Hossein Ahmadzadeh - Academia.edu (original) (raw)

Papers by Hossein Ahmadzadeh

Environmental Monitoring and Assessment

International Journal of Environmental Science and Technology

Journal of Membrane Science

ECS Meeting Abstracts

Many biochemical, biomedical, and material applications hinge on the ability to effectively separ... more Many biochemical, biomedical, and material applications hinge on the ability to effectively separate and purify nanoscale materials. Though this need is largely addressed with biological macromolecules using a variety of chromatographic and electrophoretic purification techniques, such techniques are usually laborious, time-consuming, and often require complex and costly instalments that are inaccessible to most laboratories. Synthetic nanoparticles face similar purification challenges, often relying on techniques that are material-specific. In this work, we introduce a versatile micro-preparative (MP) method based on polyacrylamide gel electrophoresis (PAGE) to purify biological samples containing proteins, nucleic acids, and complex bioconjugates, as well as synthetic nanoparticles based on graphene quantum dots (GQDs). Using a conventional vertical slab PAGE, we demonstrate the extraction of purified DNA, proteins, and DNA-protein bioconjugates from their respective mixtures usin...

Journal of Bodywork and Movement Therapies

International Journal of Environmental Science and Technology, 2022

This work proposes Artemia cysts as a dynamic and efficient biosorbent for the elimination of lea... more This work proposes Artemia cysts as a dynamic and efficient biosorbent for the elimination of lead ion contaminants which can continuously produce new and multifold cysts as a sorbent in every cycle. Cyst of Artemia is composed of multiple layers covered with a porous surface and numerous functional groups that are capable of vigorous encapsulation of lead ions. Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive spectrometry and X-ray diffraction analyses were used to assess surface properties of the cyst. The most vital parameters in evaluating adsorption rate such as pH, contact time, initial concentration of lead ions and selectivity for uptake of the lead ions in the presence of high concentration of Ca2+/Mg2+/Na+/Cd2+/Co2+/Cu2+/Mn2+/Ni2+ proved that rapid and robust biosorption occurred during these selectivity experiments. The most astounding result to appear from the data was that batch experiment showed the maximum uptake of 94.40% at pH 5.8 in less than 1 min with 50 mg L−1 of initial concentration of lead ions. Equilibrium biosorption well fitted by Langmuir isotherm. The negative value of change in Gibbs free energy (ΔG) indicated the spontaneous adsorption of lead ion on the biosorbent. The enthalpy change indicated that an exothermic reaction was occurring during the biosorption process in which the ΔH was -28.74 kJ mol−1. The results confirmed the efficient, simple and straight forward performance of Artemia cysts in purifying contaminated water from lead ions.

Journal of Phycological Research, 2019

Different salt concentrations are found in the large portion of water resources and agriculture l... more Different salt concentrations are found in the large portion of water resources and agriculture lands in which most of the plant species cannot be grown. Some microalgae species can be grown either in seawater or in brackish water which is not usable for normal agriculture. The present study analyzed the gene expressions associated with salt stress in Dunaliella Salina. The expression of three coding genes namely acetyl-CoA carboxylase (ACC), channelrhodopsin-1 DChR1 protein (DC), and sodium-coupled phosphate transporter protein (DSSPT) were evaluated at three salinity levels: 3 gl-1 (low), 32 gl-1 (control), 100 gl-1 (high) . The analysis were performed on the 5th, 10th and 17th day of culture. The results revealed that for low and high salt treatments, the lowest gene expressions were observed on 5th day of growth, however, the gene 10th day. It should be noted that, under low salinity conditions (3 gl-1), gene expressions were lower than high salinity concentration during the gro...

