scholarly journals Potential of macrophyte for removing arsenic from aqueous solution

2012 ◽  
Vol 30 (4) ◽  
pp. 683-696 ◽  
Author(s):  
F.P. Guimaraes ◽  
R. Aguiar ◽  
J.A. Oliveira ◽  
J.A.A. Silva ◽  
D. Karam
Keyword(s):  
Aquatic Macrophytes ◽  
Leaf Size ◽  
Mass Gain ◽  
Dry Mass ◽  
Phosphate Deficiency ◽  
Lemna Gibba ◽  
High Concentration ◽  
Carotenoid Synthesis ◽  
High Concentrations ◽  
Selection Of

The potential of three aquatic macrophytes, Azoll caroliniana, Salvinia minima and Lemna gibba, was evaluated in this work aimed at selection of plants to be used in remediation of environments contaminated by arsenic (As). The experiments were carried out in a greenhouse during six days in pots containing Hoagland solution (¼ ionic strength) at As concentrations of 0.5; 2.5 and 5.0 mg L-1. The three species showed greater As accumulation as the concentration of the metalloid in solution increased. However, a reduction was detected in fresh and dry mass gain when the plants were exposed to high As concentrations. The macrophytes showed differences in efficiency of removal of As in solution. A. caroliniana, S. minima and L. gibba accumulated, on average, 0.130; 0.200; and 1.397 mg mDM-1, respectively, when exposed to 5.0 mg L-1 of As. The macrophytes absorbed a greater quantity of As in solution with low phosphate content. The greater As concentration in L. gibba tissues lowered the chlorophyll and carotenoid contents as shown by the high chlorosis incidence. Lemna gibba also exhibited a decrease in leaf size, with the total chlorophyll and carotenoid synthesis not being affected by As in A. caroliniana. This species exhibited purplish leaves with high concentration of anthocyanin, whose presence suggested association to phosphate deficiency. Marginal necrosis occurred on S. minima floating leaves, with the released daughter-plants not showing any visual symptoms during the treatment. The percentage of As removed from the solution decreased when the plants were exposed to high concentrations of the pollutant. Among the three species studied, only L. gibba could be considered an As hyper-accumulator. The use of this plant species for remediation of aquatic environments was shown to be limited and requires further investigation.

The Effects of Shock Vancomycin Concentrations on the Formation of Heteroresistance in Staphylococcus aureus

2020 ◽  
Vol 65 (9-10) ◽  
pp. 3-7
Author(s):  
V. V. Gostev ◽  
Yu. V. Sopova ◽  
O. S. Kalinogorskaya ◽  
M. E. Velizhanina ◽  
I. V. Lazareva ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
In Vitro Selection ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
High Concentration ◽  
Short Term ◽  
High Concentrations ◽  
Selection Of ◽  
Selection Of Resistance ◽  
Test Cultures

Glycopeptides are the basis of the treatment of infections caused by MRSA (Methicillin-Resistant Staphylococcus aureus). Previously, it was demonstrated that antibiotic tolerant phenotypes are formed during selection of resistance under the influence of high concentrations of antibiotics. The present study uses a similar in vitro selection model with vancomycin. Clinical isolates of MRSA belonging to genetic lines ST8 and ST239, as well as the MSSA (ATCC29213) strain, were included in the experiment. Test isolates were incubated for five hours in a medium with a high concentration of vancomycin (50 μg/ml). Test cultures were grown on the medium without antibiotic for 18 hours after each exposure. A total of ten exposure cycles were performed. Vancomycin was characterized by bacteriostatic action; the proportion of surviving cells after exposure was 70–100%. After selection, there was a slight increase in the MIC to vancomycin (MIC 2 μg/ml), teicoplanin (MIC 1.5–3 μg/ml) and daptomycin (MIC 0.25–2 μg/ml). According to the results of PAP analysis, all strains showed an increase in the area under curve depending on the concentration of vancomycin after selection, while a heteroresistant phenotype (with PAP/AUC 0.9) was detected in three isolates. All isolates showed walK mutations (T188S, D235N, E261V, V380I, and G223D). Exposure to short-term shock concentrations of vancomycin promotes the formation of heteroresistance in both MRSA and MSSA. Formation of VISA phenotypes is possible during therapy with vancomycin.

