activity concentrations ranged: Topics by Science.gov

Sample records for activity concentrations ranged

Quantifying activation of perfluorocarbon-based phase-change contrast agents using simultaneous acoustic and optical observation.

PubMed

Li, Sinan; Lin, Shengtao; Cheng, Yi; Matsunaga, Terry O; Eckersley, Robert J; Tang, Meng-Xing

2015-05-01

Phase-change contrast agents in the form of nanoscale droplets can be activated into microbubbles by ultrasound, extending the contrast beyond the vasculature. This article describes simultaneous optical and acoustical measurements for quantifying the ultrasound activation of phase-change contrast agents over a range of concentrations. In experiments, decafluorobutane-based nanodroplets of different dilutions were sonicated with a high-pressure activation pulse and two low-pressure interrogation pulses immediately before and after the activation pulse. The differences between the pre- and post-interrogation signals were calculated to quantify the acoustic power scattered by the microbubbles activated over a range of droplet concentrations. Optical observation occurred simultaneously with the acoustic measurement, and the pre- and post-microscopy images were processed to generate an independent quantitative indicator of the activated microbubble concentration. Both optical and acoustic measurements revealed linear relationships to the droplet concentration at a low concentration range <10(8)/mL when measured at body temperature. Further increases in droplet concentration resulted in saturation of the acoustic interrogation signal. Compared with body temperature, room temperature was found to produce much fewer and larger bubbles after ultrasound droplet activation. Copyright © 2015. Published by Elsevier Inc.
Minerals, vitamin C, phenolics, flavonoids and antioxidant activity of Amaranthus leafy vegetables

USDA-ARS?s Scientific Manuscript database

The objective of this study was to evaluate mineral, vitamin C, phenolic and flavonoid concentrations and antioxidant activity levels in 15 leafy Amaranthus species. Across species, the concentration ranges of Ca, K, Mg, P and phenolics, and activity ranges of antioxidants in amaranth leaves were 1....
Effects of Copper Pollution on the Phenolic Compound Content, Color, and Antioxidant Activity of Wine.

PubMed

Sun, Xiangyu; Ma, Tingting; Han, Luyang; Huang, Weidong; Zhan, Jicheng

2017-05-03

The effects of copper pollution on the polyphenol content, color, and antioxidant activity of wine, as well as correlations among these factors, were investigated. Copper had clear influences on wine polyphenol content. At low copper concentrations, the concentrations of nearly all polyphenols increased, and the antioxidant activity values of the wine also increased. When the copper concentration reached the lowest level of the medium copper range (9.6~16 mg/L), most of the indices also improved. When the copper concentrations reached the latter part of the medium copper range (19.2 and 22.4 mg/L), many of the tested indices began to decrease. Furthermore, when the copper concentration reached the high ranges (32, 64, and 96 mg/L), the polyphenol content, CIELAB color parameters, and antioxidant activity of wine were substantially decreased, indicating the need to control increasing copper content in grape must.
Tributyltin distribution and producing androgenic activity in water, sediment, and fish muscle.

PubMed

Shue, Meei-Fang; Chen, Ting-Chien; Bellotindos, Luzvisminda M; Lu, Ming-Chun

2014-01-01

This study investigated the concentrations of Tributyltin (TBT) in water, sediment, and fish muscle samples taken from Kaohsiung Harbor and Kaoping River estuary, Taiwan. TBT concentrations in water and sediment samples ranged from less than 18.5 to 34.1 ng Sn L(-1) and from 2.44 to 29.7 ng Sn g(-1) weight per weight (w/w), respectively. Concentrations in the TBT-contaminated fish muscle samples ranged from 10.8 to 79.6 ng Sn g(-1) w/w. The TBT concentrations in fish muscle were higher than those in water and sediment samples. The fish muscle/water TBT bioconcentration factor (BCF) ranged from 590 to 3363 L kg(-1). Additionally, the water samples were assessed for androgenic activity with an MCF7-AR1 human breast cancer cell line. The androgenic activity ranged from 0.94 to 3.1 ng-dihydrotestosterone per litre water (ng-DHT L(-1)). Higher concentrations of TBT in water and sediment samples occurred in the dry season, but the androgenic activity had higher values in the rainy season.
In Vitro Pharmacodynamic Activities of ABT-492, a Novel Quinolone, Compared to Those of Levofloxacin against Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis

PubMed Central

Gunderson, Shana M.; Hayes, Robert A.; Quinn, John P.; Danziger, Larry H.

2004-01-01

ABT-492 is a novel quinolone with potent activity against gram-positive, gram-negative, and atypical pathogens, making this compound an ideal candidate for the treatment of community-acquired pneumonia. We therefore compared the in vitro pharmacodynamic activity of ABT-492 to that of levofloxacin, an antibiotic commonly used for the treatment of pneumonia, through MIC determination and time-kill kinetic analysis. ABT-492 demonstrated potent activity against penicillin-sensitive, penicillin-resistant, and levofloxacin-resistant Streptococcus pneumoniae strains (MICs ranging from 0.0078 to 0.125 μg/ml); β-lactamase-positive and β-lactamase-negative Haemophilus influenzae strains (MICs ranging from 0.000313 to 0.00125 μg/ml); and β-lactamase-positive and β-lactamase-negative Moraxella catarrhalis strains (MICs ranging from 0.001 to 0.0025 μg/ml), with MICs being much lower than those of levofloxacin. Both ABT-492 and levofloxacin demonstrated concentration-dependent bactericidal activities in time-kill kinetics studies at four and eight times the MIC with 10 of 12 bacterial isolates exposed to ABT-492 and with 12 of 12 bacterial isolates exposed to levofloxacin. Sigmoidal maximal-effect models support concentration-dependent bactericidal activity. The model predicts that 50% of maximal activity can be achieved with concentrations ranging from one to two times the MIC for both ABT-492 and levofloxacin and that near-maximal activity (90% effective concentration) can be achieved at concentrations ranging from two to five times the MIC for ABT-492 and one to six times the MIC for levofloxacin. PMID:14693540
In vitro pharmacodynamic activities of ABT-492, a novel quinolone, compared to those of levofloxacin against Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.

PubMed

Gunderson, Shana M; Hayes, Robert A; Quinn, John P; Danziger, Larry H

2004-01-01

ABT-492 is a novel quinolone with potent activity against gram-positive, gram-negative, and atypical pathogens, making this compound an ideal candidate for the treatment of community-acquired pneumonia. We therefore compared the in vitro pharmacodynamic activity of ABT-492 to that of levofloxacin, an antibiotic commonly used for the treatment of pneumonia, through MIC determination and time-kill kinetic analysis. ABT-492 demonstrated potent activity against penicillin-sensitive, penicillin-resistant, and levofloxacin-resistant Streptococcus pneumoniae strains (MICs ranging from 0.0078 to 0.125 micro g/ml); beta-lactamase-positive and beta-lactamase-negative Haemophilus influenzae strains (MICs ranging from 0.000313 to 0.00125 micro g/ml); and beta-lactamase-positive and beta-lactamase-negative Moraxella catarrhalis strains (MICs ranging from 0.001 to 0.0025 micro g/ml), with MICs being much lower than those of levofloxacin. Both ABT-492 and levofloxacin demonstrated concentration-dependent bactericidal activities in time-kill kinetics studies at four and eight times the MIC with 10 of 12 bacterial isolates exposed to ABT-492 and with 12 of 12 bacterial isolates exposed to levofloxacin. Sigmoidal maximal-effect models support concentration-dependent bactericidal activity. The model predicts that 50% of maximal activity can be achieved with concentrations ranging from one to two times the MIC for both ABT-492 and levofloxacin and that near-maximal activity (90% effective concentration) can be achieved at concentrations ranging from two to five times the MIC for ABT-492 and one to six times the MIC for levofloxacin.
Activity concentration, transfer factors and resultant radiological risk of 226Ra, 232Th, and 40K in soil and some vegetables consumed in Selangor, Malaysia

NASA Astrophysics Data System (ADS)

Solehah, A. R.; Yasir, M. S.; Samat, S. B.

2016-11-01

The activity concentrations of the natural radionuclides 226Ra, 232Th, and 40K were determined in vegetable crops consumed by Malaysian people in Sungai Besar, Selangor. Sample of vegetables and the soil where the crops were cultivated and collected at five different location. The activity concentrations in Bq/kg of 226Ra, 232Th, and 40K were measured by the gamma-ray spectroscopy using the high purity germanium detector. The range activity concentration in soil is between 51.81 and 71.84 Bq/kg, 64.18 and 78.00 Bq/kg, and 210.49 and 244.29 Bq/kg for 226Ra, 232Th, and 40K, respectively. The activity concentration of 226Ra, 232Th, and 40K in vegetables were found to be in the range of 2.06 to 5.44 Bq/kg, Not Detectable to 0.61 Bq/kg, and 101.00 to 1223.09 Bq/kg, respectively. The activity concentration in both soil and vegetables were all less than lower limit stated by UNSCEAR. The Transfer Factors range value for 226Ra, 232Th, and 40K varied from 0.02 to 0.06, 0.003 to 0.008, and 1.79 to 5.19 respectively. Radium equivalent for soil range from 165.57 to 194.84 Bq/kg. It was within the international accepted value (370 Bq/kg). Absorb dose rate for soil range between 73.5 to 86.40 nGyh-1, in safe range from limit of international accepted value (55nGyh-1). Effective dose rate is found to be in range of 0.09 to 0.11 mSvy-1 for soil which is less than 2.4 mSv/y. External and Internal Hazard indices of soil was all below 1, within agreement of other researcher and UNSCEAR. The estimation of the consequent radiological risk due to the presence of those radionuclides is significantly low.
Effects of sodium dodecyl sulfate on the conformation and hemolytic activity of St I and St II, two isotoxins purified from Stichodactyla helianthus.

PubMed

Lanio, M E; Alvarez, C; Pazos, F; Martinez, D; Martínez, Y; Casallanovo, F; Abuin, E; Schreier, S; Lissi, E

2003-01-01

The effect of sodium dodecyl sulfate (SDS) upon the conformation and hemolytic activity of St I and St II strongly depends on its concentration. At relatively low surfactant concentrations (ca. 0.5-5mM range) the surfactant leads to the formation of aggregates, as suggested by the turbidity observed even at relatively low (micromolar range) protein concentrations. In this surfactant range, the proteins show an increase in intrinsic fluorescence intensity and reduced quenching by acrylamide, with an almost total loss of its hemolytic activity. At higher surfactant concentrations the protein adducts disaggregates. This produces a decrease in fluorescence intensity, increase in quenching efficiency by acrylamide, loss of the native tertiary conformation (as reported by the near UV-CD spectra), and increase in alpha-helix content (as evidenced by the far UV-CD spectra). However, and in spite of these substantial changes, the toxins partially recover their hemolytic activity. The reasons for this recovering of the activity at high surfactant concentrations is discussed.
An isotherm-based thermodynamic model of multicomponent aqueous solutions, applicable over the entire concentration range.

PubMed

Dutcher, Cari S; Ge, Xinlei; Wexler, Anthony S; Clegg, Simon L

2013-04-18

In previous studies (Dutcher et al. J. Phys. Chem. C 2011, 115, 16474-16487; 2012, 116, 1850-1864), we derived equations for the Gibbs energy, solvent and solute activities, and solute concentrations in multicomponent liquid mixtures, based upon expressions for adsorption isotherms that include arbitrary numbers of hydration layers on each solute. In this work, the long-range electrostatic interactions that dominate in dilute solutions are added to the Gibbs energy expression, thus extending the range of concentrations for which the model can be used from pure liquid solute(s) to infinite dilution in the solvent, water. An equation for the conversion of the reference state for solute activity coefficients to infinite dilution in water has been derived. A number of simplifications are identified, notably the equivalence of the sorption site parameters r and the stoichiometric coefficients of the solutes, resulting in a reduction in the number of model parameters. Solute concentrations in mixtures conform to a modified Zdanovskii-Stokes-Robinson mixing rule, and solute activity coefficients to a modified McKay-Perring relation, when the effects of the long-range (Debye-Hückel) term in the equations are taken into account. Practical applications of the equations to osmotic and activity coefficients of pure aqueous electrolyte solutions and mixtures show both satisfactory accuracy from low to high concentrations, together with a thermodynamically reasonable extrapolation (beyond the range of measurements) to extreme concentration and to the pure liquid solute(s).
Effects of CO2 Concentration on Rubisco Activity, Amount, and Photosynthesis in Soybean Leaves 1

PubMed Central

Campbell, William J.; Allen, L. H.; Bowes, George

1988-01-01

Growth at an elevated CO2 concentration resulted in an enhanced capacity for soybean (Glycine max L. Merr. cv Bragg) leaflet photosynthesis. Plants were grown from seed in outdoor controlled-environment chambers under natural solar irradiance. Photosynthetic rates, measured during the seed filling stage, were up to 150% greater with leaflets grown at 660 compared to 330 microliters of CO2 per liter when measured across a range of intercellular CO2 concentrations and irradiance. Soybean plants grown at elevated CO2 concentrations had heavier pod weights per plant, 44% heavier with 660 compared to 330 microliters of CO2 per liter grown plants, and also greater specific leaf weights. Ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) activity showed no response (mean activity of 96 micromoles of CO2 per square meter per second expressed on a leaflet area basis) to short-term (∼1 hour) exposures to a range of CO2 concentrations (110-880 microliters per liter), nor was a response of activity (mean activity of 1.01 micromoles of CO2 per minute per milligram of protein) to growth CO2 concentration (160-990 microliters per liter) observed. The amount of rubisco protein was constant, as growth CO2 concentration was varied, and averaged 55% of the total leaflet soluble protein. Although CO2 is required for activation of rubisco, results indicated that within the range of CO2 concentrations used (110-990 microliters per liter), rubisco activity in soybean leaflets, in the light, was not regulated by CO2. PMID:16666460
New Perspectives in the Renin-Angiotensin-Aldosterone System (RAAS) III: Endogenous Inhibition of Angiotensin Converting Enzyme (ACE) Provides Protection against Cardiovascular Diseases

PubMed Central

Fagyas, Miklós; Úri, Katalin; Siket, Ivetta M.; Daragó, Andrea; Boczán, Judit; Bányai, Emese; Édes, István; Papp, Zoltán; Tóth, Attila

2014-01-01

ACE inhibitor drugs decrease mortality by up to one-fifth in cardiovascular patients. Surprisingly, there are reports dating back to 1979 suggesting the existence of endogenous ACE inhibitors. Here we investigated the clinical significance of this potential endogenous ACE inhibition. ACE concentration and activity was measured in patient's serum samples (n = 151). ACE concentration was found to be in a wide range (47–288 ng/mL). ACE activity decreased with the increasing concentration of the serum albumin (HSA): ACE activity was 56±1 U/L in the presence of 2.4±0.3 mg/mL HSA, compared to 39±1 U/L in the presence of 12±1 mg/mL HSA (values are mean±SEM). Effects of the differences in ACE concentration were suppressed in human sera: patients with ACE DD genotype exhibited a 64% higher serum ACE concentration (range, 74–288 ng/mL, median, 155.2 ng/mL, n = 52) compared to patients with II genotype (range, 47–194 ng/mL, median, 94.5 ng/mL, n = 28) while the difference in ACE activities was only 32% (range, 27.3–59.8 U/L, median, 43.11 U/L, and range 15.6–55.4 U/L, median, 32.74 U/L, respectively) in the presence of 12±1 mg/mL HSA. No correlations were found between serum ACE concentration (or genotype) and cardiovascular diseases, in accordance with the proposed suppressed physiological ACE activities by HSA (concentration in the sera of these patients: 48.5±0.5 mg/mL) or other endogenous inhibitors. Main implications are that (1) physiological ACE activity can be stabilized at a low level by endogenous ACE inhibitors, such as HSA; (2) angiotensin II elimination may have a significant role in angiotensin II related pathologies. PMID:24690767
Anti-Salmonella activity of medicinal plants from Cameroon.

PubMed

Nkuo-Akenji, T; Ndip, R; McThomas, A; Fru, E C

2001-06-01

To evaluate the effects of herbal extracts derived from plants commonly prescribed by traditional practitioners for the treatment of typhoid fever. A cross sectional study. Departments of Life Sciences and Chemistry, University of Buea, Cameroon. Methanol extracts of plant parts commonly used in Cameroon for the treatment of typhoid fever. Antimicrobial activity was tested using the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) assays. Methanol extracts of plant parts commonly used in Cameroon for the treatment of typhoid fever were tested for antibacterial activity against Salmonella typhi, S. paratyphi and S. typhimurium. The formulations used were: 1) Formulation A comprising Cymbogogon citratus leaves, Carica papaya leaves, and Zea mays silk. 2) Formulation B comprising C. papaya roots, Mangifera indica leaves, Citrus limon fruit and C. citratus leaves. 3) C. papaya leaves. 4) Emilia coccinea whole plant. 5) Comelina bengalensis leaves. 6) Telfaria occidentalis leaves. 7) Gossypium arboreum whole plant. Antimicrobial activity was tested using the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) assays. Generally, Formulation A elicited inhibitory activity at a lower range of 0.02 to 0.06 mg/ml. Similarly, Formulation B elicited bacterial activity at the lowest range of 0.06 to 0.25 mg/ml. C. bengalensis leaves on the other hand, showed the lowest activity with a concentration range of 0.132 to 2.0 mg/ml and 1 to 4 mg/ml in MIC and MBC assays respectively. S. paratyphi was most sensitive to the formulations (concentration range of 0.02 to 1 mg/ml in both MIC and MBC assays) while S. typhimurium was the least sensitive and concentrations of up to 4 mg/ml were required to be bactericidal. It is concluded that plant extracts with low MIC and MBC values (1 mg/ml and lower) may contain compounds with therapeutic activity.
Dioxin-like activities, halogenated flame retardants, organophosphate esters and chlorinated paraffins in dust from Australia, the United Kingdom, Canada, Sweden and China.

PubMed

Wong, Fiona; Suzuki, Go; Michinaka, Chieko; Yuan, Bo; Takigami, Hidetaka; de Wit, Cynthia A

2017-02-01

The concentrations of organic flame retardants (FRs) and dioxin-like activities in dust collected from five countries were investigated. The correlations between the concentrations of the different groups of FRs and dioxin-like activities were examined. Chlorinated paraffins (CPs, C 9 to C 31 ) were found in the highest concentration (median ∑CP 700 μg/g, range 280-4750 μg/g), followed by organophosphate esters (median ∑ 13 OPEs 56 μg/g, range 21-110 μg/g), halogenated flame retardants (median ∑ 17 HFRs 3.3 μg/g, range 0.87-14 μg/g) and polybrominated diphenyl ethers (median ∑ 17 PBDEs 2.8 μg/g, range 0.46-11 μg/g). There were no significant differences in concentrations of the FRs among the countries but differences in PBDE and CP congener profiles were found. BDE209 predominated in dust from Australia, the UK, Sweden and China, ranging from 50 to 70% of total PBDEs. The lowest percentage of BDE209 was found in the dust from Canada, representing only 20% of total PBDEs. For CPs in dust from Sweden, the long-chain CPs (especially C 18 congeners) predominated, while for other countries, medium-chain CPs (especially C 14 congeners) predominated. The dioxin-activities of the dusts ranged from 58 to 590 pg CALUX-TEQ/g, and had a median of 200 pg CALUX-TEQ/g. There were significant positive correlations between concentrations of PBDEs and CPs with dioxin-like activities. The dioxin-like activity may be due to the presence of polychlorinated or polybrominated dioxin/furans (PBDD/DFs) or polychlorinated naphthalenes (PCNs) in the dust. The PBDD/DFs are known impurities and degradation product of the penta-BDE mixture, and PCNs are known impurities of CPs which exhibit dioxin-like activities. Copyright © 2016 Elsevier Ltd. All rights reserved.
Groundwater quality of the Gulf Coast aquifer system, Houston, Texas, 2010

USGS Publications Warehouse

Oden, Jeannette H.; Brown, Dexter W.; Oden, Timothy D.

2011-01-01

Gross alpha-particle activities and beta-particle activities for all 47 samples were analyzed at 72 hours after sample collection and again at 30 days after sample collection, allowing for the measurement of the activity of short-lived isotopes. Gross alpha-particle activities reported in this report were not adjusted for activity contributions by radon or uranium and, therefore, are conservatively high estimates if compared to the U.S. Environmental Protection Agency National Primary Drinking Water Regulation for adjusted gross alpha-particle activity. The gross alpha-particle activities at 30 days in the samples ranged from R0.60 to 25.5 picocuries per liter and at 72 hours ranged from 2.58 to 39.7 picocuries per liter, and the "R" preceding the value of 0.60 picocuries per liter refers to a nondetected result less than the sample-specific critical level. Gross beta-particle activities measured at 30 days ranged from 1.17 to 14.4 picocuries per liter and at 72 hours ranged from 1.97 to 4.4 picocuries per liter. Filtered uranium was detected in quantifiable amounts in all of the 47 wells sampled. The uranium concentrations ranged from 0.03 to 42.7 micrograms per liter. One sample was analyzed for carbon-14, and the amount of modern atmospheric carbon was reported as 0.2 percent. Six source-water samples collected from municipal supply wells were analyzed for radium-226, and all of the concentrations were considered detectable concentrations (greater than their associated sample-specific critical level). Three source-water samples collected were analyzed for radon-222, and all of the concentrations were substantially greater than the associated sample-specific critical level.
Extracts of Agrimonia eupatoria L. as sources of biologically active compounds and evaluation of their antioxidant, antimicrobial, and antibiofilm activities.

PubMed

Muruzović, Mirjana Ž; Mladenović, Katarina G; Stefanović, Olgica D; Vasić, Sava M; Čomić, Ljiljana R

2016-07-01

In this study, we determined the concentration of total phenols, flavonoids, tannins, and proanthocyanidins in the water, diethyl ether, acetone, and ethanol extracts of Agrimonia eupatoria L. We also investigated the antioxidant activity of these extracts using two methods [2,2-diphenyl-1-picrylhydrazyl (DPPH) and reducing power] and their in vitro antimicrobial (antibacterial and antifungal) activity on some selected species of bacteria and fungi. In addition, the effects of the acetone and water extracts on the inhibition of biofilm formation of Proteus mirabilis and Pseudomonas aeruginosa were investigated using the crystal violet method. The concentration of total phenols was measured according to the Folin-Ciocalteu method and the values obtained ranged from 19.61 mgGA/g to 220.31 mgGA/g. The concentration of flavonoids was examined by the aluminum chloride method and the values obtained ranged from 20.58 mgRU/g to 97.06 mgRU/g. The total tannins concentration was measured by the polyvinylpolypyrrolidone method and the values obtained ranged from 3.06 mgGA/g to 207.27 mgGA/g. The concentration of proanthocyanidins was determined by the butanol-HCl method and the values obtained ranged from 4.15 CChE/g to 103.72 CChE/g. Among the various extracts studied, the acetone extract exhibited good antioxidant activity (97.13%, as determined by the DPPH method). The acetone extract was active in the absorbance value range from 2.2665 to 0.2495 (as determined by the reducing power method). The strongest antimicrobial activity was detected on G + bacteria, especially on probiotic species, and the acetone extract demonstrated the highest activity. Biofilm inhibitory concentration required to reduce biofilm coverage by 50% values for acetone extract was 4315 μg/mL for P. mirabilis and 4469.5 μg/mL for P. aeruginosa. The results provide a basis for further research of this plant species. Copyright © 2016. Published by Elsevier B.V.
Serum chemistry comparisons between captive and free-ranging giraffes (Giraffa camelopardalis).

PubMed

Schmidt, Debra A; Barbiers, Robyn B; Ellersieck, Mark R; Ball, Ray L; Koutsos, Elizabeth A; Griffin, Mark E; Grobler, Douw; Citino, Scott B; Bush, Mitchell

2011-03-01

Serum chemistry analyses were compared between captive and free-ranging giraffes (Giraffa camelopardalis) in an attempt to better understand some of the medical issues seen with captive giraffes. Illnesses, including peracute mortality, energy malnutrition, pancreatic disease, urolithiasis, hoof disease, and severe intestinal parasitism, may be related to zoo nutrition and management issues. Serum samples were collected from 20 captive giraffes at 10 United States institutions. Thirteen of the captive animal samples were collected from animals trained for blood collection; seven were banked samples obtained from a previous serum collection. These samples were compared with serum samples collected from 24 free-ranging giraffes in South Africa. Differences between captive and free-ranging giraffes, males and females, and adults and subadults were analyzed by using a 2 x 2 x 2 factorial and Fisher's least significant difference for mean separation; when necessary variables were ranked and analyzed via analysis of variance. Potassium and bilirubin concentrations and alanine aminotransferase (ALT) activities were different between captive and free-ranging giraffes, but all fell within normal bovid reference ranges. The average glucose concentration was significantly elevated in free-ranging giraffes (161 mg/dl) compared with captive giraffes (113 mg/dl). All giraffes in this study had glucose concentrations higher than bovine (42-75 mg/ dl) and caprine (48-76 mg/dl) reference ranges. Differences were also seen in lipase, chloride, and magnesium though these findings are likely not clinically significant. There were no differences detected between sexes. Adults had higher concentrations of potassium, total protein, globulins, and chloride and higher gamma glutamyltransferase activities, whereas subadults had higher concentrations of phosphorus. Within the captive group, nonimmobilized animals had higher concentrations of total protein and globulins. Captive giraffe diets need further investigation to determine if the differences seen in this study, especially glucose and bilirubin concentrations and ALT activities, may result in some health problems often seen in captive giraffes.
Electrical characterization of 6H crystalline silicon carbide. M.S. Thesis Final Report

NASA Technical Reports Server (NTRS)

Lempner, Stephen E.

1994-01-01

Crystalline silicon carbide (SiC) substrates and epilayers, undoped as well as n- and p-doped, have been electrically characterized by performing Hall effect and resistivity measurements (van der Pauw) over the temperature range of approximately 85 K to 650 K (200 K to 500 K for p-type sample). By fitting the measured temperature dependent carrier concentration data to the single activation energy theoretical model: (1) the activation energy for the nitrogen donor ranged from 0.078 eV to 0.101 eV for a doping concentration range of 10(exp 17) cm(exp -3) to 10(exp 18) cm(exp -3) and (2) the activation energy for the aluminum acceptor was 0.252 eV for a doping concentration of 4.6 x 10(exp 18) cm(exp -3). By fitting the measured temperature dependent carrier concentration data to the double activation energy level theoretical model for the nitrogen donor: (1) the activation energy for the hexagonal site was 0.056 eV and 0.093 eV corresponding to doping concentrations of 3.33 x 10 (exp 17) cm(exp -3) and 1.6 x 10(exp 18) cm(exp -3) and (2) the activation energy for the cubic site was 0.113 and 0.126 eV corresponding to doping concentrations of 4.2 x 10(exp 17) cm(exp -3) and 5.4 x 10(exp 18) cm(exp -3).
Antibacterial activity of vegetables and juices.

PubMed

Lee, Yee-Lean; Cesario, Thomas; Wang, Yang; Shanbrom, Edward; Thrupp, Lauri

2003-01-01

We evaluated the antibacterial activities of various fruit and vegetable extracts on common potential pathogens including antibiotic-resistant strains. Standardized bacterial inocula were added to serial dilutions of sterile vegetable and fruit extracts in broth, with final bacterial concentrations of 10(4-5) cells/mL. After overnight incubation at 35 degrees C, antibacterial activity was measured by minimum inhibitory and minimum bactericidal dilutions (for raw juices) or concentrations (for tea). Among the vegetable and fruit extracts tested, all green vegetables showed no antibacterial activity on Staphylococcus epidermidis and Klebsiella pneumoniae. All purple and red vegetable and fruit juices had antibacterial activities in dilutions ranging from 1:2 to 1:16. Garlic juice had significant activity, with bactericidal action in dilutions ranging up to 1:128 of the original juice. Tea also had significant activity, with bactericidal action in concentrations ranging up to 1.6 mg/mL, against a spectrum of pathogens including resistant strains such as methicillin- and ciprofloxacin-resistant staphylococci, vancomycin-resistant enterococci, and ciprofloxacin-resistant Pseudomonas aeruginosa. Tea and garlic have the potential for exploration of broader applications as antibacterial agents.
Distribution of natural and artificial radioactivity in soils, water and tuber crops.

PubMed

Darko, Godfred; Faanu, Augustine; Akoto, Osei; Acheampong, Akwasi; Goode, Eric Jude; Gyamfi, Opoku

2015-06-01

Activity concentrations of radionuclides in water, soil and tuber crops of a major food-producing area in Ghana were investigated. The average gross alpha and beta activities were 0.021 and 0.094 Bq/L, respectively, and are below the guidelines for drinking water and therefore not expected to pose any significant health risk. The average annual effective dose due to ingestion of radionuclide in water ranged from 20.08 to 53.45 μSv/year. The average activity concentration of (238)U, (232)Th, (40)K and (137)Cs in the soil from different farmlands in the study area was 23.19, 31.10, 143.78 and 2.88 Bq/kg, respectively, which is lower than world averages. The determined absorbed dose rate for the farmlands ranged from 23.63 to 50.51 nGy/year, which is within worldwide range of 18 to 93 nGy/year. The activity concentration of (238)U, (232)Th, (40)K and (137)Cs in cassava ranges from 0.38 to 6.73, 1.82 to 10.32, 17.65 to 41.01 and 0.38 to 1.02 Bq/kg, respectively. Additionally, the activity concentration of (238)U, (232)Th, (40)K and (137)Cs in yam also ranges from 0.47 to 4.89, 0.93 to 5.03, 14.19 to 35.07 and 0.34 to 0.89 Bq/kg, respectively. The average concentration ratio for (238)U, (232)Th and (40)K in yam was 0.12, 0.11 and 0.17, respectively, and in cassava was 0.11, 0.12 and 0.2, respectively. None of the radioactivity is expected to cause significant health problems to human beings.
Fate and occurrence of alkylphenolic compounds in sewage sludges determined by liquid chromatography tandem mass spectrometry.

PubMed

Koh, Y K K; Chiu, T Y; Paterakis, N; Boobis, A; Scrimshawe, M D; Lester, J N; Cartmell, E

2009-12-01

An analytical method has been developed and applied to determine the concentrations of the nonionic alkylphenol polyethoxylate surfactants and their metabolites, alkylphenoxy carboxylates and alkyphenols, in sewage sludges. The compounds were extracted with methanol/acetone (1:1 v/v) from sludge, and concentrated extracts were cleaned by silica solid-phase extraction prior to determination by liquid chromatography tandem mass spectrometry. The recoveries, determined by spiking sewage sludge at two concentrations, ranged from 51% to 89% with method detection limits from 6 microg kg(-1) to 60 microg kg(-1). The methodology was subsequently applied to sludge samples obtained from a carbonaceous activated sludge plant, a nitrifying/denitrifying activated sludge plant and a nitrifying/ denitrifying activated sludge plant with phosphorus removal. Concentrations of nonylphenolic compounds were two to three times higher than their octyl analogues. Long-chain nonylphenol polyethoxylates (NP3-12EO) ranged from 16 microg kg(-1) to 11754 microg kg(-1). The estrogenic metabolite nonylphenol was present at concentrations ranging from 33 microg kg(-1) to 6696 microg kg(-1).

In vitro activity of heather [Calluna vulgaris (L.) Hull] extracts on selected urinary tract pathogens

PubMed Central

Vučić, Dragana M.; Petković, Miroslav R.; Rodić-Grabovac, Branka B.; Stefanović, Olgica D.; Vasić, Sava M.; Čomić, Ljiljana R.

2014-01-01

Calluna vulgaris L. Hull (Ericaceae) has been used for treatment of urinary tract infections in traditional medicine. In this study we analyzed in vitro antibacterial activity of the plant extracts on different strains of Escherichia coli, Enterococcus faecalis and Proteus vulgaris, as well as the concentrations of total phenols and flavonoids in the extracts. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The concentrations of total phenols were examined by using Folin-Ciocalteu reagent and ranged between 67.55 to 142.46 mg GAE/g. The concentrations of flavonoids in extracts were determined using spectrophotometric method with aluminum chloride and the values ranged from 42.11 to 63.68 mg RUE/g. The aqueous extract of C. vulgaris showed a significant antibacterial activity. The values of MIC were in the range from 2.5 mg/ml to 20 mg/ml for this extract. Proteus vulgaris strains were found to be the most sensitive. The results obtained suggest that all tested extracts of C. vulgaris inhibit the growth of human pathogens, especially the aqueous extract. PMID:25428676
In vitro activity of heather [Calluna vulgaris (L.) Hull] extracts on selected urinary tract pathogens.

PubMed

Vučić, Dragana M; Petković, Miroslav R; Rodić-Grabovac, Branka B; Stefanović, Olgica D; Vasić, Sava M; Comić, Ljiljana R

2014-11-15

Calluna vulgaris L. Hull (Ericaceae) has been used for treatment of urinary tract infections in traditional medicine. In this study we analyzed in vitro antibacterial activity of the plant extracts on different strains of Escherichia coli, Enterococcus faecalis and Proteus vulgaris, as well as the concentrations of total phenols and flavonoids in the extracts. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The concentrations of total phenols were examined by using Folin-Ciocalteu reagent and ranged between 67.55 to 142.46 mg GAE/g. The concentrations of flavonoids in extracts were determined using spectrophotometric method with aluminum chloride and the values ranged from 42.11 to 63.68 mg RUE/g. The aqueous extract of C. vulgaris showed a significant antibacterial activity. The values of MIC were in the range from 2.5 mg/ml to 20 mg/ml for this extract. Proteus vulgaris strains were found to be the most sensitive. The results obtained suggest that all tested extracts of C. vulgaris inhibit the growth of human pathogens, especially the aqueous extract.
Interaction of tributyltin with 3,3',4,4',5-pentachlorobiphenyl-induced ethoxyresorufin O-deethylase activity in rat hepatoma cells.

PubMed

Kannan, K; Villeneuve, D L; Blankenship, A L; Giesy, J P

1998-11-13

Interaction of tributyltin (TBT) with 3,3',4,4',5-pentachlorobiphenyl (PCB-126)-induced ethoxyresorufin O-deethylase (EROD) activity was examined in vitro using H4IIE rat hepatoma cells. H4IIE cells were exposed to TBT and PCB-126, individually or in combination, at different concentrations. TBT was cytotoxic at concentrations greater than 98 nM. PCB-126 was not cytotoxic in the concentration range of 49 to 3140 pM. At concentrations greater than 49 nM, PCB-126 enhanced the cytotoxicity of TBT in the 24-98 nM range. In the absence of inducers of EROD activity, TBT significantly inhibited constitutive EROD activity in H4IIE cells in a concentration-dependent manner. EROD activity in H4IIE cells was significantly increased by exposure to PCB-126 alone. This effect was potentiated by coexposure to low, noncytotoxic concentrations of TBT. The induction of cytochrome P-4501A (CYP1A) activity in the presence of both an inducer (PCB-126) and low concentrations of an inhibitor (TBT) indicates that TBT does not interfere with the Ah receptor binding, but acts at the transcriptional level. Potentiation of EROD activity and cytotoxicity as a consequence of coexposure to PCB-126 and TBT is of considerable toxicological significance, given their coaccumulation in a variety of marine organisms.
Antimicrobial properties, antioxidant activity and bioactive compounds from six wild edible mushrooms of western ghats of Karnataka, India

PubMed Central

Ramesh, Ch.; Pattar, Manohar G.

2010-01-01

Methanolic extracts of 6 wild edible mushrooms isolated from the Western Ghats of Karnataka were used in this study. Among the isolates (Lycoperdon perlatum, Cantharellus cibarius, Clavaria vermiculris, Ramaria formosa, Marasmius oreades, Pleurotus pulmonarius), only 4 showed satisfactory results. Quantitative analysis of bioactive components revealed that total phenols are the major bioactive component found in extracts of isolates expressed as mg of GAE per gram of fruit body, which ranged from 3.20 ± 0.05 mg/mL to 6.25 ± 0.08 mg/mL. Average concentration of flavonoid ranged from 0.40 ± 0.052 mg/mL to 2.54 ± 0.08 mg/mL; followed by very small concentration of ascorbic acid (range, 0.06 ± 0.01 mg/mL to 0.16 ± 0.01 mg/mL) in all the isolates. All the isolates showed high phenol and flavonoid content, but ascorbic acid content was found in traces. Antioxidant efficiency by inhibitory concentration on 1,1-Diphenly-2-picrylhydrazyl (DPPH) was found significant when compared to standard antioxidant like Buthylated hydroxyanisol (BHA). The concentration (IC50) ranged from 0.94 ± 0.27 mg/mL to 7.57 ± 0.21 mg/mL. Determination of antimicrobial activity profile of all the isolates tested against a panel of standard pathogenic bacteria and fungi indicated that the concentrations of bioactive components directly influence the antimicrobial capability of the isolates. Agar diffusion assay showed considerable activity against all bacteria. Minimum inhibitory concentration values of the extracts of 4 isolates showed that they are also active even in least concentrations. These results are discussed in relation to therapeutic value of the studied mushrooms. PMID:21808550
Wide-range radioactive-gas-concentration detector

DOEpatents

Anderson, D.F.

1981-11-16

A wide-range radioactive-gas-concentration detector and monitor capable of measuring radioactive-gas concentrations over a range of eight orders of magnitude is described. The device is designed to have an ionization chamber sufficiently small to give a fast response time for measuring radioactive gases but sufficiently large to provide accurate readings at low concentration levels. Closely spaced parallel-plate grids provide a uniform electric field in the active region to improve the accuracy of measurements and reduce ion migration time so as to virtually eliminate errors due to ion recombination. The parallel-plate grids are fabricated with a minimal surface area to reduce the effects of contamination resulting from absorption of contaminating materials on the surface of the grids. Additionally, the ionization-chamber wall is spaced a sufficient distance from the active region of the ionization chamber to minimize contamination effects.
[Effect of glycine and strychnine on Cl(-)-activated Mg2+-ATPase from bream brain microsomes (Abamis brama L.)].

PubMed

Menzikov, S A; Menzikova, O V

2001-01-01

The effect of glycine and strychnine on Mg2+-ATPase from the microsomal fraction of the bream (Abramis brama L.) brain was studied. The glycine in the concentration range 10(-7)-10(-4) M activates the enzyme. The effect of glycine on Mg2+-ATPase is obviated by 100 microM strychnine. The strychnine in the concentration range 5-90 microM activates the basal Mg2+-ATPase but decreases the effect of the enzyme activation by 10(-4) M glycine. The effect of Cl- on Mg2+-ATPase depends on the substrate concentration (Mg2+-ATP) and is not observed in the presence of 100 microM strychnine. A receptor-dependent pathway of glycine and strychnine action on Cl(-)-activated Mg2+-ATPase from bream brain microsomes is proposed.
Relationship between peroxisome proliferator-activated receptor alpha activity and cellular concentration of 14 perfluoroalkyl substances in HepG2 cells.

PubMed

Rosenmai, Anna Kjerstine; Ahrens, Lutz; le Godec, Théo; Lundqvist, Johan; Oskarsson, Agneta

2018-02-01

Peroxisome proliferator-activated receptor alpha (PPARα) is a molecular target for perfluoroalkyl substances (PFASs). Little is known about the cellular uptake of PFASs and how it affects the PPARα activity. We investigated the relationship between PPARα activity and cellular concentration in HepG2 cells of 14 PFASs, including perfluoroalkyl carboxylates (PFCAs), perfluoroalkyl sulfonates and perfluorooctane sulfonamide (FOSA). Cellular concentrations were determined by high-performance liquid chromatography-tandem mass spectrometry and PPARα activity was determined in transiently transfected cells by reporter gene assay. Cellular uptake of the PFASs was low (0.04-4.1%) with absolute cellular concentrations in the range 4-2500 ng mg -1 protein. Cellular concentration of PFCAs increased with perfluorocarbon chain length up to perfluorododecanoate. PPARα activity of PFCAs increased with chain length up to perfluorooctanoate. The maximum induction of PPARα activity was similar for short-chain (perfluorobutanoate and perfluoropentanoate) and long-chain PFCAs (perfluorododecanoate and perfluorotetradecanoate) (approximately twofold). However, PPARα activities were induced at lower cellular concentrations for the short-chain homologs compared to the long-chain homologs. Perfluorohexanoate, perfluoroheptanoate, perfluorooctanoate, perfluorononanoate (PFNA) and perfluorodecanoate induced PPARα activities >2.5-fold compared to controls. The concentration-response relationships were positive for all the tested compounds, except perfluorooctane sulfonate PFOS and FOSA, and were compound-specific, as demonstrated by differences in the estimated slopes. The relationships were steeper for PFCAs with chain lengths up to and including PFNA than for the other studied PFASs. To our knowledge, this is the first report establishing relationships between PPARα activity and cellular concentration of a broad range of PFASs. Copyright © 2017 John Wiley & Sons, Ltd.
[Effect of nano-selenium on the activities of glutathione peroxidase and type-I deiodinase in the liver of weanling pigs].

PubMed

Zhang, Hongmei; Xia, Meisheng; Hu, Caihong

2007-02-01

To study the effects of nano elemental selenium (Nano-Se) or sodium selenite (Na2SeO3) on the activities of glutathione peroxidase (GSH-Px) and Type-I deiodinase in the liver. A total of 234 weanling pigs (Duroc x Landrace x Yorkshire) at an average initial body weight of 8.3 kg were allocated to 13 treatments. The thirteen dietary treatments were basal diet only (containing 0.04 mg/kg Se), basal diet + 0.1, 0.2, 0.3, 0.4, 0.5, 1.0 mg/kg Se as Na2SeO3 or Nano-Se, respectively. The results were as follows: Supplementation with 1.0 mg/ kg Se as Na2SeO3 reduced (P < 0.05) growth performance and GSH-Px activities as compared with the addition of a concentration range of 0.20-0.40 mg/kg Se. When Nano-Se was added to the diet, the growth and GSH-Px activities remained steady at the peak value as at a concentration of 1.0 mg/kg Se; There were no difference in the activities of GSH-Px between the treatments of Nano-Se and Na2SeO3 when added concentration of Se was 0.10-0.40 mg/kg. The pigs had higher (P < 0.05) activities of GSH-Px at a concentration range of 0.50 and 1.0 mg/kg as Nano-Se than Na2SeO3; Supplentation with Se increased the activity of Type- I deiodinase in liver, however, the increased extent was affected by neither Se sources nor added concentration of Se. The results implicated that for the best concentration range of Weinberg curve, Nano-Se is wider than Na2SeO3.
Antibacterial activity and chemical characteristics of several Western Australian honeys compared to manuka honey and pasture honey.

PubMed

Roshan, Niloufar; Rippers, Thomas; Locher, Cornelia; Hammer, Katherine A

2017-03-01

The physicochemical parameters and antibacterial activity of 10 Western Australian (WA) and two comparator honeys were determined. Honeys showed a pH range of 4.0-4.7, colour range of 41.3-470.7 mAU, methylglyoxal levels ranging from 82.2 to 325.9 mg kg -1 and hydrogen peroxide levels after 2 h of 22.7-295.5 µM. Antibacterial activity was assessed by the disc diffusion assay, phenol equivalence assay, determination of minimum inhibitory and bactericidal concentrations and a time-kill assay. Activity was shown for all honeys by one or more method, however, activity varied according to which assay was used. Minimum inhibitory concentrations for WA honeys against 10 organisms ranged from 4.0 to >32.0% (w/v). Removal of hydrogen peroxide activity by catalase resulted in decreased activity for several honeys. Overall, the data showed that honeys in addition to those derived from Leptospermum spp. have antimicrobial activity and should not be overlooked as potential sources of clinically useful honey.
Wide range radioactive gas concentration detector

DOEpatents

Anderson, David F.

1984-01-01

A wide range radioactive gas concentration detector and monitor which is capable of measuring radioactive gas concentrations over a range of eight orders of magnitude. The device of the present invention is designed to have an ionization chamber which is sufficiently small to give a fast response time for measuring radioactive gases but sufficiently large to provide accurate readings at low concentration levels. Closely spaced parallel plate grids provide a uniform electric field in the active region to improve the accuracy of measurements and reduce ion migration time so as to virtually eliminate errors due to ion recombination. The parallel plate grids are fabricated with a minimal surface area to reduce the effects of contamination resulting from absorption of contaminating materials on the surface of the grids. Additionally, the ionization chamber wall is spaced a sufficient distance from the active region of the ionization chamber to minimize contamination effects.
Phytochemical, antimicrobial, and antioxidant activities of different citrus juice concentrates.

PubMed

Oikeh, Ehigbai I; Omoregie, Ehimwenma S; Oviasogie, Faith E; Oriakhi, Kelly

2016-01-01

The search for new antimicrobial compounds is ongoing. Its importance cannot be overemphasized in an era of emerging resistant pathogenic organisms. This study therefore investigated the phytochemical composition and antioxidant and antimicrobial activities of different citrus juice concentrates. Fruit juices of Citrus tangerine (tangerine), Citrus paradisi (grape), Citrus limon (lemon), and Citrus aurantifolia (lime) were evaluated. Antimicrobial activities against five bacterial and three fungal strains were evaluated. The results revealed the presence of alkaloids, flavonoids, steroids, terpenoids, saponins, cardiac glycosides, and reducing sugars in all the juice concentrates. DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging capacities varied with tangerine and grape juices having better scavenging capacities than lemon and lime juices. Grape juice was observed to have a significantly higher (P < 0.05) ferric-reducing antioxidant potential (FRAP) value (364.2 ± 10.25 μmol/L Fe(II)/g of the extract) than the reference antioxidant, ascorbic acid (312.88 ± 5.61 μmol/L). Antimicrobial studies revealed differential antimicrobial activities against different microbial strains. Zones of inhibition ranging from 4 to 26 mm were observed for the antibacterial tests with 0-24 mm for antifungal test. Minimum inhibitory concentrations (MIC) and minimum bacteriostatic concentrations (MBC) for concentrates against bacterial strains ranged from 12.5 to 200 μg/mL. Lemon and lime juice concentrates had lower MIC and MBC values with orange and tangerine having the highest values. Minimum fungicidal concentrations ranged from 50 to 200 μg/mL. The results of this study suggest that these juice concentrates may have beneficial antimicrobial roles that can be exploited in controlling unwanted microbial growth.
Effect of HCl Loading and Ethanol Concentration over HCl-Activated Clay Catalysts for Ethanol Dehydration to Ethylene.

PubMed

Krutpijit, Chadaporn; Jongsomjit, Bunjerd

2017-01-01

Montmorillonite clay (MMT) is one of materials that can be "green material" due to its environmental safety. In this work, acid-activated MMT catalysts were prepared for the dehydration reaction of ethanol. To be the green process, the reaction with bioethanol was also studied. Ethanol concentrations in feed were varied in the range of 10-99.95 wt%. Moreover, the concentrations of hydrochloric acid activated MMT were investigated in range of 0.05-4 M. From the experiment, it reveals that different acid concentrations to activate MMT affect the catalytic activity of catalysts. The 0.3 M of HCl activated MMT exhibits the highest activity (under the best condition of 30 ml HCl aging for 1 h) with the Si/Al ratio of 7.4. It can reach the ethanol conversion and ethylene selectivity up to 95% and 98% at reaction temperature of 400°C, respectively. For the several ethanol feed concentrations, it does not remarkably affect in ethanol conversion. However, it has some different effect on ethylene selectivity between lower and higher reaction temperatures. It was found that at lower temperature reaction, ethylene selectivity is high due to the behavior of water in feed. In addition, the 0.3 M-MMT can be carried out under the hydrothermal effect.
Great horsetail (Equisetum telmateia Ehrh.): Active substances content and biological effects

PubMed Central

Radojevic, Ivana D.; Stankovic, Milan S.; Stefanovic, Olgica D.; Topuzovic, Marina D.; Comic, Ljiljana R.; Ostojic, Aleksandar M.

2012-01-01

This paper deals with the antioxidant and antimicrobial activity, total phenolic content and concentrations of flavonoids of Equisetum telmateia extracts. Total phenolic content was determined with Folin-Ciocalteu reagent and it ranged between 129.0 to 262.7 mg GA/g. The concentration of flavonoids in various extracts of E. telmateia was determined using spectrophotometric method with aluminum chloride and obtained results varied from 112.6 to 199.8 mg RU/g. Antioxidant activity was monitored spectrophotometrically and expressed in terms of IC50 (µg/ml), and its values ranged from 33.4 to 982.2 µg/ml. The highest phenolic content, concentrations of flavonoids and capacity to neutralize DPPH radicals were found in the acetone extract. In vitro antimicrobial activity was determined using microdilution method. Minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) were also determined. Testing was performed on 22 microorganisms, including 15 strains of bacteria (standard and clinical strains) and 7 species of fungi. There were statistically significant differences in activity between the extracts of E. telmateia. Different effects were noticed against the bacteria and the methanol extract appeared to be most efficient. All the extracts showed significant antibacterial activity against G+ bacteria and weak to moderate activity against other microorganisms. PMID:27350768
Radon activity concentrations and effective doses in ancient Egyptian tombs of the Valley of the Kings.

PubMed

Hafez, A F; Hussein, A S

2001-09-01

Radon concentrations and equilibrium factors were measured in three pharaonic tombs during the year 1998. The tombs, which are open to the public are located in a limestone wadi on the West Bank of the River Nile at Luxor, 650 km south of Cairo. The radon activity concentration and equilibrium factor were measured monthly by two-integral nuclear track detectors (bare and diffusion detectors). Seasonal variation of radon concentrations, with summer maximum and winter minimum were observed in all tombs investigated. The yearly mean radon activity concentrations insidc the tombs ranged from 540 to 3115 Bq m(-3). The mean equilibrium factor over a year was found to be 0.25 and 0.32 inside and at the entrance, respectively. Estimated annual effective doses to tour guides ranged from 0.33 to 1.90 mSv, visitors receive doses from 0.65 to 3.80 microSv per visit. The effective dose to tomb workers did not exceed the 20 mSv yr(-1) limit.
Screening of antimicrobial, antioxidant properties and bioactive compounds of some edible mushrooms cultivated in Bangladesh.

PubMed

Chowdhury, Mohammed; Kubra, Khadizatul; Ahmed, Sheikh

2015-02-07

For a long time mushrooms have been playing an important role in several aspects of the human activity. Recently edible mushrooms are used extensively in cooking and make part of new food in Bangladesh for their beneficial properties. The aim of this study is to screen some values of mushrooms used in Bangladesh. Methanolic extracts of 3 edible mushrooms (Pleurotus ostreatus, Lentinula edodes, Hypsizigus tessulatus) isolated from Chittagong, Bangladesh were used in this study. Phenolic compounds in the mushroom methanolic extracts were estimated by a colorimetric assay. The antioxidant activity was determined by radical 1, 1-diphenyl;-2-picrylhydrazyl (DPPH) radical scavenging assay. Eight microbial isolates were used for antimicrobial activity of methanolic extract of mushrooms by the agar well diffusion method with slight modification. Determination of antimicrobial activity indicated considerable activity against all bacteria and fungi reveling zone of inhibition ranged from 7 ± 0.2 to 20 ± 0.1 mm. Minimum inhibitory concentration values of the extracts showed that they are also active even in least concentrations ranged from 1 mg/ml to 9 mg/ml. Lentinula edodes showed the best antimicrobial activity than others. Pseudomonas aeruginosa was quite resistant and Saccharomyces cerevisiae was more sensitive than others microbial isolates. Antioxidant efficiency by inhibitory concentration on 1,1-Diphenly-2-picrylhydrazyl (DPPH) was found significant when compared to standard antioxidant like ascorbic Acid . The concentration (IC50) ranged from 100 ± 1.20 to 110 ± 1.24 μg/ml. Total phenols are the major bioactive component found in extracts of isolates expressed as mg of GAE per gram of fruit body, which ranged from 3.20 ± 0.05 to 10.66 ± 0.52 mg/ml. Average concentration of flavonoid ranged from 2.50 ± 0.008 mg/ml to 4.76 ± 0.11 mg/ml; followed by very small concentration of ascorbic acid (range, 0.06 ± 0.00 mg/ml to 0.21 ± 0.01 mg/ml) in all the isolates. All the isolates showed high phenol and flavonoid content (except Pleurotus ostreatus), but ascorbic acid content was found in traces. This study has revealed that selected edible mushrooms have not only nutritional values but also some therapeutic values. Proper and more investigations can lead us to use these as strong medicine in future.
Uranium in sediments, mussels (Mytilus sp.) and seawater of the Krka river estuary.

PubMed

Cuculić, Vlado; Cukrov, Neven; Barisić, Delko; Mlakar, Marina

2006-01-01

The response of an aquatic environment to the decrease of phosphate discharges from a technologically improved transhipment terminal, situated at the Croatian Adriatic coast in the port of Sibenik, has been assessed based on uranium activity and concentration in sediment, seawater and mussels Mytilus sp. The highest 238U activities (485+/-16Bqkg(-1) dry weight) were found in the sediment sample collected from the sampling site closest to the terminal. The maximum concentrations in the sediment samples are above the natural ranges and clearly indicate the harbour activities' influence. The 238U/226Ra activity ratios in sediment samples demonstrate the decreasing trend of phosphate ore input. Mussel samples showed levels of 238U activities in the range from 12.1+/-2.9 to 19.4+/-7.2 Bqkg(-1) dry weight, thus being slightly higher than in normally consumed mussels. Only the seawater, taken just above the bottom sediment at the sampling site closest to the terminal, shows a slightly higher uranium concentration (3.1+/-0.2 microgL(-1)) when compared to the samples taken in upper seawater layers (2.1+/-0.2 microgL(-1)) but is in the range of the concentration level of uranium in natural seawater. Since the transhipment terminal in the port of Sibenik was modernised in 1988, discharge of phosphate ore into the seawater was drastically reduced and, consequently, uranium concentration levels in seawater have decreased. However, enhanced uranium activity levels are still found in deeper sediment layer samples and in mussel.
Determination of the activity concentration levels of the artificial radionuclide137Cs in soil samples collected from Qatar using high-resolution gamma-ray spectrometry

NASA Astrophysics Data System (ADS)

Al-Sulaiti, Huda; Nasir, Tabassum; Al Mugren, K. S.; Alkhomashi, N.; Al-Dahan, N.; Al-Dosari, M.; Bradley, D. A.; Bukhari, S.; Regan, P. H.; Santawamaitre, T.; Malain, D.; Habib, A.; Al-Dosari, Hanan; Daar, Eman

2016-09-01

The goal of this study was to establish the first baseline measurements for radioactivity concentration of the artificial radionuclide 137Cs in soil samples collected from the Qatarian peninsula. The work focused on the determination of the activity concentrations levels of man-made radiation in 129 soil samples collected across the landscape of the State of Qatar. All the samples were collected before the most recent accident in Japan, “the 2011 Fukushima Dai-ichi nuclear power plant accident”. The activity concentrations have been measured via high-resolution gamma-ray spectrometry using a hyper-pure germanium detector situated in a low-background environment with a copper inner-plated passive lead shield. A radiological map showing the activity concentrations of 137Cs is presented in this work. The concentration wasfound to range from 0.21 to 15.41 Bq/kg. The highest activity concentration of 137Cs was observed in sample no. 26 in North of Qatar. The mean value was found to be around 2.15 ± 0.27 Bq/kg. These values lie within the expected range relative to the countries in the region. It is expected that this contamination is mainly due to the Chernobyl accident on 26 April 1986, but this conclusion cannot be confirmed because of the lack of data before this accident.
Antimicrobial activity of fresh garlic juice: An in vitro study

PubMed Central

Yadav, Seema; Trivedi, Niyati A.; Bhatt, Jagat D.

2015-01-01

Introduction: Antimicrobial resistance has been a global concern. Currently, interest has been focused on exploring antimicrobial properties of plants and herbs. One such botanical is Allium sativum (garlic). Aim: To evaluate the antimicrobial activity of fresh juice of garlic. Materials and Methods: Varying concentrations of fresh garlic juice (FGJ) were tested for their antimicrobial activity against common pathogenic organisms isolated at SSG Hospital, Vadodara, using well diffusion method. Moreover, minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) of FGJ were tested using broth dilution method. Sensitivity pattern of the conventional antimicrobials against common pathogenic bacteria was tested using disc diffusion method. Results: FGJ produced dose-dependent increase in the zone of inhibition at a concentration of 10% and higher. MIC of FGJ against the pathogens ranged from 4% to 16% v/v whereas MLC value ranged from 4% to 32% v/v with Escherichia coli and Staphylococcus aureus spp. showed highest sensitivity. Conclusion: FGJ has definite antimicrobial activity against common pathogenic organisms isolated at SSG Hospital, Vadodara. Further studies are needed to find out the efficacy, safety, and kinetic data of its active ingredients. PMID:27011724
Purification and properties of rennin-like enzyme from Aspergillus ochraceus.

PubMed

Ismail, A A; Foda, M S; Khorshid, M A

1978-01-01

An active milk-clotting enzyme was purified some 40-fold from culture supernatant of Aspergillus ochraceus. The purification steps included ammonium sulfate precipitation, G-100 Sephadex gel filtration, and ion exchange chromatography, using DEAE Cellulose column. The enzyme exhibited milk-clotting activity and proteolytic behaviour, an optimum at pH 6.0 and in the range of 7--8.5, respectively. The purified enzyme was actively proteolytic against casein, haemoglobin, and bovine serum albumin at pH 8. The milk-clotting activity was greatly enhanced by manganous ions and by increasing concentrations of calcium chloride. Copper, zinc, and ammonium ions were potent inhibitors of the milk-curdling activity of the purified enzyme. Significant inhibition was also noted with sodium chloride at concentrations of 3% or more. Under the specified reaction condition, maximum rate of proteolysis against casein was obtained at 0.4% substrate concentration, whereas the milk-clotting time was linear proportional to dry skim milk concentration in the range of 8 to 24%. The results are discussed in comparison with other microbial milk-clotting enzymes, and limitations of applicability are also presented.
Groundwater quality and the relation between pH values and occurrence of trace elements and radionuclides in water samples collected from private wells in part of the Kickapoo Tribe of Oklahoma Jurisdictional Area, central Oklahoma, 2011

USGS Publications Warehouse

Becker, Carol J.

2013-01-01

From 1999 to 2007, the Indian Health Service reported that gross alpha-particle activities and concentrations of uranium exceeded the Maximum Contaminant Levels for public drinking-water supplies in water samples from six private wells and two test wells in a rural residential neighborhood in the Kickapoo Tribe of Oklahoma Jurisdictional Area, in central Oklahoma. Residents in this rural area use groundwater from Quaternary-aged terrace deposits and the Permian-aged Garber-Wellington aquifer for domestic purposes. Uranium and other trace elements, specifically arsenic, chromium, and selenium, occur naturally in rocks composing the Garber-Wellington aquifer and in low concentrations in groundwater throughout its extent. Previous studies have shown that pH values above 8.0 from cation-exchange processes in the aquifer cause selected metals such as arsenic, chromium, selenium, and uranium to desorb (if present) from mineral surfaces and become mobile in water. On the basis of this information, the U.S. Geological Survey, in cooperation with the Kickapoo Tribe of Oklahoma, conducted a study in 2011 to describe the occurrence of selected trace elements and radionuclides in groundwater and to determine if pH could be used as a surrogate for laboratory analysis to quickly and inexpensively identify wells that might contain high concentrations of uranium and other trace elements. The pH and specific conductance of groundwater from 59 private wells were measured in the field in an area of about 18 square miles in Lincoln and Pottawatomie Counties. Twenty of the 59 wells also were sampled for dissolved concentrations of major ions, trace elements, gross alpha-particle and gross beta-particle activities, uranium, radium-226, radium-228, and radon-222 gas. Arsenic concentrations exceeded the Maximum Contaminant Level of 10 micrograms per liter in one sample having a concentration of 24.7 micrograms per liter. Selenium concentrations exceeded the Maximum Contaminant Level of 50 micrograms per liter in one sample having a concentration of 147 micrograms per liter. Both samples had alkaline pH values, 8.0 and 8.4, respectively. Uranium concentrations ranged from 0.02 to 383 micrograms per liter with 5 of 20 samples exceeding the Maximum Contaminant Level of 30 micrograms per liter; the five wells with uranium concentrations exceeding 30 micrograms per liter had pH values ranging from 8.0 to 8.5. Concentrations of uranium and radon-222 and gross alpha-particle activity showed a positive relation to pH, with the highest concentrations and activity in samples having pH values of 8.0 or above. The groundwater samples contained dissolved oxygen and high concentrations of bicarbonate; these characteristics are also factors in increasing uranium solubility. Concentrations of radium-226 and radium-228 (combined) ranged from 0.03 to 1.7 picocuries per liter, with a median concentration of 0.45 picocuries per liter for all samples. Radon-222 concentrations ranged from 95 to 3,600 picocuries per liter with a median concentration of 261 picocuries per liter. Eight samples having pH values ranging from 8.0 to 8.7 exceeded the proposed Maximum Contaminant Level of 300 picocuries per liter for radon-222. Eight samples exceeded the 15 picocuries per liter Maximum Contaminant Level for gross alpha-particle activity at 72 hours (after sample collection) and at 30 days (after the initial count); those samples had pH values ranging from 8.0 to 8.5. Gross beta-particle activity increased in 15 of 21 samples during the interval from 72 hours to 30 days. The increase in gross beta-particle activity over time probably was caused by the ingrowth and decay of uranium daughter products that emit beta particles. Water-quality data collected for this study indicate that pH values above 8.0 are associated with potentially high concentrations of uranium and radon-222 and high gross alpha-particle activity in the study area. High pH values also are associated with potentially high concentrations of arsenic, chromium, and selenium in groundwater when these elements occur in the aquifer matrix along groundwater-flow paths.

Wide-range particle characterization and elemental concentration in Beijing aerosol during the 2013 Spring Festival.

PubMed

Jing, Hui; Li, Yu-Feng; Zhao, Jiating; Li, Bai; Sun, Jialong; Chen, Rui; Gao, Yuxi; Chen, Chunying

2014-09-01

The number and mass concentration, size distribution, and the concentration of 16 elements were studied in aerosol samples during the Spring Festival celebrations in 2013 in Beijing, China. Both the number and mass concentration increased sharply in a wide range from 10 nm to 10 μm during the firecrackers and fireworks activities. The prominent increase of the number concentration was in 50 nm-500 nm with a peak of 1.7 × 10(5)/cm(3) at 150 nm, which is 8 times higher than that after 1.5 h. The highest mass concentration was in 320-560 nm, which is 4 times higher than the control. K, Mg, Sr, Ba and Pb increased sharply during the firework activities in PM10. Although the aerosol emission from firework activities is a short-term air quality degradation event, there may be a substantial hazard arising from the chemical composition of the emitted particles. Copyright © 2014 Elsevier Ltd. All rights reserved.
Analysis of the Effects of Cell Stress and Cytotoxicity on In ...

EPA Pesticide Factsheets

Chemical toxicity can arise from disruption of specific biomolecular functions or through more generalized cell stress and cytotoxicity-mediated processes. Here, concentration-dependent responses of 1063 chemicals including pharmaceuticals, natural products, pesticidals, consumer, and industrial chemicals across a diverse battery of 821 in vitro assay endpoints from 7 high-throughput assay technology platforms were analyzed in order to better distinguish between these types of activities. Both cell-based and cell-free assays showed a rapid increase in the frequency of responses at concentrations where cell stress / cytotoxicity responses were observed in cell-based assays. Chemicals that were positive on at least two viability/cytotoxicity assays within the concentration range tested (typically up to 100 M) activated a median of 12% of assay endpoints while those that were not cytotoxic in this concentration range activated 1.3% of the assays endpoints. The results suggest that activity can be broadly divided into: (1) specific biomolecular interactions against one or more targets (e.g., receptors or enzymes) at concentrations below which overt cytotoxicity-associated activity is observed; and (2) activity associated with cell stress or cytotoxicity, which may result from triggering of specific cell stress pathways, chemical reactivity, physico-chemical disruption of proteins or membranes, or broad low-affinity non-covalent interactions. Chemicals showing a g
Impact of ferromanganese alloy plants on household dust manganese levels: implications for childhood exposure.

PubMed

Lucas, E L; Bertrand, P; Guazzetti, S; Donna, F; Peli, M; Jursa, T P; Lucchini, R; Smith, D R

2015-04-01

Adolescents living in communities with ferromanganese alloy plant activity have been shown to exhibit deficits in olfactory and fine motor function. Household dust may serve as an important manganese (Mn) exposure pathway to children, though dust Mn concentrations have not previously been measured to assess household contamination from ferromanganese alloy plant emissions. Here we determined the association between dust concentrations and surface loadings of Mn and other metals (Al, Cd, Cr, Cu, Fe, Pb, and Zn) in indoor and outdoor household dust from three Italian communities that differ by history of ferromanganese alloy plant activity: Bagnolo Mella, with an active ferromanganese alloy plant (n=178 households); Valcamonica, with historically active plants (n=166); and Garda Lake, with no history of ferromanganese plant activity (n=99). We also evaluated Mn levels in other environmental (soil, airborne particulates) and candidate biomarker (blood, hair, saliva, fingernails) samples from children within the households. Household dust Mn concentrations and surface loadings were significantly different between the three sites, with levels highest in Bagnolo Mella (outdoor median Mn concentration=4620, range 487-183,000µg/g), intermediate in Valcamonica (median=876, range 407-8240µg/g), and lowest in Garda Lake (median=407, range 258-7240µg/g). Outdoor dust Mn concentrations in Bagnolo Mella, but not the other communities, were significantly inversely related with distance from the plant (R(2)=0.6630, P<0.0001). Moreover, outdoor dust Mn concentrations and loadings were highly predictive of but significantly higher than indoor dust Mn concentrations and loadings by ~2 to ~7-fold (Mn concentrations) and ~7 to ~20-fold (Mn loadings). Finally, both indoor and outdoor dust Mn concentrations and outdoor dust Mn loading values were highly significantly correlated with both soil and air Mn concentrations, and with children's hair and fingernail Mn concentrations, but weakly or not associated with saliva or blood Mn levels. Given the evidence associating elevated Mn exposure with neurological impairments in children, these data support that dust Mn levels should be reduced in contaminated environments to protect the health of resident children. Copyright © 2015 Elsevier Inc. All rights reserved.
Impact of Ferromanganese Alloy Plants on Household Dust Manganese Levels: Implications for Childhood Exposure

PubMed Central

Lucas, E.L.; Bertrand, P.; Guazzetti, S.; Donna, F.; Peli, M.; Jursa, T.R.; Lucchini, R.; Smith, D.R.

2015-01-01

Adolescents living in communities with ferromanganese alloy plant activity have been shown to exhibit deficits in olfactory and fine motor function. Household dust may serve as an important manganese (Mn) exposure pathway to children, though dust Mn concentrations have not previously been measured to assess household contamination from ferromanganese alloy plant emissions. Here we determined the association between dust concentrations and surface loadings of Mn and other metals (Al, Cd, Cr, Cu, Fe, Pb, and Zn) in indoor and outdoor household dust from three Italian communities that differ by history of ferromanganese alloy plant activity: Bagnolo Mella, with an active ferromanganese alloy plant (n=178 households); Valcamonica, with historically active plants (n=166); and Garda Lake, with no history of ferromanganese plant activity (n=99). We also evaluated Mn levels in other environmental (soil, airborne particulates) and candidate biomarker (blood, hair, saliva, fingernails) samples from children within the households. Household dust Mn concentrations and surface loadings were significantly different between the three sites, with levels highest in Bagnolo Mella (outdoor median Mn concentration = 4620, range 487 – 183,000 µg/g), intermediate in Valcamonica (median = 876, range 407 – 8240 µg/g), and lowest in Garda Lake (median = 407, range 258 – 7240 µg/g). Outdoor dust Mn concentrations in Bagnolo Mella, but not the other communities, were significantly inversely related with distance from the plant (R2=0.6630, P<0.0001). Moreover, outdoor dust Mn concentrations and loadings were highly predictive of but significantly higher than indoor dust Mn concentrations and loadings by ~2 to ~7-fold (Mn concentrations) and ~7 to ~20-fold (Mn loadings). Finally, both indoor and outdoor dust Mn concentrations and outdoor dust Mn loading values were highly significantly correlated with both soil and air Mn concentrations, and with children’s hair and fingernail Mn concentrations, but weakly or not associated with saliva or blood Mn levels. Given the evidence associating elevated Mn exposure with neurological impairments in children, these data support that dust Mn levels should be reduced in contaminated environments to protect the health of resident children. PMID:25747819
Submicron aerosol distributions and CCN activity measured in and around the Korean Peninsula during KORUS-AQ

NASA Astrophysics Data System (ADS)

Park, M.; Kim, N.; Yum, S. S.; Thornhill, K. L., II; Anderson, B. E.; Kim, D. S.; Kim, H. J.; Jeon, H. E.; Park, Y. S.; Lee, S. B.

2017-12-01

KORUS-AQ is a field campaign aimed at investigating formation of ozone and aerosol and interactions between chemistry, transport and various sources in the Korean Peninsula which is the region affected both by long-range transport and local emission. Aerosol number concentration and size distribution, and CCN number concentration were measured on board the NASA DC-8 research aircraft and at a ground site at Olympic Park in Seoul, capital city of Korea during the KORUS-AQ campaign (May 2nd to June 10th, 2017). There were 20 flights during the KORUS-AQ campaign and total flight time was about 150 hours. CCN counter (CCNC) on the airborne platform was operated at the fixed internal supersaturation of 0.6% and CCNC at the ground site was operated at five different supersaturations (0.2%, 0.4%, 0.6%, 0.8%, and 1.0%). Aerosol hygroscopic parameter κ was also estimated from CCN number concentration and aerosol size distribution. Airborne measurements showed a large spatio-temporal variation of aerosol number concentration and CCN activity in and around the Korean peninsula, and the ground measurements also showed a large temporal variation. The campaign period can be classified into long-range transport dominant cases, local emission dominant cases due to stagnant air mass, and others. Aerosol number concentration in the Korean Peninsula measured in stagnant air mass period was higher than those in long-range transport period, but CCN number concentration showed an opposite tendency. Both aerosol and CCN number concentrations over the Yellow Sea in local emission period were slightly higher than those in long-range transport period. Since CCN activity is different depending on time and space, our focus is on understanding how CCN activity and aerosol hygroscopicity vary with the source of aerosol. Comprehensive analysis results will be shown at the conference.
Reduced expression of dermcidin, a peptide active against propionibacterium acnes, in sweat of patients with acne vulgaris.

PubMed

Nakano, Toshiaki; Yoshino, Takashi; Fujimura, Takao; Arai, Satoru; Mukuno, Akira; Sato, Naoya; Katsuoka, Kensei

2015-09-01

Dermcidin (DCD), an antimicrobial peptide with a broad spectrum of activity against bacteria such as Propionibacterum acnes, is expressed constitutively in sweat in the absence of stimulation due to injury or inflammation. The aim of this study was to determine the relationship between DCD expression and acne vulgaris associated with P. acnes. The antimicrobial activity of recombinant full-length DCD (50 μg/ml) was 97% against Escherichia coli and 100% against Staphylococcus aureus. Antimicrobial activity against P. acnes ranged from 68% at 50 μg/ml DCD to 83% at 270 μg/ml DCD. DCD concentration in sweat from patients with acne vulgaris (median 9.8 μg/ml, range 6.9-95.3 μg/ml) was significantly lower than in healthy subjects (median 136.7 μg/ml, range 45.4-201.6 μg/ml) (p = 0.001). DCD demonstrated concentration-dependent, but partial, microbicidal activity against P. acnes. These results suggest that reduced DCD concentration in sweat in patients with inflammatory acne may permit proliferation of P. acnes in pilosebaceous units, resulting in progression of inflammatory acne.
Occurrence and risk assessment of pharmaceutically active compounds in wastewater treatment plants. A case study: Seville city (Spain).

PubMed

Santos, J L; Aparicio, I; Alonso, E

2007-05-01

The occurrence of four anti-inflammatory drugs (diclofenac, ibuprofen, ketoprofen and naproxen), an antiepileptic drug (carbamazepine) and a nervous stimulant (caffeine) in influent and effluent samples from four wastewater treatment plants (WWTPs) in Seville was evaluated. Removal rates in the WWTPs and risk assessment of the pharmaceutically active compounds have been studied. Analytical determination was carried out by high performance liquid chromatography (HPLC) with diode array (DAD) and fluorescence (Fl) detectors after sample clean up and concentration by solid phase extraction. All pharmaceutically active compounds, except diclofenac, were detected not only in wastewater influents but also in wastewater effluents. Mean concentrations of caffeine, carbamazepine, ketoprofen and naproxen ranged between 0.28-11.44 microg l(-1) and 0.21-2.62 microg l(-1) in influent and effluent wastewater, respectively. Ibuprofen was present in the highest concentrations in the range 12.13-373.11 microg l(-1) and 0.78-48.24 microg l(-1) in influent and effluent wastewater, respectively. Removal rates of the pharmaceuticals ranged between 6 and 98%. Risk quotients, expressed as ratios between the measured environmental concentration (MEC) and the predicted no effect concentrations (PNEC) were higher than 1 for ibuprofen and naproxen in influent wastewater and for ibuprofen in effluent wastewater.
Natural radionuclide emission from coal-fired power plants in the southwestern of Turkey and the population exposure to external radiation in their vicinity.

PubMed

Gür, Filiz; Yaprak, Günseli

2010-12-01

To evaluate the effect of radionuclide emission on the environment from Yatagan, Yenikoy and Kemerkoy coal-fired power plants which are located in southwestern Anatolia of Turkey, the concentrations of natural radionuclides such as (226)Ra, (232)Th and (40)K in coal, bottom ash and fly ash samples, have been measured, as well as the concentration of the same radionuclides in surface soils. The dose rate arises from the total radioactivity content of soil that the people living by the power plants are exposed to be assessed additionally. The average activity concentrations of (226)Ra for Yatagan CPP is 80 ± 22 Bq kg(-1) ranging from 56 to 131 Bq kg(-1), for Yenikoy CPP is 138 ± 20 Bq kg(-1) ranging from 115 to 189 Bq kg(-1), for Kemerkoy CPP is 238 ± 80 Bq kg(-1) ranging from 134 to 356 Bq kg(-1) in coal; average activity concentrations of (226)Ra in fly ash and in bottom ash for above-mentioned power plants are 334 ± 60 Bq kg(-1) ranging from 291 to 481 Bq kg(-1), 461 ± 33 Bq kg(-1) ranging from 398 to 511 Bq kg(-1), 815 ± 254 Bq kg(-1) ranging from 316 to 1260 Bq kg(-1), 276 ± 51 Bq kg(-1) ranging from 222 to 349 Bq kg(-1), 285 ± 69 Bq kg(-1) ranging from 213 to 409 Bq kg(-1), 743 ± 234 Bq kg(-1) ranging from 366 to 1098 Bq kg(-1), respectively. The radionuclides activity concentrations of surface soil in the vicinity of coal-fired power plants are 32 ± 9 Bq kg(-1) (18-53 Bq kg(-1)) for (226)Ra, 37 ± 16 Bq kg(-1) (17-89 Bq kg(-1)) for (232)Th, 455 ± 165 Bq kg(-1) (203-794 Bq kg(-1)) for (40)K relevant to Yatagan CPP; 42 ± 30 Bq kg(-1) (9-168 Bq kg(-1)) for (226)Ra, 32 ± 14 Bq kg(-1) (6-74 Bq kg(-1)) for (232)Th, 365 ± 151 Bq kg(-1) (117-937 Bq kg(-1)) for (40)K relevant to Yenikoy and Kemerkoy CPP. As a result, average dose rates in the vicinity of coal-fired power plants have been calculated to be 56 ± 16 nGy h(-1) ranging from 30 to 100 nGy h(-1) for Yatagan CPP, 54 ± 22 nGy h(-1) ranging from 15 to 126 nGy h(-1) for Yenikoy and Kemerkoy CPP. To sum up, the natural radionuclide activity concentrations of burnt coal and ashes thrown out from these three power plants are quite high relative to the world average UNSCEAR[1] data. In addition, the average (226)Ra, (232)Th and (40)K activity concentration values of surface soil samples and the calculated gamma dose rates in the vicinity of power plants were located within the worldwide intervals reported by UNSCEAR,[30] with some local differences.
Adsorption characteristics of selected pharmaceuticals and an endocrine disrupting compound-Naproxen, carbamazepine and nonylphenol-on activated carbon.

PubMed

Yu, Zirui; Peldszus, Sigrid; Huck, Peter M

2008-06-01

The adsorption of two representative pharmaceutically active compounds (PhACs) (naproxen and carbamazepine) and one endocrine disrupting compound (nonylphenol) were evaluated on two types of activated carbon. When determining their isotherms at environmentally relevant concentration levels, it was found that at this low concentration range (10-800 ng/L), removals of the target compounds were contrary to expectations based on their hydrophobicity. Nonylphenol (log K(ow) 5.8) was most poorly adsorbed, whereas carbamazepine (log K(ow) 2.45) was most adsorbable. Nonylphenol Freundlich isotherms at this very low concentration range had a much higher 1/n compared to isotherms at much higher concentrations. This indicates that extrapolation from an isotherm obtained at a high concentration range to predict the adsorption of nonylphenol at a concentration well below the range of the original isotherm, leads to a substantial overestimation of its removals. Comparison of isotherms for the target compounds to those for other conventional micropollutants suggested that naproxen and carbamazepine could be effectively removed by applying the same dosage utilized to remove odorous compounds (geosmin and MIB) at very low concentrations. The impact of competitive adsorption by background natural organic matter (NOM) on the adsorption of the target compounds was quantified by using the ideal adsorbed solution theory (IAST) in combination with the equivalent background compound (EBC) approach. The fulfilment of the requirements for applying the simplified IAST-EBC model, which leads to the conclusion that the percentage removal of the target compounds at a given carbon dosage is independent of the initial contaminant concentration, was confirmed for the situation examined in the paper. On this basis it is suggested that the estimated minimum carbon usage rates (CURs) to achieve 90% removal of these emerging contaminants would be valid at concentrations of less than 500 ng/L in natural water.
Immortelle (Xeranthemum annuum L.) as a natural source of biologically active substances

PubMed Central

Stankovic, Milan S.; Radojevic, Ivana D.; Stefanovic, Olgica D.; Topuzovic, Marina D.; Comic, Ljiljana R.; Brankovic, Snežana R.

2011-01-01

Antioxidant and antimicrobial effects, total phenolic content and flavonoid concentrations of methanolic, acetone and ethyl acetate extracts from Xeranthemum annuum L. were investigated in this study. The total phenolic content was determined using Folin-Ciocalteu reagent and ranged between 101.33 to 159.48 mg GA/g. The concentration of flavonoids in various X. annuum extracts was determined using spectrophotometric method with aluminum chloride and the results varied from 22.25 to 62.42 mg RU/g. Antioxidant activity was monitored spectrophotometrically using DPPH reagent and expressed in terms of IC50 (µg/ml), and it ranged from 59.25 to 956.81 µg/ml. The highest phenolic content and capacity to neutralize DPPH radicals were found in the acetone extract. In vitro antimicrobial activity was determined by microdilution method. Minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) have been determined. Testing was conducted against 24 microorganisms, including 15 strains of bacteria (standard and clinical strains) and 9 species of fungi. Statistically significant difference in activity between the extracts of X. annuum L. was observed and the acetone extract was found most active. The activity of acetone extract was in accordance with total phenol content and flavonoid concentration measured in this extract. The tested extracts showed significant antibacterial activity against G+ bacteria and weak to moderate activity against other microorganisms. Based on the obtained results, X. annuum can be considered as a rich natural source of polyphenolic compounds with very good antioxidant and antimicrobial activity. PMID:27857677
Impact of wines and wine constituents on cyclooxygenase-1, cyclooxygenase-2, and 5-lipoxygenase catalytic activity.

PubMed

Kutil, Zsofia; Temml, Veronika; Maghradze, David; Pribylova, Marie; Dvorakova, Marcela; Schuster, Daniela; Vanek, Tomas; Landa, Premysl

2014-01-01

Cyclooxygenases and lipoxygenases are proinflammatory enzymes; the former affects platelet aggregation, vasoconstriction, vasodilatation and later the development of atherosclerosis. Red wines from Georgia and central and western Europe inhibited cyclooxygenase-1 (COX-1) activity in the range of 63-94%, cyclooxygenase-2 (COX-2) activity in the range of 20-44% (tested at a concentration of 5 mL/L), and 5-lipoxygenase (5-LOX) activity in the range of 72-84% (at a concentration of 18.87 mL/L). White wines inhibited 5-LOX in the range of 41-68% at a concentration of 18.87 mL/L and did not inhibit COX-1 and COX-2. Piceatannol (IC50 = 0.76 μM) was identified as a strong inhibitor of 5-LOX followed by luteolin (IC50 = 2.25 μM), quercetin (IC50 = 3.29 μM), and myricetin (IC50 = 4.02 μM). trans-Resveratrol was identified as an inhibitor of COX-1 (IC50 = 2.27 μM) and COX-2 (IC50 = 3.40 μM). Red wine as a complex mixture is a powerful inhibitor of COX-1, COX-2, and 5-LOX, the enzymes involved in eicosanoid biosynthetic pathway.
Impact of Wines and Wine Constituents on Cyclooxygenase-1, Cyclooxygenase-2, and 5-Lipoxygenase Catalytic Activity

PubMed Central

Temml, Veronika; Maghradze, David; Vanek, Tomas

2014-01-01

Cyclooxygenases and lipoxygenases are proinflammatory enzymes; the former affects platelet aggregation, vasoconstriction, vasodilatation and later the development of atherosclerosis. Red wines from Georgia and central and western Europe inhibited cyclooxygenase-1 (COX-1) activity in the range of 63–94%, cyclooxygenase-2 (COX-2) activity in the range of 20–44% (tested at a concentration of 5 mL/L), and 5-lipoxygenase (5-LOX) activity in the range of 72–84% (at a concentration of 18.87 mL/L). White wines inhibited 5-LOX in the range of 41–68% at a concentration of 18.87 mL/L and did not inhibit COX-1 and COX-2. Piceatannol (IC50 = 0.76 μM) was identified as a strong inhibitor of 5-LOX followed by luteolin (IC50 = 2.25 μM), quercetin (IC50 = 3.29 μM), and myricetin (IC50 = 4.02 μM). trans-Resveratrol was identified as an inhibitor of COX-1 (IC50 = 2.27 μM) and COX-2 (IC50 = 3.40 μM). Red wine as a complex mixture is a powerful inhibitor of COX-1, COX-2, and 5-LOX, the enzymes involved in eicosanoid biosynthetic pathway. PMID:24976682
Effects of lead on Na+, K+-ATPase and hemolymph ion concentrations in the freshwater mussel Elliptio complanata

USGS Publications Warehouse

Mosher, Shad; Cope, W. Gregory; Weber, Frank X.; Shea, Damian; Kwak, Thomas J.

2012-01-01

Freshwater mussels are an imperiled fauna exposed to a variety of environmental toxicants such as lead (Pb) and studies are urgently needed to assess their health and condition to guide conservation efforts. A 28-day laboratory toxicity test with Pb and adult Eastern elliptio mussels (Elliptio complanata) was conducted to determine uptake kinetics and to assess the toxicological effects of Pb exposure. Test mussels were collected from a relatively uncontaminated reference site and exposed to a water-only control and five concentrations of Pb (as lead nitrate) ranging from 1 to 245 mu g/L in a static renewal test with a water hardness of 42 mg/L. Endpoints included tissue Pb concentrations, hemolymph Pb and ion (Na+, K+, Cl-, Ca2+) concentrations, and Na+, K+-ATPase enzyme activity in gill tissue. Mussels accumulated Pb rapidly, with tissue concentrations increasing at an exposure-dependent rate for the first 2 weeks, but with no significant increase from 2 to 4 weeks. Mussel tissue Pb concentrations ranged from 0.34 to 898 mu g/g dry weight, were strongly related to Pb in test water at every time interval (7, 14, 21, and 28 days), and did not significantly increase after day 14. Hemolymph Pb concentration was variable, dependent on exposure concentration, and showed no appreciable change with time beyond day 7, except for mussels in the greatest exposure concentration (245 mu g/L), which showed a significant reduction in Pb by 28 days, suggesting a threshold for Pb binding or elimination in hemolymph at concentrations near 1000 mu g/g. The Na+, K+-ATPase activity in the gill tissue of mussels was significantly reduced by Pb on day 28 and was highly correlated with tissue Pb concentration (R2 = 0.92; P = 0.013). The Na+, K+-ATPase activity was correlated with reduced hemolymph Na+ concentration at the greatest Pb exposure when enzyme activity was at 30% of controls. Hemolymph Ca2+ concentration increased significantly in mussels from the greatest Pb exposure and may be due to remobilization from the shell in an attempt to buffer the hemolymph against Pb uptake and toxicity. We conclude that Na+, K+-ATPase activity in mussels was adversely affected by Pb exposure, however, because the effects on activity were variable at the lower test concentrations, additional research is warranted over this range of exposures. (C) 2010 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Global evaluation and calibration of a passive air sampler for gaseous mercury

NASA Astrophysics Data System (ADS)

McLagan, David S.; Mitchell, Carl P. J.; Steffen, Alexandra; Hung, Hayley; Shin, Cecilia; Stupple, Geoff W.; Olson, Mark L.; Luke, Winston T.; Kelley, Paul; Howard, Dean; Edwards, Grant C.; Nelson, Peter F.; Xiao, Hang; Sheu, Guey-Rong; Dreyer, Annekatrin; Huang, Haiyong; Hussain, Batual Abdul; Lei, Ying D.; Tavshunsky, Ilana; Wania, Frank

2018-04-01

Passive air samplers (PASs) for gaseous mercury (Hg) were deployed for time periods between 1 month and 1 year at 20 sites across the globe with continuous atmospheric Hg monitoring using active Tekran instruments. The purpose was to evaluate the accuracy of the PAS vis-à-vis the industry standard active instruments and to determine a sampling rate (SR; the volume of air stripped of gaseous Hg per unit of time) that is applicable across a wide range of conditions. The sites spanned a wide range of latitudes, altitudes, meteorological conditions, and gaseous Hg concentrations. Precision, based on 378 replicated deployments performed by numerous personnel at multiple sites, is 3.6 ± 3.0 %1, confirming the PAS's excellent reproducibility and ease of use. Using a SR previously determined at a single site, gaseous Hg concentrations derived from the globally distributed PASs deviate from Tekran-based concentrations by 14.2 ± 10 %. A recalibration using the entire new data set yields a slightly higher SR of 0.1354 ± 0.016 m3 day-1. When concentrations are derived from the PAS using this revised SR the difference between concentrations from active and passive sampling is reduced to 8.8 ± 7.5 %. At the mean gaseous Hg concentration across the study sites of 1.54 ng m-3, this represents an ability to resolve concentrations to within 0.13 ng m-3. Adjusting the sampling rate to deployment specific temperatures and wind speeds does not decrease the difference in active-passive concentration further (8.7 ± 5.7 %), but reduces its variability by leading to better agreement in Hg concentrations measured at sites with very high and very low temperatures and very high wind speeds. This value (8.7 ± 5.7 %) represents a conservative assessment of the overall uncertainty of the PAS due to inherent uncertainties of the Tekran instruments. Going forward, the recalibrated SR adjusted for temperature and wind speed should be used, especially if conditions are highly variable or deviate considerably from the average of the deployments in this study (9.89 °C, 3.41 m s-1). Overall, the study demonstrates that the sampler is capable of recording background gaseous Hg concentrations across a wide range of environmental conditions with accuracy similar to that of industry standard active sampling instruments. Results at sites with active speciation units were inconclusive on whether the PASs take up total gaseous Hg or solely gaseous elemental Hg primarily because gaseous oxidized Hg concentrations were in a similar range as the uncertainty of the PAS. 1Subscripted numbers are not significant, but are reported to reduce rounding errors in subsequent studies (see Sect. 2.3 for details).
Determination of 137Cs activity in soil from Qatar using high-resolution gamma-ray spectrometry

NASA Astrophysics Data System (ADS)

Al-Sulaiti, Huda; Nasir, Tabassum; Al Mugren, K. S.; Alkhomashi, N.; Al-Dahan, N.; Al-Dosari, M.; Bradley, D. A.; Bukhari, S.; Matthews, M.; Regan, P. H.; Santawamaitre, T.; Malain, D.; Habib, A.; Al-Dosari, Hanan; Al Sadig, Ibrahim; Daar, Eman

2016-10-01

With interest in establishing baseline concentrations of 137Cs in soil from the Qatarian peninsula, we focus on determination of the activity concentrations in 129 soil samples collected across the State of Qatar prior to the 2011 Fukushima Dai-ichi nuclear power plant accident. As such, the data provides the basis of a reference map for the detection of releases of this fission product. The activity concentrations were measured via high-resolution gamma-ray spectrometry using a hyper-pure germanium detector enclosed in a copper-lined passive lead shield that was situated in a low-background environment. The activity concentrations ranged from 0.21 to 15.41 Bq/kg, with a median value of 1 Bq/kg, the greatest activity concentration being observed in a sample obtained from northern Qatar. Although it cannot be confirmed, it is expected that this contamination is mainly due to releases from the Chernobyl accident of 26 April 1986, there being a lack of data from Qatar before the accident. The values are typically within but are sometimes lower than the range indicated by data from other countries in the region. The lower values than those of others is suggested to be due to variation in soil characteristics as well as metrological factors at the time of deposition.
Metabolic Potential and Activity in Fluids of the Coast Range Ophiolite Microbial Observatory, California, USA

NASA Technical Reports Server (NTRS)

Hoehler, T.; Som, S.; Schrenk, M.; McCollom, T.; Cardace, D.

2016-01-01

Metabolic potential and activity associated with hydrogen and carbon monoxide were characterized in fluids sampled from the the Coast Range Ophiolite Microbial Observatory (CROMO). CROMO consists of two clusters of science-dedicated wells drilled to varying depths up to 35m in the actively serpentinizing, Jurassic-age Coast Range Ophiolite of Northern California, along with a suite of pre-existing monitoring wells at the same site. Consistent with the fluid chemistry observed in other serpentinizing systems, CROMO fluids are highly alkaline, with pH up to 12.5, high in methane, with concentrations up 1600 micromolar, and low in dissolved inorganic carbon (DIC), with concentrations of 10's to 100's of micromolar. CROMO is conspicuous for fluid H2 concentrations that are consistently sub-micromolar, orders of magnitude lower than is typical of other systems. However, higher H2 concentrations (10's -100's of micromolar) at an earlier stage of fluid chemical evolution are predicted by, or consistent with: thermodynamic models for fluid chemistry based on parent rock composition equivalent to local peridotite and with water:rock ratio constrained by observed pH; the presence of magnetite at several wt% in CROMO drill cores; and concentrations of formate and carbon monoxide that would require elevated H2 if formed in equilibrium with H2 and DIC. Calculated Gibbs energy changes for reaction of H2 and CO in each of several metabolisms, across the range of fluid composition encompassed by the CROMO wells, range from bioenergetically feasible (capable of driving ATP synthesis) to thermodynamically unfavorable. Active consumption relative to killed controls was observed for both CO and H2 during incubation of fluids from the pre-existing monitoring wells; in incubations of freshly cored solids, consumption was only observed in one sample set (corresponding to the lowest pH) out of three. The specific metabolisms by which H2 and CO are consumed remain to be determined.
Phenolic content, antibacterial and antioxidant activities of Erica herbacea L.

PubMed

Vucić, Dragana M; Petković, Miroslav R; Rodić-Grabovac, Branka B; Stefanović, Olgica D; Vasić, Sava M; Comić, Ljiljana R

2013-01-01

Antibacterial and antioxidant activity, total phenolic and flavonoid concentrations of aqueous, ethanol and ethyl acetate extracts from the leaves and flowers of Erica herbacea L. were studied. In vitro antibacterial activity of the extracts was determined by macrodilution method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) have been determined. Testing was performed on 30 clinical isolates, including different strains of Escherichia coli, Enterococcus faecalis and Proteus vulgaris. The values for MIC were in the range from 2.5 mg/mL to 40 mg/mL. The most sensitive bacterial strains were Proteus vulgaris strains. The aqueous extract from E. herbacea was found the most active. The total phenolic content was determined using Folin-Ciocalteu reagent and ranged between 14.98 and 119.88 mg GA/g. The concentration of flavonoids in extracts was determined using spectrophotometric method with aluminium chloride and obtained results varied from 16.19 to 26.90 mg RU/g. Antioxidant activity was monitored spectrophotometrically using DPPH reagent. The highest capacity to neutralize DPPH radicals was found in the aqueous extract from E. herbacea. The results of the total phenolic content determination of the examined extracts indicate that E. herbacea extracts are a rich source of phenolic compounds and also possess a significant antioxidant activity and moderate antibacterial activity.
Occurrence and Trends of Selected Chemical Constituents in Bottom Sediment, Grand Lake O' the Cherokees, Northeast Oklahoma, 1940-2008

USGS Publications Warehouse

Juracek, Kyle E.; Becker, Mark F.

2009-01-01

After over 100 years of continuous activity, lead and zinc mining in the Tri-State Mining District (hereafter referred to as the TSMD) in parts of southeast Kansas, southwest Missouri, and northeast Oklahoma ended in the 1970s. The mining activity resulted in substantial historical and ongoing input of cadmium, lead, and zinc to the environment including Grand Lake O' the Cherokees (hereafter referred to as Grand Lake), a large reservoir in northeast Oklahoma. To help determine the extent and magnitude of contamination in Grand Lake, a one-year study was conducted by the U.S. Geological Survey in cooperation with the U.S. Fish and Wildlife Service. Bottom-sediment coring at five sites was used to investigate the occurrence of cadmium, lead, zinc, and other selected constituents in the bottom sediment of Grand Lake. Cadmium concentrations in the bottom sediment of Grand Lake ranged from 2.3 to 3.6 mg/kg (milligrams per kilogram) with a median of 3.5 mg/kg (5 samples). Compared to an estimated local background concentration of 0.6 mg/kg, the historical mining activity increased cadmium concentrations by about 280 to 500 percent. Lead concentrations ranged from 35 to 102 mg/kg with a median of 59 mg/kg (50 samples). Compared to an estimated local background concentration of 20 mg/kg, the historical mining activity increased lead concentrations by about 75 to 410 percent. The range in zinc concentrations was 380 to 986 mg/kg with a median of 765 mg/kg (50 samples). Compared to an estimated local background concentration of 100 mg/kg, the historical mining activity increased zinc concentrations by about 280 to 890 percent. With the exception of the most upstream coring site, the lead and zinc depositional profiles generally were similar in terms of the range in concentrations measured and the temporal pattern observed. Depositional profiles for lead and zinc indicated mid-core peaks followed by concentrations that decreased since about the 1980s. The depositional profiles reflect the complex interaction of several factors including historical mining and related activities, mine drainage, remediation, landscape stabilization, precipitation and associated runoff, and the erosion and transport of contaminated and clean sediments within the basin. Compared to sediment-quality guidelines, the Grand Lake samples had cadmium concentrations that were substantially less than the general probable-effects concentration (PEC) (4.98 mg/kg) and a TSMD-specific PEC (11.1 mg/kg). The PECs represent the concentration above which toxic biological effects are likely to occur. Likewise, all sediment samples had lead concentrations that were substantially less than the general PEC (128 mg/kg) and a TSMD-specific PEC (150 mg/kg). Zinc concentrations typically exceeded the general PEC (459 mg/kg), but were substantially less than a TSMD-specific PEC (2,083 mg/kg). Throughout the history of Grand Lake, lead and zinc concentrations in the deposited sediment did not approach or exceed the TSMD-specific PECs. As of 2008, legacy effects of mining still included the delivery of contaminated sediment to Grand Lake by the Spring and Neosho Rivers. The Neosho River, with its larger flows and less-contaminated sediment, likely dilutes the load of contaminated sediment delivered to Grand Lake by the Spring River. The information contained in this report provides a baseline of Grand Lake conditions with which to compare future conditions that may represent a response to changes in mining-related activity in the Grand Lake Basin.
Cholinesterase activity in the cup oyster Saccostrea sp. exposed to chlorpyrifos, imidacloprid, cadmium and copper.

