scholarly journals Degradation of Chlorobenzenes at Nanomolar Concentrations byBurkholderia sp. Strain PS14 in Liquid Cultures and in Soil

1999 ◽  
Vol 65 (6) ◽  
pp. 2547-2552 ◽  
Author(s):  
Peter Rapp ◽  
Kenneth N. Timmis
Keyword(s):  
Incubation Period ◽  
Detection Limits ◽  
Batch Experiments ◽  
Sorptive Capacity ◽  
Residual Concentration ◽  
Soil Microcosms ◽  
Initial Concentration ◽  
High Affinity ◽  
Low Cell Density ◽  
Very High

ABSTRACT The utilization of 1,2,4,5-tetrachloro-, 1,2,4-trichloro-, the three isomeric dichlorobenzenes and fructose as the sole carbon and energy sources at nanomolar concentrations was studied in batch experiments with Burkholderia sp. strain PS14. In liquid culture, all chlorobenzenes were metabolized within 1 h from their initial concentration of 500 nM to below their detection limits of 0.5 nM for 1,2,4,5-tetrachloro- and 1,2,4-trichlorobenzene and 7.5 nM for the three dichlorobenzene isomers, with 63% mineralization of the tetra- and trichloroisomers. Fructose at the same initial concentration was, in contrast, metabolized over a 4-h incubation period down to a residual concentration of approximately 125 nM with 38% mineralization during this time. In soil microcosms, Burkholderia sp. strain PS14 metabolized tetrachlorobenzene present at 64.8 ppb and trichlorobenzene present at 54.4 ppb over a 72-h incubation period to below the detection limits of 0.108 and 0.09 ppb, respectively, with approximately 80% mineralization. A high sorptive capacity ofBurkholderia sp. strain PS14 for 1,2,4,5-tetrachlorobenzene was found at very low cell density. The results demonstrate thatBurkholderia sp. strain PS14 exhibits a very high affinity for chlorobenzenes at nanomolar concentrations.

Effects of Heparin Oligosaccharides with High Affinity for Antithrombin III in Experimental Venous Thrombosis

1982 ◽  
Vol 47 (03) ◽  
pp. 244-248 ◽  
Author(s):  
D P Thomas ◽  
Rosemary E Merton ◽  
T W Barrowcliffe ◽  
L Thunberg ◽  
U Lindahl
Keyword(s):  
Antithrombin Iii ◽  
Specific Activity ◽  
High Specific Activity ◽  
Factor Xa ◽  
Blood Levels ◽  
Thrombin Time ◽  
High Affinity ◽  
Very High

SummaryThe in vitro and in vivo characteristics of two oligosaccharide heparin fragments have been compared to those of unfractionated mucosal heparin. A decasaccharide fragment had essentially no activity by APTT or calcium thrombin time assays in vitro, but possessed very high specific activity by anti-Factor Xa assays. When injected into rabbits at doses of up to 80 ¼g/kg, this fragment was relatively ineffective in impairing stasis thrombosis despite producing high blood levels by anti-Xa assays. A 16-18 monosaccharide fragment had even higher specific activity (almost 2000 iu/mg) by chromogenic substrate anti-Xa assay, with minimal activity by APTT. When injected in vivo, this fragment gave low blood levels by APTT, very high anti-Xa levels, and was more effective in preventing thrombosis than the decasaccharide fragment. However, in comparison with unfractionated heparin, the 16-18 monosaccharide fragment was only partially effective in preventing thrombosis, despite producing much higher blood levels by anti-Xa assays.It is concluded that the high-affinity binding of a heparin fragment to antithrombin III does not by itself impair venous thrombogenesis, and that the anti-Factor Xa activity of heparin is only a partial expression of its therapeutic potential.

scholarly journals Tityus serrulatus venom contains two classes of toxins. Tityus gamma toxin is a new tool with a very high affinity for studying the Na+ channel.

1982 ◽  
Vol 257 (21) ◽  
pp. 12553-12558
Author(s):  
J Barhanin ◽  
J R Giglio ◽  
P Léopold ◽  
A Schmid ◽  
S V Sampaio ◽  
...  
Keyword(s):  
Na Channel ◽  
High Affinity ◽  
Tityus Serrulatus ◽  
Tityus Serrulatus Venom ◽  
Very High

N-terminal fragment of the anti-angiogenic human endostatin binds copper(II) with very high affinity

2009 ◽  
Vol 103 (7) ◽  
pp. 940-947 ◽  
Author(s):  
András Kolozsi ◽  
Attila Jancsó ◽  
Nóra V. Nagy ◽  
Tamás Gajda
Keyword(s):  
High Affinity ◽  
Terminal Fragment ◽  
Very High

scholarly journals Pre-treatment of desalination feed seawater by Jordanian Tripoli, Pozzolana, and Feldspar: Batch experiments

