Purification of Human Serum Albumin by Ion Exchange Chromatography

Introduction: Albumin, one of the most important plasma proteins, has a difficult process of synthesis and production. We compared two different methods for albumin purification: Carboxymethyl cellulose (CM cellulose) resin exchange and Diethylaminoethyl cellulose (DEAE cellulose) resin exchange in order to determine which resin could be more beneficial.Materials and methods: two ion exchange resins were used DEAE cellulose resin and CM cellulose resin. All resins were recruited according to the standard preparation protocol. The final results were analyzed using SDS-PAGE technique.Results: in DEAE Cellulose resin, nearly more than 75% of the purified protein was albumin; while, in CM cellulose resin, more than 90% was albumin.Conclusion: albumin purification using CM cellulose resin is much more efficacious compared to DEAE cellulose resin. Though significant laboratory findings were demonstrated in this study, clinical studies are needed to confirm clinical outcomes.

Prospects of Al2O3 and MgAl2O4-Supported CuO Oxygen Carriers in Chemical-Looping Combustion (CLC) and Chemical-Looping with Oxygen Uncoupling (CLOU)

The chemical-looping combustion (CLC) and chemical-looping with oxygen uncoupling (CLOU) processes are attractive solutions for efficient combustion with direct separation of carbon dioxide. In this work, the feasibility of CuO supported on Al2O3 and MgAl2O4 for CLC and CLOU processes is investigated. The oxygen carriers were produced by freeze-granulation and calcined at 950 and 1050 degrees C. The chemical-looping characteristics were evaluated in a laboratory-scale fluidized bed at 900 and 925 degrees C under alternating reducing and oxidizing conditions. Tendencies toward agglomeration, defluidization, and loss of active phase were analyzed by changing the experimental process variables, such as reaction time, temperature, and reducing and inert environments. Complete conversion of methane was obtained for all oxygen carriers investigated in this work Three out of four oxygen carriers also featured the rapid release of oxygen in an inert environment (CLOU). In the case of Al2O3) as support, a CLC and a CLOU oxygen carrier were obtained depending on the calcination temperature. In addition, analyses of the CuO-Al2O3 phase equilibria system under oxidizing and reducing conditions have been carried out. At the investigated temperatures, it is inferred for the case of Al2O3 as support that part of the active phase (either CuO or CuAl2O4 is bound as CuAlO2 during incomplete reduction with slow kinetics for reoxidation. However, when complete reduction is attained, the original active phase composition is rejuvenated upon oxidation. As a result, the use of CuAl2O4 is suggested for CLC processes from the point of agglomeration and attrition-free functioning of the oxygen carrier. In the case of MgAl2O4 as support, the oxygen carrier exhibited a stable oxygen-releasing behavior due to the existence of relatively intact CuO. Together with the absence of agglomeration and major morphological changes, the use of MgAl2O4-supported CuO is suggested as a suitable oxygen carrier for CLOU processes

Sulfur Tolerance of CaxMn1–yMyO3−δ (M = Mg, Ti) Perovskite-Type Oxygen Carriers in Chemical-Looping with Oxygen Uncoupling (CLOU)

