Natural water chemistry (dissolved organic carbon, pH, and hardness) modulates colloidal stability, dissolution, and antimicrobial activity of citrate functionalized silver nanoparticles

2014 ◽  
Vol 1 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Lok R. Pokhrel ◽  
Brajesh Dubey ◽  
Phillip R. Scheuerman
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Water Chemistry ◽  
Natural Water ◽  
Colloidal Stability ◽  
Natural Water Chemistry

scholarly journals Seasonal variability of natural water chemistry affects the fate and behaviour of silver nanoparticles

Chemosphere ◽  
2018 ◽  
Vol 191 ◽  
pp. 616-625 ◽  
Author(s):  
Laura-Jayne A. Ellis ◽  
Mohammed Baalousha ◽  
Eugenia Valsami-Jones ◽  
Jamie R. Lead
Keyword(s):  
Silver Nanoparticles ◽  
Water Chemistry ◽  
Natural Water ◽  
Seasonal Variability ◽  
Natural Water Chemistry

Effects of trophic status and wetland morphology, hydroperiod, and water chemistry on mercury concentrations in fish

2000 ◽  
Vol 57 (1) ◽  
pp. 171-180 ◽  
Author(s):  
Joel W Snodgrass ◽  
Charles H Jagoe ◽  
A Lawrence Bryan, Jr. ◽  
Heather A Brant ◽  
J Burger
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Water Chemistry ◽  
Maximum Depth ◽  
Trophic Levels ◽  
Whole Body ◽  
Regression Analyses ◽  
Negative Effects ◽  
Depression Wetlands ◽  
Negative Effect

We sampled fish and selected water chemistry variables (dissolved organic carbon, sulfate, and pH) in nine southeastern depression wetlands to determine relationships among wetland morphology (surface area and maximum depth), hydrology, water chemistry, and bioaccumulation of mercury (Hg) in fishes. We concentrated on three fish species representing the range of trophic levels occupied by fish in southeastern depression wetlands. Whole-body Hg concentrations were lowest in lake chubsucker (Erimyzon sucetta), a benthic detritivore, and highest in redfin pickerel (Esox americanus americanus), a top carnivore. However, variation in Hg concentrations among wetlands was greater than variation among species. Regression analyses indicated that maximum depth and hydroperiod accounted for significant portions of variation among wetlands in standardized lake chubsucker and redfin pickerel Hg concentrations. Maximum depth and dissolved organic carbon had a negative effect on standardized Hg concentrations in mud sunfish (Acantharchus pomotis). Path analysis confirmed the results of regression analyses, with maximum depth and hydroperiod having relatively large direct negative effects on Hg concentrations. Our results suggest that leaching of Hg from sediments during the drying and reflooding cycle and binding of Hg species by dissolved organic carbon in the water column are primary factors controlling the bioavailability of Hg in southeastern depression wetlands.

Ampicillin-augmented silver nanoparticles for synergistic antimicrobial response: A promising therapeutic approach

2021 ◽  
Vol 22 ◽  
Author(s):  
Kashan Khan ◽  
Mohd Aamir Qureshi ◽  
Ameer Azam ◽  
Moinuddin ◽  
Javed Musarrat ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Bacterial Infections ◽  
Colloidal Stability ◽  
Resistant Bacteria ◽  
Antimicrobial Drugs ◽  
Vis Spectroscopy ◽  
Microbial Infections ◽  
Ft Ir

Aims: Globally Scientists are working to find more efficient antimicrobial drugs to treat microbial infections and kill drug-resistant bacteria. Background: Despite the availability of numerous antimicrobial drugs bacterial infections still poses a serious threat to global health. Due to a constant decline in the effectiveness of antibiotics owing to their repeated exposure as well as shortlasting antimicrobial activity, led to the demand for developing novel therapeutic agents capable of controlling microbial infections. Objective: In this study, we report antimicrobial activity of chemically synthesized silver nanoparticles (cAgNPs) augmented with ampicillin (amp) in order to increase antimicrobial response against Escherichia coli (gram –ve), Staphylococcus aureus (gram +ve) and Streptococcus mutans (gram +ve). Methods: Nanostructure, colloidal stability, morphology and size of cAgNPs before and after functionalization were explored by UV-vis spectroscopy, FT-IR, zeta potential and TEM. The formation and functionalization of cAgNPs was confirmed from UV-vis spectroscopy and FT-IR patterns. From TEM the average sizes of cAgNPs and cAgNP-amp were found to be 13 and 7.8 nm respectively, and change in colloidal stability after augmentation was confirmed from zeta potential values. The antimicrobial efficacies of cAgNP-amp and cAgNPs against E. coli S. aureus and S. mutans were studied by determining minimum inhibitory concentrations (MICs), zone of inhibition, assessment of viable and non-viable bacterial cells and quantitative assessment of biofilm. Results & Discussion: Our results revealed cAgNP-amp to be highly bactericidal compared to cAgNPs or amp alone. The nano-toxicity studies indicated cAgNP-amp to be less toxic compared to cAgNPs alone. Results: This study manifested that cAgNPs show synergistic antimicrobial effect when they get functionalized with amp suggesting their application in curing long-term bacterial infections.