Research on the Treatment of High Concentration Dust with Bag Filter

2013 ◽  
Vol 448-453 ◽  
pp. 1369-1377
Author(s):  
Ting Shuang Leng ◽  
Bao Rui Liang ◽  
Cun Yi Song ◽  
Zhen Song Tong ◽  
Hong Qiang Liao
Keyword(s):  
Pulse Pressure ◽  
Flue Gas ◽  
Injection Pressure ◽  
Flue Gas Desulfurization ◽  
Filtration Velocity ◽  
Injection Time ◽  
Bag Filter ◽  
High Concentration ◽  
High Concentrations ◽  
Selection Of

Related trials in the treatment of high concentration desulfurization dust were operated in order to optimize the parameters of bag filter, established a set of data fit to semi-dry flue gas desulfurization dust, processed simulated flue gas with a concentration of SO2 600mg/m3, adopt filtration velocity between 0.63 ~ 0.98m/min, injection pressure between 0.3 ~ 0.4MPa, injection time between 200 ~ 300s. The experiments proved that the selection of the filtration velocity about the treatment of high concentrations desulfurization dust should be distinguished from the general cases. In addition, pulse pressure also should not be too high.

The Toxicity of Castor Beans and its Treatment with Doxycycline in Local Rabbits

2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Nael Mohammed Sarheed ◽  
Osamah Faisal Kokas ◽  
Doaa Abd Alabas Muhammed Ridh
Keyword(s):  
Castor Bean ◽  
The Body ◽  
Control Group ◽  
High Concentration ◽  
Biochemical Tests ◽  
Doxycycline Treatment ◽  
High Concentrations ◽  
Physiological Tests ◽  
Animal House ◽  
Physiological And Biochemical

The plant of castor is widely spread in the Iraqi land, and characterized with containing ricin toxin, which has a very serious effects, and because the seeds of this plant scattered in the agricultural soil and rivers water, which increases the exposure of humans and animals to these beans. Objective: This experiment was designed to study the effect of high concentration of castor bean powder in some physiological and biochemical parameters and changes in some tissues of the body, as well as trying to use doxycycline to reduce the effects of ingestion of these seeds. Materials and Methods: In the experiment, 24 local rabbits were raised and fed in the Animal House of the Faculty of Medicine / Al-Muthanna University, then divided into four groups and treated for three weeks (21 days), Control group: treated with normal saline solution (0.9) orally throughout the experiment, G1: was treated orally with a concentration of 25 mg / kg of castor bean powder daily during the experiment, G2 : orally treated 25 mg / kg of castor bean and 25 mg / kg of doxycycline, G3: orally treated 25 mg / kg of castor powder with 50 mg / kg of doxycycline daily throughout the trial period. Results: The results of the experiment showed significant changes (P less than 0.05) in all physiological and biochemical blood tests when compared with control group. There was a significant decrease in PCV, Hb, RBC, T.protein and body weights, while demonstrated a significant increase in WBC, Urea, Creatinine, ALT, AST and ALP, with distortions in liver and kidney of animals that treated with Castor beans. In contrast, the treatment with doxycycline and caster beans showed significant improvement reflected by a normal proportion in physiological tests and biochemical tests with improvement in the tissues when compared to control group. Conclusions: It can be concluded from this study that castor bean has high toxic and pathogenic effects that may be dangerous to the life of the organism. Therefore, it is advisable to be cautious of these pills and avoid exposure to them, also recommended to take high concentrations of doxycycline treatment when infected with castor bean poisoning.

Growth responses of periphyton and chironomids exposed to biologically treated bleached kraft pulp mill effluent

1997 ◽  
Vol 35 (2-3) ◽  
pp. 339-345 ◽  
Author(s):  
M. G. Dubé ◽  
J. M. Culp
Keyword(s):  
Kraft Pulp ◽  
Pulp Mill ◽  
Pulp Mill Effluent ◽  
Growth Responses ◽  
High Concentration ◽  
Wood Extractives ◽  
Kraft Pulp Mill ◽  
Bleached Kraft Pulp ◽  
Low Levels ◽  
High Concentrations

Experiments were conducted in artificial streams to determine the effects of increasing concentrations of biologically treated bleached kraft pulp mill effluent (BKPME) on periphyton and chironomid growth in the Thompson River, British Columbia. Periphyton growth, as determined by increases in chlorophyll a, was significantly stimulated at all effluent concentrations tested (0.25%, 0.5%, 1.0%, 5.0% and, 10.0%). Chironomid growth (individual weight) was also significantly stimulated at low effluent concentrations (≤1.0%). At higher concentrations (5.0% and 10.0%), chironomid growth was inhibited relative to the 1.0% treatment streams. Increases in growth were attributed to the effects of nutrient and organic enrichment from BKPME. The effluent contained high concentrations of phosphorus and appears to be an important source of carbon for benthic insects grazing on the biofilm. In high concentration effluent streams, chironomid growth decreased despite low levels of typical pulp mill contaminants. This suggests that other compounds in the effluent, such as wood extractives, may be inhibiting chironomid growth. These results support findings of field monitoring studies conducted in the Thompson River where changes in periphyton and chironomid abundance occurred downstream of the bleached kraft pulp mill.

scholarly journals Spatial Analysis (Measurements at Heights of 10 m and 20 m above Ground Level) of the Concentrations of Particulate Matter (PM10, PM2.5, and PM1.0) and Gaseous Pollutants (H2S) on the University Campus: A Case Study

