This Commentary provides a detailed analysis of the US-DPRK Peace Treaty, a proposed bilateral peace treaty between the United States and the Democratic People’s Republic of Korea (i.e., North Korea). The US-DPRK Peace Treaty was conceived as the first in a series of legal instruments to be executed in furtherance of the establishment of “peace as a system” on the Korean Peninsula. In this monograph, the authors envision that such a peace treaty would serve as a basis for peaceful co-existence between the two countries and, ultimately, a peaceful, non-volatile situation on the Korean Peninsula. The Commentary offers an in-depth explanation of each provision of the US-DPRK Peace Treaty, including the meaning, background, rationale and legal implications of individual provisions of the Peace Treaty. Additionally, it provides insight into relevant international law issues and the history of negotiations and engagement among interested parties in the context of the inter-Korean conflict.

Osteoarthritis is a disorder characterized by a loss of cartilage as common aging-associated disease in humans and animals. However, unlike human clinical trials, investigational studies in pet animals are constrained by a lack of interest and funds. In addition, pet owners would often prefer the lowest cost method to treat arthritis of pet animals. Here, we report the outstanding and inexpensive way to prepare chondrocytes for cartilage repair using rabbit adipose derived mesenchymal stem cells (MSCs). This study focused on the development and enhancement of pre-chondrogenic condensation under external electric fields even without additional growth factors. We found that highly compact structures were formed within 3 days in micromass cultures of rabbit MSCs under electrical stimulation (ES), showing increased COL2A1 gene expression compared with their control 3D micromass cultures and 2D monolayer cultures. We further found that ES enhanced the production of proteoglycan, a highly produced extracellular matrix component in chondrocytes. Collectively, these results provide the commercial potential of electrical stimulation driving chondrogenesis of mesenchymal stem cells for repair of cartilage, which is a budget-friendly regimen.

Osteoarthritis occurs when the cartilage that gradually deteriorates as common aging-associated disease in humans and animals. There is no cure, but the treatments are available to manage to relieve pain through medication such as steroids. Growing interest has been focused on the role of cell-based therapies using mesenchymal stem cells (MSCs). In addition, mesenchymal stem cells can be isolated from almost adult tissues and known for their potential of becoming cartilage. Clinical and experimental studies indicate that the development of treatment using stem cells is double-edged sword involving a possibility such as tumorigenesis. This study focused on the electrical features during articular cartilage development and hypothesized that external electric fields promote pre-chondrogenic condensation without concern relating to genetic modification or exogenous factors. Here, it has been reported that exogenous direct electric fields drive pre-chondrogenic condensation which is the stage where cartilage formation begins by condensation of stem cells and cartilage cells in the microenvironment of the joint. Time-dependent observations also support the contribution of electrical stimulation (ES) to induce gradual aggregation of MSCs into highly compact structures within 3 days. Collectively, our findings provide the potential of electrical stimulation-driven chondrogenesis of mesenchymal stem cells in the absence of exogenous factors for repair of cartilage defects.

A nationwide survey of 8 N-nitrosamines in finished water samples from drinking water treatment plants (DWTPs) in Korea was conducted. The samples were pre-treated by solid-phase extraction (SPE) and analyzed using a gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). According to the study results, four N-nitrosamines (NDMA, NDEA, NMOR, NDBA) were detected for three consecutive years, NMEA and NPYR were only found in samples collected in 2013. Two of these N-nitrosamines, N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA), have received attention and were the most commonly detected. The concentration of NDMA and NDEA in this study ranged from 0.002 μg/L to 0.013 μg/L and in 0.001 μg/L to 0.008 μg/L, respectively. In comparison to studies performed in EPA(UCMR2), the concentrations of NDMA (from 0.002 μg/L to 0.630 μg/L) and NDEA (from 0.005 μg/L to 0.100 μg/L) observed in the this study were low.

In this study, the appearance change and the heat․moisture transfer properties of knitted fabric by yarn shrinkage were examined to obtain useful data on the development of thermo-sensitive functional materials. Eleven types of knitted fabric were knitted using highly bulky acrylic-blended yarn. After shrinking the specimens using dry heat treatment, the appearance change and thickness were measured. An HEC simulator was adopted for measuring the heat․moisture transfer properties of specimens by yarn shrinkage. When holes were arranged vertically in the mesh structure, the specimens with 2,500 and 5,000 holes showed high percent change of hole area, appearance, and thickness. When holes were diagonally arranged in the mesh structure, the percent change of hole area in the specimen with 1,250 holes was larger than the one with 2,500 holes. However, the dimensional stability of the specimen with 2,500 holes was better because of its smaller appearance and thickness change. In the tuck structure, the percent change of hole area in the specimen with 625 and 416 holes was relatively large compared with the appearance and thickness change. Furthermore, the hole size in the tuck structure was smaller than that in the mesh structure but the percent change of hole area was larger. Therefore, it was proved that the tuck structure is more suitable than the mesh structure for developing thermo-sensitive functional materials. Heat․moisture transfer property test verified that the change of hole area by yarn shrinkage enabled obtaining the thermal effect due to the distinct temperature difference in the inner layer.