Perovskite-structured oxygen carriers of the type CaxMn1–yMyO3−δ (M = Mg, Ti) have been investigated for the CLOU process. The oxygen carrier particles were produced by spray-drying and were calcined at 1300 °C for 4 h. A batch fluidized-bed reactor was used to investigate the chemical-looping characteristics of the materials. The effect of calcium content, dopants (Mg and Ti), and operating temperature (900, 950, 1000, and 1050 °C) on the oxygen uncoupling property and the reactivity with CH4 in the presence and absence of SO2 was evaluated. In addition, the attrition resistance and mechanical integrity of the oxygen carriers were examined in a jet-cup attrition rig. All of the investigated perovskite-type materials were able to release gas phase oxygen in inert atmosphere. Their reactivity with methane was high and increased with temperature and calcium content, approaching complete gas yield at 1000 °C. The reactivity decreased in the presence of SO2 for all of the investigated oxygen carriers. Decreasing the calcium content resulted in a less severe decrease in reactivity in the presence of SO2, with the exception of materials doped with both Mg and Ti, for which a higher resistance to sulfur deactivation could be maintained even at higher calcium contents. The drop in reactivity in the presence of SO2 also decreased at higher temperatures, and at 1050 °C, the decrease in the reactivity of the Mg- and Ti-doped material was minimal. Sulfur balance over the reactor system indicated that the fraction of the introduced SO2 that passed through the reactor increased with temperature. It was shown that it is possible to regenerate the oxygen carriers during reduction in the absence of SO2. Most of the materials also showed relatively low attrition rates. The results indicate that it is possible to modify the operating conditions and properties of perovskite-type oxygen carriers to decrease or avoid their deactivation by sulfur

Modeling the Chlorine Gas Dispersion in the Water Treatment Plant

An issue rose for industrial safety and successful address of crisis involves quick and pragmatic decision that would reduce losses and accidents. This will become practical when in addition to studying of past accidents the industrial executives create the necessary readiness to face risks through precise estimation of the consequences of eventual accidents. The present research concerns modeling the consequences of chlorine gas dispersion in the wastewater installations. The transfer of knowledge and information in this study were gained from modeling the dispersion of chlorine in the water treatment plants, useful for managers and executives. Detection and specifying the risks of chlorine for the public and especially the staff and those residing near the water treatment plant, would result in the appropriate action against this lethal substance, which is the subject of this study. Identification of risks related to foreign agents and their negative impacts on water treatment plants containing chlorine tanks is among the objectives of this study. The modeling and accurate specification of the scope and level of danger created following the dispersion of chlorine was done using the PHAST software, which allowed a clear identification of danger zones created by the dispersion of Chlorine. This text reports the radius of areas affected by chlorine dispersion as well as the results of different conditions after running the model for variable physical and process conditions, and given their availability, these results can be compared with each other

Elevating the expression level of biologically active recombinant human alpha 1-antitrypsin in Pichia pastoris

Background: Human alpha 1-antitrypsin (AAT) is a potent inhibitor of multiple serine proteases, and protects tissues against their harmful effects. Individuals with reduced or abnormal production of this inhibitor need intravenous administration of exogenous protein. In this study, we employed the methylotrophic (methanol utilizing) yeast Pichia pastoris (P. pastoris) as a preferential host for efficient production and secretion of recombinant AAT. Furthermore, we examined different strategies to maximize the yield of the secreted protein. Results: Our findings revealed that optimizing the codon usage of AAT gene for P. pastoris had positive effects on the level of secreted AAT under the control of inducible alcohol oxidase 1 (AOX1) and constitutive glycerol aldehyde phosphate dehydrogenase (GAP) promoters. Compared to AOX1, the GAP promoter increased the yield of AAT by more than two fold. It was also demonstrated that the human AAT native signal sequence was more effective than the well-known yeast signal sequence, alpha mating factor (\u3b1-MF). Doubling gene dosage nearly doubled the production of AAT, though dosages exceeding this limit had negative effects on the yield. Conclusion: P. pastoris is shown to be an efficient expression system for production of recombinant and biologically active AAT. Also different strategies could be used to elevate the amount of this secretable protein

Thiol-reducing agents abate cholestasis-induced lung inflammation, oxidative stress, and histopathological alterations