2011 ◽  
Vol 17 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Aiman Al-Rawajfeh ◽  
Khaldoon Al-Whoosh ◽  
Dwairi Al ◽  
Ahmad Al-Maaberah ◽  
Amer Tarawneh
Keyword(s):  
Layered Double Hydroxide ◽  
Metal Ion ◽  
Raw Materials ◽  
Batch Experiments ◽  
Initial Concentration ◽  
Considerable Potential ◽  
Ion Concentrations ◽  
Pre Treatment ◽  
Co Precipitation ◽  
Double Hydroxide

In this research, composites of layered double hydroxide (LDH) with three Jordanian natural raw materials; Tripoli (T), Pozzolana (P) and Feldspar (F) were prepared by co-precipitation and have been used for feed seawater pre-treatment. The data reveals that percent adsorption decreased with increase in initial concentration, but the actual amount of adsorbed ions per unit mass of LDH/T-P-F increased with increase in metal ion concentrations. The values of ?Go were negative and within 21 to 26 KJ/mol, while the values of ?Ho and ?So were positive and within the range of 0.1 to 25 KJ/mol. The values of ?H?, ?S?, and ?G? indicate the favorability of physisorption and show that the LDH/T-P-F composites have a considerable potential as adsorbents for the removal of ions from seawater.

scholarly journals Efficient removal of arsenic from water by dielectrophoresis-assisted adsorption

2018 ◽  
Vol 19 (4) ◽  
pp. 1066-1072
Author(s):  
Q. H. Jin ◽  
C. Y. Cui ◽  
H. Y. Chen ◽  
Y. Wang ◽  
J. F. Geng ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Removal Efficiency ◽  
Solution Ph ◽  
Residual Concentration ◽  
Initial Concentration ◽  
Weight Percentage ◽  
Before And After ◽  
High Concentrations ◽  
Plant Ash ◽  
Adsorbent Dose

Abstract Adsorption (ADS) and dielectrophoresis (DEP) techniques were combined (ADS/DEP) to efficiently remove As(V) in industrial wastewater. Fly ash, activated carbon, corncob and plant ash were tested to determine the best adsorbent by their adsorption capacity. Plant ash showed the highest adsorption capacity compared with the others. Different parameters such as solution pH and adsorbent dose were explored. The maximum As(V) removal efficiency was 91.4% at the optimized conditions (pH 9.0, adsorbent dose 5 g/L) when the initial concentration of As(V) was 15 mg/L. With the ADS/DEP technique, the plant ash particles with adsorbed As(V) were trapped on the electrodes in a DEP device. The ADS/DEP process could increase the removal efficiency of As(V) to 94.7% at 14 V even when the initial concentration of As(V) was 15 mg/L. And the residual concentration of As(V) decreased to 0.34 mg/L after two series of the ADS/DEP process. The adsorbents before and after DEP were examined by scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analysis. After the DEP process, the weight percentage of As(V) on the adsorbent surface increased to 0.96% from 0.5%. The ADS/DEP process could be a new efficient way to remove arsenic pollutant at high concentrations.

scholarly journals The effect of temperature on the oxygen dissociation curves of whole blood of larval and adult lampreys (Geotria australis)

1982 ◽  
Vol 97 (1) ◽  
pp. 253-261
Author(s):  
D. J. Macey ◽  
I. C. Potter
Keyword(s):  
Whole Blood ◽  
Life Cycle Stage ◽  
Effect Of Temperature ◽  
High Affinity ◽  
Oxygen Dissociation ◽  
Geotria Australis ◽  
Oxygen Tensions ◽  
Dissociation Curves ◽  
Hill Plots ◽  
Very High

1. Oxygen dissociation curves of the whole blood of larvae and adults of the Southern Hemisphere lamprey Geotria australis have been determined between pH 6.8 and 8.2 at 5, 15 and 25 degrees C. 2. The P50's at temperatures of 5, 15 and 25 degrees C and a pH of 7.75 were respectively 0.57, 0.92 and 1.19 mmHg in larvae and 6.9, 10.3 and 19.0 mmHg in adults. 3. The relatively very high affinity of larval blood for oxygen may reflect an adaptation to low environmental oxygen tensions. 4. The Bohr shift was not significantly affected by either temperature or life-cycle stage. 5. The slope (n) in Hill plots increased with temperature and oxygen saturation, and was greater in adults than in larvae.

SH2 domains exhibit high-affinity binding to tyrosine-phosphorylated peptides yet also exhibit rapid dissociation and exchange