Solar Energy, 2021

Abstract The electrophoretic loading of porous perovskite-lanthanum cobaltite (LaCoO3) on bismuth... more Abstract The electrophoretic loading of porous perovskite-lanthanum cobaltite (LaCoO3) on bismuth doped g-C3N4 (Bi@g-C3N4) as a novel photoanode was designed for the efficient photoelectrocatalytic water splitting. Before loading cocatalyst, the photoelectrocatalytic oxygen evolution of g-C3N4 was investigated with various amounts of Bi. The photoconversion efficiency enhanced more than 3.7 times for 3.6% Bi doped compared with that of the pristine g-C3N4. The Mott-Schottky plots showed the amount of band bending for Bi@g-C3N4 is more than that of g-C3N4 resulting in better electron transfer at the photoelectrode/electrolyte interface. By loading LaCoO3 on Bi@g-C3N4 photoanode, the photoconversion efficiency of 2.3% at 0.28 V (vs. RHE) was obtained under visible light which is more than that of Bi@g-C3N4 (0.92% at 0.48 V vs. RHE) alone. The high photocurrent density of 0.40 mA cm−2 was observed for Bi@g-C3N4/LaCoO3 photoanode as compared with Bi@g-C3N4 (0.17 mA cm−2) at the redox potential of O2/H2O. Also, Bi@g-C3N4/LaCoO3 photoanode represents a smaller arc radius in electrochemical impedance spectroscopy Nyquist plot compared with those of g-C3N4 and Bi@g-C3N4.

The biochemical and biomedical fields hinge on the ability to effectively separate and purify bio... more The biochemical and biomedical fields hinge on the ability to effectively separate and purify biological macromolecules. Though this need is largely addressed with a variety of chromatographic and electrophoretic purification techniques, such techniques are usually laborious, time-consuming, and often require complex and costly instalments that are inaccessible to most laboratories. In this work, we introduce a simple micro-preparative (MP) method based on polyacrylamide gel electrophoresis (PAGE) to purify biological samples containing proteins, nucleic acids, and complex bioconjugates. Using a conventional vertical slab system, we demonstrate the extraction of purified DNA, proteins, and DNA-protein bioconjugates from their respective mixtures using MP-PAGE. We apply this system to recover DNA from a ladder mixture with yields of up to 90%, compared to the 58% yield obtained using specialized commercial devices. We also demonstrate the purification of folded enhanced yellow fluore...

The Analyst, 2019

Tethered nanoparticles (NPs) are able to improve the separation efficiency of proteins in SDS-pol... more Tethered nanoparticles (NPs) are able to improve the separation efficiency of proteins in SDS-polyacrylamide gel electrophoresis (SDS-PAGE) due to their capability of enhancing heat dissipation during electrophoresis and restriction of electrophoretic movement of NPs.

Colloids and Surfaces B: Biointerfaces, 2017

Ag-RGO nanocomposite acts as a bactericidal agent.  The antibacterial properties of Ag-RGO are t... more Ag-RGO nanocomposite acts as a bactericidal agent.  The antibacterial properties of Ag-RGO are time and concentration dependent.  Ag-RGO nanocomposite can reduce the viability of glioblastoma cancer cells.  The kinetics and mechanism of antibacterial activity of Ag-RGO were investigated.

Environmental Geology, 2005

The quality of groundwater is poorly understood in the arid northwest part of Rajasthan, whereas ... more The quality of groundwater is poorly understood in the arid northwest part of Rajasthan, whereas it is the only source of drinking and irrigation and the residents consume it without any prior treatment. This study illustrates the qualitative analysis of groundwater and its suitability in the bulk samples collected from three different canal catchment areas. Most of the samples were identified for higher values of EC, TDS, TH and fluoride, therefore considered posing restriction to drinking use. The abundance of major ions was found in the order of Na + > Ca +2 > Mg +2 > K + = Cl − > HCO 3 − > SO 4 −2 > NO 3 − > F −. The irrigation quality parameters such as sodium adsorption ratio, %Na, residual sodium carbonate, residual sodium bicarbonate, Kelley's index, potential salinity, magnesium hazard, Mg/Ca ratio and permeability index were calculated and discussed thoroughly in combination with Wilcox, USSL and Doneen diagrams. Most of the samples belong to predominant Cl − and Na + in hydrogeochemical studies. According to USSL diagram, majority of the samples fall under C 4 S 1 class. Furthermore, groundwater chemistry was found mainly influenced by evaporation-crystallization in Gibbs variation diagram. This study suggested that groundwater is unsafe for drinking purpose without purification and quality measures should be considered while cropping in its irrigation use.

