaded PLGA nanoparticles.

    PubMed

    Malinovskaja-Gomez, K; Labouta, H I; Schneider, M; Hirvonen, J; Laaksonen, T

    2016-06-30

    The objective of this study was to test in vitro a drug delivery system that combines nanoencapsulation and iontophoresis for the transdermal delivery of lipophilic model drug using poly(lactic-co-glycolic acid) (PLGA) as the carrier polymer. Negatively charged fluorescent nanoparticles loaded with negatively charged flufenamic acid were prepared. The colloidal properties of the particles were stable under iontophoretic current (constant, pulsed and alternating) profiles and in contact with skin barrier. The release of the drug from the particles was not affected by iontophoresis and remained always limited (≈50%), leading to significantly lower transdermal fluxes across human epidermis and full thickness porcine skin compared to respective free drug formulation. From nanoparticles, pulsed current profile resulted in comparable or higher fluxes compared to constant current profile although fluorescence imaging was not able to confirm deeper distribution of nanoparticles in skin. Based on our results, there is no clear advantage with respect to drug permeation from nanoencapsulating flufenamic acid into PLGA nanoparticles compared to free drug formulation, either in passive or iontophoretic delivery regimens. However, pulsed current iontophoresis could be an effective alternative instead of traditional constant current iontophoresis to enhance transdermal permeation of drugs from nanoencapsulated formulations. PMID:27131608

  15. Nectar loads as fuel for collecting nectar and pollen in honeybees: adjustment by sugar concentration.

    PubMed

    Harano, Ken-Ichi; Nakamura, Jun

    2016-06-01

    When honeybee foragers leave the nest, they receive nectar from nest mates for use as fuel for flight or as binding material to build pollen loads. We examined whether the concentration of nectar carried from the nest changes with the need for sugar. We found that pollen foragers had more-concentrated nectar (61.8 %) than nectar foragers (43.8 %). Further analysis revealed that the sugar concentration of the crop load increased significantly with waggle duration, an indicator of food-source distance, in both groups of foragers. Crop volume also increased with waggle duration. The results support our argument that foragers use concentrated nectar when the need for sugar is high and suggest that they precisely adjust the amount of sugar in the crop by altering both volume and nectar concentrations. We also investigated the impact of the area where foragers receive nectar on the crop load concentration at departure. Although nectar and pollen foragers tend to load nectar at different areas in the nest, area did not have a significant effect on crop load concentration. Departing foragers showed an average of 2.2 momentary (<1 s) begging trophallactic contacts before leaving the nest. They might be rejecting nectar with inappropriate concentrations during these contacts. PMID:27165302

  16. Estimation of background loadings and concentrations of phosphorus for lakes in the Puget Sound region, Washington

    USGS Publications Warehouse

    Gilliom, Robert J.

    1980-01-01

    For lakes in watersheds that include developed land, evaluation of eutrophication is facilitated by knowledge of changes in the lakes ' phosphorus concentration since development. A method is described for estimating background phosphorus concentration in lakes of the Puget Sound lowland, Washington. Using a mass-balance ' Vollenweider-type ' model, phosphorus loadings were calculated from present-day phosphorus concentrations measured in lake water and from easily measured physical characteristics for 24 lakes in undeveloped, or insignificantly developed, watersheds. Phosphorus loading from forest (undeveloped) land was derived for each lake as the difference between the calculated phosphorus loading directly to the lake 's surface and loading by bulk precipitation (estimated from other studies). Forest-land loading to each lake was converted to the yield (mass per unit area) of the forested part of the watershed. The phosphorus yield from forest land was related to annual runoff, and the regression equation expressing this relationship explained 73% of the sample variance. By applying that regression equation to the appropriate annual-runoff data, the yield of phosphorus from forest land can be estimated for any lake in the study area. Phosphorus loading from forested land then can be added to direct loading by bulk precipitation to estimate background phosphorus loading for each lake. By applying the mass-balance model to calculated background loadings, background total-phosphorus concentration can also be calculated for all lakes in the study area that have stable thermal stratification during the summer. The standard error of estimate for calculated background loadings and concentrations averages about 25%. (USGS)

  17. Biomechanical comparison between concentrated, follower, and muscular loads of the lumbar column.

    PubMed

    Shih, Kao-Shang; Weng, Pei-Wei; Lin, Shang-Chih; Chen, Yi-Tzu; Cheng, Cheng-Kung; Lee, Chian-Her

    2016-10-01

    Experimental and numerical methods have been extensively used to simulate the lumbar kinematics and mechanics. One of the basic parameters is the lumbar loads. In the literature, both concentrated and distributed loads have been assumed to simulate the in vivo lumbar loads. However, the inconsistent loads between those studies exist and make the comparison of their results controversial. Using finite-element method, this study aimed to numerically compare the effects of the concentrated, follower, and muscular loads on the lumbar biomechanics during flexion. Two conditions of equivalent and simple constraints were simulated. The equivalent condition assumes the identical flexion at the L1 level and loads at the L5 level for the three types of loads. Another condition is to remove such kinematic and mechanical constraints on the lumbar. The comparison indices were flexed profile, distributed stress, and transferred loads of the discs and vertebrae at the different levels. The results showed that the three modes in the equivalent condition show the nearly same flexed profiles. In the simple condition, however, the L1 vertebra of the concentrated mode anteriorly translates about 3 and 5 times that of the follower and muscular mode, respectively. By contrast, the flexion profiles of the follower and muscular are comparable. In the equivalent condition, all modes consistently show the gradually increasing stress and loads toward the caudal levels. The results of both concentrated and muscular modes exhibit the quite comparable trends and even magnitudes. In the simple condition, however, the removal of flexion and load constraints makes the results of the concentrated mode significantly different from its counterparts. In both conditions, the predictedindices of the follower mode are more uniform along the lumbar. In conclusion, the kinematic and mechanical constraints significantly affect the profile, stress, and loads of the three modes. In the equivalent condition

  18. Life at high salt concentrations, intracellular KCl concentrations, and acidic proteomes

    PubMed Central

    Oren, Aharon

    2013-01-01

    Extremely halophilic microorganisms that accumulate KCl for osmotic balance (the Halobacteriaceae, Salinibacter) have a large excess of acidic amino acids in their proteins. This minireview explores the occurrence of acidic proteomes in halophiles of different physiology and phylogenetic affiliation. For fermentative bacteria of the order Halanaerobiales, known to accumulate KCl, an acidic proteome was predicted. However, this is not confirmed by genome analysis. The reported excess of acidic amino acids is due to a high content of Gln and Asn, which yield Glu and Asp upon acid hydrolysis. The closely related Halorhodospira halophila and Halorhodospira halochloris use different strategies to cope with high salt. The first has an acidic proteome and accumulates high KCl concentrations at high salt concentrations; the second does not accumulate KCl and lacks an acidic proteome. Acidic proteomes can be predicted from the genomes of some moderately halophilic aerobes that accumulate organic osmotic solutes (Halomonas elongata, Chromohalobacter salexigens) and some marine bacteria. Based on the information on cultured species it is possible to understand the pI profiles predicted from metagenomic data from hypersaline environments. PMID:24204364

  19. A national discharge load of perfluoroalkyl acids derived from industrial wastewater treatment plants in Korea.

    PubMed

    Kim, Hee-Young; Seok, Hyun-Woo; Kwon, Hye-Ok; Choi, Sung-Deuk; Seok, Kwang-Seol; Oh, Jeong Eun

    2016-09-01

    Levels of 11 perfluoroalkyl acids (PFAAs), including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), were measured in wastewater (influent and effluent) and sludge samples collected from 25 industrial wastewater treatment plants (I-WWTPs) in five industrial sectors (chemicals, electronics, metals, paper, and textiles) in South Korea. The highest ∑11PFAAs concentrations were detected in the influent and effluent from the paper (median: 411ng/L) and textile (median: 106ng/L) industries, and PFOA and PFOS were the predominant PFAAs (49-66%) in wastewater. Exceptionally high levels of PFAAs were detected in the sludge associated with the electronics (median: 91.0ng/g) and chemical (median: 81.5ng/g) industries with PFOS being the predominant PFAA. The discharge loads of 11 PFAAs from I-WWTP were calculated that total discharge loads for the five industries were 0.146ton/yr. The textile industry had the highest discharge load with 0.055ton/yr (PFOA: 0.039ton/yr, PFOS: 0.010ton/yr). Municipal wastewater contributed more to the overall discharge of PFAAs (0.489ton/yr) due to the very small industrial wastewater discharge compared to municipal wastewater discharge, but the contribution of PFAAs from I-WWTPs cannot be ignored. PMID:27152994

  20. Concentrations and loads of nitrogen and phosphorus in the Yazoo River, northwestern Mississippi, 1996-97

    USGS Publications Warehouse

    Coupe, Richard H.

    1998-01-01

    Increased nutrient loading to the Gulf of Mexico from off-continent flux has been identified as contributing to the increase in the areal extent of the low dissolved-oxygen zone that develops annually off the coast of Louisiana and Texas. The proximity of the Yazoo River Basin in northwestern Mississippi to the Gulf of Mexico, and the intensive agriculture in the basin have lead to speculation that the Yazoo River Basin contributes a disproportionate amount of nitrogen and phosphorus to the Mississippi River and ultimately the Gulf of Mexico. Water samples from the Yazoo River were collected during 1996 and 1997 and were analyzed for total nitrogen, nitrate as nitrogen, total phosphorus, and orthophosphorus as part of the U.S. Geological Survey?s National Water-Quality Assessment Program. These data were used to compute annual loads of nitrogen and phosphorus discharged from the Yazoo River for 1996 and 1997. Annual loads of nitrogen and phosphorus were calculated by two methods. The first used multivariate regression and the second multiplied the mean annual concentration by the total annual flow. Load estimates based on the product of the mean annual concentration and the total annual flow were within the 95 percent confidence interval for the load calculated by multivariate regression in all cases. The Yazoo River loads, compared to long-term annual loads in the Mississippi River, indicated that the Yazoo River was contributing 2.3 percent or less of the total nitrogen load, 5.7 percent or less of the total phosphorus load, and 1 percent or less of the nitrate load in 1996 and 1997. The total nitrogen load from the Yazoo River Basin into the Mississippi River and ultimately the Gulf of Mexico was proportional to its discharge, the nitrate load was less than expected, whereas the total phosphorus load was slightly higher than expected based on discharge.

  1. Preparation and characterization of Fe(III)-loaded iminodiacetic acid modified GMA grafted nonwoven fabric adsorbent for anion adsorption

    NASA Astrophysics Data System (ADS)

    Kavaklı, Pınar Akkaş; Kavaklı, Cengiz; Güven, Olgun

    2014-01-01

    An Fe(III)-loaded chelating fabric with iminodiacetic acid (IDA) functional groups was prepared by radiation induced graft polymerization of an epoxy group containing monomer, glycidyl methacrylate, onto a nonwoven fabric made of polypropylene coated by polyethylene (PE/PP) and subsequent Fe(III) loading. Grafting conditions were optimized, and GMA grafted polymer was modified with iminodiacetic acid in isopropyl alcohol/water at 80 °C. In order to prepare the polymeric ligand exchanger (PLE) for the removal of phosphate, IDA fabrics were loaded with Fe(III) ions. Fe(III) loading capacity of IDA fabric was determined to be 2.83 mmol Fe(III)/g of polymer. For removal of phosphate anion, adsorption experiments were performed in batch mode at different pH (2-9) and phosphate concentrations. It was found that phosphate adsorption by the Fe(III)-loaded IDA fabric is maximum at pH 2.00. The effect of initial concentration of phosphate on the adsorption behaviour of Fe(III)-loaded IDA nonwoven fabric was determined at low phosphate concentrations (0.5-25 ppm) and at high phosphate concentrations (50-1000 ppm).

  2. STANDARDIZING TERMINOLOGY FOR ESTIMATING THE DIET-DEPENDENT NET ACID LOAD TO THE METABOLIC SYSTEM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Contemporary Western diets contain acid precursors in excess of base precursors, yielding a daily systemic net acid load of varying amounts, depending on the specific composition of the diet. Increasing evidence suggests that differences in daily net acid load, resulting predominantly from differen...

  3. Effect of reactor loading on atomic oxygen concentration as measured by NO chemiluminescence

    NASA Technical Reports Server (NTRS)

    Lerner, N. R.

    1989-01-01

    It has previously been observed that the etch rate of polyethylene samples in the afterglow of an RF discharge in oxygen increases with reactor loading. This enhancement of the etch rate is attributed to reactive gas phase products of the polymer etching. In the present work, emission spectroscopy is employed to examine the species present in the gas phase during etching of polyethylene. In particular, the concentration of atomic oxygen downstream from the polyethylene samples is studied as a function of the reactor loading. It is found that the concentration of atomic oxygen increases as the reactor loading is increased. The increase of etch rate with increased reactor loading is attributed to the increase of atomic oxygen concentration in the vicinity of the sample.

  4. Basic hydraulic experiment on the saturated concentration of suspended load due to tsunamis

    NASA Astrophysics Data System (ADS)

    Takahashi, Tomoyuki; Somekawa, Shiho

    2016-04-01

    When tsunamis arrive in the shallow sea, a huge amount of suspended load is generated by large velocity and strong turbulence. The suspended load causes the geomorphic processes of erosion and deposition. Because the suspended load cannot be increased endlessly, it should have the saturated concentration. Many numerical models of sediment transport due to tsunamis have assumed a constant value of 1% for the saturated concentration empirically. However, it is supposed as a function of velocity. In this study, a hydraulic experiment was carried out to investigate a relationship between velocity and the saturated concentration of suspended load when tsunamis attack. A water circulation pipe used in the experiment was 10 cm in a diameter, 260 cm in length and 50 cm in width. A velocity of water flow in the pipe had been controlled by two pumps and two valves. It was changed from 0.24 to 1.22 m/s. Various amounts of sand was spread on the bottom of pipe. The amount of sand was changed from 0.1 to 10% as converted in the concentration of suspended load if all sand suspended. A diameter and a density of the sand were 0.267 mm and 2.64 x 103 kg/m^3. A condition of sediment transport in the pipe was recorded by video camera from a transparent window at the side of pipe. The condition was judged as all sand particles were suspended or not. The former condition indicates that the concentration of suspended load is saturated and the latter does it is not saturated. When velocity was smaller than 0.47 m/s, there was no suspended load because of a weak tractive force. When velocity became larger, the suspended load was generated and the concentration also became higher. However, the concentration had the upper limit and surplus sand appeared on the bed of pipe when velocity became much larger. The condition gave the saturated concentration of suspended load. When velocity was 0.665 m/s, the saturated concentration was smaller than 1% which is used in many numerical simulations

  5. Reactivity of the cadmium ion in concentrated phosphoric acid solutions.

    PubMed

    De Gyves, J; Gonzales, J; Louis, C; Bessiere, J

    1989-07-01

    The solvation transfer coefficients which characterize the changes of ion reactivity with phosphoric acid concentration have been calculated for cadmium from the constants of the successive chloride complexes, and for silver and diethyldithiophosphate from potentiometric measurements. They evidence the strong desolvation of the cadmium species in concentrated phosphoric acid media, causing a remarkable increase of its reactivity. They allow the results of liquid-liquid extraction, precipitation and flotation reactions to be correctly interpreted and their changes to be foreseen when the reagents are modified. PMID:18964794

  6. Predicting stream N and P concentrations from loads and catchment characteristics at regional scale: a concentration ratio method.

    PubMed

    Oehler, F; Elliott, A H

    2011-11-15

    We used a concentration ratio method to predict yearly and summer averages of stream total nitrogen, nitrate and total phosphorus concentrations at a regional scale. The ratio of the median daily concentration on the flow weighted annual concentration was used. This ratio characterizes the concentration dynamics of a catchment. We took advantage of the commonly used budget type models applied at a regional scale to relate concentrations to loads instead of directly to land uses, as has previously been done. The relationship was modeled with Boosted Regression Trees using catchment and stream characteristics along with loads and flows obtained from the SPARROW budget model. The ratio modeling approach was compared to a direct approach for concentration prediction, and also to a simple method where the mean ratio was used. The modeling performances of the ratio models were overall satisfying (r2 of 49% to 78%), and a better choice than the two other methods tested. This ratio modeling approach is based on a steady state assumption and largely ignores temporal dynamics. As such, this modeling technique does not replace the more physically-based techniques, but allows for hybrid approaches for improved spatial interpolations. This method could be used to predict effectively the impact (at equilibrium) of land use change and management scenarios on water quality at a regional scale. PMID:21962928

  7. Acid Loading of Soils by Magmatic CO2 at Mammoth Mountain, California

    NASA Astrophysics Data System (ADS)

    McGee, K. A.; Gerlach, T. M.; Doukas, M. P.

    2003-12-01

    Areas of tree kill appeared in the early 1990's after a shallow intrusion of magma under the south flank of Mammoth Mountain, California. Subsequent field measurements have revealed high concentrations of soil CO2 in these areas, the locations of which are controlled by faults and fractures that serve as conduits for magmatic CO2 streaming to the surface from depth. Detailed surveys at the largest of these tree-kill areas, Horseshoe Lake, about 14 ha in size, have consistently shown soil CO2 concentrations that range up to 90% or greater in the shallow soil layers. Continuous soil CO2 monitoring stations established in 1995 at Horseshoe Lake reveal a pattern of both short-term and seasonal variations in magmatic CO2. Because the pressure of CO2 is externally fixed by CO2 streaming to the surface, carbonic acid activity is constrained by open-system buffering of magmatic CO2. Eight years of intensive soil CO2 monitoring have documented a consistent pattern whereby pH values as low as 4 can be achieved in the soil solution during spring melting of the winter snow pack. Coupled with the seasonal drop in pH, aluminum, which can also be toxic to forest ecosystems, is released from soils in those areas with the highest CO2 concentrations. After more than a decade of exposure to elevated levels of CO2 and repeated cycles of acid loading, along with nearly complete tree and vegetation mortality and the release of Al3+, the soils at Horseshoe Lake and the other areas of tree kill may not recover their ability to sustain any significant level of forest production for several years, even if the CO2 degassing should stop immediately. The level of in-situ acid loading by magmatic CO2 in the tree kill areas around Mammoth Mountain rivals that of the better known process of rain-out of acid gases from volcanic plumes in the troposphere.

  8. Concentration-Purification of Uranium from an Acid Leaching Solution

    NASA Astrophysics Data System (ADS)

    Guettaf, H.; Becis, A.; Ferhat, K.; Hanou, K.; Bouchiha, D.; Yakoubi, K.; Ferrad, F.

    2009-11-01

    Chemical processes for the elaboration of uranium concentrate from uranium ore have been studied. This process is composed of successive units operations: crushing, milling, acid conventional leaching, filtration-washing, purification-concentration by ion exchange resins and uranium precipitation. The acid leaching operating conditions allow us to obtain a recovery uranium rate of 93%. The uranium concentration of the pregnant solution is approximately of 1.2 g/l. This value justifies the use of ion exchange resins to the concentration-purification of our pregnant solution. We have noticed that the pregnant solution contains a relatively high phosphate concentration which causes a premature uranium precipitation at pH=1.8. This pH value is in general, considered optimal to obtain the highest amount of fixed uranium by the anionic resin. To avoid the precipitation of uranium, the pH=1.5 has been fixed. We have obtained at this condition a good adsorption capacity. A 75% uranium concentrate have been elaborated, but the filtration of this concentrate has been very difficult. We have also noticed an excessive sulphate concentration. In order to improve this process, we have tested nitrates as eluant at different operating conditions.

  9. Spatial and Temporal Variations of Nitrate Concentration and Load in an Upper Midwest Agricultural Watershed

    NASA Astrophysics Data System (ADS)

    Bauer, E.; Keefer, L. L.

    2008-12-01

    The Upper Sangamon River watershed in Illinois is intensively managed for corn and soybean production. Lake Decatur is a water supply reservoir on the Upper Sangamon River and the drinking water source for the City of Decatur in central Illinois. The reservoir has experienced excessive sedimentation since construction and, for over 25 years, high maximum nitrate concentrations that periodically exceed safe drinking water standards. Nutrient loading is not only associated with reduced drinking water quality but also with eutrophication of lakes and the growing hypoxic zone in the Gulf of Mexico. Since 1993, several monitoring studies in the Upper Sangamon River watershed have been conducted to understand the source and trends of nitrates being delivered to the reservoir. Nitrate sources were determined to be evenly distributed throughout the watershed, therefore understanding the seasonal and spatial character of nitrate concentrations and loading can contribute to more effective management practices to reduce nutrient loading. This 15 year study collected continuous discharge and weekly nitrate samples at 12 stations, 3 of which cover the entire period. These stations monitored watersheds at a variety of scales ranging from ~2 to 1,408 square kilometers where several of these watersheds were nested allowing for spatial analysis. Data shows that concentrations are consistently higher in the smaller watersheds and decrease as the watershed area increases during normal to high streamflow. However, during very low flow periods, nitrate concentrations were generally higher as watershed area increased. Maximum nitrate-N concentration during the 15-year study period ranged from 11.78 to 25.2 mg/l. Concentrations varied seasonally with high nitrate concentrations and loading occurring from spring through mid-summer and in late-winter. Nitrate loads from the tributary watersheds tended to be higher and varied greatly from year to year and between stations. The spatial and

  10. ELEVATED METHYLMALOIC ACID CONCENTRATIONS ARE COMMON AMONG ELDERLY AMERICANS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To describe serum methylmalonic acid (MMA) concentrations of elderly Americans and examine relations between serum MMA and other factors, we used surplus sera collected from elderly (n=1,145) and young-adult (n=1,026) participants in Phase 2 of the third National Health and Nutrition Examination Sur...

  11. Estimates of critical acid loads and exceedances for forest soils across the conterminous United States.

    PubMed

    McNulty, Steven G; Cohen, Erika C; Moore Myers, Jennifer A; Sullivan, Timothy J; Li, Harbin

    2007-10-01

    Concern regarding the impacts of continued nitrogen and sulfur deposition on ecosystem health has prompted the development of critical acid load assessments for forest soils. A critical acid load is a quantitative estimate of exposure to one or more pollutants at or above which harmful acidification-related effects on sensitive elements of the environment occur. A pollutant load in excess of a critical acid load is termed exceedance. This study combined a simple mass balance equation with national-scale databases to estimate critical acid load and exceedance for forest soils at a 1-km(2) spatial resolution across the conterminous US. This study estimated that about 15% of US forest soils are in exceedance of their critical acid load by more than 250eqha(-1)yr(-1), including much of New England and West Virginia. Very few areas of exceedance were predicted in the western US. PMID:17629382

  12. Solid Lipid Nanoparticles Loaded with Retinoic Acid and Lauric Acid as an Alternative for Topical Treatment of Acne Vulgaris.

    PubMed

    Silva, Elton Luiz; Carneiro, Guilherme; De Araújo, Lidiane Advíncula; Trindade, Mariana de Jesus Vaz; Yoshida, Maria Irene; Oréfice, Rodrigo Lambert; Farias, Luis de Macêdo; De Carvalho, Maria Auxiliadora Roque; Dos Santos, Simone Gonçalves; Goulart, Gisele Assis Castro; Alves, Ricardo José; Ferreira, Lucas Antônio Miranda

    2015-01-01

    Topical therapy is the first choice for the treatment of mild to moderate acne and all-trans retinoic acid is one of the most used drugs. The combination of retinoids and antimicrobials is an innovative approach for acne therapy. Recently, lauric acid, a saturated fatty acid, has shown strong antimicrobial activity against Propionibacterium acnes. However, topical application of retinoic acid is followed by high incidence of side-effects, including erythema and irritation. Solid lipid nanoparticles represent an alternative to overcome these side-effects. This work aims to develop solid lipid nanoparticles loaded with retinoic acid and lauric acid and evaluate their antibacterial activity. The influence of lipophilic stearylamine on the characteristics of solid lipid nanoparticles was investigated. Solid lipid nanoparticles were characterized for size, zeta potential, encapsulation efficiency, differential scanning calorimetry and X-ray diffraction. The in vitro inhibitory activity of retinoic acid-lauric acid-loaded solid lipid nanoparticles was evaluated against Propionibacterium acnes, Staphylococcus aureus and Staphylococcus epidermidis. High encapsulation efficiency was obtained at initial time (94 ± 7% and 100 ± 4% for retinoic acid and lauric acid, respectively) and it was demonstrated that lauric acid-loaded-solid lipid nanoparticles provided the incorporation of retinoic acid. However, the presence of stearylamine is necessary to ensure stability of encapsulation. Moreover, retinoic acid-lauric acid-loaded solid lipid nanoparticles showed growth inhibitory activity against Staphylococcus epidermidis, Propionibacterium acnes and Staphylococcus aureus, representing an interesting alternative for the topical therapy of acne vulgaris. PMID:26328443

  13. High Dietary Acid Load Predicts ESRD among Adults with CKD.

    PubMed

    Banerjee, Tanushree; Crews, Deidra C; Wesson, Donald E; Tilea, Anca M; Saran, Rajiv; Ríos-Burrows, Nilka; Williams, Desmond E; Powe, Neil R

    2015-07-01

    Small clinical trials have shown that a reduction in dietary acid load (DAL) improves kidney injury and slows kidney function decline; however, the relationship between DAL and risk of ESRD in a population-based cohort with CKD remains unexamined. We examined the association between DAL, quantified by net acid excretion (NAEes), and progression to ESRD in a nationally representative sample of adults in the United States. Among 1486 adults with CKD age≥20 years enrolled in the National Health and Nutrition Examination Survey III, DAL was determined by 24-h dietary recall questionnaire. The development of ESRD was ascertained over a median 14.2 years of follow-up through linkage with the Medicare ESRD Registry. We used the Fine-Gray competing risks method to estimate the association of high, medium, and low DAL with ESRD after adjusting for demographics, nutritional factors, clinical factors, and kidney function/damage markers and accounting for intervening mortality events. In total, 311 (20.9%) participants developed ESRD. Higher levels of DAL were associated with increased risk of ESRD; relative hazards (95% confidence interval) were 3.04 (1.58 to 5.86) for the highest tertile and 1.81 (0.89 to 3.68) for the middle tertile compared with the lowest tertile in the fully adjusted model. The risk of ESRD associated with DAL tertiles increased as eGFR decreased (P trend=0.001). Among participants with albuminuria, high DAL was strongly associated with ESRD risk (P trend=0.03). In conclusion, high DAL in persons with CKD is independently associated with increased risk of ESRD in a nationally representative population. PMID:25677388

  14. Study of node and mass sensitivity of resonant mode based cantilevers with concentrated mass loading

    SciTech Connect

    Zhang, Kewei Chai, Yuesheng; Fu, Jiahui

    2015-12-15

    Resonant-mode based cantilevers are an important type of acoustic wave based mass-sensing devices. In this work, the governing vibration equation of a bi-layer resonant-mode based cantilever attached with concentrated mass is established by using a modal analysis method. The effects of resonance modes and mass loading conditions on nodes and mass sensitivity of the cantilever were theoretically studied. The results suggested that the node did not shift when concentrated mass was loaded on a specific position. Mass sensitivity of the cantilever was linearly proportional to the square of the point displacement at the mass loading position for all the resonance modes. For the first resonance mode, when mass loading position x{sub c} satisfied 0 < x{sub c} < ∼ 0.3l (l is the cantilever beam length and 0 represents the rigid end), mass sensitivity decreased as the mass increasing while the opposite trend was obtained when mass loading satisfied ∼0.3l ≤ x{sub c} ≤ l. Mass sensitivity did not change when concentrated mass was loaded at the rigid end. This work can provide scientific guidance to optimize the mass sensitivity of a resonant-mode based cantilever.

  15. Oral Fat Exposure Pattern and Lipid Loading Effects on the Serum Triacylglycerol Concentration of Humans.

    PubMed

    Mattes, Richard D

    2009-12-01

    Orosensory exposure to dietary fat elicits an early, transient spike (first phase; minutes 0-60) and augmented, more sustained postprandial (second phase; minutes 120-360) elevation of serum triacylglycerol (TAG) in humans. To assess the physiological significance of these effects, TAG concentrations were monitored following manipulation of the oral exposure pattern and accompanying lipid load. Fifteen healthy adults participated in a randomized, 6-arm, crossover design study. Conditions consisted of ingestion of 30-g loads of safflower oil, provided as capsules to bypass oral stimulation, followed by 15 min of oral stimulation (mastication and expectoration) with full-fat or nonfat cream cheese (conditions 1 and 2); the same oral load ingested intermittently with oral stimulation by both food forms (conditions 3 and 4); and 10-g lipid loads ingested with intermittent oral stimulation by both food forms (conditions 5 and 6). Blood was collected via an indwelling catheter and TAG was measured at minutes -15, 0, 10, 20, 30, 40, 50, 60, 120, 240, and 360 relative to the onset of sensory stimulation. Testing was conducted weekly. Sequential (lipid loading followed by oral stimulation) and intermittent (intermixed lipid loading and oral stimulation) conditions led to comparable TAG responses. Significant first- and second-phase TAG concentration increases were observed with the 30-g loads, but not the 10-g loads. TAG responses to the full-fat and nonfat stimuli were similar. These data support the veracity of the earlier literature based on sequential oral exposure regimens and indicate that TAG responses reflect an interaction between oral fat signaling and gut lipid content. The augmentation of TAG associated specifically with dietary fat exposure, as compared to a nonfat food matched on other sensory properties, may only occur with higher fat loads. PMID:20352072

  16. Preparation and properties of BSA-loaded microspheres based on multi-(amino acid) copolymer for protein delivery

    PubMed Central

    Chen, Xingtao; Lv, Guoyu; Zhang, Jue; Tang, Songchao; Yan, Yonggang; Wu, Zhaoying; Su, Jiacan; Wei, Jie

    2014-01-01

    A multi-(amino acid) copolymer (MAC) based on ω-aminocaproic acid, γ-aminobutyric acid, L-alanine, L-lysine, L-glutamate, and hydroxyproline was synthetized, and MAC microspheres encapsulating bovine serum albumin (BSA) were prepared by a double-emulsion solvent extraction method. The experimental results show that various preparation parameters including surfactant ratio of Tween 80 to Span 80, surfactant concentration, benzyl alcohol in the external water phase, and polymer concentration had obvious effects on the particle size, morphology, and encapsulation efficiency of the BSA-loaded microspheres. The sizes of BSA-loaded microspheres ranged from 60.2 μm to 79.7 μm, showing different degrees of porous structure. The encapsulation efficiency of BSA-loaded microspheres also ranged from 38.8% to 50.8%. BSA release from microspheres showed the classic biphasic profile, which was governed by diffusion and polymer erosion. The initial burst release of BSA from microspheres at the first week followed by constant slow release for the next 7 weeks were observed. BSA-loaded microspheres could degrade gradually in phosphate buffered saline buffer with pH value maintained at around 7.1 during 8 weeks incubation, suggesting that microsphere degradation did not cause a dramatic pH drop in phosphate buffered saline buffer because no acidic degradation products were released from the microspheres. Therefore, the MAC microspheres might have great potential as carriers for protein delivery. PMID:24855351

  17. Explanatory characteristics for nutrient concentrations and loads in the Sava River Catchment and cross-regionally

    NASA Astrophysics Data System (ADS)

    Levi, L.; Cvetkovic, V.; Destouni, G.

    2015-12-01

    This study compiles estimates of waterborne nutrient concentrations and loads in the Sava River Catchment (SRC). Based on this compilation, we investigate hotspots of nutrient inputs and retention along the river, as well as concentration and load correlations with river discharge and various human drivers of excess nutrient inputs to the SRC. For cross-regional assessment and possible generalization, we also compare corresponding results between the SRC and the Baltic Sea Drainage Basin (BSDB). In the SRC, one small incremental subcatchment, which is located just downstream of Zagreb and has the highest population density among the SRC subcatchments, is identified as a major hotspot for net loading (input minus retention) of both total nitrogen (TN) and total phosphorus (TP) to the river and through it to downstream areas of the SRC. The other SRC subcatchments exhibit relatively similar characteristics with smaller net nutrient loading. The annual loads of both TN and TP along the Sava River exhibit dominant temporal variability with considerably higher correlation with annual river discharge (R2 = 0.51 and 0.28, respectively) than that of annual average nutrient concentrations (R2 = 0.0 versus discharge for both TN and TP). Nutrient concentrations exhibit instead dominant spatial variability with relatively high correlation with population density among the SRC subcatchments (R2=0.43-0.64). These SRC correlation characteristics compare well with corresponding ones for the BSDB, even though the two regions are quite different in their hydroclimatic, agricultural and wastewater treatment conditions. Such cross-regional consistency in dominant variability type and explanatory catchment characteristics may be a useful generalization basis, worthy of further investigation, for at least first-order estimation of nutrient concentration and load conditions in less data-rich regions.

  18. Climate Change Impacts on Forest Soils Critical Acid Loads and Exceedances at a National Scale

    NASA Astrophysics Data System (ADS)

    McNulty, S. G.; Cohen, E.; Moore Myers, J.; Sun, G.; Caldwell, P.

    2011-12-01

    The Federal agencies of the United States (US) are currently developing guidelines for forest soil critical acid loads across the US. A critical acid load is defined as the amount of acid deposition (usually expressed on a annual basis) that an ecosystem can absorb. Traditionally, an ecosystem is considered to be at risk for health impairment when the critical acid load exceeds a level known to impair forest health. The excess over the critical acid load is termed the exceedance, and the larger the exceedance, the greater the risk of ecosystem damage. This definition of critical acid load applies to a single, long-term pollutant exposure. These guidelines are often used to establish regulations designed to maintain acidic deposition (e.g., nitrogen and sulfur) inputs below the level shown to exceed an ecosystem's critical acid load. The traditional definition for a critical acid load generally assume that the ecosystem is in a steady state condition (i.e. no major changes in the factors that regulate the ecosystems ability to absorb acids. Unfortunately, climate change is altering weather patterns and, thus, impacting the factors that regulate critical acid load limits. This paper explores which factors associated with establishing forest soil critical acid load limits will most likely be influenced by climate change, and how these changes might impact forest soil critical acid load limits across the US. Base cation weathering could increase with global warming, along with nitrogen uptake as a function of increased forest growth across New England. A moderate 20% increase in base cation weathering and nitrogen uptake would result in at least a 25% decrease in the amount of forest soil area that exceeded the critical acid load limit and at least a 50% decrease in the amount of high exceedance area across the US. While these results are encouraging, they do not account for other negative potential forest health risks associated with climate change such as elevated

  19. Online monitoring of concentration and dynamics of volatile fatty acids in anaerobic digestion processes with mid-infrared spectroscopy.

    PubMed

    Falk, Harry Michael; Reichling, Peter; Andersen, Christian; Benz, Roland

    2015-02-01

    An ATR-MIR-FTIR spectrometer was integrated into a laboratory scale anaerobic digestion setup. Automatically, a sludge sample from the digester was transferred to a measurement cell; an IR spectrum was recorded and evaluated by chemometric models to estimate the concentration of the individual volatile fatty acids (VFA). The calibration set included semi-artificial samples spiked with known concentrations of the VFA as well as original samples from a continuous fermentation. High-performance liquid chromatography (HPLC) was used as a reference analysis of the samples. The models were optimized for a low root mean square error of prediction (RMSEP). R(2) for acetic acid, propionic acid, isobutyric acid, butyric acid, valeric acid, and isovaleric acid were 0.94, 0.88, 0.83, 0.75, 0.59, and 0.90, respectively. The accuracy of the models was validated in a second experiment. Considering the complex and heterogeneous sludge composition and the chemical similarity of VFA, absolute concentration and dynamic (increasing and decreasing concentration of VFA) was predicted well for acetic, propionic, isobutyric, and isovaleric acid (in their respective concentration range); Butyric acid could not be detected. The installed setup was able to gather and measure native samples from the digester (every 2 h) automatically over a period of 6 months without problems of clogging or biofouling. The instant and continuous analysis of the concentration of the VFA made it possible to evaluate the current bioprocess status and adjust the organic loading rate accordingly. PMID:25142153

  20. Electrodialysis synthesis of concentrated solutions of perrhenic acid

    NASA Astrophysics Data System (ADS)

    Palant, A. A.; Bryukvin, V. A.; Levin, A. M.; Reshetova, O. V.

    2011-03-01

    The presented results demonstrate the possibility of electrodialysis production of concentrated solutions of perrhenic acid (HReO4 concentration >400 g/l). KReO4 is used as a precursor. The investigations are performed in a three-chamber electrodialysis cell in a continuous mode. The optimal processing parameters are as follows: the current is 3-5 A, the voltage is 30-40 V, and the anode chamber temperature is 20-25°C. Grade AR-0 ammonium perrhenate is precipitated from the obtained HReO4 solution.

  1. Development of a controlled release of salicylic acid loaded stearic acid-oleic acid nanoparticles in cream for topical delivery.

    PubMed

    Woo, J O; Misran, M; Lee, P F; Tan, L P

    2014-01-01

    Lipid nanoparticles are colloidal carrier systems that have extensively been investigated for controlled drug delivery, cosmetic and pharmaceutical applications. In this work, a cost effective stearic acid-oleic acid nanoparticles (SONs) with high loading of salicylic acid, was prepared by melt emulsification method combined with ultrasonication technique. The physicochemical properties, thermal analysis and encapsulation efficiency of SONs were studied. TEM micrographs revealed that incorporation of oleic acid induces the formation of elongated spherical particles. This observation is in agreement with particle size analysis which also showed that the mean particle size of SONs varied with the amount of OA in the mixture but with no effect on their zeta potential values. Differential scanning calorimetry analysis showed that the SONs prepared in this method have lower crystallinity as compared to pure stearic acid. Different amount of oleic acid incorporated gave different degree of perturbation to the crystalline matrix of SONs and hence resulted in lower degrees of crystallinity, thereby improving their encapsulation efficiencies. The optimized SON was further incorporated in cream and its in vitro release study showed a gradual release for 24 hours, denoting the incorporation of salicylic acid in solid matrix of SON and prolonging the in vitro release. PMID:24578624

  2. Development of a Controlled Release of Salicylic Acid Loaded Stearic Acid-Oleic Acid Nanoparticles in Cream for Topical Delivery

    PubMed Central

    Woo, J. O.; Misran, M.; Lee, P. F.; Tan, L. P.

    2014-01-01

    Lipid nanoparticles are colloidal carrier systems that have extensively been investigated for controlled drug delivery, cosmetic and pharmaceutical applications. In this work, a cost effective stearic acid-oleic acid nanoparticles (SONs) with high loading of salicylic acid, was prepared by melt emulsification method combined with ultrasonication technique. The physicochemical properties, thermal analysis and encapsulation efficiency of SONs were studied. TEM micrographs revealed that incorporation of oleic acid induces the formation of elongated spherical particles. This observation is in agreement with particle size analysis which also showed that the mean particle size of SONs varied with the amount of OA in the mixture but with no effect on their zeta potential values. Differential scanning calorimetry analysis showed that the SONs prepared in this method have lower crystallinity as compared to pure stearic acid. Different amount of oleic acid incorporated gave different degree of perturbation to the crystalline matrix of SONs and hence resulted in lower degrees of crystallinity, thereby improving their encapsulation efficiencies. The optimized SON was further incorporated in cream and its in vitro release study showed a gradual release for 24 hours, denoting the incorporation of salicylic acid in solid matrix of SON and prolonging the in vitro release. PMID:24578624

  3. Preliminary weight and costs of sandwich panels to distribute concentrated loads

    NASA Technical Reports Server (NTRS)

    Belleman, G.; Mccarty, J. E.

    1976-01-01

    Minimum mass honeycomb sandwich panels were sized for transmitting a concentrated load to a uniform reaction through various distances. The form skin gages were fully stressed with a finite element computer code. The panel general stability was evaluated with a buckling computer code labeled STAGS-B. Two skin materials were considered; aluminum and graphite-epoxy. The core was constant thickness aluminum honeycomb. Various panel sizes and load levels were considered. The computer generated data were generalized to allow preliminary least mass panel designs for a wide range of panel sizes and load intensities. An assessment of panel fabrication cost was also conducted. Various comparisons between panel mass, panel size, panel loading, and panel cost are presented in both tabular and graphical form.

  4. Concentration: The Neural Underpinnings of How Cognitive Load Shields Against Distraction.

    PubMed

    Sörqvist, Patrik; Dahlström, Örjan; Karlsson, Thomas; Rönnberg, Jerker

    2016-01-01

    Whether cognitive load-and other aspects of task difficulty-increases or decreases distractibility is subject of much debate in contemporary psychology. One camp argues that cognitive load usurps executive resources, which otherwise could be used for attentional control, and therefore cognitive load increases distraction. The other camp argues that cognitive load demands high levels of concentration (focal-task engagement), which suppresses peripheral processing and therefore decreases distraction. In this article, we employed an functional magnetic resonance imaging (fMRI) protocol to explore whether higher cognitive load in a visually-presented task suppresses task-irrelevant auditory processing in cortical and subcortical areas. The results show that selectively attending to an auditory stimulus facilitates its neural processing in the auditory cortex, and switching the locus-of-attention to the visual modality decreases the neural response in the auditory cortex. When the cognitive load of the task presented in the visual modality increases, the neural response to the auditory stimulus is further suppressed, along with increased activity in networks related to effortful attention. Taken together, the results suggest that higher cognitive load decreases peripheral processing of task-irrelevant information-which decreases distractibility-as a side effect of the increased activity in a focused-attention network. PMID:27242485

  5. A comparison of load estimates using total suspended solids and suspended-sediment concentration data

    USGS Publications Warehouse

    Glysson, G.D.; Gray, J.R.; Schwarz, G.E.

    2001-01-01

    This paper presents the results to-date from a continuing investigation into the differences between total suspended solids (TSS) and suspended-sediment concentration (SSC) data and the ramifications of using each type of data to estimate sediment loads. It compares estimates of annual suspended-sediment loads that were made using regression equations developed from paired TSS and SSC data, to annual loads computed by the U.S. Geological Survey (USGS) using traditional techniques and SSC data. Load estimates were compared for 10 stations where sufficient TSS and SSC paired data were available to develop sediment-transport curves for the same time period that daily suspended-sediment records were available. Results of these analyses indicate that as the time frame over which the estimates were made increases, the overall errors associated with the estimates decreases with respect to loads computed using traditional USGS techniques. Using SSC data to compute loads tends to produce estimates closer to those computed by traditional techniques than those computed from TSS data. Loads computed from TSS data tend to be negatively biased with respect to those computed by traditional USGS techniques.

  6. EFFECTS OF NITROGEN LOADING, FRESHWATER RESIDENCE TIME, AND INTERNAL LOSSES ON NITROGEN CONCENTRATIONS IN ESTUARIES

    EPA Science Inventory

    A simple model is presented that uses the annual loading rate of total nitrogen (TN) and the water residence time to calculate: 1) average annual TN concentration and intemalloss rates (e.g. denitrification and incorporation in sediments) in an estuary, and 2) the rate of nitroge...

  7. Computation of major solute concentrations and loads in German rivers using regression analysis.

    USGS Publications Warehouse

    Steele, T.D.

    1980-01-01

    Regression functions between concentrations of several inorganic solutes and specific conductance and between specific conductance and stream discharge were derived from intermittent samples collected for 2 rivers in West Germany. These functions, in conjunction with daily records of streamflow, were used to determine monthly and annual solute loadings. -from Author

  8. RELATIONSHIPS BETWEEEN NITROGEN LOADING AND CONCENTRATIONS OF NITROGEN AND CHLOROPHYLL IN COASTAL EMBAYMENTS

    EPA Science Inventory

    We describe results obtained with a simple model that uses loading rates of total nitrogen (TN), defined as dissolved inorganic nitrogen plus dissolved and particulate organic nitrogen, to calculate annually and spatially averaged concentrations of TN in coastal embayments. We al...

  9. Modeling the Response of Nutrient Concentrations and Primary Productivity in Lake Michigan to Nutrient Loading Scenarios

    EPA Science Inventory

    A water quality model, LM3 Eutro, will be used to estimate the response of nutrient concentrations and primary productivity in Lake Michigan to nutrient loading scenarios. This work is part of a larger effort, the Future Midwestern landscapes study, that will estimate the produc...

  10. Sediment concentrations and loads in the Loxahatchee River estuary, Florida, 1980-82

    USGS Publications Warehouse

    Sonntag, Wayne H.; McPherson, Benjamin F.

    1984-01-01

    This study was conducted to estimate the magnitude of sediment loads and the general spatial and temporal patterns of sediment transport in the Loxahatchee River estuary, Florida. Mean concentrations of suspended sediment generally were higher in the Jupiter Inlet area than in the remainder of the embayment area. Concentrations of suspended sediment varied with season and weather conditions. Concentrations in selected tributaries following Tropical Storm Dennis in August 1981 immediately increased as much as 16 times over concentrations before the storm. Suspended-sediment loads from the tributaries were also highly seasonal and storm related. During a 61-day period of above-average rainfall that included Tropical Storm Dennis, 5 major tributaries discharged 926 tons (short) of suspended sediment to the estuary, accounting for 74 percent of the input for the 1981 water year and 49 percent of the input for the 20-month study period. Suspended-sediment loads at Jupiter Inlet and at the mouth of the estuary embayment on both incoming and outgoing tides far exceeded tributary loads, but the direction of long-term, net tidal transport was not determined. (USGS)

  11. Rye Cover Crop and Gamagrass Strip Effects on NO3 Concentration and Load in Tile Drainage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A significant portion of the nitrate(NO3) from agricultural fields that contaminates surface waters in the Midwest Corn Belt is transported to streams or rivers by subsurface drainage systems or tiles. We compared two cropping system modifications for NO3 concentration and load in subsurface drainag...

  12. Estimation of methane concentrations and loads in groundwater discharge to Sugar Run, Lycoming County, Pennsylvania

    USGS Publications Warehouse

    Heilweil, Victor M.; Risser, Dennis W.; Conger, Randall W.; Grieve, Paul L.; Hynek, Scott A.

    2014-01-01

    A stream-sampling study was conducted to estimate methane concentrations and loads in groundwater discharge to a small stream in an active shale-gas development area of northeastern Pennsylvania. Grab samples collected from 15 streams in Bradford, Lycoming, Susquehanna, and Tioga Counties, Pa., during a reconnaissance survey in May and June 2013 contained dissolved methane concentrations ranging from less than the minimum reporting limit (1.0) to 68.5 micrograms per liter (µg/L). The stream-reach mass-balance method of estimating concentrations and loads of methane in groundwater discharge was applied to a 4-kilometer (km) reach of Sugar Run in Lycoming County, one of the four streams with methane concentrations greater than or equal to 5 µg/L. Three synoptic surveys of stream discharge and methane concentrations were conducted during base-flow periods in May, June, and November 2013. Stream discharge at the lower end of the reach was about 0.10, 0.04, and 0.02 cubic meters per second, respectively, and peak stream methane concentrations were about 20, 67, and 29 µg/L. In order to refine estimated amounts of groundwater discharge and locations where groundwater with methane discharges to the stream, the lower part of the study reach was targeted more precisely during the successive studies, with approximate spacing between stream sampling sites of 800 meters (m), 400 m, and 200 m, in May, June, and November, respectively. Samples collected from shallow piezometers and a seep near the location of the peak methane concentration measured in streamwater had groundwater methane concentrations of 2,300 to 4,600 µg/L. These field data, combined with one-dimensional stream-methane transport modeling, indicate groundwater methane loads of 1.8 ±0.8, 0.7 ±0.3, and 0.7 ±0.2 kilograms per day, respectively, discharging to Sugar Run. Estimated groundwater methane concentrations, based on the transport modeling, ranged from 100 to 3,200 µg/L. Although total methane load

  13. A field investigation of the effect of fine sediment concentration on suspended bed material load

    NASA Astrophysics Data System (ADS)

    Lu, Jau-Yau; Su, Chih-Chiang; Huang, Hsien-Li

    2014-05-01

    The estimation of sediment transport rate has been an important issue for river planning and management. Landslide and debris flow occur frequently in the watershed in Taiwan due to the weak geology and frequent earthquakes. For example, the Chi-Chi Earthquake (Richter scale of 7.3) occurred in central Taiwan in 1999 caused a total landslide area of more than 100 km2. It was the second-deadliest quake in recorded history in Taiwan. In this study, four sets of field experiments (3 typhoons and one large rain storm) were conducted during typhoon seasons of 2012 and 2013 to collect the hydraulic and sediment data at the Tzu-Chiang Bridge of the lower Cho-Shui River after the river incision. The main objectives of this study are to increase our understanding of the variations of the sediment transport characteristics, and to evaluate the suitability of the commonly used sediment transport equations for the lower Cho-Shui River after the Chi-Chi Earthquake. After comparing with the field data collected by Tsang's during 2006-2007, it was found that the concentration of wash load plays an important role in the sediment-laden flow. High concentration of fine sediment tends to damp the turbulence of the flow, and to reduce the uniformities of both the velocity and sediment concentration (bed material load) profiles. In addition, commonly used suspended load sediment transport equations in general under-predicted the sediment load for the lower Cho-Shui River. With consideration of the effect of concentration of fine sediment on the suspended bed material load, Chiu et al.'s (2000) equation was modified and gave more reasonable sediment discharge estimations. Reference Chiu, C. L., Jin, W., and Chen, Y.C., 2000, Mathematical models of distribution of sediment concentration, J. Hydraulic Eng., ASCE, 126(1), 16-23.

  14. Untangling the complex relationship between dietary acid load and glucocorticoid metabolism.

    PubMed

    Weiner, I David

    2016-08-01

    The kidney's maintenance of the metabolic component of acid-base homeostasis is critical for normal health. The study by Esche and colleagues in this issue of Kidney International shows that normal children with higher levels of renal net acid excretion and of dietary acid loads have stimulation of glucocorticoid hormone metabolism. Thus, normal variations in dietary acid intake and renal net acid excretion have important biological correlates. PMID:27418088

  15. The effect of low fluoride concentrations on microdamage accumulation in mouse tibias under impact loading

    NASA Astrophysics Data System (ADS)

    Luo, Qing; Chen, Nan; Zhou, Yan-Heng; Rong, Qi-Guo

    2015-12-01

    Microdamage accumulation in bone is one of the mechanisms for energy dissipation during the fracture process. Changes in the ultrastructure and composition of bone constituents due to aging or diseases could affect microdamage accumulation. Low concentration (1 mM) of sodium fluoride (NaF) has been used in this study to investigate the effect of ultrastructural changes on microdamage accumulation in mouse tibias following free-fall impact loadings. Twenty-two tibias were divided randomly into control and NaF-treated groups. Free-fall impact loading was conducted twice on each tibia to produce microdamage. The elastic modulus of NaF-treated tibias decreased significantly after the impact loadings, while there was no significant difference in the modulus of untreated samples between pre- and post-damage loadings. Microdamage morphology analysis showed that less and shorter microcracks existed in NaF-treated tibias compared with control bones. Meanwhile, more and longer microcracks were observed in tensile regions in untreated samples compared with that in compressive regions, whereas no significant difference was observed between tensile and compressive regions in NaF-treated bones. The results of this study indicate that more energy is required to generate microcracks in NaF-treated bone than in normal bone. A low concentration of fluoride treatment may increase the toughness of bone under impact loading.

  16. Relationship between antigen concentration and bacterial load in Pacific salmon with bacterial kidney disease.

    PubMed

    Hamel, Owen S; Anderson, James J

    2002-08-29

    Using data collected to test spawning female Pacific salmon (Oncorhynchus kisutch and O. tshawytscha for the presence and severity of bacterial kidney disease (BKD), a mathematical model of the relationship between bacterial load and antigen concentration in tissues and ovarian fluid is developed. Renibacterium salmoninarum, the causative agent of BKD, secretes large amounts of a 57 kDa protein ('p57'), its major soluble antigen, which eventually breaks down or is otherwise removed from free circulation. Bacterial load and soluble antigen concentration in tissues are strong indicators of fish health, while in ovarian fluid they are predictors of the success of offspring. Model results indicate either an exponentially increasing antigen removal rate or an exponentially decreasing per-bacterium antigen secretion rate with increasing antigen concentration. Possible mechanisms underlying the observed relationship include a nonlinear increasing autolytic rate of the 'p57' antigen and a bacterium-antigen interaction threshold which prevents bacterial antigen secretion. PMID:12363089

  17. Application of Capmul MCM and caprylic acid for the development of danazol-loaded SEDDS.

    PubMed

    Li, Suhua; Madan, Parshotam; Lin, Senshang

    2014-07-25

    Abstract The feasibility of using Capmul MCM and caprylic acid (medium-chain triglyceride pre-digestion products) as the lipid phase was investigated for the development of self-emulsifying drug delivery system (SEDDS) as a carrier system to enhance solubilization of poorly water-soluble danazol. The composition of SEDDS was first evaluated by phase diagrams of lipid/surfactant/water systems. Thereafter, danazol-loaded SEDDS was formulated and subjected to dispersion/precipitation study in distilled water, HCl buffer, phosphate buffer, or biorelevant aqueous media. The mechanism of danazol dispersion was investigated by comparing the solubilization capacity of blank SEDDS dispersed in various aqueous media with respective dispersion/precipitation profiles obtained. Phase diagrams showed that at least 30% (w/w) Cremophor RH40, as the surfactant, was needed to properly emulsify Capmul MCM:caprylic acid (1:1), as the lipid phase. Different extent of danazol precipitation was observed upon the dispersion of danazol-loaded SEDDS in different aqueous media. Danazol precipitation was dominated by the solubilization capacity of danazol, which was influenced by the ratio of Capmul MCM:CA and Cremophor RH40, pH of aqueous media, gastrointestinal composition, and blank SEDDS concentration. PMID:25059382

  18. Uncertainty based analysis of the impact of watershed phosphorus load on reservoir phosphorus concentration

    NASA Astrophysics Data System (ADS)

    Karamouz, Mohammad; Taheriyoun, Masoud; Seyedabadi, Mohammadreza; Nazif, Sara

    2015-02-01

    In many regions of the world that depend on surface reservoirs as a source of water supply, eutrophication is a major water quality problem. Developing simulation models to evaluate the impact of watershed nutrient loads on the reservoir's water quality is an essential step in eutrophication management. In this regard, analysis of model uncertainty gives an opportunity to assess the reliability and the margin of safety of the model predictions for Total Maximum Daily Load (TMDL) from the watershed nutrient load. In this study, a computational procedure has been proposed for the analysis of the model uncertainties in simulation of watershed phosphorous load and reservoir phosphorous concentration. Data from the Aharchai watershed which is located upstream of the Satarkhan reservoir in the northwestern part of Iran, is used as the study area to test the effectiveness of the proposed methodology. The Soil and Water Assessment Tools (SWAT) is utilized for assessment of watershed phosphorus load as the main agent resulting in the reservoir eutrophication in the region. The most effective parameters in model performance are identified by a global sensitivity analysis technique named modified Fourier Amplitude Sensitivity Test (FAST) which can incorporate parameter interdependencies. The Generalized Likelihood Uncertainty Estimation (GLUE) technique is also applied to set up behavioral ranges of the parameters that are relevant to the actual observations. Finally, the cumulative weighted-likelihood distribution functions (CWLDF) are derived for outputs of the SWAT. They are used jointly for estimation of results uncertainty limits using the Copula method. To assess the effectiveness of applying Best Management Practices (BMPs) in the watershed, two scenarios of with and without BMPs application are tested. The results showed the effectiveness of the proposed model in uncertainty estimation of watershed phosphorus load and reservoir phosphorus concentration as well as the

  19. Mercury concentrations and loads in a large river system tributary to San Francisco Bay, California, USA

    USGS Publications Warehouse

    David, N.; McKee, L.J.; Black, F.J.; Flegal, A.R.; Conaway, C.H.; Schoellhamer, D.H.; Ganju, N.K.

    2009-01-01

    In order to estimate total mercury (HgT) loads entering San Francisco Bay, USA, via the Sacramento-San Joaquin River system, unfiltered water samples were collected between January 2002 and January 2006 during high flow events and analyzed for HgT. Unfiltered HgT concentrations ranged from 3.2 to 75 ng/L and showed a strong correlation (r2 = 0.8, p < 0.001, n = 78) to suspended sediment concentrations (SSC). During infrequent large floods, HgT concentrations relative to SSC were approximately twice as high as observed during smaller floods. This difference indicates the transport of more Hg-contaminated particles during high discharge events. Daily HgT loads in the Sacramento-San Joaquin River at Mallard Island ranged from below the limit of detection to 35 kg. Annual HgT loads varied from 61 ?? 22 kg (n = 5) in water year (WY) 2002 to 470 ?? 170 kg (n = 25) in WY 2006. The data collected will assist in understanding the long-term recovery of San Francisco Bay from Hg contamination and in implementing the Hg total maximum daily load, the long-term cleanup plan for Hg in the Bay. ?? 2009 SETAC.

  20. Concentration: The Neural Underpinnings of How Cognitive Load Shields Against Distraction

    PubMed Central

    Sörqvist, Patrik; Dahlström, Örjan; Karlsson, Thomas; Rönnberg, Jerker

    2016-01-01

    Whether cognitive load—and other aspects of task difficulty—increases or decreases distractibility is subject of much debate in contemporary psychology. One camp argues that cognitive load usurps executive resources, which otherwise could be used for attentional control, and therefore cognitive load increases distraction. The other camp argues that cognitive load demands high levels of concentration (focal-task engagement), which suppresses peripheral processing and therefore decreases distraction. In this article, we employed an functional magnetic resonance imaging (fMRI) protocol to explore whether higher cognitive load in a visually-presented task suppresses task-irrelevant auditory processing in cortical and subcortical areas. The results show that selectively attending to an auditory stimulus facilitates its neural processing in the auditory cortex, and switching the locus-of-attention to the visual modality decreases the neural response in the auditory cortex. When the cognitive load of the task presented in the visual modality increases, the neural response to the auditory stimulus is further suppressed, along with increased activity in networks related to effortful attention. Taken together, the results suggest that higher cognitive load decreases peripheral processing of task-irrelevant information—which decreases distractibility—as a side effect of the increased activity in a focused-attention network. PMID:27242485

  1. Effect of antacid and ascorbic acid on serum salicylate concentration.

    PubMed

    Hansten, P D; Hayton, W L

    1980-01-01

    To determine the effect of antacid or ascorbic acid administration on plateau serum salicylate concentrations, nine healthy subjects were given each of the following treatments by balanced block design: choline salicylate (equivalent to 3.76 or 5.62 Gm/day of aspirin); choline salicylate plus magnesium-aluminum hydroxide (120 ml/day); or choline salicylate plus ascorbic acid (3 Gm/day). In subjects developing a control serum salicylate level above 10 mg/dl, antacid administration produced a decrease in serum salicylate level (mean 19.8 mg/dl vs. 15.8 mg/dl) (P less than 0.01). Ascorbic acid administration was not associated with a significant change in serum salicylate. The reduction in serum salicylate following antacid appears to be due to antacid-induced alkalinization of the urine with resultant increase in renal salicylate clearance. Antacid administration should be considered a potential cause of altered serum salicylate concentration in patients receiving large doses of salicylate. PMID:7400368

  2. Use of extractive distillation to produce concentrated nitric acid

    SciTech Connect

    Campbell, P.C.; Griffin, T.P.; Irwin, C.F.

    1981-04-01

    Concentrated nitric acid (> 95 wt %) is needed for the treatment of off-gases from a fuels-reprocessing plant. The production of concentrated nitric acid by means of extractive distillation in the two-pot apparatus was studied to determine the steady-state behavior of the system. Four parameters, EDP volume (V/sub EDP/) and temperature (T/sub EDP/), acid feed rate, and solvent recycle, were independently varied. The major response factors were percent recovery (CPRR) and product purity (CCP). Stage efficiencies also provided information about the system response. Correlations developed for the response parameters are: CPRR = 0.02(V/sub EDP/ - 800 cc) + 53.5; CCP = -0.87 (T/sub EDP/ - 140/sup 0/C) + 81; eta/sub V,EDP/ = 9.1(F/sub feed/ - 11.5 cc/min) - 0.047(V/sub EDP/ - 800 cc) - 2.8(F/sub Mg(NO/sub 3/)/sub 2// - 50 cc/min) + 390; and eta/sub L,EDP/ = 1.9(T/sub EDP/ - 140/sup 0/C) + 79. A computer simulation of the process capable of predicting steady-state conditions was developed, but it requires further work.

  3. Experimental and numerical investigation of slabs on ground subjected to concentrated loads

    NASA Astrophysics Data System (ADS)

    Øverli, Jan

    2014-09-01

    An experimental program is presented where a slab on ground is subjected to concentrated loading at the centre, the edges and at the corners. Analytical solutions for the ultimate load capacity fit well with the results obtained in the tests. The non-linear behaviour of the slab is captured by performing nonlinear finite element analyses. The soil is modelled as a no-tension bedding and a smeared crack approach is employed for the concrete. Through a parametric study, the finite element model has been used to assess the influence of subgrade stiffness and shrinkage. The results indicate that drying shrinkage can cause severe cracking in slabs on grade.

  4. Stochastic empirical loading and dilution model for analysis of flows, concentrations, and loads of highway runoff constituents

    USGS Publications Warehouse

    Granato, Gregory E.; Jones, Susan C.

    2014-01-01

    In cooperation with FHWA, the U.S. Geological Survey developed the stochastic empirical loading and dilution model (SELDM) to supersede the 1990 FHWA runoff quality model. The SELDM tool is designed to transform disparate and complex scientific data into meaningful information about the adverse risks of runoff on receiving waters, the potential need for mitigation measures, and the potential effectiveness of such measures for reducing such risks. The SELDM tool is easy to use because much of the information and data needed to run it are embedded in the model and obtained by defining the site location and five simple basin properties. Information and data from thousands of sites across the country were compiled to facilitate the use of the SELDM tool. A case study illustrates how to use the SELDM tool for conducting the types of sensitivity analyses needed to properly assess water quality risks. For example, the use of deterministic values to model upstream stormflows instead of representative variations in prestorm flow and runoff may substantially overestimate the proportion of highway runoff in downstream flows. Also, the risks for total phosphorus excursions are substantially affected by the selected criteria and the modeling methods used. For example, if a single deterministic concentration is used rather than a stochastic population of values to model upstream concentrations, then the percentage of water quality excursions in the downstream receiving waters may depend entirely on the selected upstream concentration.

  5. Concentrations and mass loadings of hormones, alkylphenols, and alkylphenol ethoxylates in healthcare facility wastewaters.

    PubMed

    Nagarnaik, P M; Mills, M A; Boulanger, B

    2010-02-01

    Healthcare facility wastewaters are an anticipated source of known endocrine disrupting chemicals to the environment. In this study, the composition and magnitude of eight steroid hormones, octylphenol (OP), nonylphenol (NP), 16 nonylphenol ethoxylates (NPEOs), and 10 octylphenol ethoxylates (OPEOs) in wastewater from a(n) hospital, nursing facility, assisted living facility, and independent living facility are presented. Steroid hormone concentrations were variable for each sampling location, ranging from a non-detectable concentration of 17beta-ethynylestradiol in all samples to 127ngL(-1) androstenedione in the hospital's wastewater composite. OP and NP were not detected in any site's samples. However, NPEOs were found at each sampling location with a maximum combined concentration of 260microgL(-1) for NPEOs with a chain length between 3 and 18 units in the assisted living facility composite sample. OPEOs were only found in the hospital and nursing facilities samples with a maximum combined OPEO concentration of 13microgL(-1) for OPEOs with a chain length between 2 and 12 units in hospital wastewater. The total mass loading of hormones to the municipal sewer system from each facility ranged from 2.5mgd(-1) at the assisted living facility to 138mgd(-1) at the hospital. The total mass loading of the alklyphenol ethoxylates (NPEO+OPEO) is considerably higher than the estimated hormone mass loadings, ranging from 1.8gd(-1) at the independent living facility to 54gd(-1) at the hospital facility. PMID:20079514

  6. LC/ESI-MS/MS method for determination of salivary eicosapentaenoic acid concentration to arachidonic acid concentration ratio.

    PubMed

    Ogawa, Shoujiro; Tomaru, Koki; Matsumoto, Nagisa; Watanabe, Shui; Higashi, Tatsuya

    2016-01-01

    A simple liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) method for determination of the eicosapentaenoic acid (EPA) concentration to arachidonic acid (AA) concentration ratio in human saliva has been developed. The EPA/AA ratio in serum or plasma is widely recognized as a useful indicator in identifying the risk of cardiovascular disease, especially atherosclerosis. The salivary EPA/AA ratio is expected to be a convenient alternative to the serum or plasma EPA/AA ratio, because saliva offers the advantages of easy and noninvasive sampling. The saliva was deproteinized with acetonitrile, purified using an Oasis HLB cartridge, and derivatized with 1-[(4-dimethylaminophenyl)carbonyl]piperazine (DAPPZ). The derivatized EPA and AA were subjected to LC/ESI-MS/MS, and the EPA/AA ratio was determined using the selected reaction monitoring mode. The DAPPZ-derivatization increased the ESI sensitivity by 100- and 300-fold for EPA and AA, respectively, and enabled the detection of trace fatty acids in saliva using a 200 μL sample. The assay reproducibility was satisfactory (relative standard deviation, <5.0%). The method was successfully applied to the measurement of the salivary EPA/AA ratios of healthy Japanese subjects and their changes owing to the supplementation of EPA. PMID:25620210

  7. Nutrient and sediment concentrations and corresponding loads during the historic June 2008 flooding in eastern Iowa

    USGS Publications Warehouse

    Hubbard, L.; Kolpin, D.W.; Kalkhoff, S.J.; Robertson, D.M.

    2011-01-01

    A combination of above-normal precipitation during the winter and spring of 2007-2008 and extensive rainfall during June 2008 led to severe flooding in many parts of the midwestern United States. This resulted in transport of substantial amounts of nutrients and sediment from Iowa basins into the Mississippi River. Water samples were collected from 31 sites on six large Iowa tributaries to the Mississippi River to characterize water quality and to quantify nutrient and sediment loads during this extreme discharge event. Each sample was analyzed for total nitrogen, dissolved nitrate plus nitrite nitrogen, dissolved ammonia as nitrogen, total phosphorus, orthophosphate, and suspended sediment. Concentrations measured near peak flow in June 2008 were compared with the corresponding mean concentrations from June 1979 to 2007 using a paired t test. While there was no consistent pattern in concentrations between historical samples and those from the 2008 flood, increased flow during the flood resulted in near-peak June 2008 flood daily loads that were statistically greater (p < 0.05) than the median June 1979 to 2007 daily loads for all constituents. Estimates of loads for the 16-d period during the flood were calculated for four major tributaries and totaled 4.95 x 10(7) kg of nitrogen (N) and 2.9 x 10(6) kg of phosphorus (P) leaving Iowa, which accounted for about 22 and 46% of the total average annual nutrient yield, respectively. This study demonstrates the importance of large flood events to the total annual nutrient load in both small streams and large rivers.

  8. Nutrient and sediment concentrations and corresponding loads during the historic June 2008 flooding in eastern Iowa.

    PubMed

    Hubbard, L; Kolpin, D W; Kalkhoff, S J; Robertson, D M

    2011-01-01

    A combination of above-normal precipitation during the winter and spring of 2007-2008 and extensive rainfall during June 2008 led to severe flooding in many parts of the midwestern United States. This resulted in transport of substantial amounts of nutrients and sediment from Iowa basins into the Mississippi River. Water samples were collected from 31 sites on six large Iowa tributaries to the Mississippi River to characterize water quality and to quantify nutrient and sediment loads during this extreme discharge event. Each sample was analyzed for total nitrogen, dissolved nitrate plus nitrite nitrogen, dissolved ammonia as nitrogen, total phosphorus, orthophosphate, and suspended sediment. Concentrations measured near peak flow in June 2008 were compared with the corresponding mean concentrations from June 1979 to 2007 using a paired t test. While there was no consistent pattern in concentrations between historical samples and those from the 2008 flood, increased flow during the flood resulted in near-peak June 2008 flood daily loads that were statistically greater (p < 0.05) than the median June 1979 to 2007 daily loads for all constituents. Estimates of loads for the 16-d period during the flood were calculated for four major tributaries and totaled 4.95 x 10(7) kg of nitrogen (N) and 2.9 x 10(6) kg of phosphorus (P) leaving Iowa, which accounted for about 22 and 46% of the total average annual nutrient yield, respectively. This study demonstrates the importance of large flood events to the total annual nutrient load in both small streams and large rivers. PMID:21488505

  9. Practical preparation procedures for docetaxel-loaded nanoparticles using polylactic acid-co-glycolic acid

    PubMed Central

    Keum, Chang-Gu; Noh, Young-Wook; Baek, Jong-Suep; Lim, Ji-Ho; Hwang, Chan-Ju; Na, Young-Guk; Shin, Sang-Chul; Cho, Cheong-Weon

    2011-01-01

    Background Nanoparticles fabricated from the biodegradable and biocompatible polymer, polylactic-co-glycolic acid (PLGA), are the most intensively investigated polymers for drug delivery systems. The objective of this study was to explore fully the development of a PLGA nanoparticle drug delivery system for alternative preparation of a commercial formulation. In our nanoparticle fabrication, our purpose was to compare various preparation parameters. Methods Docetaxel-loaded PLGA nanoparticles were prepared by a single emulsion technique and solvent evaporation. The nanoparticles were characterized by various techniques, including scanning electron microscopy for surface morphology, dynamic light scattering for size and zeta potential, x-ray photoelectron spectroscopy for surface chemistry, and high-performance liquid chromatography for in vitro drug release kinetics. To obtain a smaller particle, 0.2% polyvinyl alcohol, 0.03% D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), 2% Poloxamer 188, a five-minute sonication time, 130 W sonication power, evaporation with magnetic stirring, and centrifugation at 8000 rpm were selected. To increase encapsulation efficiency in the nanoparticles, certain factors were varied, ie, 2–5 minutes of sonication time, 70–130 W sonication power, and 5–25 mg drug loading. Results A five-minute sonication time, 130 W sonication power, and a 10 mg drug loading amount were selected. Under these conditions, the nanoparticles reached over 90% encapsulation efficiency. Release kinetics showed that 20.83%, 40.07%, and 51.5% of the docetaxel was released in 28 days from nanoparticles containing Poloxamer 188, TPGS, or polyvinyl alcohol, respectively. TPGS and Poloxamer 188 had slower release kinetics than polyvinyl alcohol. It was predicted that there was residual drug remaining on the surface from x-ray photoelectron spectroscopy. Conclusion Our research shows that the choice of surfactant is important for controlled release of

  10. User's manual for estimation of dissolved-solids concentrations and loads in surface water

    USGS Publications Warehouse

    Liebermann, T.D.; Middelburg, R.F.; Irvine, S.A.

    1987-01-01

    Dissolved solids in surface water are an important indicator of overall water quality. Ordinarily, dissolved-solids concentrations and loads are estimated by indirect methods that are based on periodic chemical analyses. Three computer programs , FLAGIT, DVCOND, and SLOAD, were developed to provide a consistent and accurate method of estimating dissolved-solids concentrations and loads. FLAGIT retrieves daily values of specific conductance and discharge and periodic water quality analyses from the U.S. Geologic Survey 's National Water Data Storage and Retrieval System data base, deletes incomplete data, and flags possible data errors. DVCOND fills in missing daily values of specific conductance, when appropriate, by linear interpolation. Using water quality data, SLOAD computes 3 yr moving regressions of dissolved-solids loads as a function of specific conductance and discharge. SLOAD then applies the regression coefficients to the daily values data to estimate daily dissolved-solids loads that are summed by month and by year. Separate regressions are used to estimate the mass fractions of six major ions. The theoretical basis and underlying assumptions of the procedures are presented, with documentation of the programs and their use. (USGS)

  11. Constituent concentrations, loads, and yields to Beaver Lake, Arkansas, water years 1999-2008

    USGS Publications Warehouse

    Bolyard, Susan E.; De Lanois, Jeanne L.; Green, W. Reed

    2010-01-01

    Beaver Lake is a large, deep-storage reservoir used as a drinking-water supply and considered a primary watershed of concern in the State of Arkansas. As such, information is needed to assess water quality, especially nutrient enrichment, nutrient-algal relations, turbidity, and sediment issues within the reservoir system. Water-quality samples were collected at three main inflows to Beaver Lake: the White River near Fayetteville, Richland Creek at Goshen, and War Eagle Creek near Hindsville. Water-quality samples collected over the period represented different flow conditions (from low to high). Constituent concentrations, flow-weighted concentrations, loads, and yields from White River, Richland Creek, and War Eagle Creek to Beaver Lake for water years 1999-2008 were documented for this report. Constituents include total ammonia plus organic nitrogen, dissolved nitrite plus nitrate nitrogen, dissolved orthophosphorus (soluble reactive phosphorus), total phosphorus, total nitrogen, dissolved organic carbon, total organic carbon, and suspended sediment. Linear regression models developed by computer program S-LOADEST were used to estimate loads for each constituent for the 10-year period at each station. Constituent yields and flow-weighted concentrations for each of the three stations were calculated for the study. Constituent concentrations and loads and yields varied with time and varied among the three tributaries contributing to Beaver Lake. These differences can result from differences in precipitation, land use, contributions of nutrients from point sources, and variations in basin size. Load and yield estimates varied yearly during the study period, water years 1999-2008, with the least nutrient and sediment load and yields generally occurring in water year 2006, and the greatest occurring in water year 2008, during a year with record amounts of precipitation. Flow-weighted concentrations of most constituents were greatest at War Eagle Creek near Hindsville

  12. Finite element modeling of concentrating solar collectors for evauation of gravity loads, bending, and optical characterization.

    SciTech Connect

    Christian, Joshua M.; Ho, Clifford Kuofei

    2010-04-01

    Understanding the effects of gravity and wind loads on concentrating solar power (CSP) collectors is critical for performance calculations and developing more accurate alignment procedures and techniques. This paper presents a rigorous finite-element model of a parabolic trough collector that is used to determine the impact of gravity loads on bending and displacements of the mirror facets and support structure. The geometry of the LUZ LS-2 parabolic trough collector was modeled using SolidWorks, and gravity-induced loading and displacements were simulated in SolidWorks Simulation. The model of the trough collector was evaluated in two positions: the 90{sup o} position (mirrors facing upward) and the 0{sup o} position (mirrors facing horizontally). The slope errors of the mirror facet reflective surfaces were found by evaluating simulated angular displacements of node-connected segments along the mirror surface. The ideal (undeformed) shape of the mirror was compared to the shape of the deformed mirror after gravity loading. Also, slope errors were obtained by comparing the deformed shapes between the 90{sup o} and 0{sup o} positions. The slope errors resulting from comparison between the deformed vs. undeformed shape were as high as {approx}2 mrad, depending on the location of the mirror facet on the collector. The slope errors resulting from a change in orientation of the trough from the 90{sup o} position to the 0{sup o} position with gravity loading were as high as {approx}3 mrad, depending on the location of the facet.