scholarly journals Colloidal stability of (functionalised) fullerenes in the presence of dissolved organic carbon and electrolytes

2015 ◽  
Vol 2 (3) ◽  
pp. 280-287 ◽  
Author(s):  
Joris J.-H. Haftka ◽  
Patrick S. Bäuerlein ◽  
Erik Emke ◽  
Nienke Lammertse ◽  
Daria Belokhovstova ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Colloidal Stability ◽  
The Stability ◽  
Fullerene Clusters

Influence of various parameters on the stability and size of fullerene clusters is being investigated using DLS, MALS and flow cytometry.

scholarly journals Proximate and ultimate controls on carbon and nutrient dynamics of small agricultural catchments

2016 ◽  
Vol 13 (6) ◽  
pp. 1863-1875 ◽  
Author(s):  
Zahra Thomas ◽  
Benjamin W. Abbott ◽  
Olivier Troccaz ◽  
Jacques Baudry ◽  
Gilles Pinay
Keyword(s):  
Water Quality ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Water Chemistry ◽  
Human Disturbance ◽  
Nutrient Dynamics ◽  
Agricultural Activity ◽  
Agricultural Catchments ◽  
The Impact ◽  
The Relationship

Abstract. Direct and indirect effects from human activity have dramatically increased nutrient loading to aquatic inland and estuarine ecosystems. Despite an abundance of studies investigating the impact of agricultural activity on water quality, our understanding of what determines the capacity of a watershed to remove or retain nutrients remains limited. The goal of this study was to identify proximate and ultimate controls on dissolved organic carbon and nutrient dynamics in small agricultural catchments by investigating the relationship between catchment characteristics, stream discharge, and water chemistry. We analyzed a 5-year, high-frequency water chemistry data set from three catchments in western France ranging from 2.3 to 10.8 km2. The relationship between hydrology and solute concentrations differed between the three catchments and was associated with hedgerow density, agricultural activity, and geology. The catchment with thicker soil and higher surface roughness had relatively invariant carbon and nutrient chemistry across hydrologic conditions, indicating high resilience to human disturbance. Conversely, the catchments with smoother, thinner soils responded to both intra- and interannual hydrologic variation with high concentrations of phosphate (PO43−) and ammonium (NH4+) in streams during low flow conditions and strong increases in dissolved organic carbon (DOC), sediment, and particulate organic matter during high flows. Despite contrasting agricultural activity between catchments, the physical context (geology, topography, and land-use configuration) appeared to be the most important determinant of catchment solute dynamics based on principle components analysis. The influence of geology and accompanying topographic and geomorphological factors on water quality was both direct and indirect because the distribution of agricultural activity in these catchments is largely a consequence of the geologic and topographic context. This link between inherent catchment buffering capacity and the probability of human disturbance provides a useful perspective for evaluating vulnerability of aquatic ecosystems and for managing systems to maintain agricultural production while minimizing leakage of nutrients.

Influence of catchment topography on water chemistry in southeastern Québec Shield lakes

1997 ◽  
Vol 54 (10) ◽  
pp. 2215-2227 ◽  
Author(s):  
Pierre D'Arcy ◽  
Richard Carignan
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Water Chemistry ◽  
Surface Waters ◽  
Overland Flow ◽  
Canadian Shield ◽  
Chl A ◽  
Lake Water Chemistry ◽  
High Runoff ◽  
Shield Lakes

For 30 Canadian Shield lakes of southeastern Quebec, catchment slope and lake morphometry account for 50-70% of the variability of chlorophyll a (Chl a), dissolved organic carbon (DOC), total phosphorus (TP), NO3- , and NH4+ . Dissolved organic carbon, TP, Chl a, Ca, and Mg are negatively related to catchment slope, whereas NO3- and NH4+ increase with increasing slope. Concentrations of more conservative constituents (SO42-, Na, K) increase with decreasing elevation as a result of higher evapotranspiration and lower precipitation at low elevations. Catchment variables (slope, drainage area, percent wetlands) are as good predictors of Chl a (r2 = 0.7) as are water chemistry variables (TP, Ca, Mg, and pH). Dominant vegetation (deciduous vs. coniferous) has little or no influence on lake water chemistry. Hydrogeological data for the Canadian Shield suggest that, during periods of high runoff, the development of waterlogged areas and the importance of overland flow on saturated soils are inversely proportional to catchment slope. We propose that the strong influence of catchment slope on water quality is due to slope-dependent seasonal waterlogging, which determines the fate (retention or export to surface waters) of dissolved substances produced within and moving through the forest floor.

Influences of dissolved organic carbon on stream water chemistry in two forested catchments in central Sweden

2010 ◽  
Vol 101 (1-3) ◽  
pp. 229-241 ◽  
Author(s):  
Sara H. Norström ◽  
Jenny L. K. Vestin ◽  
Dan Bylund ◽  
Ulla S. Lundström
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Water Chemistry ◽  
Stream Water ◽  
Forested Catchments ◽  
Stream Water Chemistry
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