52 research outputs found

    Physical and mechanical properties of Oak (Quercus Persica) fruits

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    This research was conducted over one Iranian variety of Oak (Quercus Persica) with 70 observations. Physical and mechanical properties of oak are necessary for equipment used in activities such as transportation, storage, grading, packing etc. Properties which were measured include fruit dimensions, mass, volume, projected area, fruit density, geometric mean diameter, sphericity and surface area. Bulk density, porosity and also packing coefficient were measured. Experiments were carried out at Results showed that average mass and volume were 12.95 g and 10.27 mL, respectively. Dimensions increased from 41.85 to 61.09 mm in length, 14.45 to 25.02 mm in width and 14.42 to 24.38 mm in thickness. The mean projected area perpendicular to length, width and thickness obtained 433.91, 1085.48 and 1115.46 mm2, respectively. The geometric mean diameter and surface area were calculated as 27.638 mm and 2423.82 mm2, respectively, while sphericity was measured 51.78%. Elasticity modulus (E), maximum force which fruit can support (Fmax) and work which performed to this force have been determined

    COVID-19 crisis: a time for practical assessment of hygienic principles observance

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    Simultaneously with COVID-19 pandemic, numerous protocols have been developed to prevent the infection. COVID-19 can be more fatal in the bone marrow transplant ward because patients admitted to these wards have a weakened immune system. Assessment of the protocol specified for this wards and practical evaluation of the hygienic principles observance by the medical staff during COVID-19 pandemic can be a step towards saving the lives of the patients. Coinciding with COVID-19 pandemic, 40 patients underwent bone marrow transplantation at Imam Reza Hospital of Kermanshah, Iran from February 2020 to June 2022. A follow-up program was performed to evaluate the possibility of COVID-19 transmission and the rate of hygiene practice by medical staff. The principles of hygienic protocols were scored as a questionnaire in which the observance/non-observance method were applied. Real time-polymerase chain reaction (RT-PCR) based on three genes of the virus was used to diagnose the COVID-19 patients. The results of RT-PCR tests were negative in all patients who were hospitalised during the study. The rate of observance of the hygienic principles by the staff in the studied ward was 100%.The obtained result in the present study was a reflection of the step-by-step implementation of the hygienic protocol specified for bone marrow transplantation ward by the staff. The protocol specified for the bone marrow transplantation ward was highly overlapped with COVID-19 general hygienic guidelines

    An overview of hepatitis B virus surface antigen secretion inhibitors

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    Current anti-hepatitis B virus (HBV) regimen do not meet ideal result due to emerging resistance strains, cytotoxicity, and unfavorable adverse effects. In chronic HBV infection, high rates of sub-viral particles (SVPs) bearing HBV surface antigen (HBsAg) is a major obstacle regarding to raise effective immune responses and subsequently virus clearance. Development of potent HBsAg secretion inhibitors would provide a better insight into HBV immunopathogenesis and therapy. Investigating new non-toxic HBsAg secretion inhibitors targeting either viral or cellular factors could restore the immune response to remove virally infected hepatocytes after inhibiting SVPs. In this study, we overview several classes of HBV inhibitors with focus on their limitations and advantages over anti-HBsAg secretion potential. © 2018 Mohebbi, Lorestani, Tahamtan, Kargar and Tabarraei

    Viruses and long non-coding RNAs: implicating an evolutionary conserved region

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    Long non-coding RNAs (lncRNAs) are a class of cellular transcripts, which are involved in various biological processes. There is conflicting data regarding to the origin of these non-coding molecules and lncRNAs are thought to be the origin of viral genome. Here we sought to find the homology between human lncRNAs and viruses. For this purpose, the lncRNAdb database was searched for human lncRNAs. The lncRNAs’ sequences were aligned with virus taxa using NCBI’s BLAST tool. The phylogenic study was performed with maximum-likelihood based algorithm. The database contains 152 human lncRNAs. As a result, 63 (41.44) of the lncRNAs have homologies with viruses. Of which, 50 (79.36) have homology with Stealth virus. Other viruses with homology to lncRNAs were nuclear integrating DNA/RNA viruses. Moreover, 35 of 64 (23.03) of cancer-associated lncRNAs have sequence homology with the same viruses. In phylogenetic analyses, lncRNAs with no homology to viruses were found to be the ancestor of those with homology to viruses and cancer-irrelevant lncRNAs were found to be the ancestor of cancer-related transcripts. In conclusion, lncRNAs could be the origin of nuclear integrating viruses and the nuclear integrating viruses may evolved from the non-coding regions. The results imply the role of lncRNAs with homology to viruses in human cancers. © 2018, Indian Virological Society