  13. Passive treatment of acid mine drainage with high metal concentrations using dispersed alkaline substrate.

    PubMed

    Rötting, Tobias S; Thomas, Robert C; Ayora, Carlos; Carrera, Jesús

    2008-01-01

    Passive treatment systems based on the dissolution of coarse calcite grains are widely used to remediate acid mine drainage (AMD). Unfortunately, they tolerate only low metal concentrations or acidity loads, because they are prone to passivation (loss of reactivity due to coating) and/or clogging (loss of permeability) by precipitates. To overcome these problems, a dispersed alkaline substrate (DAS) composed of a fine-grained alkaline reagent (calcite sand) mixed with a coarse inert matrix (wood chips) was developed. The small grains provide a large reactive surface and dissolve almost completely before the growing layer of precipitates passivates the substrate, whereas the dispersion of nuclei for precipitation on the inert surfaces retards clogging. Chemical and hydraulic performance of DAS was investigated in two laboratory columns fed at different flow rates with natural AMD of pH 2.3 to 3.5 and inflow net acidity 1350 to 2300 mg/L as CaCO(3). The DAS columns removed 900 to 1600 mg/L net acidity, 3 to 4.5 times more than conventional passive treatment systems. Regardless of the flow rate employed, Al, Fe(III), Cu, and Pb were virtually eliminated. Minor Zn, Ni, and Cd were removed at low flow rates. High acidity removal is possible because these metals accumulate intentionally in DAS, and their precipitation promotes further calcite dissolution. During 15 mo, DAS operated without clogging at 120 g acidity/m(2).d, four times the loading rate recommended for conventional passive systems; DAS may therefore be capable of treating AMD at sites where influent chemistry precludes the use of other passive systems. PMID:18689735

  14. Feasibility of Estimating Constituent Concentrations and Loads Based on Data Recorded by Acoustic Instrumentation

    USGS Publications Warehouse

    Lietz, A.C.

    2002-01-01

    The acoustic Doppler current profiler (ADCP) and acoustic Doppler velocity meter (ADVM) were used to estimate constituent concentrations and loads at a sampling site along the Hendry-Collier County boundary in southwestern Florida. The sampling site is strategically placed within a highly managed canal system that exhibits low and rapidly changing water conditions. With the ADCP and ADVM, flow can be gaged more accurately rather than by conventional field-data collection methods. An ADVM velocity rating relates measured velocity determined by the ADCP (dependent variable) with the ADVM velocity (independent variable) by means of regression analysis techniques. The coefficient of determination (R2) for this rating is 0.99 at the sampling site. Concentrations and loads of total phosphorus, total Kjeldahl nitrogen, and total nitrogen (dependent variables) were related to instantaneous discharge, acoustic backscatter, stage, or water temperature (independent variables) recorded at the time of sampling. Only positive discharges were used for this analysis. Discharges less than 100 cubic feet per second generally are considered inaccurate (probably as a result of acoustic ray bending and vertical temperature gradients in the water column). Of the concentration models, only total phosphorus was statistically significant at the 95-percent confidence level (p-value less than 0.05). Total phosphorus had an adjusted R2 of 0.93, indicating most of the variation in the concentration can be explained by the discharge. All of the load models for total phosphorus, total Kjeldahl nitrogen, and total nitrogen were statistically significant. Most of the variation in load can be explained by the discharge as reflected in the adjusted R2 for total phosphorus (0.98), total Kjeldahl nitrogen (0.99), and total nitrogen (0.99).

  15. Large deflections of non-prismatic nonlinearly elastic cantilever beams subjected to non-uniform continuous load and a concentrated load at the free end

    NASA Astrophysics Data System (ADS)

    Brojan, Miha; Cebron, Matjaz; Kosel, Franc

    2012-06-01

    This work studies large deflections of slender, non-prismatic cantilever beams subjected to a combined loading which consists of a non-uniformly distributed continuous load and a concentrated load at the free end of the beam. The material of the cantilever is assumed to be nonlinearly elastic. Different nonlinear relations between stress and strain in tensile and compressive domain are considered. The accuracy of numerical solutions is evaluated by comparing them with results from previous studies and with a laboratory experiment.

  16. Adsorptive removal of fermentation inhibitors from concentrated acid hydrolyzates of lignocellulosic biomass.

    PubMed

    Sainio, Tuomo; Turku, Irina; Heinonen, Jari

    2011-05-01

    Adsorptive purification of concentrated acid hydrolyzate of lignocellulose was investigated. Cation exchange resin (CS16GC), neutral polymer adsorbent (XAD-16), and granulated activated carbon (GAC) were studied to remove furfural, HMF, and acetic acid from a synthetic hydrolyzate containing 20 wt.% H(2)SO(4). Adsorption isotherms were determined experimentally. Loading and regeneration were investigated in a laboratory scale column. GAC has the highest adsorption capacity, but regeneration with water was not feasible. XAD-16 and CS16GC had lower adsorption capacities but also shorter cycle times due to easier regeneration. Productivity increased when regenerating with 50 wt.% EtOH(aq) solution. To compare adsorbents, process performance was quantified by productivity and fraction of inhibitors removed. GAC yields highest performance when high purity is required and ethanol can be used in regeneration. For lower purities, XAD-16 and GAC yield approximately equal performance. When using ethanol must be avoided, CS16GC offers highest productivity. PMID:21441022

  17. Nutrient concentrations and loads in the northeastern United States - Status and trends, 1975-2003

    USGS Publications Warehouse

    Trench, Elaine C. Todd; Moore, Richard B.; Ahearn, Elizabeth A.; Mullaney, John R.; Hickman, R. Edward; Schwarz, Gregory E.

    2012-01-01

    The U.S. Geological Survey (USGS) National Water-Quality Assessment Program (NAWQA) began regional studies in 2003 to synthesize information on nutrient concentrations, trends, stream loads, and sources. In the northeastern United States, a study area that extends from Maine to central Virginia, nutrient data were evaluated for 130 USGS water-quality monitoring stations. Nutrient data were analyzed for trends in flow-adjusted concentrations, modeled instream (non-flow-adjusted) concentrations, and stream loads for 32 stations with 22 to 29 years of water-quality and daily mean streamflow record during 1975-2003 (termed the long-term period), and for 46 stations during 1993-2003 (termed the recent period), by using a coupled statistical model of streamflow and water quality developed by the USGS. Recent trends in flow-adjusted concentrations of one or more nutrients also were analyzed for 90 stations by using Tobit regression. Annual stream nutrient loads were estimated, and annual nutrient yields were calculated, for 47 stations for the long-term and recent periods, and for 37 additional stations that did not have a complete streamflow and water-quality record for 1993-2003. Nutrient yield information was incorporated for 9 drainage basins evaluated in a national NAWQA study, for a total of 93 stations evaluated for nutrient yields. Long-term downward trends in flow-adjusted concentrations of total nitrogen and total phosphorus (18 and 19 of 32 stations, respectively) indicate regional improvements in nutrient-related water-quality conditions. Most of the recent trends detected for total phosphorus were upward (17 of 83 stations), indicating possible reversals to the long-term improvements. Concentrations of nutrients in many streams persist at levels that are likely to affect aquatic habitat adversely and promote freshwater or coastal eutrophication. Recent trends for modeled instream concentrations, and modeled reference concentrations, were evaluated relative to

  18. Dietary arachidonic acid dose-dependently increases the arachidonic acid concentration in human milk.

    PubMed

    Weseler, Antje R; Dirix, Chantal E H; Bruins, Maaike J; Hornstra, Gerard

    2008-11-01

    Lactation hampers normalization of the maternal arachidonic acid (AA) status, which is reduced after pregnancy and can further decline by the presently recommended increased consumption of (n-3) long-chain PUFA [(n-3) LCPUFA]. This may be unfavorable for breast-fed infants, because they also require an optimum supply of (n-6) LCPUFA. We therefore investigated the LCPUFA responses in nursing mothers upon increased consumption of AA and (n-3) LCPUFA. In a parallel, double-blind, controlled trial, lactating women received for 8 wk no extra LCPUFA (control group, n = 8), 200 (low AA group, n = 9), or 400 (high AA group, n = 8) mg/d AA in combination with (n-3) LCPUFA [320 mg/d docosahexaenoic acid (DHA), 80 mg/d eicosapentaenoic acid, and 80 mg/d other (n-3) fatty acids], or this dose of (n-3) LCPUFA alone [DHA + eicosapentaenoic acid group, n = 8]. Relative concentrations of AA, DHA, and sums of (n-6) and (n-3) LCPUFA were measured in milk total lipids (TL) and erythrocyte phospholipids (PL) after 2 and 8 wk and changes were compared by ANCOVA. The combined consumption of AA and (n-3) LCPUFA caused dose-dependent elevations of AA and total (n-6) LCPUFA concentrations in milk TL and did not significantly affect the DHA and total (n-3) LCPUFA increases caused by (n-3) LCPUFA supplementation only. This latter treatment did not significantly affect breast milk AA and total (n-6) LCPUFA concentrations. AA and DHA concentrations in milk TL and their changes were strongly and positively correlated with their corresponding values in erythrocyte PL (r(2) = 0.27-0.50; P concentration of their milk TL. PMID:18936218

  19. Phosphorus Concentrations, Loads, and Yields in the Illinois River Basin, Arkansas and Oklahoma, 2000-2004

    USGS Publications Warehouse

    Tortorelli, Robert L.; Pickup, Barbara E.

    2006-01-01

    The Illinois River and tributaries, Flint Creek and Baron Fork, are designated scenic rivers in Oklahoma. Recent phosphorus levels in streams in the basin have resulted in the growth of excess algae, which have limited the aesthetic benefits of water bodies in the basin, especially the Illinois River and Lake Tenkiller. The Oklahoma Water Resources Board has established a standard for total phosphorus not to exceed the 30-day geometric mean concentration of 0.037 milligram per liter in Oklahoma Scenic Rivers. The U.S. Geological Survey, in cooperation with the Oklahoma Water Resources Board, conducted an investigation to summarize phosphorus concentrations and provide estimates of phosphorus loads, yields, and flow-weighted concentrations in the Illinois River and tributaries from January 2000 through December 2004. Data from water-quality samples collected from 2000 to 2004 were used to summarize phosphorus concentrations and estimate phosphorus loads, yields, and mean flow-weighted concentrations in the Illinois River basin for three 3-year periods - 2000-2002, 2001-2003, and 2002-2004, to update a previous report that used data from water-quality samples from 1997 to 2001. This report provides information needed to advance knowledge of the regional hydrologic system and understanding of hydrologic processes, and provides hydrologic data and results useful to multiple parties for interstate compacts. Phosphorus concentrations in the Illinois River basin were significantly greater in runoff samples than in base-flow samples. Phosphorus concentrations generally decreased with increasing base flow, from dilution, and decreased in the downstream direction in the Illinois River from the Watts to Tahlequah stations. Phosphorus concentrations generally increased with runoff, possibly because of phosphorus resuspension, stream bank erosion, and the addition of phosphorus from nonpoint sources. Estimated mean annual phosphorus loads were greater at the Illinois River

  20. Safety profile of solid lipid nanoparticles loaded with rosmarinic acid for oral use: in vitro and animal approaches

    PubMed Central

    Madureira, Ana Raquel; Nunes, Sara; Campos, Débora A; Fernandes, João C; Marques, Cláudia; Zuzarte, Monica; Gullón, Beatriz; Rodríguez-Alcalá, Luís M; Calhau, Conceição; Sarmento, Bruno; Gomes, Ana Maria; Pintado, Maria Manuela; Reis, Flávio

    2016-01-01

    Rosmarinic acid (RA) possesses several protective bioactivities that have attracted increasing interest by nutraceutical/pharmaceutical industries. Considering the reduced bioavailability after oral use, effective (and safe) delivery systems are crucial to protect RA from gastrointestinal degradation. This study aims to characterize the safety profile of solid lipid nanoparticles produced with Witepsol and Carnauba waxes and loaded with RA, using in vitro and in vivo approaches, focused on genotoxicity and cytotoxicity assays, redox status markers, hematological and biochemical profile, liver and kidney function, gut bacterial microbiota, and fecal fatty acids composition. Free RA and sage extract, empty nanoparticles, or nanoparticles loaded with RA or sage extract (0.15 and 1.5 mg/mL) were evaluated for cell (lymphocytes) viability, necrosis and apoptosis, and antioxidant/prooxidant effects upon DNA. Wistar rats were orally treated for 14 days with vehicle (control) and with Witepsol or Carnauba nanoparticles loaded with RA at 1 and 10 mg/kg body weight/d. Blood, urine, feces, and several tissues were collected for analysis. Free and loaded RA, at 0.15 mg/mL, presented a safe profile, while genotoxic potential was found for the higher dose (1.5 mg/mL), mainly by necrosis. Our data suggest that both types of nanoparticles are safe when loaded with moderate concentrations of RA, without in vitro genotoxicity and cytotoxicity and with an in vivo safety profile in rats orally treated, thus opening new avenues for use in nutraceutical applications. PMID:27536103

  1. Safety profile of solid lipid nanoparticles loaded with rosmarinic acid for oral use: in vitro and animal approaches.

    PubMed

    Madureira, Ana Raquel; Nunes, Sara; Campos, Débora A; Fernandes, João C; Marques, Cláudia; Zuzarte, Monica; Gullón, Beatriz; Rodríguez-Alcalá, Luís M; Calhau, Conceição; Sarmento, Bruno; Gomes, Ana Maria; Pintado, Maria Manuela; Reis, Flávio

    2016-01-01

    Rosmarinic acid (RA) possesses several protective bioactivities that have attracted increasing interest by nutraceutical/pharmaceutical industries. Considering the reduced bioavailability after oral use, effective (and safe) delivery systems are crucial to protect RA from gastrointestinal degradation. This study aims to characterize the safety profile of solid lipid nanoparticles produced with Witepsol and Carnauba waxes and loaded with RA, using in vitro and in vivo approaches, focused on genotoxicity and cytotoxicity assays, redox status markers, hematological and biochemical profile, liver and kidney function, gut bacterial microbiota, and fecal fatty acids composition. Free RA and sage extract, empty nanoparticles, or nanoparticles loaded with RA or sage extract (0.15 and 1.5 mg/mL) were evaluated for cell (lymphocytes) viability, necrosis and apoptosis, and antioxidant/prooxidant effects upon DNA. Wistar rats were orally treated for 14 days with vehicle (control) and with Witepsol or Carnauba nanoparticles loaded with RA at 1 and 10 mg/kg body weight/d. Blood, urine, feces, and several tissues were collected for analysis. Free and loaded RA, at 0.15 mg/mL, presented a safe profile, while genotoxic potential was found for the higher dose (1.5 mg/mL), mainly by necrosis. Our data suggest that both types of nanoparticles are safe when loaded with moderate concentrations of RA, without in vitro genotoxicity and cytotoxicity and with an in vivo safety profile in rats orally treated, thus opening new avenues for use in nutraceutical applications. PMID:27536103

  2. Capillary-loaded particle fluid dynamics: effect on estimation of sperm concentration.

    PubMed

    Douglas-Hamilton, Diarmaid H; Smith, Nancy G; Kuster, Christopher E; Vermeiden, Jan P W; Althouse, Gary C

    2005-01-01

    Capillary loaded chambers are frequently used for semen analysis. Poiseuille flow of specimen into these chambers causes migration of suspended particles or cells in a direction transverse to the flow, which results in their preferential accumulation in the Segre-Silberberg (SS) planes. This SS effect depends on the transverse velocity gradient in the laminar flow. For semen analysis in thin capillary-loaded slides, the SS effect can lead to erroneous estimation of sample sperm-cell concentration. To better understand chamber flow dynamics and SS effect significance, we assessed flow uniformity, inflow cell velocity, and results of concentration measurements under different flow conditions for latex bead and porcine and human sperm suspensions. Overall, a concentration peak was present at the meniscus, which continued through chamber loading. High-velocity SS preferred planes, which channeled particles toward the meniscus, were located at the fractional positions of beta = .27 and beta = .73, where beta is the distance from wall to plane normalized to the chamber depth. In computer-automated semen analysis, a standard 20-microm x 18-mm x 6-mm chamber is commonly used, and these studies supported our previously published fluid-flow theory for this type of chamber. Conversely, the SS effect does not appear to have time to develop in the 100-microm-depth hemacytometer, which is deeper than the standard slide, has lower transverse velocity gradient, and consequently does not exhibit concentration variation due to the SS effect. These findings provide further support that hemacytometry, when performed properly, remains the gold standard. Applicability of our findings to routine semen analyses was then tested in 2 studies performed with independent boar studs. These studies compared diluted boar semen concentrations estimated by standard hemacytometry and in capillary-loaded 20-microm slides, using a computer-automated semen-analysis system designed to compensate for the

  3. A Geometrically Exact Model for Externally Loaded Concentric-Tube Continuum Robots.

    PubMed

    Rucker, D Caleb; Jones, Bryan A; Webster, Robert J

    2010-01-01

    Continuum robots, which are composed of multiple concentric, precurved elastic tubes, can provide dexterity at diameters equivalent to standard surgical needles. Recent mechanics-based models of these "active cannulas" are able to accurately describe the curve of the robot in free space, given the preformed tube curves and the linear and angular positions of the tube bases. However, in practical applications, where the active cannula must interact with its environment or apply controlled forces, a model that accounts for deformation under external loading is required. In this paper, we apply geometrically exact rod theory to produce a forward kinematic model that accurately describes large deflections due to a general collection of externally applied point and/or distributed wrench loads. This model accommodates arbitrarily many tubes, with each having a general preshaped curve. It also describes the independent torsional deformation of the individual tubes. Experimental results are provided for both point and distributed loads. Average tip error under load was 2.91 mm (1.5%-3% of total robot length), which is similar to the accuracy of existing free-space models. PMID:21566688

  4. Cascade model for particle concentration and enstrophy in fully developed turbulence with mass-loading feedback.

    PubMed

    Hogan, R C; Cuzzi, J N

    2007-05-01

    A cascade model is described based on multiplier distributions determined from three-dimensional (3D) direct numerical simulations (DNS) of turbulent particle laden flows, which include two-way coupling between the phases at global mass loadings equal to unity. The governing Eulerian equations are solved using psuedospectral methods on up to 512(3) computional grid points. DNS results for particle concentration and enstrophy at Taylor microscale Reynolds numbers in the range 34-170 were used to directly determine multiplier distributions on spatial scales three times the Kolmogorov length scale. The multiplier probability distribution functions (PDFs) are well characterized by the beta distribution function. The width of the PDFs, which is a measure of intermittency, decreases with increasing mass loading within the local region where the multipliers are measured. The functional form of this dependence is not sensitive to Reynolds numbers in the range considered. A partition correlation probability is included in the cascade model to account for the observed spatial anticorrelation between particle concentration and enstrophy. Joint probability distribution functions of concentration and enstrophy generated using the cascade model are shown to be in excellent agreement with those derived directly from our 3D simulations. Probabilities predicted by the cascade model are presented at Reynolds numbers well beyond what is achievable by direct simulation. These results clearly indicate that particle mass loading significantly reduces the probabilities of high particle concentration and enstrophy relative to those resulting from unloaded runs. Particle mass density appears to reach a limit at around 100 times the gas density. This approach has promise for significant computational savings in certain applications. PMID:17677162

  5. Concentrations and loads of suspended sediment and trace element pollutants in a small semi-arid urban tributary, San Francisco Bay, California.

    PubMed

    McKee, Lester J; Gilbreath, Alicia N

    2015-08-01

    Water-quality policy documents throughout the world often identify urban stormwater as a large and controllable impact to sensitive ecosystems, yet there is often limited data to characterize concentrations and loads especially for rare and more difficult to quantify pollutants. In response, concentrations of suspended sediments and silver, mercury and selenium including speciation, and other trace elements were measured in dry and wet weather stormwater flow from a 100% urban watershed near San Francisco. Suspended sediment concentrations ranged between 1.4 and 2700 mg/L and varied with storm intensity. Turbidity was shown to correlate strongly with suspended sediments and most trace elements and was used as a surrogate with regression to estimate concentrations during unsampled periods and to compute loads. Mean suspended sediment yield was 31.5 t/km(2)/year. Total mercury ranged between 1.4 and 150 ng/L and was, on average, 92% particulate, 0.9% methylated, and 1.2% acid labile. Total mercury yield averaged 5.7 μg/m(2)/year. Total selenium ranged between non-detect and 2.9 μg/L and, on average, the total load (0.027 μg/m(2)/year) was 61% transported in dissolved phase. Selenate (Se(VI)) was the dominant species. Silver concentrations ranged between non-detect and 0.11 μg/L. Concentrations and loads of other trace elements were also highly variable and were generally similar to other urban systems with the exceptions of Ag and As (seldom reported) and Cr and Zn which exhibited concentrations and loads in the upper range of those reported elsewhere. Consistent with the semi-arid climatic setting, >95% of suspended sediment, 94% of total Hg, and 85-95 % of all other trace element loads were transported during storm flows with the exception of selenium which showed an inverse relationship between concentration and flow. Treatment of loads is made more challenging in arid climate settings due to low proportions of annual loads and greater dissolved phase during

  6. Mechanochemical leaching of chalcopyrite concentrate by sulfuric acid

    NASA Astrophysics Data System (ADS)

    Mohammadabad, Farhad Khorramshahi; Hejazi, Sina; khaki, Jalil Vahdati; Babakhani, Abolfazl

    2016-04-01

    This study aimed to introduce a new cost-effective methodology for increasing the leaching efficiency of chalcopyrite concentrates at ambient temperature and pressure. Mechanical activation was employed during the leaching (mechanochemical leaching) of chalcopyrite concentrates in a sulfuric acid medium at room temperature and atmospheric pressure. High energy ball milling process was used during the leaching to provide the mechanochemical leaching condition, and atomic absorption spectroscopy and cyclic voltammetry were used to determine the leaching behavior of chalcopyrite. Moreover, X-ray diffraction and scanning electron microscopy were used to characterize the chalcopyrite powder before and after leaching. The results demonstrated that mechanochemical leaching was effective; the extraction of copper increased significantly and continuously. Although the leaching efficiency of chalcopyrite was very low at ambient temperature, the percentages of copper dissolved in the presence of hydrogen peroxide (H2O2) and ferric sulfate (Fe2(SO4)3) after 20 h of mechanochemical leaching reached 28% and 33%, respectively. Given the efficiency of the developed method and the facts that it does not require the use of an autoclave and can be conducted at room temperature and atmospheric pressure, it represents an economical and easy-to-use method for the leaching industry.

  7. 21 CFR 146.148 - Reduced acid frozen concentrated orange juice.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Reduced acid frozen concentrated orange juice. 146... Canned Fruit Juices and Beverages § 146.148 Reduced acid frozen concentrated orange juice. (a) Reduced acid frozen concentrated orange juice is the food that complies with the requirements for...

  8. 21 CFR 146.148 - Reduced acid frozen concentrated orange juice.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Reduced acid frozen concentrated orange juice. 146... Canned Fruit Juices and Beverages § 146.148 Reduced acid frozen concentrated orange juice. (a) Reduced acid frozen concentrated orange juice is the food that complies with the requirements for...

  9. Linking CDOM spectral absorption to dissolved organic carbon concentrations and loadings in boreal estuaries

    NASA Astrophysics Data System (ADS)

    Asmala, Eero; Stedmon, Colin A.; Thomas, David N.

    2012-10-01

    The quantity of chromophoric dissolved organic matter (CDOM) and dissolved organic carbon (DOC) in three Finnish estuaries (Karjaanjoki, Kyrönjoki and Kiiminkijoki) was investigated, with respect to predicting DOC concentrations and loadings from spectral CDOM absorption measurements. Altogether 87 samples were collected from three estuarine transects which were studied in three seasons, covering a salinity range between 0 and 6.8, and DOC concentrations from 1572 μmol l-1 in freshwater to 222 μmol l-1 in coastal waters. CDOM absorption coefficient, aCDOM(375) values followed the trend in DOC concentrations across the salinity gradient and ranged from 1.67 to 33.4 m-1. The link between DOC and CDOM was studied using a range of wavelengths and algorithms. Wavelengths between 250 and 270 nm gave the best predictions with single linear regression. Total dissolved iron was found to influence the prediction in wavelengths above 520 nm. Despite significant seasonal and spatial differences in DOC-CDOM models, a universal relationship was tested with an independent data set and found to be robust. DOC and CDOM yields (loading/catchment area) from the catchments ranged from 1.98 to 5.44 g C m-2 yr-1, and 1.67 to 11.5 aCDOM(375) yr-1, respectively.

  10. Unexpectedly high indoor hydroxyl radical concentrations associated with nitrous acid.

    PubMed

    Gómez Alvarez, Elena; Amedro, Damien; Afif, Charbel; Gligorovski, Sasho; Schoemaecker, Coralie; Schoemacker, Coralie; Fittschen, Christa; Doussin, Jean-Francois; Wortham, Henri

    2013-08-13

    The hydroxyl (OH) radical is the most important oxidant in the atmosphere since it controls its self-oxidizing capacity. The main sources of OH radicals are the photolysis of ozone and the photolysis of nitrous acid (HONO). Due to the attenuation of solar radiation in the indoor environment, the possibility of OH formation through photolytic pathways indoors has been ignored up to now. In the indoor air, the ozonolysis of alkenes has been suggested as an alternative route of OH formation. Models and indirect measurements performed up to now according to this hypothesis suggest concentrations of OH radicals on the order of 10(4)-10(5) molecules per cubic centimeter. Here, we present direct measurements of significant amounts of OH radicals of up to 1.8⋅10(6) molecules per cubic centimeter during an experimental campaign carried out in a school classroom in Marseille. This concentration is on the same order of magnitude of outdoor OH levels in the urban scenario. We also show that photolysis of HONO is an important source of OH radicals indoors under certain conditions (i.e., direct solar irradiation inside the room). Additionally, the OH concentrations were found to follow a linear dependence with the product J(HONO)⋅[HONO]. This was also supported by using a simple quasiphotostationary state model on the OH radical budget. These findings force a change in our understanding of indoor air quality because the reactivity linked to OH would involve formation of secondary species through chemical reactions that are potentially more hazardous than the primary pollutants in the indoor air. PMID:23898188

  11. Unexpectedly high indoor hydroxyl radical concentrations associated with nitrous acid

    PubMed Central

    Gómez Alvarez, Elena; Amedro, Damien; Afif, Charbel; Gligorovski, Sasho; Schoemaecker, Coralie; Fittschen, Christa; Doussin, Jean-Francois; Wortham, Henri

    2013-01-01

    The hydroxyl (OH) radical is the most important oxidant in the atmosphere since it controls its self-oxidizing capacity. The main sources of OH radicals are the photolysis of ozone and the photolysis of nitrous acid (HONO). Due to the attenuation of solar radiation in the indoor environment, the possibility of OH formation through photolytic pathways indoors has been ignored up to now. In the indoor air, the ozonolysis of alkenes has been suggested as an alternative route of OH formation. Models and indirect measurements performed up to now according to this hypothesis suggest concentrations of OH radicals on the order of 104–105 molecules per cubic centimeter. Here, we present direct measurements of significant amounts of OH radicals of up to 1.8⋅106 molecules per cubic centimeter during an experimental campaign carried out in a school classroom in Marseille. This concentration is on the same order of magnitude of outdoor OH levels in the urban scenario. We also show that photolysis of HONO is an important source of OH radicals indoors under certain conditions (i.e., direct solar irradiation inside the room). Additionally, the OH concentrations were found to follow a linear dependence with the product J(HONO)⋅[HONO]. This was also supported by using a simple quasiphotostationary state model on the OH radical budget. These findings force a change in our understanding of indoor air quality because the reactivity linked to OH would involve formation of secondary species through chemical reactions that are potentially more hazardous than the primary pollutants in the indoor air. PMID:23898188

  12. Nicotinic acid modulates intracellular calcium concentration and disassembles the cytoskeleton

    PubMed Central

    LI, JIEJING; LI, YANXI; ZHANG, PENGHUI; NIU, HUA; SHI, YU

    2014-01-01

    Nicotinic acid (NA), a member of the vitamin B family, is well known for its functions in the treatment and prevention of atherosclerosis due to decreasing plasma levels of low-density lipoprotein cholesterol. In recent years, the major side effect of NA, cutaneous flushing, has also attracted extensive attention. However, the effects of NA in other aspects of physiology or cell biology have remained elusive. The present study provided evidence that high concentrations of NA were able to first reduce and later elevate intracellular [Ca2+] in the NIH3T3 cell line. The reduction of the intracellular Ca2+ concentration was achieved within the initial 10 sec, and was preceded by a gradual elevation of intracellular [Ca2+]. Notably, marked accumulation of opaque materials in the perinuclear region was observed in NIH3T3 cells treated with 70 mM NA. Further analysis revealed that treatment with 70 mM NA for 1 h disassembled the microtubule and F-actin cytoskeleton systems and resulted in β-tubulin degradation in an ubiquitin-proteasome-dependent manner. These data indicated that high concentrations of NA disrupted cytoskeleton structures, which may have contributed to minus end (nucleus region) to plus end (cell membrane region)-directed transport processes and resulted in the deposition of material in the perinuclear region. Artificially increasing [Ca2+] adding CaCl2 to the culture media effected the disassembly of F-actin, while it had no apparent effect on microtubules. These results suggested that the disruption of the cytoskeleton systems was not entirely due to the NA-induced elevation of [Ca2+]. Finally, microinjection of NA into xenopus embryos blocked the transport of melanosomes to the peripheral cellular area. In conclusion, the present study indicated that NA disassembles F-actin and microtubule systems, thereby blocking cytoskeleton-dependent intracellular transport. PMID:25241762

  13. Nicotinic acid modulates intracellular calcium concentration and disassembles the cytoskeleton.

    PubMed

    Li, Jiejing; Li, Yanxi; Zhang, Penghui; Niu, Hua; Shi, Yu

    2014-12-01

    Nicotinic acid (NA), a member of the vitamin B family, is well known for its functions in the treatment and prevention of atherosclerosis due to decreasing plasma levels of low-density lipoprotein cholesterol. In recent years, the major side effect of NA, cutaneous flushing, has also attracted extensive attention. However, the effects of NA in other aspects of physiology or cell biology have remained elusive. The present study provided evidence that high concentrations of NA were able to first reduce and later elevate intracellular [Ca2+] in the NIH3T3 cell line. The reduction of the intracellular Ca2+ concentration was achieved within the initial 10 sec, and was preceded by a gradual elevation of intracellular [Ca2+]. Notably, marked accumulation of opaque materials in the perinuclear region was observed in NIH3T3 cells treated with 70 mM NA. Further analysis revealed that treatment with 70 mM NA for 1 h disassembled the microtubule and F‑actin cytoskeleton systems and resulted in β‑tubulin degradation in an ubiquitin‑proteasome-dependent manner. These data indicated that high concentrations of NA disrupted cytoskeleton structures, which may have contributed to minus end (nucleus region) to plus end (cell membrane region)-directed transport processes and resulted in the deposition of material in the perinuclear region. Artificially increasing [Ca2+] adding CaCl2 to the culture media effected the disassembly of F‑actin, while it had no apparent effect on microtubules. These results suggested that the disruption of the cytoskeleton systems was not entirely due to the NA-induced elevation of [Ca2+]. Finally, microinjection of NA into xenopus embryos blocked the transport of melanosomes to the peripheral cellular area. In conclusion, the present study indicated that NA disassembles F‑actin and microtubule systems, thereby blocking cytoskeleton-dependent intracellular transport. PMID:25241762

  14. Stress-concentration factors for finite orthotropic laminates with a pin-loaded hole

    NASA Technical Reports Server (NTRS)

    Crews, J. H., Jr.; Hong, C. S.; Raju, I. S.

    1981-01-01

    Stresses were calculated for finite size orthotropic laminates loaded by a frictionless steel pin in a circular hole of the same diameter. The calculations were based on finite element analyses for six laminates. Stress concentration factors, based on nominal bearing stress, were determined for wide ranges of the ratios of width to diameter, w/d and edge distance to diameter, e/d. An infinite laminate case was analyzed for each laminate. Orthotropy had a significant influence on the tensile stress concentration at the hole. For example, the stress concentration factors for the infinite laminate cases ranged from 0.82 to 2.16, compared with 0.87 for the quasi-isotropic laminate. The finite widths and edge distances strongly influenced the tensile stress concentration. For the practical range w/d or = 3, the peak tensile stresses were as much as 80% larger than the infinite laminate reference value. For e/d or = 3, these stresses were amplified by as much as 50%. In contrast, the finite width and edge distance had little effect on shear-out and bearing stress concentrations.

  15. Preparation and evaluation of 17-allyamino-17-demethoxygeldanamycin (17-AAG)-loaded poly(lactic acid-co-glycolic acid) nanoparticles.

    PubMed

    Pradhan, Roshan; Poudel, Bijay Kumar; Choi, Ju Yeon; Choi, Im Soon; Shin, Beom Soo; Choi, Han-Gon; Yong, Chul Soon; Kim, Jong Oh

    2015-01-01

    In the present study, we developed the novel 17-allyamino-17-demethoxygeldanamycin (17-AAG)-loaded poly(lactic acid-co-glycolic acid) (PLGA) nanoparticles (NPs) using the combination of sodium lauryl sulfate and poloxamer 407 as the anionic and non-ionic surfactant for stabilization. The PLGA NPs were prepared by emulsification/solvent evaporation method. Both the drug/polymer ratio and phase ratio were 1:10 (w/w). The optimized formulation of 17-AAG-loaded PLGA NPs had a particle size and polydispersity index of 151.6 ± 2.0 and 0.152 ± 0.010 nm, respectively, which was further supported by TEM image. The encapsulation efficiency and drug loading capacity were 69.9 and 7.0%, respectively. In vitro release study showed sustained release. When in vitro release data were fitted to Korsmeyer-Peppas model, the n value was 0.468, which suggested that the drug was released by anomalous or non-Fickian diffusion. In addition, 17-AAG-loaded PLGA NPs in 72 h, displayed approximately 60% cell viability reduction at 10 µg/ml 17-AAG concentration, in MCF-7 cell lines, indicating sustained release from NPs. Therefore, our results demonstrated that incorporation of 17-AAG into PLGA NPs could provide a novel effective nanocarrier for the treatment of cancer. PMID:24824337

  16. Preparation, characterization, and antibacterial activity studies of silver-loaded poly(styrene-co-acrylic acid) nanocomposites.

    PubMed

    Song, Cunfeng; Chang, Ying; Cheng, Ling; Xu, Yiting; Chen, Xiaoling; Zhang, Long; Zhong, Lina; Dai, Lizong

    2014-03-01

    A simple method for preparing a new type of stable antibacterial agent was presented. Monodisperse poly(styrene-co-acrylic acid) (PSA) nanospheres, serving as matrices, were synthesized via soap-free emulsion polymerization. Field-emission scanning electron microscopy micrographs indicated that PSA nanospheres have interesting surface microstructures and well-controlled particle size distributions. Silver-loaded poly(styrene-co-acrylic acid) (PSA/Ag-NPs) nanocomposites were prepared in situ through interfacial reduction of silver nitrate with sodium borohydride, and further characterized by transmission electron microscopy and X-ray diffraction. Their effects on antibacterial activity including inhibition zone, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and bactericidal kinetics were evaluated. In the tests, PSA/Ag-NPs nanocomposites showed excellent antibacterial activity against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli. These nanocomposites are considered to have potential application in antibacterial coatings on biomedical devices to reduce nosocomial infection rates. PMID:24433897

  17. Temporal variations and scaling of streamflow and baseflow and their nitrate-nitrogen concentrations and loads

    NASA Astrophysics Data System (ADS)

    Zhang, You-Kuan; Schilling, Keith

    2005-07-01

    The patterns of temporal variations of precipitation ( P), streamflow (SF) and baseflow (BF) as well as their nitrate-nitrogen (nitrate) concentrations ( C) and loads ( L) from a long-term record (28 years) in the Raccoon River, Iowa, were analyzed using variogram and spectral analyses. The daily P is random but scaling may exist in the daily SF and BF with a possible break point in the scaling at about 18 days and 45 days, respectively. The nitrate concentrations and loads are shown to have a half-year cycle while daily P, SF, and BF have a one-year cycle. Furthermore, there may be a low-frequency cycle of 6-8 years in C. The power spectra of C and L in both SF and BF exhibit fractal 1/ f scaling with two characteristic frequencies of half-year and one-year, and are fitted well with the spectrum of the gamma distribution. The nitrate input to SF and BF at the Raccoon watershed seems likely to be a white noise process superimposed on another process with a half-year and one-year cycle.

  18. Quantifying Nutrient and Mercury Concentrations and Loads in Lake Tahoe Snowpack

    NASA Astrophysics Data System (ADS)

    Pearson, C.; Obrist, D.; Schumer, R.

    2012-12-01

    Recent climate models predict a large decrease in Sierra Nevada snowpack over the next fifty years as a result of climate change. This decrease will not only affect the hydrologic balance but also change inputs of nutrients and pollutants through atmospheric deposition. In the Lake Tahoe basin, winter precipitation dominates and snowfall provides approximately 70 percent of the annual water input. From the first snowfall until the end of melting, snowpack acts as a temporary storage for atmospheric deposition that accumulates throughout winter and spring. Through melt and runoff processes, these nutrients and pollutants can enter the aquatic ecosystem where they can have detrimental effects on lake clarity and health. Most previous studies in this basin have focused on direct atmospheric deposition loads to the lake surface, and little temporal and spatial information is available on the dynamics of atmospheric deposition in the basin's snowpack. We here present nitrogen (N), phosphorus (P), and mercury (Hg) concentrations and pool sizes in snowpack along two elevational transects in the Tahoe Basin from January to April of 2012. Total N and P concentrations in the snowpack ranged from 0.07 mg/L to 0.38 mg/L and 0.003 mg/L to 0.109 mg/L, respectively. P concentrations showed strong increases from the west-side to the east-side of the basin which we attribute to local (e.g., urban or road-dust), in-basin sources that are distributed along the dominant west-wind patterns. N species, on the other hand, generally showed little spatial trends, indicating that its sources were more diffuse and possibly from out-of- basin. Hg concentrations ranged from 0.81 ppt to 6.25 ppt and showed similar spatial patterns as N. Hg, however, also showed significant snowpack concentration decreases during storm-free periods which we attribute to gaseous losses of Hg back to the atmosphere from photochemical reduction. These emissions are further supported by lower Hg concentrations in

  19. A conceptual framework: redefining forest soil's critical acid loads under a changing climate.

    PubMed

    McNulty, Steven G; Boggs, Johnny L

    2010-06-01

    Federal agencies of several nations have or are currently developing guidelines for critical forest soil acid loads. These guidelines are used to establish regulations designed to maintain atmospheric acid inputs below levels shown to damage forests and streams. Traditionally, when the critical soil acid load exceeds the amount of acid that the ecosystem can absorb, it is believed to potentially impair forest health. The excess over the critical soil acid load is termed the exceedance, and the larger the exceedance, the greater the risk of ecosystem damage. This definition of critical soil acid load applies to exposure of the soil to a single, long-term pollutant (i.e., acidic deposition). However, ecosystems can be simultaneously under multiple ecosystem stresses and a single critical soil acid load level may not accurately reflect ecosystem health risk when subjected to multiple, episodic environmental stress. For example, the Appalachian Mountains of western North Carolina receive some of the highest rates of acidic deposition in the eastern United States, but these levels are considered to be below the critical acid load (CAL) that would cause forest damage. However, the area experienced a moderate three-year drought from 1999 to 2002, and in 2001 red spruce (Picea rubens Sarg.) trees in the area began to die in large numbers. The initial survey indicated that the affected trees were killed by the southern pine beetle (Dendroctonus frontalis Zimm.). This insect is not normally successful at colonizing these tree species because the trees produce large amounts of oleoresin that exclude the boring beetles. Subsequent investigations revealed that long-term acid deposition may have altered red spruce forest structure and function. There is some evidence that elevated acid deposition (particularly nitrogen) reduced tree water uptake potential, oleoresin production, and caused the trees to become more susceptible to insect colonization during the drought period

  20. Contribution of diffuse inputs to the aqueous mass load of perfluoroalkyl acids in river and stream catchments in Korea.

    PubMed

    Kim, Seung-Kyu; Li, Dong-Hao; Shoeib, Mahiba; Zoh, Kyung-Duk

    2014-02-01

    Recent studies disagree regarding the contributions of point versus non-point sources to the aqueous mass loads of perfluoroalkyl acids (PFAAs). This study investigated the longitudinal change in PFAA mass load from upstream to downstream stations along rivers and/or streams to assess the relative contributions of point versus nonpoint inputs. With concentrations 10 to 100 times higher than running water, point sources such as wastewater treatment plants (WWTPs) effluent and airport ditch-outlet (ADO) water were separated from neighboring upstream and downstream running waters using principal component analysis. Source waters were characterized by certain predominant components [e.g., perfluorobutylsulfonate (PFBS) and perfluorooctanoic acid (PFOA) in WWTP effluent and perfluorohexylsulfonate (PFHxS) and perfluorooctylsulfonate (PFOS) in ADO water], which were minor components of running water. From a mass balance assessment of PFAA mass load, certain compounds such as PFOA and PFBS dominated the contribution of point sources to the mass load in the running water at downstream stations or in small catchment basins with high levels of industrial activity. Most of the mass load in the investigated catchments was attributable to upstream running water with a minor influence from industrial, commercial, and domestic human activities. Furthermore, the negative relationship of per capita emission factors (hereafter, EFs) with population density and a lower contribution of PFAA from WWTPs (~30% on average) compared to the running water-derived mass load at the national level indicated that diffuse inputs were more important contributors to aqueous PFAA contamination in each catchment basin as well as the entire watershed of the country (Korea). Volatile precursor compounds, which are readily dispersed to neighboring basins and transformed to PFAAs in the ambient environment, can be an important source of these diffuse inputs and will become more significant over time

  1. Pelargonic acid weed control: Concentrations, adjuvants, and application timing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pelargonic acid is a fatty acid naturally occurring in many plants, animals, and foods. Pelargonic acid has potential as a broad-spectrum post-emergence or burn-down herbicide for organic crop production. Field research was conducted in southeast Oklahoma (Lane, OK, Atoka County) to determine the ...

  2. Quantitative XPS depth profiling of codeine loaded poly(l-lactic acid) films using a coronene ion sputter source.

    PubMed

    Rafati, Ali; Davies, Martyn C; Shard, Alexander G; Hutton, Simon; Mishra, Gautam; Alexander, Morgan R

    2009-08-19

    The controlled release of active pharmaceutical ingredients from polymers over prolonged periods of time is vital for the function of drug eluting stents and other drug loaded delivery devices. Characterisation of the drug distribution in polymers allows the in vitro and in vivo performance to be rationalised. We present the first X-ray photoelectron spectroscopy (XPS) depth profiling study of such a drug eluting stent system for which we employ a novel coronene ion sputter source. The rationale for this is to ascertain quantitative atomic concentration data through the thickness of flat films containing codeine and poly(l-lactic acid) (PLA) as a model of a drug loaded polymer device. A range of films of thickness of up to 96 nm are spun cast from chloroform onto Piranha cleaned silicon wafers. Ellipsometry of the films is undertaken prior to depth profiling to determine the total film thickness and provide a measure of the relative loading of drug within the PLA matrix through spectroscopic analysis. Progressive XPS analysis of the bottom of the sputter crater with sputter time indicated codeine to be depleted from the surface and segregated to the bulk of the polymer films by comparison with a uniform distribution calculated from the bulk loading. This serves to illustrate that surface depletion of drug occurs, which poses important implications for drug loaded polymer delivery systems. PMID:19427343

  3. Dissolved-solids sources, loads, yields, and concentrations in streams of the conterminous United States

    USGS Publications Warehouse

    Anning, David W.; Flynn, Marilyn E.

    2014-01-01

    Predicted incremental loads were cascaded down through the reach network, with loads accumulating from reach to reach. For most stream reaches, the entire incremental load of dissolved solids delivered to the reach was transport

  4. Determining the sulfuric acid fog concentration in coke oven gas

    SciTech Connect

    Zin'kovskaya, S.I.; Okhrimenko, E.L.; Sobko, L.V.

    1982-11-06

    A volumetric method for the analysis of sulfuric acid aerosols at levels of acid greater (25-40 g/m/sup 3/) than those (1 g/m/sup 3/) analyzable by current methods is described. Coke oven gas after acid scrubbing and electrofiltration is passed through a Schott filter (pressure drop 100 mm Hg), the sulfuric acid aerosol being condensed on the filter which is washed with water and the washings filtered with NaOH (0.01 N after electrofilter, 1.0 N after the acid towers) to methyl orange end point. The error is +/- 2%.

  5. The role of low acid load in vegetarian diet on bone health: a narrative review.

    PubMed

    Burckhardt, Peter

    2016-01-01

    Vegetarian and vegan diets contain low amounts of protein and calcium. For this reason they are supposed to cause low bone mineral density (BMD) and osteoporosis. But this is not the case, except for vegans with a particularly low calcium intake. The absence of osteoporosis or low BMD can be explained by the low acid load of these diets. Nutritional acid load is negatively correlated with bone mineral density (BMD) and positively with fracture risk. Low acid load is correlated with lower bone resorption and higher BMD. It is linked to high intake of potassium-rich nutrients, such as fruits and vegetables, as found in vegetarian diets. The total nutritional acid load, which not only depends on the potassium content of the nutrition, was recently assessed in several studies on vegetarian and vegan diets and was found to be very low or absent, while the diet of Western-style omnivores produces daily 50 to 70 mEq of acid. This might be an important factor for the protection of vegetarians from osteoporosis. PMID:26900949

  6. Various concentrations of erucic acid in mustard oil and mustard.

    PubMed

    Wendlinger, Christine; Hammann, Simon; Vetter, Walter

    2014-06-15

    Erucic acid is a typical constituent of mustard or rape. Foodstuff with a high content of erucic acid is considered undesirable for human consumption because it has been linked to myocardial lipidosis and heart lesions in laboratory rats. As a result, several countries have restricted its presence in oils and fats. In this study, the erucic acid content in several mustard oils and prepared mustard samples from Germany and Australia was determined. Seven of nine mustard oil samples exceeded the permitted maximum levels established for erucic acid (range: 0.3-50.8%, limit: 5%). The erucic acid content in mustard samples (n=15) varied from 14% to 33% in the lipids. Two servings (i.e. 20 g) of the mustards with the highest erucic acid content already surpassed the tolerable daily intake established by Food Standards Australia New Zealand. However, a careful selection of mustard cultivars could lower the nutritional intake of erucic acid. PMID:24491745

  7. Effects of running the Bostom Marathon on plasma concentrations of large neutral amino acids

    NASA Technical Reports Server (NTRS)

    Conlay, L. A.; Wurtman, R. J.; Lopez G-Coviella, I.; Blusztajn, J. K.; Vacanti, C. A.; Logue, M.; During, M.; Caballero, B.; Maher, T. J.; Evoniuk, G.

    1989-01-01

    Plasma large neutral amino acid concentrations were measured in thirty-seven subjects before and after completing the Boston Marathon. Concentrations of tyrosine, phenylalanine, and methionine increased, as did their 'plasma ratios' (i.e., the ratio of each amino acid's concentration to the summed plasma concentrations of the other large neutral amino acids which compete with it for brain uptake). No changes were noted in the plasma concentrations of tryptophan, leucine, isoleucine, nor valine; however, the 'plasma ratios' of valine, leucine, and isoleucine all decreased. These changes in plasma amino acid patterns may influence neurotransmitter synthesis.

  8. Different Serum Free Fatty Acid Profiles in NAFLD Subjects and Healthy Controls after Oral Fat Load

    PubMed Central

    Gambino, Roberto; Bugianesi, Elisabetta; Rosso, Chiara; Mezzabotta, Lavinia; Pinach, Silvia; Alemanno, Natalina; Saba, Francesca; Cassader, Maurizio

    2016-01-01

    Background: Free fatty acid (FFA) metabolism can impact on metabolic conditions, such as obesity and nonalcoholic fatty liver disease (NAFLD). This work studied the increase in total FFA shown in NAFLD subjects to possibly characterize which fatty acids significantly accounted for the whole increase. Methods: 21 patients with NAFLD were selected according to specified criteria. The control group consisted of nine healthy subjects. All subjects underwent an oral standard fat load. Triglycerides; cholesterol; FFA; glucose and insulin were measured every 2 h with the determination of fatty acid composition of FFA. Results: higher serum FFA levels in NAFLD subjects are mainly due to levels of oleic, palmitic and linoleic acids at different times. Significant increases were shown for docosahexaenoic acid, linolenic acid, eicosatrienoic acid, and arachidonic acid, although this was just on one occasion. In the postprandial phase, homeostatic model assessment HOMA index positively correlated with the ω3/ω6 ratio in NAFLD patients. Conclusions: the higher serum levels of FFA in NAFLD subjects are mainly due to levels of oleic and palmitic acids which are the most abundant circulating free fatty acids. This is almost exactly corresponded with significant increases in linoleic acid. An imbalance in the n-3/n-6 fatty acids ratio could modulate postprandial responses with more pronounced effects in insulin-resistant subjects, such as NAFLD patients. PMID:27043543

  9. Reduction of Dietary Acid Load as a Potential Countermeasure for Bone Loss Associated with Spaceflight

    NASA Technical Reports Server (NTRS)

    Zwart, S. R.; Watts, S. M.; Sams, C. F.; Whitson, P. A.; Smith, S. M.

    2006-01-01

    In several studies we tested the concepts that diet can alter acid-base balance and that reducing the dietary acid load has a positive effect on maintenance of bone. In study 1, (n = 11, 60-90 d bed rest), the renal acid load of the diet was estimated from its chemical composition, and was positively correlated with urinary markers of bone resorption (P less than 0.05); that is, the greater the acid load, the greater the excretion of bone resorption markers. In study 2, in males (n = 8, 30 d bed rest), an estimate of the ratio of nonvolatile acid precursors to base precursors in the diet was positively correlated (P less than 0.05) with markers of bone resorption. In study 3, for 28 d subjects received either a placebo (n = 6) or an essential amino acid supplement (n = 7) that included methionine, a known acid precursor. During bed rest (28 d), urinary calcium was greater than baseline levels in the supplemented group but not the control group (P less than 0.05), and in the supplemented group, urinary pH decreased (P less than 0.05). In study 4, less bone resorption occurred in space crew members who received potassium citrate (n = 6) during spaceflight of 4-6 months than in crew members who received placebo or were not in the study (n = 8) (P less than 0.05). Reducing acid load has the potential to mitigate increased bone resorption during spaceflight, and may serve as a bone loss countermeasure.

  10. Stress-concentration factors for finite orthotropic laminates with a circular hole and uniaxial loading

    NASA Technical Reports Server (NTRS)

    Hong, C. S.; Crews, J. H., Jr.

    1979-01-01

    Stresses were calculated for finite-width orthotropic laminates with a circular hole and remote uniaxial loading using a two-dimensional finite element analysis with both uniform stress and uniform displacement boundary conditions. Five different laminates were analyzed. Computed results are presented for selected combinations of hole diameter/sheet-width ratio d/w and length-to-width ratio L/w. For small L/w values, the stress-concentration factors K sub tn were significantly different for the uniform stress and uniform displacement boundary conditions. Typically, for the uniform stress condition, the K sub tn values were much larger than for the infinite strip reference condition; however, for the uniform displacement condition, they were only slightly smaller than for this reference. The results for long strips are also presented as width correction factors. For d/w less or = 0.33, these width correction factors are nearly equal for all five laminates.

  11. Influence of bleaching on flavor of 34% whey protein concentrate and residual benzoic acid concentration in dried whey products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies have shown that bleaching negatively affects the flavor of 70% whey protein concentrate (WPC70), but bleaching effects on lower-protein products have not been established. Benzoyl peroxide (BP), a whey bleaching agent, degrades to benzoic acid (BA) and may elevate BA concentrations...

  12. Influence of Bleaching on Flavor of 34% Whey Protein Concentrate and Residual Benzoic Acid Concentration in Dried Whey Proteins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies have shown that bleaching negatively affects the flavor of 70% whey protein concentrate (WPC70), but bleaching effects on lower-protein products have not been established. Benzoyl peroxide (BP), a whey bleaching agent, degrades to benzoic acid (BA) and may elevate BA concentrations...

  13. Preparation of ultrafine poly(methyl methacrylate-co-methacrylic acid) biodegradable nanoparticles loaded with ibuprofen.

    PubMed

    Saade, Hened; Diaz de León-Gómez, Ramón; Enríquez-Medrano, Francisco Javier; López, Raúl Guillermo

    2016-08-01

    Ibuprofen-loaded polymeric particles with around 9.2 nm in mean diameter, as determined by electron microscopy, dispersed in an aqueous media containing up to 12.8% solids were prepared by semicontinuous heterophase polymerization. The polymeric material is a (2/1 mol/mol) methyl methacrylate-co-methacrylic acid copolymer similar to Eudragit S100, deemed safe for human consumption and used in the manufacturing of drug-loaded pills as well as micro- and nanoparticles. The loading efficiency was 100%, attaining around 10-12% in drug content. Release studies showed that the drug is released from the nanoparticles at a slower rate than that in the case of free IB. Given their size as well as the pH values required for their dissolution, it is believed that this type of particles could be used as a basis for preparing nanosystems loaded with a variety of drugs. PMID:27126476

  14. Large lead/acid batteries for frequency regulation, load levelling and solar power applications

    NASA Astrophysics Data System (ADS)

    Wagner, R.

    Lead/acid batteries are suitable for a multitude of utility applications. This paper presents some examples where large lead/acid batteries have been used for frequency regulation, load levelling and solar power applications. The operational experiences are given together with a discussion about the design and technical specialities of these batteries. In 1986, a 17 MW/14 MWh battery was installed at BEWAG in Berlin which, at that time, was the largest lead/acid battery in the world. Designed to strengthen Berlin's 'island' system, it was used since the beginning of 1987 for frequency regulation and spinning reserve. In December 1993, when Berlin was connected to the electricity grid, frequency regulation was no longer required but the battery was still used for spinning reserve. For many years, the industrial battery plant of Hagen in Soest has used a large lead/acid battery for load levelling. The experience gained during more than ten years shows that load levelling and peak shaving can be a marked benefit for customers and utilities with regard to reducing their peak demand. In the summer of 1992, a 216 V and 2200 Ah lead/acid battery with positive tubular plates and gelled electrolyte was installed at a solar power plant in Flanitzhutte, a small village in the south of Germany which is not connected to the electricity grid. A report is given of the first years of use and includes a discussion about the best charge strategy for such gel batteries when used for solar power applications.

  15. Elevational Variation in Soil Amino Acid and Inorganic Nitrogen Concentrations in Taibai Mountain, China.

    PubMed

    Cao, Xiaochuang; Ma, Qingxu; Zhong, Chu; Yang, Xin; Zhu, Lianfeng; Zhang, Junhua; Jin, Qianyu; Wu, Lianghuan

    2016-01-01

    Amino acids are important sources of soil organic nitrogen (N), which is essential for plant nutrition, but detailed information about which amino acids predominant and whether amino acid composition varies with elevation is lacking. In this study, we hypothesized that the concentrations of amino acids in soil would increase and their composition would vary along the elevational gradient of Taibai Mountain, as plant-derived organic matter accumulated and N mineralization and microbial immobilization of amino acids slowed with reduced soil temperature. Results showed that the concentrations of soil extractable total N, extractable organic N and amino acids significantly increased with elevation due to the accumulation of soil organic matter and the greater N content. Soil extractable organic N concentration was significantly greater than that of the extractable inorganic N (NO3--N + NH4+-N). On average, soil adsorbed amino acid concentration was approximately 5-fold greater than that of the free amino acids, which indicates that adsorbed amino acids extracted with the strong salt solution likely represent a potential source for the replenishment of free amino acids. We found no appreciable evidence to suggest that amino acids with simple molecular structure were dominant at low elevations, whereas amino acids with high molecular weight and complex aromatic structure dominated the high elevations. Across the elevational gradient, the amino acid pool was dominated by alanine, aspartic acid, glycine, glutamic acid, histidine, serine and threonine. These seven amino acids accounted for approximately 68.9% of the total hydrolyzable amino acid pool. The proportions of isoleucine, tyrosine and methionine varied with elevation, while soil major amino acid composition (including alanine, arginine, aspartic acid, glycine, histidine, leucine, phenylalanine, serine, threonine and valine) did not vary appreciably with elevation (p>0.10). The compositional similarity of many

  16. Elevational Variation in Soil Amino Acid and Inorganic Nitrogen Concentrations in Taibai Mountain, China

    PubMed Central

    Yang, Xin; Zhu, Lianfeng; Zhang, Junhua; Jin, Qianyu; Wu, Lianghuan

    2016-01-01

    Amino acids are important sources of soil organic nitrogen (N), which is essential for plant nutrition, but detailed information about which amino acids predominant and whether amino acid composition varies with elevation is lacking. In this study, we hypothesized that the concentrations of amino acids in soil would increase and their composition would vary along the elevational gradient of Taibai Mountain, as plant-derived organic matter accumulated and N mineralization and microbial immobilization of amino acids slowed with reduced soil temperature. Results showed that the concentrations of soil extractable total N, extractable organic N and amino acids significantly increased with elevation due to the accumulation of soil organic matter and the greater N content. Soil extractable organic N concentration was significantly greater than that of the extractable inorganic N (NO3−-N + NH4+-N). On average, soil adsorbed amino acid concentration was approximately 5-fold greater than that of the free amino acids, which indicates that adsorbed amino acids extracted with the strong salt solution likely represent a potential source for the replenishment of free amino acids. We found no appreciable evidence to suggest that amino acids with simple molecular structure were dominant at low elevations, whereas amino acids with high molecular weight and complex aromatic structure dominated the high elevations. Across the elevational gradient, the amino acid pool was dominated by alanine, aspartic acid, glycine, glutamic acid, histidine, serine and threonine. These seven amino acids accounted for approximately 68.9% of the total hydrolyzable amino acid pool. The proportions of isoleucine, tyrosine and methionine varied with elevation, while soil major amino acid composition (including alanine, arginine, aspartic acid, glycine, histidine, leucine, phenylalanine, serine, threonine and valine) did not vary appreciably with elevation (p>0.10). The compositional similarity of many

  17. Development and Optimization of a Doxorubicin Loaded Poly Lactic Acid Contrast Agent for Ultrasound Directed Drug Delivery

    PubMed Central

    Eisenbrey, J.R.; Burstein, O. Mualem; Kambhampati, R.; Forsberg, F.; Liu, J-B.; Wheatley, M.A.

    2010-01-01

    An echogenic, intravenous drug delivery platform is proposed in which an encapsulated chemotherapeutic can travel to a desired location and drug delivery can be triggered using external, focused ultrasound at the area of interest. Three methods of loading poly lactic acid (PLA) shelled ultrasound contrast agents (UCA) with doxorubicin are presented. Effects on encapsulation efficiency, in vitro enhancement, stability, particle size, morphology and release during UCA rupture are compared by loading method and drug concentration. An agent containing doxorubicin within the shell was selected as an ideal candidate for future hepatocellular carcinoma studies. The agent achieved a maximal drug load of 6.2 mg Dox/g PLA with an encapsulation efficiency of 20.5%, showed a smooth surface morphology and tight size distribution (poly dispersity index = 0.309) with a peak size of 1865 nm. Acoustically, the agent provided 19 dB of enhancement in vitro at a dosage of 10 µg/ml, with a half life of over 15 mins. In vivo, the agent provided ultrasound enhancement of 13.4 ± 1.6 dB within the ascending aorta of New Zealand rabbits at a dose of 0.15 ml/kg. While the drug-incorporated agent is thought to be well suited for future drug delivery experiments, this study has shown that agent properties can be tailored for specific applications based on choice of drug loading method. PMID:20060024

  18. Connecting Source with Sink: The Role of Arabidopsis AAP8 in Phloem Loading of Amino Acids.

    PubMed

    Santiago, James P; Tegeder, Mechthild

    2016-05-01

    Allocation of large amounts of nitrogen to developing organs occurs in the phloem and is essential for plant growth and seed development. In Arabidopsis (Arabidopsis thaliana) and many other plant species, amino acids represent the dominant nitrogen transport forms in the phloem, and they are mainly synthesized in photosynthetically active source leaves. Following their synthesis, a broad spectrum of the amino nitrogen is actively loaded into the phloem of leaf minor veins and transported within the phloem sap to sinks such as developing leaves, fruits, or seeds. Controlled regulation of the source-to-sink transport of amino acids has long been postulated; however, the molecular mechanism of amino acid phloem loading was still unknown. In this study, Arabidopsis AMINO ACID PERMEASE8 (AAP8) was shown to be expressed in the source leaf phloem and localized to the plasma membrane, suggesting its function in phloem loading. This was further supported by transport studies with aap8 mutants fed with radiolabeled amino acids and by leaf exudate analyses. In addition, biochemical and molecular analyses revealed alterations in leaf nitrogen pools and metabolism dependent on the developmental stage of the mutants. Decreased amino acid phloem loading and partitioning to sinks led to decreased silique and seed numbers, but seed protein levels were unchanged, demonstrating the importance of AAP8 function for sink development rather than seed quality. Overall, these results show that AAP8 plays an important role in source-to-sink partitioning of nitrogen and that its function affects source leaf physiology and seed yield. PMID:27016446

  19. Evaluation of leaf removal as a means to reduce nutrient concentrations and loads in urban stormwater.

    PubMed

    Selbig, William R

    2016-11-15

    While the sources of nutrients to urban stormwater are many, the primary contributor is often organic detritus, especially in areas with dense overhead tree canopy. One way to remove organic detritus before it becomes entrained in runoff is to implement a city-wide leaf collection and street cleaning program. Improving our knowledge of the potential reduction of nutrients to stormwater through removal of leaves and other organic detritus on streets could help tailor more targeted municipal leaf collection programs. This study characterized an upper ideal limit in reductions of total and dissolved forms of phosphorus and nitrogen in stormwater through implementation of a municipal leaf collection and street cleaning program in Madison, WI, USA. Additional measures were taken to remove leaf litter from street surfaces prior to precipitation events. Loads of total and dissolved phosphorus were reduced by 84 and 83% (p<0.05), and total and dissolved nitrogen by 74 and 71% (p<0.05) with an active leaf removal program. Without leaf removal, 56% of the annual total phosphorus yield (winter excluded) was due to leaf litter in the fall compared to 16% with leaf removal. Despite significant reductions in load, total nitrogen showed only minor changes in fall yields without and with leaf removal at 19 and 16%, respectively. The majority of nutrient concentrations were in the dissolved fraction making source control through leaf removal one of the few treatment options available to environmental managers when reducing the amount of dissolved nutrients in stormwater runoff. Subsequently, the efficiency, frequency, and timing of leaf removal and street cleaning are the primary factors to consider when developing a leaf management program. PMID:27470671

  20. Concentrations, loads, and yields of total phosphorus, total nitrogen, and suspended sediment and bacteria concentrations in the Wister Lake Basin, Oklahoma and Arkansas, 2011-13

    USGS Publications Warehouse

    Buck, Stephanie D.

    2014-01-01

    The Poteau Valley Improvement Authority uses Wister Lake in southeastern Oklahoma as a public water supply. Total phosphorus, total nitrogen, and suspended sediments from agricultural runoff and discharges from wastewater treatment plants and other sources have degraded water quality in the lake. As lake-water quality has degraded, water-treatment cost, chemical usage, and sludge production have increased for the Poteau Valley Improvement Authority. The U.S. Geological Survey (USGS), in cooperation with the Poteau Valley Improvement Authority, investigated and summarized concentrations of total phosphorus, total nitrogen, suspended sediment, and bacteria (Escherichia coli and Enterococcus sp.) in surface water flowing to Wister Lake. Estimates of total phosphorus, total nitrogen, and suspended sediment loads, yields, and flow-weighted mean concentrations of total phosphorus and total nitrogen concentrations were made for the Wister Lake Basin for a 3-year period from October 2010 through September 2013. Data from water samples collected at fixed time increments during base-flow conditions and during runoff conditions at the Poteau River at Loving, Okla. (USGS station 07247015), the Poteau River near Heavener, Okla. (USGS station 07247350), and the Fourche Maline near Leflore, Okla. (USGS station 07247650), water-quality stations were used to evaluate water quality over the range of streamflows in the basin. These data also were collected to estimate annual constituent loads and yields by using regression models. At the Poteau River stations, total phosphorus, total nitrogen, and suspended sediment concentrations in surface-water samples were significantly larger in samples collected during runoff conditions than in samples collected during base-flow conditions. At the Fourche Maline station, in contrast, concentrations of these constituents in water samples collected during runoff conditions were not significantly larger than concentrations during base

  1. Berberine-loaded solid lipid nanoparticles are concentrated in the liver and ameliorate hepatosteatosis in db/db mice

    PubMed Central

    Xue, Mei; Zhang, Liang; Yang, Ming-xing; Zhang, Wei; Li, Xiu-min; Ou, Zhi-min; Li, Zhi-peng; Liu, Su-huan; Li, Xue-jun; Yang, Shu-yu

    2015-01-01

    Berberine (BBR) shows very low plasma levels after oral administration due to its poor absorption by the gastrointestinal tract. We have previously demonstrated that BBR showed increased gastrointestinal absorption and enhanced antidiabetic effects in db/db mice after being entrapped into solid lipid nanoparticles (SLNs). However, whether BBR-loaded SLNs (BBR-SLNs) also have beneficial effects on hepatosteatosis is not clear. We investigated the effects of BBR-SLNs on lipid metabolism in the liver using histological staining and reverse transcription polymerase chain reaction analysis. The results showed that oral administration of BBR-SLNs inhibited the increase of body weight and decreased liver weight in parallel with the reduction of serum alanine transaminase and liver triglyceride levels in db/db mice. The maximum drug concentration in the liver was 20-fold higher than that in the blood. BBR-SLNs reduced fat accumulation and lipid droplet sizes significantly in the liver, as indicated by hematoxylin and eosin and Oil Red O staining. The expression of lipogenic genes, including fatty acid synthase (FAS), stearoyl-CoA desaturase (SCD1), and sterol regulatory element-binding protein 1c (SREBP1c) were downregulated, while lipolytic gene carnitine palmitoyltransferase-1 (CPT1) was upregulated in BBR-SLN-treated livers. In summary, we have uncovered an unexpected effect of BBR-SLNs on hepatosteatosis treatment through the inhibition of lipogenesis and the induction of lipolysis in the liver of db/db mice. PMID:26346310

  2. Organic acid dipping of catfish fillets: effect on color, microbial load, and Listeria monocytogenes.

    PubMed

    Bal'a, M F; Marshall, D L

    1998-11-01

    Microbiological and color changes of catfish fillets were determined following dip treatment in solutions at 4 degrees C of 2% acetic, citric, hydrochloric, lactic, malic, or tartaric acid. Fillets were inoculated with an eight-strain mixture of Listeria monocytogenes prior to dipping. L. monocytogenes, coliform, and aerobic plate counts and surface pH and Hunter color were measured at 0, 2, 5, and 8 days of storage at 4 degrees C. Acid dipping reduced surface pH and L. monocytogenes, coliform, and aerobic microbial loads. Little microbial proliferation was observed on acid-treated fillets, however, controls had a distinct foul odor and microbial loads in excess of 10(6) CFU/g by day 8. On untreated fillets, L. monocytogenes counts did not increase during storage, perhaps due to competitive inhibition by normal catfish microflora. Hunter color analysis revealed lighter and yellower acid-treated fillets than untreated controls, with malic acid producing the least bleaching. The shelf life of refrigerated fillets increased when fillets were acid dipped. It remains to be established if this enhanced microbial quality also parallels sensory acceptability. PMID:9829187

  3. Sucrose Loading in Isolated Veins of Pisum sativum: Regulation by Abscisic Acid, Gibberellic Acid, and Cell Turgor.

    PubMed

    Estruch, J J; Peretó, J G; Vercher, Y; Beltrán, J P

    1989-09-01

    Enzymatically isolated vein networks from mature pea (Pisum sativum L. cv Alaska) leaves were employed to investigate the properties of sucrose loading and the effect of phytohormones and cell turgor on this process. The sucrose uptake showed two components: a saturable and a first-order kinetics system. The high affinity system (K(m), 3.3 millimolar) was located at the plasmalemma (p-chloromercuriphenylsulfonic acid and orthovanadate sensitivity). Further characterization of this system, including pH dependence and effects of energy metabolism inhibitors, supported the H(+)-sugar symport concept for sucrose loading. Within a physiological range (0.1-100 micromolar) and after 90 min, abscisic acid (ABA) inhibited and gibberellic acid (GA(3)) promoted 1 millimolar sucrose uptake. These responses were partially (ABA) or totally (GA(3)) turgor-dependent. In experiments of combined hormonal treatments, ABA counteracted the GA(3) positive effects on sucrose uptake. The abolishment of these responses by p-chloromercuriphenylsulfonic acid and experiments on proton flux suggest that both factors (cell turgor and hormones) are modulating the H(+) ATPase plasmalemma activity. The results are discussed in terms of their physiological relevance. PMID:16667007

  4. All-trans retinoic acid-loaded lipid nanoparticles as a transdermal drug delivery carrier.

    PubMed

    Charoenputtakhun, Ponwanit; Opanasopit, Praneet; Rojanarata, Theerasak; Ngawhirunpat, Tanasait

    2014-03-01

    The objective of this study was to investigate the effects of drug amounts (0.1%, 0.2% and 0.3% w/w), amounts of the oil (10%, 15% and 20% w/w of lipid matrix) and types of the oil (soybean oil (S), medium chain triglycerides (M), oleic acids (O) and linoleic acids (L)) in lipid matrix of all-trans retinoic acid (ATRA)-loaded nanostructured lipid carriers (NLCs) for transdermal drug delivery. The ATRA-loaded solid lipid nanoparticles (SLNs) were formulated with 30% w/w cetyl palmitate. All lipid nanoparticles had average sizes between 130 and 241 nm and had negative zeta potentials. The drug loading of all formulations was higher than 95%. The release of drug from all lipid nanoparticles followed zero-order kinetics. The amount of drug released from all the NLCs and SLNs was significantly greater than the drug released from the ATRA suspension. The ATRA flux of the SLNs was higher than the NLCs. The flux of the NLCs containing oleic acid was significantly higher than the other types of oils. The chemical stability at 4 °C, the percentage of ATRA remaining in all the lipid nanoparticles tested was higher than 80%. It can be concluded that both the SLNs and NLCs are promising dermal drug delivery systems for ATRA. PMID:23356887

  5. Biomass, lipid productivities and fatty acids composition of marine Nannochloropsis gaditana cultured in desalination concentrate.

    PubMed

    Matos, Ângelo Paggi; Feller, Rafael; Moecke, Elisa Helena Siegel; Sant'Anna, Ernani Sebastião

    2015-12-01

    In this study the feasibility of growing marine Nannochloropsis gaditana in desalination concentrate (DC) was explored and the influence of the DC concentration on the biomass growth, lipid productivities and fatty acids composition was assessed. The reuse of the medium with the optimum DC concentration in successive algal cultivation cycles and the additional of a carbon source to the optimized medium were also evaluated. On varying the DC concentration, the maximum biomass concentration (0.96gL(-1)) and lipid content (12.6%) were obtained for N. gaditana in the medium with the optimum DC concentration (75%). Over the course of the reuse of the optimum DC medium, three cultivation cycles were performed, observing that the biomass productivity is directly correlated to lipid productivity. Palmitic acid was the major fatty acid found in N. gaditana cells. The saturated fatty acids content of the algae enhanced significantly on increasing the DC concentration. PMID:26318921

  6. Concentrations, loads, and yields of organic carbon in streams of agricultural watersheds

    USGS Publications Warehouse

    Kronholm, Scott; Capel, Paul

    2012-01-01

    Carbon is cycled to and from large reservoirs in the atmosphere, on land, and in the ocean. Movement of organic carbon from the terrestrial reservoir to the ocean plays an important role in the global cycling of carbon. The transition from natural to agricultural vegetation can change the storage and movement of organic carbon in and from a watershed. Samples were collected from 13 streams located in hydrologically and agriculturally diverse watersheds, to better understand the variability in the concentrations and loads of dissolved organic carbon (DOC) and particulate organic carbon (POC) in the streams, and the variability in watershed yields. The overall annual median concentrations of DOC and POC were 4.9 (range: 2.1–6.8) and 1.1 (range: 0.4–3.8) mg C L−1, respectively. The mean DOC watershed yield (± SE) was 25 ± 6.8 kg C ha−1 yr−1. The yields of DOC from these agricultural watersheds were not substantially different than the DOC yield from naturally vegetated watersheds in equivalent biomes, but were at the low end of the range for most biomes. Total organic carbon (DOC + POC) annually exported from the agricultural watersheds was found to average 0.03% of the organic carbon that is contained in the labile plant matter and top 1 m of soil in the watershed. Since the total organic carbon exported from agricultural watersheds is a relatively small portion of the sequestered carbon within the watershed, there is the great potential to store additional carbon in plants and soils of the watershed, offsetting some anthropogenic CO2 emissions.

  7. Summary and implications of reported amino acid concentrations in the Murchison meteorite

    SciTech Connect

    Shock, E.L.; Schulte, M.D. )

    1990-11-01

    A study of literature reports of the concentrations of amino acids in extracts from the Murchison meteorite shows that many of the concentration ratios are constant. There are two possible interpretations of these ratios. One is that they are controlled by the pathways through which the amino acids formed, from which it follows that the amino acids are distributed in the same proportions throughout the meteorite. The other interpretation is that the ratios result from the analytical procedures used to extract the amino acids from the meteorite. These methods rely heavily on high-temperature (100{degree}C) aqueous extraction and subsequent high-temperature acid hydrolysis. A correlation was observed in the present study between the relative concentrations of several amino acids in the meteorite extracts and their relative aqueous solubilities at 100{degree}C. The extract solutions are dilute, and far from the saturation limits, but these correlations suggest that the sampling procedure affects directly the reported concentrations for these amino acids. If the extraction process does not bias the results, and all extractable amino acids are removed from meteorite samples, then the properties of amino acids which control both their solubilities and their concentrations in the meteorite need to be established. The possibility of sampling bias needs to be tested experimentally before concluding that extraction is complete, and that the constant relative abundances indicate that the relative concentrations of amino acids are homogeneous in the meteorite.

  8. PROTOTYPE CONCENTRATION MONITOR FOR ESTIMATING ACIDIC DRY DEPOSITION

    EPA Science Inventory

    Dry deposition contributes significantly to the acidification of the ecosystem. However, difficulties in measuring dry deposition of reactive gases and fine particles make routine direct monitoring impractical. An alternate approach is to use the 'concentration monitoring' method...

  9. Chemical concentrations and instantaneous loads, Green River to the Lower Duwamish Waterway near Seattle, Washington, 2013–15

    USGS Publications Warehouse

    Conn, Kathleen E.; Black, Robert W.; Vanderpool-Kimura, Ann M.; Foreman, James R.; Peterson, Norman T.; Senter, Craig A.; Sissel, Stephen K.

    2015-01-01

    Median chemical concentrations in suspended-sediment samples were greater than median chemical concentrations in fine bed sediment (less than 62.5 µm) samples, which were greater than median chemical concentrations in paired bulk bed sediment (less than 2 mm) samples. Suspended-sediment concentration, sediment particle-size distribution, and general water-quality parameters were measured concurrent with the chemistry sampling. From this discrete data, combined with the continuous streamflow record, estimates of instantaneous sediment and chemical loads from the Green River to the Lower Duwamish Waterway were calculated. For most compounds, loads were higher during storms than during baseline conditions because of high streamflow and high chemical concentrations. The highest loads occurred during dam releases (periods when stored runoff from a prior storm is released from the Howard Hanson Dam into the upper Green River) because of the high river streamflow and high suspended-sediment concentration, even when chemical concentrations were lower than concentrations measured during storm events. 