Cholestasis is not only influences the hepatic function but also damages many other organs. Lung injury is a critical secondary organ damage associated with cholestasis/cirrhosis. Pulmonary histopathological alterations, respiratory distress, and hypoxia are related to cholestasis/cirrhosis-induced lung injury. It has been found that oxidative stress plays a crucial role in this complication. The current study was designed to investigate the effect of N-acetyl cysteine (NAC) and dithiothreitol (DTT) as thiol-reducing and antioxidant agents against cholestasis-induced lung injury. Bile duct ligated (BDL) rats were monitored for the presence of inflammatory cells, TNF-α, and IgG levels in their broncho-alveolar fluid (BALF) at scheduled time intervals (3, 7, 14, and 28 days post-BDL surgery). These markers reached their highest level in the BALF of BDL rats on day 28 after the surgery. Therefore, in another set of experiments, the BDL animals were treated with NAC (100 and 300 mg/kg/day, i.p, for 28 consecutive days) and DTT (10 and 20 mg/kg/day, i.p, for 28 consecutive days). Meanwhile, a significant increase in the levels of TNF-α and IgG was detected in the BALF of BDL rats. The BALF level of neutrophils, monocytes, and lymphocytes was also significantly increased in cholestatic animals. A significant increase in lung tissue biomarkers of oxidative stress was detected in the BDL rats. It was found that NAC and DTT could significantly blunt pulmonary damage induced by cholestasis. The effects of these agents on oxidative stress biomarkers and inflammatory response seem to play a pivotal role in their mechanisms of protective properties

Copper in Chemical-Looping Combustion (CLC) and Chemical-Looping with Oxygen Uncoupling (CLOU)

The chemical-looping combustion (CLC) and chemical-looping with oxygen uncoupling (CLOU) processes are attractive solutions for efficient combustion with inherent separation of carbon dioxide. These processes use a metal oxide as an oxygen carrier to transfer oxygen from an air to a fuel reactor where the fuel, or gasification products of the fuel, reacts with the oxygen carrier. The feasibility of Al2O3 and MgAl2O4-supported CuO oxygen carriers for CLC and CLOU processes are investigated in this work. The reactivity of these oxygen carriers was evaluated in a laboratory-scale fluidized-bed at 900 and 925\ub0C under alternating reducing and oxidizing conditions. For Al2O3-supported oxygen carriers, CuO reacted with the support forming copper(II) aluminate (CuAl2O4), which is also a viable oxygen carrier, although it has no oxygen uncoupling properties. In the case of MgAl2O4 as support, the oxygen carrier exhibited stable oxygen release due to the presence of intact CuO. In order to establish the phase relationships in the Cu–Al–O system, the standard enthalpy of formation, ΔH_f^0, of CuAl2O4 was reassessed using thermogravimetry and differential scanning calorimetry (TGA/DSC) due to discrepancy in thermodynamic databases. The reducing and oxidizing pathways in the Cu−Al−O system and the reversibility of the phases during the redox process were also investigated. Here, the phase transformations were examined as a function of duration of the reduction period and oxygen concentration during the re-oxidation period. It was found that the CuAl2O4 is reduced to copper(I) aluminate (CuAlO2; delafossite), Cu2O and elemental Cu. The CuAlO2 phase is characterized by slow kinetics for re-oxidation into CuO and CuAl2O4. The rate of oxygen release and the rate of oxidation of the MgAl2O4-supported CuO oxygen carrier were determined in the temperature range of 850−900\ub0C. Devolatilized wood char was used to facilitate oxygen release from the oxygen carrier in N2-fluidization by maintaining low oxygen concentration around the particles. The Avrami-Erofeev mechanism was used to model the rates of oxygen release. However, during oxidation it was observed that the rate is limited by the oxygen supply, indicating rapid conversion of the oxygen carrier. From the obtained reaction rates, the total amount of the investigated oxygen carrier needed in the air and the fuel reactor is estimated to be between 73−147 kg MW_th^(-1)

Copper and Manganese-based Oxygen Carriers in Chemical-Looping Combustion (CLC) and Chemical-Looping with Oxygen Uncoupling (CLOU)

