Preparation of Thermo-Responsive and Injectable Hydrogels Based on Hyaluronic Acid and Poly(N-isopropylacrylamide) and Their Drug Release Behaviors

Ha Dong In,Lee Sang Bong,Chong Moo Sang,Lee Young Moo,Kim So Yeon,Park Young Hoon The Polymer Society of Korea 2006 Macromolecular Research Vol.14 No.1

Copolymers composed of hyaluronic acid (HA) and poly(N-isopropylacrylamide) (PNIPAAm) were prepared to create temperature-sensitive injectable gels for use in controlled drug delivery applications. Semi-telechelic PNIPAAm, with amino groups at the end of each main chain, was synthesized by radical polymerization using 2-aminoethanethiol hydrochloride (AESH) as the chain transfer agent, and was then grafted onto the carboxyl groups of HA using carbodiimide chemistry. The result of the thermo-optical analysis revealed that the phase transition of the PNIPAAm-grafted HA solution occurred at around 30$\∼$33$^{circ}C$. As the graft yield of PNIPAAm onto the HA backbone increased, the HA-g-PNIPAAm copolymer solution exhibited sharper phase transition. The short chain PNIPAAm-grafted HA ($M_{w}$=6,100) showed a narrower temperature range for optical turbidity changes than the long chain PNIPAAm-grafted HA ($M_{w}$=13,100). PNIPAAm-grafted HA exhibited an increase in viscosity above 35$^{circ}C$, thus allowing the gels to maintain their shape for 24 h after in vivo administration. From the in vitro riboflavin release study, the HA-g-PNIPAAm gel showed a more sustained release behavior when the grafting yield of PNIPAAm onto the HA backbone was increased. In addition, BSA released from the PNIPAAm-g-HA gels showed a maximum concentration in the blood 12 h after being injected into the dorsal surface of a rabbit, followed by a sustained release profile after 60 h.

Valuation of ecosystem services in the organic carbon of the Pinus densiflora forest at Mt. Namsan, Seoul Metropolitan City

Lee, Eung-Pill,Lee, Soo-In,Jeong, Heon-Mo,Han, Young-Sub,Lee, Seung-Yeon,Park, Jae-Hoon,Jang, Rae-Ha,Hong, Youg-Sik,Jung, Young-Ho,Kim, Eui-Joo,Lee, Sang-Hun,You, Young-Han The Ecological Society of Korea 2019 Journal of Ecology and Environment Vol.43 No.4

Background: Standing biomass, litter production, rate of litter decomposition, amount of litter on forest floor, and amount of soil organic carbon distribution were investigated from March 2016 to November 2018 in order to evaluate the ecosystem value through organic carbon distribution in the Pinus densiflora forest at Namsan, Seoul Metropolitan City. Results: The amount of organic carbon in the Pinus densiflora forest was 261.09 ton C ha^-1 during the research period, and fixed organic carbon in plant through net photosynthesis was 3.2 ton C ha^-1 year^-1. The organic carbon in plant was 62.77 ton C ha^-1 (24.04%), in litter on the forest floor was 3.65 ton C ha^-1 (1.40%), and in soil was 194.67 ton C ha^-1 (74.56%). The value of plant, litter on forest floor, and soil organic carbon distribution were each 6,277,000 won ha^-1, 365, 000 won ha^-1, and 19,467,000 won ha^-1. The value per ton of fixed organic carbon in plant through net photosynthesis was 320,000 won ha^-1 year^-1 and the value of ecosystem services stored in carbon in the Namsan forest ecosystem was about 26.1 million won ha^-1 for 3 years. Conclusions: The results of this study suggest that the pine forests of Namsan rapidly decompose leaves due to the high atmospheric temperature and accumulate a large amount of organic carbon in the soil to provide climate control regulatory service function.

