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Use of stem cells in bone regeneration in cleft palate patients: review and recommendations
Mohammad Amin Amiri,Fatemeh Lavaee,Hossein Danesteh 대한구강악안면외과학회 2022 대한구강악안면외과학회지 Vol.48 No.2
This study was conducted to review the efficacy of different sources of stem cells in bone regeneration of cleft palate patients. The majority of previous studies focused on the transplantation of bone marrow mesenchymal stem cells. However, other sources of stem cells have also gained considerable attention, and dental stem cells have shown especially favorable outcomes. Additionally, approaches that apply the co-culture and co-transplantation of stem cells have shown promising results. The use of different types of stem cells, based on their accessibility and efficacy in bone regeneration, is a promising method in cleft palate bone regeneration. In this regard, dental stem cells may be an ideal choice due to their efficacy and accessibility. In conclusion, stem cells, despite the lengthy procedures required for culture and preparation, are a suitable alternative to conventional bone grafting techniques.
Mohammad Amin Abbaszadeh,Hamed Hamidi,Hamid Rajabnejad,Seyed Abolfazl Naseri,Javad Vaseghi Amiri 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.3
Control of adjacent structures during an earthquake is one of the major challenges in engineering practices. Connecting two structures with the use of a damper is considered to be one of the eff ective vibration control and reducing damage approaches. Improving the seismic performance of weak structures by connecting them to substructures is an eff ective method. The type of dampers and the characteristics of input earthquake loading play an important role in the performance of connected buildings. In addition, some previous studies have shown that viscous dampers, besides the problem of sensitivity to temperature and oil leakage, could not be much eff ective against near-fault records. In this study, the vibration control of smaller frequency structures while connected to robust structures with two types of dampers (i.e., friction and yielding) was investigated Three distinctive sets of earthquake records were considered to be the excitation input data. To this end, three 3-, 5-, and 8-story buildings were selected and the eff ects of applying friction and yielding dampers to control their vibration while subjected to the abovementioned records were studied. The results imply that both dampers performed well when subjected to nearfault records; however, the performance varies depending on the type of earthquake. A maximum displacement reduction rate of 64% was observed. Friction and yielding dampers have shown more eff ective performance in the middle and at the top stories, respectively. As the number of stories increased, the eff ectiveness of lower stories dampers to reduce seismic responses decreased, so their application could be neglected.
Recycling and Utilization Assessment of Municipal Solid Waste Materials to Stabilize Aeolian Sand
Amin Amiri,Mohammad Mohsen Toufigh,Vahid Toufigh 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.3
Municipal solid waste management is a global concern due to the growth rate of population and urbanization. This paper aims to determine the possibility of utilization of municipal solid wastes such as fired clay brick powder (FCBP), eggshell powder (ESP), and recycled glass powder (RGP) for the stabilization of aeolian sand. Using such green binders can eliminate the perils associated with inappropriate waste disposal. Different combinations of FCBP, ESP, and RGP were added to the soil, and two activators (KOH and NaOH) were used to study the effects on its engineering and chemical properties. The effects of various parameters were investigated based on unconfined compression strength tests (UCS), pH tests, and scanning electron microscopy (SEM) tests. The results revealed that using all of these three precursors leads to the co-existence of calcium silicate hydrate (C-S-H) gel with the geopolymeric gel (N-A-S-H) and provides the highest UCS value. According to the obtained results, NaOH had a better ability to dissolve the precursors' particles than KOH, resulting in better polymerization. The optimum composites found in the research had a 91-day UCS of 5.32 MPa, which are suitable for the base material in pavement construction.