Introduction:  Amyloid beta (Aβ) is the major constituent of harmful plaques in the Alzheimer’s patients.  Thus, study of Aβ and understanding its related molecular and cellular mechanisms is essential for diagnosis and therapeutic interventions.  This study introduces a rapid, simple, and cost-effective technique for production and purification of this peptide, utilizing the expression of Aβ gene within bacterial system. Materials and methods: Aβ gene was synthesized and transferred into the expression vector pET26b. After induction by Lactose and  24 hours of incubation for Aβ expression the cell sediment was analyzed for presence of recombinant peptide using SDS-PAGE and Western blot.  Then the purification of recombinant peptide was carried using nickel chloride affinity chromatography. Characterization of purified Aβ was performed by evaluating cell cytotoxicity in 25 µM and 50 µM concentrations using MTT assay on Alzheimer cell line model SH-SY5Y. Results: Colony PCR and sequencing results showed the correct insertion of Aβ coding fragment into the expression vector. Presence of bands with the expected size in the results of SDS PAGE and western blot had confirmed successful expression of his-tagged recombinant peptide. MTT assay results showed the purified peptide has respectively 30 and 50% cytotoxicity for 25 µM and 50 µM concentrations. Discussion: Production of amyloid beta peptide in bacterial hosts seems to be favorable. Obtaining Aβ peptide in soluble phase is an important advantage of this study. Hence according to toxicity of the purified peptide, it can be utilized for cell line treatments and further researches on Alzheimer disease.

Primary nozzle is one of the most important factors which has a large influence on the performance of thermo-COMPRESSORs. Most of studies carried out until now, have been performed on single-nozzle thermo-COMPRESSORs. In this paper, an actual industrial thermo-COMPRESSOR is considered and the purpose is to study the effect of increasing primary nozzle number on the performance of this thermo-COMPRESSOR. For this purpose, a triple-nozzle thermo-COMPRESSOR is simulated numerically and its performance is compared with single-nozzle thermo-COMPRESSOR. Ideal gas thermodynamic properties are considered to simulate the compressible flow within the thermo-COMPRESSOR and numerical result is validated using the experimental result. In addition, the effects of variation in mixing chamber convergence angle and position of nozzles at the radial direction in triple-nozzle thermo-COMPRESSOR are investigated. The numerical results show that at the same condition, a triple-nozzle thermo-COMPRESSOR is able to provide superior critical back pressure and entrainment ratio than single-nozzle thermo-COMPRESSOR. The proximity of nozzles (with 34% changes in radial distance) increases the critical back pressure about 8% and decreases the entrainment ratio about 5%. By increasing mixing chamber convergence angle about 66%, the value of critical back pressure decreases about 29% and the value of entrainment ratio decreases about 16% in single nozzle-thermo-COMPRESSOR and 10% in triple-nozzle thermo-COMPRESSOR. Also, by 8% reduction of mixing chamber convergence angle, the critical back pressure decreases 6% but entrainment ratio decreases about 2% in single-nozzle thermo-COMPRESSOR and increases about 3% in triple-nozzle thermo-COMPRESSOR.