scholarly journals Metal-responsive elements act as positive modulators of human metallothionein-IIA enhancer activity.

1987 ◽  
Vol 7 (2) ◽  
pp. 606-613 ◽  
Author(s):  
M Karin ◽  
A Haslinger ◽  
A Heguy ◽  
T Dietlin ◽  
T Cooke
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Mutational Analysis ◽  
Enhancer Activity ◽  
Enhancer Element ◽  
Basal Activity ◽  
Before And After ◽  
Positive Modulator ◽  
Gc Box

The human metallothionein IIA (hMT-IIA) gene contains two enhancer elements whose activity is induced by heavy-metal ions such as Cd2+. To determine the nature of the relationship between the metal-responsive elements and the element(s) responsible for the basal activity of the enhancers, the basal-level enhancer element(s), the hMT-IIA enhancers were subjected to mutational analysis. We show that deletion of the metal-responsive elements had no effect on the basal activity of the enhancer but prevented further induction by Cd2+. On the other hand, replacement of the basal-level enhancer element with linker DNA led to inactivation of the enhancer both before and after treatment with Cd2+. Therefore, the metal-responsive elements seems to act as a positive modulator of enhancer function in the presence of heavy-metal ions. In addition to the two enhancers, the hMT-IIA promoter contained one other element, the GC box, required for its basal expression. Unlike deletion of the basal-level enhancer element, replacement of the GC box with linker DNA had no effect on the ability of the promoter to be induced by Cd2+.

Metal-responsive elements act as positive modulators of human metallothionein-IIA enhancer activity

1987 ◽  
Vol 7 (2) ◽  
pp. 606-613
Author(s):  
M Karin ◽  
A Haslinger ◽  
A Heguy ◽  
T Dietlin ◽  
T Cooke
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Mutational Analysis ◽  
Enhancer Activity ◽  
Enhancer Element ◽  
Basal Activity ◽  
Before And After ◽  
Positive Modulator ◽  
Gc Box

The human metallothionein IIA (hMT-IIA) gene contains two enhancer elements whose activity is induced by heavy-metal ions such as Cd2+. To determine the nature of the relationship between the metal-responsive elements and the element(s) responsible for the basal activity of the enhancers, the basal-level enhancer element(s), the hMT-IIA enhancers were subjected to mutational analysis. We show that deletion of the metal-responsive elements had no effect on the basal activity of the enhancer but prevented further induction by Cd2+. On the other hand, replacement of the basal-level enhancer element with linker DNA led to inactivation of the enhancer both before and after treatment with Cd2+. Therefore, the metal-responsive elements seems to act as a positive modulator of enhancer function in the presence of heavy-metal ions. In addition to the two enhancers, the hMT-IIA promoter contained one other element, the GC box, required for its basal expression. Unlike deletion of the basal-level enhancer element, replacement of the GC box with linker DNA had no effect on the ability of the promoter to be induced by Cd2+.

scholarly journals Simultaneous removal of lead, copper, cadmium, nickel, and cobalt heavy metal ions from the quinary system by Abies bornmulleriana cones

2020 ◽  
Vol 82 (12) ◽  
pp. 3032-3046
Author(s):  
Ensar Oguz
Keyword(s):  
Experimental Data ◽  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Metal Removal ◽  
Bet Surface Area ◽  
Order Model ◽  
Average Pore ◽  
Quinary System ◽  
Before And After

Abstract Abies bornmulleriana cone was used to investigate its biosorption efficiency and capacity of Pb2+, Cu2+, Cd2+, Co2+, and Ni2+ heavy metal ions in a quinary system. The mechanism of multi-metal removal was illustrated in terms of FTIR results. Electrophoretic mobilities of the biosorbents were determined to access the information about the competitive biosorption. BET surface area and pore volume of the biosorbents before and after the biosorption were defined to be (5.05 m2 g−1 and 0.0018 cm3 g−1) and (0.97 m2 g−1 and 0.00032 cm3 g−1), respectively. The average pore width of the biosorbent before and after the biosorption was calculated as 9.34 and 13.04 Å, respectively. The pseudo-first-order model and the pseudo-second-order model were applied to analyze the experimental data. Experimental data have been evaluated according to the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherms. The maximum biosorption efficiency and capacity for Pb2+, Cu2+, Cd2+, Ni2+, and Co2+ ions were defined as (85.4, 56.4, 35.4, 21.7 and 18.9%) and (8.5, 5.6, 3.5, 2.2 and 1.9 mg g−1), respectively. The selectivity of heavy metal ions resulted in the magnitude order of Pb2+ > Cu2+ > Cd2+ > Ni2+ > Co2+.

scholarly journals Banana Rachis CNC/Clay Composite Filter for Dye and Heavy Metals Adsorption from Industrial Wastewater