  10. Stress concentrations for straight-shank and countersunk holes in plates subjected to tension, bending, and pin loading

    NASA Technical Reports Server (NTRS)

    Shivakumar, K. N.; Newman, J. C., Jr.

    1992-01-01

    A three dimensional stress concentration analysis was conducted on straight shank and countersunk (rivet) holes in a large plate subjected to various loading conditions. Three dimensional finite element analysis were performed with 20 node isoparametric elements. The plate material was assumed to be linear elastic and isotropic, with a Poisson ratio of 0.3. Stress concentration along the bore of the hole were computed for several ratios of hole radius to plate thickness (0.1 to 2.5) and ratios of countersink depth to plate thickness (0.25 to 1). The countersink angles were varied from 80 to 100 degrees in some typical cases, but the angle was held constant at 100 degrees for most cases. For straight shank holes, three types of loading were considered: remote tension, remote bending, and wedge loading in the hole. Results for remote tension and wedge loading were used to estimate stress concentration for simulated rivet in pin loading. For countersunk holes only remote tension and bending were considered. Based on the finite element results, stress concentration equations were developed. Whenever possible, the present results were compared with other numerical solutions and experimental results from the literature.

  11. Using Conductivity Measurements to Determine the Identities and Concentrations of Unknown Acids: An Inquiry Laboratory Experiment

    ERIC Educational Resources Information Center

    Smith, K. Christopher; Garza, Ariana

    2015-01-01

    This paper describes a student designed experiment using titrations involving conductivity measurements to identify unknown acids as being either HCl or H[subscript 2]SO[subscript 4], and to determine the concentrations of the acids, thereby improving the utility of standard acid-base titrations. Using an inquiry context, students gain experience…

  12. Characterization and anticancer potential of ferulic acid-loaded chitosan nanoparticles against ME-180 human cervical cancer cell lines

    NASA Astrophysics Data System (ADS)

    Panwar, Richa; Sharma, Asvene K.; Kaloti, Mandeep; Dutt, Dharm; Pruthi, Vikas

    2016-08-01

    Ferulic acid (FA) is a widely distributed hydroxycinnamic acid found in various cereals and fruits exhibiting potent antioxidant and anticancer activities. However, due to low solubility and permeability, its availability to biological systems is limited. Non-toxic chitosan-tripolyphosphate pentasodium (CS-TPP) nanoparticles (NPs) are used to load sparingly soluble molecules and drugs, increasing their bioavailability. In the present work, we have encapsulated FA into the CS-TPP NPs to increase its potential as a therapeutic agent. Different concentrations of FA were tested to obtain optimum sized FA-loaded CS-TPP nanoparticles (FA/CS-TPP NPs) by ionic gelation method. Nanoparticles were characterized by scanning electron microscopy, Fourier transformation infrared spectroscopy (FTIR), thermogravimetric analyses and evaluated for their anticancer activity against ME-180 human cervical cancer cell lines. The FTIR spectra confirmed the encapsulation of FA and thermal analysis depicted its degradation profile. A concentration-dependent relationship between FA encapsulation efficiency and FA/CS-TPP NPs diameter was observed. Smooth and spherical FA-loaded cytocompatible nanoparticles with an average diameter of 125 nm were obtained at 40 µM FA conc. The cytotoxicity of 40 µM FA/CS-TPP NPs against ME-180 cervical cancer cell lines was found to be higher as compared to 40 µM native FA. Apoptotic morphological changes as cytoplasmic remnants and damaged wrinkled cells in ME-180 cells were visualized using scanning electron microscopic and fluorescent microscopic techniques. Data concluded that chitosan enveloped FA nanoparticles could be exploited as an excellent therapeutic drug against cancer cells proliferation.

  13. Characterization and anticancer potential of ferulic acid-loaded chitosan nanoparticles against ME-180 human cervical cancer cell lines

    NASA Astrophysics Data System (ADS)

    Panwar, Richa; Sharma, Asvene K.; Kaloti, Mandeep; Dutt, Dharm; Pruthi, Vikas

    2015-10-01

    Ferulic acid (FA) is a widely distributed hydroxycinnamic acid found in various cereals and fruits exhibiting potent antioxidant and anticancer activities. However, due to low solubility and permeability, its availability to biological systems is limited. Non-toxic chitosan-tripolyphosphate pentasodium (CS-TPP) nanoparticles (NPs) are used to load sparingly soluble molecules and drugs, increasing their bioavailability. In the present work, we have encapsulated FA into the CS-TPP NPs to increase its potential as a therapeutic agent. Different concentrations of FA were tested to obtain optimum sized FA-loaded CS-TPP nanoparticles (FA/CS-TPP NPs) by ionic gelation method. Nanoparticles were characterized by scanning electron microscopy, Fourier transformation infrared spectroscopy (FTIR), thermogravimetric analyses and evaluated for their anticancer activity against ME-180 human cervical cancer cell lines. The FTIR spectra confirmed the encapsulation of FA and thermal analysis depicted its degradation profile. A concentration-dependent relationship between FA encapsulation efficiency and FA/CS-TPP NPs diameter was observed. Smooth and spherical FA-loaded cytocompatible nanoparticles with an average diameter of 125 nm were obtained at 40 µM FA conc. The cytotoxicity of 40 µM FA/CS-TPP NPs against ME-180 cervical cancer cell lines was found to be higher as compared to 40 µM native FA. Apoptotic morphological changes as cytoplasmic remnants and damaged wrinkled cells in ME-180 cells were visualized using scanning electron microscopic and fluorescent microscopic techniques. Data concluded that chitosan enveloped FA nanoparticles could be exploited as an excellent therapeutic drug against cancer cells proliferation.

  14. Development of xylose-fermenting yeasts for ethanol production at high acetic acid concentrations

    SciTech Connect

    Mohandas, D.V.; Whelan, D.R.; Panchal, C.J.

    1995-12-31

    Mutants resistant to comparatively high levels of acetic acid were isolated from the xylose-fermenting yeasts Candida shehatae and Pichia Stipitis by adapting these cultures to increasing concentrations of acetic acid grown in shake-flask cultures. These mutants were tested for their ability to ferment xylose in presence of high acetic acid concentrations, in acid hydrolysates of wood, and in hardwood spent sulfite liquor, and compared with their wild-type counterparts and between themselves. The P. stipitis mutant exhibited faster fermentation times, better tolerance to acid hydrolysates, and tolerance to lower pH.

  15. Development of thiamine and pyridoxine loaded ferulic acid-grafted chitosan microspheres for dietary supplementation.

    PubMed

    Chatterjee, Niladri Sekhar; Anandan, Rangasamy; Navitha, Mary; Asha, K K; Kumar, K Ashok; Mathew, Suseela; Ravishankar, C N

    2016-01-01

    Therapeutic potential of water soluble vitamins has been known for long and in recent times they are being widely supplemented in processed food. Phenolic acid-grafted chitosan derivatives can serve as excellent biofunctional encapsulating materials for these vitamins. As a proof of concept, thiamine and pyridoxine loaded ferulic acid-grafted chitosan microspheres were developed. Ferulic acid was successfully grafted on chitosan by a free radical mediated reaction and the structure was confirmed by FTIR and NMR analysis. When compared to FTIR spectra of chitosan, intensity of amide I (at around 1644 cm(-1)) and amide II (at around 1549 cm(-1)) bands in spectra of ferulic acid-grafted chitosan were found increased, indicating formation of new amide linkage. Strong signals at δ = 6.3-7.9 ppm corresponding to methine protons of ferulic acid were observed in NMR spectra of ferulic acid-grafted chitosan, suggesting the successful grafting of ferulic acid onto chitosan. Grafting ratio of the derivative was 263 mg ferulic acid equivalent/g polymer. Positively charged particles (zeta potential 31 mv) of mean diameter 4.5 and 4.8 μ, corresponding to number distribution and area distribution respectively were observed. Compact microspheres with smooth surfaces and no apparent cracks or pores were observed under scanning electron microscope. Efficient microencapsulation was further proved by X-ray diffraction patterns and thermal analysis. Preliminary anti-inflammatory activity of the vitamin-loaded microspheres was demonstrated. PMID:26787974

  16. A novel nanofiber Cur-loaded polylactic acid constructed by electrospinning

    NASA Astrophysics Data System (ADS)

    Thu Trang Mai, Thi; Thu Thuy Nguyen, Thi; Duong Le, Quang; Ngoan Nguyen, Thi; Cham Ba, Thi; Binh Nguyen, Hai; Bich Hoa Phan, Thi; Tran, Dai Lam; Phuc Nguyen, Xuan; Park, Jun Seo

    2012-06-01

    Curcumin (Cur), extracted from the Curcuma longa L. plant, is well known for its anti-tumor, anti-oxidant, anti-inflammatory and anti-bacterial properties. Nanofiber mats of polylactic acid (PLA) loading Cur (5 wt%) were fabricated by electrospinning (e-spinning). Morphology and structure of the fibers were characterized by field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared (FTIR) spectroscopy, respectively. The diameters of the obtained fibers varied from 200 to 300 nm. The release capacity of curcumin from curcumin-loaded PLA fibers was investigated in phosphate buffer saline (PBS) containing ethanol. After 24 h, 50% of the curcumin was released from curcumin-loaded PLA fibers. These results of electrospun (e-spun) fibers exhibit the potential for biomedical application.

  17. Water administration of medium-chain fatty acid caprylic acid produced variable efficacy against cecal Campylobacter jejuni concentrations in broilers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Campylobacter is one of the most common causes of foodborne illness, and poultry is considered a primary source of Campylobacter infections. Caprylic acid, an eight-carbon fatty acid, has been shown in previous studies to reduce enteric cecal Campylobacter concentrations in poultry when administere...

  18. Illinois River Nitrate-Nitrogen Concentrations and Loads: Long-term Variation and Association with Watershed Nitrogen Inputs.

    PubMed

    McIsaac, Gregory F; David, Mark B; Gertner, George Z

    2016-07-01

    The Illinois River is a major contributor of nitrate-N to the Mississippi River and the Gulf of Mexico, where nitrate is a leading cause of summertime benthic hypoxia. Corn-soybean production on tile-drained land is a leading source of nitrate-N in this river system, in addition to municipal wastewater discharge. We calculated annual nitrate-N loads in the Illinois River at Valley City from 1976 to 2014 by linear interpolation. Although there was not a significant trend in annual loads during the entire study period, there was a significant downward trend in flow-weighted nitrate-N concentration after 1990 despite high concentrations in 2013 after the 2012 drought. Multivariate regression analysis revealed a statistically significant association between annual flow-weighted nitrate-N concentration and cumulative residual agricultural N inputs to the watershed during a 6-yr window. This suggests that declines in flow-weighted nitrate-N concentration may reflect increasing N use efficiency in agriculture and a depletion of legacy N stored in the watershed. The watershed appears to have transitioned from a state of stationarity in nitrate concentration to nonstationarity. The average annual nitrate-N load at Valley City from 2010 to 2014 was 10% less than the 1980-1996 average load, indicating recent progress toward Illinois' nutrient loss reduction milestone of 15% reduction by 2025 and ultimate target of 45% reduction. PMID:27380075

  19. Practical considerations in the concentration and recovery of spent nitration acids

    SciTech Connect

    Evans, C.M.

    1995-12-01

    Most organic nitrations employ sulphuric acid or oleum in the nitration acid. Even in rare nitric acid only nitrations, sulphuric acid is used as the dehydrating agent to produce 99% nitric acid. The used sulphuric acid is discharged in a diluted form contaminated with organic components and nitric/nitrous species. Pressures are emloyed to reconcentrate and reprocess such spent acids. Acid recovery and concentration is expensive. This paper discusses some of the aspects which must be considered when contemplating acid recovery. In the current industrial climate, acid recovery and recycle should be regarded as an integral part of a nitration process development rather than an afterthought. Case histories will be given in which such considerations influenced the course of the development of the nitration process itself. Emphasis will be placed on the importance of well planned bench and pilot scale test programmes.

  20. [Degradation of Acid Orange 7 with Persulfate Activated by Silver Loaded Granular Activated Carbon].

    PubMed

    Wang, Zhong-ming; Huang, Tian-yin; Chen, Jia-bin; Li, Wen-wei; Zhang, Li-ming

    2015-11-01

    Granular activated carbon with silver loaded as activator (Ag/GAC) was prepared using impregnation method. N2 adsorption, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) were adopted to characterize the Ag/GAC, showing that silver was successfully loaded on granular activated carbon. The oxidation degradation of acid orange 7 (AO7) by the Ag/GAC activated by persulfate (PS) was investigated at ambient temperature. The influences of factors such as Ag loading, PS or Ag/GAC dosages and initial pH on the degradation of AO7 were evaluated. The results demonstrated that the degradation rate of AO7 could reach more than 95.0% after 180 min when the Ag loading content, PS/AO7 molar ratio, the Ag/GAC dosage were 12.7 mg x g(-1), 120: 1, 1.0 g x L(-1), respectively. The initial pH had significant effect on the AO7 degradation, with pH 5.0 as the optimal pH for the degradation of AO7. The possible degradation pathway was proposed for the AO7 degradation by using UV-visible spectroscopy and gas chromatography-mass spectrometry (GG/MS). The azo bond and naphthalene ring in the AO7 were destroyed during the degradation, with phthalic acid and acetophenone as the main degradation products. PMID:26910999

  1. Design and characterization of antimicrobial usnic acid loaded-core/shell magnetic nanoparticles.

    PubMed

    Taresco, Vincenzo; Francolini, Iolanda; Padella, Franco; Bellusci, Mariangela; Boni, Adriano; Innocenti, Claudia; Martinelli, Andrea; D'Ilario, Lucio; Piozzi, Antonella

    2015-01-01

    The application of magnetic nanoparticles (MNPs) in medicine is considered much promising especially because they can be handled and directed to specific body sites by external magnetic fields. MNPs have been investigated in magnetic resonance imaging, hyperthermia and drug targeting. In this study, properly functionalized core/shell MNPs with antimicrobial properties were developed to be used for the prevention and treatment of medical device-related infections. Particularly, surface-engineered manganese iron oxide MNPs, produced by a micro-emulsion method, were coated with two different polymers and loaded with usnic acid (UA), a dibenzofuran natural extract possessing antimicrobial activity. Between the two polymer coatings, the one based on an intrinsically antimicrobial cationic polyacrylamide (pAcDED) resulted to be able to provide MNPs with proper magnetic properties and basic groups for UA loading. Thanks to the establishment of acid-base interactions, pAcDED-coated MNPs were able to load and release significant drug amounts resulting in good antimicrobial properties versus Staphylococcus epidermidis (MIC = 0.1 mg/mL). The use of pAcDED having intrinsic antimicrobial activity as MNP coating in combination with UA likely contributed to obtain an enhanced antimicrobial effect. The developed drug-loaded MNPs could be injected in the patient soon after device implantation to prevent biofilm formation, or, later, in presence of signs of infection to treat the biofilm grown on the device surfaces. PMID:25953542

  2. INTERCOMPARISON OF ATMOSPHERIC NITRIC ACID MEASUREMENTS AT ELEVATED AMBIENT CONCENTRATIONS

    EPA Science Inventory

    Several methods for measurement of ambient HNO3 were compared over a 9-day period during the Carbonaceous Species Methods Comparison Study at Glendora, CA, in August 1986. ourly averaged HNO3 concentrations were in the range 0.5-25 ppbv, with hourly maxima each day in excess of 1...

  3. Humic Acid Complexation of Th, Hf and Zr in Ligand Competition Experiments: Metal Loading and Ph Effects

    NASA Technical Reports Server (NTRS)

    Stern, Jennifer C.; Foustoukos, Dionysis I.; Sonke, Jeroen E.; Salters, Vincent J. M.

    2014-01-01

    The mobility of metals in soils and subsurface aquifers is strongly affected by sorption and complexation with dissolved organic matter, oxyhydroxides, clay minerals, and inorganic ligands. Humic substances (HS) are organic macromolecules with functional groups that have a strong affinity for binding metals, such as actinides. Thorium, often studied as an analog for tetravalent actinides, has also been shown to strongly associate with dissolved and colloidal HS in natural waters. The effects of HS on the mobilization dynamics of actinides are of particular interest in risk assessment of nuclear waste repositories. Here, we present conditional equilibrium binding constants (Kc, MHA) of thorium, hafnium, and zirconium-humic acid complexes from ligand competition experiments using capillary electrophoresis coupled with ICP-MS (CE- ICP-MS). Equilibrium dialysis ligand exchange (EDLE) experiments using size exclusion via a 1000 Damembrane were also performed to validate the CE-ICP-MS analysis. Experiments were performed at pH 3.5-7 with solutions containing one tetravalent metal (Th, Hf, or Zr), Elliot soil humic acid (EHA) or Pahokee peat humic acid (PHA), and EDTA. CE-ICP-MS and EDLE experiments yielded nearly identical binding constants for the metal- humic acid complexes, indicating that both methods are appropriate for examining metal speciation at conditions lower than neutral pH. We find that tetravalent metals form strong complexes with humic acids, with Kc, MHA several orders of magnitude above REE-humic complexes. Experiments were conducted at a range of dissolved HA concentrations to examine the effect of [HA]/[Th] molar ratio on Kc, MHA. At low metal loading conditions (i.e. elevated [HA]/[Th] ratios) the ThHA binding constant reached values that were not affected by the relative abundance of humic acid and thorium. The importance of [HA]/[Th] molar ratios on constraining the equilibrium of MHA complexation is apparent when our estimated Kc, MHA values

  4. Biosafety of the Novel Vancomycin-loaded Bone-like Hydroxyapatite/Poly-amino Acid Bony Scaffold

    PubMed Central

    Cao, Zhi-Dong; Jiang, Dian-Ming; Yan, Ling; Wu, Jun

    2016-01-01

    Background: Recently, local sustained-release antibiotics systems have been developed because they can increase local foci of concentrated antibiotics without increasing the plasma concentration, and thereby effectively decrease any systemic toxicity and side effects. A vancomycin-loaded bone-like hydroxyapatite/poly-amino acid (V-BHA/PAA) bony scaffold was successfully fabricated with vancomycin-loaded poly lactic-co-glycolic acid microspheres and BHA/PAA, which was demonstrated to exhibit both porosity and perfect biodegradability. The aim of this study was to systematically evaluate the biosafety of this novel scaffold by conducting toxicity tests in vitro and in vivo. Methods: According to the ISO rules for medical implant biosafety, for in vitro tests, the scaffold was incubated with L929 fibroblasts or rabbit noncoagulant blood, with simultaneous creation of positive control and negative control groups. The growth condition of L929 cells and hemolytic ratio were respectively evaluated after various incubation periods. For in vivo tests, a chronic osteomyelitis model involving the right proximal tibia of New Zealand white rabbits was established. After bacterial identification, the drug-loaded scaffold, drug-unloaded BHA/PAA, and poly (methyl methacrylate) were implanted, and a blank control group was also set up. Subsequently, the in vivo blood drug concentrations were measured, and the kidney and liver functions were evaluated. Results: In the in vitro tests, the cytotoxicity grades of V-BHA/PAA and BHA/PAA-based on the relative growth rate were all below 1. The hemolysis ratios of V-BHA/PAA and BHA/PAA were 2.27% and 1.42%, respectively, both below 5%. In the in vivo tests, the blood concentration of vancomycin after implantation of V-BHA/PAA was measured at far below its toxic concentration (60 mg/L), and the function and histomorphology of the liver and kidney were all normal. Conclusion: According to ISO standards, the V-BHA/PAA scaffold is considered to

  5. Concentrations and estimated loads of nutrients, mercury, and polychlorinated biphenyls in selected tributaries to Lake Michigan, 2005-6

    USGS Publications Warehouse

    Westenbroek, Stephen M.

    2010-01-01

    The Lake Michigan Mass Balance Project (LMMBP) measured and modeled the concentrations of environmentally persistent contaminants in air, river and lake water, sediment, and fish and bird tissues in and around Lake Michigan for an 18-month period spanning 1994-95. Tributary loads were calculated as part of the LMMBP. The work described in this report was designed to provide updated concentration data and load estimates for 5 nutrients, total mercury, and total polychlorinated biphenyl (PCB) at 5 of the original 11 LMMBP sampling sites. Samples were collected at five Lake Michigan tributary monitoring sites during 2005 and 2006. Annual loads calculated for the 2005-6 sampling period are as much as 50 percent lower relative to the 1994-95 time period. Differences between the loads calculated for the two time periods are likely related to a combination of (1) biases introduced by a reduced level of sampling effort, (2) differences in hydrological characteristics, and (3) actual environmental change. Estimated annual total mercury loads during 2005-6 ranged from 51 kilograms per year (kg/yr) in the Fox River to 2.2 kg/yr in the Indiana Harbor and Ship Canal. Estimated annual total PCB loads during 2005-6 ranged from 132 kg/yr in the Fox River to 6.2 kg/yr in the Grand River.

  6. Mercury cycling in boreal ecosystems: The long-term effect of acid rain constituents on peatland pore water methylmercury concentrations

    NASA Astrophysics Data System (ADS)

    Branfireun, Brian A.; Bishop, Kevin; Roulet, Nigel T.; Granberg, Gunnar; Nilsson, Mats

    Sulphate-reducing bacteria have been identified as primary methylators of mercury (Hg) in the laboratory and in field investigations. However, no studies have investigated the effect of long-term deposition of sulphate on methylmercury (MeHg) dynamics in peatlands, which are known to be significant sources of MeHg to downstream waters in the boreal forest zone. As an ancillary experiment to a larger project investigating the effects of acid rain constituents on peatland carbon dynamics, the influence of experimentally elevated Na2SO4 and/or NH4NO3 deposition on peat pore water MeHg concentrations was determined using a simple mesocosm experimental design. After three years, additions of S in amounts equivalent to the 1980s dry and wet deposition in Southern Sweden resulted in peat pore water MeHg concentrations up to six times above background levels. Elevated N loads had no effect on pore water MeHg concentrations.

  7. Association between Dietary Acid Load and Insulin Resistance: Tehran Lipid and Glucose Study

    PubMed Central

    Moghadam, Sajjad Khalili; Bahadoran, Zahra; Mirmiran, Parvin; Tohidi, Maryam; Azizi, Fereidoun

    2016-01-01

    In the current study, we investigated the longitudinal association between dietary acid load and the risk of insulin resistance (IR) in the Tehranian adult population. This longitudinal study was conducted on 925 participants, aged 22~80 years old, in the framework of the third (2006~2008) and fourth (2009~2011) phases of the Tehran Lipid and Glucose Study. At baseline, the dietary intake of subjects was assessed using a validated semi-quantitative food frequency questionnaire, and the potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores were calculated at baseline. Fasting serum insulin and glucose were measured at baseline and again after a 3-year of follow-up; IR was defined according to optimal cut-off values. Multiple logistic regression models were used to estimate the risk of IR according to the PRAL and NEAP quartile categories. Mean age and body mass index of the participants were 40.3 years old of 26.4 kg/m2, respectively. Mean PRAL and NEAP scores were −11.2 and 35.6 mEq/d, respectively. After adjustment for potential confounders, compared to the lowest quartile of PRAL and NEAP, the highest quartile was accompanied with increased risk of IR [odds ratio (OR)=2.81, 95% confidence interval (CI)=1.32~5.97 and OR=2.18, 95% CI=1.03 ~4.61, respectively]. Our findings suggest that higher acidic dietary acid-base load, defined by higher PRAL and NEAP scores, may be a risk factor for the development of IR and related metabolic disorders. PMID:27390726

  8. Nutrient Concentrations, Loads, and Yields in the Eucha-Spavinaw Basin, Arkansas and Oklahoma, 2002-2004

    USGS Publications Warehouse

    Tortorelli, Robert L.

    2006-01-01

    The City of Tulsa, Oklahoma, uses Lake Eucha and Spavinaw Lake in the Eucha-Spavinaw basin in northwestern Arkansas and northeastern Oklahoma for public water supply. Taste and odor problems in the water attributable to blue-green algae have increased in frequency over time. Changes in the algae community in the lakes may be attributable to increases in nutrient levels in the lakes, and in the waters feeding the lakes. The U.S. Geological Survey, in cooperation with the City of Tulsa, conducted an investigation to summarize nitrogen and phosphorus concentrations and provide estimates of nitrogen and phosphorus loads, yields, and flow-weighted concentrations in the Eucha-Spavinaw basin for a 3-year period from January 2002 through December 2004. This report provides information needed to advance knowledge of the regional hydrologic system and understanding of hydrologic processes, and provides hydrologic data and results useful to multiple parties for interstate compacts. Nitrogen and phosphorus concentrations were significantly greater in runoff samples than in base-flow samples at Spavinaw Creek near Maysville, Arkansas; Spavinaw Creek near Colcord, Oklahoma, and Beaty Creek near Jay, Oklahoma. Runoff concentrations were not significantly greater than in base-flow samples at Spavinaw Creek near Cherokee, Arkansas; and Spavinaw Creek near Sycamore, Oklahoma. Nitrogen concentrations in base-flow samples significantly increased in the downstream direction in Spavinaw Creek from the Maysville to Sycamore stations then significantly decreased from the Sycamore to the Colcord stations. Nitrogen in base-flow samples from Beaty Creek was significantly less than in those from Spavinaw Creek. Phosphorus concentrations in base-flow samples significantly increased from the Maysville to Cherokee stations in Spavinaw Creek, probably due to a point source between those stations, then significantly decreased downstream from the Cherokee to Colcord stations. Phosphorus in base

  9. A case study demonstrating analysis of stormflows, concentrations, and loads of nutrients in highway runoff and swale discharge with the Stochastic Empirical Loading and Dilution Model (SELDM)

    USGS Publications Warehouse

    Granato, Gregory; Jones, Susan C.

    2015-01-01

    The case study is hypothetical, but was formulated by using actual data from selected monitoring sites in New England. Data representing streamflow and water-quality were collected at U.S. Geological Survey (USGS) streamgage 01208950 Sasco Brook near Southport, CT, which has a drainage area of 7.38 square miles. In this hypothetical case study a 4-lane highway would replace the current 2-lane road and would have a contributing area of 2.2 acres between the topographic basin divides. Concentrations of TN and TP in highway runoff were simulated with data from USGS highway-runoff monitoring station 423027071291301 along State Route 2 in Littleton Massachusetts. Results of a highway-runoff analysis are shown in relation to three hypothetical discharge criteria for TN and two hypothetical discharge criteria for TP. The risks for exceeding TN discharge criteria of 3, 5, and 8 mg/L for highway runoff are 7.4, 0.83, and 0.13 percent of 1,721 runoff events that may occur during a stochastic 30-year simulation. If a grassy swale is used to treat the runoff, the risks for TN exceedances are reduced to 3.2, 0.33 and 0.03 percent, respectively. The risks for exceeding TP discharge criteria of 0.1 and 0.5 mg/L for highway runoff are 49 and 1.2 percent, respectively. If a grassy swale is used to treat the runoff, the risks for TP exceedances are 57 and 0.8 percent, respectively. The risks for the 0.1 mg/L criterion increase because swales can be a source of TP if pavement concentrations are low. The risks for the 0.5 mg/L criterion decrease because the swale is effective for reducing high TP concentrations. Although the results are mixed for storm-event concentrations, the grassy swale effectively reduces annual loads. Annual loads from the swale are, on average, about 49 percent of highway loads for TN and 62 percent of highway loads of TP because the swale reduces high runoff concentrations and stormflow volumes. Analysis of upstream and downstream concentrations indicates that

  10. Dynamics and control of phloem loading of indole-3-acetic acid in seedling cotyledons of Ricinus communis

    PubMed Central

    Tamas, Imre A.; Davies, Peter J.

    2016-01-01

    During seed germination, sugars and auxin are produced from stored precursors or conjugates respectively, and transported to the seedling axis. To elucidate the mode of travel of indole-3-acetic acid (IAA) into the phloem, a solution of [3H]IAA, together with [14C]sucrose, was injected into the endosperm cavity harboring the cotyledons of germinating seedlings of Ricinus communis. Phloem exudate from the cut hypocotyl was collected and the radioactivity recorded. Sucrose loading into the phloem was inhibited at higher IAA levels, and the rate of filling of the transient pool(s) was reduced by IAA. IAA was detected within 10min, with the concentration increasing over 30min and reaching a steady-state by 60min. The kinetics indicated that phloem loading of IAA involving both an active, carrier-based, and a passive, diffusion-based component, with IAA traveling along a pathway containing an intermediary pool, possibly the protoplasts of mesophyll cells. Phloem loading of IAA was altered by sucrose, K+, and a range of non-specific and IAA-specific analogs and inhibitors in a manner that showed that IAA moves into the phloem from the extra cotyledonary solution by multiple pathways, with a carrier-mediated pathway playing a principal role. PMID:27371947

  11. Dynamics and control of phloem loading of indole-3-acetic acid in seedling cotyledons of Ricinus communis.

    PubMed

    Tamas, Imre A; Davies, Peter J

    2016-08-01

    During seed germination, sugars and auxin are produced from stored precursors or conjugates respectively, and transported to the seedling axis. To elucidate the mode of travel of indole-3-acetic acid (IAA) into the phloem, a solution of [(3)H]IAA, together with [(14)C]sucrose, was injected into the endosperm cavity harboring the cotyledons of germinating seedlings of Ricinus communis Phloem exudate from the cut hypocotyl was collected and the radioactivity recorded. Sucrose loading into the phloem was inhibited at higher IAA levels, and the rate of filling of the transient pool(s) was reduced by IAA. IAA was detected within 10min, with the concentration increasing over 30min and reaching a steady-state by 60min. The kinetics indicated that phloem loading of IAA involving both an active, carrier-based, and a passive, diffusion-based component, with IAA traveling along a pathway containing an intermediary pool, possibly the protoplasts of mesophyll cells. Phloem loading of IAA was altered by sucrose, K(+), and a range of non-specific and IAA-specific analogs and inhibitors in a manner that showed that IAA moves into the phloem from the extra cotyledonary solution by multiple pathways, with a carrier-mediated pathway playing a principal role. PMID:27371947

  12. Characterisation and evaluation of metal-loaded iminodiacetic acid-silica of different porosity for the selective enrichment of phosphopeptides.

    PubMed

    Trojer, L; Stecher, G; Feuerstein, I; Lubbad, S; Bonn, G K

    2005-06-24

    Silica particles of different porosity were functionalised with iminodiacetic acid (IDA) and loaded with Fe(III) to yield immobilised metal affinity chromatography stationary phases (Fe(III)-IDA-silica) for phosphopeptide enrichment. The elution step of bound phosphopeptides was optimised with a 32P radioactive labelled peptide by a comprehensive study. Several elution systems, including phosphate buffers of different pH and concentration and ethylenediaminetetraacetic acid solutions were employed. Furthermore the effect of support porosity on elution behaviour was investigated. Under best conditions recoveries higher than 90% were achieved. A solid-phase extraction (SPE) protocol was developed for fractionation of phosphorylated and non-phosphorylated peptides and desalting of the fractions which is essential for subsequent mass spectrometric analysis by the combination of Fe(III)-IDA-silica and C18-silica particles. The pH of the loading buffer was found to be a critical parameter for the efficiency of the SPE protocol. As tryptic digests of alpha-lactalbumin, lysozyme and ribonuclease A mixed with three synthetic phosphopeptides were fractionated, pH 2.5 provided minimal proportion of unspecific bound peptides when comparing the fractions after mu-LC-electrospray ionization MS separation. The effect of a sample derivatisation reaction (methylation) on the efficiency of phosphopeptide enrichment was further investigated. Blocking carboxylate groups by methyl ester formation totally prevented unspecific interaction with the immobilised Fe(III) ions, but generated partially methylated phosphopeptides that increased the complexity of the phosphorylated fraction. PMID:16038305

  13. Impact of Dry Solids and Bile Acid Concentrations on Bile Acid Binding Capacity of Extruded Oat Cereals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extruded breakfast cereals (EBC), processed from two oat lines, N979-5-2-4 (N979) and ‘Jim’, with beta-glucan concentrations of 8.7 and 4.9%, respectively, were used to determine the impact of dry solids (DS) and bile acid (BA) concentrations on in vitro BA binding efficiency. A full fractional fact...

  14. Optical detection of concentrations for mixed acid: HF and HNO3

    NASA Astrophysics Data System (ADS)

    Kang, Gumin; Kim, Kyoungsik

    2009-02-01

    Mixed acid, which consist of HF and HNO3, is used as a good etchant for silicon dioxide in the wet etching and pickling process of stainless steel. The optical detection of concentration for such mixed acids is crucial to optimize and cut costs in the manufacturing process. Optical detection in the IR regime has been utilized to measure the concentration of the mixed acid for HF and HNO3, because that has several strong absorption peaks, which is contributed by vibrational mode of each acid molecular in this spectrum. In this research, we observed the concentrations of mixed acid to consist of HF and HNO3, as we measured the absorption intensity of OH- stretch and NO3 - stretch band by optical spectroscopy. The concentration range of HF over 1.5-3 wt% and that of HNO3 over 2-10 wt% were studied in room temperature.

  15. Techniques for estimation of storm-runoff loads, volumes, and selected constituent concentrations in urban watersheds in the United States

    USGS Publications Warehouse

    Driver, Nancy E.; Tasker, Gary D.

    1990-01-01

    Urban planners and managers need information on the quantity of precipitation and the quality and quantity of run off in their cities and towns if they are to adequately plan for the effects of storm runoff from urban areas. As a result of this need, four sets of linear regression models were developed for estimating storm-runoff constituent loads, storm-runoff volumes, storm-runoff mean concentrations of constituents, and mean seasonal or mean annual constituent loads from physical, land-use, and climatic characteristics of urban watersheds in the United States. Thirty-four regression models of storm-runoff constituent loads and storm-runoff volumes were developed, and 31 models of storm-runoff mean concentrations were developed . Ten models of mean seasonal or mean annual constituent loads were developed by analyzing long-term storm-rainfall records using at-site linear regression models. Three statistically different regions, delineated on the basis of mean annual rainfall, were used to improve linear regression models where adequate data were available . Multiple regression analyses, including ordinary least squares and generalized least squares, were used to determine the optimum linear regression models . These models can be used to estimate storm-runoff constituent loads, storm-runoff volumes, storm-runoff mean concentrations of constituents, and mean seasonal or mean annual constituent loads at gaged and ungaged urban watersheds. The most significant explanatory variables in all linear regression models were total storm rainfall and total contributing drainage area. Impervious area, land-use, and mean annual climatic characteristics also were significant in some models. Models for estimating loads of dissolved solids, total nitrogen, and total ammonia plus organic nitrogen as nitrogen generally were the most accurate, whereas models for suspended solids were the least accurate. The most accurate models were those for application in the more arid Western

  16. The design, fabrication and maintenance of semi-trailers employed in the highway transport of weight-concentrated radioactive loads

    SciTech Connect

    Huffman, D.S.

    1991-12-31

    Transportation of weight-concentrated radioactive loads by truck is an essential part of a safe and economical nuclear industry. This proposed standard presents guidance and performance criteria for the safe transport of these weight-concentrated radioactive loads. ANSI N14.30 will detail specific requirements for the design, fabrication, testing, in-service inspections, maintenance and certification of the semi-trailers to be employed in said service. Furthermore, guidelines for a quality assurance program are also enumerated. This standard would apply to any semi-trailer that may or may not be specifically designed to carry weight-concentrated loads. Equipment not suitable per the criteria established in the standard would be removed from service. The nature of the nuclear industry and the need for a positive public perception of the various processes and players, mandates that the highway transportation of weight-concentrated radioactive loads be standardized and made inherently safe. This proposed standard takes a giant step in that direction.

  17. Short communication: Association of milk fatty acids with early lactation hyperketonemia and elevated concentration of nonesterified fatty acids.

    PubMed

    Mann, S; Nydam, D V; Lock, A L; Overton, T R; McArt, J A A

    2016-07-01

    The objective of our study was to extend the limited research available on the association between concentrations of milk fatty acids and elevated nonesterified fatty acids (NEFA) and β-hydroxybutyrate (BHB) concentrations in early lactation dairy cattle. Measurement of milk fatty acids for detection of cows in excessive negative energy balance has the potential to be incorporated in routine in-line monitoring systems. Blood samples were taken from 84 cows in second or greater lactation 3 times per week between 3 to 14 d in milk. Cows were characterized as hyperketonemic (HYK) if blood BHB concentration was ≥1.2mmol/L at least once and characterized as having elevated concentrations of NEFA (NEFAH) if serum NEFA concentration was ≥1mmol/L at least once. Composition of colostrum and milk fatty acids at wk 2 postpartum was used to investigate the potential diagnostic value of individual fatty acids and fatty acid ratios for the correct classification of cows with NEFA and BHB concentrations above these thresholds, respectively. Receiver operating characteristic (ROC) curves were used to identify thresholds of fatty acid concentration and fatty acid ratios when ROC area under the curve was ≥0.70. Correct classification rate (CCR, %) was calculated as {[(number of true positives + number of true negatives)/total number tested] × 100}. None of the colostrum fatty acids yielded a sufficiently high area under the curve in ROC analysis for the association with HYK and NEFAH. The following fatty acids and fatty acid ratios were identified for an association with NEFAH (threshold, CCR): C15:0 (≤0.65g/100g, 68.3%); cis-9 C16:1 (≥1.85g/100g, 70.7%); cis-9 C18:1 (≥26g/100g, 69.5%), cis-9 C18:1 to C15:0 ratio (≥45, 69.5%); cis-9 C16:1 to C15:0 (≥2.50, 73.2%). Several fatty acids were associated with HYK (threshold, CCR): C6:0 (≤1.68g/100g, 80.5%), C8:0 (≤0.80g/100g, 80.5%), C10:0 (≤1.6g/100g, 79.3%); C12:0 (≤1.42g/100g, 82.9%); C14:0 (≤6.10g/100g, 84

  18. Effect of nitric acid concentrations on synthesis and stability of maghemite nanoparticles suspension.

    PubMed

    Nurdin, Irwan; Johan, Mohd Rafie; Yaacob, Iskandar Idris; Ang, Bee Chin

    2014-01-01

    Maghemite (γ-Fe2O3) nanoparticles have been synthesized using a chemical coprecipitation method at different nitric acid concentrations as an oxidizing agent. Characterization of all samples performed by several techniques including X-ray diffraction (XRD), transmission electron microscopy (TEM), alternating gradient magnetometry (AGM), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and zeta potential. The XRD patterns confirmed that the particles were maghemite. The crystallite size of all samples decreases with the increasing concentration of nitric acid. TEM observation showed that the particles have spherical morphology with narrow particle size distribution. The particles showed superparamagnetic behavior with decreased magnetization values at the increasing concentration of nitric acid. TGA measurement showed that the stability temperature decreases with the increasing concentration of nitric acid. DLS measurement showed that the hydrodynamic particle sizes decrease with the increasing concentration of nitric acid. Zeta potential values show a decrease with the increasing concentration of nitric acid. The increasing concentration of nitric acid in synthesis of maghemite nanoparticles produced smaller size particles, lower magnetization, better thermal stability, and more stable maghemite nanoparticles suspension. PMID:24963510

  19. Effect of Nitric Acid Concentrations on Synthesis and Stability of Maghemite Nanoparticles Suspension

    PubMed Central

    Yaacob, Iskandar Idris

    2014-01-01

    Maghemite (γ-Fe2O3) nanoparticles have been synthesized using a chemical coprecipitation method at different nitric acid concentrations as an oxidizing agent. Characterization of all samples performed by several techniques including X-ray diffraction (XRD), transmission electron microscopy (TEM), alternating gradient magnetometry (AGM), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and zeta potential. The XRD patterns confirmed that the particles were maghemite. The crystallite size of all samples decreases with the increasing concentration of nitric acid. TEM observation showed that the particles have spherical morphology with narrow particle size distribution. The particles showed superparamagnetic behavior with decreased magnetization values at the increasing concentration of nitric acid. TGA measurement showed that the stability temperature decreases with the increasing concentration of nitric acid. DLS measurement showed that the hydrodynamic particle sizes decrease with the increasing concentration of nitric acid. Zeta potential values show a decrease with the increasing concentration of nitric acid. The increasing concentration of nitric acid in synthesis of maghemite nanoparticles produced smaller size particles, lower magnetization, better thermal stability, and more stable maghemite nanoparticles suspension. PMID:24963510

  20. Doxorubicin-Loaded QuadraSphere Microspheres: Plasma Pharmacokinetics and Intratumoral Drug Concentration in an Animal Model of Liver Cancer

    SciTech Connect

    Lee, Kwang-Hun; Liapi, Eleni A.; Cornell, Curt; Reb, Philippe; Buijs, Manon; Vossen, Josephina A.; Ventura, Veronica Prieto; Geschwind, Jean-Francois H.

    2010-06-15

    The purpose of this study was to evaluate, in vitro and in vivo, doxorubicin-loaded poly (vinyl alcohol-sodium acrylate) copolymer microspheres [QuadraSphere microspheres (QSMs)] for transcatheter arterial delivery in an animal model of liver cancer. Doxorubicin loading efficiency and release profile were first tested in vitro. In vivo, 15 rabbits, implanted with a Vx-2 tumor in the liver, were divided into three groups of five rabbits each, based on the time of euthanasia. Twenty-five milligrams of QSMs was diluted in 10 ml of a 10 mg/ml doxorubicin solution and 10 ml of nonionic contrast medium for a total volume of 20 ml. One milliliter of a drug-loaded QSM solution containing 5 mg of doxorubicin was injected into the tumor feeding artery. Plasma doxorubicin and doxorubicinol concentrations, and intratumoral and peritumoral doxorubicin tissue concentrations, were measured. Tumor specimens were pathologically evaluated to record tumor necrosis. As a control, one animal was blandly embolized with plain QSMs in each group. In vitro testing of QSM doxorubicin loadability and release over time showed 82-94% doxorubicin loadability within 2 h and 6% release within the first 6 h after loading, followed by a slow release pattern. In vivo, the doxorubicin plasma concentration declined at 40 min. The peak doxorubicin intratumoral concentration was observed at 3 days and remained detectable till the study's end point (7 days). Mean percentage tumor cell death in the doxorubicin QSM group was 90% at 7 days and 60% in the bland QSM embolization group. In conclusion, QSMs can be efficiently loaded with doxorubicin. Initial experiments with doxorubicin-loaded QSMs show a safe pharmacokinetic profile and effective tumor killing in an animal model of liver cancer.

  1. Formulation, characterization and evaluation of the effect of polymer concentration on the release behavior of insulin-loaded Eudragit®-entrapped mucoadhesive microspheres

    PubMed Central

    Kenechukwu, Franklin C.; Momoh, Mumuni A.

    2016-01-01

    Introduction: The aim of this study was to use Eudragit® RL 100 (pH-independent polymer) and magnesium stearate (a hydrophobic droplet stabilizer) in combination to improve the controlled release effect of insulin-loaded Eudragit® entrapped microspheres prepared by the emulsification-coacervation technique. Materials and Methods: Mucoadhesive insulin-loaded microspheres containing magnesium stearate and varying proportions of Eudragit® RL 100 were prepared by the emulsification-coacervation technique and evaluated for thermal properties, physicochemical performance, and in vitro dissolution in acidic and subsequently basic media. Results: Stable, spherical, brownish, discrete, free-flowing and mucoadhesive insulin-loaded microspheres with size range of 14.20 ± 0.30-19.80 ± 0.60 μm and loading efficiency of 74.55 ± 1.05-75.90 ± 1.94% were formed. After 3 h, microspheres prepared with insulin: Eudragit® RL 100 ratios of 1:4, 1:6, and 1:8 released 73.40 ± 1.38, 66.20 ± 1.59, and 71.30 ± 1.27 (%) of insulin, respectively. Conclusion: The physicochemical and physico-technical properties of the microspheres developed in this study demonstrated the effectiveness of the Eudragit® RL entrapped mucoadhesive microspheres (prepared by the emulsification-coacervation technique using varying polymer concentration) as a carrier system for oral insulin delivery. PMID:27051626

  2. Cationic RAFT polymerization using ppm concentrations of organic acid.

    PubMed

    Uchiyama, Mineto; Satoh, Kotaro; Kamigaito, Masami

    2015-02-01

    A metal-free, cationic, reversible addition-fragmentation chain-transfer (RAFT) polymerization was proposed and realized. A series of thiocarbonylthio compounds were used in the presence of a small amount of triflic acid for isobutyl vinyl ether to give polymers with controlled molecular weight of up to 1×10(5) and narrow molecular-weight distributions (Mw /Mn <1.1). This "living" or controlled cationic polymerization is applicable to various electron-rich monomers including vinyl ethers, p-methoxystyrene, and even p-hydroxystyrene that possesses an unprotected phenol group. A transformation from cationic to radical RAFT polymerization enables the synthesis of block copolymers between cationically and radically polymerizable monomers, such as vinyl ether and vinyl acetate or methyl acrylate. PMID:25511364

  3. Effect of temperature and concentration on benzoyl peroxide bleaching efficacy and benzoic acid levels in whey protein concentrate.

    PubMed

    Smith, T J; Gerard, P D; Drake, M A

    2015-11-01

    Much of the fluid whey produced in the United States is a by-product of Cheddar cheese manufacture and must be bleached. Benzoyl peroxide (BP) is currently 1 of only 2 legal chemical bleaching agents for fluid whey in the United States, but benzoic acid is an unavoidable by-product of BP bleaching. Benzoyl peroxide is typically a powder, but new liquid BP dispersions are available. A greater understanding of the bleaching characteristics of BP is necessary. The objective of the study was to compare norbixin destruction, residual benzoic acid, and flavor differences between liquid whey and 80% whey protein concentrates (WPC80) bleached at different temperatures with 2 different benzoyl peroxides (soluble and insoluble). Two experiments were conducted in this study. For experiment 1, 3 factors (temperature, bleach type, bleach concentration) were evaluated for norbixin destruction using a response surface model-central composite design in liquid whey. For experiment 2, norbixin concentration, residual benzoic acid, and flavor differences were explored in WPC80 from whey bleached by the 2 commercially available BP (soluble and insoluble) at 5 mg/kg. In liquid whey, soluble BP bleached more norbixin than insoluble BP, especially at lower concentrations (5 and 10 mg/kg) at both cold (4°C) and hot (50°C) temperatures. The WPC80 from liquid whey bleached with BP at 50°C had lower norbixin concentration, benzoic acid levels, cardboard flavor, and aldehyde levels than WPC80 from liquid whey bleached with BP at 4°C. Regardless of temperature, soluble BP destroyed more norbixin at lower concentrations than insoluble BP. The WPC80 from soluble-BP-bleached wheys had lower cardboard flavor and lower aldehyde levels than WPC80 from insoluble-BP-bleached whey. This study suggests that new, soluble (liquid) BP can be used at lower concentrations than insoluble BP to achieve equivalent bleaching and that less residual benzoic acid remains in WPC80 powder from liquid whey

  4. Effect of increased protein intake on renal acid load and renal hemodynamic responses.

    PubMed

    Teunissen-Beekman, Karianna F M; Dopheide, Janneke; Geleijnse, Johanna M; Bakker, Stephan J L; Brink, Elizabeth J; de Leeuw, Peter W; van Baak, Marleen A

    2016-03-01

    Increased protein intake versus maltodextrin intake for 4 weeks lowers blood pressure. Concerns exist that high-protein diets reduce renal function. Effects of acute and 4-week protein intake versus maltodextrin intake on renal acid load, glomerular filtration rate and related parameters were compared in this study. Seventy-nine overweight individuals with untreated elevated blood pressure and normal kidney function were randomized to consume a mix of protein isolates (60 g/day) or maltodextrin (60 g/day) for 4 weeks in energy balance. Twenty-four-hour urinary potential renal acid load (uPRAL) was compared between groups. A subgroup (maltodextrin N = 27, protein mix N = 25) participated in extra test days investigating fasting levels and postprandial effects of meals supplemented with a moderate protein- or maltodextrin-load on glomerular filtration rate, effective renal plasma flow, plasma renin, aldosterone, pH, and bicarbonate. uPRAL was significantly higher in the protein group after 4 weeks (P ≤ 0.001). Postprandial filtration fraction decreased further after the protein-supplemented breakfast than after the maltodextrin-supplemented breakfast after 4 weeks of supplementation (P ≤ 0.001). Fasting and postprandial levels of glomerular filtration rate, effective renal plasma flow, renin, aldosterone, angiotensin-converting enzyme, pH and bicarbonate did not differ between groups. In conclusion, 4 weeks on an increased protein diet (25% of energy intake) increased renal acid load, but did not affect renal function. Postprandial changes, except for filtration fraction, also did not differ between groups. These data suggest that a moderate increase in protein intake by consumption of a protein mix for 4 weeks causes no (undesirable) effects on kidney function in overweight and obese individuals with normal kidney function. PMID:26997623

  5. High aerosol acidity despite declining atmospheric sulfate concentrations over the past 15 years

    NASA Astrophysics Data System (ADS)

    Weber, Rodney J.; Guo, Hongyu; Russell, Armistead G.; Nenes, Athanasios

    2016-04-01

    Particle acidity affects aerosol concentrations, chemical composition and toxicity. Sulfate is often the main acid component of aerosols, and largely determines the acidity of fine particles under 2.5 μm in diameter, PM2.5. Over the past 15 years, atmospheric sulfate concentrations in the southeastern United States have decreased by 70%, whereas ammonia concentrations have been steady. Similar trends are occurring in many regions globally. Aerosol ammonium nitrate concentrations were assumed to increase to compensate for decreasing sulfate, which would result from increasing neutrality. Here we use observed gas and aerosol composition, humidity, and temperature data collected at a rural southeastern US site in June and July 2013 (ref. ), and a thermodynamic model that predicts pH and the gas-particle equilibrium concentrations of inorganic species from the observations to show that PM2.5 at the site is acidic. pH buffering by partitioning of ammonia between the gas and particle phases produced a relatively constant particle pH of 0-2 throughout the 15 years of decreasing atmospheric sulfate concentrations, and little change in particle ammonium nitrate concentrations. We conclude that the reductions in aerosol acidity widely anticipated from sulfur reductions, and expected acidity-related health and climate benefits, are unlikely to occur until atmospheric sulfate concentrations reach near pre-anthropogenic levels.

  6. Interactions of valproic acid with carbamazepine and its metabolites' concentrations, concentrations ratios, and level/dose ratios in epileptic children.

    PubMed

    Liu, H; Delgado, M R; Browne, R H

    1995-02-01

    In two groups of epileptic children receiving carbamazepine (CBZ) therapy with or without valproic acid (VPA) comedication, we investigate the drug interactions of VPA on serum CBZ and its metabolites' concentrations, concentration ratios, and level/dose ratios. Serum total and free CBZ-10, 11-epoxide (CBZ-E) concentrations are significantly increased in patients taking CBZ plus VPA, together with higher CBZ-E/CBZ concentration ratios and CBZ-E level/dose ratios. These results reflect the accumulation of CBZ-E. The decreased concentration ratios of trans-10, 11-dihydroxy-10, 11-dihydro-CBZ (CBZ-H)/CBZ-E observed in patients taking CBZ plus VPA suggest an inhibition in the biotransformation from CBZ-E to CBZ-H. Significant negative correlations are found between serum VPA level and CBZ-H/CBZ-E concentration ratios, indicating that the inhibition of CBZ-E hydrolysis by VPA may depend on the concentration of VPA (total or free CBZ-H/CBZ-E concentration ratio = [formula: see text], respectively). VPA concentration also shows significant positive correlations with CBZ-E and CBZ level/dose ratios. Patients taking CBZ plus VPA have significant higher free fractions of CBZ and CBZ-E than do patients on CBZ alone, suggesting a protein-binding displacement by VPA. PMID:8665529

  7. Dose-response of five bile acids on serum and liver bile Acid concentrations and hepatotoxicty in mice.

    PubMed

    Song, Peizhen; Zhang, Youcai; Klaassen, Curtis D

    2011-10-01

    Feeding bile acids (BAs) to rodents has been used to study BA signaling and toxicity in vivo. However, little is known about the effect of feeding BAs on the concentrations of BAs in serum and liver as well as the dose of the fed BAs that causes liver toxicity. The present study was designed to investigate the relative hepatotoxicity of individual BAs by feeding mice cholic acid (CA), chenodeoxycholic acid (CDCA), deoxycholic acid (DCA), lithocholic acid (LCA), or ursodeoxycholic acid (UDCA) at concentrations of 0.01, 0.03, 0.1, 0.3, 1.0, or 3% in their diet for 7 days. The data demonstrate that (1) the ability of the fed BAs to produce hepatotoxicity is UDCAconcentration of each BA in the feed that causes hepatotoxicity in mice is CA and CDCA at 0.3%, DCA at 0.1%, and LCA at 0.03%; (3) BA feeding results in a dose-dependent increase in the total serum BA concentrations but had little effect on liver total BA concentrations; (4) hepatotoxicity of the fed BAs does not simply depend on the concentration or hydrophobicity of total BAs in the liver; and (5) liver BA-conjugation enzymes are saturated by feeding UDCA at concentrations higher than 0.3%. In conclusion, the findings of the present study provide guidance for choosing the feeding concentrations of BAs in mice and will aid in interpreting BA hepatotoxicity as well as BA-mediated gene regulation. PMID:21747115

  8. Preparation and evaluation of lysozyme-loaded nanoparticles coated with poly-γ-glutamic acid and chitosan.

    PubMed

    Liu, Yong; Sun, Yan; Xu, Yaoxing; Feng, Hai; Fu, Sida; Tang, Jiangwu; Liu, Wei; Sun, Dongchang; Jiang, Hua; Xu, Shaochun

    2013-08-01

    To improve the application of lysozymes, methods for coating lysozymes with poly-γ-glutamic acid and chitosan were studied. Several lysozyme-loaded chitosan/poly-γ-glutamic acid composite nanosystems for loading and controlling the release of lysozymes were established. The lysozyme loading content and efficiency of the different systems were examined. The antibacterial activity of the composite nanoparticles was also investigated. Results showed that when the lysozymes were coated with poly-γ-glutamic acid and further rewrapped with chitosan, smooth spherical composite nanoparticles were obtained; the loading efficiency and loading content reached 76% and 40%, respectively. The lysozyme release in vitro was slow and presented a two-stage programmed release. Antibacterial testing in vitro indicated that lysozyme-loaded nanoparticles coated with poly-γ-glutamic acid/chitosan had outstanding antibacterial activity. An obvious assembly of bacterial cells and composite nanoparticles was observed during co-incubation. Therefore, the poly-γ-glutamic acid/chitosan composite coating broadened the antibacterial spectrum of the composite lysozyme nanoreagent, and presented satisfactory antibacterial effect. The lysozyme-loaded chitosan/poly-γ-glutamic acid nanocoating system established in this research could provide reference for coating and controlled releasing of alkaline proteins. PMID:23628585

  9. Impact of reduced anthropogenic emissions and century flood on the phosphorus stock, concentrations and loads in the Upper Danube

    PubMed Central

    Zoboli, Ottavia; Viglione, Alberto; Rechberger, Helmut; Zessner, Matthias

    2015-01-01

    Patterns of changes in the concentration of total and soluble reactive phosphorus (TP, SRP) and suspended sediments at different flow levels from 1991 to 2013 in the Austrian Danube are statistically analyzed and related to point and diffuse emissions, as well as to extreme hydrological events. Annual loads are calculated with three methods and their development in time is examined taking into consideration total emissions and hydrological conditions. The reduction of point discharges achieved during the 1990s was well translated into decreasing TP and SRP baseflow concentrations during the same period, but it did not induce any change in the concentrations at higher flow levels nor in the annual transport of TP loads. A sharp and long-lasting decline in TP concentration, affecting all flow levels, took place after a major flood in 2002. It was still visible during another major flood in 2013, which recorded lower TP concentrations than its predecessor. Such decline could not be linked to changes in point or diffuse emissions. This suggests that, as a result of the flood, the river system experienced a significant depletion of its in-stream phosphorus stock and a reduced mobilization of TP rich sediments afterwards. This hypothesis is corroborated by the decoupling of peak phosphorus loads from peak maximum discharges after 2002. These results are highly relevant for the design of monitoring schemes and for the correct interpretation of water quality data in terms of assessing the performance of environmental management measures. PMID:25747371

  10. Concentrations and loads of suspended sediment-associated pesticides in the San Joaquin River, California and tributaries during storm events

    USGS Publications Warehouse

    Hladik, M.L.; Domagalski, J.L.; Kuivila, K.M.

    2009-01-01

    Current-use pesticides associated with suspended sediments were measured in the San Joaquin River, California and its tributaries during two storm events in 2008. Nineteen pesticides were detected: eight herbicides, nine insecticides, one fungicide and one insecticide synergist. Concentrations for the herbicides (0.1 to 3000 ng/g; median of 6.1 ng/g) were generally greater than those for the insecticides (0.2 to 51 ng/g; median of 1.5 ng/g). Concentrations in the tributaries were usually greater than in the mainstem San Joaquin River and the west side tributaries were higher than the east side tributaries. Estimated instantaneous loads ranged from 1.3 to 320 g/day for herbicides and 0.03 to 53 g/day for insecticides. The greatest instantaneous loads came from the Merced River on the east side. Instantaneous loads were greater for the first storm of 2008 than the second storm in the tributaries while the instantaneous loads within the San Joaquin River were greater during the second storm. Pesticide detections generally reflected pesticide application, but other factors such as physical-chemical properties and timing of application were also important to pesticide loads.

  11. Productivity of concentrated hyaluronic acid using a Maxblend fermentor.

    PubMed

    Hasegawa, S; Nagatsuru, M; Shibutani, M; Yamamoto, S; Hasebe, S

    1999-01-01

    Application of the Maxblend impeller to the fermentative production of hyaluronic acid (HA) was investigated. A 2-m3-scale fermentor fitted with this impeller (MBF) was used and the main fermentation was started with 85% of the nominal volume containing the pre-culture broth and medium. The kinetic characteristics of the MBF were compared with those of a conventional-type fermentor fitted with a turbine blade (TBN). The HA production yield in the MBF was over 20% higher than that in the TBN under the operating conditions of a high aeration rate and low vessel pressure since the broth viscosity increased. The apparent viscosity of the broth at the end of the cultivation rose to about 70 Pa.s. The molecular weight of the HA produced was independent of the agitation speed within the investigated range, and no significant difference was observed between the viscosity-average molecular weights of the HA obtained in the two types of fermentor, each having an estimated value of 4.3 x 10(6) under the same agitation power. PMID:16232576

  12. Relationship between adipic acid concentration and the core symptoms of autism spectrum disorders.

    PubMed

    Puig-Alcaraz, Carmen; Fuentes-Albero, Milagros; Cauli, Omar

    2016-08-30

    Dicarboxylic acids are an important source of information about metabolism and potential physiopathological alterations in children with autism spectrum disorders (ASDs). We measured the concentration between dicarboxylic adipic and suberic acids in children with an ASD and typically-developing (TD) children and analyzed any relationships between the severity of the core symptoms of ASDs and other clinical features (drugs, supplements, drugs, or diet). The core symptoms of autism were evaluated using the DSM-IV criteria, and adipic acid and suberic acid were measured in urine samples. Overall, no increase in the concentration of adipic acid in children with ASDs compared to TD children, however when considering vitamin B supplementation in ASD there were significantly increased level of urinary adipic acid in children with an ASD not taking vitamin B supplementation compared to supplemented children or to TD children. No significant difference were observed in suberic acid. Interestingly, the increase in adipic acid concentration was significantly and indirectly correlated with the severity of the deficit in socialization and communication skills in children with an ASD. Therefore, therapeutic treatments aimed at decreasing adipic acid concentration might not be beneficial for treating the core symptoms of ASDs. PMID:27259135

  13. Impact of fluctuations in gaseous H2S concentrations on sulfide uptake by sewer concrete: The effect of high H2S loads.

    PubMed

    Sun, Xiaoyan; Jiang, Guangming; Bond, Philip L; Keller, Jurg

    2015-09-15

    The acid production from the oxidation of hydrogen sulfide (H2S) in sewer air results in serious corrosion of exposed concrete surfaces in sewers. Large fluctuations of gaseous H2S concentrations occur in sewers due to the diurnal profiles of sewage flow and retention times and the necessity of intermittent pumping of sewage from pressure pipes into gravity pipes. How the high concentrations of H2S due to these events may affect H2S uptake and subsequent corrosion by concrete sewers is largely unknown. This study determined the effect of short- and long-term increases in H2S levels on the sulfide uptake rate (SUR) of concrete surfaces with an active corrosion layer. The results showed that during the high load situation the SUR increased significantly but then decreased (compared to the baseline SUR) by about 7-14% and 41-50% immediately after short- and long-term H2S high-load periods, respectively. For both exposure conditions, the SUR gradually (over several hours) recovered to approximately 90% of the baseline SUR. Further tests suggest multiple factors may contribute to the observed decrease of SUR directly after the high H2S load. This includes the temporary storage of elemental sulfur in the corrosion layer and inhibition of sulfide oxidizing bacteria (SOB) due to high H2S level and temporary acid surge. Additionally, the delay of the corrosion layer to fully recover the SUR after the high H2S load suggests that there is a longer-term inhibitive effect of the high H2S levels on the activity of the SOB in the corrosion layer. Due to the observed activity reductions, concrete exposed to occasional short-term high H2S load periods had an overall lower H2S uptake compared to concrete exposed to constant H2S levels at the same average concentration. To accurately predict H2S uptake by sewer concrete and hence the likely maximum corrosion rates, a correction factor should be adopted for the H2S fluctuations when average H2S levels are used in the prediction. PMID

  14. Mercury concentrations and loads in a large river system tributary to San Francisco Bay, California, U.S.A.

    PubMed

    David, Nicole; McKee, Lester J; Black, Frank J; Flegal, A Russell; Conaway, Christopher H; Schoellhamer, David H; Ganju, Neil K

    2009-10-01

    In order to estimate total mercury (HgT) loads entering San Francisco Bay, U.S.A., via the Sacramento-San Joaquin River system, unfiltered water samples were collected between January 2002 and January 2006 during high flow events and analyzed for HgT. Unfiltered HgT concentrations ranged from 3.2 to 75 ng/L and showed a strong correlation (r2 = 0.8, p < 0.001, n=78) to suspended sediment concentrations (SSC). During infrequent large floods, HgT concentrations relative to SSC were approximately twice as high as observed during smaller floods. This difference indicates the transport of more Hg-contaminated particles during high discharge events. Daily HgT loads in the Sacramento-San Joaquin River at Mallard Island ranged from below the limit of detection to 35 kg. Annual HgT loads varied from 61 +/- 22 kg (n=5) in water year (WY) 2002 to 470 +/- 170 kg (n=25) in WY 2006. The data collected will assist in understanding the long-term recovery of San Francisco Bay from Hg contamination and in implementing the Hg total maximum daily load, the long-term cleanup plan for Hg in the Bay. PMID:19499967

  15. Concentrations, loads, and yields of particle-associated contaminants in urban creeks, Austin, Texas, 1999-2004

    USGS Publications Warehouse

    Mahler, B.J.; Van Metre, P.C.; Wilson, J.T.; Guilfoyle, A.L.; Sunvison, M.W.

    2006-01-01

    Concentrations, loads, and yields of particle-associated (hydrophobic) contaminants (PACs) in urban runoff in creeks in Austin, Texas, were characterized using an innovative approach: large-volume suspended-sediment sampling. This approach isolates suspended sediment from the water column in quantities sufficient for direct chemical analysis of PACs. During 1999-2004, samples were collected after selected rain events from each of five stream sites and Barton Springs for a study by the U.S. Geological Survey, in cooperation with the City of Austin. Sediment isolated from composited samples was analyzed for major elements, metals, organochlorine compounds, and polycyclic aromatic hydrocarbons (PAHs). In addition, at the Shoal Creek and Boggy Creek sites, individual samples for some events were analyzed to investigate within-event variation in sediment chemistry. Organochlorine compounds detected in suspended sediment included chlordane, dieldrin, DDD, DDE, DDT, and polychlorinated biphenyls (PCBs). Concentrations of PACs varied widely both within and between sites, with higher concentrations at the more urban sites and multiple nondetections at the least-urban sites. Within-site variation for metals and PAHs was smaller than between-site variation, and concentrations and yields of these and the organochlorine compounds correlated positively to the percentage of urban land use in the watershed. Loads of most PACs tested correlated significantly with suspended-sediment loads. Concentrations of most PACs correlated strongly with three measures of urban land use. Variation in suspended-sediment chemistry during runoff events was investigated at the Shoal and Boggy Creek sites. Five of the eight metals analyzed, dieldrin, chlordane, PCBs, and PAHs were detected at the highest concentrations in the first sample collected at the Shoal Creek site, a first-flush effect, but not at the Boggy Creek site. Temporal patterns in concentrations of DDT and its breakdown products

  16. Concentrations, Loads, and Yields of Particle-Associated Contaminants in Urban Creeks, Austin, Texas, 1999-2004

    USGS Publications Warehouse

    Mahler, B.J.; Van Metre, P.C.; Wilson, J.T.; Guilfoyle, A.L.; Sunvison, M.W.

    2006-01-01

    Concentrations, loads, and yields of particle-associated (hydrophobic) contaminants (PACs) in urban runoff in creeks in Austin, Texas, were characterized using an innovative approach: large-volume suspended-sediment sampling. This approach isolates suspended sediment from the water column in quantities sufficient for direct chemical analysis of PACs. During 1999-2004, samples were collected after selected rain events from each of five stream sites and Barton Springs for a study by the U.S. Geological Survey, in cooperation with the City of Austin. Sediment isolated from composited samples was analyzed for major elements, metals, organochlorine compounds, and polycyclic aromatic hydrocarbons (PAHs). In addition, at the Shoal Creek and Boggy Creek sites, individual samples for some events were analyzed to investigate within-event variation in sediment chemistry. Organochlorine compounds detected in suspended sediment included chlordane, dieldrin, DDD, DDE, DDT, and polychlorinated biphenyls (PCBs). Concentrations of PACs varied widely both within and between sites, with higher concentrations at the more urban sites and multiple nondetections at the least-urban sites. Within-site variation for metals and PAHs was smaller than between-site variation, and concentrations and yields of these and the organochlorine compounds correlated positively to the percentage of urban land use in the watershed. Loads of most PACs tested correlated significantly with suspended-sediment loads. Concentrations of most PACs correlated strongly with three measures of urban land use. Variation in suspended-sediment chemistry during runoff events was investigated at the Shoal and Boggy Creek sites. Five of the eight metals analyzed, dieldrin, chlordane, PCBs, and PAHs were detected at the highest concentrations in the first sample collected at the Shoal Creek site, a first-flush effect, but not at the Boggy Creek site. Temporal patterns in concentrations of DDT and its breakdown products

  17. Concentration and fractionation of hydrophobic organic acid constituents from natural waters by liquid chromatography

    USGS Publications Warehouse

    Thurman, E.M.; Malcolm, R.L.

    1979-01-01

    A scheme is presented which used adsorption chromatography with pH gradient elution and size-exclusion chromatography to concentrate and separate hydrophobic organic acids from water. A review of chromatographic processes involved in the flow scheme is also presented. Organic analytes which appear in each aqueous fraction are quantified by dissolved organic carbon analysis. Hydrophobic organic acids in a water sample are concentrated on a porous acrylic resin. These acids usually constitute approximately 30-50 percent of the dissolved organic carbon in an unpolluted water sample and are eluted with an aqueous eluent (dilute base). The concentrate is then passed through a column of polyacryloylmorpholine gel, which separates the acids into high- and low-molecular-weight fractions. The high- and low-molecular-weight eluates are reconcentrated by adsorption chromatography, then are eluted with a pH gradient into strong acids (predominately carboxylic acids) and weak acids (predominately phenolic compounds). For standard compounds and samples of unpolluted waters, the scheme fractionates humic substances into strong and weak acid fractions that are separated from the low molecular weight acids. A new method utilizing conductivity is also presented to estimate the acidic components in the methanol fraction.

  18. Preparation of magnetic polylactic acid microspheres and investigation of its releasing property for loading curcumin

    NASA Astrophysics Data System (ADS)

    Li, Fengxia; Li, Xiaoli; Li, Bin

    2011-11-01

    In order to obtain a targeting drug carrier system, magnetic polylactic acid (PLA) microspheres loading curcumin were synthesized by the classical oil-in-water emulsion solvent-evaporation method. In the Fourier transform infrared spectra of microspheres, the present functional groups of PLA were all kept invariably. The morphology and size distribution of magnetic microspheres were observed with scanning electron microscopy and dynamic light scattering, respectively. The results showed that the microspheres were regularly spherical and the surface was smooth with a diameter of 0.55-0.75 μm. Magnetic Fe 3O 4 was loaded in PLA microspheres and the content of magnetic particles was 12 wt% through thermogravimetric analysis. The magnetic property of prepared microspheres was measured by vibrating sample magnetometer. The results showed that the magnetic microspheres exhibited typical superparamagnetic behavior and the saturated magnetization was 14.38 emu/g. Through analysis of differential scanning calorimetry, the curcumin was in an amorphous state in the magnetic microspheres. The drug loading, encapsulation efficiency and releasing properties of curcumin in vitro were also investigated by ultraviolet-visible spectrum analysis. The results showed that the drug loading and encapsulation efficiency were 8.0% and 24.2%, respectively. And curcumin was obviously slowly released because the cumulative release percentage of magnetic microspheres in the phosphate buffer (pH=7.4) solution was only 49.01% in 72 h, and the basic release of curcumin finished in 120 h.

  19. Delivery of LLKKK18 loaded into self-assembling hyaluronic acid nanogel for tuberculosis treatment.

    PubMed

    Silva, João P; Gonçalves, Carine; Costa, César; Sousa, Jeremy; Silva-Gomes, Rita; Castro, António G; Pedrosa, Jorge; Appelberg, Rui; Gama, F Miguel

    2016-08-10

    Tuberculosis (TB), a disease caused by the human pathogen Mycobacterium tuberculosis, recently joined HIV/AIDS on the top rank of deadliest infectious diseases. Low patient compliance due to the expensive, long-lasting and multi-drug standard therapies often results in treatment failure and emergence of multi-drug resistant strains. In this scope, antimicrobial peptides (AMPs) arise as promising candidates for TB treatment. Here we describe the ability of the exogenous AMP LLKKK18 to efficiently kill mycobacteria. The peptide's potential was boosted by loading into self-assembling Hyaluronic Acid (HA) nanogels. These provide increased stability, reduced cytotoxicity and degradability, while potentiating peptide targeting to main sites of infection. The nanogels were effectively internalized by macrophages and the peptide presence and co-localization with mycobacteria within host cells was confirmed. This resulted in a significant reduction of the mycobacterial load in macrophages infected in vitro with the opportunistic M. avium or the pathogenic M. tuberculosis, an effect accompanied by lowered pro-inflammatory cytokine levels (IL-6 and TNF-α). Remarkably, intra-tracheal administration of peptide-loaded nanogels significantly reduced infection levels in mice infected with M. avium or M. tuberculosis, after just 5 or 10 every other day administrations. Considering the reported low probability of resistance acquisition, these findings suggest a great potential of LLKKK18-loaded nanogels for TB therapeutics. PMID:27261333

  20. Forced swimming and imipramine modify plasma and brain amino acid concentrations in mice.

    PubMed

    Murakami, Tatsuro; Yamane, Haruka; Tomonaga, Shozo; Furuse, Mitsuhiro

    2009-01-01

    The relationships between monoamine metabolism and forced swimming or antidepressants have been well studied, however information is lacking regarding amino acid metabolism under these conditions. Therefore, the aim of the present study was to investigate the effects of forced swimming and imipramine on amino acid concentrations in plasma, the cerebral cortex and the hypothalamus in mice. Forced swimming caused cerebral cortex concentrations of L-glutamine, L-alanine, and taurine to be increased, while imipramine treatment caused decreased concentrations of L-glutamate, L-alanine, L-tyrosine, L-methionine, and L-ornithine. In the hypothalamus, forced swimming decreased the concentration of L-serine while imipramine treatment caused increased concentration of beta-alanine. Forced swimming caused increased plasma concentration of taurine, while concentrations of L-serine, L-asparagine, L-glutamine and beta-alanine were decreased. Imipramine treatment caused increased plasma concentration of all amino acid, except for L-aspartate and taurine. In conclusion, forced swimming and imipramine treatment modify central and peripheral amino acid metabolism. These results may aid in the identification of amino acids that have antidepressant-like effects, or may help to refine the dosages of antidepressant drugs. PMID:19010319

  1. Acid loaded porous silicon as a proton exchange membrane for micro-fuel cells

    NASA Astrophysics Data System (ADS)

    Gold, Scott; Chu, Kuan-Lun; Lu, Chang; Shannon, Mark A.; Masel, Richard I.

    Silicon-based fuel cells are under active development to supply chip-scale electrical power supply. In this paper, we demonstrate the use of sulfuric acid loaded nanoporous silicon as a proton electrolytic membrane (PEM) material for micro-fuel cell applications. Sulfuric acid loaded nanoporous silicon membranes with thickness of 40-70 μm have proton conductivities (0.0068-0.33 S/cm) comparable to, and in some cases better than, Nafion ® (0.05 S/cm), which is the most commonly used commercial PEM material. Additionally, the permeability of formic acid at room temperature through nanoporous silicon membranes was found to be similar to that of Nafion ® membranes, which increases with increasing anodization current density (4.3 × 10 -8 to 3.9 × 10 -7 mol/(s cm 2) for nanoporous silicon as compared to 1.23 × 10 -7 mol/(s cm 2) for Nafion ® 117). These results represent the discovery of a new class of protonic conductor that can be integrated into standard silicon microfabrication processes.

