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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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DRASTIC model has been used to map groundwater vulnerability to pollution in many areas. Since this method is used in different places without any changes, it cannot consider the effects of pollution type and characteristics. Therefore, the method needs to be calibrated and corrected for a specific aquifer and pollution. In the present research, the rates of DRASTIC parameters have been corrected so that the vulnerability potential to pollution can be assessed more accurately. The new rates were computed using the relationships between each parameter and the nitrate concentration in the groundwater. The proposed methodology was applied to Astaneh aquifer located in north of Iran. Samples from groundwater wells were analyzed for nitrate content in thirteen locations. The measured nitrate concentration values were used to correlate the pollution potential in the aquifer to DRASTIC index. Pearson correlation was used to find the relationship between the index and the measured pollution in each point and, therefore, to modify the rates. The results showed that the modified DRASTIC is better than the original method for nonpoint source pollutions in agricultural areas. For the modified model, the correlation coefficient between vulnerability index and nitrate concentration was 68 percent that was substantially higher than 23 percent obtained for the original model

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ABCG2 (ATP binding cassette subfamily G member 2) gene, located on chromosome 6 encodes the ABCG2 protein that transports various xenobiotics, cytostatic drugs across the plasma membrane as well as cholesterol into milk. A single nucleotide change (A/C) in base 86 of exon 14 is capable of encoding a substitution of tyrosine with serine in the ABCG2 gene and increase milk yield while decreasing milk fat and protein concentrations. The major aim followed in this research was to study Single Nucleotide Polymorphisms (SNPs) of ABCG2 gene and their association with milk production traits in Iranian Holstein bulls. Genomic DNA of 105 ified bulls was extracted from semen samples using highly Pure PCR template preparation kit. Primers were designed through Oligo software (Version 5.0) and utilized in PCR. Then the PCR fragments were sequenced. The A/C substitution in base number 86 of exon 14 was observed with 2% frequency which affected protein percentage (P< 0.05). Some SNPs were detected for the first time in intron 13, exon and intron 14 in comparison with sequences in the NCBI database. A deletion mutation in base number 20 (T/-) and a missense mutation in base number 67 (A/G) of exon 14 that cause the substitution of serine with glycine were discovered which were significantly associated with protein yield and fat percentage, respectively (P< 0.05). Furthermore, significant association was observed between fat percentage and mutations in base numbers 4,133 (T/C) and 4,137 (T/G) of intron 13 (P< 0.05). Substitutions in base numbers 2 (T/C) and 55 (G/C) of intron 14 resulted in a significant effect on fat yield and fat percentage (P< 0.05).

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In this research, control of vibration in multilayered cylindrical panel with piezoelectric patch, under dynamic load is investigated, for the first time. The finite element method is used to solve the dynamic equations of the structure, which is based on first-order shear deformation theory, and equivalent single layer models with different rotations for the substrate and the piezoelectric patch is developed. The governing equations are obtained by using the Hamilton’s principle of virtual work, are discretized over the mid-plane, by using eight node shell element, leading into the matrix system of equations. The maximum controllability criterion is used for finding the optimal size and location of piezo-patch. According to the used control law, the applied voltage on the piezo-patch is proportional to the radial velocity component at the point, where the sensor is installed. In order to evaluate the performance of the formulation and finite element model, the natural frequencies obtained for the substrate laminated panel are compared with those in the literature. Then, having the dynamics of the optimal system, the frequency response for open and closed loop controls are studied. Finally, the effects of controller gain values and dimensions of panel and patch on the time response and damping rate of vibrations are illustrated.

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Abstract Background and Purpose: Instability of slopes leading to roads in steep mountainous areas is a major problem in the development of roads worldwide, causing excessive human as well as financial losses. Soil nailing is one way of in-situ soil reinforcement. The behavior of a reinforced soil system depends on different parameters including geometry of the structure, mechanical characteristics of the soil, density of the reinforcing material, and length of the soil reinforcing material as well as the angle it makes with the failure plane. Though much research has been conducted on earth slope stability, few studies have examined the effect on slope stability of the soil nailing angle and tensile force distribution along the nail. In spite of the extensive studies conducted on slope stability, no specific insight has been obtained so far on the effect of the failure plane or soil nailing angle on the tensile force distribution along the nails. In view of these facts, this study aims to examine the effect of nail angle as well as nail length on the nail safety factor with due consideration of the effect of shear strain distribution on slope stability. Selecting the slope leading to Ilam-Salehabad Road in western Iran as our case study, we studied the stability of this slope at different nail lengths and angles. Methodology: The slope leading to Ilam-Saalehabad Road (after the Karbala Road tunnel) was selected as the case study. To determine the mechanical parameters of the soil, we provided soil samples from the slope site and tested them at the laboratory in accordance with ASTM code to obtain the required soil characteristics. The powerful geotechnical software FLAC2 was subsequently used for modeling the slope leading to the road. Upon completion of analysis, we compared the settlement obtained from the software at two points on the earth slope with similar measurements obtained from the instruments, and observed a good agreement between them, with an approximate maximum error of 3%. In the following, the effect of soil nailing angle (with the horizontal line) as well as the length of the nail on the nail safety factor and nail tensile force is discussed. Discussion and Conclusion: Our results showed that increasing the soil nailing angle (i.e., nail driving angle defined as the angle between the soil nail and the horizontal line) from 0 to 30 degrees would increase the nail safety factor by about 23%. Thereafter, increasing the nail driving angle from 30 to 45 would cause a reduction of 2.8% in the safety factor. A further increase of nail angle (with the horizon) caused a corresponding increase in the tensile force induced in the nails, so that the maximum tensile force at 30 degrees increased by about 6%. The maximum nail driving angle efficiency was observed at the points undergoing maximum shear strain: increasing the drive angle to 30 degrees led to a 10-fold increase in the tensile force developed in the nails at points with maximum shear strains. On the other hand, increasing the nail length increased nail safety factor, so that increasing the nail length by 1 meter would increase nail safety factor by 4.3%. However, increasing the nail length beyond 1 meter reduced the rate of increase of the safety factor. Accordingly, the optimum length increase in the nails was taken as 1 meter.

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