PubMed

Moncaleano-Niño, Angela M; Luna-Acosta, Andrea; Gómez-Cubillos, Maria Camila; Villamil, Luisa; Ahrens, Michael J

2018-04-30

In the present study, the sensitivity and concentration dependence of three functionally-defined components of cholinesterase activity (total: T-ChE; eserine-sensitive: Es-ChE; and eserine-resistant: Er-ChE) were quantified in the gill, digestive gland and adductor muscle of the tropical cup oyster Saccostrea sp., following acute (96h) aqueous exposure to commercial formulations of the organophosphate (OP) insecticide chlorpyrifos and the neonicotinoid (NN) imidacloprid (concentration range: 0.1-100mg/L), as well as to dissolved cadmium and copper (concentration range: 1-1000μg/L). Oysters (1.5-5.0cm shell length), field-collected from a boating marina in Santa Marta, Colombia (Caribbean Sea) were exposed in the laboratory to each substance at five concentrations. T-ChE, Es-ChE, and Er-ChE activity were quantified in the three tissues in pools of 5 individuals (3 replicates per concentration), before and after inhibition with the total cholinesterase inhibitor eserine (physostigmine, 100µM). Oysters exposed to chlorpyrifos, imidacloprid and Cd showed reduced T-ChE and Es-ChE activity in gills at highest exposure concentrations, with Es-ChE activity being inhibited proportionally more so than T-ChE, whereas Er-ChE activity showed no significant concentration-response. Digestive gland also showed diminished T-ChE, Es-ChE and Er-ChE activity for highest chlorpyrifos and Cd concentrations relative to controls, but an increase of T-ChE and Er-ChE activity at the highest imidacloprid concentration (100mg/L). For Cu, T-ChE, Es-ChE and Er-ChE activities in gills and digestive gland were elevated relative to controls in oysters exposed to Cu concentrations > 100µg/L. In adductor muscle, T-ChE, Es-ChE and Er-ChE activity showed no apparent pattern for any of the four xenobiotics and concentration levels tested. Although this study confirms acute (96h) concentration-dependent reduction of tissue T-ChE and Es-ChE activity in gills and digestive glands of Saccostrea sp. exposed to high concentrations of chlorpyrifos (100mg/L), significant changes in T-ChE, Es-ChE and Er-ChE were also caused by exposure to Cd and Cu at concentrations > 100µg/L and by exposure to imidacloprid (100mg/L), indicating that cholinesterase activity is not a specific biomarker of organophosphate exposure in this species, but, rather, a biomarker of diverse xenobiotic exposure. Copyright © 2018 Elsevier Inc. All rights reserved.
Serum biochemistry of captive and free-ranging gray wolves (Canis lupus)

USGS Publications Warehouse

Constable, Peter; Hinchcliff, Ken; Demma, Nick; Callahan, Margaret; Dale, B.W.; Fox, Kevin; Adams, Layne G.; Wack, Ray; Kramer, Lynn

1998-01-01

Normal serum biochemistry values are frequently obtained from studies of captive sedentary (zoo) or free-ranging (wild) animals. It is frequently assumed that values from these two populations are directly referable to each other. We tested this assumption using 20 captive gray wolves (Canis lupus) in Minnesota, USA, and 11 free-ranging gray wolves in Alaska, USA. Free-ranging wolves had significantly (P<0.05) lower sodium, chloride, and creatine concentrations and significantly higher potassium and blood urea nitrogen (BUN) concentrations; BUN to creatine ratios; and alanine aminotransferase, aspartate aminotransferase, and creatine kinase activities relative to captive wolves. Corticosteroid-induced alkaline phosphatase activity (a marker of stress in domestic dogs) was detected in 3 of 11 free-ranging wolves and in 0 of 20 captive wolves (P = 0.037). This study provides clear evidence that serum biochemical differences can exist between captive and free-ranging populations of one species. Accordingly, evaluation of the health status of an animal should incorporate an understanding of the potential confounding effect that nutrition, activity level, and environmental stress could have on the factor(s) being measured.

Activation of pollen tube callose synthase by detergents. Evidence for different mechanisms of action.

PubMed Central

Li, H; Bacic, A; Read, S M

1997-01-01

In pollen tubes of Nicotiana alata, a membrane-bound, Ca(2+)-independent callose synthase (CalS) is responsible for the biosynthesis of the (1,3)-beta-glucan backbone of callose, the main cell wall component. Digitonin increases CalS activity 3- to 4-fold over a wide range of concentrations, increasing the maximum initial velocity without altering the Michaelis constant for UDP-glucose. The CalS activity that requires digitonin for assay (the latent CalS activity) is not inhibited by the membrane-impermeant, active site-directed reagent UDP-pyridoxal when the reaction is conducted in the absence of digitonin. This is consistent with digitonin increasing CalS activity by the permeabilization of membrane vesicles. A second group of detergents, including 3-[(3-cholamidopropyl)dimethylammonio]-1-propane-sulfonate (CHAPS), Zwittergent 3-16, and 1-alpha-lysolecithin, activate pollen tube CalS 10- to 15-fold, but only over a narrow range of concentrations just below their respective critical micellar concentrations. This activation could not be attributed to any particular chemical feature of these detergents. CHAPS increases maximum initial velocity and decreases the Michaelis constant for UDP-glucose and activates CalS even in the presence of permeabilizing concentrations of digitonin. Inhibition studies with UDP-pyridoxal indicate that activation by CHAPS occurs by recruitment of previously inactive CalS molecules to the pool of active enzyme. The activation of pollen tube CalS by these detergents therefore resembles activation of the enzyme by trypsin. PMID:9276948
Antibacterial and antioxidant activities of Musa sp. leaf extracts against multidrug resistant clinical pathogens causing nosocomial infection

PubMed Central

Karuppiah, Ponmurugan; Mustaffa, Muhammed

2013-01-01

Objective To investigate different Musa sp. leave extracts of hexane, ethyl acetate and methanol were evaluated for antibacterial activity against multi-drug resistant pathogens causing nosocomial infection by agar well diffusion method and also antioxidant activities. Methods The four different Musa species leaves were extracted with hexane, ethyl acetate and methanol. Antibacterial susceptibility test, minimum inhibitory concentration and minimum inhibitory bacterial concentration were determined by agar well diffusion method. Total phenolic content and in vitro antioxidant activity was determined. Results All the Musa sp. extracts showed moderate antibacterial activities expect Musa paradisiaca with the inhibition zone ranging from 8.0 to 18.6 mm. Among four species ethyl acetate extracts of Musa paradisiaca showed highest activity against tested pathogens particularly E. coli, P. aeruginosa and Citrobacter sp. The minimum inhibitory concentrations were within the value of 15.63- 250 µg/mL and minimum bactericidal concentrations were ranging from 31.25- 250 µg/mL. Antioxidant activity of Musa acuminate exhibited maximum activity among other three Musa species. Conclusions The present study concluded that among the different Musa species, Musa paradisiaca displayed efficient antibacterial activity followed by Musa acuminata against multi-drug resistant nosocomial infection causing pathogens. Further, an extensive study is needed to identify the bioactive compounds, mode of action and toxic effect in vivo of Musa sp. PMID:23998016
Antibacterial and antioxidant activities of Musa sp. leaf extracts against multidrug resistant clinical pathogens causing nosocomial infection.

PubMed

Karuppiah, Ponmurugan; Mustaffa, Muhammed

2013-09-01

To investigate different Musa sp. leave extracts of hexane, ethyl acetate and methanol were evaluated for antibacterial activity against multi-drug resistant pathogens causing nosocomial infection by agar well diffusion method and also antioxidant activities. The four different Musa species leaves were extracted with hexane, ethyl acetate and methanol. Antibacterial susceptibility test, minimum inhibitory concentration and minimum inhibitory bacterial concentration were determined by agar well diffusion method. Total phenolic content and in vitro antioxidant activity was determined. All the Musa sp. extracts showed moderate antibacterial activities expect Musa paradisiaca with the inhibition zone ranging from 8.0 to 18.6 mm. Among four species ethyl acetate extracts of Musa paradisiaca showed highest activity against tested pathogens particularly E. coli, P. aeruginosa and Citrobacter sp. The minimum inhibitory concentrations were within the value of 15.63- 250 µg/mL and minimum bactericidal concentrations were ranging from 31.25- 250 µg/mL. Antioxidant activity of Musa acuminate exhibited maximum activity among other three Musa species. The present study concluded that among the different Musa species, Musa paradisiaca displayed efficient antibacterial activity followed by Musa acuminata against multi-drug resistant nosocomial infection causing pathogens. Further, an extensive study is needed to identify the bioactive compounds, mode of action and toxic effect in vivo of Musa sp.
Phenolic compound concentration and antioxidant activities of edible and medicinal mushrooms from Korea.

PubMed

Kim, Min-Young; Seguin, Philippe; Ahn, Joung-Kuk; Kim, Jong-Jin; Chun, Se-Chul; Kim, Eun-Hye; Seo, Su-Hyun; Kang, Eun-Young; Kim, Sun-Lim; Park, Yool-Jin; Ro, Hee-Myong; Chung, Ill-Min

2008-08-27

A study was conducted to determine the content of phenolic compounds and the antioxidative activity of five edible and five medicinal mushrooms commonly cultivated in Korea. Phenolic compounds were analyzed using high performance liquid chromatography, and antioxidant activity was evaluated by 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and superoxide dismutase activity. A total of 28 phenolic compounds were detected in the mushrooms studied. The average total concentration of phenolic compounds was 326 microg/g, the average being of 174 microg/g in edible mushrooms and 477 microg/g in medicinal mushrooms. The average total flavonoids concentration was 49 microg/g, with averages of 22 and 76 microg/g in edible and medicinal mushrooms, respectively. The DPPH radical scavenging activities ranged between 15 (Pleurotus eryngii) and 70% (Ganoderma lucidum) when reaction time was for 1 min. When reaction time was 30 min, the values ranged between 5 (Pleurotus eryngii) and 78% (Agaricus bisporus). The SOD activity averaged 28% among the 10 mushroom species, averages for edible and medicinal mushrooms being comparable. DPPH activities was significantly correlated (p < 0.01) with total content of phenolic compounds in edible mushrooms, while in medicinal mushrooms there was a significant correlation (p < 0.01) between SOD activity and total concentration of phenolic compounds. Numerous significant positive correlations were observed between phenolic compounds detected and antioxidative potential.
Versatile Molecular Functionalization for Inhibiting Concentration Quenching of Thermally Activated Delayed Fluorescence.

PubMed

Lee, Jiyoung; Aizawa, Naoya; Numata, Masaki; Adachi, Chihaya; Yasuda, Takuma

2017-01-01

Concentration quenching of thermally activated delayed fluorescence is found to be dominated by electron-exchange interactions, as described by the Dexter energy-transfer model. Owing to the short-range nature of the electron-exchange interactions, even a small modulation in the molecular geometric structure drastically affects the concentration-quenching, leading to enhanced solid-state photoluminescence and electroluminescence quantum efficiencies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
The Concentration of Nutrients in Tissues of Plantation-Grown Eastern Cottonwood (Populus deltoides Bart.)

Treesearch

M. G. Shelton; L. E. Nelson; G. L. Switzer; B. G. Blackmon

1981-01-01

Nutrient concentrations were determined for 10 tissues from each of 24 cottonwood trees that ranged in age from four to 16 years. Highest concentrations occurred in the most physiologically active tissues; i.e., stemtips, current branches and foliage. Tree age had little influence on the variation in nutrient concentration of tissues. Some differences in concentrations...
Natural radioactivity levels in granitic plutons and groundwaters in Southeast part of Eskisehir, Turkey.

PubMed

Orgün, Y; Altinsoy, N; Gültekin, A H; Karahan, G; Celebi, N

2005-08-01

The present work investigated the radioactivity level of the granitoid plutons and its effect on the groundwaters in the southeast part of Eskisehir. Fourteen granitic samples from the Kaymaz and Sivrihisar plutons and 11 groundwater samples from the near vicinity of the pluton were analyzed. The activity concentrations measured for (238)U and (232)Th ranged from 43.59+/-2 to 651.80+/-24 Bq/kg, and 51.16+/-3 to 351.94+/-13 Bq/kg, respectively. The activity concentrations obtained for (40)K varied from 418.50+/-17 to 1618.03+/-66 Bq/kg. The absorbed dose rates in air outdoors ranged from 87.14 to 531.81 nGy/h. All the results obtained from the Kaymaz pluton are higher than those from the Sivrihisar. The U (ave. 16.6 ppm) and Th (ave. 49.9 ppm) values of the Kaymaz pluton are higher than the average concentrations of the magmatic rocks of granitic composition. These results are consistent with high dose rates of the pluton. The gross-alpha activities in the groundwater samples ranged from 0.009 to 1.64 Bq/l and the gross-beta activities from 0.006 to 0.89 Bq/l. The highest gross-alpha value was found in the sample taken from near the Kaymaz pluton. The concentrations of (222)Rn varied from 0.060 to 0.557 Bq/l.
Biological activities of extracts from cultivated Granadilla Passiflora alata.

PubMed

Vasic, Sava M; Stefanovic, Olgica D; Licina, Braho Z; Radojevic, Ivana D; Comic, Ljiljana R

2012-01-01

Research conducted in this study showed the influence of ethanol, acetone and ethyl acetate extracts of the outgrowth of cultivated Passiflora alata on microorganisms, as well as the antioxidant activity and the concentrations of total phenols, flavonoids and tannins. In vitro antimicrobial activities of extracts were studied on 27 species of microorganisms, of which 17 species of bacteria and 10 species of fungi. The strongest antimicrobial activity was detected on G+ bacteria while the activities on other species were moderate. Ethyl acetate extract showed the strongest effect. The concentrations of total phenols were examined by using Folin-Ciocalteu reagent and the obtained values ranged from 14.04 to 34.22 mg GA/g. By using aluminium chloride method, the concentrations of flavonoids were obtained and the values ranged from 33.19 to 62.30 mg RU/g. In determining the amount of tannins we used the method with buthanol-HCl reagent and the obtained value was 5.1 % of dry matter. The efficiency of antioxidation, which we identified through the reduction of DPPH, was in the range from 808.69 to 1107.79 µg/ml for a particular IC50, and AAI values were between 0.07 and 0.10. The best parameters were shown by ethanol extract. All data were statistically analyzed. Overall, extracts showed potential for further investigation and use.
Natural radioactivity (226Ra, 232Th and 40K) and assessment of radiological hazards in the Kestanbol granitoid, Turkey.

PubMed

Canbaz, Buket; Cam, N Füsun; Yaprak, Günseli; Candan, Osman

2010-09-01

The surveys of natural gamma-emitting radionuclides in rocks and soils from the Ezine plutonic area were conducted during 2007. Direct dose measurement using a survey meter was carried out simultaneously. The present study, which is part of the survey, analysed the activity concentrations of (238)U, (232)Th and (40)K in granitoid samples from all over the region by HPGe gamma spectrometry. The activity concentrations of (226)Ra ranged from 94 to 637 Bq kg(-1), those of (232)Th ranged from 120 to 601 Bq kg(-1)and those of (40)K ranged from 1074 to 1527 Bq kg(-1) in the analysed rock samples from different parts of the pluton. To evaluate the radiological hazard of the natural radioactivity in the samples, the absorbed dose rate (D), the annual effective dose rate, the radium equivalent activity (Ra(eq)) and the external (H(ex)) hazard index were calculated according to the UNSCEAR 2000 report. The thorium-to-uranium concentration ratios were also estimated.
A kinetic model to explain the maximum in alpha-amylase activity measurements in the presence of small carbohydrates.

PubMed

Baks, Tim; Janssen, Anja E M; Boom, Remko M

2006-06-20

The effect of the presence of several small carbohydrates on the measurement of the alpha-amylase activity was determined over a broad concentration range. At low carbohydrate concentrations, a distinct maximum in the alpha-amylase activity versus concentration curves was observed in several cases. At higher concentrations, all carbohydrates show a decreasing alpha-amylase activity at increasing carbohydrate concentrations. A general kinetic model has been developed that can be used to describe and explain these phenomena. This model is based on the formation of a carbohydrate-enzyme complex that remains active. It is assumed that this complex is formed when a carbohydrate binds to alpha-amylase without blocking the catalytic site and its surrounding subsites. Furthermore, the kinetic model incorporates substrate inhibition and substrate competition. Depending on the carbohydrate type and concentration, the measured alpha-amylase activity can be 75% lower than the actual alpha-amylase activity. The model that has been developed can be used to correct for these effects in order to obtain the actual amount of active enzyme. 2006 Wiley Periodicals, Inc.
Radon Levels Measured at a Touristic Thermal Spa Resort in Montagu (South Africa) and Associated Effective Doses.

PubMed

Botha, R; Newman, R T; Maleka, P P

2016-09-01

Radon activity concentrations (in water and in air) were measured at 13 selected locations at the Avalon Springs thermal spa resort in Montagu (Western Cape, South Africa) to estimate the associated effective dose received by employees and visitors. A RAD-7 detector (DURRIDGE), based on alpha spectrometry, and electret detectors (E-PERM®Radelec) were used for these radon measurements. The primary source of radon was natural thermal waters from the hot spring, which were pumped to various locations on the resort, and consequently a range of radon in-water analyses were performed. Radon in-water activity concentration as a function of time (short term and long term measurements) and spatial distributions (different bathing pools, etc.) were studied. The mean radon in-water activity concentrations were found to be 205 ± 6 Bq L (source), 112 ± 5 Bq L (outdoor pool) and 79 ± 4 Bq L (indoor pool). Radon in-air activity concentrations were found to range between 33 ± 4 Bq m (at the outside bar) to 523 ± 26 Bq m (building enclosing the hot spring's source). The most significant potential radiation exposure identified is that due to inhalation of air rich in radon and its progeny by the resort employees. The annual occupational effective dose due to the inhalation of radon progeny ranges from 0.16 ± 0.01 mSv to 0.40 ± 0.02 mSv. For the water samples collected, the Ra in-water activity concentrations from samples collected were below the lower detection limit (~0.7 Bq L) of the γ-ray detector system used. No significant radiological health risk can be associated with radon and progeny from the hot spring at the Avalon Springs resort.
In vitro and intracellular activities of peptide deformylase inhibitor GSK1322322 against Legionella pneumophila isolates.

PubMed

Dubois, Jacques; Dubois, Maïtée; Martel, Jean-François; Aubart, Kelly; Butler, Deborah

2015-01-01

GSK1322322, a novel peptide deformylase inhibitor currently in development as an oral and intravenous agent for the treatment of hospitalized community-acquired bacterial pneumonia, showed poor in vitro activity against a panel of 50 Legionella pneumophila strains, with MICs ranging from 1 to 16 μg/ml and an MIC90 of 16 μg/ml, but very potent intracellular activity, with the minimum extracellular concentrations capable of inhibiting intracellular proliferation (MIECs) ranging from 0.12 to 2 μg/ml and 98% of the strains being inhibited by concentrations of ≤ 1 μg/ml. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
The status of photovoltaic concentrator development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maish, A. B.

1992-10-01

Several companies in the United States are actively pursuing the commercialization of photovoltaic concentrator technology. Under the auspices of the US Department of Energy`s Concentrator Initiative, the Electric Power Research Institute`s High Concentration Photovoltaic Program and several privately funded programs, these companies are developing a range of designs from low-concentration linear-focus to high-concentration point-focus cells and collectors. Design details and status of each development program is presented.
Natural and anthropogenic radionuclide activity concentrations in the New Zealand diet.

PubMed

Pearson, Andrew J; Gaw, Sally; Hermanspahn, Nikolaus; Glover, Chris N

2016-01-01

To support New Zealand's food safety monitoring regime, a survey was undertaken to establish radionuclide activity concentrations across the New Zealand diet. This survey was undertaken to better understand the radioactivity content of the modern diet and also to assess the suitability of the current use of milk as a sentinel for dietary radionuclide trends. Thirteen radionuclides were analysed in 40 common food commodities, including animal products, fruits, vegetables, cereal grains and seafood. Activity was detected for (137)Caesium, (90)Strontium and (131)Iodine. No other anthropogenic radionuclides were detected. Activity concentrations of the three natural radionuclides of Uranium and the daughter radionuclide (210)Polonium were detected in the majority of food sampled, with a large variation in magnitude. The maximum activity concentrations were detected in shellfish for all these radionuclides. Based on the established activity concentrations and ranges, the New Zealand diet contains activity concentrations of anthropogenic radionuclides far below the Codex Alimentarius guideline levels. Activity concentrations obtained for milk support its continued use as a sentinel for monitoring fallout radionuclides in terrestrial agriculture. The significant levels of natural and anthropogenic radionuclide activity concentrations detected in finfish and molluscs support undertaking further research to identify a suitable sentinel for New Zealand seafood monitoring. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
Larvicidal, ovicidal and pupicidal activities of Gliricidia sepium (Jacq.) (Leguminosae) against the malarial vector, Anopheles stephensi Liston (Culicidae: Diptera).

PubMed

Krishnappa, Kaliyamoorthy; Dhanasekaran, Shanmugam; Elumalai, Kuppusamy

2012-08-01

To investigate the potentiality of mosquitocidal activity of Gliricidia sepium (G. sepium) (Jacq.) (Leguminosae). Twenty five early third instar larvae of Anopheles stephensi (An. stephensi) were exposed to various concentrations (50-250 ppm) and the 24 h LC(50) values of the G. sepium extract was determined by probit analysis. The ovicidal activity was determined against An. stephensi to various concentrations ranging from 25-100 ppm under laboratory conditions. The eggs hatchability was assessed 48 h post treatment. The pupicidal activity was determined against An. stephensi to various concentrations ranging from 25-100 ppm. Mortality of each pupa was recorded after 24 h of exposure to the extract. Results pertaining to the experiment clearly revealed that ethanol extract showed significant larvicidal, ovicidal and pupicidal activity against the An. stephensi. Larvicidal activity of ethanol extracts of G. sepium showed maximum mortality in 250 ppm concentration (96.0±2.4)%. Furthermore, the LC(50) was found to be 121.79 and the LC(90) value was recorded to be 231.98 ppm. Ovicidal activity of ethanol extract was assessed by assessing the egg hatchability. Highest concentration of both solvent extracts exhibited 100% ovicidal activity. Similarly, pupae exposed to different concentrations of ethanol extract were found dead with 58.10% adult emergence when it was treated with 25 ppm concentration. Similarly, 18.36 (n=30; 61.20%); 21.28(70.93) and 27.33(91.10) pupal mortality was recorded from the experimental pupae treated with 50, 75 and 100 ppm concentration of extracts. Three fractions have been tested for their larvicidal activity of which the Fraction 3 showed the LC(50) and LC(90) values of 23.23 and 40.39 ppm. With regard to the ovicidal effect fraction 3 showed highest ovicidal activities than the other two fractions. Furthermore, there were no hatchability was recorded above 50 ppm (100% egg mortality) in the experimental group. Statistically significant pupicidal activity was recorded from 75 ppm concentration. From the results it can be concluded the crude extract of G. sepium is an excellent potential for controlling An. stephensi mosquito. It is apparent that, fraction 3 possess a novel and active principle which could be responsible for those biological activities. Copyright © 2012 Hainan Medical College. Published by Elsevier B.V. All rights reserved.
Soil processes and tree growth at shooting ranges in a boreal forest reflect contamination history and lead-induced changes in soil food webs.

PubMed

Selonen, Salla; Setälä, Heikki

2015-06-15

The effects of shooting-derived lead (Pb) on the structure and functioning of a forest ecosystem, and the recovery of the ecosystem after range abandonment were studied at an active shotgun shooting range, an abandoned shooting range where shooting ceased 20 years earlier and an uncontaminated control site. Despite numerous lead-induced changes in the soil food web, soil processes were only weakly related to soil food web composition. However, decomposition of Scots pine (Pinus sylvestris) needle litter was retarded at the active shooting range, and microbial activity, microbial biomass and the rate of decomposition of Pb-contaminated grass litter decreased with increasing soil Pb concentrations. Tree (P. sylvestris) radial growth was suppressed at the active shooting range right after shooting activities started. In contrast, the growth of pines improved at the abandoned shooting range after the cessation of shooting, despite reduced nitrogen and phosphorus contents of the needles. Higher litter degradation rates and lower Pb concentrations in the topmost soil layer at the abandoned shooting range suggest gradual recovery after range abandonment. Our findings suggest that functions in lead-contaminated coniferous forest ecosystems depend on the successional stage of the forest as well as the time since the contamination source has been eliminated, which affects, e.g., the vertical distribution of the contaminant in the soil. However, despite multiple lead-induced changes throughout the ecosystem, the effects were rather weak, indicating high resistance of coniferous forest ecosystems to this type of stress. Copyright © 2015 Elsevier B.V. All rights reserved.
Interlaboratory comparability of serum cotinine measurements at smoker and nonsmoker concentration levels: A round-robin study

PubMed Central

Jacob, Peyton; Holiday, David B.; Benowitz, Neal L.; Sosnoff, Connie S.; Doig, Mira V.; Feyerabend, Colin; Aldous, Kenneth M.; Sharifi, Mehran; Kellogg, Mark D.; Langman, Loralie J.

2009-01-01

Introduction: Cotinine, the primary proximate metabolite of nicotine, is commonly measured as an index of exposure to tobacco in both active users of tobacco and nonsmokers with possible exposure to secondhand smoke (SHS). A number of laboratories have implemented analyses for measuring serum cotinine in recent years, but there have been few interlaboratory comparisons of the results. Among nonsmokers exposed to SHS, the concentration of cotinine in blood can be quite low, and extensive variability in these measurements has been reported in the past. Methods: In this study, a group of seven laboratories, all experienced in serum cotinine analysis, measured eight coded serum pools with concentrations ranging from background levels of about 0.05 ng/ml to relatively high concentrations in the active smokers range. All laboratories used either gas–liquid chromatography with nitrogen–phosphorus detection or liquid chromatography with mass spectrometric detection. Results: All seven laboratories reliably measured the cotinine concentrations in samples that were within the range of their methods. In each case, the results for the pools were correctly ranked in order, and no significant interlaboratory bias was observed at the 5% level of significance for results from any of the pools. Discussion: We conclude that present methods of chromatographic analysis of serum cotinine, as used by these experienced laboratories, are capable of providing accurate and precise results in both the smoker and the nonsmoker concentration range. PMID:19933777
Present and Reference Concentrations and Yields of Suspended Sediment in Streams in the Great Lakes Region and Adjacent Areas

USGS Publications Warehouse

Robertson, Dale M.; Saad, David A.; Heisey, Dennis M.

2006-01-01

In-stream suspended sediment and siltation and downstream sedimentation are common problems in surface waters throughout the United States. The most effective way to improve surface waters impaired by sediments is to reduce the contributions from human activities rather than try to reduce loadings from natural sources. Total suspended sediment/solids (TSS) concentration data were obtained from 964 streams in the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy River Basins from 1951 to 2002. These data were used to estimate median concentrations, loads, yields, and volumetrically (flow) weighted (VW) concentrations where streamflow data were available. SPAtial Regression-Tree Analysis (SPARTA) was applied to land-use-adjusted (residualized) TSS data and environmental-characteristic data to determine the natural factors that best described the distribution of median and VW TSS concentrations and yields and to delineate zones with similar natural factors affecting TSS, enabling reference or natural concentrations and yields to be estimated. Soil properties (clay and organic-matter content, erodibility, and permeability), basin slope, and land use (percentage of agriculture) were the factors most strongly related to the distribution of median and VW TSS concentrations. TSS yields were most strongly related to amount of precipitation and the resulting runoff, and secondarily to the factors related to high TSS concentrations. Reference median TSS concentrations ranged from 5 to 26 milligrams per liter (mg/L), reference median annual VW TSS concentrations ranged from 10 to 168 mg/L, and reference TSS yields ranged from about 980 to 90,000 kilograms per square kilometer per year. Independent streams (streams with no overlapping drainage areas) with TSS data were ranked by how much their water quality exceeded reference concentrations and yields. Most streams exceeding reference conditions were in the central part of the study area, where agricultural activities are the most intensive; however, other sites exceeding reference conditions were identified outside of this area. Whether concentrations or yields should be considered in guiding rehabilitation efforts depends on whether in-stream or downstream effects are more important. Although this study attempted to obtain all available water-quality data for the study area, any actual prioritization of sites for remediation would need to rely on more extensive data collection or numerical models that can accurately simulate the effects of various human activities in a range of environmental settings.
Thermodynamics of Activation Gating in Olfactory-Type Cyclic Nucleotide-Gated (CNGA2) Channels

PubMed Central

Nache, Vasilica; Kusch, Jana; Biskup, Christoph; Schulz, Eckhard; Zimmer, Thomas; Hagen, Volker; Benndorf, Klaus

2008-01-01

Olfactory-type cyclic nucleotide-gated (CNG) ion channels open by the binding of cyclic nucleotides to a binding domain in the C-terminus. Employing the Eyring rate theory, we performed a thermodynamic analysis of the activation gating in homotetrameric CNGA2 channels. Lowering the temperature shifted the concentration-response relationship to lower concentrations, resulting in a decrease of both the enthalpy ΔH and entropy ΔS upon channel opening, suggesting that the order of an open CNGA2 channel plus its environment is higher than that of the closed channel. Activation time courses induced by cGMP concentration jumps were used to study thermodynamics of the transition state. The activation enthalpies ΔH‡ were positive at all cGMP concentrations. In contrast, the activation entropy ΔS‡ was positive at low cGMP concentrations and became then negative at increasing cGMP concentrations. The enthalpic and entropic parts of the activation energies approximately balance each other at all cGMP concentrations, leaving the free enthalpy of activation in the range between 19 and 21 kcal/mol. We conclude that channel activation proceeds through different pathways at different cGMP concentrations. Compared to the unliganded channel, low cGMP concentrations generate a transitional state of lower order whereas high cGMP concentrations generate a transitional state of higher order. PMID:18567637
Effect of pH and nitrite concentration on nitrite oxidation rate.

PubMed

Jiménez, E; Giménez, J B; Ruano, M V; Ferrer, J; Serralta, J

2011-10-01

The effect of pH and nitrite concentration on the activity of the nitrite oxidizing bacteria (NOB) in an activated sludge reactor has been determined by means of laboratory batch experiments based on respirometric techniques. The bacterial activity was measured at different pH and at different total nitrite concentrations (TNO₂). The experimental results showed that the nitrite oxidation rate (NOR) depends on the TNO₂ concentration independently of the free nitrous acid (FNA) concentration, so FNA cannot be considered as the real substrate for NOB. NOB were strongly affected by low pH values (no activity was detected at pH 6.5) but no inhibition was observed at high pH values (activity was nearly the same for the pH range 7.5-9.95). A kinetic expression for nitrite oxidation process including switch functions to model the effect of TNO₂ concentration and pH inhibition is proposed. Substrate half saturation constant and pH inhibition constants have been obtained. Copyright © 2011 Elsevier Ltd. All rights reserved.

Contents and leachability of heavy metals (Pb, Cu, Sb, Zn, As) in soil at the Pantex firing range, Amarillo, Texas.

PubMed

Basunia, S; Landsberger, S

2001-10-01

Pantex firing range soil samples were analyzed for Pb, Cu, Sb, Zn, and As. One hundred ninety-seven samples were collected from the firing range and vicinity area. There was a lack of knowledge about the distribution of Pb in the firing range, so a random sampling with proportional allocation was chosen. Concentration levels of Pb and Cu in the firing range were found to be in the range of 11-4675 and 13-359 mg/kg, respectively. Concentration levels of Sb were found to be in the range of 1-517 mg/kg. However, the Zn and As concentration levels were close to average soil background levels. The Sn concentration level was expected to be higher in the Pantex firing range soil samples. However, it was found to be below the neutron activation analysis (NAA) detection limit of 75 mg/kg. Enrichment factor analysis showed that Pb and Sb were highly enriched in the firing range with average magnitudes of 55 and 90, respectively. Cu was enriched approximately 6 times more than the usual soil concentration levels. Toxicity characteristic leaching procedure (TCLP) was carried out on size-fractionated homogeneous soil samples. The concentration levels of Pb in leachates were found to be approximately 12 times higher than the U.S. Environmental Protection Agency (EPA) regulatory concentration level of 5 mg/L. Sequential extraction (SE) was also performed to characterize Pb and other trace elements into five different fractions. The highest Pb fraction was found with organic matter in the soil.
Fish pollution with anthropogenic 137Cs in the southern Baltic Sea.

PubMed

Zalewska, Tamara; Suplińska, Maria

2013-02-01

This paper presents the results of a study on changes in (137)Cs activity concentrations in three fish species from the southern Baltic Sea: cod (Gadus morhua), herring (Clupea harengus) and flounder (Platichtys flesus), in the period 2000-2010. During the study period a marked decline in cesium activity concentration in fish muscle tissue was observed, which reflected changes in radionuclide activity concentration in seawater. No statistically significant temporal trends were determined in changes of concentration factors (CF(fish/seawater)) calculated for the examined fish species. The analysis of (137)Cs activity as a function of ichthyological parameters revealed the lack of a relationship between radionuclide activity concentrations in herring muscle tissue and the fish age in an narrow age range (2-4 years). However, a reverse proportionality of total fish mass, as well as body length, against (137)Cs activity concentrations in muscles was well documented. The latter observation can be the direct result of the dilution effect related to the increase of fish body weight. (137)Cs activity concentration in muscle tissue of the five fish species forms a declining sequence: Gadus morhua, Platichthys flesus, Clupea harengus, Perca fluviatilis and Neogobius melanostomus. Copyright © 2012 Elsevier Ltd. All rights reserved.
Synthesis of Five Known Brassinosteroid Analogs from Hyodeoxycholic Acid and Their Activities as Plant-Growth Regulators.

PubMed

Duran, María Isabel; González, Cesar; Acosta, Alison; Olea, Andrés F; Díaz, Katy; Espinoza, Luis

2017-03-08

Brassinosteroids (BRs) are plant hormones that promote growth in different plant organs and tissues. The structural requirements that these compounds should possess to exhibit this biological activity have been studied. In this work, a series of known BR analogs 5 - 15 , were synthesized starting from hyodeoxycholic acid 4 , and maintaining the alkyl side chain as cholic acid or its methyl ester. The growth-promoting effects of brassinolide ( 1 ) and synthesized analogs were evaluated by using the rice lamina inclination assay at concentrations ranging from 1 × 10 -8 -1 × 10 -6 M. Our results indicate that in this concentration range the induced bending angle of rice seedlings increases with increasing concentration of BRs. Analysis of the activities, determined at the lowest tested concentration, in terms of BR structures shows that the 2α,3α-dihydroxy-7-oxa-6-ketone moiety existing in brassinolide is required for the plant growing activity of these compounds, as it has been proposed by some structure-activity relationship studies. The effect of compound 8 on cell elongation was assessed by microscopy analysis, and the results indicate that the growth-promoting effect of analog 8 is mainly due to cell elongation of the adaxial sides, instead of an increase on cell number.
Synthesis of Five Known Brassinosteroid Analogs from Hyodeoxycholic Acid and Their Activities as Plant-Growth Regulators

PubMed Central

Duran, María Isabel; González, Cesar; Acosta, Alison; Olea, Andrés F.; Díaz, Katy; Espinoza, Luis

2017-01-01

Brassinosteroids (BRs) are plant hormones that promote growth in different plant organs and tissues. The structural requirements that these compounds should possess to exhibit this biological activity have been studied. In this work, a series of known BR analogs 5–15, were synthesized starting from hyodeoxycholic acid 4, and maintaining the alkyl side chain as cholic acid or its methyl ester. The growth-promoting effects of brassinolide (1) and synthesized analogs were evaluated by using the rice lamina inclination assay at concentrations ranging from 1 × 10−8–1 × 10−6 M. Our results indicate that in this concentration range the induced bending angle of rice seedlings increases with increasing concentration of BRs. Analysis of the activities, determined at the lowest tested concentration, in terms of BR structures shows that the 2α,3α-dihydroxy-7-oxa-6-ketone moiety existing in brassinolide is required for the plant growing activity of these compounds, as it has been proposed by some structure-activity relationship studies. The effect of compound 8 on cell elongation was assessed by microscopy analysis, and the results indicate that the growth-promoting effect of analog 8 is mainly due to cell elongation of the adaxial sides, instead of an increase on cell number. PMID:28282853
Occurrence of fibrates and their metabolites in source and drinking water in Shanghai and Zhejiang, China.

PubMed

Ido, Akiko; Hiromori, Youhei; Meng, Liping; Usuda, Haruki; Nagase, Hisamitsu; Yang, Min; Hu, Jianying; Nakanishi, Tsuyoshi

2017-04-12

Fibrates, which are widely used lipidaemic-modulating drugs, are emerging environmental pollutants. However, fibrate concentrations in the environment have not been thoroughly surveyed. Here, we determined concentrations of the most commonly used fibrates and their metabolites in source water and drinking water samples from ten drinking water treatment plants in Shanghai and Zhejiang, China, using solid-phase extraction and liquid chromatography-tandem mass spectrometry. All the target compounds were detected in at least some of the source water samples, at concentrations ranging from 0.04 ng/L (fenofibrate) to 1.53 ng/L (gemfibrozil). All the compounds except fenofibrate were also detected in at least some of the drinking water samples, at recoveries ranging from 35.5% to 91.7%, suggesting that these compounds are poorly removed by typical drinking water treatment processes. In a peroxisome proliferator-activated receptor α agonistic activity assay, the target compounds showed no significant activity at nanogram per litre concentrations; therefore, our results suggest that the fibrate concentrations in drinking water in Shanghai and Zhejiang, China do not significantly affect human health. However, because of the increasing westernization of the Chinese diet, fibrate use may increase, and thus monitoring fibrate concentrations in aquatic environments and drinking water in China will become increasingly important.
Occurrence of fibrates and their metabolites in source and drinking water in Shanghai and Zhejiang, China

PubMed Central

Ido, Akiko; Hiromori, Youhei; Meng, Liping; Usuda, Haruki; Nagase, Hisamitsu; Yang, Min; Hu, Jianying; Nakanishi, Tsuyoshi

2017-01-01

Fibrates, which are widely used lipidaemic-modulating drugs, are emerging environmental pollutants. However, fibrate concentrations in the environment have not been thoroughly surveyed. Here, we determined concentrations of the most commonly used fibrates and their metabolites in source water and drinking water samples from ten drinking water treatment plants in Shanghai and Zhejiang, China, using solid-phase extraction and liquid chromatography–tandem mass spectrometry. All the target compounds were detected in at least some of the source water samples, at concentrations ranging from 0.04 ng/L (fenofibrate) to 1.53 ng/L (gemfibrozil). All the compounds except fenofibrate were also detected in at least some of the drinking water samples, at recoveries ranging from 35.5% to 91.7%, suggesting that these compounds are poorly removed by typical drinking water treatment processes. In a peroxisome proliferator-activated receptor α agonistic activity assay, the target compounds showed no significant activity at nanogram per litre concentrations; therefore, our results suggest that the fibrate concentrations in drinking water in Shanghai and Zhejiang, China do not significantly affect human health. However, because of the increasing westernization of the Chinese diet, fibrate use may increase, and thus monitoring fibrate concentrations in aquatic environments and drinking water in China will become increasingly important. PMID:28401920
Occurrence of fibrates and their metabolites in source and drinking water in Shanghai and Zhejiang, China

NASA Astrophysics Data System (ADS)

Ido, Akiko; Hiromori, Youhei; Meng, Liping; Usuda, Haruki; Nagase, Hisamitsu; Yang, Min; Hu, Jianying; Nakanishi, Tsuyoshi

2017-04-01

Fibrates, which are widely used lipidaemic-modulating drugs, are emerging environmental pollutants. However, fibrate concentrations in the environment have not been thoroughly surveyed. Here, we determined concentrations of the most commonly used fibrates and their metabolites in source water and drinking water samples from ten drinking water treatment plants in Shanghai and Zhejiang, China, using solid-phase extraction and liquid chromatography-tandem mass spectrometry. All the target compounds were detected in at least some of the source water samples, at concentrations ranging from 0.04 ng/L (fenofibrate) to 1.53 ng/L (gemfibrozil). All the compounds except fenofibrate were also detected in at least some of the drinking water samples, at recoveries ranging from 35.5% to 91.7%, suggesting that these compounds are poorly removed by typical drinking water treatment processes. In a peroxisome proliferator-activated receptor α agonistic activity assay, the target compounds showed no significant activity at nanogram per litre concentrations; therefore, our results suggest that the fibrate concentrations in drinking water in Shanghai and Zhejiang, China do not significantly affect human health. However, because of the increasing westernization of the Chinese diet, fibrate use may increase, and thus monitoring fibrate concentrations in aquatic environments and drinking water in China will become increasingly important.
Beyond conventional dose-response curves: Sensorgram comparison in SPR allows single concentration activity and similarity assessment.

PubMed

Gassner, C; Karlsson, R; Lipsmeier, F; Moelleken, J

2018-05-30

Previously we have introduced two SPR-based assay principles (dual-binding assay and bridging assay), which allow the determination of two out of three possible interaction parameters for bispecific molecules within one assay setup: two individual interactions to both targets, and/or one simultaneous/overall interaction, which potentially reflects the inter-dependency of both individual binding events. However, activity and similarity are determined by comparing report points over a concentration range, which also mirrors the way data is generated by conventional ELISA-based methods So far, binding kinetics have not been specifically considered in generic approaches for activity assessment. Here, we introduce an improved slope-ratio model which, together with a sensorgram comparison based similarity assessment, allows the development of a detailed, USP-conformal ligand binding assay using only a single sample concentration. We compare this novel analysis method to the usual concentration-range approach for both SPR-based assay principles and discuss its impact on data quality and increased sample throughput. Copyright © 2018 Elsevier B.V. All rights reserved.
Evaluation of new geological reference materials for uranium-series measurements: Chinese Geological Standard Glasses (CGSG) and macusanite obsidian.

PubMed

Denton, J S; Murrell, M T; Goldstein, S J; Nunn, A J; Amato, R S; Hinrichs, K A

2013-10-15

Recent advances in high-resolution, rapid, in situ microanalytical techniques present numerous opportunities for the analytical community, provided accurately characterized reference materials are available. Here, we present multicollector thermal ionization mass spectrometry (MC-TIMS) and multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) uranium and thorium concentration and isotopic data obtained by isotope dilution for a suite of newly available Chinese Geological Standard Glasses (CGSG) designed for microanalysis. These glasses exhibit a range of compositions including basalt, syenite, andesite, and a soil. Uranium concentrations for these glasses range from ∼2 to 14 μg g(-1), Th/U weight ratios range from ∼4 to 6, (234)U/(238)U activity ratios range from 0.93 to 1.02, and (230)Th/(238)U activity ratios range from 0.98 to 1.12. Uranium and thorium concentration and isotopic data are also presented for a rhyolitic obsidian from Macusani, SE Peru (macusanite). This glass can also be used as a rhyolitic reference material, has a very low Th/U weight ratio (around 0.077), and is approximately in (238)U-(234)U-(230)Th secular equilibrium. The U-Th concentration data agree with but are significantly more precise than those previously measured. U-Th concentration and isotopic data agree within estimated errors for the two measurement techniques, providing validation of the two methods. The large (238)U-(234)U-(230)Th disequilibria for some of the glasses, along with the wide range in their chemical compositions and Th/U ratios should provide useful reference points for the U-series analytical community.
Antimicrobial Activity of a Neem Cake Extract in a Broth Model Meat System

PubMed Central

Del Serrone, Paola; Nicoletti, Marcello

2013-01-01

This work reports on the antimicrobial activity of an ethyl acetate extract of neem (Azadirachta indica) cake (NCE) against bacteria affecting the quality of retail fresh meat in a broth model meat system. NCE (100 µg) was also tested by the agar disc diffusion method. It inhibited the growth of all tested microorganisms. The NCE growth inhibition zone (IZ) ranged 11.33–22.67 mm while the ciprofloxacin (10 µg) IZ ranged from 23.41–32.67 mm. There was no significant difference (p ≤ 0.05) between the antimicrobial activity of NCE and ciprofloxacin vs. C. jejuni and Leuconostoc spp. The NCE antibacterial activity was moreover determined at lower concentrations (1:10–1:100,000) in micro-assays. The percent growth reduction ranged from 61 ± 2.08–92 ± 3.21. The higher bacterial growth reduction was obtained at 10 µg concentration of NCE. Species-specific PCR and multiplex PCR with the DNA dye propidium monoazide were used to directly detect viable bacterial cells from experimentally contaminated meat samples. The numbers of bacterial cells never significantly (p ≤ 0.05) exceeded the inocula concentration used to experimentally contaminate the NCE treated meat. This report represents a screening methodology to evaluate the antimicrobial capability of a herbal extract to preserve meat. PMID:23917814
Concentration and variability of ice nuclei in the subtropical maritime boundary layer

NASA Astrophysics Data System (ADS)

Welti, André; Müller, Konrad; Fleming, Zoë L.; Stratmann, Frank

2018-04-01

Measurements of the concentration and variability of ice nucleating particles in the subtropical maritime boundary layer are reported. Filter samples collected in Cabo Verde over the period 2009-2013 are analyzed with a drop freezing experiment with sensitivity to detect the few rare ice nuclei active at low supercooling. The data set is augmented with continuous flow diffusion chamber measurements at temperatures below -24 °C from a 2-month field campaign in Cabo Verde in 2016. The data set is used to address the following questions: what are typical concentrations of ice nucleating particles active at a certain temperature? What affects their concentration and where are their sources? Concentration of ice nucleating particles is found to increase exponentially by 7 orders of magnitude from -5 to -38 °C. Sample-to-sample variation in the steepness of the increase indicates that particles of different origin, with different ice nucleation properties (size, composition), contribute to the ice nuclei concentration at different temperatures. The concentration of ice nuclei active at a specific temperature varies over a range of up to 4 orders of magnitude. The frequency with which a certain ice nuclei concentration is measured within this range is found to follow a lognormal distribution, which can be explained by random dilution during transport. To investigate the geographic origin of ice nuclei, source attribution of air masses from dispersion modeling is used to classify the data into seven typical conditions. While no source could be attributed to the ice nuclei active at temperatures higher than -12 °C, concentrations at lower temperatures tend to be elevated in air masses originating from the Sahara.
Sub-lethal effects of the neurotoxic pyrethroid insecticide Fastac 50EC on the general motor and locomotor activities of the non-targeted beneficial carabid beetle Platynus assimilis (Coleoptera: Carabidae).

PubMed

Tooming, Ene; Merivee, Enno; Must, Anne; Sibul, Ivar; Williams, Ingrid

2014-06-01

Sub-lethal effects of pesticides on behavioural endpoints are poorly studied in carabids (Coleoptera: Carabidae) though changes in behaviour caused by chemical stress may affect populations of these non-targeted beneficial insects. General motor activity and locomotion are inherent in many behavioural patterns, and changes in these activities that result from xenobiotic influence mirror an integrated response of the insect to pesticides. Influence of pyrethroid insecticides over a wide range of sub-lethal doses on the motor activities of carabids still remains unclear. Video tracking of Platynus assimilis showed that brief exposure to alpha-cypermethrin at sub-lethal concentrations ranged from 0.01 to 100 mg L(-1) caused initial short-term (< 2 h) locomotor hyperactivity followed by a long-term (>24 h) locomotor hypo-activity. In addition, significant short- and long-term concentration and time-dependent changes occurred in general motor activity patterns and rates. Conspicuous changes in motor activity of Platynus assimilis beetles treated at alpha-cypermethrin concentrations up to 75,000-fold lower than maximum field recommended concentration (MFRC) suggest that many, basic fitness-related behaviours might be severely injured as well. These changes may negatively affect carabid populations in agro-ecosystems. Long-term hypo-activity could directly contribute to decreased trap captures of carabids frequently observed after insecticide application in the field. © 2013 Society of Chemical Industry.
Biological activities of extracts from cultivated Granadilla Passiflora alata

PubMed Central

Vasic, Sava M.; Stefanovic, Olgica D.; Licina, Braho Z.; Radojevic, Ivana D.; Comic, Ljiljana R.

2012-01-01

Research conducted in this study showed the influence of ethanol, acetone and ethyl acetate extracts of the outgrowth of cultivated Passiflora alata on microorganisms, as well as the antioxidant activity and the concentrations of total phenols, flavonoids and tannins. In vitro antimicrobial activities of extracts were studied on 27 species of microorganisms, of which 17 species of bacteria and 10 species of fungi. The strongest antimicrobial activity was detected on G+ bacteria while the activities on other species were moderate. Ethyl acetate extract showed the strongest effect. The concentrations of total phenols were examined by using Folin-Ciocalteu reagent and the obtained values ranged from 14.04 to 34.22 mg GA/g. By using aluminium chloride method, the concentrations of flavonoids were obtained and the values ranged from 33.19 to 62.30 mg RU/g. In determining the amount of tannins we used the method with buthanol-HCl reagent and the obtained value was 5.1 % of dry matter. The efficiency of antioxidation, which we identified through the reduction of DPPH, was in the range from 808.69 to 1107.79 µg/ml for a particular IC50, and AAI values were between 0.07 and 0.10. The best parameters were shown by ethanol extract. All data were statistically analyzed. Overall, extracts showed potential for further investigation and use. PMID:27385958
Comparison of several von Willebrand factor (VWF) activity assays for monitoring patients undergoing treatment with VWF/FVIII concentrates: improved performance with a new modified automated method.

PubMed

Hillarp, A; Friedman, K D; Adcock-Funk, D; Tiefenbacher, S; Nichols, W L; Chen, D; Stadler, M; Schwartz, B A

2015-11-01

The ability of von Willebrand factor (VWF) to bind platelet GP Ib and promote platelet plug formation is measured in vitro using the ristocetin cofactor (VWF:RCo) assay. Automated assay systems make testing more accessible for diagnosis, but do not necessarily improve sensitivity and accuracy. We assessed the performance of a modified automated VWF:RCo assay protocol for the Behring Coagulation System (BCS(®) ) compared to other available assay methods. Results from different VWF:RCo assays in a number of specialized commercial and research testing laboratories were compared using plasma samples with varying VWF:RCo activities (0-1.2 IU mL(-1) ). Samples were prepared by mixing VWF concentrate or plasma standard into VWF-depleted plasma. Commercially available lyophilized standard human plasma was also studied. Emphasis was put on the low measuring range. VWF:RCo accuracy was calculated based on the expected values, whereas precision was obtained from repeated measurements. In the physiological concentration range, most of the automated tests resulted in acceptable accuracy, with varying reproducibility dependent on the method. However, several assays were inaccurate in the low measuring range. Only the modified BCS protocol showed acceptable accuracy over the entire measuring range with improved reproducibility. A modified BCS(®) VWF:RCo method can improve sensitivity and thus enhances the measuring range. Furthermore, the modified BCS(®) assay displayed good precision. This study indicates that the specific modifications - namely the combination of increased ristocetin concentration, reduced platelet content, VWF-depleted plasma as on-board diluent and a two-curve calculation mode - reduces the issues seen with current VWF:RCo activity assays. © 2015 John Wiley & Sons Ltd.
Stability of nitrate-ion concentrations in simulated deposition samples used for quality-assurance activities by the U.S. Geological Survey

USGS Publications Warehouse

Willoughby, T.C.; See, R.B.; Schroder, L.J.

1989-01-01

Three experiments were conducted to determine the stability of nitrate-ion concentrations in simulated deposition samples. In the four experiment-A solutions, nitric acid provided nitrate-ion concentrations ranging from 0.6 to 10.0 mg/L and that had pH values ranging from 3.8 to 5.0. In the five experiment-B solutions, sodium nitrate provided nitrate-ion concentrations ranging from 0.5 to 3.0 mg/L. The pH was adjusted to about 4.5 for each of the solutions by addition of sulfuric acid. In the four experiment-C solutions, nitric acid provided nitrate-ion concentrations ranging from 0.5 to 3.0 mg/L. Major cation and anion concentrations were added to each solution to simulate natural deposition. Aliquots were removed from the 13 original solutions and analyzed by ion chromatography about once a week for 100 days to determine if any changes occurred in nitrate-ion concentrations throughout the study period. No substantial changes were observed in the nitrate-ion concentrations in solutions that had initial concentrations below 4.0 mg/L in experiments A and B, although most of the measured nitrate-ion concentrations for the 100-day study were below the initial concentrations. In experiment C, changes in nitrate-ion concentrations were much more pronounced; the measured nitrate-ion concentrations for the study period were less than the initial concentrations for 62 of the 67 analyses. (USGS)
The activity concentration of 210Po in Romanian commercial cigarettes and the radiation exposure estimation derived from their regular consumption.

PubMed

Begy, R Cs; Somlai, J; Kovacs, T; Dumitru Rusu, O A; Cosma, C

2013-11-01

Due to the relatively high activity concentrations of (210)Po that are found in tobacco, cigarette smoking has been found to be the principal pathway of the intake of this radionuclide. The (210)Po concentrations in the lung tissues may contribute significantly to an increase in the internal radiation dose and in the number of instances of lung cancer observed among smokers. The study of (210)Po in tobacco is required due to its potential for human radiation exposure through ingestion and inhalation. The risk factor caused by (210)Po in Romanian commercial cigarettes is not yet evaluated. Ten of the most frequently smoked brands of cigarettes sold in Romania were investigated in this work for this purpose. The activity concentration of (210)Po was determined by alpha spectrometry using a PIPS detector after chemical leaching and spontaneous deposition of (210)Po on a stainless steel disc from diluted HCl solution. The samples were spiked with (209)Po for chemical recovery calculation. The (210)Po activity concentrations of the measured types of cigarettes ranged from 4.65 to 10.22 mBq sample(-1) and the resulted average concentration of (210)Po isotopes is 8.35±0.80 mBq cigarette(-1) (the errors form a 2σ interval of confidence). When comparing the results of this study with the activity concentration values reported by other countries it was found that the results of this study are in the lower end of the world range. The estimation of this study shows that cigarette smokers, who are smoking one pack (20 cigarettes) per day, are exposed to an effective dose of 75.51 μSv y(-1).
Zeta potential response of human erythrocyte membranes to the modulators of Gardos channel activity under low rate β-radiation.

PubMed

Zhirnov, V V; Iakovenko, I N; Voitsitskiy, V M; Khyzhnyak, S V; Zubrikova-Chugainova, O G; Gorobetz, V A

2015-12-01

Study of human erythrocyte DP response under modification by activators and blockers of the functional state of Ca2+-dependent K+ channels under low rate β-radiation. Erythrocytes were isolated from the donor blood. The zeta potential was computed from the value of the cell electrophoretic mobility. The investigated drugs preliminary introduced in cellular suspensions, and then aliquote of 90Sr(NO3)2 solution to get the final activity concentration of 44,4kBq⋅l-1. The radioisotope radiation of 90Sr/90Y (RR, 15 μGy⋅h-1) increases an absolute value of erythrocyte membranes DP (DPab), and its action is reversible. It specifies the effect is mediated by non-ionizing part of the RR. Dibutyril-cAMP dose-independent increases DPab of erythrocyte membranes in the concentration range of 1-100 мкМ, but RR does not amplify this effect. Anaprilin increases dose-independent DPab in concentrations 10 and 100 μМ. The effect of maximal concentration of anaprilin (100 μМ) decreases by RR. Clotrimazol increases DPab of erythrocyte membranes in the concentration range of 0,1-10 μМ relatively control, while its maximal concentration - decreases, and the minimal level does not reliably influence on this index The action of сlotrimazol on DP in concentrations of 10-100 μМ is abolished by RR, and is not changed in the range of 0,1-1,0 μМ. Nitrendipine raises DPab of erythrocyte membranes in all of range of concentrations, and RR amplifies the effect of the drug. 1. There is a threshold of the biological action on cells for the ionizing component of radioisotope radiation determined by efficiency of operation their antioxidant system.2. At dose rates below a threshold, the action of ionizing radiation is mediated by its non-ionizing component, and is reversible, and therefore is determined only in the field of radiation. V. V. Zhirnov, I. N. Iakovenko, V.M. Voitsitskiy, S. V. Khyzhnyak, О. G. Zubrikova-Chugainova, V.A. Gorobetz.
pH effects on the hyaluronan hydrolysis catalysed by hyaluronidase in the presence of proteins: Part I. Dual aspect of the pH-dependence.

PubMed

Lenormand, Hélène; Deschrevel, Brigitte; Vincent, Jean-Claude

2010-05-01

Hyaluronan (HA) hydrolysis catalysed by hyaluronidase (HAase) is strongly inhibited when performed at a low ratio of HAase to HA concentrations and at low ionic strength. This is because long HA chains can form non-active complexes with HAase. Bovine serum albumin (BSA) is able to compete with HAase to form electrostatic complexes with HA so freeing HAase which then recovers its catalytic activity. This BSA-dependence is characterised by two main domains separated by the optimal BSA concentration: below this concentration the HAase activity increases when the BSA concentration is increased, above this concentration the HAase activity decreases. This occurs provided that HA is negatively charged and BSA is positively charged, i.e. in a pH range from 3 to 5.25. The higher the pH value the higher the optimal BSA concentration. Other proteins can also modulate HAase activity. Lysozyme, which has a pI higher than that of BSA, is also able to compete with HAase to form electrostatic complexes with HA and liberate HAase. This occurs over a wider pH range that extends from 3 to 9. These results mean that HAase can form complexes with HA and recover its enzymatic activity at pH as high as 9, consistent with HAase having either a high pI value or positively charged patches on its surface at high pH. Finally, the pH-dependence of HAase activity, which results from the influence of pH on both the intrinsic HAase activity and the formation of complexes between HAase and HA, shows a maximum at pH 4 and a significant activity up to pH 9. Copyright 2009 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.
Transfer factor of 226Ra, 232Th and 40K from soil to Alpinia Galangal plant grown in northern Thailand

NASA Astrophysics Data System (ADS)

Kritsananuwat, R.; Chanyotha, S.; Kranrod, C.; Pengvanich, P.

2017-06-01

This paper reports the activity concentration of three natural radionuclides, 226Ra, 232Th and 40K, found in Alpinia Galangal plants which are widely used in various Asian cuisines and traditional medicine. The galangal plants and their relevant soils were collected from four provinces in the north of Thailand under natural field conditions. The activity concentration of radionuclides was determined using gamma-ray spectrometry. Soil-to-plant transfer factors (TFs) for 226Ra, 232Th and 40K were investigated in rhizome and aerial parts of the galangal plants. The activity concentration in the soils ranged from 22 to 88 Bq kg-1 for 226Ra, 27 to 157 Bq kg-1 for 232Th and 58 to 1157 Bq kg-1 for 40K. In Alpinia Galangal, the concentration ranged from < 0.2 to 2.0 Bq kg-1 for 226Ra, < 0.1 to 2.9 Bq kg-1 for 232Th and 205 to 2247 Bq kg-1 for 40K. The TF ranged from < 0.002 to 0.073 for 226Ra, < 0.001 to 0.061 for 232Th and 0.26 to 7.9 for 40K. The TFs in the aerial parts were higher than those for the rhizomes. The obtained values can be considered as a baseline data for activity concentrations of natural radionuclides and their TFs in Thailand for future environmental radiation monitoring. The Annual effective ingestion dose due to ingestion of 226Ra, 232Th and 40K in galangals is significantly below the worldwide value reported by UNSCEAR 2000.
Aloe vera: an in vitro study of effects on corneal wound closure and collagenase activity.

PubMed

Curto, Elizabeth M; Labelle, Amber; Chandler, Heather L

2014-11-01

To evaluate the in vitro effects of an aloe vera solution on (i) the viability and wound healing response of corneal cells and (ii) the ability to alter collagenase and gelatinase activities. Primary cultures of corneal epithelial cells and fibroblasts were prepared from grossly normal enucleated canine globes and treated with an aloe solution (doses ranging from 0.0-2 mg/mL). Cellular viability was evaluated using a colorimetric assay. A corneal wound healing model was used to quantify cellular ingrowth across a defect made on the confluent surface. Anticollagenase and antigelatinase activities were evaluated by incubating a bacterial collagenase/gelatinase with aloe solution (doses ranging from 0.0-500 μg/mL) and comparing outcome measures to a general metalloproteinase inhibitor, 1, 10-phenanthroline, and canine serum (doses ranging from 0.0-100%). None of the concentrations of aloe solution tested significantly affected the viability of corneal epithelial cells or fibroblasts. Concentrations ≤175 μg/mL slightly accelerated corneal epithelial cell wound closure; this change was not significant. Concentrations ≥175 μg/mL significantly (P ≤ 0.001) slowed the rate of corneal fibroblast wound closure, while aloe concentrations <175 μg/mL did not significantly alter fibroblast wound closure. Aloe solution did not alter the ability for collagenase to degrade gelatin or collagen Type I but increased the ability for collagenase to degrade Type IV collagen. Although additional experiments are required, lower concentrations of aloe solution may be beneficial in healing of superficial corneal wounds to help decrease fibrosis and speed epithelialization. An increase in collagenase activity with aloe vera warrants further testing before considering in vivo studies. © 2014 American College of Veterinary Ophthalmologists.

Spatial distribution, bioavailability, and health risk assessment of soil Hg in Wuhu urban area, China.

PubMed

Fang, Fengman; Wang, Haidong; Lin, Yuesheng

2011-08-01

Total mercury (Hg(T)) and bioavailability Hg (Hg(HCl)) concentrations in soil were determined in five districts in Wuhu urban area. Spatial pattern of soil Hg concentration was generated through kriging technology. Results showed that Hg concentration in soil ranged from 0.024 to 2.844 mg kg( -1) with an average of 0.207 mg kg( -1). Hg concentration in soil appeared to have a block distribution and decreased from downtown to surrounding district. And Hg concentrations appeared to have a medium scale spatial auto correlation, strongly affected by human activity. The maximal Hg average concentration (0.332 mg kg( -1)) in soil appeared in Jinghu district, where the high intensity of human activities is. Second highest Hg average concentration (0.263 mg kg( -1)) in soil appeared in development district, where the intensive industrial activities are. Bioavailability Hg concentration in soil ranged from 2.6 to 4.9 μg kg( -1) with an average of 3.8 μg kg( -1), which had a ratio of 0.28~6.44% to total Hg. The ratios of bioavailability Hg to total Hg in vegetable soil were bigger than those of park soil. Correlation analysis showed that total Hg, organic matter, total phosphorus, and bioavailability Hg concentrations in soil were significantly positively correlated. Hg concentration in vegetable ranged from 2.7 to 15.2 μg kg( -1) with an average of 6.5 μg kg( -1). Hg concentration in vegetable was positively correlated with Hg(HCl) concentration in soil. According to the calculation on hazard quotient (HQ) for children, inhalation of Hg vapor from soil is the main exposure pathway, in which HQ is 2.517 × 10( -2), accounting for 80.3% of the four exposure pathways. Hazard index (HI) of the four exposure pathways is lower than the "safe" level of HI = 1; therefore, exposure of soil Hg exhibited little potential health risk to children in Wuhu urban area.
Occurrence of radium-224, radium-226, and radium-228 in water of the unconfined Kirkwood-Cohansey aquifer system, southern New Jersey

USGS Publications Warehouse

Szabo, Zoltan; dePaul, Vincent T.; Kraemer, Thomas F.; Parsa, Bahman

2005-01-01

Water in the unconfined Kirkwood-Cohansey aquifer system in the New Jersey Coastal Plain contains elevated concentrations (above 3 pCi/L (picocuries per liter)) of the alpha-particle-emitting radionuclide radium-224. Previously, water from the aquifer system had been found to contain radium-226 and radium-228. This observation is of concern because the previously undetected presence of radium-224 may pose an additional, quantifiable health risk that currently is not accounted for by the Maximum Contaminant Level (MCL) of 5 pCi/L for combined radium (the sum of radium-226 plus radium-228 is termed 'combined radium') in drinking water. Water samples were collected from a regional network of 88 wells for determination of concentrations of radium-224, radium-226, and radium-228; gross alpha-particle activity; and concentrations of major ions and selected trace elements. Both gamma and alpha spectroscopic techniques were used to determine concentrations of radium-224, which ranged from <0.5 to 16.8 pCi/L (median 2.1 pCi/L, interquartile range 1.2-3.7 pCi/L). Concentrations of radium-226 and radium-228 in the same samples ranged from <0.5 to 17.4 pCi/L (median 1.7 pCi/L, interquartile range 0.9-2.9 pCi/L) and <0.5 to 12.8 pCi/L (median 1.6 pCi/L, interquartile range, 0.9-2.6 pCi/L), respectively. Concentrations of radium-224 typically were greater than those of the other two radium radionuclides, as evidenced by the highest median, third quartile, and maximum concentrations, as well as the highest concentration among the three radium radioisotopes in 52 (59 percent) of the 88 samples. Concentrations of 5.0 to 5.5 pCi/L of radium-224 result in a gross alpha-particle activity of about 15 pCi/L (the MCL) 36 to 48 hours, respectively, after sample collection when ingrowth of radium-224 progeny radionuclides is considered, even with the unlikely assumption that no other alpha-particle-emitting radionuclide is present in the water. Concentrations of 3.4 to 3.7 pCi/L radium-224 result in a gross alpha-particle activity of 10 pCi/L 36 to 48 hours, respectively, after sample collection when ingrowth of Ra-224 progeny radionuclides is considered. In this latter case, it is possible that the summed alpha-particle activity from radium-226 present at a concentration less than or equal to 5 pCi/L (the MCL for combined radium) and from radium-224 present at a concentration about 3.4 pCi/L or greater may exceed the 15-pCi/L MCL for gross alpha-particle activity. In this study, gross alpha-particle activities were measured within 48 hours after sample collection and were found to exceed the MCL of 15 pCi/L in nearly half (43) of the 88 samples collected. The concentration of radium-224 exceeded that of radium-226 in 55 (62.5 percent) of the 88 samples. Concentrations of radium-224 correlate strongly with those of both radium-226 and radium-228 (Spearman correlation coefficients r=0.74 and 0.91, respectively). Concentrations of radium-224, radium-226, and radium-228 were greatest in the most acidic ground water. Concentrations of radium-224 and combined radium-226 and radium-228 in samples of ground water with pH less than 4.7 exceeded 5 pCi/L in 33 and 67 percent of the samples, respectively. Concentrations of radium-224, radium-226, and radium-228 (measured separately) were greatest in water from the southern part of the aquifer outcrop area. In water from the northern part of the aquifer system outcrop area, radium-224 concentrations were as high as 3.6 pCi/L, and concentrations of combined radium and gross alpha-particle activity in some samples exceeded their respective MCLs. The presence of gross alpha-particle activities greater than 15 pCi/L and combined radium-226 and radium-228 concentrations greater than 5 pCi/L in the southwestern part of the aquifer system outcrop area is common and had been documented before 1997. Results of this study confirm these earlier findings. In northeastern and southeastern parts of the aquifer
Aqueous synthesis of ZnTe/dendrimer nanocomposites and their antimicrobial activity: implications in therapeutics

NASA Astrophysics Data System (ADS)

Ghosh, S.; Ghosh, D.; Bag, P. K.; Bhattacharya, S. C.; Saha, A.

2011-03-01

The present strategy proposes a simple and single step aqueous route for synthesizing stable, fluorescent ZnTe/dendrimer nanocomposites with varying dendrimer terminal groups. In these hybrid materials, the fluorescence of the semiconductor combines with the biomimetic properties of the dendrimer making them suitable for various biomedical applications. The ZnTe nanocomposites thus obtained demonstrate bactericidal activity against enteropathogenic bacteria without having toxic effects on the human erythrocytes. The average size of the ZnTe nanoparticles within the dendrimer matrix was in the range of 2.9-6.0 nm, and they have a good degree of crystallinity with a hexagonal crystal phase. The antibacterial activities of the ZnTe/dendrimer nanocomposites (ZnTe DNCs) as well other semiconductor nanocomposites were evaluated against enteropathogenic bacteria including multi-drug resistant Vibrio cholerae serogroup O1 and enterotoxigenic Escherichia coli (ETEC). ZnTe DNCs had significant antibacterial activity against strains of V. cholerae and ETEC with minimum inhibitory concentrations ranging from 64 to 512 μg ml-1 and minimum bactericidal concentrations ranging from 128 to 1000 μg ml-1. Thus, the observed results suggest that these water-soluble active nanocomposites have potential for the treatment of enteric diseases like diarrhoea and cholera.The present strategy proposes a simple and single step aqueous route for synthesizing stable, fluorescent ZnTe/dendrimer nanocomposites with varying dendrimer terminal groups. In these hybrid materials, the fluorescence of the semiconductor combines with the biomimetic properties of the dendrimer making them suitable for various biomedical applications. The ZnTe nanocomposites thus obtained demonstrate bactericidal activity against enteropathogenic bacteria without having toxic effects on the human erythrocytes. The average size of the ZnTe nanoparticles within the dendrimer matrix was in the range of 2.9-6.0 nm, and they have a good degree of crystallinity with a hexagonal crystal phase. The antibacterial activities of the ZnTe/dendrimer nanocomposites (ZnTe DNCs) as well other semiconductor nanocomposites were evaluated against enteropathogenic bacteria including multi-drug resistant Vibrio cholerae serogroup O1 and enterotoxigenic Escherichia coli (ETEC). ZnTe DNCs had significant antibacterial activity against strains of V. cholerae and ETEC with minimum inhibitory concentrations ranging from 64 to 512 μg ml-1 and minimum bactericidal concentrations ranging from 128 to 1000 μg ml-1. Thus, the observed results suggest that these water-soluble active nanocomposites have potential for the treatment of enteric diseases like diarrhoea and cholera. Electronic supplementary information (ESI) available: Dynamic light scattering, atomic force microscopy and hemolytic activity of the nanocomposites. See DOI: 10.1039/c0nr00610f
Stem bark extract and fraction of Persea americana (Mill.) exhibits bactericidal activities against strains of bacillus cereus associated with food poisoning.

PubMed

Akinpelu, David A; Aiyegoro, Olayinka A; Akinpelu, Oluseun F; Okoh, Anthony I

2014-12-30

The study investigates the in vitro antibacterial potentials of stem bark extracts of Persea americana on strains of Bacillus cereus implicated in food poisoning. The crude stem bark extracts and butanolic fraction at a concentration of 25 mg/mL and 10 mg/mL, respectively, exhibited antibacterial activities against test isolates. The zones of inhibition exhibited by the crude extract and the fraction ranged between 10 mm and 26 mm, while the minimum inhibitory concentration values ranged between 0.78 and 5.00 mg/mL. The minimum bactericidal concentrations ranged between 3.12 mg/mL-12.5 mg/mL and 1.25-10 mg/mL for the extract and the fraction, respectively. The butanolic fraction killed 91.49% of the test isolates at a concentration of 2× MIC after 60 min of contact time, while a 100% killing was achieved after the test bacterial cells were exposed to the butanolic fraction at a concentration of 3× MIC after 90 min contact time. Intracellular protein and potassium ion leaked out of the test bacterial cells when exposed to certain concentrations of the fraction; this is an indication of bacterial cell wall disruptions by the extract's butanolic fraction and, thus, caused a biocidal effect on the cells, as evident in the killing rate test results.
First radon measurements and occupational exposure assessments in underground geodynamic laboratory the Polish Academy of Sciences Space Research Centre in Książ Castle (SW Poland).

PubMed

Fijałkowska-Lichwa, Lidia; Przylibski, Tadeusz A

2016-12-01

The article presents the results of the first radon activity concentration measurements conducted continuously between 17 th May 2014 and 16 th May 2015 in the underground geodynamic laboratory of the Polish Academy of Sciences Space Research Centre in Książ. The data were registered with the use of three Polish semiconductor SRDN-3 detectors located the closest (SRDN-3 No. 6) to and the furthest (SRDN-3 No. 3) from the facility entrance, and in the fault zone (SRDN-3 No. 4). The study was conducted to characterize the radon behaviour and check it possibility to use with reference to long- and short-term variations of radon activity concentration observed in sedimentary rocks strongly fractured and intersected by systems of multiple faults, for integrated comparative assessments of changes in local orogen kinetics. The values of radon activity concentration in the underground geodynamic laboratory of the Polish Academy of Sciences (PAN) Space Research Centre in Książ undergo changes of a distinctly seasonal character. The highest values of radon activity concentration are recorded from late spring (May/June) to early autumn (October), and the lowest - from November to April. Radon activity concentrations varied depending on the location of measurement points. Between late spring and autumn they ranged from 800 Bq·m -3 to 1200 Bq·m -3 , and even 3200 Bq·m -3 in the fault zone. Between November and April, values of radon activity concentration are lower, ranging from 500 Bq·m -3 to 1000 Bq·m -3 and 2700 Bq·m -3 in the fault zone. The values of radon activity concentration recorded in the studied facility did not undergo short-term changes in either the whole annual measuring cycle or any of its months. Effective doses received by people staying in the underground laboratory range from 0.001 mSv/h to 0.012 mSv/h. The mean annual effective dose, depending on the measurement site, equals 1 or is slightly higher than 10 mSv/year, while the maximum dose exceeds 20 mSv/year. The estimated annual effective doses are comparable to the standard value of 20 mSv/year defined by Polish law for people employed in the conditions of radiation exposure. They are also in the range of annual effective dose value (8 mSv/year) recommended in workplaces by International Commission on Radiation Protection. Copyright Â© 2016 Elsevier Ltd. All rights reserved.
Potency of a tau fibrillization inhibitor is influenced by its aggregation state

PubMed Central

Congdon, Erin E.; Necula, Mihaela; Blackstone, Robert D.; Kuret, Jeff

2007-01-01

Tau fibrillization is a potential therapeutic target for Alzheimer’s and other neurodegenerative diseases. Several small molecule inhibitors of tau aggregation have been developed for this purpose. One of them, 3,3′-bis(β-hydroxyethyl)-9-ethyl-5,5′-dimethoxythiacarbocyanine iodide (N744), is a cationic thiacarbocyanine dye that inhibits recombinant tau filament formation when present at submicromolar concentrations. To prepare dosing regimens for testing N744 activity in biological models, its full concentration-effect relationship in the range 0.01 – 60 μM was examined in vitro by electron microscopy and laser light scattering methods. Results revealed that N744 concentration dependence was biphasic, with fibrillization inhibitory activity appearing at submicromolar concentration, but with relief of inhibition and increases in fibrillization apparent above 10 μM. Therefore, fibrillization was inhibited ≥50% only over a narrow concentration range, which was further reduced by filament stabilizing modifications such as tau pseudophosphorylation. N744 inhibitory activity also was paralleled by changes in its aggregation state, with dimer predominating at inhibitory concentrations and large dye aggregates appearing at high concentrations. Ligand dimerization was promoted by the presence of tau protein, which lowered the equilibrium dissociation constant for dimerization more than an order of magnitude relative to controls. The results suggest that ligand aggregation may play an important role in both inhibitory and disinhibitory phases of the concentration-effect curve, and may lead to complex dose response relationships in model systems. PMID:17559794
Evaluation of metal concentration and antioxidant, antimicrobial, and anticancer potentials of two edible mushrooms Lactarius deliciosus and Macrolepiota procera.

PubMed

Kosanić, Marijana; Ranković, Branislav; Rančić, Aleksandar; Stanojković, Tatjana

2016-07-01

This study is designed for the determination of metal concentrations, antioxidant, antimicrobial, and anticancer potential of two edible mushrooms Lactarius deliciosus and Macrolepiota procera. Concentrations of nine metals are determined and all metals are present in the allowable concentrations in the tested mushrooms except Cd in M. procera. Antioxidant activity was evaluated by free radical scavenging and reducing power. M. procera extract had more potent free radical scavenging activity (IC 50 =311.40 μg/mL) than L. deliciosus extract. Moreover, the tested extracts had effective reducing power. The total content of phenol in the extracts was examined using Folin-Ciocalteu reagent and obtained values expressed as pyrocatechol equivalents. Further, the antimicrobial potential was determined with a microdilution method on 15 microorganisms. Among the tested species, extract of L. deliciosus showed a better antimicrobial activity with minimum inhibitory concentration values ranging from 2.5 mg/mL to 20 mg/mL. Finally, the cytotoxic activity was tested using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method on human epithelial carcinoma HeLa cells, human lung carcinoma A549 cells, and human colon carcinoma LS174 cells. Extract of both mushrooms expressed similar cytotoxic activity with IC 50 values ranging from 19.01 μg/mL to 80.27 μg/mL. Copyright © 2016. Published by Elsevier B.V.
Quenching And Luminescence Efficiency Of Nd3+ In YAG

NASA Astrophysics Data System (ADS)

Lupei, Voicu; Lupei, Aurelia; Georgescu, Serban; Ionescu, Christian I.; Yen, William M.

1989-05-01

The effect of the concentration luminescence quenching of the 4F 3/2, level of Nd3+ in YAG on the relative efficiency is presented. Based on the analysis of the decay curves in terms of the energy transfer theory, an analytical expression for the relative luminescence efficiency is obtained. In the low concentration range (up to q,1.5 at % Nd3+), the efficiency linearly decreases when Nd3+ concentration increases. It is also stressed that pairs quenching contribute about 20 % to the nonradiative energy transfer losses. Quantum efficiency of luminescence is an important parameter for the characterization of laser active media; its lowering is due to either multiphonon relaxation or energy transfer processes. The multiphonon non-radiative probability depends on the energy gap between levels, on the phonon energy and temperature; usually at low activator doping it is practically independent on concentration. On the other hand, energy transfer losses show a marked dependence on activator concentration, a fact that severely limits the range of useful con-centration of active centers in some laser crystals. In the YAG:Nd case the minimum energy gap between the Stark components of the 4F,I.) and the next lower level 4F15/2 is of about 4700 cm-1. Since in YAG tree phonons most effdbtively coupled to the Rare pi.th ions have an energy of 1, 700 cm-1, the probability for multiphonon relaxation from the 'F3/, level, even at room temperature, is very low and therefore for low Nd 3+ concentrations quantum efficiency is expected to be close to 1.
Antifungal Activity of Commercial Essential Oils and Biocides against Candida Albicans.

PubMed

Serra, Elisa; Hidalgo-Bastida, Lilia Araida; Verran, Joanna; Williams, David; Malic, Sladjana

2018-01-25

Management of oral candidosis, most frequently caused by Candida albicans , is limited due to the relatively low number of antifungal drugs and the emergence of antifungal tolerance. In this study, the antifungal activity of a range of commercial essential oils, two terpenes, chlorhexidine and triclosan was evaluated against C. albicans in planktonic and biofilm form. In addition, cytotoxicity of the most promising compounds was assessed using murine fibroblasts and expressed as half maximal inhibitory concentrations (IC50). Antifungal activity was determined using a broth microdilution assay. The minimum inhibitory concentration (MIC) was established against planktonic cells cultured in a range of concentrations of the test agents. The minimal biofilm eradication concentration (MBEC) was determined by measuring re-growth of cells after pre-formed biofilm was treated for 24 h with the test agents. All tested commercial essential oils demonstrated anticandidal activity (MICs from 0.06% ( v / v ) to 0.4% ( v / v )) against planktonic cultures, with a noticeable increase in resistance exhibited by biofilms (MBECs > 1.5% ( v / v )). The IC50s of the commercial essential oils were lower than the MICs, while a one hour application of chlorhexidine was not cytotoxic at concentrations lower than the MIC. In conclusion, the tested commercial essential oils exhibit potential as therapeutic agents against C. albicans , although host cell cytotoxicity is a consideration when developing these new treatments.
Ambient concentrations of total suspended particulate matter and its elemental constituents at the wider area of the mining facilities of TVX Hellas in Chalkidiki, Greece.

PubMed

Gaidajis, George

2003-01-01

To assess ambient air quality at the wider area of TVX Hellas mining facilities, the Total Suspended Particulate matter (TSP) and its content in characteristic elements, i.e., As, Cd, Cu, Fe, Mn, Pb, Zn are being monitored for more than thirty months as part of the established Environmental Monitoring Program. High Volume air samplers equipped with Tissue Quartz filters were employed for the collection of TSP. Analyses were effected after digestion of the suspended particulate with an HNO3-HCl solution and determination of elemental concentrations with an Atomic Absorption Spectroscopy equipped with graphite furnace. The sampling stations were selected to record representatively the existing ambient air quality in the vicinity of the facilities and at remote sites not affected from industrial activities. Monitoring data indicated that the background TSP concentrations ranged from 5-60 microg/m3. Recorded TSP concentrations at the residential sites close to the facilities ranged between 20-100 microg/m3, indicating only a minimal influence from the mining and milling activities. Similar spatial variation was observed for the TSP constituents and specifically for Pb and Zn. To validate the monitoring procedures, a parallel sampling campaign took place with different High Volume samplers at days where low TSP concentrations were expected. The satisfactory agreement (+/- 11%) at low concentrations (50-100 microg/m3) clearly supported the reproducibility of the techniques employed specifically at the critical range of lower concentrations.
Measurements of the size dependence of the concentration of nonvolatile material in fog droplets

NASA Astrophysics Data System (ADS)

Ogren, J. A.; Noone, K. J.; Hallberg, A.; Heintzenberg, J.; Schell, D.; Berner, A.; Solly, I.; Kruisz, C.; Reischl, G.; Arends, B. G.; Wobrock, W.

1992-11-01

Measurements of the size dependence of the mass concentration of nonvolatile material dissolved and suspended in fog droplets were obtained with three complementary approaches, covering a size range from c. 1 50µm diameter: a counterflow virtual impactor, an eight-stage aerosol impactor, and a two-stage fogwater impactor. Concentrations were observed to decrease with size over the entire range, contrary to expectations of increasing concentrations at larger sizes. It is possible that the larger droplets had solute concentrations that increased with increasing size, but that the increase was too weak for the measurements to resolve. Future studies should consider the hypothesis that the droplets were coated with a surface-active substance that hindered their uptake of water.
Dust Plume Modeling at Fort Bliss: Full Training Scenario

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chapman, Elaine G.; Rishel, Jeremy P.; Rutz, Frederick C.

2006-09-26

The potential for air quality impacts from heavy mechanized vehicles operating in the training ranges and on the unpaved main supply routes at Fort Bliss is being investigated. The investigation uses the atmospheric modeling system DUSTRAN to simulate fugitive dust emission and dispersion from typical activities occurring on the installation. This report conveys the results of DUSTRAN simulations conducted using a “Full Training” scenario developed by Fort Bliss personnel. he Full Training scenario includes simultaneous off-road activities of two full Heavy Brigade Combat Teams (HCBTs) and one HCBT battalion on three training ranges. Simulations were conducted for the six-day period,more » April 25-30, 2005, using previously archived meteorological records. Simulation results are presented in the form of 24-hour average PM10 plots and peak 1-hour PM10 concentration plots, where the concentrations represent contributions resulting from the specified military vehicular activities, not total ambient PM10 concentrations. Results indicate that the highest PM10 contribution concentrations occurred on April 30 when winds were light and variable. Under such conditions, lofted particulates generated by vehicular movement stay in the area of generation and are not readily dispersed. The effect of training duration was investigated by comparing simulations with vehicular activity extending over a ten hour period (0700 to 1700 MST) with simulations where vehicular activity was compressed into a one hour period (0700 to 0800 MST). Compressing all vehicular activity into one hour led to higher peak one-hour and 24-hour average concentration contributions, often substantially higher.« less
Vertical Migration Potential of Metal Contaminants at Small Arms Firing Ranges, Camp Edwards Military Reservation, Massachusetts.

DTIC Science & Technology

1998-03-01

halloysite on lead concentration in solution 57 Figure 41. Solubility of lead carbonate as a function of pH for a total activity aH2C03...Effects of adsorption by halloysite (a clay) on lead concentration in solution. Contours are equilibrium lead concentrations at different clay
Carbonic anhydrase levels and internal lacunar CO/sub 2/ concentrations in aquatic macrophytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weaver, C.I.

1979-01-01

Carbonic anhydrase levels were examined in a variety of aquatic macrophytes from different habitats. In general, carbonic anhydrase levels increased across the habitat gradient such that activities were low in submersed aquatic macrophytes and high in emergent macrophytes with floating-leaved and free-floating plants exhibiting intermediate activities. Internal lacunar CO/sub 2/ concentrations were analyzed in relation to carbonic anhydrase activities. There was no correlation between these two parameters. Internal CO/sub 2/ concentrations ranged from low to high in submersed macrophytes, but were low in floating-leaved and emergent macrophytes. The observed internal CO/sub 2/ concentrations are discussed in relation to the individualmore » morphologies of the plants and the environments in which they occurred.« less
SI-traceable calibration-free analysis for the active concentration of G2-EPSPS protein using surface plasmon resonance.

PubMed

Su, Ping; He, Zhangjing; Wu, Liqing; Li, Liang; Zheng, Kangle; Yang, Yi

2018-02-01

Active proteins play important roles in the function regulation of human bodies and attract much interest for use in pharmaceuticals and clinical diagnostics. However, the lack of primary methods to analyze active proteins means there is currently no metrology standard for active protein measurement. In recent years, calibration-free concentration analysis (CFCA), which is based on surface plasmon resonance (SPR) technology, has been proposed to determine the active concentration of proteins that have specific binding activity with a binding partner without any higher order standards. The CFCA experiment observes the changes of binding rates at totally different two flow rates and uses the known diffusion coefficient of an analyte to calculate the active concentration of proteins, theoretically required, the binding process have to be under diffusion-limited conditions. Measuring the active concentration of G2-EPSPS protein by CFCA was proposed in this study. This method involves optimization of the regeneration buffer and preparation of chip surfaces for appropriate reaction conditions by immobilizing ligands (G2-EPSPS antibodies) on sensor chips (CM5) via amine coupling. The active concentration of G2-EPSPS was then determined by injection of G2-EPSPS protein samples and running buffer over immobilized and reference chip surfaces at two different flow rates (5 and 100μLmin -1 ). The active concentration of G2-EPSPS was obtained after analyzing these sensorgrams with the 1:1 model. Using the determined active concentration of G2-EPSPS, the association, dissociation, and equilibrium constants of G2-EPSPS and its antibody were determined to be 2.18 ± 0.03 × 10 6 M -1 s -1 , 5.79 ± 0.06 ×10 -3 s -1 , and 2.65 ± 0.06 × 10 -9 M, respectively. The performance of the proposed method was evaluated. The within-day precisions were from 3.26% to 4.59%, and the between-day precision was 8.36%. The recovery rate of the method was from 97.46% to 104.34% in the concentration range of 1.5-8nM. The appropriate concentration range of G2-EPSPS in the proposed method was determined to be 1.5-8nM. The active G2-EPSPS protein concentration determined by our method was only 17.82% of that obtained by isotope dilution mass spectrometry, showing the active protein was only a small part of the total G2-EPSPS protein. The measurement principle of the proposed method can be clearly described by equations and the measurement result can be expressed in SI units. Therefore, the proposed method shows promise to become a primary method for active protein concentration measurement, which can benefit the development of certified reference materials for active proteins. Copyright © 2017 Elsevier B.V. All rights reserved.
Comparison of antimicrobial activities of naphthoquinones from Impatiens balsamina.

PubMed

Sakunphueak, Athip; Panichayupakaranant, Pharkphoom

2012-01-01

Lawsone (1), lawsone methyl ether (2), and methylene-3,3'-bilawsone (3) are the main naphthoquinones in the leaf extracts of Impatiens balsamina L. (Balsaminaceae). Antimicrobial activities of these three naphthoquinones against dermatophyte fungi, yeast, aerobic bacteria and facultative anaerobic and anaerobic bacteria were evaluated by determination of minimal inhibitory concentrations (MICs) and minimal bactericidal or fungicidal concentrations (MBCs or MFCs) using a modified agar dilution method. Compound 2 showed the highest antimicrobial activity. It showed antifungal activity against dermatophyte fungi and Candida albicans with the MICs and MFCs in the ranges of 3.9-23.4 and 7.8-23.4 µg mL(-1), respectively, and also had some antibacterial activity against aerobic, facultative anaerobic and anaerobic bacteria with MICs in the range of 23.4-93.8, 31.2-62.5 and 125 µg mL(-1), respectively. Compound 1 showed only moderate antimicrobial activity against dermatophytes (MICs and MFCs in the ranges of 62.5-250 and 125-250 µg mL(-1), respectively), but had low potency against aerobic bacteria, and was not active against C. albicans and facultative anaerobic bacteria. In contrast, 3 showed significant antimicrobial activity only against Staphylococus epidermidis and Bacillus subtilis (MIC and MBC of 46.9 and 93.8 µg mL(-1), respectively).
Antibacterial potential assessment of jasmine essential oil against e. Coli.

PubMed

Rath, C C; Devi, S; Dash, S K; Mishra, R K

2008-01-01

The antibacterial activity of Jasmine (Jasminum sambac L.) flower hydro steam distilled essential oil, synthetic blends and six major individual components was assessed against Escherichia coli (MTCC-443) strain. The activity was bactericidal. Minimum inhibitory concentration was determined by tube dilution technique, and the Minimum inhibitory concentration ranged between 1.9-31.25 mul/ml. Phenolcoefficient of the oil, synthetic blends and components varied between 0.6-1.7. The activity of the chemicals was possibly due to the inhibition of cell membrane synthesis.
Study of the adsorption of Cd and Zn onto an activated carbon: Influence of pH, cation concentration, and adsorbent concentration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seco, A.; Marzal, P.; Gabaldon, C.

1999-06-01

The single adsorption of Cd and Zn from aqueous solutions has been investigated on Scharlau Ca 346 granular activated carbon in a wide range of experimental conditions: pH, metal concentration, and carbon concentration. The results showed the efficiency of the activated carbon as sorbent for both metals. Metal removals increase on raising the pH and carbon concentration, and decrease on raising the initial metal concentration. The adsorption processes have been modeled using the surface complex formation (SCF) Triple Layer Model (TLM). The adsorbent TLM parameters were determined. Modeling has been performed assuming a single surface bidentate species or an overallmore » surface species with fractional stoichiometry. The bidentate stoichiometry successfully predicted cadmium and zinc removals in all the experimental conditions. The Freundlich isotherm has been also checked.« less
Low concentrations of bilirubin inhibit activation of hepatic stellate cells in vitro.

PubMed

Tang, Yinhe; Zhang, Qiyu; Zhu, Yefan; Chen, Gang; Yu, Fuxiang

2017-04-01

Hepatic stellate cell (HSC) activation serves a key role in liver fibrosis, and is associated with chronic liver diseases. Bilirubin, a product of heme degradation, has been demonstrated to have antioxidant properties. The present study investigated the effects of physiological concentrations of bilirubin on rat HSC activation. Rat HSCs were isolated and cultured for several generations to induce activation. The activated HSCs were subsequently treated with 0, 1, 10 or 20 mg/l bilirubin and assayed for parameters of cell activation. As the bilirubin concentration increased, HSCs demonstrated reduced production of reactive oxygen species, reduced protein expression levels of α‑smooth muscle actin, a decreased mRNA expression ratio of tissue inhibitor of matrix metalloproteinase‑1/matrix metalloproteinase‑2, decreased proliferation and increased apoptosis. In conclusion, elevated bilirubin levels, within its physiological concentration range, appeared to inhibit HSC activation. These findings suggested a potential role for bilirubin in the treatment of fibrosis that requires further investigation.
[Study of ammonium-nitrogen removal in suspended carrier biofilm reactor].

PubMed

Wang, Wen-bin; Qi, Pei-shi

2006-12-01

In order to improve the ammonium-nitrogen (NH4+ -N) biodegradation rate, a suspended carrier was exploited and biofilm was cultivated in three different phases in a sequencing batch reactor (SBR). A flimsy honeycomb-shape biofilm was formed between the endocentric columns on the suspended carrier,which increased the cling amount of nitrobacteria and provided the better condition for nitrobacteria. The bioreactor was operated at the temperature ranges of 24-29 degrees C and pH between 7.8 and 8.2. When the influent COD and NH4+-N concentrations varied in a range of 140-300 mg x L(-1) and 40- 78 mg x L(-1) , respectively, under 90 min aeration, the effluent concentrations were less than 40 mg x L(-1) and 2 mg x L(-1) , respectively. Under 180 min aeration, the influent COD concentration varied from 150 to 350 mg x L(-1) and NH4+-N concentration in the range of 80 - 130 mg x L (-1), the effluent concentration below 45 mg x L(-1) and 3.5 mg x L(-1), respectively. The results indicated that the ammonium-nitrogen biodegradation rate is much greater than that of the conventional activated sludge process. The active fraction of the biofilm is affected by the concentration of substrates in the bulk liquid, the actual metabolic rates within the biofilm, and the thickness of the biofilm. The suspended carrier configuration used in this investigation and the method of cultivating biofilm are beneficial for decreasing biofilm thickness, for increasing the activated biomass of nitrobacteria, and for increasing surface area of the biofilm relative to the volume of the reactors, which insulting in a high rate of nitrification.

An international marine-atmospheric {sup 222}Rn measurement intercomparison in Bermuda. Part 2: Results for the participating laboratories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colle, R.; Unterweger, M.P.; Hutchinson, J.M.R.

1996-01-01

As part of an international measurement intercomparison of instruments used to measure atmospheric {sup 222}Rn, four participating laboratories made nearly simultaneous measurements of {sup 222}Rn activity concentration in commonly sampled, ambient air over approximately a 2 week period, and three of these four laboratories participated in the measurement comparison of 14 introduced samples with known, but undisclosed (blind) {sup 222}Rn activity concentration. The exercise was conducted in Bermuda in October 1991. The {sup 222}Rn activity concentrations in ambient Bermudian air over the course of the intercomparison ranged from a few hundredths of a Bq {center_dot} m{sup {minus}3} to about 2more » Bq {center_dot} m{sup {minus}3}, while the standardized sample additions covered a range from approximately 2.5 Bq {center_dot} m{sup {minus}3} to 35 Bq {center_dot} m{sup {minus}3}. The overall uncertainty in the latter concentrations was in the general range of 10%, approximating a 3 standard deviation uncertainty interval. The results of the intercomparison indicated that two of the laboratories were within very good agreement with the standard additions, and almost within expected statistical variations. These same two laboratories, however, at lower ambient concentrations, exhibited a systematic difference with an averaged offset of roughly 0.3 Bq {center_dot} m{sup {minus}3}. The third laboratory participating in the measurement of standardized sample additions was systematically low by about 65% to 70%, with respect to the standard addition which was also confirmed in their ambient air concentration measurements. The fourth laboratory, participating in only the ambient measurement part of the intercomparison, was also systematically low by at least 40% with respect to the first two laboratories.« less
Diurnal and seasonal variations of concentration and size distribution of nano aerosols (10-1100 nm) enclosing radon decay products in the Postojna Cave, Slovenia.

PubMed

Bezek, M; Gregoric, A; Kávási, N; Vaupotic, J

2012-11-01

At the lowest point along the tourist route in the Postojna Cave, the activity concentration of radon ((222)Rn) short-lived decay products and number concentration and size distribution of background aerosol particles in the size range of 10-1100 nm were measured. In the warm yearly season, aerosol concentration was low (52 cm(-3)) with 21 % particles smaller than 50 nm, while in the cold season, it was higher (1238 cm(-3)) with 8 % of <50 nm particles. Radon activity concentrations were 4489 and 1108 Bq m(-3), and fractions of unattached radon decay products were 0.62 and 0.13, respectively.
Hematology and serum clinical chemistry reference intervals for free-ranging Scandinavian gray wolves (Canis lupus).

