فهرست مطالب یحیی احتشامی نیا

In order to increase durability and maintain quality of foods, natural and artificial preservatives are used to the extent permitted and sometimes unauthorized. Some preservatives are harmful to humans and are sometimes classified as carcinogenic. Therefore, familiarity with preservatives, especially in high-consumption foods can be very important and basic. Because the amount of food consumed at the same time in a unit of time can sometimes raise the risk of overdosing on preservatives. Especially if this action is combined with foods with unauthorized preservatives, it can cause more risk. In this study, the websites of PubMed, Google Scholar, SID, Magiran, Web of Science, IranDoc were searched and articles related to the title up to 2020 were reviewed.  The most common preservatives include nitrite, benzoate, sulfite, and sorbic acid with a permissible limit of 200-200, 200, 200-300, and 200 ppm, respectively, as well as ADI 0.06, 5, 0.7, and 0-25 mg / kg. It is daily. Therefore, more efforts have been made by researchers and food manufacturers to use natural preservatives or non-additive methods such as vacuum packaging, etc. Also, due to the increasing consumption of foods containing preservatives in the food basket, especially in children and young people, it can have very adverse effects on the future health of society.

Legionella is a Gram-negative bacterium that is present worldwide in natural and man-made water sources such as hospital water distribution networks and causes two types of Legionnaires and Pontiac fever. The aim of this study was to review the of effect of biological and environmental factors on legionella growth in the water distribution networks of hospitals.

In this study, the databases of PubMed,Scopus, SID, Magiran, Web of Science, IranDoc and google scholar were searched and related articles from 2001 to 2020 were reviewed.

Symbiosis of Legionella with other bacteria in biofilm and the presence of amoebae increases Legionella growth. For each increase in iron and manganese concentration, the chances of Legionella presence increase 1.22 and 3.3 times, respectively. By increasing the concentration of zinc by 1 mg/l, the density of Legionella is increased by 17% and concentrations of zinc greater than 200 g/l and less than 100 g/l are considered inhibitory. Increasing the concentration of copper by 1 mg/l reduces the density of Legionella by 7%. The optimum temperature for growing Legionella is 35⁰C.

Amoebae and biofilm structure, metal ions, temperature and pH affect the persistence and growth of Legionella and finding complete information about these factors can be useful in future studies, better design and construction of hospital water distribution network and provide a suitable solution to control this bacterium.

In 2019, the world has witnessed the emergence of a virus that caused acute respiratory distress syndrome in human with high mortality rates (approximately 3.7%). So far, no effective treatment has been proven against COVID-19. This study aimed at designing a multi-epitope vaccine combining several T-cell and B-cell epitopes of the SARS-CoV-2.

Based on immunoinformatics strategies, B-cell and T-cell epitopes were predicted using immune Epitope Database and Analysis Resource (IEDB). Then, the appropriate predicted epitopes were joined to each other by suitable linkers, and the multi-epitope vaccine constructed was suggested as a vaccine candidate against SARS-CoV-2.

In this study, 28 B-cell epitopes and 33 T-cell epitopes were predicted. Then, to design the multi epitope vaccine, 5 epitopes were used from the virion surface of spike protein and one epitope was used from intravirion region of the Envelope, Membrane, and Nucleocapsid proteins that later on were joined with flexible glycine linker.

Based on the immunoinformatics results obtained, it seems that different epitopes from SARS-CoV-2 structural proteins have high ability to stimulate humoral and cellular immune responses, so the multi-epitope vaccine designed with these epitopes, can help to accelerate the production of effective vaccines against COVID-19.