• Biomolecules & Therapeutics
• /
• v.29 no.2
• /
• pp.144-153
• /
• 2021

Astrocytes play various important roles such as maintaining brain homeostasis, supporting neurons, and secreting inflammatory mediators to protect the brain cells. In aged subjects, astrocytes show diversely changed phenotypes and dysfunctions. But, the study of aged astrocytes or astrocytes from aged subjects is not yet sufficient to provide a comprehensive understanding of their important processes in the regulation of brain function. In this study, we induced an in vitro aged astrocyte model through late passage cultivation of rat primary cultured astrocytes. Astrocytes were cultured until passage 7 (P7) as late passage astrocytes and compared with passage 1 (P1) astrocytes as early passage astrocytes to confirm the differences in phenotypes and the effects of serial passage. In this study, we confirmed the morphological, molecular, and functional changes of late passage astrocytes showing aging phenotypes through SA-β-gal staining and measurement of nuclear size. We also observed a reduced expression of inflammatory mediators including IL-1β, IL-6, TNFα, iNOS, and COX2, as well as dysregulation of wound-healing, phagocytosis, and mitochondrial functions such as mitochondrial membrane potential and mitochondrial oxygen consumption rate. Culture-conditioned media obtained from P1 astrocytes promoted neurite outgrowth in immature primary cultures of rat cortices, which is significantly reduced when we treated the immature neurons with the culture media obtained from P7 astrocytes. These results suggest that late passage astrocytes show senescent astrocyte phenotypes with functional defects, which makes it a suitable model for the study of the role of astrocyte senescence on the modulation of normal and pathological brain aging.

• Korean Journal of Agricultural Science
• /
• v.49 no.3
• /
• pp.629-641
• /
• 2022

This research was conducted to secure fundamental data for development of a recirculating hydroponic system. To achieve this, Lycopersicum esculentum var. 'Dafnis' and 'TY Tiny' were grown with Yamazaki hydroponic solution and the inorganic element concentrations of plant leaves and nutrient solution of supplied and drained were analyzed periodically. The T-N and P contents in both varieties of tomato leaves showed gradual decreasing tendencies with the passage of time. The 'TY Tiny' tomato had higher contents of those two nutrients than 'Dafnis' tomato in the late stage. The K content of 'Dafnis' tomato was high in the early growth stage, but low in the late stage. However, that of 'TY Tiny' tomatoes rose in the late stage. The Ca content gradually increased in both varieties of tomato in the latter stages. The EC of the drained nutrient solution in both varieties of tomato showed increasing tendencies as time had passed, but the pH was get lowered in the drained solution. The concentrations of NO₃-N, K, Ca, Mg, Na, Fe, and B, except PO₄-P in the drained nutrient solution were generally higher than those in the supplied solution, especially in the period of October through December. The above results can be used for controlling of nutrient concentrations in the recirculated hydroponic cultivation of tomato.

• Journal of the Korean association of regional geographers
• /
• v.13 no.2
• /
• pp.129-142
• /
• 2007

The Purpose of this study is to evaluate the value of abandoned paddy fields as wetland ecosystems and their suitability as habitats for various species. Physical and chemical characteristics of soils and the change of vegetation in paddy fields were analysed -with the passage of time after cease of cultivation. The results of analyses for soil characteristics, vegetation succession, and functional values of abandoned paddy fields as wetlands were as follows: First, top soils become coarser as years after abandonment increase. Second, as the years of abandonment passed. there were significant differences in organic matter, available phosphorate and calcium, while not in magnesium and cation exchange capacity(CEC). Third, species increased from early stage till middle stage, and decreased in late stage. In similarity analysis of species composition, sites were classified into three groups according to the stage of succession. Upper and lower terraces at Daetgol were classified as early stage of succession. The 1st, 2nd and 3rd terraces at Nonbanggol were in middle stage, while tile 4th and 5th were in late stage. Forth, according to evaluation sheets of MoE and RAM(Rapid Assessment Method) standards, me overall average of functional value of Nonbanggol site were 2.13, classified as "common".

• Journal of the Daesoon Academy of Sciences
• /
• v.37
• /
• pp.1-52
• /
• 2021

The Naejeong, the inner court, which is one of the structures found in the temple complexes of Daesoon Jinrihoe. It serves the function of leading and controlling the operation and direction of Korean religions in general. Considering that the dictionary meaning of 'Naejeong' is 'a place to manage the affairs of the state from inside a palace,' the name and function of the structure appear to be in harmony. However, in the Daesoon Jinrihoe context, it is said that the name 'Naejeong (內庭 'Neiting' in Chinese)' is related to a verse from a Daoist scripture. It has not been revealed whether or not the scripture is historical, and what contents or contextual meanings it contains. This study tries to pursue this matter and introduce the original source of the Naejeong in Daesoon Jinrihoe as likely coming from Qianbapinxianjing (前八品仙經, The Former Scripture of the Eight Phases That Reveal the Means to Acquire Immortality). This scripture was compiled in Lüzu-quanshu(呂祖全書, The Entire Collection of Ancestor Lü). This text and its contextual meanings will also be examined. The origin of Qianbapinxianjing dates back to either the late Ming Dynasty or the early Qing. In those days, there existed a group of literati who worshipped Ancestor Lü because he had saved people and taught the art of immortality. The group organized Daoist Spirit-Writing Altars (鸞壇道敎) and invoked the spirit of Ancestor Lü. They were said to have been taught through messages received from spirit-writing sessions (降乩) with Ancestor Lü and several Daoist scriptures were composed by them in this manner. At Immortals-Gathering Pavilion (集仙樓) of Wandian (萬店) in Guangling (廣陵), China, some literati in that group conducted a spirit-writing session with Ancestor Lü between 1589 and 1626, and they produced a scripture which contained the passage, "A crow and a rabbit gather in the middle valley (烏兎結中谷) while a turtle entwined with a snake is in the inner court (龜蛇盤內庭)." They titled the scripture, The Five Movements and Filial Piety (五行端孝). This passage symbolically expresses the accomplishment of immortality in Neidan (internal alchemy) which, within the human body, combines the two energies of yin and yang which are Water and Fire in the Five Movements scheme. This kind of cultivation is said to be achieved only by maintaining the highest possible degree of filial piety. In this context, the Naejeong where a turtle is entwined with a snake (龜蛇合體) was a term that symbolically depicted a place wherein one transforms into an immortal through cultivation. The Five Movements and Filial Piety was included in Qianbapinxianjing after it had been compiled with the other scriptures containing Ancestor Lü's teachings. In 1744, Qianbapinxianjing was included in Lüzu-quanshu, the entire 32-volume collection of Ancestor Lü and printed for the first time. This underlies the belief in Ancestor Lü (呂祖信仰) which embraces the idea of the redemption of people, teaches the arts of immortality, and features Daoist Spirit-Writing Altars, filial piety, the art of Neidan, and the combination of Water and Fire.