    Advanced sequence optimization for the high efficient yield of human group A rotavirus VP6 recombinant protein in Escherichia coli and its use as immunogen

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    Rotavirus is the important etiological agents of infectious diarrhea among children under 5 years old. Rotaviruses are divided into 10 serogroups (A�J) and each group is based on genetic properties of major structural protein VP6. We designed a novel VP6 sequence optimization to increase the expression level of this protein. Numerous factors such as codon adaptation index, codon pair bias, and guanine-cytosine content were adapted based on Escherichia coli codon usage. In addition, the ribosome binding site (RBS) of pET-15b was redesigned by the RBS calculator and the secondary structure of VP6 messenger RNA was optimized in the whole length of the coding sequence. Various factors including isopropyl beta-d-thiogalactoside (IPTG) concentration, temperature, and induction time were analyzed for the optimization of the best expression in E. coli by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western blotting. The recombinant VP6 (rVP6) protein was purified by the Ni-sepharose and then the hyperimmune sera were generated against rVP6 in rabbits. Among three different temperatures, IPTG concentrations, and postinductions, the level of rVP6 was higher at 37°C, 1 mM of IPTG, and 8 h, respectively. Also, the high expression level of rVP6 was obtained in the insoluble aggregate form (43.8 g/L). After purification, the yield of rVP6 was 10.83 g/L. The rVP6 specific antiserum was confirmed by both immunofluorescent and western blotting. The versatile sequence optimization was the reason to produce a high level of rVP6 compared to other reports and can potentially apply to produce cheaper commercial kits to diagnose serological tests and new rotavirus vaccines. © 2020 Wiley Periodicals LL

    Molecular and serologic characterization of rotavirus from children with acute gastroenteritis in northern Iran, Gorgan

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    Background: The pattern and distribution of human rotavirus genotypes in young children in developing countries play an important role in epidemiological studies, as well as providing a strategy for the development of future rotavirus vaccine. Methods: We evaluated stool samples from 349 children with acute gastroenteritis from Northern Iran (Gorgan city, Golestan province). Polyacrylamide Gel Electrophoresis (PAGE) and Latex Agglutination Test (LAT) were utilized to determine the prevalence of human rotavirus in fecal samples. Moreover semi-multiplex RT-PCR technique was carried out in order to determine the P and G genotypes of human rotavirus in rotavirus-positive samples. Results: A total of 46 rotavirus-positive samples were G and P genotyped. Whereas 28 (60.8) fecal specimens contained only one rotavirus strain, 14 (30.4) were mixed rotavirus infections and 4 (8.8) was non-typeable. Overall, during the study, 57.82 of strains identified as genotype G1, G2 (18.70), G3 (4.69), G4 (3.13), G8 (3.13), G9 (6.26) and non-typeable G (6.26). From all these mentioned rotavirus strains, 46 were characterized as P 8 (97.80%) and P 4 (2.20%).Our analysis of the G and P genotyping of strains from all 46 rotavirus-infected children has revealed that 4/46(6.26%) of G type strains were non-typeable. The predominant single G/P combination was G1P 8 (57.82%), followed by, G2P 8 (16.98%), G2P 4 (1.72%), G3P 8 (4.69%), G4P 8 (3.13%) G8P 8 (3.13%), G9P 8 (6.26%) and four cases of non-typeable G (6.26%). Rotavirus was detected in 39 specimens (11.17%) by PAGE and in 38 specimens (10.88%) by LAT. Both tests were 100% specific; however, the LAT was 82.61% sensitive compared to the PAGE, which was 84.78% sensitive. Conclusions: The results suggest that to characterize rotavirus strains as well as design new effective vaccines for children with acute gastroenteritis, a large-scale study is needed in future. © 2019 The Author(s)

