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Background: Health care workers (HCWs) are at the risk of the acquisition of occupational transmissible diseases. Controversial results have been reported about hepatitis C virus (HCV). The main objective of the recent study was to evaluate the seroprevalence of HCV and its relationship to the occupational history and exposure of HCWs in two teaching hospitals in Tehran-Iran.

Materials and Methods: A seroprevalence survey of HCV was conducted using serum samples obtained from 1400 HCWs in two teaching hospitals during 2012. The samples were screened by ELISA for the presence of anti-HCV antibodies.

Results: In none of the participants the HCV antibody was detected. Needle stick injury was significantly higher among nurses. Younger HCWs with a shorter professional life had more frequent needle stick injury (p<0.001).

Conclusion: The seroprevalence of HCV in HCWs was considerably lower than that reported in the general population, and needs to be evaluated on a larger scale.

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Background: Several SARS-CoV-2 variants with distinct characteristics have emerged, with Omicron sub-variants such as BA.1 to BA.5 being predominant since late 2021. Distinguishing sub-variants using phylogenetic and molecular analyzes provides a valuable approach in the context of epidemiological research.
Materials & Methods: Molecular epidemiology and sub-variants of SARS-CoV-2 omicron were investigated using 150 nasopharyngeal samples from COVID-19 patients in Tehran (Iran) from May 2022 to August 2023. Omicron lineages were differentiated using RT-PCR targeting Q493R, L452R, and ∆69-70 spike mutations. SARS-CoV-2 omicron sub-variants were determined by amplicon sequencing.
Findings: The mean age of the study participants was 44±7 years, comprising 38.6% males and 61.4% females , which may have an effect on transmission and susceptibility of different ages. Also, 117 (78%) samples were positive for one of the three lineages, while 33 (22%) was none of the lineages, which were referred to as conclusive and inconclusive results, respectively. 60.7% of the samples was the omicron lineage BA.4 or BA.5.
Conclusion: Considering the prevalence of BA.4 and BA.5 in the study population and their differences with the parental SARS-CoV-2 variant, the primary vaccine seems to be not effective against the current omicron sub-variants. These results underscore the importance of vaccination as a critical strategy to prevent the spread of these variants. The suggested primer sets could be an easy way to screen sample variants and lineages and are useful for screening and sequencing samples in countries with limited resources. Continuous monitoring of omicron sub-variants is recommended for preventing the resurgence of COVID-19.
 

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This research investigated the impact of cold plasma treatment on the characteristics of raw sheep's milk. In this study, the effect of cold plasma was considered at three voltage levels (0.5, 0.7, and 0.9 kV) and three treatment times (3, 5, and 7 minutes). The physicochemical properties of raw sheep's milk, including pH, antioxidant activity (DPPH radical scavenging activity), color indices (L, a, b), microbiological tests (total bacterial count), protein, and fat, were examined. Analysis of variance (ANOVA) showed that both voltage and treatment time significantly affected pH, with an average increase to 6.82 as voltage and time increased. Antioxidant activity was also influenced, increasing to 21.03% with increasing voltage and time. Color indices changed significantly. The lightness index (L) reached 74.58 due to voltage and treatment time, while the redness index (a) and yellowness index (b) changed to 2.15 and 10.94, respectively. Additionally, in microbiological tests, the total bacterial count decreased significantly, indicating a significant improvement in milk safety. Finally, the examination of protein and fat levels showed that with increasing voltage and treatment time, protein levels reached 3.86 g/100 mL and fat levels reached 4.53 g/100 mL. These results indicate that the use of cold plasma can be considered as an effective method for improving the quality and increasing the nutritional value of milk in the dairy industry.
 

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Heavy metal pollutants containing lead have consistently been major sources of environmental contamination over the past decades. Human and industrial activities have directly or indirectly led to the introduction of substantial amounts of lead-based pollutants into soil and groundwater. The Solidification/Stabilization (S/S) technique using cement, by significantly reducing the mobility and solubility of lead in soil, serves as an effective tool for remediating lead-contaminated soils. Conversely, the heavy metal pollutant lead significantly affects the setting time of cement, and the setting time directly impacts the efficiency of cementitious compounds. Consequently, understanding the interaction between lead and cement is of paramount importance. In this regard, the present study aims to investigate the influence of the heavy metal lead on the setting time and microstructural interaction of lead and cement. To achieve this, lead nitrate solution with concentrations of 0, 10,25,50, 100, 250 and 500 kg/cmol-solid, was added to cement. The effect of lead on the hydration process and setting time of cement was examined through setting time tests, X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) images, and leachability analysis (TCLP). According to the research results, the precipitation and chemical complexation of the heavy metal lead in the form of Pb(OH)₂ and Pb-C-S-H delayed the cement hydration process, extended the initial and final setting times of cement paste, and immobilized and solidified lead pollution effectively. By adding 25 kg/cmol-solid lead nitrate, the initial setting time of cement increased from 65 minutes to 155 minutes. Microstructural results demonstrated that cement effectively interacted with heavy metal lead up to a concentration of 100 cmol/kg-solid during the Solidification/Stabilization (S/S) process, keeping pollutant levels within permissible limits for soil.