Recently, there is an increasing the pavement distresses such as rutting with an increase in heavy vehicles on the road in Mongolia. Rutting is the longitudinal depression in the wheel path in asphalt pavements and it causes a hydroplaning and severe safety concern for users. This study aims to develop paving material that can prevent rutting on the road pavement by improving the durability of the asphalt mixture in Mongolia. Therefore, this study was carried out using the technique of reinforcing the material by adding fibers to conventional asphalt mixture. Fibers have been used to reinforce various materials for many decades in various parts of the world. It is generally understood that asphalt is strong in compression and weak in tension. Adding fibers with high tensile strength can help increase the strength of a mixture[1]. A mixture of glass fibers was used in this study to evaluate the performance characteristics. In coordination with the City of Ulaanbaatar, The test section selected in this study was Peace Avenue in Ulaanbaatar. The test section was a bus lane with severe rutting by heavy vehicles. The designated road test section performed cutting and overlay using five asphalt mixtures: Glass Fiber-reinforced Asphalt, Hot Mix Asphalt(10mm, 19mm), Polymer Modify Asphalt(2 types). The performance survey was conducted after the summer. As a result, No noticeable cracks were observed in glass-reinforced mixture section and the rut-depth of the glass-reinforced mixture is lower than other mixtures[2].

Recently, Cambodia has been investing a lot of money in the construction and maintenance of roads, which are social infrastructures. However, damage to the existing pavement is accelerating due to the old age of the road pavement, poor drainage facilities and increase in heavy traffic. To solve this problem, a fundamental solution such as a high-performance asphalt mixture is required to extend the life of road pavement. In this study, a high performance glass fiber reinforced asphalt mixture developed in Korea was applied to Cambodia. Prior to field application, Marshall stability tests were performed on glass fiber reinforced asphalt mixtures, SBS modified asphalt mixtures and asphalt mixtures commonly used in Cambodia. The Marshall stability test showed that the glass fiber reinforced asphalt mixture and the SBS modified asphalt mixture had the same strength (about 1.3 times higher strength than the usual asphalt mixture). In addition, the test construction was carried out on the National Highway 2 of Cambodia for the evaluation of the performance of the three mixtures. In the future, the long-term performance evaluation of each mixture will be conducted through follow-up survey of the test construction area.

Mesenchymal stem cells (MSC) are of great interest for cell-based therapies and tissue engineering approaches, as these cells are capable for extensive self-renewal and display a multilineage differentiation potential. Clinical application of these cells for degenerative and age-related diseases has been accumulating. However, preparation of MSC before the onset of the diseases, it needs to develop the cryopreservation method. Most cryopreservation methods include fetal bovine serum (FBS) which is essential for effective cryopreservation. Yet it should not be used clinically because of the potential risk of infection. In the present study, we investigated whether human serum albumin (HSA), human serum (HS), and knockout serum replacement (KSR) can be used as an alternative of FBS for cryopreservation of human adipose derived stem cells (hADSC). Cells cryopreserved with 9% HSA showed much higher viability after thawing compared with cells frozen with 5% or 1% HSA. Cells cryopreserved with 90% HS or KSR exhibited greater viability than cells frozen with 25% and 5% HS or KSR, respectively. Viability of cells frozen with 9% HSA, 90% HS or 90% KSR was comparable to that with 90% FBS. Morphology and proliferation ability of these cells were not affected by cryopreservation when compared the freshly obtained cells. Cryopreserved hADSC expressed transcription factor genes including Oct3/4, Nanog, Nestin and Sox2, which are related to the self-renewal of stem cells. Flow cytometric analyses showed that both fresh and cryopreserved hADSC were positive for the antigens of HLA-ABC, CD44, CD73, CD90, and CD105, CD166, and negative for HLA-DR, CD31, and CD34. Similar to fresh cells, cryopreserved hADSC could differentiate into mesodermal lineages, adipogenic, osteogenic, or chondrogenic cells. These results suggest that 9% HSA, 90% HS or 90% KSR can be used to replace FBS during successful cryopreservation of hADSC.

The human eyelid adipose-derived stem cells (HEACs) are known as a candidate source for stem cell-based therapy. HEACs possess the ability to proliferate in vitro and multipotency to differentiate into adipogenic, osteogenic and chondrogenic cells. To be used later than the time of collection, a long-term storage is needed. In this study, we investigated stem cell characteristics after cryopreservation of HEACs for 6 months and 1 year in liquid nitrogen. Frozen-thawed stem cells have shown that cumulative cell and doubling numbers were similar to those of fresh HEACs. After thawing, HEACs expressed stem cell-related genes of SCF, NANOG, OCT4, and TERT, ectoderm-related genes of NCAM and FGF5, mesoderm/endoderm-related genes of CK18 and VIM. They also consistently expressed transcripts of the immune-related genes of HLA-ABC and β2M. To induce mesodermal differentiation, cell were cultivated in adipogenic, osteogenic or chondrogenic medium for 2～3 weeks. After each differentiation culture, HEACs expressed adipocyte-, osteocyte- and chondrocytespecific genes. They were also stained with Oil red O, von Kossa, or alcian blue, revealing adipogenic, osteogenic, or chondrogenic character, respectively. The results suggest that long-term storage up to 1 year do not affect their biological properties, HEACs may be suitable for clinical application on cell-based therapies.