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Aim and Background: Enzyme action at high salt concentrations is of practical relevance in a number of application areas. Both activity and stability of the horse liver alcohol dehydrogenase correlate well with the Hofmeister series in terms of the salt's kosmotropic/chaotropic properties, which are assessed by the Jones–Dole viscosity B coefficients (B+ for cations and B− for anions). In this study thermal stability and activity of the enzyme were invetigated. 

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Aim and Background: Formation of the blood clot inside a blood vessel is known as thrombose or thrombosis. This complication usually appears through the blood platelets. The tendency to clot originates from external and genetic factors which in turn, is a result of changing in the clotting mechanism.

With the aim of applying a method known as ''Taq man Allele- Specific Real-Time'' for diagnosis and screening of V617F mutation in JAK₂ gene, this study was carried out in those patients being susceptible to thrombosis.

Materials and Methods: In this study, through referring to the Pathobiology Laboratory of RASHT city situated in Guilan province, 110 perfect bloods from the afflicted individuals and 105 perfect bloods from the ordinary individuals (lacking past record of the disease) were provided out of the referrers in order to study the thrombosis factors and, after DNA extraction from the whole samples, required measures to study presence of V617F mutation in JAK₂ gene were taken by a method known as Taq man Allele-Specific Real-Time PCR, then, using statistical methods, the results were analyzed.

Results: After confirming the accuracy of the desired technique applied on the control samples, the results of screening this method in the population of individual referring to study the factors of thrombosis, including factors of 2 and 5, presence of this change was suggested. Also, none of the V617F mutation in JAK₂ was identified by screening on the samples of the control population.

Conclusion: Our findings showed that the applied technique is sufficiently capable of diagnosing the V617F mutation in JAK₂ gene. Also, lack of identification of V617F mutation in JAK₂ gene in the population of those referring to the Pathobiology Laboratory for thrombosis in order to investigate factors of 2 and 5 showed that V617F mutation in JAK₂ gene in the studied population is not propounded as one of the thrombosis factors.

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Aim and Background: Nanoparticles are widely used in medical, pharmaceutical and health sciences. The aim of this project was to evaluate the mesophilic bacteria isolated from the Gulf coast in the production of silver nanoparticles and investigate the antimicrobial effect of these nanoparticles on some pathogenic bacteria.
Material and methods: This descriptive and cross-sectional study was performed over a period of 8-month from April to November 2017. The isolates were purified from water and sediments samples of the coasts of Hormozgan Province - Iran, after that the purified isolates were cultivated in Zobell Marine Broth medium. The obtained supernatant of the medium was added to the silver nitrate (AgNO3) solution (0/001 M) with (1:5) ratio at the light condition in order to the reduction of AgNO3 to metallic silver. The synthesis of silver nanoparticles (AgNPs) was investigated by UV-Vis spectrophotometer, Transmission electron microscope(TEM), and Fourier transform infrared (FTIR) spectroscopy analysis. The antimicrobial activity of AgNPs was evaluated against 6 microbes.
Results: The results indicated that supernatants of all isolates are capable of producing silver nanoparticles. The surface plasmon resonance of AgNPs showed a maximum peak near 420 nm, which UV–vis spectra correspond to the absorbance of AgNPs. The results of TEM micrographs image of silver nanoparticles produced by dominant strain showed spherical shapes and size of 2/88 to 19 nm. The synthesized AgNPs showed the antimicrobial activity and inhibitory effects on the growth of tested microbes. 
Conclusion: The desired isolates have a potential ability to producing AgNPs, and to summarize, this is a low cost, ecofriendly, and quick method for the synthesis of AgNPs.
 

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Aim and background: Hyaluronic acid (HA) is a natural linear polysaccharide with excellent viscoelasticity, high water retention capacity and biocompatibility finding wide-range of application in medicine, drug delivery and cosmetics. Currently, microbial fermentation is used for industrial HA production. The present study reports screening and optimization of HA production by clinical Streptococcus equisimilis group C and G (GCS and GGS) isolates from Iranian patients.
Materials and Methods: The 11 S.equisimilis strains including 9 GCS and 2 GGS were characterized and primary HA production was quantified by carbazol assay. Accordingly, three strains were selected for further optimization. The effect of pH on HA yields at 12 points ranging from 3.1-7.5 and glucose concentrations ranging from 0.3-15 mg/ml at 11 points at optimized pH were determined for selected strains.
Results: The range of HA concentration among 11 strains was 216.6-729.7 µg/ml. The three higher producer strains including GCS-08, GGS-88 and GGS132 with an average production of 573.0, 579.7 and 729.7 µg/ml, respectively was selected. The HA concentrations at optimized pH of selected strains were (6.5, 744.3 µg/ml), (4.8, 598.9 µg/ml) and (6.8, 1041.8 µg/ml) respectively. Cultivation at 15 mg/ml of glucose led to increasing HA yield by GCS-08:1096.4, GGS-88:1234.3 and GGS-132:1993.6 µg/ml.
Conclusion: The findings showed the significant effect of pH and direct correlation of glucose concentration on HA production that can increase the yield up to 2.73 folds. Identification of high producer strain at pH 4.8 would be an advantage for HA production under unusual condition at industrial scale.

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Aim and Background: Enterococcus faecalis species are significant issue in severe nosocomial infections. In this study we aimed to investigate the effect of ionic liquids based on amino acids on pathogenic genes of this bacterium using Real time PCR.
Material and Methods: In this study, 100 samples of oral infections were taken from patients and Enterococcus faecalis strains were identified using biochemical tests. The presence and frequency of cyl, hyl and esp genes and their expression under the influence of ionic fluid were evaluated using real time-PCR.
Results: From the total samples taken, twelve Enterococcus faecalis bacteria were isolated and identified. The highest frequency of pathogenic genes was related to cyl gene which was present in 11 strains and the expression of target genes in the treated group under the influence of ionic fluid decreased compared to the control group (p <0.05). With decreasing ion-based amino acid concentration, the ability of bacteria to form biofilms increased (p <0.05).
Conclusion: Widespread antibiotic resistance is the most important concern about Enterococcus and cytolysin is a gelatinase enzyme and one of the most important invasive agents of Enterococcus faecalis. The results of this study provide a basis for promoting the use of new antibacterial agents, including ionic fluid, to prevent further pathogenicity of Enterococcus faecalis.