  2. Hyaluronic Acid Modified Hollow Prussian Blue Nanoparticles Loading 10-hydroxycamptothecin for Targeting Thermochemotherapy of Cancer

    PubMed Central

    Jing, Lijia; shao, shangmin; Wang, Yang; Yang, Yongbo; Yue, Xiuli; Dai, Zhifei

    2016-01-01

    This paper reported the fabrication of a multifunctional nanoplatform by modifying hollow Prussian blue nanoparticles with hyaluronic acid grafting polyethylene glycol, followed by loading 10-hydroxycamptothecin for tumor-targeted thermochemotherapy. It was found that the surface modification of hollow Prussian blue nanoparticles with hyaluronic acid grafting polyethylene endowed a great colloidal stability, long blood circulation time and the capability for targeting Hela cells over-expressing the CD44 receptor. The obtained nanoagent exhibited efficient photothermal effect and a light triggered and stepwise release behavior of 10-hydroxycamptothecin due to the strong optical absorption in the near-infrared region. The investigations on the body weight change, histological injury and blood biochemical indexes showed that such nanoagent had excellent biocompatibility for medical application. Both in vitro and in vivo experiments proved that the combination of chemotherapy and photothermal therapy through the agent of hyaluronic acid modified Prussian blue nanoparticles loading 10-hydroxycamptothecin could significantly improve the therapeutic efficacy compared with either therapy alone because of a good synergetic effect. PMID:26722372

  3. Hormesis in Cholestatic Liver Disease; Preconditioning with Low Bile Acid Concentrations Protects against Bile Acid-Induced Toxicity

    PubMed Central

    Verhaag, Esther M.; Buist-Homan, Manon; Koehorst, Martijn; Groen, Albert K.; Moshage, Han; Faber, Klaas Nico

    2016-01-01

    Introduction Cholestasis is characterized by accumulation of bile acids and inflammation, causing hepatocellular damage. Still, liver damage markers are highest in acute cholestasis and drop when this condition becomes chronic, indicating that hepatocytes adapt towards the hostile environment. This may be explained by a hormetic response in hepatocytes that limits cell death during cholestasis. Aim To investigate the mechanisms that underlie the hormetic response that protect hepatocytes against experimental cholestatic conditions. Methods HepG2.rNtcp cells were preconditioned (24 h) with sub-apoptotic concentrations (0.1–50 μM) of various bile acids, the superoxide donor menadione, TNF-α or the Farsenoid X Receptor agonist GW4064, followed by a challenge with the apoptosis-inducing bile acid glycochenodeoxycholic acid (GCDCA; 200 μM for 4 h), menadione (50 μM, 6 h) or cytokine mixture (CM; 6 h). Levels of apoptotic and necrotic cell death, mRNA expression of the bile salt export pump (ABCB11) and bile acid sensors, as well as intracellular GCDCA levels were analyzed. Results Preconditioning with the pro-apoptotic bile acids GCDCA, taurocholic acid, or the protective bile acids (tauro)ursodeoxycholic acid reduced GCDCA-induced caspase-3/7 activity in HepG2.rNtcp cells. Bile acid preconditioning did not induce significant levels of necrosis in GCDCA-challenged HepG2.rNtcp cells. In contrast, preconditioning with cholic acid, menadione or TNF-α potentiated GCDCA-induced apoptosis. GCDCA preconditioning specifically reduced GCDCA-induced cell death and not CM- or menadione-induced apoptosis. The hormetic effect of GCDCA preconditioning was concentration- and time-dependent. GCDCA-, CDCA- and GW4064- preconditioning enhanced ABCB11 mRNA levels, but in contrast to the bile acids, GW4064 did not significantly reduce GCDCA-induced caspase-3/7 activity. The GCDCA challenge strongly increased intracellular levels of this bile acid, which was not lowered by GCDCA

  4. Association between Circulating Vitamin D Metabolites and Fecal Bile Acid Concentrations.

    PubMed

    Jacobs, Elizabeth T; Haussler, Mark R; Alberts, David S; Kohler, Lindsay N; Lance, Peter; Martínez, María Elena; Roe, Denise J; Jurutka, Peter W

    2016-07-01

    Although hydrophobic bile acids have been demonstrated to exhibit cytotoxic and carcinogenic effects in the colorectum, ursodeoxycholic acid (UDCA) has been investigated as a potential chemopreventive agent. Vitamin D has been shown to play a role in both bile acid metabolism and in the development of colorectal neoplasia. Using a cross-sectional design, we sought to determine whether baseline circulating concentrations of the vitamin D metabolites 25(OH)D and 1,25(OH)2D were associated with baseline fecal bile acid concentrations in a trial of UDCA for the prevention of colorectal adenoma recurrence. We also prospectively evaluated whether vitamin D metabolite concentrations modified the effect of UDCA on adenoma recurrence. After adjustment for age, sex, BMI, physical activity, and calcium intake, adequate concentrations of 25(OH)D (≥30 ng/mL) were statistically significantly associated with reduced odds for high levels of total [OR, 0.61; 95% confidence interval (CI), 0.38-0.97], and primary (OR, 0.61; 95% CI, 0.38-0.96) bile acids, as well as individually with chenodeoxycholic acid (OR, 0.39; 95% CI, 0.24-0.63) and cholic acid (OR, 0.56; 95% CI, 0.36-0.90). No significant associations were observed for 1,25(OH)2D and high versus low fecal bile acid concentrations. In addition, neither 25(OH)D nor 1,25(OH)2D modified the effect of UDCA on colorectal adenoma recurrence. In conclusion, this is the first study to demonstrate an inverse relationship between circulating levels of 25(OH)D and primary fecal bile acid concentrations. These results support prior data demonstrating that vitamin D plays a key role in bile acid metabolism, and suggest a potential mechanism of action for 25(OH)D in colorectal cancer prevention. Cancer Prev Res; 9(7); 589-97. ©2016 AACR. PMID:27138789

  5. Environmental burden of acid gas emissions associated with the exceedence of critical loads

    NASA Astrophysics Data System (ADS)

    Fisher, Bernard E. A.

    This paper demonstrates an approach to assessing environmental burdens based on optimising the integrated deposition footprints of characteristic sources, such as power stations, urban areas or poultry farms, relative to 1 km×1 km ecosystem-dependent critical loads. It makes use of a penalty function and an adjoint Green's function method describing how the deposition of acid gases and reduced nitrogen compounds compare with critical loads, from which the optimum source location in Great Britain may be found. The effect of a unit of emission from a source category can be described on a single map. This simple risk based approach to environmental burdens is compared to a more elaborate optimisation, using large combustion plant emissions as an example.

  6. Electrospinning of curcumin loaded chitosan/poly (lactic acid) nanofilm and evaluation of its medicinal characteristics

    NASA Astrophysics Data System (ADS)

    Dhurai, Bhaarathi; Saraswathy, Nachimuthu; Maheswaran, Ramasamy; Sethupathi, Ponnusamy; Vanitha, Palanisamy; Vigneshwaran, Sukumar; Rameshbabu, Venugopal

    2013-12-01

    The curcumin loaded chitosan/poly (lactic acid) (PLA) nanofibers were produced using electrospinning. Box—Behnken experimental design was used for the optimization of variables (-1, 0, + 1 coded level) like chitosan/PLA strength (% w/v), curcumin strength (% w/v) and applied voltage (kV) to obtain uniform fiber diameter. The morphology of nanofibers was shown by SEM. Molecular interactions and the presence of each chemical compound of curcumin loaded chitosan/PLA fibers were characterized by FTIR and EDX analysis. Antioxidant, drug release and in vitro cytotoxicity tests were performed to evaluate the suitability of nanofibers that would be used for wound healing. In vivo wound healing studies on excision and incision wounds created on rat model showed significant reduction of wound area when compared to untreated. The better healing efficiency can be attributed to the presence of curcumin and chitosan.

  7. Broiler skin color as affected by organic acids: influence of concentration and method of application.

    PubMed

    Bilgili, S F; Conner, D E; Pinion, J L; Tamblyn, K C

    1998-05-01

    Color of broiler skin was evaluated after exposure to organic acids under various concentrations and simulated potential plant application conditions. Breast skin from chilled broiler carcasses was treated with acetic (AA), citric (CA), lactic (LA), malic (ML), mandelic (MN), propionic (PA), or tartaric (TA) acids at 0.5, 1, 2, 4, and 6% concentrations. Each acid and concentration was applied in simulated dip (23 C for 15 s), scalder (50 C for 2 min), and immersion chiller (1 C for 60 min) conditions. A tap water control was included with each application method. Objective color values of L* (lightness), a* (redness), and b* (yellowness) were measured before and after the treatments to calculate color differentials under a factorial arrangement of organic acids and concentrations. Skin lightness increased (P < 0.01) in simulated chiller as compared to dip and scalder applications. Skin redness was reduced significantly in scalder, and yellowness in dip and scalder applications, respectively. In simulated dip application, with the exception of PA, all acids decreased lightness and increased redness and yellowness values. Propionic acid had little affect on lightness and redness values, but decreased yellowness values. In simulated scalder application, with the exception of PA, all acids decreased lightness with increasing concentration. The redness values changed little in scalder application. However, yellowness values were increased with all acids, except for PA, which decreased yellowness values. In simulated chiller conditions, all acids, except for PA, decreased lightness and redness and increased yellowness values. Propionic acid increased lightness and decreased yellowness values significantly in chiller conditions. Alterations in skin color should be taken into account in the selection and application of organic acids as carcass disinfectants. PMID:9603365

  8. Organosulfates and organic acids in Arctic aerosols: speciation, annual variation and concentration levels

    NASA Astrophysics Data System (ADS)

    Hansen, A. M. K.; Kristensen, K.; Nguyen, Q. T.; Zare, A.; Cozzi, F.; Nøjgaard, J. K.; Skov, H.; Brandt, J.; Christensen, J. H.; Ström, J.; Tunved, P.; Krejci, R.; Glasius, M.

    2014-02-01

    Sources, composition and occurrence of secondary organic aerosols (SOA) in the Arctic were investigated at Zeppelin Mountain, Svalbard, and Station Nord, northeast Greenland, during the full annual cycle of 2008 and 2010 respectively. We focused on the speciation of three types of SOA tracers: organic acids, organosulfates and nitrooxy organosulfates from both anthropogenic and biogenic precursors, here presenting organosulfate concentrations and compositions during a full annual cycle and chemical speciation of organosulfates in Arctic aerosols for the first time. Aerosol samples were analysed using High Performance Liquid Chromatography coupled to a quadrupole Time-of-Flight mass spectrometer (HPLC-q-TOF-MS). A total of 11 organic acids (terpenylic acid, benzoic acid, phthalic acid, pinic acid, suberic acid, azelaic acid, adipic acid, pimelic acid, pinonic acid, diaterpenylic acid acetate (DTAA) and 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA)), 12 organosulfates and one nitrooxy organosulfate were identified at the two sites. Six out of the 12 organosulfates are reported for the first time. Concentrations of organosulfates follow a distinct annual pattern at Station Nord, where high concentration were observed in late winter and early spring, with a mean total concentration of 47 (±14) ng m-3, accounting for 7 (±2)% of total organic matter, contrary to a considerably lower organosulfate mean concentration of 2 (±3) ng m-3 (accounting for 1 (±1)% of total organic matter) observed during the rest of the year. The organic acids followed the same temporal trend as the organosulfates at Station Nord; however the variations in organic acid concentrations were less pronounced, with a total mean organic acid concentration of 11.5 (±4) ng m-3 (accounting for 1.7 (±0.6)% of total organic matter) in late winter and early spring, and 2.2 (±1) ng m-3 (accounting for 0.9 (±0.4)% of total organic matter) during the rest of the year. At Zeppelin Mountain

  9. Computing time-series suspended-sediment concentrations and loads from in-stream turbidity-sensor and streamflow data

    USGS Publications Warehouse

    Rasmussen, Patrick P.; Gray, John R.; Glysson, G. Doug; Ziegler, Andrew C.

    2010-01-01

    Over the last decade, use of a method for computing suspended-sediment concentration and loads using turbidity sensors—primarily nephelometry, but also optical backscatter—has proliferated. Because an in- itu turbidity sensor is capa le of measuring turbidity instantaneously, a turbidity time series can be recorded and related directly to time-varying suspended-sediment concentrations. Depending on the suspended-sediment characteristics of the measurement site, this method can be more reliable and, in many cases, a more accurate means for computing suspended-sediment concentrations and loads than traditional U.S. Geological Survey computational methods. Guidelines and procedures for estimating time s ries of suspended-sediment concentration and loading as a function of turbidity and streamflow data have been published in a U.S. Geological Survey Techniques and Methods Report, Book 3, Chapter C4. This paper is a summary of these guidelines and discusses some of the concepts, s atistical procedures, and techniques used to maintain a multiyear suspended sediment time series.

  10. Doxorubicin-loaded glycyrrhetinic acid modified recombinant human serum albumin nanoparticles for targeting liver tumor chemotherapy.

    PubMed

    Qi, Wen-Wen; Yu, Hai-Yan; Guo, Hui; Lou, Jun; Wang, Zhi-Ming; Liu, Peng; Sapin-Minet, Anne; Maincent, Philippe; Hong, Xue-Chuan; Hu, Xian-Ming; Xiao, Yu-Ling

    2015-03-01

    Due to overexpression of glycyrrhetinic acid (GA) receptor in liver cancer cells, glycyrrhetinic acid modified recombinant human serum albumin (rHSA) nanoparticles for targeting liver tumor cells may result in increased therapeutic efficacy and decreased adverse effects of cancer therapy. In this study, doxorubicin (DOX) loaded and glycyrrhetinic acid modified recombinant human serum albumin nanoparticles (DOX/GA-rHSA NPs) were prepared for targeting therapy for liver cancer. GA was covalently coupled to recombinant human serum albumin nanoparticles, which could efficiently deliver DOX into liver cancer cells. The resultant GA-rHSA NPs exhibited uniform spherical shape and high stability in plasma with fixed negative charge (∼-25 mV) and a size about 170 nm. DOX was loaded into GA-rHSA NPs with a maximal encapsulation efficiency of 75.8%. Moreover, the targeted NPs (DOX/GA-rHSA NPs) showed increased cytotoxic activity in liver tumor cells compared to the nontargeted NPs (DOX/rHSA NPs, DOX loaded recombinant human serum albumin nanoparticles without GA conjugating). The targeted NPs exhibited higher cellular uptake in a GA receptor-positive liver cancer cell line than nontargeted NPs as measured by both flow cytometry and confocal laser scanning microscopy. Biodistribution experiments showed that DOX/GA-rHSA NPs exhibited a much higher level of tumor accumulation than nontargeted NPs at 1 h after injection in hepatoma-bearing Balb/c mice. Therefore, the DOX/GA-rHSA NPs could be considered as an efficient nanoplatform for targeting drug delivery system for liver cancer. PMID:25584860

  11. Size-resolved sulfuric acid mist concentrations at phosphate fertilizer manufacturing facilities in Florida.

    PubMed

    Hsu, Yu-Mei; Wu, Chang-Yu; Lundgren, Dale A; Birky, Brian K

    2007-01-01

    Strong inorganic acid mists containing sulfuric acid were identified as a 'known human carcinogen' in a National Toxicology Program (NTP) report where phosphate fertilizer manufacture was listed as one of many occupational exposures to strong acids. To properly assess the occupational exposure to sulfuric acid mists in modern facilities, approved National Institute for Occupational Safety and Health (NIOSH) Method 7903 and a cascade impactor were used for measuring the total sulfuric acid mist concentration and size-resolved sulfuric acid mist concentration, respectively. Sampling was conducted at eight phosphate fertilizer plants and two background sites in Florida and there were 24 sampling sites in these plants. Samples were analyzed by ion chromatography (IC) to quantify the water-soluble ion species. The highest sulfuric acid concentrations by the cascade impactor were obtained at the sulfuric acid pump tank area. When high aerosol mass concentrations (100 micro g m(-3)) were observed at this area, the sulfuric acid mists were in the coarse mode. The geometric mean sulfuric acid concentrations (+/-geometric standard deviation) of PM(23) (aerodynamic cut size smaller than 23 micro m), PM(10) and PM(2.5) from the cascade impactor were 41.7 (+/-5.5), 37.9 (+/-5.8) and 22.1 (+/-4.5) micro g m(-3), respectively. The geometric mean (+/-geometric standard deviation) for total sulfuric acid concentration from the NIOSH method samples was 143 (+/-5.08) micro g m(-3). Sulfuric acid mist concentrations varied significantly among the plants and even at the same location. The measurements by the NIOSH method were 1.5-229 times higher than those by the cascade impactor. Moreover, using the NIOSH method, the sulfuric acid concentrations measured at the lower flow rate (0.30 Lpm) were higher than those at the higher flow rate (0.45 Lpm). One possible reason for the significant differences between the results from the cascade impactor and the NIOSH method is the potential

  12. Effect of citric acid concentration and hydrolysis time on physicochemical properties of sweet potato starches.

    PubMed

    Surendra Babu, Ayenampudi; Parimalavalli, Ramanathan; Rudra, Shalini Gaur

    2015-09-01

    Physicochemical properties of citric acid treated sweet potato starches were investigated in the present study. Sweet potato starch was hydrolyzed using citric acid with different concentrations (1 and 5%) and time periods (1 and 11 h) at 45 °C and was denoted as citric acid treated starch (CTS1 to CTS4) based on their experimental conditions. The recovery yield of acid treated starches was above 85%. The CTS4 sample displayed the highest amylose (around 31%) and water holding capacity its melting temperature was 47.66 °C. The digestibility rate was slightly increased for 78.58% for the CTS3 and CTS4. The gel strength of acid modified starches ranged from 0.27 kg to 1.11 kg. RVA results of acid thinned starches confirmed a low viscosity profile. CTS3 starch illustrated lower enthalpy compared to all other modified starches. All starch samples exhibited a shear-thinning behavior. SEM analysis revealed that the extent of visible degradation was increased at higher hydrolysis time and acid concentration. The CTS3 satisfied the criteria required for starch to act as a fat mimetic. Overall results conveyed that the citric acid treatment of sweet potato starch with 5% acid concentration and 11h period was an ideal condition for the preparation of a fat replacer. PMID:26188303

  13. Nutrient Concentrations, Loads, and Yields in the Eucha-Spavinaw Basin, Arkansas and Oklahoma, 2002-2006

    USGS Publications Warehouse

    Tortorelli, Robert L.

    2008-01-01

    The City of Tulsa, Oklahoma, uses Lake Eucha and Spavinaw Lake in the Eucha-Spavinaw basin in northwestern Arkansas and northeastern Oklahoma for public water supply. Taste and odor problems in the water attributable to blue-green algae have increased in frequency. Changes in the algae community in the lakes may be attributable to increases in nutrient levels in the lakes, and in the waters feeding the lakes. The U.S. Geological Survey, in cooperation with the City of Tulsa, investigated and summarized nitrogen and phosphorus concentrations and provided estimates of nitrogen and phosphorus loads, yields, and flow-weighted concentrations in the Eucha-Spavinaw basin for three 3-year periods - 2002-2004, 2003-2005, and 2004-2006, to update a previous report that used data from water-quality samples for a 3-year period from January 2002 through December 2004. This report provides information needed to advance knowledge of the regional hydrologic system and understanding of hydrologic processes, and provides hydrologic data and results useful to multiple agencies for interstate agreements. Nitrogen and phosphorus concentrations were significantly greater in runoff samples than in base-flow samples for all three periods at Spavinaw Creek near Maysville, Arkansas; Spavinaw Creek near Colcord, Oklahoma, and Beaty Creek near Jay, Oklahoma. Runoff concentrations were not significantly greater than base-flow concentrations at Spavinaw Creek near Cherokee, Arkansas; and Spavinaw Creek near Sycamore, Oklahoma except for phosphorus during 2003-2005. Nitrogen concentrations in base-flow samples significantly increased downstream in Spavinaw Creek from the Maysville to Sycamore stations then significantly decreased from the Sycamore to the Colcord stations for all three periods. Nitrogen in base-flow samples from Beaty Creek was significantly less than in samples from Spavinaw Creek. Phosphorus concentrations in base-flow samples significantly increased from the Maysville to

  14. Physiological concentrations of bile acids down-regulate agonist induced secretion in colonic epithelial cells.

    PubMed

    Keating, Niamh; Mroz, Magdalena S; Scharl, Michael M; Marsh, Christine; Ferguson, Gail; Hofmann, Alan F; Keely, Stephen J

    2009-08-01

    In patients with bile acid malabsorption, high concentrations of bile acids enter the colon and stimulate Cl(-) and fluid secretion, thereby causing diarrhoea. However, deoxycholic acid (DCA), the predominant colonic bile acid, is normally present at lower concentrations where its role in regulating transport is unclear. Thus, the current study set out to investigate the effects of physiologically relevant DCA concentrations on colonic epithelial secretory function. Cl(-) secretion was measured as changes in short-circuit current across voltage-clamped T(84) cell monolayers. At high concentrations (0.5-1 mM), DCA acutely stimulated Cl(-) secretion but this effect was associated with cell injury, as evidenced by decreased transepithelial resistance (TER) and increased lactate dehydrogenase (LDH) release. In contrast, chronic (24 hrs) exposure to lower DCA concentrations (10-200 microM) inhibited responses to Ca(2+) and cAMP-dependent secretagogues without altering TER, LDH release, or secretagogue-induced increases in intracellular second messengers. Other bile acids - taurodeoxycholic acid, chenodeoxycholic acid and cholic acid - had similar antisecretory effects. DCA (50 microM) rapidly stimulated phosphorylation of the epidermal growth factor receptor (EGFr) and both ERK and p38 MAPKs (mitogen-activated protein kinases). The EGFr inhibitor, AG1478, and the protein synthesis inhibitor, cycloheximide, reversed the antisecretory effects of DCA, while the MAPK inhibitors, PD98059 and SB203580, did not. In summary, our studies suggest that, in contrast to its acute prosecretory effects at pathophysiological concentrations, lower, physiologically relevant, levels of DCA chronically down-regulate colonic epithelial secretory function. On the basis of these data, we propose a novel role for bile acids as physiological regulators of colonic secretory capacity. PMID:19583809

  15. Physiological concentrations of bile acids down‐regulate agonist induced secretion in colonic epithelial cells

    PubMed Central

    Keating, Niamh; Mroz, Magdalena S.; Scharl, Michael M.; Marsh, Christine; Ferguson, Gail; Hofmann, Alan F.

    2009-01-01

    Abstract In patients with bile acid malabsorption, high concentrations of bile acids enter the colon and stimulate Cl− and fluid secretion, thereby causing diarrhoea. However, deoxycholic acid (DCA), the predominant colonic bile acid, is normally present at lower concentrations where its role in regulating transport is unclear. Thus, the current study set out to investigate the effects of physiologically relevant DCA concentrations on colonic epithelial secretory function. Cl− secretion was measured as changes in short‐circuit current across voltage‐clamped T84 cell monolayers. At high concentrations (0.5–1 mM), DCA acutely stimulated Cl− secretion but this effect was associated with cell injury, as evidenced by decreased transepithelial resistance (TER) and increased lactate dehydrogenase (LDH) release. In contrast, chronic (24 hrs) exposure to lower DCA concentrations (10–200 μM) inhibited responses to Ca2+ and cAMP‐dependent secretagogues without altering TER, LDH release, or secretagogue‐induced increases in intracellular second messengers. Other bile acids – taurodeoxycholic acid, chenodeoxycholic acid and cholic acid – had similar antisecretory effects. DCA (50 μM) rapidly stimulated phosphorylation of the epidermal growth factor receptor (EGFr) and both ERK and p38 MAPKs (mitogen‐activated protein kinases). The EGFr inhibitor, AG1478, and the protein synthesis inhibitor, cycloheximide, reversed the antisecretory effects of DCA, while the MAPK inhibitors, PD98059 and SB203580, did not. In summary, our studies suggest that, in contrast to its acute prosecretory effects at pathophysiological concentrations, lower, physiologically relevant, levels of DCA chronically down‐regulate colonic epithelial secretory function. On the basis of these data, we propose a novel role for bile acids as physiological regulators of colonic secretory capacity. PMID:19583809

  16. The Effect of Temperature and Acid Gas Loading on Corrosion Behavior of API 5L X52 Carbon Steel in Amine Unit

    NASA Astrophysics Data System (ADS)

    Javidi, M.; Lalehparvar, M. M.; Ghassemi, A.

    2016-05-01

    The effect of temperature and H2S concentration on amine corrosion of API 5L X52 carbon steel in a CO2-saturated 25 wt.% diethanolamine solution was investigated via electrochemical techniques. It was found that increase in temperature from 25 to 80 °C resulted in severe increase in corrosion rate from 0.88 to 16.24 mpy due to increase in degradation rate of amine. Also, it was concluded that increase in H2S concentration led to increase in corrosion rate because of formation of more heat stable amine salts. The effect of temperature on corrosion rate was more significant than acid gas loading.

  17. Microbial and Nutrient Concentration and Load Data During Stormwater Runoff at a Swine Concentrated Animal Feeding Operation in the North Carolina Coastal Plain, 2006-2007

    USGS Publications Warehouse

    Harden, Stephen L.

    2008-01-01

    This report summarizes water-quality and hydrologic data collected during 2006-2007 to characterize bacteria and nutrient loads associated with overland runoff and subsurface tile drainage in spray fields at a swine concentrated animal feeding operation. Four monitoring locations were established at the Lizzie Research Site in the North Carolina Coastal Plain Physiographic Province for collecting discharge and water-quality data during stormwater-runoff events. Water stage was measured continuously at each monitoring location. A stage-discharge relation was developed for each site and was used to compute instantaneous discharge values for collected samples. Water-quality samples were collected for five storm events during 2006-2007 for analysis of nutrients and fecal indicator bacteria. Instantaneous loads of nitrite plus nitrate, total coliform, Escherichia coli (E. coli), and enterococci were computed for selected times during the five storm events.

  18. Concentrations and loads of polychlorinated biphenyls in major tributaries entering Green Bay, Lake Michigan, 1989-90

    USGS Publications Warehouse

    House, L.B.; Hughes, P.E.; Waschbusch, R.J.

    1993-01-01

    The U.S. Geological Survey collected water samples from the five major tributaries to Green Bay, Lake Michigan, to determine the load of total polychlorinated biphenyls (RGB's) entering the bay. These samples were collected from January 1989 through early May 1990 from the Escanaba, Menominee, Peshtigo, Oconto, and Fox Rivers. Sampling sites were located near the mouth of each river and also just upstream of De Pere dam on the Fox River. Water samples were collected for analysis of total, dissolved, and particulate concentrations of PCB's at the nanogram-per-liter level. Loads of PCB's entering Green Bay were computed using a total-integration method. The methods used to collect water samples and compute the loads of total PCB's entering the bay are described in this report. Graphs showing total PCB's concentrations and loads are presented for each site, along with the corresponding data tables. These data indicate that the amount of total PCB's entering the bay from the Fox River is greater than from all other major tributaries combined.

  19. Effect of acid leaching on upgrading the graphite concentrate from West Kalimantan (Indonesia)

    NASA Astrophysics Data System (ADS)

    Syarifuddin, Fahmi; Florena, Fenfen Fenda; Hanam, Eko Sulistio; Trisko, Nici; Kustiyanto, Eko; Enilisiana, Rianto, Anton; Arinton, Ghenadi

    2016-02-01

    In this research an attempt has been done for upgrading the carbon content on processed graphite concentrate obtained from Sanggau Regency, West Kalimantan, Indonesia by acid leaching. The purpose of this research was to find optimal conditions for increasing graphite purity by eliminating the impurities, in particular, sillica - which is easy to remove by hydrofluoric acid. The concentrate contained 69.74% FC ranging from 149 µm to 841 µm. The optimal leaching parameters were time reaction 120 minutes, temperature 180° C, solid-liquid ratio 1:5 and purity of acid 48%. The determination of the carbon content showed that the carbon grade was 98% FC.

  20. Systematic review of the association between dietary acid load, alkaline water and cancer

    PubMed Central

    Fenton, Tanis R; Huang, Tian

    2016-01-01

    Objectives To evaluate the evidence for a causal relationship between dietary acid/alkaline and alkaline water for the aetiology and treatment of cancer. Design A systematic review was conducted on published and grey literature separately for randomised intervention and observational studies with either varying acid–base dietary intakes and/or alkaline water with any cancer outcome or for cancer treatment. Outcome measures Incidence of cancer and outcomes of cancer treatment. Results 8278 citations were identified, and 252 abstracts were reviewed; 1 study met the inclusion criteria and was included in this systematic review. No randomised trials were located. No studies were located that examined dietary acid or alkaline or alkaline water for cancer treatment. The included study was a cohort study with a low risk of bias. This study revealed no association between the diet acid load with bladder cancer (OR=1.15: 95% CI 0.86 to 1.55, p=0.36). No association was found even among long-term smokers (OR=1.72: 95% CI 0.96 to 3.10, p=0.08). Conclusions Despite the promotion of the alkaline diet and alkaline water by the media and salespeople, there is almost no actual research to either support or disprove these ideas. This systematic review of the literature revealed a lack of evidence for or against diet acid load and/or alkaline water for the initiation or treatment of cancer. Promotion of alkaline diet and alkaline water to the public for cancer prevention or treatment is not justified. PMID:27297008

  1. Plasma amino acid concentrations in 36 dogs with histologically confirmed superficial necrolytic dermatitis.

    PubMed

    Outerbridge, Catherine A; Marks, Stanley L; Rogers, Quinton R

    2002-08-01

    Plasma amino acid concentrations were measured in 36 dogs diagnosed with superficial necrolytic dermatitis (SND) via skin biopsy. The median age of the dogs was 10 years, and 27 out of 36 (75%) were male. Twenty-two out of 36 (61%) of the dogs were accounted for by six breeds; West Highland white terriers (six), Shetland sheepdogs (five), cocker spaniels (four), Scottish terriers (three), Lhasa apsos (two) and Border collies (two). The mean concentration (+/- standard deviation) was calculated for each measured plasma amino acid and compared to previously documented concentrations of plasma amino acids measured in dogs with acute and chronic hepatitis. The ratio of branched chain amino acids to aromatic amino acids in the dogs with SND was 2.6, slightly lower than that in normal dogs. The mean plasma amino acid concentrations for dogs with SND were significantly lower than for dogs with acute and chronic hepatitis. A metabolic hepatopathy in which there is increased hepatic catabolism of amino acids is hypothesized to explain the hypoaminoacidaemia seen in SND. PMID:12174180

  2. Concentrations and Loads of Selenium in Selected Tributaries to the Colorado River in the Grand Valley, Western Colorado, 2004-2006

    USGS Publications Warehouse

    Leib, Kenneth J.

    2008-01-01

    The reach of the Colorado River from the Gunnison River confluence to the Utah Border, and tributaries in the Grand Valley, are on the State of Colorado 303(d) list of impaired water bodies because the concentrations of dissolved selenium in these streams exceed the State of Colorado chronic standard of 4.6 micrograms per liter at the 85th percentile level. In response to concerns raised by a local watershed initiative about the issue of selenium in the Grand Valley, the U.S. Geological Survey, in cooperation with Mesa County and the City of Grand Junction, developed a study to characterize and determine the sources of selenium and how these sources are related to changes in land use. This report describes the methods and results of a study of concentrations and loads of selenium in three tributaries to the Colorado River in the Grand Valley. The study area consists of three subbasins, Persigo Wash, Adobe Creek, and Lewis Wash, each representing transitional agricultural to residential, agricultural, and residential land-use types, respectively. These subbasins represent different land-use types and the tributaries that drain each subbasin contribute moderate to high concentrations and loads of selenium to the Colorado River. Two synoptic-sampling events were conducted in each tributary to characterize variations in water quality during the nonirrigation season. Water samples were collected for analysis of dissolved selenium, total nitrogen, and total dissolved solids (salinity). Streamflow was measured by either the tracer-dilution or standard current-meter method. In Persigo Wash selenium concentrations generally decreased or remained constant in a downstream direction whereas selenium loads increased. Effluent from the Persigo Wash wastewater treatment plant diluted selenium concentrations in Persigo Wash and increased the selenium load. The concentrations and loads of salinity and total nitrogen generally increased downstream in Persigo Wash. Concentrations and

  3. Determination of effect factor for effective parameter on saccharification of lignocellulosic material by concentrated acid

    NASA Astrophysics Data System (ADS)

    Aghili, Sina; Nodeh, Ali Arasteh

    2015-12-01

    Tamarisk usage as a new group of lignocelluloses material to produce fermentable sugars in bio ethanol process was studied. The overall aim of this work was to establish the optimum condition for acid hydrolysis of this new material and a mathematical model predicting glucose release as a function of operation variable. Sulfuric acid concentration in the range of 20 to 60%(w/w), process temperature between 60 to 95oC, hydrolysis time from 120 to 240 min and solid content 5,10,15%(w/w) were used as hydrolysis conditions. HPLC was used to analysis of the product. This analysis indicated that glucose was the main fermentable sugar and was increase with time, temperature and solid content and acid concentration was a parabola influence in glucose production. The process was modeled by a quadratic equation. Curve study and model were found that 42% acid concentration, 15 % solid content and 90oC were optimum condition.

  4. Evaluation Of Glass Density To Support The Estimation Of Fissile Mass Loadings From Iron Concentrations In SB8 Glasses

    SciTech Connect

    Edwards, T. B.; Peeler, D. K.; Kot, W. K.; Gan, H.; Pegg, I. L.

    2013-04-30

    The Department of Energy – Savannah River (DOE-SR) has provided direction to Savannah River Remediation (SRR) to maintain fissile concentration in glass below 897 g/m{sup 3}. In support of that guidance, the Savannah River National Laboratory (SRNL) provided a technical basis and a supporting Microsoft® Excel® spreadsheet for the evaluation of fissile loading in Sludge Batch 5 (SB5), Sludge Batch 6 (SB6), Sludge Batch 7a (SB7a), and Sludge Batch 7b (SB7b) glass based on the iron (Fe) concentration in glass as determined by the measurements from the Slurry Mix Evaporator (SME) acceptability analysis. SRR has since requested that the necessary density information be provided to allow SRR to update the Excel® spreadsheet so that it may be used to maintain fissile concentration in glass below 897 g/m{sup 3} during the processing of Sludge Batch 8 (SB8). One of the primary inputs into the fissile loading spreadsheet includes an upper bound for the density of SB8-based glasses. Thus, these bounding density values are to be used to assess the fissile concentration in this glass system. It should be noted that no changes are needed to the underlying structure of the Excel-based spreadsheet to support fissile assessments for SB8. However, SRR should update the other key inputs to the spreadsheet that are based on fissile and Fe concentrations reported from the SB8 Waste Acceptance Product Specification (WAPS) sample.

  5. Nitrite accumulation performance of aerobic MBBR treating Lurgi coal gasification waste water by adjusting pollutant load and DO concentration.

    PubMed

    Li, Hui-Qiang; Han, Hong-Jun

    2015-01-01

    An aerobic moving bed biofilm reactor (MBBR) was adopted to treat Lurgi coal gasification waste water (LCGW) in about 10 months. The pollutant load and dissolve oxygen (DO) concentration were adjusted by trying to maximize the accumulation of [Formula: see text] in the MBBR for LCGW treatment. The highest [Formula: see text] accumulation proportion [Formula: see text] was 73.9%, but was not stable with influent chemical oxygen demand (COD) and DO concentrations of around 1000 and 1.5 mg/L, respectively. Around 1500 mg/L of influent COD concentration and 1.5 mg/L of DO concentration were proper operation conditions for the aerobic MBBR to achieve relatively stable [Formula: see text] accumulation, with [Formula: see text] ratio at 53% and [Formula: see text] ratio at just 4.3% in the effluent. More specifically, free ammonia concentration and DO concentration affected [Formula: see text] accumulation much more obvious than phenols concentration. The activity and quantity of nitrifying bacteria growth in suspended sludge and biofilm of the MBBR were monitored simultaneously to explain the variations of [Formula: see text] accumulation performance under different operation conditions. An aerobic moving bed biofilm reactor (MBBR) was adopted to treat Lurgi coal gasification waste water (LCGW)in about 10 months. The pollutant load and dissolve oxygen (DO) concentration were adjusted by trying to maximize the accumulation of NO(−)(2)−N in the MBBR for LCGW treatment. The highest NO(−)(2)−N accumulation proportion(NO(−)(2)−Neffluent/TN effluent) was 73.9%, but was not stable with influent chemical oxygen demand (COD) and DO concentrations of around 1000 and 1.5 mg/L, respectively. Around 1500 mg/L of influent COD concentration and 1.5 mg/L of DO concentration were proper operation conditions for the aerobic MBBR to achieve relatively stable NO(−)(2)−N accumulation,with NO(−)(2)−N/TN ratio at 53% and NO(-)(3)−N/TN ratio at just 4.3% in the

  6. Comparison of XAD macroporous resins for the concentration of fulvic acid from aqueous solution

    USGS Publications Warehouse

    Aiken, G.R.

    1979-01-01

    Five macroreticular, nonlonlc AmberlHe XAD resins were evaluated for concentration and Isolation of fulvlc acid from aqueous solution. The capacity of each resin for fulvlc acid was measured by both batch and column techniques. Elution efficiencies were determined by desorptlon with 0.1 N NaOH. Highest recoveries were obtained with the acrylic ester resins which proved to be most efficient for both adsorption and elution of fulvlc acid. Compared to the acrylic ester resins, usefulness of the styrene dvlnybenzene resins to remove fulvlc acid is limited because of slow diffusion-controlled adsorption and formation of charge-transfer complexes, which hinders elution. ?? 1979 American Chemical Society.

  7. Endogenous flow of amino acids in the avian ileum as influenced by increasing dietary peptide concentrations.

    PubMed

    Ravindran, Velmurugu; Morel, Patrick C H; Rutherfurd, Shane M; Thomas, Donald V

    2009-03-01

    The aim of the present study was to establish whether feeding broiler chickens with diets containing increasing dietary peptide concentrations would cause increases in ileal endogenous amino acid flow. The flow of N and most amino acids increased quadratically (P < 0.05 to 0.001) with increasing dietary concentrations of peptides. The exceptions were the flow of threonine, serine, glycine, tyrosine and cystine, which increased linearly (P < 0.001) with dietary peptide levels. Another notable exception to the general trend was the flow of proline, which was significantly higher (P < 0.01) in birds fed the protein-free diet. The amino acid profile of endogenous protein, expressed as proportion of crude protein, indicated that the ratios of threonine, glutamic acid, proline, glycine, leucine, histidine, arginine and cystine were influenced (P < 0.05) with increasing dietary peptide concentrations. In general, compared with the protein-free diet, the ratios of threonine and arginine in endogenous protein were lower (P < 0.05) and those of glutamic acid, glycine and histidine were greater (P < 0.05) in diets with high concentrations of peptides. The ratio of proline was found to decrease (P < 0.05) with increasing dietary peptide concentrations. These changes in the amino acid profile of endogenous protein are probably reflective of changes in the output of one or more of the components of endogenous protein. Overall, the present results demonstrated that increasing dietary peptide concentrations increased the flow of endogenous amino acid flow at the terminal ileum of broiler chickens in a dose-dependent manner and also caused changes in the composition of endogenous protein. The observed changes in endogenous amino flow will influence the maintenance requirements for amino acids and also have implications for the calculation of true digestibility coefficient of feedstuffs. PMID:18662428

  8. Preparation and characterization of silver loaded montmorillonite modified with sulfur amino acid

    NASA Astrophysics Data System (ADS)

    Li, Tian; Lin, Oulian; Lu, Zhiyuan; He, Liuimei; Wang, Xiaosheng

    2014-06-01

    The Na+ montmorillonite (MMT) was modified with sulfur containing amino acid (L-cystine, L-cysteine or L-methionine) and characterized by energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and Fourier transform infrared spectrum (FT-IR). The results showed the modification was smooth and the surface condition of MMT was changed with sulfur containing groups. Then silver was loaded on the modified MMTs via ion-exchange reaction under microwave irradiation, the spectra of X-ray photoelectron spectroscopy (XPS), EDS and FT-IR confirmed the successful loading of massive silver and the strong interaction between sulfur and silver, the silver loaded L-cystine modified MMT (Ag@AA-MMT-3) with a silver content of 10.93 wt% was the highest of all. Further more, the Ag@AA-MMT-3 was under the irradiation of a UV lamp to turn silver ions to silver nano particles (Ag NPs). The XPS, specific surface area (SSA), transmission electron microscopy (TEM), XRD patterns and UV-vis spectra proved the existence of uniform nano scaled metallic Ag NPs. By contrast, the UV irradiated Ag@AA-MMT-3 (Ag@AA-MMT-UV) showed a much better slow release property than Ag@AA-MMT-3 or Ag@MMT. The Ag@AA-MMT-UV showing a large inhibition zone and high inhibition ratio presented very good antibacterial property.

  9. The anticancer efficacy of pixantrone-loaded liposomes decorated with sialic acid-octadecylamine conjugate.

    PubMed

    She, Zhennan; Zhang, Ting; Wang, Xuling; Li, Xuan; Song, Yanzhi; Cheng, Xiaobo; Huang, Zhenjun; Deng, Yihui

    2014-06-01

    Based on the knowledge that sialic acid is a critical element for tumor development and its receptors are highly expressed on the tumor-associated macrophages (TAMs) which play important roles in the growth and metastasis of tumors, we synthesized a sialic acid-octadecylamine conjugate (SA-ODA) and anchored it on the surface of pixantrone (Pix)-loaded liposomes, to achieve an improved anticancer effect. Four Pix formulations (Pix-S, Pix-CL, Pix-PL and Pix-SAL represent solution, conventional liposome, stealth liposome, and SA-ODA modified liposome, respectively) were developed, and various parameters, including drug loading, stability, in vitro release, cytotoxicity and pharmacokinetics, were evaluated. The tumor growth inhibition and toxicity studies were performed in S180-bearing Kunming mice. Pix-S exhibited a strong toxicity to the immune system, accelerated the growth of tumors and reduced the lifespan of mice. In contrast, Pix-SAL displayed the strongest anticancer and life-prolonging effects among all of the formulations in this study. More importantly, injection of Pix-SAL induced a phenomenon whereby the cancerous tissues were "shed" from mice, after which the wound healed. We speculate that this special efficacy may be partly due to the killing of TAMs by Pix-SAL. This study suggests that SA-ODA modified liposomes may serve as an effective intravenous delivery vehicle for Pix. PMID:24703714

  10. Preliminary characterization of dexamethasone-loaded cross-linked hyaluronic acid films for topical ocular therapy.

    PubMed

    Calles, J A; López-García, A; Vallés, E M; Palma, S D; Diebold, Y

    2016-07-25

    The aim of this work was to design and characterize cross-linked hyaluronic acid (HA)-itaconic acid (IT) films loaded with dexamethasone sodium phosphate salt (DEX) for topical therapy of inflammatory ocular surface diseases. Films were chemically cross-linked with polyethylene glycol diglycidyl ether (PEGDE), then physical and mechanical characterization by stress-strain, X-ray diffraction, X-ray fluorescence spectrometry and swelling assays was conducted. A sequential in vitro therapeutic efficacy model was designed to assess changes in interleukin (IL)-6 production in an inflamed human corneal epithelial (HCE) cell line after film exposure. Changes in cell proliferation after film exposure were assessed using the alamarBlue(®) proliferation assay. Experimental findings showed desirable mechanical properties and in vitro efficacy to reduce cell inflammation. A moderately decreased proliferation rate was induced in HCE cells by DEX-loaded films, compared to commercial DEX eye drops. These results suggest that DEX and HA have opposite effects. The sequential in vitro therapeutic efficacy model arises as an efficient tool to study drug release from delivery systems by indirect measurement of a biological response. PMID:27242313

  11. A Novel Cationic Microbubble Coated with Stearic Acid-Modified Polyethylenimine to Enhance DNA Loading and Gene Delivery by Ultrasound

    PubMed Central

    Jin, Qiaofeng; Wang, Zhiyong; Yan, Fei; Deng, Zhiting; Ni, Fei; Wu, Junru; Shandas, Robin; Liu, Xin; Zheng, Hairong

    2013-01-01

    A novel cationic microbubble (MB) for improvement of the DNA loading capacity and the ultrasound-mediated gene delivery efficiency has been developed; it has been prepared with commercial lipids and a stearic acid modified polyethylenimine 600 (Stearic-PEI600) polymer synthesized via acylation reaction of branched PEI600 and stearic acid mediated by N, N'-carbonyldiimidazole (CDI). The MBs’ concentration, size distribution, stability and zeta potential (ζ-potential) were measured and the DNA loading capacity was examined as a function of the amount of Stearic-PEI600. The gene transfection efficiency and cytotoxicity were also examined using breast cancer MCF-7 cells via the reporter plasmid pCMV-Luc, encoding the firefly luciferase gene. The results showed that the Stearic-PEI600 polymer caused a significant increase in magnitude of ζ-potential of MBs. The addition of DNA into cationic MBs can shift ζ-potentials from positive to negative values. The DNA loading capacity of the MBs grew linearly from (5±0.2) ×10−3 pg/µm2 to (20±1.8) ×10−3 pg/µm2 when Stearic-PEI600 was increased from 5 mol% to 30 mol%. Transfection of MCF-7 cells using 5% PEI600 MBs plus ultrasound exposure yielded 5.76±2.58×103 p/s/cm2/sr average radiance intensity, was 8.97- and 7.53-fold higher than those treated with plain MBs plus ultrasound (6.41±5.82) ×102 p/s/cm2/sr, (P<0.01) and PEI600 MBs without ultrasound (7.65±6.18) ×102 p/s/cm2/sr, (P<0.01), respectively. However, the PEI600 MBs showed slightly higher cytotoxicity than plain MBs. The cells treated with PEI600-MBs and plain MBs plus ultrasound showed 59.5±6.1% and 71.4±7.1% cell viability, respectively. In conclusion, our study demonstrated that the novel cationic MBs were able to increase DNA loading capacity and gene transfection efficiency and could be potentially applied in targeted gene delivery and therapy. PMID:24086748

  12. Covalent and non-covalent curcumin loading in acid-responsive polymeric micellar nanocarriers

    NASA Astrophysics Data System (ADS)

    Gao, Min; Chen, Chao; Fan, Aiping; Zhang, Ju; Kong, Deling; Wang, Zheng; Zhao, Yanjun

    2015-07-01

    Poor aqueous solubility, potential degradation, rapid metabolism and elimination lead to low bioavailability of pleiotropic impotent curcumin. Herein, we report two types of acid-responsive polymeric micelles where curcumin was encapsulated via both covalent and non-covalent modes for enhanced loading capacity and on-demand release. Biodegradable methoxy poly(ethylene glycol)-poly(lactic acid) copolymer (mPEG-PLA) was conjugated with curcumin via a hydrazone linker, generating two conjugates differing in architecture (single-tail versus double-tail) and free curcumin was encapsulated therein. The two micelles exhibited similar hydrodynamic size at 95 ± 3 nm (single-tail) and 96 ± 3 nm (double-tail), but their loading capacities differed significantly at 15.0 ± 0.5% (w/w) (single-tail) and 4.8 ± 0.5% (w/w) (double-tail). Under acidic sink conditions (pH 5.0 and 6.0), curcumin displayed a faster release from the single-tail nanocarrier, which was correlated to a low IC50 of 14.7 ± 1.6 (μg mL-1) compared to the value of double-tail micelle (24.9 ± 1.3 μg mL-1) in HeLa cells. The confocal imaging and flow cytometry analysis demonstrated a superior capability of single-tail micelle for intracellular curcumin delivery, which was a consequence of the higher loading capacity and lower degree of mPEG surface coverage. In conclusion, the dual loading mode is an effective means to increase the drug content in the micellar nanocarriers whose delivery efficiency is highly dependent on its polymer-drug conjugate architecture. This strategy offers an alternative nanoplatform for intracellularly delivering impotent hydrophobic agents (i.e. curcumin) in an efficient stimuli-triggered way, which is valuable for the enhancement of curcumin’s efficacy in managing a diverse range of disorders.

  13. Effects of squat exercise and branched-chain amino acid supplementation on plasma free amino acid concentrations in young women.

    PubMed

    Shimomura, Yoshiharu; Kobayashi, Hisamine; Mawatari, Kazunori; Akita, Keiichi; Inaguma, Asami; Watanabe, Satoko; Bajotto, Gustavo; Sato, Juichi

    2009-06-01

    The present study was conducted to examine alterations in plasma free amino acid concentrations induced by squat exercise and branched-chain amino acid (BCAA) supplementation in young, untrained female subjects. In the morning on the exercise session day, participants ingested drinks containing either BCAA (isoleucine:leucine:valine=1:2.3:1.2) or dextrin (placebo) at 0.1 g/kg body weight 15 min before a squat exercise session, which consisted of 7 sets of 20 squats, with 3 min intervals between sets. In the placebo trial, plasma BCAA concentrations were decreased subsequent to exercise, whereas they were significantly increased in the BCAA trial until 2 h after exercise. Marked changes in other free amino acids in response to squat exercise and BCAA supplementation were observed. In particular, plasma concentrations of methionine and aromatic amino acids were temporarily decreased in the BCAA trial, being significantly lower than those in the placebo trial. These results suggest that BCAA intake before exercise affects methionine and aromatic amino acid metabolism. PMID:19602839

  14. Retinoic acid stimulation of human dermal fibroblast proliferation is dependent on suboptimal extracellular Ca2+ concentration

    SciTech Connect

    Varani, J.; Shayevitz, J.; Perry, D.; Mitra, R.S.; Nickoloff, B.J.; Voorhees, J.J. )

    1990-06-01

    Human dermal fibroblasts failed to proliferate when cultured in medium containing 0.15 mmol/l (millimolar) Ca2+ (keratinocyte growth medium (KGM)) but did when the external Ca2+ concentration was raised to 1.4 mmol/l. All-trans retinoic acid (retinoic acid) stimulated proliferation in KGM but did not further stimulate growth in Ca2(+)-supplemented KGM. The ability of retinoic acid to stimulate proliferation was inhibited in KGM prepared without Ca2+ or prepared with 0.03 mmol/l Ca2+ and in KGM treated with 1 mmol/l ethylene-glycol-bis-(beta-aminoethyl ether)N,N'-tetra acetic acid. Using 45Ca2+ to measure Ca2+ influx and efflux, it was found that retinoic acid minimally increased Ca2+ uptake into fibroblasts. In contrast, retinoic acid treatment of fibroblasts that had been pre-equilibrated for 1 day with 45Ca2+ inhibited release of intracellular Ca2+ into the extracellular fluid. Retinoic acid also stimulated 35S-methionine incorporation into trichloroacetic acid-precipitable material but in contrast to its effect on proliferation, stimulation of 35S-methionine incorporation occurred in both high-Ca2+ and low-Ca2+ medium. These data indicate that retinoic acid stimulation of proliferation, but not protein synthesis, is dependent on the concentration of Ca2+ in the extracellular environment.

  15. Estimating Summer Nutrient Concentrations in Northeastern Lakes from SPARROW Load Predictions and Modeled Lake Depth and Volume

    PubMed Central

    Milstead, W. Bryan; Hollister, Jeffrey W.; Moore, Richard B.; Walker, Henry A.

    2013-01-01

    Global nutrient cycles have been altered by the use of fossil fuels and fertilizers resulting in increases in nutrient loads to aquatic systems. In the United States, excess nutrients have been repeatedly reported as the primary cause of lake water quality impairments. Setting nutrient criteria that are protective of a lakes ecological condition is one common solution; however, the data required to do this are not always easily available. A useful solution for this is to combine available field data (i.e., The United States Environmental Protection Agency (USEPA) National Lake Assessment (NLA)) with average annual nutrient load models (i.e., USGS SPARROW model) to estimate summer concentrations across a large number of lakes. In this paper we use this combined approach and compare the observed total nitrogen (TN) and total phosphorus (TN) concentrations in Northeastern lakes from the 2007 National Lake Assessment to those predicted by the Northeast SPARROW model. We successfully adjusted the SPARROW predictions to the NLA observations with the use of Vollenweider equations, simple input-output models that predict nutrient concentrations in lakes based on nutrient loads and hydraulic residence time. This allows us to better predict summer concentrations of TN and TP in Northeastern lakes and ponds. On average we improved our predicted concentrations of TN and TP with Vollenweider models by 18.7% for nitrogen and 19.0% for phosphorus. These improved predictions are being used in other studies to model ecosystem services (e.g., aesthetics) and dis-services (e.g. cyanobacterial blooms) for ~18,000 lakes in the Northeastern United States. PMID:24260579

  16. Anti-glioma activity and the mechanism of cellular uptake of asiatic acid-loaded solid lipid nanoparticles.

    PubMed

    Garanti, Tanem; Stasik, Aneta; Burrow, Andrea Julie; Alhnan, Mohamed A; Wan, Ka-Wai

    2016-03-16

    Asiatic acid (AA), a pentacyclic triterpene found in Centella Asiatica, has shown neuroprotective and anti-cancer activity against glioma. However, owing to its poor aqueous solubility, effective delivery and absorption across biological barriers, in particular the blood brain barrier (BBB), are challenging. Solid lipid nanoparticles (SLNs) have shown a promising potential as a drug delivery system to carry lipophilic drugs across the BBB, a major obstacle in brain cancer therapy. Nevertheless, limited information is available about the cytotoxic mechanisms of nano-lipidic carriers with AA on normal and glioma cells. This study assessed the anti-cancer efficacy of AA-loaded SLNs against glioblastoma and their cellular uptake mechanism in comparison with SVG P12 (human foetal glial) cells. SLNs were systematically investigated for three different solid lipids; glyceryl monostearate (MS), glyceryl distearate (DS) and glyceryl tristearate (TS). The non-drug containing MS-SLNs (E-MS-SLNs) did not show any apparent toxicity towards normal SVG P12 cells, whilst the AA-loaded MS-SLNs (AA-MS-SLNs) displayed a more favourable drug release profile and higher cytotoxicity towards U87 MG cells. Therefore, MS-SLNs were chosen for further in vitro studies. Cytotoxicity studies of SLNs (± AA) were performed using MTT assay where AA-SLNs showed significantly higher cytotoxicity towards U87 MG cells than SVG P12 normal cells, as confirmed by flow cell cytometry. Cellular uptake of SLNs also appeared to be preferentially facilitated by energy-dependent endocytosis as evidenced by fluorescence imaging and flow cell cytometry. Using the Annexin V-PI double staining technique, it was found that these AA-MS-SLNs displayed concentration-dependent apoptotic activity on glioma cells, which further confirms the potential of exploiting these AA-loaded MS-SLNs for brain cancer therapy. PMID:26775062

  17. Testing and evaluation of an industrial lead-acid battery for utility load-leveling

    SciTech Connect

    Varma, R.; Corp, D.; Folke, E.; Tillery, G.; Loutfy, R.O.

    1986-01-01

    Constant-power/constant-voltage charging, as well as constant-current/constant-voltage charging, was investigated. Electrolyte stratification observed in the battery during cycling indicates discharge of the battery from the top down. Uneven concentration of acid during charge may be avoided by mixing. This study shows that a minimization in cycle time can be achieved by proper choice of charge/discharge parameters.

  18. Nanostructured lipid carrier-loaded hyaluronic acid microneedles for controlled dermal delivery of a lipophilic molecule.

    PubMed

    Lee, Sang Gon; Jeong, Jae Han; Lee, Kyung Min; Jeong, Kyu Ho; Yang, Huisuk; Kim, Miroo; Jung, Hyungil; Lee, Sangkil; Choi, Young Wook

    2014-01-01

    Nanostructured lipid carriers (NLCs) were employed to formulate a lipophilic drug into hydrophilic polymeric microneedles (MNs). Hyaluronic acid (HA) was selected as a hydrophilic and bioerodible polymer to fabricate MNs, and nile red (NR) was used as a model lipophilic molecule. NR-loaded NLCs were consolidated into the HA-based MNs to prepare NLC-loaded MNs (NLC-MNs). A dispersion of NLCs was prepared by high-pressure homogenization after dissolving NR in Labrafil and mixing with melted Compritol, resulting in 268 nm NLCs with a polydispersity index of 0.273. The NLC dispersion showed a controlled release of NR over 24 hours, following Hixson-Crowell's cube root law. After mixing the NLC dispersion with the HA solution, the drawing lithography method was used to fabricate NLC-MNs. The length, base diameter, and tip diameter of the NLC-MNs were approximately 350, 380, and 30 μm, respectively. Fluorescence microscopic imaging of the NLC-MNs helped confirm that the NR-loaded NLCs were distributed evenly throughout the MNs. In a skin permeation study performed using a Franz diffusion cell with minipig dorsal skin, approximately 70% of NR was localized in the skin after 24-hour application of NLC-MNs. Confocal laser scanning microscopy (z-series) of the skin at different depths showed strong fluorescence intensity in the epidermal layer, which appeared to spread out radially with the passage of time. This study indicated that incorporation of drug-loaded NLCs into MNs could represent a promising strategy for controlled dermal delivery of lipophilic drugs. PMID:24403833

  19. Docetaxel-loaded polyglutamic acid-PEG nanocapsules for the treatment of metastatic cancer.

    PubMed

    Borrajo, Erea; Abellan-Pose, Raquel; Soto, Atenea; Garcia-Fuentes, Marcos; Csaba, Noemi; Alonso, Maria J; Vidal, Anxo

    2016-09-28

    The design of nanomedicines with suitable physicochemical characteristics for the lymphatic targeting of drugs is critical in order to reach the lymph nodes, where metastatic cells often accumulate. Based on the known effect of particle size and surface hydrophilicity on the capacity of nanocarriers to reach the lymph nodes, here we report the formation and characterization of 100nm polyglutamic acid-polyethylene glycol (PGA-PEG) nanocapsules together with the assessment of their potential for the treatment of cancer with lymphatic metastatic spread. To this purpose, we first studied the biodistribution of fluorescently labeled PGA-PEG nanocapsules (100nm), following, either intravenous or subcutaneous administration. The results confirmed the accumulation of nanocapsules in the lymphatic system, especially upon subcutaneous administration. Next, we evaluated the efficacy and toxicity of the docetaxel-loaded nanocapsules in an orthotopic lung cancer model that metastasizes to the lymph nodes. As expected from the rational design, DCX-loaded PGA-PEG nanocapsules exhibited a greatly enhanced antitumoral efficacy and a reduced toxicity when compared with the commercial formulation Taxotere®. Furthermore, the administration of DCX-loaded PGA-PEG nanocapsules resulted in the practical elimination of the metastatic load in the mediastinal lymph nodes, whereas the treatment with the commercial formulation had a minor effect. Overall, these findings underscore the potential of PGA-PEG nanocapsules for the delivery of anticancer drugs to both, the tumor tissue and the metastatic lymph nodes. Therefore, they represent a promising therapy for the treatment of lung metastatic cancer. PMID:27476608

  20. Changes in Streamflow, Concentrations, and Loads in Selected Nontidal Basins in the Chesapeake Bay Watershed, 1985-2006

    USGS Publications Warehouse

    Langland, Michael J.; Moyer, Douglas; Blomquist, Joel

    2007-01-01

    Water-quality and streamflow data from 34 sites in nontidal parts of the Chesapeake Bay watershed are presented to document annual nutrient and sediment loads and trends for 1985 through 2006, as part of an annual evaluation of water-quality conditions by the U.S. EPA Chesapeake Bay Program. This study presents the results of trends analysis for streamflow, loads, and concentrations. Annual mean flow to the bay for 2006 (78,650 cubic feet per second) was approximately 1 percent above the long-term annual mean flow from 1937 to 2005. Total freshwater flow entering the bay for the summer season (July-August-September) was the only season classified as 'wet' in 2006. For the period 1985 through 2006, streamflow was significantly increasing at two of the 34 sites. Observed (bias-corrected) concentration summaries indicate higher ranges in concentrations of total nitrogen in the northern major river basins (Pennsylvania, Maryland, and northern Virginia) than in the southern basins in Virginia. Results indicate almost half of the monitoring sites in the northern basins exhibited significant downward bias-corrected concentration trends in total nitrogen over time; results were similar for total phosphorus and sediment. Generally, loads for all constituents at the nine River Input Monitoring Program (RIM) sites, which comprise 78 percent of the streamflow entering the bay, were lower in 2006 than in 2005. The loads for total nitrogen are below the long-term average loads at eight of the nine RIM sites and total phosphorus and sediment loads are also below the long-term average at seven RIM sites. Combined annual mean total nitrogen flow-weighted concentrations from the nine RIM sites indicated an upward tendency in 2006; in contrast, total phosphorus and sediment indicated a downward tendency. From 1990 to 2006 for the 9 RIM sites, the mean concentrations of total nitrogen, total phosphorus, and sediment were 3.49, 0.195, and 116 milligrams per liter, respectively. Flow

  1. Chloride concentrations, loads, and yields in four watersheds along Interstate 95, southeastern Connecticut, 2008-11: factors that affect peak chloride concentrations during winter storms

    USGS Publications Warehouse

    Brown, Craig J.; Mullaney, John R.; Morrison, Jonathan; Martin, Joseph W.; Trombley, Thomas J.

    2015-01-01

    The addition of a lane mile in both directions on I–95 would result in an estimate of approximately 2 to 11 percent increase in Cl- input from deicers applied to I–95 and other roads maintained by Connecticut Department of Transportation. The largest estimated increase in Cl- load was in the watersheds with the greatest number miles of I–95 corridor relative to the total lane miles maintained by Connecticut Department of Transportation. On the basis of these estimates and the estimated peak Cl- concentrations during the study period, it is unlikely that the increased use of deicers on the additional lanes would lead to Cl- concentrations that exceed the aquatic habitat criteria.

  2. Continuous Ethanol Production with a Membrane Bioreactor at High Acetic Acid Concentrations

    PubMed Central

    Ylitervo, Päivi; Franzén, Carl Johan; Taherzadeh, Mohammad J.

    2014-01-01

    The release of inhibitory concentrations of acetic acid from lignocellulosic raw materials during hydrolysis is one of the main concerns for 2nd generation ethanol production. The undissociated form of acetic acid can enter the cell by diffusion through the plasma membrane and trigger several toxic effects, such as uncoupling and lowered intracellular pH. The effect of acetic acid on the ethanol production was investigated in continuous cultivations by adding medium containing 2.5 to 20.0 g·L−1 acetic acid at pH 5.0, at a dilution rate of 0.5 h−1. The cultivations were performed at both high (~25 g·L−1) and very high (100–200 g·L−1) yeast concentration by retaining the yeast cells inside the reactor by a cross-flow membrane in a membrane bioreactor. The yeast was able to steadily produce ethanol from 25 g·L−1 sucrose, at volumetric rates of 5–6 g·L−1·h−1 at acetic acid concentrations up to 15.0 g·L−1. However, the yeast continued to produce ethanol also at a concentration of 20 g·L−1 acetic acid but at a declining rate. The study thereby demonstrates the great potential of the membrane bioreactor for improving the robustness of the ethanol production based on lignocellulosic raw materials. PMID:25028956

  3. Variability of Near-stream, Sub-surface Major-ion and Tracer Concentrations in an Acid Mine Drainage Environment

    NASA Astrophysics Data System (ADS)

    Bencala, K. E.; Kimball, B. A.; Runkel, R. L.

    2006-12-01

    In acid mine drainage environments, tracer-injection and synoptic sampling approaches provide tools for making operational estimates of solute loading within a stream segment. Identifying sub-surface contaminant sources remains a challenge both for characterization of in-stream metal loading and hydrological process research. There is a need to quantitatively define the character and source of contaminants entering streams from ground-water pathways, as well as the potential for changes in water chemistry and contaminant concentrations along these flow paths crossing the sediment-water interface. Complicating the identification of inflows is the mixing of solute sources which may occur in the `near-stream' subsurface areas and specifically along hyporheic exchange flows (HEFs). In Mineral Creek (Silverton, Colorado), major-ion (SO42-, Cl-, Na+, Ca2+, Mg2+) meter-scale sampling shows that subsurface inflows and likely HEFs occur in a hydro- geochemical setting of significant, one order-of-magnitude, spatial variation in the solute concentrations. Transient Storage Models (TSMs) are a tool for interpreting the in-stream responses of solute transport in streams influenced by hyporheic exchange flows. Simulations using the USGS TSM code OTIS are interpreted as suggesting that in Mineral Creek the strong concentration `tailing' of bromide following the tracer injection occurred, at least in part, from HEFs in a hydro - solute transport setting of likely multiple, dispersed and mixed sources of water along a 64 m sub-reach of the nominally gaining stream. In acid mine drainage environments, the ability to distinguish between local and deep solute sources is critical in modeling reactive transport along the stream, as well as in identifying the geochemical evolution of dispersed, subsurface inflows thorough the catchment.

  4. Multi-variable operational characteristic studies of on-column oxidative protein refolding at high loading concentrations.

    PubMed

    Saremirad, Pegah; Wood, Jeffery A; Zhang, Yan; Ray, Ajay K

    2014-09-12

    Chromatographic-based protein refolding techniques have proven to be superior to conventional dilution refolding methods, due to the higher loading concentration and simultaneous purification. Among these techniques, Size Exclusion Chromatography (SEC) has in particular been demonstrated as an effective method for refolding of variety of proteins. To date existing studies of protein refolding at high concentrations (>1mg/mL) in SEC have primarily been conducted as single factor studies, in which a single parameter is varied to assess impact on operating performance, which does not allow for determination of the interactions of different operating parameters and optimized operating conditions. In this work a multi-variable investigation of size exclusion protein refolding at high protein concentration using lysozyme as a model protein was performed, in order to quantify the interaction of factors and optimize performance. It was observed when l-arginine is used as an additive the refolding yield becomes independent of the protein concentration and refolding buffer pH, providing that a redox couple is used to assist the reformation of disulfide bridges. Furthermore, the pore accessibility for small molecules was reduced at the presence of this additive particularly at higher protein concentrations indicating slower removal of these molecules and a possible additional mechanism of aggregation prevention. Using the subsequent optimized refolding buffer, a refolding yield of more than 90% was obtained for up to 40mg/mL loading concentration of lysozyme which has only been reported for a urea gradient SEC (8-2M) with lower equilibration and elution flow rates due to high viscosity of buffer containing high concentrations of urea. PMID:25092593

  5. Block and random copolymers bearing cholic acid and oligo(ethylene glycol) pendant groups: aggregation, thermosensitivity, and drug loading.

    PubMed

    Shao, Yu; Jia, Yong-Guang; Shi, Changying; Luo, Juntao; Zhu, X X

    2014-05-12

    A series of block and random copolymers consisting of oligo(ethylene glycol) and cholic acid pendant groups were synthesized via ring-opening metathesis polymerization of their norbornene derivatives. These block and random copolymers were designed to have similar molecular weights and comonomer ratios; both types of copolymers showed thermosensitivity in aqueous solutions with similar cloud points. The copolymers self-assembled into micelles in water as shown by dynamic light scattering and transmission electron microscopy. The hydrodynamic diameter of the micelles formed by the block copolymer is much larger and exhibited a broad and gradual shrinkage from 20 to 54 °C below its cloud point, while the micelles formed by the random copolymers are smaller in size but exhibited some swelling in the same temperature range. Based on in vitro drug release studies, 78% and 24% paclitaxel (PTX) were released in 24 h from micelles self-assembled by the block and random copolymers, respectively. PTX-loaded micelles formed by the block and random copolymers exhibited apparent antitumor efficacy toward the ovarian cancer cells with a particularly low half-maximal inhibitory concentration (IC50) of 27.4 and 40.2 ng/mL, respectively. Cholic acid-based micelles show promise as a versatile and potent platform for cancer chemotherapy. PMID:24725005

  6. Block and Random Copolymers Bearing Cholic Acid and Oligo(ethylene glycol) Pendant Groups: Aggregation, Thermosensitivity, and Drug Loading

    PubMed Central

    2015-01-01

    A series of block and random copolymers consisting of oligo(ethylene glycol) and cholic acid pendant groups were synthesized via ring-opening metathesis polymerization of their norbornene derivatives. These block and random copolymers were designed to have similar molecular weights and comonomer ratios; both types of copolymers showed thermosensitivity in aqueous solutions with similar cloud points. The copolymers self-assembled into micelles in water as shown by dynamic light scattering and transmission electron microscopy. The hydrodynamic diameter of the micelles formed by the block copolymer is much larger and exhibited a broad and gradual shrinkage from 20 to 54 °C below its cloud point, while the micelles formed by the random copolymers are smaller in size but exhibited some swelling in the same temperature range. Based on in vitro drug release studies, 78% and 24% paclitaxel (PTX) were released in 24 h from micelles self-assembled by the block and random copolymers, respectively. PTX-loaded micelles formed by the block and random copolymers exhibited apparent antitumor efficacy toward the ovarian cancer cells with a particularly low half-maximal inhibitory concentration (IC50) of 27.4 and 40.2 ng/mL, respectively. Cholic acid-based micelles show promise as a versatile and potent platform for cancer chemotherapy. PMID:24725005

  7. Preparation and characterization of poly(lactic-co-glycolic acid) microspheres loaded with a labile antiparkinson prodrug.

    PubMed

    D'Aurizio, E; van Nostrum, C F; van Steenbergen, M J; Sozio, P; Siepmann, F; Siepmann, J; Hennink, W E; Di Stefano, A

    2011-05-16

    L-dopa-α-lipoic acid (LD-LA) is a new multifunctional prodrug for the treatment of Parkinson's disease. In human plasma, LD-LA catechol esters and amide bonds are chemically and enzymatically cleaved, respectively, resulting in a half-life time of about fifty minutes. In the present work, the unstable LD-LA was entrapped into biodegradable poly(lactic-co-glycolic acid) (PLGA) microspheres designed as depot systems to protect this prodrug against degradation and to obtain a sustained release of the intact compound. The microspheres were prepared by an oil-in-water emulsion/solvent evaporation technique and the effect of formulation and processing parameters (polymer concentration in the organic solvent, volumes ratio of the phases, rate of the organic solvent evaporation) on microspheres characteristics (size, loading, morphology, release) was investigated. Also emphasis was given on the stability of the drug before and after release as well as on the underlying mass transport mechanisms controlling LD-LA release. Interestingly, when encapsulated in appropriate conditions into PLGA microspheres, the labile prodrug was stabilized and released via Fickian diffusion up to more than one week. PMID:21356295

  8. [Concentrations and acidity contributions of acetate and formate in precipitation at 14 stations of China].

    PubMed

    He, Xiao-huan; Xu, Xiao-bin; Yu, Xiao-lan; Tang, Jie

    2010-04-01

    To investigate the concentrations of organic acids in precipitation in China and their contributions to the total acidity of precipitation, samples were taken at 14 stations of regional representativeness in 2007 and analyzed for acetate and formate using ion chromatography. In this paper, data of acetate and formate in precipitation at 14 stations are presented, wet depositions of these organic acids are calculated, and contributions of them to the total free acidity (TFA) of precipitation are estimated. Based on the measurements, the mean concentrations of formate at different stations were in the range of 0.96-3.43 micromol/L, and those of acetate in the range of 0-5.13 micromol/L, close to the levels at remote sites in other countries and at the lower ends of concentration ranges from previous measurements in China. Comparisons indicate that the concentrations of the organic acids at remote sites are lower than those at sites in the vicinity of urban areas. The annual wet depositions of formate and acetate were estimated to be in the ranges of 0.38-4.18 mmol/(m2 x a) and 0.06-5.87 mmol/(m2 x a), respectively, with larger depositions in southern China and smaller depositions in northern China. The relative contributions of the two organic acids to the TFA of precipitation were estimated to be in the range of 0.02%-51.6%, with an overall average of 2.95%. This suggests that although acid rain in China is mainly caused by emissions of sulfur and nitrogen oxides, organic acids can significantly contribute to the acidification of precipitation in some regions and during some periods, hence need to be included in observational studies of acid rain. PMID:20527162

  9. Comprehensive Profiling of Plasma Fatty Acid Concentrations in Young Healthy Canadian Adults

    PubMed Central

    Abdelmagid, Salma A.; Clarke, Shannon E.; Nielsen, Daiva E.; Badawi, Alaa; El-Sohemy, Ahmed; Mutch, David M.; Ma, David W. L.

    2015-01-01

    Circulating fatty acids (FA) are associated with a multitude of chronic diseases. However, a major gap in establishing such relationships is the lack of accepted fatty acid reference ranges representing healthy individuals. Data on validated FA reference ranges would provide a better understanding of study baseline measures and aid in the evaluation and interpretation of pharmaceutical or dietary interventions. Reference ranges for plasma FA levels have been reported in a few small studies and on a limited number of FA. Therefore, we determined the average and percentiles of a broad set of 61 FA (C14 - C24:1) from plasma total lipids from an ethnically diverse population of healthy young Canadian males and females (Total n = 826). Plasma concentrations of some of the major FA ranged from 0.3 to 4.1 mmol/L for palmitic acid, 0.1 to 1.0 mmol/L for stearic acid, 0.03 to 3.2 mmol/L for oleic acid, 0.2 to 5.0 mmol/L for linoleic acid (LA), 12.0 to 186.9 μmol/L for α-linolenic acid, and 7.2 to 237.5 μmol/L for docosahexaenoic acid (DHA). Males had significantly higher plasma concentrations of γ-linolenic acid (GLA) and n-3 docosapentaenoic acid and lower concentrations of palmitoleic acid, LA and DHA than females. Comparison of FA concentrations between Caucasians, East Asians and South Asians revealed that South Asians had significantly lower levels of palmitoleic acid (p < 0.01) and oleic acid (p = 0.01) while East Asians had lower levels of GLA (p = 0.02) and dihomo-γ-linolenic acid (p = 0.03). Overall, these data provide a comprehensive set of quantitative values that profiles a small cohort of Canadians which highlights the utility of establishing validated FA reference ranges that may be used to understand how deficient, suboptimal, or excess amounts of a given FA may be associated with chronic disease. PMID:25675440

  10. Herbicide concentrations in and loads transported by the Conestoga River and Pequea Creek, Lancaster County, Pennsylvania, 1992-95

    USGS Publications Warehouse

    Reed, Lloyd A.; Koerkle, Edward H.; Takita, Charles S.

    1997-01-01

    Water samples were collected from four streams in Lancaster County from 1992 through 1995 and analyzed for selected herbicides. Samples were collected from the Little Conestoga Creek near Churchtown, Mill Creek (a tributary to the Conestoga River) at Elshelman Mill Road near Lyndon, the Conestoga River at Conestoga, and Pequea Creek at Martic Forge. Most samples were collected from stormflow that occurred during the growing season. Samples were analyzed for alachlor, aldrin, atrazine, chlordane, cyanazine, dieldrin, malathion, metolachlor, propazine, simazine, and toxaphene. Most samples had detectable concentrations of alachlor, atrazine, metolachlor, and simazine, and the loads of these constituents that were transported during each of the 4 years were computed. Of the samples collected from each of the streams?Little Conestoga Creek, Mill Creek, Conestoga River, and Pequea Creek?10, 12, 15, and 18 percent, respectively, had atrazine concentrations greater than 3.0 micrograms per liter, the U.S. Environmental Protection Agency maximum contaminant level. Loads of atrazine, metolochlor, and simazine were greater than loads of any other herbicides. The largest loads were transported during 1994. Loads of atrazine transported by the four streams during periods of storm- flow from May to September 1994 totaled 3.46, 28.3, 263, and 46.8 pounds, respectively. The total loads of atrazine transported by the four streams?Little Conestoga Creek, Mill Creek, Conestoga River, and Pequea Creek?during calendar year 1994 were 6.48, 54.1, 498, and 102 pounds, respectively. A little less than half the atrazine load transported by each stream?45, 39, 42, and 42 percent, respectively?was transported during storms that occurred from May through September. Average annual yields of atrazine for the period 1992-95 were 0.59, 0.64, 0.68, and 0.51 pounds per square mile from the Little Conestoga Creek, Mill Creek, Conestoga River, and Pequea Creek, respectively. Average annual yields of

  11. CONCENTRATIONS AND LOADS OF NITRATE IN THE ATCHAFALAYA RIVER, LOUISIANA, USING CONTINUOUS MONITORING

    EPA Science Inventory

    Specific Results/Outcomes Expected: Deliverables of each Tasks include: Task 1. Several field studies by USGS personnel have shown that iono-selective nitrate probes currently marketed do not meet performance minimum criteria for accurately measuring nitrate concentrations. The...