2021 ◽  
pp. 44-56
Author(s):  
Md. Monjurul Islam ◽  
Md. Shafiqul Islam ◽  
Mohd. Maniruzzaman ◽  
Md. Minhaz-Ul Haque ◽  
Anika Amir Mohana
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Cellulose Nanocrystals ◽  
Industrial Wastewater ◽  
Heavy Metal Ions ◽  
Dye Adsorption ◽  
Before And After ◽  
Composite Filter ◽  
Hydrolysis Of ◽  
Adsorption Capability

This study demonstrates a successful processing and utilization of banana rachis cellulose nanocrystals (CNCs) dispersed clay composite filter which is capable of adsorbing dye and heavy metal ions namely Pb(II) and Cr(III) from industrial wastewater. The composite of different compositions was prepared by dispersing the cellulose nanocrystals, obtained by acid hydrolysis of banana rachis fibres, within the tri-ethyl amine treated clay. The CNC and treated clay were characterized by Fourier transform infrared (FTIR), X-ray diffractometry (XRD), and scanning electron microscopy (SEM) analyses. Industrial wastewater containing a basic yellow2 dye and two heavy metal ions, Pb(II) and Cr(III), was passed through the prepared filters set in a column. The dye and metal ions adsorption capability of the filters were analyzed by determining the dye and metal ions concentration into the water before and after passing through the composite filter. The concentration of dye and metal ions in water was determined by a UV-visible spectrophotometer and an atomic absorption spectrophotometer, respectively. It was found that the dye adsorption capacity of the composite filters was about 50 mg per gram of composite as well as Pb(II) and Cr(III) ions adsorption capacities of the composite filters were ˃10.0 mg and ˃12.4 mg respectively per gram of the composite when CNC content in the composite was ˃30 wt.%. It was also found that the metal ions adsorption capability of the composite filter was improved with increasing CNC content in the composites.

scholarly journals Study on the adsorption of heavy metals by biochar modified with different modifiers under room temperature

2021 ◽  
Vol 293 ◽  
pp. 03014
Author(s):  
Jiajia Ding ◽  
Yu Tian ◽  
Tao Lu ◽  
Jiang Kang
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Room Temperature ◽  
Adsorption Mechanism ◽  
Physical Adsorption ◽  
Complexation Reaction ◽  
Waste Biomass ◽  
Adsorption Effect ◽  
Before And After

In order to obtain an environment-friendly biochar adsorption material with excellent adsorption performance, the biochar made from corn straw was modified with FeCl3, Na2S and KMnO4 as modifiers, and the adsorption effect of biochar on several heavy metal ions in water before and after modification was studied. The properties of biochar before and after modification were characterized by SEM, XRD, FTIR and BET, and the adsorption mechanism was discussed. The results showed that the three modified reagents could effectively improve the adsorption capacity of biochar for three heavy metal ions in water, and the adsorption effect was still good at room temperature. The adsorption difference is related to the specific surface area, pore structure, aromatic structure and SiO2 content of biochar. The adsorption mechanism mainly includes the complexation reaction between physical adsorption and surface functional groups. This study is beneficial to promote the resource utilization of agricultural and forestry waste biomass, and provides a certain reference basis for related research.

Bioadsorption of Multiple Heavy Metal Ions by Rhizophora Apiculate sp. and Elaesis Guineensis sp.

2017 ◽  
Vol 14 (1) ◽  
pp. 15
Author(s):  
M.B. Nicodemus Ujih ◽  
Mohammad Isa Mohamadin ◽  
Milla-Armila Asli ◽  
Bebe Norlita Mohammed
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Removal Efficiency ◽  
Heavy Metal Ions ◽  
Agricultural Waste ◽  
Living Organism ◽  
Heavy Metal Concentration ◽  
Industrial Area ◽  
Electrochemical Treatment ◽  
Chemical Oxidation

Heavy metal ions contamination has become more serious which is caused by the releasing of toxic water from industrial area and landfill that are very harmful to all living organism especially human and can even cause death if contaminated in small amount of heavy metal concentration. Currently, peoples are using classic method namely electrochemical treatment, chemical oxidation/reduction, chemical precipitation and reverse osmosis to eliminate the metal ions from toxic water. Unfortunately, these methods are costly and not environmentally friendly as compared to bioadsorption method, where agricultural waste is used as biosorbent to remove heavy metals. Two types of agricultural waste used in this research namely oil palm mesocarp fiber (Elaesis guineensis sp.) (OPMF) and mangrove bark (Rhizophora apiculate sp.) (MB) biomass. Through chemical treatment, the removal efficiency was found to improve. The removal efficiency is examined based on four specification namely dosage, of biosorbent to adsorb four types of metals ion explicitly nickel, lead, copper, and chromium. The research has found that the removal efficiency of MB was lower than OPMF; whereas, the multiple metals ions removal efficiency decreased in the order of Pb2+ > Cu2+ > Ni2+ > Cr2+.

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