PubMed

Thoresen, Stein I; Arnemo, Jon M; Liberg, Olof

2009-06-01

Scandinavian free-ranging wolves (Canis lupus) are endangered, such that laboratory data to assess their health status is increasingly important. Although wolves have been studied for decades, most biological information comes from captive animals. The objective of the present study was to establish reference intervals for 30 clinical chemical and 8 hematologic analytes in Scandinavian free-ranging wolves. All wolves were tracked and chemically immobilized from a helicopter before examination and blood sampling in the winter of 7 consecutive years (1998-2004). Seventy-nine blood samples were collected from 57 gray wolves, including 24 juveniles (24 samples), 17 adult females (25 samples), and 16 adult males (30 samples). Whole blood and serum samples were stored at refrigeration temperature for 1-3 days before hematologic analyses and for 1-5 days before serum biochemical analyses. Reference intervals were calculated as 95% confidence intervals except for juveniles where the minimum and maximum values were used. Significant differences were observed between adult and juvenile wolves for RBC parameters, alkaline phosphatase and amylase activities, and total protein, albumin, gamma-globulins, cholesterol, creatinine, calcium, chloride, magnesium, phosphate, and sodium concentrations. Compared with published reference values for captive wolves, reference intervals for free-ranging wolves reflected exercise activity associated with capture (higher creatine kinase activity, higher glucose concentration), and differences in nutritional status (higher urea concentration).
Distillation Time as Tool for Improved Antimalarial Activity and Differential Oil Composition of Cumin Seed Oil.

PubMed

Zheljazkov, Valtcho D; Gawde, Archana; Cantrell, Charles L; Astatkie, Tess; Schlegel, Vicki

2015-01-01

A steam distillation extraction kinetics experiment was conducted to estimate essential oil yield, composition, antimalarial, and antioxidant capacity of cumin (Cuminum cyminum L.) seed (fruits). Furthermore, regression models were developed to predict essential oil yield and composition for a given duration of the steam distillation time (DT). Ten DT durations were tested in this study: 5, 7.5, 15, 30, 60, 120, 240, 360, 480, and 600 min. Oil yields increased with an increase in the DT. Maximum oil yield (content, 2.3 g/100 seed), was achieved at 480 min; longer DT did not increase oil yields. The concentrations of the major oil constituents α-pinene (0.14-0.5% concentration range), β-pinene (3.7-10.3% range), γ-cymene (5-7.3% range), γ-terpinene (1.8-7.2% range), cumin aldehyde (50-66% range), α-terpinen-7-al (3.8-16% range), and β-terpinen-7-al (12-20% range) varied as a function of the DT. The concentrations of α-pinene, β-pinene, γ-cymene, γ-terpinene in the oil increased with the increase of the duration of the DT; α-pinene was highest in the oil obtained at 600 min DT, β-pinene and γ-terpinene reached maximum concentrations in the oil at 360 min DT; γ-cymene reached a maximum in the oil at 60 min DT, cumin aldehyde was high in the oils obtained at 5-60 min DT, and low in the oils obtained at 240-600 min DT, α-terpinen-7-al reached maximum in the oils obtained at 480 or 600 min DT, whereas β-terpinen-7-al reached a maximum concentration in the oil at 60 min DT. The yield of individual oil constituents (calculated from the oil yields and the concentration of a given compound at a particular DT) increased and reached a maximum at 480 or 600 min DT. The antimalarial activity of the cumin seed oil obtained during the 0-5 and at 5-7.5 min DT timeframes was twice higher than the antimalarial activity of the oils obtained at the other DT. This study opens the possibility for distinct marketing and utilization for these improved oils. The antioxidant capacity of the oil was highest in the oil obtained at 30 min DT and lowest in the oil from 360 min DT. The Michaelis-Menton and the Power nonlinear regression models developed in this study can be utilized to predict essential oil yield and composition of cumin seed at any given duration of DT and may also be useful to compare previous reports on cumin oil yield and composition. DT can be utilized to obtain cumin seed oil with improved antimalarial activity, improved antioxidant capacity, and with various compositions.
From the Cover: Manganese Stimulates Mitochondrial H2O2 Production in SH-SY5Y Human Neuroblastoma Cells Over Physiologic as well as Toxicologic Range

PubMed Central

Fernandes, Jolyn; Hao, Li; Bijli, Kaiser M.; Chandler, Joshua D.; Orr, Michael; Hu, Xin; Jones, Dean P.

2017-01-01

Manganese (Mn) is an abundant redox-active metal with well-characterized mitochondrial accumulation and neurotoxicity due to excessive exposures. Mn is also an essential co-factor for the mitochondrial antioxidant protein, superoxide dismutase-2 (SOD2), and the range for adequate intake established by the Institute of Medicine Food and Nutrition Board is 20% of the interim guidance value for toxicity by the Agency for Toxic Substances and Disease Registry, leaving little margin for safety. To study toxic mechanisms over this critical dose range, we treated human neuroblastoma SH-SY5Y cells with a series of MnCl2 concentrations (from 0 to 100 μM) and measured cellular content to compare to human brain Mn content. Concentrations ≤10 μM gave cellular concentrations comparable to literature values for normal human brain, whereas concentrations ≥50 μM resulted in values comparable to brains from individuals with toxic Mn exposures. Cellular oxygen consumption rate increased as a function of Mn up to 10 μM and decreased with Mn dose ≥50 μM. Over this range, Mn had no effect on superoxide production as measured by aconitase activity or MitoSOX but increased H2O2 production as measured by MitoPY1. Consistent with increased production of H2O2, SOD2 activity, and steady-state oxidation of total thiol increased with increasing Mn. These findings have important implications for Mn toxicity by re-directing attention from superoxide anion radical to H2O2-dependent mechanisms and to investigation over the entire physiologic range to toxicologic range. Additionally, the results show that controlled Mn exposure provides a useful cell manipulation for toxicological studies of mitochondrial H2O2 signaling. PMID:27701121
Antimicrobial and antioxidant properties of the flavonoid extract from Raphanus sativus L.

NASA Astrophysics Data System (ADS)

Ngoc, Pham Thi Kim; Nguyet, Nguyen Thi Minh; Dao, Dong Thi Anh

2017-09-01

This study was conducted to evaluate the in vitro antimicrobial and antioxidant activities of flavonoid extract from white radish roots (Raphanus sativus L.). Antimicrobial activity was determined by agar diffusion method against 4 strains: Bacillus cereus, Staphylococus aureus, Pseudomonas aeruginosa and Salmonella typhi. Antioxidant activity was determined by ABTS* radical scavenging activity and total antioxidant capacity (TAC). The constituent elements of flavonoid extract were identified by LC-MS. Results showed that the flavonoid extract from Raphanus sativus L. had antibacterial activity against to all four tested bacteria strains with antibacterial ring diameters in the range 8 - 20 mm in the test concentrations from 100 to 1600 mg/ml. Minimum concentration to inhibit (MIC) in the range 20 - 40 mg/ml. In addition, the extract also has the ability to eliminate ABTS* free radical with IC50 = 7.074 µg/ml. The total antioxidant capacity of extract at concentration of 100 µg/ml was 3.424 ± 0.043 mg ascorbic acid/mg. In the extract, there are three flavonoids were found: rutin, quercetin and narigenin. This is the first time narigenin was found in Raphanus sativus L. extract.
Induction of hsp70, hsp90, and catalase activity in planarian Dugesia japonica exposed to cadmium.

PubMed

Zhang, Xiufang; Mo, Yehua; Zhou, Luming; Wang, Yinan; Wang, Zhongchen; Zhao, Bosheng

2016-08-01

The hsp70 and hsp90 expression patterns and catalase (CAT) activity in the freshwater planaria Dugesia japonica exposed to cadmium (Cd) under laboratory conditions were investigated. Planaria were exposed to a range of Cd concentrations (0-150 μg Cd/L) for 24 h. The expression levels of hsp70 and hsp90 were determined by relative quantitative real-time polymerase chain reaction. Within the overall dose range in the experiment, the expression level of hsp70 and the activity of CAT in D. japonica were altered significantly. Hsp70 was induced in D. japonica upon Cd exposure concentrations as low as 9.375 μg Cd/L. No significant effect on the expression level of hsp90 was observed. Our findings demonstrated that stress gene hsp70, but not hsp90, was responsive to Cd contamination in D. japonica CAT activity was significantly induced at concentrations of 18.75, 37.5, and 75 μg Cd/L after 24-h exposure. We recommend that the use of hsp70 as a biomarker should be complemented by evidence of changes in other parameters, such as CAT activity, in D. japonica. © The Author(s) 2014.
Radionuclides from the Fukushima accident in the air over Lithuania: measurement and modelling approaches.

PubMed

Lujanienė, G; Byčenkienė, S; Povinec, P P; Gera, M

2012-12-01

Analyses of (131)I, (137)Cs and (134)Cs in airborne aerosols were carried out in daily samples in Vilnius, Lithuania after the Fukushima accident during the period of March-April, 2011. The activity concentrations of (131)I and (137)Cs ranged from 12 μBq/m(3) and 1.4 μBq/m(3) to 3700 μBq/m(3) and 1040 μBq/m(3), respectively. The activity concentration of (239,240)Pu in one aerosol sample collected from 23 March to 15 April, 2011 was found to be 44.5 nBq/m(3). The two maxima found in radionuclide concentrations were related to complicated long-range air mass transport from Japan across the Pacific, the North America and the Atlantic Ocean to Central Europe as indicated by modelling. HYSPLIT backward trajectories and meteorological data were applied for interpretation of activity variations of measured radionuclides observed at the site of investigation. (7)Be and (212)Pb activity concentrations and their ratios were used as tracers of vertical transport of air masses. Fukushima data were compared with the data obtained during the Chernobyl accident and in the post Chernobyl period. The activity concentrations of (131)I and (137)Cs were found to be by 4 orders of magnitude lower as compared to the Chernobyl accident. The activity ratio of (134)Cs/(137)Cs was around 1 with small variations only. The activity ratio of (238)Pu/(239,240)Pu in the aerosol sample was 1.2, indicating a presence of the spent fuel of different origin than that of the Chernobyl accident. Copyright © 2011 Elsevier Ltd. All rights reserved.
Functionality based detection of airborne engineered nanoparticles in quasi real time: a new type of detector and a new metric.

PubMed

Neubauer, Nicole; Seipenbusch, Martin; Kasper, Gerhard

2013-08-01

A new type of detector which we call the Catalytic Activity Aerosol Monitor (CAAM) was investigated towards its capability to detect traces of commonly used industrial catalysts in ambient air in quasi real time. Its metric is defined as the catalytic activity concentration (CAC) expressed per volume of sampled workplace air. We thus propose a new metric which expresses the presence of nanoparticles in terms of their functionality - in this case a functionality of potential relevance for damaging effects - rather than their number, surface, or mass concentration in workplace air. The CAAM samples a few micrograms of known or anticipated airborne catalyst material onto a filter first and then initiates a chemical reaction which is specific to that catalyst. The concentration of specific gases is recorded using an IR sensor, thereby giving the desired catalytic activity. Due to a miniaturization effort, the laboratory prototype is compact and portable. Sensitivity and linearity of the CAAM response were investigated with catalytically active palladium and nickel nano-aerosols of known mass concentration and precisely adjustable primary particle size in the range of 3-30 nm. With the miniature IR sensor, the smallest detectable particle mass was found to be in the range of a few micrograms, giving estimated sampling times on the order of minutes for workplace aerosol concentrations typically reported in the literature. Tests were also performed in the presence of inert background aerosols of SiO2, TiO2, and Al2O3. It was found that the active material is detectable via its catalytic activity even when the particles are attached to a non-active background aerosol.
The effect of pasteurization on transforming growth factor alpha and transforming growth factor beta 2 concentrations in human milk.

PubMed

McPherson, R J; Wagner, C L

2001-01-01

Transforming growth factor alpha (TGF-alpha) and beta 2 (TGF-beta2) are present in human milk and are involved in growth differentiation and repair of neonatal intestinal epithelia. Heat treatment at 56 degrees C has been shown effective for providing safe banked donor milk, with good retention of other biologically active factors. The purpose of our study was to determine the effect of heat sterilization on TGF-alpha and TGF-beta2 concentrations in human milk. Twenty milk samples were collected from 20 lactating mothers in polypropylene containers and frozen at -20 degrees C for transport or storage. Before heat treatment by holder pasteurization, the frozen milk was thawed and divided into 1-mL aliquots. All samples were heated in an accurately regulated water bath until a holding temperature was achieved, then held for 30 minutes using constant agitation. Holding temperature ranged from 56.5 degrees C to 56.9 degrees C. The milk was then stored at 4 degrees C overnight for analysis the following day. The concentration of TGF-alpha was measured by radioimmunoassay. Mean concentration +/- SD of TGF-alpha in raw milk samples was 119+/-50 pg/mL, range 57 to 234. The mean concentration +/- SD of TGF-alpha in heat treated samples was 113+/-50 pg/mL, range 51 to 227. TGF-alpha concentration was minimally affected by pasteurization, with an overall loss of 6.1%. Of 19 samples, 4 had increased and 15 had decreased concentrations after pasteurization (mean percent SEM: 94%+/-7% of raw milk, range 72%+/-107%). The concentration of acid-activated TGF-beta2 was measured by enzyme-linked immunosorbent assay. Mean concentration +/- SD of TGF-beta2 in raw milk samples was 5624+/-5038 pg/mL, range 195 to 15480. The mean concentration +/- SD of TGF-beta2 in heat-treated samples was 5073+/-4646 pg/mL, range 181 to 15140. TGF-beta2 survived with relatively little loss (0.6%): of 18 samples, 11 had increased and 7 had decreased concentrations after pasteurization (mean percent +/- SEM: 99.4+/-6.7% of raw milk, range 79%-120%). In conclusion, both TGF-alpha and TGF-beta2 were well-preserved in whole milk after holder pasteurization at 56.5 degrees C. The relative increase in growth factor concentration in some of the samples may be attributable to the release of that factor from the cellular and/or fat compartments into the aqueous fraction of human milk. These findings have implications regarding use of donor milk as an alternate source of growth factors and cytokines for the newborn gut when mother's milk is unavailable.
Preliminary survey of radioactivity level in Thai medicinal herb plants

NASA Astrophysics Data System (ADS)

Kranrod, C.; Chanyotha, S.; Kritsananuwat, R.; Ploykrathok, T.; Pengvanich, P.; Tumnoi, Y.; Thumvijit, T.; Sriburee, S.

2017-06-01

In this research, the natural radioactivity concentrations and their respective annual effective dose of the naturally occurring radionuclides 226Ra, 228Ra and 40K in selected medicinal herb plants were investigated. Seven kinds of popular Thai medicinal herb plants had been studied: turmeric, ginger, safflower, moringa, gotu kola, garlic and alexandria senna. The radiological risk associated with the use of these medicinal plants was assessed. The activity concentrations of 226Ra, 228Ra and 40K were determined using the gamma-ray spectrometry technique. The radioactivity concentrations were found to range from less than 0.20 to 6.67 Bqkg-1 for 226Ra, less than 0.10 to 9.69 Bqkg-1 for 228Ra, and from 159.42 to 1216.25 Bqkg-1 for 40K. Gotu kola showed the highest activity concentrations of 226Ra and 228Ra, while ginger showed the highest activity concentration of 40K. The total annual effective dose due to ingestion of these herb plants were found to range from 0.0028 to 0.0097 mSvy-1 with an average value of 0.0060±0.0001 mSvy-1. The results conclude that the Thai medicinal herb plants samples from this research are considered safe in terms of the radiological hazard.
The effectiveness of processed grapefruit-seed extract as an antibacterial agent: II. Mechanism of action and in vitro toxicity.

PubMed

Heggers, John P; Cottingham, John; Gusman, Jean; Reagor, Lee; McCoy, Lana; Carino, Edith; Cox, Robert; Zhao, Jian-Gang; Reagor, Lana

2002-06-01

Recent testimonials report grapefruit-seed extract, or GSE (Citricidal) to be effective against more than 800 bacterial and viral strains, 100 strains of fungus, and a large number of single and multicelled parasites. This study investigated GSE for antibacterial activity at varying time intervals and concentration levels and tissue toxicity at varying concentrations in an effort to determine if a concentration existed that was both microbicidal and nontoxic and in what period of time. Gram-negative and gram-positive isolates were introduced into graduated dilutions of GSE (twofold concentrations ranging from 1:1, through 1:512) for determination of bacterial activity. In vitro assays with human skin fibroblast cells were also performed at the same dilutions to determine toxicity. These tests indicated that from the 1:1 through the 1:128 concentrations, GSE remained toxic as well as bactericidal. However, test results indicated that at the 1:512 dilution, GSE remained bactericidal, but completely nontoxic. The initial data shows GSE to have antimicrobial properties against a wide range of gram-negative and gram-positive organisms at dilutions found to be safe. With the aid of scanning transmission electron microscopy (STEM), the mechanism of GSE's antibacterial activity was revealed. It was evident that GSE disrupts the bacterial membrane and liberates the cytoplasmic contents within 15 minutes after contact even at more dilute concentrations.
Factors affecting 210Po and 210Pb activity concentrations in mussels and implications for environmental bio-monitoring programmes.

PubMed

Carvalho, Fernando P; Oliveira, João M; Alberto, G

2011-02-01

The activity of (210)Po and (210)Pb was determined in mussels of the same size (3.5-4.0 cm shell length) sampled monthly over a 17-month period at the Atlantic coast of Portugal. Average radionuclide concentration values in mussels were 759±277 Bq kg(-1) for (210)Po (range 460-1470 Bq kg(-1) dry weight), and 45±19 Bq kg(-1) for (210)Pb (range 23-96 Bq kg(-1) dry weight). Environmental parameters and mussel biometric parameters were monitored during the same period. Although there was no seasonal variation of radionuclide concentrations in sea water during the study period, the concentration of radionuclide activity in mussels varied seasonally displaying peaks of high concentrations in winter and low concentrations in summer. Analysis of radionuclide data in relation to the physiological Condition Index of mussels revealed that (210)Po and (210)Pb activities in the mussel (average activity per individual) remained nearly constant during the investigation period, while mussel body weight fluctuated due to fat storage/expenditure in the soft tissues. Similar variation of radionuclide concentrations was observed in mussels transplanted from the sea coast into the Tejo Estuary. However, under estuarine environmental conditions and with higher food availability throughout the year, transplanted mussel Condition Index was higher than in coastal mussels and average radionuclide concentrations were 210±75 Bq kg(-1) (dry weight) for (210)Po and 10±4 Bq kg(-1) (dry weight) for (210)Pb, therefore lower than in coastal mussels with similar shell length. It is concluded that the apparent seasonal fluctuation and inter-site difference of radionuclide concentrations were mostly caused by mussel body weight fluctuation and not by radionuclide body burden fluctuation. This interpretation can be extended to the apparent seasonal fluctuation in concentrations of lipophilic and lipophobic contaminants in mussels, and provides an explanation for occasional high concentrations of (210)Po and man-made contaminants measured in mussels far from pollution sources. Copyright © 2010 Elsevier Ltd. All rights reserved.
Pharmacodynamic Evaluation of the Intracellular Activities of Antibiotics against Staphylococcus aureus in a Model of THP-1 Macrophages

PubMed Central

Barcia-Macay, Maritza; Seral, Cristina; Mingeot-Leclercq, Marie-Paule; Tulkens, Paul M.; Van Bambeke, Françoise

2006-01-01

The pharmacodynamic properties governing the activities of antibiotics against intracellular Staphylococcus aureus are still largely undetermined. Sixteen antibiotics of seven different pharmacological classes (azithromycin and telithromycin [macrolides]; gentamicin [an aminoglycoside]; linezolid [an oxazolidinone]; penicillin V, nafcillin, ampicillin, and oxacillin [β-lactams]; teicoplanin, vancomycin, and oritavancin [glycopeptides]; rifampin [an ansamycin]; and ciprofloxacin, levofloxacin, garenoxacin, and moxifloxacin [quinolones]) have been examined for their activities against S. aureus (ATCC 25923) in human THP-1 macrophages (intracellular) versus that in culture medium (extracellular) by using a 0- to 24-h exposure time and a wide range of extracellular concentrations (including the range of the MIC to the maximum concentration in serum [Cmax; total drug] of humans). All molecules except the macrolides caused a net reduction in bacterial counts that was time and concentration/MIC ratio dependent (four molecules tested in detail [gentamicin, oxacillin, moxifloxacin, and oritavancin] showed typical sigmoidal dose-response curves at 24 h). Maximal intracellular activities remained consistently lower than extracellular activities, irrespective of the level of drug accumulation and of the pharmacological class. Relative potencies (50% effective concentration or at a fixed extracellular concentration/MIC ratio) were also decreased, but to different extents. At an extracellular concentration corresponding to their Cmaxs (total drug) in humans, only oxacillin, levofloxacin, garenoxacin, moxifloxacin, and oritavancin had truly intracellular bactericidal effects (2-log decrease or more, as defined by the Clinical and Laboratory Standards Institute guidelines). The intracellular activities of antibiotics against S. aureus (i) are critically dependent upon their extracellular concentrations and the duration of cell exposure (within the 0- to 24-h time frame) to antibiotics and (ii) are always lower than those that can be observed extracellularly. This model may help in rationalizing the choice of antibiotic for the treatment of S. aureus intracellular infections. PMID:16495241
Maternal serum soluble CD30 is increased in pregnancies complicated with acute pyelonephritis.

PubMed

Kusanovic, Juan Pedro; Romero, Roberto; Esoinoza, Jimmy; Gotsch, Francesca; Edwin, Samuel; Chaiworapongsa, Tinnakorn; Mittal, Pooja; Soto, Eleazar; Erez, Offer; Mazaki-Tovi, Shali; Than, Nandor Gabor; Friel, Lara A; Yoon, Bo Hyun; Mazor, Moshe; Hassan, Sonia S

2007-11-01

Normal pregnancy is characterized by activation of the innate immunity and suppression of the adaptive limb of the immune response. However, pregnant women are more susceptible to the effects of infection and microbial products than non-pregnant women. CD30 is a member of the tumor necrosis factor receptor superfamily and is preferentially expressed by activated T cells producing Th2-type cytokines. Its soluble form (sCD30) is proposed to be an index of Th2 immune response. High serum concentrations of sCD30 have been found in the acute phase of viral infections, such as HIV-1 and hepatitis B. There is, however, conflicting evidence about serum sCD30 concentration in patients with bacterial infections. The objective of this study was to determine whether there are changes in the serum concentration of sCD30 in pregnant women with pyelonephritis. This cross-sectional study included normal pregnant women (N = 89) and pregnant women with pyelonephritis (N = 41). Maternal serum concentration of sCD30 was measured by a specific and sensitive enzyme-linked immunoassay. Non-parametric tests were used for comparisons. A p value <0.05 was considered statistically significant. (1) Pregnant women with pyelonephritis had a significantly higher median serum concentration of sCD30 than those with a normal pregnancy (median 44.3 U/mL, range 16-352.5 vs. median 29.7 U/mL, range 12.2-313.2, respectively; p < 0.001), and (2) No significant differences were found in the median maternal serum concentration of sCD30 between pregnant women with pyelonephritis who had a positive blood culture compared to those with a negative blood culture (median 47.7 U/mL, range 17.1-118.8 vs. median 42.6 U/mL, range 16-352.5, respectively; p = 0.86). Acute pyelonephritis during pregnancy is associated with a higher maternal serum concentration of sCD30 than normal pregnancy. This finding is novel and suggests that pregnant women with pyelonephritis may have a complex immune state in which there is activation of some components of what is considered a Th2 immune response.
Uptake and intracellular activity of AM-1155 in phagocytic cells.

PubMed Central

Yamamoto, T; Kusajima, H; Hosaka, M; Fukuda, H; Oomori, Y; Shinoda, H

1996-01-01

The uptake and intracellular activity of AM-1155 in murine J774.1 macrophages and human polymorphonuclear leukocytes were investigated. AM-1155 penetrated phagocytic cells rapidly and reversibly, although the penetration process was not affected by metabolic inhibitors such as sodium fluoride, cyanide m-chlorophenylhydrazone, or ouabain or by nucleoside transport system inhibitors such as adenosine. The intracellular concentration-to-extracellular concentration ratio of AM-1155 in both cell types of phagocytes ranged from 5 to 7. These ratios were almost equal to those for sparfloxacin. The intracellular activity of AM-1155 in J774.1 macrophages, examined with Staphylococcus aureus 209P as a test bacterium, was dependent on the extracellular concentration. AM-1155 at a concentration of 1 microgram/ml reduced the number of viable cells of S. aureus ingested by more than 90%. The intracellular activity of AM-1155 was more potent than those of sparfloxacin, ofloxacin, ciprofloxacin, flomoxef, and erythromycin. These results suggest that the potent intracellular activity of AM-1155 might mainly be due to the high intracellular concentration and its potent in vitro activity. PMID:9124835
Occurrence and In Vitro Bioactivity of Estrogen, Androgen, and Glucocorticoid Compounds in a Nationwide Screen of United States Stream Waters.

PubMed

Conley, Justin M; Evans, Nicola; Cardon, Mary C; Rosenblum, Laura; Iwanowicz, Luke R; Hartig, Phillip C; Schenck, Kathleen M; Bradley, Paul M; Wilson, Vickie S

2017-05-02

In vitro bioassays are sensitive, effect-based tools used to quantitatively screen for chemicals with nuclear receptor activity in environmental samples. We measured in vitro estrogen (ER), androgen (AR), and glucocorticoid receptor (GR) activity, along with a broad suite of chemical analytes, in streamwater from 35 well-characterized sites (3 reference and 32 impacted) across 24 states and Puerto Rico. ER agonism was the most frequently detected with nearly all sites (34/35) displaying activity (range, 0.054-116 ng E2Eq L -1 ). There was a strong linear relationship (r 2 = 0.917) between in vitro ER activity and concentrations of steroidal estrogens after correcting for the in vitro potency of each compound. AR agonism was detected in 5/35 samples (range, 1.6-4.8 ng DHTEq L -1 ) but concentrations of androgenic compounds were largely unable to account for the in vitro activity. Similarly, GR agonism was detected in 9/35 samples (range, 6.0-43 ng DexEq L -1 ); however, none of the recognized GR-active compounds on the target-chemical analyte list were detected. The utility of in vitro assays in water quality monitoring was evident from both the quantitative agreement between ER activity and estrogen concentrations, as well as the detection of AR and GR activity for which there were limited or no corresponding target-chemical detections to explain the bioactivity. Incorporation of in vitro bioassays as complements to chemical analyses in standard water quality monitoring efforts would allow for more complete assessment of the chemical mixtures present in many surface waters.
Occurrence and in vitro bioactivity of estrogen, androgen, and glucocorticoid compounds in a nationwide screen of United States stream waters

USGS Publications Warehouse

Conley, Justin M.; Evans, Nicola; Cardon, Mary C.; Rosenblum, Laura; Iwanowicz, Luke R.; Hartig, Phillip C.; Schenck, Kathleen M.; Bradley, Paul M.; Wilson, Vickie S.

2017-01-01

In vitro bioassays are sensitive, effect-based tools used to quantitatively screen for chemicals with nuclear receptor activity in environmental samples. We measured in vitro estrogen (ER), androgen (AR), and glucocorticoid receptor (GR) activity, along with a broad suite of chemical analytes, in streamwater from 35 well-characterized sites (3 reference and 32 impacted) across 24 states and Puerto Rico. ER agonism was the most frequently detected with nearly all sites (34/35) displaying activity (range, 0.054–116 ng E2Eq L–1). There was a strong linear relationship (r2 = 0.917) between in vitro ER activity and concentrations of steroidal estrogens after correcting for the in vitro potency of each compound. AR agonism was detected in 5/35 samples (range, 1.6–4.8 ng DHTEq L–1) but concentrations of androgenic compounds were largely unable to account for the in vitro activity. Similarly, GR agonism was detected in 9/35 samples (range, 6.0–43 ng DexEq L–1); however, none of the recognized GR-active compounds on the target-chemical analyte list were detected. The utility of in vitro assays in water quality monitoring was evident from both the quantitative agreement between ER activity and estrogen concentrations, as well as the detection of AR and GR activity for which there were limited or no corresponding target-chemical detections to explain the bioactivity. Incorporation of in vitro bioassays as complements to chemical analyses in standard water quality monitoring efforts would allow for more complete assessment of the chemical mixtures present in many surface waters.
Adsorption-desorption mediated separation of low concentrated D2O from water with hydrophobic activated carbon fiber.

PubMed

Ono, Yuji; Futamura, Ryusuke; Hattori, Yoshiyuki; Sakai, Toshio; Kaneko, Katsumi

2017-12-15

The adsorption and desorption of D 2 O on hydrophobic activated carbon fiber (ACF) occurs at a smaller pressure than the adsorption and desorption of H 2 O. The behavior of the critical desorption pressure difference between D 2 O and H 2 O in the pressure range of 1.25-1.80kPa is applied to separate low concentrated D 2 O from water using the hydrophobic ACF, because the desorption branches of D 2 O and H 2 O drop almost vertically. The deuterium concentration of all desorbed water in the above pressure range is lower than that of water without adsorption-treatment on ACF. The single adsorption-desorption procedure on ACF at 1.66kPa corresponding to the maximum difference of adsorption amount between D 2 O and H 2 O reduced the deuterium concentration of desorbed water to 130.6ppm from 143.0ppm. Thus, the adsorption-desorption procedure of water on ACF is a promising separation and concentration method of low concentrated D 2 O from water. Copyright © 2017 Elsevier Inc. All rights reserved.
Can air pollution negate the health benefits of cycling and walking?

PubMed

Tainio, Marko; de Nazelle, Audrey J; Götschi, Thomas; Kahlmeier, Sonja; Rojas-Rueda, David; Nieuwenhuijsen, Mark J; de Sá, Thiago Hérick; Kelly, Paul; Woodcock, James

2016-06-01

Active travel (cycling, walking) is beneficial for the health due to increased physical activity (PA). However, active travel may increase the intake of air pollution, leading to negative health consequences. We examined the risk-benefit balance between active travel related PA and exposure to air pollution across a range of air pollution and PA scenarios. The health effects of active travel and air pollution were estimated through changes in all-cause mortality for different levels of active travel and air pollution. Air pollution exposure was estimated through changes in background concentrations of fine particulate matter (PM2.5), ranging from 5 to 200μg/m3. For active travel exposure, we estimated cycling and walking from 0 up to 16h per day, respectively. These refer to long-term average levels of active travel and PM2.5 exposure. For the global average urban background PM2.5 concentration (22μg/m3) benefits of PA by far outweigh risks from air pollution even under the most extreme levels of active travel. In areas with PM2.5 concentrations of 100μg/m3, harms would exceed benefits after 1h 30min of cycling per day or more than 10h of walking per day. If the counterfactual was driving, rather than staying at home, the benefits of PA would exceed harms from air pollution up to 3h 30min of cycling per day. The results were sensitive to dose-response function (DRF) assumptions for PM2.5 and PA. PA benefits of active travel outweighed the harm caused by air pollution in all but the most extreme air pollution concentrations. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Concentration-Dependent Multiple Binding Sites on Saliva-Treated Hydroxyapatite for Streptococcus sanguis

PubMed Central

Gibbons, R. J.; Moreno, E. C.; Etherden, I.

1983-01-01

The influence of bacterial cell concentration on estimates of the number of binding sites and the affinity for the adsorption of a strain of Streptococcus sanguis to saliva-treated hydroxyapatite was determined, and the possible presence of multiple binding sites for this organism was tested. The range of concentrations of available bacteria varied from 4.7 × 106 to 5,960 × 106 cells per ml. The numbers of adsorbed bacteria increased over the entire range tested, but a suggestion of a break in an otherwise smooth adsorption isotherm was evident. Values for the number of binding sites and the affinity varied considerably depending upon the range of available bacterial concentrations used to estimate them; high correlation coefficients were obtained in all cases. The use of low bacterial cell concentrations yielded lower values for the number of sites and much higher values for the affinity constant than did the use of high bacterial cell concentrations. When data covering the entire range of bacterial concentrations were employed, values for the number of sites and the affinity were similar to those obtained by using only high bacterial cell concentrations. The simplest explanation for these results is that there are multiple binding sites for S. sanguis on saliva-treated hydroxyapatite surfaces. When present in low concentration, the streptococci evidently attach to more specific high-affinity sites which become saturated when higher bacterial concentrations are employed. The possibility of multiple binding sites was substantiated by comparing estimates of the adsorption parameters from a computer-simulated isotherm with those derived from the experimentally generated isotherm. A mathematical model describing bacterial adsorption to binary binding sites was further evidence for the existence of at least two classes of binding sites for S. sanguis. Far fewer streptococci adsorbed to experimental pellicles prepared from saliva depleted of bacterial aggregating activity when low numbers of streptococci were used, but the magnitude of this difference was considerably less when high streptococcal concentrations were employed. This suggests an association between salivary components which possess bacterial-aggregating activity and bacterial adsorption to high-affinity specific binding sites on saliva-treated hydroxyapatite surfaces. PMID:6822416
(238)U and total radioactivity in drinking waters in Van province, Turkey.

PubMed

Selçuk Zorer, Özlem; Dağ, Beşir

2014-06-01

As part of the national survey to evaluate natural radioactivity in the environment, concentration levels of total radioactivity and natural uranium have been analysed in drinking water samples. A survey to study natural radioactivity in drinking waters was carried out in the Van province, East Turkey. Twenty-three samples of drinking water were collected in the Van province and analysed for total α, total β and (238)U activity. The total α and total β activities were counted by using the α/β counter of the multi-detector low background system (PIC MPC-9604), and the (238)U concentrations were determined by inductively coupled plasma-mass spectrometry (Thermo Scientific Element 2). The samples were categorised according to origin: tap, spring or mineral supply. The activity concentrations for total α were found to range from 0.002 to 0.030 Bq L(-1) and for total β from 0.023 to 1.351 Bq L(-1). Uranium concentrations ranging from 0.562 to 14.710 μg L(-1) were observed in drinking waters. Following the World Health Organisation rules, all investigated waters can be used as drinking water.
Concentrated dispersions of equilibrium protein nanoclusters that reversibly dissociate into active monomers

NASA Astrophysics Data System (ADS)

Truskett, Thomas M.; Johnston, Keith; Maynard, Jennifer; Borwankar, Ameya; Miller, Maria; Wilson, Brian; Dinin, Aileen; Khan, Tarik; Kaczorowski, Kevin

2012-02-01

Stabilizing concentrated protein solutions is of wide interest in drug delivery. However, a major challenge is how to reliably formulate concentrated, low viscosity (i.e., syringeable) solutions of biologically active proteins. Unfortunately, proteins typically undergo irreversible aggregation at intermediate concentrations of 100-200 mg/ml. In this talk, I describe how they can effectively avoid these intermediate concentrations by reversibly assembling into nanoclusters. Nanocluster assembly is achieved by balancing short-ranged, cosolute-induced attractions with weak, longer-ranger electrostatic repulsions near the isoelectric point. Theory predicts that native proteins are stabilized by a self-crowding mechanism within the concentrated environment of the nanoclusters, while weak cluster-cluster interactions can result in colloidally-stable dispersions with moderate viscosities. I present experimental results where this strategy is used to create concentrated antibody dispersions (up to 260 mg/ml) comprising nanoclusters of proteins [monoclonal antibody 1B7, polyclonal sheep Immunoglobin G and bovine serum albumin], which upon dilution in vitro or administration in vivo, are conformationally stable and retain activity.
An experimental phantom study of the effect of gadolinium-based MR contrast agents on PET attenuation coefficients and PET quantification in PET-MR imaging: application to cardiac studies.

PubMed

O' Doherty, Jim; Schleyer, Paul

2017-12-01

Simultaneous cardiac perfusion studies are an increasing trend in PET-MR imaging. During dynamic PET imaging, the introduction of gadolinium-based MR contrast agents (GBCA) at high concentrations during a dual injection of GBCA and PET radiotracer may cause increased attenuation effects of the PET signal, and thus errors in quantification of PET images. We thus aimed to calculate the change in linear attenuation coefficient (LAC) of a mixture of PET radiotracer and increasing concentrations of GBCA in solution and furthermore, to investigate if this change in LAC produced a measurable effect on the image-based PET activity concentration when attenuation corrected by three different AC strategies. We performed simultaneous PET-MR imaging of a phantom in a static scenario using a fixed activity of 40 MBq [18 F]-NaF, water, and an increasing GBCA concentration from 0 to 66 mM (based on an assumed maximum possible concentration of GBCA in the left ventricle in a clinical study). This simulated a range of clinical concentrations of GBCA. We investigated two methods to calculate the LAC of the solution mixture at 511 keV: (1) a mathematical mixture rule and (2) CT imaging of each concentration step and subsequent conversion to LAC at 511 keV. This comparison showed that the ranges of LAC produced by both methods are equivalent with an increase in LAC of the mixed solution of approximately 2% over the range of 0-66 mM. We then employed three different attenuation correction methods to the PET data: (1) each PET scan at a specific millimolar concentration of GBCA corrected by its corresponding CT scan, (2) each PET scan corrected by a CT scan with no GBCA present (i.e., at 0 mM GBCA), and (3) a manually generated attenuation map, whereby all CT voxels in the phantom at 0 mM were replaced by LAC = 0.1 cm -1 . All attenuation correction methods (1-3) were accurate to the true measured activity concentration within 5%, and there were no trends in image-based activity concentrations upon increasing the GBCA concentration of the solution. The presence of high GBCA concentration (representing a worst-case scenario in dynamic cardiac studies) in solution with PET radiotracer produces a minimal effect on attenuation-corrected PET quantification.
Mercury in the Walker River Basin, Nevada and California--sources, distribution, and potential effects on the ecosystem

USGS Publications Warehouse

Seiler, Ralph L.; Lico, Michael S.; Wiemeyer Evers, David C.

2004-01-01

Mercury is one of the most serious contaminants of water, sediment, and biota in Nevada because of its use during 19th century mining activities to recover gold and silver from ores. In 1998, mercury problems were discovered in the Walker River Basin of California and Nevada when blood drawn from three common loons from Walker Lake was analyzed and found to have severely elevated mercury levels. From 1999 to 2001, the U.S. Geological Survey and the U.S. Fish and Wildlife Service collected water, sediment, and biological samples to determine mercury sources, distribution, and potential effects on the Walker River Basin ecosystem. Total-mercury concentrations ranged from 0.62 to 57.11 ng/L in streams from the Walker River system and ranged from 1.02 to 26.8 ng/L in lakes and reservoirs. Total-mercury concentrations in streambed sediment ranged from 1 to 13,600 ng/g, and methylmercury concentrations ranged from 0.07 to 32.1 ng/g. The sediment-effects threshold for mercury for fresh-water invertebrates is 200 ng/g, which was exceeded at nine stream sites in the Walker River Basin. The highest mercury concentrations were in streams with historic mines and milling operations in the watershed. The highest mercury concentration in sediment, 13,600 ng/g, was found in Bodie Creek near Bodie, Calif., a site of extensive gold mining and milling activities during the 19th century. Sediment cores taken from Walker Lake show total-mercury concentrations exceeding 1,000 ng/g at depths greater than 15 cm below lake bottom. The presence of 137Cs above 8 cm in one core indicates that the upper 8 cm was deposited sometime after 1963. The mercury peak at 46 cm in that core, 2,660 ng/g, likely represents the peak of mining and gold extraction in the Bodie and Aurora mining districts between 1870 and 1880. Mercury concentrations in aquatic invertebrates at all sites downstream from mining activities in the Rough Creek watershed, which drains the Bodie and Aurora mining districts, were elevated (range 0.263 to 0.863 ?g/g, dry weight). Mercury concentrations in the Walker Lake tui chub, the most abundant and likely prey for common loons, ranged from approximately 0.09 ?g/g to approximately 0.9 ?g/g (wet weight). Larger tui chub in the lake, which are most likely older, had the highest mercury concentrations. Blood samples from 94 common loons collected at Walker Lake between 1998 and 2001 contained a mean mercury concentration of 2.96 ?g/g (standard deviation 1.72 ?g/g). These levels were substantially higher than those found in more than 1,600 common loons tested across North America. Among the 1,600 common loons, the greatest blood mercury concentration, 9.46 ?g/g, was from a loon at Walker Lake. According to risk assessments for northeastern North America, blood mercury concentrations exceeding 3.0 ?g/g cause behavioral, reproductive, and physiological effects. At least 52 percent of the loons at Walker Lake are at risk for adverse effects from mercury on the basis of their blood-mercury concentrations. The larger loons staging in the spring are the most at risk group. The elevated mercury levels found in tui chub and common loons indicate that there is a potential threat to the well being and reproduction of fish and wildlife that use Walker Lake. Wildlife that use Weber Reservoir may also be at risk because it is the first reservoir downstream from mining activities in the Bodie and Aurora areas and mercury concentrations in sediment were elevated. Additional data on mercury concentrations in top level predators, such as piscivorous fish and birds, are needed to assess public health and other environmental risks.
The assessment of bore-hole water quality of Kakamega County, Kenya

NASA Astrophysics Data System (ADS)

Christine, Adika A.; Kibet, Joshua K.; Kiprop, Ambsrose K.; Were, Munyendo L.

2018-03-01

Numerous deleterious impacts of anthropogenic activities on water quality are typically observed in areas bursting with mineral exploitation, agricultural activities, and industrial processes. Therefore, this contribution details the water quality and water origin in selected hand-dug wells of one the most prominent mining areas in Kenya (Kakamega County). The toxicological impacts of drinking water from a mining site may include cancer and genetic aberrations largely because of the toxic effects of waterborne metals including Hg and As. Accordingly, this study focuses primarily on the investigation of heavy metals, essential elements such as Na and K. Heavy metals and essential elements were determined using spectroscopic and titrimetric techniques. The study revealed that mercury (Hg) concentration ranged between 0.00256 and 0.0611 ± 0.00005 mg/L while arsenic (As) concentration ranged from 0.0103 to 0.0119 ± 0.00005 mg/L. The concentration of potassium ranged from 2.53 to 4.08 ± 0.15 mg/L while that of sodium varied from 6.74 to 9.260 ± 0.2 mg/L. Although the concentration of cadmium was lower than that recommended by W.H.O, the concentrations of Hg, Pb, and As in Kakamega waters were higher than the internationally accepted levels. The generally high level of heavy metals in Kakamega bore-hole waters is, therefore, a public health concern that needs immediate intervention.
Assessment of natural radioactivity and radiation hazard indices in soil samples of East Khasi Hills District, Meghalaya, India

NASA Astrophysics Data System (ADS)

Lyngkhoi, B.; Nongkynrih, P.

2018-04-01

The Activity Concentrations of naturally occurring radionuclides such as 40K, 238U and 232Th were determined from 20 (twenty) villages of East Khasi Hills District of Meghalaya, India using gamma-ray spectroscopy. This District is adjacent to the South-West Khasi Hills District located in the same state where heavy deposit of uranium has been identified [1]. The measured activities of 40K, 238U and 232Th were found ranging from 93.4 to 606.3, 23.2 to 140.9 and 25.1 to 158.9 Bq kg-1 with their average values of 207.9, 45.6 and 63.8 Bq kg-1, respectively. The obtained value of activity concentration for 40K is lower than the world average value 400.0 Bq kg-1 while for 238U and 232Th, the average concentrations are above the world average values 35.0 and 30.0 Bq kg-1, respectively. The calculated Absorbed Dose Rate gamma-radiation of the natural radionuclides ranged from 37.4 to 186.5 nGy h-1 with an average of 71.3 nGy h-1. The outdoor Annual Effective Dose Rate received by an individual ranged from 50.0-230.0 µSv y-1 with an average value of 87.5 µSv y-1. The physical and chemical properties of the soil have no effects on the naturally occurring radionuclides concentrations. This has been revealed by the results obtained as there is no positive correlation between physical/chemical parameters and the radionuclides concentrations in the soil samples [2]. It is observed that good positive correlations among the radionuclides concentrations and with the measured dose rate prevail. The findings show that the values of external and internal hazard indices resulting from the measured activity concentrations of natural radionuclides in soil from the collected sampling areas are less than the International Recommended safety limits of 1 (unity) with the exception of Mylliem (1.12) where the External hazard index is slightly higher.
Torque, power and muscle activation of eccentric and concentric isokinetic cycling.

PubMed

Green, David J; Thomas, Kevin; Ross, Emma Z; Green, Steven C; Pringle, Jamie S M; Howatson, Glyn

2018-06-01

This study aimed to establish the effect of cycling mode and cadence on torque, external power output, and lower limb muscle activation during maximal, recumbent, isokinetic cycling. After familiarisation, twelve healthy males completed 6 × 10 s of maximal eccentric (ECC) and concentric (CON) cycling at 20, 40, 60, 80, 100, and 120 rpm with five minutes recovery. Vastus lateralis, medial gastrocnemius, rectus femoris, and biceps femoris surface electromyography was recorded throughout. As cadence increased, peak torque linearly decreased during ECC (350-248 N·m) and CON (239-117 N·m) and peak power increased in a parabolic manner. Crank angle at peak torque increased with cadence in CON (+13°) and decreased in ECC (-9.0°). At all cadences, peak torque (mean +129 N·m, range 111-143 N·m), and power (mean +871 W, range 181-1406 W), were greater during ECC compared to CON. For all recorded muscles the crank angle at peak muscle activation was greater during ECC compared to CON. This difference increased with cadence in all muscles except the vastus lateralis. Additionally, peak vastus laterallis and biceps femoris activation was greater during CON compared to ECC. Eccentric cycling offers a greater mechanical stimulus compared to concentric cycling but the effect of cadence is similar between modalities. Markers of technique (muscle activation, crank angle at peak activation and torque) were different between eccentric and concentric cycling and respond differently to changes in cadence. Such data should be considered when comparing between, and selecting cadences for, recumbent, isokinetic, eccentric and concentric cycling. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.
Bacteriolytic Activity Of Human Interleukin-2, Chicken Egg Lysozyme In The Presence Of Potential Effectors

PubMed Central

Levashov, P. A.; Matolygina, D. A.; Ovchinnikova, E. D.; Atroshenko, D. L.; Savin, S. S.; Belogurova, N. G.; Smirnov, S. A.; Tishkov, V. I.; Levashov, A. V.

2017-01-01

The bacteriolytic activity of interleukin-2 and chicken egg lysozyme in the presence of various substances has been studied. Glycine and lysine do not affect the activity of interleukin-2 but increase that of lysozyme, showing a bell-shape concentration dependence peaking at 1.5 mM glycine and 18 mM lysine. Arginine and glutamate activate both interleukin-2 and lysozyme with a concentration dependence of the saturation type. Aromatic amino acids have almost no effect on the activity of both interleukin-2 and lysozyme. Aromatic amines, tryptamine, and tyramine activate interleukin-2 but inhibit lysozyme. Peptide antibiotics affect interleukin and lysozyme similarly and exhibit maximum activity in the micromolar range of antibiotics. Taurine has no effect on the activity of interleukin-2 and lysozyme. Mildronate showed no influence on lysozyme, but it activated interleukin-2 with the activity maximum at 3 mM. EDTA activates both interleukin-2 and lysozyme at concentrations above 0.15 mM. PMID:28740730
The impact of military activities on the concentration of mercury in soils of military training grounds and marine sediments.

PubMed

Gębka, Karolina; Bełdowski, Jacek; Bełdowska, Magdalena

2016-11-01

Military activities have been conducted on land and at sea. Both during conflicts and in peace time, some regions served as a military training ground which included firing positions and bunkers. Mercury fulminate has been used in ammunition primers and detonators. Certain amount of ammunition was dumped into the Baltic Sea after the Second World War. Because of corroded containers, mercury can be released into the marine environment. The soil and sediment samples were taken from military training grounds, southern Baltic in 2014 and 2015. The concentration of mercury was determined by AMA-254 analyzer. Hg concentration was higher in the places of military activities, as compared to other areas. Ten times increased concentration of Hg was determined in soil sample collected in area of active gun range compared to the reference station. The significant higher concentration of mercury was detected in stations where chemical warfare agents were found.
Bactericidal activity of antibiotics against Legionella micdadei (Pittsburgh pneumonia agent).

PubMed Central

Dowling, J N; Weyant, R S; Pasculle, A W

1982-01-01

The bactericidal activity of five antibiotics for Legionella micdadei was determined by the construction of time-kill curves. Erythromycin, rifampin, penicillin G, cephalothin, and gentamicin were bactericidal for L. micdadei at readily achievable concentrations. The minimal bactericidal concentrations, defined as those producing 99.9% killing within 24 h, were: erythromycin, 4.6; rifampin, 0.13; penicillin G, 0.25; cephalothin, 2.5; and gentamicin, 0.25 micrograms/ml. The ratios of the minimal bactericidal to minimal inhibitory concentrations for these antibiotics ranged from 1 to 8. Thus, the poor in vivo activity of beta-lactam and aminoglycoside antibiotics against L. micdadei cannot be ascribed to a lack of killing by these agents. PMID:6927637
Persistence of 137Cs in the litter layers of forest soil horizons of Mount IDA/Kazdagi, Turkey.

PubMed

Karadeniz, Özlem; Karakurt, Hidayet; Çakır, Rukiye; Çoban, Fatih; Büyükok, Emir; Akal, Cüneyt

2015-01-01

In 2010-2012, an extensive study was performed in forest sites of Mount IDA (Kazdagi)/Edremit 26 years after the Chernobyl accident. The (137)Cs activity concentrations were determined by gamma-ray spectrometry in the forest soil layers (OL, OF + OH and A horizons) separately. Based on 341 surface soil samples and 118 soil profiles, activity concentrations of (137)Cs in OL horizons varied between 0.25 ± 0.14 and 70 ± 1 Bq kg(-1), while the ranges of (137)Cs activity concentrations in OF + OH and A horizons were 13 ± 1-555 ± 3 Bq kg(-1) and 2 ± 1-253 ± 2 Bq kg(-1), respectively. Cesium-137 deposition in the study area was estimated to be in the range of 1-39 kBq m(-2) and a linear relationship between the deposition of (137)Cs and the altitude was observed. The distributions of (137)Cs activities in OL, OF + OH and A horizons throughout the region were mapped in detail. The highest (137)Cs activities were found in OF + OH horizons, with markedly lower (137)Cs activity in mineral horizons of soil profiles. It is observed that (137)Cs content of humus layer increases with the thickness of the humus layer for coniferous forest sites. The (137)Cs activity concentrations were higher than the recommended screening limits (150 Bq kg(-1)) at some of the investigated areas. The current activity concentration of top soil layers indicates that over many years since the initial deposition, (137)Cs activity is keeping still high in the organic horizons. Copyright © 2014 Elsevier Ltd. All rights reserved.
The measurement of the size distribution of artificial fogs

NASA Technical Reports Server (NTRS)

Deepak, A.; Cliff, W. C.; Mcdonald, J. R.; Ozarski, R.; Thomson, J. A. L.; Huffaker, R. M.

1974-01-01

The size-distribution of the fog droplets at various fog particle concentrations in fog chamber was determined by two methods: (1) the Stokes' velocity photographic method and (2) using the active scattering particle spectrometer. It is shown that the two techniques are accurate in two different ranges of particle size - the former in the radii range (0.1 micrometers to 10.0 micrometers), and the latter for radii greater than 10.0 micrometers. This was particularly true for high particle concentration, low visibility fogs.
Environmental 238U and 232Th concentration measurements in an area of high level natural background radiation at Palong, Johor, Malaysia.

PubMed

Ramli, A Termizi; Hussein, A Wahab M A; Wood, A Khalik

2005-01-01

Concentrations of uranium-238 and thorium-232 in soil, water, grass, moss and oil-palm fruit samples collected from an area of high background radiation were determined using neutron activation analysis (NAA). U-238 concentration in soil ranged from 4.9 mg kg(-1) (58.8 Bq kg(-1)) to 40.4 mg kg(-1) (484.8 Bq kg(-1)), Th-232 concentration ranged from 14.9 mg kg(-1) (59.6 Bq kg(-1)) to 301.0 mg kg(-1) (1204 Bq kg(-1)). The concentration of U-238 in grass samples ranged from below the detection limit to 0.076 mg kg(-1) (912 mBq kg(-1)), and Th-232 ranged from 0.008 mg kg(-1) (32 mBq kg(-1)) to 0.343 mg kg(-1) (1.372 Bq kg(-1)). U-238 content in water samples ranged from 0.33 mg kg(-1) (4.0 Bq L(-1)) to 1.40 mg kg(-1) (16.8 Bq L(-1)), and Th-232 ranged from 0.19 mg kg(-1) (0.76 Bq L(-1)) to 0.66 mg kg(-1) (2.64 Bq L(-1)). It can be said that the concentrations of environmental U-238 and Th-232 in grass and water samples in the study area are insignificant. Mosses were found to be possible bio-radiological indicators due to their high absorption of the heavy radioelements from the environment.
Effect of increasing Helicobacter pylori ammonia production by urea infusion on plasma gastrin concentrations.

PubMed Central

Chittajallu, R S; Neithercut, W D; Macdonald, A M; McColl, K E

1991-01-01

It has been proposed that the hypergastrinaemia in subjects with Helicobacter pylori infection is caused by the action of the ammonia produced by the organism's urease activity on the antral G cells. To investigate this hypothesis we examined the effect on plasma gastrin of increasing the bacterium's ammonia production by infusing urea intragastrically to eight H pylori positive duodenal ulcer patients. After a 60 minute control intragastric infusion of dextrose solution at 2 ml/minute, a similar infusion containing urea (50 mmol/l) was continued for four hours. During the urea infusion, the median gastric juice urea concentration rose from 1.1 mmol/l (range 0.3-1.6) to 15.5 mmol/l (range 7.9-21.3) and this resulted in an increase in the ammonium concentration from 2.3 mmol/l (range 1.3-5.9) to 6.1 mmol/l (range 4.2-11.9) (p less than 0.01). This appreciable rise in ammonia production did not result in any change in the plasma gastrin concentration. The experiment was repeated one month after eradication of H pylori, at which time the median basal gastrin was 20 ng/l (range 15-25), significantly less than the value before eradication (30 ng/l range 15-60) (p less than 0.05). On this occasion, the gastric juice ammonium concentration was considerably reduced at 0.4 mmol/l (range 0.1-0.9) and the urea infusion did not raise the ammonium concentration or change the plasma gastrin concentration. In conclusion, augmenting H pylori ammonia production does not cause any early change in plasma gastrin. PMID:1991633
High extracellular concentration of excitatory amino acids glutamate and aspartate in human brain abscess.

PubMed

Dahlberg, Daniel; Ivanovic, Jugoslav; Hassel, Bjørnar

2014-04-01

Brain abscesses often cause symptoms of brain dysfunction, including seizures, suggesting interference with normal neurotransmission. We determined the concentration of extracellular neuroactive amino acids in brain abscesses from 16 human patients. Glutamate was present at 3.6 mmol/L (median value, range 0.5-10.8), aspartate at 1.0 mmol/L (range 0.09-6.8). For comparison, in cerebroventricular fluid glutamate was ∼0.6 μmol/L, and aspartate was not different from zero. The total concentration of amino acids was higher in eight patients with seizures: 66 mmol/L (median value, range 19-109) vs. 21 mmol/L (range 4-52) in eight patients without seizures (p=0.026). The concentration of aspartate and essential amino acids tryptophan, phenylalanine, tyrosine, leucine, and isoleucine was higher in pus from patients with seizures (p⩽0.040), whereas that of glutamate was not (p=0.095). The median concentration of the non-proteinogenic, inhibitory amino acid taurine was similar in the two groups, 0.7-0.8 mmol/L (range 0.1-6.1). GABA could not be detected in pus. The patient groups did not differ with respect to abscess volume, the cerebral lobe affected, age, or time from symptom onset to surgery. Seven patients with extracerebral, intracranial abscesses had significantly lower pus concentration of glutamate (352 μmol/L, range 83-1368) and aspartate (71 μmol/L, range 22-330) than intracerebral abscesses (p<0.001). We conclude that excitatory amino acids glutamate and aspartate may reach very high concentrations in brain abscesses, probably contributing to symptoms through activation of glutamate receptors in the surrounding brain tissue. Copyright © 2014 Elsevier Ltd. All rights reserved.
Enzymatic assay for calmodulins based on plant NAD kinase activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harmon, A.C.; Jarrett, H.W.; Cormier, M.J.

NAD kinase with increased sensitivity to calmodulin was purified from pea seedlings (Pisum sativum L., Willet Wonder). Assays for calmodulin based on the activities of NAD kinase, bovine brain cyclic nucleotide phosphodiesterase, and human erythrocyte Ca/sup 2 -/-ATPase were compared for their sensitivities to calmodulin and for their abilities to discriminate between calmodulins from different sources. The activities of the three enzymes were determined in the presence of various concentrations of calmodulins from human erythrocyte, bovine brain, sea pansy (Renilla reniformis), mung bean seed (Vigna radiata L. Wilczek), mushroom (Agaricus bisporus), and Tetrahymena pyriformis. The concentrations of calmodulin required formore » 50% activation of the NAD kinase (K/sub 0.5/) ranged from 0.520 ng/ml for Tetrahymena to 2.20 ng/ml for bovine brain. The A/sub 0.5/ s ranged from 19.6 ng/ml for bovine brain calmodulin to 73.5 ng/ml for mushroom calmodulin for phosphodiesterase activation. The K/sub 0.5/'s for the activation of Ca/sup 2 +/-ATPase ranged from 36.3 ng/mol for erythrocyte calmodulin to 61.7 ng/ml for mushroom calmodulin. NAD kinase was not stimulated by phosphatidylcholine, phosphatidylserine, cardiolipin, or palmitoleic acid in the absence or presence of Ca/sup 2 +/. Palmitic acid had a slightly stimulatory effect in the presence of Ca/sup 2 +/ (10% of maximum), but no effect in the absence of Ca/sup 2 +/. Palmitoleic acid inhibited the calmodulin-stimulated activity by 50%. Both the NAD kinase assay and radioimmunoassay were able to detect calmodulin in extracts containing low concentrations of calmodulin. Estimates of calmodulin contents of crude homogenates determined by the NAD kinase assay were consistent with amounts obtained by various purification procedures. 30 references, 1 figure, 4 tables.« less
Antibacterial Potential Assessment of Jasmine Essential Oil Against E. Coli

PubMed Central

Rath, C. C.; Devi, S.; Dash, S. K.; Mishra, R. K.

2008-01-01

The antibacterial activity of Jasmine (Jasminum sambac L.) flower hydro steam distilled essential oil, synthetic blends and six major individual components was assessed against Escherichia coli (MTCC-443) strain. The activity was bactericidal. Minimum inhibitory concentration was determined by tube dilution technique, and the Minimum inhibitory concentration ranged between 1.9-31.25 μl/ml. Phenolcoefficient of the oil, synthetic blends and components varied between 0.6-1.7. The activity of the chemicals was possibly due to the inhibition of cell membrane synthesis. PMID:20046722
Risk screening of pharmaceutical compounds in Romanian aquatic environment.

PubMed

Gheorghe, Stefania; Petre, Jana; Lucaciu, Irina; Stoica, Catalina; Nita-Lazar, Mihai

2016-06-01

The aquatic environment is under increased pressure by pharmaceutically active compounds (PhACs) due to anthropogenic activities. In spite of being found at very low concentrations (ng/L to μg/L) in the environment, PhACs represent a real danger to aquatic ecosystems due to their bioaccumulation and long-term effects. In this study, the presence in the aquatic environment of six non-steroidal anti-inflammatory drugs (ibuprofen, diclofenac, acetaminophen, naproxen, indomethacin, and ketoprofen), caffeine, and carbamazepine were monitored. Moreover, their aquatic risk and ecotoxicity by three biological models were evaluated. The monitoring studies performed in Romania showed that all studied PhACs were naturally present at concentrations >0.01 μg/L, pointing out the necessity to perform further toxicity tests for environmental risk assessment. The toxicity studies were carried out on aquatic organisms or bacteria and they indicated, for most of the tested PhACs, an insignificant or low toxicity effects: lethal concentrations (LC50) on fish Cyprinus carpio ranged from 42.60 mg/L to more than 100 mg/L; effective concentrations (EC50) on planktonic crustacean Daphnia magna ranged from 11.02 mg/L to more than 100 mg/L; inhibitory concentrations (IC50)/microbial toxic concentrations (MTC) on Vibrio fischeri and other bacterial strains ranged from 7.02 mg/L to more than 100 mg/L. The PhAC aquatic risk was assessed by using the ratio between measured environmental concentration (MEC) and predicted no effect concentration (PNEC) calculated for each type of organism. The average of quotient risks (RQs) revealed that the presence of these compounds in Romania's aquatic environment induced a lower or moderate aquatic risk.
Palytoxin isolated from marine coelenterates. The inhibitory action on (Na,K)-ATPase.

PubMed

Ishida, Y; Takagi, K; Takahashi, M; Satake, N; Shibata, S

1983-07-10

Palytoxin (PTX), C129H223N3O54, a highly toxic substance isolated from zoanthids of Palythoa tuberculosa, inhibited (Na,K)-ATPase (ATP phosphohydrolase, EC 3.6.1.3) prepared from guinea pig heart and hog cerebral cortex in a dose-dependent manner at concentrations greater than 10(-8) M. In the presence of Na (100 mM) and K (20 mM), PTX showed potency nearly equal to that of ouabain. When the ATPase was activated by the various Na concentrations at a constant K concentration, both PTX and ouabain inhibited the ATPase activity noncompetitively. On the other hand, when K concentration was changed at a constant Na concentration, PTX caused a competitive inhibition in all ranges of K concentrations employed, whereas ouabain caused a competitive inhibition at low concentrations and a noncompetitive inhibition at high concentrations.

Hemolytic and antimicrobial activities differ among saponin-rich extracts from guar, quillaja, yucca, and soybean.

PubMed

Hassan, Sherif M; Byrd, James A; Cartwright, Aubry L; Bailey, Chris A

2010-10-01

Hemolytic and antibacterial activities of eight serial concentrations ranged from 5-666 microg/mL of saponin-rich extracts from guar meal (GM), quillaja, yucca, and soybean were tested in 96-well plates and read by enzyme-linked immunosorbent assay plate-well as 650 nm. Hemolytic assay used a 1% suspension of chicken red blood cells with water and phosphate buffered saline as positive and negative controls, respectively. Antibacterial activity against Staphylococcus aureus, Salmonella typhimurium, and Escherichia coli were evaluated using ampicillin and bacteria without saponin-rich extract as positive and negative controls, respectively. The 100% MeOH GM and commercial quillaja saponin-rich extracts were significantly the highest in both hemolytic and antibacterial activities against all bacteria at the same concentration tested. Soybean saponin-rich extract had no antibacterial activity against any of the bacteria at the concentrations tested while yucca saponin-rich extract had no antibacterial activity against the gram-negative bacteria at the concentrations tested. GM and quillaja saponin-rich extracts were hemolytic, while yucca and soybean saponin-rich extracts were not hemolytic at the concentrations tested. No saponin-rich extract source had antibacterial activity against S. typhimurium or E. coli at the concentrations tested. Both GM and quillaja saponin-rich extracts exhibited antibacterial activity against S. aureus. Saponin-rich extracts from different plant sources have different hemolytic and antibacterial activities.
How incense and joss paper burning during the worship activities influences ambient mercury concentrations in indoor and outdoor environments of an Asian temple?

PubMed

Shen, Huazhen; Tsai, Cheng-Mou; Yuan, Chung-Shin; Jen, Yi-Hsiu; Ie, Iau-Ren

2017-01-01

This study firstly investigated the species, concentration variation, and emission factors of mercury emitted from the burning of incenses and joss papers in an Asian temple. Both indoor and outdoor speciated mercury (GEM, GOM, and PHg) were sampled by manual samplers, while ambient GEM at an indoor site was in-situ monitored by a continuous GEM monitor. Field measurement results showed that the total atmospheric mercury (TAM) concentrations in indoor and outdoor environments were in the range of 8.03-35.72 and 6.03-31.35 ng/m 3 , respectively. The indoor and outdoor ratios (I/O) of TAM in the daytime and at nighttime were in the range of 0.64-0.90 and 1.50-2.04, respectively. The concentrations of GEM, GOM, and PHg during the holiday periods were approximately 1-4 times higher than those during the non-holiday periods. GEM was the dominant mercury species in the indoor and outdoor environments and accounted for 63-81% of TAM, while the oxidized mercury accounted for 19-37% of TAM. Burning incenses and joss papers in a combustion chamber showed that the concentration of GEM from joss paper burning ranged from 4.07 to 11.62 μg/m 3 , or about 13.97 times higher than that of incense burning, while the concentration of PHg from incense burning ranged from 95.91 to 135.07 ng/m 3 , or about 3.29 times higher than that of joss paper burning. The emission factors of incense burning were 10.39 ng/g of GEM and 1.40 ng/g of PHg, while those of joss paper burning were 12.65 ng/g of GEM and 1.27 ng/g of PHg, respectively. This study revealed that speciated mercury emitted from worship activities had significant influence on the indoor and outdoor mercury concentrations in an Asian temple. Higher intensity of worship activities during holidays resulted in a higher concentration of speciated mercury in indoor and outdoor air, which might cause health threats to worshipers, staffs, and surrounding inhabitants through long-term exposure. Copyright © 2016 Elsevier Ltd. All rights reserved.
Determination of activity coefficient of lanthanum chloride in molten LiCl-KCl eutectic salt as a function of cesium chloride and lanthanum chloride concentrations using electromotive force measurements

NASA Astrophysics Data System (ADS)

Bagri, Prashant; Simpson, Michael F.

2016-12-01

The thermodynamic behavior of lanthanides in molten salt systems is of significant scientific interest for the spent fuel reprocessing of Generation IV reactors. In this study, the apparent standard reduction potential (apparent potential) and activity coefficient of LaCl3 were determined in a molten salt solution of eutectic LiCl-KCl as a function of concentration of LaCl3. The effect of adding up to 1.40 mol % CsCl was also investigated. These properties were determined by measuring the open circuit potential of the La-La(III) redox couple in a high temperature molten salt electrochemical cell. Both the apparent potential and activity coefficient exhibited a strong dependence on concentration. A low concentration (0.69 mol %) of CsCl had no significant effect on the measured properties, while a higher concentration (1.40 mol %) of CsCl caused an increase (become more positive) in the apparent potential and activity coefficient at the higher range of LaCl3 concentrations.
Effects of ascorbate on leucocytes: Part II. Effects of ascorbic acid and calcium and sodium ascorbate on neutrophil phagocytosis and post-phagocytic metabolic activity.

PubMed

Anderson, R

1979-09-01

The effects of ascorbic acid and calcium and sodium ascorbate at a concentration range of 10(-6)M - 10(-1)M on polymorphonuclear leucocyte (PMN) phagocytosis of Candida albicans and post-phagocytic nitroblue tetrazolium (NBT) reduction, hexose monophosphate shunt (HMS) activity and myeloperoxidase-mediated iodination of ingested protein were investigated. Phagocytosis of C. albicans was unaffected by ascorbate concentrations of 10(-6)M - 10(-2)M; however, progressive inhibition was observed at concentrations of 10(-2)M upwards. Enhancement of resting and stimulated HMS activity and NBT reduction was evident at ascorbate concentrations of 10(-5) M - 10(-2)M. The stimulations of HMS activity and NBT reduction was independent of myeloperoxidase iodination of ingested protein and this latter function was strongly inhibited by ascorbate. Concentrations of ascorbic acid and calcium and sodium ascorbate which caused inhibition of phagocytosis and HMS activity were the same as those which mediated stimulation of cell motility, indicating that independent cellular mechanisms may govern motility and phagocytosis.
Distribution of some natural and man-made radionuclides in soil from the city of Veles (Republic of Macedonia) and its environs.

PubMed

Dimovska, Snezana; Stafilov, Trajce; Sajn, Robert; Frontasyeva, Marina

2010-02-01

A systematic study of soil radioactivity in the metallurgical centre of the Republic of Macedonia, the city of Veles and its environs, was carried out. The measurement of the radioactivity was performed in 55 samples from evenly distributed sampling sites. The gross alpha and gross beta radioactivity measurements were made as a screening, using a low background gas-flow proportional counter. For the analysis of (40)K, (238)U, (232)Th and (137)Cs, a P-type coaxial high purity germanium detector was used. The values for the activity concentrations of the natural radionuclides fall well within the worldwide range as reported in the literature. It is shown that the activity of man-made radionuclides, except for (137)Cs, is below the detection limit. (137)Cs originated from the atmospheric deposition and present in soil in the activity concentration range of 2-358 Bq kg(-1) is irregularly distributed over the sampled territory owing to the complicated orography of the land. The results of gamma spectrometry are compared to the K, U, and Th concentrations previously obtained by the reactor neutron activation analysis in the same soil samples.
Optimization of free ammonia concentration for nitrite accumulation in shortcut biological nitrogen removal process.

PubMed

Chung, Jinwook; Shim, Hojae; Park, Seong-Jun; Kim, Seung-Jin; Bae, Wookeun

2006-03-01

A shortcut biological nitrogen removal (SBNR) utilizes the concept of a direct conversion of ammonium to nitrite and then to nitrogen gas. A successful SBNR requires accumulation of nitrite in the system and inhibition of the activity of nitrite oxidizers. A high concentration of free ammonia (FA) inhibits nitrite oxidizers, but unfortunately decreases the ammonium removal rate as well. Therefore, the optimal range of FA concentration is necessary not only to stabilize nitrite accumulation but also to achieve maximum ammonium removal. In order to derive such optimal FA concentrations, the specific substrate utilization rates of ammonium and nitrite oxidizers were measured. The optimal FA concentration range appeared to be 5-10 mg/L for the adapted sludge. The simulated results from the modified inhibition model expressed by FA and ammonium/nitrite concentrations were shown very similar to the experimental results.
Long-range transport of Xe-133 emissions under convective and non-convective conditions.

PubMed

Kuśmierczyk-Michulec, J; Krysta, M; Kalinowski, M; Hoffmann, E; Baré, J

2017-09-01

To investigate the transport of xenon emissions, the Provisional Technical Secretariat (PTS) operates an Atmospheric Transport Modelling (ATM) system based on the Lagrangian Particle Dispersion Model FLEXPART. The air mass trajectory ideally provides a "link" between a radionuclide release and a detection confirmed by radionuclide measurements. This paper investigates the long-range transport of Xe-133 emissions under convective and non-convective conditions, with special emphasis on evaluating the changes in the simulated activity concentration values due to the inclusion of the convective transport in the ATM simulations. For that purpose a series of 14 day forward simulations, with and without convective transport, released daily in the period from 1 January 2011 to 30 June 2013, were analysed. The release point was at the ANSTO facility in Australia. The simulated activity concentrations for the period January 2011 to February 2012 were calculated using the daily emission values provided by the ANSTO facility; outside the aforementioned period, the median daily emission value was used. In the simulations the analysed meteorological input data provided by the European Centre for Medium-Range Weather Forecasts (ECMWF) were used with the spatial resolution of 0.5°. It was found that the long-range transport of Xe-133 emissions under convective conditions, where convection was included in the ATM simulation, led to a small decrease in the activity concentration, as compared to transport without convection. In special cases related to deep convection, the opposite effect was observed. Availability of both daily emission values and measured Xe-133 activity concentration values was an opportunity to validate the simulations. Based on the paired t-test, a 95% confidence interval for the true mean difference between simulations without convective transport and measurements was constructed. It was estimated that the overall uncertainty lies between 0.08 and 0.25 mBq/m 3 . The uncertainty for the simulations with the convective transport included is slighted shifted to the lower values and is in the range between 0.06 and 0.20 mBq/m 3 . Copyright © 2017. Published by Elsevier Ltd.
{sup 40}K, {sup 115}Cs and {sup 226}Ra Soil and Plant Content in Seminatural Grasslands of Central Argentina

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ayub, J. Juri; Velasco, R. H.; Rizzotto, M.

2008-08-07

Activity concentrations of {sup 40}K, {sup 226}Ra and {sup 137}Cs have been analyzed in soil and plant samples, collected in permanent grassland in central Argentina. Two near areas (A1 and A2) under field conditions with soil undisturbed at least in the last four decades were selected. For each of the three studied radionuclides we do not find differences in the inventories between both areas. The inventories range from 143 kBq m{sup -2} to 197 kBq m{sup -2} for {sup 40}K and from 13 kBq m{sup -2} to 18 kBq m{sup -2} for {sup 226}Ra. The vertical distributions of {sup 40}Kmore » and {sup 226}Ra are uniform through de soil profile. For {sup 137}Cs the inventories range from 0.33 kBq m{sup -2} to 0.73 kBq m{sup -2}. In spite of {sup 137}Cs inventories are similar in both areas the distribution through vertical profile is different. {sup 137}Cs activity concentration has a maximum for layers 5-10 cm depth in A1 and 10-15 cm depth in A2. For deeper layers both areas show similar activity concentrations. The diffusion coefficient (D{sub s}) and convection velocity (v{sub s}) are estimated with a convection-diffusion model. D{sub s} values are in the range reported in the bibliography, while v{sub s} values are one order of magnitude higher. After 40 years most {sup 137}Cs fallout is still in the layer 10-15 cm depth. The great penetration of {sup 137}Cs (25 cm) in these soils may be the result of a high sand and low fine materials content. {sup 137}Cs and {sup 226}Ra were not detected in grass samples. Activity concentration of {sup 40}K in vegetal samples ranges from 116 Bq kg{sup -1} to 613 Bq kg{sup -1}. The TF values obtained for {sup 40}K show a lognormal distribution and ranges from 0.05 to 0.42.« less
Time and size resolved Measurement of Mass Concentration at an Urban Site

NASA Astrophysics Data System (ADS)

Karg, E.; Ferron, G. A.; Heyder, J.

2003-04-01

Time- and size-resolved measurements of ambient particles are necessary for modelling of atmospheric particle transport, the interpretation of particulate pollution events and the estimation of particle deposition in the human lungs. In the size range 0.01 - 2 µm time- and size-resolved data are obtained from differential mobility and optical particle counter measurements and from gravimetric filter analyses on a daily basis (PM2.5). By comparison of the time averaged and size integrated particle volume concentration with PM2.5 data, an average density of ambient particles can be estimated. Using this density, the number concentration data can be converted in time- and size-resolved mass concentration. Such measurements were carried out at a Munich downtown crossroads. The spectra were integrated in the size ranges 10 - 100 nm, 100 - 500 nm and 500 - 2000 nm. Particles in these ranges are named ultrafine, fine and coarse particles. These ranges roughly represent freshly emitted particles, aged/accumulated particles and particles entrained by erosive processes. An average number concentration of 80000 1/cm3 (s.d. 67%), a particle volume concentration of 53 µm3/cm3 (s.d. 76%) and a PM2.5 mass concentration of 27 µg/m3 was found. These particle volume- and PM2.5 data imply an average density of 0.51 g/cm3. Average number concentration showed 95.3%, 4.7% and 0.006% of the total particle concentration in the size ranges mentioned above. Mass concentration was 14.7%, 80.2% and 5.1% of the total, assuming the average density to be valid for all particles. The variability in mass concentration was 94%, 75% and 33% for the three size ranges. Nearly all ambient particles were in the ultrafine size range, whereas most of the mass concentration was in the fine size range. However, a considerable mass fraction of nearly 15% was found in the ultrafine size range. As the sampling site was close to the road and traffic emissions were the major source of the particles, 1) the density was very low due to agglomerated and porous structures of freshly emitted combustion particles and 2) the variability was highest in the ultrafine range, obviously correlated to traffic activity and lowest in the micron size range. In conclusion, almost all ambient particles were ultrafine particles, whereas most of the particle mass was associated with fine particles. Nevertheless, a considerable mass fraction was found in the ultrafine size range. These particles had a very low density so that they can be considered as agglomerated and porous particles emitted from vehicles passing the crossroads. Therefore they showed a much higher variation in mass concentration than the fine and coarse particles.
The role of counterions in the membrane-disruptive properties of pH-sensitive lysine-based surfactants.

PubMed

Nogueira, D R; Mitjans, M; Infante, M R; Vinardell, M P

2011-07-01

Surfactants are among the most versatile and widely used excipients in pharmaceuticals. This versatility, together with their pH-responsive membrane-disruptive activity and low toxicity, could also enable their potential application in drug delivery systems. Five anionic lysine-based surfactants which differ in the nature of their counterion were studied. Their capacity to disrupt the cell membrane was examined under a range of pH values, concentrations and incubation times, using a standard hemolysis assay as a model for endosomal membranes. The surfactants showed pH-sensitive hemolytic activity and improved kinetics at the endosomal pH range. Low concentrations resulted in negligible hemolysis at physiological pH and high membrane lytic activity at pH 5.4, which is in the range characteristic of late endosomes. With increasing concentration, the surfactants showed an enhanced capacity to lyse cell membranes, and also caused significant membrane disruption at physiological pH. This observation indicates that, at high concentrations, surfactant behavior is independent of pH. The mechanism of surfactant-mediated membrane destabilization was addressed, and scanning electron microscopy studies were also performed to evaluate the effects of the compounds on erythrocyte morphology as a function of pH. The in vitro cytotoxicity of the surfactants was assessed by MTT and NRU assays with the 3T3 cell line. The influence of different types of counterion on hemolytic activity and the potential applications of these surfactants in drug delivery are discussed. The possibility of using pH-sensitive surfactants for endosome disruption could hold great promise for intracellular drug delivery systems in future therapeutic applications. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Quality control of the paracetamol drug by chemometrics and imaging spectroscopy in the near infrared region

NASA Astrophysics Data System (ADS)

Baptistao, Mariana; Rocha, Werickson Fortunato de Carvalho; Poppi, Ronei Jesus

2011-09-01

In this work, it was used imaging spectroscopy and chemometric tools for the development and analysis of paracetamol and excipients in pharmaceutical formulations. It was also built concentration maps to study the distribution of the drug in the tablets surface. Multivariate models based on PLS regression were developed for paracetamol and excipients concentrations prediction. For the construction of the models it was used 31 samples in the tablet form containing the active principle in a concentration range of 30.0-90.0% (w/w) and errors below to 5% were obtained for validation samples. Finally, the study of the distribution in the drug was performed through the distribution maps of concentration of active principle and excipients. The analysis of maps showed the complementarity between the active principle and excipients in the tablets. The region with a high concentration of a constituent must have, necessarily, absence or low concentration of the other one. Thus, an alternative method for the paracetamol drug quality monitoring is presented.
Determination of natural radioactivity by gross alpha and beta measurements in ground water samples.

PubMed

Turhan, S; Ozçitak, E; Taşkin, H; Varinlioğlu, A

2013-06-01

In this study, the activity concentrations of the gross α and β in ground water samples collected from the different drilled wells in Nevşehir province were measured to assess annual effective dose due to the ingestion of the water samples. Nevşehir province is one of the major cities of Cappadocia Region which is a popular tourist destination as it has many areas with unique geological, historic, and cultural features. Sampling and measurements were carried out in the autumn of 2011 and the spring of 2012. The values of the activity concentrations of the gross α and β measured in the water samples ranged from 80 to 380 mBq L(-1) with a mean of 192 mBq L(-1) and 120-3470 mBq L(-1) with a mean of 579 mBq L(-1) respectively. All values of the gross α were lower than the limit value of 500 mBq L(-1) while two ground water samples were found to have gross β activity concentrations of greater than 1000 mBq L(-1). Therefore two water samples were the subject of further radioisotope-specific analysis. The obtained result indicated that the elevated activity concentrations of the gross β in these water samples are dominated by (40)K activity. Annual effective doses ranged from 0.04 to 0.20 mSv y(-1). Copyright © 2013 Elsevier Ltd. All rights reserved.
Distribution of artificial gamma-ray emitting radionuclide activity concentration in the top soil in the vicinity of the Ignalina Nuclear Power Plant and other regions in Lithuania.

PubMed

Lukšienė, Benedikta; Marčiulionienė, Danutė; Rožkov, Andrej; Gudelis, Arūnas; Holm, Elis; Galvonaitė, Audronė

2012-11-15

The impact of the operating Ignalina Nuclear Power Plant (INPP) on the contamination of top soil layer with artificial radionuclides has been studied. Results of the investigation of artificial gamma-ray emitting radionuclide distribution in soil in the vicinity of the INPP and distant regions in Lithuania in 1996-2008 (INPP operational period) show that nowadays (137)Cs remains the most important artificial gamma-ray emitting radionuclide in the upper soil layer. Mean (137)Cs activity concentrations in the top soil layer in the vicinity of the INPP were found to be significantly lower compared to those in remote regions of Varėna and Plungė (~300 km from INPP). In 1996 and 1998 mean (137)Cs activity concentrations were in the range of 28-45 Bq/kg in the nearest vicinity to the INPP, 103 Bq/kg in Varėna and 340 Bq/kg in Plungė region. (137)Cs activity concentrations were 5-20 times lower in meadow soil (4-14 Bq/kg) compared to swamp and forest soil. (60)Co, the INPP origin radionuclide, was detected in samples only in 1996 and 2000, and the activity concentration of (60)Co was found to be in the range from 0.4 to 7.0 Bq/kg at the sampling ground nearest to the INPP. Average annual activity concentrations of the INPP origin (137)Cs and (60)Co in the air and depositions in the INPP region were modeled using Pasquill-Gifford equations. The modeling results of (137)Cs and (60)Co depositional load in the INPP vicinity agree with the experimentally obtained values. Our results provide the evidence that the operation of INPP did not cause any significant contamination in soil surface. Copyright © 2012 Elsevier B.V. All rights reserved.
Natural and anthropogenic radioactivity levels and the associated radiation hazard in the soil of Oodalia Tea Estate in the hilly region of Fatickchari in Chittagong, Bangladesh

PubMed Central

Absar, Nurul; Rahman, M. Mashiur; Kamal, Masud; Siddique, Naziba; Chowdhury, Mantazul Islam

2014-01-01

Radioactivity in the soil of a tea garden in the Fatickchari area in Chittagong, Bangladesh, was measured using a high-resolution HPGe detector. The soil samples were collected from depths of up to 20 cm beneath the soil surface. The activity concentrations of naturally occurring 238U and 232Th were observed to be in the range of 27 ± 7 to 53 ± 8 Bq kg−1 and 36 ± 11 to 72 ± 11 Bq kg−1, respectively. The activity concentration of 40K ranged from 201 ± 78 to 672 ± 81 Bq kg−1, and the highest activity of fallout 137Cs observed was 10 ± 1 Bq kg−1. The average activity concentration observed for 238U was 39 ± 8 Bq kg−1, for 232Th was 57 ± 11 Bq kg−1, for 40K was 384 ± 79 Bq kg−1 and for 137Cs was 5 ± 0.5 Bq kg−1. The radiological hazard parameters (representative level index, radium equivalent activity, outdoor and indoor dose rates, outdoor and indoor annual effective dose equivalents, and radiation hazard index) were calculated from the radioactivity in the soil. PMID:25078001
Multi-wavelength dye concentration determination for enzymatic assays: evaluation of chromogenic para-nitrophenol over a wide pH range.

PubMed

Max, Jean-Joseph; Meddeb-Mouelhi, Fatma; Beauregard, Marc; Chapados, Camille

2012-12-01

Enzymatic assays need robust, rapid colorimetric methods that can follow ongoing reactions. For this, we developed a highly accurate, multi-wavelength detection method that could be used for several systems. Here, it was applied to the detection of para-nitrophenol (pNP) in basic and acidic solutions. First, we confirmed by factor analysis that pNP has two forms, with unique spectral characteristics in the 240 to 600 nm range: Phenol in acidic conditions absorbs in the lower range, whereas phenolate in basic conditions absorbs in the higher range. Thereafter, the method was used for the determination of species concentration. For this, the intensity measurements were made at only two wavelengths with a microtiter plate reader. This yielded total dye concentration, species relative abundance, and solution pH value. The method was applied to an enzymatic assay. For this, a chromogenic substrate that generates pNP after hydrolysis catalyzed by a lipase from the fungus Yarrowia lipolytica was used. Over the pH range of 3-11, accurate amounts of acidic and basic pNP were determined at 340 and 405 nm, respectively. This method surpasses the commonly used single-wavelength assay at 405 nm, which does not detect pNP acidic species, leading to activity underestimations. Moreover, alleviation of this pH-related problem by neutralization is not necessary. On the whole, the method developed is readily applicable to rapid high-throughput of enzymatic activity measurements over a wide pH range.
Natural radioactivity and radon exhalation rates in man-made tiles used as building materials in Japan.

PubMed

Iwaoka, K; Hosoda, M; Suwankot, N; Omori, Y; Ishikawa, T; Yonehara, H; Tokonami, S

2015-11-01

Man-made tiles frequently used in Japan were collected, and activity concentrations and radon ((222)Rn) exhalation rates in these tiles were measured. Dose estimations for inhabitants living in houses built using these tiles were also carried out. The activity concentrations of (226)Ra, (228)Ra and (40)K in the man-made tiles were 31-170, 35-110 and 260-980 Bq kg(-1), respectively. The (222)Rn exhalation rates in the tiles were 8.8-21 μBq m(-2) s(-1). The ranges of experimental activity concentrations and (222)Rn exhalation rates were almost identical to those of natural rocks used as typical building materials in Japan. The maximum value of effective dose to inhabitants living in houses built with the man-made tiles was 0.14 mSv y(-1), which is lower than the reference level range (1-20 mSv y(-1)) for abnormally high levels of natural background radiation published in the ICRP Publication 103. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Area G Perimeter Surface-Soil and Single-Stage Water Sampling: Environmental Surveillance for Fiscal Years 1996 and 1997, Group ESH-19

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marquis Childs; Ron Conrad

1998-10-01

Area Gin Technical Area 54, has been the principal facility at Los Alamos National Laboratory for the storage and disposal of low-level, solid mixed, and transuranic radioactive waste since 1957. Soil samples were analyzed for tritium, isotopic plutonium, americium-241, and cesium-137. Thirteen metals-silver, arsenic, barium, beryllium, cadmium, chromium, mercury, nickel, lead, antimony, selenium, thallium and zinc-were analyzed on filtered-sediment fractions of the single-stage samples using standard analytical chemistry techniques. During the two years of sampling discussed in this report elevated levels of tritium (as high as 716,000 pCi/L) in soil were found for sampling sites adjacent to the tritium burialmore » shafts located on the south- central perimeter of Area G. Additionally, tritium concentrations in soil as high as 38,300 pCi/L were detected adjacent to the TRU pads in the northeast comer of Area G. Plutonium-238 activities in FY96 soils ranged from 0.001-2.866 pCi/g, with an average concentration of 0.336& 0.734 pCdg. Pu-238 activities in FY97 soils ranged from 0.002-4.890 pCi/g, with an average concentration of 0.437 & 0.928 pCdg. Pu-239 activities in FY96 soils ranged from 0.009 to 1.62 pCdg, with an average of 0.177- 0.297 pCdg. Pu-239 activities in FY97 soils ranged from 0.005 to 1.71 pCi/g, with an average of 0.290- 0.415 pCi/g. The locations of elevated plutonium readings were consistent with the history of plutonium disposal at Area G. The two areas of elevated Am-241 activity reflected the elevated activities found for plutonium, the average values for Am-241 on soils were 0.6-2.07 pCi/g, and 0.10-0.14 pCi/g respectively for samples collected in FY96 and FY97. CS-137 activities in soils had average values of 0.33 pCi/g, and 0.28 pCi/g respectively for samples collected in FY96 and 97. There was no perimeter area where soil concentrations of CS-137 were significantly elevated.« less
Distillation Time as Tool for Improved Antimalarial Activity and Differential Oil Composition of Cumin Seed Oil

PubMed Central

Zheljazkov, Valtcho D.; Gawde, Archana; Cantrell, Charles L.; Astatkie, Tess; Schlegel, Vicki

2015-01-01

A steam distillation extraction kinetics experiment was conducted to estimate essential oil yield, composition, antimalarial, and antioxidant capacity of cumin (Cuminum cyminum L.) seed (fruits). Furthermore, regression models were developed to predict essential oil yield and composition for a given duration of the steam distillation time (DT). Ten DT durations were tested in this study: 5, 7.5, 15, 30, 60, 120, 240, 360, 480, and 600 min. Oil yields increased with an increase in the DT. Maximum oil yield (content, 2.3 g/100 seed), was achieved at 480 min; longer DT did not increase oil yields. The concentrations of the major oil constituents α-pinene (0.14–0.5% concentration range), β-pinene (3.7–10.3% range), γ-cymene (5–7.3% range), γ-terpinene (1.8–7.2% range), cumin aldehyde (50–66% range), α-terpinen-7-al (3.8–16% range), and β-terpinen-7-al (12–20% range) varied as a function of the DT. The concentrations of α-pinene, β-pinene, γ-cymene, γ-terpinene in the oil increased with the increase of the duration of the DT; α-pinene was highest in the oil obtained at 600 min DT, β-pinene and γ-terpinene reached maximum concentrations in the oil at 360 min DT; γ-cymene reached a maximum in the oil at 60 min DT, cumin aldehyde was high in the oils obtained at 5–60 min DT, and low in the oils obtained at 240–600 min DT, α-terpinen-7-al reached maximum in the oils obtained at 480 or 600 min DT, whereas β-terpinen-7-al reached a maximum concentration in the oil at 60 min DT. The yield of individual oil constituents (calculated from the oil yields and the concentration of a given compound at a particular DT) increased and reached a maximum at 480 or 600 min DT. The antimalarial activity of the cumin seed oil obtained during the 0–5 and at 5–7.5 min DT timeframes was twice higher than the antimalarial activity of the oils obtained at the other DT. This study opens the possibility for distinct marketing and utilization for these improved oils. The antioxidant capacity of the oil was highest in the oil obtained at 30 min DT and lowest in the oil from 360 min DT. The Michaelis-Menton and the Power nonlinear regression models developed in this study can be utilized to predict essential oil yield and composition of cumin seed at any given duration of DT and may also be useful to compare previous reports on cumin oil yield and composition. DT can be utilized to obtain cumin seed oil with improved antimalarial activity, improved antioxidant capacity, and with various compositions. PMID:26641276
Personal Exposure to Particulate Matter and Endotoxin in California Dairy Workers

NASA Astrophysics Data System (ADS)

Garcia, Johnny

The average number of cows per dairy has increased over the last thirty years, with little known about how this increase may impact occupational exposure. Thirteen California dairies and 226 workers participated in this study throughout the 2008 summer months. Particulate Matter (PM) and endotoxin concentrations were quantified using ambient area based and personal air samplers. Two size fractions were collected, Total Suspended Particulate matter (TSP) and PM 2.5. Differences across dairies were evaluated by placing area based integrated air samplers in established locations on the dairies, e.g. milking parlor, drylot corral, and freestall barns. The workers occupational exposure was quantified using personal air samplers. We analyzed concentrations along with the time workers spent conducting specific job tasks during their shift to identify high exposure job tasks. Biological and chemical analytical methods were employed to ascertain endotoxin concentrations in personal and area based air samples. Recombinant factor C assays (rFC) were used to analyze biologically active endotoxin and gas chromatography coupled with mass spectrometry in tandem (GC-MS/MS) was used to quantify total endotoxin. The PM2.5 concentrations ranged from 2-116 mug/m3 for ambient area concentration and 7-495 mug/m3 for personal concentrations while TSP concentrations ranged from 74-1690 mug/m3 for area ambient concentrations and 191-4950 mug/m3 for personal concentrations. Biologically active endotoxin concentrations in the TSP size fraction from ambient area based samples ranged from 11-2095 EU/m3 and 45-2061 EU/m3 for personal samples. Total endotoxin in the TSP size fraction ranged from 75-10,166 pmol/m3 for area based samples and 34-11,689 pmol/m3 for personal samples. Drylot corrals were found to have higher sample mean concentrations when compared to other locations on the dairies for PM and endotoxin. Re-bedding, of the freestalls, was found to consistently lead to higher personal sample mean concentrations when compared to other tasks performed on dairies for both endotoxin and PM. In mixed effect regression models, regional ambient concentrations of PM 2.5 helped account for variation in PM2.5 concentration outcomes. We found that while upwind and downwind mean concentrations were not significantly different, central mean concentrations were higher than upwind concentration. Variation in TSP levels was largely explained by dairy-level characteristics such as the age of the dairy and number of animals in the drylot corrals and freestall barns. The different locations within the dairy were found to differ in mean concentrations for TSP. Biologically active and total endotoxin concentration variation was explained by meteorological data, wind speed, relative humidity, and dairy waste management practices. Personal exposure levels where found to be higher than area based concentrations for PM and endotoxin. Endotoxin characteristics differed by particle size and location within the dairy. The chain length proportion for endotoxin in the PM 2.5 size fraction was dominated by C12 and C16 in the TSP size fraction.
Determination of natural and artificial radioactivity in soil at North Lebanon province.

PubMed

El Samad, O; Baydoun, R; Nsouli, B; Darwish, T

2013-11-01

The concentrations of natural and artificial radionuclides at 57 sampling locations along the North Province of Lebanon are reported. The samples were collected from uncultivated areas in a region not previously reported. The samples were analyzed by gamma spectrometers with High Purity Germanium detectors of 30% and 40% relative efficiency. The activity concentrations of primordial naturally occurring radionuclides of (238)U, (232)Th, and (40)K varied between 4-73 Bq kg(-1), 5-50 Bq kg(-1), and 57-554 Bq kg(-1) respectively. The surface activity concentrations due to the presence of these radionuclides were calculated and Kriging-geostatistical method was used to plot the obtained data on the Lebanese radioactive map. The results for (238)U, (232)Th, and (40)K ranged from 0.2 kBq m(-2) to 9 kBq m(-2), from 0.2 kBq m(-2) to 3 kBq m(-2), and from 3 kBq m(-2) to 29 kBq m(-2) respectively. For the anthropogenic radionuclides, the activity concentrations of (137)Cs founded in soil ranged from 2 Bq kg(-1) to 113 Bq kg(-1), and the surface activity concentration from 0.1 kBq m(-2) to 5 kBq m(-2). The total absorbed gamma dose rates in air from natural and artificial radionuclides in these locations were calculated. The minimum value was 6 nGy h(-1) and the highest one was 135 nGy h(-1) with an average of 55 nGy h(-1) in which the natural terrestrial radiation contributes in 99% and the artificial radionuclides mainly (137)Cs contributes only in 1%. The total effective dose calculated varied in the range of 7 μSv y(-1) and 166 μSv y(-1) while the average value was 69 μSv y(-1) which is below the permissible limit 1000 μSv y(-1). Copyright © 2013 Elsevier Ltd. All rights reserved.

Propionibacterium acnes Has Low Susceptibility to Chlorhexidine Digluconate.