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 62
Author(s):  
Robert Cichowicz ◽  
Maciej Dobrzański
Keyword(s):  
Spatial Distribution ◽  
Hydrogen Sulfide ◽  
Particulate Matter ◽  
Air Quality ◽  
Spatial Analysis ◽  
Ground Level ◽  
Leeward Side ◽  
High Concentration ◽  
Above Ground Level ◽  
High Concentrations

Spatial analysis of the distribution of particulate matter PM10, PM2.5, PM1.0, and hydrogen sulfide (H2S) gas pollution was performed in the area around a university library building. The reasons for the subject matter were reports related to the perceptible odor characteristic of hydrogen sulfide and a general poor assessment of air quality by employees and students. Due to the area of analysis, it was decided to perform measurements at two heights, 10 m and 20 m above ground level, using measuring equipment attached to a DJI Matrice 600 unmanned aerial vehicle (UAV). The aim of the measurements was air quality assessment and investigate the convergence of the theory of air flow around the building with the spatial distribution of air pollutants. Considerable differences of up to 63% were observed in the concentrations of pollutants measured around the building, especially between opposite sides, depending on the direction of the wind. To explain these differences, the theory of aerodynamics was applied to visualize the probable airflow in the direction of the wind. A strong convergence was observed between the aerodynamic model and the spatial distribution of pollutants. This was evidenced by the high concentrations of dust in the areas of strong turbulence at the edges of the building and on the leeward side. The accumulation of pollutants was also clearly noticeable in these locations. A high concentration of H2S was recorded around the library building on the side of the car park. On the other hand, the air turbulence around the building dispersed the gas pollution, causing the concentration of H2S to drop on the leeward side. It was confirmed that in some analyzed areas the permissible concentration of H2S was exceeded.

scholarly journals Photocrosslinking and photopatterning of magneto-optical nanocomposite sol–gel thin film under deep-UV irradiation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
C. Bidaud ◽  
D. Berling ◽  
D. Jamon ◽  
E. Gamet ◽  
S. Neveu ◽  
...  
Keyword(s):  
Uv Irradiation ◽  
Cobalt Ferrite ◽  
Sol Gel ◽  
Optical Devices ◽  
High Concentration ◽  
Nanocomposite Thin Films ◽  
Deep Uv ◽  
High Concentrations ◽  
193 Nm ◽  
The Impact

AbstractThis paper is aimed at investigating the process of photocrosslinking under Deep-UV irradiation of nanocomposite thin films doped with cobalt ferrite magnetic nanoparticles (MNPs). This material is composed of a hybrid sol–gel matrix in which MNP can be introduced with high concentrations up to 20 vol%. Deep-UV (193 nm) is not only interesting for high-resolution patterning but we also show an efficient photopolymerization pathway even in the presence of high concentration of MNPs. In this study, we demonstrate that the photocrosslinking is based on the free radical polymerization of the methacrylate functions of the hybrid precursor. This process is initiated by Titanium-oxo clusters. The impact of the nanoparticles on the photopolymerization kinetic and photopatterning is investigated. We finally show that the photosensitive nanocomposite is suitable to obtain micropatterns with sub-micron resolution, with a simple and versatile process, which opens many opportunities for fabrication of miniaturized magneto-optical devices for photonic applications.

scholarly journals Association of beta-cytoplasmic actin with high concentrations of acetylcholine receptor (AChR) in normal and anti-AChR-treated primary rat muscle cultures.

1984 ◽  
Vol 32 (9) ◽  
pp. 973-981 ◽  
Author(s):  
B W Lubit
Keyword(s):  
Acetylcholine Receptor ◽  
Acetylcholine Receptors ◽  
Neuromuscular Junctions ◽  
Morphological Changes ◽  
Muscle Cells ◽  
High Concentration ◽  
Rat Muscle ◽  
Cytoplasmic Actin ◽  
High Concentrations

Previous immunocytochemical studies in which an antibody specific for mammalian cytoplasmic actin was used showed that a high concentration of cytoplasmic actin exists at neuromuscular junctions of rat muscle fibers such that the distribution of actin corresponded exactly to that of the acetylcholine receptors. Although clusters of acetylcholine receptors also are present in noninnervated rat and chick muscle cells grown in vitro, neither the mechanism for the formation and maintenance of these clusters nor the relationship of these clusters to the high density of acetylcholine receptors at the neuromuscular junction in vivo are known. In the present study, a relationship between beta-cytoplasmic actin and acetylcholine receptors in vitro has been demonstrated immunocytochemically using an antibody specific for the beta-form of cytoplasmic actin. Networks of cytoplasmic actin-containing filaments were found in discrete regions of the myotube membrane that also contained high concentrations of acetylcholine receptors; such high concentrations of acetylcholine receptors have been described in regions of membrane-substrate contact. Moreover, when primary rat myotubes were exposed to human myasthenic serum, gross morphological changes, accompanied by an apparent rearrangement of the cytoplasmic actin-containing cytoskeleton, were produced. Although whether the distribution of cytoplasmic actin-containing structures was influenced by the organization of acetylcholine receptor or vice versa cannot be determined from these studies, these findings suggest that in primary rat muscle cells grown in vitro, acetylcholine receptors and beta-cytoplasmic actin-containing structures may be somehow connected.