폐렴구균의 용혈능 변화와 pneumolysin 유전자의 변이 양상

오원섭,장현하,정숙인,김연숙,이혁,김신우,김성민,백경란,이남용,송재훈 대한화학요법학회 2002 대한화학요법학회지 Vol.20 No.3

목적 : 폐렴구균은 인체에서 폐렴, 수막염 및 패혈증 등을 일으키는 중요한 병원균으로 현재 전 세계적으로 항균제 내성이 큰 문제가 되고 있다. 하지만 폐렴구균의 항균제 내성에 따라 병독성이 어떻게 변화하는지에 대해서는 구체적으로 알려져 있지 않다. 이에 기능적 및 구조적 분석을 통하여 폐렴구균의 주요 병독성 인자인 pneumolysin의 병인론적 역할을 규명하고자 하였다. 방법 : 임상 검체에서 분리된 페니실링 감수성 균주 20주와 내성 균주 20주를 대상으로 하였다. Pneumolysin의 세포 독성의 변화를 관찰하기 위하여 각각의 균주들의 용혈능을 측정하였고, pneumolysin 유전자를 중합효소 연쇄반응으로 증폭한 후 증폭 산물의 유전자 구조를 분석하였다. 결과 : 페니실린 감수성 균주와 내성 균주간의 용혈능은 유의한 차이를 보이지 않았으나, 일부 용혈능이 매우 낮은 균주에서 Lys152→Thr, Thr-172→Ile, Lys-224→Arg와 같은 변이가 관찰되었다. 결론: pneumolysin의 세포 독성의 변화는 항균제 내성 정도와는 무관하였으나, 일부 용혈능이 저하된 균주에서 발견된 pneumolysin 유전자의 변이가 pneumolysin의 세포 독성에 영향을 주는 것으로 보인다. Background : Pnumolysin (Ply) is one of the most important virulence factors of Streptococcus pneumoniae. To investigate the functional and structural variation of Ply, hemolytic activity (HA) and gene sequences of pneumolvsin were determined. Methods : A total of 40 invasive pneumococcal isolated (20 penicillin-susceptible & 20-resistant strains) were analyzed. HA of each isolate was measured in crude extracts (1×10^8 CFU/mL) hourly from the time of inoculation to 9h. Crude extracts (50㎕) and DTT buffer (100㎕) were serially diluted in 96-well plate and mixed with 1% sheep blood (50㎕). HA was represented as the reciprocal of the greatest dilution, which resulted in the complete lysis. Two sets of oligonucleotide primers were used to amplify a 1,474-bp fragment containing the coding region and a 578-bp fragment of upstream region of ply gene, respectively. Amplified products were directly sequenced. Results : HA showed a wide variation from 0 to 87,480 regardiess of penicillin MICs, serotypes or specimen sources. Two bacteremic strains showed completely no hemolytic activity. No significant differences in HA between penicillin-susceptible (Mean± SE : 15,468± 4,693) and penicillin-resistant strains (21,384± 4,087) were found (p > 0.05).Sequencing of the coding region showed unique alterations in amino acids in strains with markedly reduced hemolytic activity (≤ 40): Thr-172-Ile and Lys-224-Arg. However, upstream region of ply gene was highly conserved. Conclusions : Ply activity was not related with antibiotic resistance. Absence of HA in some strains was associated with unique alterations in amino acid sequences in ply gene. Relationnship between genomic alteration and functional changes in pneumolysin should be further investigated.

Current Status of Ginseng Cultivation and Soil Characteristics of Northeastern Three Provinces in China

Yang Ho Park,Jang Uk Kim,Dong Hwi Kim,Yeon Kyu Sonn,Jin Ha Yun,Huhn Pal Moon,Soo Yeon Cho 한국토양비료학회 2016 한국토양비료학회지 Vol.49 No.6