  12. Body mass index, gestational weight gain and fatty acid concentrations during pregnancy: the Generation R Study.

    PubMed

    Vidakovic, Aleksandra Jelena; Jaddoe, Vincent W V; Gishti, Olta; Felix, Janine F; Williams, Michelle A; Hofman, Albert; Demmelmair, Hans; Koletzko, Berthold; Tiemeier, Henning; Gaillard, Romy

    2015-11-01

    Obesity during pregnancy may be correlated with an adverse nutritional status affecting pregnancy and offspring outcomes. We examined the associations of prepregnancy body mass index and gestational weight gain with plasma fatty acid concentrations in mid-pregnancy. This study was embedded in a population-based prospective cohort study among 5636 women. We obtained prepregnancy body mass index and maximum weight gain during pregnancy by questionnaires. We measured concentrations of saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), n-3 polyunsaturated fatty acid (n-3 PUFA) and n-6 polyunsaturated fatty acid (n-6 PUFA) at a median gestational age of 20.5 (95% range 17.1-24.9) weeks. We used multivariate linear regression models. As compared to normal weight women, obese women had higher total SFA concentrations [difference: 0.10 standard deviation (SD) (95% Confidence Interval (CI) 0, 0.19)] and lower total n-3 PUFA concentrations [difference: - 0.11 SD (95% CI - 0.20, - 0.02)]. As compared to women with sufficient gestational weight gain, those with excessive gestational weight gain had higher SFA concentrations [difference: 0.16 SD (95% CI 0.08, 0.25)], MUFA concentrations [difference: 0.16 SD (95% CI 0.08, 0.24)] and n-6 PUFA concentrations [difference: 0.12 SD (95% CI 0.04, 0.21)]. These results were not materially affected by adjustment for maternal characteristics. Our results suggest that obesity and excessive weight gain during pregnancy are associated with an adverse fatty acids profile. Further studies are needed to assess causality and direction of the observed associations. PMID:26666541

  13. Circadian changes in endogenous concentrations of indole-3-acetic acid, melatonin, serotonin, abscisic acid and jasmonic acid in Characeae (Chara australis Brown)

    PubMed Central

    Beilby, Mary J; Turi, Christina E; Baker, Teesha C; Tymm, Fiona JM; Murch, Susan J

    2015-01-01

    Giant-celled Characeae (Chara australis Brown), grown for 4 months on 12/12 hr day/night cycle and summer/autumn temperatures, exhibited distinct concentration maxima in auxin (indole-3-acetic acid; IAA), melatonin and serotonin about 4 hr after subjective daybreak. These concentration peaks persisted after 3 day pretreatment in continuous darkness: confirming a circadian rhythm, rather than a response to “light on.” The plants pretreated for 3 d in continuous light exhibited several large IAA concentration maxima throughout the 24 hr. The melatonin and serotonin concentrations decreased and were less synchronized with IAA. Chara plants grown on 9/15 hr day/night cycle for 4 months and winter/spring temperatures contained much smaller concentrations of IAA, melatonin and serotonin. The IAA concentration maxima were observed in subjective dark phase. Serotonin concentration peaks were weakly correlated with those of IAA. Melatonin concentration was low and mostly independent of circadian cycle. The “dark” IAA concentration peaks persisted in plants treated for 3 d in the dark. The plants pretreated for 3 d in the light again developed more IAA concentration peaks. In this case the concentration maxima in melatonin and serotonin became more synchronous with those in IAA. The abscisic acid (ABA) and jasmonic acid (JA) concentrations were also measured in plants on winter regime. The ABA concentration did not exhibit circadian pattern, while JA concentration peaks were out of phase with those of IAA. The data are discussed in terms of crosstalk between metabolic pathways. PMID:26382914

  14. Liver copper concentrations in cull cattle in the UK: are cattle being copper loaded?

    PubMed

    Kendall, N R; Holmes-Pavord, H R; Bone, P A; Ander, E L; Young, S D

    2015-11-14

    With the release of the Department for the Environment, Food and Rural Affairs/Advisory Committee on Animal Feed Guidance Note for Supplementing Copper to Bovines it was noted that the current copper status of the national herd was not known. Liver samples were recovered from 510 cull cattle at a single abattoir across a period of three days. The samples were wet-ashed and liver copper concentrations determined by inductively coupled plasma mass spectrometry analysis. Breed, age and previous location information were obtained from the British Cattle Movement Service. Dairy breeds had higher liver copper concentrations than beef breeds. Holstein-Friesian and 'other' dairy breeds had 38.3 per cent and 40 per cent of cattle above the Animal Health and Veterinary Laboratories Agency (AHVLA) reference range (8000 µmol/kg dry matter), respectively, whereas only 16.9 per cent of animals in the combined beef breeds exceeded this value. It was found that underlying topsoil copper concentration was not related to liver copper content and that age of the animal also had little effect on liver concentration. In conclusion, over 50 per cent of the liver samples tested had greater-than-normal concentrations of copper with almost 40 per cent of the female dairy cattle having liver copper concentrations above the AHVLA reference range, indicating that a significant proportion of the UK herd is at risk of chronic copper toxicity. PMID:26489996

  15. Liver copper concentrations in cull cattle in the UK: are cattle being copper loaded?

    PubMed Central

    Kendall, N. R.; Holmes-Pavord, H. R.; Bone, P. A.; Ander, E. L.; Young, S. D.

    2015-01-01

    With the release of the Department for the Environment, Food and Rural Affairs/Advisory Committee on Animal Feed Guidance Note for Supplementing Copper to Bovines it was noted that the current copper status of the national herd was not known. Liver samples were recovered from 510 cull cattle at a single abattoir across a period of three days. The samples were wet-ashed and liver copper concentrations determined by inductively coupled plasma mass spectrometry analysis. Breed, age and previous location information were obtained from the British Cattle Movement Service. Dairy breeds had higher liver copper concentrations than beef breeds. Holstein-Friesian and ‘other’ dairy breeds had 38.3 per cent and 40 per cent of cattle above the Animal Health and Veterinary Laboratories Agency (AHVLA) reference range (8000 µmol/kg dry matter), respectively, whereas only 16.9 per cent of animals in the combined beef breeds exceeded this value. It was found that underlying topsoil copper concentration was not related to liver copper content and that age of the animal also had little effect on liver concentration. In conclusion, over 50 per cent of the liver samples tested had greater-than-normal concentrations of copper with almost 40 per cent of the female dairy cattle having liver copper concentrations above the AHVLA reference range, indicating that a significant proportion of the UK herd is at risk of chronic copper toxicity. PMID:26489996

  16. Generation of doubly charged vortex beam by concentrated loading of glass disks along their diameter.

    PubMed

    Skab, Ihor; Vasylkiv, Yuriy; Krupych, Oleh; Savaryn, Viktoriya; Vlokh, Rostyslav

    2012-04-10

    We show that a system of glass disks compressed along their diameters enables one to induce a doubly charged vortex beam in the emergent light when the incident light is circularly polarized. Using such a disk system, one can control the efficiency of conversion of the spin angular momentum to the orbital angular momentum by a loading force. The consideration presented here can be extended for the case of crystalline materials with high optical damage thresholds in order to induce high-power vortex beams. PMID:22505151

  17. Alpha-lipoic acid loaded in chitosan conduit enhances sciatic nerve regeneration in rat

    PubMed Central

    Azizi, Saeed; Heshmatian, Behnam; Amini, Keyvan; Raisi, Abbas; Azimzadeh, Mohammad

    2015-01-01

    Objective(s): To investigate the effect of topical administration of alpha-lipoic acid into chitosan conduit on peripheral nerve regeneration using a rat sciatic nerve transection model. Materials and Methods: Forty five Wistar rats were divided into three experimental groups randomly. A 10-mm gap of sciatic nerve was bridged with a chitosan conduit following surgical preparation and anesthesia. In treatment group, the conduit was filled with 30 µl alpha-lipoic acid (10 mg/kg/bw).It was filled with 30 µl phosphate buffered saline solution in control group. In Sham group sciatic nerve was just exposed. Results: The recovery of nerve function was faster in treatment group than in control, at 4 and 8 weeks after surgery (P-value<0.05). Conduction velocity was better in treatment group than in control group at 4 and 12 weeks (P-value<0.05). Recovery index was higher in treatment group than the control group, 8 weeks after surgery (P-value <0.05). Greater nerve fiber diameter, axon diameter, and myelin sheath thickness were observed in treatment group compared to control group at 8 and 12 weeks after surgery (P-value<0.05). The immunoreactivity of regenerated axons and myelin sheath in treatment group were far more similar to sham group. Conclusion: Alpha-lipoic acid when loaded in a chitosan conduit could improve transected sciatic nerve regeneration in rat. PMID:25945234

  18. Effects of varying media, temperature, and growth rates on the intracellular concentrations of yeast amino acids.

    PubMed

    Martínez-Force, E; Benítez, T

    1995-01-01

    Variations of the yeast free amino acid pool under different culture conditions were studied in two Saccharomyces strains, the laboratory haploid strain S288C and the industrial fermentative yeast IFI256. The internal amino acid pool of both strains was measured when grown in laboratory (minimal and complete) versus semiindustrial (molasses with or without added biotin and/or diammonium phosphate) media, in fermentable (glucose, fructose, sucrose) versus respirable (glycerol) carbon sources, in different temperatures (22, 30, and 37 degrees C), pHs (2.0-4.75), and growth rates (0.018-0.24 h-1) in continuous culture, and at different phases of the growth curve in batch culture (lag, exponential, early and late stationary). Results indicated that environmental conditions, particularly the presence of amino acids in the media, enormously influenced the intracellular amino acid concentration. Higher values were detected in molasses than in laboratory media and in fermentable carbon sources (glucose, fructose, sucrose) than in glycerol. Variations in the amino acid pool along the growth curve were greater at 37 degrees C than at other temperatures; in all cases, the highest values were measured at the beginning of the exponential phase. In continuous culture and at different growth rates, intracellular free amino acid concentrations increased by 3-10-fold when the growth rate was lower than 0.05 h-1, representing 20-35% of the total (free plus protein) amino acid content and indicating that amino acid yield was a partly growth-linked parameter. PMID:7654310

  19. Pyrethroid insecticide concentrations and toxicity in streambed sediments and loads in surface waters of the San Joaquin Valley, California, USA

    USGS Publications Warehouse

    Domagalski, J.L.; Weston, D.P.; Zhang, M.; Hladik, M.

    2010-01-01

    Pyrethroid insecticide use in California, USA, is growing, and there is a need to understand the fate of these compounds in the environment. Concentrations and toxicity were assessed in streambed sediment of the San Joaquin Valley of California, one of the most productive agricultural regions of the United States. Concentrations were also measured in the suspended sediment associated with irrigation or storm-water runoff, and mass loads during storms were calculated. Western valley streambed sediments were frequently toxic to the amphipod, Hyalella azteca, with most of the toxicity attributable to bifenthrin and cyhalothrin. Up to 100% mortality was observed in some locations with concentrations of some pyrethroids up to 20 ng/g. The western San Joaquin Valley streams are mostly small watersheds with clay soils, and sediment-laden irrigation runoff transports pyrethroid insecticides throughout the growing season. In contrast, eastern tributaries and the San Joaquin River had low bed sediment concentrations (<1 ng/g) and little or no toxicity because of the preponderance of sandy soils and sediments. Bifenthrin, cyhalothrin, and permethrin were the most frequently detected pyrethroids in irrigation and storm water runoff. Esfenvalerate, fenpropathrin, and resmethrin were also detected. All sampled streams contributed to the insecticide load of the San Joaquin River during storms, but some compounds detected in the smaller creeks were not detected in the San Joaquin River. The two smallest streams, Ingram and Hospital Creeks, which had high sediment toxicity during the irrigation season, accounted for less than 5% of the total discharge of the San Joaquin River during storm conditions, and as a result their contribution to the pyrethroid mass load of the larger river was minimal. ?? 2010 SETAC.

  20. INTERNATIONAL STUDIES OF ENHANCED WASTE LOADING AND IMPROVED MELT RATE FOR HIGH ALUMINA CONCENTRATION NUCLEAR WASTE GLASSES

    SciTech Connect

    Fox, K; David Peeler, D; James Marra, J

    2008-09-11

    The goal of this study was to determine the impacts of glass compositions with high aluminum concentrations on melter performance, crystallization and chemical durability for Savannah River Site (SRS) and Hanford waste streams. Glass compositions for Hanford targeted both high aluminum concentrations in waste sludge and a high waste loading in the glass. Compositions for SRS targeted Sludge Batch 5, the next sludge batch to be processed in the Defense Waste Processing Facility (DWPF), which also has a relatively high aluminum concentration. Three frits were selected for combination with the SRS waste to evaluate their impact on melt rate. The glasses were melted in two small-scale test melters at the V. G. Khlopin Radium Institute. The results showed varying degrees of spinel formation in each of the glasses. Some improvements in melt rate were made by tailoring the frit composition for the SRS feeds. All of the Hanford and SRS compositions had acceptable chemical durability.

  1. Sex Differences in Long Chain Fatty Acid Utilization and Fatty Acid Binding Protein Concentration in Rat Liver

    PubMed Central

    Ockner, Robert K.; Burnett, David A.; Lysenko, Nina; Manning, Joan A.

    1979-01-01

    Female sex and estrogen administration are associated with increased hepatic production of triglyceride-rich lipoproteins; the basis for this has not been fully elucidated. Inasmuch as hepatic lipoprotein production is also influenced by FFA availability and triglyceride biosynthesis, we investigated sex differences in FFA utilization in rat hepatocyte suspensions and in the components of the triglyceride biosynthetic pathway. Isolated adult rat hepatocyte suspensions were incubated with albumin-bound [14C]oleate for up to 15 min. At physiological and low oleate concentrations, cells from females incorporated significantly more 14C into glycerolipids, especially triglycerides, and into oxidation products than did male cells, per milligram cell protein. At 0.44 mM oleate, incorporation into triglycerides in female cells was approximately twice that in male cells. Comparable sex differences were observed in cells from fasted animals and when [14C]-glycerol incorporation was measured. At higher oleate concentrations, i.e., fatty acid:albumin mole ratios in excess of 2:1, these sex differences were no longer demonstrable, suggesting that maximal rates of fatty acid esterification and oxidation were similar in female and male cells. In female and male hepatic microsomes, specific activities of long chain acyl coenzyme A synthetase, phosphatidate phosphohydrolase, and diglyceride acyltransferase were similar, but glycerol-3-phosphate acyltransferase activity was slightly greater in females at certain substrate concentrations. Microsomal incorporation of [14C]oleate into total glycerolipids was not significantly greater in females. In further contrast to intact cells, microsomal incorporation of [14C]oleate into triglycerides, although significantly greater in female microsomes, accounted for only a small fraction of the fatty acid esterified. The binding affinity and stoichiometry of partially purified female hepatic fatty acid binding protein (FABP) were similar to

  2. Neuroprotective effect of estradiol-loaded poly(lactic-co-glycolic acid) nanoparticles on glutamate-induced excitotoxic neuronal death.

    PubMed

    Kim, Jeong Hwan; Kim, Gyu Hyun; Jeong, Ji Heun; Lee, In Ho; Lee, Ye Ji; Lee, Nam Seob; Jeong, Young Gil; Lee, Je Hun; Yu, Kwang Sik; Lee, Shin Hye; Hong, Seul Ki; Kang, Seong Hee; Kang, Bo Sun; Kim, Do Kyung; Han, Seung Yun

    2014-11-01

    Different concentrations of estradiol (E2)-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (E2-PLGA-NPs) were synthesized using the emulsion-diffusion method. Transmission electron microscopy results showed that the average particle size of E2-PLGA-NPs was 98 ± 1.9 nm when stabilized with polyvinyl alcohol and 103 ± 4.9 nm when stabilized with Tween-80. Fourier transform-infrared spectroscopy with diamond attenuated total reflectance was used to identify the presence or absence of E2 molecules in PLGA nanocapsules. Cell proliferation was assessed after treating SH-SY5Y neuroblastoma cells with 1 nM-1 μM of E2 and E2-PLGA-NPs. The neuroprotective efficacy against glutamate-induced excitotoxicity was also investigated in SH-SY5Y neuroblastoma cells. Neuroprotection was greater in E2-PLGA-NP-treated cells than in cells treated with the same concentration of E2. Furthermore, E2- and E2-PLGA-NP-treated cells expressed more p-ERK1/2 and p-CREB than cells treated with glutamate only. Moreover, the expression of p-ERK1/2 was higher than that of p-CREB. In this study, p-ERK1/2 had a greater influence on the neuroprotective effect of E2 and E2-PLGA-NPs than p-CREB. PMID:25958534

  3. Effects of Dietary Acid Load on Exercise Metabolism and Anaerobic Exercise Performance

    PubMed Central

    Caciano, Susan L.; Inman, Cynthia L.; Gockel-Blessing, Elizabeth E.; Weiss, Edward P.

    2015-01-01

    Dietary acid load, quantified as the potential renal acid load (PRAL) of the diet, affects systemic pH and acid-base regulation. In a previous cross-sectional study, we reported that a low dietary PRAL (i.e. alkaline promoting diet) is associated with higher respiratory exchange ratio (RER) values during maximal exercise. The purpose of the present study was to confirm the previous findings with a short-term dietary intervention study. Additionally, we sought to determine if changes in PRAL affects submaximal exercise RER (as a reflection of substrate utilization) and anaerobic exercise performance. Subjects underwent a graded treadmill exercise test (GXT) to exhaustion and an anaerobic exercise performance test on two occasions, once after following a low-PRAL diet and on a separate occasion, after a high-PRAL diet. The diets were continued as long as needed to achieve an alkaline or acid fasted morning urine pH, respectively, with all being 4-9 days in duration. RER was measured during the GXT with indirect calorimetry. The anaerobic performance test was a running time-to-exhaustion test lasting 1-4 min. Maximal exercise RER was lower in the low-PRAL trial compared to the high-PRAL trial (1.10 ± 0.02 vs. 1.20 ± 0.05, p = 0.037). The low-PRAL diet also resulted in a 21% greater time to exhaustion during anaerobic exercise (2.56 ± 0.36 vs. 2.11 ± 0.31 sec, p = 0.044) and a strong tendency for lower RER values during submaximal exercise at 70% VO2max (0.88 ± 0.02 vs. 0.96 ± 0.04, p = 0.060). Contrary to our expectations, a short-term low-PRAL (alkaline promoting) diet resulted in lower RER values during maximal-intensity exercise. However, the low-PRAL diet also increased anaerobic exercise time to exhaustion and appears to have shifted submaximal exercise substrate utilization to favor lipid oxidation and spare carbohydrate, both of which would be considered favorable effects in the context of exercise performance. Key points Short-term (4-9 days) changes in

  4. [Preparation of tranexamic acid-loaded porous starch and evaluation of its hemostatic ability].

    PubMed

    Xi, Chao-Yun; Zhuang, Yuan; Chen, Lin Feng; Liu, Ya-Qian; Wang, Shu-Fang; Wang, De-Qing

    2014-04-01

    This study was aimed to develop a new generation of ideal hemostatic powder which can be safely, effectively and easily used mainly to first aid anterior to hospital by the synergistic effect of physical and chemical hemostatic mechanisms. The tranexamic acid(TA)-loaded porous starch(PS) (TAPS) was prepared by using PS as carrier and TA as loaded drug component. The absorption property of TAPS was evaluated by water absorption; the hemostatic ability of TAPS was evaluated by test in vitro and in vivo, the blood coagulation time of TAPS was detected by using Lee-white method. The experiment was divided into 3 groups: blank control group, Yunnan Baiyao group and TAPS group, each group with 10 blood samples in vitro test; the 27 SD rats were used to test in vivo, and randomly were divided into 3 groups: PS,Yunnan Baiyao and TAPS, each group consisted of 9 rats for establishing the animal model of liver trauma and detecting the complete hemostasis time. The results showed that the water absorption of PS did not be affected by TA when dose of TA loaded in PS was <0.02 g/g PS. There was no statistic difference in blood coagulation time between TAPS and PS groups(P > 0.05). The complete hemostatic time of TAPS for trauma of left lobe liver was 236.67 ± 55.00 seconds, which was shorter than that of Yunnan Baiyao (340.00 ± 73.48 seconds) and PS (396.67 ± 68.37 seconds) (P < 0.05 and P < 0.01, respectively). It is concluded that PS can load TA and play the hemostatic effect through releasing TA; the TA loading <0.02 g/g PS did not affect the water absorption and pro-coagulation properties. The TA can enhance the hemostatic efficacy of PS, the hemostatic property of TAPS is derived from synergism of physical and chemical hemostatic mechanisms. PMID:24763031

  5. Metal loading effect on rare earth element binding to humic acid: Experimental and modelling evidence

    NASA Astrophysics Data System (ADS)

    Marsac, Rémi; Davranche, Mélanie; Gruau, Gérard; Dia, Aline

    2010-03-01

    The effect of metal loading on the binding of rare earth elements (REE) to humic acid (HA) was studied by combining ultrafiltration and Inductively Coupled Plasma Mass Spectrometry techniques. REE-HA complexation experiments were performed at pH 3 for REE/C molar ratios ranging from ca 4 × 10 -4 to 2.7 × 10 -2. Results show that the relative amount of REE bound to HA strongly increases with decreasing REE/C. A middle-REE (MREE) downward concavity is shown by patterns at high metal loading, whereas patterns at low metal loading display a regular increase from La to Lu. Humic Ion Model VI modelling are close to the experimental data variations, provided that (i) the ΔLK 2 parameter (i.e. the Model VI parameter taken into account the presence of strong but low density binding sites) is allowed to increase regularly from La to Lu (from 1.1 to 2.1) and (ii) the published log KMA values (i.e. the REE-HA binding constants specific to Model VI) are slightly modified, in particular with respect to heavy REE. Modelling approach provided evidence that logKdREE patterns with varying REE/C likely arises because REE binding to HA occurs through two types of binding sites in different density: (i) a few strong sites that preferentially complex the heavy REE and thus control the logKdREE atterns at low REE/C; (ii) a larger amount of weaker binding sites that preferentially complex the middle-REE and thus control the logKdREE pattern at high REE/C. Hence, metal loading exerts a major effect on HA-mediated REE binding, which could explain the diversity of published conditional constants for REE binding with HA. A literature survey suggests that the few strong sites activated at low REE/C could be multidentate carboxylic sites, or perhaps N-, or P-functional groups. Finally, an examination of the literature field data proposed that the described loading effect could account for much of the variation in REE patterns observed in natural organic-rich waters (DOC > 5 mg L -1 and 4

  6. How biogenic terpenes govern the correlation between sulfuric acid concentrations and new particle formation

    NASA Astrophysics Data System (ADS)

    Bonn, B.; Kulmala, M.; Riipinen, I.; Sihto, S.-L.; Ruuskanen, T. M.

    2008-06-01

    New particle formation has been observed to take place all around the world. However, because of the inability to determine the chemical composition of the smallest clusters or particles, indirect tools such as the correlation between nucleation rate and measured sulfuric acid concentrations have been used to infer the nucleation mechanism. In this study we describe the observed correlation with gaseous sulfuric acid concentrations by interactions of sesquiterpene oxidation products with sulfuric acid. Two formation pathways of nucleation initiating molecules are considered. The interaction of sulfuric acid with organic sulfates, which are formed from stabilized Criegee intermediates (sCIs, formed from sesquiterpenes), can be used to explain the observed squared relationship between particle formation rate and ambient sulfuric acid concentrations. The corresponding linear dependence is explained with the participation of secondary ozonides, which are formed from sCIs and aldehydes. Both pathways are negatively affected by increasing water vapor concentration as observed in recent studies. In order to check the assumptions made we apply the derived nucleation coefficients to measurements of the BACCI/QUEST IV campaign made during spring 2005 in Hyytiälä, Finland. A reasonable agreement between the measurement data and the predicted nucleation rates is found, giving support for the presented nucleation description.

  7. Concentration methods for high-resolution THz spectroscopy of nucleic-acid biomolecules and crystals

    NASA Astrophysics Data System (ADS)

    Brown, E. R.; Zhang, W.; Mendoza, E. A.; Kuznetsova, Y.; Brueck, S. R. J.; Rahman, M.; Norton, M. L.

    2012-03-01

    Biomolecules can exhibit low-lying vibrational modes in the THz region which are detectable in transmission given a strong molecular dipole moment and optical depth, and a spectrometer of adequate sensitivity. The nucleic acids are particularly interesting because of applications such as label-free gene assay, bio-agent detection, etc. However for nucleic acids, sample preparation and THz coupling are of paramount importance because of the strong absorption by liquid water and the small concentration of molecules present in physiological solutions. Concentration methods become necessary to make the THz vibrational modes detectable, either by concentrating the nucleic-acid sample itself in a small volume but large area, or by concentrating the THz radiation down to the volume of the sample. This paper summarizes one type of the first method: nanofluidic channel arrays for biological nucleic acids; and two types of the second method: (1) a circular-waveguide pinhole, and (2) a circular-waveguide, conical-horn coupling structure, both for DNA crystals. The first method has been demonstrated on a very short artificial nucleic acid [small-interfering (si) RNA (17-to-25 bp)] and a much longer, biological molecule [Lambda-phage DNA (48.5 kbp)]. The second method has been demonstrated on small (~100 micron) single crystals of DNA grown by the sitting-drop method.

  8. Perfluoroalkyl Acid Concentrations in Blood Samples Subjected to Transportation and Processing Delay

    PubMed Central

    Bach, Cathrine Carlsen; Henriksen, Tine Brink; Bossi, Rossana; Bech, Bodil Hammer; Fuglsang, Jens; Olsen, Jørn; Nohr, Ellen Aagaard

    2015-01-01

    Background In studies of perfluoroalkyl acids, the validity and comparability of measured concentrations may be affected by differences in the handling of biospecimens. We aimed to investigate whether measured plasma levels of perfluoroalkyl acids differed between blood samples subjected to delay and transportation prior to processing and samples with immediate processing and freezing. Methods Pregnant women recruited at Aarhus University Hospital, Denmark, (n = 88) provided paired blood samples. For each pair of samples, one was immediately processed and plasma was frozen, and the other was delayed and transported as whole blood before processing and freezing of plasma (similar to the Danish National Birth Cohort). We measured 12 perfluoroalkyl acids and present results for compounds with more than 50% of samples above the lower limit of quantification. Results For samples taken in the winter, relative differences between the paired samples ranged between -77 and +38% for individual perfluoroalkyl acids. In most cases concentrations were lower in the delayed and transported samples, e.g. the relative difference was -29% (95% confidence interval -30; -27) for perfluorooctane sulfonate. For perfluorooctanoate there was no difference between the two setups [corresponding estimate 1% (0, 3)]. Differences were negligible in the summer for all compounds. Conclusions Transport of blood samples and processing delay, similar to conditions applied in some large, population-based studies, may affect measured perfluoroalkyl acid concentrations, mainly when outdoor temperatures are low. Attention to processing conditions is needed in studies of perfluoroalkyl acid exposure in humans. PMID:26356420

  9. Dietary acid load and chronic kidney disease among adults in the United States

    PubMed Central

    2014-01-01

    Background Diet can markedly affect acid-base status and it significantly influences chronic kidney disease (CKD) and its progression. The relationship of dietary acid load (DAL) and CKD has not been assessed on a population level. We examined the association of estimated net acid excretion (NAEes) with CKD; and socio-demographic and clinical correlates of NAEes. Methods Among 12,293 U.S. adult participants aged >20 years in the National Health and Nutrition Examination Survey 1999–2004, we assessed dietary acid by estimating NAEes from nutrient intake and body surface area; kidney damage by albuminuria; and kidney dysfunction by eGFR < 60 ml/min/1.73m2 using the MDRD equation. We tested the association of NAEes with participant characteristics using median regression; while for albuminuria, eGFR, and stages of CKD we used logistic regression. Results Median regression results (β per quintile) indicated that adults aged 40–60 years (β [95% CI] = 3.1 [0.3–5.8]), poverty (β [95% CI] = 7.1 [4.01–10.22]), black race (β [95% CI] = 13.8 [10.8–16.8]), and male sex (β [95% CI] = 3.0 [0.7- 5.2]) were significantly associated with an increasing level of NAEes. Higher levels of NAEes compared with lower levels were associated with greater odds of albuminuria (OR [95% CI] = 1.57 [1.20–2.05]). We observed a trend toward greater NAEes being associated with higher risk of low eGFR, which persisted after adjustment for confounders. Conclusion Higher NAEes is associated with albuminuria and low eGFR, and socio-demographic risk factors for CKD are associated with higher levels of NAEes. DAL may be an important target for future interventions in populations at high risk for CKD. PMID:25151260

  10. The electro-responsive drug delivery from salicylic acid -loaded polyacrylamide hydrogels

    NASA Astrophysics Data System (ADS)

    Niamlang, Sumonman; Sirivat, Anuvat

    2007-03-01

    The release mechanisms and the diffusion coefficients of salicylic acid -loaded polyacrylamide hydrogels were investigated experimentally by using a modified Franz-Diffusion cell at the temperature of 37 ^0C to determine the effects of crosslinking ratio and electric field strength. The fabricated hydrogels retain their physical shapes and sizes during the experiments along with data reproducibility. A significant amount of salicylic is released within 48 hours from the hydrogels of various crosslinking ratios with and without electric field; the release profile follows the Q vs. t^1/2 relationship. Diffusion coefficients, as determined from the Higuchi equation, increase with electric field strength and reach maximum values at electric field strength of 0.1 V due to the electrophoresis of salicylic drug and become saturated at electric field strengths between 0.5 -- 10 V.

  11. Fabrication of poly hydroxybutyrate-polyethylene glycol-folic acid nanoparticles loaded by paclitaxel.

    PubMed

    Rezaei, Fatemeh; Rafienia, Mohammad; Keshvari, Hamid; Sattary, Mansooreh; Naeimi, Mitra; Keyvani, Hossein

    2016-01-01

    In this study drug (paclitaxel)-loaded nanoparticles of poly hydroxybutyrate-polyethylene glycol-folic acid (PHB-PEG-FOL) were prepared by using an oil-in-water (O/W) emulsion-solvent evaporation method. The functionalization and conjugation steps in the chemical synthesis were confirmed using Fourier transform infrared (FTIR) and nuclear magnetic resonance tests ((1)H NMR). Morphology of nanoparticles was evaluated by scanning electron microscopy (SEM). Nanoparticles were characterized by particle size analyzer. Between two samples containing drug, the lower doses showed more homogeneous distribution, and the lowest aggregation. The drug release profiles showed a two-phase release including initial rapid release and a continuous release. MG63 cells were used to evaluate cytotoxicity. The cytotoxicity of PHB-PEG-FOL nanoparticles with drug against cancer cells was much higher and longer than free drug sample. These nanoparticles were successfully synthesized as a novel system for targeted drug delivery against cancer cells. PMID:26234551

  12. A Novel Method for the Preparation of Retinoic Acid-Loaded Nanoparticles

    PubMed Central

    Errico, Cesare; Gazzarri, Matteo; Chiellini, Federica

    2009-01-01

    The goal of present work was to investigate the use of bioerodible polymeric nanoparticles as carriers of retinoic acid (RA), which is known to induce differentiation of several cell lines into neurons. A novel method, named “Colloidal-Coating”, has been developed for the preparation of nanoparticles based on a copolymer of maleic anhydride and butyl vinyl ether (VAM41) loaded with RA. Nanoparticles with an average diameter size of 70 nm and good morphology were prepared. The activity of the encapsulated RA was evaluated on SK-N-SH human neuroblastoma cells, which are known to undergo inhibition of proliferation and neuronal differentiation upon treatment with RA. The activity of RA was not affected by the encapsulation and purification processes. PMID:19564952

  13. Tertiary treatment of textile wastewater with combined media biological aerated filter (CMBAF) at different hydraulic loadings and dissolved oxygen concentrations.

    PubMed

    Liu, Fang; Zhao, Chao-Cheng; Zhao, Dong-Feng; Liu, Guo-Hua

    2008-12-15

    An up-flow biological aerated filter packed with two layers media was employed for tertiary treatment of textile wastewater secondary effluent. Under steady state conditions, good performance of the reactor was achieved and the average COD, NH(4)(+)-N and total nitrogen (TN) in the effluent were 31, 2 and 8mg/L, respectively. For a fixed dissolved oxygen (DO) concentration, an increase of hydraulic loading resulted in a decrease in substrate removal. With the increase of hydraulic loadings from 0.13 to 0.78m(3)/(m(2)h), the removal efficiencies of COD, NH(4)(+)-N and TN all decreased, which dropped from 52 to 38%, from 90 to 68% and from 45 to 33%, respectively. In addition, the results also confirmed that the increase of COD and NH(4)(+)-N removal efficiencies resulted from the increase of DO concentrations, but this variation trend was not observed for TN removal. With the increase of DO concentrations from 2.4 to 6.1mg/L, the removal efficiencies of COD and NH(4)(+)-N were 39-53% and 64-88%, whenas TN removal efficiencies increased from 39 to 42% and then dropped to 35%. PMID:18396373

  14. Characterization of naproxen-loaded solid SMEDDSs prepared by spray drying: the effect of the polysaccharide carrier and naproxen concentration.

    PubMed

    Čerpnjak, Katja; Zvonar, Alenka; Vrečer, Franc; Gašperlin, Mirjana

    2015-05-15

    The purpose of this study was to prepare solid SMEDDS (sSMEDDS) particles produced by spray-drying using maltodextrin (MD), hypromellose (HPMC), and a combination of the two as a solid carrier. Naproxen (NPX) as the model drug was dissolved (at 6% concentration) or partially suspended (at 18% concentration) in a liquid SMEDDS composed of Miglyol(®) 812, Peceol™, Gelucire(®) 44/14, and Solutol(®) HS 15. Among the sSMEDDSs tested, the MD-based sSMEDDSs (with a granular, smooth-surfaced, microspherical appearance) preserved the self-microemulsifying properties of liquid SMEDDSs and exhibited dissolution profiles similar to those of liquid SMEDDSs, irrespective of the concentration of NPX. In contrast, HPMC-based sSMEDDSs (irregular-shaped microparticles) exhibited slightly prolonged release times due to the polymeric nature of the carrier. Differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), and Raman mapping analysis confirmed molecularly dissolved NPX (at 6% of drug loading), whereas at 18% NPX loading drug is partially molecularly dissolved and partially in the crystalline state. PMID:25772420

  15. Effect of temperature and concentration on thermal conductivity and viscosity of ferrofluid loaded with carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Shahsavar, A.; Saghafian, M.; Salimpour, M. R.; Shafii, M. B.

    2015-12-01

    The aim of this paper is to investigate the thermal conductivity and viscosity of a hybrid nanofluid containing tetramethylammonium hydroxide (TMAH) coated Fe3O4 nanoparticles and gum arabic (GA) coated carbon nanotubes (CNTs), experimentally. The magnetic nanoparticles and CNTs are physically attached as the result of interaction between the TMAH and GA molecules. The morphology and structure of the samples are characterized with X-ray diffraction (XRD) and transmission electron microscopy (TEM). The experiments are carried out in the magnetic nanoparticles volume concentration range of 0.1-0.9 %, CNT volume concentration range of 0.05-1.35 % and the temperature range of 25-55 °C. The viscosity of the hybrid nanofluid increases with the increase of volume concentration, while it decreases with the increase of temperature. Besides, results show that hybrid nanofluid behaves as a shear thinning fluid. Furthermore, it is observed that the thermal conductivity of the hybrid nanofluid enhances with temperature and volume concentration.

  16. Metal loading assessment of a small mountainous sub-basin characterized by acid drainage -- Prospect Gulch, upper Animas River watershed, Colorado

    USGS Publications Warehouse

    Wirt, Laurie; Leib, Kenneth J.; Melick, Roger; Bove, Dana J.

    2001-01-01

    strongly affected by natural acidity from pyrite weathering. Metal content in the water column is a composite of multiple sources affected by hydrologic, geologic, climatic, and anthropogenic conditions. Identifying sources of metals from various drainage areas was determined using a tracer injection approach and synoptic sampling during low flow conditions on September 29, 1999 to determine loads. The tracer data was interpreted in conjunction with detailed geologic mapping, topographic profiling, geochemical characterization, and the occurrence and distribution of trace metals to identify sources of ground-water inflows. For this highly mineralized sub-basin, we demonstrate that SO4, Al, and Fe load contributions from drainage areas that have experienced historical mining?although substantial?are relatively insignificant in comparison with SO4, Al, and Fe loads from areas experiencing natural weathering of highlyaltered, pyritic rocks. Regional weathering of acid-sulfate mineral assemblages produces moderately low pH waters elevated in SO4, Al, and Fe; but generally lacking in Cu, Cd, Ni, and Pb. Samples impacted by mining are also characterized by low pH and large concentrations of SO4, Al, and Fe; but contained elevated dissolved metals from ore-bearing vein minerals such as Cu, Zn, Cd, Ni, and Pb. Occurrences of dissolved trace metals were helpful in identifying ground-water sources and flow paths. For example, cadmium was greatest in inflows associated with drainage from inactive mine sites and absent in inflows that were unaffected by past mining activities and thus served as an important indicator of mining contamination for this environmental setting. The most heavily mine-impacted reach (PG153 to PG800), contributed 8% of the discharge, and 11%, 9%, and 12% of the total SO4, Al, and Fe loads in Prospect Gulch. The same reach yielded 59% and 37% of the total Cu and Zn loads for the subbasin. In contrast, the naturally acidic inflows from the Red Chemotroph

  17. [Acid-soluble collagen in the skin of rats who received a tryptophan load and were kept on a protein-free diet].

    PubMed

    Pechenova, T N; Gulyĭ, M F; Volodina, T T; Solodova, E V; Popova, N N

    1983-01-01

    Crystalline preparations of acid-soluble collagen of rat skin in norm and with tryptophan load against a background of the protein-free diet were fractionated by differential salting out using NaCl in concentrations corresponding to precipitation zones of collagen 1,3 and 4. Amino acid composition, electrophoretic mobility in polyacrylamide gel, profiles of elution from CM-cellulose, content of the carbohydrate component and--S--S-bonds were studied in proteins of the mentioned fractions and in the precipitate insoluble after the pepsin action. Essential differences as compared to the normal level in the amino acid composition and elution profiles were detected in the fraction corresponding to collagen I. Quantitative changes in the carbohydrate component and--S--S-bonds occur due to the fraction inaccessible to the persin action. PMID:6829075

  18. Liraglutide-loaded poly(lactic-co-glycolic acid) microspheres: Preparation and in vivo evaluation.

    PubMed

    Wu, Junzi; Williams, Gareth R; Branford-White, Christopher; Li, Heyu; Li, Yan; Zhu, Li-Min

    2016-09-20

    In this work, we sought to generate sustained-release injectable microspheres loaded with the GLP-1 analogue liraglutide. Using water-in-oil-in-water double emulsion methods, poly(lactic-co-glycolic acid) (PLGA) microspheres loaded with liraglutide were prepared. The microspheres gave sustained drug release over 30days, with cumulative release of up to 90% reached in vitro. The microspheres were further studied in a rat model of diabetes, and their performance compared with a group given daily liraglutide injections. Reduced blood sugar levels were seen in the microsphere treatment groups, with the results being similar to those obtained with conventional injections between 10 and 25days after the commencement of treatment. After 5 and 30days of treatment, the microspheres seem a little slower to act than the injections. The pathology of the rats' spleen, heart, kidney and lungs was probed after the 30-day treatment period, and the results indicated that the microspheres were safe and had beneficial effects on the liver, reducing the occurrence of fatty deposits seen in untreated diabetic rats. Moreover, in terms of liver, renal and cardiac functions, and blood lipid and antioxidant levels, the microspheres were as effective as the injections. The expression of several proteases linked to the metabolism of aliphatic acids and homocysteine was promoted by the microsphere formulations. Inflammatory markers in the microsphere treatment groups were somewhat higher than the injection group, however. The liraglutide/PLGA microspheres prepared in this work are overall shown to be efficacious in a rat model of diabetes, and we thus believe they have strong potential for clinical use. PMID:27343696

  19. Poly(lactic-co-glycolic) Acid-Chitosan Dual Loaded Nanoparticles for Antiretroviral Nanoformulations.

    PubMed

    Makita-Chingombe, Faithful; Kutscher, Hilliard L; DiTursi, Sara L; Morse, Gene D; Maponga, Charles C

    2016-01-01

    Poly(lactic-co-glycolic acid) (PLGA) chitosan (CS) coated nanoparticles (NPs) were loaded with two antiretrovirals (ARVs) either lamivudine (LMV) which is hydrophilic or nevirapine (NVP) which is hydrophobic or both LMV and NVP. These ARVs are of importance in resource-limited settings, where they are commonly used in human immunodeficiency virus (HIV-1) treatment due to affordability and accessibility. NPs prepared by a water-oil-water emulsion and reduced pressure solvent evaporation technique were determined to have a positive zeta potential, a capsule-like morphology, and an average hydrodynamic diameter of 240 nm. Entrapment of NVP as a single ARV had a notable increase in NP size compared to LMV alone or in combination with LMV. NPs stored at room temperature in distilled water maintained size, polydispersity (PDI), and zeta potential for one year. No changes in size, PDI, and zeta potential were observed for NPs in 10% sucrose in lyophilized or nonlyophilized states stored at 4°C and -20°C, respectively. Freezing NPs in the absence of sucrose increased NP size. Drug loading, encapsulation efficiency, and kinetic release profiles were quantified by high performance liquid chromatography (HPLC). Our novel nanoformulations have the potential to improve patient outcomes and expand drug access in resource-limited countries for the treatment of HIV-1. PMID:27190651

  20. Poly(lactic-co-glycolic) Acid-Chitosan Dual Loaded Nanoparticles for Antiretroviral Nanoformulations

    PubMed Central

    Makita-Chingombe, Faithful; Kutscher, Hilliard L.; DiTursi, Sara L.; Morse, Gene D.; Maponga, Charles C.

    2016-01-01

    Poly(lactic-co-glycolic acid) (PLGA) chitosan (CS) coated nanoparticles (NPs) were loaded with two antiretrovirals (ARVs) either lamivudine (LMV) which is hydrophilic or nevirapine (NVP) which is hydrophobic or both LMV and NVP. These ARVs are of importance in resource-limited settings, where they are commonly used in human immunodeficiency virus (HIV-1) treatment due to affordability and accessibility. NPs prepared by a water-oil-water emulsion and reduced pressure solvent evaporation technique were determined to have a positive zeta potential, a capsule-like morphology, and an average hydrodynamic diameter of 240 nm. Entrapment of NVP as a single ARV had a notable increase in NP size compared to LMV alone or in combination with LMV. NPs stored at room temperature in distilled water maintained size, polydispersity (PDI), and zeta potential for one year. No changes in size, PDI, and zeta potential were observed for NPs in 10% sucrose in lyophilized or nonlyophilized states stored at 4°C and −20°C, respectively. Freezing NPs in the absence of sucrose increased NP size. Drug loading, encapsulation efficiency, and kinetic release profiles were quantified by high performance liquid chromatography (HPLC). Our novel nanoformulations have the potential to improve patient outcomes and expand drug access in resource-limited countries for the treatment of HIV-1. PMID:27190651

  1. Determination of cytoplasmic calcium concentration in Dryopteris spores: a developmentally non-disruptive technique for loading of the calcium indicator fura-2

    NASA Technical Reports Server (NTRS)

    Scheuerlein, R.; Schmidt, K.; Poenie, M.; Roux, S. J.

    1991-01-01

    Germination of Dryopteris spores is mediated by the physiologically active, far-red-absorbing form of phytochrome, Pfr, and external Ca2+ is necessary for the transduction of the light signal. Because knowledge about the cytoplasmic calcium ion concentration, [Ca2+]i, is of great importance for understanding the role of calcium during signal transduction, this value was measured using fura-2 in fern spores undergoing the normal developmental progression into germination. Fura-2 was loaded into the spores by electroporation, which does not disrupt the normal process of germination. The intensity of the fluorescence emission of the loaded fura-2 was analysed by a microspectrophotometric assay of single spores, and successful loading could be obtained by the application of ten electrical pulses (field strength 7.5 kV cm-1, half-life (time constant) 230 microseconds). Fura-2 was alternately excited by light of wavelengths 355 and 385 nm through an inverted fluorescence microscope, and the emitted fura-2 fluorescence was collected by a silicon-intensified video camera. The cytoplasmic calcium ion concentration was calculated from the ratio of the camera output obtained for both wavelengths and displayed by a pseudo-color technique. Spores responded to changes of the extracellular Ca2+ concentration, and this observation is considered as evidence that fura-2 is loaded into the cytoplasm. The substitution of a low external [Ca2+] (1 mM ethyleneglycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA)) by 1 mM CaCl2 caused a fast increase of [Ca2+]i from approx. 50 nM to above 500 nM. In contrast, the subsequent substitution of CaCl2 by EGTA decreased [Ca2+]i again below 100 nM within 0.5 h. Furthermore, the application of ionomycin could initiate a change in [Ca2+]i according to the Ca2+ gradient established between the extracellular medium and cytoplasm. In spores sown on a Ca(2+) -free medium, [Ca2+]i, analysed in a buffer containing EGTA, was found to be around

  2. Concentrations, loads and yields of selected water-quality constituents during low flow and storm runoff from three watersheds at Fort Leavenworth, Kansas, May 1994 through September 1996

    USGS Publications Warehouse

    Rasmussen, P.P.

    1998-01-01

    A study of the effects of storm runoff from urban areas on water quality at Fort Leavenworth, Kansas, was conducted from May 1994 through September 1996. The purpose of this report is to present information to assess the current (1994-96) conditions and possible methods for anticipating future water-quality effects from storm runoff and changes in land use. Three sampling sites were established to monitor streamflow and water quality from three watersheds draining the study area. Streamflow was monitored continuously, and water-quality samples were collected during low-flow (12 samples) and storm-runoff (21 samples) conditions to determine mean annual constituent loads. Constituent concentrations for the most part were smallest during low flow with the exception of major ions, dissolved solids, and some nutrients. Concentrations of suspended solids and total recoverable metals at all three sites were much larger in storm-runoff samples than in low-flow samples--typically an order of magnitude larger than low-flow concentrations. Mean low-flow nutrient concentrations were either larger than or smaller than storm-runoff concentrations depending on the watershed. Total chloroform and total tetrachloroethylene were the only two volatile organic compounds detected, and acid-base/neutral organic compounds were not detected in any of the samples collected. Eight pesticides were detected in low-flow samples, and 15 pesticides were detected in storm-runoff samples. The only mean concentrations of the selected constituents in this study that exceeded either the U.S. Environmental Protection Agency's Maximum Contaminant Level or the Secondary Maximum Contaminant Level were dissolved solids and total recoverable iron and manganese.

  3. Renal response to acid loading in the developing lamb fetus, intact in utero.

    PubMed

    Daniel, S S; Bowe, E T; Lallemand, R; Yeh, M N; James, L S

    1975-01-01

    the 90 minutes of infusion, blood pH fell from 7.36 to 7.13, base deficit rose from 3.8 to 16.4 mEq/L and lactate rose from 2.2 to 14.8 mM/L; there was also a small but significant rise in both blood PCO2 and PO2 (Figs. 1 to 2, Tabs. I to II). During the following three hours of recovery, pH rose gradually to 7.29, base deficit and lactate fell to 7.4 mEq/L and 8.7 mM/L respectively. Since renal excretion of net acid and lactate was small, the decrease in blood base deficit and lactate levels during the recovery must therefore be mainly due to equilibration in various fetal compartments as well as placental transfer. These experiments indicate that, in the lamb fetus, intact in utero, the kidney although limited by immaturity of several mechanisms, is capable of responding to an acid load and thus can make a small contribution to fetal homeostasis. The increase in excretion of net acid is accompanied by loss of sodium and chloride in the urine. PMID:479

  4. Assessment of zinc loading in an acid rock drainage alpine catchment using a tracer-injection and synoptic-sampling study

    NASA Astrophysics Data System (ADS)

    Crouch, C. M.; McKnight, D. M.; Todd, A.

    2010-12-01

    Seasonal low flow conditions in acid rock drainage (ARD) streams result in increased acidity and metal ion concentrations - changes that have been shown to become more pronounced with longer dry periods. These resulting increases in acidity and metals concentrations may pose an increasing danger to aquatic ecosystems and drinking water supplies. For example, in many ARD-impacted mountain streams, fish populations are not self-sustaining. The study site in the Upper Snake River watershed in Colorado is an alpine catchment impacted by acid rock drainage thought to originate from the natural weathering of pyrite whereas the main stem of the Snake River and its other tributaries are impacted by accelerated ARD resulting from historic mining activities. Because concentrations toxic to aquatic life persist well downstream of the ARD inputs, dissolved zinc is the primary metal of concern in this study. A compilation of historic data from the Snake River Watershed during the low flow months of September and October indicates that zinc concentrations have increased four-fold over the past 30 years. We hypothesize that this increase is due to changes in groundwater flow patterns caused by climate change and associated earlier peak snowmelt (by 2-3 weeks), resulting in lower stream flows and drier soils in late summer. The observed increase in background metals concentrations has implications for mitigation of former mining sites. A synoptic study to identify discrete surface water sources of zinc loading indicated a significant input from a tributary on the north side of the catchment. Zinc concentrations here measured an order of magnitude higher than in the main stem of the stream, and were correlated with increases in sulfate, hardness, and total metals, supporting our contention that increasing zinc concentrations are driven by the acceleration of ARD in the watershed. The current research further investigates sources of metal-rich inflows to the tributary using a tracer

  5. Shifts in production of perfluoroalkyl acids affect emissions and concentrations in the environment of the Xiaoqing River Basin, China.

    PubMed

    Wang, Pei; Lu, Yonglong; Wang, Tieyu; Meng, Jing; Li, Qifeng; Zhu, Zhaoyun; Sun, Yajun; Wang, Ruoshi; Giesy, John P

    2016-04-15

    Perfluoroalkyl acids (PFAAs) have been widely used in surfactant applications, especially as processing acids for fluoropolymer production. This study provides an analysis of sources of certain PFAAs emitted from the intensive fluoropolymer facilities in the Xiaoqing River Basin of China. Concentrations of perfluorooctanoic acid (PFOA) as great as 0.97mg/L in surface water and 10.5μg/g dry weight in surface sediment have been detected near the effluent of one facility (F1) that produces polytetrafluoroethylene (PTFE) and other fluoropolymers with massive capacity. With the great emission of PFAAs to water in natural conditions, the log KOC values decreased for short-chain PFCAs. Mass loads of PFAAs indicated that emissions of PFAAs from other facilities or sources were much less than those from F1, which emitted 174kg/d of PFAAs including 159kg/d of PFOA to the rivers. Even though production and emissions of PFOA have been strictly controlled in other countries since 2006, production of PFOA as well as several other fluoropolymers that use PFOA as processing aids has been increasing at F1 in recent years. We recommended that production shift should be taken into consideration in PFOA elimination actions. PMID:26775106

  6. Simultaneous saccharification and co-fermentation of dry diluted acid pretreated corn stover at high dry matter loading: Overcoming the inhibitors by non-tolerant yeast.

    PubMed

    Zhu, Jia-Qing; Qin, Lei; Li, Wen-Chao; Zhang, Jian; Bao, Jie; Huang, Yao-Dong; Li, Bing-Zhi; Yuan, Ying-Jin

    2015-12-01

    Dry dilute acid pretreatment (DDAP) is a promising method for lignocellulose bioconversion, although inhibitors generated during the pretreatment impede the fermentation severely. We developed the simultaneous saccharification and co-fermentation (SScF) of DDAP pretreated biomass at high solid loading using xylose fermenting Saccharomyces cerevisiae, SyBE005. Effect of temperature on SScF showed that ethanol yield at 34°C was 10.2% higher than that at 38°C. Ethanol concentration reached 29.5 g/L at 15% (w/w) dry matter loading, while SScF almost ceased at the beginning at 25% (w/w) dry matter loading of DDAP pretreated corn stover. According to the effect of the diluted hydrolysate on the fermentation of strain SyBE005, a fed-batch mode was developed for the SScF of DDAP pretreated corn stover with 25% dry matter loading without detoxification, and 40.0 g/L ethanol was achieved. In addition, high yeast inoculation improved xylose utilization and the final ethanol concentration reached 47.2 g/L. PMID:26363500

  7. Salicylic acid induces apoptosis in colon carcinoma cells grown in-vitro: Influence of oxygen and salicylic acid concentration

    SciTech Connect

    Zitta, Karina; Meybohm, Patrick; Bein, Berthold; Huang, Ying; Heinrich, Christin; Scholz, Jens; Steinfath, Markus; Albrecht, Martin

    2012-04-15

    In solid tumors the hypoxic environment can promote tumor progression and resistance to therapy. Recently, acetylsalicylic acid a major component of analgesic drugs and its metabolite salicylic acid (SA) have been shown to reduce the risk of colon cancer, but the mechanisms of action remain still unclear. Here we elucidate the effects of physiologically relevant concentrations of SA on colon carcinoma cells (CaCo-2) grown under normoxic and hypoxic conditions. Western blotting, caspase-3/7 apoptosis assays, MTS cell-proliferation assays, LDH cytotoxicity assays and hydrogen peroxide measurements were performed to investigate the effects of 1 and 10 {mu}M SA on CaCo-2 cells grown under normoxic conditions and cells exposed to hypoxia. Under normoxic conditions, SA did not influence cell proliferation or LDH release of CaCo-2 cells. However, caspase-3/7 activity was significantly increased. Under hypoxia, cell proliferation was reduced and LDH release and caspase-3/7 activities were increased. None of these parameters was altered by the addition of SA under hypoxic conditions. Hypoxia increased hydrogen peroxide concentrations 300-fold and SA significantly augmented the release of hydrogen peroxide under normoxic, but not under hypoxic conditions. Phosphorylation of the pro-survival kinases akt and erk1/2 was not changed by SA under hypoxic conditions, whereas under normoxia SA reduced phosphorylation of erk1/2 after 2 hours. We conclude that in colon carcinoma cells effects of SA on apoptosis and cellular signaling are dependent on the availability of oxygen. -- Highlights: Black-Right-Pointing-Pointer Effects of salicylic acid on colon carcinoma cells grown under normoxic and hypoxic conditions Black-Right-Pointing-Pointer Salicylic acid increases caspase-3/7 activity and hydrogen peroxide release under normoxia Black-Right-Pointing-Pointer Salicylic acid decreases pro-survival erk-1/2 phosphorylation under normoxia Black-Right-Pointing-Pointer Salicylic acid does

  8. Post-Bariatric Surgery Changes in Quinolinic and Xanthurenic Acid Concentrations Are Associated with Glucose Homeostasis

    PubMed Central

    Pigeyre, Marie; Caiazzo, Robert; Raverdy, Violeta; Verkindt, Hélène; Leloire, Audrey; Guillemin, Gilles J.; Yengo, Loïc; Allorge, Delphine; Froguel, Philippe; Pattou, François

    2016-01-01

    Background An increase of plasma kynurenine concentrations, potentially bioactive metabolites of tryptophan, was found in subjects with obesity, resulting from low-grade inflammation of the white adipose tissue. Bariatric surgery decreases low-grade inflammation associated with obesity and improves glucose control. Objective Our goal was to determine the concentrations of all kynurenine metabolites after bariatric surgery and whether they were correlated with glucose control improvement. Design Kynurenine metabolite concentrations, analysed by liquid or gas chromatography coupled with tandem mass spectrometry, circulating inflammatory markers, metabolic traits, and BMI were measured before and one year after bariatric surgery in 44 normoglycemic and 47 diabetic women with obesity. Associations between changes in kynurenine metabolites concentrations and in glucose control and metabolic traits were analysed between baseline and twelve months after surgery. Results Tryptophan and kynurenine metabolite concentrations were significantly decreased one year after bariatric surgery and were correlated with the decrease of the usCRP in both groups. Among all the kynurenine metabolites evaluated, only quinolinic acid and xanthurenic acid were significantly associated with glucose control improvement. The one year delta of quinolinic acid concentrations was negatively associated with the delta of fasting glucose (p = 0.019) and HbA1c (p = 0.014), whereas the delta of xanthurenic acid was positively associated with the delta of insulin sensitivity index (p = 0.0018). Conclusion Bariatric surgery has induced a global down-regulation of kynurenine metabolites, associated with weight loss. Our results suggest that, since kynurenine monoxygenase diverts the kynurenine pathway toward the synthesis of xanthurenic acid, its inhibition may also contribute to glucose homeostasis. PMID:27327770

  9. Design maps for failure of all-ceramic layer structures in concentrated cyclic loading

    PubMed Central

    Bhowmick, Sanjit; Meléndez-Martínez, Juan José; Zhang, Yu; Lawn, Brian R.

    2009-01-01

    A study is made of the competition between failure modes in ceramic-based bilayer structures joined to polymer-based substrates, in simulation of dental crown-like structures with a functional but weak “veneer” layer bonded onto a strong “core” layer. Cyclic contact fatigue tests are conducted in water on model flat systems consisting of glass plates joined to glass, sapphire, alumina or zirconia support layers glued onto polycarbonate bases. Critical numbers of cycles to take each crack mode to failure are plotted as a function of peak contact load on failure maps showing regions in which each fracture mode dominates. In low-cycle conditions, radial and outer cone cracks are competitive in specimens with alumina cores, and outer cone cracks prevail in specimens with zirconia cores; in high-cycle conditions, inner cone cracks prevail in all cases. The roles of other factors, e.g. substrate modulus, layer thickness, indenter radius and residual stresses from specimen preparation, are briefly considered. PMID:19562095

  10. Spontaneous arrangement of a tumor targeting hyaluronic acid shell on irinotecan loaded PLGA nanoparticles.

    PubMed

    Giarra, Simona; Serri, Carla; Russo, Luisa; Zeppetelli, Stefania; De Rosa, Giuseppe; Borzacchiello, Assunta; Biondi, Marco; Ambrosio, Luigi; Mayol, Laura

    2016-04-20

    The arrangement of tumor targeting hyaluronic acid (HA) moieties on irinotecan (IRIN)-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) has been directed by means of a gradient of lipophilicity between the oil and water phases of the emulsion used to produce the NPs. PLGA constitutes the NP bulk while HA is superficially exposed, with amphiphilic poloxamers acting as a bridge between PLGA and HA. Differential scanning calorimetry, zeta potential analyses and ELISA tests were employed to support the hypothesis of polymer assembly in NP formulations. The presence of flexible HA chains on NP surface enhances NP size stability over time due to an increased electrostatic repulsion between NPs and a higher degree of hydration of the device surface. IRIN in vitro release kinetics can be sustained up to 7-13 days. In vitro biologic studies indicated that HA-containing NPs were more toxic than bare PLGA NPs against CD44-overexpressing breast carcinoma cells (HS578T), therefore indicating their ability to target CD44 receptor. PMID:26876867

  11. Release behavior of tetracycline hydrochloride loaded chitosan/poly(lactic acid) antimicrobial nanofibrous membranes.

    PubMed

    Jiang, Suwei; Lv, Jian; Ding, Man; Li, Yanan; Wang, Hualin; Jiang, Shaotong

    2016-02-01

    The present work aimed to evaluate the release behavior of tetracycline hydrochloride loaded chitosan/poly(lactic acid) (Tet-CS/PLA) antimicrobial nanofibrous membranes fabricated via electrospinning technique. The electrospinning solution was a blend of Tet, CS formic acid solution and PLA chloroform/ethanol solution. The interaction between CS and PLA in CS/PLA nanofibers was confirmed to be hydrogen bond. The incorporation of Tet caused a slight decrease in the diameter of nanofibers with Tet content below 30%. Tet-CS/PLA nanofibrous membrane showed a slight initial burst within the first 4h before a gradual increase in cumulative release, and the release percentage increased with increasing Tet contents. Tet release (Mt/M∞<0.6) from the medicated nanofibers could be described by Fickian diffusion model and the release profiles showed two sequential stages. Tet-CS/PLA nanofibrous membranes exhibited an effective and sustainable inhabitance on the growth of Staphylococcus aureus, and the antimicrobial activity increased rapidly with increasing Tet contents below 20%. Furthermore, the incorporation of Tet promoted the degradation of nanofibrous membranes. PMID:26652352

  12. Imaging of the GI tract by QDs loaded heparin-deoxycholic acid (DOCA) nanoparticles.

    PubMed

    Khatun, Zehedina; Nurunnabi, Md; Cho, Kwang Jae; Lee, Yong-kyu

    2012-11-01

    This study presents an approach to deliver non invasive, near-IR imaging agent using oral delivery system. Low molecular weight heparin (LMWH)-deoxycholic acid (DOCA)/(LHD) nanoparticles formed by a self-assembly method was prepared to evaluate their physicochemical properties and oral absorption in vitro and in vivo. Near-IR QDs were prepared and loaded into LHD nanoparticles for imaging of the gastro-intestinal (GI) tract absorption. Q-LHD nanoparticles were almost spherical in shape with diameters of 194-217 nm. The size and fluorescent intensity of the Q-LHD nanoparticles were stable in 10% FBS solution and retained their fluorescent even after 5 days of incubation. Cell viability of Q-LHD nanoparticles maintained in the range of 80-95% for 24h incubation. No damage was found in tissues or organs during animal experiments. The in vivo oral absorption of Q-LHD was observed in SKH1 mice for 3h under different doses. From the results, we confirmed that Q-LHD was absorbed mostly into the ileum of small intestine containing intestinal bile acid transporter as observed in TEM and molecular imaging system. Our designed nanoparticles could be administered orally for bio-imaging and studying the bio-distribution of drug. PMID:22944403

  13. Acidic loadings in South Korean ecosystems by long-range transport and local emissions

    NASA Astrophysics Data System (ADS)

    Shim, Jae-Myun; Park, Soon-Ung

    2004-10-01

    Exceedances of sulfur and nitrogen critical loads in South Korean ecosystems caused by long-range transport and local emissions of sulfur and nitrogen have been estimated using the maximum critical load of sulfur and the critical load of nutrient nitrogen. The long-term-averaged deposition of sulfur and nitrogen is estimated with a simplified chemical model and the K-mean clustering technique. The three consecutive days of gridded daily mean National Center for Environmental Protection (NCEP) reanalyzed 850 hPa geopotential height fields with and without precipitation on the last day over South Korea are used for clustering of synoptic patterns for the period of 1994-1998. Two emission conditions are simulated for each cluster to estimate long-term averaged depositions of sulfur and nitrogen by long-range transport and local emissions over South Korea. One condition takes all emissions within the simulated domain into account as a base case and the other condition excludes all South Korean emissions but includes all of the other emissions, as a control case. The results of the present study indicate that the contribution of long-range transport to the annual total deposition over South Korea is found to be about 40% (530 eqha-1yr-1) for sulfur and 49% (650 eqha-1yr-1) for nitrogen, of which 55% for sulfur and 58% for nitrogen are contributed by wet deposition. This suggests the importance of wet deposition through the transformed acidic precursors for long-range transport to South Korea's total deposition of sulfur and nitrogen. The estimated exceedance for South Korean ecosystems indicates that the current estimate of total sulfur deposition affects about 42% of the South Korean ecosystems adversely, of which 14% is attributed to South Korean source only and the rest 28% is attributed to long-range transport together with South Korean source. Long-range transport of sulfur itself does not exceed the maximum critical load of sulfur. On the other hand, the current

  14. Concentrations and specific loads of UV filters in sewage sludge originating from a monitoring network in Switzerland.

    PubMed

    Plagellat, Cécile; Kupper, Thomas; Furrer, Reinhard; de Alencastro, Luiz Felippe; Grandjean, Dominique; Tarradellas, Joseph

    2006-02-01

    Many substances related to human activities end up in wastewater and accumulate in sewage sludge. The present study focuses on the analysis of widely used UV filters 3-(4-methylbenzylidene) camphor (4-MBC), octyl-methoxycinnamate (OMC), octocrylene (OC) and octyl-triazone (OT) in sewage sludge originating from a monitoring network in Switzerland. Mean concentrations in stabilised sludge from 14 wastewater treatment plants were 1780, 110, 4840 and 5510 microg/kg dry matter for 4-MBC, OMC, OC and OT, respectively. Specific loads in sewage sludge show that UV filters originate mainly from private households, but surface runoff and industries may be considered as additional sources. This indicates that besides use for sunscreens and cosmetics UV filters might occur in plastics and other materials and be released to the environment by volatilization or leaching. Differences between the modeled per capita loads of UV filters in sewage sludge and the observed specific loads in sewage sludge are probably due to erroneous figures of production volumes, degradation and sorption during wastewater treatment as well as degradation processes during transport in the sewer or sludge treatment. Thus, further research is needed to elucidate the fate of UV filters after application and release into the environment. Other compounds used as UV filters should be included in future studies. PMID:15996716

  15. Propagated fixed-bed mixed-acid fermentation: effect of volatile solid loading rate and agitation at near-neutral pH.

    PubMed

    Golub, Kristina W; Golub, Stacey R; Meysing, Daniel M; Holtzapple, Mark T

    2012-11-01

    To increase conversion and product concentration, mixed-acid fermentation can use a countercurrent strategy where solids and liquids pass in opposite directions through a series of fermentors. To limit the requirement for moving solids, this study employed a propagated fixed-bed fermentation, where solids were stationary and only liquid was transferred. To evaluate the role of agitation, continuous mixing was compared with periodic mixing. The periodically mixed fermentation had similar conversion, but lower yield and selectivity. Increasing volatile solid loading rate from 1.5 to 5.1g non-acid volatile solids/(L(liq)·d) and increasing liquid retention time decreased yield, conversion, selectivity, but increased product concentrations. Compared to a previous study at high pH (~9), this study achieved higher performance at near neutral pH (~6.5) and optimal C-N ratios. Compared to countercurrent fermentation, propagated fixed-bed fermentations have similar selectivities and produce similar proportions of acetic acid, but have lower yields, conversion, productivities, and acid concentrations. PMID:22995159

  16. NHI-Acid Concentration Membranes -- Membrane Recommendations for the S-I Cycle

    SciTech Connect

    Frederick F Stewart

    2007-03-01

    Scope: The purpose of this draft report is to make recommendations concerning the applicability of specific membrane materials for acid concentration processes to the Sulfur-Iodine (S-I) thermochemical cycle integrated laboratory scale (ILS) demonstration. Introduction Acid concentration membrane processes have been studied for possible inclusion in the Sulfur-Iodine integrated laboratory scale (S-I ILS) demonstration. The need for this technology is driven by the chemical processes required for economical water splitting using the S-I cycle. Of the chemical processes inherent to the S-I cycle that have been identified as targets for deployment of membrane technology, three have been studied during the past three fiscal years as a part of the DOE Nuclear Hydrogen Initiative. First, the ability to concentrate hydriodic acid (HI) and iodine mixtures was sought as a method for aiding in the isolation of HI away from water and iodine. Isolated HI would then be delivered to the HI decomposition process for liberation of product hydrogen. Second, an extension of this technology to sulfuric acid was proposed to benefit sulfuric acid decomposition recycle. Third, decomposition of HI to form hydrogen is equilibrium limited. Removal of hydrogen, utilizing Le Chatelier’s principle, will increase to overall conversion and thus increasing the efficiency of the S-I cycle.

  17. Biofilter for generation of concentrated sulphuric acid from H2S.

    PubMed

    Rabbani, K A; Charles, W; Kayaalp, A; Cord-Ruwisch, R; Ho, G

    2016-08-01

    Biofilters are used for the conversion of odorous hydrogen sulphide to odourless sulphate in wastewater treatment plants under the right conditions of moisture and pH. One of the consequences of maintaining the suitable pH and moisture content is the production of large volumes of weakly acidic leachate. This paper presents a biofilter with a maximum H2S elimination capacity of 16.3 g m(-3) h(-1) and removal efficiency greater than 95 % which produces small volumes (1 mL of solution L(-1) of reactor day(-1)) of sulphuric acid with a concentration greater than 5.5 M after 150 days of continuous operation. The concentrated sulphuric acid was produced by intermittently trickling a minimum amount of nutrient solution down the upflow biofilter which created a moisture and pH gradient within the biofilter resulting in an environment at the top for the bacterial conversion of H2S, while sulphuric acid was accumulated at the base. Genetic diversity profiling of samples taken from different sections of the biofilter confirms that the upper sections of the biofilter had the best environment for the bacteria to convert H2S to sulphate. The formation of concentrated sulphuric acid presents an opportunity for the recovery of sulphur from the waste stream as a usable product. PMID:27189453

  18. Effect of sulfuric acid concentration of bentonite and calcination time of pillared bentonite

    NASA Astrophysics Data System (ADS)

    Mara, Ady; Wijaya, Karna; Trisunaryati, Wega; Mudasir

    2016-04-01

    An activation of natural clay has been developed. Activation was applied by refluxing the natural bentonite in variation of the sulfuric acid concentration and calcination time of pillared bentonite (PLC). Calcination was applied using oven in microwave 2,45 GHz. Determination of acidity was applied by measuring the amount of adsorbed ammonia and pyridine. Morphological, functional groups and chrystanility characterizations were analyzed using SEM, TEM, FTIR and XRD. Porosity was analyzed using SSA. The results showed that the greater of the concentration of sulfuric acid and calcination time was, the greater the acidity of bentonite as well as the pore diameter were. FTIR spectra showed no fundamental changes in the structure of the natural bentonite, SEM, and TEM images were showing an increase in space or field due to pillarization while the XRD patterns showed a shift to a lower peak. Optimization was obtained at a concentration of 2 M of sulfuric acid and calcination time of 20 minutes, keggin ion of 2.2 and suspension of 10 mmol, respectively each amounted to 11.7490 mmol/gram of ammonia and 2.4437 mmol/gram of pyridine with 154.6391 m2/gram for surface area, 0.130470 m3/gram of pore volume and 3.37484 nm of pore diameter.

  19. Higher diet-dependent renal acid load associates with higher glucocorticoid secretion and potentially bioactive free glucocorticoids in healthy children.

    PubMed

    Esche, Jonas; Shi, Lijie; Sánchez-Guijo, Alberto; Hartmann, Michaela F; Wudy, Stefan A; Remer, Thomas

    2016-08-01

    Metabolic acidosis induces elevated glucocorticoid (GC) levels. However, the influence of less strong daily acid loads on GCs is largely unexplored. To investigate this, we studied whether higher acid loads in children, fully within the normal range of habitual diets, associate with endogenous GCs. In a specific quasi-experimental design, we examined 200 6- to 10-year-old healthy participants of the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study equally divided to either high or low 24-hour renal net acid excretion. Major urinary GC metabolites were analyzed by gas chromatography-mass spectrometry to assess daily adrenal GC secretion and metabolites of tissue cortisol catabolism (6β-hydroxycortisol and 20α-dihydrocortisol). Liquid chromatography-mass spectrometry was used to quantify urinary free cortisol and cortisone. After confounder adjustment, significant positive associations were unmasked for urinary potential renal acid load and net acid excretion with adrenal GC secretion, free cortisone, free cortisone plus cortisol, 6β-hydroxycortisol, and 20α-dihydrocortisol. An inverse association emerged for an enzymatic marker (5β-reductase) of irreversible GC inactivation. Our data suggest that existing moderate elevations in diet-dependent acid loads suffice to raise GCs and affect cortisol metabolism. Thus, potential detrimental effects of high acid loading appear to be mediated, in part, by increased GC activity via increased GC secretion and/or reduced GC inactivation. Higher cortisone levels, directly available for intracrine activation to cortisol may play a special role. PMID:27165611

  20. Plasma Amino Acid Concentrations Predict Mortality in Patients with End-Stage Liver Disease

    PubMed Central

    Kinny-Köster, Benedict; Bartels, Michael; Becker, Susen; Scholz, Markus; Thiery, Joachim

    2016-01-01

    Background The liver plays a key role in amino acid metabolism. In former studies, a ratio between branched-chain and aromatic amino acids (Fischer’s ratio) revealed associations with hepatic encephalopathy. Furthermore, low concentrations of branched-chain amino acids were linked to sarcopenia in literature. Encephalopathy and sarcopenia are known to dramatically worsen the prognosis. Aim of this study was to investigate a complex panel of plasma amino acids in the context of mortality in patients with end-stage liver disease. Methods 166 patients evaluated for orthotopic liver transplantation were included. 19 amino acids were measured from citrated plasma samples using mass spectrometry. We performed survival analysis for plasma amino acid constellations and examined the relationship to established mortality predictors. Results 33/166 (19.9%) patients died during follow-up. Lower values of valine (p<0.001), Fischer’s ratio (p<0.001) and valine to phenylalanine ratio (p<0.001) and higher values of phenylalanine (p<0.05) and tyrosine (p<0.05) were significantly associated with mortality. When divided in three groups, the tertiles discriminated cumulative survival for valine (p = 0.016), phenylalanine (p = 0.024) and in particular for valine to phenylalanine ratio (p = 0.003) and Fischer’s ratio (p = 0.005). Parameters were also significantly correlated with MELD and MELD-Na score. Conclusions Amino acids in plasma are valuable biomarkers to determine increased risk of mortality in patients with end-stage liver disease. In particular, valine concentrations and constellations composed of branched-chain and aromatic amino acids were strongly associated with prognosis. Due to their pathophysiological importance, the identified amino acids could be used to examine individual dietary recommendations to serve as potential therapeutic targets. PMID:27410482

  1. Tuning the concentration of dye loaded polymer films for maximum photosensitization efficiency: phloxine B in poly(2-hydroxyethyl methacrylate).

    PubMed

    Litman, Yair; Rodríguez, Hernán B; San Román, Enrique

    2016-01-01

    Fluorescence and singlet molecular oxygen ((1)O2) quantum yields for phloxine B loaded poly(2-hydroxyethyl methacrylate) thin films are determined at dye concentrations from 0.015 to 22 wt%. Fluorescence self-quenching and the fall off of the (1)O2 quantum yield observed above 0.1 wt% are attributed to very weakly interacting close-lying dye molecules acting as energy traps arising from molecular confinement. The maximum singlet oxygen generation efficiency (quantum yield × absorption factor) lies at concentrations around 2 wt%, where fluorescence self quenching amounts to more than 80%. Data are fitted quantitatively by using a quenching radius model involving energy migration and trapping with rQ = 1.2 nm. The present results constitute a proof of concept for the rational design of heterogeneous photosensitizers in general and, particularly, for applications in which the antimicrobial activity of singlet oxygen is central. PMID:26661564

  2. Total volatile fatty acid concentrations are unreliable estimators of treatment effects on ruminal fermentation in vivo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Volatile fatty acid concentrations ([VFA], mM) have long been used to assess impact of dietary treatments on ruminal fermentation in vivo. However, discrepancies in statistical results between VFA and VFA pool size (VFAmol), possibly related to ruminal digesta liquid amount (LIQ, kg), suggest issues...

  3. Abscisic acid form, concentration, and application timing influence phenology and bud cold hardiness in Merlot grapevines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of abscisic acid (ABA) form, concentration and application timing on bud cold hardiness, phenology and fruiting performance on ‘Merlot’ grapevines (Vitis vinifera) were evaluated in a three year field trial with site locations in British Columbia Canada, Ontario Canada, Washington U.S. ...

  4. GASEOUS AND PARTICULATE AMMONIA AND NITRIC ACID CONCENTRATIONS, COLUMBUS, OHIO AREA--SUMMER 1980

    EPA Science Inventory

    Data is presented for gaseous ammonia and nitric acid and particulate ammonium ion and nitrate ion concentrations in air samples collected in support of the PEPE-NEROS study during the summer of 1980. Ground-level samples were collected near Croton, Ohio; aerial samples were also...

