Comparison of expression systems for the production of human interferon-a2b.

The production of human interferon alpha2b (IFN-α2b) in two expression systems, tobacco (Nicotiana tabaccum) and Escherichia coli, was compared in various aspects such as safety, yield, quality of product and productivity. In the E. coli system, IFN-α2b was expressed under a pelB signal sequence and a T7lac promoter in a pET 26b(+) vector. The same gene was also cloned in expression plant vector (pCAMBIA1304) between cauliflower mosaic virus promoter (CaMV35S) and poly A termination region (Nos) and expressed in transgenic tobacco plants. The expression of protein in both systems was confirmed by western immunoblotting and the quantity of the protein was determined by immunoassay. The amount of periplasmic expression in E. coli was 60 µg/L of culture, while the amount of nuclear expression in the plant was 4.46 µg/kg of fresh leaves. The result of this study demonstrated that IFN-α2b was successfully expressed in periplasm of bacterial and plant systems. The limitations on the production of IFN-α2b by both systems are addressed and discussed to form the basis for the selection of the appropriate expression platform

Cloning and periplasmic expression of peptidoglycan-associated lipoprotein (PAL) protein of Legionella pneumophila in Escherichia coli

Abstract Introduction and objective: Legionella pneumophila, the etiological agent of Legionnaires’ disease, is an important cause of both community-acquired and nosocomial pneumonia; therefore, rapid diagnosis and early antibiotic treatment of pneumonia are required. Urinary antigen testing to detect Legionella antigen has proven to be the most powerful diagnostic method. Peptidoglycan-associated lipoprotein (PAL) protein of L. pneumophila, as a component of Legionella antigens, will be detected efficiently by the PAL antigen capture assay and is considered as useful diagnostic antigen to diagnose Legionella infection. Because of the transfer of protein to the periplasmic region of Escherichia coli has numerous advantages including separation from cytoplasmic proteins and the concentration of recombinant proteins in periplasm, the aim of this study was to produce periplasmic PAL protein of L. pneumophila in E. coli. Materials and methods: The pal gene of L. pneumophila serogroup 1 was amplified with specific primers, cloned and expressed under pelB signal sequence and T7 lac promoter in pET26b+ plasmid. Results: The cloning was confirmed with digestion and sequencing of recombinant pET- 26b-pal plasmid. The expression of r-PAL protein in cytoplasm and periplasmic space of E. coli was approved by SDS-PAGE and western blotting. Conclusion: The results of this study demonstrated that the r-PAL protein successfully expressed in E. coli

Photocatalytic Activity of Quantum Dots

In recent years, nanoscale semiconductors have attracted great interest due to their unique structural, optical and electronic properties, which arise due to their large surface-to-volume ratio and quantum confinement effect. Quantum dots (QDs) as zero-dimensional semiconductor nanomaterials, which are confined to a size of 2–8 nm in three dimensions, are defined as particles with physical dimensions smaller than the exciton Bohr radius. One of the attractive research fields in recent years is the synthesis of various sizes and shapes of semiconductor material nanoparticles as doped with different dopants. The aim of this chapter is to focus on the photocatalytic activity of QDs as new, green and efficient nanophotocatalysts

The effect of high intensity interval training on cardioprotection against ischemia-reperfusion injury in Wistar rats

The aims of the present study were to determine whether short term high intensity interval training (HIIT) could protect the heart against ischemia reperfusion (IR) injury; and if so, to evaluate how long the exercise-associated protection can be lasted. Sixty-three rats were randomly assigned into sedentary (n = 15), sham (n = 7), and exercise groups (n = 41). Rats in the exercise groups performed 5 consecutive days of HIIT on treadmill: 5 min warm up with 50 % VO2max, 6×2min with 95-105 % VO2max (about 40 to 45 m/min), 5×2 min recovery with 65-75 % VO2max (about 28 to 32 m/min), and 3 min cool down with 50 % VO2max, all at 0 % grade. Animals exposed to an in vivo cardiac IR surgery, performed at days 1, 7, and 14 following the final exercise session. Ischemia-induced arrhythmias, myocardial infarct size (IS), plasma lactate dehydrogenase (LDH) and creatine kinase (CK) activities were measured in all animals. Compared to sedentary rats, exercised animals sustained less IR injury as evidenced by a lower size of infarction and lower levels of LDH and CK at day one and day 7 post exercise. In comparison of sedentary group, IS significantly decreased in EX-IR1 and EX-IR7 groups (50 and 35 %, respectively), but not in EX-IR14 group (19 %). The exercise-induced cardioprotection disappeared 14 days following exercise cessation. There were no significant changes in ischemia-induced arrhythmia between exercised and sedentary rats. The results clearly demonstrate that HIIT protects the heart against myocardial IR injury. This protective effect can be sustained for at least one week following the cessation of the training

