Volume 13, Issue 3 (8-2010)
Abstract
Objective: Hepatitis C virus (HCV) is one of the most relevant persistent infections afflicting the human population. Control of viral replication in HCV infection has been associated with the cellular component of the host immune response. Several mechanisms have been proposed to explain this abnormal immune response, among them an altered activity of regulatory T cells (Tregs) being the most recently postulated. As the first report, in the present study the ability of HCV-core antigen in increase the frequency of natural Tregs (nTregs) in the mixed population of PBMCs was evaluated.
Materials and Methods: Peripheral blood mononuclear cells (PBMCs) from chronic HCV infected patients (n = 19) and normal controls (n = 6) were analyzed to study the effect of HCV-core antigen in frequency of HCV specific nTregs. For this, PBMCs of different groups were isolated, cultured and stimulated with core antigen. Then an in-house triple-stain flowcytometric method was used to investigate the frequency of nTregs.
Results: The results showed that, following incubation with HCV-core Ag, a population of nTregs was increased but, in negative controls the number of nTregs did not increase.
Conclusion: The present data supporting the idea that nTregs are able to respond specifically to HCV antigen suggests that Tregs could contribute to an inadequate response against the HCV infection, leading to chronic infection and supports the view that specific natural Tregs may be implicated in host immune tolerance during HCV infection. It is reasonable that HCV vaccine candidates avoid epitopes that lead to strong nTregs stimulation.
Mostafa Mafi, Morteza Shomali, Hamidreza Ajorloo,
Volume 16, Issue 12 (2-2017)
Abstract
In the recent decades, due to environmental sustainability, abundance, availability and appropriate thermo-physical properties, natural refrigerants are being considered with potential of substitute refrigerants. In this study, Propylene (R1270), Propane (R290), Isobutane (R600a), R407c, R410a, R12, R22 and R134a have been investigated as refrigerant in common refrigeration systems. In the case studies, the thermodynamic and technical parameters of the cycle, using above mentioned refrigerants, have been investigated for common refrigeration systems in temperature range of -30°C to 10°C in the evaporator, and also for heat pump systems with a temperature range of 45°C to 60°C in the condenser. Finally, Propylene was introduced as a refrigerant to replace with synthetic refrigerants in the above mentioned temperature ranges in common refrigeration cycles.
Volume 28, Issue 3 (7-2021)
Abstract
Masjid i-Kabud was built upon the order of Jahan Shah, the ruler of the Kara Koyunlu dynasty, in Tabriz, Northwest Iran. This building is among the most important remains of Islamic architecture and has repeatedly been the object of research by historians of architecture. While the configuration of this building finds a corresponding prototype in Timurid Iran, in the view of a wider audience the construction purpose of this building conceptualizes the theme of Anatolian architecture. Thus, there remain several controversies about the inception of architectural layout that need to be further explored. Using a comparative-analytical method, the aim is to trace back the architectural predecessors of Masjid i-Kabud. Unlike recent studies that attest a Perso-Ottoman interaction in shaping this monument, material evidences confirm beyond any doubt that this was built under the guidance of a master-architect who came from Central Asia a short time before its construction in Tabriz, a grand new capital. According to the results, it is possible to point out a general architectural consistency from the Timurid Empire to the Turkoman era that is largely visible in this building: a tomb in the rear of the central dome aligned with an axial portal, while auxiliary rooms surrounding the main dome on the three sides is a modification of the old traditional Iranian form and might have a close relationship with changes occurring within the religious doctrine in providing adequate space for pilgrimages and educational purposes.