PubMed

Nakase, Keisuke; Fukushima, Hanae; Yukawa, Tomoko; Nakaminami, Hidemasa; Fujii, Takeshi; Noguchi, Norihisa

2018-04-01

The skin bacterium Propionibacterium acnes has been reported to be responsible for surgical site infections (SSIs). Skin disinfection before surgery therefore is of the utmost importance in the prevention of SSIs caused by skin bacteria. We assessed the susceptibility of clinical isolates of two skin bacteria, P. acnes and Staphylococcus epidermidis, to disinfectants. The range of chlorhexidine digluconate (CHG) minimum inhibitory concentrations (MICs) for P. acnes isolates was 0.25-1 mcg/mL. Furthermore, the minimum bactericidal concentrations (MBCs) for a range of disinfectants were determined to evaluate their rapid bactericidal activity. The MBC range of CHG against the P. acnes isolates was 4,096->32,768 mcg/mL (MBC 80 16,384 mcg/mL) after one minute of exposure and 1,024-32,768 mcg/mL (MBC 80 8,192 mcg/mL) after five minutes, indicating that some strains required a CHG MBC higher than the commercial concentration of 2% (20,000 mcg/mL). In contrast, the MBCs of glutaraldehyde, sodium hypochlorite, povidone-iodine, ethanol, benzalkonium chloride, and olanexidine gluconate were all sufficiently lower than their commercial concentrations. In S. epidermidis, the MBC range of CHG was 128-1,024 mcg/mL at one minute of exposure and 4-8 mcg/mL at five minutes. Different skin bacteria have different susceptibilities to disinfectants. To prevent SSIs, the selected disinfectant agent and the disinfection time should have bactericidal activity toward all the bacteria that pose a risk of infection.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaur, Ramneek; Tripathi, S. K., E-mail: surya@pu.ac.in, E-mail: surya-tr@yahoo.com

This paper reports the synthesis and electrical characterization of CdSe-PMMA nanocomposite. CdSe-PMMA nanocomposite has been prepared by ex-situ technique through chemical route. The influence of three different Ag doping concentrations on the electrical properties has been studied in the temperature range ∼ 303-353 K. Transmission electron micrograph reveals the spherical morphology of the CdSe nanoparticles and their proper dispersion in the PMMA matrix. The electrical conduction of the polymer nanocomposites is through thermally activated process with single activation energy. With Ag doping, initially the activation energy increases upto 0.2 % Ag doping concentration but with further increase in Ag concentration, itmore » decreases. This behavior has been discussed on the basis of randomly oriented grain boundaries and defect states. Thus, the results indicate that the transport properties of the polymer nanocomposites can be tailored by controlled doping concentration.« less
A viscometric approach of pH effect on hydrodynamic properties of human serum albumin in the normal form.

PubMed

Monkos, Karol

2013-03-01

The paper presents the results of viscosity determinations on aqueous solutions of human serum albumin (HSA) at isoelectric point over a wide range of concentrations and at temperatures ranging from 5°C to 45°C. On the basis of a modified Arrhenius equation and Mooney's formula some hydrodynamic parameters were obtained. They are compared with those previously obtained for HSA in solutions at neutral pH. The activation energy and entropy of viscous flow and the intrinsic viscosity reach a maximum value, and the effective specific volume, the self-crowding factor and the Huggins coefficient a minimum value in solutions at isoelectric point. Using the dimensionless parameter [η]c, the existence of three ranges of concentrations: diluted, semi-diluted and concentrated, was shown. By applying Lefebvre's relation for the relative viscosity in the semi-dilute regime, the Mark-Houvink-Kuhn-Sakurada (MHKS) exponent was established. The analysis of the results obtained from the three ranges of concentrations showed that both conformation and stiffness of HSA molecules in solutions at isoelectric point and at neutral pH are the same.
Concentration dependence of molal conductivity and dielectric constant of 1-alcohol electrolytes using the compensated arrhenius formalism.

PubMed

Fleshman, Allison M; Petrowsky, Matt; Frech, Roger

2013-05-02

The molal conductivity of liquid electrolytes with low static dielectric constants (ε(s) < 10) decreases to a minimum at low concentrations (region I) and increases to a maximum at higher concentrations (region II) when plotted against the square root of the concentration. This behavior is investigated by applying the compensated Arrhenius formalism (CAF) to the molal conductivity, Λ, of a family of 1-alcohol electrolytes over a broad concentration range. A scaling procedure is applied that results in an energy of activation (E(a)) and an exponential prefactor (Λ0) that are both concentration dependent. It is shown that the increasing molal conductivity in region II results from the combined effect of (1) a decrease in the energy of activation calculated from the CAF, and (2) an inherent concentration dependence in the exponential prefactor that is partly due to the dielectric constant.
In vitro inflammatory and cytotoxic effects of size-segregated particulate samples collected during long-range transport of wildfire smoke to Helsinki.

PubMed

Jalava, Pasi I; Salonen, Raimo O; Hälinen, Arja I; Penttinen, Piia; Pennanen, Arto S; Sillanpää, Markus; Sandell, Erik; Hillamo, Risto; Hirvonen, Maija-Riitta

2006-09-15

The impact of long-range transport (LRT) episodes of wildfire smoke on the inflammogenic and cytotoxic activity of urban air particles was investigated in the mouse RAW 264.7 macrophages. The particles were sampled in four size ranges using a modified Harvard high-volume cascade impactor, and the samples were chemically characterized for identification of different emission sources. The particulate mass concentration in the accumulation size range (PM(1-0.2)) was highly increased during two LRT episodes, but the contents of total and genotoxic polycyclic aromatic hydrocarbons (PAH) in collected particulate samples were only 10-25% of those in the seasonal average sample. The ability of coarse (PM(10-2.5)), intermodal size range (PM(2.5-1)), PM(1-0.2) and ultrafine (PM(0.2)) particles to cause cytokine production (TNFalpha, IL-6, MIP-2) reduced along with smaller particle size, but the size range had a much smaller impact on induced nitric oxide (NO) production and cytotoxicity or apoptosis. The aerosol particles collected during LRT episodes had a substantially lower activity in cytokine production than the corresponding particles of the seasonal average period, which is suggested to be due to chemical transformation of the organic fraction during aging. However, the episode events were associated with enhanced inflammogenic and cytotoxic activities per inhaled cubic meter of air due to the greatly increased particulate mass concentration in the accumulation size range, which may have public health implications.
Hemostatic variables, plasma lactate concentration, and inflammatory biomarkers in dogs with gastric dilatation-volvulus.

PubMed

Verschoof, J; Moritz, A; Kramer, M; Bauer, N

2015-01-01

Prospective characterization of hemostastatic variables, plasma lactate concentration, and inflammatory biomarkers in dogs with gastric dilatation-volvulus (GDV). Coagulation variables (platelets, prothrombin time [PT], activated partial thromboplastin time [aPTT], fibrinogen, antithrombin [AT], protein C [PC], protein S [PS], D-dimers), plasma lactate concentration and inflammatory biomarkers (C-reactive protein, white blood cell [WBC] count, lymphocyte and neutrophil numbers) were assessed in 20 dogs with GDV presented between 2011 and 2012. Blood was taken preoperatively and at days 1 and 3 postoperatively. The prognostic value of these variables before and after surgery was evaluated as well as the behavior of variables during the study. Overall, 7/20 (35%) dogs did not survive; two dogs (29%) were euthanized during surgery due to severe gastric necrosis and 5 (71%) dogs after surgery due to sepsis and disseminated intravascular coagulopathy. Prior to surgery, median plasma lactate concentration was significantly (p = 0.01) lower in survivors (6.2 mmol/l, range 1.9-9.7 mmol/l) when compared to non-survivors (11.8 mmol/l, range 7.5-16.2 mmol/l). In dogs dying after surgery, significantly higher plasma lactate concentration, coagulation times and D-dimer concentration were present as well as lower fibrinogen concentration and activity of PC and AT compared to survivors. At discharge, activity of AT, PC and PS were markedly below the reference interval in 6/13 (46%), 11/13 (85%), and 8/13 (62%) dogs, respectively. Only lactate plasma concentration was of preoperative prognostic value. After surgery, severe abnormalities of coagulation variables, especially the endogenous anticoagulants were present in most of the dogs. The severity of the abnormalities was associated with survival.
The catalytic removal of ammonia and nitrogen oxides from spacecabin atmospheres

NASA Technical Reports Server (NTRS)

Gully, A. J.; Graham, R. R.; Halligan, J. E.; Bentsen, P. C.

1973-01-01

Investigations were made on methods for the removal of ammonia and to a lesser extent nitrogen oxides in low concentrations from air. The catalytic oxidation of ammonia was studied over a temperature range of 250 F to 600 F and a concentration range 20 ppm to 500 ppm. Of the catalysts studied, 0.5 percent ruthenium supported on alumina was found to be superior. This material is active at temperatures as low as 250 F and was found to produce much less nitrous oxide than the other two active catalysts, platinum on alumina and Hopcalite. A quantitative design model was developed which will permit the performance of an oxidizer to be calculated. The ruthenium was found to be relatively insensitive to low concentrations of water and to oxygen concentration between 21 percent and 100 percent. Hydrogen sulfide was found to be a poison when injected in relatively large quantities. The adsorption of ammonia by copper sulfate treated silica gel was investigated at temperatures of 72 F and 100 F. A quantitative model was developed for predicting adsorption bed behavior.
Two combined mechanisms responsible to hexavalent chromium removal on active anaerobic granular consortium.

PubMed

Durán, U; Coronado-Apodaca, K G; Meza-Escalante, E R; Ulloa-Mercado, G; Serrano, D

2018-05-01

Hexavalent chromium (Cr VI) from industrial wastewaters represents a highly toxic source at low concentrations. Biological treatments with anaerobic granular biomass are a promising alternative for the Cr VI bioremediation. This study evaluated the Cr VI removal in a range of 5-500 mg/L, using an active anaerobic granular consortium. Two removal mechanisms were differentiated from the assays: 1) biological reduction of 70 mg/L to Cr III at a concentration of 250 mg Cr VI/L and 2) physical bioadsorption of 297 mg of Cr VI/L or 31.39 mg of Cr VI/g biomass at concentration of 500 mg Cr VI /L. The half-maximal inhibitory concentration (IC 50 ) values for the rate and production of methane were 1.4 and 253 mg/L, respectively. In addition, Cr VI is a biostimulant that increase the methane production, in a range from 5 to 100 mg/L, of the anaerobic consortium. This work demonstrates the potential application of the anaerobic granular consortium in metal bioremediation. Copyright © 2018 Elsevier Ltd. All rights reserved.
Blood concentrations of clobazam and norclobazam in a lethal case involving clobazam, meprobamate and clorazepate.

PubMed

Pok, Phak-Rop Pos; Mauras, Michel; De Saint Léger, Marie-Noëlle; Kuhlmann, Erika; Charpenel-Durat, Catherine; Navarette, Claudie; Duval, Marie-Laure; De Meo, Pierre

2010-11-01

Clobazam is a benzodiazepine with anti-anxiety and anticonvulsant properties marketed in several countries. Norclobazam, a metabolite of clobazam, has similar pharmacological activity but weaker sedative and tranquilizing effect. The two drugs were detected by GC-MS and determined by HPLC-DAD in the samples from a postmortem case. The femoral blood concentrations of clobazam and norclobazam were 0.72 and 36 μg/mL, respectively. The concentration of the active norclobazam was very high. The sum of both clobazam and norclobazam blood concentration (36.72 μg/mL) was clearly toxic, but was not necessarily fatal. Other associated drugs concentrations were within their therapeutic ranges. Interactions due to drug association were discussed. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.
α-Chymotrypsin in water-ethanol mixtures: Effect of preferential interactions

NASA Astrophysics Data System (ADS)

Sirotkin, Vladimir A.; Kuchierskaya, Alexandra A.

2017-12-01

We investigated preferential interactions of α-chymotrypsin with water-ethanol mixtures at 25 °C. Our approach is based on the analysis of residual enzyme activity and water/alcohol sorption. There are three concentration regimes. α-Chymotrypsin is preferentially hydrated at high water content. The residual enzyme activity is close to 100%. α-Chymotrypsin has a higher affinity for alcohol than for water at intermediate water content. Residual enzyme activity is close to zero in this concentration range. At low water content, ethanol is preferentially excluded from the protein surface. This results in preferential hydration of α-chymotrypsin and significant residual catalytic activity (∼50%) in water-poor ethanol.
Desorption of CO{sub 2} from MDEA and activated MDEA solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, G.W.; Zhang, C.F.; Qin, S.J.

1995-03-01

A packed column was used for investigating the desorption rate of CO{sub 2} from aqueous methyldiethanolamine (MDEA) and activated MDEA solutions. Experiments were conducted within the temperature range 30--70 C, the concentration of MDEA was 4.28 kmol/m{sup 3}, and the concentration of piperazine (PZ) was 0.10 kmol/m{sup 3} for aqueous activated MDEA solutions. Experimental data confirmed that the kinetics model of absorption CO{sub 2} into aqueous MDEA and activated MDEA solutions can be applicable to the situations in which desorption occurs, and the desorption rate of model predictions agree well with that of experimental determination.
Toxicological effects of the herbicide oxyfluorfen on acetylcholinesterase in two fish species: Oreochromis niloticus and Gambusia affinis.

PubMed

Hassanein, Hamdy M A

2002-01-01

The alterations of the AChE activity in the brains of two fresh water fishes; Oreochromis niloticus and Gambusia affinis were measured after exposure to acute, sub-acute and chronic concentrations from the widely used herbicide; oxyfluorfen. Bioassays were conducted under controlled laboratory conditions. The used concentrations were acute: LC50 for 6 days, sub-acute 1/3 LC50 for 15 days and chronic 1/10 LC50 for 30 days. The obtained results showed marked inhibitory effects of the herbicide on the activity of AChE in both fishes. However, these effects were more pronounced in O. niloticus where the decline in the enzyme activity ranged from 19.7 to 81.28% while in case of G. affinis it ranged from 5.7 to 36.7%. These findings demonstrate that G. affinis is most tolerant to oxyfluorfen toxicity compared with O. niloticus.
Oxidation kinetics of model compounds of metabolic waste in supercritical water

NASA Technical Reports Server (NTRS)

Webley, Paul A.; Holgate, Henry R.; Stevenson, David M.; Tester, Jefferson W.

1990-01-01

In this NASA-funded study, the oxidation kinetics of methanol and ammonia in supercritical water have been experimentally determined in an isothermal plug flow reactor. Theoretical studies have also been carried out to characterize key reaction pathways. Methanol oxidation rates were found to be proportional to the first power of methanol concentration and independent of oxygen concentration and were highly activated with an activation energy of approximately 98 kcal/mole over the temperature range 480 to 540 C at 246 bar. The oxidation of ammonia was found to be catalytic with an activation energy of 38 kcal/mole over temperatures ranging from 640 to 700 C. An elementary reaction model for methanol oxidation was applied after correction for the effect of high pressure on the rate constants. The conversion of methanol predicted by the model was in good agreement with experimental data.
Effects of long-term oral administration of levothyroxine sodium on serum thyroid hormone concentrations, clinicopathologic variables, and echocardiographic measurements in healthy adult horses.

PubMed

Frank, Nicholas; Buchanan, Benjamin R; Elliott, Sarah B

2008-01-01

To determine the effects of long-term oral levothyroxine sodium (L-T(4)) administration on serum thyroid hormone concentrations, thyroid gland function, clinicopathologic variables, and echocardiographic examination measurements in adult euthyroid horses. 6 healthy adult mares. Horses received L-T(4) (48 mg/d) orally for 48 weeks. Every 4 weeks, physical examinations were performed; blood samples were collected for CBC, plasma biochemical analyses, and assessments of serum total triiodothyronine (tT(3)) and thyroxine (tT(4)) concentrations. Plasma creatine kinase MB activity and cardiac troponin I concentration were also measured. Echocardiographic examinations were performed before and at 16, 32, and 48 weeks during the treatment period. During the treatment period, mean body weight decreased significantly; heart rate varied significantly, but the pattern of variation was not consistent. Significant time effects were detected for certain clinicopathologic variables, but mean values remained within reference ranges. Cardiac troponin I was only detectable in 8 of 24 plasma samples (concentration range, 0.01 to 0.03 ng/mL). Serum creatine kinase MB activity did not change significantly over time. Compared with the pretreatment value, 5.4-, 4.0-, and 3.7-fold increases in mean serum tT(4) concentrations were detected at 16, 32, and 48 weeks, respectively. Some cardiac measurements changed significantly over time, but mean values remained within published reference ranges. Mean fractional shortening was lower than the pretreatment mean value at 16 and 32 weeks. In horses, long-term oral administration of 48 mg of L-T(4)/d significantly increased serum tT(4) concentrations and did not appear to adversely affect health.
Calcium promotes activity and confers heat stability on plant peroxidases

PubMed Central

Plieth, Christoph; Vollbehr, Sonja

2012-01-01

In this paper we demonstrate how peroxidase (PO) activities and their heat stability correlate with the availability of free Ca2+ ions. Calcium ions work as a molecular switch for PO activity and exert a protective function, rendering POs heat stable. The concentration ranges of these two activities differ markedly. POs are activated by µM Ca2+ concentration ranges, whereas heat stabilization is observed in the nM range. This suggests the existence of different Ca2+ binding sites. The heat stability of POs depends on the source plant species. Terrestrial plants have POs that exhibit higher temperature stability than those POs from limnic and marine plants. Different POs from a single species can differ in terms of heat stability. The abundance of different POs within a plant is dependent on age and developmental stage. The heat stability of a PO does not necessarily correlate with the maximum temperature the source species is usually exposed to in its natural habitat. This raises questions on the role of POs in the heat tolerance of plants. Consequently, detailed investigations are needed to identify and characterize individual POs, with regard to their genetic origin, subcellular expression, tissue abundance, developmental emergence and their functions in innate and acquired heat tolerance. PMID:22580695
Biopharmaceutical evaluation of surface active ophthalmic excipients using in vitro and ex vivo corneal models.

PubMed

Juretić, Marina; Cetina-Čižmek, Biserka; Filipović-Grčić, Jelena; Hafner, Anita; Lovrić, Jasmina; Pepić, Ivan

2018-07-30

The objective of this study was to systematically investigate the effects of surface active ophthalmic excipients on the corneal permeation of ophthalmic drugs using in vitro (HCE-T cell-based model) and ex vivo (freshly excised porcine cornea) models. The permeation of four ophthalmic drugs (i.e., timolol maleate, chloramphenicol, diclofenac sodium and dexamethasone) across in vitro and ex vivo corneal models was evaluated in the absence and presence of four commonly used surface active ophthalmic excipients (i.e., Polysorbate 80, Tyloxapol, Cremophor® EL and Pluronic® F68). The concentration and self-aggregation-dependent effects of surface active ophthalmic excipients on ophthalmic drug permeability were studied from the concentration region where only dissolved monomer molecules of surface active ophthalmic excipients exist, as well as the concentration region in which aggregates of variable size and dispersion are spontaneously formed. Neither the surface active ophthalmic excipients nor the ophthalmic drugs at all concentrations that were tested significantly affected the barrier properties of both corneal models, as assessed by transepithelial electrical resistance (TEER) monitoring during the permeability experiments. The lowest concentration of all investigated surface active ophthalmic excipients did not significantly affect the ophthalmic drug permeability across both of the corneal models that were used. For three ophthalmic drugs (i.e., chloramphenicol, diclofenac sodium and dexamethasone), depressed in vitro and ex vivo permeability were observed in the concentration range of either Polysorbate 80, Tyloxapol, Cremophor® EL or Pluronic® F68, at which self-aggregation is detected. The effect was the most pronounced for Cremophor® EL (1 and 2%, w/V) and was the least pronounced for Pluronic® F68 (1%, w/V). However, all surface active ophthalmic excipients over the entire concentration range that was tested did not significantly affect the in vitro and ex vivo permeability of timolol maleate, which is the most hydrophilic ophthalmic drug that was investigated. The results of the dynamic light scattering measurements point to the association of ophthalmic drugs with self-aggregates of surface active ophthalmic excipients as the potential mechanism of the observed permeability-depressing effect of surface active ophthalmic excipients. A strong and statistically significant correlation was observed between in vitro and ex vivo permeability of ophthalmic drugs in the presence of surface active ophthalmic excipients, which indicates that the observed permeability-altering effects of surface active ophthalmic excipients were comparable and were mediated by the same mechanism in both corneal models. Copyright © 2018 Elsevier B.V. All rights reserved.
Assessment of natural and artificial radioactivity levels and radiation hazards and their relation to heavy metals in the industrial area of Port Said city, Egypt.

PubMed

Attia, T E; Shendi, E H; Shehata, M A

2015-02-01

A detailed gamma ray spectrometry survey was carried out to make an action in environmental impact assessment of urbanization and industrialization on Port Said city, Egypt. The concentrations of the measured radioelements U-238, Th-232 in ppm, and K-40 %, in addition to the total counts of three selected randomly dumping sites (A, B, and C) were mapped. The concentration maps represent a base line for the radioactivity in the study area in order to detect any future radioactive contamination. These concentrations are ranging between 0.2 and 21 ppm for U-238 and 0.01 to 13.4 ppm for Th-232 as well as 0.15 to 3.8 % for K-40, whereas the total count values range from 8.7 to 123.6 uR. Moreover, the dose rate was mapped using the same spectrometer and survey parameters in order to assess the radiological effect of these radioelements. The dose rate values range from 0.12 to 1.61 mSv/year. Eighteen soil samples were collected from the sites with high radioelement concentrations and dose rates to determine the activity concentrations of Ra-226, Th-232, and K-40 using HPGe spectrometer. The activity concentrations of Ra-226, Th-232, and K-40 in the measured samples range from 18.03 to 398.66 Bq kg(-1), 5.28 to 75.7 Bq kg(-1), and 3,237.88 to 583.12 Bq kg(-1), respectively. In addition to analyze heavy metal for two high reading samples (a 1 and a 10) which give concentrations of Cd and Zn elements (a 1 40 ppm and a 10 42 ppm) and (a 1 0.90 ppm and a 10 0.97 ppm), respectively, that are in the range of phosphate fertilizer products that suggested a dumped man-made waste in site A. All indicate that the measured values for the soil samples in the two sites of three falls within the world ranges of soil in areas with normal levels of radioactivity, while site A shows a potential radiological risk for human beings, and it is important to carry out dose assessment program with a specifically detailed monitoring program periodically.
Norcocaine and cocaethylene distribution patterns in hair samples from light, moderate, and heavy cocaine users

PubMed Central

Rossi, Riccardo; Aroni, Kyriaki; Gili, Alessio; Bacci, Mauro; Pascali, Vincenzo; Fucci, Nadia

2015-01-01

Even though hair analysis often seems to be the best choice for retrospective monitoring of cocaine intake, differentiating between incorporated cocaine and external contamination is widely debated. In this study we report results obtained in 90 hair samples from addicts. All samples were analyzed for cocaine, benzoylecgonine, norcocaine, cocaethylene, and tropococaine by gas chromatography‐mass spectrometry (GC‐MS) techniques coupled with direct immersion solid‐phase micro‐extraction. Cocaine concentrations were stratified into three classes of usage: light (0.5–3 ng/mg), moderate (3.1–10 ng/mg) and heavy (10.1–40 ng/mg). The Substance Abuse and Mental Health Services Administration cut‐off criteria for establishing active cocaine use were applied to the results. For all samples criteria were cocaine levels above 0.5 ng/mg (ranging from 1.63 to 39.29 ng/mg, mean 9.49 ng/mg), benzoylecgonine concentrations ≥ 0.05 ng/mg (ranging from 0.19 to 5.77 ng/mg, mean 1.40), and benzoylecgonine to cocaine % ratio ≥5% (from 6.43 to 26.09%). Norcocaine was present in 58.9% of samples (concentration range: 0.22–3.14 ng/mg) and was strongly predictive only of heavy cocaine use (sensitivity 100% for cocaine concentrations above 9.58 ng/mg). Twenty hair samples from moderate and heavy users tested positive for cocaethylene (concentration range: 0.22–1.98 ng/mg, mean 0.73 ng/mg). This study on hair samples with no chance of false positive cases highlights the very limited applications of testing minor cocaine metabolites for definitive proof of active cocaine consumption. © 2015 The Authors. Drug Testing and Analysis Published by John Wiley & Sons, Ltd. PMID:26621770
Norcocaine and cocaethylene distribution patterns in hair samples from light, moderate, and heavy cocaine users.

PubMed

Gambelunghe, Cristiana; Rossi, Riccardo; Aroni, Kyriaki; Gili, Alessio; Bacci, Mauro; Pascali, Vincenzo; Fucci, Nadia

2017-02-01

Even though hair analysis often seems to be the best choice for retrospective monitoring of cocaine intake, differentiating between incorporated cocaine and external contamination is widely debated. In this study we report results obtained in 90 hair samples from addicts. All samples were analyzed for cocaine, benzoylecgonine, norcocaine, cocaethylene, and tropococaine by gas chromatography-mass spectrometry (GC-MS) techniques coupled with direct immersion solid-phase micro-extraction. Cocaine concentrations were stratified into three classes of usage: light (0.5-3 ng/mg), moderate (3.1-10 ng/mg) and heavy (10.1-40 ng/mg). The Substance Abuse and Mental Health Services Administration cut-off criteria for establishing active cocaine use were applied to the results. For all samples criteria were cocaine levels above 0.5 ng/mg (ranging from 1.63 to 39.29 ng/mg, mean 9.49 ng/mg), benzoylecgonine concentrations ≥ 0.05 ng/mg (ranging from 0.19 to 5.77 ng/mg, mean 1.40), and benzoylecgonine to cocaine % ratio ≥5% (from 6.43 to 26.09%). Norcocaine was present in 58.9% of samples (concentration range: 0.22-3.14 ng/mg) and was strongly predictive only of heavy cocaine use (sensitivity 100% for cocaine concentrations above 9.58 ng/mg). Twenty hair samples from moderate and heavy users tested positive for cocaethylene (concentration range: 0.22-1.98 ng/mg, mean 0.73 ng/mg). This study on hair samples with no chance of false positive cases highlights the very limited applications of testing minor cocaine metabolites for definitive proof of active cocaine consumption. © 2015 The Authors. Drug Testing and Analysis Published by John Wiley & Sons, Ltd. © 2015 The Authors. Drug Testing and Analysis Published by John Wiley & Sons, Ltd.
Influence of lorcainide on microsomal Na+, K(+)-ATPase in guinea-pig isolated heart preparations.

PubMed Central

Almotrefi, A. A.; Dzimiri, N.

1991-01-01

1. The effects of lorcainide on the myocardial Mg2(+)-dependent, Na+ and K(+)-activated adenosine triphosphatase (Na+, K(+)-ATPase) were compared in guinea-pig heart preparations with those of ouabain, a specific inhibitor of the enzyme activity. 2. Both ouabain and lorcainide inhibited the microsomal Na+, K(+)-ATPase activity in a concentration-dependent fashion. Their inhibitory effective ranges were 0.05-100 microM and 0.15-125 microM, respectively, and the concentrations for half maximal inhibition (IC50 values) were 2.1 +/- 0.3 and 33.5 +/- 7.3 microM, respectively. 3. In a second series of experiments, the combined effects of the two drugs on the enzyme activity were studied. In these experiments, lorcainide produced a concentration-dependent potentiation of the inhibitory effects of ouabain on Na+, K(+)-ATPase activity. 4. The present study demonstrates that lorcainide is a potent inhibitor of myocardial Na+, K(+)-ATPase. PMID:1849773

Chemical composition and in vitro antimicrobial activity of the essential oil of the flowers of Tridax procumbens.

PubMed

Joshi, Rajesh K; Badakar, Vijaylaxmi

2012-07-01

The essential oil of the flowers of Tridax procumbens L. was obtained by hydro-distillation and analyzed by gas chromatography equipped with a flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS). Twenty-six compounds were identified, which comprised 90.6% of the total constituents. The most abundant compound was (Z)-falcarinol (25.9%), followed by alpha-selinene (15.3%), limonene (8.3%) and zerumbone (4.3%). Antimicrobial activity was tested against six Gram-positive and eight Gram-negative bacteria, and three fungi. The oil was active against the tested Gram-positive bacteria at a concentration range of 0.14 +/- 0.03 - 0.57 +/- 0.05 mg/mL, while 0.67 +/- 0.12 - 4.58 +/- 0.41 mg/mL was effective against the studied Gram-negative bacteria. Remarkable antifungal activity was found against the tested fungi at a concentration range of 0.06 +/- 0.008 - 0.10 +/- 0.01 mg/mL.
Picomolar-affinity binding and inhibition of adenylate cyclase activity by melatonin in Syrian hamster hypothalamus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Niles, L.P.; Hashemi, F.

1. The effect of melatonin on forskolin-stimulated adenylate cyclase activity was measured in homogenates of Syrian hamster hypothalamus. In addition, the saturation binding characteristics of the melatonin receptor ligand, ({sup 125}I)iodomelatonin, was examined using an incubation temperature (30{degree}C) similar to that used in enzyme assays. 2. At concentrations ranging from 10 pM to 1 nM, melatonin caused a significant decrease in stimulated adenylate cyclase activity with a maximum inhibition of approximately 22%. 3. Binding experiments utilizing ({sup 125}I)iodomelatonin in a range of approximately 5-80 pM indicated a single class of high-affinity sites: Kd = 55 +/- 9 pM, Bmax =more » 1.1 +/- 0.3 fmol/mg protein. 4. The ability of picomolar concentrations of melatonin to inhibit forskolin-stimulated adenylate cyclase activity suggests that this affect is mediated by picomolar-affinity receptor binding sites for this hormone in the hypothalamus.« less
Maternal serum soluble CD30 is increased in pregnancies complicated with acute Pyelonephritis

PubMed Central

Kusanovic, Juan Pedro; Romero, Roberto; Espinoza, Jimmy; Gotsch, Francesca; Edwin, Samuel; Chaiworapongsa, Tinnakorn; Mittal, Pooja; Soto, Eleazar; Erez, Offer; Mazaki-Tovi, Shali; Than, Nandor Gabor; Friel, Lara; Yoon, Bo Hyun; Mazor, Moshe; Hassan, Sonia

2007-01-01

Objectives Normal pregnancy is characterized by activation of the innate immunity and suppression of the adaptive limb of the immune response. However, pregnant women are more susceptible to the effects of infection and microbial products than non-pregnant women. CD30 is a member of the tumor necrosis factor receptor superfamily and is preferentially expressed by activated T cells producing Th2-type cytokines. Its soluble form (sCD30) is proposed to be an index of Th2 immune response. High serum concentrations of sCD30 have been found in the acute phase of viral infections, such as HIV-1 and hepatitis B. There is, however, conflicting evidence about serum sCD30 concentration in patients with bacterial infections. The objective of this study was to determine whether there are changes in the serum concentration of sCD30 in pregnant women with pyelonephritis. Methods This cross-sectional study included normal pregnant women (N=89) and pregnant women with pyelonephritis (N=41). Maternal serum concentration of sCD30 was measured by a specific and sensitive enzyme-linked immunoassay. Non-parametric tests were used for comparisons. A p value <0.05 was considered statistically significant. Results (1) Pregnant women with pyelonephritis had a significantly higher median serum concentration of sCD30 than those with a normal pregnancy (median: 44.3 U/ml, range: 16–352.5 vs. median: 29.7 U/ml, range: 12.2–313.2, respectively; p<0.001); and (2) No significant differences were found in the median maternal serum concentration of sCD30 between pregnant women with pyelonephritis who had a positive blood culture compared to those with a negative blood culture (median:47.7 U/mL, range: 17.1–118.8 vs. median: 42.6 U/mL, range: 16–352.5, respectively; p=0.86). Conclusions Acute pyelonephritis during pregnancy is associated with a higher maternal serum concentration of sCD30 than normal pregnancy. This finding is novel, and suggests that pregnant women with pyelonephritis may have a complex immune state in which there is activation of some components of what is considered a Th2 immune response. PMID:17853184
A rise in the plasma activities of hepatic enzymes is not a common consequence of hypoglycaemia.

PubMed

Jones, R G; Grant, P J; Brown, D; Stickland, M; Wiles, P G

1988-04-01

Eight otherwise healthy insulin-dependent diabetic patients were subjected to controlled, symptomatic hypoglycaemia for 20 min (median glucose concentration 1.7 mmol/l, range 1.0-2.6 mmol/l). Concentrations of plasma adrenaline and plasma vasopressin were significantly increased, indicating normal counter-regulatory responses for these hormones. Plasma activities of the hepatic enzymes AST, ALT, LDH, GGT, and CK did not increase during or following the period of hypoglycaemia. Thus, abnormal plasma enzyme activities noted after clinical hypoglycaemia should be fully investigated, and not disregarded as due to the hypoglycaemic episode.
Neighbourhood food and physical activity environments in England, UK: does ethnic density matter?

PubMed Central

2012-01-01

Background In England, obesity is more common in some ethnic minority groups than in Whites. This study examines the relationship between ethnic concentration and access to fast food outlets, supermarkets and physical activity facilities. Methods Data on ethnic concentration, fast food outlets, supermarkets and physical activity facilities were obtained at the lower super output area (LSOA) (population average of 1500). Poisson multilevel modelling was used to examine the association between own ethnic concentration and facilities, adjusted for area deprivation, urbanicity, population size and clustering of LSOAs within local authority areas. Results There was a higher proportion of ethnic minorities residing in areas classified as most deprived. Fast food outlets and supermarkets were more common and outdoor physical activity facilities were less common in most than least deprived areas. A gradient was not observed for the relationship between indoor physical activity facilities and area deprivation quintiles. In contrast to White British, increasing ethnic minority concentration was associated with increasing rates of fast food outlets. Rate ratios comparing rates of fast food outlets in high with those in low level of ethnic concentration ranged between 1.28, 95% confidence interval 1.06-1.55 (Bangladeshi) and 2.62, 1.46-4.70 (Chinese). Similar to White British, however, increasing ethnic minority concentration was associated with increasing rate of supermarkets and indoor physical activity facilities. Outdoor physical activity facilities were less likely to be in high than low ethnic concentration areas for some minority groups. Conclusions Overall, ethnic minority concentration was associated with a mixture of both advantages and disadvantages in the provision of food outlets and physical activity facilities. These issues might contribute to ethnic differences in food choices and engagement in physical activity. PMID:22709527
Neighbourhood food and physical activity environments in England, UK: does ethnic density matter?

PubMed

Molaodi, Oarabile R; Leyland, Alastair H; Ellaway, Anne; Kearns, Ade; Harding, Seeromanie

2012-06-18

In England, obesity is more common in some ethnic minority groups than in Whites. This study examines the relationship between ethnic concentration and access to fast food outlets, supermarkets and physical activity facilities. Data on ethnic concentration, fast food outlets, supermarkets and physical activity facilities were obtained at the lower super output area (LSOA) (population average of 1500). Poisson multilevel modelling was used to examine the association between own ethnic concentration and facilities, adjusted for area deprivation, urbanicity, population size and clustering of LSOAs within local authority areas. There was a higher proportion of ethnic minorities residing in areas classified as most deprived. Fast food outlets and supermarkets were more common and outdoor physical activity facilities were less common in most than least deprived areas. A gradient was not observed for the relationship between indoor physical activity facilities and area deprivation quintiles. In contrast to White British, increasing ethnic minority concentration was associated with increasing rates of fast food outlets. Rate ratios comparing rates of fast food outlets in high with those in low level of ethnic concentration ranged between 1.28, 95% confidence interval 1.06-1.55 (Bangladeshi) and 2.62, 1.46-4.70 (Chinese). Similar to White British, however, increasing ethnic minority concentration was associated with increasing rate of supermarkets and indoor physical activity facilities. Outdoor physical activity facilities were less likely to be in high than low ethnic concentration areas for some minority groups. Overall, ethnic minority concentration was associated with a mixture of both advantages and disadvantages in the provision of food outlets and physical activity facilities. These issues might contribute to ethnic differences in food choices and engagement in physical activity.
ALUMINUM CHLORIDE EFFECT ON Ca2+,Mg(2+)-ATPase ACTIVITY AND DYNAMIC PARAMETERS OF SKELETAL MUSCLE CONTRACTION.

PubMed

Nozdrenko, D M; Abramchuk, O M; Soroca, V M; Miroshnichenko, N S

2015-01-01

We studied enzymatic activity and measured strain-gauge contraction properties of the frog Rana temporaria m. tibialis anterior muscle fascicles during the action of aluminum chloride solution. It was shown that AlCl3 solutions did not affect the dynamic properties of skeletal muscle preparation in concentrations less than 10(-4) M Increasing the concentration of AlCl3 to 10(-2) M induce complete inhibition of muscle contraction. A linear correlation between decrease in Ca2+,Mg(2+)-ATPase activity of sarcoplasmic reticulum and the investigated concentrations range of aluminum chloride was observed. The reduction in the dynamic contraction performance and the decrease Ca2+,Mg(2+)-ATPase activity of the sarcoplasmic reticulum under the effect of the investigated AlCl3 solution were minimal in pre-tetanus period of contraction.
The Activity of Cotinus coggygria Scop. Leaves on Staphylococcus aureus Strains in Planktonic and Biofilm Growth Forms.

PubMed

Rendeková, Katarína; Fialová, Silvia; Jánošová, Lucia; Mučaji, Pavel; Slobodníková, Lívia

2015-12-30

The purpose of this study was to detect the effectiveness of Cotinus coggygria Scop. leaves methanol extract against planktonic and biofilm growth forms of Staphylococcus aureus. The antimicrobial activity was determined by the broth microdilution test. Minimal inhibitory concentrations and minimal bactericidal concentrations were detected against two collection and ten clinical S. aureus strains. Anti-biofilm activity of the tested extract was detected using 24 h bacterial biofilm on the surface of microtiter plate wells. The biofilm inhibitory activity was evaluated visually after 24 h interaction of extract with biofilm, and the eradicating activity by a regrowth method. The tested extract showed bactericidal activity against all S. aureus strains (methicillin susceptible or methicillin resistant) in concentrations ranging from 0.313 to 0.625 mg·mL(-1). Biofilm inhibitory concentrations were 10-times higher and biofilm eradicating concentrations 100-times higher (8 and 32 mg·mL(-1), respectively). The phytochemical analysis of C. coggygria leaves 60% methanol extract performed by LC-DAD-MS/MS revealed quercetin rhamnoside, methyl gallate, and methyl trigallate as main constituents. Results of our study indicate that C. coggygria, rich in tannins and flavonoids, seems to be a prospective topical antibacterial agent with anti-biofilm activity.
Antimicrobial efficacy of 3 oral antiseptics containing octenidine, polyhexamethylene biguanide, or Citroxx: can chlorhexidine be replaced?

PubMed

Rohrer, Nadine; Widmer, Andreas F; Waltimo, Tuomas; Kulik, Eva M; Weiger, Roland; Filipuzzi-Jenny, Elisabeth; Walter, Clemens

2010-07-01

Use of oral antiseptics decreases the bacterial load in the oral cavity. To compare the antimicrobial activity of 3 novel oral antiseptics with that of chlorhexidine, which is considered the "gold standard" of oral hygiene. Comparative in vitro study. Four common oral microorganisms (Streptococcus sanguinis, Streptococcus mutans, Candida albicans, and Fusobacterium nucleatum) were tested under standard conditions and at different concentrations, by use of a broth dilution assay and an agar diffusion assay and by calculating the log10 reduction factor (RF). The antimicrobial activity of each antiseptic was assessed by counting the difference in bacterial densities (ie, the log10 number of colony-forming units of bacteria) before and after the disinfection process. The oral antiseptics containing octenidine (with an RF in the range of 7.1-8.24 CFU/mL) and polyhexamethylene biguanide (with an RF in the range of 7.1-8.24 CFU/mL) demonstrated antimicrobial activity comparable to that of chlorhexidine (with an RF in the range of 1.03-8.24 CFU/mL), whereas the mouth rinse containing Citroxx (Citroxx Biosciences; with an RF in the range of 0.22-1.36 CFU/mL) showed significantly weaker antimicrobial efficacy. Overall, octenidine and polyhexamethylene biguanide were more active at lower concentrations.conclusion. Oral antiseptics containing the antimicrobial agent octenidine or polyhexamethylene biguanide may be considered as potent alternatives to chlorhexidine-based preparations.
Evaluation of aqueous and ethanol extract of bioactive medicinal plant, Cassia didymobotrya (Fresenius) Irwin & Barneby against immature stages of filarial vector, Culex quinquefasciatus Say (Diptera: Culicidae).

PubMed

Nagappan, Raja

2012-09-01

To evaluate aqueous and ethanol extract of Cassia didymobotrya leaves against immature stages of Culex quinquefasciatus. The mortality rate of immature mosquitoes was tested in wide and narrow range concentration of the plant extract based on WHO standard protocol. The wide range concentration tested in the present study was 10 000, 1 000, 100, 10 and 1 mg/L and narrow range concentration was 50, 100, 150, 200 and 250 mg/L. 2nd instar larvae exposed to 100 mg/L and above concentration of ethanol extract showed 100% mortality. Remaining stages such as 3rd, 4th and pupa, 100% mortality was observed at 1 000 mg/L and above concentration after 24 h exposure period. In aqueous extract all the stages 100% mortality was recorded at 1 000 mg/L and above concentration. In narrow range concentration 2nd instar larvae 100% mortality was observed at 150 mg/L and above concentration of ethanol extract. The remaining stages 100% mortality was recorded at 250 mg/L. In aqueous extract all the tested immature stages 100% mortality was observed at 250 mg/L concentration after 24 h exposure period. The results clearly indicate that the rate of mortality was based dose of the plant extract and stage of the mosquitoes. From this study it is confirmed and concluded that Cassia didymobotrya is having active principle which is responsible for controlling Culex quinquefasciatus. The isolation of bioactive molecules and development of simple formulation technique is important for large scale implementation.
Measurement of Ultrafine Particles and Other Air Pollutants Emitted by Cooking Activities

PubMed Central

Zhang, Qunfang; Gangupomu, Roja H.; Ramirez, David; Zhu, Yifang

2010-01-01

Cooking emissions show a strong dependence on cooking styles and parameters. Measurements of the average ultrafine particle (UFP) concentration, PM2.5 and black carbon concentrations emitted by cooking activities ranged from 1.34 × 104 to 6.04 × 105 particles/cm3, 10.0 to 230.9 μg/m3 and 0.1 to 0.8 μg/m3, respectively. Lower UFP concentrations were observed during boiling, while higher levels were emitted during frying. The highest UFP concentrations were observed when using a gas stove at high temperature with the kitchen exhaust fan turned off. The observed UFP profiles were similar in the kitchen and in another room, with a lag of approximately 10 min. PMID:20617057
Indoor radon activity concentration measurements in the great historical museums of University of Naples, Italy.

PubMed

Quarto, Maria; Pugliese, Mariagabriella; Loffredo, Filomena; La Verde, Giuseppe; Roca, Vincenzo

2016-01-01

Indoor radon activity concentrations were measured in seven Museums of University of Naples, very old buildings of great historical value. The measurements were performed using a time-integrated technique based on LR-115 solid-state nuclear track detectors. The annual average concentrations were found to range from 40 up to 1935 Bq m(-3) and in 26 % of measurement sites, the values were higher than 500 Bq m(-3) which is the limit value of Italian legislation for workplace. Moreover, we analysed the seasonal variations of radon concentrations observing the highest average in cold weather than in warm. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Mercury and selenium concentrations in biofilm, macroinvertebrates, and fish collected in the Yankee Fork of the Salmon River, Idaho, USA, and their potential effects on fish health.

PubMed

Rhea, Darren T; Farag, Aïda M; Harper, David D; McConnell, Elizabeth; Brumbaugh, William G

2013-01-01

The Yankee Fork is a large tributary of the Salmon River located in central Idaho, USA, with an extensive history of placer and dredge-mining activities. Concentrations of selenium (Se) and mercury (Hg) in various aquatic trophic levels were measured in the Yankee Fork during 2001 and 2002. Various measurements of fish health were also performed. Sites included four on the mainstem of the Yankee Fork and two off-channel sites in partially reclaimed dredge pools used as rearing habitat for cultured salmonid eggs and fry. Hg concentrations in whole mountain whitefish and shorthead sculpin ranged from 0.28 to 0.56 μg/g dry weight (dw), concentrations that are generally less than those reported to have significant impacts on fish. Biofilm and invertebrates ranged from 0.05 to 0.43 μg Hg/g dw. Se concentrations measured in biota samples from the Yankee Fork were greater than many representative samples collected in the Snake and Columbia watersheds and often exceeded literature-based toxic thresholds. Biofilm and invertebrates ranged from 0.58 to 4.66 μg Se/g dw. Whole fish ranged from 3.92 to 7.10 μg Se/g dw, and gonads ranged from 6.91 to 31.84 μg Se/g dw. Whole-body Se concentrations exceeded reported toxicological thresholds at three of four sites and concentrations in liver samples were mostly greater than concentrations shown to have negative impacts on fish health. Histological examinations performed during this study noted liver abnormalities, especially in shorthead sculpin, a bottom-dwelling species.
Mercury and selenium concentrations in biofilm, macroinvertebrates, and fish collected in the Yankee Fork of the Salmon River, Idaho, USA, and their potential effects on fish health

USGS Publications Warehouse

Rhea, Darren T.; Farag, Aïda M.; Harper, David D.; McConnell, Elizabeth; Brumbaugh, William G.

2013-01-01

The Yankee Fork is a large tributary of the Salmon River located in central Idaho, USA, with an extensive history of placer and dredge-mining activities. Concentrations of selenium (Se) and mercury (Hg) in various aquatic trophic levels were measured in the Yankee Fork during 2001 and 2002. Various measurements of fish health were also performed. Sites included four on the mainstem of the Yankee Fork and two off-channel sites in partially reclaimed dredge pools used as rearing habitat for cultured salmonid eggs and fry. Hg concentrations in whole mountain whitefish and shorthead sculpin ranged from 0.28 to 0.56 μg/g dry weight (dw), concentrations that are generally less than those reported to have significant impacts on fish. Biofilm and invertebrates ranged from 0.05 to 0.43 μg Hg/g dw. Se concentrations measured in biota samples from the Yankee Fork were greater than many representative samples collected in the Snake and Columbia watersheds and often exceeded literature-based toxic thresholds. Biofilm and invertebrates ranged from 0.58 to 4.66 μg Se/g dw. Whole fish ranged from 3.92 to 7.10 μg Se/g dw, and gonads ranged from 6.91 to 31.84 μg Se/g dw. Whole-body Se concentrations exceeded reported toxicological thresholds at three of four sites and concentrations in liver samples were mostly greater than concentrations shown to have negative impacts on fish health. Histological examinations performed during this study noted liver abnormalities, especially in shorthead sculpin, a bottom-dwelling species.
Natural soil gamma radioactivity levels and resultant population dose in the cities of Zacatecas and Guadalupe, Zacatecas, Mexico.

PubMed

Mireles, F; Dávila, J I; Quirino, L L; Lugo, J F; Pinedo, J L; Ríos, C

2003-03-01

The study of natural gamma radioactivity was made to determine the concentrations of natural radionuclides in soil. Twenty soil samples collected in the cities of Zacatecas and Guadalupe and their suburban areas in the Mexican state of Zacatecas were analyzed by gamma-ray spectrometry to determine the activity concentrations of 226Ra, 232Th, and 40K. Gamma-spectrometry measurements were made using a hyperpure germanium detector surrounded with shielding material to reduce the background counting rate. The GammaVision-32 MCA emulation software was used for gamma-ray spectrum analysis and the TRUMP card of 2k as a MCA emulator. Conversion factors were used to calculate the dose to the population from outdoor exposure to terrestrial gamma rays. The measured activity concentration of 226Ra varies from 11 to 38 Bq kg(-1), the activity concentration of 232Th varies from 8 to 38 Bq kg(-1). The activity concentration of 40K is in the range 309-1,049 Bq kg(-1). The overall population mean outdoor terrestrial gamma dose rate is 44.94 nGy h(-1).
Biochemical characterisation of the esterase activities of wine lactic acid bacteria.

PubMed

Matthews, Angela; Grbin, Paul R; Jiranek, Vladimir

2007-11-01

Esters are an important group of volatile compounds that can contribute to wine flavour. Wine lactic acid bacteria (LAB) have been shown to produce esterases capable of hydrolysing ester substrates. This study aims to characterise the esterase activities of nine LAB strains under important wine conditions, namely, acidic conditions, low temperature (to 10 degrees C) and in the presence of ethanol (2-18% v/v). Esterase substrate specificity was also examined using seven different ester substrates. The bacteria were generally found to have a broad pH activity range, with the majority of strains showing maximum activity close to pH 6.0. Exceptions included an Oenococcus oeni strain that retained most activity even down to a pH of 4.0. Most strains exhibited highest activity across the range 30-40 degrees C. Increasing ethanol concentration stimulated activity in some of the strains. In particular, O. oeni showed an increase in activity up to a maximum ethanol concentration of around 16%. Generally, strains were found to have greater activity towards short-chained esters (C2-C8) compared to long-chained esters (C10-C18). Even though the optimal physicochemical conditions for enzyme activity differed from those found in wine, these findings are of potential importance to oenology because significant activities remained under wine-like conditions.
Long-range electrostatic screening in ionic liquids

PubMed Central

Gebbie, Matthew A.; Dobbs, Howard A.; Valtiner, Markus; Israelachvili, Jacob N.

2015-01-01

Electrolyte solutions with high concentrations of ions are prevalent in biological systems and energy storage technologies. Nevertheless, the high interaction free energy and long-range nature of electrostatic interactions makes the development of a general conceptual picture of concentrated electrolytes a significant challenge. In this work, we study ionic liquids, single-component liquids composed solely of ions, in an attempt to provide a novel perspective on electrostatic screening in very high concentration (nonideal) electrolytes. We use temperature-dependent surface force measurements to demonstrate that the long-range, exponentially decaying diffuse double-layer forces observed across ionic liquids exhibit a pronounced temperature dependence: Increasing the temperature decreases the measured exponential (Debye) decay length, implying an increase in the thermally driven effective free-ion concentration in the bulk ionic liquids. We use our quantitative results to propose a general model of long-range electrostatic screening in ionic liquids, where thermally activated charge fluctuations, either free ions or correlated domains (quasiparticles), take on the role of ions in traditional dilute electrolyte solutions. This picture represents a crucial step toward resolving several inconsistencies surrounding electrostatic screening and charge transport in ionic liquids that have impeded progress within the interdisciplinary ionic liquids community. More broadly, our work provides a previously unidentified way of envisioning highly concentrated electrolytes, with implications for diverse areas of inquiry, ranging from designing electrochemical devices to rationalizing electrostatic interactions in biological systems. PMID:26040001
THE ALTERATION OF INTRACELLULAR ENZYMES

PubMed Central

Kaplan, J. Gordin

1954-01-01

1. The ability of homologous series of alcohols, ketones, and aldehydes to cause alteration of intracellular catalase increases approximately threefold for each methylene group added, thus following Traube's rule. Equiactive concentrations of alcohols (methanol to octanol) varied over a 4,000-fold range, yet the average corresponding surface tension was 42 ± 2 dynes/cm., that for ketones 43 ± 2, and for aldehydes (above C1) 41 ± 3. 2. Above C8 the altering activity of alcohols ceased to follow Traube's rule, and at C18 was nil. Yet the surface activities of alcohols from nonanol to dodecanol did follow Traube's rule. These two facts show that the interface which is being affected by these agents is not the cell surface, for if it were, altering activity should not fall off between C9 and C12 where surface activity is undiminished; they show also that micelle formation by short range association of hydrocarbon "tails," usually invoked to explain decrease in biological activity of compounds above C8, is not responsible for this effect in these experiments, in which permeability of the cell membrane probably is involved. 3. The most soluble alcohols and aldehydes (alcohols C1 to C8; aldehydes C1, C2), but not ketones, cause, above optimal concentration, an irreversible inhibition of yeast catalase. 4. The critical concentration of altering agent (i.e., that concentration just sufficient to cause doubling of the catalase activity of the yeast suspension) was independent of the concentration of the yeast cells. 5. Viability studies show that the number of yeast cells killed by the altering agents was not related to the degree of activation of the catalase produced. While all the cells were invariably killed by concentrations of altering agent which produced complete activation, all the cells had been killed by concentrations which were insufficient to cause more than 50 per cent maximal activation. Further, the evidence suggested that the catalase may be partially activated by concentrations of altering agent which cause no decrease in viability at all. Hence alteration, unlike death, may not be all-or-none per cell. 6. The fact that the biological criterion being examined was the activation of a water-soluble enzyme rules out the possibility that the reason for the logarithmic increase in altering activity with chain length was increase in concentration of the altering agent in some intracellular fat phase. It is concluded that these surface-active agents cause enzyme alteration by becoming adsorbed at some intracellular interface and thus causing, directly or indirectly, the modification of catalase properties. 7. It is considered that these data support, but do not provide critical proof for, the interfacial hypothesis, which states that catalase is present at the intracellular interface in question, but is desorbed into solution as a consequence of the alteration process. PMID:13211996
Antifungal activity of four honeys of different types from Algeria against pathogenic yeast: Candida albicans and Rhodotorula sp.

PubMed

Moussa, Ahmed; Noureddine, Djebli; Saad, Aissat; Abdelmelek, Meslem; Abdelkader, Benhalima

2012-07-01

To evaluate the antifungal activity of four honeys of different types from Algeria against pathogenic yeast i.e. Candida albicans (C. albicans) and Rhodotorula sp. Four Algeria honeys of different botanical origin were analyzed to test antifungal effect against C. albicans, and Rhodotorula sp. Different concentrations (undiluted, 10%, 30%, 50% and 70% w/v) of honey were studied in vitro for their antifugal activity using C. albicans and Rhodotorula sp. as fungal strains. The range of the diameter of zone of inhibition of various concentrations of tested honeys was (7-23 mm) for Rhodotorula sp., while C. albicans showed clearly resistance towards all concentrations used. The MICs of tested honey concentrations against C. albicans and Rhodotorula sp. were (70.09-93.48)% and (4.90-99.70)% v/v, respectively. This study demonstrates that, in vitro, these natural products have clearly an antifungal activity against Rhodotorula sp. and C. albicans.
Antifungal activity of four honeys of different types from Algeria against pathogenic yeast: Candida albicans and Rhodotorula sp.

PubMed Central

Moussa, Ahmed; Noureddine, Djebli; Saad, Aissat; Abdelmelek, Meslem; Abdelkader, Benhalima

2012-01-01

Objective To evaluate the antifungal activity of four honeys of different types from Algeria against pathogenic yeast i.e. Candida albicans (C. albicans) and Rhodotorula sp. Methods Four Algeria honeys of different botanical origin were analyzed to test antifungal effect against C. albicans, and Rhodotorula sp. Different concentrations (undiluted, 10%, 30%, 50% and 70% w/v) of honey were studied in vitro for their antifugal activity using C. albicans and Rhodotorula sp. as fungal strains. Results The range of the diameter of zone of inhibition of various concentrations of tested honeys was (7–23 mm) for Rhodotorula sp., while C. albicans showed clearly resistance towards all concentrations used. The MICs of tested honey concentrations against C. albicans and Rhodotorula sp. were (70.09–93.48)% and (4.90–99.70)% v/v, respectively. Conclusions This study demonstrates that, in vitro, these natural products have clearly an antifungal activity against Rhodotorula sp. and C. albicans. PMID:23569970

Antibacterial, antifungal and cytotoxic evaluation of some new quinazolinone derivatives

PubMed Central

Hassanzadeh, F.; Jafari, E.; Hakimelahi, G.H.; Khajouei, M. Rahmani; Jalali, M.; Khodarahmi, G.A.

2012-01-01

Quinazolinone ring system is renown because of its wide spectrum of pharmacological activities due to various substitutions on this ring system. In this study, the minimum inhibitory concentration of the synthesized compounds in our laboratory was determined by micro dilution Alamar Blue® Assay against six strains of bacteria (three Gram-positive and three Gram-negative) and three strains of fungi. Following a broth micro dilution minimum inhibitory concentration (MIC) test, Minimum Bactericidal Concentration (MBC) and Minimum Fungicidal Concentration (MFC) tests were performed. Cytotoxic effects of the compounds were measured using the MTT colorimetric assay on HeLa cell line. Results of antimicrobial screening showed that compounds had better bacteriostatic activity against Gram-negative bacteria. Results from MBC revealed that these compounds had more significant bacteriostatic than bactericidal activities. Nearly all screened compounds showed good activity against C. albicans and A. niger. Results from MFC indicated that these compounds had better fungistatic rather than fungicidal activities. The synthesized target molecules were found to exhibit different cytotoxicity in the range of 10 to 100 μM on HeLa cell line. Compounds 6 and 7 exhibited acceptable cytotoxicity approximately 50% at 10 μM concentration. PMID:23181085
Anti-leptospiral activities of an endemic plant Glyptopetalum calocarpum (Kurz.) Prain used as a medicinal plant by Nicobarese of Andaman and Nicobar Islands.

PubMed

Chander, M Punnam; Kumar, K Vinod; Shriram, A N; Vijayachari, P

2015-01-01

Leaves of an endemic plant Glyptopetalum calocarpum are used by Nicobarese tribes of Andaman and Nicobar Islands, India, to prepare traditional medicine for treating fever. In the present investigation, pharmacologically active compounds were isolated from this plant and their antimicrobial efficacy was evaluated against the leptospiral strains. The anti-leptospiral activity of six plant-derived compounds was determined by both microdilution and macrodilution methods. Two out of six compounds, namely lupenone and stigmasterol, showed anti-leptospiral activity. The minimum inhibitory concentrations of the two compounds tested against pathogenic leptospiral strains belonging to 10 serovars were in the range of 100-200 μg/mL. The range of minimum bactericidal concentrations was 400-800 μg/mL. Compounds lupenone, stigmasterol, lupeol, β-amyrin and β-amyrin acetate had negligible or no haemolytic activity, exhibiting IC50 values of greater than 5 mg/mL. Further in vivo studies are needed to investigate the pharmacological and toxicological properties of G. calocarpum before it can be considered as a new anti-leptospiral agent.
Rhodiola sacra aqueous extract (RSAE) improves biochemical and sperm characteristics in cryopreserved boar semen.

PubMed

Zhao, H-W; Li, Q-W; Ning, G-Z; Han, Z-S; Jiang, Z-L; Duan, Y-F

2009-03-15

Although Rhodiola sacra aqueous extract (RSAE) has been used in many studies as an antioxidant, its effects on semen characteristics and its antioxidant properties during cryopreservation of boar sperm have never been evaluated. Semen was collected from five Duroc boars (2-4-year-old) twice weekly and frozen-thawed in extender with RSEA. Motion characteristics were assessed with a computer-aided semen analysis (CASA) system, whereas other sperm quality end points were assessed by routine methods. The effective concentration of RSEA in extender ranged from 4 to 8mg/L and the effect of RSEA on sperm quality was better in glycerol-free extender than extender containing glycerol (P<0.05). In frozen-thawed boar semen, there was a direct correlation (P<0.05) between RSEA concentration and glutathione (GSH) concentrations, mitochondrial activity, and hypoosmotic swelling test (HOST), and an inverse correlation (r=-0.982, P<0.05) between RSEA concentration and malondialdehyde (all end points were significantly higher at 6mg/L than in the control group). In summary: (i) the effective concentration of RSEA in extender ranged from 4 to 8mg/L; (ii) the effect of RSEA on sperm quality was better in extender without glycerol; and (iii) there was a significant correlation between RSEA concentrations and concentrations of GSH and MAD in frozen-thawed boar semen (antioxidant effects of RSEA were concentration-dependent). Further studies are needed to define the active ingredient in RSEA that protects boar sperm against ROS.
Diurnal variations of radon and thoron activity concentrations and effective doses in dwellings in Niška Banja, Serbia.

PubMed

Vaupotič, J; Streil, T; Tokonami, S; Žunic, Z S

2013-12-01

In Niška Banja, a spa town in a radon-prone area in southern Serbia, radon ((222)Rn) and thoron ((220)Rn) activity concentrations were measured continuously for one day in indoor air of 10 dwellings with a SARAD RTM 2010-2 Radon/Thoron Monitor, and equilibrium factor between radon and its decay products and the fraction of unattached radon decay products with a SARAD EQF 3020-2 Equilibrium Factor Monitor. Radon concentration in winter time ranged from 26 to 73 100 Bq m(-3) and that of thoron, from 10 to 8650 Bq m(-3). In the same period, equilibrium factor and the unattached fraction varied in the range of 0.08 to 0.90 and 0.01 to 0.27, respectively. One-day effective doses were calculated and were in winter conditions from 4 to 2599 μSv d(-1) for radon and from 0.2 to 73 μSv d(-1) for thoron.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai, X.; Antal, M.J. Jr.

Macadamia nut shell charcoal was heated in an inert environment to temperatures above 1000 K (carbonized), reacted with oxygen (Po{sub 2} = 2.68--11.3 kPa) at temperatures between 525 and 586 K (oxygenated), and heated again in an inert environment to temperatures above 1000 K (activated) to produce an activated carbon. Carbons produced by this process possess surface areas and iodine numbers in the range of 400--550. Overall yields of these carbons (based on the dry, raw macadamia nut shell feed) ranged from 24 to 30 wt %. Under the conditions employed in this work, the rates of chemisorption and gasificationmore » were not mass transfer limited. Initially, the gasification reaction was first-order with respect to oxygen concentration but became independent of oxygen concentration as the surface sites of the carbon became saturated with oxygen.« less
Effects of depleted uranium on survival, growth, and metamorphosis in the african clawed frog (Xenopus laevis)

USGS Publications Warehouse

Mitchell, S.E.; Caldwell, C.A.; Gonzales, G.; Gould, W.R.; Arimoto, R.

2005-01-01

Embryos (stage 8-47, Nieuwkoop and Faber) of the African clawed frog (Xenopus laevis) were subjected to water-borne depleted uranium (DU) concentrations that ranged from 4.8 to 77.7 mg/Lusing an acute 96-h frog embryo teratogenesis assay-Xenopus (FETAX). In a chronic 64-d assay, X. laevis (from embryo through metamorphosis; stages 8-66) were subjected to concentrations of DU that ranged from 6.2 to 54.3 mg/L Our results indicate DU is a non teratogenic metal. No effects on mortality, malformations, or growth were observed in the 96-h FETAX with concentrations of DU that ranged from 4.8 to 77.7 mg/L From stage 8 to stage 47, X. laevis tadpoles do not actively feed and the gills are not well developed. Thus, uptake of DU was reduced despite exposure to elevated concentrations. The 64-d assay resulted in no concentration response for either mortality or malformations; however, a delay in metamorphosis was observed in tadpoles subjected to elevated DU concentrations (from 13.1 to 54.3 mg/L) compared to tadpoles in both the well-water control and reference. The delay in metamorphosis was likely due to increasing body burden of DU that ranged from 0.98 to 2.82 mg/kg. Copyright?? Taylor & Francis Inc.
Radioactive artificial 137Cs and natural 40K activity in 21 edible mushrooms of the genus Boletus species from SW China.

PubMed

Falandysz, Jerzy; Zhang, Ji; Zalewska, Tamara

2017-03-01

This study, for the first time, presents the results of activity concentration determinations for 137 Cs and 40 K in a high number (21 species, 87 composite samples, and 807 fruiting bodies) of mushrooms of the genus Boletus from across Yunnan in 2011-2014 and Sichuan (Boletus tomentipes) using high-resolution high-purity germanium detector. Activity concentrations of 137 Cs demonstrated some variability and range from <4.4 to 83 ± 3 Bq kg -1 dry biomass in caps and from <3.8 to 37 ± 3 Bq kg -1 dry biomass in stipes, and of 40 K, respectively, from 420 ± 41 to 1300 ± 110 and from 520 ± 61 to 1300 ± 140 Bq kg -1 dry biomass. No significant variations were observed regarding 137 Cs and 40 K activity concentrations among the same Boletus species from different sampling sites. No activity concentrations from 134 Cs were detected in any mushrooms. Internal dose rates estimated were from intake of 1 kg of mushrooms per annum for 137 Cs range for species and regions from around <0.0031 to 0.047 ± 0.003 μSv, while those for 40 K were from around 0.22 ± 0.04 to 1.2 ± 0.1 μSv. The overall intake of 137 Cs was low since low contamination was found in Boletus species.
The assessment of the antibacterial and antifungal activities of aspirin, EDTA and aspirin-EDTA combination and their effectiveness as antibiofilm agents.

PubMed

Al-Bakri, A G; Othman, G; Bustanji, Y

2009-07-01

To evaluate the antimicrobial activities of aspirin, EDTA and an aspirin-EDTA (A-EDTA) combination against Pseudomonas aeruginosa, Escherichia coli and Candida albicans in planktonic and biofilm cultures. Minimal inhibitory concentrations (MIC) and minimal biocidal concentrations (MBC) were determined using twofold broth microdilution and viable counting methods, respectively. Aspirin's recorded MIC values ranged from 1.2 to 2.7 mg ml(-1). Checkerboard assay demonstrated a synergism in antimicrobial activity upon combination. Aspirin's minimal biofilm eradication concentration values (MBEC) against the established biofilms ranged between 1.35 and 3.83 mg ml(-1). A complete eradication of bacterial biofilms was achieved after a 4-h treatment with the A-EDTA combination. Both aspirin and EDTA possess broad-spectrum antimicrobial activity for both planktonic and biofilm cultures. Aspirin used at the MBEC for 24 h was successful in eradicating P. aeruginosa, E. coli and C. albicans biofilms established on abiotic surfaces. Moreover, the exposure to the A-EDTA combination (4 h) effected complete bacterial biofilm eradication. There is a continuous need for the discovery of new antimicrobial agents. Aspirin and EDTA are 'nonantibiotic drugs', the combination of which can be used successfully to treat and eradicate biofilms established on abiotic surfaces.
Antiprotozoal Activity of 1-Phenethyl-4-Aminopiperidine Derivatives ▿

PubMed Central

Dardonville, Christophe; Fernández-Fernández, Cristina; Gibbons, Sarah-Louise; Jagerovic, Nadine; Nieto, Lidia; Ryan, Gary; Kaiser, Marcel; Brun, Reto

2009-01-01

A series of 44 4-aminopiperidine derivatives was screened in vitro against four protozoan parasites (Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani, and Plasmodium falciparum). This screening identified 29 molecules selectively active against bloodstream-form T. b. rhodesiense trypomastigotes, with 50% inhibitory concentrations (IC50) ranging from 0.12 to 10 μM, and 33 compounds active against the chloroquine- and pyrimethamine-resistant K1 strain of P. falciparum (IC50 range, 0.17 to 5 μM). In addition, seven compounds displayed activity against intracellular T. cruzi amastigotes in the same range as the reference drug benznidazole (IC50, 1.97 μM) but were also cytotoxic to L-6 cells, showing little selectivity for T. cruzi. None of the molecules tested showed interesting antileishmanial activity against axenic amastigotes of L. donovani. To our knowledge, this is the first report of the antitrypanosomal activity of molecules bearing the 4-aminopiperidine skeleton. PMID:19564359
Carbon monoxide degassing from seismic fault zones in the Basin and Range province, west of Beijing, China

NASA Astrophysics Data System (ADS)

Sun, Yutao; Zhou, Xiaocheng; Zheng, Guodong; Li, Jing; Shi, Hongyu; Guo, Zhengfu; Du, Jianguo

2017-11-01

Degassing of carbon monoxide (CO), which plays a significant role in the contribution of deep carbon to the atmosphere, commonly occurs within active fault zones. CO degassing from soil to the atmosphere in the Basin and Range province, west of Beijing (BRPB), China, was investigated by in-situ field measurements in the active fault zones. The measured concentrations of CO in soil gas in the BRPB ranged from 0.29 × 10-6 to 1.1 × 10-6 with a mean value of 0.6 × 10-6, which is approximately twice as large as that in the atmosphere. Net fluxes of CO degassing ranged from -48.6 mg m-2 d-1 to 12.03 mg m-2 d-1. The diffusion of CO from soil to the atmosphere in the BRPB was estimated to be at least 7.6 × 103 ton/a, which is comparable to the corresponding result of about 1.2 × 104 ton/a for CO2. CO concentrations were spatially heterogeneous with clearly higher concentrations along the NE-SW trending in the BRPB. These elevated values of CO concentrations were also coincident with the region with low-velocity and high conductivity in deep mantle, and high Poisson's ratio in the crust, thereby suggesting that CO degassing from the soil might be linked to upwelling of the asthenospheric mantle. Other sources of CO in the soil gas are suggested to be dominated by chemical reactions between deep fluids and carbonate minerals (e.g., dolomite, limestone, and siderite) in country rocks. Biogenic processes may also contribute to the CO in soil gas. The spatial distribution patterns of CO concentrations are coincident with the stress field, suggesting that the concentrations of CO could be a potential indicator for crustal stress field and, hence is potential useful for earthquake monitoring in the BRPB.
Physicochemical and toxicological characteristics of welding fume derived particles generated from real time welding processes.

PubMed

Chang, Cali; Demokritou, Philip; Shafer, Martin; Christiani, David

2013-01-01

Welding fume particles have been well studied in the past; however, most studies have examined welding fumes generated from machine models rather than actual exposures. Furthermore, the link between physicochemical and toxicological properties of welding fume particles has not been well understood. This study aims to investigate the physicochemical properties of particles derived during real time welding processes generated during actual welding processes and to assess the particle size specific toxicological properties. A compact cascade impactor (Harvard CCI) was stationed within the welding booth to sample particles by size. Size fractionated particles were extracted and used for both off-line physicochemical analysis and in vitro cellular toxicological characterization. Each size fraction was analyzed for ions, elemental compositions, and mass concentration. Furthermore, real time optical particle monitors (DustTrak™, TSI Inc., Shoreview, Minn.) were used in the same welding booth to collect real time PM2.5 particle number concentration data. The sampled particles were extracted from the polyurethane foam (PUF) impaction substrates using a previously developed and validated protocol, and used in a cellular assay to assess oxidative stress. By mass, welding aerosols were found to be in coarse (PM 2.5–10), and fine (PM 0.1–2.5) size ranges. Most of the water soluble (WS) metals presented higher concentrations in the coarse size range with some exceptions such as sodium, which presented elevated concentration in the PM 0.1 size range. In vitro data showed size specific dependency, with the fine and ultrafine size ranges having the highest reactive oxygen species (ROS) activity. Additionally, this study suggests a possible correlation between welders' experience, the welding procedure and equipment used and particles generated from welding fumes. Mass concentrations and total metal and water soluble metal concentrations of welding fume particles may be greatly influenced by these factors. Furthermore, the results also confirmed the hypothesis that smaller particles generate more ROS activity and should be evaluated carefully for risk assessment.
Synergistic Effects of Micro-electrolysis-Photocatalysis on Water Treatment and Fish Performance in Saline Recirculating Aquaculture System

PubMed Central

Ye, Zhangying; Wang, Shuo; Gao, Weishan; Li, Haijun; Pei, Luowei; Shen, Mingwei; Zhu, Songming

2017-01-01

A new physico-chemical process for TAN (total ammonia nitrogen) removal and disinfection is introduced in saline recirculating aquaculture system (RAS), in which the biofilter is replaced with an integrated electrolysis cell and an activated carbon filter. The electrolysis cell which is based on micro current electrolysis combined with UV-light was self-designed. After the fundamental research, a small pilot scale RAS was operated for 30 days to verify the technical feasibility. The system was stocked by 42 GIFT tilapia (Oreochromis niloticus) fish with the rearing density of 13 kg/m3. During the experiments, the TAN concentration remained below 1.0 mg/L. The nitrite concentration was lower than 0.2 mg/L and the nitrate concentration had increased continuously to 12.79 mg/L at the end. Furthermore, the concentration of residual chlorine in culture ponds remained below 0.3 mg/L, ORP maintained slight fluctuations in the range of 190~240 mV, and pH of the water showed the downtrend. Tilapia weight increased constantly to 339.3 ± 10 g. For disinfection, the active chlorine generated by electrochemical treatment caused Escherichia coli inactivation. Enzyme activity assay indicated that the activity of glutamate dehydrogenase, carbonic anhydrase and glutamic pyruvic transaminase increased within the normal range. The preliminary feasibility was verified by using this physico-chemical technology in the RAS. PMID:28345583
Synergistic Effects of Micro-electrolysis-Photocatalysis on Water Treatment and Fish Performance in Saline Recirculating Aquaculture System

NASA Astrophysics Data System (ADS)

Ye, Zhangying; Wang, Shuo; Gao, Weishan; Li, Haijun; Pei, Luowei; Shen, Mingwei; Zhu, Songming

2017-03-01

A new physico-chemical process for TAN (total ammonia nitrogen) removal and disinfection is introduced in saline recirculating aquaculture system (RAS), in which the biofilter is replaced with an integrated electrolysis cell and an activated carbon filter. The electrolysis cell which is based on micro current electrolysis combined with UV-light was self-designed. After the fundamental research, a small pilot scale RAS was operated for 30 days to verify the technical feasibility. The system was stocked by 42 GIFT tilapia (Oreochromis niloticus) fish with the rearing density of 13 kg/m3. During the experiments, the TAN concentration remained below 1.0 mg/L. The nitrite concentration was lower than 0.2 mg/L and the nitrate concentration had increased continuously to 12.79 mg/L at the end. Furthermore, the concentration of residual chlorine in culture ponds remained below 0.3 mg/L, ORP maintained slight fluctuations in the range of 190~240 mV, and pH of the water showed the downtrend. Tilapia weight increased constantly to 339.3 ± 10 g. For disinfection, the active chlorine generated by electrochemical treatment caused Escherichia coli inactivation. Enzyme activity assay indicated that the activity of glutamate dehydrogenase, carbonic anhydrase and glutamic pyruvic transaminase increased within the normal range. The preliminary feasibility was verified by using this physico-chemical technology in the RAS.
Minimum inhibitory concentrations of medicinal plants used in Northern Peru as antibacterial remedies

PubMed Central

Malca-García, G.; Glenn, A.; Sharon, D.; Chait, G.; Díaz, D.; Pourmand, K.; Jonat, B.; Somogy, S.; Guardado, G.; Aguirre, C.; Chan, R.; Meyer, K.; Kuhlman, A.; Townesmith, A.; Effio-Carbajal, J.; Frías-Fernandez, F.; Benito, M.

2010-01-01

Aim The plant species reported here are traditionally used in Northern Peru to treat bacterial infections, often addressed by the local healers as “inflammation”. The aim of this study was to evaluate the Minimum Inhibitory Concentration (MIC) of their antibacterial properties against Gram-positive and Gram-negative bacteria. Materials and methods The antimicrobial activity of ethanolic and water extracts of 141 plant species was determined using a deep-well broth microdilution method on commercially available bacterial strains. Results The ethanolic extracts of 51 species inhibited Escherichia coli, and 114 ethanolic extracts inhibited Staphylococcus aureus. In contrast, only 30 aqueous extracts showed activity against E. coli and 38 extracts against S. aureus. The MIC concentrations were mostly very high and ranged from 0.008 to 256mg/ml, with only 36 species showing inhibitory concentrations of <4mg/ml. The ethanolic extracts exhibited stronger activity and a much broader spectrum of action than the aqueous extracts. Hypericum laricifolium, Hura crepitans, Caesalpinia paipai, Cassia fistula, Hyptis sidifolia, Salvia sp., Banisteriopsis caapi, Miconia salicifolia and Polygonum hydropiperoides showed the lowest MIC values and would be interesting candidates for future research. Conclusions The presence of antibacterial activity could be confirmed in most species used in traditional medicine in Peru which were assayed in this study. However, the MIC for the species employed showed a very large range, and were mostly very high. Nevertheless, traditional knowledge might provide some leads to elucidate potential candidates for future development of new antibiotic agents. PMID:20678568
Minimum inhibitory concentrations of medicinal plants used in Northern Peru as antibacterial remedies.

PubMed

Bussmann, R W; Malca-García, G; Glenn, A; Sharon, D; Chait, G; Díaz, D; Pourmand, K; Jonat, B; Somogy, S; Guardado, G; Aguirre, C; Chan, R; Meyer, K; Kuhlman, A; Townesmith, A; Effio-Carbajal, J; Frías-Fernandez, F; Benito, M

2010-10-28

The plant species reported here are traditionally used in Northern Peru to treat bacterial infections, often addressed by the local healers as "inflammation". The aim of this study was to evaluate the minimum inhibitory concentration (MIC) of their antibacterial properties against gram-positive and gram-negative bacteria. The antimicrobial activity of ethanolic and water extracts of 141 plant species was determined using a deep-well broth microdilution method on commercially available bacterial strains. The ethanolic extracts of 51 species inhibited Escherichia coli, and 114 ethanolic extracts inhibited Staphylococcus aureus. In contrast, only 30 aqueous extracts showed activity against Escherichia coli and 38 extracts against Staphylococcus aureus. The MIC concentrations were mostly very high and ranged from 0.008 to 256 mg/ml, with only 36 species showing inhibitory concentrations of <4 mg/ml. The ethanolic extracts exhibited stronger activity and a much broader spectrum of action than the aqueous extracts. Hypericum laricifolium, Hura crepitans, Caesalpinia paipai, Cassia fistula, Hyptis sidifolia, Salvia sp., Banisteriopsis caapi, Miconia salicifolia and Polygonum hydropiperoides showed the lowest MIC values and would be interesting candidates for future research. The presence of antibacterial activity could be confirmed in most species used in traditional medicine in Peru which were assayed in this study. However, the MIC for the species employed showed a very large range, and were mostly very high. Nevertheless, traditional knowledge might provide some leads to elucidate potential candidates for future development of new antibiotic agents. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.
Dissolved Organophosphate Esters and Polybrominated Diphenyl Ethers in Remote Marine Environments: Arctic Surface Water Distributions and Net Transport through Fram Strait.

PubMed

McDonough, Carrie A; De Silva, Amila O; Sun, Caoxin; Cabrerizo, Ana; Adelman, David; Soltwedel, Thomas; Bauerfeind, Eduard; Muir, Derek C G; Lohmann, Rainer

2018-06-05

Organophosphate esters (OPEs) have been found in remote environments at unexpectedly high concentrations, but very few measurements of OPE concentrations in seawater are available, and none are available in subsurface seawater. In this study, passive polyethylene samplers (PEs) deployed on deep-water moorings in the Fram Strait and in surface waters of Canadian Arctic lakes and coastal sites were analyzed for a suite of common OPEs. Total OPEs ( ∑ 11 OPE) at deep-water sites were dominated by chlorinated OPEs, and ranged from 6.3 to 440 pg/L. Concentrations were similar in eastern and western Fram Strait. Chlorinated OPEs were also dominant in Canadian Arctic surface waters (mean concentration ranged from < DL to 4400 pg/L), while nonhalogenated alkyl/aryl-substituted OPEs remained low (1.3-55 pg/L), possibly due to the greater long-range transport potential of chlorinated OPEs. Polybrominated diphenyl ethers (PBDEs) were found at much lower concentrations than OPEs (
Assessing the impact of electrolyte conductivity and viscosity on the reactor cost and pressure drop of redox-active polymer flow batteries

NASA Astrophysics Data System (ADS)

Iyer, Vinay A.; Schuh, Jonathon K.; Montoto, Elena C.; Pavan Nemani, V.; Qian, Shaoyi; Nagarjuna, Gavvalapalli; Rodríguez-López, Joaquín; Ewoldt, Randy H.; Smith, Kyle C.

2017-09-01

Redox-active small molecules, used traditionally in redox flow batteries (RFBs), are susceptible to crossover and require expensive ion exchange membranes (IEMs) to achieve long lifetimes. Redox-active polymer (RAP) solutions show promise as candidate electrolytes to mitigate crossover through size-exclusion, enabling the use of porous separators instead of IEMs. Here, poly(vinylbenzyl ethyl viologen) is studied as a surrogate RAP for RFBs. For oxidized RAPs, ionic conductivity varies weakly between 1.6 and 2.1 S m-1 for RAP concentrations of 0.13-1.27 mol kg-1 (monomeric repeat unit per kg solvent) and 0.32 mol kg-1 LiBF4 with a minor increase upon reduction. In contrast, viscosity varies between 1.8 and 184.0 mPa s over the same concentration range with weakly shear-thinning rheology independent of oxidation state. Techno-economic analysis is used to quantify reactor cost as a function of electrolyte transport properties for RAP concentrations of 0.13-1.27 mol kg-1, assuming a hypothetical 3V cell and facile kinetics. Among these concentrations, reactor cost is minimized over a current density range of 600-1000 A m-2 with minimum reactor cost between 11-17 per kWh, and pumping pressures below 10 kPa. The predicted low reactor cost of RAP RFBs is enabled by sustained ionic mobility in spite of the high viscosity of concentrated RAP solutions.
Antimicrobial and cytotoxic activities of 1,2,3-triazole-sucrose derivatives.

PubMed

Petrova, Krasimira T; Potewar, Taterao M; Correia-da-Silva, Paula; Barros, M Teresa; Calhelha, Ricardo C; Ćiric, Ana; Soković, Marina; Ferreira, Isabel C F R

2015-11-19

A library of 1-(1',2,3,3',4,4',6-hepta-O-acetyl-6'-deoxy-sucros-6'-yl)-1,2,3-triazoles have been investigated for their antibacterial, antifungal and cytotoxic activities. Most of the target compounds showed good inhibitory activity against a variety of clinically and food contaminant important microbial pathogens. In particular, 1-(1',2,3,3',4,4',6-hepta-O-acetyl-6'-deoxy-sucros-6'-yl)-4-(4-pentylphenyl)-1,2,3-triazole (5) was highly active against all the tested bacteria with minimal inhibitory concentrations (MICs) ranging between 1.1 and 4.4 µM and bactericidal concentrations (MBCs) from 2.2 and 8.4 µM. The compound 1-(1',2,3,3',4,4',6-hepta-O-acetyl-6'-deoxy-sucros-6'-yl)-4-(4-bromophenyl)-1,2,3-triazole (3) showed antifungal activity with MICs from 0.6 to 4.8 µM and minimal fungicidal concentrations (MFCs) ranging between 1.2 and 8.9 µM. Furthermore, some of the compounds possessed moderate cytotoxicity against human breast, lung, cervical and hepatocellular carcinoma cell lines, without showing toxicity for non-tumor liver cells. The above mentioned derivatives represent promising leads for the development of new generation of sugar-triazole antifungal agents. Copyright © 2015 Elsevier Ltd. All rights reserved.
Natural and anthropogenic radioactivity levels and the associated radiation hazard in the soil of Oodalia Tea Estate in the hilly region of Fatickchari in Chittagong, Bangladesh.

PubMed

Absar, Nurul; Rahman, M Mashiur; Kamal, Masud; Siddique, Naziba; Chowdhury, Mantazul Islam

2014-11-01

Radioactivity in the soil of a tea garden in the Fatickchari area in Chittagong, Bangladesh, was measured using a high-resolution HPGe detector. The soil samples were collected from depths of up to 20 cm beneath the soil surface. The activity concentrations of naturally occurring (238)U and (232)Th were observed to be in the range of 27 ± 7 to 53 ± 8 Bq kg(-1) and 36 ± 11 to 72 ± 11 Bq kg(-1), respectively. The activity concentration of (40)K ranged from 201 ± 78 to 672 ± 81 Bq kg(-1), and the highest activity of fallout (137)Cs observed was 10 ± 1 Bq kg(-1). The average activity concentration observed for (238)U was 39 ± 8 Bq kg(-1), for (232)Th was 57 ± 11 Bq kg(-1), for (40)K was 384 ± 79 Bq kg(-1) and for (137)Cs was 5 ± 0.5 Bq kg(-1). The radiological hazard parameters (representative level index, radium equivalent activity, outdoor and indoor dose rates, outdoor and indoor annual effective dose equivalents, and radiation hazard index) were calculated from the radioactivity in the soil. © The Author 2014. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.
Enzymatic biomarkers can portray nanoCuO-induced oxidative and neuronal stress in freshwater shredders.

PubMed

Pradhan, Arunava; Silva, Carla O; Silva, Carlos; Pascoal, Cláudia; Cássio, Fernanda

2016-11-01

Commercial applications of nanometal oxides have increased concern about their release into natural waters and consequent risks to aquatic biota and the processes they drive. In forest streams, the invertebrate shredder Allogamus ligonifer plays a key role in detritus food webs by transferring carbon and energy from plant litter to higher trophic levels. We assessed the response profiles of oxidative and neuronal stress enzymatic biomarkers in A. ligonifer after 96h exposure to nanoCuO at concentration ranges

Influence of zinc on bacterial populations and their proteolytic enzyme activities in freshwater environments: a cross-site comparison.

PubMed

Rasmussen, Lauren; Olapade, Ola A

2016-04-01

Temporal responses of indigenous bacterial populations and proteolytic enzyme (i.e., aminopeptidase) activities in the bacterioplankton assemblages from 3 separate freshwater environments were examined after exposure to various zinc (Zn) concentrations under controlled microcosm conditions. Zn concentrations (ranging from 0 to 10 μmol/L) were added to water samples collected from the Kalamazoo River, Rice Creek, and Huron River and examined for bacterial abundance and aminopeptidase activities at various time intervals over a 48 h incubation period in the dark. The results showed that the Zn concentrations did not significantly influence total bacterial counts directly; however, aminopeptidase activities varied significantly to increasing zinc treatments over time. Also, analysis of variance and linear regression analyses revealed significant positive relationships between bacterial numbers and their hydrolytic enzyme activities, suggesting that both probably co-vary with increasing Zn concentrations in aquatic systems. The results from this study serve as additional evidence of the ecological role of Zn as an extracellular peptidase cofactor on the dynamics of bacterial assemblages in aquatic environments.
Active/passive microwave sensor comparison of MIZ-ice concentration estimates. [Marginal Ice Zone (MIZ)

NASA Technical Reports Server (NTRS)

Burns, B. A.; Cavalieri, D. J.; Keller, M. R.

1986-01-01

Active and passive microwave data collected during the 1984 summer Marginal Ice Zone Experiment in the Fram Strait (MIZEX 84) are used to compare ice concentration estimates derived from synthetic aperture radar (SAR) data to those obtained from passive microwave imagery at several frequencies. The comparison is carried out to evaluate SAR performance against the more established passive microwave technique, and to investigate discrepancies in terms of how ice surface conditions, imaging geometry, and choice of algorithm parameters affect each sensor. Active and passive estimates of ice concentration agree on average to within 12%. Estimates from the multichannel passive microwave data show best agreement with the SAR estimates because the multichannel algorithm effectively accounts for the range in ice floe brightness temperatures observed in the MIZ.
In vitro activity of natural honey alone and in combination with curcuma starch against Rhodotorula mucilaginosa in correlation with bioactive compounds and diastase activity

PubMed Central

Ahmed, Moussa; Djebli, Noureddine; Aissat, Saad; Khiati, Baghdad; Meslem, Abdelmalek; Bacha, Salima

2013-01-01

Objective To evaluate the in vitro activity and synergism of the combinations of natural honey and curcuma starch against Rhodotorula mucilaginosa in correlation with total phenolic, flavonoid contents, and diastase activity. Methods The Folin-Ciocalteu test was used to determine the total polyphenols content and the flavonoid content was analyzed using by the aluminum chloride method. The antifungal activity of the natural honey, determined by an agar well diffusion assay and agar incorporation method. Results Total phenolic content varied from (63.93±0.11) to (95.36±6.08) mg GAE/100 g honey as gallic acid equivalent. Total flavonoids content varied from (5.41±0.04) to (9.94±0.54) mg CE/100 g. Diastase activity values were between (7.3±2.8) and (26±2.8). The zone inhibition diameter for the six honey samples without starch ranged between 6 and 20 mm. When starch was mixed with honey and then added to well, a zone inhibition increase diameter 7 and 21 mm. The percentage increase was noticed with each variety and it ranged between 5% and 62.5%. The minimal inhibitory concentrations for the six varieties of honey without starch against Rhodotorula mucilaginosa ranged between 28% and 36% (v/v). When starch was incubated with honey and then added to media, a minimal inhibitory concentration drop has been noticed with each variety. It ranged between 6.66 % and 20% (w/v). No significant correlation was established between diastase activity and bioactive compounds. Conclusions The mixture of curcuma starch and honey could lead to the development of new combination antibiotics against Rhodotorula infections PMID:24075348
In vitro activity of natural honey alone and in combination with curcuma starch against Rhodotorula mucilaginosa in correlation with bioactive compounds and diastase activity.

PubMed

Ahmed, Moussa; Djebli, Noureddine; Aissat, Saad; Khiati, Baghdad; Meslem, Abdelmalek; Bacha, Salima

2013-10-01

To evaluate the in vitro activity and synergism of the combinations of natural honey and curcuma starch against Rhodotorula mucilaginosa in correlation with total phenolic, flavonoid contents, and diastase activity. The Folin-Ciocalteu test was used to determine the total polyphenols content and the flavonoid content was analyzed using by the aluminum chloride method. The antifungal activity of the natural honey, determined by an agar well diffusion assay and agar incorporation method. Total phenolic content varied from (63.930.11) to (95.366.08) mg GAE/100 g honey as gallic acid equivalent. Total flavonoids content varied from (5.41±0.04) to (9.94±0.54) mg CE/100 g. Diastase activity values were between (7.3±2.8) and (26±2.8). The zone inhibition diameter for the six honey samples without starch ranged between 6 and 20 mm. When starch was mixed with honey and then added to well, a zone inhibition increase diameter 7 and 21 mm. The percentage increase was noticed with each variety and it ranged between 5% and 62.5%. The minimal inhibitory concentrations for the six varieties of honey without starch against Rhodotorula mucilaginosa ranged between 28% and 36% (v/v). When starch was incubated with honey and then added to media, a minimal inhibitory concentration drop has been noticed with each variety. It ranged between 6.66 % and 20% (w/v). No significant correlation was established between diastase activity and bioactive compounds. The mixture of curcuma starch and honey could lead to the development of new combination antibiotics against Rhodotorula infections. Copyright © 2013 Asian Pacific Tropical Biomedical Magazine. Published by Elsevier B.V. All rights reserved.
Spatial patterns and ratios of ¹³⁷Cs, ⁹⁰Sr, and Pu isotopes in the top layer of undisturbed meadow soils as indicators for contamination origin.

PubMed

Lukšienė, Benedikta; Puzas, Andrius; Remeikis, Vidmantas; Druteikienė, Rūta; Gudelis, Arūnas; Gvozdaitė, Rasa; Buivydas, Šarūnas; Davidonis, Rimantas; Kandrotas, Gintautas

2015-05-01

Spatial distribution of activity concentrations of (137)Cs, (90)Sr, and (239,240)Pu in the top layer of undisturbed meadow soils was compared between two regional transects across Lithuania: one in the SW region, more affected by the Chernobyl radioactive fallout, and the other in the NE region. Radiochemical, γ-, α-, β-, and mass spectrometric methods were used to determine the radionuclide activity. Our results validate that higher activity concentrations in the top soil layer were present in the SW region, despite the fact that sampling was performed after 22 years of the Chernobyl Nuclear Power Plant (NPP) accident. Using the activity concentration ratio (137)Cs/(239,240)Puglobal, the contribution of the Chernobyl NPP accident to the total radiocesium activity concentrations in these meadow soils was evaluated and found to be in the range of 6.5-59.1%. Meanwhile, the activity concentration ratio (238)Pu/(239,240)Pu showed that Chernobyl-derived Pu occurred at almost half of the sampling sites. The locations with maximal values of 47% of Chernobyl-derived Pu material were close to northeastern Poland, where deposition of most of non-volatile radioisotopes from the Chernobyl plume was determined.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Ning; He, Yuqing; Mao, Xun

This paper presents a novel approach to electrochemically determine enzymatically active PSA using ferrocene-functionalized helix peptide (CHSSLKQK). The principle of electrochemical measurement is based on the specific proteolytic cleavage events of the FC-peptide on the gold electrode surface in the presence of PSA, resulting the change of the current signal of the electrode. The percentage of the decreased current is linear with the concentration of active PSA at the range of 0.5-40 ng/mL with a detection limit of 0.2 ng/mL. The direct transduction of peptide cleavage events into an electrical signal provides a simple, sensitive method for detecting the enzymaticmore » activity of PSA and determining the active PSA concentration.« less
Effect on the growth and development and induction of abnormalities by a glyphosate commercial formulation and its active ingredient during two developmental stages of the South-American Creole frog, Leptodactylus latrans.

PubMed

Bach, Nadia Carla; Natale, Guillermo Sebastián; Somoza, Gustavo Manuel; Ronco, Alicia Estela

2016-12-01

We evaluated the acute lethal and sublethal effects of technical-grade glyphosate (GLY) and the GLY-based commercial formulation Roundup ULTRA MAX® (RU) on two Gosner stages (Gss) 25 and 36 of the South-American Creole frog, Leptodactylus latrans. Bioassays were performed following standardized methods within a wide range of concentrations (0.0007-9.62 mg of acid equivalents per liter-a.e./L-of RU and 3-300 mg/L of GLY). The endpoints evaluated were mortality, swimming activity, growth, development, and the presence of morphologic abnormalities, especially in the mouthparts. No lethal effects were observed on larvae exposed to GLY during either Gs-25 or Gs-36. The concentrations inducing 50 % lethality in RU-exposed larvae at different exposure times and Gss ranged from 3.26 to 9.61 mg a.e./L. Swimming activity was affected by only RU. Effects on growth and development and the induction of morphologic abnormalities-like oral abnormalities and edema-were observed after exposure to either GLY or RU. Gs-25 was the most sensitive stage to both forms of the herbicide. The commercial formulation was much more toxic than the active ingredient on all the endpoints assessed. Effects on growth, development, and the induction of morphologic abnormalities observed in the range of environmental concentrations reported for agroecosystems of Argentina constitute an alert to the potential detrimental effects of the herbicide that could be affecting the fitness and survival of anurans in agroecosystems.
In vitro inflammatory and cytotoxic effects of size-segregated particulate samples collected during long-range transport of wildfire smoke to Helsinki

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jalava, Pasi I.; Salonen, Raimo O.; Haelinen, Arja I.

2006-09-15

The impact of long-range transport (LRT) episodes of wildfire smoke on the inflammogenic and cytotoxic activity of urban air particles was investigated in the mouse RAW 264.7 macrophages. The particles were sampled in four size ranges using a modified Harvard high-volume cascade impactor, and the samples were chemically characterized for identification of different emission sources. The particulate mass concentration in the accumulation size range (PM{sub 1-0.2}) was highly increased during two LRT episodes, but the contents of total and genotoxic polycyclic aromatic hydrocarbons (PAH) in collected particulate samples were only 10-25% of those in the seasonal average sample. The abilitymore » of coarse (PM{sub 10-2.5}), intermodal size range (PM{sub 2.5-1}), PM{sub 1-0.2} and ultrafine (PM{sub 0.2}) particles to cause cytokine production (TNF{alpha}, IL-6, MIP-2) reduced along with smaller particle size, but the size range had a much smaller impact on induced nitric oxide (NO) production and cytotoxicity or apoptosis. The aerosol particles collected during LRT episodes had a substantially lower activity in cytokine production than the corresponding particles of the seasonal average period, which is suggested to be due to chemical transformation of the organic fraction during aging. However, the episode events were associated with enhanced inflammogenic and cytotoxic activities per inhaled cubic meter of air due to the greatly increased particulate mass concentration in the accumulation size range, which may have public health implications.« less
Evidence for activation of nuclear factor kappaB in obstructive sleep apnea.