The chemical structures of perfluorinated compounds(PFCs) have unique properties such as thermal and chemical stability that make them useful components in a wide variety of consumer and industrial products. Two of these PFCs, perfluorooctane sulfonate(PFOS) and perfluorooctanoic acid(PFOA), have received attention and were the most commonly detected. In this study it was analyzed the concentrations of 8 PFCs in samples were collected from drinking water treatment plants for 5 years(2012-2016). PFOS and PFOA were also high concentration and frequency. The mean concentrations of PFOA and PFOS were detected 0.0026-0.0069 μg/L and 0.0009-0.0024 μg/L in samples from drinking water treatment plants. These were relatively lower or similar compared to PFOS concentrations in Osaka(Japan). In general, these levels are below health-based values set by international authoritative bodies for drinking water. These results will be serve as the first monitoring data for PFCs in drinking water and be useful for characterizing the concentration distribution and management of PFCs in future studies.

Although disinfection in drinking water treatment plants provides a safer water supply by inactivating pathogenic microorganisms, harmful disinfection by-products may be formed. In this study, the disinfectant, chlorine, was produced on-site from the electrolysis of salt (NaCl), and the by-products of the disinfection process, bromate and chlorate, were analyzed. The provisional guideline levels for bromate and chlorate in drinking water are 10 μg/L and 700 μg/L, in Korea, respectively. Bromide salt was detected at concentrations ranging from 6.0 ~ 622 mg/kg. Bromate and chlorate were detected at concentrations ranging from non-detect (ND) ~ 45.3mg/L and 40.5 ~ 1,202 mg/L, respectively. When comparing the bromide concentration in the salt to the bromate concentration in the chlorine produced by salt electrolysis, the correlation of bromide to bromate concentration was 0.870 (active chlorine concentration from on-site production: 0.6–0.8%, n=40). The correlation of bromate concentration in the chlorine produced to that in the treated water was 0.866.

The spatial and temporal distributions of phosphorus and nitrogen and a number of physical, chemical and biological parameters were analyzed to in the Youngsan and the Sumjin River systems, Korea. Substantial amount of P and N was observed in both the rivers all the year round. Mean N/P ratios showed large variations among the sampling sites; highest ratio was observed in most sampling sites during summer. Relative proportions of DOP: TP were fairly constant (0.08~0.09) in both the rivers. In the composition of nitrogen almost all sampling sites of both the rivers were dominated with NO3-N followed by NH3-N and NO2-N. Variations in dissolved nutrients tended to co-vary with particulate forms (PON and POP), implying that dissolved nutrients are primarily released from the decomposition of particulate forms or dissolved forms are in equilibrium with particulate forms. Chlorophyll a levels in the Sumjin River appear to be negatively correlated with the ammonia, implying ammonia is absorbed by algae with preference. While chlorophyll a was positively correlated with TP and DIP in the Sumjin River, negative correlations of these parameters was observed in the Youngsan River. The pattern of nutrients level was found to be related with land use and domestic sewage in the study area. Inter-parameter relationships may be strongly influenced by geographical factors relative to temporal factors.

본 연구는 오른쪽 어깨관절에 칼텐본-에비엔즈컨셉 미끄러뜨림 등급Ⅱ와 Ⅲ으로 아래쪽미끄러뜨림적용시 위팔뼈머리의 이동거리 및 벌림각도(abduction angle)의 변화를 알아보고자 하였다. 미끄러뜨림 등급Ⅱ(Grade Ⅱ) 적용시 위팔뼈머리는 초기보다 아래쪽으로 5㎜ 가량 이동하였고 등급Ⅲ 적용시 8㎜ 가량 이동하였다. 이동거리에 대한 성별 비교에서는 남자가 여자에 비해 등급별로 이동거리가 높게 나타났으나 통계적으로 유의한 차이는 나타나지 않았다. 등급Ⅱ(Grade Ⅱ) 적용시 벌림각도는 초기보다 10°가량, 등급Ⅲ(Grade Ⅲ) 적용시 12°가량 증가하였다. 벌림각도에 대한성별 비교에서는 모든 등급별로 여자가 남자보다 벌림각도가 크게 나타났으나 통계적으로 유의한 차이는 나타나지 않았다.본 연구를 통해 미끄러뜨림 등급 적용시 위팔뼈머리의 운동형상학적 변화를 알아보았으며 향후 추가 연구를 통해이들 변화가 주변 구조물에 미치는 영향에 대해 알아본다면 보다 과학적인 근거중심의 치료를 기대할 수 있을 것으로사료된다.