  5. EFFECTS OF THREE CONCENTRATIONS OF MIXED FATTY ACIDS ON DECHLORINATION OF TETRACHLOROETHENE IN AQUIFER MICROCOSMS

    EPA Science Inventory

    Chloroethenes are among the most common organic contaminants of ground water. he biotransformation of these compounds by reductive dechlorination is a promising technology for in situ treatment. he effects of three concentrations of a fatty acids mixture on the reductive dehaloge...

  6. CONCENTRATION OF GLIAL FIBRILLARY ACIDIC PROTEIN INCREASES WITH AGE IN THE MOUSE AND RAT BRAIN

    EPA Science Inventory

    The role of aging in the expression of the astrocyte protein, glial fibrillary acidic protein (GFAP), was examined. n both mice and rats the concentration of GFAP increased throughout the brain as a function of aging. he largest increase (2-fold) was observed in striatum for both...

  7. EFFECTS OF THREE CONCENTRATIONS OF MIXED FATTY ACIDS ON DECHLORINATION OF TETRACHLOROETHENE IN AQUIFER MICRO- COSMS

    EPA Science Inventory

    Chloroethenes are among the most common organic contaminants of ground water. The biotransformation of these compounds by reductive dechlorination is a promising technology for in situ treatment. The effects of three concentrations of a fatty acids mixture on the reductive dehalo...

  8. Mineral, flavonoid, and fatty acid concentrations in ten diverse Lablab purpureus (L.) sweet accessions.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seeds of Hyacinth bean (Lablab purpureus [L.]) Sweet containing high concentrations of minerals, flavonoids and fatty acids may provide government agencies with a nutrient-dense and health-beneficial food for use in hunger stricken and nutrient deprived people. Seeds from ten hyacinth bean accession...

  9. Role of lauric acid-potassium hydroxide concentration on bacterial contamination of spray washed broiler carcasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of experiments were conducted to examine reductions in bacterial contamination of broiler carcasses washed in a spray cabinet with various concentrations of lauric acid (LA)-potassium hydroxide (KOH) solutions. Fifty eviscerated carcasses and 5 ceca were obtained from the processing line of...

  10. Dry Matter Production and Leaf Elemental Concentrations of Rambutan Grown on an Acid Ultisol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known about the adaptability of rambutan (Nephelium lappaceum) to highly acidic soils rich in aluminum (Al). A 2-yr field study was conducted to determine the effects of various levels of soil Al on dry matter production, plant growth, and nutrient concentration in the leaves of four cult...

  11. Concentrations, loads, and sources of polychlorinated biphenyls, Neponset River and Neponset River Estuary, eastern Massachusetts

    USGS Publications Warehouse

    Breault, Robert F.

    2011-01-01

    Polychlorinated biphenyls (PCBs) are known to contaminate the Neponset River, which flows through parts of Boston, Massachusetts, and empties into the Neponset River Estuary, an important fish-spawning area. The river is dammed and impassable to fish. The U.S. Geological Survey, in cooperation with the Massachusetts Department of Fish and Game, Division of Ecological Restoration, Riverways Program, collected, analyzed, and interpreted PCB data from bottom-sediment, water, and (or) fish-tissue samples in 2002, 2004-2006. Samples from the Neponset River and Neponset River Estuary were analyzed for 209 PCB congeners, PCB homologs, and Aroclors. In order to better assess the overall health quality of river-bottom sediments, sediment samples were also tested for concentrations of 31 elements. PCB concentrations measured in the top layers of bottom sediment ranged from 28 nanograms per gram (ng/g) just upstream of the Mother Brook confluence to 24,900 ng/g measured in Mother Brook. Concentrations of elements in bottom sediment were generally higher than background concentrations and higher than levels considered toxic to benthic organisms according to freshwater sediment-quality guidelines defined by the U.S. Environmental Protection Agency. Concentrations of dissolved PCBs in water samples collected from the Neponset River (May 13, 2005 to April 28, 2006) averaged about 9.2 nanograms per liter (ng/L) (annual average of monthly values); however, during the months of August (about 16.5 ng/L) and September (about 15.6 ng/L), dissolved PCB concentrations were greater than 14 ng/L, the U.S. Environmental Protection Agency's freshwater continuous chronic criterion for aquatic organisms. Concentrations of PCBs in white sucker (fillets and whole fish) were all greater than 2,000 ng/g wet wt, the U.S. Environmental Protection Agency's guideline for safe consumption of fish: PCB concentrations measured in fish-tissue samples collected from the Tileston and Hollingsworth and

  12. Runoff concentration and load of nitrogen and phosphorus from a residential area in an intensive agricultural watershed.

    PubMed

    Lang, Man; Li, Ping; Yan, Xiaoyuan

    2013-08-01

    To evaluate the runoff load of nitrogen (N) and phosphorus (P) in a rural residential area with high N deposition and few wastewater treatment systems in East China, we monitored the concentrations of N and P during 21 rainfall events in a typical village catchment in Jiangsu Province, China. The results showed that the average event mean concentrations (EMC, mg L(-1)) were 6.20 for dissolved nitrogen (DN), 4.18 for nitrate nitrogen (NO3(-)), 0.26 for ammonium nitrogen (NH4(+)), 1.76 for dissolved organic nitrogen (DON), 0.40 for dissolved phosphorus (DP) and 0.32 for phosphate (PO4(3-)). In addition, the annual loads (kg ha(-1)year(-1)) were 24.1 for DN, 16.3 for NO3(-), 1.01 for NH4(+), 6.83 for DON, 1.56 for DP, and 1.25 for PO4(3-). Concentrations of DN and DP in runoff water were 2.57 and 4.06 times higher than those in rainfall, indicating that waste produced by anthropogenic activity was the dominant pollution source of receiving water in rural residential areas. The average discharged concentrations of DN and DP exceeded the Class V surface water quality standard promulgated by the Ministry of Environmental Protection of China, suggesting that the surface runoff should be dealt with for controlling N and P during rainfall events. The runoff characteristics differed among pollutant species, as DP, PO4(3-) and NH4(+) showed medium mass first-flush, whereas that of DN, NO3(-) and DON was weak. These differences should be considered when planning mitigation measures and developing water quality models. PMID:23660519

  13. Breath concentration of acetic acid vapour is elevated in patients with cystic fibrosis.

    PubMed

    Smith, David; Sovová, Kristýna; Dryahina, Kseniya; Doušová, Tereza; Dřevínek, Pavel; Španěl, Patrik

    2016-01-01

    A study has been carried out of the volatile organic compounds present in the exhaled breath of 58 cystic fibrosis (CF) patients. An important observation is that the acetic acid vapour concentration measured by selected ion flow tube mass spectrometry (SIFT-MS) is significantly elevated in the exhaled breath of CF patients, independent of the Pseudomonas aeruginosa (PA) infection status (PA-infected median 170 ppbv; PA-negative median 182 ppbv), compared to that of healthy controls (median 48 ppbv). The cause for this may be decreased pH of the mucus lining the CF airways. Thus, we speculate that non-invasive measurement of breath acetic acid concentration could serve as an indicator of the acidity of the CF airways mucosa. PMID:27184114

  14. Evaluation of Glass Density to Support the Estimation of Fissile Mass Loadings from Iron Concentrations in SB6 Glasses

    SciTech Connect

    Edwards, T.; Peeler, D.

    2010-12-15

    The Department of Energy - Savannah River (DOE-SR) previously provided direction to Savannah River Remediation (SRR) to maintain fissile concentration in glass below 897 g/m{sup 3}. In support of the guidance, the Savannah River National Laboratory (SRNL) provided a technical basis and a supporting Microsoft{reg_sign} Excel{reg_sign} spreadsheet for the evaluation of fissile loading in Sludge Batch 5 glass based on the Fe concentration in glass as determined by the measurements from the Slurry Mix Evaporator (SME) acceptability analysis. SRR has since requested that SRNL provide the necessary information to allow SRR to update the Excel spreadsheet so that it may be used to maintain fissile concentration in glass below 897 g/m{sup 3} during the processing of Sludge Batch 6 (SB6). One of the primary inputs into the fissile loading spreadsheet includes a bounding density for SB6-based glasses. Based on the measured density data of select SB6 variability study glasses, SRNL recommends that SRR utilize the 99/99 Upper Tolerance Limit (UTL) density value at 38% WL (2.823 g/cm{sup 3}) as a bounding density for SB6 glasses to assess the fissile concentration in this glass system. That is, the 2.823 g/cm{sup 3} is recommended as a key (and fixed) input into the fissile concentration spreadsheet for SB6 processing. It should be noted that no changes are needed to the underlying structure of the Excel based spreadsheet to support fissile assessments for SB6. However, SRR should update the other key inputs to the spreadsheet that are based on fissile and Fe concentrations reported from the SB6 Waste Acceptance Product Specification (WAPS) sample. The purpose of this technical report is to present the density measurements that were determined for the SB6 variability study glasses and to conduct a statistical evaluation of these measurements to provide a bounding density value that may be used as input to the Excel{reg_sign} spreadsheet to be employed by SRR to maintain the

  15. Synthesis, characterization, and in vitro evaluation of curcumin-loaded albumin nanoparticles surface-functionalized with glycyrrhetinic acid

    PubMed Central

    Li, Jingjing; Chen, Tong; Deng, Feng; Wan, Jingyuan; Tang, Yalan; Yuan, Pei; Zhang, Liangke

    2015-01-01

    We have designed and developed curcumin (Ccn)-loaded albumin nanoparticles (BNPs) surface-functionalized with glycyrrhetinic acid (Ccn-BNP-GA) for GA receptor-mediated targeting. Ccn-BNP-GA was prepared by conjugating GA as a hepatoma cell-specific binding molecule onto the surface of BNPs. Ccn-BNP-GA showed a narrow distribution with an average size of 258.8±6.4 nm, a regularly spherical shape, an entrapment efficiency of 88.55%±5.54%, and drug loading of 25.30%±1.58%. The density of GA as the ligand conjugated to BNPs was 140.48±2.784 μg/g bovine serum albumin. Cytotoxicity assay results indicated that Ccn-BNP-GA was significantly more cytotoxic to HepG2 cells and in a concentration-dependent manner. Ccn-BNP-GA also appeared to be taken up to a greater extent by HepG2 cells than undecorated groups, which might be due to the high affinity of GA for GA receptors on the HepG2 cell surface. These cytotoxicity assay results were corroborated by analysis of cell apoptosis and the cell cycle. Further, Ccn-BNP-GA showed an approximately twofold higher rate of cell apoptosis than the other groups. Moreover, proliferation of HepG2 cells was arrested in G2/M phase based on cell cycle analysis. These results, which were supported by the GA receptor-mediated endocytosis mechanism, indicate that BNPs surface-functionalized with GA could be used in targeted cancer treatment with high efficacy, sufficient targeting, and reduced toxicity. PMID:26346750

  16. Effects of water management on cadmium and arsenic accumulation and dimethylarsinic acid concentrations in Japanese rice.

    PubMed

    Arao, Tomohito; Kawasaki, Akira; Baba, Koji; Mori, Shinsuke; Matsumoto, Shingo

    2009-12-15

    Rice consumption is a major source of cadmium and arsenic for the population of Asia. We investigated the effects of water management in rice paddy on levels of cadmium and arsenic in Japanese rice grains. Flooding increased arsenic concentrations in rice grains, whereas aerobic treatment increased the concentration of cadmium. Flooding for 3 weeks before and after heading was most effective in reducing grain cadmium concentrations, but this treatment increased the arsenic concentration considerably, whereas aerobic treatment during the same period was effective in reducing arsenic concentrations but increased the cadmium concentration markedly. Flooding treatment after heading was found to be more effective than flooding treatment before heading in reducing rice grain cadmium without a concomitant increase in total arsenic levels, although it increased inorganic arsenic levels. Concentrations of dimethylarsinic acid (DMA) in grain were very low under aerobic conditions but increased under flooded conditions. DMA accounted for 3-52% of the total arsenic concentration in grain grown in soil with a lower arsenic concentration and 10-80% in soil with a higher arsenic concentration. A possible explanation for the accumulation of DMA in rice grains is that DMA translocates from shoots/roots to the grains more readily than does inorganic arsenic. PMID:20000530

  17. Extreme carbon dioxide concentrations in acidic pit lakes provoked by water/rock interaction.

    PubMed

    Sánchez-España, Javier; Boehrer, Bertram; Yusta, Iñaki

    2014-04-15

    We quantify the gas pressure and concentration of a gas-charged acidic pit lake in SW Spain. We measured total dissolved gas pressure, carbon dioxide (CO2) concentration, major ion concentration, isotopic composition of dissolved inorganic carbon (δ(13)C(DIC)), and other physicochemical parameters. CO2 is the dominant dissolved gas in this lake and results mainly from carbonate dissolution during the interaction of acidic water with wall rocks, followed by diffusive and advective transport through the water column. The δ(13)C(DIC) values suggest that the biological contribution is comparatively small. Maximum CO2 concentrations higher than 0.1 M (∼5000 mg/L) have been measured, which are only comparable to those found in volcanic crater lakes. The corresponding gas pressures of CO2 alone (pCO2 ∼3.6 bar) imply 60% saturation relative to local pressure at 50 m depth. High CO2 concentrations have been observed in other pit lakes of the region. We recommend gas-specific monitoring in acidic pit lakes and, if necessary, the design of feasible degassing strategies. PMID:24628479

  18. Dietary supplementation with cholesterol and docosahexaenoic acid affects concentrations of amino acids in tissues of young pigs

    PubMed Central

    Li, Peng; Kim, Sung Woo; Li, Xilong; Datta, Sujay; Pond, Wilson G.

    2013-01-01

    Cholesterol and docosahexaenoic acid (DHA) are important nutrients for neural development of infants. However, little is known about the effect of cholesterol or DHA on concentrations of amino acids (AA) in neonatal tissues. This study was conducted with the piglet (an established model for studying human infant nutrition) to test the hypothesis that dietary supplementation with the lipids may modulate AA availability in tissues. Sixteen newborn pigs were nursed by sows for 24 h and then assigned to one of four treatment groups, representing supplementation with 0.0% (control), 0.2% cholesterol, 0.2% DHA, or cholesterol plus DHA to the basal milk-formula. All piglets were euthanized at 49 days of age. In brain, cholesterol supplementation reduced (P < 0.05) concentrations of glutamate, serine, glutamine, threonine, β-alanine, alanine, methionine, isoleucine, leucine, and γ-aminobutyrate but increased (P < 0.05) concentrations of glycine and lysine, whereas DHA supplementation similarly affected (P < 0.05) concentrations of the same AA (except for isoleucine and lysine) and taurine. In addition, concentrations of most AA in liver, muscle and plasma were substantially altered by dietary supplementation of cholesterol and DHA in a tissue-dependent manner. Further, DHA reduced concentrations of carnosine in skeletal muscle, as well as ammonia in both plasma and brain. The results reveal that cholesterol and DHA can regulate AA metabolism and availability in various tissues of piglets. These novel findings have important implications for designing the next generation of infant formula to optimize neonatal growth and development. PMID:18972185

  19. Two-stage electrodialytic concentration of glyceric acid from fermentation broth.

    PubMed

    Habe, Hiroshi; Shimada, Yuko; Fukuoka, Tokuma; Kitamoto, Dai; Itagaki, Masayuki; Watanabe, Kunihiko; Yanagishita, Hiroshi; Sakaki, Keiji

    2010-12-01

    The aim of this research was the application of a two-stage electrodialysis (ED) method for glyceric acid (GA) recovery from fermentation broth. First, by desalting ED, glycerate solutions (counterpart is Na+) were concentrated using ion-exchange membranes, and the glycerate recovery and energy consumption became more efficient with increasing the initial glycerate concentration (30 to 130 g/l). Second, by water-splitting ED, the concentrated glycerate was electroconverted to GA using bipolar membranes. Using a culture broth of Acetobacter tropicalis containing 68.6 g/l of D-glycerate, a final D-GA concentration of 116 g/l was obtained following the two-stage ED process. The total energy consumption for the D-glycerate concentration and its electroconversion to D-GA was approximately 0.92 kWh per 1 kg of D-GA. PMID:20674487

  20. Electrochemical oxidation of humic acid and sanitary landfill leachate: Influence of anode material, chloride concentration and current density.

    PubMed

    Fernandes, A; Santos, D; Pacheco, M J; Ciríaco, L; Lopes, A

    2016-01-15

    The influence of applied current density and chloride ion concentration on the ability of Ti/Pt/PbO2 and Ti/Pt/SnO2-Sb2O4 anodes for the electrochemical oxidation of humic acid and sanitary landfill leachate samples was assessed and compared with that of BDD anode. For the experimental conditions used, results show that both organic load and nitrogen removal rates increase with the applied current density and chloride ion concentration, although there is an optimum COD/[Cl-]0 ratio below which there is no further increase in COD removal. Metal oxide anodes present a similar performance to that of BDD, being the results obtained for Ti/Pt/PbO2 slightly better than for Ti/Pt/SnO2-Sb2O4. Contrary to BDD, Ti/Pt/PbO2 promotes lower nitrate formation and is the most suitable material for total nitrogen elimination. The importance of the optimum ratio of Cl-/COD/NH4 +initial concentrations is discussed. PMID:26410703

  1. Dynamics of biocide emissions from buildings in a suburban stormwater catchment - concentrations, mass loads and emission processes.

    PubMed

    Bollmann, Ulla E; Vollertsen, Jes; Carmeliet, Jan; Bester, Kai

    2014-06-01

    Biocides such as isothiazolinones, carbamates, triazines, phenylureas, azoles and others are used to protect the surfaces of buildings, e.g. painted or unpainted render or wood. These biocides can be mobilized from the materials if rainwater gets into contact with these buildings. Hence, these biocides will be found in rainwater runoff (stormwater) from buildings that is traditionally managed as "clean water" in stormwater sewer systems and often directly discharged into surface waters without further treatment. By means of a 9 month event-based high resolution sampling campaign the biocide emissions in a small suburban stormwater catchment were analysed and the emission dynamics throughout the single rain events were investigated. Five out of twelve of the rain events (peak events) proved significantly higher concentrations than the rest (average) for at least one compound. Highest median concentrations of 0.045 and 0.052 μg L(-1) were found for terbutryn and carbendazim, while the concentrations for isoproturon, diuron, N-octylisothiazolinone, benzoisothiazolinone, cybutryn, propiconazole, tebuconazole, and mecoprop were one order of magnitude lower. However, during the peak events the concentrations reached up to 1.8 and 0.3 μg L(-1) for terbutryn and carbendazim, respectively. Emissions of an averaged single family house into the stormwater sewer turned out to be 59 and 50 μg event(-1) house(-1) terbutryn and carbendazim, respectively. Emissions for the other biocides ranged from 0.1 to 11 μg event(-1) house(-1). Mass load analysis revealed that peak events contributed in single events as much to the emissions as 11 average events. However, the mass loads were highly dependent on the amounts of rainwater, i.e. the hydraulic flow in the receiving sewer pipe. The analysis of the emission dynamics showed first flush emissions only for single parameters in three events out of twelve. Generally biocides seemed to be introduced into the stormwater system

  2. Separate and Concentrate Lactic Acid Using Combination of Nanofiltration and Reverse Osmosis Membranes

    NASA Astrophysics Data System (ADS)

    Li, Yebo; Shahbazi, Abolghasem; Williams, Karen; Wan, Caixia

    The processes of lactic acid production include two key stages, which are (a) fermentation and (b) product recovery. In this study, free cell of Bifidobacterium longum was used to produce lactic acid from cheese whey. The produced lactic acid was then separated and purified from the fermentation broth using combination of nanofiltration and reverse osmosis membranes. Nanofiltration membrane with a molecular weight cutoff of 100-400 Da was used to separate lactic acid from lactose and cells in the cheese whey fermentation broth in the first step. The obtained permeate from the above nanofiltration is mainly composed of lactic acid and water, which was then concentrated with a reverse osmosis membrane in the second step. Among the tested nanofiltration membranes, HL membrane from GE Osmonics has the highest lactose retention (97±1%). In the reverse osmosis process, the ADF membrane could retain 100% of lactic acid to obtain permeate with water only. The effect of membrane and pressure on permeate flux and retention of lactose/lactic acid was also reported in this paper.

  3. Self-assembly and β-carotene loading capacity of hydroxyethyl cellulose-graft-linoleic acid nanomicelles.

    PubMed

    Yang, Yang; Guo, Yanzhu; Sun, Runcang; Wang, Xiaohui

    2016-07-10

    A series of linoleic acid conjugated hydroxyethyl cellulose polymers (HEC-g-LA) were synthesized and characterized. And their solubilities in a variety of solvents were compared. The prepared HEC-g-LA polymers showed typical properties of amphiphilic polymers and were able to self-assemble into spherical nanomicelles in aqueous solution. The micelle sizes and critical micelle concentrations (CMC) were found correlated with the molecular structure of polymers, and were varied in the range of 20-50nm and 1.92-21.76μg/ml, respectively. Furthermore, the hydrophobic active component β-carotene (β-C) was successfully encapsulated into the HEC-g-LA micelles by sonication-dialysis method. The β-C encapsulation efficiency and loading content were found to be as high as 84.67% (w/w) and 4.23%. The results of in vitro release showed that the encapsulated β-C was continuously released from the micelles in phosphate buffered saline (PBS) medium for about 7days. The self-assembled HEC-g-LA nanomicelles are potential nanocarriers of hydrophobic active compounds for functional food applications. PMID:27106151

  4. Maximum power output and load matching of a phosphoric acid fuel cell-thermoelectric generator hybrid system

    NASA Astrophysics Data System (ADS)

    Chen, Xiaohang; Wang, Yuan; Cai, Ling; Zhou, Yinghui

    2015-10-01

    Based on the current models of phosphoric acid fuel cells (PAFCs) and thermoelectric generators (TGs), a new hybrid system is proposed, in which the effects of multi-irreversibilities resulting from the activation, concentration, and ohmic overpotentials in the PAFC, Joule heat and heat leak in the TG, finite-rate heat transfer between the TG and the heat reservoirs, and heat leak from the PAFC to the environment are taken into account. Expressions for the power output and efficiency of the PAFC, TG, and hybrid system are analytically derived and directly used to discuss the performance characteristics of the hybrid system. The optimal relationship between the electric currents in the PAFC and TG is obtained. The maximum power output is numerically calculated. It is found that the maximum power output density of the hybrid system will increase about 150 Wm-2, compared with that of a single PAFC. The problem how to optimally match the load resistances of two subsystems is discussed. Some significant results for practical hybrid systems are obtained.

  5. Magnetoliposomes Loaded with Poly-Unsaturated Fatty Acids as Novel Theranostic Anti-Inflammatory Formulations

    PubMed Central

    Calle, Daniel; Negri, Viviana; Ballesteros, Paloma; Cerdán, Sebastián

    2015-01-01

    We describe the preparation, physico-chemical characterization and anti-inflammatory properties of liposomes containing the superparamagnetic nanoparticle Nanotex, the fluorescent dye Rhodamine-100 and omega-3 polyunsaturated fatty acid ethyl ester (ω-3 PUFA-EE), as theranostic anti-inflammatory agents. Liposomes were prepared after drying chloroform suspensions of egg phosphatidylcholine, hydration of the lipid film with aqueous phases containing or not Nanotex, Rhodamine-100 dye or ω-3 PUFA-EE, and eleven extrusion steps through nanometric membrane filters. This resulted in uniform preparations of liposomes of approximately 200 nm diameter. Extraliposomal contents were removed from the preparation by gel filtration chromatography. High Resolution Magic Angle Spinning 1H NMR Spectroscopy of the liposomal preparations containing ω-3 PUFA-EE revealed well resolved 1H resonances from highly mobile ω-3 PUFA-EE, suggesting the formation of very small (ca. 10 nm) ω-3 PUFA-EE nanogoticules, tumbling fast in the NMR timescale. Chloroform extraction of the liposomal preparations revealed additionally the incorporation of ω-3 PUFA-EE within the membrane domain. Water diffusion weighted spectra, indicated that the goticules of ω-3 PUFA-EE or its insertion in the membrane did not affect the average translational diffusion coefficient of water, suggesting an intraliposomal localization, that was confirmed by ultrafiltration. The therapeutic efficacy of these preparations was tested in two different models of inflammatory disease as inflammatory colitis or the inflammatory component associated to glioma development. Results indicate that the magnetoliposomes loaded with ω-3 PUFA-EE allowed MRI visualization in vivo and improved the outcome of inflammatory disease in both animal models, decreasing significantly colonic inflammation and delaying, or even reversing, glioma development. Together, our results indicate that magnetoliposomes loaded with ω-3 PUFA-EE may become

  6. Optimization of the production of solid Witepsol nanoparticles loaded with rosmarinic acid.

    PubMed

    Campos, Débora A; Madureira, Ana Raquel; Gomes, Ana Maria; Sarmento, Bruno; Pintado, Maria Manuela

    2014-03-01

    During the last decade there has been a growing interest in the formulation of new food and nutraceutical products containing compounds with antioxidant activity. Unfortunately, due to their structure, certain compounds such as polyphenols, in particular rosmarinic acid (RA) are not stable and may interact easily with matrices in which they are incorporated. To overcome such limitations, the formulation of loaded polyphenols nanoparticles can offer an efficient solution to protect such compounds. Based on this rationale, the aim of this study was to prepare solid lipid nanoparticles (SLNs) loaded with RA using a hot melt ultrasonication method, where Witepsol H15 was used as lipid and Polysorbate 80 (Tween 80) as surfactant, following a 3(2) fractional factorial design, resulting in the use of 3 different percentages of surfactant (viz. 1, 2 and 3%, v/v) and lipid (0.5, 1.0 and 1.5%, w/v). The stability of the nanoparticles systems were tested during 28 d in aqueous solution stored at refrigeration temperature (ca. 5 °C), tracking the mean particle size of different formulations by photon correlation spectroscopy. To confirm RA entrapment, thermal analyses of the nanoparticles by DSC and FTIR were performed. The association efficiencies percentages (AE%) were determined using HPLC to quantitatively assess the RA in supernatants. Results showed that Witepsol H15 produced nanoparticles with initial mean diameters between 270 and 1000 nm, yet over time, a slight increase occurred, but without occurrence of aggregation. The AE% showed a high percentage of encapsulation (ca. 99%), which reveals low polyphenol releases from SLNs throughout storage time. In general, results showed a successful production of SLNs with properties that can be used to food applications. PMID:24413308

  7. Magnetoliposomes loaded with poly-unsaturated fatty acids as novel theranostic anti-inflammatory formulations.

    PubMed

    Calle, Daniel; Negri, Viviana; Ballesteros, Paloma; Cerdán, Sebastián

    2015-01-01

    We describe the preparation, physico-chemical characterization and anti-inflammatory properties of liposomes containing the superparamagnetic nanoparticle Nanotex, the fluorescent dye Rhodamine-100 and omega-3 polyunsaturated fatty acid ethyl ester (ω-3 PUFA-EE), as theranostic anti-inflammatory agents. Liposomes were prepared after drying chloroform suspensions of egg phosphatidylcholine, hydration of the lipid film with aqueous phases containing or not Nanotex, Rhodamine-100 dye or ω-3 PUFA-EE, and eleven extrusion steps through nanometric membrane filters. This resulted in uniform preparations of liposomes of approximately 200 nm diameter. Extraliposomal contents were removed from the preparation by gel filtration chromatography. High Resolution Magic Angle Spinning (1)H NMR Spectroscopy of the liposomal preparations containing ω-3 PUFA-EE revealed well resolved (1)H resonances from highly mobile ω-3 PUFA-EE, suggesting the formation of very small (ca. 10 nm) ω-3 PUFA-EE nanogoticules, tumbling fast in the NMR timescale. Chloroform extraction of the liposomal preparations revealed additionally the incorporation of ω-3 PUFA-EE within the membrane domain. Water diffusion weighted spectra, indicated that the goticules of ω-3 PUFA-EE or its insertion in the membrane did not affect the average translational diffusion coefficient of water, suggesting an intraliposomal localization, that was confirmed by ultrafiltration. The therapeutic efficacy of these preparations was tested in two different models of inflammatory disease as inflammatory colitis or the inflammatory component associated to glioma development. Results indicate that the magnetoliposomes loaded with ω-3 PUFA-EE allowed MRI visualization in vivo and improved the outcome of inflammatory disease in both animal models, decreasing significantly colonic inflammation and delaying, or even reversing, glioma development. Together, our results indicate that magnetoliposomes loaded with ω-3 PUFA-EE may

  8. Stress corrosion cracking and corrosion fatigue on 316L stainless steel in boric acid concentrated media at 320 C

    SciTech Connect

    Herms, E.; Olive, J.M.; Puiggali, M.; Boursier, J.M.

    1999-07-01

    Stress Corrosion Cracking (SCC) and Corrosion-Fatigue (CF) tests were performed in autoclave at 320 C in concentrated boric acid chlorinated media in presence of oxygen or hydrogen on type 316L austenitic stainless steel. Crack Growth Rates (CGR) are higher in non deaerated solutions for both SCC and CF than in hydrogenated solutions. CGR are relatively similar in CF and in SCC, excepted for high load ratio in CF where CGR are higher than in SCC. Detailed analysis of the fracture surface shows some distinct features between SCC and CF. Intergranular and transgranular mode of fracture are observed on SCC and CF. Fracture modes depend on the chemistry of solution in SCC and on frequency in CF. Traces of slip bands and crack front marking associated with oxide scale present on fracture surfaces exist in SCC and CF. Fatigue striations appear for low load ratio and high frequency. Secondary intergranular and transgranular cracking is observed only on SCC fracture surfaces and ligament morphology can be different in SCC relative to FC.

  9. Predictors of Third Trimester Blood Trihalomethanes and Urinary Trichloroacetic Acid Concentrations among Pregnant Women.

    PubMed

    Zeng, Qiang; Cao, Wen-Cheng; Zhou, Bin; Yang, Pan; Wang, Yi-Xin; Huang, Zhen; Li, Jin; Lu, Wen-Qing

    2016-05-17

    Prenatal exposure to disinfection byproducts (DBPs) has been associated with a variety of adverse birth outcomes. However, little is known about predictors of prenatal biomarkers of exposure to DBPs among pregnant women. We aimed to identify predictors of third trimester blood trihalomethanes (THMs) and urinary trichloroacetic acid (TCAA) concentrations, two biomarkers of exposure to DBPs, among pregnant women. Blood samples, urine samples, and questionnaires on individual characteristics and water-use activities were collected from 893 pregnant women in a Chinese cohort study. Maternal blood THM [chloroform (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), and bromoform (TBM)] and urinary TCAA concentrations were measured. We used multivariable linear regression to identify the predictors of third trimester blood THM and creatinine-adjusted urinary TCAA concentrations. The geometric mean of blood TTHM (sum of TCM, BDCM, DBCM, and TBM) and creatinine-adjusted urinary TCAA concentrations were 51.90 ng/L and 9.66 μg/g creatinine, respectively. Study city was the strongest significant predictors of blood THM and creatinine-adjusted urinary TCAA concentrations. Prenatal body mass index (BMI) was associated with decreased blood THM and decreased creatinine-adjusted urinary TCAA concentrations. Age was associated with increased blood Br-THM (sum of BDCM, DBCM, and TBM) concentrations. Intake of boiled water and passive smoking were associated with lower blood THM concentrations. The predictors of blood THM and urinary TCAA concentrations identified in this study provide potential health implications on how to reduce DBP exposure during pregnancy. PMID:27095243

  10. The concentration of ascorbic acid and glutathione in 13 provenances of Acacia melanoxylon.

    PubMed

    Wujeska-Klause, Agnieszka; Bossinger, Gerd; Tausz, Michael

    2016-04-01

    Climate change can negatively affect sensitive tree species, affecting their acclimation and adaptation strategies. A common garden experiment provides an opportunity to test whether responses of trees from different provenances are genetically driven and if this response is related to factors at the site of origin. We hypothesized that antioxidative defence systems and leaf mass area ofAcacia melanoxylonR. Br. samples collected from different provenances will vary depending on local rainfall. Thirteen provenances ofA. melanoxylonoriginating from different rainfall habitats (500-2000 mm) were grown for 5 years in a common garden. For 2 years, phyllode samples were collected during winter and summer, for measurements of leaf mass area and concentrations of glutathione and ascorbic acid. Leaf mass area varied between seasons, years and provenances ofA. melanoxylon, and an increase was associated with decreasing rainfall at the site of origin. Ascorbic acid and glutathione concentrations varied between seasons, years (i.e., environmental factors) and among provenances ofA. melanoxylon In general, glutathione and ascorbic acid concentrations were higher in winter compared with summer. Ascorbic acid and glutathione were different among provenances, but this was not associated with rainfall at the site of origin. PMID:26960387

  11. The concentration of amino acids by yeast cells depleted of adenosine triphosphate

    PubMed Central

    Eddy, A. A.; Backen, K.; Watson, G.

    1970-01-01

    1. The ATP content of preparations of a strain of Saccharomyces carlsbergensis was lowered below 0.3nmol/mg of yeast by starving the yeast cells in the presence of both antimycin and 5mm-deoxyglucose. 2. When the depleted cells were put at pH4.5 with glycine up to about 20nmol of the amino acid/mg of yeast was absorbed without being chemically modified. The mechanism did not depend on an exchange with endogenous amino acids. 3. The concentration of the absorbed glycine could apparently reach 100–200 times that outside the cells. 4. Replacement of the cellular K+ by Na+ almost stopped amino acid absorption in the presence of antimycin and deoxyglucose, but not in their absence. 5. It is suggested that, when energy metabolism itself had stopped, a purely physical process, namely the movements of H+ and K+ into and out of the yeast respectively, served to concentrate the amino acids in the cells. Both ionic species appear to be co-substrates of the system transporting amino acids. PMID:5495157

  12. Capillary electrophoresis method with UV-detection for analysis of free amino acids concentrations in food.

    PubMed

    Omar, Mei Musa Ali; Elbashir, Abdalla Ahmed; Schmitz, Oliver J

    2017-01-01

    Simple and inexpensive capillary electrophoresis with UV-detection method (CE-UV) was optimized and validated for determination of six amino acids namely (alanine, asparagine, glutamine, proline, serine and valine) for Sudanese food. Amino acids in the samples were derivatized with 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl) prior to CE-UV analysis. Labeling reaction conditions (100mM borate buffer at pH 8.5, labeling reaction time 60min, temperature 70°C and NBD-Cl concentration 40mM) were systematically investigated. The optimal conditions for the separation were 100mM borate buffer at pH 9.7 and detected at 475nm. The method was validated in terms of linearity, limit of detection (LOD), limit of quantification (LOQ), precision (repeatability) (RSD%) and accuracy (recovery). Good linearity was achieved for all amino acids (r(2)>0.9981) in the concentration range of 2.5-40mg/L. The LODs in the range of 0.32-0.56mg/L were obtained. Recoveries of amino acids ranging from 85% to 108%, (n=3) were obtained. The validated method was successfully applied for the determination of amino acids for Sudanese food samples. PMID:27507479

  13. In vitro antimicrobial activity of solution blow spun poly(lactic acid)/ polyvinylpyrrolidone nanofibers loaded with Copaiba (Copaifera sp.) oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study poly(lactic acid)(PLA) and polyvinylpyrrolidone (PVP) micro and nanofibers mats loaded with copaiba (Copaifera sp.) oil were produced by solution blow spinning (SBS). The copaiba (Copaifera sp.) oil was characterized by gas chromatography (GC). Neat PLA and four PLA/ PVP blends contain...

  14. Predictive Value of 8 Genetic Loci for Serum Uric Acid Concentration

    PubMed Central

    Gunjača, Grgo; Boban, Mladen; Pehlić, Marina; Zemunik, Tatijana; Budimir, Danijela; Kolčić, Ivana; Lauc, Gordan; Rudan, Igor; Polašek, Ozren

    2010-01-01

    Aim To investigate the value of genomic information in prediction of individual serum uric acid concentrations. Methods Three population samples were investigated: from isolated Adriatic island communities of Vis (n = 980) and Korčula (n = 944), and from general population of the city of Split (n = 507). Serum uric acid concentration was correlated with the genetic risk score based on 8 previously described genes: PDZK1, GCKR, SLC2A9, ABCG2, LRRC16A, SLC17A3, SLC16A9, and SLC22A12, represented by a total of 16 single-nucleotide polymorphisms (SNP). The data were analyzed using classification and regression tree (CART) and general linear modeling. Results The most important variables for uric acid prediction with CART were genetic risk score in men and age in women. The percent of variance for any single SNP in predicting serum uric acid concentration varied from 0.0%-2.0%. The use of genetic risk score explained 0.1%-2.5% of uric acid variance in men and 3.9%-4.9% in women. The highest percent of variance was obtained when age, sex, and genetic risk score were used as predictors, with a total of 30.9% of variance in pooled analysis. Conclusion Despite overall low percent of explained variance, uric acid seems to be among the most predictive human quantitative traits based on the currently available SNP information. The use of genetic risk scores is a valuable approach in genetic epidemiology and increases the predictability of human quantitative traits based on genomic information compared with single SNP approach. PMID:20162742

  15. Crop residue effects on Ca, Mg, K and Na concentrations and loads in runoff water

    NASA Astrophysics Data System (ADS)

    Miras-Avalos, J. M.; Sande-Fouz, P.; Bertol, I.; Paz-Gonzalez, A.

    2009-04-01

    Soil organic matter constitutes and important source of macro and micronutrients for plants and microorganisms while improving some physical and chemical properties of the soil. In Galicia (NW Spain), cultivated soils developed on schists from the Ordenes series show a relatively high susceptibility to surface degradation, which tends to be increased when soil organic content decreases. Therefore, management systems providing a high protection to the soil and increasing its organic matter content should also improve its quality. However, tillage practices may reduce the organic matter content in soil surface horizons, causing crust formation. Degraded soil surface conditions favor surface runoff, thus enhancing nutrient losses. This study examined the effect of applying crop residues to the soil surface on main nutrient (Ca, Mg, K and Na) losses by runoff from a tilled soil with a relatively low organic matter content. Runoff and sediment yield were made over 1 m2 plots using a rainfall simulator with constant 65 mmh-1 intensity. Four successive rainfall applications were performed, the first three ones 25 mm each and the last one 65 mm. Added corn straw varied between 0 and 4 tha-1 in the five studied treatments. Total and dissolved concentrations of the studied elements showed a trend to decrease due to the effect of corn straw on soil losses. After 140 mm cumulative rainfall, total nutrient losses were as follows: Ca from 12.32 to 28.94 mg L-1, Mg from 20.81 to 148.90 mg L-1, K from 14.20 to 35.17 mg L-1 and Na from 14.99 to 23.41 mg L-1. The relative contribution of the dissolved fraction to the total nutrient content loss was highly variable, being up to 90% in the case of Na. The obtained results confirmed that corn residues applied to a degraded soil, with low structural stability, prevented macronutrient losses.

  16. Elevated non-esterified fatty acid concentrations during bovine oocyte maturation compromise early embryo physiology.

    PubMed

    Van Hoeck, Veerle; Sturmey, Roger G; Bermejo-Alvarez, Pablo; Rizos, Dimitrios; Gutierrez-Adan, Alfonso; Leese, Henry J; Bols, Peter E J; Leroy, Jo L M R

    2011-01-01

    Elevated concentrations of serum non-esterified fatty acids (NEFA), associated with maternal disorders such as obesity and type II diabetes, alter the ovarian follicular micro-environment and have been associated with subfertility arising from reduced oocyte developmental competence. We have asked whether elevated NEFA concentrations during oocyte maturation affect the development and physiology of zygotes formed from such oocytes, using the cow as a model. The zygotes were grown to blastocysts, which were evaluated for their quality in terms of cell number, apoptosis, expression of key genes, amino acid turnover and oxidative metabolism. Oocyte maturation under elevated NEFA concentrations resulted in blastocysts with significantly lower cell number, increased apoptotic cell ratio and altered mRNA abundance of DNMT3A, IGF2R and SLC2A1. In addition, the blastocysts displayed reduced oxygen, pyruvate and glucose consumption, up-regulated lactate consumption and higher amino acid metabolism. These data indicate that exposure of maturing oocytes to elevated NEFA concentrations has a negative impact on fertility not only through a reduction in oocyte developmental capacity but through compromised early embryo quality, viability and metabolism. PMID:21858021

  17. Relative Amino Acid Concentrations as a Signature for Parent Body Processes of Carbonaceous Chondrites

    NASA Technical Reports Server (NTRS)

    Botta, Oliver; Glavin, Daniel P.; Kminek, Gerhard; Bada, Jeffrey L.

    2002-01-01

    Most meteorites are thought to have originated from objects in the asteroid belt. Carbonaceous chondrites, which contain significant amounts of organic carbon including complex organic compounds, have also been suggested to be derived from comets. The current model for the synthesis of organic compounds found in carbonaceous chondrites includes the survival of interstellar organic compounds and the processing of some of these compounds on the meteoritic parent body. The amino acid composition of five CM carbonaceous chondrites, two CIs, one CR, and one CV3 have been measured using hot water extraction-vapor hydrolysis, OPA/NAC derivatization and high-performance liquid chromatography (HPLC). Total amino acid abundances in the bulk meteorites as well as the amino acid concentrations relative to glycine = 1.0 for beta-alanine, alpha-aminoisobutyric acid and D-alanine were determined. Additional data for three Antarctic CM meteorites were obtained from the literature. All CM meteorites analyzed in this study show a complex distribution of amino acids and a high variability in total concentration ranging from approx. 15,300 to approx. 5800 parts per billion (ppb), while the CIs show a total amino acid abundance of approx. 4300 ppb. The relatively (compared to glycine) high AIB content found in all the CMs is a strong indicator that Strecker-cyanohydrin synthesis is the dominant pathway for the formation of amino acids found in these meteorites. The data from the Antarctic CM carbonaceous chondrites are inconsistent with the results from the other CMs, perhaps due to influences from the Antarctic ice that were effective during their residence time. In contrast to CMs, the data from the CI carbonaceous chondrites indicate that the Strecker synthesis was not active on their parent bodies.

  18. Airborne concentrations of metals and total dust during solid catalyst loading and unloading operations at a petroleum refinery.

    PubMed

    Lewis, Ryan C; Gaffney, Shannon H; Le, Matthew H; Unice, Ken M; Paustenbach, Dennis J

    2012-09-01

    Workers handle catalysts extensively at petroleum refineries throughout the world each year; however, little information is available regarding the airborne concentrations and plausible exposures during this type of work. In this paper, we evaluated the airborne concentrations of 15 metals and total dust generated during solid catalyst loading and unloading operations at one of the largest petroleum refineries in the world using historical industrial hygiene samples collected between 1989 and 2006. The total dust and metals, which included aluminum, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel, platinum, silicon, silver, vanadium, and zinc, were evaluated in relation to the handling of four different types of solid catalysts associated with three major types of catalytic processes. Consideration was given to the known components of the solid catalysts and any metals that were likely deposited onto them during use. A total of 180 analytical results were included in this analysis, representing 13 personal and 54 area samples. Of the long-term personal samples, airborne concentrations of metals ranged from <0.001 to 2.9mg/m(3), and, in all but one case, resulted in concentrations below the current U.S. Occupational Safety and Health Administration's Permissible Exposure Limits and the American Conference of Governmental Industrial Hygienists' Threshold Limit Values. The arithmetic mean total dust concentration resulting from long-term personal samples was 0.31mg/m(3). The data presented here are the most complete set of its kind in the open literature, and are useful for understanding the potential exposures during solid catalyst handling activities at this petroleum refinery and perhaps other modern refineries during the timeframe examined. PMID:22177528

  19. Three Patients Needing High Doses of Valproic Acid to Get Therapeutic Concentrations

    PubMed Central

    Jackson, James; McCollum, Betsy; Ognibene, Judy; Diaz, Francisco J.; de Leon, Jose

    2015-01-01

    Valproic acid (VPA) can autoinduce its own metabolism. Cases requiring VPA doses >4000 mg/day to obtain therapeutic plasma concentrations, such as these 3 cases, have never been published. Case 1 received VPA for seizures and schizophrenia and had >50 VPA concentrations in 4 years. A high dose of 5,250 mg/day of VPA concentrate was prescribed for years but this dose led to an intoxication when switched to the enterocoated divalproex sodium formulation, requiring a normal dose of 2000 mg/day. VPA metabolic capacity was significantly higher (t = −9.6; df = 6.3, p < 0.001) during the VPA concentrate therapy, possibly due to autoinduction in that formulation. Case 2 had VPA for schizoaffective psychosis with 10 VPA concentrations during an 8-week admission. To maintain a VPA level ≥50 μg/mL, VPA doses increased from 1500 to 4000 mg/day. Case 3 had tuberous sclerosis and epilepsy and was followed up for >4 years with 137 VPA concentrations. To maintain VPA concentrations ≥50 μg/mL, VPA doses increased from 3,375 to 10,500 mg/day. In Cases 2 and 3, the duration of admission and the VPA dose were strongly correlated (r around 0.90; p < 0.001) with almost no change after controlling for VPA concentrations, indicating progressive autoinduction that increased with time. PMID:26000191

  20. Self-assembled amphotericin B-loaded polyglutamic acid nanoparticles: preparation, characterization and in vitro potential against Candida albicans

    PubMed Central

    Zia, Qamar; Khan, Aijaz Ahmed; Swaleha, Zubair; Owais, Mohammad

    2015-01-01

    In the present study, we developed a self-assembled biodegradable polyglutamic acid (PGA)-based formulation of amphotericin B (AmB) and evaluated its in vitro antifungal potential against Candida albicans. The AmB-loaded PGA nanoparticles were prepared in-house and had a mean size dimension of around 98±2 nm with a zeta potential of −35.2±7.3 mV. Spectroscopic studies revealed that the drug predominantly acquires an aggregated form inside the formulation with an aggregation ratio above 2. The PGA-based AmB formulation was shown to be highly stable in phosphate-buffered saline as well as in serum (only 10%–20% of the drug was released after 10 days). The AmB–PGA nanoparticles were less toxic to red blood cells (<15% lysis at an AmB concentration of 100 μg/mL after 24 hours) when compared with Fungizone®, a commercial antifungal product. An MTT assay showed that the viability of mammalian cells (KB and RAW 264.7) was negligibly affected at AmB concentrations as high as 200 μg/mL. Histopathological examination of mouse kidney revealed no signs of tissue necrosis. The AmB–PGA formulation showed potent antimicrobial activity similar to that of Fungizone against C. albicans. Interestingly, AmB-bearing PGA nanoparticles were found to inhibit biofilm formation to a considerable extent. In summary, AmB–PGA nanoparticles showed highly attenuated toxicity when compared with Fungizone, while retaining equivalent active antifungal properties. This study indicates that the AmB–PGA preparation could be a promising treatment for various fungal infections. PMID:25784804

  1. Bioregeneration of mono-amine modified silica and granular activated carbon loaded with Acid Orange 7 in batch system.

    PubMed

    Al-Amrani, Waheeba Ahmed; Lim, Poh-Eng; Seng, Chye-Eng; Ngah, Wan Saime Wan

    2012-08-01

    The objectives of this study were: (1) to investigate the role of mixed culture of biomass in the regeneration of mono-amine modified silica (MAMS) and granular activated carbon (GAC) loaded with Acid Orange 7 (AO7), (2) to quantify and compare the bioregeneration efficiencies of AO7-loaded MAMS and GAC using the sequential adsorption and biodegradation approach and (3) to evaluate the reusability of bioregenerated MAMS. The results show that considerably higher bioregeneration efficiency of AO7-loaded MAMS as compared to that of AO7-loaded GAC was achieved due to higher reversibility of adsorption of MAMS for AO7 and favorable pH factor resulting in more AO7 desorption. The progressive loss of adsorption capacity of MAMS for AO7 with multiple cycles of use suggests possible chemical and microbial fouling of the adsorption sites. PMID:22704829

  2. Growth factors-loaded stents modified with hyaluronic acid and heparin for induction of rapid and tight re-endothelialization.

    PubMed

    Choi, Dong Hoon; Kang, Sung Nam; Kim, Seong Min; Gobaa, Samy; Park, Bang Ju; Kim, Ik Hwan; Joung, Yoon Ki; Han, Dong Keun

    2016-05-01

    Rapid re-endothelialization of damaged vessel lining efficiently prevents restenosis and thrombosis and restores original vascular functions. In this study, we designed a novel metallic stent with a heparin-modified surface and used different methods, including 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and divinyl sulfone (DVS), to load growth factors. First we loaded heparin into a dopamine-conjugated hyaluronic acid (HA) coating to serve as a growth factor reservoir. In a second step, we took advantage of the heparin-binding domain of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) to gain advanced re-endothelialization capabilities. We demonstrated that DVS technique offered higher amount of growth factor loading. In vitro assessment also showed better capillary-like structure formation and localized gap junctions when DVS coating was employed. This study suggested that growth factor loaded stent modified by HA and heparin provided the advantage to rapid and tight restoration of endothelium. PMID:26928466

  3. Changes in plasma kynurenic acid concentration in septic shock patients undergoing continuous veno-venous haemofiltration.

    PubMed

    Dabrowski, Wojciech; Kocki, Tomasz; Pilat, Jacek; Parada-Turska, Jolanta; Malbrain, Manu L N G

    2014-02-01

    Kynurenic acid (KYNA) is one of the end products of tryptophan metabolism. The aim of this study was to analyse plasma KYNA concentration in septic shock patients (SSP) with acute kidney injury (AKI) undergoing continuous veno-venous haemofiltration (CVVH). Changes in KYNA content were compared to alterations in the levels of procalcitonin (PCT), C-reactive protein and lactate. Adult SSP with AKI were examined. Measurements were conducted at seven time points: before beginning CVVH and at 6, 12, 24, 48, 72 and 96 h after the beginning of CVVH. Based on clinical outcomes, the data were analysed separately for survivors and non-survivors. Twenty-seven patients were studied. CVVH was associated with reduced plasma KYNA concentration only in survivors. Plasma KYNA concentration correlated with the levels of lactate and PCT only in survivors. (1) CVVH reduced plasma KYNA concentration only in survivors; (2) lack of this reduction may predict fatal outcomes in SSP. PMID:24043287

  4. Effects of Eimeria acervulina infection severity on growth performance, apparent ileal amino acid digestibility, and plasma concentrations of amino acids, carotenoids, and α1-acid glycoprotein in broilers.

    PubMed

    Rochell, S J; Parsons, C M; Dilger, R N

    2016-07-01

    An experiment was conducted to evaluate growth performance, apparent ileal digestibility (AID) of amino acids, and plasma concentrations of amino acids, carotenoids, and α1-acid glycoprotein, an acute-phase protein, in broilers inoculated with graded doses of E. acervulina oocysts. Ross 308 male broilers (400 total) were housed in battery cages from 1 to 21 d post-hatch and received common corn-soybean meal-based diets throughout the experiment. At 9 d post-hatch, birds were individually weighed and allotted to 4 treatment groups with 10 replicate cages of 10 birds per cage. At 15 d post-hatch, all birds were inoculated with 1 mL of distilled water that contained 0, 2.5 × 10(5), 5.0 × 10(5), or 1.0 × 10(6) sporulated E. acervulina oocysts. At 21 d, birds were euthanized for collection of blood and ileal digesta. Body weight gain and feed efficiency decreased linearly (P < 0.05) with increasing E. acervulina dose. With the exception of Trp and Gly, AID values decreased (P < 0.05) linearly or quadratically for all amino acids by an average of 2.6 percentage units for birds inoculated with 1.0 × 10(6) oocysts compared with uninfected birds. Infection with E. acervulina caused a quadratic decrease (P < 0.05) in plasma carotenoid concentrations. Plasma concentrations of Arg and Tyr decreased linearly (P < 0.05) with increasing E. acervulina inoculation dose and plasma Gln and Asn decreased quadratically (P < 0.01). Linear increases (P < 0.05) were observed for plasma Lys, Leu, Ile, Val, Pro, and Orn as E. acervulina inoculation dose increased. Plasma α1-acid glycoprotein of broilers was not influenced (P > 0.05) by E. acervulina infection. In conclusion, E. acervulina challenge adversely impacted growth performance, plasma carotenoids, and AID of amino acids in a dose-dependent manner. However, plasma amino acid responses to graded E. acervulina inoculation doses varied considerably among amino acids. Thus, these results indicated that alterations

  5. Improvement of Transdermal Delivery of Exendin-4 Using Novel Tip-Loaded Microneedle Arrays Fabricated from Hyaluronic Acid.

    PubMed

    Liu, Shu; Wu, Dan; Quan, Ying-Shu; Kamiyama, Fumio; Kusamori, Kosuke; Katsumi, Hidemasa; Sakane, Toshiyasu; Yamamoto, Akira

    2016-01-01

    The purpose of this study was to evaluate the characteristics of exendin-4 tip-loaded microneedle arrays and to compare their acute efficacy with subcutaneous injections in type 2 diabetic GK/Slc rats. Fluorescein isothiocyanate labeled dextran with an average molecular weight of 4,000 (FD4) was selected as a model drug, and FD4 tip-loaded microneedle arrays were prepared in this study. In addition, intraperitoneal glucose tolerance tests after application of exendin-4 tip-loaded microneedle arrays were also compared with those after subcutaneous injection in type 2 diabetic GK/Slc rats. The release of FD4 from the tip-loaded microneedle arrays was very rapid, particularly in the initial 30 s, and most of the FD4 was released within 5 min. In addition, glucose tolerance was improved and the insulin secretion was enhanced after application of exendin-4 tip-loaded microneedle arrays, and these effects were comparable to those after subcutaneous injection of exendin-4. Similar plasma concentration profiles were seen after application of exendin-4 tip-loaded microneedle arrays, as was the case with subcutaneous injection in type 2 diabetic GK/Slc rats. These findings indicate that exendin-4 tip-loaded microneedle arrays can be used as an alternative to achieve sufficient delivery of exendin-4 for treatment of type 2 diabetes. To our knowledge, this is the first report of transdermal exendin-4 delivery using tip-loaded microneedle arrays. PMID:26649921

  6. Lack of correlation between organic acid concentrations and predominant electron-accepting processes in a contaminated aquifer

    USGS Publications Warehouse

    Vroblesky, D.A.; Bradley, P.M.; Chapelle, F.H.

    1997-01-01

    Long-term (1992-1995) monitoring data from a petroleum hydrocarbon- contaminated aquifer were used to examine the hypothesis that concentrations of low molecular weight (LMW) aliphatic organic acids reflect terminal electron-accepting processes. During the period of study, concentrations of dissolved hydrogen (H2) indicated that methanogenic, sulfate-reducing, and iron(III)-reducing conditions predominated at the site. However, there was no correlation between LMW organic acid concentrations and concentrations of dissolved H2. These results indicate that organic acid concentrations are not a reliable indicator of local redox conditions at this site.

  7. Life evaluation of valve-regulated lead-acid batteries for load-leveling applications

    NASA Astrophysics Data System (ADS)

    Deluca, W. H.; Miller, J. F.; Webster, C. E.; Hogrefe, R. L.

    Argonne National Laboratory (ANL) has initiated a test program to evaluate the suitability of valve-regulated lead-acid (VRLA) batteries for use in deep-discharge cycling applications. The program includes the examination of VRLA batteries of the gelled-electrolyte design and the absorbed-electrolyte type. This work is sponsored by the Electric Power Research Institute (EPRI) and the International Lead Zinc Research Organization (ILZRO). While VRLA batteries have found use in standby and uninterruptable power source applications, insufficient data are available to determine their performance and life in repetitive cycling applications. The objectives of the ANL test plan are: (1) to use accelerated testing techniques to obtain evidence within a 6 month test period that indicate an expected life in a utility operating environment; (2) to determine VRLA battery life within a 2 to 3 year time period under conditions (temperature and depth-of-discharge) that closely simulate those encountered in load-leveling operations; and (3) to assess the applicability and usefulness of accelerated testing procedures for deep-discharge cycling applications.

  8. Doxorubicin hydrochloride-oleic acid conjugate loaded nanostructured lipid carriers for tumor specific drug release.

    PubMed

    Zhao, Shuangni; Minh, Le Van; Li, Na; Garamus, Vasil M; Handge, Ulrich A; Liu, Jianwen; Zhang, Rongguang; Willumeit-Römer, Regine; Zou, Aihua

    2016-09-01

    The hydrophilic drug Doxorubicin hydrochloride (DOX) paired with oleic acid (OA) was successfully incorporated into nanostructured lipid carriers (NLCs) by a high-pressure homogenization (HPH) method. Drug nanovehicles with proper physico-chemical characteristics (less than 200nm with narrow size distribution, spherical shape, layered internal organization, and negative electrical charge) were prepared and characterized by dynamic light scattering, zeta potential measurements, transmission electron microscopy, small-angle X-ray scattering and differential scanning calorimetry. The drug loading and entrapment efficiency of DOX-OA/NLCs were 4.09% and 97.80%, respectively. A pH-dependent DOX release from DOX-OA/NLCs, i.e., fast at pH 3.8 and 5.7 and sustained at pH 7.4, was obtained. A cytotoxicity assay showed that DOX-OA/NLCs had comparable cytotoxicity to pure DOX and were favorably taken up by HCT 116 cells. The intracellular distribution of DOX was also studied using a confocal laser scanning microscope. All of these results demonstrated that DOX-OA/NLCs could be a promising drug delivery system with tumor-specific DOX release for cancer treatment. PMID:27137808

  9. Ursolic acid-loaded chitosan nanoparticles induce potent anti-angiogenesis in tumor.

    PubMed

    Jin, Hua; Pi, Jiang; Yang, Fen; Wu, Chaomin; Cheng, Xueli; Bai, Haihua; Huang, Dan; Jiang, Jinhuan; Cai, Jiye; Chen, Zheng W

    2016-08-01

    Angiogenesis provides necessary nutrients and oxygen for tumor growth and metastasis; thus, every stage of angiogenesis process is the potential target for cancer therapies. Ursolic acid (UA) is reported to decrease tumor burden through anti-angiogenesis pathway, but its poor water solubility greatly limits its efficiency and clinical application. Here, a simple method for preparing UA-loaded chitosan nanoparticles (CH-UA-NPs) with anti-angiogenesis and anti-tumor activity was demonstrated. In vitro, CH-UA-NPs could significantly inhibit the proliferation, migration, and tube formation of human umbilical vascular endothelial cells (HUVECs). After uptake by HUVECs, CH-UA-NPs were mainly localized in lysosomes and mitochondria, but not nuclei. CH-UA-NPs induced the destruction of lysosome membrane integrity, collapse of mitochondrial membrane potential, and reorganization of cell cytoskeleton. All these changes led to the apoptosis or necrosis in HUVECs. In vivo, CH-UA-NPs could inhibit the angiogenesis in chicken chorioallantoic membrane (CAM) model and H22 xenograft model. Notably, comparing with free UA, such synthesized CH-UA-NPs could save about tenfold of UA doses, implying that this could significantly decrease the side effects induced by high doses of UA in biological organism. Our data showed that CH-UA-NPs and this nanoparticle-based drug delivery system could be as a potential drug candidate for anti-angiogenesis treatment. PMID:26883344

  10. The Pharmacokinetics and Pharmacodynamics of Lidocaine-Loaded Biodegradable Poly(lactic-co-glycolic acid) Microspheres

    PubMed Central

    Liu, Jianming; Lv, Xin

    2014-01-01

    The purpose of this study was to develop novel lidocaine microspheres. Microspheres were prepared by the oil-in-water (o/w) emulsion technique using poly(d,l-lactide-co-glycolide acid) (PLGA) for the controlled delivery of lidocaine. The average diameter of lidocaine PLGA microspheres was 2.34 ± 0.3 μm. The poly disperse index was 0.21 ± 0.03, and the zeta potential was +0.34 ± 0.02 mV. The encapsulation efficiency and drug loading of the prepared microspheres were 90.5% ± 4.3% and 11.2% ± 1.4%. In vitro release indicated that the lidocaine microspheres had a well-sustained release efficacy, and in vivo studies showed that the area under the curve of lidocaine in microspheres was 2.02–2.06-fold that of lidocaine injection (p < 0.05). The pharmacodynamics results showed that lidocaine microspheres showed a significant release effect in rats, that the process to achieve efficacy was calm and lasting and that the analgesic effect had a significant dose-dependency. PMID:25268618

  11. Chasing bacteria within the cells using levofloxacin-loaded hyaluronic acid nanohydrogels.

    PubMed

    Montanari, E; D'Arrigo, G; Di Meo, C; Virga, A; Coviello, T; Passariello, C; Matricardi, P

    2014-08-01

    In the present work, an innovative approach based on the delivery of levofloxacin (LVF) from polysaccharide nanohydrogels for the treatment of bacterial intracellular infections is described. The nanohydrogels (NHs) were obtained by self-assembling of the hyaluronic acid-cholesterol amphiphilic chains in aqueous environment. LVF, a fluoroquinolone antibiotic scarcely efficient in intracellular infections, was entrapped within such NHs by nanoprecipitation, thus forming a drug delivery system (LVF-NHs) that was tested for its activity on different bacteria strains. The MIC values of levofloxacin-loaded nanohydrogels were determined for Staphylococcus aureus and Pseudomonas aeruginosa strains and compared to those obtained using free LVF. The intracellular antimicrobial activity of LVF-NHs and free LVF was compared on HeLa epithelial cell line infected by the above mentioned bacteria, and the increase in antibacterial efficacy of LVF-NHs with respect to that of free LVF was evidenced. The obtained results allow to conclude that this new approach can be considered as really promising method for intracellular infection treatments. PMID:24642185

  12. Gadolinium diethylenetriaminopentaacetic acid-loaded chitosan microspheres for gadolinium neutron-capture therapy.

    PubMed

    Saha, Tapan Kumar; Ichikawa, Hideki; Fukumori, Yoshinobu

    2006-12-11

    In order to provide a suitable device that would contain water-soluble drugs, highly water-soluble gadolinium diethylenetriaminopentaacetic acid-loaded chitosan microspheres (CMS-Gd-DTPA) were prepared by the emulsion method using glutaraldehyde as a cross-linker and Span 80 as a surfactant for gadolinium neutron-capture therapy of cancer. The gadolinium content and the mass median diameter of CMS-Gd-DTPA were estimated. The size and morphology of the CMS-Gd-DTPA were strongly influenced by the initial applied weight ratio of Gd-DTPA:chitosan. FTIR spectra showed that the electrostatic interaction between chitosan and Gd-DTPA accelerated the formation of gadolinium-enriched chitosan microspheres. Sufficient amounts of glutaraldehyde and Span 80 were necessary for producing discrete CMS-Gd-DTPA. The CMS-Gd-DTPA having a mass median diameter 11.7microm and 11.6% of gadolinium could be used in Gd-NCT following intratumoral injection. PMID:17045253

  13. Evaluation of five biocarriers as supports for immobilized bacteria: Comparative performance during high chemical loading, acid shocking, drying and heat shocking

    SciTech Connect

    Heitkamp, M.A.; Adams, W.J. . Environmental Sciences Center); Camel, V. )

    1993-06-01

    Immobilized bacteria technology (IBT) utilizes inert biocarriers to support high concentrations of chemical-degrading bacteria in reactors designed to provide optimal conditions for microbial activity. This study evaluated IBT performance inpacked bed reactors (PBRs) using a porous inorganic biocarrier (diatomaceous earth), nonporous biocarriers (glass beads), and organic biocarriers having carbon adsorption properties (granular activated carbon) with different porosity. Each reactor was challenged with high chemical loading, acid, dryness, and heat shock conditions. Benchtop PBSs inoculated with a p-nitrophenol (PNP)-degrading Pseudomonas sp. and fed a synthetic waste containing 100 to 1,300 mg/L of PNP showed removal of PNP from effluents within 24 h of start-up. Chemical loading studies showed maximum PNP removal rates of 6.45 to 7.35 kg/m[sup 3]/d for bacteria in PBRs containing diatomaceous earth beads, glass beads, and activated coconut carbon. A lower PNP removal rate of 1.47 kg/m[sup 3]/d was determined for the activated anthracite carbon, and this PBR responded more slowly to increases in chemical loading. The PBR containing bacteria immobilized on activated coconut carbon showed exceptional tolerance to acid shocking, drying, and heat shocking by maintaining PNP removal rates > 85% throughout the entire study. The other biocarriers showed nearly complete loss of PNP degradation during the perturbations, but all recovered high rates of PNP degradation (> 98% removal) within 48 h after an acid shock at pH2, within 8 d after an acid shock at pH 1.0, within 24 h after drying for 72 h, and within 48 h of heat shocking. The resiliency and high chemical removal efficiency demonstrated by immobilized bacteria in this study support the concept of using IBT for the biotreatment of industrial wastes..

  14. Inhibitory effect of gels loaded with a low concentration of antibiotics against biofilm formation by Enterococcus faecalis and Porphyromonas gingivalis.

    PubMed

    A Algarni, Amnah; H Yassen, Ghaeth; L Gregory, Richard

    2015-09-01

    We explored longitudinally the inhibitory effect of gels loaded with 1 mg/mL modified triple antibiotic paste (MTAP) or double antibiotic paste (DAP) against biofilm formation by Enterococcus faecalis and Porphyromonas gingivalis. Methylcellulose-based antibiotic gels of MTAP (ciprofloxacin, metronidazole and clindamycin) and DAP (ciprofloxacin and metronidazole) were prepared at a concentration of 1 mg/mL. Individually cultured E. faecalis and P. gingivalis bacterial suspensions were treated with MTAP, DAP, or placebo (vehicle only) gels at different dilutions and allowed to grow in 96-well microtiter plates. Untreated bacterial suspensions served as a negative control. Crystal violet assays were used to evaluate biofilm formation after 48 h. The ability of the gels to inhibit biofilm formation was determined immediately, and at 1 month and 3 months after the gels had been prepared. Data were analyzed using a mixed-model ANOVA. The MTAP and DAP gels significantly reduced biofilm formation by both bacterial species at all time points, regardless of the tested dilution. No-significant differences in biofilm-inhibitory effects between MTAP and DAP gels were observed at the majority of the tested dilutions through various time points. Gels loaded with 1 mg/mL MTAP and DAP demonstrated a significant antibiofilm effect against E.faecalis and P. gingivalis. PMID:26369485

  15. Optimum concentration ratio of photodecomposable quencher to acid generator in chemically amplified extreme ultraviolet resists

    NASA Astrophysics Data System (ADS)

    Kozawa, Takahiro

    2015-12-01

    In chemically amplified resists used for ionizing radiations such as an extreme ultraviolet radiation, thermalized electrons and protons play important roles in pattern formation. Photodecomposable quenchers are important for 11 nm half-pitch fabrication because they capture both thermalized electrons and protons. However, their effects are complicated for the same reason. In this study, the optimum concentration ratio of photodecomposable quenchers to acid generators in terms of the trade-off relationships between resolution, line width roughness (LWR), and sensitivity was theoretically investigated, assuming line-and-space patterns of 11 nm half-pitch. To suppress LWR to less than 20% critical dimension (CD), the recommended total sensitizer concentration (the sum of acid generator and photodecomposable quencher concentrations) was in the range of 0.20-0.22 nm-3. The expected sensitivities were 30-40 mJ cm-2 when the resist performance of the latest chemically amplified resists was assumed. The optimum ratio of photodecomposable quencher concentration to the total sensitizer concentration was 0.55.

  16. Trichloroacetic acid in urine as biological exposure equivalent for low exposure concentrations of trichloroethene.

    PubMed

    Csanády, György A; Göen, Thomas; Klein, Dominik; Drexler, Hans; Filser, Johannes G

    2010-11-01

    A urinary trichloroacetic acid (TCA) concentration of 100 mg/l at the end of the last work shift (8 h/day, 5 days/week) of the week has been established in workers as exposure equivalent for the carcinogenic substance trichloroethene (EKA for TRI) at an exposure concentration of 50 ppm TRI. Due to the continuous reduction of atmospheric TRI concentrations during the last years, the quantitative relation given by the EKA for TRI is revised for exposures to low TRI concentrations. A physiological two-compartment model is presented by which the urinary TCA concentrations are calculated that result from inhaled TRI in humans. The model contains one compartment for trichloroethanol (TCE) and one for TCA. Inhaled TRI is metabolized to TCA and to TCE. The latter is in part further oxidized to TCA. Urinary elimination of TCA is modeled to obey first order kinetics. All required model parameters were taken form the literature. In order to evaluate the model performance on the urinary TCA excretion at low exposure concentrations, predicted urinary TCA concentrations were compared with data obtained in two volunteer studies and in one field study. The model was evaluated at exposure concentrations as low as 12.5 ppm TRI. It is demonstrated that the correlation described by the hitherto used EKA for TRI is also valid at low TRI concentrations. For TRI exposure concentrations of 0.6 and 6 ppm, the resulting urinary TCA concentrations at the end of the last work shift of a week are predicted to be 1.2 and 12 mg/l, respectively. PMID:20414643

  17. Improved In Vitro Antileukemic Activity of All-Trans Retinoic Acid Loaded in Cholesteryl Butyrate Solid Lipid Nanoparticles.

    PubMed

    Silva, Elton Luiz; Lima, Flávia Alves; Carneiro, Guilherme; Ramos Jonas Periera; Gomes, Dawidson Assis; de Souza-Fagundes, Elaine Maria; Ferreira, Lucas Antônio Miranda

    2016-02-01

    All-trans retinoic acid, a hydrophobic drug, has become one of the most successful examples of differentiation agents used for treatment of acute promyelocytic leukemia. On the other hand, histone deacetylase inhibitors, such as cholesteryl butyrate, present differentiating activity and.can potentiate action of drugs such as all-trans retinoic acid. Solid lipid nanoparticles represent a promising alternative for administration of hydrophobic drugs such as ATRA. This study aimed to develop, characterize, and evaluate the cytotoxicity of all-trans retinoic acid-loaded solid lipid nanoparticles for leukemia treatment. The influence of in situ formation of an ion pairing between all-trans retinoic acid and lipophilic amines on the characteristics of the particles (size, zeta potential, encapsulation efficiency) was evaluated. Cholesteryl butyrate, a butyric acid donor, was used as a component of the lipid matrix. In vitro activity on cell viability and distribution of cell cycle phases were evaluated for HL-60, Jurkat, and THP-1 cell lines. The encapsulation efficiency of all-trans retinoic acid in cholesteryl butyrate-solid lipid nanoparticles was significantly increased by the presence of the amine. Inhibition of cell viability by all-trans retinoic acid-loaded solid lipid nanoparticles was more pronounced than the free drug. Analysis of the distribution of cell cycle phases also showed increased activity for all-trans retinoic acid-loaded cholesteryl butyrate-solid lipid nanoparticles, with a clear increase in subdiploid DNA content. The ion pair formation in SLN containing cholesteryl butyrate can be explored as a simple and inexpensive strategy to improve the efficacy and bioavail-ability of ATRA in the treatment of the cancer and metabolic diseases in which this retinoid plays an important role. PMID:27433579

  18. An experimental and modeling study of humic acid concentration effect on H(+) binding: Application of the NICA-Donnan model.

    PubMed

    Vidali, Roza; Remoundaki, Emmanouela; Tsezos, Marios

    2009-11-15

    Humic substances are the most abundant components of the colloidal and the dissolved fraction of natural organic matter (NOM) and they are characterized by a strong binding capacity for both metals and organic pollutants, affecting their mobility and bioavailability. The understanding of the humic acidic character is the first necessary step for the study of the mechanisms of binding of other positively charged soluble metal species by humic molecules. The present work, which constitutes part of the Ph.D. thesis of Roza Vidali, reports results on the influence of the concentration of humic acids on the binding of protons obtained through both an experimental and a modeling approach. A reference purified peat humic acid (PPHA) isolated by the International Humic Substances Society (IHSS) and a humic acid from a Greek soil (GHA) were experimentally studied at various humic acid concentrations, ranging from 20 to 200mgL(-1). The proton binding isotherms obtained at different humic acid concentrations have shown that proton binding is dependent on the concentration of both humic acids. Proton binding experimental data were fitted to the NICA-Donnan model and the model parameter values were calculated for humic acid concentrations of 20 and >or=100mgL(-1). The results obtained for the NICA-Donnan parameters at humic acid concentrations >or=100mgL(-1) are in excellent agreement with those reported in the literature. However, these model parameter values cannot be used for modeling and predicting cation binding in natural aquatic systems, where humic acid concentrations are much lower. Two sets of the NICA-Donnan parameters are reported: one for humic acid concentrations of >or=100mgL(-1) and one for humic acid concentration of 20mgL(-1). The significance of the parameters values for each concentration level is also discussed. PMID:19744666

  19. Effects of branched-chain amino acid supplementation on plasma concentrations of free amino acids, insulin, and energy substrates in young men.

    PubMed

    Zhang, Yi; Kobayashi, Hisamine; Mawatari, Kazunori; Sato, Juichi; Bajotto, Gustavo; Kitaura, Yasuyuki; Shimomura, Yoshiharu

    2011-01-01

    The present study was conducted to examine alterations in the concentrations of plasma free amino acids, glucose, insulin, free fatty acids (FFAs), and urea nitrogen induced by branched-chain amino acid (BCAA) supplementation in young men. Overnight-fasted subjects ingested drinks containing 1 or 5 g of a BCAA mixture (weight ratio of 1 : 2.3 : 1.2 for isoleucine : leucine : valine), and blood was intermittently collected for 3 h after ingestion. Ingestion of the BCAA mixture resulted in significant increases in the plasma concentrations of individual BCAAs, corresponding to the amounts of amino acids ingested. On the other hand, plasma concentrations of methionine and aromatic amino acids tended to decrease in the trial with 5 g BCAAs, suggesting that BCAA ingestion affects the metabolism of these amino acids. The ingestion of BCAAs temporarily increased plasma insulin levels and affected plasma concentrations of FFAs, but had almost no effect on glucose or urea nitrogen. PMID:21512300

  20. An intercomparison of measurement systems for vapor and particulate phase concentrations of formic and acetic acids

    NASA Technical Reports Server (NTRS)

    Keene, William C.; Talbot, Robert W.; Andreae, Meinrat O.; Beecher, Kristene; Berresheim, Harold

    1989-01-01

    During June 1986, eight systems for measuring vapor phase and four for measuring particulate phase concentrations of formic acid (HCOOH) and acetic acid (CH3COOH) were intercompared in central Virginia. HCOOH and CH3COOH vapors were sampled by condensate, mist, Chromosorb 103 GC resin, NaOH-coated annular denuders, NaOH-impregnated quartz filters, K2CO3 and NaCO3-impregnated cellulose filters, and Nylasorb membranes. Atmospheric aerosol was collected on Teflon and Nuclepore filters using both hi-vol and lo-vol systems to measure particulate phase concentrations. Performances of the mist chamber and K2CO3-impregnated filter techniques were evaluated using zero air and ambient air spiked with HCOOH(g) and CH3COOH(g), and formaldehyde from permeation sources. The advantages and drawbacks of these methods are reported and discussed.