This study was conducted to improve the continuous techniques for international competitiveness of ginseng industry to Korea-China FTA negotiation and conclusion, and provide the basic information for ginseng industry development of Korea. It was carried out the visiting of the northeastern three provinces (Jilin, Liaoling and Heilongjang) in China for 3-year from 2014 to 2016 and observed the farmers’ fields of ginseng cultivation with soil environmental status. The types of ginseng cultivation could be observed in small scales of 0.5∼3.0 ha, in middle scales of 4.0∼10.0 ha and in large scales of 30∼700 ha with the kinds of imhasam, Chinese ginseng, Korean ginseng and western ginseng. Also ginseng was cultivated in newly reclaimed land of forest in two types of direct seeding and transplanting of ginseng seedlings. The field beds of ginseng growing were covered with vinyl films in arch design of 100∼130 cm height and vinyl was painted in spraying with blue, green and yellow colours for shading. It was investigated in status of the physico-chemical properties of soils. The physical information on the field soils were silt loam, loam and sandy loam in soil textures, and some plain in low slope, some alluvial fan or local valley in forest of land topography. Soil pH ranged within 5.0∼5.2, soil EC was 0.93∼3.78 dS m<SUP>-1</SUP>, organic matter was 37∼35 g kg<SUP>-1</SUP>, nitrate nitrogen 63∼490 mg kg<SUP>-1</SUP>, available P2O5 55∼163 mg kg-1, and in exchangeable cations, K was 0.30∼0.98, Ca was 6.5∼14.0, Mg was 1.1∼5.3 cmolc kg<SUP>-1</SUP> in ranges. Farmers used the fertilizer for ginseng cultivation in 10∼11 t of compost, 200∼400 kg ha<SUP>-</SUP>1 of complex fertilizer and 750 kg ha<SUP>-1</SUP> of oil cakes. The northeastern three provinces of China can use the newly lands with large areas of ginseng cultivation in soil sickness by continuous cropping. and the soil basic fertility is batter than that of Korean in standard guide of ginseng cultivation soil.

Current Status of Ginseng Cultivation and Soil Characteristics of Northeastern Three Provinces in China

Park, Yang Ho,Kim, Jang Uk,Kim, Dong Hwi,Sonn, Yeon Kyu,Yun, Jin Ha,Moon, Huhn Pal,Cho, Soo Yeon 한국토양비료학회 2016 한국토양비료학회지 Vol.49 No.6

This study was conducted to improve the continuous techniques for international competitiveness of ginseng industry to Korea-China FTA negotiation and conclusion, and provide the basic information for ginseng industry development of Korea. It was carried out the visiting of the northeastern three provinces (Jilin, Liaoling and Heilongjang) in China for 3-year from 2014 to 2016 and observed the farmers' fields of ginseng cultivation with soil environmental status. The types of ginseng cultivation could be observed in small scales of 0.5~3.0 ha, in middle scales of 4.0~10.0 ha and in large scales of 30~700 ha with the kinds of imhasam, Chinese ginseng, Korean ginseng and western ginseng. Also ginseng was cultivated in newly reclaimed land of forest in two types of direct seeding and transplanting of ginseng seedlings. The field beds of ginseng growing were covered with vinyl films in arch design of 100~130 cm height and vinyl was painted in spraying with blue, green and yellow colours for shading. It was investigated in status of the physico-chemical properties of soils. The physical information on the field soils were silt loam, loam and sandy loam in soil textures, and some plain in low slope, some alluvial fan or local valley in forest of land topography. Soil pH ranged within 5.0~5.2, soil EC was $0.93{\sim}3.78dS\;m^{-1}$, organic matter was $37{\sim}35g\;kg^{-1}$, nitrate nitrogen $63{\sim}490mg\;kg^{-1}$, available $P_2O_5$ $55{\sim}163mg\;kg^{-1}$, and in exchangeable cations, K was 0.30~0.98, Ca was 6.5~14.0, Mg was $1.1{\sim}5.3cmol_c\;kg^{-1}$ in ranges. Farmers used the fertilizer for ginseng cultivation in 10~11 t of compost, $200{\sim}400kg\;ha^{-1}$ of complex fertilizer and $750kg\;ha^{-1}$ of oil cakes. The northeastern three provinces of China can use the newly lands with large areas of ginseng cultivation in soil sickness by continuous cropping. and the soil basic fertility is batter than that of Korean in standard guide of ginseng cultivation soil.

논문 : 강원도 양양지역 소나무림의 지상부 바이오매스와 수관층 연료특성에 관한 연구

김성용 ( Sung Yong Kim ),이영진 ( Young Jin Lee ),장미나 ( Mi Na Jang ),서연옥 ( Yeon Ok Seo ),구교상 ( Kyo Sang Koo ),정성철 ( Sung Cheol Jung ),김경하 ( Kyung Ha Kim ) 한국임학회 2012 한국산림과학회지 Vol.101 No.2