The chemical-looping combustion (CLC) and chemical-looping with oxygen uncoupling (CLOU) processes are attractive solutions for efficient combustion with inherent separation of carbon dioxide. These processes use a metal oxide as an oxygen carrier to transfer oxygen from an air to a fuel reactor where the fuel, or gasification products of the fuel, is converted. When solid fuel is used in CLC, the char needs to be gasified, by e.g. steam, to form H2 and CO that can subsequently be oxidized to H2O and CO2 by the oxygen carrier. In the case of CLOU, the oxygen carrier releases gas-phase oxygen in the fuel reactor. This enables a high rate of conversion of char from solid fuels, as CLOU eliminates the need for the gasification step required in normal CLC with solid fuels.In this work, copper- and manganese-based oxygen carriers were investigated for the CLC and the CLOU processes. Their chemical-looping performance was examined in a laboratory-scale fluidized-bed reactor under alternating reducing and oxidizing conditions at different temperatures. The materials were generally evaluated with respect to oxygen release, reactivity and performance. Detailed material analysis and characterization of various oxygen carriers were carried out. Different gaseous fuels such as methane and synthesis gas (50% CO in H2) as well as solid fuels such as petroleum coke and wood char were used.As copper-based materials, freeze-granulated Al2O3 and MgAl2O4-supported CuO oxygen carriers were investigated for CLC and CLOU applications using methane. In order to establish the phase relationships in the Cu–Al–O system, the standard enthalpy of formation, ΔH_f^0, of CuAl2O4 was reassessed using differential scanning calorimetry (DSC). The reducing and oxidizing pathways in the Cu−Al−O system and the reversibility of the phases during the redox process were also studied. As manganese-based materials, various manganese-based perovskite-type oxygen carriers produced by extrusion and spray-drying and different manganese ores were studied. The effect of dopants, operating temperature and calcium content on the reactivity of oxygen carriers towards methane and the stability of the perovskite-structured materials as well as tolerance towards deactivation with sulphur were examined for the CLOU process. The reactivity of manganese ores with gaseous fuels and their influence on the rate of char gasification was scrutinized for CLC application with gasification of solid fuels. A method for obtaining the rate of oxygen release for CLOU by utilizing a devolatilized wood char has been developed and was applied to the MgAl2O4-supported CuO oxygen carrier and the extruded perovskite-type materials. Furthermore, the oxidation rate of the MgAl2O4-supported CuO oxygen carrier for CLOU was studied. Based on the obtained rates, the minimum solids inventories using these oxygen carriers were determined for a CLOU unit

Effect of water-based polymers of cement base with fly ash on the stress and strain of concrete in the metro segment

This Research Aimed To Examine The Effect Of Water-Based Polymers Of Cement Base With Fly Ash On The Displacement Of Concrete In The Urban Metro Segment. The Mix Variants Of The Study Are Comprised Of 2 Water/Cement Ratios Of 0.5 And 0.45, Each Of Which Has Four Weight Ratios (5%, 10%, 15%, 20%) Of Fly Ash Added To The Cement, Amassing Eight Different Mixes. Moreover, 150x150x150 Mm Cubic Molds Were Used For Sample Preparation And Sampling. Nine Cubic Samples Were Retrieved From Each Mixing Scheme. After Removing The Samples From The Mold, They Were Compressed For 7, 28 And 42 Days. The Findings Indicated That The Concrete Samples Of The Variant With The Water/Cement Ratio Of 0.45 And Fly Ash/Cement Ratio Of 15% Exhibited Maximum Strength. The Maximum Displacement Values ​​Before The Earthquake Were 12.4 Cm In The Vertical Direction For Concrete With Fly Ash And 18.4 Cm For The Applied Concrete. After The Earthquake, These Values ​​Were 25.4 Cm And 36.4 Cm, Respectively. Also, The Displacement Values In The X Direction Have Decreased By 5 To 6 Cm At Different Loading Steps.&nbsp

Refined models of extensible elastic beams for studying nonlinear vibrations

Bibliography: p. 95-9