  1. Connecting Source with Sink: The Role of Arabidopsis AAP8 in Phloem Loading of Amino Acids1[OPEN

    PubMed Central

    Santiago, James P.; Tegeder, Mechthild

    2016-01-01

    Allocation of large amounts of nitrogen to developing organs occurs in the phloem and is essential for plant growth and seed development. In Arabidopsis (Arabidopsis thaliana) and many other plant species, amino acids represent the dominant nitrogen transport forms in the phloem, and they are mainly synthesized in photosynthetically active source leaves. Following their synthesis, a broad spectrum of the amino nitrogen is actively loaded into the phloem of leaf minor veins and transported within the phloem sap to sinks such as developing leaves, fruits, or seeds. Controlled regulation of the source-to-sink transport of amino acids has long been postulated; however, the molecular mechanism of amino acid phloem loading was still unknown. In this study, Arabidopsis AMINO ACID PERMEASE8 (AAP8) was shown to be expressed in the source leaf phloem and localized to the plasma membrane, suggesting its function in phloem loading. This was further supported by transport studies with aap8 mutants fed with radiolabeled amino acids and by leaf exudate analyses. In addition, biochemical and molecular analyses revealed alterations in leaf nitrogen pools and metabolism dependent on the developmental stage of the mutants. Decreased amino acid phloem loading and partitioning to sinks led to decreased silique and seed numbers, but seed protein levels were unchanged, demonstrating the importance of AAP8 function for sink development rather than seed quality. Overall, these results show that AAP8 plays an important role in source-to-sink partitioning of nitrogen and that its function affects source leaf physiology and seed yield. PMID:27016446

  2. Poly(lactic) acid fibers loaded with mesoporous silica for potential applications in the active food packaging

    NASA Astrophysics Data System (ADS)

    Cacciotti, Ilaria; Nanni, Francesca

    2016-06-01

    Multifunctional fibrous systems based on poly(lactic) acid (PLA), mesoporous silica (SiO2) and ascorbic acid (AA) were produced by means of electrospinning technique, for potential applications in the active food packaging sector, as platform for the controlled release of antioxidant and/or antimicrobial agents with the additional filtering function. The ascorbic acid was physisorbed on the surface of mesoporous silica in order to stabilize it and to extend its antioxidant action. The influence of mesoporous silica and ascorbic acid on the microstructural and mechanical properties was investigated, revealing a revelant mechanical reinforcement in the case of fibers loaded only with SiO2 and a decrement in the case of SiO2 with physisorbed ascorbic acid, due to the worse interface between the fillers and the polymeric matrix.

  3. Autoclave leaching of molybdenite concentrates with catalytic additives of nitric acid

    NASA Astrophysics Data System (ADS)

    Smirnov, K. M.; Raspopov, N. A.; Shneerson, Ya. M.; Lapin, A. Yu.; Bitkov, G. A.; Men'shikov, Yu. A.; Paskhin, P. N.; Kirichenko, V. P.

    2010-07-01

    The scientific theoretical prerequisites for the use of small additives of nitric acid for the intensification of the autoclave oxidative leaching (AOL) of sulfide concentrates are checked in order to increase the degree of extraction of the base metal with a simultaneous decrease in the cost of the process. The technological parameters of the AOL conditions applied to molybdenite are also refined, and recommendations for a practical application of the apparatus of the process and for a decrease in its cost are made.

  4. Higher breakfast glycaemic load is associated with increased metabolic syndrome risk, including lower HDL-cholesterol concentrations and increased TAG concentrations, in adolescent girls.

    PubMed

    Nicholl, Analise; du Heaume, Mary; Mori, Trevor A; Beilin, Lawrence J; Oddy, Wendy H; Bremner, Alexandra P; O'Sullivan, Therese A

    2014-12-28

    Almost all previous studies examining the associations between glycaemic load (GL) and metabolic syndrome risk have used a daily GL value. The daily value does not distinguish between peaks of GL intake over the day, which may be more closely associated with the risk of the metabolic syndrome. The aim of the present study was to investigate the cross-sectional associations between daily and mealtime measures of GL and metabolic syndrome risk, including metabolic syndrome components, in adolescents. Adolescents participating in the 14-year follow-up of the Western Australian Pregnancy Cohort (Raine) Study completed 3 d food records and metabolic assessments. Breakfast GL, lunch GL, dinner GL and a score representing meal GL peaks over the day were determined in 516 adolescents. Logistic regression models were used to investigate whether GL variables were independent predictors of the metabolic syndrome in this population-based cohort (3.5% prevalence of the metabolic syndrome). Breakfast GL was found to be predictive of the metabolic syndrome in girls (OR 1.15, 95% CI 1.04, 1.27; P <0.01), but not in boys. Other meal GL values and daily GL were found to be not significant predictors of the metabolic syndrome. When breakfast GL was examined in relation to each of the components of the metabolic syndrome in girls, it was found to be negatively associated with fasting HDL-cholesterol concentrations (P= 0.037; β = - 0.004; 95% CI - 0.008, - 0.002) and positively associated with fasting TAG concentrations (P= 0.008; exp(β) = 1.002; 95% CI 1.001, 1.004). he results of the present study suggest that there may be an association between breakfast composition and metabolic syndrome components in adolescent girls. These findings support further investigation into including lower-GL foods as part of a healthy breakfast in adolescence, particularly for girls. PMID:25327283

  5. Effect of dimethylamine on the gas phase sulfuric acid concentration measured by Chemical Ionization Mass Spectrometry

    PubMed Central

    Ehrhart, S.; Kürten, A.; Adamov, A.; Bianchi, F.; Breitenlechner, M.; Duplissy, J.; Franchin, A.; Dommen, J.; Donahue, N. M.; Dunne, E. M.; Flagan, R. C.; Hakala, J.; Hansel, A.; Keskinen, H.; Kim, J.; Jokinen, T.; Lehtipalo, K.; Leiminger, M.; Praplan, A.; Riccobono, F.; Rissanen, M. P.; Sarnela, N.; Schobesberger, S.; Simon, M.; Sipilä, M.; Smith, J. N.; Tomé, A.; Tröstl, J.; Tsagkogeorgas, G.; Vaattovaara, P.; Winkler, P. M.; Williamson, C.; Wimmer, D.; Baltensperger, U.; Kirkby, J.; Kulmala, M.; Petäjä, T.; Worsnop, D. R.; Curtius, J.

    2016-01-01

    Abstract Sulfuric acid is widely recognized as a very important substance driving atmospheric aerosol nucleation. Based on quantum chemical calculations it has been suggested that the quantitative detection of gas phase sulfuric acid (H2SO4) by use of Chemical Ionization Mass Spectrometry (CIMS) could be biased in the presence of gas phase amines such as dimethylamine (DMA). An experiment (CLOUD7 campaign) was set up at the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber to investigate the quantitative detection of H2SO4 in the presence of dimethylamine by CIMS at atmospherically relevant concentrations. For the first time in the CLOUD experiment, the monomer sulfuric acid concentration was measured by a CIMS and by two CI‐APi‐TOF (Chemical Ionization‐Atmospheric Pressure interface‐Time Of Flight) mass spectrometers. In addition, neutral sulfuric acid clusters were measured with the CI‐APi‐TOFs. The CLOUD7 measurements show that in the presence of dimethylamine (<5 to 70 pptv) the sulfuric acid monomer measured by the CIMS represents only a fraction of the total H2SO4, contained in the monomer and the clusters that is available for particle growth. Although it was found that the addition of dimethylamine dramatically changes the H2SO4 cluster distribution compared to binary (H2SO4‐H2O) conditions, the CIMS detection efficiency does not seem to depend substantially on whether an individual H2SO4 monomer is clustered with a DMA molecule. The experimental observations are supported by numerical simulations based on A Self‐contained Atmospheric chemistry coDe coupled with a molecular process model (Sulfuric Acid Water NUCleation) operated in the kinetic limit. PMID:27610289

  6. Effect of dimethylamine on the gas phase sulfuric acid concentration measured by Chemical Ionization Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Rondo, L.; Ehrhart, S.; Kürten, A.; Adamov, A.; Bianchi, F.; Breitenlechner, M.; Duplissy, J.; Franchin, A.; Dommen, J.; Donahue, N. M.; Dunne, E. M.; Flagan, R. C.; Hakala, J.; Hansel, A.; Keskinen, H.; Kim, J.; Jokinen, T.; Lehtipalo, K.; Leiminger, M.; Praplan, A.; Riccobono, F.; Rissanen, M. P.; Sarnela, N.; Schobesberger, S.; Simon, M.; Sipilä, M.; Smith, J. N.; Tomé, A.; Tröstl, J.; Tsagkogeorgas, G.; Vaattovaara, P.; Winkler, P. M.; Williamson, C.; Wimmer, D.; Baltensperger, U.; Kirkby, J.; Kulmala, M.; Petäjä, T.; Worsnop, D. R.; Curtius, J.

    2016-03-01

    Sulfuric acid is widely recognized as a very important substance driving atmospheric aerosol nucleation. Based on quantum chemical calculations it has been suggested that the quantitative detection of gas phase sulfuric acid (H2SO4) by use of Chemical Ionization Mass Spectrometry (CIMS) could be biased in the presence of gas phase amines such as dimethylamine (DMA). An experiment (CLOUD7 campaign) was set up at the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber to investigate the quantitative detection of H2SO4 in the presence of dimethylamine by CIMS at atmospherically relevant concentrations. For the first time in the CLOUD experiment, the monomer sulfuric acid concentration was measured by a CIMS and by two CI-APi-TOF (Chemical Ionization-Atmospheric Pressure interface-Time Of Flight) mass spectrometers. In addition, neutral sulfuric acid clusters were measured with the CI-APi-TOFs. The CLOUD7 measurements show that in the presence of dimethylamine (<5 to 70 pptv) the sulfuric acid monomer measured by the CIMS represents only a fraction of the total H2SO4, contained in the monomer and the clusters that is available for particle growth. Although it was found that the addition of dimethylamine dramatically changes the H2SO4 cluster distribution compared to binary (H2SO4-H2O) conditions, the CIMS detection efficiency does not seem to depend substantially on whether an individual H2SO4 monomer is clustered with a DMA molecule. The experimental observations are supported by numerical simulations based on A Self-contained Atmospheric chemistry coDe coupled with a molecular process model (Sulfuric Acid Water NUCleation) operated in the kinetic limit.

  7. Monitoring of phosphorus in Danish surface waters 1990-2012: Trends in phosphorus loading and phosphorus concentrations in streams, lakes and estuaries

    NASA Astrophysics Data System (ADS)

    Windolf, Jørgen; Kronvang, Brian; Carstensen, Jacob; Larsen, Søren E.; Bøgestrand, Jens; Trolle, Dennis

    2014-05-01

    For more than 20 years an integrated, standardized monitoring programme of Danish surface waters has provided information on status and trends in the phosphorus loading and phosphorus concentrations of Danish waters. Although the land-based phosphorus loading of Danish coastal waters has been reduced by 60For several decades the excess loading of phosphorus from diffuse sources and sewage outlets contributed significantly to the eutrophication of surface waters, and this is still the case. Measures taken to combat this eutrophication have included among others improved sewage treatment, diversion of sewage outlets from lakes and reduction of the phosphorus surplus on agricultural land. The overall effects of the measures taken to reduce the phosphorus loading and thereby improve the water quality will be presented for 15 Danish lakes and 10 estuaries and for 160 Danish streams draining catchments with varying anthropogenic impacts. The generally reduced phosphorus loading has led to a decrease in phosphorus concentrations in Danish lakes and estuaries due to the direct - long-term - link between phosphorus loading and phosphorus concentrations in lakes and estuaries. Special focus will be given to the development since 1990 in phosphorus concentrations in 31 streams draining farmed catchments with no significant sewage outlets and the potential factors influencing trends and variations. In 14 of these streams there has been a significant reduction in phosphorus concentrations since 1990, and for all the streams a general reduction of 17

  8. Nutrient concentrations, loads, and yields in the Eucha-Spavinaw Basin, Arkansas and Oklahoma, 2002-09

    USGS Publications Warehouse

    Esralew, Rachel A.; Tortorelli, Robert L.

    2010-01-01

    The city of Tulsa, Oklahoma, uses Lake Eucha and Spavinaw Lake in the Eucha-Spavinaw Basin in northwestern Arkansas and northeastern Oklahoma for public water supply. The city has spent millions of dollars over the last decade to eliminate taste and odor problems in the drinking water from the Eucha-Spavinaw system, which may be attributable to blue-green algae. Increases in the algal biomass in the lakes may be attributable to increases in nutrient concentrations in the lakes and in the waters feeding the lakes. The U.S. Geological Survey, in cooperation with the City of Tulsa, investigated and summarized total nitrogen and total phosphorus concentrations in water samples and provided estimates of nitrogen and phosphorus loads, yields, and flow-weighted concentrations during base flow and runoff for two streams discharging to Lake Eucha for the period January 2002 through December 2009. This report updates a previous report that used data from water-quality samples collected from January 2002 through December 2006. Based on the results from the Mann-Whitney statistical test, unfiltered total nitrogen concentrations were significantly greater in runoff water samples than in base-flow water samples collected from Spavinaw Creek near Maysville and near Cherokee City, Arkansas; Spavinaw Creek near Colcord, Oklahoma, and Beaty Creek near Jay, Oklahoma. Nitrogen concentrations in runoff water samples collected from all stations generally increased with increasing streamflow. Nitrogen concentrations in base-flow and runoff water samples collected in Spavinaw Creek significantly increased from the station furthest upstream (near Maysville) to the Sycamore station and then significantly decreased from the Sycamore station to the station furthest downstream (near Colcord). Nitrogen concentrations in base-flow and runoff water samples collected from Beaty Creek were significantly less than base-flow and runoff water samples collected from Spavinaw Creek. Based on the results

  9. [Have Case Loads of Radical Surgery for Prostate Cancer Been Concentrated in Hospitals with Robotic Equipment ?--Analyses with Questionnaire Survey and Diagnostic Procedure Combination (DPC) Data].

    PubMed

    Tsukamoto, Taiji; Tanaka, Shigeru

    2016-04-01

    We investigated whether installation of robot-assisted surgical equipment in hospitals resulted in concentration of the case loads of radical prostatectomy. We selected 11 areas with populations of around 1 million or more where there were one or more hospitals with robotic equipment and 4 or more without it. In addition, annual changes of case loads for prostatectomy over 4 years from 2010 to 2013 were clearly determined in these areas. The case loads were determined based on the results of a questionnaire survey for the hospitals with robots and on the Diagnostic Procedures Combination data provided by the Ministry of Health, Labor and Wealth for those without such equipment. The concentration of the case loads was principally defined as when hospitals with robots had more predominant proportion of cases than those without them in the comparison between case loads prior to instillation of robots (or in the initial year of the study) and those in the final years. The 11 selected areas included 44 hospitals with robots and 156 without them. Concentration of case loads was found in 5 areas. In 4 areas, installation of robots did not have a specific relation to the distribution pattern s of case loads in hospitals with or without the equipment. The remaining 2 areas tended to have a weak but not definite concentration of case loads. In the areas in which installation did not influence case loads the further analysis revealed that their case loads had already been concentrated in the initial year (2010) of the study. Although the current results were found in a single department of the hospital, robotic installation may result in concentration of prostatectomy case loads for such hospitals in some areas. The current results are intriguing when we consider the future roles of acute care hospitals and beds in our country where the number of aged patients having chronic diseases will increase. In conclusion, installation of robotic equipment may result in concentration

  10. Cell type-specific response to high intracellular loading of polyacrylic acid-coated magnetic nanoparticles.

    PubMed

    Lojk, Jasna; Bregar, Vladimir B; Rajh, Maruša; Miš, Katarina; Kreft, Mateja Erdani; Pirkmajer, Sergej; Veranič, Peter; Pavlin, Mojca

    2015-01-01

    Magnetic nanoparticles (NPs) are a special type of NP with a ferromagnetic, electron-dense core that enables several applications such as cell tracking, hyperthermia, and magnetic separation, as well as multimodality. So far, superparamagnetic iron oxide NPs (SPIONs) are the only clinically approved type of metal oxide NPs, but cobalt ferrite NPs have properties suitable for biomedical applications as well. In this study, we analyzed the cellular responses to magnetic cobalt ferrite NPs coated with polyacrylic acid (PAA) in three cell types: Chinese Hamster Ovary (CHO), mouse melanoma (B16) cell line, and primary human myoblasts (MYO). We compared the internalization pathway, intracellular trafficking, and intracellular fate of our NPs using fluorescence and transmission electron microscopy (TEM) as well as quantified NP uptake and analyzed uptake dynamics. We determined cell viability after 24 or 96 hours' exposure to increasing concentrations of NPs, and quantified the generation of reactive oxygen species (ROS) upon 24 and 48 hours' exposure. Our NPs have been shown to readily enter and accumulate in cells in high quantities using the same two endocytic pathways; mostly by macropinocytosis and partially by clathrin-mediated endocytosis. The cell types differed in their uptake rate, the dynamics of intracellular trafficking, and the uptake capacity, as well as in their response to higher concentrations of internalized NPs. The observed differences in cell responses stress the importance of evaluation of NP-cell interactions on several different cell types for better prediction of possible toxic effects on different cell and tissue types in vivo. PMID:25733835

  11. Cell type-specific response to high intracellular loading of polyacrylic acid-coated magnetic nanoparticles

    PubMed Central

    Lojk, Jasna; Bregar, Vladimir B; Rajh, Maruša; Miš, Katarina; Kreft, Mateja Erdani; Pirkmajer, Sergej; Veranič, Peter; Pavlin, Mojca

    2015-01-01

    Magnetic nanoparticles (NPs) are a special type of NP with a ferromagnetic, electron-dense core that enables several applications such as cell tracking, hyperthermia, and magnetic separation, as well as multimodality. So far, superparamagnetic iron oxide NPs (SPIONs) are the only clinically approved type of metal oxide NPs, but cobalt ferrite NPs have properties suitable for biomedical applications as well. In this study, we analyzed the cellular responses to magnetic cobalt ferrite NPs coated with polyacrylic acid (PAA) in three cell types: Chinese Hamster Ovary (CHO), mouse melanoma (B16) cell line, and primary human myoblasts (MYO). We compared the internalization pathway, intracellular trafficking, and intracellular fate of our NPs using fluorescence and transmission electron microscopy (TEM) as well as quantified NP uptake and analyzed uptake dynamics. We determined cell viability after 24 or 96 hours’ exposure to increasing concentrations of NPs, and quantified the generation of reactive oxygen species (ROS) upon 24 and 48 hours’ exposure. Our NPs have been shown to readily enter and accumulate in cells in high quantities using the same two endocytic pathways; mostly by macropinocytosis and partially by clathrin-mediated endocytosis. The cell types differed in their uptake rate, the dynamics of intracellular trafficking, and the uptake capacity, as well as in their response to higher concentrations of internalized NPs. The observed differences in cell responses stress the importance of evaluation of NP–cell interactions on several different cell types for better prediction of possible toxic effects on different cell and tissue types in vivo. PMID:25733835

  12. A Novel Preparation Method for Camptothecin (CPT) Loaded Folic Acid Conjugated Dextran Tumor-Targeted Nanoparticles

    PubMed Central

    Zu, Yuangang; Wang, Dan; Zhao, Xiuhua; Jiang, Ru; Zhang, Qi; Zhao, Dongmei; Li, Yong; Zu, Baishi; Sun, Zhiqiang

    2011-01-01

    In this study, folic-dextran-camptothecin (Fa-DEX-CPT) tumor-targeted nanoparticles were produced with a supercritical antisolvent (SAS) technique by using dimethyl sulfoxide (DMSO) as a solvent and carbon dioxide as an antisolvent. A factorial design was used to reveal the effect of various process parameters on the mean particle size (MPS) and morphology of the particles formed. Under the optimum operation conditions, Fa-DEX-CPT nanoparticles with a MPS of 182.21 nm were obtained. Drug encapsulation efficiency and loading efficiency were 62.13% and 36.12%, respectively. It was found that the concentrations of the camptothecin (CPT) and dextran solution had a major influence upon morphology and shape of the final product. In addition, the samples were characterized by Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) with the purpose of developing a suitable targeted drug delivery system for cancer chemotherapy. PMID:21845075

  13. Reduced gamma-aminobutyric acid concentration is associated with physical disability in progressive multiple sclerosis

    PubMed Central

    Solanky, Bhavana S.; Muhlert, Nils; Tur, Carmen; Edden, Richard A. E.; Wheeler-Kingshott, Claudia A. M.; Miller, David H.; Thompson, Alan J.; Ciccarelli, Olga

    2015-01-01

    Neurodegeneration is thought to be the major cause of ongoing, irreversible disability in progressive stages of multiple sclerosis. Gamma-aminobutyric acid is the principle inhibitory neurotransmitter in the brain. The aims of this study were to investigate if gamma-aminobutyric acid levels (i) are abnormal in patients with secondary progressive multiple sclerosis compared with healthy controls; and (ii) correlate with physical and cognitive performance in this patient population. Thirty patients with secondary progressive multiple sclerosis and 17 healthy control subjects underwent single-voxel MEGA-PRESS (MEscher-GArwood Point RESolved Spectroscopy) magnetic resonance spectroscopy at 3 T, to quantify gamma-aminobutyric acid levels in the prefrontal cortex, right hippocampus and left sensorimotor cortex. All subjects were assessed clinically and underwent a cognitive assessment. Multiple linear regression models were used to compare differences in gamma-aminobutyric acid concentrations between patients and controls adjusting for age, gender and tissue fractions within each spectroscopic voxel. Regression was used to examine the relationships between the cognitive function and physical disability scores specific for these regions with gamma-aminobuytric acid levels, adjusting for age, gender, and total N-acetyl-aspartate and glutamine-glutamate complex levels. When compared with controls, patients performed significantly worse on all motor and sensory tests, and were cognitively impaired in processing speed and verbal memory. Patients had significantly lower gamma-aminobutyric acid levels in the hippocampus (adjusted difference = −0.403 mM, 95% confidence intervals −0.792, −0.014, P = 0.043) and sensorimotor cortex (adjusted difference = −0.385 mM, 95% confidence intervals −0.667, −0.104, P = 0.009) compared with controls. In patients, reduced motor function in the right upper and lower limb was associated with lower gamma-aminobutyric acid

  14. Reduced gamma-aminobutyric acid concentration is associated with physical disability in progressive multiple sclerosis.

    PubMed

    Cawley, Niamh; Solanky, Bhavana S; Muhlert, Nils; Tur, Carmen; Edden, Richard A E; Wheeler-Kingshott, Claudia A M; Miller, David H; Thompson, Alan J; Ciccarelli, Olga

    2015-09-01

    Neurodegeneration is thought to be the major cause of ongoing, irreversible disability in progressive stages of multiple sclerosis. Gamma-aminobutyric acid is the principle inhibitory neurotransmitter in the brain. The aims of this study were to investigate if gamma-aminobutyric acid levels (i) are abnormal in patients with secondary progressive multiple sclerosis compared with healthy controls; and (ii) correlate with physical and cognitive performance in this patient population. Thirty patients with secondary progressive multiple sclerosis and 17 healthy control subjects underwent single-voxel MEGA-PRESS (MEscher-GArwood Point RESolved Spectroscopy) magnetic resonance spectroscopy at 3 T, to quantify gamma-aminobutyric acid levels in the prefrontal cortex, right hippocampus and left sensorimotor cortex. All subjects were assessed clinically and underwent a cognitive assessment. Multiple linear regression models were used to compare differences in gamma-aminobutyric acid concentrations between patients and controls adjusting for age, gender and tissue fractions within each spectroscopic voxel. Regression was used to examine the relationships between the cognitive function and physical disability scores specific for these regions with gamma-aminobuytric acid levels, adjusting for age, gender, and total N-acetyl-aspartate and glutamine-glutamate complex levels. When compared with controls, patients performed significantly worse on all motor and sensory tests, and were cognitively impaired in processing speed and verbal memory. Patients had significantly lower gamma-aminobutyric acid levels in the hippocampus (adjusted difference = -0.403 mM, 95% confidence intervals -0.792, -0.014, P = 0.043) and sensorimotor cortex (adjusted difference = -0.385 mM, 95% confidence intervals -0.667, -0.104, P = 0.009) compared with controls. In patients, reduced motor function in the right upper and lower limb was associated with lower gamma-aminobutyric acid concentration in the

  15. The effect of convalescent meridian acupressure after exercise on stress hormones and lactic acid concentration changes

    PubMed Central

    Shin, Won

    2013-01-01

    Meridian acupressure has been used as the one way recovering body conditions. The purpose of this study was to investigate whether meridian acupressure is effective on removing cortisol, norepinephrine, epinephrine, and lactic acid in blood following exercise. The subjects were 12 healthy male college students and data were processed using SPSS 12.0 statistical program and the results were calculated by setting the significance level at P< 0.05. First, there was a significant difference between exercise recovery group except for stability group and acupressure recovery group in convalescent cortisol concentration changes after exercise (P= 0.001). And acupressure recovery group showed a significant difference compared with two groups (P= 0.001). Second, exercise recovery group showed nonsignificant difference in convalescent norepinephrine concentration changes but meridian acupressure recovery group showed a significant difference (P= 0.001). There was a significance difference in the groups rather than exercise recovery group and rest recovery group (P= 0.001). Third, exercise recovery group and acupressure recovery group showed a significant difference in convalescent epinephrine concentration changes after exercise (P= 0.001). However, rest recovery group showed nonsignificant difference. In addition, three groups showed nonsignificant difference in the groups. However, it showed in order of acupressure= exercise> rest recovery. Fourth, three groups showed a significant difference in convalescent lactic acid concentration changes after exercise (P = 0.001). And it showed in order of acupressure= exercise> rest recovery after recovery treatment in the groups (P= 0.001). PMID:24278880

  16. nC60 deposition kinetics: the complex contribution of humic acid, ion concentration, and valence.

    PubMed

    McNew, Coy P; LeBoeuf, Eugene J

    2016-07-01

    The demonstrated toxicity coupled with inevitable environmental release of nC60 raise serious concerns about its environmental fate and transport, therefore it is crucial to understand how nC60 will interact with subsurface materials including attached phase soil and sediment organic matter (AP-SOM). This study investigated the attachment of nC60 onto a Harpeth humic acid (HHA) coated silica surface under various solution conditions using a quartz crystal microbalance with dissipation monitoring. The HHA coating greatly enhanced nC60 attachment at low ion concentrations while hindering attachment at high ion concentrations in the presence of both mono and divalent cations. At low ion concentrations, the HHA greatly reduced the surface potential of the silica, enhancing nC60 deposition through reduction in the electrostatic repulsion. At high ion concentrations however, the reduced surface potential became less important due to the near zero energy barrier to deposition and therefore non-DLVO forces dominated, induced by compaction of the HHA layer, and leading to hindered attachment. In this manner, observed contributions from the HHA layer were more complex than previously reported and by monitoring surface charge and calculated DLVO interaction energy alongside attachment experiments, this study advances the mechanistic understanding of the variable attachment contributions from the humic acid layer. PMID:27061365

  17. A method for concentrating organic dyes: colorimetric measurements of nitric oxides and sialic acids.

    PubMed

    Lalezari, Parviz; Lekhraj, Rukmani; Casper, Diana

    2011-09-01

    A new method for extraction and concentration of organic dyes that uses a reagent composed of a nonionic detergent mixed with an alcohol is described. We have observed that water-soluble organic dyes are also soluble in nonionic detergents and can be extracted by adding salt, which separates the dye-detergent component from the aqueous phase. We have also found that mixing nonionic detergents with alcohols markedly reduces their viscosity and produces stable, free-flowing, and effective reagents for color extraction. On the basis of these observations, we used a mixture of Triton X-100 and 1-butanol and observed that water-soluble natural and synthetic chromophores, as well as dyes generated in biochemical reactions, can be extracted, concentrated, and analyzed spectrophotometrically. Trypan blue and phenol red are used as examples of synthetic dyes, and red wine is used as an example of phenolic plant pigments. Applications for quantification of nitric oxides and sialic acids are described in more detail and show that as little as 0.15 nmol of nitric oxide and 0.20 nmol of sialic acid can be detected. A major advantage of this method is its ability to concentrate chromophores from dye-containing solutions that otherwise cannot be measured because of their low concentrations. PMID:21605540

  18. Synthesis of nanosilver loaded chitosan/poly(acrylamide-co-itaconic acid) based inter-polyelectrolyte complex films for antimicrobial applications.

    PubMed

    Bajpai, S K; Jyotishi, Pooja; Bajpai, M

    2016-12-10

    In the present work, AgNPs loaded chitosan/poly(acrylamide-co-itaconic acid) inter-polyelectrolyte complex (IPC) films have been prepared for antimicrobial applications. The AgNPs-loaded IPC films have been characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA) and Surface plasmon resonance (SPR). Particle size of synthesized AgNPs was found to be in the range 10-30nm. These films exhibited a remarkable antibacterial property against strong pathogen E.Coli, thus offering their candidature for antimicrobial applications. PMID:27577913

  19. Mass concentration coupled with mass loading rate for evaluating PM(2.5) pollution status in the atmosphere: A case study based on dairy barns.

    PubMed

    Joo, HungSoo; Park, Kihong; Lee, Kwangyul; Ndegwa, Pius M

    2015-12-01

    This study investigated particulate matter (PM) loading rates and concentrations in ambient air from naturally ventilated dairy barns and also the influences of pertinent meteorological factors, traffic, and animal activities on mass loading rates and mass concentrations. Generally, relationships between PM2.5 concentration and these parameters were significantly poorer than those between the PM loading rate and the same parameters. Although ambient air PM2.5 loading rates correlated well with PM2.5 emission rates, ambient air PM2.5 concentrations correlated poorly with PM2.5 concentrations in the barns. A comprehensive assessment of PM2.5 pollution in ambient air, therefore, requires both mass concentrations and mass loading rates. Emissions of PM2.5 correlated strongly and positively with wind speed, temperature, and solar radiation (R(2) = 0.84 to 0.99) and strongly but negatively with relative humidity (R(2) = 0.93). Animal activity exhibited only moderate effect on PM2.5 emissions, while traffic activity did not significantly affect PM2.5 emissions. PMID:26452004

  20. Salicylhydroxamic acid (SHAM) inhibition of the dissolved inorganic carbon concentrating process in unicellular green algae

    SciTech Connect

    Goyal, A.; Tolbert, N.E. )

    1990-03-01

    Rates of photosynthetic O{sub 2} evolution, for measuring K{sub 0.5}(CO{sub 2} + HCO{sub 3}{sup {minus}}) at pH 7, upon addition of 50 micromolar HCO{sub 3}{sup {minus}} to air-adapted Chlamydomonas, Dunaliella, or Scenedesmus cells, were inhibited up to 90% by the addition of 1.5 to 4.0 millimolar salicylhydroxamic acid (SHAM) to the aqueous medium. The apparent K{sub i}(SHAM) for Chlamydomonas cells was about 2.5 millimolar, but due to low solubility in water effective concentrations would be lower. Salicylhydroxamic acid did not inhibit oxygen evolution or accumulation of bicarbonate by Scenedesmus cells between pH 8 to 11 or by isolated intact chloroplasts from Dunaliella. Thus, salicylhydroxamic acid appears to inhibit CO{sub 2} uptake, whereas previous results indicate that vanadate inhibits bicarbonate uptake. These conclusions were confirmed by three test procedures with three air-adapted algae at pH 7. Salicylhydroxamic acid inhibited the cellular accumulation of dissolved inorganic carbon, the rate of photosynthetic O{sub 2} evolution dependent on low levels of dissolved inorganic carbon (50 micromolar NaHCO{sub 3}), and the rate of {sup 14}CO{sub 2} fixation with 100 micromolar ({sup 14}C)HCO{sub 3}{sup {minus}}. Salicylhydroxamic acid inhibition of O{sub 2} evolution and {sup 14}CO{sub 2}-fixation was reversed by higher levels of NaHCO{sub 3}. Thus, salicylhydroxamic acid inhibition was apparently not affecting steps of photosynthesis other than CO{sub 2} accumulation. Although salicylhydroxamic acid is an inhibitor of alternative respiration in algae, it is not known whether the two processes are related.

  1. Developing Critical Loads of acidity for streams in the Great Smoky Mountains National Park, using PnET-BGC model

    NASA Astrophysics Data System (ADS)

    Fakhraei, H.

    2015-12-01

    Acid deposition has impaired acid-sensitive streams and reduced aquatic biotic integrity in Great Smoky Mountains National Park (GRSM) by decreasing pH and acid neutralizing capacity (ANC). Twelve streams in GRSM are listed by the state of Tennessee as impaired due to low stream pH (pH<6.0) under Section 303(d) of the Clean Water Act. A dynamic biogeochemical model, PnET-BGC, was used to evaluate past, current and potential future changes in soil and water chemistry of watersheds of GRSM in response to changes in acid deposition. Calibrating 30 stream-watersheds in GRSM (including 12 listed impaired streams) to the long-term stream chemistry observations, the model was parameterized for the Park. The calibrated model was used to evaluate the level of atmospheric deposition above which harmful effects occur, known as "critical loads", for individual study watersheds. Estimated critical loads and exceedances (levels of deposition above the critical load) of atmospheric sulfur and nitrogen deposition were depicted through geographic information system maps. Accuracy of model simulations in the presence of uncertainties in the estimated model parameters and inputs was assessed using three uncertainty and sensitivity techniques.

  2. Crop harvest in Denmark and Central Europe contributes to the local load of airborne Alternaria spore concentrations in Copenhagen

    NASA Astrophysics Data System (ADS)

    Skjøth, C. A.; Sommer, J.; Frederiksen, L.; Gosewinkel Karlson, U.

    2012-11-01

    This study examines the hypothesis that Danish agricultural areas are the main source of airborne Alternaria spores in Copenhagen, Denmark. We suggest that the contribution to the overall load is mainly local or regional, but with intermittent long distance transport (LDT) from more remote agricultural areas. This hypothesis is supported by investigating a 10 yr bi-hourly record of Alternaria spores in the air from Copenhagen. This record shows 232 clinically relevant episodes (daily average spore concentration above 100 m-3) with a distinct daily profile. The data analysis also revealed potential LDT episodes almost every year. A source map and analysis of atmospheric transport suggest that LDT always originates from the main agricultural areas in Central Europe. A dedicated emission study in cereal crops under harvest during 2010 also supports our hypothesis. The emission study showed that although the fields had been treated against fungal infections, harvesting still produced large amounts of airborne fungal spores. It is likely that such harvesting periods can cause clinically relevant levels of fungal spores in the atmosphere. Our findings suggest that crop harvest in Central Europe causes episodes of high airborne Alternaria spore concentrations in Copenhagen as well as other urban areas in this region. It is likely that such episodes could be simulated using atmospheric transport models.

  3. Influences of nanoscale zero valent iron loadings and bicarbonate and calcium concentrations on hydrogen evolution in anaerobic column experiments.

    PubMed

    Paar, Hendrik; Ruhl, Aki Sebastian; Jekel, Martin

    2015-01-01

    The estimation of nanoscale zero-valent iron (nZVI) reactivity after its injection into the subsurface is essential for its application in groundwater remediation. In the present study H₂ generation of commercially available nZVI and novel milled nZVI flakes were investigated in column experiments with varying nZVI loads (ranging from 8 to 43 g nZVI per kg sand). H₂ evolution rates were determined for column experiments without and with hydrogen carbonate and/or calcium. On average 0.29 mmol H₂/L per g Fe⁰ evolved within the first 30 days in column experiments with spherical, commercial nZVI particles. The H₂ evolution developed almost independently of the water matrices applied. The application of nZVI flakes resulted in lower H₂ generation rates. In general corrosion rates accelerated linearly with increasing initial amounts of iron. This was evident in experiments with both particle types. Concentration profiles of carbonate and calcium in influent and effluent were used to estimate corrosion products and precipitates. Despite the presence of high concentrations of inorganic carbon, Fe²⁺ reacted preferably with hydroxide ions to form ferrous hydroxide which is the precursor of magnetite. As a result only minor passivation of the reactive nZVI was observed. PMID:25462777

  4. Change in the plasmid copy number in acetic acid bacteria in response to growth phase and acetic acid concentration.

    PubMed

    Akasaka, Naoki; Astuti, Wiwik; Ishii, Yuri; Hidese, Ryota; Sakoda, Hisao; Fujiwara, Shinsuke

    2015-06-01

    Plasmids pGE1 (2.5 kb), pGE2 (7.2 kb), and pGE3 (5.5 kb) were isolated from Gluconacetobacter europaeus KGMA0119, and sequence analyses revealed they harbored 3, 8, and 4 genes, respectively. Plasmid copy numbers (PCNs) were determined by real-time quantitative PCR at different stages of bacterial growth. When KGMA0119 was cultured in medium containing 0.4% ethanol and 0.5% acetic acid, PCN of pGE1 increased from 7 copies/genome in the logarithmic phase to a maximum of 12 copies/genome at the beginning of the stationary phase, before decreasing to 4 copies/genome in the late stationary phase. PCNs for pGE2 and pGE3 were maintained at 1-3 copies/genome during all phases of growth. Under a higher concentration of ethanol (3.2%) the PCN for pGE1 was slightly lower in all the growth stages, and those of pGE2 and pGE3 were unchanged. In the presence of 1.0% acetic acid, PCNs were higher for pGE1 (10 copies/genome) and pGE3 (6 copies/genome) during the logarithmic phase. Numbers for pGE2 did not change, indicating that pGE1 and pGE3 increase their PCNs in response to acetic acid. Plasmids pBE2 and pBE3 were constructed by ligating linearized pGE2 and pGE3 into pBR322. Both plasmids were replicable in Escherichia coli, Acetobacter pasteurianus and G. europaeus, highlighting their suitability as vectors for acetic acid bacteria. PMID:25575969

  5. Study of urinary concentrations of mandelic acid in employees exposed to styrene.

    PubMed

    Poláková, Mária; Krajcovicová, Zdenka; Melus, Vladimír; Stefkovicová, Mária; Sulcová, Margaréta

    2012-09-01

    Mandelic acid (MA) is an important metabolite of styrene. In humans, measurement of its concentration in urine provides an important assessment of the overall level of styrene exposure in workers of the reinforced plastic manufacturing industry. The aim of our study was to investigate in these workers the relationship between MA concentration and styrene exposure time and intensity as well as its dependence on work occupation. The concentration of MA in the urine samples of 35 employees was analyzed with HPLC (high performance liquid chromatography). Out of 35 workers, 11 performed laminating, 11 milling and finalizing, 6 laying-up and spraying-up, and 7 worked in background support. Urinal samples were obtained twice a day over the course of three weeks, at the beginning and the end of the work shift. We found a significant increase in MA concentrations during a work shift in all tested days (Wilcoxon test p < 0.05). Employees working in elevated atmospheric concentrations of styrene (93.77-159.88 mg/m3) had significantly higher MA concentrations in urine compared to other groups at both the beginning and the end of the shift (Kruskal Wallis test p < 0.001) (p < 0.001). Only samples from laminating workers exceeded the biological limit of MA concentration (640 mg/L) at the end of the shift. Normalisation of MA concentration to body mass index (BMI, normal range: 21.7 +/- 3.2 kg/m2) refined differences within groups (Kruskal-Wallis analysis p < 0.001). The accumulation of MA at the end of the work shift for measured time period was not significant for the measured time period (Friedman analysis p > 0.11). Our results confirmed that MA is a sensitive metabolic marker of styrene exposure without cumulative effect. However, normalization of MA concentrations to BMI can improve the accuracy of styrene exposure estimates in certain groups of employees. PMID:23285526

  6. Gas phase C{sub 2}-C{sub 10} organic acids concentrations in the Los Angeles atmosphere

    SciTech Connect

    Nolte, C.G.; Fraser, M.P.; Cass, G.R.

    1999-02-15

    The atmospheric concentrations of gas-phase C{sub 2}--C{sub 10} monocarboxylic and benzoic acids are reported in samples collected during a severe Los Angeles area photochemical smog episode. Average urban concentrations are 10--50 {times} greater than concentrations observed at a remote background location, indicating an anthropogenic origin for these compounds. Average urban concentrations during the episode were 16.1 {micro}g m{sup {minus}3} (6.6 ppb) for acetic acid and 1.67 {micro}g m{sup {minus}3} (0.55 ppb) for propionic acid, with progressively lesser amounts as the carbon chain length of the acids is increased. Spatial and diurnal variations in atmospheric organic acids concentrations point to the importance of both direct emissions from primary sources and formation by photochemical reaction of precursor compounds.

  7. Effects of total gastrectomy on plasma silicon and amino acid concentrations in men.

    PubMed

    Tatara, Marcin R; Krupski, Witold; Szpetnar, Maria; Dąbrowski, Andrzej; Bury, Paweł; Szabelska, Anna; Charuta, Anna; Boguszewska-Czubara, Anna; Maciejewski, Ryszard; Wallner, Grzegorz

    2015-12-01

    The aim of the study was to determine one-year effects of total gastrectomy on plasma silicon and free amino acid concentrations in patients and evaluate changes of volumetric bone mineral density (vBMD) in lumbar spine. Eight patients were enrolled to the control (CTR) group. Six patients subjected to total gastrectomy (GX group) were included to the experimental group. vBMD in trabecular and cortical bone was measured in lumbar vertebrae at baseline (before surgery) and one year later using quantitative computed tomography. Plasma concentrations of silicon and free amino acids were determined at baseline and one year later using photometric method and ion-exchange chromatography. Body weights within CTR and GX groups were not different after one-year follow-up when compared to the baseline values (P > 0.05). An average annual decrease of vBMD in the trabecular bone in the gastrectomized patients reached 15.0% in lumbar spine and was significantly different in comparison to the percentage changes observed in CTR group (P = 0.02). One-year percentage change of vBMD in the cortical bone in L1 and L2 has shown significantly decreased values by 10.5 and 9.1% in the GX group when compared to the percentage change observed in the controls (P < 0.05). Plasma concentration of adipic acid was significantly higher by 101.6% one year after total gastrectomy procedure in the patients when compared to the baseline value (P = 0.01). Plasma concentration of silicon was significantly lowered by 26.7% one year after the total gastrectomy when compared to the baseline value (P = 0.009). Total gastrectomy in patients has induced severe osteoporotic changes in lumbar spine within one-year period. The observed osteoporotic changes were associated with decreased plasma concentration of silicon indicating importance of exocrine and endocrine functions of stomach for silicon homeostasis maintenance. Gastrectomy-induced bone loss was not related to decreased amino acid

  8. Fatty Acid and Cholesterol Concentrations in Usually Consumed Fish in Brazil

    PubMed Central

    Scherr, Carlos; Gagliardi, Ana Carolina Moron; Miname, Marcio Hiroshi; Santos, Raul Dias

    2015-01-01

    Background Several studies have demonstrated clinical benefits of fish consumption for the cardiovascular system. These effects are attributed to the increased amounts of polyunsaturated fatty acids in these foods. However, the concentrations of fatty acids may vary according to region. Objective The goal of this study was to determine the amount of,cholesterol and fatty acids in 10 Brazilian fishes and in a non-native farmed salmon usually consumed in Brazil. Methods The concentrations of cholesterol and fatty acids, especially omega-3, were determined in grilled fishes. Each fish sample was divided in 3 sub-samples (chops) and each one was extracted from the fish to minimize possible differences in muscle and fat contents. Results The largest cholesterol amount was found in white grouper (107.6 mg/100 g of fish) and the smallest in badejo (70 mg/100 g). Omega-3 amount varied from 0.01 g/100 g in badejo to 0.900 g/100 g in weakfish. Saturated fat varied from 0.687 g/100 g in seabass to 4.530 g/100 g in filhote. The salmon had the greatest concentration of polyunsaturated fats (3.29 g/100 g) and the highest content of monounsaturated was found in pescadinha (5.98 g/100 g). Whiting and boyfriend had the best omega-6/omega 3 ratios respectively 2.22 and 1.19, however these species showed very little amounts of omega-3. Conclusion All studied Brazilian fishes and imported salmon have low amounts of saturated fat and most of them also have low amounts of omega-3. PMID:25424160

  9. Concentration-Effect Relationships for the Drug of Abuse γ-Hydroxybutyric Acid

    PubMed Central

    Felmlee, Melanie A.; Roiko, Samuel A.; Morse, Bridget L.

    2010-01-01

    γ-Hydroxybutyric acid (GHB) is an endogenous neurotransmitter that is abused because of its sedative/hypnotic and euphoric effects. The objectives of this study were to evaluate the concentration-effect relationships of GHB in plasma, cerebrospinal fluid (CSF), brain (whole and discrete brain regions), and brain frontal cortex extracellular fluid. This information is crucial for future studies to evaluate effects of therapeutic interventions on the toxicodynamics of GHB. GHB (200–1000 mg/kg) was administered intravenously to rats, and plasma and frontal cortex microdialysate samples were collected for up to 6 h after the dose, or plasma, CSF, and brain (whole, frontal cortex, striatum, and hippocampus) concentrations were determined at the offset of its sedative/hypnotic effect [return to righting reflex (RRR)]. GHB-induced changes in the brain neurotransmitters γ-aminobutyric acid (GABA) and glutamate were also determined. GHB, GABA, and glutamate concentrations were measured by liquid chromatography/tandem mass spectrometry. GHB-induced sleep time significantly increased in a dose-dependent manner (20-fold increase from 200 to 1000 mg/kg). GHB concentrations in plasma (300–400 μg/ml), whole brain (70 μg/g), discrete brain regions (80–100 μg/g), and brain microdialysate (29–39 μg/ml) correlated with RRR. In contrast, CSF GHB and GABA and glutamate concentrations in discrete brain regions exhibited no relationship with RRR. Our results suggest that GHB-induced sedative/hypnotic effects are mediated directly by GHB and that at high GHB doses, GABA formation from GHB may not contribute to the observed sedative/hypnotic effect. These results support the use of a clinical GHB detoxification strategy aimed at decreasing plasma and brain GHB concentrations after GHB overdoses. PMID:20215411

  10. Concentrations, and Estimated Loads and Yields of Total Nitrogen and Total Phosphorus at Selected Stations in Kentucky, 1979-2004

    USGS Publications Warehouse

    Crain, Angela S.; Martin, Gary R.

    2009-01-01

    To evaluate the State's water quality, the Kentucky Division of Water collects data from a statewide network of primary ambient stream water-quality monitoring stations and flexible, rotating watershed-monitoring stations. This ambient stream water-quality monitoring network program is directed to assess the conditions of surface waters throughout Kentucky. Water samples were collected monthly for the majority of the stations from 1979 to 1998, which represented agricultural, undeveloped (mainly forested), and areas of mixed land use/land cover. In 1998, the number of water samples collected was reduced to a collection frequency of six times per year (every 2 months) every 4 of 5 years, because a new monitoring network was implemented involving a 5-year rotating Basin Management Unit scheme of monitoring. This report presents the results of a study conducted by the U.S. Geological Survey, in cooperation with the Kentucky Energy and Environment Cabinet-Kentucky Division of Water, to summarize concentrations of total nitrogen and total phosphorus and provide estimates of total nitrogen and total phosphorus loads and yields in 55 selected streams in Kentucky's ambient stream water-quality monitoring network, which was operated from 1979 through 2004. Streams in predominately agricultural basins had higher concentrations of total nitrogen (TN) and concentrations of total phosphorus (TP) than streams in predominately undeveloped (forested) basins. Streams in basins in intensely developed karst areas characterized by caves, springs, sinkholes, and sinking streams had a higher median concentration of TN (1.5 milligrams per liter [mg/L]) than streams in basins with limited or no karst areas (0.63 mg/L). As with TN, median concentrations of TP also were higher in areas of intense karst (0.05 mg/L) than in areas with limited or no karst (0.02 mg/L). The U.S. Environmental Protection Agency (USEPA) has recommended ecoregional nutrient water-quality criteria as a starting

  11. Predicting the toxicity of sediment-associated trace metals with simultaneously extracted trace metal: Acid-volatile sulfide concentrations and dry weight-normalized concentrations: A critical comparison

    USGS Publications Warehouse

    Long, E.R.; MacDonald, D.D.; Cubbage, J.C.; Ingersoll, C.G.

    1998-01-01

    The relative abilities of sediment concentrations of simultaneously extracted trace metal: acid-volatile sulfide (SEM:AVS) and dry weight- normalized trace metals to correctly predict both toxicity and nontoxicity were compared by analysis of 77 field-collected samples. Relative to the SEM:AVS concentrations, sediment guidelines based upon dry weight-normalized concentrations were equally or slightly more accurate in predicting both nontoxic and toxic results in laboratory tests.

  12. Antitumor Activity of Doxorubicin-Loaded Carbon Nanotubes Incorporated Poly(Lactic-Co-Glycolic Acid) Electrospun Composite Nanofibers

    NASA Astrophysics Data System (ADS)

    Yu, Yuan; Kong, Lijun; Li, Lan; Li, Naie; Yan, Peng

    2015-08-01

    The drug-loaded composite electrospun nanofiber has attracted more attention in biomedical field, especially in cancer therapy. In this study, a composite nanofiber was fabricated by electrospinning for cancer treatment. Firstly, the carbon nanotubes (CNTs) were selected as carriers to load the anticancer drug—doxorubicin (DOX) hydrochloride. Secondly, the DOX-loaded CNTs (DOX@CNTs) were incorporated into the poly(lactic-co-glycolic acid) (PLGA) nanofibers via electrospinning. Finally, a new drug-loaded nanofibrous scaffold (PLGA/DOX@CNTs) was formed. The properties of the prepared composite nanofibrous mats were characterized by various techniques. The release profiles of the different DOX-loaded nanofibers were measured, and the in vitro antitumor efficacy against HeLa cells was also evaluated. The results showed that DOX-loaded CNTs can be readily incorporated into the nanofibers with relatively uniform distribution within the nanofibers. More importantly, the drug from the composite nanofibers can be released in a sustained and prolonged manner, and thereby, a significant antitumor efficacy in vitro is obtained. Thus, the prepared composite nanofibrous mats are a promising alternative for cancer treatment.

  13. Multiarticular isokinetic high-load eccentric training induces large increases in eccentric and concentric strength and jumping performance.

    PubMed

    Papadopoulos, Christos; Theodosiou, Konstantinos; Bogdanis, Gregory C; Gkantiraga, Evangelia; Gissis, Ioannis; Sambanis, Michalis; Souglis, Athanasios; Sotiropoulos, Aristomenis

    2014-09-01

    This study investigated the effects of short-term eccentric exercise training using a custom-made isokinetic leg press device, on concentric and eccentric strength and explosiveness as well as jumping performance. Nineteen healthy males were divided into an eccentric (ECC, n = 10) and a control group (CG, n = 9). The ECC group trained twice per week for 8 weeks using an isokinetic hydraulic leg press machine against progressively increasing resistance ranging from 70 to 90% of maximal eccentric force. Jumping performance and maximal force generating capacity were measured before and after eccentric training. In the ECC group, drop jump (DJ) height and maximal power were increased by 13.6 ± 3.2% (p < 0.01) and 25.8 ± 1.2% (p < 0.01), whereas ground contact time was decreased by 17.6 ± 2.6% (p < 0.01). Changes in ankle, knee, and hip joint angles were also reduced by 33.9 ± 1.1%, 31.1 ± 1.0%, and 32.4 ± 1.6% (all p < 0.01), respectively, indicating an increase in muscle stiffness during the DJ. Maximal eccentric and concentric leg press force was increased by 64.9 ± 5.5% (p < 0.01) and 32.2 ± 8.8% (p < 0.01), respectively, and explosiveness, measured as force attained in the first 300 milliseconds, was increased by 49.1 ± 4.8% (p < 0.01) and 77.1 ± 7.7% (p < 0.01), respectively. The CG did not show any statistically significant changes in all parameters measured. The main findings of this study were that maximal concentric and eccentric force, explosiveness, and DJ performance were markedly increased after only 16 training sessions, possibly because of the high eccentric load attained during the bilateral eccentric leg press exercise performed on this custom-made device. PMID:24626142

  14. Concentrations and Loads of Organic Compounds and Trace Elements in Tributaries to Newark and Raritan Bays, New Jersey

    USGS Publications Warehouse

    Wilson, Timothy P.; Bonin, Jennifer L.

    2007-01-01

    A study was undertaken to determine the concentrations and loads of sediment and chemicals delivered to Newark and Raritan Bays by five major tributaries: the Raritan, Passaic, Rahway, Elizabeth, and Hackensack Rivers. This study was initiated by the State of New Jersey as Study I-C of the New Jersey Toxics Reduction Workplan for the New York-New Jersey Harbor, working under the NY-NJ Harbor Estuary Program (HEP) Contaminant Assessment and Reduction Program (CARP). The CARP is a comprehensive effort to evaluate the levels and sources of toxic contaminants to the tributaries and estuarine areas of the NY-NJ Harbor, including Newark and Raritan Bays. The Raritan and Passaic Rivers are large rivers (mean daily discharges of 1,189 and 1,132 cubic feet per second (ft3/s), respectively), that drain large, mixed rural/urban basins. The Elizabeth and Rahway Rivers are small rivers (mean daily discharges of 25.9 and 49.1 ft3/s, respectively) that drain small, highly urbanized and industrialized basins. The Hackensack River drains a small, mixed rural/urban basin, and its flow is highly controlled by an upstream reservoir (mean daily discharge of 90.4 ft3/s). These rivers flow into urbanized estuaries and ultimately, to the Atlantic Ocean. Each of these tributaries were sampled during two to four storm events, and twice each during low-flow discharge conditions. Samples were collected using automated equipment installed at stations adjacent to U.S. Geological Survey streamflow-gaging stations near the heads-of-tide of these rivers. Large-volume (greater than 50 liters of water and a target of 1 gram of sediment), flow-weighted composite samples were collected for chemical analysis using filtration to collect suspended particulates and exchange resin (XAD-2) to sequester dissolved contaminants. Composite whole-water samples were collected for dissolved polycyclic aromatic hydrocarbons (PAH) and for trace element analysis. Additional discrete grab samples were collected

  15. Water Deficit-Induced Changes in Concentrations in Proline and Some Other Amino Acids in the Phloem Sap of Alfalfa.

    PubMed Central

    Girousse, C.; Bournoville, R.; Bonnemain, J. L.

    1996-01-01

    Changes in amino acid composition of alfalfa (Medicago sativa L.) phloem sap were studies in response to a water deficit. Sap was collected by stylectomy. As the leaf water potential ([psi]) decreased from -0.4 to -2.0 MPa, there was significant increase of the total amino acid concentration, due to that of some amino acids: proline, valine, isoleucine, leucine, glutamic acid, aspartic acid, and threonine. Asparagine concentration, which is the main amino acid assayed in the phloem sap of alfalfa (it accounts for 70% of the total content), did not vary with the plant water status. The other amino acid concentrations remained stable as [psi] varied; in particular, [gamma]-amino butyric acid concentration remained unchanged, whereas it varied in response to wounding. The more striking change in the sieve tubes was the accumulation of proline, which was observed below a [psi] threshold value of about -0.9 MPa (concentration x60 for a decrease of [psi] from -0.9 to -2.0 MPa). The role of such changes in phloem sap amino acid concentration in osmotic adjustment of growing tissues is discussed. PMID:12226278

  16. Advances in Acid Concentration Membrane Technology for the Sulfur-Iodine Thermochemical Cycle

    SciTech Connect

    Frederick F. Stewart; Christopher J. Orme

    2006-11-01

    One of the most promising cycles for the thermochemical generation of hydrogen is the Sulfur-Iodine (S-I) process, where aqueous HI is thermochemically decomposed into H2 and I2 at approximately 350 degrees Celsius. Regeneration of HI is accomplished by the Bunsen reaction (reaction of SO2, water, and iodine to generate H2SO4 and HI). Furthermore, SO2 is regenerated from the decomposition of H2SO4 at 850 degrees Celsius yielding the SO2 as well as O2. Thus, the cycle actually consists of two concurrent oxidation-reduction loops. As HI is regenerated, co-produced H2SO4 must be separated so that each may be decomposed. Current flowsheets employ a large amount (~83 mol% of the entire mixture) of elemental I2 to cause the HI and the H2SO4 to separate into two phases. To aid in the isolation of HI, which is directly decomposed into hydrogen, water and iodine must be removed. Separation of iodine is facilitated by removal of water. Sulfuric acid concentration is also required to facilitate feed recycling to the sulfuric acid decomposer. Decomposition of the sulfuric acid is an equilibrium limited process that leaves a substantial portion of the acid requiring recycle. Distillation of water from sulfuric acid involves significant corrosion issues at the liquid-vapor interface. Thus, it is desirable to concentrate the acid without boiling. Recent efforts at the INL have concentrated on applying pervaporation through Nafion-117, Nafion-112, and sulfonated poly(etheretherketone) (S-PEEK) membranes for the removal of water from HI/water and HI/Iodine/water feedstreams. In pervaporation, a feed is circulated at low pressure across the upstream side of the membrane, while a vacuum is applied downstream. Selected permeants sorb into the membrane, transport through it, and are vaporized from the backside. Thus, a concentration gradient is established, which provides the driving force for transport. In this work, membrane separations have been performed at temperatures as high as

  17. Effect of aeration rate and waste load on evolution of volatile fatty acids and waste stabilization during thermophilic aerobic digestion of a model high strength agricultural waste.

    PubMed

    Ugwuanyi, J Obeta; Harvey, L M; McNeil, B

    2005-04-01

    Thermophilic aerobic digestion (TAD) is a relatively new, dynamic and versatile low technology for the economic processing of high strength waste slurries. Waste so treated may be safely disposed of or reused. In this work a model high strength agricultural waste, potato peel, was subjected to TAD to study the effects of oxygen supply at 0.1, 0.25, 0.5 and 1.0 vvm (volume air per volume slurry per minute) under batch conditions at 55 degrees C for 156 h on the process. Process pH was controlled at 7.0 or left unregulated. Effects of waste load, as soluble chemical oxygen demand (COD), on TAD were studied at 4.0, 8.0, 12.0 and 16.0 gl(-1) (soluble COD) at pH 7.0, 0.5 vvm and 55 degrees C. Efficiency of treatment, as degradation of total solids, total suspended solids and soluble solid, as well as soluble COD significantly increased with aeration rate, while acetate production increased as the aeration rate decreased or waste load increased, signifying deterioration in treatment. Negligible acetate, and no other acids were produced at 1.0 vvm. Production of propionate and other acids increased after acetate concentration had started to decrease and, during unregulated reactions coincided with the drop in the pH of the slurry. Acetate production was more closely associated with periods of oxygen limitation than were other acids. Reduction in oxygen availability led to deterioration in treatment efficiency as did increase in waste load. These variables may be manipulated to control treated waste quality. PMID:15588774

  18. Effect of acid concentration and pulp properties on hydrolysis reactions of mercerized sisal.

    PubMed

    Lacerda, Talita M; Zambon, Márcia D; Frollini, Elisabete

    2013-03-01

    The influence of sulfuric acid concentration (H2SO4 5-25%, 100°C), crystallinity and fibers size on the hydrolysis reaction of sisal pulps were investigated, with the goal of evaluating both the liquor composition, as an important step in the production of bioethanol, and the residual non-hydrolyzed pulp, to determine its potential application as materials. Aliquots were withdrawn from the reaction media, and the liquor composition was analyzed by HPLC. The residual non-hydrolyzed pulps were characterized by SEM, their average molar mass and crystallinity index, and their size distribution was determined using a fiber analyzer. Sulfuric acid 25% led to the highest glucose content (approximately 10gL(-1)), and this acid concentration was chosen to evaluate the influence of both the fiber size and crystallinity of the starting pulp on hydrolysis. The results showed that fibers with higher length and lower crystallinity favored glucose production in approximately 12%, with respect to the highly crystalline shorter fibers. PMID:23465940

  19. Poly(ε-caprolactone)/triclosan loaded polylactic acid nanoparticles composite: A long-term antibacterial bionanocomposite with sustained release.

    PubMed

    Kaffashi, Babak; Davoodi, Saeed; Oliaei, Erfan

    2016-07-11

    In this study, the antibacterial bionanocomposites of poly(ε-caprolactone) (PCL) with different concentrations of triclosan (TC) loaded polylactic acid (PLA) nanoparticles (30wt% triclosan) (LATC30) were fabricated via a melt mixing process in order to lower the burst release of PCL and to extend the antibacterial activity during its performance. Due to the PLA's higher glass transition temperature (Tg) and less flexibility compared with PCL; the PLA nanoparticles efficiently trapped the TC particles, reduced the burst release of TC from the bionanocomposites; and extended the antibacterial property of the samples up to two years. The melt mixing temperature was adjusted to a temperature lower than the melting point of LATC30 nanoparticles; therefore, these nanoparticles were dispersed in the PCL matrix without any chemical reaction and/or drug extraction. The sustained release behavior of TC from PCL remained unchanged since no significant changes occurred in the samples' crystallinity compared with that in the neat PCL. The elastic moduli of samples were enhanced once LATC30 is included. This is necessary since the elastic modulus is decreased with water absorption. The rheological behaviors of samples showed appropriate properties for melt electro-spinning. A stable process was established as the relaxation time of the bionanocomposites was increased. The hydrophilic properties of samples were increased with increasing LATC30. The proliferation rate of the fibroblast (L929) cells was enhanced as the content of nanoparticles was increased. A system similar to this could be implemented to prepare long-term antibacterial and drug delivery systems based on PCL and various low molecular weight drugs. The prepared bionanocomposites are considered as candidates for the soft connective tissue engineering and long-term drug delivery. PMID:27155590

  20. Hyaluronic Acid Suppresses the Expression of Metalloproteinases in Osteoarthritic Cartilage Stimulated Simultaneously by Interleukin 1β and Mechanical Load

    PubMed Central

    Pohlig, Florian; Guell, Florian; Lenze, Ulrich; Lenze, Florian W.; Mühlhofer, Heinrich M. L.; Schauwecker, Johannes; Toepfer, Andreas; Mayer-Kuckuk, Philipp; von Eisenhart-Rothe, Rüdiger; Burgkart, Rainer; Salzmann, Gian M.

    2016-01-01

    Purpose In patients with osteoarthritis (OA), intraarticular injection of hyaluronic acid (HA) frequently results in reduced pain and improved function for prolonged periods of time, i.e. more than 6 months. However, the mechanisms underlying these effects are not fully understood. Our underlying hypothesis is that HA modifies the enzymatic breakdown of joint tissues. Methods To test this hypothesis, we examined osteochondral cylinders from 12 OA patients. In a bioreactor, these samples were stimulated by interleukin 1β (Il1ß) (2 ng/ml) plus mechanical load (2.0 Mpa at 0.5 Hz horizontal and 0.1 Hz vertical rotation), thus the experimental setup recapitulated both catabolic and anabolic clues of the OA joint. Results Upon addition of HA at either 1 or 3 mg/ml, we observed a significant suppression of expression of metalloproteinase (MMP)-13. A more detailed analysis based on the Kellgren and Lawrence (K&L) OA grade, showed a much greater degree of suppression of MMP-13 expression in grade IV as compared to grade II OA. In contrast to the observed MMP-13 suppression, treatment with HA resulted in a suppression of MMP-1 expression only at 1 mg/ml HA, while MMP-2 expression was not significantly affected by either HA concentration. Conclusion Together, these data suggest that under concurrent catabolic and anabolic stimulation, HA exhibits a pronounced suppressive effect on MMP-13. In the long-run these findings may benefit the development of treatment strategies aimed at blocking tissue degradation in OA patients. PMID:26934732

  1. Preparation and drug-loading properties of Fe3O4/Poly(styrene-co-acrylic acid) magnetic polymer nanocomposites

    NASA Astrophysics Data System (ADS)

    Lu, Wensheng; Shen, Yuhua; Xie, Anjian; Zhang, Weiqiang

    2013-11-01

    Fe3O4/poly(styrene-co-acrylic acid) magnetic polymer nanocomposites were synthesized by the dispersion polymerization method using styrene as hard monomer, acrylic acid as functional monomer, Fe3O4 nanoparticles modified with oleic acid as core, and poly(styrene-co-acrylic acid) as shell. Drug-loading properties of magnetic polymer nanocomposites with curcumin as a model drug were also studied. The results indicated that magnetic polymer nanocomposites with monodisperse were obtained, the particle size distribution was 50-120 nm, and the average size was about 100 nm. The contents of poly(styrene-co-acrylic acid) and Fe3O4 nanoparticles in magnetic polymer nanocomposites were 74% and 24.7%, respectively. The drug-loading capacity and entrapment efficiency were 2.5% and 44.4%, respectively. The saturation magnetization of magnetic polymer nanocomposites at 300 K was 20.2 emu/g without coercivity and remanence. The as-prepared magnetic polymer nanocomposites have not only lots of functional carboxyl groups but also stronger magnetic response, which might have potential applications in drug carrier and targeted drug release.

  2. Lowering the platinum loading of high temperature polymer electrolyte membrane fuel cells with acid doped polybenzimidazole membranes

    NASA Astrophysics Data System (ADS)

    Martin, S.; Li, Q.; Jensen, J. O.

    2015-10-01

    Membrane electrode assemblies (MEAs) with ultra-low Pt loading electrodes were prepared for high temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) based on acid doped polybenzimidazole. With no electrode binders or ionomers, the triple phase boundary of the catalyst layer was established by the acid transfer from the acid doped membrane to the electrodes and can therefore be tailored by using catalysts with varied Pt to C ratios. With a loading of ca. 0.1 mgPtcm-2 on each electrode the best performance was obtained with electrodes prepared from 10 wt.% Pt/C due to the improved Pt dispersion, extended triple phase boundary upon the acid transfer and the alleviated acid flooding of the catalytic layer. The MEA delivered a peak power density of 482 mW cm-2 for H2/O2 and 321 mW cm-2 for H2/air, corresponding to an overall Pt utilization of 2.5 and 1.7 kW gPt-1, respectively. The durability test revealed no net voltage decay during more than 1700 h of uninterrupted operation at 200 mA cm-2 and 160 °C.

  3. Mechanism of trichloroethylene-induced elevation of individual serum bile acids. I. Correlation of trichloroethylene concentrations to bile acids in rat serum.

    PubMed

    Hamdan, H; Stacey, N H

    1993-08-01

    The temporal relationship between trichloroethylene (TRI) and individual serum bile acids (SBA) has been investigated to gain insight into the mechanism of solvent-induced increases in SBA. Male Sprague-Dawley rats were treated with 1 mmol/kg TRI in corn oil, while control rats received only corn oil. Blood samples were collected from the abdominal aorta at 2, 4, 8, and 16 hr after dosing. Individual SBA were determined by high-performance liquid chromatography (HPLC). Liver and blood concentrations of TRI and one of its metabolites, trichloroethanol (TCEOH), were determined by gas chromatography. SBA levels reached their peak at 4 hr and returned to control levels by 16 hr. There was a relationship between SBA levels and TRI concentrations, which were also at their peak 4 hr after dosing. By 16 hr the levels were undetectable. However, peak blood concentrations of TCEOH were reached 8 hr after dosing, and remained high at 16 hr. Cholic acid and taurocholic acid showed the highest levels of bile acids. Some other bile acids were also elevated, including deoxycholic acid, taurodeoxycholic acid, ursodeoxycholic acid, chenodeoxycholic acid, and taurochenodeoxycholic acid. Determination of total bile acids in serum using an enzymatic/colorimetric method showed a similar pattern of response to that obtained with the HPLC analysis. The data are consistent with TRI having a rapid and specific effect on SBA levels by a mechanism other than liver cell damage. PMID:8346545

  4. Comparison among model estimates of critical loads of acidic deposition using different sources and scales of input data.

    PubMed

    McDonnell, T C; Cosby, B J; Sullivan, T J; McNulty, S G; Cohen, E C

    2010-09-01

    The critical load (CL) of acidic atmospheric deposition represents the load of acidity deposited from the atmosphere to the earth's surface at which harmful acidification effects on sensitive biological receptors are thought to occur. In this study, the CL for forest soils was estimated for 27 watersheds throughout the United States using a steady-state mass balance approach based on both national and site-specific data and using different approaches for estimating base cation weathering. Results suggested that the scale and source of input data can have large effects on the calculated CL and that the most important parameter in the steady-state model used to estimate CL is base cation weathering. These results suggest that the data and approach used to estimate weathering must be robust if the calculated CL is to be useful for its intended purpose. PMID:20609503

  5. Rare earth element concentrations in dissolved and acid available particulate forms for eastern UK rivers

    NASA Astrophysics Data System (ADS)

    Neal, C.

    2007-01-01

    Variations in concentration of yttrium (Y), lanthanum (La), cerium (Ce), neodymium (Nd), samarium (Sm) and gadolinium (Gd) among rivers of eastern England and the border with Scotland are described in relation to the dissolved (<0.45 µM) fraction and acid-available particulate (AAP) fractions. The rivers cover a range of rural, agricultural and urban/industrial environments. Yttrium and the lanthanides show significant levels of both dissolved and acid-available particulate forms (typically about 40% in the dissolved form). For the dissolved phase, Y and the lanthanides are linearly correlated with each other and with iron: most of this dissolved component may be in a micro-particulate/colloidal form. The Y and lanthanide relationships show marked scatter and there are anomalously high La concentrations at times for the rivers Great Ouse, Thames and Wear that are probably linked to pollutant sources. For the Ouse, and especially for one of its tributaries, the Swale, relatively high Sm concentrations are probably associated with mineralisation within the catchment and contamination of the associated flood plain. For the AAP components, there are strong linear relationships with Y and the lanthanides across all the rivers. There is also a strong link between these AAP associated REE and AAP iron, although the scatter is greater and the industrial rivers have a lower lanthanide to iron ratio, probably due to iron-rich contaminants.

  6. Effect of polymer species and concentration on the production of mefenamic acid nanoparticles by media milling.

    PubMed

    Ito, Atsutoshi; Konnerth, Christoph; Schmidt, Jochen; Peukert, Wolfgang

    2016-01-01

    The effect of four structurally different polymer species (hydroxypropylcellulose, polyvinylpyrrolidone, vinylpyrrolidone-vinyl acetate copolymer and polyvinyl alcohol) on the production of mefenamic acid nanoparticles during media milling has been studied. It was found that product particle sizes are strongly determined by the type of polymeric stabiliser as well as by its concentration at constant process conditions. With respect to small product particle sizes an optimum excipient concentration was identified and adjusted for colloidal stability of the drug nanosuspensions. Furthermore, it was found that overdosing of excipients must be omitted to suppress ripening due to enhanced solubilisation phenomena. Hence, the smallest product particle sizes were obtained using a polymeric stabiliser which exhibits a high affinity to the model drug compound and a low solubilisation capacity. Affinities of each polymer species to mefenamic acid and corresponding surface concentrations were determined using straightforward and simple viscosity measurements of the supernatant. A relationship between polymer affinity, solubilisation capacity and limiting product particle size has been observed, which supports the hypothesis that final product particle sizes are rather determined by the solid-liquid equilibrium than by pure mechanical fracture. PMID:26592155

  7. Hexavalent uranium diffusion into soils from concentrated acidic and alkaline solutions

    SciTech Connect

    Tokunaga, Tetsu K.; Wan, Jiamin; Pena, Jasquelin; Sutton, Stephen R.; Newville, Matthew

    2004-03-29

    Uranium contamination of soils and sediments often originates from acidic or alkaline waste sources, with diffusion being a major transport mechanism. Measurements of U(VI) diffusion from initially pH 2 and pH 11 solutions into a slightly alkaline Altamont soil and a neutral Oak Ridge soil were obtained through monitoring uptake from boundary reservoirs and from U concentration profiles within soil columns. The soils provided pH buffering, resulting in diffusion at nearly constant pH. Micro x-ray absorption near edge structure spectra confirmed that U remained in U(VI) forms in all soils. Time trends of U(VI) depletion from reservoirs, and U(VI) concentration profiles within soil columns yielded K{sub d} values consistent with those determined in batch tests at similar concentrations ({approx} 1 mM), and much lower than values for sorption at much lower concentrations (nM to {mu}M). These results show that U(VI) transport at high concentrations can be relatively fast at non-neutral pH, with negligible surface diffusion, because of weak sorption.

  8. Nanostructured lipid carriers loaded with tributyrin as an alternative to improve anticancer activity of all-trans retinoic acid

    PubMed Central

    Silva, Elton Luiz; Carneiro, Guilherme; Caetano, Priscila Albuquerque; Costa, Daniel Ferreira; de Souza-Fagundes, Elaine Maria; Gomes, Dawidson Assis; Ferreira, Lucas Antônio Miranda

    2015-01-01

    Objectives All-trans retinoic acid (ATRA) is one of the most successful examples of differentiation agents and histone deacetylase inhibitors, such as tributyrin (TB), are known for their antitumor activity and potentiating action of drugs such as ATRA. Nanostructured lipid carriers (NLC) represent a promising alternative to the encapsulation of lipophilic drugs such as ATRA. This study aimed to develop, characterize, and evaluate the cytotoxicity of ATRA-TB-loaded nanostructured lipid carriers (NLC) for cancer treatment. Methods The influence of in situ formation of an ion pairing between ATRA and a lipophilic amine (benethamine; BNT) on the characteristics of NLC (size, zeta potential, encapsulation efficiency) was evaluated. Tributyrin (TB), a butyric acid donor, was used as a component of the lipid matrix. In vitro activity on cell viability and distribution of cell cycle phases were evaluated for MCF-7, MDA-MB-231, HL-60, and Jurkat cell lines. Results The presence of the amine significantly increased the encapsulation efficiency of ATRA in NLC. Inhibition of cell viability by TB-ATRA-loaded NLC was more pronounced than the free drug. Analysis of the distribution of cell cycle phases also showed increased activity for TB-ATRA-loaded NLC, with the clear effect of cell cycle arrest in G0/G1 phase transition. The presence of TB played an important role in the activity of the formulation. Conclusion Taken together, these findings suggest that TB-ATRA-loaded NLC represent a promising alternative to intravenous administration of ATRA in cancer treatment. PMID:25611812

  9. Measuring the concentration of carboxylic acid groups in torrefied spruce wood.

    PubMed

    Khazraie Shoulaifar, Tooran; Demartini, Nikolai; Ivaska, Ari; Fardim, Pedro; Hupa, Mikko

    2012-11-01

    Torrefaction is moderate thermal treatment (∼200-300°C) to improve the energy density, handling and storage properties of biomass fuels. In biomass, carboxylic sites are partially responsible for its hygroscopic. These sites are degraded to varying extents during torrefaction. In this paper, we apply methylene blue sorption and potentiometric titration to measure the concentration of carboxylic acid groups in spruce wood torrefied for 30min at temperatures between 180 and 300°C. The results from both methods were applicable and the values agreed well. A decrease in the equilibrium moisture content at different humidity was also measured for the torrefied wood samples, which is in good agreement with the decrease in carboxylic acid sites. Thus both methods offer a means of directly measuring the decomposition of carboxylic groups in biomass during torrefaction as a valuable parameter in evaluating the extent of torrefaction which provides new information to the chemical changes occurring during torrefaction. PMID:22940339

  10. A simple hydrothermal preparation of TiO 2 nanomaterials using concentrated hydrochloric acid

    NASA Astrophysics Data System (ADS)

    Nguyen Phan, Thuy-Duong; Pham, Hai-Dinh; Viet Cuong, Tran; Jung Kim, Eui; Kim, Sunwook; Woo Shin, Eun

    2009-12-01

    A TiO 2 nanostructure was synthesized via a simple method using only concentrated hydrochloric acid as the morphological/crystallographic controlling agent. Microscopy images showed that the texture of the TiO 2 powder could be easily engineered and tuned by tailoring the HCl volume, creating cuboid, flower, cauliflower, and ball-shaped particles. Three-dimensional TiO 2 microparticles resulted from the self-assembly of nanostructured sub-units including nanocubes, nanoprisms, and nanorods. The crystalline anatase and rutile phases were also identified depending on the acidic medium. HCl played a key role in orchestrating the structures and morphologies of the TiO 2 nanoscale materials. The phase transformation and morphological changes were strongly related to the crystal growth mechanism of the TiO 2 nanostructure.