Cytokine Profiles and Cell Proliferation Responses to Truncated ORF2 Protein in Iranian Patients Recovered from Hepatitis E Infection

Background.The aim of this study was to evaluate hepatitis E virus (HEV) specific cellular immune responses to truncated ORF2 protein in Iranian patients recovered from HEV infection. Information about HEV-specific immune responses could be useful in finding an effective way for development of HEV vaccine. Methods. A truncated formof HEVORF2 protein containing amino acids 112-608 was used to stimulate peripheral blood mononuclear cells (PBMCs) separated from HEV-recovered and control groups. Finally, the levels of four cytokines, IFN

Employability of Iranian Engineering graduates: Influential factors, consequences, and strategies

Abstract University education is a significant factor in the socio-economic development of a nation and as such is expected to improve the employability capacity of the graduates. Achieving this goal, however, depends on various factors. The present study investigated the factors affecting the employability of engineering graduates of Iranian universities. To analyse this issue, a systematic grounded theory (GT) approach, drawing on in-depth interviews with academic and industry experts, was used. The participants were selected using a purposive strategy. The data analyses showed that employability is a context-oriented issue, and in addition to the university and its internal mechanisms, external factors are also involved. Based on the data, a model is presented and analysed to explain the employability of engineering graduates

Theoretical study on the distribution of profit earnings and stocks returns

People make decisions in their daily life that are based on predictions made about the future. In fact, we are all trying to make a connection between two or more variables in a way that could be used for prediction. Profit and cash flow in a private profit making unit make the most fundamental part of information and are the base of most financial information users’ decision making. And judgments and profit making prediction have always been one of the interesting subjects for financial information users, because correct estimation of these figures can play an important role in making the correct decisions (Jahankhani and Saffarian, 2003). Investors buy assets hoping that their expected return over the next period is achieved efficiently. These returns can be predicted, however, it may not be the expected return. In fact, one can predict the profit-making trend of a company by analyzing the previous trend and studying some of the economic variables. However, actual happenings are different from the numbers and data achieved in predictions. The roots of most of these differences lie in the variability of criteria that are the basis for predictive models (Azad, 2004)

Theoretical study on the distribution of profit earnings and stocks returns

People make decisions in their daily life that are based on predictions made about the future. In fact, we are all trying to make a connection between two or more variables in a way that could be used for prediction. Profit and cash flow in a private profit making unit make the most fundamental part of information and are the base of most financial information users’ decision making. And judgments and profit making prediction have always been one of the interesting subjects for financial information users, because correct estimation of these figures can play an important role in making the correct decisions (Jahankhani and Saffarian, 2003). Investors buy assets hoping that their expected return over the next period is achieved efficiently. These returns can be predicted, however, it may not be the expected return. In fact, one can predict the profit-making trend of a company by analyzing the previous trend and studying some of the economic variables. However, actual happenings are different from the numbers and data achieved in predictions. The roots of most of these differences lie in the variability of criteria that are the basis for predictive models (Azad, 2004)

Theoretical study on the distribution of profit earnings and stocks returns

People make decisions in their daily life that are based on predictions made about the future. In fact, we are all trying to make a connection between two or more variables in a way that could be used for prediction. Profit and cash flow in a private profit making unit make the most fundamental part of information and are the base of most financial information users’ decision making. And judgments and profit making prediction have always been one of the interesting subjects for financial information users, because correct estimation of these figures can play an important role in making the correct decisions (Jahankhani and Saffarian, 2003). Investors buy assets hoping that their expected return over the next period is achieved efficiently. These returns can be predicted, however, it may not be the expected return. In fact, one can predict the profit-making trend of a company by analyzing the previous trend and studying some of the economic variables. However, actual happenings are different from the numbers and data achieved in predictions. The roots of most of these differences lie in the variability of criteria that are the basis for predictive models (Azad, 2004)