Journal of the Geological Society of India, 2012

The suitability of groundwater for irrigation uses was assessed in Alathur Block located in Peram... more The suitability of groundwater for irrigation uses was assessed in Alathur Block located in Perambalur District of the state of Tamil Nadu. Groundwater samples from ten villages were analyzed in two seasons for major cations, anions and other parameters such as electrical conductivity, total dissolved solids, Kelly's ratio, sodium absorption ratio (SAR), magnesium ratio, % sodium, chloro-alkaline indices, residual sodium carbonate and permeability index to know the suitability of groundwater for irrigation purpose. Piper trilinear diagram interpretations were made to know the suitability of chemical type of the groundwater. It reveals that the subsurface water is alkaline (Na ? K) than the alkaline earth (Ca ? Mg) type. According to the SAR values plotted in the USSL Staff diagram, most of the groundwater samples belong to class high-salinity hazard and low-sodium hazard (C3-S1) and high-salinity hazard and medium-sodium hazard (C3-S2), which indicate that the groundwater of most stations require a special type of irrigation method.

Frontiers in Marine Science

Microalgae are considered as a promising feedstock for the production of valuable fatty acids. In... more Microalgae are considered as a promising feedstock for the production of valuable fatty acids. In this study, individual fatty acid profiles during the growth period of Chlorella vulgaris were investigated. The results showed that the quantity and the type of fatty acids changed with varying rates during the growth of microalgal cells. Interchanging the fatty acid profiles may provide some metabolic information as a complementary method to radiolabeling studies. For C. vulgaris, two unsaturated fatty acids, oleic and linoleic acids, were the major components. Constant concentration of palmitic and oleic acids shows that they may serve as precursors for longer-chain fatty acids. Higher concentration of palmitic rather than palmitoleic acid (about 16 to 34 times depending on the cultivation day) shows that palmitic acid production rate is higher than its conversion rate to longer-chain fatty acids. In fact, palmitoleic acid might have been partly converted to oleic and linoleic acids....

Chemical cytometry uses capillary microseparation with highly sensitive detection for detailed ch... more Chemical cytometry uses capillary microseparation with highly sensitive detection for detailed chemical analyses of single cells. Here, we studied microscopy and chemical cytometry in measurements of total fluorescence from single cells. An inverted fluorescence microscope was modified so that the fluorescence intensity of a sample could be automatically measured for different vertical positions of the sample with respect to the objective lens. The capillary of a custom-made chemical cytometer was mounted in a vertical position over the microscope stage. A diluted suspension of 4T1 (mouse mammary gland tumor) cells stably expressing green fluorescent protein (GFP) was placed on a microscope slide. A single cell was positioned in the center of the field of view of the microscope. The intensity of its total GFP fluorescence was measured with the microscope detector first. The cell was then analyzed in the chemical cytometer as follows. The cell was injected into a capillary and lysed ...

The textile and dye industries produce waste streams with considerable concentrations of heavy me... more The textile and dye industries produce waste streams with considerable concentrations of heavy metals and complex organic compounds. There are a number of conventional approaches for the removal of these pollutants but they require a significant amount of capital investment and energy. Some of these treatment processes include coagulation/flocculation/precipitation, reverse osmosis, electro-dialysis and ultrafiltration. Most of these processes reduce the contaminant load to environmentally safe levels but in most cases they produce a large volume of low-density toxic sludge. Alternative bioremediation-based treatment systems have slowly been gaining acceptance in the industrial effluent treatment industry in recent years. Natural organisms are used to break down hazardous substances into less toxic or non-toxic substances. This chapter describes the role of conventional treatment processes and the use of microalgae in the breakdown of complex organic compounds and the concentration ...

Physical Chemistry Research, 2019

The role of carbon dioxide in global warming is one of the contemporary environmental issues and ... more The role of carbon dioxide in global warming is one of the contemporary environmental issues and it is, therefore, necessary to have available technology to capture the released CO2 into the atmosphere. Amino acids have the same amine functionality as alkanolamines with similar behavior towards CO2 absorption. The solubility of carbon dioxide in potassium glycinate (KG) solutions with different concentrations at various temperatures was measured. The results showed that the mole of CO2‌‌ adsorbed, increases both by temperature and the concentration of KG. The against the KG concentration at different temperatures was fitted with a sigmoidal function so that the moles of CO2‌‌ adsorbed can be reproduced in the temperature range of 300.15 to 327.15 K and the concentrations of 0.01-1.00 M of KG within the experimental errors.

Colloid and Interface Science Communications