  11. Pharmacokinetics and plasma concentrations of acetylsalicylic acid after intravenous, rectal, and intragastric administration to horses.

    PubMed

    Broome, Ted A; Brown, Murray P; Gronwall, Ronald R; Casey, Matthew F; Meritt, Kelly A

    2003-10-01

    Six healthy adult horses (5 mares and 1 stallion) were given a single dose of acetylsalicylic acid (ASA), 20 mg/kg of body weight, by intravenous (IV), rectal, and intragastric (IG) routes. Serial blood samples were collected via jugular venipuncture over a 36-h period, and plasma ASA and salicylic acid (SA) concentrations were determined by high-performance liquid chromatography. After IV administration, the mean elimination rate constant of ASA (+/- the standard error of the mean) was 1.32 +/- 0.09 h(-1), the mean elimination half-life was 0.53 +/- 0.04 h, the area under the plasma concentration-versus-time curve (AUC) was 2555 +/- 98 microg x min/mL, the plasma clearance was 472 +/- 18.9 mL/h/kg, and the volume of distribution at steady state was 0.22 +/- 0.01 L/kg. After rectal administration, the plasma concentration of ASA peaked at 5.05 +/- 0.80 microg/mL at 0.33 h, then decreased to undetectable levels by 4 h; the plasma concentration of SA peaked at 17.39 +/- 5.46 microg/mL at 2 h, then decreased to 1.92 +/- 0.25 microg/mL by 36 h. After rectal administration, the AUC for ASA was 439.4 +/- 94.55 microg x min/mL and the bioavailability was 0.17 +/- 0.037. After IG administration, the plasma concentration of ASA peaked at 1.26 +/- 0.10 microg/mL at 0.67 h, then declined to 0.37 +/- 0.37 microg/mL by 36 h; the plasma concentration of SA peaked at 23.90 +/- 4.94 microg/mL at 4 h and decreased to 0.85 +/- 0.31 microg/mL by 36 h. After IG administration, the AUC for ASA was 146.70 +/- 24.90 microg x min/mL and the bioavailability was 0.059 +/- 0.013. Administration of a single rectal dose of ASA of 20 mg/kg to horses results in higher peak plasma ASA concentrations and greater bioavailability than the same dose given IG. Plasma ASA concentrations after rectal administration should be sufficient to inhibit platelet thromboxane production, and doses lower than those suggested for IG administration may be adequate. PMID:14620867

  12. Influence of acid volatile sulfides and metal concentrations on metal partitioning in contaminated sediments

    USGS Publications Warehouse

    Lee, J.-S.; Lee, B.-G.; Luoma, S.N.; Choi, H.J.; Koh, C.-H.; Brown, C.L.

    2000-01-01

    The influence of acid volatile sulfide (AVS) on the partitioning of Cd, Ni, and Zn in porewater (PW) and sediment as reactive metals (SEM, simultaneously extracted metals) was investigated in laboratory microcosms. Two spiking procedures were compared, and the effects of vertical geochemical gradients and infaunal activity were evaluated. Sediments were spiked with a Cd-Ni-Zn mixture (0.06, 3, 7.5 ??mol/g, respectively) containing four levels of AVS (0.5, 7.5, 15, 35 ??mol/g). The results were compared to sediments spiked with four levels of Cd-Ni-Zn mixtures at one AVS concentration (7.5 ??mol/g). A vertical redox gradient was generated in each treatment by an 18-d incubation with an oxidized water column. [AVS] in the surface sediments decreased by 65-95% due to oxidation during incubation; initial [AVS] was maintained at 0.5-7.5 cm depth. PW metal concentrations were correlated with [SEM - AVS] among all data. But PW metal concentrations were variable, causing the distribution coefficient, Kd(pw) (the ratio of [SEM] to PW metal concentrations) to vary by 2-3 orders of magnitude at a given [SEM - AVS]. One reason for the variability was that vertical profiles in PW metal concentrations appeared to be influenced by diffusion as well as [SEM - AVS]. The presence of animals appeared to enhance the diffusion of at least Zn. The generalization that PW metal concentrations are controlled by [SEM - AVS] is subject to some important qualifications if vertical gradients are complicated, metal concentrations vary, or equilibration times differ.The influence of acid volatile sulfide (AVS) on the partitioning of Cd, Ni, and Zn in porewater (PW) and sediment as reactive metals (SEM, simultaneously extracted metals) was investigated in laboratory microcosms. Two spiking procedures were compared, and the effects of vertical geochemical gradients and infaunal activity were evaluated. Sediments were spiked with a Cd-Ni-Zn mixture (0.06, 3, 7.5 ??mol/g, respectively) containing

  13. New method for the direct determination of dissolved Fe(III) concentration in acid mine waters

    USGS Publications Warehouse

    To, T.B.; Nordstrom, D.K.; Cunningham, K.M.; Ball, J.W.; McCleskey, R.B.

    1999-01-01

    A new method for direct determination of dissolved Fe(III) in acid mine water has been developed. In most present methods, Fe(III) is determined by computing the difference between total dissolved Fe and dissolved Fe(II). For acid mine waters, frequently Fe(II) >> Fe(III); thus, accuracy and precision are considerably improved by determining Fe(III) concentration directly. The new method utilizes two selective ligands to stabilize Fe(III) and Fe(II), thereby preventing changes in Fe reduction-oxidation distribution. Complexed Fe(II) is cleanly removed using a silica-based, reversed-phase adsorbent, yielding excellent isolation of the Fe(III) complex. Iron(III) concentration is measured colorimetrically or by graphite furnace atomic absorption spectrometry (GFAAS). The method requires inexpensive commercial reagents and simple procedures that can be used in the field. Calcium(II), Ni(II), Pb(II), AI(III), Zn(II), and Cd(II) cause insignificant colorimetric interferences for most acid mine waters. Waters containing >20 mg of Cu/L could cause a colorimetric interference and should be measured by GFAAS. Cobalt(II) and Cr(III) interfere if their molar ratios to Fe(III) exceed 24 and 5, respectively. Iron(II) interferes when its concentration exceeds the capacity of the complexing ligand (14 mg/L). Because of the GFAAS elemental specificity, only Fe(II) is a potential interferent in the GFAAS technique. The method detection limit is 2 ??g/L (40 nM) using GFAAS and 20 ??g/L (0.4 ??M) by colorimetry.A new method for direct determination of dissolved Fe(III) in acid mine water has been developed. In most present methods, Fe(III) is determined by computing the difference between total dissolved Fe and dissolved Fe(II). For acid mine waters, frequently Fe(II)???Fe(III); thus, accuracy and precision are considerably improved by determining Fe(III) concentration directly. The new method utilizes two selective ligands to stabilize Fe(III) and Fe(II), thereby preventing changes

  14. Elevated formic acid concentrations in putrefied post-mortem blood and urine samples.

    PubMed

    Viinamäki, Jenni; Rasanen, Ilpo; Vuori, Erkki; Ojanperä, Ilkka

    2011-05-20

    Formic acid (FA) concentration was measured in post-mortem blood and urine samples as methyl formate using a headspace in-tube extraction gas-chromatography-mass-spectrometry method. A total of 113 cases were analyzed, each including a blood and urine sample fortified with 1% sodium fluoride. The cases were divided into three groups: regular (n=59), putrefied (n=30), and methanol-positive (n=22) cases. There was no evidence of ante-mortem methanol consumption in the regular and putrefied cases. In regular cases, the mean (and median) FA concentrations were 0.04 g/l (0.04 g/l) and 0.06 g/l (0.04 g/l) in blood and urine, respectively. In putrefied cases, the mean (and median) FA concentrations were substantially higher, 0.24 g/l (0.22 g/l) and 0.25 g/l (0.15 g/l) in blood and urine, respectively. In three putrefied cases, FA concentration in blood exceeded 0.5 g/l, a level associated with fatal methanol poisoning. Ten putrefied cases were reanalyzed after 3-4 months storage, and no significant changes in FA concentrations were seen. These observations suggest that FA was formed by putrefaction during the post-mortem period, not during sample storage when sodium fluoride was added as a preservative. In methanol-positive cases, the mean (and median) FA concentrations were 0.80 g/l (0.88 g/l) and 3.4 g/l (3.3 g/l) in blood and urine, respectively, and the concentrations ranged from 0.19 to 1.0 g/l in blood and from 1.7 to 5.6 g/l in urine. The mean (and median) methanol concentrations in methanol-positive cases were 3.0 g/l (3.0 g/l) and 4.4 g/l (4.7 g/l) in blood and in urine, respectively. The highest methanol concentrations were 6.0 g/l and 8.7 g/l in blood and urine, respectively. No ethyl alcohol was found in the methanol-positive blood samples. Poor correlation was shown between blood and urine concentrations of FA. Poor correlations were also shown, in both blood and urine, between methanol and FA concentrations. PMID:21112705

  15. The effect of formic acid concentration on the conductivity and corrosion resistance of chromium carbide coatings electroplated with trivalent chromium

    NASA Astrophysics Data System (ADS)

    Lu, Chen-En; Pu, Nen-Wen; Hou, Kung-Hsu; Tseng, Chun-Chieh; Ger, Ming-Der

    2013-10-01

    Different concentrations of formic acid were added into a trivalent chromium electroplating solution to produce chromium carbide (Crsbnd C) coatings. The influence of the formic acid concentration on chemical composition, microstructure, surface morphology, corrosion resistance, conductivity and carbon content of the resulting Crsbnd C coatings was studied. Formic acid was found to increase the carbon content in the coatings so as to form Crsbnd C films. These coatings had a nearly amorphous structure containing Cr, Cr2O3, and various Crsbnd C compounds with carbon content uniformly distributed throughout the coatings. The carbon content and the conductivity of the Crsbnd C layer were correlated with formic acid concentration. For a formic acid concentration of 2 M, the Crsbnd C layer had the highest carbon content (∼28%), the lowest contact resistance, and the best corrosion resistance along with a corrosion current density of ∼6.4 × 10-7 A/cm2.

  16. The role of glycyrrhetinic acid modification on preparation and evaluation of quercetin-loaded chitosan-based self-aggregates.

    PubMed

    Du, Hongliang; Liu, Mengrui; Yang, Xiaoye; Zhai, Guangxi

    2015-12-15

    Quercetin (QC), a type of plant-based chemical, has been reported to own anticancer activity in vivo. However, the poor water solubility limits its pharmaceutical application. In this study, two kinds of QC-loaded self-aggregates based on O-carboxymethyl chitosan-cholic acid conjugates (CMCA) were developed to improve the drug bioavailability in which glycyrrhetinic acid (GA) modification was utilized in the nanocarrier fabrication (QC-GA-CMCA) or not (QC-CMCA). These self-aggregates were prepared by a modified ultrasound-dialysis method and the role of GA modification on the evaluation of QC-loaded self-aggregates was investigated. Transmission Electron Microscopy (TEM) images revealed the formation of spherical particles of both self-aggregates. Dynamic Light Scattering (DLS) analysis and UV-VIS spectroscopy showed that the QC-GA-CMCA had smaller size, narrower size distribution, higher drug loading and entrapment efficiency than corresponding QC-CMCA aggregates. QC-GA-CMCA showed more obvious sensitivity to acidic pH condition based on the zeta potential measurements at various pHs, and fastest drug release was observed at pH 5.7 for QC-CMCA while at pH 6.5 for QC-GA-CMCA. In addition, QC-GA-CMCA demonstrated enhanced cell cytotoxicity and higher cell apoptosis rate in vitro, and also higher AUC value and a prolonged residence time of drug in vivo. PMID:26319324

  17. Promoting endothelial recovery and reducing neointimal hyperplasia using sequential-like release of acetylsalicylic acid and paclitaxel-loaded biodegradable stents

    PubMed Central

    Lee, Cheng-Hung; Yu, Chia-Ying; Chang, Shang-Hung; Hung, Kuo-Chun; Liu, Shih-Jung; Wang, Chao-Jan; Hsu, Ming-Yi; Hsieh, I-Chang; Chen, Wei-Jan; Ko, Yu-Shien; Wen, Ming-Shien

    2014-01-01

    Introduction This work reports on the development of a biodegradable dual-drug-eluting stent with sequential-like and sustainable drug-release of anti-platelet acetylsalicylic acid and anti-smooth muscle cell (SMC) proliferative paclitaxel. Methods To fabricate the biodegradable stents, poly-L-lactide strips are first cut from a solvent-casted film. They are rolled onto the surface of a metal pin to form spiral stents. The stents are then consecutively covered by acetylsalicylic acid and paclitaxel-loaded polylactide-polyglycolide nanofibers via electrospinning. Results Biodegradable stents exhibit mechanical properties that are superior to those of metallic stents. Biodegradable stents sequentially release high concentrations of acetylsalicylic acid and paclitaxel for more than 30 and 60 days, respectively. In vitro, the eluted drugs promote endothelial cell numbers on days 3 and 7, and reduce the proliferation of SMCs in weeks 2, 4, and 8. The stents markedly inhibit the adhesion of platelets on days 3, 7, and 14 relative to a non-drug-eluting stent. In vivo, the implanted stent is intact, and no stent thrombosis is observed in the stent-implanted vessels without the administration of daily oral acetylsalicylic acid. Promotion of endothelial recovery and inhibition of neointimal hyperplasia are also observed on the stented vessels. Conclusion The work demonstrates the efficiency and safety of the biodegradable dual-drug-eluting stents with sequential and sustainable drug release to diseased arteries. PMID:25206303

  18. Enhanced anti-cancer efficacy to cancer cells by doxorubicin loaded water-soluble amino acid-modified β-cyclodextrin platinum complexes.

    PubMed

    Zhao, Mei-Xia; Zhao, Meng; Zeng, Er-Zao; Li, Yang; Li, Jin-Ming; Cao, Qian; Tan, Cai-Ping; Ji, Liang-Nian; Mao, Zong-Wan

    2014-08-01

    The effective targeted delivery of insoluble anticancer drugs to increase the intracellular drug concentration has become a focus in cancer therapy. In this system, two water-soluble amino acid-modified β-cyclodextrin (β-CD) platinum complexes were reported. They showed preferable binding ability to DNA and effective inhibition to cancer cells, and they could bind and unwind pBR322 DNA in a manner which was similar to cisplatin. Besides, our platinum complexes could effectively deliver the anticancer drug doxorubicin (Dox) into cells and had higher cell inhibition ratio, but less toxicity on the normal cells, compared with cancer cells. In this combination system, Dox was encapsulated into the hydrophobic cavities of β-CD at the optimum molar ratio of 1:1, which were validated by UV-visible (UV-vis) absorption spectroscopy, fluorescence spectroscopy and MTT experiments. Moreover, the combination system had higher cell inhibition ratio than free Dox and amino acid-modified β-CD platinum complexes, and the results of high content screening (HCS) showed that Dox-loaded amino acid-modified β-CD platinum complexes could permeate the cell membrane and enter cells, suggesting the efficient transport of Dox across the membranes with the aid of the β-CD. We expect that the amino acid-modified β-CD platinum complexes will deliver the antitumor drug Dox to enhance intracellular drug accumulation and such combination system showed great potential as an antitumor drug. PMID:24803024

  19. Circadian rhythm in plasma concentrations of gamma-hydroxybutyric acid in alcoholics.

    PubMed

    Hoes, M J; Vree, T B; Guelen, P J

    1981-08-01

    Gamma-hydroxybutyric acid (GHB) was orally administered to six alcoholics at 09.00 and 23.00 h. The plasma concentrations of GHB show a clear circadian pattern, the area under the curve in the daytime experiments being 61% of that in the night experiments. The significance of alcohol dehydrogenase, the catabolic enzyme of GHB, for the difference is discussed. It is concluded that, although the activity of alcohol dehydrogenase in alcoholics is quantitatively disturbed, it remains subject to physiologic circadian activation. PMID:7341501

  20. Macroporous chitosan hydrogels: Effects of sulfur on the loading and release behaviour of amino acid-based compounds.

    PubMed

    Elviri, Lisa; Asadzadeh, Maliheh; Cucinelli, Roberta; Bianchera, Annalisa; Bettini, Ruggero

    2015-11-01

    Chitosan is a biodegradable, biocompatible polymer of natural origin widely applied to the preparation of functional hydrogels suitable for controlled release of drugs, peptides and proteins. Non-covalent interactions, expecially ionic interactions, are the main driver of the loading and release behaviour of amino acids or peptides from chitosan hydrogels. With the aim to improve the understanding of the mechanisms governing the behaviour of chitosan hydrogels on peptide uptake and delivery, in this paper the attention was focused on the role played by sulfur on the interactions of chitosan hydrogels with sulfur-containing amino acids (AA) and peptides. Hence, loading and release experiments on cysteine, cystine and glutathione (SH containing amino acid, dipeptide and tripeptide, respectively) as well as on glycine and valine as apolar amino acids were carried out. For these puroses, chitosan hydrogels were prepared in an easy and reproducible manner by a freeze-gelation process on a poly-L-lysine coated support. The hydrogel surface pore size, uniformity and distribution were tested. Optimal results (D50 = 26 ± 4 μm) were obtained by using the poly-L-lysine positively-charged surface. The loading results gathered evidenced that the sulfur-containing molecules presented an increased absorption both in terms of rate and extent by chitosan hydrogels with respect to nonpolar amino acids, mainly due to ionic and hydrogen bond interactions. ATR-FTIR analysis carried out on chitosan hydrogels, with and without the AA related compounds to study putative interactions, supported these apparent sulfur-dependent results. Finally, chitosan hydrogels displayed excellent retention capabilities (AA release <5%) for all AA, strongly supporting the use of chitosan hydrogels as matrix for controlled drug release. PMID:26256323

  1. Development of a total maximum daily load (TMDL) for acid-impaired lakes in the Adirondack region of New York

    NASA Astrophysics Data System (ADS)

    Fakhraei, Habibollah; Driscoll, Charles T.; Selvendiran, Pranesh; DePinto, Joseph V.; Bloomfield, Jay; Quinn, Scott; Rowell, H. Chandler

    2014-10-01

    Acidic deposition has impaired acid-sensitive surface waters in the Adirondack region of New York by decreasing pH and acid neutralizing capacity (ANC). In spite of air quality programs over past decades, 128 lakes in the Adirondacks were classified as “impaired” under Section 303(d) of the Clean Water Act in 2010 due to elevated acidity. The biogeochemical model, PnET-BGC, was used to relate decreases in atmospheric sulfur (S) and nitrogen (N) deposition to changes in lake water chemistry. The model was calibrated and confirmed using observed soil and lake water chemistry data and then was applied to calculate the maximum atmospheric deposition that the impaired lakes can receive while still achieving ANC targets. Two targets of ANC were used to characterize the recovery of acid-impaired lakes: 11 and 20 μeq L-1. Of the 128 acid-impaired lakes, 97 currently have ANC values below the target value of 20 μeq L-1 and 83 are below 11 μeq L-1. This study indicates that a moderate control scenario (i.e., 60% decrease from the current atmospheric S load) is projected to recover the ANC of lakes at a mean rate of 0.18 and 0.05 μeq L-1 yr-1 during the periods 2022-2050 and 2050-2200, respectively. The total maximum daily load (TMDL) of acidity corresponding to this moderate control scenario was estimated to be 7.9 meq S m-2 yr-1 which includes a 10% margin of safety.

  2. Ostα depletion protects liver from oral bile acid load

    PubMed Central

    Velazquez, Heino; Mennone, Albert; Ballatori, Nazzareno; Boyer, James L.

    2011-01-01

    Bile acid homeostasis is tightly maintained through interactions between the liver, intestine, and kidney. During cholestasis, the liver is incapable of properly clearing bile acids from the circulation, and alternative excretory pathways are utilized. In obstructive cholestasis, urinary elimination is often increased, and this pathway is further enhanced after bile duct ligation in mice that are genetically deficient in the heteromeric, basolateral organic solute transporter alpha-beta (Ostα-Ostβ). In this study, we examined renal and intestinal function in Ostα-deficient and wild-type mice in a model of bile acid overload. After 1% cholic acid feeding, Ostα-deficient mice had significantly lower serum ALT levels compared with wild-type controls, indicating partial protection from liver injury. Urinary clearance of bile acids, but not clearance of [3H]inulin, was significantly higher in cholic acid-fed Ostα-deficient mice compared with wild-type mice but was not sufficient to account for the protection. Fecal excretion of bile acids over the 5 days of cholic acid feeding was responsible for almost all of the bile acid loss in Ostα-deficient mice, suggesting that intestinal losses of bile acids accounted for the protection from liver injury. Thus fecal loss of bile acids after bile acid overload reduced the need for the kidney to filter and excrete the excess bile acids. In conclusion, Ostα-deficient mice efficiently eliminate excess bile acids via the feces. Inhibition of intestinal bile acid absorption might be an effective therapeutic target in early stages of cholestasis when bile acids are still excreted into bile. PMID:21719738

  3. Ostα depletion protects liver from oral bile acid load.

    PubMed

    Soroka, Carol J; Velazquez, Heino; Mennone, Albert; Ballatori, Nazzareno; Boyer, James L

    2011-09-01

    Bile acid homeostasis is tightly maintained through interactions between the liver, intestine, and kidney. During cholestasis, the liver is incapable of properly clearing bile acids from the circulation, and alternative excretory pathways are utilized. In obstructive cholestasis, urinary elimination is often increased, and this pathway is further enhanced after bile duct ligation in mice that are genetically deficient in the heteromeric, basolateral organic solute transporter alpha-beta (Ostα-Ostβ). In this study, we examined renal and intestinal function in Ostα-deficient and wild-type mice in a model of bile acid overload. After 1% cholic acid feeding, Ostα-deficient mice had significantly lower serum ALT levels compared with wild-type controls, indicating partial protection from liver injury. Urinary clearance of bile acids, but not clearance of [(3)H]inulin, was significantly higher in cholic acid-fed Ostα-deficient mice compared with wild-type mice but was not sufficient to account for the protection. Fecal excretion of bile acids over the 5 days of cholic acid feeding was responsible for almost all of the bile acid loss in Ostα-deficient mice, suggesting that intestinal losses of bile acids accounted for the protection from liver injury. Thus fecal loss of bile acids after bile acid overload reduced the need for the kidney to filter and excrete the excess bile acids. In conclusion, Ostα-deficient mice efficiently eliminate excess bile acids via the feces. Inhibition of intestinal bile acid absorption might be an effective therapeutic target in early stages of cholestasis when bile acids are still excreted into bile. PMID:21719738

  4. Changes in unbound and total valproic acid concentrations after replacement of carbamazepine with oxcarbazepine.

    PubMed

    Battino, D; Croci, D; Granata, T; Bernardi, G; Monza, G

    1992-10-01

    Total and free valproic acid (VPA) concentrations were measured in patients switched from a combined VPA and carbamazepine (CBZ) to a combined VPA and oxcarbazepine (OXC) therapy, both administered in individualized daily doses. Four young epileptic patients (13-17 years old) were studied for a 12-week period, total and free VPA concentrations being analyzed just before and 4 h after the morning dose, at the end of VPA and CBZ therapy, and 2 and 10 weeks after CBZ was replaced by OXC. The expected increase in the level/dose (L/D) ratio of total VPA observed at the end of the study was preceded by a clear-cut increase in the L/D ratio of free VPA, which led to VPA-related side effects and required the retitration of VPA daily doses. PMID:1448844

  5. Acid-responsive properties of fibrils from heat-induced whey protein concentrate.

    PubMed

    Xu, Hong-Hua; Wang, Jing; Dong, Shi-Rong; Cheng, Wen; Kong, Bao-Hua; Tan, Jun-Yan

    2016-08-01

    The heat-induced fibrils of whey protein concentrate (WPC) have demonstrated an acid-responsive property; that is, the fibrils went through formation-depolymerization-reformation as pH was adjusted to 1.8, 6.5, and back to 1.8. We investigated the microstructure, driving force, and thermal stability of 3.0% (wt) WPC nanofibrils adjusted between pH 6.5 and 1.8 twice. The results showed that the nanofibrils had acid-responsive properties and good thermal stability after reheating for 10h at 90°C and adjusting pH from 1.8 to 6.5 to 1.8. The content of WPC fibril aggregates was not much different with the prolongation of heating times during pH variation. Although the nanofibrils' structure could be destroyed only by changing the pH, the essence of this destruction might only form fiber fragments, polymers that would restore a fibrous structure upon returning to pH 1.8. A described model for the acid-responsive assembly of fibrils of WPC was proposed. The fibrils went through formation-depolymerization-reformation by weaker noncovalent interactions (surface hydrophobicity) as pH changed from 1.8 to 6.5 back to 1.8. However, the fibrils lost the acid-responsive properties because much more S-S (disulfide) formation occurred when the solution was adjusted to pH 6.5 and reheated. Meanwhile, fibrils still possessed acid-responsive properties when reheated at pH 1.8, and the content of fibrils slightly increased with a further reduction of α-helix structure. PMID:27265171

  6. Concentration Dependent Influence of Lipopolysaccharides on Separation of Hoof Explants and Supernatant Lactic Acid Concentration in an Ex Vivo/In Vitro Laminitis Model.

    PubMed

    Reisinger, Nicole; Schaumberger, Simone; Nagl, Veronika; Hessenberger, Sabine; Schatzmayr, Gerd

    2015-01-01

    Laminitis is one of the most common diseases in horses. It is not only painful for the animal, but also has a significant financial impact on the equine industry. This multifactorial disease affects the connective tissue of the hoof. However, the pathogenesis of laminitis is still not fully understood. Endotoxins, also known as lipopolysaccharides (LPS), and bacterial exotoxins seem to play an important role during the development of laminitis. The aim of our study was to investigate the effect of increasing LPS concentrations (0, 2.5, 5, 10, and 100 μg/mL) on cell viability of isolated epidermal and dermal hoof cells as well as on the tissue integrity of hoof explants. Furthermore, glucose, acetic acid, lactic acid, and propionic acid concentrations in explant supernatants were measured to evaluate the energy metabolism in the hoof tissue. LPS did not exhibit cytotoxic effects on epidermal or dermal cells. Force required to separate LPS treated hoof explants decreased in a concentration dependent manner. Specifically, explants incubated with 10 and 100 μg/mL needed significantly less force to separate compared to control explants. Lactic acid concentrations were significantly decreased in explants incubated with 5, 10, or 100 μg/mL LPS, while glucose, acetic acid and propionic acid concentrations were unaffected by LPS treatment. Our study indicates that LPS has no cytotoxic effect on epidermal and dermal cells isolated from hoof tissue, but impairs integrity of hoof explants. In addition, LPS led to an alteration of the lactic acid production in the lamellar tissue. Since our data highlight that LPS can affect the integrity of the equine hoof tissue in vitro, endotoxins should be further explored for their contribution to facilitate the development of laminitis. PMID:26599864

  7. Concentration Dependent Influence of Lipopolysaccharides on Separation of Hoof Explants and Supernatant Lactic Acid Concentration in an Ex Vivo/In Vitro Laminitis Model

    PubMed Central

    Reisinger, Nicole; Schaumberger, Simone; Nagl, Veronika; Hessenberger, Sabine; Schatzmayr, Gerd

    2015-01-01

    Laminitis is one of the most common diseases in horses. It is not only painful for the animal, but also has a significant financial impact on the equine industry. This multifactorial disease affects the connective tissue of the hoof. However, the pathogenesis of laminitis is still not fully understood. Endotoxins, also known as lipopolysaccharides (LPS), and bacterial exotoxins seem to play an important role during the development of laminitis. The aim of our study was to investigate the effect of increasing LPS concentrations (0, 2.5, 5, 10, and 100 μg/mL) on cell viability of isolated epidermal and dermal hoof cells as well as on the tissue integrity of hoof explants. Furthermore, glucose, acetic acid, lactic acid, and propionic acid concentrations in explant supernatants were measured to evaluate the energy metabolism in the hoof tissue. LPS did not exhibit cytotoxic effects on epidermal or dermal cells. Force required to separate LPS treated hoof explants decreased in a concentration dependent manner. Specifically, explants incubated with 10 and 100 μg/mL needed significantly less force to separate compared to control explants. Lactic acid concentrations were significantly decreased in explants incubated with 5, 10, or 100 μg/mL LPS, while glucose, acetic acid and propionic acid concentrations were unaffected by LPS treatment. Our study indicates that LPS has no cytotoxic effect on epidermal and dermal cells isolated from hoof tissue, but impairs integrity of hoof explants. In addition, LPS led to an alteration of the lactic acid production in the lamellar tissue. Since our data highlight that LPS can affect the integrity of the equine hoof tissue in vitro, endotoxins should be further explored for their contribution to facilitate the development of laminitis. PMID:26599864

  8. Elevated anthranilic acid plasma concentrations in type 1 but not type 2 diabetes mellitus

    PubMed Central

    Oxenkrug, Gregory; van der Hart, Marieke; Summergrad, Paul

    2015-01-01

    Experimental data suggested involvement of tryptophan (Trp) – kynurenine (Kyn) pathway (TKP) in mechanisms of autoimmune, type 1 (T1D), and metabolic, type 2 (T2D), diabetes. However, clinical evaluations of TKP metabolites were limited to T2D. We assessed Trp, Kyn and TKP metabolites: anthranilic (AA), kynurenic (KYNA) and xanthurenic (XA) acids, in plasma samples of fifteen T1D, thirty T2D patients and twenty eight non-diabetic subjects by HPLC-mass spectrometry. Trp concentrations were higher in T1D than in T2D and controls while Kyn concentrations were not changed suggesting down-regulation of indoleamine-2,3-dioxygenase (IDO), a rate-limiting enzyme of TKP, in T1D. AA concentrations were 2.3-fold higher in T1D than in T2D and in controls. KYNA and XA concentrations were higher in T1D than in controls, and in previously reported T2D. AA elevation might be a specific feature of T1D. TKP shift towards AA formation in T1D may result from riboflavin deficiency, that increases AA in rats and baboons, and is highly associated with T1D but not T2D. AA augments autoimmune-induced apoptosis of pancreatic cells (PC) by increasing formation of antibodies to PC auto-antigen. Marked increase of AA was reported in rheumatoid arthritis, another autoimmune disorder. Trp, an essential amino acid for humans, is synthesized from AA by diabetogenic intestinal microbiome. AA down-regulates IDO by inhibition of Trp entry into cells. Resulting elevation of Trp attenuates Trp depletion-induced protection of PC against autoimmunity. Further studies of TKP might offer new tools for prevention and treatment of T1D and other autoimmune disorders. PMID:26523229

  9. Associations between concentrations of uric acid with concentrations of vitamin A and beta-carotene among adults in the United States☆

    PubMed Central

    Ford, Earl S.; Choi, Hyon K.

    2015-01-01

    Our objective was to examine the cross-sectional associations between concentrations of vitamin A and beta-carotene, a major source of vitamin A, with concentrations of uric acid in a nationally representative sample of adults from the United States. We conducted a cross-sectional study using data from up to 10893 participants aged ≥20 years of National Health and Nutrition Examination Survey from 2001 to 2006. Concentrations of uric acid adjusted for numerous covariates increased from 305.8 μmol/L in the lowest quintile of vitamin A to 335.3 μmol/L in the highest quintile (p for linear trend <0.001). The prevalence ratio for hyperuricemia also increased progressively across quintiles of serum vitamin A reaching 1.82 (95% confidence interval [CI]: 1.52, 2.16; p for linear trend <0.001) in the top quintile in the maximally adjusted model. Adjusted mean concentrations of uric acid decreased progressively from quintile 1 (333.8 μmol/L) through quintile 4 of concentrations of beta-carotene and were similar for quintiles 4 (313.5 μmol/L) and 5 (313.8 μmol/L). Concentrations of beta-carotene were inversely associated with hyperuricemia (adjusted prevalence ratio comparing highest with lowest quintile = 0.61; 95% CI: 0.52, 0.72; p for linear trend <0.001). Concentrations of uric acid were significantly and positively associated with concentrations of vitamin A and inversely with concentrations of beta-carotene. These cross-sectional findings require confirmation with experimental studies of vitamin A and beta-carotene supplementation. PMID:24267038

  10. Organic amendments increase soil solution phosphate concentrations in an acid soil: A controlled environment study

    SciTech Connect

    Schefe, C.R.; Patti, A.F.; Clune, T.S.; Jackson, R.

    2008-04-15

    Soil acidification affects at least 4 million hectares of agricultural land in Victoria, Australia. Low soil pH can inhibit plant growth through increased soluble aluminum (Al) concentrations and decreased available phosphorus (P). The addition of organic amendments may increase P availability through competition for P binding sites, solubilization of poorly soluble P pools, and increased solution pH. The effect of two organic amendments (lignite and compost) on P solubility in an acid soil was determined through controlled environment (incubation) studies. Three days after the addition of lignite and compost, both treatments increased orthophosphate and total P measured in soil solution, with the compost treatments having the greatest positive effect. Increased incubation time (26 days) increased soil solution P concentrations in both untreated and amended soils, with the greatest effect seen in total P concentrations. The measured differences in solution P concentrations between the lignite- and compost-amended treatments were likely caused by differences in solution chemistry, predominantly solution pH and cation dynamics. Soil amendment with lignite or compost also increased microbial activity in the incubation systems, as measured by carbon dioxide respiration. Based on the results presented, it is proposed that the measured increase in soil solution P with amendment addition was likely caused by both chemical and biological processes, including biotic and abiotic P solubilization reactions, and the formation of soluble organic-metal complexes.

  11. Rapeseed and sunflower oilcake as supplements for dairy sheep: animal performance and milk fatty acid concentrations.

    PubMed

    Amores, Gustavo; Virto, Mailo; Nájera, Ana Isabel; Mandaluniz, Nerea; Arranz, Josune; Bustamante, María Angeles; Valdivielso, Izaskun; Ruiz de Gordoa, Juan Carlos; García-Rodríguez, Aser; Barron, Luis J R; de Renobales, Mertxe

    2014-11-01

    The influence of different amounts of oilseed cake (rapeseed and sunflower) on animal production parameters and fatty acid (FA) concentrations of the milk was studied in a Latxa dairy sheep experimental flock, both in winter (50% oilcakes; indoor feeding) and in spring (30% oilcakes; part-time grazing). The two different levels of the oilcakes tested did not affect animal production parameters or milk yield. Milk fat content and the fat/protein ratio decreased significantly with 30 and 50% sunflower cake. Yet, fat/protein ratio values were within the range for cheesemaking. Both levels of either type of oilcake tested significantly increased the concentrations of nutritionally interesting FA (CLA isomer C18:2cis-9, trans-11, vaccenic, oleic, and total unsaturated FA), while simultaneously decreasing the concentration of atherogenic FA. The atherogenicity indexes of milks from ewes fed 50 or 30% of either oilcake were significantly lower than those of their corresponding control. The use of cakes in winter increased the concentration of nutritionally interesting FA to the values obtained with part-time grazing. PMID:25287696

  12. Comparative response of lead-acid and nickel/iron batteries to pulsed and constant-current loads

    SciTech Connect

    DeLuca, W.H.; Tummillo, A.F.; Biwer, T.L.; Christianson, C.C.; Hornstra, F.; Yao, N.P.

    1983-01-01

    Improved lead-acid and nickel/iron batteries are currently being developed for use in electric vehicles. The response of these batteries to given discharge conditions differs due to the inherent characteristics of each system. The discharge capacity of the lead-acid system is reduced (>25%) at increased discharge rates and its internal resistance is a function of both depth-of-discharge (DOD) and discharge rate. However, open-circuit stand times (0.5 to 2.0 h) at DOD levels >50% reduce the internal resistance of the lead-acid system and provide a corresponding increase in its availability capacity. In comparison, the discharge capacity and internal resistance of the nickel/iron system are virtually independent of both discharge rate and open-circuit stand times during discharge. With pulsed-current loads, the available energy and power output of both battery systems are always less than those obtained with equivalent constant-current loads due to increased internal power losses. The nickel/iron system exhibits an internal inductance that is significantly greater than that for the lead-acid system thereby causing potentially damaging voltage transients. This paper describes the test procedures and system employed, presents the test data, and methods for predicting battery response, and discusses the results obtained.

  13. Investigation of nitrous acid concentration in an indoor environment using an in-situ monitoring system

    NASA Astrophysics Data System (ADS)

    Park, Seung Shik; Hong, Jin H.; Lee, Jai H.; Kim, Young J.; Cho, Sung Y.; Kim, Seung J.

    An in-situ measurement system for the determination of nitrous acid (HONO) was developed and used at an indoor residential environment. The system uses a diffusion scrubber to sample gaseous HONO and the peroxynitrite-induced luminol chemiluminescent method to quantify the amount of HONO. In this system, the detection limit of HONO, estimated as three times the noise level of the scrubbing solution blank, was 120 pptv for a 2-min integrated sample. Indoor HONO and NO x concentrations were determined for 7 days in the living room of an apartment with a gas range for cooking in the kitchen. Close examination of the relationships among HONO, NO, and NO 2 concentrations during both the background and combustion periods confirm that the observed HONO was formed not only by direct emission from gas combustion, but also from heterogeneous reactions of NO 2 with H 2O on indoor surfaces. The average ratio of HONO to NO 2 over the study period was 0.12 ± 0.05. The HONO/NO 2 concentration ratio was 0.04-0.08 during the combustion period, whereas it was 0.10-0.25 after combustion had stopped. This suggests that HONO was generated through different production processes, both during combustion and after the completion of combustion. The controlled combustion experiments indicate that the burning rate is an important factor to determine the peak HONO concentration. In darkness, HONO had a nearly constant removal rate for all of the combustion experiments, whereas the removal rates of NO and NO 2 depended on the burning rates of the gas range. Combustion experiments conducted at the fixed burning rate setting show also that ventilation decreased HONO concentration. This indicates that the airflow rate of the range hood fan is an important factor to control the concentration of indoor air pollutants.

  14. Determination of tolerable fatty acids and cholera toxin concentrations using human intestinal epithelial cells and BALB/c mouse macrophages.

    PubMed

    Tamari, Farshad; Tychowski, Joanna; Lorentzen, Laura

    2013-01-01

    The positive role of fatty acids in the prevention and alleviation of non-human and human diseases have been and continue to be extensively documented. These roles include influences on infectious and non-infectious diseases including prevention of inflammation as well as mucosal immunity to infectious diseases. Cholera is an acute intestinal illness caused by the bacterium Vibrio cholerae. It occurs in developing nations and if left untreated, can result in death. While vaccines for cholera exist, they are not always effective and other preventative methods are needed. We set out to determine tolerable concentrations of three fatty acids (oleic, linoleic and linolenic acids) and cholera toxin using mouse BALB/C macrophages and human intestinal epithelial cells, respectively. We solubilized the above fatty acids and used cell proliferation assays to determine the concentration ranges and specific concentrations of the fatty acids that are not detrimental to human intestinal epithelial cell viability. We solubilized cholera toxin and used it in an assay to determine the concentration ranges and specific concentrations of cholera toxin that do not statistically decrease cell viability in BALB/C macrophages. We found the optimum fatty acid concentrations to be between 1-5 ng/μl, and that for cholera toxin to be < 30 ng per treatment. This data may aid future studies that aim to find a protective mucosal role for fatty acids in prevention or alleviation of cholera infections. PMID:23748896

  15. Effect of enoxacin, felbinac, and sparfloxacin on fatty acid metabolism and glucose concentrations in rat tissues.

    PubMed

    Kasuya, Fumiyo; Miwa, Yasushi; Kazumi, Maya; Inoue, Hiroyuki; Ohta, Hiroyuki

    2011-05-01

    Multiple changes in metabolic levels could be useful for understanding physiological toxicity. To explore further risk factors for the convulsions induced by the interaction of nonsteroidal anti-inflammatory and new quinolone antimicrobial drugs, the effect of sparfloxacin, enoxacin, and felbinac on fatty acid metabolism and glucose concentrations in the liver, brain, and blood of rats was investigated. The levels of long-chain acyl-CoAs (C(18:1) and C(20:4)) in the liver and brain were decreased at the onset of convulsions induced by the coadministration of enoxacin with felbinac. Then, glucose concentrations in the liver and blood were decreased, whereas they were increased in a dose-dependant manner in the brain. However, the formation of acyl-CoAs and glucose levels in the liver, brain, and blood was not significantly influenced by enoxacin, felbinac, and sparfloxacin alone, respectively. The disturbance of both fatty acid metabolism and glucose levels might be associated with the increased susceptibility to convulsions, which may contribute to further understanding of the toxic effects associated with these drugs. PMID:21633127

  16. Estimates of late Quaternary mode and intermediate water silicic acid concentration in the Pacific Southern Ocean

    NASA Astrophysics Data System (ADS)

    Rousseau, Jonathon; Ellwood, Michael J.; Bostock, Helen; Neil, Helen

    2016-04-01

    The Southern Ocean plays a critical role in the exchange of carbon between the ocean and atmosphere over glacial-interglacial timescales. Hypotheses used to explain late Quaternary variations in atmospheric carbon dioxide (CO2) implicate changes in the nutrient dynamics and circulation of the Southern Ocean. Here we present silicon isotope (δ30Si) records of late Quaternary sponges and diatoms from the NZ-sector of the Southern Ocean. Analysis of our sponge δ30Si records strongly suggests that the silicic acid concentration at mode and intermediate depths was higher during the LGM and the deglacial period compared to the present day. Our diatom δ30Si record suggests biological productivity near of the Polar Front was greater during the deglacial period, but not significantly different during the LGM compared to the present day. Taking our dataset in context with other regional paleoceanographic records, we interpret the predicted elevation in LGM and deglacial silicic acid concentration to reflect a shoaling of water masses during the LGM and 'leakage' of excess Southern Ocean dissolved silicon during the deglacial period.

  17. Effect of dissolved oxygen concentration on iron efficiency: Removal of three chloroacetic acids.

    PubMed

    Tang, Shun; Wang, Xiao-mao; Mao, Yu-qin; Zhao, Yu; Yang, Hong-wei; Xie, Yuefeng F

    2015-04-15

    The monochloroacetic, dichloroacetic and trichloroacetic acid (MCAA, DCAA and TCAA) removed by metallic iron under controlled dissolved oxygen conditions (0, 0.75, 1.52, 2.59, 3.47 or 7.09 mg/L DO) was investigated in well-mixed batch systems. The removal of CAAs increased first and then decreased with increasing DO concentration. Compared with anoxic condition, the reduction of MCAA and DCAA was substantially enhanced in the presence of O2, while TCAA reduction was significantly inhibited above 2.59 mg/L. The 1.52 mg/L DO was optimum for the formation of final product, acetic acid. Chlorine mass balances were 69-102%, and carbon mass balances were 92-105%. With sufficient mass transfer from bulk to the particle surface, the degradation of CAAs was limited by their reduction or migration rate within iron particles, which were dependent on the change of reducing agents and corrosion coatings. Under anoxic conditions, the reduction of CAAs was mainly inhibited by the available reducing agents in the conductive layer. Under low oxic conditions, the increasing reducing agents and thin lepidocrocite layer were favorable for CAA dechlorination. Under high oxic conditions, the redundant oxygen competing for reducing agents and significant lepidocrocite growth became the major restricting factors. Various CAA removal mechanisms could be potentially applied to explaining the effect of DO concentration on iron efficiency for contaminant reduction in water and wastewater treatment. PMID:25697696

  18. Tobacco mosaic virus-directed reprogramming of auxin/indole acetic acid protein transcriptional responses enhances virus phloem loading.

    PubMed

    Collum, Tamara D; Padmanabhan, Meenu S; Hsieh, Yi-Cheng; Culver, James N

    2016-05-10

    Vascular phloem loading has long been recognized as an essential step in the establishment of a systemic virus infection. In this study, an interaction between the replication protein of tobacco mosaic virus (TMV) and phloem-specific auxin/indole acetic acid (Aux/IAA) transcriptional regulators was found to modulate virus phloem loading in an age-dependent manner. Promoter expression studies show that in mature tissues TMV 126/183-kDa-interacting Aux/IAAs predominantly express and accumulate within the nuclei of phloem companion cells (CCs). Furthermore, CC Aux/IAA nuclear localization is disrupted upon infection with an interacting virus. In situ analysis of virus spread shows that the inability to disrupt Aux/IAA CC nuclear localization correlates with a reduced ability to load into the vascular tissue. Subsequent systemic movement assays also demonstrate that a virus capable of disrupting Aux/IAA localization is significantly more competitive at moving out of older plant tissues than a noninteracting virus. Similarly, CC expression and overaccumulation of a degradation-resistant Aux/IAA-interacting protein was found to inhibit TMV accumulation and phloem loading selectively in flowering plants. Transcriptional expression studies demonstrate a role for Aux/IAA-interacting proteins in the regulation of salicylic and jasmonic acid host defense responses as well as virus-specific movement factors, including pectin methylesterase, that are involved in regulating plasmodesmata size-exclusion limits and promoting virus cell-to-cell movement. Combined, these findings indicate that TMV directs the reprogramming of auxin-regulated gene expression within the vascular phloem of mature tissues as a means to enhance phloem loading and systemic spread. PMID:27118842

  19. Detailed Dimethylacetal and Fatty Acid Composition of Rumen Content from Lambs Fed Lucerne or Concentrate Supplemented with Soybean Oil

    PubMed Central

    Alves, Susana P.; Santos-Silva, José; Cabrita, Ana R. J.; Fonseca, António J. M.; Bessa, Rui J. B.

    2013-01-01

    Lipid metabolism in the rumen is responsible for the complex fatty acid profile of rumen outflow compared with the dietary fatty acid composition, contributing to the lipid profile of ruminant products. A method for the detailed dimethylacetal and fatty acid analysis of rumen contents was developed and applied to rumen content collected from lambs fed lucerne or concentrate based diets supplemented with soybean oil. The methodological approach developed consisted on a basic/acid direct transesterification followed by thin-layer chromatography to isolate fatty acid methyl esters from dimethylacetal, oxo- fatty acid and fatty acid dimethylesters. The dimethylacetal composition was quite similar to the fatty acid composition, presenting even-, odd- and branched-chain structures. Total and individual odd- and branched-chain dimethylacetals were mostly affected by basal diet. The presence of 18∶1 dimethylacetals indicates that biohydrogenation intermediates might be incorporated in structural microbial lipids. Moreover, medium-chain fatty acid dimethylesters were identified for the first time in the rumen content despite their concentration being relatively low. The fatty acids containing 18 carbon-chain lengths comprise the majority of the fatty acids present in the rumen content, most of them being biohydrogenation intermediates of 18∶2n−6 and 18∶3n−3. Additionally, three oxo- fatty acids were identified in rumen samples, and 16-O-18∶0 might be produced during biohydrogenation of the 18∶3n−3. PMID:23484024

  20. Influence of deficit irrigation strategies on fatty acid and tocopherol concentration of almond (Prunus dulcis).

    PubMed

    Zhu, Ying; Taylor, Cathy; Sommer, Karl; Wilkinson, Kerry; Wirthensohn, Michelle

    2015-04-15

    The effects of deficit irrigation on almond fatty acid and tocopherol levels were studied in a field trial. Mature almond trees were subjected to three levels of deficit irrigation (85%, 70% and 55% of potential crop evapotranspiration (ETo), as well as control (100% ETo) and over-irrigation (120% ETo) treatments. Two deficit irrigation strategies were employed: regulated deficit irrigation (RDI) and sustained deficit irrigation (SDI). Moderate deficit irrigation (85% RDI and 85% SDI) had no detrimental impact on almond kernel lipid content, but severe and extreme deficiencies (70% and 55%) influenced lipid content. Unsaturated fatty acid (USFA) and saturated fatty acid (SFA) contents fluctuated under these treatments, the oleic/linoleic ratio increased under moderate water deficiency, but decreased under severe and extreme water deficiency. Almond tocopherols concentration was relatively stable under deficit irrigation. The variation between years indicated climate has an effect on almond fruit development. In conclusion it is feasible to irrigate almond trees using less water than the normal requirement, without significant loss of kernel quality. PMID:25466095

  1. Solute load concentrations in some streams in the Upper Osun and Owena drainage basins, central western Nigeria

    NASA Astrophysics Data System (ADS)

    Jeje, L. K.; Ogunkoya, O. O.; Oluwatimilehin, J. M.

    1999-12-01

    The solute load dynamics of 12 third-order streams in central western Nigeria are presented, during storm and non-storm runoff events. The relevance of the Walling and Foster model for explaining storm period solute load dynamics in the humid tropical environment was assessed and it was found that this model was generally applicable to the study area. Exceptions appear to be streams draining settlements and/or farms where fertilizers are applied heavily. The solute load ranged from 5 mg l -1 to 580 mg l -1 with streams draining basins with tree-crop plantations ( Theobroma cacao, Cola sp.) as the dominant land cover having the highest solute load.

  2. Effects of precursor concentration and acidic sulfate in aqueous glyoxal-OH radical oxidation and implications for secondary organic aerosol.

    PubMed

    Tan, Yi; Perri, Mark J; Seitzinger, Sybil P; Turpin, Barbara J

    2009-11-01

    Previous experiments demonstrated that aqueous OH radical oxidation of glyoxal yields low-volatility compounds. When this chemistry takes place in clouds and fogs, followed by droplet evaporation (or if it occurs in aerosol water), the products are expected to remain partially in the particle phase, forming secondary organic aerosol (SOA). Acidic sulfate exists ubiquitously in atmospheric water and has been shown to enhance SOA formation through aerosol phase reactions. In this work, we investigate how starting concentrations of glyoxal (30-3000 microM) and the presence of acidic sulfate (0-840 microM) affect product formation in the aqueous reaction between glyoxal and OH radical. The oxalic acid yield decreased with increasing precursor concentrations, and the presence of sulfuric acid did not alter oxalic acid concentrations significantly. A dilute aqueous chemistry model successfully reproduced oxalic acid concentrations, when the experiment was performed at cloud-relevant concentrations (glyoxal <300 microM), but predictions deviated from measurements at increasing concentrations. Results elucidate similarities and differences in aqueous glyoxal chemistry in clouds and in wet aerosols. They validate for the first time the accuracy of model predictions at cloud-relevant concentrations. These results suggest that cloud processing of glyoxal could be an important source of SOA. PMID:19924930

  3. Separation of proteins and peptides by capillary electrophoresis in acid buffers containing high concentrations of surfactants.

    PubMed

    Miksík, I; Deyl, Z

    1999-08-01

    Separations of proteins at acid pH in the presence of a high concentration of surfactant [sodium laurylsulfate (SDS), 50 mmol/l] was investigated. The purpose of using high concentrations of SDS as background electrolyte modifier was threefold: First, the surfactant exerts a washing effect upon the capillary wall thus preventing binding of analytes and possible clogging of the capillary. Second, it was revealed that even under very acid conditions (below pH 3) the surfactant is capable of forming associates with protein analytes which still bear considerable negative charge and can be separated on this basis. Third, the system can be applied not only for protein mixtures sufficiently soluble in neutral to alkaline media (leukocyte lysates, standard proteins), but it can be used also with proteins, that are under such conditions virtually insoluble and their solubilization is possible in acid buffers only (eggshell proteins or collagen CNBr fragments). The result was that adsorption to the capillary wall was minimized and the analytes were separated as negatively charged associates with high efficiency. With collagen fragments partition was possible on the affinity differences of the peptides to the surfactant micelles and inner wall of the capillary. Theoretical plate counts approaching 100,000 were easily achieved even with proteins which under the more conventional operation conditions exhibit considerable sticking to the capillary wall. The other feature of this system is that the associates move very rapidly to the anode. Owing to the low pH, endoosmotic flow is negligible, and therefore the system has to be operated at reversed polarity. PMID:10480258

  4. Dry deposition and heavy acid loading in the vicinity of Masaya Volcano, a major sulfur and chlorine source in Nicaragua.

    PubMed

    Delmelle, P; Stix, J; Bourque, C P; Baxter, P J; Garcia-Alvarez, J; Barquero, J

    2001-04-01

    Certain volcanoes constitute the world's largest sources of SO2, HCl, and HF emissions and contribute significantly to regional acid deposition. However, the impact of volcanic acid emissions to nearby ecosystems remain poorly documented. In this paper, the spatial pattern of acid dry depositions was monitored within 44 km of Masaya Volcano, Nicaragua, with a network of sulfation plates. Measured SO2 deposition rates were <2-791 mg m(-2) day(-1). The plates also collected the dry deposition of HCI at rates of <1-297 mg m(-2) day(-1). A similar deposition velocity Vd (gas transfer) of 1.6 +/- 0.8 cm/s was calculated for SO2 and HCl above the plate surfaces. Quantities of SO2 and HCI deposited daily within the area surveyed amounted to 1.5 x 10(8) g and 5.7 x 10(7) g, respectively, which correspond to about 10% of the total SO2 and HCl released by the volcano. These depositions may generate an equivalent hydrogen flux ranging from <1 to 30 mg m(-2) day(-1). Our results demonstrate that volcano emissions can dramatically affect acid deposition downwind and in turn cause extreme acid loading of the local ecosystems. This study opens exciting prospects for investigating the sensivity of volcanic ash soils to acid inputs. PMID:11348058

  5. Water-lactose behavior as a function of concentration and presence of lactic acid in lactose model systems.

    PubMed

    Wijayasinghe, Rangani; Vasiljevic, Todor; Chandrapala, Jayani

    2015-12-01

    The presence of high amounts of lactic acid in acid whey restricts its ability to be further processed because lactose appears to remain in its amorphous form. A systematic study is lacking in this regard especially during the concentration step. Hence, the main aim of the study was to establish the structure and behavior of water molecules surrounding lactose in the presence of 1% (wt/wt) lactic acid at a concentration up to 50% (wt/wt). Furthermore, the crystallization nature of freeze-dried lactose with or without lactic acid was established using differential scanning calorimetry and Fourier transform infrared spectroscopy. Two mechanisms were proposed to describe the behavior of water molecules around lactose molecules during the concentration of pure lactose and lactose solutions with lactic acid. Pure lactose solution exhibited a water evaporation enthalpy of ~679 J·g(-1), whereas lactose+ lactic acid solution resulted in ~965 J·g(-1) at a 50% (wt/wt) concentration. This indicates a greater energy requirement for water removal around lactose in the presence of lactic acid. Higher crystallization temperatures were observed with the presence of lactic acid, indicating a delay in crystallization. Furthermore, less crystalline lactose (~12%) was obtained in the presence of lactic acid, indicating high amorphous nature compared with pure lactose where ~50% crystallinity was obtained. The Fourier transform infrared spectra revealed that the strong hydration layer consisting lactic acid and H3O(+) ions surrounded lactose molecules via strong H bonds, which restricted water mobility, induced a change in structure of lactose, or both, creating unfavorable conditions for lactose crystallization. Thus, partial or complete removal of lactic acid from acid whey may be the first step toward improving the ability of acid whey to be processed. PMID:26476948

  6. Impact of sampling frequency on mean concentrations and estimated loads of suspended sediment in a Norwegian river: implications for water management.

    PubMed

    Skarbøvik, Eva; Stålnacke, Per; Bogen, Jim; Bønsnes, Truls E

    2012-09-01

    Reliable estimates of mean concentrations and loads of pollutants in rivers have become increasingly important for management purposes, particularly with the implementation of the European Union Water Framework Directive (WFD). Here, the Numedalslågen River (5500 km(2)) in southern Norway was used as a case study to evaluate the effects of sampling frequency on mean concentrations and estimated loads of suspended particulate matter (SPM). Daily monitoring data from five seasons (April/June-October/November 2001-2005) were analyzed, and three different load estimation techniques were tested: rating curves, linear interpolation, and the ratio method. The reliability of mean SPM concentrations improved with increasing sampling frequency, but even weekly sampling gave error rates as high as 70% in seasons with elevated sediment loads. Load estimates varied considerably depending on both the sampling frequency and the calculation method used. None of the methods provided consistently good results, but the lowest error rate was achieved when using the rating curve on data from fortnightly sampling and additional sampling during floods. Sampling at monthly intervals gave the highest error rates and cannot be recommended for any of the calculation methods applied here. SPM concentrations were correlated (r(2)>0.5) with arsenic, lead, nickel, orthophosphate, and total phosphorus in the Numedalslågen River. Therefore, the current findings may also have implications for substances other than SPM. The discussion considers examples from actual use of infrequently collected data, and it is advised that managers account for uncertainties in both concentration means and load estimates when assessing the state of a water body or planning mitigation measures. PMID:22820615

  7. Addition of formic acid or starter cultures to liquid feed. Effect on pH, microflora composition, organic acid concentration and ammonia concentration.

    PubMed

    Canibe, N; Miquel, N; Miettinen, H; Jensen, B B

    2001-01-01

    Some of the charateristics of good quality fermented liquid feed (FLF) are low pH, high numbers of lactic acid bacteria, and low numbers of enterobacteria. In order to test strategies to avoid a proliferation of enterobacteria during the initial phase of FLF elaboration, two in vitro studies were carried out. Addition of various doses of formic acid or two different starter cultures were tested. Adding 0.1% formic acid or L. plantarum VTT E-78076 to the liquid feed seemed to be addecuate ways of inhibiting the growth of enterobacteria, without depleting the growth of lactic acid bacteria. PMID:15954629

  8. Perfluoroalkyl Acid Concentrations in Livers of Fox (Vulpes vulpes) and Chamois (Rupicapra rupicapra) from Germany and Austria.

    PubMed

    Riebe, Rika Alessa; Falk, Sandy; Georgii, Sebastian; Brunn, Hubertus; Failing, Klaus; Stahl, Thorsten

    2016-07-01

    The concentrations of 11 perfluorinated alkyl acids (PFAAs) were measured in the livers of foxes (Vulpes vulpes) from Germany, a primarily carnivorous species, and chamois (Rupicapra rupicapra) from Austria, an herbivorous species. Perfluorooctanesulfonate (PFOS) at concentrations [all results refer to wet weight (ww)] of 3.2-320 µg/kg were detected in all 40 fox livers tested, yielding an arithmetic mean of 46.6 µg/kg and a median of 29.8 µg/kg. Long-chain PFAAs were detected at concentrations of 1.7 µg/kg perfluorononanoic acid (PFNA) to 2.4 µg/kg perfluorodecanoic acid (PFDA) and perfluorododecanoic acid (PFDoDA). Of the short-chain PFAAs tested, only perfluorohexanoic acid (PFHxA) was found in 1 fox liver at a concentration of 1.4 µg/kg, and perfluorohexane sulfonate (PFHxS) was found in 2 fox livers at a concentration of 1 µg/kg each. PFOS and PFNA concentrations higher than limit of quantification (LOQ) were detected in 90.9 and 81.8 % of chamois livers, respectively. The arithmetic mean for PFOS concentrations was 2.2 µg/kg (median 2.4 µg/kg), a factor of 21 (median factor of 12) lower than in fox livers. The arithmetic mean for PFNA concentrations was 2.0 µg/kg (median 1.9 µg/kg). Perfluorobutanoic acid, PFHxA, perfluorooctanoic acid, perfluorobutanesulfonate, and PFHxS were not detected at concentrations higher than the LOQ in any of the samples. The various results are compared with one another and with the results of other studies of herbivorous, carnivorous, and omnivorous wild animals. The highest concentrations of PFAA, in particular PFOS, were found in omnivorous animals followed by carnivores. The lowest levels were present in herbivores. PMID:26714691

  9. Intrinsic resistance triggered under acid loading within normal esophageal epithelial cells: NHE1- and ROS-mediated survival.

    PubMed

    Park, Sun Young; Lee, Yeon Joo; Cho, Eun Jeong; Shin, Chang Yell; Sohn, Uy Dong

    2015-07-01

    The transition to a pathological phenotype such as Barrett's esophagus occurs via induction of resistance upon repeated contact with gastric refluxate in esophagus. This study examined the molecular changes within normal esophageal epithelial cells (EECs) under short-term acid loading and the role of these changes in defensive resistance against acidic cytotoxicity. After primary cultured EECs were exposed to pH 4-acidified medium (AM4), cell viability was determined by the MTT assay. Reactive oxygen species (ROS) and NAD(P)H oxidase (NOX) activity were measured. Activation of the mitogen-activated protein kinases (MAPKs) MEK/ERK1/2, p38 and JNK; phosphoinositol-3-kinase (PI3K)/Akt, and nuclear factor-kappa B (NF-κB) were detected by Western blot analysis or immunofluorescence staining. AM4 incubation induced intracellular ROS generation accompanied by increase in NOX activity, which was further increased by Na(+) /H(+) exchange-1 (NHE1)-dependent inhibition but was prevented by inhibition of NOX or mitochondria complex I. AM4 also induced phosphorylation of MEK/ERK1/2, p38 MAPK, PI3K/Akt, and nuclear translocation of NF-κB, and all these effects, except for p38 MAPK phosphorylation, were abolished by inhibition of ROS. ROS-dependent PI3K/Akt activation, which mediates NF-κB nuclear translocation, was inhibited by protein tyrosine kinase (PTK) inhibitors and NHE1-specific inhibitor. All inhibitors of NHE, ROS, PTK, PI3K, or NF-κB further decreased AM4-induced cell viability. Acid loading in the presence of NHE1-dependent protection induced ROS generation by activating NOX and mitochondria complex I, which stimulated PTK/PI3K/Akt/NF-κB-dependent survival in EEC. Our data indicate that normal EEC initially respond to acid loading through intrinsic survival activation. PMID:25522216

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

    PubMed

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

    2014-05-01

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

  11. Phenylbutyrate exerts adverse effects on liver regeneration and amino acid concentrations in partially hepatectomized rats.

    PubMed

    Holecek, Milan; Vodenicarovova, Melita

    2016-06-01

    Phenylbutyrate is recommended in urea cycle disorders and liver injury to enhance nitrogen disposal by the urine. However, hypothetically there may be adverse responses to the use of phenylbutyrate in the treatment of liver disease because of its role as a histone deacetylase inhibitor and its stimulatory effect on branched-chain alpha-keto acid dehydrogenase, the rate-limiting enzyme in the catabolism of branched-chain amino acids (BCAA; valine, leucine and isoleucine). We report the effects of phenylbutyrate on liver regeneration and amino acid levels in plasma of partially hepatectomized (PH) rats. Phenylbutyrate or saline was administered at 12-h intervals to PH or laparotomized rats. Phenylbutyrate delayed the onset of liver regeneration compared to the saline-treated controls, as indicated by lower hepatic DNA specific activities 18 and 24( ) h post-PH, decreased hepatic fractional protein synthesis rates 24 h post-PH and lowered the increases in liver weights and hepatic protein and DNA contents 48 h after PH. Hepatic DNA fragmentation (a hallmark of apoptosis) was higher in the phenylbutyrate-treated animals than in controls. Phenylbutyrate decreased the glutamine and BCAA concentrations and the ratio of the BCAA to aromatic amino acids (phenylalanine and tyrosine) in the blood plasma in both hepatectomized and laparotomized animals. In conclusion, the delayed onset of liver regeneration and the decrease in BCAA/AAA ratio in blood suggest that phenylbutyrate administration may be disastrous in subjects with acute hepatic injury and BCAA supplementation is needed when phenylbutyrate is used therapeutically. PMID:27381898

  12. Rumen ciliate protozoa contain high concentrations of conjugated linoleic acids and vaccenic acid, yet do not hydrogenate linoleic acid or desaturate stearic acid.

    PubMed

    Devillard, Estelle; McIntosh, Freda M; Newbold, C James; Wallace, R John

    2006-10-01

    Conjugated linoleic acids (CLA) have been shown to improve human health. They are derived from the microbial conversion of dietary linoleic acid (cis-9,cis-12-18 : 2 (LA)) in the rumen. An investigation was undertaken to determine the role of ruminal ciliate protozoa v. bacteria in the formation of CLA and its precursor in animal tissues, vaccenic acid (trans-11-18 : 1 (VA)). Mixed protozoa from the sheep rumen contained at least two to three times more unsaturated fatty acids, including CLA and VA, than bacteria. Different species had different composition, with larger fibrolytic species such as Epidinium ecaudatum caudatum containing more than ten times more CLA and VA than some small species, including Entodinium nanellum. In incubations with ruminal microbial fractions (bacterial fraction (BAC), protozoal fraction (PRO)), LA metabolism was very similar in strained ruminal fluid (SRF) and in the BAC, while the PRO had LA-metabolising activity an order of magnitude lower. Using PCR-based methods, no genes homologous to fatty acid desaturase genes were found in cDNA libraries from ruminal protozoa. The absence of an alternative route of VA/CLA formation via desaturation of stearate was confirmed by incubations of SRF, BAC or PRO with [14C]stearate. Thus, although protozoa are rich in CLA and VA, they appear to lack the ability to form these two fatty acids from LA or stearate. The most likely explanation is that protozoa preferentially incorporate CLA and VA formed by bacteria. The implication of the present findings is that the flow of unsaturated fatty acids, including CLA and VA, from the rumen could depend on the flow of protozoa rather than bacteria. PMID:17010229

  13. Identification of research relating to the critical loads concept and its potential application to the regulation of acidic deposition

    SciTech Connect

    Bhatti, N.

    1993-12-01

    The overwhelming majority of strategies currently implemented to regulate acidic deposition have focused on source-based or emission-control techniques. In the past few years, however, the fact that such source-based. strategies may not be sufficient to prevent adverse ecological effects and may therefore need to be supplemented with other control options, such as receptor-based strategies, has become apparent. Partly in response to this insufficiency of regulatory controls, the US Congress has required the National Acid Precipitation Assessment Program to determine (1) what deposition levels are needed to prevent such ecological damage, (2) whether such safe deposition levels (i.e., critical loads) can realistically be identified, and (3) what the costs and benefits of attaining such deposition levels are. This report reviews and culls the existing research on these alternative control strategies, emphasizing the critical loads concept, to determine the advantages and limitations and the cost-benefit relationships associated with receptor-based control options. The results of this study indicate that in spite of the significant limitations associated with the critical loads concept, this strategy dominates all discussions of non-source-based control options and offers considerable advantages, including cost-effectiveness, over the more traditional source-based control methods. Summaries of 10 of the most relevant studies dealing with alternative control strategies and the costs and benefits associated with them are also presented in this report.

  14. Paclitaxel-loaded nanoparticles of star-shaped cholic acid-core PLA-TPGS copolymer for breast cancer treatment

    NASA Astrophysics Data System (ADS)

    Tang, Xiaolong; Cai, Shuyu; Zhang, Rongbo; Liu, Peng; Chen, Hongbo; Zheng, Yi; Sun, Leilei

    2013-10-01

    A system of novel nanoparticles of star-shaped cholic acid-core polylactide- d-α-tocopheryl polyethylene glycol 1000 succinate (CA-PLA-TPGS) block copolymer was developed for paclitaxel delivery for breast cancer treatment, which demonstrated superior in vitro and in vivo performance in comparison with paclitaxel-loaded poly( d, l-lactide- co-glycolide) (PLGA) nanoparticles and linear PLA-TPGS nanoparticles. The paclitaxel- or couramin 6-loaded nanoparticles were fabricated by a modified nanoprecipitation method and then characterized in terms of size, surface charge, surface morphology, drug encapsulation efficiency, and in vitro drug release. The CA-PLA-TPGS nanoparticles were found to be spherical in shape with an average size of around 120 nm. The nanoparticles were found to be stable, showing no change in the particle size and surface charge during 90-day storage of the aqueous solution. The release profiles of the paclitaxel-loaded nanoparticles exhibited typically biphasic release patterns. The results also showed that the CA-PLA-TPGS nanoparticles have higher antitumor efficacy than the PLA-TPGS nanoparticles and PLGA nanoparticles in vitro and in vivo. In conclusion, such nanoparticles of star-shaped cholic acid-core PLA-TPGS block copolymer could be considered as a potentially promising and effective strategy for breast cancer treatment.

  15. A Common Polymorphism in HIBCH Influences Methylmalonic Acid Concentrations in Blood Independently of Cobalamin.

    PubMed

    Molloy, Anne M; Pangilinan, Faith; Mills, James L; Shane, Barry; O'Neill, Mary B; McGaughey, David M; Velkova, Aneliya; Abaan, Hatice Ozel; Ueland, Per M; McNulty, Helene; Ward, Mary; Strain, J J; Cunningham, Conal; Casey, Miriam; Cropp, Cheryl D; Kim, Yoonhee; Bailey-Wilson, Joan E; Wilson, Alexander F; Brody, Lawrence C

    2016-05-01

    Methylmalonic acid (MMA) is a by-product of propionic acid metabolism through the vitamin B12 (cobalamin)-dependent enzyme methylmalonyl CoA mutase. Elevated MMA concentrations are a hallmark of several inborn errors of metabolism and indicators of cobalamin deficiency in older persons. In a genome-wide analysis of 2,210 healthy young Irish adults (median age 22 years) we identified a strong association of plasma MMA with SNPs in 3-hydroxyisobutyryl-CoA hydrolase (HIBCH, p = 8.42 × 10(-89)) and acyl-CoA synthetase family member 3 (ACSF3, p = 3.48 × 10(-19)). These loci accounted for 12% of the variance in MMA concentration. The most strongly associated SNP (HIBCH rs291466; c:2T>C) causes a missense change of the initiator methionine codon (minor-allele frequency = 0.43) to threonine. Surprisingly, the resulting variant, p.Met1?, is associated with increased expression of HIBCH mRNA and encoded protein. These homozygotes had, on average, 46% higher MMA concentrations than methionine-encoding homozygotes in young adults with generally low MMA concentrations (0.17 [0.14-0.21] μmol/L; median [25(th)-75(th) quartile]). The association between MMA levels and HIBCH rs291466 was highly significant in a replication cohort of 1,481 older individuals (median age 79 years) with elevated plasma MMA concentrations (0.34 [0.24-0.51] μmol/L; p = 4.0 × 10(-26)). In a longitudinal study of 185 pregnant women and their newborns, the association of this SNP remained significant across the gestational trimesters and in newborns. HIBCH is unique to valine catabolism. Studies evaluating flux through the valine catabolic pathway in humans should account for these variants. Furthermore, this SNP could help resolve equivocal clinical tests where plasma MMA values have been used to diagnose cobalamin deficiency. PMID:27132595

  16. Early structural remodeling and deuterium oxide-derived protein metabolic responses to eccentric and concentric loading in human skeletal muscle

    PubMed Central

    Franchi, Martino V; Wilkinson, Daniel J; Quinlan, Jonathan I; Mitchell, William K; Lund, Jonathan N; Williams, John P; Reeves, Neil D; Smith, Kenneth; Atherton, Philip J; Narici, Marco V

    2015-01-01

    We recently reported that the greatest distinguishing feature between eccentric (ECC) and concentric (CON) muscle loading lays in architectural adaptations: ECC favors increases in fascicle length (Lf), associated with distal vastus lateralis muscle (VL) hypertrophy, and CON increases in pennation angle (PA). Here, we explored the interactions between structural and morphological remodeling, assessed by ultrasound and dual x-ray absorptiometry (DXA), and long-term muscle protein synthesis (MPS), evaluated by deuterium oxide (D2O) tracing technique. Ten young males (23 ± 4 years) performed unilateral resistance exercise training (RET) three times/week for 4 weeks; thus, one-leg trained concentrically while the contralateral performed ECC exercise only at 80% of either CON or ECC one repetition maximum (1RM). Subjects consumed an initial bolus of D2O (150 mL), while a 25-mL dose was thereafter provided every 8 days. Muscle biopsies from VL midbelly (MID) and distal myotendinous junction (MTJ) were collected at 0 and 4-weeks. MPS was then quantified via GC–pyrolysis–IRMS over the 4-week training period. Expectedly, ECC and CON RET resulted in similar increases in VL muscle thickness (MT) (7.5% vs. 8.4%, respectively) and thigh lean mass (DXA) (2.3% vs. 3%, respectively), albeit through distinct remodeling: Lf increasing more after ECC (5%) versus CON (2%) and PA increasing after CON (7% vs. 3%). MPS did not differ between contractile modes or biopsy sites (MID-ECC: 1.42 vs. MID-CON: 1.4% day−1; MTJ-ECC: 1.38 vs. MTJ-CON: 1.39% day−1). Muscle thickness at MID site increased similarly following ECC and CON RET, reflecting a tendency for a contractile mode-independent correlation between MPS and MT (P = 0.07; R2 = 0.18). We conclude that, unlike MT, distinct structural remodeling responses to ECC or CON are not reflected in MPS; the molecular mechanisms of distinct protein deposition, and/or the role of protein breakdown in mediating these responses

  17. Impact of confinement on proteins concentrated in lithocholic acid based organic nanotubes.

    PubMed

    Lu, Qin; Kim, Youngchan; Bassim, Nabil; Collins, Greg E

    2015-09-15

    Organic nanotubes form in aqueous solution near physiological pH by self-assembly of lithocholic acid (LCA) with inner diameters of 20-40nm. The encapsulation of enhanced green fluorescent protein (eGFP) and resultant confinement effect for eGFP within these nanotubes is studied via confocal microscopy. Timed release rate studies of eGFP encapsulated in LCA nanotubes and fluorescence recovery after photobleaching (FRAP) indicate that the diffusive transport of eGFP out of and/or within the nanotubes is very slow, in contrast to the rapid introduction of eGFP into the nanotubes. By encapsulating two fluorescent proteins in LCA nanotubes, eGFP and mCherry, as a fluorescence resonance energy transfer (FRET) pair, the FRET efficiencies are determined using FRET imaging microscopy at three different protein concentrations with a fixed donor-to-acceptor ratio of 1:1. Förster theory reveals that the proteins are spatially separated by 4.8-7.2nm in distance inside these nanotubes. The biomimetic nanochannels of LCA nanotubes not only afford a confining effect on eGFP that results in enhanced chemical and thermal stability under conditions of high denaturant concentration and temperature, but also function as protein concentrators for enriching protein in the nanochannels from a diluted protein solution by up to two orders of magnitude. PMID:26004574

  18. Estimation of Constituent Concentrations, Loads, and Yields in Streams of Johnson County, Northeast Kansas, Using Continuous Water-Quality Monitoring and Regression Models, October 2002 through December 2006

    USGS Publications Warehouse

    Rasmussen, Teresa J.; Lee, Casey J.; Ziegler, Andrew C.

    2008-01-01

    Johnson County is one of the most rapidly developing counties in Kansas. Population growth and expanding urban land use affect the quality of county streams, which are important for human and environmental health, water supply, recreation, and aesthetic value. This report describes estimates of streamflow and constituent concentrations, loads, and yields in relation to watershed characteristics in five Johnson County streams using continuous in-stream sensor measurements. Specific conductance, pH, water temperature, turbidity, and dissolved oxygen were monitored in five watersheds from October 2002 through December 2006. These continuous data were used in conjunction with discrete water samples to develop regression models for continuously estimating concentrations of other constituents. Continuous regression-based concentrations were estimated for suspended sediment, total suspended solids, dissolved solids and selected major ions, nutrients (nitrogen and phosphorus species), and fecal-indicator bacteria. Continuous daily, monthly, seasonal, and annual loads were calculated from co