본 연구의 목적은 강원도 양양지역에 분포하는 소나무림을 대상으로 지상부 바이오매스와 수관층 연료특성에 대하여 분석하고자 하였다. 연구대상지는 강원도 양양군 현남면 하월천리 일대 소나무림으로 선정하였으며, 총 13본의 표본목을 벌채하여 분석하였다. 본 연구 결과에 의하면, 양양지역 소나무림의 줄기밀도(g·cm-3)는 0.347~0.409, 지상부 바이오매스 확장계수는 1.251~1.419의 범위로 나타났다. 지상부 연료량은 총 161.6 Mg·ha-1로 나타났으며, 줄기 126.4 Mg·ha-1, 가지 29.3 Mg·ha-1, 잎 5.9 Mg·ha-1로 나타났다. 수관층 연료특성 인자에 관한 연구에서는 수관화 확산 시 연소될 수 있는 연소가능 연료(잎~1 cm이하 가지)의 비율은 45.2%로 나타났고, 연료량을 수관체적으로 나눈 연소가능 연료밀도(kg·m-3)는 평균 0.178로 나타났다. 본 연구의 결과는 소나무림의 바이오매스 및 탄소 흡수량 추정과 수관화 위험성을 연료적 관점에서 평가하는데 있어 유용한 기초자료가 될 것으로 사료된다. The objective of this study was to analyze the above-ground biomass and crown fuel characteristics of Pinus densiflora stands in Yangyang, Gangwon province. A total of thirteen representative trees were destructively sampled in Yangyang region. The results showed that the stem density (g·cm-3) was 0.347~0.409, whereas the above-ground biomass expansion factors ranged from 1.251~1.419. In terms of crown fuel biomass, the above-ground biomass was 161.6 Mg·ha-1 while the stem biomass, branch biomass and needle biomass were 126.4 Mg·ha-1, 29.3 Mg·ha-1 and 5.9 Mg·ha-1, respectively. Needles and twigs with less than 1 cm diameter accounted 45.2% of the total crown fuel load. The available crown bulk density, which was calculated by dividing the crown fuel load to the crown volume, was 0.178 kg·m-3. The results of this study on the biomass and carbon stocks estimation of the Pinus densiflora together with the crown fire hazard assessment based on crown fuel loads are very significant information for the forest managers.

Bloodstream Infections and Clinical Significance of Healthcare-associated Bacteremia: A Multicenter Surveillance Study in Korean Hospitals

Son, Jun Seong,Song, Jae-Hoon,Ko, Kwan Soo,Yeom, Joon Sup,Ki, Hyun Kyun,Kim, Shin-Woo,Chang, Hyun-Ha,Ryu, Seong Yeol,Kim, Yeon-Sook,Jung, Sook-In,Shin, Sang Yop,Oh, Hee Bok,Lee, Yeong Seon,Chung, Doo The Korean Academy of Medical Sciences 2010 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.25 No.7

<P>Recent changes in healthcare systems have changed the epidemiologic paradigms in many infectious fields including bloodstream infection (BSI). We compared clinical characteristics of community-acquired (CA), hospital-acquired (HA), and healthcare-associated (HCA) BSI. We performed a prospective nationwide multicenter surveillance study from 9 university hospitals in Korea. Total 1,605 blood isolates were collected from 2006 to 2007, and 1,144 isolates were considered true pathogens. HA-BSI accounted for 48.8%, CA-BSI for 33.2%, and HCA-BSI for 18.0%. HA-BSI and HCA-BSI were more likely to have severe comorbidities. <I>Escherichia coli</I> was the most common isolate in CA-BSI (47.1%) and HCA-BSI (27.2%). In contrast, <I>Staphylococcus aureus</I> (15.2%), coagulase-negative <I>Staphylococcus</I> (15.1%) were the common isolates in HA-BSI. The rate of appropriate empiric antimicrobial therapy was the highest in CA-BSI (89.0%) followed by HCA-BSI (76.4%), and HA-BSI (75.0%). The 30-day mortality rate was the highest in HA-BSI (23.0%) followed by HCA-BSI (18.4%), and CA-BSI (10.2%). High Pitt score and inappropriate empirical antibiotic therapy were the independent risk factors for mortality by multivariate analysis. In conclusion, the present data suggest that clinical features, outcome, and microbiologic features of causative pathogens vary by origin of BSI. Especially, HCA-BSI shows unique clinical characteristics, which should be considered a distinct category for more appropriate antibiotic treatment.</P>