PubMed

Yamauchi, Motoo; Tamaki, Shinji; Tomoda, Koichi; Yoshikawa, Masanori; Fukuoka, Atsuhiko; Makinodan, Kiyoshi; Koyama, Noriko; Suzuki, Takahiro; Kimura, Hiroshi

2006-12-01

Obstructive sleep apnea (OSA) is a risk factor for atherosclerosis, and atherosclerosis evolves from activation of the inflammatory cascade. We propose that activation of the nuclear factor kappaB (NF-kappaB), a key transcription factor in the inflammatory cascade, occurs in OSA. Nine age-matched, nonsmoking, and non-hypertensive men with OSA symptoms and seven similar healthy subjects were recruited for standard polysomnography followed by the collection of blood samples for monocyte nuclear p65 concentrations (OSA and healthy groups). In the OSA group, p65 and of monocyte production of tumor necrosis factor alpha (TNF-alpha) were measured at the same time and after the next night of continuous positive airway pressure (CPAP). p65 Concentrations in the OSA group were significantly higher than in the control group [median, 0.037 ng/microl (interquartile range, 0.034 to 0.051) vs 0.019 ng/microl (interquartile range, 0.013 to 0.032); p = 0.008], and in the OSA group were significantly correlated with apnea-hypopnea index and time spent below an oxygen saturation of 90% (r = 0.77 and 0.88, respectively) after adjustment for age and BMI. One night of CPAP resulted in a reduction in p65 [to 0.020 ng/mul (interquartile range, 0.010 to 0.036), p = 0.04] and levels of TNF-alpha production in cultured monocytes [16.26 (interquartile range, 7.75 to 24.85) to 7.59 ng/ml (interquartile range, 5.19 to 12.95), p = 0.01]. NF-kappaB activation occurs with sleep-disordered breathing. Such activation of NF-kappaB may contribute to the pathogenesis of atherosclerosis in OSA patients.
Measurements of radon concentrations in Spa waters in Amasya, Turkey

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yigitoglu, I., E-mail: ibrahim.yigitoglu@gop.edu.tr; Ucar, B.; Oner, F.

The aim of this study is to determine the radon concentrations in thermal waters in the Amasya basin in Turkey and to explore the relationship between radon anomalies and active geological faults. The radon concentration measurements were performed in four thermal Spas around Amasya basin. The water samples were collected from tap waters in thermal water sources. The obtained radon concentrations ranged from 0.15 ± 0.12 to 0.71 ± 0.32 BqL{sup −1} for Spa waters. The relationship between the radon concentration anomalies and earthquakes that occurred in the sampling period are discussed.
Assessment of combined antiandrogenic effects of binary parabens mixtures in a yeast-based reporter assay.

PubMed

Ma, Dehua; Chen, Lujun; Zhu, Xiaobiao; Li, Feifei; Liu, Cong; Liu, Rui

2014-05-01

To date, toxicological studies of endocrine disrupting chemicals (EDCs) have typically focused on single chemical exposures and associated effects. However, exposure to EDCs mixtures in the environment is common. Antiandrogens represent a group of EDCs, which draw increasing attention due to their resultant demasculinization and sexual disruption of aquatic organisms. Although there are a number of in vivo and in vitro studies investigating the combined effects of antiandrogen mixtures, these studies are mainly on selected model compounds such as flutamide, procymidone, and vinclozolin. The aim of the present study is to investigate the combined antiandrogenic effects of parabens, which are widely used antiandrogens in industrial and domestic commodities. A yeast-based human androgen receptor (hAR) assay (YAS) was applied to assess the antiandrogenic activities of n-propylparaben (nPrP), iso-propylparaben (iPrP), methylparaben (MeP), and 4-n-pentylphenol (PeP), as well as the binary mixtures of nPrP with each of the other three antiandrogens. All of the four compounds could exhibit antiandrogenic activity via the hAR. A linear interaction model was applied to quantitatively analyze the interaction between nPrP and each of the other three antiandrogens. The isoboles method was modified to show the variation of combined effects as the concentrations of mixed antiandrogens were changed. Graphs were constructed to show isoeffective curves of three binary mixtures based on the fitted linear interaction model and to evaluate the interaction of the mixed antiandrogens (synergism or antagonism). The combined effect of equimolar combinations of the three mixtures was also considered with the nonlinear isoboles method. The main effect parameters and interaction effect parameters in the linear interaction models of the three mixtures were different from zero. The results showed that any two antiandrogens in their binary mixtures tended to exert equal antiandrogenic activity in the linear concentration ranges. The antiandrogenicity of the binary mixture and the concentration of nPrP were fitted to a sigmoidal model if the concentrations of the other antiandrogens (iPrP, MeP, and PeP) in the mixture were lower than the AR saturation concentrations. Some concave isoboles above the additivity line appeared in all the three mixtures. There were some synergistic effects of the binary mixture of nPrP and MeP at low concentrations in the linear concentration ranges. Interesting, when the antiandrogens concentrations approached the saturation, the interaction between chemicals were antagonistic for all the three mixtures tested. When the toxicity of the three mixtures was assessed using nonlinear isoboles, only antagonism was observed for equimolar combinations of nPrP and iPrP as the concentrations were increased from the no-observed-effect-concentration (NOEC) to effective concentration of 80%. In addition, the interactions were changed from synergistic to antagonistic as effective concentrations were increased in the equimolar combinations of nPrP and MeP, as well as nPrP and PeP. The combined effects of three binary antiandrogens mixtures in the linear ranges were successfully evaluated by curve fitting and isoboles. The combined effects of specific binary mixtures varied depending on the concentrations of the chemicals in the mixtures. At low concentrations in the linear concentration ranges, there was synergistic interaction existing in the binary mixture of nPrP and MeP. The interaction tended to be antagonistic as the antiandrogens approached saturation concentrations in mixtures of nPrP with each of the other three antiandrogens. The synergistic interaction was also found in the equimolar combinations of nPrP and MeP, as well as nPrP and PeP, at low concentrations with another method of nonlinear isoboles. The mixture activities of binary antiandrogens had a tendency towards antagonism at high concentrations and synergism at low concentrations.
Mesospheric sodium over Gadanki during Geminid meteor shower 2007

NASA Astrophysics Data System (ADS)

Lokanadham, B.; Rakesh Chandra, N.; Bhaskara Rao, S. Vijaya; Raghunath, K.; Yellaiah, G.

Resonance LIDAR system at Gadanki has been used for observing the mesospheric sodium during the night of 12-13 Dec 2007 when the peak activity of Geminid meteor shower occurred. Geminid meteor shower is observed along with the co-located MST radar in the altitude range 80-110 km. Sodium density profiles have been obtained with a vertical resolution of 300 m and a temporal resolution of 120 s with sodium resonance scattering LIDAR system. The sodium layers were found to exist in the altitude range 90-100 km. The enhanced Geminid meteor rates were recorded with the co-located MST radar in the same altitude range. The sodium concentration in the atmospheric altitude of ~93 km is estimated to be 2000 per cc where the meteoric concentration of Geminid is maximum and reduced to around 800 on the non activity of Geminid. These observations showed that the sodium levels in the E-region are found to be increasing during meteor shower nights at least by a factor of two.
Fluoride geochemistry of thermal waters in Yellowstone National Park: I. Aqueous fluoride speciation

USGS Publications Warehouse

Deng, Y.; Nordstrom, D. Kirk; McCleskey, R. Blaine

2011-01-01

Thermal water samples from Yellowstone National Park (YNP) have a wide range of pH (1–10), temperature, and high concentrations of fluoride (up to 50 mg/l). High fluoride concentrations are found in waters with field pH higher than 6 (except those in Crater Hills) and temperatures higher than 50 °C based on data from more than 750 water samples covering most thermal areas in YNP from 1975 to 2008. In this study, more than 140 water samples from YNP collected in 2006–2009 were analyzed for free-fluoride activity by ion-selective electrode (ISE) method as an independent check on the reliability of fluoride speciation calculations. The free to total fluoride concentration ratio ranged from <1% at low pH values to >99% at high pH. The wide range in fluoride activity can be explained by strong complexing with H+ and Al3+ under acidic conditions and lack of complexing under basic conditions. Differences between the free-fluoride activities calculated with the WATEQ4F code and those measured by ISE were within 0.3–30% for more than 90% of samples at or above 10−6 molar, providing corroboration for chemical speciation models for a wide range of pH and chemistry of YNP thermal waters. Calculated speciation results show that free fluoride, F−, and major complexes (HF(aq)0">HF(aq)0, AlF2+, AlF2+">AlF2+and AlF30">AlF30) account for more than 95% of total fluoride. Occasionally, some complex species like AlF4-">AlF4-, FeF2+, FeF2+">FeF2+, MgF+ and BF2(OH)2-">BF2(OH)2- may comprise 1–10% when the concentrations of the appropriate components are high. According to the simulation results by PHREEQC and calculated results, the ratio of main fluoride species to total fluoride varies as a function of pH and the concentrations and ratios of F and Al.
Evaluation of Antimicrobial Activity of the Methanol Extracts from 8 Traditional Medicinal Plants

PubMed Central

Kang, Chang-Geun; Hah, Dae-Sik; Kim, Chung-Hui; Kim, Young-Hwan; Kim, Euikyung

2011-01-01

The methanol extract of 12 medicinal plants were evaluated for its antibacterial activity against Gram-positive (5 strains) and Gram-negative bacteria (10 strains) by assay for minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) . The antibacterial activity was determined by an agar dilution method (according to the guidelines of Clinical and Laboratory Standard Institute) . All the compounds (12 extracts) of the 8 medicinal plants (leaf or root) were active against both Gram-negative and Gram-positive bacteria. Gram-negative showed a more potent action than Gram positive bacteria. The MIC concentrations were various ranged from 0.6 μg/ml to 5000 μg/ml. The lowest MIC (0.6 μg/ml) and MBC (1.22 μg/ml) values were obtained with extract on 4 and 3 of the 15 microorganisms tested, respectively. PMID:24278548
Toxicity of TiO2 nanoparticles on soil nitrification at environmentally relevant concentrations: Lack of classical dose-response relationships.

PubMed

Simonin, Marie; Martins, Jean M F; Le Roux, Xavier; Uzu, Gaëlle; Calas, Aude; Richaume, Agnès

2017-03-01

Titanium-dioxide nanoparticles (TiO 2 -NPs) are increasingly released in agricultural soils through, e.g. biosolids, irrigation or nanoagrochemicals. Soils are submitted to a wide range of concentrations of TiO 2 -NPs depending on the type of exposure. However, most studies have assessed the effects of unrealistically high concentrations, and the dose-response relationships are not well characterized for soil microbial communities. Here, using soil microcosms, we assessed the impact of TiO 2 -NPs at concentrations ranging from 0.05 to 500 mg kg -1 dry-soil, on the activity and abundance of ammonia-oxidizing archaea (AOA) and bacteria (AOB), and nitrite-oxidizing bacteria (Nitrobacter and Nitrospira). In addition, aggregation and oxidative potential of TiO 2 -NPs were measured in the spiking suspensions, as they can be important drivers of TiO 2 -NPs toxicity. After 90 days of exposure, non-classical dose-response relationships were observed for nitrifier abundance or activity, making threshold concentrations impossible to compute. Indeed, AOA abundance was reduced by 40% by TiO 2 -NPs whatever the concentration, while Nitrospira was never affected. Moreover, AOB and Nitrobacter abundances were decreased mainly at intermediate concentrations nitrification was reduced by 25% at the lowest (0.05 mg kg -1 ) and the highest (100 and 500 mg kg -1 ) TiO 2 -NPs concentrations. Path analyses indicated that TiO 2 -NPs affected nitrification through an effect on the specific activity of nitrifiers, in addition to indirect effects on nitrifier abundances. Altogether these results point out the need to include very low concentrations of NPs in soil toxicological studies, and the lack of relevance of classical dose-response tests and ecotoxicological dose metrics (EC50, IC50…) for TiO 2 -NPs impact on soil microorganisms.
Distribution of pesticides and PCBs in sediments of agricultural drains in the Culiacan Valley, Sinaloa, Mexico.

PubMed

García-de la Parra, Luz María; Cervantes-Mojica, L Juleny; González-Valdivia, Carolina; Martínez-Cordero, Francisco J; Aguilar-Zárate, Gabriela; Bastidas-Bastidas, Pedro; Betancourt-Lozano, Miguel

2012-10-01

Agriculture is one of the most important economic activities in Sinaloa, Mexico. The Culiacan Valley is an extensive agricultural region characterized by a variety of crops with high-yield productions. In this study, concentrations of organochlorine (OCPs) and organophosphorus (OPs) pesticides and polychlorobiphenyls (PCBs) were determined in sediments of the agricultural drainage system of Culiacan Valley. Overall, 32 compounds were detected, with concentrations widely ranging from 0.03 to 1 294 ng g(-1) dry weight. OCP concentrations (15) ranged from 0.1 to 20.19 ng g(-1) dw. OP concentrations (8) ranged from 0.03 to 1294 ng g(-1) dw, and diazinon was the compound with the highest concentration. PCB concentrations were also determined and varied from 0.05 to 3.29 ng g(-1) dw. Other compounds detected included permethrin, triadimefon, and fipronil. The central zone registered the higher concentrations and the greatest number of compounds, which could be related to the occurrence of horticultural fields in this zone. According to sediment quality guidelines, the compounds exceeding the probable effect level were γ-HCH, p,p'-DDT and p,p'-DDE, while the pesticides above the maximum permissible concentration were endosulfan, azinphos methyl, diazinon, dichlorvos, and permethrin. Although Sinaloa is an important agricultural crop producer in northwest Mexico, there are not many studies dealing with pesticide distribution in agricultural areas.
Design of aromatic-containing cell-penetrating peptide mimics with structurally modified π electronics.

PubMed

deRonde, Brittany M; Birke, Alexander; Tew, Gregory N

2015-02-09

Cell-penetrating peptides (CPPs) and their synthetic mimics (CPPMs) represent a class of molecules that facilitate the intracellular delivery of various cargo. Previous studies indicated that the presence of aromatic functionalities improved CPPM activity. Given that aromatic functionalities play prominent roles in membrane biology and participate in various π interactions, we explored whether these interactions could be optimized for improved CPPM activity. CPPMs were synthesized by ring-opening metathesis polymerization by using monomers that contained aromatic rings substituted with electron-donating and electron-withdrawing groups and covered an electrostatic potential range from -29.69 to +15.57 kcal mol(-1) . These groups altered the quadrupole moments of the aromatic systems and were used to test if such structural modifications changed CPPM activity. CPPMs were added to dye-loaded vesicles and the release of carboxyfluorescein was monitored as a function of polymer concentration. Changes in the effective polymer concentration to release 50% of the dye (effective concentration, EC50 ) were monitored. Results from this assay showed that the strength of the electron-donating and electron-withdrawing groups incorporated in the CPPMs did not alter polymer EC50 values or activity. This suggests that other design parameters may have a stronger impact on CPPM activity. In addition, these results indicate that a wide range of aromatic groups can be incorporated without negatively impacting polymer activity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Red blood cell hypoxanthine phosphoribosyltransferase activity measured using 6-mercaptopurine as a substrate: a population study in children with acute lymphoblastic leukaemia.

PubMed Central

Lennard, L; Hale, J P; Lilleyman, J S

1993-01-01

1. 6-Mercaptopurine (6-MP) is used in the continuing chemotherapy of childhood acute lymphoblastic leukaemia. The formation of red blood cell (RBC) 6-thioguanine nucleotide (6-TGN) active metabolites, not the dose of 6-MP, is related to cytotoxicity and prognosis. But there is an apparent sex difference in 6-MP metabolism. Boys require more 6-MP than girls to produce the same range of 6-TGN concentrations. Given the same dose, they experience fewer dose reductions because of cytotoxicity, and have a higher relapse rate. 2. The enzyme hypoxanthine phosphoribosyltransferase (HPRT) catalyses the initial activation step in the metabolism of 6-MP to 6-TGNs, a step that requires endogenous phosphoribosyl pyrophosphate (PRPP) as a cosubstrate. Both HPRT and the enzyme responsible for the formation of PRPP are X-linked. 3. RBC HPRT activity was measured in two populations, 86 control children and 63 children with acute lymphoblastic leukaemia. 6-MP was used as the substrate and the formation of the nucleotide product, 6-thioinosinic acid (TIA) was measured. RBC 6-TGN concentrations were measured in the leukaemic children at a standard dose of 6-MP. 4. There was a 1.3 to 1.7 fold range in HPRT activity when measured under optimal conditions. The leukaemic children had significantly higher HPRT activities than the controls (median difference 4.2 micromol TIA ml(-1) RBCs h(-1), 95% C.I. 3.7 to 4.7, P < 0.0001). In the leukaemic children HPRT activity (range 20.4 to 26.6 micromol TIA ml(-1) RBCs h(-1), median 23.6) was not related to the production of 6-TGNs (range 60 to 1,024 pmol 8 x 10(-8) RBCs, median 323). RBC HPRT was present at a high activity even in those children with low 6-TGN concentrations. 5. When HPRT is measured under optimal conditions it does not appear to be the metabolic step responsible for the observed sex difference in 6-MP metabolism. This may be because RBC HPRT activity is not representative of other tissues but it could equally be because other sex-linked factors are influencing substrate availability. PMID:12959304
Temporal and spatial variation of beaked and sperm whales foraging activity in Hawai'i, as determined with passive acoustics.

PubMed

Giorli, Giacomo; Neuheimer, Anna; Copeland, Adrienne; Au, Whitlow W L

2016-10-01

Beaked and sperm whales are top predators living in the waters off the Kona coast of Hawai'i. Temporal and spatial analyses of the foraging activity of these two species were studied with passive acoustics techniques. Three passive acoustics recorders moored to the ocean floor were used to monitor the foraging activity of these whales in three locations along the Kona coast of the island of Hawaii. Data were analyzed using automatic detector/classification systems: M3R (Marine Mammal Monitoring on Navy Ranges), and custom-designed Matlab programs. The temporal variation in foraging activity was species-specific: beaked whales foraged more at night in the north, and more during the day-time off Kailua-Kona. No day-time/night-time preference was found in the southern end of the sampling range. Sperm whales foraged mainly at night in the north, but no day-time/night-time preference was observed off Kailua-Kona and in the south. A Generalized Linear Model was then applied to assess whether location and chlorophyll concentration affected the foraging activity of each species. Chlorophyll concentration and location influenced the foraging activity of both these species of deep-diving odontocetes.
Thorium isotopes in colloidal fraction of water from San Marcos Dam, Chihuahua, Mexico

NASA Astrophysics Data System (ADS)

Cabral-Lares, M.; Melgoza, A.; Montero-Cabrera, M. E.; Renteria-Villalobos, M.

2013-07-01

The main interest of this stiidy is to assess the contents and distribution of Th-series isotopes in colloidal fraction of surface water from San Marcos dam, because the suspended particulate matter serves as transport medium for several pollutants. The aim of this work was to assess the distribution of thorium isotopes (232Th and 230Th) contained in suspended matter. Samples were taken from three surface points along the San Marcos dam: water input, midpoint, and near to dam wall. In this last point, a depth sampling was also carried out. Here, three depth points were taken at 0.4, 8 and 15 meters. To evaluate the thorium behavior in surface water, from every water sample the colloidal fraction was separated, between 1 and 0.1 μm. Thorium isotopes concentraron in samples were obtained by alpha spectrometry. Activity concentrations obtained of 232Th and 230Th in surface points ranged from 0.3 to 0.5 Bq ṡ L-1, whereas in depth points ranged from 0.4 to 3.2 Bq ṡ L-1, respectively. The results show that 230Th is in higher concentration than 232Th in colloidal fraction. This can be attributed to a preference of these colloids to adsorb uranium. Thus, the activity ratio 230Th/232Th in colloidal fraction showed values from 2.3 to 10.2. In surface points along the dam, 230Th activity concentration decreases while 232Th concentration remains constant. On the other hand, activity concentrations of both isotopes showed a pointed out enhancement with depth. The results have shown a possible lixiviation of uranium from geological substrate into the surface water and an important fractionation of thorium isotopes, which suggest that thorium is non-homogeneously distributed along San Marcos dam.

Overcoming non-specific binding to measure the active concentration and kinetics of serum anti-HLA antibodies by surface plasmon resonance.

PubMed

Visentin, Jonathan; Couzi, Lionel; Dromer, Claire; Neau-Cransac, Martine; Guidicelli, Gwendaline; Veniard, Vincent; Coniat, Karine Nubret-le; Merville, Pierre; Di Primo, Carmelo; Taupin, Jean-Luc

2018-06-07

Human leukocyte antigen (HLA) donor-specific antibodies are key serum biomarkers for assessing the outcome of transplanted patients. Measuring their active concentration, i.e. the fraction that really interacts with donor HLA, and their affinity could help deciphering their pathogenicity. Surface plasmon resonance (SPR) is recognized as the gold-standard for measuring binding kinetics but also active concentrations, without calibration curves. SPR-based biosensors often suffer from non-specific binding (NSB) occurring with the sensor chip surface and the immobilized targets, especially for complex media such as human serum. In this work we show that several serum treatments such as dialysis or IgG purification reduce NSB but insufficiently for SPR applications. We then demonstrate that the NSB contribution to the SPR signal can be eliminated to determine precisely and reliably the active concentration and the affinity of anti-HLA antibodies from patients' sera. This was achieved even at concentrations close to the limit of quantification of the method, in the 0.5-1 nM range. The robustness of the assay was demonstrated by using a wide range of artificially generated NSB and by varying the density of the targets captured onto the surface. The assay is of general interest and can be used with molecules generating strong NSB, as far as a non-cognate target structurally close to the target can be captured on the same flow cell, in a different binding cycle. Compared with current fluorescence-based methods that are semi-quantitative, we expect this SPR-based assay to help better understanding anti-HLA antibodies pathogenicity and improving organ recipients' management. Copyright © 2018 Elsevier B.V. All rights reserved.
Environmental assessment of aromatic hydrocarbons-contaminated sediments of the Mexican Salina Cuz Bay.

PubMed

González-Macías, C; Schifter, I; Lluch-Cota, D B; Méndez-Rodríguez, L; Hernández-Vázquez, S

2007-10-01

Concentrations of total aromatic hydrocarbons and extractable organic matter in the water column and sediment were determined in samples collected in the course of the last 20 years from the Salina Cruz Harbor, México, to assess the degree of organic contamination. In sediments, organic compounds accumulate in shallow areas mostly associated with extractable organic matter and fine fractions. Calculated geocumulation index and enrichment factors suggest that contamination could be derived from anthropogenic activities attributed to harbor and ship scrapping activities, as well as transboundary source. Concentration of total aromatic hydrocarbons (as chrysene equivalents) ranged from 0.01 to 534 microg l(-1) in water, and from 0.10 to 2,160 microg g(-1) in sediments. Total aromatic concentration of 5 microg g(-1) is proposed as background concentration.
Runoff of particle bound pollutants from urban impervious surfaces studied by analysis of sediments from stormwater traps.

PubMed

Jartun, Morten; Ottesen, Rolf Tore; Steinnes, Eiliv; Volden, Tore

2008-06-25

Runoff sediments from 68 small stormwater traps around the harbor of urban Bergen, Norway, were sampled and the concentrations of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), heavy metals, and total organic carbon (TOC) were determined in addition to grain size. Our study provides empirical data from a large area in the interface between the urban and marine environment, studying the active transport of pollutants from land-based sources. The results of the analyses clearly demonstrate the importance of the urban environment representing a variety of contamination sources, and that stormwater runoff is an important dispersion mechanism of toxic pollutants. The concentrations of different pollutants in urban runoff sediments show that there are several active pollution sources supplying the sewage systems with PCBs, PAHs and heavy metals such as lead (Pb), zinc (Zn) and cadmium (Cd). The concentration of PCB7 in the urban runoff sediments ranged between < 0.0004 and 0.704 mg/kg. For PAH16, the concentration range was < 0.2-80 mg/kg, whereas the concentration ranges of Pb, Zn and Cd were 9-675, 51.3-4670 and 0.02-11.1 mg/kg respectively. Grain size distribution in 21 selected samples varied from a median particle diameter of 13 to 646 microm. However, several samples had very fine-grained particles even up to the 90 percentile of the samples, making them available for stormwater dispersion in suspended form. The sampling approach proposed in this paper will provide environmental authorities with a useful tool to examine ongoing urban contamination of harbors and similar recipients.
The effect of artichoke (Cynara scolymus L.) extract on respiratory chain system activity in rat liver mitochondria.

PubMed

Juzyszyn, Z; Czerny, B; Myśliwiec, Z; Pawlik, A; Droździk, M

2010-06-01

The effect of artichoke extract on mitochondrial respiratory chain (MRC) activity in isolated rat liver mitochondria (including reaction kinetics) was studied. The effect of the extract on the activity of isolated cytochrome oxidase was also studied. Extract in the range of 0.68-2.72 microg/ml demonstrated potent and concentration-dependent inhibitory activity. Concentrations > or =5.4 microg/ml entirely inhibited MRC activity. The succinate oxidase system (MRC complexes II-IV) was the most potently inhibited, its activity at an extract concentration of 1.36 microg/ml being reduced by 63.3% compared with the control (p < 0.05). The results suggest a complex inhibitory mechanism of the extract. Inhibition of the succinate oxidase system was competitive (K(i) = 0.23 microg/ml), whereas isolated cytochrome oxidase was inhibited noncompetitively (K(i) = 126 microg/ml). The results of this study suggest that the salubrious effects of artichoke extracts may rely in part on the effects of their active compounds on the activity of the mitochondrial respiratory chain system.
Phytochemical analysis of Gymnema sylvestre and evaluation of its antimicrobial activity.

PubMed

Chodisetti, Bhuvaneswari; Rao, Kiranmayee; Giri, Archana

2013-01-01

Gymnema sylvestre (CS 149), known to be a rich source of saponins and other valuable phytochemicals, has been analysed for antimicrobial activity. The chloroform extracts of aerial and root parts of G. sylvestre exhibited higher antimicrobial activity as compared to diethyl ether and acetone. The root extracts of chloroform have shown competitive minimum inhibitory concentration and minimum bactericidal concentration values in the range of 0.04-1.28 mg mL(-1) and 0.08-2.56 mg/mL, respectively, towards the pathogens. The GC-MS analysis of chloroform extracts has shown the presence of compounds like eicosane, oleic acid, stigmasterol and vitamin E.
Distribution and environmental impacts of heavy metals and radioactivity in sediment and seawater samples of the Marmara Sea.

PubMed

Otansev, Pelin; Taşkın, Halim; Başsarı, Asiye; Varinlioğlu, Ahmet

2016-07-01

In this study, the natural and anthropogenic radioactivity levels in the sediment samples collected from the Marmara Sea in Turkey were determined. The average activity concentrations (range) of (226)Ra, (238)U, (232)Th, (40)K and (137)Cs were found to be 23.8 (13.8-34.2) Bq kg(-1), 18.8 (6.4-25.9) Bq kg(-1), 23.02 (6.3-31.1) Bq kg(-1), 558.6 (378.8-693.6) Bq kg(-1) and 9.14 (4.8-16.3) Bq kg(-1), respectively. Our results showed that the average activity concentrations of (226)Ra, (238)U and (232)Th in the sediment samples were within the acceptable limits; whereas the average activity concentration of (40)K in the sediment samples was higher than the worldwide average concentration. The average radium equivalent activity, the average absorbed dose rate and the average external hazard index were calculated as 100.01 Bq kg(-1), 48.32 nGy h(-1) and 0.27, respectively. The average gross alpha and beta activity in the seawater samples were found to be 0.042 Bq L(-1) and 13.402 Bq L(-1), respectively. The gross alpha and beta activity concentrations increased with water depth in the same stations. The average heavy metal concentrations (range) in the sediment samples were 114.6 (21.6-201.7) μg g(-1) for Cr, 568.2 (190.8-1625.1) μg g(-1) for Mn, 39.3 (4.9-83.4) μg g(-1) for Cu, 85.5 (11.0-171.8) μg g(-1) for Zn, 32.9 (9.1-73.1) μg g(-1) for Pb and 49.1 (6.8-103.0) μg g(-1) for Ni. S5 station was heavily polluted by Cr, Cu, Ni and Pb. The results showed that heavy metal enrichment in sediments of the Marmara Sea was widespread. Copyright © 2016 Elsevier Ltd. All rights reserved.
Trace anesthetic vapors in hospital operating-room environments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi-Lao, A.T.

1981-05-01

This study investigated concentrations of halothane anesthetic vapors in the operating rooms of two hospitals in the Ottawa, Ontario, Canada, area. Air samples, taken by active charcoal tubes and dosimeter badges, were analyzed by a gas chromatographic technique. Readings of 71 samples taken from hospital A and 65 samples from hospital B ranged from 1.0 to 29.4 parts per billion (ppb) for the active period and 0.1 to 3.8 ppb for the inactive period. All samples showed trace concentrations of halothane, but were well below the recommended maximal level.
Honey Bee as Alternative Medicine to Treat Eleven Multidrug-Resistant Bacteria Causing Urinary Tract Infection during Pregnancy.

PubMed

Bouacha, Mabrouka; Ayed, Hayette; Grara, Nedjoud

2018-04-13

Medicinal benefits of honey bee have been recognized in the medical community since ancient times as a remedy for many diseases and infections. This study aimed to investigate the in vitro susceptibility of 11 multidrug-resistant bacterial strains, isolated from urinary tract infections of pregnant women, to six honey samples collected from different localities in the east of Algeria. The evaluation of the antibacterial activity was performed by the well method followed by the broth dilution method using two-fold dilutions of each honey sample ranging from 2.5 to 80% (w/v). The results obtained in this study revealed that all tested honeys exhibited potent antibacterial activity against the tested strains. The diameters of inhibition ranged from 19.67 to 53.33 mm, with minimum inhibitory concentrations (MICs) ranging from 2.5 to 40% (w/v) and minimum bactericidal concentration (MBCs) varied between 2.5 and 80% (w/v). Gram-positive bacteria were found to be more susceptible than Gram-negative bacteria with diameters ranging from 43.33 to 53.33 mm; MIC and MBC values ranged from 2.5 to 5% (w/v). The P.aeruginosa strain was found to be less susceptible than other strains with inhibitory diameters ranging from 19.67 to 27.33 mm; MICs ranged from 20 to 40% and MBCs ranged from 20 to 80% ( w/v ). This contribution has provided a broad overview of the antibacterial activity of Algerian honey and shown that honey bee has great potential for therapeutic use as an alternative therapy for urinary tract infection treatment which is safe and efficient during pregnancy.
Environmental implications and spatial distribution of natural radionuclides and heavy metals in sediments from four harbours in the Egyptian Red Sea coast.

PubMed

El-Taher, Atef; Zakaly, Hesham M H; Elsaman, Reda

2018-01-01

Measurements of natural radionuclides concentrations ( 226 Ra, 232 Th and 40 K) in sediments collected from sea, rivers or ocean is significant to protect the sea water ecosystem and to human health from radiation. Thirty-three sample of sediment have been collected from four ports in the Red Sea coast, Egypt for investigation by gamma-ray spectrometer using NaI(Tl) detector. The average and range activity concentrations of 226 Ra, 232 Th and 40 K were 26(5-58), 19(4-33) and 458(16-2665)Bqkg -1 in Quseir Harbour, 30(14-53), 20(14-34) and 430(378-511)Bqkg -1 in Abu-Tartour Harbour. However, the average and range activity concentrations were 23(14-35), 21(15-32), and 602(327-821)Bqkg -1 in Touristic Harbour and 14(5-26), 13(2-23) and 489(36-950)Bqkg -1 in Hurghada harbour. These results were compared with reported ranges in the literature from other location in the world. The radiation hazard parameters; radium equivalent activity annual dose, external hazard were also calculated and compared with the recommended levels by UNSCEAR reports. Eight heavy metals (Fe, Mn, Ni, Co, Zn, Cu, Pb and Cd) have been measured and analyzed by atomic absorption spectrometer. The concentration for the investigated heavy metals overtakes the allowable limits recommended by the Canadian Environmental Quality Guidelines. Because there are no existing databases for the natural radioactivity in the sediment samples from Egyptian Red Sea ports, our results are a start to establishing a database for Red Sea harbours environment. Copyright © 2017 Elsevier Ltd. All rights reserved.
Growth response of Douglas-fir seedlings to nitrogen fertilization: importance of Rubisco activation state and respiration rates.

Treesearch

Daniel K. Manter; Kathleen L. Kavanagh; Cathy L. Rose

2005-01-01

High foliar nitrogen concentration ([N]) is associated with high rates of photosynthesis and thus high tree productivity; however, at excessive [N], tree productivity is reduced. Reports of excessive [N] in the Douglas-fir forests of the Oregon Coast Range prompted this investigation of growth and needle physiological responses to increasing foliar N concentrations in...
How reliable an indicator of inflammation is myeloperoxidase activity?

PubMed

Faith, Minnie; Sukumaran, Abitha; Pulimood, Anna B; Jacob, Molly

2008-10-01

Myeloperoxidase (MPO) and interleukin-6 (IL-6) are often used as markers of inflammation. The aim of this study was to ascertain whether MPO activity is as reliable as IL-6 as an indicator of inflammation. Inflammation was induced in mice, using either turpentine or indomethacin. Duodenal tissue was removed from these animals at various time periods ranging from 6 h to 7 days later. Concentrations of IL-6 and MPO activity were estimated in the tissue. Histopathological examination was also carried out at some of the time periods to determine the presence of neutrophil infiltration in turpentine-treated mice. Concentrations of IL-6 and MPO activity were significantly higher in tissue that had been treated with the agents used, at all the time periods studied, when compared with corresponding control tissue. Fold-increases in MPO activity were higher than fold-increases in IL-6. Concentrations of the 2 parameters showed significant positive correlation. Histopathological examination did not show significantly higher numbers of neutrophils infiltrating the tissue in response to turpentine, at the time periods studied. Estimation of MPO activity is a reliable indicator of inflammation, being more sensitive than histopathological examination of tissue and as good as measurement of IL-6 concentrations.
Quantification of hair cortisol concentration in common marmosets (Callithrix jacchus) and tufted capuchins (Cebus apella).

PubMed

Phillips, Kimberley A; Tukan, Alyson N; Rigodanzo, Anna D; Reusch, Ryan T; Brasky, Kathleen M; Meyer, Jerrold S

2018-06-04

Quantifying cortisol concentration in hair is a non-invasive biomarker of long-term hypothalamic-pituitary-adrenal (HPA) activation, and thus can provide important information on laboratory animal health. Marmosets (Callithrix jacchus) and capuchins (Cebus apella) are New World primates increasingly used in biomedical and neuroscience research, yet published hair cortisol concentrations for these species are limited. Review of the existing published hair cortisol values from marmosets reveals highly discrepant values and the use of variable techniques for hair collection, processing, and cortisol extraction. In this investigation we utilized a well-established, standardized protocol to extract and quantify cortisol from marmoset (n = 12) and capuchin (n = 4) hair. Shaved hair samples were collected from the upper thigh during scheduled exams and analyzed via methanol extraction and enzyme immunoassay. In marmosets, hair cortisol concentration ranged from 2,710 to 6,267 pg/mg and averaged 4,070 ± 304 pg/mg. In capuchins, hair cortisol concentration ranged from 621 to 2,089 pg/mg and averaged 1,092 ± 338 pg/mg. Hair cortisol concentration was significantly different between marmosets and capuchins, with marmosets having higher concentrations than capuchins. The incorporation of hair cortisol analysis into research protocols provides a non-invasive measure of HPA axis activity over time, which offers insight into animal health. Utilization of standard protocols across laboratories is essential to obtaining valid measurements and allowing for valuable future cross-species comparisons. © 2018 Wiley Periodicals, Inc.
Manifestation of cryptic fibroblast tissue factor occurs at detergent concentrations which dissolve the plasma membrane.

PubMed

Carson, S D

1996-04-01

Cultured fibroblasts treated with increasing concentrations of detergents expressed only encrypted levels of tissue factor activity (measured by fX activation in the presence of fVIIa), characteristic of undamaged cells, until each detergent reached a critical concentration at which the cryptic tissue factor activity was manifested. Beyond the narrow ranges of concentrations over which the detergents stimulated tissue factor activity, the detergents were inhibitory. Studies with Triton X-100 and octyl glucoside revealed that manifestation of tissue factor activity coincided with breakdown of the plasma membrane. The magnitude of the increased tissue factor activity differed among detergents, with octyl glucoside giving the largest response. The tissue factor that was active after Triton X-100 treatment remained mostly associated with the insoluble cell residue, whereas the concentration of octyl glucoside which stimulated activity released tissue factor activity into the supernatant. Radiolabeled antibody against human tissue factor was used to show that a small percentage of the total accessible tissue factor remained in the insoluble fraction after treatment with either non-ionic detergent. Chromatographic analysis of lipids extracted from cells treated with detergents and dansyl chloride showed dansyl-reactivity of phosphatidylserine on intact cells, and solubilization of membrane lipids at sublytic concentrations of detergents. These findings reveal that there is a critical level of detergent-induced membrane damage at which tissue factor activity is maximally expressed, in essentially an all-or-none manner. The results are consistent with a major role for phospholipid asymmetry in regulation of tissue factor specific activity, but require either maintenance of asymmetry during sublytic detergent perturbation of the plasma membrane or additional control mechanisms.
Marine and freshwater concentration ratios (CR(wo-water)): review of Japanese data.

PubMed

Tagami, K; Uchida, S

2013-12-01

The water-to-organism (whole body) concentration ratio (CR(wo-water)), which is defined as the ratio of the concentration of a radionuclide in the biota (Bq kg(-1) fresh weight) to that in water (Bq L(-1)), has been used in mathematical models for environmental radiation protection. In the present paper, published global fallout (90)Sr, (137)Cs, (106)Ru, (144)Ce and (239+240)Pu activity concentration data and stable element concentration data for Na, K, Ca, Mg, Fe, Cu and Mn for organisms living in freshwater or seawater areas in Japan were collated. The data suitable for obtaining CR(wo-water) values were identified. CR(wo-water) values of (137)Cs were similar for pelagic fish, benthic fish and whitebait (immature, small fish) with respective geometric means of 30 (range: 4.4-69), 32 (range: 15-54) and 33 (range: 13-84). The calculated CR(wo-water) values of the other radionuclides and stable elements were generally similar to other previously reported values; with the exception that those for Ce were lower for marine biota and those of Cu were higher for freshwater fish. Copyright © 2012 Elsevier Ltd. All rights reserved.
Use of real-time sensors to characterise human exposures to combustion related pollutants.

PubMed

Delgado-Saborit, Juana Maria

2012-07-01

Concentrations of black carbon and nitrogen dioxide have been collected concurrently using a MicrAeth AE-51 and an Aeroqual GSS NO(2) sensor. Forty five sampling events with a duration spanning between 16 and 22 hours have collected 10,800 5 min data in Birmingham (UK) from July to October 2011. The high temporal resolution database allowed identification of peak exposures and which activities contributed the most to these peaks, such as cooking and commuting. Personal exposure concentrations for non-occupationally exposed subjects ranged between 0.01 and 50 μg m(-3) for BC with average values of 1.3 ± 2.2 μg m(-3) (AM ± SD). Nitrogen dioxide exposure concentrations were in the range
Habitability from the Surface to the Deep

NASA Astrophysics Data System (ADS)

Cox, A. D.; Schmidt, R.; Dahlquist, G. R.; Foster, J.; Dillard, M.

2016-12-01

Merging aqueous geochemical parameters of habitability with microbial identity and activity will help determine microbial contributions to observed water-rock reactions in surface to deep environments. To determine habitability for microbial life and decipher mechanisms by which microbes survive and perform chemical reactions, over one hundred sites in diverse geological and geochemical environs have been sampled for aqueous geochemistry, mineralogy, and microbial identity and activity. Sites ranged from surficial creeks and rivers to the flooded mine shafts beneath to hydrothermal features in the caldera of a supervolcano 250 km distant; these environments contain metal scarcity, extreme anoxia, and wide variations in metal, organic carbon, and oxygen scarcity, respectively. Aqueous geochemistry included in situ measurement of temperature, pH, conductivity, and dissolved oxygen by meters; field spectrophotometry for redox active species; and synchronous sample collection and preservation for water isotopes, major cations and anions, trace elements, and dissolved inorganic and organic carbon, and more. Concurrent collection and preservation of planktonic and sediment biomass at each site will allow for microbial community identification and assessment of microbial activity. DNA extraction and PCR amplification using universal, eukaryotic, bacterial, and archaeal small subunit ribosomal RNA gene primers yielded products for sequencing. For many of the aqueous geochemical parameters analyzed, including Li and B, concentrations in flooded mine shafts fell on a continuum directly between local surface waters and those resulting from hydrothermal alteration suggesting an intermediate level of water-rock interaction in flooded mine shaft habitats. Concentrations of Li and B ranged from low micromolal in surface waters to millimolal in thermal waters. Other elements - Fe, Mn, Zn, and As included - were enriched in anoxic mine shafts by three to four orders of magnitude, due to exposure to and reaction with minerals. Concentrations of Fe and Zn ranged up to tens of millimolal whereas millimolal Mn and submillimolal As concentrations were reached. The transition from mostly unreacted surface water to waters nearly in equilibrium with rock provides vast geochemical habitat for microbes to exploit.
Effect of gas velocity and influent concentration on biofiltration of gasoline off-gas from soil vapor extraction.

PubMed

Namkoong, Wan; Park, Joon-Seok; VanderGheynst, Jean S

2004-11-01

This study was conducted to evaluate the effects of gas inlet concentration and velocity on the biofiltration of gasoline vapor. Gasoline vapor was treated using a compost biofilter operated in an upflow mode for about 3 months. The inlet concentration of gasoline total petroleum hydrocarbon (TPH) ranged from about 300 to 7000 mgm(-3) and gas was injected at velocities of 6 and 15 mh(-1) (empty bed residence time (EBRT)=10 and 4 min, respectively). The maximum elimination capacities of TPH at 6 and 15 mh(-1) found in this research were over 24 and 19 gm(-3) of filling material h(-1), respectively. TPH removal data was fit using a first-order kinetic relationship. In the low concentration range of 300-3000 mg m(-3), the first-order kinetic constants varied between about 0.10 and 0.29 min(-1) regardless of gas velocities. At TPH concentrations greater than 3000 mgm(-3), the first-order kinetic constants were about 0.09 and 0.07 min(-1) at gas velocities of 6 mh(-1) and 15 mh(-1), respectively. To evaluate microbial dynamics, dehydrogenase activity, CO2 generation and microbial species diversity were analyzed. Dehydrogenase activity could be used as an indicator of microbial activity. TPH removal corresponded well with CO2 evolution. The average CO2 recovery efficiency for the entire biofilter ranged between 60% and 70%. When the gas velocity was 6 mh(-1), most of the microbial activity and TPH removal occurred in the first quarter of the biofilter. However, when the gas velocity was 15 mh(-1), the entire column contributed to removal. Spatial and temporal variations in the biofilter microbial population were also observed. Nearly 60% of the colonies isolated from the compost media prior to biofiltration were Bacillus. After 90 days of biofiltration, the predominant species in the lower portion (0-50 cm) of the filter were Rhodococcus, while Pseudomonas and Acinetobacter dominated the upper portion (75-100 cm). copyright 2004 Elsevier Ltd.
Assessment of dioxin-like activity in ambient air particulate matter using recombinant yeast assays

NASA Astrophysics Data System (ADS)

Olivares, Alba; van Drooge, Barend L.; Pérez Ballesta, Pascual; Grimalt, Joan O.; Piña, Benjamin

2011-01-01

Ectopic activation of the aryl hydrocarbon receptor (AhR), also known as dioxin-like activity, is a major component of the toxicity associated with polycyclic aromatic hydrocarbons (PAH). Filtration of ambient air particulate matter through PM 10 filters followed by chemical determination of PAH concentrations and a yeast-based bioassay (RYA) were combined to evaluate and characterize dioxin-like activity in ambient air. Samples were collected in a semirural area of Northern Italy between September 2008 and February 2009. Total PAH contents ranged between 0.3 ng m -3 and 34 ng m -3 and were in correlation with seasonal variations of meteorological conditions and combustion processes. Dioxin-like activity values in air samples showed an excellent correlation (0.71 < R2 < 0.86) with the observed PAH concentrations and the predicted toxicity equivalents for PAH. This RYA-bioassay reported in the present study provides a simple and low-cost routine control for toxic PAH emissions, even at background air concentration levels.
Synthesis, spectroscopic characterization, DFT study and antimicrobial activity of novel alkylaminopyrazole derivatives

NASA Astrophysics Data System (ADS)

Zalaru, Christina; Dumitrascu, Florea; Draghici, Constantin; Tarcomnicu, Isabela; Tatia, Rodica; Moldovan, Lucia; Chifiriuc, Mariana-Carmen; Lazar, Veronica; Marinescu, Maria; Nitulescu, Mihai George; Ferbinteanu, Marilena

2018-03-01

A new series of substituted N,N-bis-[(1H-pyrazol-1-yl)methyl]-aminohexadecane Mannich bases were synthesized, characterized by IR, 1H NMR 13C NMR, UV-Vis, MS and elemental analysis, and tested for their biological activity. All the synthesized compounds were tested for in vitro antimicrobial activity against a panel of selected bacterial and fungal strains using erythromycin and clotrimazole as standards. Most of the synthesized compounds demonstrated very good activity at minimum inhibitory concentrations (MICs). Compound 3b with an halogen atom into the pharmacophore structure exhibited the most significant activity against Bacillus subtilis (MIC = 0.007 μgmLL-1) versus erythromycin as standard. In vitro cytotoxicity of the new compounds was studied using MTT assay. The analysis of the test cells showed that the newly synthesized alkylaminopyrazoles derivatives were biocompatible until a concentration of 5 μgmL-1; two compounds presented a high degree of biocompatibility on the studied concentration range.
Leishmanicidal activity of saponins isolated from the leaves of Eclipta prostrata and Gymnema sylvestre.

PubMed

Khanna, Venkatesan Gopiesh; Kannabiran, Krishnan; Getti, Giulia

2009-02-01

To evaluate the leishmanicidal activity of saponin, dasyscyphin C of Eclipta prostrata and sapogenin, gymnemagenol from Gymnema sylvestre leaves under in vitro conditions. Dasyscyphin C/Gymnemagenol were dissolved in phosphate buffered saline (PBS) and diluted with liquid medium to obtain concentrations ranging from 1000 to 15 mug /ml. The leishmanicidal activity against leishmanial parasites, Leishmania major, Leishmania aethiopica and Leishmania tropica promastigotes was studied by the MTS assay. The Dasyscyphin C isolated from E. prostrata showed good leishmanicidal activity at 1000mug/ml concentration, with the IC(50) value of 450mug/ml against L. major promastigote and the percentage of parasitic death was 73; whereas, gymnemagenol of G. sylvestre showed only 52% parasitic death at 1000 mug/ml concentration. The other Leishmania species, L. aethiopica and L. tropica promastigotes, were less sensitive to the saponins of E. prostrata and G. sylvestre. From this study, it can be concluded that the dasyscyphin C of E. prostrata has significant leishmanicidal activity against L. major promastigote.

Alternative method for quantification of alfa-amylase activity.

PubMed

Farias, D F; Carvalho, A F U; Oliveira, C C; Sousa, N M; Rocha-Bezerrra, L C B; Ferreira, P M P; Lima, G P G; Hissa, D C

2010-05-01

A modification of the sensitive agar diffusion method was developed for macro-scale determination of alfa-amylase. The proposed modifications lower costs with the utilisation of starch as substrate and agar as supporting medium. Thus, a standard curve was built using alfa-amylase solution from Aspergillus oryzae, with concentrations ranging from 2.4 to 7,500 U.mL-1. Clear radial diffusion zones were measured after 4 hours of incubation at 20 A degrees C. A linear relationship between the logarithm of enzyme activities and the area of clear zones was obtained. The method was validated by testing alpha-amylase from barley at the concentrations of 2.4; 60; 300 and 1,500 U.mL-1. The proposed method turned out to be simpler, faster, less expensive and able to determine on a macro-scale alpha-amylase over a wide range (2.4 to 7,500 U.mL-1) in scientific investigation as well as in teaching laboratory activities.
Rapid and sensitive method for determination of withaferin-A in human plasma by HPLC.

PubMed

Patial, Pankaj; Gota, Vikram

2011-02-01

To develop and validate a rapid and sensitive high-performance liquid chromatographic method for determination of withaferin-A in human plasma. Withaferin-A, the active molecule of a traditional Indian herb, has demonstrated several biological activities in preclinical models. A validated bioassay is not available for its pharmacokinetic evaluation. The chromatographic system used a reverse-phase C18 column with UV-visible detection at 225 nm. The mobile phase consisted of water and acetonitrile applied in a gradient flow. Withaferin-A was extracted by simple protein-precipitation technique. The calibration curve was linear in the concentration range of 0.05-1.6 µg/ml. The method has the desired sensitivity to detect the plasma concentration range of withaferin-A that is likely to show biological activity based on in vitro data. This is the first HPLC method ever described for the estimation of withaferin-A in human plasma which could be applied for pharmacokinetic studies.
Natural radioactivity levels of geothermal waters and their influence on soil and agricultural activities.

PubMed

Murat Saç, Müslim; Aydemir, Sercan; Içhedef, Mutlu; Kumru, Mehmet N; Bolca, Mustafa; Ozen, Fulsen

2014-01-01

All over the world geothermal sources are used for different purposes. The contents of these waters are important to understand positive/negative effects on human life. In this study, natural radioactivity concentrations of geothermal waters were investigated to evaluate the effect on soils and agricultural activities. Geothermal water samples were collected from the Seferihisar Geothermal Region, and the radon and radium concentrations of these waters were analysed using a collector chamber method. Also soil samples, which are irrigated with geothermal waters, were collected from the surroundings of geothermal areas, and natural radioactivity concentrations of collected samples (U, Th and K) were determined using an NaI(Tl) detector system. The activity concentrations of radon and radium were found to be 0.6-6.0 and 0.1-1.0 Bq l(-1), respectively. Generally, the obtained results are not higher compared with the geothermal waters of the world. The activity concentrations in soils were found to be in the range of 3.3-120.3 Bq kg(-1) for (226)Ra (eU), 0.3-108.5 Bq kg(-1) for (232)Th (eTh), 116.0-850.0 Bq kg(-1) for (40)K (% K).
Gender differences in bone turnover in 2-year-old Thoroughbreds.

PubMed

Jackson, B F; Lonnell, C; Verheyen, K; Wood, J L N; Pfeiffert, D U; Price, J S

2003-11-01

Injuries to the skeleton are a major cause of morbidity and mortality in racehorses and age, gender and season have all been shown to influence risk of injury. To use biochemical markers of bone cell activity to establish to whether cellular processes in bone underlie these described effects. Blood samples were collected monthly from 2-year-old horses in race training between November 1998 and September 1999. Mean age at the start of the study was 20 months (range 18-23 months), with no significant difference in average age between colts (n = 84) and fillies (n = 63). Three markers were measured; osteocalcin (OC, bone formation), the carboxyterminal cross-linked telopeptide of type I collagen (ICTP, bone resorption) and the carboxyterminal propeptide of type I collagen (PICP), which is less 'bone-specific' than the other 2 markers. Colts had, on average, 3.62 ng/ml higher OC concentrations (P = 0.044) and 0.68 mg/l higher ICTP concentrations (P = 0.01) than fillies. The effect of gender was not statistically significant for PICP. However, in May, PICP concentrations were on average 157 mg/l higher in fillies than colts. There was no effect of age or season on marker concentrations. This study has shown that there are gender differences in bone turnover markers in 2-year-old Thoroughbreds; however, age, within the limited range studied, did not have a significant effect on bone cell activity. Lower bone marker concentrations may reflect smaller bone size and/or earlier skeletal maturation in fillies. An increase in concentrations of PICP in fillies in spring and early summer may relect an influence of sex hormones on collagen turnover. Gender differences in bone cell activity in 2-year-old colts and fillies may influence bone's adaptive responses to training and risk of injury.
Two Degrees of Separation: Abrupt Climate Change and the Adverse Impact to US National Security

DTIC Science & Technology

2009-04-01

concentrations of CO2 , CH4 and N2O have increased markedly as a result of human activities since 1750 and now far exceed pre-industrial values...determined from ice cores spanning many thousands of years. The atmospheric concentrations of CO2 and CH4 in 2005 exceed by far the natural range over the...last 650,000 years. Global increases in CO2 concentrations are due primarily to fossil fuel use, with land-use change providing another significant
Comparative Analysis of Native Crocus Taxa as a Great Source of Flavonoids with High Antioxidant Activity.

PubMed

Šola, Ivana; Stipaničev, Mirta; Vujčić, Valerija; Mitić, Božena; Huđek, Ana; Rusak, Gordana

2018-06-02

Native Crocus taxa are abundant in regions with moderate and dry climate; however, their potential in the food industry has thus far been neglected. The objective of this study was to compare the quantitative and qualitative flavonoid content and antioxidant and cytotoxic activity in organs of several populations of Croatian native taxa and assess their potential for application in the food industry. The dominant flavonoids in the native Crocus taxa were kaempferol and quercetin. Tepals contained similar or higher concentrations of flavonoid-glycosides than other organs. Tepals from Cvv1 and Cvv2 populations contained more flavonoid-glycosides than the commonly used spice saffron (C. sativus stigmas). The FRAP antioxidant activity of Cvv1 and Cvv5 tepals was similar to that of standard Trolox. DPPH inhibition of Cvv1 and Cvv3 tepals was within the range of that recorded for saffron. Cvv1 tepals significantly reduced reactive oxygen species in the broadest concentration range (50-1000 μg/ml), and showed considerable antioxidant activity in the ABTS assay, equal to 82% of standard Trolox antioxidant activity. A significantly higher concentration of kaempferol-rutinoside was recorded in this than in other taxa. The flavonoid showed a very strong or strong correlation with antioxidant assays results, and a negative correlation with cellular reactive oxygen species concentration. We therefore presumed that kaempferol-rutinoside is one of the main antioxidant phenolics in Crocus tepals. None of the tested extracts showed cytotoxicity toward Caco-2 cells. The results revealed that Cvv tepals have potential as a food supplement and are a promising material for further food safety tests.
Inter-laboratory comparison measurements of radiochemical laboratories in Slovakia.

PubMed

Meresová, J; Belanová, A; Vrsková, M

2010-01-01

The first inter-laboratory comparison organized by the radiochemistry laboratory of Water Research Institute (WRI) in Bratislava was carried out in 1993 and since then is it realized on an annual basis and about 10 radiochemical laboratories from all over Slovakia are participating. The gross alpha and gross beta activities, and the activity concentrations of (222)Rn, tritium, and (226)Ra, and U(nat) concentration in synthetic water samples are compared. The distributed samples are covering the concentration range prevailing in potable and surface waters and are prepared by dilution of certified reference materials. Over the course of the years 1993-2008, we observed the improvement in the quality of results for most of the laboratories. However, the success rate of the gross alpha determination activity is not improving as much as the other parameters. Copyright 2009 Elsevier Ltd. All rights reserved.
Effects of fluorine on crops, soil exoenzyme activities, and earthworms in terrestrial ecosystems.

PubMed

Chae, Yooeun; Kim, Dokyung; An, Youn-Joo

2018-04-30

Fluorine can flow into the environment after leakage or spill accidents and these excessive amounts can cause adverse effects on terrestrial ecosystems. Using three media (filter paper, soil, and filter-paper-on-soil), we investigated the toxic effects of fluorine on the germination and growth of crops (barley, mung bean, sorghum, and wheat), on the activities of soil exoenzymes (acid phosphatase, arylsulfatase, fluorescein diacetate hydrolase, and urease) and on the survival, abnormality, and cytotoxicity of Eisenia andrei earthworms. The germination and growth of crops were affected by fluorine as exposure concentration increased. The activities of the four enzymes after 0-, 3-, 10-, and 20-day periods varied as exposure concentration increased. According to in vivo and in vitro earthworm assays, E. andrei mortality, abnormality, and cytotoxicity increased with increasing fluorine concentration. Overall, fluorine significantly affected each tested species in the concentration ranges used in this study. The activities of soil exoenzymes were also affected by soil fluorine concentration, although in an inconsistent manner. Albeit the abnormally high concentrations of fluorine in soil compared to that observed under natural conditions, its toxicity was much restrained possibly due to the adsorption of fluorine on soil particles and its combination with soil cations. Copyright © 2017 Elsevier Inc. All rights reserved.
Contribution of indoor-generated particles to residential exposure

NASA Astrophysics Data System (ADS)

Isaxon, C.; Gudmundsson, A.; Nordin, E. Z.; Lönnblad, L.; Dahl, A.; Wieslander, G.; Bohgard, M.; Wierzbicka, A.

2015-04-01

The majority of airborne particles in residences, when expressed as number concentrations, are generated by the residents themselves, through combustion/thermal related activities. These particles have a considerably smaller diameter than 2.5 μm and, due to the combination of their small size, chemical composition (e.g. soot) and intermittently very high concentrations, should be regarded as having potential to cause adverse health effects. In this study, time resolved airborne particle measurements were conducted for seven consecutive days in 22 randomly selected homes in the urban area of Lund in southern Sweden. The main purpose of the study was to analyze the influence of human activities on the concentration of particles in indoor air. Focus was on number concentrations of particles with diameters <300 nm generated by indoor activities, and how these contribute to the integrated daily residential exposure. Correlations between these particles and soot mass concentration in total dust were also investigated. It was found that candle burning and activities related to cooking (using a frying pan, oven, toaster, and their combinations) were the major particle sources. The frequency of occurrence of a given concentration indoors and outdoors was compared for ultrafine particles. Indoor data was sorted into non-occupancy and occupancy time, and the occupancy time was further divided into non-activity and activity influenced time. It was found that high levels (above 104 cm-3) indoors mainly occur during active periods of occupancy, while the concentration during non-activity influenced time differs very little from non-occupancy time. Total integrated daily residential exposure of ultrafine particles was calculated for 22 homes, the contribution from known activities was 66%, from unknown activities 20%, and from background/non-activity 14%. The collected data also allowed for estimates of particle source strengths for specific activities, and for some activities it was possible to estimate correlations between the number concentration of ultrafine particles and the mass concentration of soot in total dust in 10 homes. Particle source strengths (for 7 specific activities) ranged from 1.6·1012 to 4.5·1012 min-1. The correlation between ultrafine particles and mass concentration of soot in total dust varied between 0.37 and 0.85, with an average of 0.56 (Pearson correlation coefficient). This study clearly shows that due to the importance of indoor sources, residential exposure to ultrafine particles cannot be characterized by ambient measurements alone.
Nutrient, sediment, and pesticide data collected at four small agricultural basins in the Beaver Creek watershed, West Tennessee, 1990-1995

USGS Publications Warehouse

Williams, Shannon D.; Harris, Robin M.

1996-01-01

In 1989, the U.S. Geological Survey began a cooperative study with the Tennessee Department of Agriculture to assess the impact of agricultural activities on water quality in the Beaver Creek watershed in West Tennessee. Quantification of the transport of nutrients, sediment, and pesticides from agricultural fields was one of the objectives of the study. This report presents nutrient, sediment, and pesticide data collected during selected storm events from 1990 through 1995 at four relatively small, agricultural basins (28 to 422 acres) in the Beaver Creek watershed. Approximately 3,000 water samples (500 to 1,000 at each site) were analyzed for nitrogen and phosphorus species. Total nitrogen (N) concentrations ranged from 0.2 to 41.2 milligrams per liter (mg/L). Median concentrations for samples from each site ranged from 2.0 to 2.7 mg/L for total nitrogen, 1.2 to 1.9 mg/L for organic nitrogen, 0.05 to 0.14 mg/L for ammonia (measured as N), and 0.2 to 0.8 mg/L for nitrate plus nitrite (measured as N). Total phosphorus (P) concentrations ranged from 0.03 to 16.0 mg/L. Median concentrations for samples from each site ranged from 0.80 to 1.2 mg/L for total phosphorus and 0.15 to 0.72 for orthophosphate (measured as P). Approximately 6,000 water samples (1,300 to 1,800 at each site) were analyzed for suspended sediment. Suspended-sediment concentrations ranged from 8.0 to 98,353 mg/L. Concentrations exceeded 1,000 mg/L in 33 percent of the samples collected and exceeded 10,000 mg/L in 6 percent of the samples. Median concentrations ranged from 347 to 713 mg/L at the four sites. Several herbicides and insecticides were detected in water samples. Maximum concentrations detected were 37 micrograms per liter for metolachlor, 3.2 for trifluralin, 150 for fluometuron, and 430 for aldicarb. Aldicarb metabolites were also detected in several samples. The maximum aldicarb sulfoxide and aldicarb sulfone concentrations detected were 68.4 and 14.3 micrograms per liter, respectively.
Predicting Pharmacokinetic Stability by Multiple Oral Administration of Atypical Antipsychotics

PubMed Central

Aoki, Kazuo; Sakiyama, Yojiro; Ohnishi, Takashi; Sugita, Makoto

2013-01-01

Lower fluctuation, i.e., lower peak-to-trough plasma-concentration variation at steady-state pharmacokinetics, has several advantages for the treatment of schizophrenia with antipsychotics. The reduction of peak concentration can decrease the risk of dose-dependent side effects, such as extrapyramidal symptom and somnolence, and by contrast the increase in trough concentration can decrease the incidence of lack of efficacy due to subtherapeutic drug concentration. Using a one-compartment simulation technique with pharmacokinetic parameters of each atypical antipsychotic collected from package inserts, the fluctuation index was calculated. Among the antipsychotics, the indices varied from 0.018 to 1.9, depending on dosing regimens, formulations and several pharmacokinetic properties. The order of simulated fluctuation index is active-moiety aripiprazole (b.i.d.)
Synergistic action of starch and honey against Candida albicans in correlation with diastase number

PubMed Central

Boukraa, Laïd; Benbarek, Hama; Moussa, Ahmed

2008-01-01

To evaluate the synergistic action of starch on the antifungal activity of honey, a comparative method of adding honey with and without starch to culture media was used. Candida albicans has been used to determine the minimum inhibitory concentration (MIC) of five varieties of honey. In a second step, lower concentrations of honey than the MIC were incubated with a set of concentrations of starch added to media to determine the minimum synergistic inhibitory concentration (MSIC). The MIC for the five varieties of honey without starch against C. albicans ranged between 40% and 45% (v/v). When starch was incubated with honey and then added to media, a MIC drop has been noticed with each variety. It ranged between 7% and 25%. A negative correlation has been established between the MIC drop and the diastase number (DN). PMID:24031175
Butyltin compounds in River Otters (Lutra canadensis) from the Northwestern United States

USGS Publications Warehouse

Kannan, K.; Grove, Robert A.; Senthilkumar, K.; Henny, Charles J.; Geisy, J.P.

1999-01-01

Butyltin compounds, including mono-, di-, and tributyltin (MBT, DBT, and TBT) were measured in livers of 40 adult river otters (Lutra canadensis) collected from rivers and coastal bays in Washington and Oregon, USA. Butyltins were found in all the river otters, at a concentration range of 8.5a??2,610 ng/g, WW. The greatest concentration of total butyltins of 2,610 ng/g, WW, was found in a river otter collected in Puget Sound from Fort Ward, Washington. River otters collected near areas with major shipping activities, such as the Puget Sound, contained significantly greater concentrations (geometric mean: 367 ng/g, WW) of butyltins than those from rivers. Among butyltin compounds, MBT and DBT predominated in livers. The concentrations of butyltins in river otters ranged from comparable (Puget Sound) to less (rivers) than what was found in coastal cetaceans.
Quantitative investigation of a novel small field of view hybrid gamma camera (HGC) capability for sentinel lymph node detection

PubMed Central

Lees, John E; Bugby, Sarah L; Jambi, Layal K; Perkins, Alan C

2016-01-01

Objective: The hybrid gamma camera (HGC) has been developed to enhance the localization of radiopharmaceutical uptake in targeted tissues during surgical procedures such as sentinel lymph node (SLN) biopsy. To assess the capability of the HGC, a lymph node contrast (LNC) phantom was constructed to simulate medical scenarios of varying radioactivity concentrations and SLN size. Methods: The phantom was constructed using two clear acrylic glass plates. The SLNs were simulated by circular wells of diameters ranging from 10 to 2.5 mm (16 wells in total) in 1 plate. The second plate contains four larger rectangular wells to simulate tissue background activity surrounding the SLNs. The activity used to simulate each SLN ranged between 4 and 0.025 MBq. The activity concentration ratio between the background and the activity injected in the SLNs was 1 : 10. The LNC phantom was placed at different depths of scattering material ranging between 5 and 40 mm. The collimator-to-source distance was 120 mm. Image acquisition times ranged from 60 to 240 s. Results: Contrast-to-noise ratio analysis and full-width-at-half-maximum (FWHM) measurements of the simulated SLNs were carried out for the images obtained. Over the range of activities used, the HGC detected between 87.5 and 100% of the SLNs through 20 mm of scattering material and 75–93.75% of the SLNs through 40 mm of scattering material. The FWHM of the detected SLNs ranged between 11.93 and 14.70 mm. Conclusion: The HGC is capable of detecting low accumulation of activity in small SLNs, indicating its usefulness as an intraoperative imaging system during surgical SLN procedures. Advances in knowledge: This study investigates the capability of a novel small-field-of-view (SFOV) HGC to detect low activity uptake in small SLNs. The phantom and procedure described are inexpensive and could be easily replicated and applied to any SFOV camera, to provide a comparison between systems with clinically relevant results. PMID:27537079
Kinetics of Alkaline Decomposition and Cyaniding of Argentian Rubidium Jarosite in NaOH Medium

NASA Astrophysics Data System (ADS)

Rodríguez, Eleazar Salinas; Sáenz, Eduardo Cerecedo; Ramírez, Marius; Cardona, Francisco Patiño; Labra, Miguel Pérez

2012-10-01

The alkaline decomposition of Argentian rubidium jarosite in NaOH media is characterized by an induction period and a progressive conversion period in which the sulfate and rubidium ions pass to the solution, leaving an amorphous iron hydroxide residue. The process is chemically controlled and the order of reaction with respect to hydroxide concentration in the range of 1.75 and 20.4 mol OH- m-3 is 0.94, while activation energy in the range of temperatures of 298 K to 328 K (25 °C to 55 °C) is 91.3 kJ mol-1. Cyaniding of Argentian rubidium jarosite in NaOH media presents a reaction order of 0 with respect to NaCN concentration (in the range of 5 to 41 mol m-3) and an order of reaction of 0.62 with respect to hydroxide concentration, in the range of 1.1 and 30 mol [OH-] m-3. In this case, the cyaniding process can be described, as in other jarosites, as the following two-step process: (1) a step (slow) of alkaline decomposition that controls the overall process followed by (2) a fast step of silver complexation. The activation energy during cyaniding in the range of temperatures of 298 K to 333 K (25 °C to 60 °C) is 43.5 kJ mol-1, which is characteristic of a process controlled by chemical reaction. These results are quite similar to that observed for several synthetic jarosites and that precipitated in a zinc hydrometallurgical plant (Industrial Minera México, San Luis Potosi).
Activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in brands of fertilisers used in Nigeria.

PubMed

Jibiri, N N; Fasae, K P

2012-01-01

The activity concentration of naturally occurring radionuclides ⁴⁰K, ²²⁶Ra and ²³²Th have been measured in different brands of fertiliser samples sold to farmers in retail markets in six commercial cities in southwestern Nigeria. Gamma ray spectroscopy was employed in the measurements of these radionuclides. The results of measurements showed that the average activity concentration of ⁴⁰K in the nitrogen, phosphorus and potassium fertilisers across the cities varied from 3972.0 ± 416.9 to 5089.3 ± 111.3 Bq kg⁻¹, 9.9 ± 7.3 to 450.6 ± 14.3 Bq kg⁻¹ for ²²⁶Ra, while for ²³²Th it varied from less than lower limit of detection to 15.1 ± 2.8 Bq kg⁻¹. The activity concentrations of ⁴⁰K, ²²⁶Ra and ²³²Th in single super phosphate (SSP) fertilisers and phosphate rocks were also determined. However, high activity concentrations of ²²⁶Ra were obtained in the SSP fertiliser and phosphate rocks and in particular, two brands of fertilisers from ITL/TAK and F & C companies. The values of the activity concentration of the radionuclides in the brands of fertilisers used in Nigeria are within the range of values reported in several other countries except ⁴⁰K.
Solution Behavior and Activity of a Halophilic Esterase under High Salt Concentration

PubMed Central

Rao, Lang; Zhao, Xiubo; Pan, Fang; Li, Yin; Xue, Yanfen; Ma, Yanhe; Lu, Jian R.

2009-01-01

Background Halophiles are extremophiles that thrive in environments with very high concentrations of salt. Although the salt reliance and physiology of these extremophiles have been widely investigated, the molecular working mechanisms of their enzymes under salty conditions have been little explored. Methodology/Principal Findings A halophilic esterolytic enzyme LipC derived from archeaon Haloarcula marismortui was overexpressed from Escherichia coli BL21. The purified enzyme showed a range of hydrolytic activity towards the substrates of p-nitrophenyl esters with different alkyl chains (n = 2−16), with the highest activity being observed for p-nitrophenyl acetate, consistent with the basic character of an esterase. The optimal esterase activities were found to be at pH 9.5 and [NaCl] = 3.4 M or [KCl] = 3.0 M and at around 45°C. Interestingly, the hydrolysis activity showed a clear reversibility against changes in salt concentration. At the ambient temperature of 22°C, enzyme systems working under the optimal salt concentrations were very stable against time. Increase in temperature increased the activity but reduced its stability. Circular dichroism (CD), dynamic light scattering (DLS) and small angle neutron scattering (SANS) were deployed to determine the physical states of LipC in solution. As the salt concentration increased, DLS revealed substantial increase in aggregate sizes, but CD measurements revealed the maximal retention of the α-helical structure at the salt concentration matching the optimal activity. These observations were supported by SANS analysis that revealed the highest proportion of unimers and dimers around the optimal salt concentration, although the coexistent larger aggregates showed a trend of increasing size with salt concentration, consistent with the DLS data. Conclusions/Significance The solution α-helical structure and activity relation also matched the highest proportion of enzyme unimers and dimers. Given that all the solutions studied were structurally inhomogeneous, it is important for future work to understand how the LipC's solution aggregation affected its activity. PMID:19759821
Effect of repeated applications of buprofezin and acephate on soil cellulases, amylase, and invertase.

PubMed

Raju, M Naga; Venkateswarlu, K

2014-10-01

The impact of repeated applications of buprofezin and acephate, at concentrations ranging from 0.25 to 1.0 kg ha(-1), on activities of cellulases, amylase, and invertase in unamended and nitrogen, phosphorous, and potassium (NPK) fertilizer-amended soil planted with cotton was studied. The nontarget effect of selected insecticides, when applied once, twice, or thrice on soil enzyme activities, was dose-dependent; the activities decreased with increasing concentrations of insecticides. However, there was a rapid decline in activities of enzymes after three repeated applications of insecticides in unamended or NPK-amended soil. Our data clearly suggest that insecticides must be applied judiciously in pest management in order to protect the enzymes largely implicated in soil fertility.
Fate and effect of naphthenic acids on oil refinery activated sludge wastewater treatment systems.

PubMed

Misiti, Teresa; Tezel, Ulas; Pavlostathis, Spyros G

2013-01-01

Naphthenic acids (NAs) are a complex group of alkyl-substituted acyclic, monocyclic and polycyclic carboxylic acids present in oil sands process waters, crude oil, refinery wastewater and petroleum products. Crude oil, desalter brine, influent, activated sludge mixed liquor and effluent refinery samples were received from six United States refineries. The total acid number (TAN) of the six crudes tested ranged from 0.12 to 1.5 mg KOH/g crude oil and correlated to the total NA concentration in the crudes. The total NA concentration in the desalter brine, influent, activated sludge mixed liquor and effluent samples ranged from 4.2 to 40.4, 4.5 to 16.6, 9.6 to 140.3 and 2.8 to 11.6 mg NA/L, respectively. The NAs in all wastewater streams accounted for less than 16% of the total COD, indicating that many other organic compounds are present and that NAs are a minor component in refinery wastewaters. Susceptibility tests showed that none of the activated sludge heterotrophic microcosms was completely inhibited by NAs up to 400 mg/L. Growth inhibition ranging from 10 to 59% was observed in all microcosms at and above 100 mg NA/L. NAs chronically-sorbed to activated sludge mixed liquor biomass and powdered activated carbon (PAC) were recalcitrant and persistent. More than 80% of the total NAs remained in the solid phase at the end of the 10-day desorption period (five successive desorption steps). Throughout a 90-day incubation period, the total NA concentration decreased by 33 and 51% in PAC-free and PAC-containing mixed liquor microcosms, respectively. The lower molecular weight fraction of NAs was preferentially degraded in both mixed liquors. The persistence of the residual, higher molecular weight NAs is likely a combination of molecular recalcitrance and decreased bioavailability when chronically-sorbed to the biomass and/or PAC. Copyright © 2012 Elsevier Ltd. All rights reserved.
Effect of heavy metals ions on enzyme activity in the Mediterranean mussel, Donax trunculus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mizrahi, L.; Achituv, Y.

Heavy metal ions strongly are bound by sulfhydryl groups of proteins. Sulfhydryl binding changes the structure and enzymatic activities of proteins and causes toxic effects evident at the whole organism level. Heavy metal ions like Cd, Cu, Hg, Zn, and Pb in sufficiently high concentrations might kill organisms or cause other adverse effects that changing aquatic community structures. Bivalves are known to be heavy metal accumulators. The aim of the present study was to examine the effects of different concentrations of each of five heavy metal ions on the activity of four enzymes in D. trunculus. As it is knownmore » that heavy metals inhibit the activity of a wide range of enzymes, the authors chose representative examples of dehydrogenases (lactate and malate dehydrogenases), respiratory enzyme (cytochrome oxidase) and digestive enzyme ({alpha}-amylase). The acute effects of different concentrations of selected metals were examined. These concentrations were higher than those found usually in the locality where the animals occur, but might be encountered during a given event of pollution.« less

PCDD/PCDF and dl-PCB in the ambient air of a tropical Andean city: passive and active sampling measurements near industrial and vehicular pollution sources.

PubMed

Cortés, J; González, C M; Morales, L; Abalos, M; Abad, E; Aristizábal, B H

2014-09-01

Concentration gradients were observed in gas and particulate phases of PCDD/F originating from industrial and vehicular sources in the densely populated tropical Andean city of Manizales, using passive and active air samplers. Preliminary results suggest greater concentrations of dl-PCB in the mostly gaseous fraction (using quarterly passive samplers) and greater concentrations of PCDD/F in the mostly particle fraction (using daily active samplers). Dioxin-like PCB predominance was associated with the semi-volatility property, which depends on ambient temperature. Slight variations of ambient temperature in Manizales during the sampling period (15°C-27°C) may have triggered higher concentrations in all passive samples. This was the first passive air sampling monitoring of PCDD/F conducted in an urban area of Colombia. Passive sampling revealed that PCDD/F in combination with dioxin-like PCB ranged from 16 WHO-TEQ2005/m(3) near industrial sources to 7 WHO-TEQ2005/m(3) in an intermediate zone-a reduction of 56% over 2.8 km. Active sampling of particulate phase PCDD/F and dl-PCB were analyzed in PM10 samples. PCDD/F combined with dl-PCB ranged from 46 WHO-TEQ2005/m(3) near vehicular sources to 8 WHO-TEQ2005/m(3) in the same intermediate zone, a reduction of 83% over 2.6 km. Toxic equivalent quantities in both PCDD/F and dl-PCB decreased toward an intermediate zone of the city. Variations in congener profiles were consistent with variations expected from nearby sources, such as a secondary metallurgy plant, areas of concentrated vehicular emissions and a municipal solid waste incinerator (MSWI). These variations in congener profile measurements of dioxins and dl-PCBs in passive and active samples can be partly explained by congener variations expected from the various sources. Copyright © 2014 Elsevier B.V. All rights reserved.
Activation and injury of Clostridium perfringens spores by alcohols.

PubMed Central

Craven, S E; Blankenship, L C

1985-01-01

The activation properties of Clostridium perfringens NCTC 8679 spores were demonstrated by increases in CFU after heating in water or aqueous alcohols. The temperature range for maximum activation, which was 70 to 80 degrees C in water, was lowered by the addition of alcohols. The response at a given temperature was dependent on the time of exposure and the alcohol concentration. The monohydric alcohols and some, but not all, of the polyhydric alcohols could activate spores at 37 degrees C. The concentration of a monohydric alcohol that produced optimal spore activation was inversely related to its lipophilic character. Spore injury, which was manifested as a dependence on lysozyme for germination and colony formation, occurred under some conditions of alcohol treatment that exceeded those for optimal spore activation. Treatment with aqueous solutions of monohydric alcohols effectively activated C. perfringens spores and suggests a hydrophobic site for spore activation. PMID:2864897
Correlation of glucosinolate content to myrosinase activity in horseradish (Armoracia rusticana).

PubMed

Li, Xian; Kushad, Mosbah M

2004-11-17

Fully developed horseradish (Armoracia rusticana Gaertn., Mey., & Scherb.) roots from 27 accessions and leaves from a subset of 9 accessions were evaluated for glucosinolates and myrosinase enzyme activity. Eight different glucosinolates were detected (based on HPLC retention times as desulfoglucosinolates) in both root and leaf tissues. The sum of these glucosinolates, referred to as total, ranged from 2 to 296 micromol g(-1) of dry weight (DW) in both tissues. Four glucosinolates (sinigrin, glucobrassicin, neoglucobrassicin, and gluconasturtiin) were detected in major quantities. In fully developed roots, sinigrin concentration represented approximately 83%, gluconasturtiin approximately 11%, and glucobrassicin approximately 1% of the total glucosinolates. Approximately the same proportions of individual glucosinolates appeared in fully developed leaves, except that glucobrassicin was substituted by neoglucobrassicin and gluconasturtiin concentration was significantly lower (<1%). At least four other glucosinolates were detected in very small quantities (<1%) in both roots and leaves. Myrosinase (beta-thioglucoside glucohydrolase, EC 3.2.3.1) is the enzyme responsible for the hydrolysis of the parent glucosinolates into biologically active products. Very little is known about myrosinase activity and the correlation of its activity to total and individual glucosinolates in plant tissues. Significant differences in myrosinase activity were detected between the roots and leaves, ranging from 1.2 to 57.1 units g(-1) of DW. Data showed no correlation between myrosinase activity and total and/or individual glucosinolates in the roots. However, in the leaves, significant correlations were found between myrosinase activity and total glucosinolates (0.78 at P = 0.01) and between myrosinase activity and sinigrin (0.80 at P = 0.01). Glucosinolates content and myrosinase activity were also correlated in young and fully developed roots and leaves and during tissue crushing. Glucobrassicin concentration in the roots and neoglucobrassicin concentration in the leaves were significantly higher in young than in fully developed tissue. Crushing of the tissue resulted in rapid hydrolysis of sinigrin and glucobrassicin, as expected, from the presence of myrosinase. Likewise, myrosinase activity declined rapidly after crushing, perhaps due to inactivation by the reaction products and/or the depletion of its substrates.
Properties of a Purified Halophilic Malic Dehydrogenase

PubMed Central

Holmes, P. K.; Halvorson, H. Orin

1965-01-01

Holmes, P. K. (University of Illinois, Urbana), and H. Orin Halvorson. Properties of a purified halophilic malic dehydrogenase. J. Bacteriol. 90:316–326. 1965.—The malic dehydrogenase (MDH) from Halobacterium salinarium required high concentrations of monovalent ions for stability and activity. Studies of inactivation rates at different salt concentrations suggested that approximately 25% NaCl (w/v) is required to stabilize MDH. From 50 to 100% reactivation, depending on the salt concentration present during inactivation, could occur in 2.5 to 5 m NaCl or KCl. The optimal salt concentration for activity of MDH was a function of the pH, and ranged from 1 to 3 m NaCl or KCl. The effect of salt concentration on the pH-activity curves occurred chiefly below pH 7.0. Inactivation of MDH with heat or thiol reagents showed that the enzyme was more labile in the state induced by absence of salt. The activation of MDH by salts was attributed to a decreased rate of dissociation of MDH and reduced nicotinamide adenine dinucleotide (NADH2). The inactivation of the enzyme in the absence of salt could be largely prevented by the presence of NADH2. The S20.w of MDH decreased threefold at low salt concentrations. The enzyme was assumed to be in its native compact configuration only in the presence of a high concentration of salt. PMID:14329442
Detergent sclerosants at sub-lytic concentrations induce endothelial cell apoptosis through a caspase dependent pathway.

PubMed

Cooley-Andrade, Osvaldo; Cheung, Kelvin; Chew, An-Ning; Connor, David Ewan; Parsi, Kurosh

2016-07-01

To investigate the apoptotic effects of detergent sclerosants sodium tetradecylsulphate (STS) and polidocanol (POL) on endothelial cells at sub-lytic concentrations. Human umbilical vein endothelial cells (HUVECs) were isolated and labelled with antibodies to assess for apoptosis and examined with confocal microscopy and flow cytometry. Isolated HUVECs viability was assessed using propidium iodide staining. Early apoptosis was determined by increased phosphatidylserine exposure by lactadherin binding. Caspase 3, 8, 9 and Bax activation as well as inhibitory assays with Pan Caspase (Z-VAD-FMK) and Bax (BI-6C9) were assessed to identify apoptotic pathways. Porimin activation was used to assess cell membrane permeability. Cell lysis reached almost 100 % with STS at 0.3 % and with POL at 0.6 %. Apoptosis was seen with both STS and POL at concentrations ranging from 0.075 to 0.15 %. PS exposure increased with both STS and POL and exhibited a dose-dependent trend. Active Caspase 3, 8 and 9 but not Bax were increased in HUVECs stimulated with low concentrations of both STS and POL. Inhibitory assays demonstrated Caspase 3, 8, 9 inhibition at low concentrations (0.075 to 0.6 %) with both STS and POL. Both agents increased the activation of porimin at all concentrations. Both sclerosants induced endothelial cell (EC) apoptosis at sub-lytic concentrations through a caspase-dependant pathway. Both agents induced EC oncosis.
Hemin potentiates the anti-hepatitis C virus activity of the antimalarial drug artemisinin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paeshuyse, Jan; Coelmont, Lotte; Vliegen, Inge

2006-09-15

We report that the antimalarial drug artemisinin inhibits hepatitis C virus (HCV) replicon replication in a dose-dependent manner in two replicon constructs at concentrations that have no effect on the proliferation of the exponentially growing host cells. The 50% effective concentration (EC{sub 5}) for inhibition of HCV subgenomic replicon replication in Huh 5-2 cells (luciferase assay) by artemisinin was 78 {+-} 21 {mu}M. Hemin, an iron donor, was recently reported to inhibit HCV replicon replication [mediated by inhibition of the viral polymerase (C. Fillebeen, A.M. Rivas-Estilla, M. Bisaillon, P. Ponka, M. Muckenthaler, M.W. Hentze, A.E. Koromilas, K. Pantopoulos, Iron inactivatesmore » the RNA polymerase NS5B and suppresses subgenomic replication of hepatitis C virus, J. Biol. Chem. 280 (2005) 9049-9057.)] at a concentration that had no adverse effect on the host cells. When combined, artemisinin and hemin resulted, over a broad concentration range, in a pronounced synergistic antiviral activity. Also at a concentration (2 {mu}M) that alone had no effect on HCV replication, hemin still potentiated the anti-HCV activity of artemisinin.« less
Neem (Azadirachta indica A. Juss) Oil to Tackle Enteropathogenic Escherichia coli

PubMed Central

Del Serrone, Paola; Nicoletti, Marcello

2015-01-01

Neem (Azadirachta indica A. Juss) oil (NO) was assayed against forty-eight isolates of Escherichia coli by standardised disc diffusion test and microdilution test. By molecular biology characterization, fourteen isolates resulted in diarrheagenic E. coli with sixteen primer pairs that specifically amplify unique sequences of virulence genes and of 16S rRNA. The NO showed biological activity against all isolates. The bacterial growth inhibition zone by disc diffusion method (100 µL NO) ranged between 9.50 ± 0.70 and 30.00 ± 1.00 mm. The antibacterial activity was furthermore determined at lower NO concentrations (1 : 10–1 : 10,000). The percent of growth reduction ranged between 23.71 ± 1.00 and 99.70 ± 1.53. The highest bacterial growth reduction was 1 : 10 NO concentration with 50 µL of bacterial suspension (ca. 1 × 106 CFU/mL). There is significant difference between the antibacterial activities against pathogenic and nonpathogenic E. coli, as well as NO and ciprofloxacin activities. Viable cells after the different NO concentration treatments were checked by molecular biology assay using PMA dye. On the basis of the obtained results, NO counteracts E. coli and also influences the virulence of E. coli viable cells after NO treatment. The NO metabolomic composition was obtained using fingerprint HPTLC. PMID:26064900
Neem (Azadirachta indica A. Juss) Oil to Tackle Enteropathogenic Escherichia coli.

PubMed

Del Serrone, Paola; Toniolo, Chiara; Nicoletti, Marcello

2015-01-01

Neem (Azadirachta indica A. Juss) oil (NO) was assayed against forty-eight isolates of Escherichia coli by standardised disc diffusion test and microdilution test. By molecular biology characterization, fourteen isolates resulted in diarrheagenic E. coli with sixteen primer pairs that specifically amplify unique sequences of virulence genes and of 16S rRNA. The NO showed biological activity against all isolates. The bacterial growth inhibition zone by disc diffusion method (100 µL NO) ranged between 9.50 ± 0.70 and 30.00 ± 1.00 mm. The antibacterial activity was furthermore determined at lower NO concentrations (1 : 10-1 : 10,000). The percent of growth reduction ranged between 23.71 ± 1.00 and 99.70 ± 1.53. The highest bacterial growth reduction was 1 : 10 NO concentration with 50 µL of bacterial suspension (ca. 1 × 10(6) CFU/mL). There is significant difference between the antibacterial activities against pathogenic and nonpathogenic E. coli, as well as NO and ciprofloxacin activities. Viable cells after the different NO concentration treatments were checked by molecular biology assay using PMA dye. On the basis of the obtained results, NO counteracts E. coli and also influences the virulence of E. coli viable cells after NO treatment. The NO metabolomic composition was obtained using fingerprint HPTLC.
Factors influencing production of lipase under metal supplementation by bacterial strain, Bacillus subtilis BDG-8.

PubMed

Dhevahi, B; Gurusamy, R

2014-11-01

Lipases are biocatalyst having wide applications in industries due to their versatile properties. In the present study, a lipolytic bacterial strain, Bacillus subtilis BDG-8 was isolated from an oil based industrial soil. The effect of selenium and nickel as a media supplement on enhancement of lipase production, was studied individually with the isolated strain by varying the concentration of selected metal. 60 μg l(-1) selenium enhanced lipase production to an enzyme activity measuring 7.8 U ml(-1) while 40 μgI(-1) nickel gave the maximum enzyme activity equivalent to 7.5 U ml(-1). However, nickel and selenium together at a range of concentration with an equal w/v ratio, at 60 μg l(-1) each, showed the maximum lipase activity of 8.5 U ml(-1). The effect of pH and temperature on lipase production showed maximum enzyme activity in the presence of each of the metals at pH 7 and 35°C among the other tested ranges. After optimisation of the parameters such as metal concentration, pH and temperature lipase production by Bacillus subtilis BDG-8 had increased several folds. This preliminary investigation may consequently lead as to various industrial applications such as treatment of wastewater contaminated with metal or oil with simultaneous lipase production.
The presence of natural radioactivity and 137Cs in the South China Sea bordering peninsular Malaysia.

PubMed

Amin, Y M; Mahat, R H; Nor, R M; Khandaker, Mayeen Uddin; Takleef, Ghazwa Hatem; Bradley, D A

2013-10-01

The presence of natural radioactivity and (137)Cs has been investigated in fresh media obtained from South China Sea locations off the coast of peninsular Malaysia. The media include seafood, sea water and sediment. The samples were collected some weeks prior to the devastating 2011 Tōhoku earthquake and associated tsunami, the occurrence of which precipitated the Fukushima incident. All samples showed the presence of naturally occurring (226)Ra, (228)Ra and primordial (40)K, all at typically prevailing levels. The concentrations of natural radioactivity in molluscs were found to be greater than that of other marine life studied herein, the total activity ranging from 337 to 393 Bq kg(-1) dry weight. The total activity in sea water ranged from 15 to 88 Bq l(-1). Sediment samples obtained at deep sea locations more than 20 km offshore further revealed the presence of (137)Cs. The activity of (137)Cs varied from ND to 0.5 Bq kg(-1) dry weight, the activity increasing with offshore distance and depth. The activity concentrations presented herein should be considered useful in assessing the impact of any future radiological contamination to the marine environment.
137Cs and 90Sr IN lizards of Semipalatinsk test site.

PubMed

Panitskiy, А V; Lukashenko, S N; Kadyrova, N Zh

2017-01-01

The paper provides research results of 137 Cs and 90 Sr radionuclides concentrations in bodies of Lacertidae family lizards, inhabiting different parts of Semipalatinsk Test Site, and the parameters of these radionuclides' transfer into lizards' bodies. It shows that high activity concentration of radionuclides in lizards' bodies can be noticed if they live directly at locally contaminated areas. Since the distance from contaminated spots exceeds home range of the studied animals, no increased values of radionuclides' activity were found in the animal bodies. At some individual radioactively contaminated spots, very high activity concentrations of 90 Sr radionuclide up to 7.8 × 10 5 Bq kg -1 were found in lizards. So under certain conditions, lizards can significantly contribute to radionuclides redistribution in the natural environment. Mean concentration ratios (CR) of radionuclides were as follows: 137 Cs-6.2 × 10 -3 , 90 Sr-1.1 × 10 -2 . Copyright Â© 2016 Elsevier Ltd. All rights reserved.
Gas1 extends the range of Hedgehog action by facilitating its signaling

PubMed Central

Martinelli, David C.; Fan, Chen-Ming

2007-01-01

Cellular signaling initiated by Hedgehog binding to Patched1 has profound importance in mammalian embryogenesis, genetic disease, and cancer. Hedgehog acts as a morphogen to specify distinctive cell fates using different concentration thresholds, but our knowledge of how the concentration gradient is interpreted into the activity gradient is incomplete. The membrane protein Growth Arrest-Specific Gene 1 (GAS1) was thought to be a negative regulator of the Hedgehog concentration gradient. Here, we report unexpected genetic evidence that Gas1 positively regulates Hedgehog signaling in multiple developmental contexts, an effect particularly noticeable at regions where Hedgehog acts at low concentration. Using a combination of in vitro cell culture and in ovo electroporation assays, we demonstrate that GAS1 acts cooperatively with Patched1 for Hedgehog binding and enhances signaling activity in a cell-autonomous manner. Our data support a model in which GAS1 helps transform the Hedgehog protein gradient into the observed activity gradient. We propose that Gas1 is an evolutionarily novel, vertebrate-specific Hedgehog pathway regulator. PMID:17504940
Effects of polyamines and calcium and sodium ions on smooth muscle cytoskeleton-associated phosphatidylinositol (4)-phosphate 5-kinase.

PubMed

Chen, H; Baron, C B; Griffiths, T; Greeley, P; Coburn, R F

1998-10-01

In many different cell types, including smooth muscle cells (Baron et al., 1989, Am. J. Physiol., 256: C375-383; Baron et al., J. Pharmacol. Exp. Ther. 266: 8-15), phosphatidylinositol (4)-phosphate 5-kinase plays a critical role in the regulation of membrane concentrations of phosphatidylinositol (4,5)-bisphosphate and formation of inositol (1,4,5)-trisphosphate. In unstimulated porcine trachealis smooth muscle, 70% of total cellular phosphatidylinositol (4)-phosphate 5-kinase activity was associated with cytoskeletal proteins and only trace activity was detectable in isolated sarcolemma. Using two different preparations, we studied cytoskeleton-associated phosphatidyl inositol (4)-phosphate 5-kinase under conditions that attempted to mimic the ionic and thermal cytoplasmic environment of living cells. The cytoskeleton-associated enzyme, studied using phosphatidylinositol (4)-phosphate substrate concentrations that produced phosphatidylinositol 4,5-bisphosphate at about 10% of the maximal rate, was sensitive to free [Mg2+], had an absolute requirement for phosphatidylserine, phosphatidic acid, or phosphatidylinositol, and included type I isoforms. At 0.5 mM free [Mg2+], physiological spermine concentrations, 0.2-0.4 mM, increased phosphatidylinositol (4)-phosphate 5-kinase activity two to four times compared to controls run without spermine. The EC50 for spermine-evoked increases in activity was 0.17 +/- 0.02 mM. Spermine-evoked enzyme activity was a function of both free [Mg2+] and substrate concentration. Cytoskeleton-associated phosphatidylinositol (4)-phosphate 5-kinase was inhibited by free [Ca2+] over a physiological range for cytoplasm--10(-8) to 10(-5) M, an effect independent of the presence of calmodulin. Na+ over the range 20 to 50 mM also inhibited this enzyme activated by 5 mM Mg2+ but had no effect on spermine-activated enzyme. Na+, Ca2+, and spermine appear to be physiological modulators of smooth muscle cytoskeleton-bound phosphatidylinositol (4)-phosphate 5-kinase.
Validation of an immunoassay to measure plasminogen-activator inhibitor-1 concentrations in human saliva

PubMed Central

Zhang, Xi; Dimeski, Goce; Punyadeera, Chamindie

2014-01-01

Introduction: We have previously shown that the concentrations of D-dimer are significantly elevated in saliva compared with plasma. Saliva offers several advantages compared with blood analysis. We hypothesised that human saliva contains plasminogen activator inhibitor-1 (PAI-1) and that the concentrations are not affected by the time of saliva collection. The aim was to adopt and validate an immunoassay to quantify PAI-1 concentrations in saliva and to determine whether saliva collection time has an influence in the measurement. Materials and methods: Two saliva samples (morning and afternoon) from the same day were collected from healthy subjects (N = 40) who have had no underlying heart conditions. A customized AlphaLISA® immunoassay (PerkinElmer®, MA, USA) was adopted and used to quantify PAI-1 concentrations. We validated the analytical performance of the customized immunoassay by calculating recovery of known amount of analyte spiked in saliva. Results: The recovery (95.03%), intra- (8.59%) and inter-assay (7.52%) variations were within the acceptable ranges. The median salivary PAI-1 concentrations were 394 pg/mL (interquartile ranges (IQR) 243.4–833.1 pg/mL) in the morning and 376 (129.1–615.4) pg/mL in the afternoon and the plasma concentration was 59,000 (24,000–110,000) pg/mL. Salivary PAI-1 did not correlate with plasma (P = 0.812). Conclusions: The adopted immunoassay produced acceptable assay sensitivity and specificity. The data demonstrated that saliva contains PAI-1 and that its concentration is not affected by the time of saliva collection. There is no correlation between salivary and plasma PAI-1 concentrations. Further studies are required to demonstrate the utility of salivary PAI-1 in CVD risk factor studies. PMID:24969919
Kinetic model of excess activated sludge thermohydrolysis.

PubMed

Imbierowicz, Mirosław; Chacuk, Andrzej

2012-11-01

Thermal hydrolysis of excess activated sludge suspensions was carried at temperatures ranging from 423 K to 523 K and under pressure 0.2-4.0 MPa. Changes of total organic carbon (TOC) concentration in a solid and liquid phase were measured during these studies. At the temperature 423 K, after 2 h of the process, TOC concentration in the reaction mixture decreased by 15-18% of the initial value. At 473 K total organic carbon removal from activated sludge suspension increased to 30%. It was also found that the solubilisation of particulate organic matter strongly depended on the process temperature. At 423 K the transfer of TOC from solid particles into liquid phase after 1 h of the process reached 25% of the initial value, however, at the temperature of 523 K the conversion degree of 'solid' TOC attained 50% just after 15 min of the process. In the article a lumped kinetic model of the process of activated sludge thermohydrolysis has been proposed. It was assumed that during heating of the activated sludge suspension to a temperature in the range of 423-523 K two parallel reactions occurred. One, connected with thermal destruction of activated sludge particles, caused solubilisation of organic carbon and an increase of dissolved organic carbon concentration in the liquid phase (hydrolysate). The parallel reaction led to a new kind of unsolvable solid phase, which was further decomposed into gaseous products (CO(2)). The collected experimental data were used to identify unknown parameters of the model, i.e. activation energies and pre-exponential factors of elementary reactions. The mathematical model of activated sludge thermohydrolysis appropriately describes the kinetics of reactions occurring in the studied system. Copyright © 2012 Elsevier Ltd. All rights reserved.
Optimized angiotensin-converting enzyme activity assay for the accurate diagnosis of sarcoidosis.