    Genotyping and sequence characterization of the NSP4 gene of human group A rotavirus strains in Northern Iran

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    Rotavirus is known to be responsible for remarkable numbers of severe diarrheal episodes and even death in infants and young children. In this study, we aimed to survey genetic diversity and variation analysis of viroporin, which is encoded by the rotavirus NSP4 segment. Thirty-five rotavirus-positive specimens were obtained, and RNA extraction and polymerase chain reaction amplification were performed. After the sequencing process, four specimens were excluded, and the final 31 samples remained for genetic diversity and variation analysis. The predominant single G/P combination was G1P8 (~78%), followed by G2P8 (~13%), and equal percentages (3%) of G2P4, G3P8, and G-non-typeable-P8. Further analyses revealed that variations could be found in the three regions of NSP4, including VP4 binding site (aa 112�146), double-layered particle binding site (aa 161�175), and finally, in the predicted amphipathic alpha-helix. Phylogenic tree analysis demonstrated that the mentioned samples clustered with genotype E1 and E2 reference sequences. As previously reported in the literature, in this study, it was revealed that no apparent correlation exists in the deduced amino acid sequences corresponding to this region between the rotaviruses collected from patients with and without diarrhea. © 2021 Wiley Periodicals LL

    A Toxoplasma MORN1 null mutant undergoes repeated divisions but is defective in basal assembly, apicoplast division and cytokinesis.

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    The membrane occupation and recognition nexus protein 1 (MORN1) is highly conserved among apicomplexan parasites and is associated with several structures that have a role in cell division. Here we dissected the role of MORN1 using the relatively simple budding process of Toxoplasma gondii as a model. Ablation of MORN1 in a conditional null mutant resulted in pronounced defects suggesting a central role for MORN1 in apicoplast segregation and in daughter cell budding. Lack of MORN1 resulted in double-headed parasites. These Janus-headed parasites form two complete apical complexes but fail to assemble a basal complex. Moreover, these parasites were capable of undergoing several more budding rounds resulting in the formation of up to 16-headed parasites conjoined at the basal end. Despite this segregation defect, the mother's cytoskeleton was completely disassembled in every budding round. Overall this argues that successful completion of the budding is not required for cell cycle progression. None of the known basal complex components, including a set of recently identified inner membrane complex (IMC) proteins, localized correctly in these multi-headed parasites. These data suggest that MORN1 is essential for assembly of the basal complex, and that lack of the basal complex abolishes the contractile capacity assigned to the basal complex late in daughter formation. Consistent with this hypothesis we observe that MORN1 mutants fail to efficiently constrict and divide the apicoplast. We used the null background provided by the mutant to dissect the function of subdomains of the MORN1 protein. This demonstrated that deletion of a single MORN domain already prevented the function of MORN1 whereas a critical role for the short linker between MORN domains 6 and 7 was identified. In conclusion, MORN1 is required for basal complex assembly and loss of MORN1 results in defects in apicoplast division and daughter segregation

    A family of intermediate filament-like proteins is sequentially assembled into the cytoskeleton of Toxoplasma gondii.

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    The intracellular protozoan parasite Toxoplasma gondii divides by a unique process of internal budding that involves the assembly of two daughter cells within the mother. The cytoskeleton of Toxoplasma, which is composed of microtubules associated with an inner membrane complex (IMC), has an important role in this process. The IMC, which is directly under the plasma membrane, contains a set of flattened membranous sacs lined on the cytoplasmic side by a network of filamentous proteins. This network contains a family of intermediate filament-like proteins or IMC proteins. In order to elucidate the division process, we have characterized a 14-member subfamily of Toxoplasma IMC proteins that share a repeat motif found in proteins associated with the cortical alveoli in all alveolates. By creating fluorescent protein fusion reporters for the family members we determined the spatiotemporal patterns of all 14 IMC proteins through tachyzoite development. This revealed several distinct distribution patterns and some provide the basis for novel structural models such as the assembly of certain family members into the basal complex. Furthermore we identified IMC15 as an early marker of budding and, lastly, the dynamic patterns observed throughout cytokinesis provide a timeline for daughter parasite development and division
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