scholarly journals Periphytic algae dynamics in lentic ecosystems in the Brazilian semiarid

2016 ◽  
Vol 77 (3) ◽  
pp. 495-505 ◽  
Author(s):  
R. S. Cordeiro ◽  
J. E. L. Barbosa ◽  
G. Q. Lima Filho ◽  
L. G. Barbosa
Keyword(s):  
Aquatic Macrophytes ◽  
Soluble Reactive Phosphorus ◽  
Algal Community ◽  
Aquatic Communities ◽  
Dry Period ◽  
Rainy Period ◽  
Brazilian Semiarid ◽  
High Concentrations ◽  
Reactive Phosphorus ◽  
Reduced Density

Abstract The hydrological periods drive the structure and organization of aquatic communities in semiarid regions. We hypothesize that a decrease of the precipitation during the dry period will favor the development of the periphytic algal community, leading to higher richness and density in this period. To test this hypothesis, we investigated the changes in the periphytic algal community structure in three shallow and eutrophic ecosystems of the Brazilian semiarid. The sampling was performed between 2007 and 2010 at two-mensal intervals. The sampling of periphytic algal was performed in aquatic macrophytes and rocks. The abiotic variables were analyzed simultaneously. Dominance in diatoms, cyanobacteria and chlorophytes, respectively, was observed in two periods. In the dry period, waters were alkaline and had high concentrations of nitrate and total phosphorus associated with the highest densities of Bacillariophyceae. In the rainy period the water was warmer, oxygenated and high concentrations of ammonia and soluble reactive phosphorus with diatoms remained dominant but with reduced density, while cyanobacteria and chlorophytes increased. Overall, periphytic algal community composition no responded to changes in the hydrological periods. However, the hydrological periods altered the dynamics of periphytic algal community, supported by the alternation of the most representative classes (diatoms and cyanobacteria) between the hydrologic periods. Our data suggest that the morphometric and chemical and physical characteristics of lentic aquatic ecosystems studied were more important in the dynamics of periphytic algal community than the hydrological periods and types of substrates.

Leakage of Endotoxins through the Endotoxin Retentive Filter: An in vitro Study

2022 ◽  
pp. 1-9
Author(s):  
Hiroshi Nozaki ◽  
Yoshihiro Tange ◽  
Yoji Inada ◽  
Takashi Uchino ◽  
Nakanobu Azuma
Keyword(s):  
Sodium Hypochlorite ◽  
Peracetic Acid ◽  
In Vitro Study ◽  
Dialysis Fluid ◽  
High Concentration ◽  
Membrane Pores ◽  
Polyether Sulfone ◽  
Repeated Use ◽  
High Concentrations

<b><i>Introduction:</i></b> Ultrapurification of dialysis fluid has enabled highly efficient dialysis treatments. Online hemodiafiltration is one such treatment that uses a purified dialysis fluid as a supplemental fluid. In this method, an endotoxin retentive filter (ETRF) is used in the final step of dialysis fluid purification, with the aim of preventing leakage of endotoxins. Sodium hypochlorite and peracetic acid are used as disinfecting agents for the dialysis fluid pipes containing the ETRF; however, the effects of these agents on ETRF membrane pores have not been fully clarified. <b><i>Methods:</i></b> Water permeability (flux) and endotoxin permeability were assessed in 3 types of ETRFs made with different membrane materials: polyester polymer alloy (PEPA), polyether sulfone (PES), and polysulfone (PS). High-concentration sodium hypochlorite and 2 types of peracetic acid were used as disinfecting agents, and the changes in flux and the endotoxin sieving coefficient (SC) were measured. <b><i>Results:</i></b> After repeated use of high concentrations of sodium hypochlorite and peracetic acid, the PEPA and PES ETRFs did not permit passage of endotoxins, regardless of their flux. However, in the PS ETRF, the flux and endotoxin SC increased with the number of cleaning cycles. No differences were observed according to the concentration of peracetic acid disinfecting agents. <b><i>Conclusion:</i></b> PEPA and PES ETRFs completely prevent endotoxin leakage and can be disinfected at concentrations higher than the conventionally recommended concentration without affecting pore expansion. Even new PS ETRFs have low levels of endotoxin leakage, which increase after disinfection cycles using sodium hypochlorite and peracetic acid.

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