PubMed

Csongrádi, Alexandra; Enyedi, Attila; Takács, István; Végh, Tamás; Mányiné, Ivetta S; Pólik, Zsófia; Altorjay, István Tibor; Balla, József; Balla, György; Édes, István; Kappelmayer, János; Tóth, Attila; Papp, Zoltán; Fagyas, Miklós

2018-06-27

Serum angiotensin-converting enzyme (ACE) activity determination can aid the early diagnosis of sarcoidosis. We aimed to optimize a fluorescent kinetic assay for ACE activity by screening the confounding effects of endogenous ACE inhibitors and interfering factors. Genotype-dependent and genotype-independent reference values of ACE activity were established, and their diagnostic accuracies were validated in a clinical study. Internally quenched fluorescent substrate, Abz-FRK(Dnp)P-OH was used for ACE-activity measurements. A total of 201 healthy individuals and 59 presumably sarcoidotic patients were enrolled into this study. ACE activity and insertion/deletion (I/D) genotype of the ACE gene were determined. Here we report that serum samples should be diluted at least 35-fold to eliminate the endogenous inhibitor effect of albumin. No significant interferences were detected: up to a triglyceride concentration of 16 mM, a hemoglobin concentration of 0.71 g/L and a bilirubin concentration of 150 μM. Genotype-dependent reference intervals were considered as 3.76-11.25 U/L, 5.22-11.59 U/L, 7.19-14.84 U/L for II, ID and DD genotypes, respectively. I/D genotype-independent reference interval was established as 4.85-13.79 U/L. An ACE activity value was considered positive for sarcoidosis when it exceeded the upper limit of the reference interval. The optimized assay with genotype-dependent reference ranges resulted in 42.5% sensitivity, 100% specificity, 100% positive predictive value and 32.4% negative predictive value in the clinical study, whereas the genotype-independent reference range proved to have inferior diagnostic efficiency. An optimized fluorescent kinetic assay of serum ACE activity combined with ACE I/D genotype determination is an alternative to invasive biopsy for confirming the diagnosis of sarcoidosis in a significant percentage of patients.
Physicochemical and Functional Properties of Vegetable and Cereal Proteins as Potential Sources of Novel Food Ingredients

PubMed Central

Soria-Hernández, Cintya; Serna-Saldívar, Sergio

2015-01-01

Summary Proteins from vegetable and cereal sources are an excellent alternative to substitute animal-based counterparts because of their reduced cost, abundant supply and good nutritional value. The objective of this investigation is to study a set of vegetable and cereal proteins in terms of physicochemical and functional properties. Twenty protein sources were studied: five soya bean flour samples, one pea flour and fourteen newly developed blends of soya bean and maize germ (five concentrates and nine hydrolysates). The physicochemical characterization included pH (5.63 to 7.57), electrical conductivity (1.32 to 4.32 mS/cm), protein content (20.78 to 94.24% on dry mass basis), free amino nitrogen (0.54 to 2.87 mg/g) and urease activity (0.08 to 2.20). The functional properties showed interesting differences among proteins: water absorption index ranged from 0.41 to 18.52, the highest being of soya and maize concentrates. Nitrogen and water solubility ranged from 10.14 to 74.89% and from 20.42 to 95.65%, respectively. Fat absorption and emulsification activity indices ranged from 2.59 to 4.72 and from 3936.6 to 52 399.2 m2/g respectively, the highest being of pea flour. Foam activity (66.7 to 475.0%) of the soya and maize hydrolysates was the best. Correlation analyses showed that hydrolysis affected solubility-related parameters whereas fat-associated indices were inversely correlated with water-linked parameters. Foam properties were better of proteins treated with low heat, which also had high urease activity. Physicochemical and functional characterization of the soya and maize protein concentrates and hydrolysates allowed the identification of differences regarding other vegetable and cereal protein sources such as pea or soya bean. PMID:27904358
Salt Inactivates Endothelial Nitric Oxide Synthase in Endothelial Cells12

PubMed Central

Li, Juan; White, James; Guo, Ling; Zhao, Xiaomin; Wang, Jiafu; Smart, Eric J.; Li, Xiang-An

2009-01-01

There is a 1–4 mmol/L rise in plasma sodium concentrations in individuals with high salt intake and in patients with essential hypertension. In this study, we used 3 independent assays to determine whether such a small increase in sodium concentrations per se alters endothelial nitric oxide synthase (eNOS) function and contributes to hypertension. By directly measuring NOS activity in living bovine aortic endothelial cells, we demonstrated that a 5-mmol/L increase in salt concentration (from 137 to 142 mmol/L) caused a 25% decrease in NOS activity. Importantly, the decrease in NOS activity was in a salt concentration-dependent manner. The NOS activity was decreased by 25, 45, and 70%, with the increase of 5, 10, and 20 mmol/L of NaCl, respectively. Using Chinese hamster ovary cells stably expressing eNOS, we confirmed the inhibitory effects of salt on eNOS activity. The eNOS activity was unaffected in the presence of equal milliosmol of mannitol, which excludes an osmotic effect. Using an ex vivo aortic angiogenesis assay, we demonstrated that salt attenuated the nitric oxide (NO)-dependent proliferation of endothelial cells. By directly monitoring blood pressure changes in response to salt infusion, we found that in vivo infusion of salt induced an acute increase in blood pressure in a salt concentration-dependent manner. In conclusion, our findings demonstrated that eNOS is sensitive to changes in salt concentration. A 5-mmol/L rise in salt concentration, within the range observed in essential hypertension patients or in individuals with high salt intake, could significantly suppress eNOS activity. This salt-induced reduction in NO generation in endothelial cells may contribute to the development of hypertension. PMID:19176751
Salt inactivates endothelial nitric oxide synthase in endothelial cells.

PubMed

Li, Juan; White, James; Guo, Ling; Zhao, Xiaomin; Wang, Jiafu; Smart, Eric J; Li, Xiang-An

2009-03-01

There is a 1-4 mmol/L rise in plasma sodium concentrations in individuals with high salt intake and in patients with essential hypertension. In this study, we used 3 independent assays to determine whether such a small increase in sodium concentrations per se alters endothelial nitric oxide synthase (eNOS) function and contributes to hypertension. By directly measuring NOS activity in living bovine aortic endothelial cells, we demonstrated that a 5-mmol/L increase in salt concentration (from 137 to 142 mmol/L) caused a 25% decrease in NOS activity. Importantly, the decrease in NOS activity was in a salt concentration-dependent manner. The NOS activity was decreased by 25, 45, and 70%, with the increase of 5, 10, and 20 mmol/L of NaCl, respectively. Using Chinese hamster ovary cells stably expressing eNOS, we confirmed the inhibitory effects of salt on eNOS activity. The eNOS activity was unaffected in the presence of equal milliosmol of mannitol, which excludes an osmotic effect. Using an ex vivo aortic angiogenesis assay, we demonstrated that salt attenuated the nitric oxide (NO)-dependent proliferation of endothelial cells. By directly monitoring blood pressure changes in response to salt infusion, we found that in vivo infusion of salt induced an acute increase in blood pressure in a salt concentration-dependent manner. In conclusion, our findings demonstrated that eNOS is sensitive to changes in salt concentration. A 5-mmol/L rise in salt concentration, within the range observed in essential hypertension patients or in individuals with high salt intake, could significantly suppress eNOS activity. This salt-induced reduction in NO generation in endothelial cells may contribute to the development of hypertension.
Radiation-induced biologic bystander effect elicited in vitro by targeted radiopharmaceuticals labeled with alpha-, beta-, and auger electron-emitting radionuclides.

PubMed

Boyd, Marie; Ross, Susan C; Dorrens, Jennifer; Fullerton, Natasha E; Tan, Ker Wei; Zalutsky, Michael R; Mairs, Robert J

2006-06-01

Recent studies have shown that indirect effects of ionizing radiation may contribute significantly to the effectiveness of radiotherapy by sterilizing malignant cells that are not directly hit by the radiation. However, there have been few investigations of the importance of indirect effects in targeted radionuclide treatment. Our purpose was to compare the induction of bystander effects by external beam gamma-radiation with those resultant from exposure to 3 radiohaloanalogs of metaiodobenzylguanidine (MIBG): (131)I-MIBG (low-linear-energy-transfer [LET] beta-emitter), (123)I-MIBG (potentially high-LET Auger electron emitter), and meta-(211)At-astatobenzylguanidine ((211)At-MABG) (high-LET alpha-emitter). Two human tumor cell lines-UVW (glioma) and EJ138 (transitional cell carcinoma of bladder)-were transfected with the noradrenaline transporter (NAT) gene to enable active uptake of MIBG. Medium from cells that accumulated the radiopharmaceuticals or were treated with external beam radiation was transferred to cells that had not been exposed to radioactivity, and clonogenic survival was determined in donor and recipient cultures. Over the dose range 0-9 Gy of external beam radiation of donor cells, 2 Gy caused 30%-40% clonogenic cell kill in recipient cultures. This potency was maintained but not increased by higher dosage. In contrast, no corresponding saturation of bystander cell kill was observed after treatment with a range of activity concentrations of (131)I-MIBG, which resulted in up to 97% death of donor cells. Cellular uptake of (123)I-MIBG and (211)At-MABG induced increasing recipient cell kill up to levels that resulted in direct kill of 35%-70% of clonogens. Thereafter, the administration of higher activity concentrations of these high-LET emitters was inversely related to the kill of recipient cells. Over the range of activity concentrations examined, neither direct nor indirect kill was observed in cultures of cells not expressing the NAT and, thus, incapable of active uptake of MIBG. Potent toxins are generated specifically by cells that concentrate radiohalogenated MIBG. These may be LET dependent and distinct from those elicited by conventional radiotherapy.

Investigating organic molecules responsible of auxin-like activity of humic acid fraction extracted from vermicompost.

PubMed

Scaglia, Barbara; Nunes, Ramom Rachide; Rezende, Maria Olímpia Oliveira; Tambone, Fulvia; Adani, Fabrizio

2016-08-15

This work studied the auxin-like activity of humic acids (HA) obtained from vermicomposts produced using leather wastes plus cattle dung at different maturation stages (fresh, stable and mature). Bioassays were performed by testing HA concentrations in the range of 100-6000mgcarbonL(-1). (13)C CPMAS-NMR and GC-MS instrumental methods were used to assess the effect of biological processes and starting organic mixtures on HA composition. Not all HAs showed IAA-like activity and in general, IAA-like activity increased with the length of the vermicomposting process. The presence of leather wastes was not necessary to produce the auxin-like activity of HA, since HA extracted from a mix of cattle manure and sawdust, where no leather waste was added, showed IAA-like activity as well. CPMAS (13)CNMR revealed that HAs were similar independently of the mix used and that the humification process involved the increasing concentration of pre-existing alkali soluble fractions in the biomass. GC/MS allowed the identification of the molecules involved in IAA-like effects: carboxylic acids and amino acids. The concentration of active molecules, rather than their simple presence in HA, determined the bio-stimulating effect, and a good linear regression between auxin-like activity and active stimulating molecules concentration was found (R(2)=-0.85; p<0.01, n=6). Copyright © 2016 Elsevier B.V. All rights reserved.
Synergy, Pharmacodynamics, and Time-Sequenced Ultrastructural Changes of the Interaction between Nikkomycin Z and the Echinocandin FK463 against Aspergillus fumigatus

PubMed Central

Chiou, Christine C.; Mavrogiorgos, Nikolaos; Tillem, Elizabeth; Hector, Richard; Walsh, Thomas J.

2001-01-01

We investigated the potential synergy between two cell wall-active agents, the echinocandin FK463 (FK) and the chitin synthase inhibitor nikkomycin Z (NZ), against 16 isolates of filamentous fungi. Susceptibility testing was performed with a broth macrodilution procedure by NCCLS methods. The median minimal effective concentration (MEC) of FK against all Aspergillus species was 0.25 μg/ml (range, 0.05 to 0.5 μg/ml). For Fusarium solani and Rhizopus oryzae, MECs of FK were >512 μg/ml. The median MEC of NZ against Aspergillus fumigatus was 32 μg/ml (range, 8 to 64 μg/ml), and that against R. oryzae was 0.5 μg/ml (range, 0.06 to 2 μg/ml); however, for the other Aspergillus species, as well as F. solani, MECs were >512 μg/ml. A checkerboard inhibitory assay demonstrated synergy against A. fumigatus (median fractional inhibitory concentration index = 0.312 [range, 0.15 to 0.475]). The effect was additive to indifferent against R. oryzae and indifferent against other Aspergillus spp. and F. solani. We further investigated the pharmacodynamics of hyphal damage by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and examined the time-sequenced changes in hyphal ultrastructure. Significant synergistic hyphal damage was demonstrated with the combination of NZ (2 to 32 μg/ml) and FK (0.03 to 0.5 μg/ml) over a wide range of concentrations (P < 0.001). The synergistic effect was most pronounced after 12 h of incubation and was sustained through 24 h. Time-sequenced light and electron microscopic studies demonstrated that structural alterations of hyphae were profound, with marked transformation of hyphae to blastospore-like structures, in the presence of FK plus NZ, while fungi treated with a single drug showed partial recovery at 24 h. The methods used in this study may be applicable to elucidating the activity and interaction of other cell wall-active agents. In summary, these two cell wall-targeted antifungal agents, FK and NZ, showed marked time-dependent in vitro synergistic activity against A. fumigatus. PMID:11709302
Enhancement of anti-Aeromonas salmonicida activity in Atlantic salmon (Salmo salar) macrophages by a mannose-binding lectin

USGS Publications Warehouse

Ottinger, C.A.; Johnson, S.C.; Ewart, K.V.; Brown, L.L.; Ross, N.W.

1999-01-01

We investigated the effects of a calcium-dependent mannose-binding lectin isolated from the serum of Atlantic salmon on Aeromonassalmonicida viability and the anti-A. salmonicida activity of Atlantic salmon macrophages. In the absence of other factors, binding of this lectin at concentrations of 0.8, 4.0 and 20.0 ng ml−1 to virulent A. salmonicida failed to significantly reduce (P>0.05) cell viability. However, binding of the lectin to A. salmonicida did result in significant (P≤0.05) dose-dependent increases in phagocytosis, and bactericidal activity. Significant increases (P≤0.05) were also observed in phagocyte respiratory burst activity within the lectin concentration range of 4.0–20.0 ng ml−1 but the stimulation was not dose dependent at these lectin concentrations. At the lowest lectin concentration tested (0.32 ng ml−1), a significant decrease (P≤0.05) in respiratory burst was observed. The structure and activity of this lectin are similar to that of mammalian mannose-binding lectins, which are known to play a pivotal role in innate immunity. The presence of this lectin may be an important defense mechanism against Gram-negative bacteria such as A. salmonicida.
Activity of Allyl Isothiocyanate and Its Synergy with Fluconazole against Candida albicans Biofilms.

PubMed

Raut, Jayant Shankar; Bansode, Bhagyashree Shridhar; Jadhav, Ashwini Khanderao; Karuppayil, Sankunny Mohan

2017-04-28

Candidiasis involving the biofilms of Candida albicans is a threat to immunocompromised patients. Candida biofilms are intrinsically resistant to the antifungal drugs and hence novel treatment strategies are desired. The study intended to evaluate the anti- Candida activity of allyl isothiocyanate (AITC) alone and with fluconazole (FLC), particularly against the biofilms. Results revealed the concentration-dependent activity of AITC against the planktonic growth and virulence factors of C. albicans . Significant ( p <0.05) inhibition of the biofilms was evident at < or =1 mg/ml concentrations of AITC. Notably, a combination of 0.004 mg/ml of FLC and 0.125 mg/ml of AITC prevented the biofilm formation. Similarly, the preformed biofilms were significantly ( p <0.05) inhibited by the AITC-FLC combination. The fractional inhibitory concentration indices ranging from 0.132 to 0.312 indicated the synergistic activity of AITC and FLC against the biofilm formation and the preformed biofilms. No hemolytic activity at the biofilm inhibitory concentrations of AITC and the AITC-FLC combination suggested the absence of cytotoxic effects. The recognizable synergy between AITC and FLC offers a potential therapeutic strategy against biofilm-associated Candida infections.
The effect of chlorpyrifos upon ATPase activity of sarcoplasmic reticulum and biomechanics of skeleta l muscle contraction.

PubMed

Nozdrenko, D M; Miroshnychenko, M S; Soroca, V M; Korchins ka, L V; Zavodovskiy, D O

2016-01-01

We investigated the effect of chlorpyrifos, an organophosphate insecticide, on Ca2+,Mg2+-ATPase activity of sarcoplasmic reticulum and on contraction dynamics (force and length changes) of Rana temporaria m. tibialis anterior muscle fiber bundles. All of the used concentrations of chlorpyrifos (10-6 to 10-5 M) caused decrease of Ca2+,Mg2+-ATPase activity. The inhibition of Ca2+,Mg2+-ATPase activity by chlorpyriphos in concentrations of 10-6 M to 7.5·10-6 M is due to permeation of sarcoplasmic reticulum rather than due to direct enzyme inhibition by organophosphate insecticides. The inhibitory properties of the compound were higher at increased concentration and exposure timeframes. Chlorpyrifos in concentration range of 10-6 to 7.5·10-6 M causes changes in muscle fiber response force that were more pronounced than changes in contractile length. We demonstrated inhibition of Ca2+,Mg2+-ATPase activity caused by noncholinergic effects of chlorpyriphos. It is possible to conclude that influence of organophosphate insecticides happens not only in the neuromuscular transmission but also on the level of subcellular structures.
Impedance measurement of Cobalt doped ZnO Quantum dots

NASA Astrophysics Data System (ADS)

Tiwari, Ram; Kaphle, Amrit; Hari, Parameswar

We investigated structural, thermal and electrical properties of ZnO Quantum dots grown by precipitation method. QDs were spin coated on ITO and annealed at various temperatures ranging from 1000C to 300 0C. ZnO QDs were doped with cobalt for concentration ranging from 0-15%. XRD measurement showed increase in bond length, strain, dislocation density and Cell volume as the doping level varied from 0% to 15%. Impedance Spectroscopy measurements represented by Cole-Cole plot showed reduction in resistance as the cobalt doping concentration increased from 0-15%. Thermal activation energy was obtained by plotting resistivity Vs temperature for doped samples at temperatures from 1000C to 3000C. The thermal activation energy decreased from 85.13meV to 58.21meV as doping increased from 0-15%. Relaxation time was extracted by fitting data to RC model. Relaxation time varied from 61.57 ns to 3.76 ns as the cobalt concentration increased from 0% to 15%. We will also discuss applications of cobalt doped ZnO QDs on improving conversion efficiency of solar cells.
Interface interactions in benzophenone doped by multiwalled carbon nanotubes

NASA Astrophysics Data System (ADS)

Lebovka, N. I.; Goncharuk, A.; Melnyk, V. I.; Puchkovska, G. A.

2009-08-01

The interface interactions were studied by methods of conductometry, low-temperature phosphorescence and differential scanning calorimetry (DSC) in multiwalled carbon nanotubes (MWCNT) and benzophenone (BP) composite. The concentration of MWCNTs was varied within 0-1 wt%. A percolative threshold was found at MWCNT concentrations exceeding 0.1 wt%. The integration of MWCNTs caused melting temperature increase (≈3 K for 1 wt% of MWCNTs). The effect of positive thermal resistively coefficient, as well as substantial hysteretic behaviour of electrical conductivity σ in a heating-cooling cycle, was observed near the melting point of BP ( T m=321.5 K). The activation-type temperature behaviour of electrical conductivity was observed in the temperature range of supercooled BP. The activation energy was decreasing with increase of MWCNT concentration. The observed nonlinear dependencies of electrical conductivity σ vs. applied voltage U reflect the transport mechanism of the charge carriers through amorphous interface films formed near the surface of the MWCNTs. The thermal shifts of phosphorescence spectra measured within the temperature range 5-200 K evidence existence of such interface films of amorphous BP with width of the order of 0.1 μm.
Alteration of natural (37)Ar activity concentration in the subsurface by gas transport and water infiltration.

PubMed

Guillon, Sophie; Sun, Yunwei; Purtschert, Roland; Raghoo, Lauren; Pili, Eric; Carrigan, Charles R

2016-05-01

High (37)Ar activity concentration in soil gas is proposed as a key evidence for the detection of underground nuclear explosion by the Comprehensive Nuclear Test-Ban Treaty. However, such a detection is challenged by the natural background of (37)Ar in the subsurface, mainly due to Ca activation by cosmic rays. A better understanding and improved capability to predict (37)Ar activity concentration in the subsurface and its spatial and temporal variability is thus required. A numerical model integrating (37)Ar production and transport in the subsurface is developed, including variable soil water content and water infiltration at the surface. A parameterized equation for (37)Ar production in the first 15 m below the surface is studied, taking into account the major production reactions and the moderation effect of soil water content. Using sensitivity analysis and uncertainty quantification, a realistic and comprehensive probability distribution of natural (37)Ar activity concentrations in soil gas is proposed, including the effects of water infiltration. Site location and soil composition are identified as the parameters allowing for a most effective reduction of the possible range of (37)Ar activity concentrations. The influence of soil water content on (37)Ar production is shown to be negligible to first order, while (37)Ar activity concentration in soil gas and its temporal variability appear to be strongly influenced by transient water infiltration events. These results will be used as a basis for practical CTBTO concepts of operation during an OSI. Copyright © 2016 Elsevier Ltd. All rights reserved.
The effects of vinblastine on endothelial cells.

PubMed

Gallagher, H; Carroll, W M; Dowd, M; Rochev, Y

2008-01-01

The development of drug-eluting stents to combat the problem of in-stent restenosis has revolutionized interventional cardiology. However, concerns have emerged about the risk of late angiographic stent thromboses associated with drug-eluting stents. It has been shown that noncytotoxic concentrations of paclitaxel exert an antiangiogenic effect, suggesting that paclitaxel and similar agents may inhibit key cellular functions in a threshold-independent manner. In this study, the effect of vinblastine, an antimitotic drug, on endothelial cells is analyzed. It is investigated whether noncytotoxic concentrations of the drug could exert an antirestenotic effect. The change in levels of cell proliferation, activity, and viability in human umbilical vein endothelial cells was measured at a range of concentrations and over a number of time points. Also, the level of apoptotic activity in response to vinblastine was analyzed. This study shows that the concentration of vinblastine most appropriate in restenosis treatment would be between 0.1 and 1 nM. At this concentration, vinblastine exerts a distinct biological effect without causing an increase in apoptotic activity. These results emphasize the importance of finding an appropriate concentration window in order to minimize the risk of delayed endothelialization and thrombosis.
Inhibitory effect of high calcium concentration on municipal solid waste leachate treatment by the activated sludge process.

PubMed

Xia, Yi; He, Pin Jing; Pu, Hong Xia; Lü, Fan; Shao, Li Ming; Zhang, Hua

2017-05-01

This research focused on the inhibitory effects of Ca on the aerobic biological treatment of landfill leachate containing extremely high Ca concentrations. When the Ca concentration in leachate to be treated was more than 4500 mg l -1 , the total organic carbon removal rate was significantly reduced and the processing time to achieve the same removal efficiency was 1.4 times that in the control treatment without added Ca. In contrast, the total nitrogen and ammonia nitrogen (NH 4 + -N) removal efficiencies were positively related to the Ca concentration, increasing from 65.2% to 81.2% and from 69.2% to 83.7%, respectively, when the dosage of added Ca increased from zero to 8000 mg l -1 . During aerobic treatment, the reductions of solution Ca concentration were in the range of 1003-2274 mg l -1 and were matched with increases in the Ca content in the residual sludge. The inhibition threshold of Ca in the leachate treated by the activated sludge process appeared to be 4500 mg l -1 , which could be realized by controlling the influent Ca concentration and using an appropriate sludge return ratio in the activated sludge process.
Nonimaging polygonal mirrors achieving uniform irradiance distributions on concentrating photovoltaic cells.

PubMed

Schmitz, Max; Dähler, Fabian; Elvinger, François; Pedretti, Andrea; Steinfeld, Aldo

2017-04-10

We introduce a design methodology for nonimaging, single-reflection mirrors with polygonal inlet apertures that generate a uniform irradiance distribution on a polygonal outlet aperture, enabling a multitude of applications within the domain of concentrated photovoltaics. Notably, we present single-mirror concentrators of square and hexagonal perimeter that achieve very high irradiance uniformity on a square receiver at concentrations ranging from 100 to 1000 suns. These optical designs can be assembled in compound concentrators with maximized active area fraction by leveraging tessellation. More advanced multi-mirror concentrators, where each mirror individually illuminates the whole area of the receiver, allow for improved performance while permitting greater flexibility for the concentrator shape and robustness against partial shading of the inlet aperture.
Characterization of the Structure and Membrane Interaction of the Antimicrobial Peptides Aurein 2.2 and 2.3 from Australian Southern Bell Frogs

PubMed Central

Pan, Yeang-Ling; Cheng, John T.-J.; Hale, John; Pan, Jinhe; Hancock, Robert E. W.; Straus, Suzana K.

2007-01-01

The structure and membrane interaction of the antimicrobial peptide aurein 2.2 (GLFDIVKKVVGALGSL-CONH2), aurein 2.3 (GLFDIVKKVVGAIGSL-CONH2), both from Litoria aurea, and a carboxy C-terminal analog of aurein 2.3 (GLFDIVKKVVGAIGSL-COOH) were studied to determine which features of this class of peptides are key to activity. Circular dichroism and solution-state NMR data indicate that all three peptides adopt an α-helical structure in the presence of trifluoroethanol or lipids such as 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and a 1:1 mixture of DMPC and 1,2-dimyristoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (DMPG). Oriented circular dichroism was used to determine the orientation of the peptides in lipid bilayers over a range of concentrations (peptide/lipid molar ratios (P/L) = 1:15–1:120) in DMPC and 1:1 DMPC/DMPG, in the liquid crystalline state. The results demonstrate that in DMPC all three peptides are surface adsorbed over a range of low peptide concentrations but insert into the bilayers at high peptide concentrations. This finding is corroborated by 31P-solid-state NMR data of the three peptides in DMPC, which shows that at high peptide concentrations the peptides perturb the membrane. Oriented circular dichroism data of the aurein peptides in 1:1 DMPC/DMPG, on the other hand, show that the peptides with amidated C-termini readily insert into the membrane bilayers over the concentration range studied (P/L = 1:15–1:120), whereas the aurein 2.3 peptide with a carboxy C-terminus inserts at a threshold concentration of P/L* between 1:80 and 1:120. Overall, the data presented here suggest that all three peptides studied interact with phosphatidylcholine membranes in a manner which is similar to aurein 1.2 and citropin 1.1, as reported in the literature, with no correlation to the reported activity. On the other hand, both aurein 2.2 and aurein 2.3 behave similarly in phosphatidylcholine/phosphatidylglycerol (PC/PG) membranes, whereas aurein 2.3-COOH inserts less readily. As this does not correlate with reported activities, minimal inhibitory concentrations of the three peptides against Staphylococcus aureus (strain C622, ATCC 25923) and Staphylococcus epidermidis (strain C621—clinical isolate) were determined. The correlation between structure, membrane interaction, and activity are discussed in light of these results. PMID:17259271
Characterization of the structure and membrane interaction of the antimicrobial peptides aurein 2.2 and 2.3 from Australian southern bell frogs.

PubMed

Pan, Yeang-Ling; Cheng, John T-J; Hale, John; Pan, Jinhe; Hancock, Robert E W; Straus, Suzana K

2007-04-15

The structure and membrane interaction of the antimicrobial peptide aurein 2.2 (GLFDIVKKVVGALGSL-CONH(2)), aurein 2.3 (GLFDIVKKVVGAIGSL-CONH(2)), both from Litoria aurea, and a carboxy C-terminal analog of aurein 2.3 (GLFDIVKKVVGAIGSL-COOH) were studied to determine which features of this class of peptides are key to activity. Circular dichroism and solution-state NMR data indicate that all three peptides adopt an alpha-helical structure in the presence of trifluoroethanol or lipids such as 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and a 1:1 mixture of DMPC and 1,2-dimyristoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (DMPG). Oriented circular dichroism was used to determine the orientation of the peptides in lipid bilayers over a range of concentrations (peptide/lipid molar ratios (P/L) = 1:15-1:120) in DMPC and 1:1 DMPC/DMPG, in the liquid crystalline state. The results demonstrate that in DMPC all three peptides are surface adsorbed over a range of low peptide concentrations but insert into the bilayers at high peptide concentrations. This finding is corroborated by (31)P-solid-state NMR data of the three peptides in DMPC, which shows that at high peptide concentrations the peptides perturb the membrane. Oriented circular dichroism data of the aurein peptides in 1:1 DMPC/DMPG, on the other hand, show that the peptides with amidated C-termini readily insert into the membrane bilayers over the concentration range studied (P/L = 1:15-1:120), whereas the aurein 2.3 peptide with a carboxy C-terminus inserts at a threshold concentration of P/L* between 1:80 and 1:120. Overall, the data presented here suggest that all three peptides studied interact with phosphatidylcholine membranes in a manner which is similar to aurein 1.2 and citropin 1.1, as reported in the literature, with no correlation to the reported activity. On the other hand, both aurein 2.2 and aurein 2.3 behave similarly in phosphatidylcholine/phosphatidylglycerol (PC/PG) membranes, whereas aurein 2.3-COOH inserts less readily. As this does not correlate with reported activities, minimal inhibitory concentrations of the three peptides against Staphylococcus aureus (strain C622, ATCC 25923) and Staphylococcus epidermidis (strain C621--clinical isolate) were determined. The correlation between structure, membrane interaction, and activity are discussed in light of these results.
Spatial use and habitat selection of golden eagles in southwestern Idaho

USGS Publications Warehouse

Marzluff, J.M.; Knick, Steven T.; Vekasy, M.S.; Schueck, Linda S.; Zarriello, T.J.

1997-01-01

We measured spatial use and habitat selection of radio-tagged Golden Eagles (Aquila chrysaetos) at eight to nine territories each year from 1992 to 1994 in the Snake River Birds of Prey National Conservation Area. Use of space did not vary between years or sexes, but did vary among seasons (home ranges and travel distances were larger during the nonbreeding than during the breeding season) and among individuals. Home ranges were large, ranging from 190 to 8,330 ha during the breeding season and from 1,370 to 170,000 ha outside of the breeding season, but activity was concentrated in small core areas of 30 to 1,535 ha and 485 to 6,380 ha during the breeding and nonbreeding seasons, respectively. Eagles selected shrub habitats and avoided disturbed areas, grasslands, and agriculture. This resulted in selection for habitat likely to contain their principal prey, black-tailed jackrabbits (Lepus californicus). Individuals with home ranges in extensive shrubland (n = 3) did not select for shrubs in the placement of their core areas or foraging points, but individuals in highly fragmented or dispersed shrublands (n = 5) concentrated their activities and foraged preferentially in jackrabbit habitats (i.e. areas with abundant and large shrub patches). As home ranges expanded outside of the breeding season, individuals selected jackrabbit habitats within their range. Shrubland fragmentation should be minimized so that remaining shrub patches are large enough to support jackrabbits.
Screening of multiple hormonal activities in surface water and sediment from the Pearl River system, South China, using effect-directed in vitro bioassays.

PubMed

Zhao, Jian-Liang; Ying, Guang-Guo; Yang, Bin; Liu, Shan; Zhou, Li-Jun; Chen, Zhi-Feng; Lai, Hua-Jie

2011-10-01

This paper reports screening of multiple hormonal activities (estrogenic and androgenic activities, antiestrogenic and antiandrogenic activities) for surface water and sediment from the Pearl River system (Liuxi, Zhujiang, and Shijing rivers) in South China, using in vitro recombinant yeast bioassays. The detection frequencies for estrogenic and antiandrogenic activities were both 100% in surface water and 81 and 93% in sediment, respectively. The levels of estrogenic activity were 0.23 to 324 ng 17β-estradiol equivalent concentration (EEQ)/L in surface water and 0 to 101 ng EEQ/g in sediment. Antiandrogenic activities were in the range of 20.4 to 935 × 10(3) ng flutamide equivalent concentration (FEQ)/L in surface water and 0 to 154 × 10(3) ng FEQ/g in sediment. Moreover, estrogenic activity and antiandrogenic activity in sediment showed good correlation (R(2) = 0.7187), suggesting that the agonists of estrogen receptor and the antagonists of androgen receptor co-occurred in sediment. The detection frequencies for androgenic and antiestrogenic activities were 41 and 29% in surface water and 61 and 4% in sediment, respectively. The levels of androgenic activities were 0 to 45.4 ng dihydrotestosterone equivalent concentration (DEQ)/L in surface water, and the potency was very weak in the only detected sediment site. The levels of antiestrogenic activity were 0 to 1,296 × 10(3) ng tamoxifen equivalent concentration (TEQ)/L in surface water and 0 to 89.5 × 10(3) ng TEQ/g in sediment. The Shijing River displayed higher levels of hormonal activities than the Zhujiang and Liuxi rivers, indicating that the Shijing River had been suffering from heavy contamination with endocrine-disrupting chemicals. The equivalent concentrations of hormonal activities in some sites were greater than the lowest-observed-effect concentrations reported in the literature, suggesting potential adverse effects on aquatic organisms. Copyright © 2011 SETAC.
Uranium-238 and thorium-232 series concentrations in soil, radon-222 indoor and drinking water concentrations and dose assessment in the city of Aldama, Chihuahua, Mexico.

PubMed

Colmenero Sujo, L; Montero Cabrera, M E; Villalba, L; Rentería Villalobos, M; Torres Moye, E; García León, M; García-Tenorio, R; Mireles García, F; Herrera Peraza, E F; Sánchez Aroche, D

2004-01-01

High-resolution gamma spectrometry was used to determine the concentration of 40K, 238U and 232Th series in soil samples taken from areas surrounding the city of Aldama, in Chihuahua. Results of indoor air short-time sampling, with diffusion barrier charcoal detectors, revealed relatively high indoor radon levels, ranging from 29 to 422 Bq/m3; the radon concentrations detected exceeded 148 Bq/m3 in 76% of the homes tested. Additionally, liquid scintillation counting showed concentrations of radon in drinking water ranging from 4.3 to 42 kBq/m3. The high activity of 238U in soil found in some places may be a result of the uranium milling process performed 20 years ago in the area. High radon concentrations indoor and in water may be explained by assuming the presence of uranium-bearing rocks underneath of the city, similar to a felsic dike located near Aldama. The estimated annual effective dose of gamma radiation from the soil and radon inhalation was 3.83 mSv.
Determination of element composition and extraterrestrial material occurrence in moss and lichen samples from King George Island (Antarctica) using reactor neutron activation analysis and SEM microscopy.

PubMed

Mróz, Tomasz; Szufa, Katarzyna; Frontasyeva, Marina V; Tselmovich, Vladimir; Ostrovnaya, Tatiana; Kornaś, Andrzej; Olech, Maria A; Mietelski, Jerzy W; Brudecki, Kamil

2018-01-01

Seven lichens (Usnea antarctica and U. aurantiacoatra) and nine moss samples (Sanionia uncinata) collected in King George Island were analyzed using instrumental neutron activation analysis, and concentration of major and trace elements was calculated. For some elements, the concentrations observed in moss samples were higher than corresponding values reported from other sites in the Antarctica, but in the lichens, these were in the same range of concentrations. Scanning electron microscopy (SEM) and statistical analysis showed large influence of volcanic-origin particles. Also, the interplanetary cosmic particles (ICP) were observed in investigated samples, as mosses and lichens are good collectors of ICP and micrometeorites.
Compounds Released from Biomass Deconstruction: Understanding Their Effect on Cellulose Enzyme Hydrolysis and Their Biological Activity

NASA Astrophysics Data System (ADS)

Djioleu, Angele Mezindjou

The effect of compounds produced during biomass pretreatment on cellulolytic enzyme was investigated. Liquid prehydrolyzates were prepared by pretreating switchgrass using 24 combinations of temperature, time, and sulfuric acid concentration based on a full factorial design. Temperature was varied from 140°C to 180°C; time ranged from 10 to 40 min; and the sulfuric acid concentrations were 0.5% or 1% (v/v). Identified products in the prehydrolyzates included xylose, glucose, hydroxymethylfurfural (HMF), furfural, acetic acid, formic acid, and phenolic compounds at concentration ranging from 0 to 21.4 g/L. Pretreatment conditions significantly affected the concentrations of compounds detected in prehydrolyzates. When assayed in the presence of switchgrass prehydrolyzates against model substrates, activities of cellulase, betaglucosidase, and exoglucanase, were significantly reduced by at least 16%, 31.8%, and 57.8%, respectively, as compared to the control. A strong positive correlation between inhibition of betaglucosidase and concentration of glucose, acetic acid, and furans in prehydrolyzate was established. Exoglucanase inhibition correlated with the presence of phenolic compounds and acetic acid. The prehydrolyzate, prepared at 160°C, 30 min, and 1% acid, was fractionated by centrifugal partition chromatography (CPC) into six fractions; the inhibition effect of these fractions on betaglucosidase and exoglucanase was determined. The initial hydrolysis rate of cellobiose by betaglucosidase was significantly reduced by the CPC sugar-rich fraction; however, exoglucanase was deactivated by the CPC phenolic-rich fraction. Finally, biological activities of water-extracted compounds from sweetgum bark and their effect on cellulase was investigated. It was determined that 12% of solid content of the bark extract could be accounted by phenolic compounds with gallic acid identified as the most concentrated phytochemical. Sweetgum bark extract inhibited Staphylococcus aureus growth and copper-induced peroxidation of human low-density lipoprotein, confirming antimicrobial and antioxidant activities of the extract. On the other hand, bark extract inhibited cellulase cocktail activity by reducing cellulose hydrolysis by 82.32% after 48 h of incubation. Overall, phenolic compounds generated from biomass fractionation are important players in cellulolytic enzyme inhibition; removal of biomass extractives prior to pretreatment could reduce inhibitory compounds in prehydrolyzate while generating phytochemicals with societal benefits.
Determination of concentration factors for Cs-137 and Ra-226 in the mullet species Chelon labrosus (Mugilidae) from the South Adriatic Sea.

PubMed

Antovic, Ivanka; Antovic, Nevenka M

2011-07-01

Concentration factors for Cs-137 and Ra-226 transfer from seawater, and dried sediment or mud with detritus, have been determined for whole, fresh weight, Chelon labrosus individuals and selected organs. Cesium was detected in 5 of 22 fish individuals, and its activity ranged from 1.0 to 1.6 Bq kg(-1). Radium was detected in all fish, and ranged from 0.4 to 2.1 Bq kg(-1), with an arithmetic mean of 1.0 Bq kg(-1). In regards to fish organs, cesium activity concentration was highest in muscles (maximum - 3.7 Bq kg(-1)), while radium was highest in skeletons (maximum - 25 Bq kg(-1)). Among cesium concentration factors, those for muscles were the highest (from seawater - an average of 47, from sediment - an average of 3.3, from mud with detritus - an average of 0.8). Radium concentration factors were the highest for skeleton (from seawater - an average of 130, from sediment - an average of 1.8, from mud with detritus - an average of 1.5). Additionally, annual intake of cesium and radium by human adults consuming muscles of this fish species has been estimated to provide, in aggregate, an effective dose of about 4.1 μSv y(-1). 2011 Elsevier Ltd. All rights reserved.
Bactericidal Activity and Postantibiotic Effect of Levofloxacin against Anaerobes

PubMed Central

Pendland, Susan L.; Diaz-Linares, Mariela; Garey, Kevin W.; Woodward, Jennifer G.; Ryu, Seonyoung; Danziger, Larry H.

1999-01-01

The bactericidal activity and postantibiotic effect (PAE) of levofloxacin against nine anaerobes were determined. Levofloxacin at concentrations of the MIC and twice the MIC was bactericidal at 24 h to five of nine and nine of nine strains, respectively. The PAE of levofloxacin following a 2-h exposure ranged from 0.06 to 2.88 h. PMID:10508042

Seasonal variations in activity concentrations of 99Tc and 137Cs in the edible meat fraction of crabs and lobsters from the central Irish Sea.

PubMed

Copplestone, D; Jackson, D; Hartnoll, R G; Johnson, M S; McDonald, P; Wood, N

2004-01-01

Discharges of most radionuclides into the Irish Sea from the BNFL site at Sellafield have decreased over the past 20 years or so. For a few radionuclides, however, discharges have peaked more recently. Notably, operation of the Enhanced Actinide Removal Plant (EARP) since 1994 has led to an increase in discharges of (99)Tc, as a result of the treatment of previously stored waste, with consequent increases in (99)Tc activity concentrations in a number of marine species, particularly in crustaceans such as lobsters. Previous research has considered the significance of factors such as sex and body weight on radionuclide concentrations. The current project set out to investigate whether seasonal variations in radionuclide concentrations in crabs and lobsters occur, with particular emphasis on the dynamics of (99)Tc and (137)Cs. Organisms were obtained from a site off the Isle of Man, where radionuclide concentrations were measurable but the site was sufficiently distant from Sellafield that the radionuclides were well mixed in the water column and not likely to be influenced by the pulsed nature of discharges of (99)Tc. Crab and lobster samples were collected monthly, between February 2000 and February 2001. Fifteen or 16 individuals (evenly split as male and female) of each species were collected on each occasion. Seawater samples were also collected over the 12-month period. Activity concentrations of (99)Tc in the edible meat fraction (both brown and white meat) ranged from 0.23 to 2.46 Bq kg(-1) (fresh weight (fw)) in crabs and 124 to 216 Bq kg(-1) (fw) in lobsters, with no observed seasonal variations. Activity concentrations of (137)Cs in both crab and lobster were lower, ranging from <0.16 to 0.85 Bq kg(-1) for crab meat (fw) and <0.3 to 3.3 Bq kg(-1) for lobster meat (fw). A statistically significant increase in activity concentrations of (137)Cs in the meat was observed in the summer months for both crab and lobster. The cause has not been investigated but may be related to the laying down of energy reserves during the active feeding period over the summer. At all times, uptake of (99)Tc is higher in the brown meat fraction of both crabs and lobsters, whilst (137)Cs is more uniformly distributed. These results are used to discuss the implications for sampling and monitoring programmes.
Unitary Responses in Frog Olfactory Epithelium to Sterically Related Molecules at Low Concentrations

PubMed Central

Getchell, Thomas V.

1974-01-01

Responses of receptor cells in the frog's olfactory epithelium were recorded using platinum-black metal-filled microelectrodes. Spontaneous activity varied over a wide range from 0.07 to 1.8 spikes/s. Mean interspike intervals ranged from 13.7 to 0.5 s. Excitatory responses to six sterically related compounds at low concentrations were investigated. Stimuli were delivered in an aqueous medium. Thresholds for impulse initiation varied from greater than 1 mM down to the nanomolar concentration range. Thresholds of different olfactory receptors to the same stimulus could vary by several log units. Thresholds of the same receptor cell to different stimuli could be within the same order of magnitude, or could vary by as much as 5 log units. Based upon quantitative measures of stimulus-evoked excitatory responses it appeared that some receptors did not discriminate among sterically related molecules, whereas other receptors clearly discriminated between stimuli which evoke similar odor sensations. PMID:4211101
Soda Creek springs - metamorphic waters in the eastern Alaska Range

USGS Publications Warehouse

Richter, D.H.; Donaldson, D.E.; Lamarre, R.A.

1973-01-01

The Soda Creek springs are a group of small, cold mineral springs on the southern flank of the eastern Alaska Range. The spring waters contain anomalous concentrations of carbon dioxide, sodium, chlorine, sulfate, boron, and ammonia and are actively precipitating deposits of calcite and aragonite. Sparingly present in these deposits are mixed-layer illite-montmorillonite clays and zeolite minerals. Low-temperaturemetamorphic reactions in subjacent marine sedimentary rocks of Jurassic and Cretaceous age may have produced the fluids and silicate minerals. With only a few exceptions, cool bicarbonate-rich springs in Alaska are concentrated south of the Denali fault system in south-central Alaska, southeastern Alaska, and along the Kaltag-Tintina fault system. These areas are characterized by active or recently activetectonism, major faults and folds, and an abundance of marine sedimentary rocks.
Cytotoxicity and antiviral activities of Asplenium nidus, Phaleria macrocarpa and Eleusine indica

NASA Astrophysics Data System (ADS)

Tahir, Mariya Mohd; Ibrahim, Nazlina; Yaacob, Wan Ahmad

2014-09-01

Three local medicinal plants namely Asplenium nidus (langsuyar), Eleusine indica (sambau) and Phaleria macrocarpa (mahkota dewa) were screened for the cytotoxicity and antiviral activities. Six plant extracts were prepared including the aqueous and methanol extracts from A. nidus leaf and root, aqueous extract from dried whole plant of E. indica and methanol extract from P. macrocarpa fruits. Cytotoxicity screening in Vero cell line by MTT assay showed that the CC50 values ranged from 15 to 60 mg/mL thus indicating the safety of the extracts even at high concentrations. Antiviral properties of the plant extracts were determined by plaque reduction assay. The EC50 concentrations were between 3.2 to 47 mg/mL. The selectivity indices (SI = CC50/EC50) of each tested extracts ranged from 4.3 to 63.25 indicating the usefulness of the extracts as potential antiviral agents.
The antibacterial properties of Malaysian tualang honey against wound and enteric microorganisms in comparison to manuka honey

PubMed Central

Tan, Hern Tze; Rahman, Rosliza Abdul; Gan, Siew Hua; Halim, Ahmad Sukari; Hassan, Siti Asma'; Sulaiman, Siti Amrah; BS, Kirnpal-Kaur

2009-01-01

Background Antibiotic resistance of bacteria is on the rise, thus the discovery of alternative therapeutic agents is urgently needed. Honey possesses therapeutic potential, including wound healing properties and antimicrobial activity. Although the antimicrobial activity of honey has been effectively established against an extensive spectrum of microorganisms, it differs depending on the type of honey. To date, no extensive studies of the antibacterial properties of tualang (Koompassia excelsa) honey on wound and enteric microorganisms have been conducted. The objectives of this study were to conduct such studies and to compare the antibacterial activity of tualang honey with that of manuka honey. Methods Using a broth dilution method, the antibacterial activity of tualang honey against 13 wound and enteric microorganisms was determined; manuka honey was used as the control. Different concentrations of honey [6.25-25% (w/v)] were tested against each type of microorganism. Briefly, two-fold dilutions of honey solutions were tested to determine the minimum inhibitory concentration (MIC) against each type of microorganism, followed by more assays within a narrower dilution range to obtain more precise MIC values. MICs were determined by both visual inspection and spectrophotometric assay at 620 nm. Minimum bactericidal concentration (MBC) also was determined by culturing on blood agar plates. Results By visual inspection, the MICs of tualang honey ranged from 8.75% to 25% compared to manuka honey (8.75-20%). Spectrophotometric readings of at least 95% inhibition yielded MIC values ranging between 10% and 25% for both types of honey. The lowest MBC for tualang honey was 20%, whereas that for manuka honey was 11.25% for the microorganisms tested. The lowest MIC value (8.75%) for both types of honey was against Stenotrophomonas maltophilia. Tualang honey had a lower MIC (11.25%) against Acinetobacter baumannii compared to manuka honey (12.5%). Conclusion Tualang honey exhibited variable activities against different microorganisms, but they were within the same range as those for manuka honey. This result suggests that tualang honey could potentially be used as an alternative therapeutic agent against certain microorganisms, particularly A. baumannii and S. maltophilia. PMID:19754926
Modelling the maximum voluntary joint torque/angular velocity relationship in human movement.

PubMed

Yeadon, Maurice R; King, Mark A; Wilson, Cassie

2006-01-01

The force exerted by a muscle is a function of the activation level and the maximum (tetanic) muscle force. In "maximum" voluntary knee extensions muscle activation is lower for eccentric muscle velocities than for concentric velocities. The aim of this study was to model this "differential activation" in order to calculate the maximum voluntary knee extensor torque as a function of knee angular velocity. Torque data were collected on two subjects during maximal eccentric-concentric knee extensions using an isovelocity dynamometer with crank angular velocities ranging from 50 to 450 degrees s(-1). The theoretical tetanic torque/angular velocity relationship was modelled using a four parameter function comprising two rectangular hyperbolas while the activation/angular velocity relationship was modelled using a three parameter function that rose from submaximal activation for eccentric velocities to full activation for high concentric velocities. The product of these two functions gave a seven parameter function which was fitted to the joint torque/angular velocity data, giving unbiased root mean square differences of 1.9% and 3.3% of the maximum torques achieved. Differential activation accounts for the non-hyperbolic behaviour of the torque/angular velocity data for low concentric velocities. The maximum voluntary knee extensor torque that can be exerted may be modelled accurately as the product of functions defining the maximum torque and the maximum voluntary activation level. Failure to include differential activation considerations when modelling maximal movements will lead to errors in the estimation of joint torque in the eccentric phase and low velocity concentric phase.
Enzymatic activity, osmotic stress and degradation of pesticide mixtures in soil extract liquid broth inoculated with Phanerochaete chrysosporium and Trametes versicolor.

PubMed

Fragoeiro, Silvia; Magan, Naresh

2005-03-01

In this study we examined the extracellular enzymatic activity of two white rot fungi (Phanerochaete chrysosporium and Trametes versicolor) in a soil extract broth in relation to differential degradation of a mixture of different concentrations (0-30 p.p.m.) of simazine, dieldrin and trifluralin under different osmotic stress (-0.7 and -2.8 MPa) and quantified enzyme production, relevant to P and N release (phosphomonoesterase, protease), carbon cycling (beta-glucosidase, cellulase) and laccase activity, involved in lignin degradation. Our results suggest that T. versicolor and P. chrysosporium have the ability to degrade different groups of pesticides, supported by the capacity for expression of a range of extracellular enzymes at both -0.7 and -2.8 MPa water potential. Phanerochaete chrysosporium was able to degrade this mixture of pesticides independently of laccase activity. In soil extract, T. versicolor was able to produce the same range of enzymes as P. chrysoporium plus laccase, even in the presence of 30 p.p.m. of the pesticide mixture. Complete degradation of dieldrin and trifluralin was observed, while about 80% of the simazine was degraded regardless of osmotic stress treatment in a nutritionally poor soil extract broth. The capacity of tolerance and degradation of high concentrations of mixtures of pesticides and production of a range of enzymes, even under osmotic stress, suggest potential bioremediation applications.
Monohalogenated maleimides as potential agents for the inhibition of Pseudomonas aeruginosa biofilm.

PubMed

Carteau, David; Soum-Soutéra, Emmanuelle; Faÿ, Fabienne; Dufau, Chrystèle; Cérantola, Stéphane; Vallée-Réhel, Karine

2010-01-01

New monohalogenated maleimide derivatives (with bromine, chlorine or iodine) were synthesized to test the effect of halogen atoms in inhibiting the formation of Pseudomonas aeruginosa biofilm. The evaluation of their biological activities clearly defines a structure-activity relationship. In this study, the bactericidal action of the three compounds was observed at the concentration range 0.3-5.0 mM on Luria-Bertani agar plates. The halogen atom of these molecules was critical in modulating the antibacterial activity, with a slightly higher effectiveness for chlorine. Confocal laser scanning microscopy was used to examine P. aeruginosa biofilms cultivated in flow cells. At concentration as low as 40 microM, the bromine and iodine compounds displayed a total inhibition towards the formation of bacterial biofilm. At this concentration, the bacterial attachment to glass surfaces was strongly affected by the presence of bromine and iodine whereas the chlorine derivative behaved as a bactericidal compound. A bioluminescent reporter strain was then used to detect the effect of the chemically synthesized maleimides on quorum sensing (QS) in P. aeruginosa. At the concentration range 10-100 microM, bioluminescence assays reveal that halogenated maleimides were able to interfere with the QS of the bacterium. Although the relationship between the weak inhibition of cell-to-cell communication (15-55% of the signal) and the high inhibition of biofilm formation has not been elucidated clearly, the results demonstrate that bromo- and iodo-N-substituted maleimides bromine and iodine may be used as new potent inhibitors that control bacterial biofilms.
A novel active-passive sampling approach for measuring time-averaged concentrations of pollutants in water.

PubMed

Amato, Elvio D; Covaci, Adrian; Town, Raewyn M; Hereijgers, Jonas; Bellekens, Ben; Giacometti, Valentina; Breugelmans, Tom; Weyn, Maarten; Dardenne, Freddy; Bervoets, Lieven; Blust, Ronny

2018-06-14

Passive sampling with in situ devices offers several advantages over traditional sampling methods (i.e., discrete spot sampling), however, data interpretation from conventional passive samplers is hampered by difficulties in estimating the thickness of the diffusion layer at the sampler/medium interface (δ), often leading to inaccurate determinations of target analyte concentrations. In this study, the performance of a novel device combining active and passive sampling was investigated in the laboratory. The active-passive sampling (APS) device is comprised of a diffusion cell fitted with a pump and a flowmeter. Three receiving phases traditionally used in passive sampling devices (i.e., chelex resin, Oasis HLB, and silicone rubber), were incorporated in the diffusion cell and allowed the simultaneous accumulation of cationic metals, polar, and non-polar organic compounds, respectively. The flow within the diffusion cell was accurately controlled and monitored, and, combined with diffusion coefficients measurements, enabled the average δ to be estimated. Strong agreement between APS and time-averaged total concentrations measured in discrete water samples was found for most of the substances investigated. Accuracies for metals ranged between 87 and 116%, except Cu and Pb (∼50%), whilst accuracies between 64 and 101%, and 92 and 151% were achieved for polar and non-polar organic compounds, respectively. These results indicate that, via a well-defined in situ preconcentration step, the proposed APS approach shows promise for monitoring the concentration of a range of pollutants in water. Copyright © 2018 Elsevier Ltd. All rights reserved.
Interference with the Mannose Binding and Epithelial Cell Adherence of Escherichia coli by Sublethal Concentrations of Streptomycin

PubMed Central

Eisenstein, Barry I.; Ofek, Itzhak; Beachey, Edwin H.

1979-01-01

When Escherichia coli was grown in sublethal concentrations of streptomycin, mannose binding activity and epithelial cell adherence of the E. coli cultures at stationary phase were significantly reduced in the drug-grown organisms. In a strain whose minimal inhibitory concentrations was 30 μg/ml, the percentage of reduction in mannose binding activity was dose related over a range of concentrations between 0.5 and 10 μg/ml streptomycin. Concomitant with the drug-induced suppression of mannose binding activity, antigenic and ultrastructural alterations on the surface of the drug-grown organisms were observed by agglutination tests and electron microscopy, respectively. The streptomycin effect was reversible, required actively growing organisms, and was most apparent in the early log-phase of growth. High doses of antibiotic were ineffective when added to cultures which had acquired mannose binding activity. An isogenic derivative with high-level resistance to streptomycin was obtained as a single-step mutation from the test E. coli strain. Whereas the isogenic mutant possessed mannose binding activity and adhering ability similar to the parent strain, it was resistant to the streptomycin-induced suppression of the two activities at enormous concentrations (up to 10,000 μg/ml) of streptomycin. Taken together the results suggest that the suppression of epithelial cell adherence and mannose binding activity of E. coli grown in sublethal concentrations of streptomycin is a result of classic mechanisms of drug action upon the bacterial ribosome. The results support the possibility that antibiotics may act through mechanisms other than inhibition of growth and bacterial killing to eradicate bacteria from mucosal surfaces. Images PMID:376556
Concentration of arsenic in water, sediments and fish species from naturally contaminated rivers.

PubMed

Rosso, Juan José; Schenone, Nahuel F; Pérez Carrera, Alejo; Fernández Cirelli, Alicia

2013-04-01

Arsenic (As) may occur in surface freshwater ecosystems as a consequence of both natural contamination and anthropogenic activities. In this paper, As concentrations in muscle samples of 10 fish species, sediments and surface water from three naturally contaminated rivers in a central region of Argentina are reported. The study area is one of the largest regions in the world with high As concentrations in groundwater. However, information of As in freshwater ecosystems and associated biota is scarce. An extensive spatial variability of As concentrations in water and sediments of sampled ecosystems was observed. Geochemical indices indicated that sediments ranged from mostly unpolluted to strongly polluted. The concentration of As in sediments averaged 6.58 μg/g ranging from 0.23 to 59.53 μg/g. Arsenic in sediments barely followed (r = 0.361; p = 0.118) the level of contamination of water. All rivers showed high concentrations of As in surface waters, ranging from 55 to 195 μg/L. The average concentration of As in fish was 1.76 μg/g. The level of contamination with As differed significantly between species. Moreover, the level of bioaccumulation of As in fish species related to the concentration of As in water and sediments also differed between species. Whilst some fish species seemed to be able to regulate the uptake of this metalloid, the concentration of As in the large catfish Rhamdia quelen mostly followed the concentration of As in abiotic compartments. The erratic pattern of As concentrations in fish and sediments regardless of the invariable high levels in surface waters suggests the existence of complex biogeochemical processes behind the distribution patterns of As in these naturally contaminated ecosystems.
Responses of Florida panthers to recreational deer and hog hunting

USGS Publications Warehouse

Janis, Michael W.; Clark, Joseph D.

2002-01-01

Big Cypress National Preserve constitutes approximately one-third of the range of the endangered Florida panther (Puma concolor coryi). Because recreational hunting is allowed in Big Cypress National Preserve, we examined 8 response variables (activity rates, movement rates, predation success, home-range size, home-range shifts, proximity to off-road vehicle trails, use of areas with concentrated human activity, and habitat selection) to evaluate how Florida panthers respond to human activity associated with deer and hog hunting. Data consisted of panther radiolocations collected since 1981 by the Florida Fish and Wildlife Conservation Commission and the National Park Service, which we augmented with radiolocations and activity monitoring from 1994 to 1998. A split-plot (treatment and control) study design with repeated measures of the variables for each panther taken before, during, and after the hunting season was used. We did not detect responses to hunting for variables most directly related to panther energy intake or expenditure (i.e., activity rates, movement rates, predation success of females; P>0.10). However, panthers reduced their use of Bear Island (P=0.021), an area of concentrated human activity, and were found farther from off-road vehicle trails (P≤0.001) during the hunting season, which was indicative of a reaction to human disturbance. Whereas the reaction to human activity on off-road vehicle trails probably has minor biological implications and may be linked to prey behavior, the decreased use of Bear Island is most likely a direct reaction to human activity and resulted in increased use of adjacent private lands. Future habitat loss on those private lands could exacerbate the negative consequences of this response by panthers.
The relationship between sea ice concentration and the spatio-temporal distribution of vocalizing bearded seals (Erignathus barbatus) in the Bering, Chukchi, and Beaufort Seas from 2008 to 2011

NASA Astrophysics Data System (ADS)

MacIntyre, Kalyn Q.; Stafford, Kathleen M.; Conn, Paul B.; Laidre, Kristin L.; Boveng, Peter L.

2015-08-01

Bearded seals (Erignathus barbatus) are widely distributed in the Arctic and sub-Arctic; the Beringia population is found throughout the Bering, Chukchi and Beaufort Seas (BCB). Bearded seals are highly vocal, using underwater calls to advertise their breeding condition and maintain aquatic territories. They are also closely associated with pack ice for reproductive activities, molting, and resting. Sea ice habitat for this species varies spatially and temporally throughout the year due to differences in underlying physical and oceanographic features across its range. To test the hypothesis that the vocal activity of bearded seals is related to variations in sea ice, passive acoustic data were collected from nine locations throughout the BCB from 2008 to 2011. Recording instruments sampled on varying duty cycles ranging from 20% to 100% of each hour, and recorded frequencies up to 8192 Hz. Spectrograms of acoustic data were analyzed manually to calculate the daily proportion of hours with bearded seal calls at each sampling location, and these call activity proportions were correlated with daily satellite-derived estimates of sea ice concentration. Bearded seals were vocally active nearly year-round in the Beaufort and Chukchi Seas with peak activity occurring from mid-March to late June during the mating season. The duration of call activity in the Bering Sea was shorter, lasting typically only five months, and peaked from mid-March to May at the northernmost recorders. In all areas, call activity was significantly correlated with higher sea ice concentrations (p < 0.01). These results suggest that losses in ice cover may negatively impact bearded seals, not just by loss of habitat but also by altering the behavioral ecology of the BCB population.
In vitro Inhibitory Effects of Andrographis paniculata, Gynura procumbens, Ficus deltoidea, and Curcuma xanthorrhiza Extracts and Constituents on Human Liver Glucuronidation Activity.

PubMed

Husni, Zulhilmi; Ismail, Sabariah; Zulkiffli, Mohd Halimhilmi; Afandi, Atiqah; Haron, Munirah

2017-07-01

Andrographis paniculata , Gynura procumbens , Ficus deltoidea and Curcuma xanthorrhiza are commonly consumed as herbal medicines. However their effects on human liver glucuronidation activity are not yet evaluated. In this study, we evaluate the inhibitory Effects of Andrographis paniculata, Gynura procumbens, Ficus deltoidea and Curcuma xanthorrhiza extracts and their constituents on human liver glucuronidation activity. Herbal extracts (aqueous, methanolic and ethanolic extracts) and their constituents were incubated with human liver microsomes with the addition of UDPGA to initiate the reaction. Working concentrations of herbal extracts and their constituents ranged from 10 μg/mL to 1000 μg/mL and 10 μM to 300 μM respectively. IC50 was determined by monitoring the decrement of glucuronidation activity with the increment of herbal extracts or phytochemical constituent's concentrations. All herbal extracts inhibited human liver glucuronidation activity in range of 34.69 μg/mL to 398.10 μg/mL whereas for the constituents, only xanthorrhizol and curcumin (constituents of Curcuma xanthorrhiza ) inhibited human liver glucuronidation activity with IC50 of 538.50 and 32.26 μM respectively. In the present study, we have proved the capabilities of Andrographis paniculata , Gynura procumbens , Ficus deltoidea and Curcuma xanthorrhiza to interfere with in vitro glucuronidation process in human liver microsomes. This study documented the capabilities of Andrographis paniculata , Gynura procumbens , Ficus deltoidea and Curcuma xanthorrhiza to inhibit human liver glucuronidation activity which may affect the metabolism of therapeutic drugs or hazardous toxicants that follow the same glucuronidation pathway. Abbreviations used: UGT: Uridine 5'-diphospho-glucuronosyltransferase; 4-MU: 4-methylumbelliferone; IC50: Half Maximal Inhibitory Concentration; Km: Michaelis constant; Vmax: Maximum velocity.
In vitro Inhibitory Effects of Andrographis paniculata, Gynura procumbens, Ficus deltoidea, and Curcuma xanthorrhiza Extracts and Constituents on Human Liver Glucuronidation Activity

PubMed Central

Husni, Zulhilmi; Ismail, Sabariah; Zulkiffli, Mohd Halimhilmi; Afandi, Atiqah; Haron, Munirah

2017-01-01

Background: Andrographis paniculata, Gynura procumbens, Ficus deltoidea and Curcuma xanthorrhiza are commonly consumed as herbal medicines. However their effects on human liver glucuronidation activity are not yet evaluated. Objective: In this study, we evaluate the inhibitory Effects of Andrographis paniculata, Gynura procumbens, Ficus deltoidea and Curcuma xanthorrhiza extracts and their constituents on human liver glucuronidation activity. Materials and Methods: Herbal extracts (aqueous, methanolic and ethanolic extracts) and their constituents were incubated with human liver microsomes with the addition of UDPGA to initiate the reaction. Working concentrations of herbal extracts and their constituents ranged from 10 μg/mL to 1000 μg/mL and 10 μM to 300 μM respectively. IC50 was determined by monitoring the decrement of glucuronidation activity with the increment of herbal extracts or phytochemical constituent's concentrations. Results: All herbal extracts inhibited human liver glucuronidation activity in range of 34.69 μg/mL to 398.10 μg/mL whereas for the constituents, only xanthorrhizol and curcumin (constituents of Curcuma xanthorrhiza) inhibited human liver glucuronidation activity with IC50 of 538.50 and 32.26 μM respectively. Conclusion: In the present study, we have proved the capabilities of Andrographis paniculata, Gynura procumbens, Ficus deltoidea and Curcuma xanthorrhiza to interfere with in vitro glucuronidation process in human liver microsomes. SUMMARY This study documented the capabilities of Andrographis paniculata, Gynura procumbens, Ficus deltoidea and Curcuma xanthorrhiza to inhibit human liver glucuronidation activity which may affect the metabolism of therapeutic drugs or hazardous toxicants that follow the same glucuronidation pathway. Abbreviations used: UGT: Uridine 5’-diphospho-glucuronosyltransferase; 4-MU: 4-methylumbelliferone; IC50: Half Maximal Inhibitory Concentration; Km: Michaelis constant; Vmax: Maximum velocity. PMID:28808386
Vertical distributions of (99)Tc and the (99)Tc/(137)Cs activity ratio in the coastal water off Aomori, Japan.

PubMed

Nakanishi, Takahiro; Zheng, Jian; Aono, Tatsuo; Yamada, Masatoshi; Kusakabe, Masashi

2011-08-01

Using a sector-field ICP-MS the vertical distributions of the (99)Tc concentration and (99)Tc/(137)Cs activity ratio were measured in the coastal waters off Aomori Prefecture, Japan, where a spent-nuclear-fuel reprocessing plant has begun test operation. The (99)Tc concentrations in surface water ranged from 1.8 to 2.4 mBq/m(3), no greater than the estimated background level. Relatively high (99)Tc/(137)Cs activity ratios (10-12 × 10(-4)) would be caused by the inflow of the high-(99)Tc/(137)Cs water mass from the Japan Sea. There is no observable contamination from the reprocessing plant in the investigated area. The (99)Tc concentration and the (99)Tc/(137)Cs activity ratio in water column showed gradual decreases with depth. Our results implied that (99)Tc behaves in a more conservative manner than (137)Cs in marine environments. Copyright © 2011 Elsevier Ltd. All rights reserved.
Effects of different temperature treatments on biological ice nuclei in snow samples

NASA Astrophysics Data System (ADS)

Hara, Kazutaka; Maki, Teruya; Kakikawa, Makiko; Kobayashi, Fumihisa; Matsuki, Atsushi

2016-09-01

The heat tolerance of biological ice nucleation activity (INA) depends on their types. Different temperature treatments may cause varying degrees of inactivation on biological ice nuclei (IN) in precipitation samples. In this study, we measured IN concentration and bacterial INA in snow samples using a drop freezing assay, and compared the results for unheated snow and snow treated at 40 °C and 90 °C. At a measured temperature of -7 °C, the concentration of IN in untreated snow was 100-570 L-1, whereas the concentration in snow treated at 40 °C and 90 °C was 31-270 L-1 and 2.5-14 L-1, respectively. In the present study, heat sensitive IN inactivated by heating at 40 °C were predominant, and ranged 23-78% of IN at -7 °C compared with untreated samples. Ice nucleation active Pseudomonas strains were also isolated from the snow samples, and heating at 40 °C and 90 °C inactivated these microorganisms. Consequently, different temperature treatments induced varying degrees of inactivation on IN in snow samples. Differences in the concentration of IN across a range of treatment temperatures might reflect the abundance of different heat sensitive biological IN components.
Differentiating high priority pathway-based toxicity from non ...

EPA Pesticide Factsheets

The ToxCast chemical screening approach enables the rapid assessment of large numbers of chemicals for biological effects, primarily at the molecular level. Adverse outcome pathways (AOPs) offer a means to link biomolecular effects with potential adverse outcomes at the level of the individual or population, thus enhancing the utility of the ToxCast effort for hazard assessment. Thus, efforts are underway to develop AOPs relevant to the pathway perturbations detected in ToxCast assays. However, activity (?‘hits’) determined for chemical-assay pairs may reflect target-specific activity relevant to a molecular initiating event of an AOP, or more generalized cell stress and cytotoxicity-mediated effects. Previous work identified a ?‘cytotoxic burst’ phenomenon wherein large numbers of assays begin to respond at or near concentrations that elicit cytotoxicity. The concentration range at which the “burst” occurs is definable, statistically. Consequently, in order to focus AOP development on the ToxCast assay targetswhich are most sensitive and relevant to pathway-specific effects, we conducted a meta-analysis to identify which assays were frequently responding at concentrations well below the cytotoxic burst. Assays were ranked by the fraction of chemical hits below the burst concentration range compared to the number of chemicals tested, resulting in a preliminary list of potentially important, target-specific assays. After eliminating cytotoxicity a
Time Series Analysis of Heavy Metal Concentrations along the Watershed Gradient in Cameron Highlands: Geospatial Approaches

NASA Astrophysics Data System (ADS)

Haron, S. H.; Ismail, B. S.; Mispan, M. R.; Abd Rahman, N. F.; Khalid, K.; Rasid, M. Z. Abdul; Sidek, L. M.

2016-03-01

Heavy metal, particularly cadmium, lead, and arsenic, constitute a significant potential threat to human health. Some metals are extremely toxic to humans and the toxic heavy metals of greatest concern include cadmium, lead, and arsenic. The objective of the study conducted was to determine the accumulation and distribution status of heavy metal cadmium (Cd) in the sediment of Bertam River from September 2014 to February 2015 in the agricultural areas of Cameron Highlands, Malaysia. The sediment samples were collected randomly in three replicates from ten sampling points in the agricultural areas of Cameron Highlands. The heavy metals in the sediment were extracted using the wet acid method and the sample concentrations are then tested for metal concentrations by the spectrography method using Inductively Coupled Plasma (ICP) spectrography. Inverse distance weighting (IDW) was used to create a map of metal concentrations for a point on the polygon dataset spatial interpolation. There is an increasing trend of Cd from the upstream to downstream stations along Bertam River during the rainy season. The activity range of Cd is 0.07 to 2.83 µg/g during the rainy season, whereas, during the dry season, Cd activity ranged from 0.26-0.83µg/g.
Antibacterial, antifungal, and antiviral activities of the lipophylic extracts of Pistacia vera.

PubMed

Ozçelik, Berrin; Aslan, Mustafa; Orhan, Ilkay; Karaoglu, Taner

2005-01-01

In the present study, antibacterial, antifungal, and antiviral properties of 15 lipohylic extracts obtained from different parts (leaf, branch, stem, kernel, shell skins, seeds) of Pistacia vera were screened against both standard and the isolated strains of Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, Candida albicans and C. parapsilosis by microdilution method. Both Herpes simplex (DNA) and Parainfluenza viruses (RNA) were used for the determination of antiviral activity of the P. vera extracts by using Vero cell line. Ampicilline, ofloxocine, ketoconazole, fluconazole, acyclovir and oseltamivir were used as the control agents. The extracts showed little antibacterial activity between the range of 128-256 microg/ml concentrations whereas they had noticeable antifungal activity at the same concentrations. Kernel and seed extracts showed significant antiviral activity compared to the rest of the extracts as well as the controls.

The food colorant erythrosine is a promiscuous protein-protein interaction inhibitor.

PubMed

Ganesan, Lakshmi; Margolles-Clark, Emilio; Song, Yun; Buchwald, Peter

2011-03-15

Following our observation that erythrosine B (FD&C Red No. 3) is a relatively potent inhibitor of the TNF-R-TNFα and CD40-CD154 protein-protein interactions, we investigated whether this inhibitory activity extends to any other protein-protein interactions (PPI) as well as whether any other approved food colors possess such inhibitory activity. We found erythrosine, a poly-iodinated xanthene dye, to be a non-specific promiscuous inhibitor of a number of PPIs within the tumor necrosis factor superfamily (TNF-R-TNFα, CD40-CD154, BAFF-R-BAFF, RANK-RANKL, OX40-OX40L, 4-1BB-4-1BBL) as well as outside of it (EGF-R-EGF) with a remarkably consistent median inhibitory concentration (IC(50)) in the 2-20 μM (approximately 2-20mg/L) range. In agreement with this, erythrosine also showed cellular effects including clear cytotoxic effects around this concentration range (IC₅₀≈50 μM). Among the seven FDA-approved food colorants, only erythrosine showed consistent PPI inhibitory activity in the sub-100 μM range, which might also explain (at least partially) why it also has the lowest approved acceptable daily intake (ADI) (0.1 mg/kg body weight/day). Among a number of xanthene structural analogs of erythrosine tested for activity, rose Bengal, a food colorant approved in Japan, showed similar, maybe even more pronounced, promiscuous inhibitory activity, whereas fluorescein was inactive and gallein, phloxine, and eosin were somewhat active in some of the assays. Copyright © 2011 Elsevier Inc. All rights reserved.
The antibacterial activity of compounds isolated from oakmoss against Legionella pneumophila and other Legionella spp.

PubMed

Nomura, Harue; Isshiki, Yasunori; Sakuda, Keisuke; Sakuma, Katsuya; Kondo, Seiichi

2012-01-01

Oakmoss is a natural fragrance ingredient exhibiting highly specific, potent antibacterial activity against Legionella pneumophila, a causative agent of severe water-bone pneumonia. In the present study, the antibacterial activity of individual compounds isolated from oakmoss was investigated against L. pneumophila and other Legionella spp. A total of 18 known compounds and two minor novel compounds (i.e., 3-methoxy-5-methylphenyl-2,4-dihydroxy-6-methylbenzoate (compound 9) and 8-(2,4-dihydroxy-6-(2-oxoheptyl)-phenoxy)-6-hydroxy-3-pentyl-1H-isochromen-1-one (compound 20)) were purified from oakmoss. The minimum inhibitory concentrations (MICs) against clinical and environmental isolates of L. pneumophila, L. bozemanii, L. micdadei, L. longbeachae, and L. dumoffii for 11 of the 20 compounds were less than 100 µg/mL (range 0.8-64.0 µg/mL). Novel compounds 9 and 20 exhibited potent antibacterial activity against L. pneumophila strains (MIC ranges of 1.3-8.0 µg/mL and 3.3-13.3 µg/mL, respectively) and also against four other Legionella species (MIC ranges of 0.8-8.0 µg/mL and 3.3-21.3 µg/mL, respectively). Time-kill assays indicated that compounds 9 and 20 kill bacteria at a concentration equivalent to 2×MIC after 1 h and 6 h co-incubations, respectively. While oakmoss and the purified components exhibited antibacterial activity against Legionella spp., they were not active against other Gram-negative and -positive bacteria such as Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus.
Occupational exposure to airborne asbestos from phenolic molding material (Bakelite) during sanding, drilling, and related activities.

PubMed

Mowat, Fionna; Bono, Michael; Lee, R J; Tamburello, Susan; Paustenbach, Dennis

2005-10-01

In this study, a historical phenolic (Bakelite) molding material, BMMA-5353, was tested to determine the airborne concentrations of asbestos fibers released during four different activities (sawing, sanding, drilling, and cleanup of dust generated from these activities). Each activity was performed for 30 min, often in triplicate. The primary objective for testing BMMA-5353 was to quantitatively determine the airborne concentration of asbestos fibers, if any, in the breathing zone of workers. Uses of this product typically did not include sawing or sanding, but it may have been drilled occasionally. For this reason, only small quantities were sawed, sanded, and drilled in this simulation study. Personal (n = 40), area (n = 80), and background/clearance (n = 88) air samples were collected during each activity and analyzed for total fiber concentrations using phase contrast microscopy (PCM) and, for asbestos fiber counts, transmission electron microscopy (TEM). The raw PCM-total fiber concentrations were adjusted based on TEM analyses that reported the fraction of asbestos fibers, to derive a PCM-asbestos concentration that would enable calculation of an 8-hour time-weighted average (TWA). The estimated 8-hour TWAs ranged from 0.006 to 0.08 fibers per cubic centimeter using a variety of worker exposure scenarios. Therefore, assuming an exposure scenario in which a worker uses power tools to cut and sand products molded from BMMA-5353 and similar products in the manner evaluated in this study, airborne asbestos concentrations should not exceed current or historical occupational exposure limits.
Transfer of ²¹⁰Po, ²¹⁰Pb and ²³⁸U from some medicinal plants to their essential oils.

PubMed

Al-Masri, M S; Amin, Y; Ibrahim, S; Nassri, M

2015-03-01

Essential oils were extracted from 35 medicinal plants used by Syrians, organic compounds were determined in these oils and concentrations of (210)Po (210)Pb and (238)U were determined in the original plants and in the essential oils. The results showed that the highest activity concentrations of (210)Po and (210)Pb were found in leaves with large surfaces and in Sage were as high as 73.5 Bq kg(-1) and 73.2 Bq kg(-1), respectively. The activity concentration of (238)U was as high as 4.26 Bq kg(-1) in Aloe. On the other hand, activity concentrations of (210)Po ranged between 0.2 and 71.1 Bq kg(-1) in extracted essential oils for Rosemary and False yellowhead, respectively. The activity concentration of (210)Pb reached 63.7 Bq kg(-1) in Aloe oil. The activity concentrations of (238)U were very low in all extracted oils; the highest value was 0.31 Bq kg(-1) in peel of Orange oil. The transfer of (210)Po and (210)Pb from plant to its oil was the highest for Eugenia; 7.1% and 5.5% for (210)Po and (210)Pb, respectively. A linear relationship was found between the transfer factor of radionuclides from plant to its essential oil and the chemical content of this oil. Copyright © 2014 Elsevier Ltd. All rights reserved.
A Theoretical Basis for the Transition to Denitrification at Nanomolar Oxygen Concentrations

NASA Astrophysics Data System (ADS)

Zakem, E.; Follows, M. J.

2016-02-01

Current climate change is likely to expand the size and intensity of marine oxygen minimum zones. How will this affect denitrification rates? Current global biogeochemical models typically prescribe a critical oxygen concentration below which anaerobic activity occurs, rather than resolve the underlying microbial processes. Here, we explore the dynamics of an idealized, simulated anoxic zone in which multiple prokaryotic metabolisms are resolved mechanistically, defined by redox chemistry and biophysical constraints. We first ask, what controls the critical oxygen concentration governing the favorability of aerobic or anaerobic respiration? The predicted threshold oxygen concentration varies as a function of the environment as well as of cell physiology, and lies within the nanomolar range. The model thus provides a theoretical underpinning for the recent observations of nanomolar oxygen concentrations in oxygen minimum zones. In the context of an idealized, two-dimensional intensified upwelling simulation, we also predict denitrification at oxygen concentrations orders of magnitude higher due to physical mixing, reconciling observations of denitrification over a similar range and demonstrating a decoupling of denitrification from the local oxygen concentration. In a sensitivity study with the idealized ocean model, we comment upon the relationship between the volume of anoxic waters and total denitrification.
In vitro reconstruction of branched tubular structures from lung epithelial cells in high cell concentration gradient environment.

PubMed

Hagiwara, Masaya; Peng, Fei; Ho, Chih-Ming

2015-01-27

We have succeeded in developing hollow branching structure in vitro commonly observed in lung airway using primary lung airway epithelial cells. Cell concentration gradient is the key factor that determines production of the branching cellular structures, as optimization of this component removes the need for heterotypic culture. The higher cell concentration leads to the more production of morphogens and increases the growth rate of cells. However, homogeneous high cell concentration does not make a branching structure. Branching requires sufficient space in which cells can grow from a high concentration toward a low concentration. Simulation performed using a reaction-diffusion model revealed that long-range inhibition prevents cells from branching when they are homogeneously spread in culture environments, while short-range activation from neighboring cells leads to positive feedback. Thus, a high cell concentration gradient is required to make branching structures. Spatial distributions of morphogens, such as BMP-4, play important roles in the pattern formation. This simple yet robust system provides an optimal platform for the further study and understanding of branching mechanisms in the lung airway, and will facilitate chemical and genetic studies of lung morphogenesis programs.
Metal modulation epitaxy growth for extremely high hole concentrations above 1019 cm-3 in GaN

NASA Astrophysics Data System (ADS)

Namkoong, Gon; Trybus, Elaissa; Lee, Kyung Keun; Moseley, Michael; Doolittle, W. Alan; Look, David C.

2008-10-01

The free hole carriers in GaN have been limited to concentrations in the low 1018cm-3 range due to the deep activation energy, lower solubility, and compensation from defects, therefore, limiting doping efficiency to about 1%. Herein, we report an enhanced doping efficiency up to ˜10% in GaN by a periodic doping, metal modulation epitaxy growth technique. The hole concentrations grown by periodically modulating Ga atoms and Mg dopants were over ˜1.5×1019cm-3.
Developing a Highly Active Blood Anticoagulant—a Heparin Complex with Glutamic Acid—by Simulating Chemical Equilibria Based on pH-Metric Data

NASA Astrophysics Data System (ADS)

Nikolaeva, L. S.; Semenov, A. N.

2018-02-01

The anticoagulant activity of high-molecular-weight heparin is increased by developing a new highly active heparin complex with glutamate using the thermodynamic model of chemical equilibria based on pH-metric data. The anticoagulant activity of the developed complexes is estimated in the pH range of blood plasma according to the drop in the calculated equilibrium Ca2+ concentration associated with the formation of mixed ligand complexes of Ca2+ ions, heparin (Na4hep), and glutamate (H2Glu). A thermodynamic model is calculated by mathematically modelling chemical equilibria in the CaCl2-Na4hep-H2Glu-H2O-NaCl system in the pH range of 2.30 ≤ pH ≤ 10.50 in diluted saline that acts as a background electrolyte (0.154 M NaCl) at 37°C and initial concentrations of the main components of ν × 10-3 M, where n ≤ 4. The thermodynamic model is used to determine the main complex of the monomeric unit of heparin with glutamate (HhepGlu5-) and the most stable mixed ligand complex of Ca2+ with heparin and glutamate (Ca2hepGlu2-) in the pH range of blood plasma (6.80 ≤ pH ≤ 7.40). It is concluded that the Ca2hepGlu2- complex reduces the Ca2+ concentration 107 times more than the Ca2+ complex with pure heparin. The anticoagulant effect of the developed HhepGlu5- complex is confirmed in vitro and in vivo via coagulation tests on the blood plasma of laboratory rats. Additional antithrombotic properties of the developed complex are identified. The new highly active anticoagulant, HhepGlu5- complex with additional antithrombotic properties, is patented.
Cosmogenic nuclide budgeting of floodplain sediment transfer

NASA Astrophysics Data System (ADS)

Wittmann, H.; von Blanckenburg, F.

2009-08-01

Cosmogenic nuclides produced in quartz may either decay or accumulate while sediment is moved through a river basin. A change in nuclide concentration resulting from storage in a floodplain is potentially important in large drainage basins in which sediment is prone to repeated burial and remobilization as a river migrates through its floodplain. We have modeled depth- and time-dependent cosmogenic nuclide concentration changes for 10Be, 26Al, and 14C during sediment storage and mixing in various active floodplain settings ranging from confined, shallow rivers with small floodplains to foreland-basin scale floodplains traversed by deep rivers. Floodplain storage time, estimated from channel migration rates, ranges from 0.4 kyr for the Beni River basin (Bolivia) to 7 kyr for the Amazon River basin, while floodplain storage depth, estimated from channel depth, ranges from 1 to 25 m. For all modeled active floodplain settings, the long-lived nuclides 10Be and 26Al show neither significant increase in nuclide concentration from irradiation nor decrease from decay. We predict a hypothetical response time after which changes in 10Be or 26Al concentrations become analytically resolvable. This interval ranges from 0.07 to 2 Myr and exceeds in all cases the typical residence time of sediment in a floodplain. Due to the much shorter half life of 14C, nuclide concentrations modeled for the in situ-produced variety of this nuclide are, however, sensitive to floodplain storage on residence times of < 20 kyr. The cosmogenic nuclide composition of old deposits in currently inactive floodplains that have been isolated for periods of millions of years from the river that once deposited them is predicted to either increase or decrease in 10Be and 26Al concentration, depending on the depositional depth. These conditions can be evaluated using the 26Al/ 10Be ratio that readily discloses the depth and duration of storage. We illustrate these models with examples from the Amazon basin. As predicted, modern bedload collected from an Amazon tributary, the Bolivian Beni River, shows no systematic change in nuclide concentration as sediment is moved through 500 km of floodplain by river meandering. In contrast, in the central Amazon floodplain currently untouched by the modern river system, low 26Al/ 10Be ratios account for minimum burial depths of 5 to 10 m for a duration of > 5 Myr. The important result of this analysis is that in all likely cases of active floodplains, cosmogenic 10Be and 26Al concentrations remain virtually unchanged over the interval sediment usually spends in the basin. Thus, spatially-averaged denudation rates of the sediment-producing area can be inferred throughout the entire basin, provided that nuclide production rates are scaled for the altitudes of the sediment-producing area only, because floodplain storage does not modify nuclide concentrations introduced from the sediment source area.
Adsorption of cesium on cement mortar from aqueous solutions.

PubMed

Volchek, Konstantin; Miah, Muhammed Yusuf; Kuang, Wenxing; DeMaleki, Zack; Tezel, F Handan

2011-10-30

The adsorption of cesium on cement mortar from aqueous solutions was studied in series of bench-scale tests. The effects of cesium concentration, temperature and contact time on process kinetics and equilibrium were evaluated. Experiments were carried out in a range of initial cesium concentrations from 0.0103 to 10.88 mg L(-1) and temperatures from 278 to 313 K using coupons of cement mortar immersed in the solutions. Non-radioactive cesium chloride was used as a surrogate of the radioactive (137)Cs. Solution samples were taken after set periods of time and analyzed by inductively coupled plasma mass spectroscopy. Depending on the initial cesium concentration, its equilibrium concentration in solution ranged from 0.0069 to 8.837 mg L(-1) while the respective surface concentration on coupons varied from 0.0395 to 22.34 μg cm(-2). Equilibrium test results correlated well with the Freundlich isotherm model for the entire test duration. Test results revealed that an increase in temperature resulted in an increase in adsorption rate and a decrease in equilibrium cesium surface concentration. Among several kinetic models considered, the pseudo-second order reaction model was found to be the best to describe the kinetic test results in the studied range of concentrations. The adsorption activation energy determined from Arrhenius equation was found to be approximately 55.9 kJ mol(-1) suggesting that chemisorption was the prevalent mechanism of interaction between cesium ions and cement mortar. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.
Folding of the natural hammerhead ribozyme is enhanced by interaction of auxiliary elements

PubMed Central

PENEDO, J. CARLOS; WILSON, TIMOTHY J.; JAYASENA, SUMEDHA D.; KHVOROVA, ANASTASIA; LILLEY, DAVID M.J.

2004-01-01

It has been shown that the activity of the hammerhead ribozyme at μM magnesium ion concentrations is markedly increased by the inclusion of loops in helices I and II. We have studied the effect of such loops on the magnesium ion-induced folding of the ribozyme, using fluorescence resonance energy transfer. We find that with the loops in place, folding into the active conformation occurs in a single step, in the μM range of magnesium ion concentration. Disruption of the loop–loop interaction leads to a reversion to two-step folding, with the second stage requiring mM concentrations of magnesium ion. Sodium ions also promote the folding of the natural form of the ribozyme at high concentrations, but the folding occurs as a two-stage process. The loops clearly act as important auxiliary elements in the function of the ribozyme, permitting folding to occur efficiently under physiological conditions. PMID:15100442
Investigation of radioactivity concentration in spent technetium generators

NASA Astrophysics Data System (ADS)

Idriss, Hajo; Salih, Isam; Alaamer, Abdulaziz S.; Eisa, M. H.; Sam, A. K.

2014-04-01

This study was carried out to survey and measure radioactivity concentration and estimate radiation dose level at the surface of spent technetium generator columns for the safe final disposal of radioactive waste. High resolution γ-spectrometry with the aid of handheld radiation survey meters has been used. The radioactivity measurements has shown that 238U, 40K and 137Cs were only measurable in one sample whereas 125Sb was found in 14 samples out of total of 20 samples with an activity concentration which ranged from 21 to 7404 with an average value of 1095 Bq/kg. The activity concentration of 125Sb is highly variable indicating that the spent 99mTc generator columns are of different origin. This investigation highlighted the importance of radiation monitoring of spent technetium generators in the country in order to protect workers, and the public from the dangers posed by radioactive waste.
Exposure of northern leopard frogs in the Green Bay ecosystem to polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans is measured by direct chemistry but not hepatic ethoxyresorufin-O-deethylase activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Y.W.; Karasov, W.H.; Patnode, K.A.

1999-10-01

The authors measured concentrations of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) in northern leopard frogs collected from the Green Bay ecosystem and explored the catalytic activity of hepatic cytochrome P450-associated monooxygenase (P450 enzyme) as a biomarker for exposure to aryl hydrocarbon receptor (AhR) agonists. The two hypotheses tested were PCH concentrations in northern leopard frogs would be positively correlated with sediment polychlorinated hydrocarbon (PCH) levels in wetland habitats along a contamination gradient and hepatic ethoxyresorufin-O-deethylase (EROD) activity of northern leopard frogs, which is presumably mediated by aryl hydrocarbon receptor (AhR), would be positively correlated with PCHmore » concentrations in frog carcasses from different collection sites. In 1994 and 1995, frogs from seven sites along the lower Fox River and Green Bay, USA, were assayed for hepatic EROD activities and whole carcass concentrations of PCBs, PCDDs, and PCDFs. Tissue total PCB concentrations ranging from 3 to 154 ng/g were significantly correlated with sediment PCB levels. Only one PCDD and two PCDFs at concentrations of 6 to 8 pg/g were found in the frogs collected with frog body weight and was similar among sites except for Peter's Marsh. No significant correlation was found between EROD activity and carcass PCB concentration. This result was consistent with the fact that the frogs collected from the Green Bay ecosystem had relatively low PCB concentrations compared with what was required for induction in the laboratory.« less
Biochemical Foundations of Health and Energy Conservation in Hibernating Free-ranging Subadult Brown Bear Ursus arctos*

PubMed Central

Hansen, Rasmus; Sønderkær, Mads; Arinell, Karin; Swenson, Jon E.; Revsbech, Inge G.

2016-01-01

Brown bears (Ursus arctos) hibernate for 5–7 months without eating, drinking, urinating, and defecating at a metabolic rate of only 25% of the summer activity rate. Nonetheless, they emerge healthy and alert in spring. We quantified the biochemical adaptations for hibernation by comparing the proteome, metabolome, and hematological features of blood from hibernating and active free-ranging subadult brown bears with a focus on conservation of health and energy. We found that total plasma protein concentration increased during hibernation, even though the concentrations of most individual plasma proteins decreased, as did the white blood cell types. Strikingly, antimicrobial defense proteins increased in concentration. Central functions in hibernation involving the coagulation response and protease inhibition, as well as lipid transport and metabolism, were upheld by increased levels of very few key or broad specificity proteins. The changes in coagulation factor levels matched the changes in activity measurements. A dramatic 45-fold increase in sex hormone-binding globulin levels during hibernation draws, for the first time, attention to its significant but unknown role in maintaining hibernation physiology. We propose that energy for the costly protein synthesis is reduced by three mechanisms as follows: (i) dehydration, which increases protein concentration without de novo synthesis; (ii) reduced protein degradation rates due to a 6 °C reduction in body temperature and decreased protease activity; and (iii) a marked redistribution of energy resources only increasing de novo synthesis of a few key proteins. The comprehensive global data identified novel biochemical strategies for bear adaptations to the extreme condition of hibernation and have implications for our understanding of physiology in general. PMID:27609515
In vitro anti-mycobacterial activities of three species of Cola plant extracts (Sterculiaceae).

PubMed

Adeniyi, B A; Groves, M J; Gangadharam, P R J

2004-05-01

Extracts obtained from three Nigerian Sterculiaceae plants: Cola accuminata, C. nitida and C. milleni were screened for anti-mycobacterium properties using a slow growing Mycobacterium bovis ATCC 35738 (designated BCG Mexican and known to have some virulence in mouse and guinea pig) at 1000 microg/ml using the radiometric (BACTEC) method. The extracts were also tested against six fast growing ATCC strains of M. vaccae using the broth microdilution method. The methanol extracts from both leaves, stem bark and root bark of Cola accuminata and from the leaves and stem bark of C. nitida and C. milleni were not active at the highest concentration of 1000 microg/ml. Only the methanol extract of root bark for both C. nitida and C. milleni were found to be potent against both M. bovis and strains of M. vaccae. The minimum inhibitory concentration (MIC) of C. nitida against M. bovis is 125 microg/ml while the MIC of C. milleni against M. bovis is 62.5 microg/ml after at least 6 days of inhibition with growth index (GI) units lesser than or equal to the change in GI units inoculated with a 1/100 of the BACTEC inoculum for a control vial. The minimum inhibitory concentration of C. milleni against the six ATCC strain of M. vaccae ranged from 62.5 microg/ml to 250 microg/ml while for C. nitida ranged from 500 microg/ml to above 1000microg/ml. Evidently, C. milleni has the highest inhibitory activity against both M. bovis and strains of M. vaccae used. Rifampicin, the positive control used has strong activity against M. bovis at the tested concentration of 5 microg and 10 microg/ml and 4 to 8 microg/ml against the six strains of M. vaccae. Copyright 2004 John Wiley & Sons, Ltd.
Hillslope soil erosion estimated from aerosol concentrations, North Halawa Valley, Oahu, Hawaii

USGS Publications Warehouse

Hill, B.R.; Fuller, C.C.; DeCarlo, E.H.