1993 ◽  
Vol 13 (3) ◽  
pp. 1449-1455
Author(s):  
S Felder ◽  
M Zhou ◽  
P Hu ◽  
J Ureña ◽  
A Ullrich ◽  
...  
Keyword(s):  
Growth Factor ◽  
Intracellular Signaling ◽  
Interaction Analysis ◽  
Growth Factor Receptors ◽  
Signaling Molecules ◽  
Sequence Motif ◽  
Sh2 Domains ◽  
High Affinity ◽  
Phosphorylated Peptides ◽  
Very High

src homology 2 (SH2) domains of intracellular signaling molecules such as phospholipase C-gamma and phosphatidylinositol 3'-kinase-associated protein p85 represent recognition motifs for specific phosphotyrosine-containing regions on activated growth factor receptors. The binding of SH2 domains to activated growth factor receptors controls the interaction with signaling molecules and the regulation of their activities. In this report, we describe the kinetic parameters and binding affinities of SH2 domains of p85 toward short phosphotyrosine-containing peptides with the amino acid sequence motif YMXM, derived from a major insulin receptor substrate, IRS-1, by using real time biospecific interaction analysis (BIAcore). Associations were specific and of very high affinity, with dissociation constants of 0.3 to 3 nM, between phosphopeptides and the two separate SH2 domains contained within p85. Nonphosphorylated peptides showed no measurable binding, and the interactions were specific for the primary sequence very close to the phosphotyrosine residue. Moreover, the interactions between phosphopeptides and SH2 domains of other signaling molecules were of much lower affinity. Interestingly, the binding of the SH2 domains to the tyrosine-phosphorylated peptides was of high affinity as a result of a very high on rate, of 3 x 10(7) to 40 x 10(7)/M/s; at the same time, the rate of dissociation, of 0.11 to 0.19/s, was rapid, allowing for rapid exchange of associating proteins with the tyrosine phosphorylation sites.

scholarly journals Measurement of alkyl and multifunctional organic nitrates by proton-transfer-reaction mass spectrometry

2017 ◽  
Vol 10 (4) ◽  
pp. 1445-1463 ◽  
Author(s):  
Marius Duncianu ◽  
Marc David ◽  
Sakthivel Kartigueyane ◽  
Manuela Cirtog ◽  
Jean-François Doussin ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Transfer Reaction ◽  
Detection Limits ◽  
Proton Transfer Reaction ◽  
Reaction Mass ◽  
Organic Nitrate ◽  
Organic Nitrates ◽  
Alkyl Nitrates ◽  
High Affinity ◽  
Tof Ms

Abstract. A commercial PTR-TOF-MS has been optimized in order to allow the measurement of individual organic nitrates in the atmosphere. This has been accomplished by shifting the distribution between different ionizing analytes, H3O+∕ H3O+(H2O)n or NO+∕ NO2+. The proposed approach has been proven to be appropriate for the online detection of individual alkyl nitrates and functionalized nitrates. It has been shown that hydroxyl and ketonitrates have a high affinity towards NO+, leading to the formation of an adduct that allows the easy identification of the organic nitrate (R) from the R–NO+ ion signal. The recorded sensitivities for both ionization modes correspond to detection limits of tens of ppt min−1 in the case of hydroxy- and ketonitrates. Alkyl nitrates exhibit a moderate affinity towards NO+ ionization leading to detection units of few hundreds of ppt and the highest sensitivity in H3O+ mode was obtained for the water adducts signals. However, this method exhibits much lower capabilities for the detection of peroxyacetyl nitrates with detection limits in the ppb range.

scholarly journals SH2 domains exhibit high-affinity binding to tyrosine-phosphorylated peptides yet also exhibit rapid dissociation and exchange.

1993 ◽  
Vol 13 (3) ◽  
pp. 1449-1455 ◽  
Author(s):  
S Felder ◽  
M Zhou ◽  
P Hu ◽  
J Ureña ◽  
A Ullrich ◽  
...  
Keyword(s):  
Growth Factor ◽  
Intracellular Signaling ◽  
Interaction Analysis ◽  
Growth Factor Receptors ◽  
Signaling Molecules ◽  
Sequence Motif ◽  
Sh2 Domains ◽  
High Affinity ◽  
Phosphorylated Peptides ◽  
Very High

src homology 2 (SH2) domains of intracellular signaling molecules such as phospholipase C-gamma and phosphatidylinositol 3'-kinase-associated protein p85 represent recognition motifs for specific phosphotyrosine-containing regions on activated growth factor receptors. The binding of SH2 domains to activated growth factor receptors controls the interaction with signaling molecules and the regulation of their activities. In this report, we describe the kinetic parameters and binding affinities of SH2 domains of p85 toward short phosphotyrosine-containing peptides with the amino acid sequence motif YMXM, derived from a major insulin receptor substrate, IRS-1, by using real time biospecific interaction analysis (BIAcore). Associations were specific and of very high affinity, with dissociation constants of 0.3 to 3 nM, between phosphopeptides and the two separate SH2 domains contained within p85. Nonphosphorylated peptides showed no measurable binding, and the interactions were specific for the primary sequence very close to the phosphotyrosine residue. Moreover, the interactions between phosphopeptides and SH2 domains of other signaling molecules were of much lower affinity. Interestingly, the binding of the SH2 domains to the tyrosine-phosphorylated peptides was of high affinity as a result of a very high on rate, of 3 x 10(7) to 40 x 10(7)/M/s; at the same time, the rate of dissociation, of 0.11 to 0.19/s, was rapid, allowing for rapid exchange of associating proteins with the tyrosine phosphorylation sites.

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