“Did You Enjoy Dining Alone?” An Examination of Solo Diners

Ha,Joo-Yeon,Park,Jeong-Yeol,Robin M,Back 한국식공간학회 2020 식공간연구 Vol.15 No.3

As the number of people spending time alone continues to increase, more people are engaging in solo consumption experiences, resulting in dining alone at a restaurant becoming more prevalent. Restaurants have responded in a number of ways to provide accommodations for solo diners’preferences, including the provision of different table layouts such as small tables, bar seating, and communal tables. However, a close examination on the impact of such table arrangements on solo diners’ behavioral intentions is lacking. This study was designed to examine the influence of table layouts, in conjunction with three restaurant quality dimensions (food quality, service quality, and atmospheric quality), on solo diners’ positive emotions and situational loneliness, which ultimately influences behavioral intentions. Structural equation modeling was used to analyze data collected from 286 United States residents who had dined alone at a restaurant within the previous two weeks. Results suggested that food quality and service quality stimulated positive emotions, while food quality decreased situational loneliness. Bar seating increased positive emotions and decreased loneliness. Positive emotions increased both revisit intentions in general and revisit intentions as a solo diner. Loneliness, on the other hand, was shown to decrease revisit intentions as a solo diner.

The Comparisional Analysis of Colostrum Protein between the First and Third Days after Calving using Proteomic Analysis

Woo Tae Ha1,Hyun Jung Park,Won-Young Lee,Ha Yeon Jeong,Hyuk Song 한국동물생명공학회(구 한국동물번식학회) 2017 Reproductive & Developmental Biology(Supplement) Vol.41 No.2

The colostrum proteins are an important energy source for newborns and improves their innate immune system. Recently, there are many interest about beneficial factors in colostrum to health and many products using colostrum are attentive into dietary supplements in global industry. The aim of this study was to compare the enriched proteins between the colostrum from the first and the third day after calving using proteomic analysis and to analyze which enriched protein will be useful to industry of dietary supplements. In this study, cows in the experimental group were fed a standard composition of feed for 12 months, after which we collected the colostrum on the first and the third day after calving. By comparison between the first and the third day colostrum, several factors, including beta-lactoglobulin, fibrinogen gamma-B chain, complement C3, zinc-alpha-2 glycoprotein, bP47 protein, beta casein, and alpha-S2 casein were enriched in the third day colostrum, whereas immunoglobulin gamma 1 and beta- casein A2 were enriched in the first day colostrum. The results suggest that the colostrum composition depends on time and the first day colostrum is important to establish the primary specific immune system, whereas the third day colostrum might regulate the non-specific immune system and increase nutrition using casein and the third day colostrum might be useful dietary products for supporting the immune system.

Regeneration of Bovine Mammary Gland in Immunodeficient Mice by Transplantation of Bovine Mammary Epithelial Cells mixed with Matrigel

Woo Tae Ha1,Hyun Jung Park,Won-Young Lee,Ha Yeon Jeong,Hyuk Song 한국동물생명공학회(구 한국동물번식학회) 2017 Reproductive & Developmental Biology(Supplement) Vol.41 No.2

With the global demand for dairy protein for consumption growing annually, there has been increasing activity in the research field of dairy protein synthesis and production. From a manipulation perspective, it is more difficult to use live cattle for laboratory studies on the production of milk as well as of dairy protein such as casein, as compared with using laboratory animals like rodents. Therefore, we aimed to develop a mouse model of bovine mammary alveolar ducts for laboratory-scale studies. We studied the formation of the bovine mammary gland ductal structure by transplanting the MAC-T bovine alveolar cell line into mice. MAC-T cells (1×107) were suspended in Matrigel and injected into the dorsal tissue of 8-week-old male BALB/C nude mice. Histological analysis of tissue dissected from the MAC-T cell-transplanted mice after 6 weeks showed the typical morphology of the tubuloalveolar female gland, as well as glands made up of branching ducts that were surrounded by smooth muscle with small alveoli budding off the ducts. In addition, the epithelial markers CK14 and CK18 were expressed within the duct-like structure. Prolactin was detected in the duct interior in these CK14+ and CK18+ cells but not in the non-transplanted MAC-T cells. These results showed that duct-like tissue had been successfully formed after 6 weeks of transplantation of the CK14+ and CK18+ MAC-T cells into mice dorsal tissue. This mouse model will be a useful tool for further research on the bovine mammary gland.