1997-01-01

Concentrations of aerosolic quartz and 137Cs were used to estimate rates of hillslope soil erosion during 1990-91 in the North Halawa Valley on the island of Oahu, Hawaii. Fluvial transport of quartz was estimated to be 6.1 Mg in 1990 and 14.9 Mg in 1991. Fluvial transport of 137Cs from North Halawa Valley was estimated to be 1.29 ?? 109 pCi in 1991. Results were used with quartz contents, 137Cs activities, and bulk densities of hillslope soils to compute rates of basinwide hillslope soil erosion ranging from 0.1 to 0.3 mm yr-1. These rates are within the range of previous estimates of denudation computed for drainage basins on Oahu. The aerosol-concentration approach, therefore, is a useful method for assessing basinwide soil erosion.
Occurrence of Radium-224, Radium-226 and Radium-228 in Water from the Vincentown and Wenonah-Mount Laurel Aquifers, the Englishtown Aquifer System, and the Hornerstown and Red Bank Sands, Southwestern and South-Central New Jersey

USGS Publications Warehouse

dePaul, Vincent T.; Szabo, Zoltan

2007-01-01

This investigation is the first regionally focused study of the presence of natural radioactivity in water from the Vincentown and Wenonah-Mount Laurel aquifers, Englishtown aquifer system, and the Hornerstown and Red Bank Sands. Geologic materials composing the Vincentown and Wenonah-Mount Laurel aquifers and the Hornerstown and Red Bank Sands previously have been reported to contain radioactive (uranium-enriched) phosphatic strata, which is common in deposits from some moderate-depth coastal marine environments. The decay of uranium and thorium gives rise to natural radioactivity and numerous radioactive progeny, including isotopes of radium. Naturally occurring radioactive isotopes, especially those of radium, are of concern because radium is a known human carcinogen and ingestion (especially in water used for drinking) can present appreciable health risks. A regional network in southwestern and south-central New Jersey of 39 wells completed in the Vincentown and Wenonah-Mount Laurel aquifers, the Englishtown aquifer system, and the Hornerstown and Red Bank Sands was sampled for determination of gross alpha-particle activity; concentrations of radium radionuclides, major ions, and selected trace elements; and physical properties. Concentrations of radium-224, radium-226, and radium-228 were determined for water from 28 of the 39 wells, whereas gross alpha-particle activity was determined for all 39. The alpha spectroscopic technique was used to determine concentrations of radium-224, which ranged from less than 0.5 to 2.7 pCi/L with a median concentration of less than 0.5pCi/L, and of radium-226, which ranged from less than 0.5 to 3.2 pCi/L with a median concentration of less than 0.5 pCi/L. The beta-counting technique was used to determine concentrations of radium-228. The concentration of radium-228 ranged from less than 0.5 to 4.3 pCi/L with a median of less than 0.5. Radium-228, when quantifiable, had the greatest concentration of the three radium radioisotopes in 9 of the 12 samples (75 percent). The concentration of radium-224 exceeded that of radium-226 in five of the six (83 percent) samples when both were quantifiable. The radium concentration distribution differed by aquifer, with the highest Ra-228 concentrations present in the Englishtown aquifer system and the highest Ra-226 concentrations present in the Wenonah-Mount Laurel aquifer. Radium-224 generally contributed a considerable amount of gross alpha-particle activity to water produced from all the sampled aquifers, but was not the dominant radionuclide as it is in water from the Kirkwood-Cohansey aquifer system, nor were concentrations greater than 1 pCi/L of radium-224 widespread. Gross alpha-particle activity was found to exceed the U.S Environmental Protection Agency (USEPA) Maximum Contaminant Level (MCL) of 15 pCi/L in one sample (16 pCi/L) from the Vincentown aquifer. A greater part of the gross alpha-particle activity in water from the Wenonah-Mount Laurel aquifer resulted from the decay of Ra-226 than did the gross alpha-particle activity in the other sampled aquifers; this relation is consistent with the concentration distribution of the Ra-226 itself. Concentrations of radium-224 correlate strongly with those of both radium-226 and radium-228 (Spearman correlation coefficients, r, +0.86 and +0.66, respectively). The greatest concentrations of radium-224, radium-226, and radium-228 were present in the most acidic ground water. All radium-224, radium-226, and radium-228 concentrations greater than 2.5 pCi/L were present in ground-water samples with a pH less than 5.0. The presence of combined radium-226 and radium-228 concentrations greater than 5 pCi/L in samples from the Vincentown and Wenonah-Mount Laurel aquifers and the Englishtown aquifer system was not nearly as common as in samples from the Kirkwood-Cohansey aquifer system, likely because of the slightly higher pH of water from these aquifers relative to that of Kirkwood-Cohansey aqu
Determination of homocysteine in human saliva by liquid chromatography and electrospray ionization quadrupole time-of-flight mass spectrometry: profiles in healthy adults.

PubMed

Abaye, Daniel A; Nielsen, Birthe; Boateng, Joshua S

2013-12-01

Homocysteine (Hcys) is a non-essential amino acid associated with a range of diseased and abnormal metabolic conditions. Hcys concentration in saliva is routinely determined by enzyme assays, which are broadly specific, but can be expensive and suffer from cross-reactivity. Total Hcys (tHcys) concentrations in eight healthy adults were determined to establish the inter-day variation during resting, normal and intensive physical activity, using the more sensitive analytical techniques of liquid chromatography and tandem mass spectrometry without prior derivatization. Saliva (~ 1.5 mL) was collected over four days; early morning (EA), normal activity (NA) and during physical activity (PA). Samples were processed by disulphide reduction, acetonitrile precipitation and then centrifugation-filtration. Extracts were chromatographically resolved and analysed on a quadrupole time- of-flight (QToF) mass spectrometer. The protonated [M+H]+, m/z 136.101 and product ([M+H]+- HCOOH) m/z 90.103 ions were then monitored against an internal standard (13CHcys) and external set of calibration standards. Mean tHcys concentration for the whole group, including exercise was 6.6 ± 8.0 (range 0.2 - 29.6 nmol/mL). Overall, concentration of tHcys was greater in males than the females but not significantly (p > 0.05). The mean EA concentration was significantly (p < 0.05) greater than NA for both males (p = 0340) and females (p = 0.0045). There were large within-subject variations (coefficient of variation; CV%; 24% to 103%). The limits of detection (LOD) and quantification (LOQ) were 0.07 and 0.22 nmol/mL, respectively. The procedure potentially provides a convenient means of analyzing salivary Hcys as a diagnostic disease marker.
H2O activity in concentrated NaCl solutions at high pressures and temperatures measured by the brucite-periclase equilibrium

NASA Astrophysics Data System (ADS)

Aranovich, L. Y.; Newton, R. C.

1996-10-01

H2O activities in concentrated NaCl solutions were measured in the ranges 600° 900° C and 2 15 kbar and at NaCl concentrations up to halite saturation by depression of the brucite (Mg(OH)2) periclase (MgO) dehydration equilibrium. Experiments were made in internally heated Ar pressure apparatus at 2 and 4.2 kbar and in 1.91-cm-diameter piston-cylinder apparatus with NaCl pressure medium at 4.2, 7, 10 and 15 kbar. Fluid compositions in equilibrium with brucite and periclase were reversed to closures of less than 2 mol% by measuring weight changes after drying of punctured Pt capsules. Brucite-periclase equilibrium in the binary system was redetermined using coarsely crystalline synthetic brucite and periclase to inhibit back-reaction in quenching. These data lead to a linear expression for the standard Gibbs free energy of the brucite dehydration reaction in the experimental temperature range: ΔG° (±120J)=73418 134.95 T(K). Using this function as a baseline, the experimental dehydration points in the system MgO-H2O-NaCl lead to a simple systematic relationship of high-temperature H2O activity in NaCl solution. At low pressure and low fluid densities near 2 kbar the H2O activity is closely approximated by its mole fraction. At pressures of 10 kbar and greater, with fluid densities approaching those of condensed H2O, the H2O activity becomes nearly equal to the square of its mole fraction. Isobaric halite saturation points terminating the univariant brucite-periclase curves were determined at each experimental pressure. The five temperature-composition points in the system NaCl-H2O are in close agreement with the halite saturation curves (liquidus curves) given by existing data from differential thermal analysis to 6 kbar. Solubility of MgO in the vapor phase near halite saturation is much less than one mole percent and could not have influenced our determinations. Activity concentration relations in the experimental P-T range may be retrieved for the binary system H2O-NaCl from our brucite-periclase data and from halite liquidus data with minor extrapolation. At two kbar, solutions closely approach an ideal gas mixture, whereas at 10 kbar and above the solutions closely approximate an ideal fused salt mixture, where the activities of H2O and NaCl correspond to an ideal activity formulation. This profound pressure-induced change of state may be characterized by the activity ( a) concentration ( X) expression: a H 2O= X H 2O/(1+α X NaCl), and a NaCl=(1+α)(1+α)[ X NaCl/(1+α X NaCl)](1+α). The parameter α is determined by regression of the brucite-periclase H2O activity data: α=exp[A B/ϱH 2O ]-C P/ T, where A=4.226, B=2.9605, C=164.984, and P is in kbar, T is in Kelvins, and ϱH 2O is the density of H2O at given P and T in g/cm3. These formulas reproduce both the H2O activity data and the NaCl activity data with a standard deviation of ±0.010. The thermodynamic behavior of concentrated NaCl solutions at high temperature and pressure is thus much simpler than portrayed by extended Debye-Hückel theory. The low H2O activity at high pressures in concentrated supercritical NaCl solutions (or hydrosaline melts) indicates that such solutions should be feasible as chemically active fluids capable of coexisting with solid rocks and silicate liquids (and a CO2-rich vapor) in many processes of deep crustal and upper mantle metamorphism and metasomatism.
Metal and hydrocarbon behavior in sediments from Brazilian shallow waters drilling activities using nonaqueous drilling fluids (NAFs).

PubMed

do Carmo R Peralba, Maria; Pozebon, Dirce; dos Santos, João H Z; Maia, Sandra M; Pizzolato, Tânia M; Cioccari, Giovani; Barrionuevo, Simone

2010-08-01

The impact of drilling oil activities in the Brazilian Bonito Field/Campos Basin (Rio de Janeiro) shell drilling (300 m) using nonaqueous fluids (NAFs) was investigated with respect to Al, Fe, Mn, Ba, Co, Pb, Cu, As, Hg, Cr, Ni, Zn, Cd, V, and aliphatic and polynuclear aromatic hydrocarbons concentrations in the sediment. Sampling took place in three different times during approximately 33 months. For the metals Al, As, Co, Cr, Cu, Cd, Fe, Ni, Mn, V, and Zn, no significant variation was observed after drilling activities in most of the stations. However, an increase was found in Ba concentration--due to the drilling activity--without return to the levels found 22 months after drilling. High Ba contents was already detected prior to well drilling, probably due to drilling activities in other wells nearby. Hydrocarbon contents also suggest previous anthropogenic activities. Aliphatic hydrocarbon contents were in the range usually reported in other drilling sites. The same behavior was observed in the case of polyaromatic hydrocarbons. Nevertheless, the n-alkane concentration increased sharply after drilling, returning almost to predrilling levels 22 months after drilling activities.

Leishmanicidal activity of saponins isolated from the leaves of Eclipta prostrata and Gymnema sylvestre

PubMed Central

Khanna, Venkatesan Gopiesh; Kannabiran, Krishnan; Getti, Giulia

2009-01-01

Objective: To evaluate the leishmanicidal activity of saponin, dasyscyphin C of Eclipta prostrata and sapogenin, gymnemagenol from Gymnema sylvestre leaves under in vitro conditions. Materials and Methods: Dasyscyphin C/Gymnemagenol were dissolved in phosphate buffered saline (PBS) and diluted with liquid medium to obtain concentrations ranging from 1000 to 15 μg /ml. The leishmanicidal activity against leishmanial parasites, Leishmania major, Leishmania aethiopica and Leishmania tropica promastigotes was studied by the MTS assay. Result: The Dasyscyphin C isolated from E. prostrata showed good leishmanicidal activity at 1000μg/ml concentration, with the IC50 value of 450μg/ml against L. major promastigote and the percentage of parasitic death was 73; whereas, gymnemagenol of G. sylvestre showed only 52% parasitic death at 1000 μg/ml concentration. The other Leishmania species, L. aethiopica and L. tropica promastigotes, were less sensitive to the saponins of E. prostrata and G. sylvestre. Conclusion: From this study, it can be concluded that the dasyscyphin C of E. prostrata has significant leishmanicidal activity against L. major promastigote. PMID:20177579
Characteristic of total suspended particulate (TSP) containing Pb and Zn at solid waste landfill

NASA Astrophysics Data System (ADS)

Budihardjo, M. A.; Noveandra, K.; Samadikun, B. P.

2018-05-01

Activities conducted at municipal solid waste landfills (MSWLs) potentially cause air pollution. Heavy vehicles in MSWLs release various pollutants that can have negative impacts for humans. One noticeable pollutant at MSWLs is airborne total suspended particulate (TSP) which may contain heavy metals such as Pb and Zn and can cause disease when inhaled by humans. In this study, TSP from a landfill in Semarang, Indonesia was collected and characterized to quantify the concentration of Pb and Zn. Meteorological factors (i.e. temperature, humidity and wind velocity) and landfill activities were considered as factors affecting pollutant concentrations. TSP was sampled using dust samplers while the concentrations of heavy metals in TSP were analyzed using an Atomic Absorption Spectrophotometer (AAS). Pb concentration ranged from 0.84 to 1.78 µg/m3 while Zn concentration was from 7.87 to 8.76 µg/m3. The levels of Pb were below the threshold specified by the Indonesian Government. Meanwhile, the threshold for Zn has not yet been determined.
Effects of low concentrations of the phenylurea herbicide diuron on biofilm algae and bacteria.

PubMed

Ricart, Marta; Barceló, Damià; Geiszinger, Anita; Guasch, Helena; de Alda, Miren López; Romaní, Anna M; Vidal, Gemma; Villagrasa, Marta; Sabater, Sergi

2009-09-01

A system of recirculating channels was used in this study to examine the long-term effects (29d) of environmentally realistic concentrations of the herbicide diuron (from 0.07 to 7 microg L(-1)) on biofilm communities. The autotrophic activity of biofilms was affected by this herbicide, as reflected by a marked decrease in the photosynthetic efficiency. Diuron exposure also increased chlorophyll-a content and reduced the biovolume of diatom taxa at low concentrations. The effects on bacteria were also remarkable. Bacterial abundance was reduced after a week of exposure to the herbicide at a range of concentrations. Effects were on the number of live bacteria and on the increase in the leucine-aminopeptidase activity. It is suggested that inputs of herbicides to the river ecosystem at low concentrations may cause a chain of effects in the biofilm, which include inhibitory effects on algae but also indirect effects on the relationships between biofilm components.
[Membrane mechanisms of effects of antihypoxic agents bemethyl and almide on neurons of Mollusca].

PubMed

Vislobokov, A I; Marysheva, V V; Shabanov, P D

2003-01-01

Membranotropic effects of the antihypoxants bemithyl and almide, structural analogs of thiobenzimidazole, have been studied on the isolated neuronal preparations of Lymaea stagnalis branchycephalic mollusk. Both drugs in a concentration range of 100-1000 microM produced a reversible, dose-dependent nonselective single-phase blocking action upon the ion channels and completely blocked the channels at a concentration of 10 mM. Therefore, bemithyl and almide are active membranotropic compounds capable (in sufficiently high concentrations) of changing the conductivity of slow sodium, calcium, and potassium ion channels in excitable cells. The protective antihypoxant drug reactions on a systemic level of the organism are probably related to the fact that both drugs in small concentrations are capable of hyperpolarizing the cell membrane, activating the ion channel function, and stabilizing the action potential under hypoxia conditions; in greater concentrations, bemithyl and almide are capable of blocking ion currents, thus reducing the excitability of cells and protecting them from overstress.
Simultaneous Measurements of Nanoaerosols and Radioactive Aerosols Containing the Short-lived Radon Isotopes.

PubMed

Otahal, P P S; Burian, I; Ondracek, J; Zdimal, V; Holub, R F

2017-11-01

The activity size distribution of the Equilibrium-Equivalent Concentration (EER) of 222Rn is one of the most important parameters for the estimation of radiation dose by inhalation of radon decay products. A series of measurements of the EER activity size distribution were performed by the screen diffusion battery in Radon-Aerosol chamber (10 m3) at the National Institute for Nuclear, Chemical, and Biological Protection (SUJCHBO). These measurements were performed at different levels of radon concentration. For this study, the Graded Screen Array Diffusion Battery (GSA DB), developed by the SUJCHBO (based on Earl Knutson and Robert F Holub design), consists of 10 screens and backup filter used to collect all particles that penetrated the screens. The measuring range of this GSA DB allows measuring the radioactive nanoaerosols in the size range from 0.5 to 100 nm. The Earl Knutson algorithm was used for EER activity size distribution evaluation. The results of EER activity size distribution were subsequently compared with the aerosol particle size distribution measured by Scanning Mobility Particle Sizer Spectrometer (SMPS 3936 N, TSI Inc., MN, USA). © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Therapeutic drug monitoring of antimetabolic cytotoxic drugs

PubMed Central

Lennard, L

1999-01-01

Therapeutic drug monitoring is not routinely used for cytotoxic agents. There are several reasons, but one major drawback is the lack of established therapeutic concentration ranges. Combination chemotherapy makes the establishment of therapeutic ranges for individual drugs difficult, the concentration-effect relationship for a single drug may not be the same as that when the drug is used in a drug combination. Pharmacokinetic optimization protocols for many classes of cytotoxic compounds exist in specialized centres, and some of these protocols are now part of large multicentre trials. Nonetheless, methotrexate is the only agent which is routinely monitored in most treatment centres. An additional factor, especially in antimetabolite therapy, is the existence of pharmacogenetic enzymes which play a major role in drug metabolism. Monitoring of therapy could include assay of phenotypic enzyme activities or genotype in addition to, or instead of, the more traditional measurement of parent drug or drug metabolites. The cytotoxic activities of mercaptopurine and fluorouracil are regulated by thiopurine methyltransferase (TPMT) and dihydropyrimidine dehydrogenase (DPD), respectively. Lack of TPMT functional activity produces life-threatening mercaptopurine myelotoxicity. Very low DPD activity reduces fluorouracil breakdown producing severe cytotoxicity. These pharmacogenetic enzymes can influence the bioavailability, pharmacokinetics, toxicity and efficacy of their substrate drugs. PMID:10190647
Polonium-210 and lead-210 in the terrestrial environment: a historical review.

PubMed

Persson, Bertil R R; Holm, Elis

2011-05-01

The radionuclides (210)Po and (210)Pb widely present in the terrestrial environment are the final long-lived radionuclides in the decay of (238)U in the earth's crust. Their presence in the atmosphere is due to the decay of (222)Rn diffusing from the ground. The range of activity concentrations in ground level air for (210)Po is 0.03-0.3 Bq m(-3) and for (210)Pb 0.2-1.5 Bq m(-3). In drinking water from private wells the activity concentration of (210)Po is in the order of 7-48 mBq l(-1) and for (210)Pb around 11-40 mBq l(-1). From water works, however, the activity concentration for both (210)Po and (210)Pb is only in the order of 3 mBq l(-1). Mosses, lichens and peat have a high efficiency in capturing (210)Po and (210)Pb from atmospheric fallout and exhibit an inventory of both (210)Po and (210)Pb in the order of 0.5-5 kBq m(-2) in mosses and in lichens around 0.6 kBq m(-2). The activity concentrations in lichens lies around 250 Bq kg(-1), dry mass. Reindeer and caribou graze lichen which results in an activity concentration of (210)Po and (210)Pb of about 1-15 Bq kg(-1) in meat from these animals. The food chain lichen-reindeer or caribou, and Man constitutes a unique model for studying the uptake and retention of (210)Po and (210)Pb in humans. The effective annual dose due to (210)Po and (210)Pb in people with high consumption of reindeer/caribou meat is estimated to be around 260 and 132 μSv a(-1) respectively. In soils, (210)Po is adsorbed to clay and organic colloids and the activity concentration varies with soil type and also correlates with the amount of atmospheric precipitation. The average activity concentration levels of (210)Po in various soils are in the range of 20-240 Bq kg(-1). Plants become contaminated with radioactive nuclides both by absorption from the soil (supported Po) and by deposition of radioactive fallout on the plants directly (unsupported Po). In fresh leafy plants the level of (210)Po is particularly high as the result of the direct deposition of (222)Rn daughters from atmospheric deposition. Tobacco is a terrestrial product with high activity concentrations of (210)Po and (210)Pb. The overall average activity concentration of (210)Po is 13 ± 2 Bq kg(-1). It is rather constant over time and by geographical origin. The average median daily dietary intakes of (210)Po and (210)Pb for the adult world population was estimated to 160 mBq day(-1) and 110 mBq day(-1), corresponding to annual effective doses of 70 μSv a(-1) and 28 μSv a(-1), respectively. The dietary intakes of (210)Po and (210)Pb from vegetarian food was estimated to only 70 mBq day(-1) and 40 mBq day(-1) corresponding to annual effective doses of 30.6 μSv a(-1) and 10 μSv a(-1), respectively. Since the activity concentration of (210)Po and (210)Pb in seafood is significantly higher than in vegetarian food the effective dose to populations consuming a lot of seafood might be 5-15 fold higher. Copyright © 2011 Elsevier Ltd. All rights reserved.
In Vitro Antibacterial and Antibiofilm Activities of Chlorogenic Acid against Clinical Isolates of Stenotrophomonas maltophilia including the Trimethoprim/Sulfamethoxazole Resistant Strain

PubMed Central

Karunanidhi, Arunkumar; Thomas, Renjan; van Belkum, Alex; Neela, Vasanthakumari

2013-01-01

The in vitro antibacterial and antibiofilm activity of chlorogenic acid against clinical isolates of Stenotrophomonas maltophilia was investigated through disk diffusion, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), time-kill and biofilm assays. A total of 9 clinical S. maltophilia isolates including one isolate resistant to trimethoprim/sulfamethoxazole (TMP/SMX) were tested. The inhibition zone sizes for the isolates ranged from 17 to 29 mm, while the MIC and MBC values ranged from 8 to 16 μg mL−1 and 16 to 32 μg mL−1. Chlorogenic acid appeared to be strongly bactericidal at 4x MIC, with a 2-log reduction in viable bacteria at 10 h. In vitro antibiofilm testing showed a 4-fold reduction in biofilm viability at 4x MIC compared to 1x MIC values (0.085 < 0.397 A 490 nm) of chlorogenic acid. The data from this study support the notion that the chlorogenic acid has promising in vitro antibacterial and antibiofilm activities against S. maltophilia. PMID:23509719
Radical scavenging ability of some compounds isolated from Piper cubeba towards free radicals.

PubMed

Aboul-Enein, Hassan Y; Kładna, Aleksandra; Kruk, Irena

2011-01-01

The purpose of this study was to identify the antioxidant activity of 16 compounds isolated from Piper cubeba (CNCs) through the extent of their capacities to scavenge free radicals, hydroxyl radical (HO(•)), superoxide anion radical O•(2)(-) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH(•)), in different systems. Electron paramagnetic resonance (EPR) and 5,5-dimethyl-1-pyrroline-N-oxide, DMPO, as the spin trap, and chemiluminescence techniques were applied. Using the Fenton-like reaction [Fe(II) + H(2)O(2)], CNCs were found to inhibit DMPO-OH radical formation ranging from 5 to 57% at 1.25 mmol L(-1) concentration. The examined CNCs also showed a high DPPH antiradical activity (ranging from 15 to 99% at 5 mmol L(-1) concentration). Furthermore, the results indicated that seven of the 16 tested compounds may catalyse the conversion of superoxide radicals generated in the potassium superoxide/18-crown-6 ether system, thus showing superoxide dismutase-like activity. The data obtained suggest that radical scavenging properties of CNCs might have potential application in many plant medicines. Copyright © 2010 John Wiley & Sons, Ltd.
The effect of glyphosate-based herbicide Roundup and its co-formulant, POEA, on the motoric activity of rat intestine - In vitro study.

PubMed

Chłopecka, Magdalena; Mendel, Marta; Dziekan, Natalia; Karlik, Wojciech

2017-01-01

The study was aimed at evaluating the effect of Roundup, polyoxyethylene tallow amine (POEA) and mixture of glyphosate and POEA in different levels on the motoric activity of jejunum strips. The incubation in the Roundup solutions caused a significant, mostly miorelaxant, reversible reaction of smooth muscle; only in the highest tested dose which is equivalent to the agricultural concentration (1% corresponding to 1.7g glyphosate/L) there was an irreversible disturbance of the spontaneous contractility and reactivity. The incubation in POEA solutions in the range of low doses (0.256; 1.28; 6.4mg/L) resulted in a biphasic muscle reaction (relaxation and contraction); whereas in the range of high doses, i.e. 32; 160 and 800mg/L (agricultural spray concentrations) induced only a miorelaxant, irreversible response. The results indicate very high toxicity of POEA which exceeds the toxicity of the commercial formulations. Besides, it is postulated that glyphosate and POEA may display antagonistic interaction towards the motoric activity of gastrointestinal tract. Copyright © 2016 Elsevier B.V. All rights reserved.
How the Emitted Size Distribution and Mixing State of Feldspar Affect Ice Nucleating Particles in a Global Model

NASA Technical Reports Server (NTRS)

Perlwitz, Jan P.; Fridlind, Ann M.; Knopf, Daniel A.; Miller, Ron L.; García-Pando, Carlos Perez

2017-01-01

The effect of aerosol particles on ice nucleation and, in turn, the formation of ice and mixed phase clouds is recognized as one of the largest sources of uncertainty in climate prediction. We apply an improved dust mineral specific aerosol module in the NASA GISS Earth System ModelE, which takes into account soil aggregates and their fragmentation at emission as well as the emission of large particles. We calculate ice nucleating particle concentrations from K-feldspar abundance for an active site parameterization for a range of activation temperatures and external and internal mixing assumption. We find that the globally averaged INP concentration is reduced by a factor of two to three, compared to a simple assumption on the size distribution of emitted dust minerals. The decrease can amount to a factor of five in some geographical regions. The results vary little between external and internal mixing and different activation temperatures, except for the coldest temperatures. In the sectional size distribution, the size range 24 micrometer contributes the largest INP number.
How the Emitted Size Distribution and Mixing State of Feldspar Affect Ice Nucleating Particles in a Global Model

NASA Astrophysics Data System (ADS)

Perlwitz, J. P.; Fridlind, A. M.; Knopf, D. A.; Miller, R. L.; Pérez García-Pando, C.

2017-12-01

The effect of aerosol particles on ice nucleation and, in turn, the formation of ice and mixed phase clouds is recognized as one of the largest sources of uncertainty in climate prediction. We apply an improved dust mineral specific aerosol module in the NASA GISS Earth System ModelE, which takes into account soil aggregates and their fragmentation at emission as well as the emission of large particles. We calculate ice nucleating particle concentrations from K-feldspar abundance for an active site parameterization for a range of activation temperatures and external and internal mixing assumption. We find that the globally averaged INP concentration is reduced by a factor of two to three, compared to a simple assumption on the size distribution of emitted dust minerals. The decrease can amount to a factor of five in some geographical regions. The results vary little between external and internal mixing and different activation temperatures, except for the coldest temperatures. In the sectional size distribution, the size range 2-4 μm contributes the largest INP number.
Antibacterial Activities of Jatropha curcas (LINN) on Coliforms Isolated from Surface Waters in Akure, Nigeria

PubMed Central

Dada, E. O.; Ekundayo, F. O.; Makanjuola, O. O.

2014-01-01

This study investigated the antibacterial activities of hot water, ethanol and acetone extracts of Jatropha curcas (LINN) leaves on coliforms isolated from surface waters using growth inhibition indices based on agar plate technique. The percentage recovery of the extracts was 19.17%, 18.10% and 18.80% for hot water, ethanol and acetone respectively. Phytochemical screening of the extracts was also determined. Qualitative phytochemical screening showed that the plant extracts contained steroids, tannins, flavonoids and cardiac glycosides, while alkaloids, phlobatannin, terpenoids and anthraquinones were absent. Only ethanolic extract did not possess saponins. Aqueous extracts of J. curcas compared most favourably with the standard antibiotics (gentamycin) on all the coliform bacteria except on K. pneumoniae and E. coli likely due to a measurably higher antibacterial activity compared to the organic extracts. The minimum inhibitory concentration of the aqueous extract ranged from 3.00 to 7.00 mg/L while minimum bactericidal concentration ranged from 4.00 to 10.00 mg/L. Aqueous extract of J. curcas could be used as antibacterial agents against diseases caused by coliforms. PMID:24711746
Representation of sweet and salty taste intensity in the brain.

PubMed

Spetter, M S; Smeets, P A M; de Graaf, C; Viergever, M A

2010-11-01

The intensity of the taste of a food is affected mostly by the amount of sugars (mono- and disaccharides) or salt it contains. To season savory-tasting foods mainly table salt (NaCl) is used and to sweeten foods, sugars like sucrose are used. Foods with highly intense tastes are consumed in smaller amounts. The optimal taste intensity of a food is the intensity at which it is perceived as most pleasant. When taste intensity decreases or increases from optimal, the pleasantness of a food decreases. Here, we investigated the brain representation of sweet and salty taste intensity using functional magnetic resonance imaging. Fifteen subjects visited twice and tasted a range of 4 watery solutions (0-1 M) of either sucrose or NaCl in water. Middle insula activation increased with increasing concentration for both NaCl and sucrose. Despite similar subjective intensity ratings, anterior insula activation by NaCl increased more with concentration than that by sucrose. Amygdala activation increased with increasing NaCl concentration but not sucrose concentration. In conclusion, sweet and salty taste intensity are represented in the middle insula. Amygdala activation is only modulated by saltiness. Further research will need to extrapolate these results from simple solutions to real foods.
Particulate matter dynamics in naturally ventilated freestall dairy barns

NASA Astrophysics Data System (ADS)

Joo, H. S.; Ndegwa, P. M.; Heber, A. J.; Ni, J.-Q.; Bogan, B. W.; Ramirez-Dorronsoro, J. C.; Cortus, E. L.

2013-04-01

Particulate matter (PM) concentrations and ventilation rates, in two naturally ventilated freestall dairy barns, were continuously monitored for two years. The first barn (B1) housed 400 fresh lactating cows, while the second barn (B2) housed 835 non-fresh lactating cows and 15 bulls. The relationships between PM concentrations and accepted governing parameters (environmental conditions and cattle activity) were examined. In comparison with other seasons, PM concentrations were lowest in winter. Total suspended particulate (TSP) concentrations in spring and autumn were relatively higher than those in summer. Overall: the concentrations in the barns and ambient air, for all the PM categories (PM2.5, PM10, and TSP), exhibited non-normal positively skewed distributions, which tended to overestimate mean or average concentrations. Only concentrations of PM2.5 and PM10 increased with ambient air temperature (R2 = 0.60-0.82), whereas only concentrations of TSP increased with cattle activity. The mean respective emission rates of PM2.5, PM10, and TSP for the two barns ranged between 1.6-4.0, 11.9-15.0, and 48.7-52.5 g d-1 cow-1, indicating similar emissions from the two barns.
Interpreting Tacrolimus Concentrations During Pregnancy and Postpartum

PubMed Central

Hebert, Mary F.; Zheng, Songmao; Hays, Karen; Shen, Danny D.; Davis, Connie L.; Umans, Jason G.; Miodovnik, Menachem; Thummel, Kenneth E.; Easterling, Thomas R.

2012-01-01

Summary Pregnancy following solid organ transplantation, although considered high risk for maternal, fetal and neonatal complications, has been quite successful. Tacrolimus pharmacokinetic changes during pregnancy make interpretation of whole blood trough concentrations particularly challenging. There are multiple factors that can increase the fraction of unbound tacrolimus, including but not limited to low albumin concentration and low RBC count. The clinical titration of dosage to maintain whole blood tacrolimus trough concentrations in the usual therapeutic range can lead to elevated unbound concentrations and possibly toxicity in pregnant women with anemia and hypoalbuminemia. Measurement of plasma or unbound tacrolimus concentrations for pregnant women might better reflect the active form of the drug, though these are technically-challenging and often unavailable in usual clinical practice. Tacrolimus crosses the placenta with in utero exposure being approximately 71% of maternal blood concentrations. The lower fetal blood concentrations are likely due to active efflux transport of tacrolimus from the fetus toward the mother by placental P-glycoprotein. To date, tacrolimus has not been linked to congenital malformations, but can cause reversible nephrotoxicity and hyperkalemia in the newborn. In contrast, very small amounts of tacrolimus are excreted in the breast milk and are unlikely to elicit adverse effects in the nursing infant. PMID:23274970
Mechanism linking glycogen concentration and glycogenolytic rate in perfused contracting rat skeletal muscle.

PubMed Central

Hespel, P; Richter, E A

1992-01-01

The influence of differences in glycogen concentration on glycogen breakdown and on phosphorylase activity was investigated in perfused contracting rat skeletal muscle. The rats were preconditioned by a combination of swimming exercise and diet (carbohydrate-free or carbohydrate-rich) in order to obtain four sub-groups of rats with varying resting muscle glycogen concentrations (range 10-60 mumol/g wet wt.). Pre-contraction muscle glycogen concentration was closely positively correlated with glycogen breakdown over 15 min of intermittent short tetanic contractions (r = 0.75; P less than 0.001; n = 56) at the same tension development and oxygen uptake. Additional studies in supercompensated and glycogen-depleted hindquarters during electrical stimulation for 20 s or 2 min revealed that the difference in glycogenolytic rate was found at the beginning rather than at the end of the contraction period. Phosphorylase alpha activity was approximately twice as high (P less than 0.001) in supercompensated muscles as in glycogen-depleted muscles after 20 s as well as after 2 min of contractions. It is concluded that glycogen concentration is an important determinant of phosphorylase activity in contracting skeletal muscle, and probably via this mechanism a regulator of glycogenolytic rate during muscle contraction. PMID:1622395
Improving bioaerosol exposure assessments of composting facilities — Comparative modelling of emissions from different compost ages and processing activities

NASA Astrophysics Data System (ADS)

Taha, M. P. M.; Drew, G. H.; Tamer, A.; Hewings, G.; Jordinson, G. M.; Longhurst, P. J.; Pollard, S. J. T.

We present bioaerosol source term concentrations from passive and active composting sources and compare emissions from green waste compost aged 1, 2, 4, 6, 8, 12 and 16 weeks. Results reveal that the age of compost has little effect on the bioaerosol concentrations emitted for passive windrow sources. However emissions from turning compost during the early stages may be higher than during the later stages of the composting process. The bioaerosol emissions from passive sources were in the range of 10 3-10 4 cfu m -3, with releases from active sources typically 1-log higher. We propose improvements to current risk assessment methodologies by examining emission rates and the differences between two air dispersion models for the prediction of downwind bioaerosol concentrations at off-site points of exposure. The SCREEN3 model provides a more precautionary estimate of the source depletion curves of bioaerosol emissions in comparison to ADMS 3.3. The results from both models predict that bioaerosol concentrations decrease to below typical background concentrations before 250 m, the distance at which the regulator in England and Wales may require a risk assessment to be completed.
Shallow ground-water quality in selected agricultural areas of south-central Georgia, 1994

USGS Publications Warehouse

Crandall, C.A.

1996-01-01

The Georgia-Florida Coastal Plain National Water-Quality Assessment Program began an agricultural land-use study in March 1994. The study area is located in the upper Suwannee River basin in Tift, Turner, Worth, Irwin, Wilcox, and Crisp Counties, Ga. Twenty-three shallow monitoring wells were installed in a 1,335-square- mile area characterized by intensive row-crop agriculture (peanuts, corn, cotton, and soybeans). The study focused on recently recharged shallow ground water in surficial aquifers to assess the relation between land-use activities and ground- water quality. All wells were sampled in March and April (spring) 1994, and 14 of these wells were resampled in August (summer) 1994. Shallow ground water in the study area is characterized by oxic and acidic conditions, low bicarbonate, and low dissolved-solids concentrations. The median pH of shallow ground water was 4.7 and the median bicarbonate concentration was 1.7 mg/L (milligrams per liter). Dissolved oxygen concentrations ranged from 3.0 to 8.0 mg/L. The median dissolved-solids concentration in samples collected in the spring was 86 mg/L. Major inorganic ion composition was generally mixed with no dominant cation; nitrate was the dominant anion (greater than 60 percent of the anion composition) in 14 of 23 samples. Only concentrations of bicarbonate, dissolved organic carbon, and nitrate had significant differences in concentrations between samples collected in the spring and the background samples. However, median concentrations of some of the major ingredients in fertilizer (including magnesium, chloride, nitrate, iron, and manganese) were higher in water samples from agricultural wells than in background samples. The median concentration of dissolved solids in ground-water samples collected in the spring (86 mg/L) was more than double the median concentration (41 mg/L) of the background samples. The median nitrate as nitrogen concentration of 6.7 mg/L in the spring samples reflects the effects of agricultural activities on ground-water quality. Samples from 30 percent of the wells exceeded the maximum contaminant level (MCL) for nitrate in drinking water (10 mg/L as N). Nitrogen isotope ratios ranged from 2.4 to 9.0 parts per thousand and indicate that most nitrogen in shallow ground water is probably from inorganic fertilizer. In addition, nitrate concentrations were positively correlated (p-values all less than 0.01) with concentrations of some of the major ingredients in fertilizer, such as potassium, calcium, magnesium, manganese, and chloride, and with values of specific conductance. Concentrations of pesticides and volatile organic compounds, detected in samples from 11 wells, were all below the MCLs. Of these constituents, only alachlor, metolachlor, metribuzin, toluene, benzene, and methyl chloride were detected in ground water at concentrations that ranged from 0.01 to 1.0 mg/L (micrograms per liter). Maximum concentrations of 1.0 mg/L of metolachlor and toluene were detected in two wells. Radon concentrations ranged from 530 to 1,400 pCi/L (picocuries per liter), exceeding the proposed MCL of 300 pCi/L in all samples; the median concentration was 1,000 pCi/L.
Rapid and simultaneous determination of Strontium-89 and Strontium-90 in seawater.

PubMed

Tayeb, Michelle; Dai, Xiongxin; Sdraulig, Sandra

2016-03-01

A rapid method has been developed for the direct determination of radiostrontium ((89)Sr and (90)Sr) released in seawater in the early phase of an accident. The method employs a fast and effective pre-concentration of radiostrontium by Sr-Ca co-precipitation followed by separation of radiostrontium using extraction chromatography technique. Radiostrontium is effectively separated in the presence of excessive dominant salts of seawater. Čerenkov and liquid scintillation assay (LSA) techniques are used to determine (89)Sr and (90)Sr. Sample preparation time is approximately 4 h for a set of 10 samples. The method was validated using spiked seawater samples at various activity ratios of (89)Sr:(90)Sr ranging from 1:10 to 9:1. The mean chemical recovery of Sr was 85 ± 3%. (90)Sr showed variable relative bias which enhanced with increasing ratio of (89)Sr:(90)Sr and was in the range ± 21%. The highest biases of (90)Sr determination were due to lower activity concentrations of (90)Sr and are regarded as acceptable in emergency situations with elevated levels of radiostrontium in the sample. The minimum detectable concentration (MDC) of (90)Sr and (89)Sr varied at different (89)Sr:(90)Sr ratios. For 0.1 L seawater and 15 min counting time on a low background Hidex liquid scintillation counter (LSC), the MDC of (90)Sr was in the range of 1.7-3.5 Bq L(-1) and MDC of (89)Sr was in the range 0.5-2.4 Bq L(-1). Copyright © 2016 Elsevier Ltd. All rights reserved.

The Effect of Inorganic Particles on Metabolism by Marine Bacteria.

DTIC Science & Technology

1982-05-01

Wright, 1974; 1978). Glucose is the dominant monosaccharide in seawater I (Mopper et al., 1980). It is found in seawater at concentrations ranging from... monosaccharides in seawater (Stumm and Morgan, 1981). However, concentrations of specific amino acids are lower than those reported for glucose (Lee and Bada...Fletcher, 1979B; this study). However there is also an active process involved in attachment; this is the secretion of polysaccharide holdfast material
Organic solvent tolerance of an α-amylase from haloalkaliphilic bacteria as a function of pH, temperature, and salt concentrations.

PubMed

Pandey, Sandeep; Singh, S P

2012-04-01

A haloalkaliphilic bacterium was isolated from salt-enriched soil of Mithapur, Gujarat (India) and identified as Bacillus agaradhaerens Mi-10-6₂ based on 16S rRNA sequence analysis (NCBI gene bank accession, GQ121032). The bacterium was studied for its α-amylase characteristic in the presence of organic solvents. The enzyme was quite active and it retained considerable activity in 30% (v/v) organic solvents, dodecane, decane, heptane, n-hexane, methanol, and propanol. At lower concentrations of solvents, the catalysis was quite comparable to control. Enzyme catalysis at wide range of alkanes and alcohol was an interesting finding of the study. Mi-10-6₂ amylase retained activity over a broader alkaline pH range, with the optimal pH at 10-11. Two molars of salt was optimum for catalysis in the presence of most of the tested solvents, though the enzyme retained significant activity even at 4 M salt. With dodecane, the optimum temperature shifted from 50 °C to 60 °C, while the enzyme was active up to 80 °C. Over all, the present study focused on the effect of organic solvents on an extracellular α-amylase from haloalkaliphilic bacteria under varying conditions of pH, temperature, and salt.
Thiadiazolidinones: A New Class of Alanine Racemase Inhibitors with Antimicrobial Activity against Methicillin- Resistant S. aureus

PubMed Central

Ciustea, Mihai; Mootien, Sara; Rosato, Adriana E.; Perez, Oriana; Cirillo, Pier; Yeung, Kacheong R.; Ledizet, Michel; Cynamon, Michael H.; Aristoff, Paul A.; Koski, Raymond A.; Kaplan, Paul A.; Anthony, Karen G.

2012-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a human pathogen and a major cause of hospital-acquired infections. New antibacterial agents that have not been compromised by bacterial resistance are needed to treat MRSA-related infections. We chose the S. aureus cell wall synthesis enzyme, alanine racemase (Alr) as the target for a high-throughput screening effort to obtain novel enzyme inhibitors, which inhibit bacterial growth. Among the ‘hits’ identified was a thiadiazolidinone with chemical properties attractive for lead development. This study evaluated the mode of action, antimicrobial activities, and mammalian cell cytotoxicity of the thiadiazolidinone family in order to assess its potential for development as a therapeutic agent against MRSA. The thiadiazolidones inhibited Alr activity with 50% inhibitory concentrations (IC50) ranging from 0. 36 – 6. 4 μM, and they appear to inhibit the enzyme irreversibly. The series inhibited the growth of S. aureus, including MRSA strains, with minimal inhibitory concentrations (MICs) ranging from 6. 25–100 μg/mL. The antimicrobial activity showed selectivity against Gram-positive bacteria and fungi, but not Gram-negative bacteria. The series inhibited human HeLa cell proliferation. Lead development centering on the thiadiazolidinone series would require additional medicinal chemistry efforts to enhance the antibacterial activity and minimize mammalian cell toxicity. PMID:22146584
Assessment of antioxidant activity of spray dried extracts of Psidium guajava leaves by DPPH and chemiluminescence inhibition in human neutrophils.

PubMed

Fernandes, M R V; Azzolini, A E C S; Martinez, M L L; Souza, C R F; Lucisano-Valim, Y M; Oliveira, W P

2014-01-01

This work evaluated the physicochemical properties and antioxidant activity of spray dried extracts (SDE) from Psidium guajava L. leaves. Different drying carriers, namely, maltodextrin, colloidal silicon dioxide, Arabic gum, and β -cyclodextrin at concentrations of 40 and 80% relative to solids content, were added to drying composition. SDE were characterized through determination of the total phenolic, tannins, and flavonoid content. Antioxidant potential of the SDE was assessed by two assays: cellular test that measures the luminol-enhanced chemiluminescence (LumCL) produced by neutrophils stimulated with phorbol myristate acetate (PMA) and the DPPH radical scavenging (DPPH∗ method). In both assays the antioxidant activity of the SDE occurred in a concentration-dependent manner and showed no toxicity to the cells. Using the CLlum method, the IC50 ranged from 5.42 to 6.50 µg/mL. The IC50 of the SDE ranged from 7.96 to 8.11 µg/mL using the DPPH(•) method. Psidium guajava SDE presented significant antioxidant activity; thus they show high potential as an active phytopharmaceutical ingredient. Our findings in human neutrophils are pharmacologically relevant since they indicate that P. guajava SDE is a potential antioxidant and anti-inflammatory agent in human cells.
Assessment of Antioxidant Activity of Spray Dried Extracts of Psidium guajava Leaves by DPPH and Chemiluminescence Inhibition in Human Neutrophils

PubMed Central

Fernandes, M. R. V.; Azzolini, A. E. C. S.; Martinez, M. L. L.; Souza, C. R. F.; Lucisano-Valim, Y. M.; Oliveira, W. P.

2014-01-01

This work evaluated the physicochemical properties and antioxidant activity of spray dried extracts (SDE) from Psidium guajava L. leaves. Different drying carriers, namely, maltodextrin, colloidal silicon dioxide, Arabic gum, and β-cyclodextrin at concentrations of 40 and 80% relative to solids content, were added to drying composition. SDE were characterized through determination of the total phenolic, tannins, and flavonoid content. Antioxidant potential of the SDE was assessed by two assays: cellular test that measures the luminol-enhanced chemiluminescence (LumCL) produced by neutrophils stimulated with phorbol myristate acetate (PMA) and the DPPH radical scavenging (DPPH∗ method). In both assays the antioxidant activity of the SDE occurred in a concentration-dependent manner and showed no toxicity to the cells. Using the CLlum method, the IC50 ranged from 5.42 to 6.50 µg/mL. The IC50 of the SDE ranged from 7.96 to 8.11 µg/mL using the DPPH• method. Psidium guajava SDE presented significant antioxidant activity; thus they show high potential as an active phytopharmaceutical ingredient. Our findings in human neutrophils are pharmacologically relevant since they indicate that P. guajava SDE is a potential antioxidant and anti-inflammatory agent in human cells. PMID:24822200
Nitrifying bacterial biomass and nitrification activity evaluated by FISH and an automatic on-line instrument at full-scale Fusina (Venice, Italy) WWTP.

PubMed

Badoer, S; Miana, P; Della Sala, S; Marchiori, G; Tandoi, V; Di Pippo, F

2015-12-01

In this study, monthly variations in biomass of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) were analysed over a 1-year period by fluorescence in situ hybridization (FISH) at the full-scale Fusina WWTP. The nitrification capacity of the plant was also monitored using periodic respirometric batch tests and by an automated on-line titrimetric instrument (TITrimetric Automated ANalyser). The percentage of nitrifying bacteria in the plant was the highest in summer and was in the range of 10-15 % of the active biomass. The maximum nitrosation rate varied in the range 2.0-4.0 mg NH4 g(-1) VSS h(-1) (0.048-0.096 kg TKN kg(-1) VSS day(-1)): values obtained by laboratory measurements and the on-line instrument were similar and significantly correlated. The activity measurements provided a valuable tool for estimating the maximum total Kjeldahl nitrogen (TKN) loading possible at the plant and provided an early warning of whether the TKN was approaching its limiting value. The FISH analysis permitted determination of the nitrifying biomass present. The main operational parameter affecting both the population dynamics and the maximum nitrosation activity was mixed liquor volatile suspended solids (MLVSS) concentration and was negatively correlated with ammonia-oxidizing bacteria (AOB) (p = 0.029) and (NOB) (p = 0.01) abundances and positively correlated with maximum nitrosation rates (p = 0.035). Increases in concentrations led to decreases in nitrifying bacteria abundance, but their nitrosation activity was higher. These results demonstrate the importance of MLVSS concentration as key factor in the development and activity of nitrifying communities in wastewater treatment plants (WWTPs). Operational data on VSS and sludge volume index (SVI) values are also presented on 11-year basis observations.
Influence of tap water quality and household water use activities on indoor air and internal dose levels of trihalomethanes.

PubMed

Nuckols, John R; Ashley, David L; Lyu, Christopher; Gordon, Sydney M; Hinckley, Alison F; Singer, Philip

2005-07-01

Individual exposure to trihalomethanes (THMs) in tap water can occur through ingestion, inhalation, or dermal exposure. Studies indicate that activities associated with inhaled or dermal exposure routes result in a greater increase in blood THM concentration than does ingestion. We measured blood and exhaled air concentrations of THM as biomarkers of exposure to participants conducting 14 common household water use activities, including ingestion of hot and cold tap water beverages, showering, clothes washing, hand washing, bathing, dish washing, and indirect shower exposure. We conducted our study at a single residence in each of two water utility service areas, one with relatively high and the other low total THM in the residence tap water. To maintain a consistent exposure environment for seven participants, we controlled water use activities, exposure time, air exchange, water flow and temperature, and nonstudy THM sources to the indoor air. We collected reference samples for water supply and air (pre-water use activity), as well as tap water and ambient air samples. We collected blood samples before and after each activity and exhaled breath samples at baseline and post-activity. All hot water use activities yielded a 2-fold increase in blood or breath THM concentrations for at least one individual. The greatest observed increase in blood and exhaled breath THM concentration in any participant was due to showering (direct and indirect), bathing, and hand dishwashing. Average increase in blood THM concentration ranged from 57 to 358 pg/mL due to these activities. More research is needed to determine whether acute and frequent exposures to THM at these concentrations have public health implications. Further research is also needed in designing epidemiologic studies that minimize data collection burden yet maximize accuracy in classification of dermal and inhalation THM exposure during hot water use activities.
Neuromuscular performance of maximal voluntary explosive concentric contractions is influenced by angular acceleration.

PubMed

Hahn, D; Bakenecker, P; Zinke, F

2017-12-01

Torque production during maximal voluntary explosive contractions is considered to be a functionally more relevant neuromuscular measure than steady-state torque, but little is known about accelerated concentric contractions. This study investigated torque, muscle activity, and fascicle behavior during isometric and fast concentric contractions of quadriceps femoris. Ten participants performed maximal voluntary explosive isometric, isovelocity, and additional concentric knee extensions at angular accelerations ranging from 700 to 4000° s -2 that resulted in an angular velocity of 300° s -1 at 40° knee flexion. Concentric torque at 40° knee flexion was corrected for inertia, and the corresponding isometric torque was matched to the time when the target knee angle of 40° was reached during concentric contractions. Electromyography of quadriceps femoris and hamstrings and ultrasound of vastus lateralis were measured to determine muscle activity, fascicle length, and fascicle velocity (FV). The faster the acceleration, the more torque was produced during concentric contractions at 40° knee flexion, which was accompanied by a reduction in FV. In comparison with isometric conditions, concentric quadriceps muscle activity was increased and torque during accelerations ≥3000° s -2 equaled the time-matched isometric torque. Our results provide novel evidence that acceleration influences torque production during maximal voluntary explosive concentric contractions. This is suggested to be due to series elasticity and reduced force depression. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
A climatology of ⁷Be in surface air in European Union.

PubMed

Hernández-Ceballos, M A; Cinelli, G; Ferrer, M Marín; Tollefsen, T; De Felice, L; Nweke, E; Tognoli, P V; Vanzo, S; De Cort, M

2015-03-01

This study presents a European-wide analysis of the spatial and temporal distribution of the cosmogenic isotope (7)Be in surface air. This is the first time that a long term database of 34 sampling sites that regularly provide data to the Radioactivity Environmental Monitoring (REM) network, managed by the Joint Research Centre (JRC) in Ispra, is used. While temporal coverage varies between stations, some of them have delivered data more or less continuously from 1984 to 2011. The station locations were considerably heterogeneous, both in terms of latitude and altitude, a range which should ensure a high degree of representativeness of the results. The mean values of (7)Be activity concentration presented a spatial distribution value ranging from 2.0 to 5.4 mBq/m(3) over the European Union. The results of the ANOVA analysis of all (7)Be data available indicated that its temporal and spatial distributions were mainly explained by the location and characteristic of the sampling sites rather than its temporal distribution (yearly, seasonal and monthly). Higher (7)Be concentrations were registered at the middle, compared to high-latitude, regions. However, there was no correlation with altitude, since all stations are sited within the atmospheric boundary layer. In addition, the total and yearly analyses of the data indicated a dynamic range of (7)Be activity for each solar cycle and phase (maximum or minimum), different impact on stations having been observed according to their location. Finally, the results indicated a significant seasonal and monthly variation for (7)Be activity concentration across the European Union, with maximum concentrations occurring in the summer and minimum in the winter, although with differences in the values reached. The knowledge of the horizontal and vertical distribution of this natural radionuclide in the atmosphere is a key parameter for modelling studies of atmospheric processes, which are important phenomena to be taken into account in the case of a nuclear accident. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.
Mercury in fish of the Madeira river (temporal and spatial assessment), Brazilian Amazon.

PubMed

Bastos, Wanderley R; Dórea, José G; Bernardi, José Vicente E; Lauthartte, Leidiane C; Mussy, Marilia H; Lacerda, Luiz D; Malm, Olaf

2015-07-01

The Madeira River is the largest tributary of the Amazon River Basin and one of the most impacted by artisanal gold-mining activities, deforestation for agricultural projects, and recent hydroelectric reservoirs. Total Hg (and methylmercury-MeHg) concentrations was determined in 3182 fish samples of 84 species from different trophic levels as a function of standard size. Species at the top of the trophic level (Piscivorous, Carnivorous) showed the highest mean total Hg concentrations (51-1242 µg/kg), Planctivorous and Omnivorous species showed intermediate total Hg concentrations (26-494 µg/kg), while Detritivorous and Herbivorous species showed the lowest range of mean total Hg concentrations (9-275 µg/kg). Significant correlations between fish size (standard length) and total Hg concentrations were seen for Planctivorous (r=0.474, p=0.0001), Piscivorous (r=0.459, p=0.0001), Detritivorous (r=0.227, p=0.0001), Carnivorous (r=0.212, p=0.0001), and Herbivorous (r=0.156, p=0.01), but not for the Omnivorous species (r=-0.064, p=0.0685). Moreover, fish trophic levels influenced the ratio of MeHg to total Hg (ranged from 70% to 92%). When adjusted for standard body length, significant increases in Hg concentrations in the last 10 years were species specific. Spatial differences, albeit significant for some species, were not consistent with time trends for environmental contamination from past alluvial gold mining activities. Fish-Hg bioaccumulation is species specific but fish feeding strategies are the predominant influence in the fish-Hg bioaccumulation pattern. Copyright © 2015 Elsevier Inc. All rights reserved.
Volatile organic compounds in fourteen U.S. retail stores.

PubMed

Nirlo, E L; Crain, N; Corsi, R L; Siegel, J A

2014-10-01

Retail buildings have a potential for both short-term (customer) and long-term (occupational) exposure to indoor pollutants. However, little is known about volatile organic compound (VOC) concentrations in the retail sector and influencing factors, such as ventilation, in-store activities, and store type. We measured VOC concentrations and ventilation rates in 14 retail stores in Texas and Pennsylvania. With the exception of formaldehyde and acetaldehyde, VOCs were present in retail stores at concentrations well below health guidelines. Indoor formaldehyde concentrations ranged from 4.6 ppb to 67 ppb. The two mid-sized grocery stores in the sample had the highest levels of ethanol and acetaldehyde, with concentrations up to 2.6 ppm and 92 ppb, respectively, possibly due to the preparation of dough and baking activities. Indoor-to-outdoor concentration ratios indicated that indoor sources were the main contributors to indoor VOC concentrations for the majority of compounds. There was no strong correlation between ventilation and VOC concentrations across all stores. However, increasing the air exchange rates at two stores led to lower indoor VOC concentrations, suggesting that ventilation can be used to reduce concentrations for some specific stores. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Apple juice inhibits human low density lipoprotein oxidation.

PubMed

Pearson, D A; Tan, C H; German, J B; Davis, P A; Gershwin, M E

1999-01-01

Dietary phenolic compounds, ubiquitous in vegetables and fruits and their juices possess antioxidant activity that may have beneficial effects on human health. The phenolic composition of six commercial apple juices, and of the peel (RP), flesh (RF) and whole fresh Red Delicious apples (RW), was determined by high performance liquid chromatography (HPLC), and total phenols were determined by the Folin-Ciocalteau method. HPLC analysis identified and quantified several classes of phenolic compounds: cinnamates, anthocyanins, flavan-3-ols and flavonols. Phloridzin and hydroxy methyl furfural were also identified. The profile of phenolic compounds varied among the juices. The range of concentrations as a percentage of total phenolic concentration was: hydroxy methyl furfural, 4-30%; phloridzin, 22-36%; cinnamates, 25-36%; anthocyanins, n.d.; flavan-3-ols, 8-27%; flavonols, 2-10%. The phenolic profile of the Red Delicious apple extracts differed from those of the juices. The range of concentrations of phenolic classes in fresh apple extracts was: hydroxy methyl furfural, n.d.; phloridzin, 11-17%; cinnamates, 3-27%; anthocyanins, n.d.-42%; flavan-3-ols, 31-54%; flavonols, 1-10%. The ability of compounds in apple juices and extracts from fresh apple to protect LDL was assessed using an in vitro copper catalyzed human LDL oxidation system. The extent of LDL oxidation was determined as hexanal production using static headspace gas chromatography. The apple juices and extracts, tested at 5 microM gallic acid equivalents (GAE), all inhibited LDL oxidation. The inhibition by the juices ranged from 9 to 34%, and inhibition by RF, RW and RP was 21, 34 and 38%, respectively. Regression analyses revealed no significant correlation between antioxidant activity and either total phenolic concentration or any specific class of phenolics. Although the specific components in the apple juices and extracts that contributed to antioxidant activity have yet to be identified, this study found that both fresh apple and commercial apple juices inhibited copper-catalyzed LDL oxidation. The in vitro antioxidant activity of apples support the inclusion of this fruit and its juice in a healthy human diet.
Canine (Pet Dog) Tumor Microsurgery and Intratumoral Concentration and Safety of Metronomic Chlorambucil for Spontaneous Glioma: A Phase I Clinical Trial.

PubMed

Bentley, R Timothy; Thomovsky, Stephanie A; Miller, Margaret A; Knapp, Deborah W; Cohen-Gadol, Aaron A

2018-06-04

Metronomic (daily low-dose) chlorambucil requires further study before use in human patients with glioma. The aim of this study was to investigate distribution and safety of metronomic chlorambucil in naturally occurring canine glioma. Eight client-owned (pet) dogs with newly diagnosed spontaneous glioma were prospectively enrolled. Chlorambucil was administered preoperatively at 4 mg/m 2 every 24 hours for ≥3 days and continued postoperatively until death or dose-limiting adverse events. Chlorambucil concentrations in the surgical glioma specimen, cerebrospinal fluid, and serum were analyzed. Dogs additionally received lomustine postoperatively. Dogs were monitored for seizures, myoclonus, cytopenias, and tumor recurrence. Complete microsurgical resection was achieved in 7 oligodendrogliomas and 1 astrocytoma (6 high grade, 2 low grade). Median surgical glioma specimen chlorambucil concentration was 0.52 ng/g (range, 0-2.62 ng/g), or 37% (range, 0%-178%) of serum concentration. Median cerebrospinal fluid concentration was 0.1 ng/mL (range, 0-0.3 ng/mL). Chlorambucil was not associated with increase in seizure activity. Six dogs displayed prolonged seizure-free intervals. There was no myoclonus. Three dogs developed asymptomatic thrombocytopenia after 8-12 months of chlorambucil. Median progression-free survival was 253 days (range, 63-860 days). Median overall survival was 257 days (range, 64-860 days). The presence of intratumoral chlorambucil indicated an altered blood-brain barrier that varied from case to case. Despite sporadic previous reports of neurotoxicity, prolonged seizure-free intervals supported a high safety margin at this dose in this species. Metronomic chlorambucil was well tolerated. Spontaneous canine glioma offers a robust preclinical model. Copyright © 2018 Elsevier Inc. All rights reserved.
Critical Concentration of Lecithin Enhances the Antimicrobial Activity of Eugenol against Escherichia coli.

PubMed

Zhang, Haoshu; Dudley, Edward G; Davidson, P Michael; Harte, Federico

2017-04-15

Lecithin is a natural emulsifier used in a wide range of food and nonfood applications to improve physical stability, with no known bioactive effects. In this study, the effect of lecithin on the antimicrobial performance of a constant eugenol concentration was tested against three Escherichia coli strains (C600, 0.1229, and O157:H7 strain ATCC 700728). This is the first study, to our knowledge, focusing on lecithin at concentrations below those commonly used in foods to improve the stability of oil in water emulsions (≤10 mg/100 ml). For all three cultures, significant synergistic antimicrobial effects were observed when E. coli cultures were exposed to a constant eugenol concentration (ranging from 0.043 to 0.050% [wt/wt]) together with critical lecithin concentrations ranging from 0.5 to 1 mg/100 ml. Increasing the concentration of lecithin above 1 mg/100 ml (up to 10 mg/100 ml lecithin) diminished the antibacterial effect to values similar to those with eugenol-only treatments. The formation of aggregates (<100 nm) at the critical lecithin concentration was observed using cryo-transmission electron microscopy (cryo-TEM), together with a reduction in light absorbance at 284 nm. At critically low concentrations of lecithin, the formation of nanoscale aggregates is responsible for improving eugenol antimicrobial effects. IMPORTANCE Essential oils (EOs) are effective natural antimicrobials. However, their hydrophobicity and strong aromatic character limit the use of essential oils in food systems. Emulsifiers (e.g., lecithin) increase the stability of EOs in water-based systems but fail to consistently improve antimicrobial effects. We demonstrate that lecithin, within a narrow critical concentration window, can enhance the antimicrobial properties of eugenol. This study highlights the potential bioactivity of lecithin when utilized to effectively control foodborne pathogens. Copyright © 2017 American Society for Microbiology.
Evaluation of Serum 3-Bromotyrosine Concentrations in Dogs with Steroid-Responsive Diarrhea and Food-Responsive Diarrhea.

PubMed

Sattasathuchana, P; Allenspach, K; Lopes, R; Suchodolski, J S; Steiner, J M

2017-07-01

The clinical usefulness of serum 3-BrY concentrations for subclassifying dogs with food-responsive diarrhea (FRD) and steroid-responsive diarrhea (SRD) has not been studied. To compare serum 3-BrY concentrations in dogs with FRD, dogs with SRD, and healthy control dogs. 38 dogs with FRD, 14 dogs with SRD, and 46 healthy dogs. Prospective study. Measurement of 3-BrY concentration in serum samples was performed by gas chromatography/mass spectrometry. There was no association of peripheral eosinophilia in dogs with FRD, SRD, and healthy control dogs (P = 0.069). There was no significant correlation between peripheral eosinophil counts and serum 3-BrY concentrations (ρ = -0.15, P = 0.13). Serum 3-BrY concentrations in dogs with SRD (median [range] = 3.27, 0.9-26.23 μmol/L) were significantly higher than in dogs with FRD (median [range] = 0.99, 0.62-8.82 μmol/L; P = 0.007) or in healthy dogs (median [range] = 0.62, 0.62-1.79 μmol/L; P < 0.001). Also, serum 3-BrY concentrations in dogs with FRD were significantly higher than in healthy dogs (P = 0.025). There was no significant correlation between the canine chronic enteropathy clinical activity index and serum 3-BrY concentrations (ρ = 0.17, P = 0.23). Measurement of serum 3-BrY concentrations, but not the peripheral eosinophil count, is helpful for detecting dogs with SRD and FRD. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.
Critical Concentration of Lecithin Enhances the Antimicrobial Activity of Eugenol against Escherichia coli

PubMed Central

Zhang, Haoshu; Dudley, Edward G.; Davidson, P. Michael

2017-01-01

ABSTRACT Lecithin is a natural emulsifier used in a wide range of food and nonfood applications to improve physical stability, with no known bioactive effects. In this study, the effect of lecithin on the antimicrobial performance of a constant eugenol concentration was tested against three Escherichia coli strains (C600, 0.1229, and O157:H7 strain ATCC 700728). This is the first study, to our knowledge, focusing on lecithin at concentrations below those commonly used in foods to improve the stability of oil in water emulsions (≤10 mg/100 ml). For all three cultures, significant synergistic antimicrobial effects were observed when E. coli cultures were exposed to a constant eugenol concentration (ranging from 0.043 to 0.050% [wt/wt]) together with critical lecithin concentrations ranging from 0.5 to 1 mg/100 ml. Increasing the concentration of lecithin above 1 mg/100 ml (up to 10 mg/100 ml lecithin) diminished the antibacterial effect to values similar to those with eugenol-only treatments. The formation of aggregates (<100 nm) at the critical lecithin concentration was observed using cryo-transmission electron microscopy (cryo-TEM), together with a reduction in light absorbance at 284 nm. At critically low concentrations of lecithin, the formation of nanoscale aggregates is responsible for improving eugenol antimicrobial effects. IMPORTANCE Essential oils (EOs) are effective natural antimicrobials. However, their hydrophobicity and strong aromatic character limit the use of essential oils in food systems. Emulsifiers (e.g., lecithin) increase the stability of EOs in water-based systems but fail to consistently improve antimicrobial effects. We demonstrate that lecithin, within a narrow critical concentration window, can enhance the antimicrobial properties of eugenol. This study highlights the potential bioactivity of lecithin when utilized to effectively control foodborne pathogens. PMID:28213539
Efficient sorption of polyphenols to soybean flour enables natural fortification of foods

PubMed Central

Roopchand, Diana E.; Grace, Mary H.; Kuhn, Peter; Cheng, Diana M.; Plundrich, Nathalie; Poulev, Alexander; Howell, Amy; Fridlender, Bertold; Lila, Mary Ann; Raskin, Ilya

2013-01-01

The present study demonstrated that defatted soybean flour (DSF) can sorb polyphenols from blueberry and cranberry juices while separating them from sugars. Depending on DSF concentration and juice dilution, the concentration of blueberry anthocyanins and total polyphenols sorbed to DSF ranged from 2 – 22 mg/g and 10 – 95 mg/g, respectively while the concentration of anthocyanins and proanthocyanidins in cranberry polyphenol-enriched DSF ranged from 2.5 – 17 mg/g and 21 – 101 mg/g, respectively. Blueberry polyphenols present in one serving of fresh blueberries (73g) were delivered in just 1.4 g of blueberry polyphenol-enriched DSF. Similarly, one gram of cranberry polyphenol-enriched DSF delivered the amount of proanthocyanidins available in three 240 ml servings of cranberry juice cocktail. The concentration of blueberry anthocyanins and total polyphenols eluted from DSF remained constant after 22 weeks of incubation at 37°C, demonstrating the high stability of the polyphenol-DSF matrix. LC-MS analysis of eluates confirmed DSF retained major cranberry and blueberry polyphenols remained intact. Blueberry polyphenol-enriched DSF exhibited significant hypoglycemic activities in C57bl/6J mice, and cranberry polyphenol-enriched DSF showed anti-microbial and anti-UTI activities in vitro, confirming its efficacy. The described sorption process provides a means to create protein-rich food ingredients containing concentrated plant bioactives without excess sugars, fats and water that can be incorporated in a variety of scientifically validated functional foods and dietary supplements. PMID:23950619
Efficient sorption of polyphenols to soybean flour enables natural fortification of foods.

PubMed

Roopchand, Diana E; Grace, Mary H; Kuhn, Peter; Cheng, Diana M; Plundrich, Nathalie; Poulev, Alexander; Howell, Amy; Fridlender, Bertold; Lila, Mary Ann; Raskin, Ilya

2012-04-15

The present study demonstrated that defatted soybean flour (DSF) can sorb polyphenols from blueberry and cranberry juices while separating them from sugars. Depending on DSF concentration and juice dilution, the concentration of blueberry anthocyanins and total polyphenols sorbed to DSF ranged from 2 - 22 mg/g and 10 - 95 mg/g, respectively while the concentration of anthocyanins and proanthocyanidins in cranberry polyphenol-enriched DSF ranged from 2.5 - 17 mg/g and 21 - 101 mg/g, respectively. Blueberry polyphenols present in one serving of fresh blueberries (73g) were delivered in just 1.4 g of blueberry polyphenol-enriched DSF. Similarly, one gram of cranberry polyphenol-enriched DSF delivered the amount of proanthocyanidins available in three 240 ml servings of cranberry juice cocktail. The concentration of blueberry anthocyanins and total polyphenols eluted from DSF remained constant after 22 weeks of incubation at 37°C, demonstrating the high stability of the polyphenol-DSF matrix. LC-MS analysis of eluates confirmed DSF retained major cranberry and blueberry polyphenols remained intact. Blueberry polyphenol-enriched DSF exhibited significant hypoglycemic activities in C57bl/6J mice, and cranberry polyphenol-enriched DSF showed anti-microbial and anti-UTI activities in vitro, confirming its efficacy. The described sorption process provides a means to create protein-rich food ingredients containing concentrated plant bioactives without excess sugars, fats and water that can be incorporated in a variety of scientifically validated functional foods and dietary supplements.
N-nitrosodimethylamine (NDMA) removal by reverse osmosis and UV treatment and analysis via LC-MS/MS.

PubMed

Plumlee, Megan H; López-Mesas, Montserrat; Heidlberger, Andy; Ishida, Kenneth P; Reinhard, Martin

2008-01-01

N-nitrosodimethylamine (NDMA) is a probable human carcinogen found in ng/l concentrations in chlorinated and chloraminated water. A method was developed for the determination of ng/l levels of NDMA using liquid chromatography-tandem mass spectrometry (LC-MS/MS) preceded by sample concentration via solid-phase extraction with activated charcoal. Recoveries were greater than 90% and allowed a method reporting limit as low as 2ng/l. Using this method, the removal of NDMA was determined for the Interim Water Purification Facility (IWPF), an advanced wastewater treatment facility operated by the Orange County Water District (OCWD) in Southern California. The facility treats effluent from an activated sludge treatment plant with microfiltration (MF), reverse osmosis (RO), and an ultraviolet-hydrogen peroxide advanced oxidation process (UV-AOP). Six nitrosamines were surveyed: NDMA, N-nitrosomethylethylamine (NMEA), N-nitrosodiethylamine (NDEA), N-nitrosodi-n-propylamine (NDPA), N-nitrosopiperidine (NPip), and N-nitrosopyrrolidine (NPyr). Only NDMA was detected and at all treatment steps in the IWPF, with influent concentrations ranging from 20 to 59 ng/l. Removals for RO and UV ranged from 24% to 56% and 43% to 66%, respectively. Overall, 69+/-7% of the original NDMA concentration was removed from the product water across the advanced treatment process and, in combination with blending, the final concentration did not exceed the California drinking water notification level of 10 ng/l. NDMA removal data are consistent with findings reviewed for other advanced treatment facilities and laboratory studies.
Dynamics of reactive microbial hotspots in concentration gradients

NASA Astrophysics Data System (ADS)

Hubert, Antoine; Farasin, Julien; Tabuteau, Hervé; Méheust, Yves; Le Borgne, Tanguy

2017-04-01

In subsurface environments, bacteria play a major role in controlling the kinetics of a broad range of biogeochemical reactions. In such environments, nutrients fluxes and solute concentrations needed for bacteria metabolism may be highly variable in space and intermittent in time. This can lead to the formation of reactive hotspots where and when conditions are favorable to particular microorganisms, hence inducing biogeochemical reaction kinetics that differ significantly from those measured in homogeneous model environments. To investigate the impact of chemical gradients on the spatial structure and temporal dynamics of subsurface microorganism populations, we develop microfluidic cells allowing for a precise control of flow and chemical gradient conditions, as well as a quantitative monitoring of the bacteria's spatial distribution and biofilm development. Using the non-motile Escherichia coli JW1908-1 strain and Gallionella as model organisms, we investigate the behavior and development of bacteria over a range of single and double concentration gradients in the concentrations of nutrients, electron donors and electron acceptors. To quantify bacterial activity we use Fluorescein Diacetate (FDA) hydrolysis by bacterial enzymes which transforms FDA into Fluorescein, whose local concentration is measured optically. We thus measure bacterial activity locally from the time derivative of the measured fluorescence. This approach allows time-resolved monitoring of the location and intensity of reactive hotspots in micromodels as a function of the flow and chemical gradient conditions. We discuss consequences for the formation and temporal dynamics of biofilms in the subsurface.

Antibacterial activity of Hylomecon hylomeconoides against methicillin-resistant Staphylococcus aureus.

PubMed

Choi, Jang-Gi; Kang, Ok-Hwa; Chae, Hee-Sung; Obiang-Obounou, Brice; Lee, Young-Seob; Oh, You-Chang; Kim, Min-San; Shin, Dong-Won; Kim, Jeong-Ah; Kim, Young-Ho; Kwon, Dong-Yeul

2010-04-01

Methicillin-resistant Staphylococcus aureus (MRSA) is serious clinical urgent problems worldwide. In the present study, the antibacterial activity of Hylomecon hylomeconoides was investigated. The EtOH extract and its fraction (n-hexane, CH(2)Cl(2), EtOAc, and H(2)O) were investigated against MRSA. The most active extract (CH(2)Cl(2)) led to the isolation of 6-methoxydihydrosanguinarine (6-MS), 6-acetonylhydrosanguinarine, and dihydrosanguinarine. These compounds were very active against MRSA strains with minimum inhibitory concentrations (MICs) ranging from 1.95 to 250 microg/ml. Our study did however focus on 6-MS as it appeared to be the most active with MICs in the range of 1.9 to 3.9 microg/ml. These results encourage us to think that 6-MS can be used as a natural antibacterial agent.
Mycophenolic acid exposure and complement fraction C3 influence inosine 5'-monophosphate dehydrogenase activity in systemic lupus erythematosus.

PubMed

Mino, Yasuaki; Naito, Takafumi; Shimoyama, Kumiko; Ogawa, Noriyoshi; Kawakami, Junichi

2017-07-01

Background Mycophenolate mofetil has recently been reported to be effective against systemic lupus erythematosus. The influence of the pharmacokinetics of mycophenolic acid, the active form of mycophenolate mofetil and the major inactive mycophenolic acid phenolic glucuronide on the activity of the target enzyme inosine 5'-monophosphate dehydrogenase, is expected to be revealed. The aim of this study was to identify the factors associated with inosine 5'-monophosphate dehydrogenase activity in systemic lupus erythematosus patients. Methods Fifty systemic lupus erythematosus patients in remission maintenance phase (29 received mycophenolate mofetil [MMF+] and 21 did not [MMF-]) were enrolled. Median and interquartile range of dose of mycophenolate mofetil were 1500 and 1000-1500 mg/day, respectively. Stepwise multiple linear regression analysis was performed to assess the dependence between inosine 5'-monophosphate dehydrogenase activity and 25 predictor values including predose plasma concentrations of free mycophenolic acid and mycophenolic acid phenolic glucuronide. Results Median and interquartile range of predose total plasma concentrations of mycophenolic acid and mycophenolic acid phenolic glucuronide were 2.73 and 1.43-5.73 and 25.5 and 13.1-54.7 µg/mL, respectively. Predose inosine 5'-monophosphate dehydrogenase activity was significantly higher in MMF+ than MMF- patients (median 38.3 and 20.6 nmoL xanthosine 5'-monophosphate/g haemoglobin/h, P<0.01). The plasma concentration of free mycophenolic acid phenolic glucuronide, complement fraction C3 and body weight were significant predictors accounting for interindividual variability in the inosine 5'-monophosphate dehydrogenase activity (adjusted R 2 = 0.52, P < 0.01) in a multivariate analysis. Conclusions Predose inosine 5'-monophosphate dehydrogenase activity was higher in systemic lupus erythematosus patients receiving mycophenolate mofetil therapy. Inosine 5'-monophosphate dehydrogenase activity may be determined by mycophenolic acid exposure and complement fraction C3 in systemic lupus erythematosus patients.
An analysis of nitrification during the aerobic digestion of secondary sludges.

PubMed

Bhargava, D S; Datar, M T

1989-01-01

Investigations were undertaken to study the occurrence and progress of nitrification during aerobic digestion of activated sludge in a wide range of initial concentrations of total solids (1000 to 80 000 mg litre(-1), initial pH range of 4.5 to 10.4 and digestion temperature range of 5 degrees to 60 degrees C. Batch aerobic digestion studies on activated sludge grown on wastewater (enriched with organic solids from human excretal material) indicate that almost complete elimination of the 'biodegradable' matter of the activated sludge was one of the essential prerequisites to initiate nitrification. Favourable ranges of temperature and pH for nitrification were observed to be 25 degrees to 30 degrees C and 6.0 to 8.3, respectively. With all favourable conditions, a minimum period of about 2 days was necessary for population build-up of genera Nitrosomonas and Nitrobacter, and to initiate nitrification. Nitrate formation invariably lagged behind nitrite formation, but under certain conditions both phases of nitrification were observed to progress hand in hand.
Tracking human footprints in Antarctica through passive sampling of polycyclic aromatic hydrocarbons in inland lakes.

PubMed

Yao, Yao; Meng, Xiang-Zhou; Wu, Chen-Chou; Bao, Lian-Jun; Wang, Feng; Wu, Feng-Chang; Zeng, Eddy Y

2016-06-01

Freely dissolved polycyclic aromatic hydrocarbons (PAHs) were monitored in seven inland lakes of Antarctica by a polyethylene (PE)-based passive sampling technique, with the objective of tracking human footprints. The measured concentrations of PAHs were in the range of 14-360 ng L(-1) with the highest values concentrated around the Russian Progress II Station, indicating the significance of human activities to the loading of PAHs in Antarctica. The concentrations of PAHs in the inland lakes were in the upper part of the PAHs levels in aquatic environments from remote and background regions across the globe. The composition profiles of PAHs indicated that PAHs in the inland lakes were derived mainly from local oil spills, which was corroborated by a large number of fuel spillage reports from ship and plane crash incidents in Antarctica during recent years. Clearly, local human activities, rather than long-range transport, are the dominant sources of PAH contamination to the inland lakes. Finally, the present study demonstrates the efficacy of PE-based passive samplers for investigating PAHs in the aquatic environment of Antarctica under complex field conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.
Determination of 210Pb concentration in NORM waste - An application of the transmission method for self-attenuation corrections for gamma-ray spectrometry

NASA Astrophysics Data System (ADS)

Bonczyk, Michal

2018-07-01

This article deals with the problem of the self-attenuation of low-energy gamma-rays from the isotope of lead 210Pb (46.5 keV) in industrial waste. The 167 samples of industrial waste, belonging to nine categories, were tested by means of gamma spectrometry in order to determine 210Pb activity concentration. The experimental method for self-attenuation corrections for gamma rays emitted by lead isotope was applied. Mass attenuation coefficients were determined for energy of 46.5 keV. Correction factors were calculated based on mass attenuation coefficients, sample density and thickness. A mathematical formula for correction calculation was evaluated. The 210Pb activity concentration obtained varied in the range from several Bq·kg-1 up to 19,810 Bq kg-1. The mass attenuation coefficients varied across the range of 0.19-4.42 cm2·g-1. However, the variation of mass attenuation coefficient within some categories of waste was relatively small. The calculated corrections for self-attenuation were 0.98 - 6.97. The high value of correction factors must not be neglect in radiation risk assessment.
Amphibian antimicrobial peptide fallaxin analogue FL9 affects virulence gene expression and DNA replication in Staphylococcus aureus.

PubMed

Gottschalk, Sanne; Gottlieb, Caroline T; Vestergaard, Martin; Hansen, Paul R; Gram, Lone; Ingmer, Hanne; Thomsen, Line E

2015-12-01

The rapid rise in antibiotic-resistant pathogens is causing increased health concerns, and consequently there is an urgent need for novel antimicrobial agents. Antimicrobial peptides (AMPs), which have been isolated from a wide range of organisms, represent a very promising class of novel antimicrobials. In the present study, the analogue FL9, based on the amphibian AMP fallaxin, was studied to elucidate its mode of action and antibacterial activity against the human pathogen Staphylococcus aureus. Our data showed that FL9 may have a dual mode of action against S. aureus. At concentrations around the MIC, FL9 bound DNA, inhibited DNA synthesis and induced the SOS DNA damage response, whereas at concentrations above the MIC the interaction between S. aureus and FL9 led to membrane disruption. The antibacterial activity of the peptide was maintained over a wide range of NaCl and MgCl(2) concentrations and at alkaline pH, while it was compromised by acidic pH and exposure to serum. Furthermore, at subinhibitory concentrations of FL9, S. aureus responded by increasing the expression of two major virulence factor genes, namely the regulatory rnaIII and hla, encoding α-haemolysin. In addition, the S. aureus-encoded natural tolerance mechanisms included peptide cleavage and the addition of positive charge to the cell surface, both of which minimized the antimicrobial activity of FL9. Our results add new information about FL9 and its effect on S. aureus, which may aid in the future development of analogues with improved therapeutic potential.
Krypton and Xenon Radionuclides Monitoring in the Northwest Region of Russia

NASA Astrophysics Data System (ADS)

Dubasov, Yuri V.; Okunev, Nikolay S.

2010-05-01

Monitoring of Xe and Kr radionuclides was conducted from August 2006 to 30 July 2008 within the framework of ISTC Project #2133. Cherepovets City in Vologda Province and St. Petersburg were chosen as monitoring locations. Kr-Xe concentrate samples were obtained as a result of processing of several thousand m3 of atmospheric air. New results of 85Kr monitoring show, that for last 15 years, the 85Kr volumetric activity in the atmospheric air of the northwest region of Russia has increased approximately 50% and has achieved a level of 1.5 Bq/m3. This value correlates well with similar data for Western Europe and Japan. The xenon fraction (80-160 cm3 under STP) is adsorbed on charcoal in the ampoule, which is measured in the well of HPGe gamma detector. Minimum detectable concentration (MDC) of 133Xe for this technique is 0.008 mBq/m3, and it is the most sensitive method used today. The 133Xe concentration in the atmospheric air of Cherepovets City varied in the monitoring period ranging from 0.09 to 2.5 mBq/m3. During the period of March 2007-30 July 2008, 133Xe activity concentration in the atmospheric air of St. Petersburg changed from background values (0.2-0.3 mBq/m3) to 185 mBq/m3 and for approximately 20% of the samples 135Xe was also measured with the 135Xe/133Xe activity ratio varied within the range of 0.03-3.5.
Atmospheric Ice-Nucleating Particles in the Dusty Tropical Atlantic

NASA Astrophysics Data System (ADS)

Price, H. C.; Baustian, K. J.; McQuaid, J. B.; Blyth, A.; Bower, K. N.; Choularton, T.; Cotton, R. J.; Cui, Z.; Field, P. R.; Gallagher, M.; Hawker, R.; Merrington, A.; Miltenberger, A.; Neely, R. R., III; Parker, S. T.; Rosenberg, P. D.; Taylor, J. W.; Trembath, J.; Vergara-Temprado, J.; Whale, T. F.; Wilson, T. W.; Young, G.; Murray, B. J.

2018-02-01

Desert dust is one of the most important atmospheric ice-nucleating aerosol species around the globe. However, there have been very few measurements of ice-nucleating particle (INP) concentrations in dusty air close to desert sources. In this study we report the concentration of INPs in dust laden air over the tropical Atlantic within a few days' transport of one of the world's most important atmospheric sources of desert dust, the Sahara. These measurements were performed as part of the Ice in Clouds Experiment-Dust campaign based in Cape Verde, during August 2015. INP concentrations active in the immersion mode, determined using a droplet-on-filter technique, ranged from around 102 m-3 at -12°C to around 105 m-3 at -23°C. There is about 2 orders of magnitude variability in INP concentration for a particular temperature, which is determined largely by the variability in atmospheric dust loading. These measurements were made at altitudes from 30 to 3,500 m in air containing a range of dust loadings. The ice active site density (ns) for desert dust dominated aerosol derived from our measurements agrees with several laboratory-based parameterizations for ice nucleation by desert dust within 1 to 2 orders of magnitude. The small variability in ns values determined from our measurements (within about 1 order of magnitude) is striking given that the back trajectory analysis suggests that the sources of dust were geographically diverse. This is consistent with previous work, which indicates that desert dust's ice-nucleating activity is only weakly dependent on source.
Radioactivity in three species of eastern Mediterranean jellyfish.

PubMed

Mamish, S; Al-Masri, M S; Durgham, H

2015-11-01

Activity concentrations of (137)Cs, (40)K, (210)Po, (210)Pb, (234)U and (238)U were determined in umbrella and oral arms of three widely distributed jellyfish species; namely Rhopilema nomadica Galil, 1990, Aurelia aurita Linne, 1758 and Aequorea forskalea Péron & Lesueur, 1810 collected from February 2011 to January 2012 in four sampling locations along the Syrian coast (Eastern Mediterranean Sea). The results have shown significant variations in radionuclides activity concentrations amongst the species. The average activity concentrations of (40)K, (210)Po, (210)Pb, (234)U and (238)U in the umbrella of R. nomadica species were higher than the average activity concentrations in the umbrella of A. aurita species by about 3.2, 1.4, 1.8, 3.2 and 3.2 folds, and A. forskalea species by about 45.5, 15.4, 19, 7.4 and 7.6 folds, respectively. The average activity concentrations of (40)K, (210)Po, (210)Pb, (234)U and (238)U in oral arms of R. nomadica species were higher than the average activity concentrations in oral arms of A. aurita species by about 3.8, 1.7, 1.9, 2.8 and 2.9 folds, respectively. (137)Cs activity concentrations were below the detection limit in all measured samples. In addition, activity concentrations of (137)Cs, (40)K, (210)Po, (210)Pb, (234)U and (238)U were also determined in 44 surface seawater samples and the activity concentrations ranged between 10.6 and 11.9 Bq l(-1) for (40)K, 1.1 and 1.4 mBq l(-1) for (210)Po, 0.5 and 0.7 mBq l(-1) for (210)Pb, 40.8 and 44.5 mBq l(-1) for (234)U, and 36.9 and 38.4 mBq l(-1) for (238)U, while (137)Cs activity concentrations were below the detection limit in all measured samples. Moreover, the umbrella and oral arms readily accumulated (40)K, (210)Po, (210)Pb, (234)U and (238)U above ambient seawater levels in the sequence of (210)Po > (210)Pb > (4) K > (234)U and (238)U. Concentration ratio (CR) values were relatively high for (210)Po and (210)Pb and reached 10(3) and 10(2), respectively for the jellyfish R. nomadica species compared to A. aurita and A. forskalea species. Therefore, R. nomadica can be used as biomonitor for these two radionuclides in the Eastern Mediterranean Sea. However, the obtained data can be considered the first reported baseline values for radioactivity in jellyfish. Copyright © 2015 Elsevier Ltd. All rights reserved.
Virtual screening of a milk peptide database for the identification of food-derived antimicrobial peptides.

PubMed

Liu, Yufang; Eichler, Jutta; Pischetsrieder, Monika

2015-11-01

Milk provides a wide range of bioactive substances, such as antimicrobial peptides and proteins. Our study aimed to identify novel antimicrobial peptides naturally present in milk. The components of an endogenous bovine milk peptide database were virtually screened for charge, amphipathy, and predicted secondary structure. Thus, 23 of 248 screened peptides were identified as candidates for antimicrobial effects. After commercial synthesis, their antimicrobial activities were determined against Escherichia coli NEB5α, E. coli ATCC25922, and Bacillus subtilis ATCC6051. In the tested concentration range (<2 mM), bacteriostatic activity of 14 peptides was detected including nine peptides inhibiting both Gram-positive and Gram-negative bacteria. The most effective fragment was TKLTEEEKNRLNFLKKISQRYQKFΑLPQYLK corresponding to αS2 -casein151-181 , with minimum inhibitory concentration (MIC) of 4.0 μM against B. subtilis ATCC6051, and minimum inhibitory concentrations of 16.2 μM against both E. coli strains. Circular dichroism spectroscopy revealed conformational changes of most active peptides in a membrane-mimic environment, transitioning from an unordered to α-helical structure. Screening of food peptide databases by prediction tools is an efficient method to identify novel antimicrobial food-derived peptides. Milk-derived antimicrobial peptides may have potential use as functional food ingredients and help to understand the molecular mechanisms of anti-infective milk effects. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
CO2, NOx, and particle emissions from aircraft and support activities at a regional airport.

PubMed

Klapmeyer, Michael E; Marr, Linsey C

2012-10-16

The goal of this research was to quantify emissions of carbon dioxide (CO(2)), nitrogen oxides (NO(x)), particle number, and black carbon (BC) from in-use aircraft and related activity at a regional airport. Pollutant concentrations were measured adjacent to the airfield and passenger terminal at the Roanoke Regional Airport in Virginia. Observed NO(x) emission indices (EIs) for jet-powered, commuter aircraft were generally lower than those contained in the International Civil Aviation Organization databank for both taxi (same as idle) and takeoff engine settings. NO(x) EIs ranged from 1.9 to 3.7 g (kg fuel)(-1) across five types of aircraft during taxiing, whereas EIs were consistently higher, 8.8-20.6 g (kg fuel)(-1), during takeoff. Particle number EIs ranged from 1.4 × 10(16) to 7.1 × 10(16) (kg fuel)(-1) and were slightly higher in taxi mode than in takeoff mode for four of the five types of aircraft. Diurnal patterns in CO(2) and NO(x) concentrations were influenced mainly by atmospheric conditions, while patterns in particle number concentrations were attributable mainly to patterns in aircraft activity. CO(2) and NO(x) fluxes measured by eddy covariance were higher at the terminal than at the airfield and were lower than found in urban areas.
Antibacterial, antifungal, and antiviral effects of three essential oil blends.

PubMed

Brochot, Amandine; Guilbot, Angèle; Haddioui, Laïla; Roques, Christine

2017-08-01

New agents that are effective against common pathogens are needed particularly for those resistant to conventional antimicrobial agents. Essential oils (EOs) are known for their antimicrobial activity. Using the broth microdilution method, we showed that (1) two unique blends of Cinnamomum zeylanicum, Daucus carota, Eucalyptus globulus and Rosmarinus officinalis EOs (AB1 and AB2; cinnamon EOs from two different suppliers) were active against the fourteen Gram-positive and -negative bacteria strains tested, including some antibiotic-resistant strains. Minimal inhibitory concentrations (MICs) ranged from 0.01% to 3% v/v with minimal bactericidal concentrations from <0.01% to 6.00% v/v; (2) a blend of Cinnamomum zeylanicum, Daucus carota, Syzygium aromaticum, Origanum vulgare EOs was antifungal to the six Candida strains tested, with MICs ranging from 0.01% to 0.05% v/v with minimal fungicidal concentrations from 0.02% to 0.05% v/v. Blend AB1 was also effective against H1N1 and HSV1 viruses. With this dual activity, against H1N1 and against S. aureus and S. pneumoniae notably, AB1 may be interesting to treat influenza and postinfluenza bacterial pneumonia infections. These blends could be very useful in clinical practice to combat common infections including those caused by microorganisms resistant to antimicrobial drugs. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.
210Po and 210Pb Activity Concentrations in Cigarettes Produced in Vietnam and Their Estimated Dose Contribution Due to Smoking

NASA Astrophysics Data System (ADS)

Tran, Thuy-Ngan N.; Le, Cong-Hao; Chau, Van-Tao

Smoking cigarettes contributes significantly to the increase of radiation in human body because 210Po and 210Pb exist relatively high in tobacco leaves. Therefore, these two radioisotopes in eighteen of the most frequently sold cigarette brands produced in Vietnam were examined in this study. 210Po was determined by alpha spectroscopy using a passivated implanted planar silicon (PIPS) detector after a procedure including radiochemical separation and spontaneous deposition of polonium on a copper disc (the deposition efficiency of 210Po on a copper disc was approximately 94%). Sequentially, 210Pb was determined through the ingrowth of 210Po after storing the sample solutions for approximately six months. The activity concentrations of 210Po in cigarettes ranged from 13.8 to 82.6 mBq/cigarette (the mean value was 26.4 mBq/cigarette) and the activity concentrations of 210Pb in cigarettes ranged from 13.9 to 78.8 mBq/cigarette (the mean value was 25.8 mBq/cigarette). The annual committed effective dose for smokers who smoke one pack per day was also estimated to be 295.4 µSv/year (223.0 µSv/year and 72.4 µSv/year from 210Po and 210Pb, respectively). These indicated that smoking increased the risk of developing lung cancer was approximately 60 times greater for smokers than for non-smokers.
Biphasic Elimination of Tenofovir Diphosphate and Nonlinear Pharmacokinetics of Zidovudine Triphosphate in a Microdosing Study

PubMed Central

Chen, Jianmeng; Flexner, Charles; Liberman, Rosa G.; Skipper, Paul L.; Louissaint, Nicolette; Tannenbaum, Steven R.; Hendrix, Craig; Fuchs, Edward

2012-01-01

Objective Phase 0 studies can provide initial pharmacokinetics (PK) data in humans and help to facilitate early drug development, but their predictive value for standard dosing is controversial. To evaluate the prediction of microdosing for active intracellular drug metabolites, we compared the PK profile of two antiretroviral drugs, zidovudine (ZDV) and tenofovir (TFV), in microdose and standard dosing regimens. Study Design We administered a microdose (100 μg) of 14C-labeled drug (ZDV or tenofovir disoproxil fumarate (TDF)) with or without a standard unlabelled dose (300 mg) to healthy volunteers. Both the parent drug in plasma and the active metabolite, ZDV-triphosphate (ZDV-TP) or TFV-diphosphate (TFV-DP) in PBMCs and CD4+ cells were measured by AMS. Results The intracellular ZDV-TP concentration increased less than proportionally over the dose range studied (100 μg to 300 mg), while the intracellular TFV-DP PK were linear over the same dose range. ZDV-TP concentrations were lower in CD4+ cells versus total peripheral blood mononuclear cells (PBMCs), while TFV-DP concentrations were not different in CD4+ cells and PBMCs. Conclusion Our data were consistent with a rate-limiting step in the intracellular phosphorylation of ZDV but not TFV. AMS shows promise for predicting the PK of active intracellular metabolites of nucleosides, but nonlinearity of PK may be seen with some drugs. PMID:23187888
Impurity effect of iron(III) on the growth of potassium sulfate crystal in aqueous solution

NASA Astrophysics Data System (ADS)

Kubota, Noriaki; Katagiri, Ken-ichi; Yokota, Masaaki; Sato, Akira; Yashiro, Hitoshi; Itai, Kazuyoshi

1999-01-01

Growth rates of the {1 1 0} faces of a potassium sulfate crystal were measured in a flow cell in the presence of traces of impurity Fe(III) (up to 2 ppm) over the range of pH=2.5-6.0. The growth rate was significantly suppressed by the impurity. The effect became stronger as the impurity concentration was increased and at pH<5. It became weaker with increasing supersaturation. It also became weaker as the pH was increased and at pH>5 it finally disappeared completely. The concentration and supersaturation effects on the impurity action were reasonably explained with a model proposed by Kubota and Mullin [J. Crystal Growth, 152 (1995) 203]. The surface coverage of the active sites by Fe(III) is estimated to increase linearly on increasing its concentration in solution in the range examined by growth experiments. The impurity effectiveness factor is confirmed to increase inversely proportional to the supersaturation as predicted by the model. Apart from the discussion based on the model, the pH effect on the impurity action is qualitatively explained by assuming that the first hydrolysis product of aqua Fe(III) complex compound, [Fe(H 2O) 5(OH)] 2+, is both growth suppression and adsorption active, but the second hydrolysis product, [Fe(H 2O) 4(OH) 2] +, is only adsorption active.
Shallow groundwater quality and geochemistry in the Fayetteville Shale gas-production area, north-central Arkansas, 2011

USGS Publications Warehouse

Kresse, Timothy M.; Warner, Nathaniel R.; Hays, Phillip D.; Down, Adrian; Vengosh, Avner; Jackson, Robert B.

2012-01-01

The Mississippian Fayetteville Shale serves as an unconventional gas reservoir across north-central Arkansas, ranging in thickness from approximately 50 to 550 feet and varying in depth from approximately 1,500 to 6,500 feet below the ground surface. Primary permeability in the Fayetteville Shale is severely limited, and successful extraction of the gas reservoir is the result of advances in horizontal drilling techniques and hydraulic fracturing to enhance and develop secondary fracture porosity and permeability. Drilling and production of gas wells began in 2004, with a steady increase in production thereafter. As of April 2012, approximately 4,000 producing wells had been completed in the Fayetteville Shale. In Van Buren and Faulkner Counties, 127 domestic water wells were sampled and analyzed for major ions and trace metals, with a subset of the samples analyzed for methane and carbon isotopes to describe general water quality and geochemistry and to investigate the potential effects of gas-production activities on shallow groundwater in the study area. Water-quality analyses from this study were compared to historical (pregas development) shallow groundwater quality collected in the gas-production area. An additional comparison was made using analyses from this study of groundwater quality in similar geologic and topographic areas for well sites less than and greater than 2 miles from active gas-production wells. Chloride concentrations for the 127 groundwater samples collected for this study ranged from approximately 1.0 milligram per liter (mg/L) to 70 mg/L, with a median concentration of 3.7 mg/L, as compared to maximum and median concentrations for the historical data of 378 mg/L and 20 mg/L, respectively. Statistical analysis of the data sets revealed statistically larger chloride concentrations (p-value <0.001) in the historical data compared to data collected for this study. Chloride serves as an important indicator parameter based on its conservative transport characteristics and relatively elevated concentrations in production waters associated with gas extraction activities. Major ions and trace metals additionally had lower concentrations in data gathered for this study than in the historical analyses. Additionally, no statistical difference existed between chloride concentrations from water-quality data collected for this study from 94 wells located less than 2 miles from a gas-production well and 33 wells located 2 miles or more from a gas-production well; a Wilcoxon rank-sum test showed a p-value of 0.71. Major ion chemistry was investigated to understand the effects of geochemical and reduction-oxidation (redox) processes on the shallow groundwater in the study area along a continuum of increased rock-water interaction represented by increases in dissolved solids concentration. Groundwater in sandstone formations is represented by a low dissolved solids concentration (less than 30 mg/L) and slightly acidic water type. Shallow shale aquifers were represented by dissolved solids concentrations ranging upward to 686 mg/L, and water types evolving from a dominantly mixed-bicarbonate and calcium-bicarbonate to a strongly sodium-bicarbonate water type. Methane concentration and carbon isotopic composition were analyzed in 51 of the 127 samples collected for this study. Methane occurred above a detection limit of 0.0002 mg/L in 32 of the 51 samples, with concentrations ranging upward to 28.5 mg/L. Seven samples had methane concentrations greater than or equal to 0.5 mg/L. The carbon isotopic composition of these higher concentration samples, including the highest concentration of 28.5 mg/L, shows the methane was likely biogenic in origin with carbon isotope ratio values ranging from -57.6 to -74.7 per mil. Methane concentrations increased with increases in dissolved solids concentrations, indicating more strongly reducing conditions with increasing rock-water interaction in the aquifer. As such, groundwater-quality data collected for this study indicate that groundwater chemistry in the shallow aquifer system in the study area is a result of natural processes, beginning with recharge of dilute atmospheric precipitation and evolution of observed groundwater chemistry through rock-water interaction and redox processes.
Evaluation of cytotoxicity, immune compatibility and antibacterial activity of biogenic silver nanoparticles.

PubMed

Składanowski, M; Golinska, P; Rudnicka, K; Dahm, H; Rai, M

2016-12-01

The study was focused on assessment of antibacterial activity, cytotoxicity and immune compatibility of biogenic silver nanoparticles (AgNPs) synthesized from Streptomyces sp. NH28 strain. Nanoparticles were biosynthesized and characterized by UV-Vis spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, nanoparticle tracking analysis system and zeta potential. Antibacterial activity was tested against Gram-positive and Gram-negative bacteria; minimal inhibitory concentration was recorded. Cytotoxicity was estimated using L929 mouse fibroblasts via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test. Biocompatibility of AgNPs was performed using THP1-XBlue™ cells. Biogenic AgNPs presented high antibacterial activity against all tested bacteria. Minimum inhibitory concentration of AgNPs against bacterial cells was found to be in range of 1.25-10 μg/mL. Silver nanoparticles did not show any harmful interaction to mouse fibroblast cell line, and no activation of nuclear factor kappa-light-chain-enhancer of activated B (NF-κB) cells was observed at concentration below 10 µg/mL. The half-maximal inhibitory concentration (IC 50 ) value was established at 64.5 μg/mL. Biological synthesis of silver can be used as an effective system for formation of metal nanoparticles. Biosynthesized AgNPs can be used as an antibacterial agent, which can be safe for eukaryotic cells.
Antimicrobial activity of commercial Olea europaea (olive) leaf extract.

PubMed

Sudjana, Aurelia N; D'Orazio, Carla; Ryan, Vanessa; Rasool, Nooshin; Ng, Justin; Islam, Nabilah; Riley, Thomas V; Hammer, Katherine A

2009-05-01

The aim of this research was to investigate the activity of a commercial extract derived from the leaves of Olea europaea (olive) against a wide range of microorganisms (n=122). Using agar dilution and broth microdilution techniques, olive leaf extract was found to be most active against Campylobacter jejuni, Helicobacter pylori and Staphylococcus aureus [including meticillin-resistant S. aureus (MRSA)], with minimum inhibitory concentrations (MICs) as low as 0.31-0.78% (v/v). In contrast, the extract showed little activity against all other test organisms (n=79), with MICs for most ranging from 6.25% to 50% (v/v). In conclusion, olive leaf extract was not broad-spectrum in action, showing appreciable activity only against H. pylori, C. jejuni, S. aureus and MRSA. Given this specific activity, olive leaf extract may have a role in regulating the composition of the gastric flora by selectively reducing levels of H. pylori and C. jejuni.
Copper at low levels impairs memory of adult zebrafish (Danio rerio) and affects swimming performance of larvae.

PubMed

Acosta, Daiane da Silva; Danielle, Naissa Maria; Altenhofen, Stefani; Luzardo, Milene Dornelles; Costa, Patrícia Gomes; Bianchini, Adalto; Bonan, Carla Denise; da Silva, Rosane Souza; Dafre, Alcir Luiz

2016-01-01

Metal contamination at low levels is an important issue because it usually produces health and environmental effects, either positive or deleterious. Contamination of surface waters with copper (Cu) is a worldwide event, usually originated by mining, agricultural, industrial, commercial, and residential activities. Water quality criteria for Cu are variable among countries but allowed limits are generally in the μg/L range, which can disrupt several functions in the early life-stages of fish species. Behavioral and biochemical alterations after Cu exposure have also been described at concentrations close to the allowed limits. Aiming to search for the effects of Cu in the range of the allowed limits, larvae and adult zebrafish (Danio rerio) were exposed to different concentrations of dissolved Cu (nominally: 0, 5, 9, 20 and 60μg/L; measured: 0.4, 5.7, 7.2 16.6 and 42.3μg/L, respectively) for 96h. Larvae swimming and body length, and adult behavior and biochemical biomarkers (activity of glutathione-related enzymes in gills, muscle, and brain) were assessed after Cu exposure. Several effects were observed in fish exposed to 9μg/L nominal Cu, including increased larvae swimming distance and velocity, abolishment of adult inhibitory avoidance memory, and decreased glutathione S-transferase (GST) activity in gills of adult fish. At the highest Cu concentration tested (nominally: 60μg/L), body length of larvae, spatial memory of adults, and gill GST activity were decreased. Social behavior (aggressiveness and conspecific interaction), and glutathione reductase (GR) activity were not affected in adult zebrafish. Exposure to Cu, at concentrations close to the water quality criteria for this metal in fresh water, was able to alter larvae swimming performance and to induce detrimental effects on the behavior of adult zebrafish, thus indicating the need for further studies to reevaluate the currently allowed limits for Cu in fresh water. Copyright © 2016 Elsevier Inc. All rights reserved.
Combining physico-chemical analysis with a Daphnia magna bioassay to evaluate a recycling technology for drinking water treatment plant waste residuals.

PubMed

Chen, Ting; Xu, Yongpeng; Zhu, Shijun; Cui, Fuyi

2015-12-01

Recycling water treatment plant (WTP) waste residuals is considered to be a feasible method to enhance the efficiency of pollutant removal. This study also evaluated the safety and water quality of a pilot-DWTP waste residuals recycling technology by combining physical-chemistry analysis with a Daphnia magna assay. The water samples taken from each treatment step were extracted and concentrated by XAD-2 resin and were then analyzed for immobilization and enzyme activity with D. magna. The measured parameters, such as the dissolve organic carbon (DOC), UV254 and THM formation potential (THMFPs) of the recycling process, did not obviously increase over 15 days of continuous operation and were even lower than typical values from a conventional process. The extract concentration ranged from 0 to 2 Leq/ml as measured on the 7th and 15th days and the immobilization of D. magna exposed to water treated by the recycling process was nearly equivalent to that of the conventional process. Both the superoxide dismutase (SOD) and the catalase (CAT) activity assay indicated that a lower dose of water extract (0.5, 1, 1.5 Leq/ml) could stimulate the enzyme activity of D. magna, whereas a higher dose (2 Leq/ml at the sampling point C3, R3, R4 ) inhibits the activity. Moreover, the SOD and CAT activity of D. magna with DOC and UV254 showed a strong concentration-effect relationship, where the concentration range of DOC and UV254 were 4.1-16.2 mg/L and 0.071-4.382 cm(-1), respectively. The results showed that there was no statistically significant difference (p>0.05) between the conventional and recycling treatment processes and the toxicity of water samples in the recycling process did not increase during the 15-day continuous recycling trial. Copyright © 2015 Elsevier Inc. All rights reserved.

Plasma Selenium Concentrations Are Sufficient and Associated with Protease Inhibitor Use in Treated HIV-Infected Adults123

PubMed Central

Hileman, Corrilynn O; Dirajlal-Fargo, Sahera; Lam, Suet Kam; Kumar, Jessica; Lacher, Craig; Combs, Gerald F; McComsey, Grace A

2015-01-01

Background: Selenium is an essential constituent of selenoproteins, which play a substantial role in antioxidant defense and inflammatory cascades. Selenium deficiency is associated with disease states characterized by inflammation, including cardiovascular disease (CVD). Although HIV infection has been associated with low selenium, the role of selenium status in HIV-related CVD is unclear. Objectives: We sought to assess associations between plasma selenium and markers of inflammation, immune activation, and subclinical vascular disease in HIV-infected adults on contemporary antiretroviral therapy (ART) and to determine if statin therapy modifies selenium status. Methods: In the Stopping Atherosclerosis and Treating Unhealthy bone with RosuvastatiN trial, HIV-infected adults on stable ART were randomly assigned 1:1 to rosuvastatin or placebo. Plasma selenium concentrations were determined at entry, week 24, and week 48. Spearman correlation and linear regression analyses were used to assess relations between baseline selenium, HIV-related factors and markers of inflammation, immune activation, and subclinical vascular disease. Changes in selenium over 24 and 48 wk were compared between groups. Results: One hundred forty-seven HIV-infected adults were included. All participants were on ART. Median current CD4+ count was 613, and 76% had HIV-1 RNA ≤48 copies/mL (range: <20–600). Median plasma selenium concentration was 122 μg/L (range: 62–200). At baseline, higher selenium was associated with protease inhibitor (PI) use, lower body mass index, and a higher proportion of activated CD8+ T cells (CD8+CD38+human leukocyte antigen-DR+), but not markers of inflammation or subclinical vascular disease. Over 48 wk, selenium concentrations increased in the statin group (P < 0.01 within group), but the change did not differ between groups (+13.1 vs. +5.3 μg/L; P = 0.14 between groups). Conclusions: Plasma selenium concentrations were within the normal range for the background population and were not associated with subclinical vascular disease in HIV-infected adults on contemporary ART. The association between current PI use and higher selenium may have implications for ART allocation, especially in resource-limited countries. Also, it appears that statin therapy may increase selenium concentrations; however, larger studies are necessary to confirm this finding. This trial was registered at clinicaltrials.gov as NCT01218802. PMID:26269240
Fecal 20-oxo-pregnane concentrations in free-ranging African elephants (Loxodonta africana) treated with porcine zona pellucida vaccine.

PubMed

Ahlers, M J; Ganswindt, A; Münscher, S; Bertschinger, H J

2012-07-01

Because of overpopulation of African elephants in South Africa and the consequent threat to biodiversity, the need for a method of population control has become evident. In this regard, the potential use of the porcine zona pellucida (pZP) vaccine as an effective means for population control is explored. While potential effects of pZP treatment on social behavior of African elephants have been investigated, no examination of the influence of pZP vaccination on the endocrine correlates in treated females has been undertaken. In this study, ovarian activity of free-ranging, pZP-treated African elephant females was monitored noninvasively for 1 yr at Thornybush Private Nature Reserve, South Africa, by measuring fecal 5α-pregnan-3β-ol-20-on concentrations via enzyme immunoassay. A total of 719 fecal samples from 19 individuals were collected over the study period, averaging 38 samples collected per individual (minimum, maximum: 16, 52). Simultaneously, behavioral observations were made to record the occurrence of estrous behavior for comparison. Each elephant under study showed 5α-pregnan-3β-ol-20-on concentrations rising above baseline at some period during the study indicating luteal activity. Average 5α-pregnan-3β-ol-20-on concentrations were 1.61 ± 0.46 μg/g (mean ± SD). Within sampled females, 42.9% exhibited estrous cycles within the range reported for captive African elephants, 14.3% had irregular cycles, and 42.9% did not appear to be cycling. Average estrous cycle duration was 14.72 ± 0.85 wk. Estrous behavior coincided with the onset of the luteal phase and a subsequent rise in 5α-pregnan-3β-ol-20-on concentrations. Average 5α-pregnan-3β-ol-20-on levels positively correlated with rainfall. No association between average individual 5α-pregnan-3β-ol-20-on concentrations or cyclicity status with age or parity were detected. Earlier determination of efficacy was established via fecal hormone analysis with no pregnancies determined 22 mo post-treatment and onward. Results indicate the presence of ovarian activity amongst pZP-treated female African elephants in 2 yr after initial immunization. Further study should now be aimed toward investigating the long-term effects of pZP vaccination on the reproductive function of female African elephants. Copyright © 2012 Elsevier Inc. All rights reserved.
Landscape scale attributes of elk centers of activity in the central Black Hills of South Dakota

Treesearch

Cynthia H. Stubblefield; Kerri T. Vierling; Mark A. Rumble

2006-01-01

We researched the environmental attributes (n = 28) associated with elk (n = 50) summer range (1 May Â30 Sep) in the central Black Hills of South Dakota, USA, during 1998-Â2001. We defined high-use areas or centers of activity as landscapes underlying large concentrations of elk locations resulting from the shared fidelity of...
Influence of Tap Water Quality and Household Water Use Activities on Indoor Air and Internal Dose Levels of Trihalomethanes

PubMed Central

Nuckols, John R.; Ashley, David L.; Lyu, Christopher; Gordon, Sydney M.; Hinckley, Alison F.; Singer, Philip

2005-01-01

Individual exposure to trihalomethanes (THMs) in tap water can occur through ingestion, inhalation, or dermal exposure. Studies indicate that activities associated with inhaled or dermal exposure routes result in a greater increase in blood THM concentration than does ingestion. We measured blood and exhaled air concentrations of THM as biomarkers of exposure to participants conducting 14 common household water use activities, including ingestion of hot and cold tap water beverages, showering, clothes washing, hand washing, bathing, dish washing, and indirect shower exposure. We conducted our study at a single residence in each of two water utility service areas, one with relatively high and the other low total THM in the residence tap water. To maintain a consistent exposure environment for seven participants, we controlled water use activities, exposure time, air exchange, water flow and temperature, and nonstudy THM sources to the indoor air. We collected reference samples for water supply and air (pre–water use activity), as well as tap water and ambient air samples. We collected blood samples before and after each activity and exhaled breath samples at baseline and postactivity. All hot water use activities yielded a 2-fold increase in blood or breath THM concentrations for at least one individual. The greatest observed increase in blood and exhaled breath THM concentration in any participant was due to showering (direct and indirect), bathing, and hand dishwashing. Average increase in blood THM concentration ranged from 57 to 358 pg/mL due to these activities. More research is needed to determine whether acute and frequent exposures to THM at these concentrations have public health implications. Further research is also needed in designing epidemiologic studies that minimize data collection burden yet maximize accuracy in classification of dermal and inhalation THM exposure during hot water use activities. PMID:16002374
Biomarkers of metals exposure in fish from lead-zinc mining areas of Southeastern Missouri, USA

USGS Publications Warehouse

Schmitt, C.J.; Whyte, J.J.; Roberts, A.P.; Annis, M.L.; May, T.W.; Tillitt, D.E.

2007-01-01

The potential effects of proposed lead-zinc mining in an ecologically sensitive area were assessed by studying a nearby mining district that has been exploited for about 30 y under contemporary environmental regulations and with modern technology. Blood and liver samples representing fish of three species (largescale stoneroller, Campostoma oligolepis, n=91; longear sunfish, Lepomis megalotis, n=105; and northern hog sucker, Hypentelium nigricans, n=20) from 16 sites representing a range of conditions relative to mining activities were collected. Samples were analyzed for metals (also reported in a companion paper) and for biomarkers of metals exposure [erythrocyte ??-aminolevulinic acid dehydratase (ALA-D) activity; concentrations of zinc protoporphyrin (ZPP), iron, and hemoglobin (Hb) in blood; and hepatic metallothionein (MT) gene expression and lipid peroxidation]. Blood lead concentrations were significantly higher and ALA-D activity significantly lower in all species at sites nearest to active lead-zinc mines and in a stream contaminated by historical mining than at reference or downstream sites. ALA-D activity was also negatively correlated with blood lead concentrations in all three species but not with other metals. Iron and Hb concentrations were positively correlated in all three species, but were not correlated with any other metals in blood or liver in any species. MT gene expression was positively correlated with liver zinc concentrations, but neither MT nor lipid peroxidase differences among fish grouped according to lead concentrations were statistically significant. ZPP was not detected by hematofluorometry in most fish, but fish with detectable ZPP were from sites affected by mining. Collectively, these results confirm that metals are released to streams from active lead-zinc mining sites and are accumulated by fish. ?? 2007 Elsevier Inc. All rights reserved.
Concentration of Ra-226 in Malaysian Drinking and Bottled Mineral Water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amin, Y. B. Mohd; Jemangin, M. H.; Mahat, R. H.

2010-07-07

The concentration of the radionuclide {sup 226}Ra was determined in the drinking water which was taken from various sources. It was found that the concentration varies from non-detectable (ND) to highest value of 0.30 Bq per liter. The concentration was found to be high in mineral water as compare with surface water such as domestic pipe water. Some of these values have exceeded the EPA (Environmental Protection Agency) of America regulations. The activity concentrations obtained are compared with data from other countries. The estimated annual effective doses from drinking the water are determined. The values obtained range from 0.02 mSvmore » to about 0.06 mSv per year.« less
Volatile organic compounds in industrial, urban, and suburban areas: Sources and exposures

NASA Astrophysics Data System (ADS)

Jia, Chunrong

This research was aimed at evaluating and refining sampling and analytical methods for airborne volatile organic compounds (VOCs), and at characterizing concentrations and potential exposures of VOCs found in indoor and ambient air in industrial, urban and suburban communities. A new analytical strategy of combining selective ion monitoring (SIM) and scan mode mass spectrometer analyses was developed and evaluated. This strategy improved sensitivity and selectivity without extra cost or calibration efforts. An intermittent active sampling method for collecting VOCs, which has not been previously evaluated, was compared to continuous active and passive sampling methods with the aim of obtaining long-term integrated measurements. Results obtained by the three methods agreed over a wide concentration range after accounting for the sampling rate. Intermittent sampling provides greater flexibility with respect to sampling period and flow rate, and enables the use of multi-bed adsorbents that increase the range of VOCs that can be monitored. VOC concentrations were measured inside and outside of 159 residences in suburban (Ann Arbor), urban (Ypsilanti) and urban/industrial (Dearborn) communities in southeastern Michigan from 2004 to 2005. A total of 53 and 46 VOCs were detected indoors and outdoors, respectively. Outdoors, benzene, toluene, p,m-xylene and carbon tetrachloride had the highest concentrations, and differences were seen between cities and seasons. Factor analyses identified four types of outdoor sources: vehicle exhaust/gasoline vapor, industrial solvents, biogenic emissions, and industrial sources. Indoors, benzene, toluene, p,m-xylene, n-heptane, alpha-pinene and d-limonene had the highest concentrations. Indoor to outdoor concentration ratios ranged from 1 to 10 for most compounds. Higher indoor concentrations were associated with the presence of attached garages, recent renovations, indoor smoking, residence age, infrequent window/door opening, high CO2 concentration, lower ventilation, and community. Factor analyses identified up to ten VOC source types in residences. This is one of the most comprehensive VOC surveys conducted in the US since 2000. A semi-parametric probability framework was developed to characterize VOC mixtures in residences. High concentration VOC mixtures resulted from the presence of several features (e.g. strong sources and ventilation conditions), and many characteristics of the observed mixtures could be represented using multivariate and correlated lognormal distributions.
Tunable mechanical stability and deformation response of a resilin-based elastomer.

PubMed

Li, Linqing; Teller, Sean; Clifton, Rodney J; Jia, Xinqiao; Kiick, Kristi L

2011-06-13

Resilin, the highly elastomeric protein found in specialized compartments of most arthropods, possesses superior resilience and excellent high-frequency responsiveness. Enabled by biosynthetic strategies, we have designed and produced a modular, recombinant resilin-like polypeptide bearing both mechanically active and biologically active domains to create novel biomaterial microenvironments for engineering mechanically active tissues such as blood vessels, cardiovascular tissues, and vocal folds. Preliminary studies revealed that these recombinant materials exhibit promising mechanical properties and support the adhesion of NIH 3T3 fibroblasts. In this Article, we detail the characterization of the dynamic mechanical properties of these materials, as assessed via dynamic oscillatory shear rheology at various protein concentrations and cross-linking ratios. Simply by varying the polypeptide concentration and cross-linker ratios, the storage modulus G' can be easily tuned within the range of 500 Pa to 10 kPa. Strain-stress cycles and resilience measurements were probed via standard tensile testing methods and indicated the excellent resilience (>90%) of these materials, even when the mechanically active domains are intercepted by nonmechanically active biological cassettes. Further evaluation, at high frequencies, of the mechanical properties of these materials were assessed by a custom-designed torsional wave apparatus (TWA) at frequencies close to human phonation, indicating elastic modulus values from 200 to 2500 Pa, which is within the range of experimental data collected on excised porcine and human vocal fold tissues. The results validate the outstanding mechanical properties of the engineered materials, which are highly comparable to the mechanical properties of targeted vocal fold tissues. The ease of production of these biologically active materials, coupled to their outstanding mechanical properties over a range of compositions, suggests their potential in tissue regeneration applications.
Metastable Solution Thermodynamic Properties and Crystal Growth Kinetics

NASA Technical Reports Server (NTRS)

Kim, Soojin; Myerson, Allan S.

1996-01-01

The crystal growth rates of NH4H2PO4, KH2PO4, (NH4)2SO4, KAl(SO4)2 central dot 12H2O, NaCl, and glycine and the nucleation rates of KBr, KCl, NaBr central dot 2H2O, (NH4)2Cl, and (NH4)2SO4 were expressed in terms of the fundamental driving force of crystallization calculated from the activity of supersaturated solutions. The kinetic parameters were compared with those from the commonly used kinetic expression based on the concentration difference. From the viewpoint of thermodynamics, rate expressions based on the chemical potential difference provide accurate kinetic representation over a broad range of supersaturation. The rates estimated using the expression based on the concentration difference coincide with the true rates of crystallization only in the concentration range of low supersaturation and deviate from the true kinetics as the supersaturation increases.
Atom-efficient regioselective 1,2-dearomatization of functionalized pyridines by an earth-abundant organolanthanide catalyst

NASA Astrophysics Data System (ADS)

Dudnik, Alexander S.; Weidner, Victoria L.; Motta, Alessandro; Delferro, Massimiliano; Marks, Tobin J.

2014-12-01

Developing earth-abundant, non-platinum metal catalysts for high-value chemical transformations is a critical challenge to contemporary chemical synthesis. Dearomatization of pyridine derivatives is an important transformation to access a wide range of valuable nitrogenous natural products, pharmaceuticals and materials. Here, we report an efficient 1,2-regioselective organolanthanide-catalysed pyridine dearomatization process using pinacolborane, which is compatible with a broad range of pyridines and functional groups and employs equimolar reagent stoichiometry. Regarding the mechanism, derivation of the rate law from NMR spectroscopic and kinetic measurements suggests first order in catalyst concentration, fractional order in pyridine concentration and inverse first order in pinacolborane concentration, with C=N insertion into the La-H bond as turnover-determining. An energetic span analysis affords a more detailed understanding of experimental activity trends and the unusual kinetic behaviour, and proposes the catalyst ‘resting’ state and potential deactivation pathways.
Enzyme-polyelectrolyte complexes in water-ethanol mixtures: negatively charged groups artificially introduced into alpha-chymotrypsin provide additional activation and stabilization effects.

PubMed

Kudryashova, E V; Gladilin, A K; Vakurov, A V; Heitz, F; Levashov, A V; Mozhaev, V V

1997-07-20

Formation of noncovalent complexes between alpha-chymotrypsin (CT) and a polyelectrolyte, polybrene (PB), has been shown to produce two major effects on enzymatic reactions in binary mixtures of polar organic cosolvents with water. (i) At moderate concentrations of organic cosolvents (10% to 30% v/v), enzymatic activity of CT is higher than in aqueous solutions, and this activation effect is more significant for CT in complex with PB (5- to 7-fold) than for free enzyme (1.5- to 2.5-fold). (ii) The range of cosolvent concentrations that the enzyme tolerates without complete loss of catalytic activity is much broader. For enhancement of enzyme stability in the complex with the polycation, the number of negatively charged groups in the protein has been artificially increased by using chemical modification with pyromellitic and succinic anhydrides. Additional activation effect at moderate concentrations of ethanol and enhanced resistance of the enzyme toward inactivation at high concentrations of the organic solvent have been observed for the modified preparations of CT in the complex with PB as compared with an analogous complex of the native enzyme. Structural changes behind alterations in enzyme activity in water-ethanol mixtures have been studied by the method of circular dichroism (CD). Protein conformation of all CT preparations has not changed significantly up to 30% v/v of ethanol where activation effects in enzymatic catalysis were most pronounced. At higher concentrations of ethanol, structural changes in the protein have been observed for different forms of CT that were well correlated with a decrease in enzymatic activity. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 55: 267-277, 1997.
Synthesis of fructooligosaccharides (FosA) and inulin (InuO) by GH68 fructosyltransferases from Bacillus agaradhaerens strain WDG185.

PubMed

Kralj, Slavko; Leeflang, Chris; Sierra, Estefanía Ibáñez; Kempiński, Błażej; Alkan, Veli; Kolkman, Marc

2018-01-01

Fructooligosaccharides (FOS) and inulin, composed of β-2-1 linked fructose units, have a broad range of industrial applications. They are known to have various beneficial health effects and therefore have broad application potential in nutrition. For (modified) inulin also for non-food purposes more applications are arising. Examples are carboxymethylated inulin as anti-scalant and carboymlated inulin as emulsifiers. Various plants synthesize FOS and/or inulin type of fructans. However, isolating of FOS and inulin from plants is challenging due to for instance varying chains length. There is an increasing demand for FOS and inulin oligosaccharides and alternative procedures for their synthesis are attractive. We identified and characterized two fructosyltransferases from Bacillus agaradhaerens WDG185. FosA, a β-fructofuranosidase, synthesises short chain fructooligosaccharides (GF2-GF4) at high sucrose concentration, whereas InuO, an inulosucrase, synthesises a broad range of inulooligosaccharides (GF2-GF24) from sucrose, very similar to plant derived inulin. FosA and InuO showed activity over a broad pH range from 6 to 10 and optimal temperature at 60°C. Calcium ions and EDTA were found to have no effect on the activity of both enzymes. Kinetic analysis showed that only at relatively low substrate concentrations both enzymes showed Michaelis-Menten type of kinetics for total and transglycosylation activity. Both enzymes showed increased transglycosylation upon increasing substrate concentrations. These are the first examples of the molecular and biochemical characterization of a β-fructofuranosidase (FosA) and an inulosucrase enzyme (InuO) and its product from a Bacillus agaradhaerens strain. Copyright © 2017 Elsevier Ltd. All rights reserved.
Facile design of red-emitting waveguides using hybrid nanocomposites made of inorganic clusters dispersed in SU8 photoresist host

NASA Astrophysics Data System (ADS)

Huby, Nolwenn; Bigeon, John; Lagneaux, Quentin; Amela-Cortes, Maria; Garreau, Alexandre; Molard, Yann; Fade, Julien; Desert, Anthony; Faulques, Eric; Bêche, Bruno; Duvail, Jean-Luc; Cordier, Stéphane

2016-02-01

Integration of stable emissive entities into organic waveguide with minimum scattering is essential to design efficient optically active devices. Here we present a new class of doped nanocomposite waveguides exploiting 1-nm diameter metallic cluster-based building blocks as red-NIR luminescent dyes embedded in a SU8 polymeric matrix, a reference photoresist for organic photonics. These building blocks are [Mo6Ii8(OOCC2F5)a6]2- cluster anionic units with unique chemical and physical features well suited for optical nanocomposites such as a ligand-promoted dispersibility, a large Stokes shift with a broad absorption window and an emission window in the range 600-900 nm. A whole investigation of the nanocomposite has been first performed. Optical characterizations of Cs2[Mo6Ii8(OOCCnF2n+1)a6]@SU8 nanocomposites thin film and waveguiding structures show their relevance as active layers in integrated structures with a significant increase of the refractive index of 3 × 10-2 when the cluster concentration increases up to 4 wt%, while keeping high values for the transmitted power, as shown for different waveguide dimensions and clusters concentrations. The efficiency of photoluminescence propagation is investigated as a function of clusters concentration in the excitation area for several waveguides dimensions. Attenuation coefficient ranges between 5 and 18 dB/cm, values of the same order of magnitude as those obtained in polymeric waveguide doped with QDs or organic dyes. This original, stable and efficient nanocomposite is promising for downscaling complex nanosources and active waveguides in the visible and NIR range.
Can sterile and pyrogen-free on-line substitution fluid be routinely delivered? A multicentric study on the microbiological safety of on-line haemodiafiltration.

PubMed

Vaslaki, L; Karátson, A; Vörös, P; Major, L; Pethö, F; Ladányi, E; Weber, C; Mitteregger, R; Falkenhagen, D

2000-01-01

Microbial contamination is characterized not only by the presence of bacteria, but also by high concentrations of biologically active by-products. They are potentially able to cross ultrafiltration and dialysis membranes and stimulate immunocompetent blood cells to synthesize cytokines. In turn, cytokine induction causes acute symptoms and has been incriminated in the long-term complications of haemodialysis patients. Infusion of large volumes of substitution fluids following ultrafiltration of microbially contaminated dialysis fluids may place patients on on-line therapies at particular risk. In this study we evaluated 30 machines with a two-stage ultrafiltration system in routine clinical haemodiafiltration settings in six centres for 6 months. Microbiological safety was assessed monthly and at the last use of the filters by determining microbial counts, endotoxin concentration and cytokine-inducing activity. No pyrogenic episodes were observed during the study period. Double-filtration of standard dialysis fluid (range, <1-895 cfu/ml, 0.0028-4.6822 IU/ml) resulted in sterile substitution fluids with endotoxin concentrations well below the Ph.Eur. standard for haemofiltration solutions (range, 0.0014-0.0281 vs 0.25 IU/ml). Moreover, they did not differ from commercial haemofiltration solutions and depyrogenated saline. Likewise, there was no difference in the cytokine-inducing activity between the solutions tested. The high microbiological quality of the ultrafiltered dialysis fluid, which was in the same range as substitution fluid, translates into both the absence of cytokine induction by dialyser back-transport and a redundant safety mode of the on-line system by a second filtration step. On-line HDF treatment can routinely be provided with ultra-pure dialysis fluids and sterile substitution fluids at pyrogen-free levels. The online preparation of substitution fluids thus can be considered microbiologically safe.
Phytochemical profiles and antimicrobial activity of aromatic Malaysian herb extracts against food-borne pathogenic and food spoilage microorganisms.

PubMed

Aziman, Nurain; Abdullah, Noriham; Noor, Zainon Mohd; Kamarudin, Wan Saidatul Syida Wan; Zulkifli, Khairusy Syakirah

2014-04-01

Preliminary phytochemical and flavonoid compounds of aqueous and ethanolic extracts of 6 aromatic Malaysian herbs were screened and quantified using Reverse-Phase High Performance Liquid Chromatography (RP-HPLC). The herbal extracts were tested for their antimicrobial activity against 10 food-borne pathogenic and food spoilage microorganisms using disk diffusion assay. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)/minimum fungicidal concentration (MFC) of herbal extracts were determined. In the phytochemical screening process, both aqueous and ethanolic extracts of P. hydropiper exhibited presence of all 7 tested phytochemical compounds. Among all herbal extracts, the aqueous P. hydropiper and E. elatior extracts demonstrated the highest antibacterial activity against 7 tested Gram-positive and Gram-negative bacteria with diameter ranging from 7.0 to 18.5 mm and 6.5 to 19 mm, respectively. The MIC values for aqueous and ethanolic extracts ranged from 18.75 to 175 mg/mL and 0.391 to 200 mg/mL, respectively while the MBC/MFC values for aqueous and ethanolic extracts ranged from 25 to 200 mg/mL and 3.125 to 50 mg/mL, respectively. Major types of bioactive compounds in aqueous P. hydropiper and E. elatior extracts were identified using RP-HPLC instrument. Flavonoids found in these plants were epi-catechin, quercetin, and kaempferol. The ability of aqueous Persicaria hydropiper (L.) H. Gross and Etlingera elatior (Jack) R.M. Sm. extracts to inhibit the growth of bacteria is an indication of its broad spectrum antimicrobial potential. Hence these herbal extracts may be used as natural preservative to improve the safety and shelf-life of food and pharmaceutical products. © 2014 Institute of Food Technologists®
Effect of high aluminum consumption on mechanics and composition of furculae of free-ranging coots

USGS Publications Warehouse

Hui, C.A.; Ellers, O.

1999-01-01

High levels of ingested Al can affect mechanical properties of bones. Because of the spring action of the furcula during the wingbeat, small changes in the mechanical properties of this bone may have measurable impacts on long-distance flight. We examined the furculae and ingesta of free- ranging American coots (Fulica americana) in San Francisco Bay (California, USA), where they consume a diet high in Al. We measured the spring stiffness and phase angle (??) of the furculae and the concentrations of Al, Ca, F. Mg, and P in both the furculae and ingesta. The ingesta had mean Al concentrations (2,384 ??g/g, dry weight) and Al:P molar ratios (6.4:1) predicted to affect bone integrity but the bone concentrations of Al were near the normal range and the furcula stiffness did not change with Al concentration. The tan ?? of the furculae changed with Al concentration but the relationship was weak. The chemical speciation of the ingested Al may have affected its physiologic role and the high mean levels of ingested calcium (71,283 ??g/g, dry weight) very likely neutralized the activity of the Al. Controlled feeding studies have shown that F strengthens avian bones. The bones in our study had molar concentrations of F more than two orders of magnitude greater than Al (170:1) but F appears to have insignificant influence on bone mechanics. The coots in San Francisco Bay apparently are not suffering furcula impairment despite a diet high in Al.
Concentrations of polychlorinated biphenyls in soil and indoor dust associated with electricity generation facilities in Lagos, Nigeria.

PubMed

Folarin, Bilikis Temitope; Abdallah, Mohamed Abou-Elwafa; Oluseyi, Temilola; Olayinka, Kehinde; Harrad, Stuart

2018-09-01

Concentrations of 7 indicator polychlorinated biphenyls (PCBs) were measured in dust and soil samples from 12 power stations collected over the two major seasons of the Nigerian climate. Median ƩPCB 7 concentrations in soil ranged from 2 ng/g for power station A to 220 ng/g for power station I; while those in dust ranged from 21 ng/g for power station L to 2200 ng/g for power station I. For individual congeners, median PCB concentrations ranged from 3.8 ng/g for PCB 101 to 52 ng/g for PCB 180 in dust, and <0.07 ng/g for PCB 28 to 5.9 ng/g for PCB 153 in soil. The type of power station activity exerted a significant influence on concentrations of ΣPCB 7 in dust and soil (generation > transmission > distribution). Congener patterns in dust and soil samples were compared using principal component analysis (PCA) with those in transformer oil samples from 3 of the power stations studied and with common PCB mixtures (Aroclors). This revealed congener patterns in soil were more closely related to that in the transformer oil than dust. Congener patterns in most samples were similar to Aroclor 1260. Concentrations of PCBs in soil samples close to the transformers significantly exceeded those in soil sampled further away. Copyright © 2018 Elsevier Ltd. All rights reserved.
Environmental setting of benchmark streams in agricultural areas of eastern Wisconsin

USGS Publications Warehouse

Rheaume, S.J.; Stewart, J.S.; Lenz, B.N.

1996-01-01

Differences in land use/land cover, and riparian vegetation and instream habitat characteristics are presented. Summaries of field measurements of water temperature, pH, specific conductance and concentrations of dissolved oxygen, total organic plus ammonia nitrogen, dissolved ammonium, nitrate plus nitrte as nitrogen, total phosphorus, dissolved orthophosphate, and atrazine are listed. Concentrations of dissolved oxygen for the sampled streams ranged from 6 A to 14.3 and met the standards set by the Wisconsin Department of Natural Resources (WDNR) for supporting fish and aquatic life. Specific conductance ranged from 98 to 753 u,Scm with values highest in RHU's 1 and 3, where streams are underlain by carbonate bedrock. Median pH did not vary greatly among the four RHU's and ranged from 6.7 to 8.8 also meeting the WDNR standards. Concentrations of total organic plus ammonia nitrogen, dissolved ammonium, total phosphorus, and dissolved orthophosphate show little variation between streams and are generally low, compared to concentrations measured in agriculturally-affected streams in the same RHU's during the same sampling period. Concentrations of the most commonly used pesticide in the study unit, atrazine, were low in all streams, and most concentrations were below trn 0.1 u,g/L detection limit. Riparian vegetation for the benchmark streams were characterized by lowland species of the native plant communities described by John T. Curtis in the "Vegetation of Wisconsin." Based on the environmental setting and water-quality information collected to date, these streams appear to show minimal adverse effects from human activity.
CCN and IN concentration measurements during the Antarctic Circumnavigation Expedition

NASA Astrophysics Data System (ADS)

Stratmann, F.; Henning, S.; Löffler, M.; Welti, A.; Hartmann, M.; Wernli, H.; Baccarini, A.; Schmale, J.

2017-12-01

Cloud condensation nuclei (CCN) and ice nuclei (IN) concentrations measured during the Antarctic Circumnavigation Expedition (ACE) within the Study of Preindustrial-like Aerosol-Climate Effects (SPACE) are presented. The measurements give a circumpolar transect through the Sub Antarctic Ocean, where existing measurements are scarce. ACE took place during the austral summer 2016/17 and included exploration of different environments from pristine open Ocean to Antarctic islands and the southernmost ports of the 3 surrounding continents. CCN concentrations are measured over the entire range of expected in-cloud supersaturations from 0.1 to 1% using a CCNc instrument from DMT. IN concentrations are determined from filter samples at water saturated conditions from -5°C to -25°C, covering common temperatures of mixed-phase cloud glaciation. The sensitivity of measured IN and CCN concentrations to meteorological parameters, activity of marine biology and location is assessed to gain insight into potential sources of CCN and IN. Back trajectory modelling is used to allocate regional variations to aerosol sources originating in the marine boundary layer or long-range transport. The gained datasets constrain CCN and IN concentrations in the marine boundary layer along the cruise track. The comprehensive set of parallel measured parameters during ACE allow to evaluate contributions of local ocean-surface sources versus long-range transport to Sub-Antarctic CCN and IN. The measurements can be used as input to climate models, e.g. pristine Sub Antarctic conditions can provide an approximation for a pre-industrial environment.
Biogeochemical mercury methylation influenced by reservoir eutrophication, Salmon Falls Creek Reservoir, Idaho, USA

USGS Publications Warehouse

Gray, J.E.; Hines, M.E.

2009-01-01

Salmon Falls Creek Reservoir (SFCR) in southern Idaho has been under a mercury (Hg) advisory since 2001 as fish in this reservoir contain elevated concentrations of Hg. Concentrations of total Hg (HgT) and methyl-Hg (MeHg) were measured in reservoir water, bottom sediment, and porewater to examine processes of Hg methylation at the sediment/water interface in this reservoir. Rates of Hg methylation and MeHg demethylation were also measured in reservoir bottom sediment using isotopic tracer techniques to further evaluate methylation of Hg in SFCR. The highest concentrations for HgT and MeHg in sediment were generally found at the sediment/water interface, and HgT and MeHg concentrations declined with depth. Porewater extracted from bottom sediment contained highly elevated concentrations of HgT ranging from 11-230??ng/L and MeHg ranging from 0.68-8.5??ng/L. Mercury methylation was active at all sites studied. Methylation rate experiments carried out on sediment from the sediment/water interface show high rates of Hg methylation ranging from 2.3-17%/day, which is significantly higher than those reported in other Hg contaminant studies. Using porewater MeHg concentrations, we calculated an upward diffusive MeHg flux of 197??g/year for the entire reservoir. This sediment derived MeHg is delivered to the overlying SFCR water column, and eventually transferred to biota, such as fish. This study indicates that methylation of Hg is highly influenced by the hypolimnetic and eutrophic conditions in SFCR.

A new method to measure effective soil solution concentration predicts copper availability to plants.

PubMed

Zhang, H; Zhao, F J; Sun, B; Davison, W; McGrath, S P

2001-06-15

Risk assessments of metal contaminated soils need to address metal bioavailability. To predict the bioavailability of metals to plants, it is necessary to understand both solution and solid phase supply processes in soils. In striving to find surrogate chemical measurements, scientists have focused either on soil solution chemistry, including free ion activities, or operationally defined fractions of metals. Here we introduce the new concept of effective concentration, CE, which includes both the soil solution concentration and an additional term, expressed as a concentration, that represents metal supplied from the solid phase. CE was measured using the technique of diffusive gradients in thin films (DGT) which, like a plant, locally lowers soil solution concentrations, inducing metal supply from the solid phase, as shown by a dynamic model of the DGT-soil system. Measurements of Cu as CE, soil solution concentration, by EDTA extraction and as free Cu2+ activity in soil solution were made on 29 different soils covering a large range of copper concentrations. Theywere compared to Cu concentrations in the plant material of Lepidium heterophyllum grown on the same soils. Plant concentrations were linearly related and highly correlated with CE but were more scattered and nonlinear with respect to free Cu2+ activity, EDTA extraction, or soil solution concentrations. These results demonstrate that the dominant supply processes in these soils are diffusion and labile metal release, which the DGT-soil system mimics. The quantity CE is shown to have promise as a quantitative measure of the bioavailable metal in soils.
Halotolerant and Resistant to High pH Hydrogenase from Haloalkaliphilic Sulfate-Reducing Bacterium Desulfonatronum thiodismutans

NASA Technical Reports Server (NTRS)

Detkova, Ekaterina N.; Pikuta, Elena V.; Hoover, Richard B.

2004-01-01

Hydrogenase is the key enzyme of energetic metabolism in cells, it catalyzing the converse reaction of hydrogen oxidation and responsible for consumption and excretion of hydrogen in bacteria. Hydrogenases are proteins containing either Nickel and Iron, or the only Iron in theirs active center. Hydrogenases have been found in many microorganisms, such as Methanogenic, acetogenic, nitrogen-fixing, photosynthetic and sulfate-reducing bacteria that could utilize the hydrogen as energy source or use it as electron sink. Hydrogenases are subject for wide physiological, biochemical, physicochemical and genetic studies due to theirs abilities produce the molecular hydrogen as alternative source of pure energy. Notwithstanding on enough large quantity of works that deal with intracellular and extrasellular enzymes of halophilic bacteria, the data about hydrogenases and theirs functions of salts practically are absent. The study of hydrogenase in cell-free extracts of extremely halophilic eubacterium Acetohalobium mabaticum showed dramatic increasing activity of the enzyme at high concentrations of NaCl and KCI (close to saturated solution). Here we present the data of free-cells extracted hydrogenase from new haloalkaliphilic sulfate-reducing bacterium Desulfonatronum thiodismutans, which grow on highly miniralized carbonate-bicarbonate medium in salinity range 1 to 7 % and at pH 7.8 - 10.5. Studied enzyme was active in Concentration range from 0 to 4.3 M NaCl with optimum at 1.0 M NaCl. At 1.0 M NaCl the enzyme activity was increased on 20 %, but with changing concentration from 2.1 M to 3.4 M the activity decreased and was kept on constant level. NaHCO3 inhibited hydrogenase activity on more then 30 %. The maximum of enzyme activity was observed at pH 9.5 with limits 7.5 and 11.5 that practically equal to pH optimum of bacterial growth. Therefore the hydrogenase of Desulfanatronum thiodismutans is tolerant to high concentrations of sodium salts and it also resistant to high pH that make it the unique subject for different biochemical research and detects the possibility for biotechnological application.
Kinetics of absorption of CO{sub 2} in concentrated aqueous methyldiethanolamine solutions in the range 296 K to 343 K

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pani, F.; Gaunand, A.; Cadours, R.

1997-03-01

The kinetics of CO{sub 2} absorption by aqueous solutions of methyl diethanol amine (MDEA) were measured in the temperature range (296--343) K and MDEA concentration range (830--4,380) mol/m{sup 3} (10--50 mass %). A thermoregulated constant interfacial area Lewis-type cell was operated by recording the pressure drop during batch absorption. The kinetic results are in agreement with a fast regime of absorption according to film theory. MDEA depletion at the interface has a significant effect on the kinetics at the CO{sub 2} pressures (100 to 200 kPa) studied in this work, especially at low temperatures and low MDEA concentrations. Considering onlymore » the reaction between CO{sub 2} and MDEA, the CO{sub 2} absorption appears as a first-order reaction with respect to MDEA. The activation energy found for the reaction between CO{sub 2} and MDEA is 45 kJ/mol, but this value depends significantly (by about 10% in the worst case) on the vapor-liquid equilibrium data used.« less
Persistent organic pollutants (POPs) in killer whales (Orcinus orca) from the Crozet Archipelago, southern Indian Ocean.

PubMed

Noël, Marie; Barrett-Lennard, Lance; Guinet, Christophe; Dangerfield, Neil; Ross, Peter S

2009-10-01

Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs), are ubiquitous environmental contaminants of which significant concentrations are reported in upper trophic level animals. In 1998, we collected blubber biopsy samples (n=11) from killer whales (Orcinus orca) inhabiting the coastal waters around Possession Island, Crozet Archipelago, southern Indian Ocean, for contaminant analyses. Despite inhabiting an isolated region far removed from industrial activities, these killer whales can presently be considered among the most PCB-contaminated cetaceans in the southern hemisphere, with concentrations ranging from 4.4 to 20.5mg/kg lipid weight (lw). PCDD levels ranged from below the detection limit (5 ng/kg) to 77.1 ng/kg lw and PCDF levels from below the detection limit (7 ng/kg) to 36.1 ng/kg lw. Over 70% of our study animals had PCB concentrations which exceeded a 1.3mg/kg PCB threshold established for endocrine disruption and immunotoxicity in free-ranging harbour seals, suggesting that organic contaminants cannot be ruled out as an additional threat to this declining population.
Effects of cadmium on bioaccumulation and biochemical stress response in rice (Oryza sativa L.).

PubMed

Xie, Pan-pan; Deng, Juan-wei; Zhang, Hui-min; Ma, You-hua; Cao, De-ju; Ma, Ru-xiao; Liu, Ren-jing; Liu, Cheng; Liang, Yue-gan

2015-12-01

This study investigated the effects of various Cd concentrations on the bioaccumulation, antioxidative defense, and stress responses of rice (Oryza sativa L.). The distribution characteristics of Cd in rice were in the following order: roots>stems>grains. The bioconcentration factor values of Cd increased at concentrations lower than 3.00 mg Cd/kg and approximately decreased to a constant value at concentrations higher than 3.00 mg Cd/kg. Rice showed a higher Cd accumulation potential at low Cd concentrations than at high Cd concentrations. The Freundlich isotherm model described well the adsorption isotherms of Cd in rice roots. The biosorption mechanism of rice roots was determined to be cooperative adsorption. The malondialdehyde (MDA) content increased at a concentration range of 0.00-5.00 mg/L, indicating the enhancement of lipid peroxidation. By contrast, the MDA content slightly decreased at concentrations higher than 5.00 mg/L. Peroxidase (POD) activity exhibited active response to oxidative stress at concentrations lower than 5.00 mg/L but was inhibited at concentrations higher than 5.00 mg/L. The response to Cd stress of the N-H, O-H and C-O functional groups in rice shoots was observed via Fourier transform infrared spectroscopy. Copyright © 2015 Elsevier Inc. All rights reserved.
Erbium concentration anomaly as an indicator of nuclear activity: Focus on Natural waters in the Chernobyl exclusion zone.

PubMed

Plausinaitis, Deivis; Prokopchik, Aleksandr; Karaliunas, Algimantas; Bohdan, Leonid; Balashevska, Yuliya

2018-04-15

This study focused on measurement of lanthanides in surface water (SW) and ground water (GW) samples from the Chernobyl Exclusion Zone. Results showed that the total lanthanide concentration in SW ranges from 500 to 1100ngL -1 and is about 10 times lower than the GW concentration. The normalized patterns of lanthanide concentrations increase from lighter elements to heavier lanthanides. Concurrently, concentration anomalies of Ce, Eu, and Er are visible. The Er anomaly is the most noticeable and exceeds the theoretical calculation by about 13 times. The Ce and Eu anomalies are likely related to the variety of oxidation states of these elements. Meanwhile, the cause of the Er anomaly is not completely clear, but is likely related to the Chernobyl Nuclear Power Plant accident, since increased concentrations correlate with the distribution of contamination in the zone. 137 Cs activity measurements partially confirm this hypothesis. Simultaneously, there is a relationship between the positive Er anomaly and increase in 235 U concentrations. However, there is no reliable information in the literature that indicates that Er was used in the Chernobyl Nuclear Power Plant before the reactor accident. Copyright © 2017 Elsevier B.V. All rights reserved.
Rediscovering the Schulze-Hardy rule in competitive adsorption to an air-water interface.

PubMed

Stenger, Patrick C; Isbell, Stephen G; St Hillaire, Debra; Zasadzinski, Joseph A

2009-09-01

The ratio of divalent to monovalent ion concentration necessary to displace the surface-active protein, albumin, by lung surfactant monolayers and multilayers at an air-water interface scales as 2(-6), the same concentration dependence as the critical flocculation concentration (CFC) for colloids with a high surface potential. Confirming this analogy between competitive adsorption and colloid stability, polymer-induced depletion attraction and electrostatic potentials are additive in their effects; the range of the depletion attraction, twice the polymer radius of gyration, must be greater than the Debye length to have an effect on adsorption.
Detection of mercury compounds using invertase-glucose oxidase-based biosensor

NASA Astrophysics Data System (ADS)

Amine, A.; Cremisini, C.; Palleschi, G.

1995-10-01

Mercury compounds have been determined with an electrochemical biosensor based on invertase inhibition. When invertase is in the presence of mercury its activity decreases; this causes a decrease of glucose production which is monitored by the glucose sensor and correlated to the concentration of mercury in solution. Parameters as pH, enzyme concentration, substrate concentration, and reaction and incubation time were optimized. Mercury compounds determination using soluble or immobilized invertase were reported. Results show that the inhibition was competitive and reversible. Mercury compounds can be detected directly in aqueous solution in the range 2 - 10 ppb.
Active Stand-off Detection of Gas Leaks Using a Short Range Hard-target Backscatter Differential Optical Absorption System Based on a Quantum Cascade Laser Transmitter

NASA Astrophysics Data System (ADS)

Diaz, Adrian; Thomas, Benjamin; Castillo, Paulo; Gross, Barry; Moshary, Fred

2016-06-01

Fugitive gas emissions from agricultural or industrial plants and gas pipelines are an important environmental concern as they can contribute to the global increase of greenhouse gas concentration. Moreover, they are also a security and safety concern because of possible risk of fire/explosion or toxicity. This study presents gas concentration measurements using a quantum cascade laser open path system (QCLOPS). The system retrieves the pathaveraged concentration of N2O and CH4 by collecting the backscattered light from a scattering target. The gas concentration measurements have a high temporal resolution (68 ms) and are achieved at sufficient range (up to 40 m, ~ 130 feet) with a detection limit of 2.6 ppm CH4 and 0.4 ppm for N2O. Given these characteristics, this system is promising for mobile/multidirectional remote detection and evaluation of gas leaks. The instrument is monostatic with a tunable QCL emitting at ~ 7.7 μm wavelength range. The backscattered radiation is collected by a Newtonian telescope and focused on an infrared light detector. Puffs of N2O and CH4 are released along the optical path to simulate a gas leak. The measured absorption spectrum is obtained using the thermal intra-pulse frequency chirped DFB QCL and is analyzed to obtain path averaged gas concentrations.
Impacts of urbanization on surface sediment quality: evidence from polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) contaminations in the Grand Canal of China.

PubMed

Hong, Youwei; Yu, Shen; Yu, Guangbin; Liu, Yi; Li, Guilin; Wang, Min

2012-06-01

Organic pollutants, especially synthetic organic compounds, can indicate paces of anthropogenic activities. Effects of urbanization on polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) distributions in surface sediment were conducted in urban sections of the Grand Canal, China, consisting of a four-level urbanization gradient. The four-level urbanization gradients include three countryside towns, two small-size cities, three medium-size cities, and a large-size city. Diagnostic ratio analysis and factor analysis-multiple linear regression model were used for source apportionment of PAHs. Sediment quality guidelines (SQGs) of USA and Canada were employed to assess ecological risks of PAHs and PCBs in surface sediments of the Canal. Ranges of PAH and PCB concentrations in surface sediments were 0.66-22 mg/kg and 0.5-93 μg/kg, respectively. Coal-related sources were primary PAH sources and followed by vehicular emission. Total concentration, composition, and source apportionment of PAHs exhibited urbanization gradient effects. Total PCB concentrations increased with the urbanization gradient, while total PAHs concentration in surface sediments presented an inverted U Kuznets curve with the urbanization gradient. Elevated concentrations of both PAHs and PCBs ranged at effect range low levels or interim SQG, assessed by USA and Canadian SQGs. PAHs and PCBs in surface sediments of the Grand Canal showed urbanization gradient effects and low ecological risks.
Effect of racing on the serum concentrations of cardiac troponin I and creatine kinase myocardial band in racing camels (Camelus dromedarius).

PubMed

Tharwat, Mohamed; Al-Sobayil, Fahd; Buczinski, Sébastien

2013-06-01

This study was designed to investigate the effect of racing on the serum concentrations of cardiac troponin I (cTnI) and creatine kinase myocardial (CK-MB) in healthy racing camels (Camelus dromedarius). Twenty-three racing camels scheduled for a 5 km race were investigated in this study. From each camel, 3 blood samples were collected: 24 h before racing (T0), within 2 h after the race (T1) and 24 h post-race (T2). Following the 5 km race, 91.3 % of the racing camels had increases in serum cTnI concentrations, while concentrations remained unchanged in 8.7 %. The cTnI concentration (median 0.06 ng/mL; range, 0.03-0.15 ng/mL) was significantly higher (P < 0.001) than the pre-race values (median 0.04 ng/mL; range, 0.01-0.07 ng/mL). Twenty-four hours post-race, the cTnI concentrations had returned very nearly to their pre-race values (median 0.04 ng/mL; range, 0.00-0.09 ng/mL) and were not significantly different (P = 0.35) from the pre-race values. Following the 5 km race, increases in CK-MB mass were seen in 17.4 % of the camels, with no changes in 4.3 % and decreases in 78.3 %. The CK-MB mass (median 0.41 ng/mL; range, 0.19-0.60 ng/mL) did not differ significantly (P = 0.84) when compared to the pre-race values (median 0.42 ng/mL; range, 0.32-0.55 ng/mL). Twenty-four hours post-race, the CK-MB mass concentrations (median 0.41 ng/mL; range, 0.15-0.55 ng/mL) did not differ significantly (P > 0.05) compared to pre-race or immediate post-race values. Resting cTnI concentrations in the racing camels were initially low, but increased above the baseline level in most of the camels immediately after racing, and returned to pre-race values within the 24-h post-race period. CK-MB is a less sensitive biomarker for myocardial activity as compared with cTnI. These findings could be of importance when evaluating racing camels with suspected cardiac disease after recent hard exercise.
In-vitro activity of essential oils, in particular Melaleuca alternifolia (tea tree) oil and tea tree oil products, against Candida spp.

PubMed

Hammer, K A; Carson, C F; Riley, T V

1998-11-01

The in-vitro activity of a range of essential oils, including tea tree oil, against the yeast candida was examined. Of the 24 essential oils tested by the agar dilution method against Candida albicans ATCC 10231, three did not inhibit C. albicans at the highest concentration tested, which was 2.0% (v/v) oil. Sandalwood oil had the lowest MIC, inhibiting C. albicans at 0.06%. Melaleuca alternifolia (tea tree) oil was investigated for activity against 81 C. albicans isolates and 33 non-albicans Candida isolates. By the broth microdilution method, the minimum concentration of oil inhibiting 90% of isolates for both C. albicans and non-albicans Candida species was 0.25% (v/v). The minimum concentration of oil killing 90% of isolates was 0.25% for C. albicans and 0.5% for non-albicans Candida species. Fifty-seven Candida isolates were tested for sensitivity to tea tree oil by the agar dilution method; the minimum concentration of oil inhibiting 90% of isolates was 0.5%. Tests on three intra-vaginal tea tree oil products showed these products to have MICs and minimum fungicidal concentrations comparable to those of non-formulated tea tree oil, indicating that the tea tree oil contained in these products has retained its anticandidal activity. These data indicate that some essential oils are active against Candida spp., suggesting that they may be useful in the topical treatment of superficial candida infections.
Strontium-90 activity concentration in soil samples from the exclusion zone of the Fukushima daiichi nuclear power plant

NASA Astrophysics Data System (ADS)

Sahoo, Sarata Kumar; Kavasi, Norbert; Sorimachi, Atsuyuki; Arae, Hideki; Tokonami, Shinji; Mietelski, Jerzy Wojciech; Łokas, Edyta; Yoshida, Satoshi

2016-04-01

The radioactive fission product 90Sr has a long biological half-life (˜18 y) in the human body. Due to its chemical similarity to calcium it accumulates in bones and irradiates the bone marrow, causing its high radio-toxicity. Assessing 90Sr is therefore extremely important in case of a nuclear disaster. In this work 16 soil samples were collected from the exclusion zone (<30 km) of the earthquake-damaged Fukushima Daiichi nuclear power plant, to measure 90Sr activity concentration using liquid scintillation counting. 137Cs activity concentration was also measured with gamma-spectroscopy in order to investigate correlation with 90Sr. The 90Sr activity concentrations ranged from 3.0 ± 0.3 to 23.3 ± 1.5 Bq kg-1 while the 137Cs from 0.7 ± 0.1 to 110.8 ± 0.3 kBq kg-1. The fact that radioactive contamination originated from the Fukushima nuclear accident was obvious due to the presence of 134Cs. However, 90Sr contamination was not confirmed in all samples although detectable amounts of 90Sr can be expected in Japanese soils, as a background, stemming from global fallout due to the atmospheric nuclear weapon tests. Correlation analysis between 90Sr and 137Cs activity concentrations provides a potentially powerful tool to discriminate background 90Sr level from its Fukushima contribution.
Radioactivity in wastes generated from shale gas exploration and production - North-Eastern Poland.

PubMed

Jodłowski, Paweł; Macuda, Jan; Nowak, Jakub; Nguyen Dinh, Chau

2017-09-01

In the present study, the K-40, U-238, Ra-226, Pb-210, Ra-228 and Th-228 activity concentrations were measured in 64 samples of wastes generated from shale gas exploration in North-Eastern Poland. The measured samples consist of drill cuttings, solid phase of waste drilling muds, fracking fluids, return fracking fluids and waste proppants. The measured activity concentrations in solid samples vary in a wide range from 116 to around 1100 Bq/kg for K-40, from 14 to 393 Bq/kg for U-238, from 15 to 415 Bq/kg for Ra-226, from 12 to 391 Bq/kg for Pb-210, from a few Bq/kg to 516 Bq/kg for Ra-228 and from a few Bq/kg to 515 Bq/kg for Th-228. Excluding the waste proppants, the measured activity concentrations in solid samples oscillate around their worldwide average values in soil. In the case of the waste proppants, the activity concentrations of radionuclides from uranium and thorium decay series are significantly elevated and equal to several hundreds of Bq/kg but it is connected with the mineralogical composition of proppants. The significant enhancement of Ra-226 and Ra-228 activity concentrations after fracking process was observed in the case of return fracking fluids, but the radium isotopes content in these fluids is comparable with that in waste waters from copper and coal mines in Poland. Copyright © 2017 Elsevier Ltd. All rights reserved.
Changes in the biological activity of heavy metal- and oil-polluted soils in urban recreation territories

NASA Astrophysics Data System (ADS)

Trifonova, T. A.; Zabelina, O. N.

2017-04-01

Urban recreation areas of different sizes were investigated in the city of Vladimir. The degree of their contamination with heavy metals and oil products was revealed. The content of heavy metals exceeded their maximum permissible concentrations by more than 2.5 times. The total content of heavy metals decreased in the sequence: Zn > Pb > Co > Mn > Cr > Ni. The mass fraction of oil products in the studied soils varied within the range of 0.016-0.28 mg/g. The reaction of soils in public gardens and a boulevard was neutral or close to neutral; in some soil samples, it was weakly alkaline. The top layer of all the soils significantly differed from the lower one by the higher alkalinity promoting the deposition of heavy metals there. As the content of Ni, Co, and Mn increased and exceeded the background concentrations, but did not reach the three-fold value of the maximum permissible concentrations, the activity of catalase was intensified. The stimulating effect of nickel on the catalase activity was mostly pronounced at the neutral soil reaction. The urease activity increased when heavy metals and oil products were present together in the concentrations above the background ones, but not higher than the three-fold maximal permissible concentrations for heavy metals and 0.3 mg/g for the content of oil products. The nitrifying activity was inhibited by oil hydrocarbons that were recorded in the soils in different amounts.
Strontium-90 activity concentration in soil samples from the exclusion zone of the Fukushima daiichi nuclear power plant.

PubMed

Sahoo, Sarata Kumar; Kavasi, Norbert; Sorimachi, Atsuyuki; Arae, Hideki; Tokonami, Shinji; Mietelski, Jerzy Wojciech; Łokas, Edyta; Yoshida, Satoshi

2016-04-06

The radioactive fission product (90)Sr has a long biological half-life (˜18 y) in the human body. Due to its chemical similarity to calcium it accumulates in bones and irradiates the bone marrow, causing its high radio-toxicity. Assessing (90)Sr is therefore extremely important in case of a nuclear disaster. In this work 16 soil samples were collected from the exclusion zone (<30 km) of the earthquake-damaged Fukushima Daiichi nuclear power plant, to measure (90)Sr activity concentration using liquid scintillation counting. (137)Cs activity concentration was also measured with gamma-spectroscopy in order to investigate correlation with (90)Sr. The (90)Sr activity concentrations ranged from 3.0 ± 0.3 to 23.3 ± 1.5 Bq kg(-1) while the (137)Cs from 0.7 ± 0.1 to 110.8 ± 0.3 kBq kg(-1). The fact that radioactive contamination originated from the Fukushima nuclear accident was obvious due to the presence of (134)Cs. However, (90)Sr contamination was not confirmed in all samples although detectable amounts of (90)Sr can be expected in Japanese soils, as a background, stemming from global fallout due to the atmospheric nuclear weapon tests. Correlation analysis between (90)Sr and (137)Cs activity concentrations provides a potentially powerful tool to discriminate background (90)Sr level from its Fukushima contribution.
Strontium-90 activity concentration in soil samples from the exclusion zone of the Fukushima daiichi nuclear power plant

PubMed Central

Sahoo, Sarata Kumar; Kavasi, Norbert; Sorimachi, Atsuyuki; Arae, Hideki; Tokonami, Shinji; Mietelski, Jerzy Wojciech; Łokas, Edyta; Yoshida, Satoshi

2016-01-01

The radioactive fission product 90Sr has a long biological half-life (˜18 y) in the human body. Due to its chemical similarity to calcium it accumulates in bones and irradiates the bone marrow, causing its high radio-toxicity. Assessing 90Sr is therefore extremely important in case of a nuclear disaster. In this work 16 soil samples were collected from the exclusion zone (<30 km) of the earthquake-damaged Fukushima Daiichi nuclear power plant, to measure 90Sr activity concentration using liquid scintillation counting. 137Cs activity concentration was also measured with gamma-spectroscopy in order to investigate correlation with 90Sr. The 90Sr activity concentrations ranged from 3.0 ± 0.3 to 23.3 ± 1.5 Bq kg−1 while the 137Cs from 0.7 ± 0.1 to 110.8 ± 0.3 kBq kg−1. The fact that radioactive contamination originated from the Fukushima nuclear accident was obvious due to the presence of 134Cs. However, 90Sr contamination was not confirmed in all samples although detectable amounts of 90Sr can be expected in Japanese soils, as a background, stemming from global fallout due to the atmospheric nuclear weapon tests. Correlation analysis between 90Sr and 137Cs activity concentrations provides a potentially powerful tool to discriminate background 90Sr level from its Fukushima contribution. PMID:27048779
Assessment of combinations of antiandrogenic compounds vinclozolin and flutamide in a yeast based reporter assay.

PubMed

Kolle, Susanne N; Melching-Kollmuss, Stephanie; Krennrich, Gerhard; Landsiedel, Robert; van Ravenzwaay, Bennard

2011-08-01

Humans are exposed to a combination of various substances such as cosmetic ingredients, drugs, biocides, pesticides and natural-occurring substances in food. The combined toxicological effects of two or more substances can simply be additive on the basis of response-addition, or it can be greater (synergistic) or smaller (antagonistic) than this. The need to assess combined effects of compounds with endocrine activity is currently discussed for regulatory risk assessment. We have used a well described yeast based androgen receptor transactivation assay YAS to assess the combinatorial effects of vinclozolin and flutamide; both mediating antiandrogenicity via the androgen receptor. Both vinclozolin and flutamide were antiandrogens of similar potency in the YAS assay. In the concentration range tested the two antiandrogens vinclozolin and flutamide did not act synergistically. Concentration additivity was observed in the linear, non-receptor-saturated concentration range. At high concentrations of one of the two substances tested the contribution of the second at lower concentration levels was less than additive. The combined response of both compounds at high concentration levels was also less than additive (saturation effect). At concentration levels which did not elicit a response of the individual compounds, the combination of these compounds also did not elicit a response. Copyright © 2011 Elsevier Inc. All rights reserved.
D-malate production by permeabilized Pseudomonas pseudoalcaligenes; optimization of conversion and biocatalyst productivity.

PubMed

Michielsen, M J; Frielink, C; Wijffels, R H; Tramper, J; Beeftink, H H

2000-04-14

For the development of a continuous process for the production of solid D-malate from a Ca-maleate suspension by permeabilized Pseudomonas pseudoalcaligenes, it is important to understand the effect of appropriate process parameters on the stability and activity of the biocatalyst. Previously, we quantified the effect of product (D-malate2 -) concentration on both the first-order biocatalyst inactivation rate and on the biocatalytic conversion rate. The effects of the remaining process parameters (ionic strength, and substrate and Ca2 + concentration) on biocatalyst activity are reported here. At (common) ionic strengths below 2 M, biocatalyst activity was unaffected. At high substrate concentrations, inhibition occurred. Ca2+ concentration did not affect biocatalyst activity. The kinetic parameters (both for conversion and inactivation) were determined as a function of temperature by fitting the complete kinetic model, featuring substrate inhibition, competitive product inhibition and first-order irreversible biocatalyst inactivation, at different temperatures simultaneously through three extended data sets of substrate concentration versus time. Temperature affected both the conversion and inactivation parameters. The final model was used to calculate the substrate and biocatalyst costs per mmol of product in a continuous system with biocatalyst replenishment and biocatalyst recycling. Despite the effect of temperature on each kinetic parameter separately, the overall effect of temperature on the costs was found to be negligible (between 293 and 308 K). Within pertinent ranges, the sum of the substrate and biocatalyst costs per mmol of product was calculated to decrease with the influent substrate concentration and the residence time. The sum of the costs showed a minimum as a function of the influent biocatalyst concentration.
Estimation of Radionuclide Concentrations and Average Annual Committed Effective Dose due to Ingestion for the Population in the Red River Delta, Vietnam.

PubMed

Van, Tran Thi; Bat, Luu Tam; Nhan, Dang Duc; Quang, Nguyen Hao; Cam, Bui Duy; Hung, Luu Viet

2018-02-16

Radioactivity concentrations of nuclides of the 232 Th and 238 U radioactive chains and 40 K, 90 Sr, 137 Cs, and 239+240 Pu were surveyed for raw and cooked food of the population in the Red River delta region, Vietnam, using α-, γ-spectrometry, and liquid scintillation counting techniques. The concentration of 40 K in the cooked food was the highest compared to those of other radionuclides ranging from (23 ± 5) (rice) to (347 ± 50) Bq kg -1 dw (tofu). The 210 Po concentration in the cooked food ranged from its limit of detection (LOD) of 5 mBq kg -1 dw (rice) to (4.0 ± 1.6) Bq kg -1 dw (marine bivalves). The concentrations of other nuclides of the 232 Th and 238 U chains in the food were low, ranging from LOD of 0.02 Bq kg -1 dw to (1.1 ± 0.3) Bq kg -1 dw. The activity concentrations of 90 Sr, 137 Cs, and 239+240 Pu in the food were minor compared to that of the natural radionuclides. The average annual committed effective dose to adults in the study region was estimated and it ranged from 0.24 to 0.42 mSv a -1 with an average of 0.32 mSv a -1 , out of which rice, leafy vegetable, and tofu contributed up to 16.2%, 24.4%, and 21.3%, respectively. The committed effective doses to adults due to ingestion of regular diet in the Red River delta region, Vietnam are within the range determined in other countries worldwide. This finding suggests that Vietnamese food is safe for human consumption with respect to radiation exposure.

Mid-infrared tunable metamaterials

DOEpatents

Brener, Igal; Miao, Xiaoyu; Shaner, Eric A.; Passmore, Brandon Scott

2017-07-11

A mid-infrared tunable metamaterial comprises an array of resonators on a semiconductor substrate having a large dependence of dielectric function on carrier concentration and a semiconductor plasma resonance that lies below the operating range, such as indium antimonide. Voltage biasing of the substrate generates a resonance shift in the metamaterial response that is tunable over a broad operating range. The mid-infrared tunable metamaterials have the potential to become the building blocks of chip based active optical devices in mid-infrared ranges, which can be used for many applications, such as thermal imaging, remote sensing, and environmental monitoring.
Mid-infrared tunable metamaterials

DOEpatents

Brener, Igal; Miao, Xiaoyu; Shaner, Eric A; Passmore, Brandon Scott; Jun, Young Chul

2015-04-28

A mid-infrared tunable metamaterial comprises an array of resonators on a semiconductor substrate having a large dependence of dielectric function on carrier concentration and a semiconductor plasma resonance that lies below the operating range, such as indium antimonide. Voltage biasing of the substrate generates a resonance shift in the metamaterial response that is tunable over a broad operating range. The mid-infrared tunable metamaterials have the potential to become the building blocks of chip based active optical devices in mid-infrared ranges, which can be used for many applications, such as thermal imaging, remote sensing, and environmental monitoring.
Use of biocidal products (insect sprays and electro-vaporizer) in indoor areas--exposure scenarios and exposure modeling.

PubMed

Berger-Preiss, Edith; Koch, Wolfgang; Gerling, Susanne; Kock, Heiko; Appel, Klaus E

2009-09-01

Five commercially available insect sprays were applied in a model room. Spraying was performed in accordance with the manufacturers' instructions and in an overdosed manner in order to simulate worst-case conditions or an unforeseeable misuse. In addition, we examined electro-vaporizers. The Respicon aerosol monitoring system was applied to determine inhalation exposure. During normal spraying (10 seconds) and during the following 2-3 minutes, exposure concentrations ranged from 70 to 590 microg/m3 for the pyrethroids tetramethrin, d-phenothrin, cyfluthrin, bioallethrin, and the pyrethrins. Calculated inhalable doses were 2-16 microg. A concentration of approximately 850 microg chlorpyrifos/m(3) (inhalable dose: approximately 20 microg) was determined when the "Contra insect fly spray" was applied. Highest exposure concentrations (1100-2100 microg/m3) were measured for piperonyl butoxide (PBO), corresponding to an inhalation intake of 30-60microg. When simulating worst-case conditions, exposure concentrations of 200-3400microg/m3 and inhalable doses of 10-210microg were determined for the various active substances. Highest concentrations (4800-8000 microg/m3) were measured for PBO (inhalable: 290-480 microg). By applying the electro-vaporizer "Nexa Lotte" plug-in mosquito killer concentrations for d-allethrin were in the range of 5-12microg/m3 and 0.5-2 microg/m3 for PBO while with the "Paral" plug-in mosquito killer concentrations of 0.4-5microg/m3 for pyrethrins and 1-7 microg/m3 for PBO were measured. Potential dermal exposures were determined using exposure pads. Between 80 and 1000microg active substance (tetramethrin, phenothrin, cyfluthrin, bioallethrin, pyrethrins, chlorpyrifos) were deposited on the clothing of the total body surface area of the spray user. Highest levels (up to 3000 microg) were determined for PBO. Worst-case uses of the sprays led to 5-9 times higher concentrations. Also a 2-hour stay nearby an operating electro-vaporizer led to a contamination of the clothing (total amounts on the whole body were 450 microg d-allethrin and 50 microg PBO for "Nexa Lotte" plug-in mosquito killer and 80 microg pyrethrins and 190 microg PBO for "Paral" plug-in mosquito killer). Human biomonitoring data revealed urine concentrations of the metabolite (E)-trans-chrysanthemum dicarboxylic acid ((E)-trans-CDCA) between 1.7 microg/l and 7.1 microg/l after 5 minutes of exposure to the different sprays. Also the use of electro-vaporizers led to (E)-trans-CDCA concentrations in the urine in the range of 1.0 microg/l to 6.2 microg/l (1-3 hours exposure period). The exposure data presented can be used for performing human risk assessment when these biocidal products were applied indoors. The airborne concentrations of the non-volatile active chemical compounds could be predicted from first principles using a deterministic exposure model (SprayExpo).
Levels and transfer of 210Po and 210Pb in Nordic terrestrial ecosystems.

PubMed

Brown, J E; Gjelsvik, R; Roos, P; Kålås, J A; Outola, I; Holm, E

2011-05-01

Recent developments regarding environmental impact assessment methodologies for radioactivity have precipitated the need for information on levels of naturally occurring radionuclides within and transfer to wild flora and fauna. The objectives of this study were therefore to determine activity concentrations of the main dose forming radionuclides (210)Po and (210)Pb in biota from terrestrial ecosystems thus providing insight into the behaviour of these radioisotopes. Samples of soil, plants and animals were collected at Dovrefjell, Central Norway and Olkiluoto, Finland. Soil profiles from Dovrefjell exhibited an approximately exponential fall in (210)Pb activity concentrations from elevated levels in humus/surface soils to "supported" levels at depth. Activity concentrations of (210)Po in fauna (invertebrates, mammals, birds) ranged between 2 and 123 Bq kg(-1)d.w. and in plants and lichens between 20 and 138 Bq kg(-1)d.w. The results showed that soil humus is an important reservoir for (210)Po and (210)Pb and that fauna in close contact with this media may also exhibit elevated levels of (210)Po. Concentration ratios appear to have limited applicability with regards to prediction of activity concentrations of (210)Po in invertebrates and vertebrates. Biokinetic models may provide a tool to explore in a more mechanistic way the behaviour of (210)Po in this system. Copyright © 2010 Elsevier Ltd. All rights reserved.
Incorporation of liposomes containing squid tunic ACE-inhibitory peptides into fish gelatin.

PubMed

Mosquera, Mauricio; Giménez, Begoña; Montero, Pilar; Gómez-Guillén, Maria Carmen

2016-02-01

Hydrolysates from collagen of jumbo squid (Dosidicus gigas) tunics have shown excellent angiotensin I-converting enzyme (ACE)-inhibitory activity. However, peptides directly included in food systems may suffer a decrease in activity, which could be minimized by loading them into nanoliposomes. A fraction of peptides with molecular weights <1 kDa obtained from hydrolyzed squid tunics, with reasonably high ACE-inhibitory activity (half-maximal inhibitory concentration IC50 = 0.096 g L(-1)), was encapsulated in phosphatidylcholine nanoliposomes. The peptide concentration affected the encapsulation efficiency and the stability of the resulting liposomes, which remained with a high zeta potential value (-54.3 mV) for at least 1 week at the most suitable peptide concentration. The optimal peptide concentration was established as 1.75 g L(-1). Liposomes obtained with this peptide concentration showed an encapsulation efficiency of 53%, a zeta potential of -59 mV, an average diameter of 70.3 nm and proved to be stable in the pH range 3-7 at 4 °C. Liposomes containing ACE-inhibitory peptides were incorporated in fish gelatin without detriment to the rheological properties and thermal stability of the resulting cold-induced gel. The ACE-inhibitory activity of the peptide fraction, which was not affected by the encapsulation process, conferred the bioactive potential to the nanoliposome-containing gelatin gel. © 2015 Society of Chemical Industry.
Changes in the structure and function of soil ecosystems in soils contaminated with heavy metals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuperman, R.; Parmelee, R.; Carreiro, M.

1995-09-01

The structure and function of soil communities in an area with a wide range of concentrations of heavy metals was studied in portions of the U.S. Army`s Aberdeen Proving Ground, Maryland. The study included survey of soil macro- and microinvertebrate communities, soil microorganisms, enzyme activities and the rates of nutrient dynamics in soil. Soil macroinvertebrate communities showed significant reductions in the adundance of several taxonomic and functional groups in contaminated areas. The total numbers of nematodes and numbers of fungivore, bacterivore and omnivore-predator nematodes were lower in the more contaminated areas. The numbers of active bacteria and fungi were lowermore » in areas of soil contamination. Significant reduction in the activities of all enzymes closely paralleled the increase in heavy metal concentrations. Ten-to-fifty fold reductions in enzyme activities were observed as heavy metal concentrations increased. These results suggest that soil contamination with heavy metals may have detrimental effects on soil biota and the rates of organic matter degradation and subsequent release of nutrients to aboveground communities in the area.« less
Changes in the structure and function of soil ecosystems in soils contaminated with heavy metals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuperman, R.; Parmelee, R.; Carreiro, M.

1995-06-01

The structure and function of soil communities in an area with a wide range of concentrations of heavy metals was studied in portions of the U.S. Army`s Aberdeen Proving Ground, Maryland. The study included survey of soil macro- and microinvertebrate communities, soil microorganisms, enzyme activities and the rates of nutrient dynamics in soil. Soil macroinvertebrate communities showed significant reductions in the abundance of several taxonomic and functional groups in contaminated areas. The total numbers of nematodes and numbers of fungivore, bacterivore and omnivore-predator nematodes were lower in the more contaminated areas. The numbers of active bacteria and fungi were lowermore » in areas of soil contamination. Significant reduction in the activities of all enzymes closely paralleled the increase in heavy metal concentrations. Ten-to-fifty fold reductions in enzyme activities were observed as heavy metal concentrations increased. These results suggest that soil contamination with heavy metals may have detrimental effects on soil biota and the rates of organic matter degradation and subsequent release of nutrients to aboveground communities in the area.« less
Altered erythrocyte sodium-lithium counter-transport and Na+/K(+)-ATPase activity in cystic fibrosis.

PubMed

Luczay, A; Vásárhelyi, B; Dobos, M; Holics, K; Ujhelyi, R; Tulassay, T

1997-03-01

Patients with cystic fibrosis (CF) exhibit normal concentrations of sodium and chloride in spite of the disturbance of Cl- and Na+ transport in epithelial cells. To characterize compensatory mechanisms in the regulation of sodium homeostasis, erythrocytes of 13 CF patients were analysed for sodium-lithium counter-transport (SLC), Na+/K(+)-ATPase activity and intracellular sodium content. Values were compared to those of healthy controls. Patients with CF had normal serum sodium and chloride concentrations and renal excretions of these ions were within the physiological range. Intracellular sodium concentration was similar in the CF and the control group (6.8 +/- 2.2 vs 5.7 +/- 1.0 mmol/l RBCs). Red blood cells' SLC and Na+/ K(+)-ATPase activity were elevated in CF patients (381 +/- 106 mumol/h/l RBCs vs 281 +/- 64; p < 0.01) and (445 +/- 129 mumol ATP mg prot/h vs 322 +/- 84, p < 0.01). Our study demonstrates that transmembrane cation transport systems are highly activated in CF. The increased sodium transport may be part of a compensatory mechanism of sodium homeostasis in children with CF.
Application of response surface methodology to optimize pressurized liquid extraction of antioxidant compounds from sage (Salvia officinalis L.), basil (Ocimum basilicum L.) and thyme (Thymus vulgaris L.).

PubMed

Hossain, M B; Brunton, N P; Martin-Diana, A B; Barry-Ryan, C

2010-12-01

The present study optimized pressurized liquid extraction (PLE) conditions using Dionex ASE® 200, USA to maximize the antioxidant activity [Ferric ion Reducing Antioxidant Power (FRAP)] and total polyphenol content (TP) of the extracts from three spices of Lamiaceae family (sage, basil and thyme). Optimal conditions with regard to extraction temperature (66-129 °C) and solvent concentration (32-88% methanol) were identified using response surface methodology (RSM). For all three spices, results showed that 129 °C was the optimum temperature with regard to antioxidant activity. Optimal methanol concentrations with respect to the antioxidant activity of sage and basil extracts were 58% and 60% respectively. Thyme showed a different trend with regard to methanol concentration and was optimally extracted at 33%. Antioxidant activity yields of the optimal PLE were significantly (p < 0.05) higher than solid/liquid extracts. Predicted models were highly significant (p < 0.05) for both total phenol (TP) and FRAP values in all the spices with high regression coefficients (R(2)) ranging from 0.651 to 0.999.
Enhanced antioxidant activity of gold nanoparticle embedded 3,6-dihydroxyflavone: a combinational study

NASA Astrophysics Data System (ADS)

Medhe, Sharad; Bansal, Prachi; Srivastava, Man Mohan

2014-02-01

The antioxidative effect of selected dietary compounds (3,6-dihydroxyflavone, lutein and selenium methyl selenocysteine) was determined in single and combination using DPPH (2,2-diphenyl-l-picrylhydrazyl), OH (hydroxyl), H2O2 (hydrogen peroxide) and NO (nitric oxide) radical scavenging assays. Radical scavenging effect of the dietary phytochemicals individually are found to be in the order: ascorbic acid (standard) > lutein > 3,6-dihydroxyflavone > selenium methyl selenocysteine, at concentration 100 μg/ml, confirmed by all the four bioassays (p < 0.05). Among the various combinations studied, the triplet combination of 3,6-dihydroxyflavone, lutein and selenium methyl selenocysteine (1:1:1), exhibited enhancement in the target activity at same concentration level. Synthesized gold nanoparticle embedded 3,6-dihydroxyflavone further enhanced the target antioxidant activity. The combinational study including gold nanoparticle embedded 3,6-dihydroxyflavone with other native dietary nutrients showed remarkable increase in antioxidant activity at the same concentration level. The present in vitro study on combinational and nanotech enforcement of dietary phytochemicals shows the utility in the architecture of nanoparticle embedded phytoproducts having a wide range of applications in medical science.
Cholinesterase assay for monitoring the kinetics of the JD6. 5 organophosphorus acid anhydrase in detoxification of diisopropylfluorophosphate. Final report, January-June 1988

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yeh, H.R.; Cheng, T.C.; DeFrank, J.J.

1992-06-01

In the present studies, cholinesterase was used for monitoring the enzymatic activities of the JD6.5 organophosphorus acid anhydrase. The kinetic data indicated that: (1) the first order of kinetic constants (k) and Vmax values of the enzymatic reactions increased as the concentrations of the enzyme increased; (2) while the half-life (tl/2) of diisopropylfluorophosphate (DFP) hydrolysis decreased as the enzyme concentrations increased; (3) the minimum time required for hydrolysis of 9mM of DFP was 3 min at the concentrations of the enzyme present; Km values of DFP were found to be in range of 5mM; and (4) both MnCl2 and NaClmore » were found to be required for the optimal activity of the enzyme.« less
Synthesis and structure-activity relationships of fenbufen amide analogs.

PubMed

Lin, Kun-I; Yang, Chao-Hsun; Huang, Chia-Wen; Jian, Jhen-Yi; Huang, Yu-Chun; Yu, Chung-Shan

2010-12-02

The previous discoveries of butyl fenbufen amide analogs with antitumor effects were further examined. The amide analogs with 1, 3, 4 and 8 carbons chains were prepared in 70-80% yield. Fenbufen had no cytotoxic effects at concentrations ranging from 10 to 100 μM. Methyl fenbufen amide had significant cytotoxic effects at a concentration of 100 μM. As the length of the alkyl amide side chain increased, the cytotoxic effects increased, and the octyl fenbufen amide had the greatest cytotoxic effect. After treatment with 30 μM octyl fenbufen amide, nearly seventy percent of the cells lost their viability. At the concentration of 10 μM, fenbufen amide analogs did not show cytotoxicity according to the MTT assay results. The NO scavenging activities of the fenbufen amide analogs were not significantly different from those of fenbufen.
Non-omnia moriantur-toxicity of mancozeb on dead wood microarthropod fauna.

PubMed

Adamski, Zbigniew; Bloszyk, Jerzy; Bruin, Jan; Ziemnicki, Kazimierz

2007-01-01

The effect of Dithane M-45 (dithiocarbamate fungicide; active substance: mancozeb) was studied on microarthropod fauna inhabiting dead wood. Although the exposure was almost never 100% lethal for the majority of observed taxa, almost all (Mesostigmata, Oribatida, some Uropodina, Actinedida, Collembola and Diplopoda) showed very high correlation between concentration of the fungicide and mortality (r > 0.86). Only Stigmaeidae showed low correlation (r = 0.293). For the majority of taxa LC(50 )values were close to the concentrations used during agrochemical activities in woods. Only Trachytes aegrota showed full susceptibility to the fungicide within the range of recommended field concentrations used in forestry (characterised by the low LC(95 )value). Tolerance of mesostigmatid and oribatid mites was found to differ between juveniles and adults, but not consistently. Related Uropodina species varied in susceptibility to the fungicide.
pH regulation of the kinetic stability of the lipase from Thermomyces lanuginosus.

PubMed

Wang, H; Andersen, K K; Sehgal, P; Hagedorn, J; Westh, P; Borch, K; Otzen, D E

2013-01-08

Thermomyces lanuginosus lipase (TlL) is a kinetically stable protein, resistant toward both denaturation and refolding in the presence of the ionic surfactant sodium dodecyl sulfate (SDS) and the nonionic surfactant decyl maltoside (DecM). We investigate the pH dependence of this kinetic stability. At pH 8, TlL remains folded and enzymatically active at multimillimolar surfactant concentrations but fails to refold from the acid urea-denatured state at submillimolar concentrations of SDS and DecM, indicating a broad concentration range of kinetic trapping or hysteresis. At pH 8, very few SDS molecules bind to TlL. The hysteresis SDS concentration range shrinks when moving to pH 4-6; in this pH range, SDS binds as micellelike clusters. Although hysteresis can be eliminated by reducing disulfide bonds, destabilizing the native state, and lowering the unfolding activation barrier, SDS sensitivity is not directly linked to intrinsic kinetic stability [its resistance to the general chemical denaturant guanidinium chloride (GdmCl)], because TlL unfolds more slowly in GdmCl at pH 6.0 than at pH 8.0. However, the estimated net charge drops from approximately -12 to approximately -5 between pH 8 and 6. SDS denatures TlL at pH 6.0 by nucleating via a critical number of bound SDS molecules on the surface of native TlL to form clusters. These results imply that SDS sensitivity is connected to the availability of appropriately charged regions on the protein. We suggest that conformational rigidity is a necessary but not sufficient feature of SDS resistance, because this has to be combined with sufficient negative electrostatic potential to avoid extensive SDS binding.
Isocyanatocyclohexane and isothiocyanatocyclohexane levels in urban and industrial areas and possible emission-related activities

NASA Astrophysics Data System (ADS)

Gallego, E.; Roca, F. X.; Perales, F.; Ribes, A.; Carrera, G.; Guardino, X.; Berenguer, M. J.

Isocyanatocyclohexane and isothiocyanatocyclohexane are becoming relevant compounds in urban and industrial air, as they are used in important amounts in automobile industry and building insulation, as well as in the manufacture of foams, rubber, paints and varnishes. Glass multi-sorbent tubes (Carbotrap, Carbopack, Carboxen) were connected to LCMA-UPC pump samplers for the retention of iso- and isothiocyanatocyclohexanes. The analysis was performed by automatic thermal desorption (ATD) coupled with capillary gas chromatography (GC)/mass spectrometry detector (MSD). TD-GC/MS was chosen as analytical method due to its versatility and the possibility of analysis of a wide range of volatility and polarity VOC in air samples. The method was satisfactory sensitive, selective and reproducible for the studied compounds. The concentrations of iso- and isothioisocyanatocyclohexanes were evaluated in different urban, residential and industrial locations from extensive VOC air quality and odour episode studies in several cities in the Northeastern edge of Spain. Around 200-300 VOC were determined qualitatively in each sample. Higher values of iso- and isothiocyanatocyclohexane were found in industrial areas than in urban or residential locations. The concentrations ranged between n.d.-246 and n.d.-29 μg m -3 for isocyanatocyclohexane and isothiocyanatocyclohexane, respectively, for industrial areas. On the other hand, urban and residential locations showed concentrations ranging between n.d.-164 and n.d.-29 μg m -3 for isocyanatocyclohexane and isothiocyanatocyclohexane, respectively. The site location (urban or industrial), the kind and nearness of possible iso- and isothiocyanatocyclohexane emission activities (industrial or building construction) and the changes of wind regimes throughout the year have been found the most important factors influencing the concentrations of these compounds in the different places.
Mercury concentrations in museum specimens of tuna and swordfish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, G.E.; Grant, P.M.; Kishore, R.

1972-03-10

The mercury levels of museum specimens of seven tuna caught 62 to 93 years ago and a swordfish caught 25 years ago have been determined by instrumental neutron activation analysis. These levels are in the same range as those found in specimens caught recently.
Variations of biomarkers response in mussels Mytilus galloprovincialis to low, moderate and high concentrations of organic chemicals and metals.

PubMed

Perić, Lorena; Nerlović, Vedrana; Žurga, Paula; Žilić, Luka; Ramšak, Andreja

2017-05-01

The changes of acetylcholinesterase activity (AChE), metallothioneins content (MTs), catalase activity (CAT) and lipid peroxidation (LPO) were assessed after 4 days exposure of mussels Mytilus galloprovincialis to a wide range of sublethal concentrations of chlorpyrifos (CHP, 0.03-100 μg/L), benzo(a)pyrene (B(a)P, 0.01-100 μg/L), cadmium (Cd, 0.2-200 μg/L) and copper (Cu, 0.2-100 μg/L). The activity of AChE in the gills decreased after exposure to CHP and Cu, whereas no change of activity was detected after exposure to B(a)P and Cd. Both induction and decrease of MTs content in digestive gland occurred after exposure to CHP and B(a)P, while a marked increase was evident at highest exposure concentrations of Cd. The content of MTs progressively decreased of MTs with increasing concentration of Cu. CAT activity and LPO in the gills did not change after exposure to any of the chemicals. The results demonstrate different response profile in relation to the type of chemical compound, and highlight the potential implications for evaluation of biological effect of contaminants in marine environment. Furthermore, the AChE activity in the gills and MTs content in the digestive gland could be modulated by CHP and Cu at environmentally relevant concentrations indicating the potential risks of short-term transient mussels exposure that may occur due to run-off from land or accidental releases. Copyright © 2017 Elsevier Ltd. All rights reserved.
Plackett-Burman Design for rGILCC1 Laccase Activity Enhancement in Pichia pastoris: Concentrated Enzyme Kinetic Characterization.

PubMed

Morales-Álvarez, Edwin D; Rivera-Hoyos, Claudia M; Cardozo-Bernal, Ángela M; Poutou-Piñales, Raúl A; Pedroza-Rodríguez, Aura M; Díaz-Rincón, Dennis J; Rodríguez-López, Alexander; Alméciga-Díaz, Carlos J; Cuervo-Patiño, Claudia L

2017-01-01

Laccases are multicopper oxidases that catalyze aromatic and nonaromatic compounds with concomitant reduction of molecular oxygen to water. They are of great interest due to their potential biotechnological applications. In this work we statistically improved culture media for recombinant GILCC1 (rGILCC1) laccase production at low scale from Ganoderma lucidum containing the construct pGAPZ α A- GlucPost -Stop in Pichia pastoris . Temperature, pH stability, and kinetic parameter characterizations were determined by monitoring concentrate enzyme oxidation at different ABTS substrate concentrations. Plackett-Burman Design allowed improving enzyme activity from previous work 36.08-fold, with a laccase activity of 4.69 ± 0.39 UL -1 at 168 h of culture in a 500 mL shake-flask. Concentrated rGILCC1 remained stable between 10 and 50°C and retained a residual enzymatic activity greater than 70% at 60°C and 50% at 70°C. In regard to pH stability, concentrated enzyme was more stable at pH 4.0 ± 0.2 with a residual activity greater than 90%. The lowest residual activity greater than 55% was obtained at pH 10.0 ± 0.2. Furthermore, calculated apparent enzyme kinetic parameters were a V max of 6.87 × 10 -5 mM s -1 , with an apparent K m of 5.36 × 10 -2 mM. Collectively, these important stability findings open possibilities for applications involving a wide pH and temperature ranges.
Plackett-Burman Design for rGILCC1 Laccase Activity Enhancement in Pichia pastoris: Concentrated Enzyme Kinetic Characterization

PubMed Central

Morales-Álvarez, Edwin D.; Rivera-Hoyos, Claudia M.; Cardozo-Bernal, Ángela M.; Pedroza-Rodríguez, Aura M.; Díaz-Rincón, Dennis J.; Rodríguez-López, Alexander; Alméciga-Díaz, Carlos J.; Cuervo-Patiño, Claudia L.

2017-01-01

Laccases are multicopper oxidases that catalyze aromatic and nonaromatic compounds with concomitant reduction of molecular oxygen to water. They are of great interest due to their potential biotechnological applications. In this work we statistically improved culture media for recombinant GILCC1 (rGILCC1) laccase production at low scale from Ganoderma lucidum containing the construct pGAPZαA-GlucPost-Stop in Pichia pastoris. Temperature, pH stability, and kinetic parameter characterizations were determined by monitoring concentrate enzyme oxidation at different ABTS substrate concentrations. Plackett-Burman Design allowed improving enzyme activity from previous work 36.08-fold, with a laccase activity of 4.69 ± 0.39 UL−1 at 168 h of culture in a 500 mL shake-flask. Concentrated rGILCC1 remained stable between 10 and 50°C and retained a residual enzymatic activity greater than 70% at 60°C and 50% at 70°C. In regard to pH stability, concentrated enzyme was more stable at pH 4.0 ± 0.2 with a residual activity greater than 90%. The lowest residual activity greater than 55% was obtained at pH 10.0 ± 0.2. Furthermore, calculated apparent enzyme kinetic parameters were a Vmax of 6.87 × 10−5 mM s−1, with an apparent Km of 5.36 × 10−2 mM. Collectively, these important stability findings open possibilities for applications involving a wide pH and temperature ranges. PMID:28421142
Fate of personal care and household products in source separated sanitation.

PubMed

Butkovskyi, A; Rijnaarts, H H M; Zeeman, G; Hernandez Leal, L

2016-12-15

Removal of twelve micropollutants, namely biocides, fragrances, ultraviolet (UV)-filters and preservatives in source separated grey and black water treatment systems was studied. All compounds were present in influent grey water in μg/l range. Seven compounds were found in influent black water. Their removal in an aerobic activated sludge system treating grey water ranged from 59% for avobenzone to >99% for hexylcinnamaldehyde. High concentrations of hydrophobic micropollutants in sludge of aerobic activated sludge system indicated the importance of sorption for their removal. Six micropollutants were found in sludge of an Up-flow anaerobic sludge blanket (UASB) reactor treating black water, with four of them being present at significantly higher concentrations after addition of grey water sludge to the reactor. Hence, addition of grey water sludge to the UASB reactor is likely to increase micropollutant content in UASB sludge. This approach should not be followed when excess UASB sludge is designed to be reused as soil amendment. Copyright © 2016 Elsevier B.V. All rights reserved.

Some links on this page may take you to non-federal websites. Their policies may differ from this site.