• Polymer(Korea)
• /
• v.35 no.6
• /
• pp.520-525
• /
• 2011

Superporous hydrogels (SPHs) with fast swelling and superabsorbent properties are useful materials in various biomedical fields, by improving the swelling properties of conventional hydrogels based on their unique porous structure. In this study, Eudragit polymers were used as coating materials to control the swelling properties of poly(acrylic acid-co-acrylamide) based SPHs by environmental pH. The SPHs were coated with Eudragit L100 and S100 that have different pH characteristics as enteric coating materials by a dip coating method, and their pH dependent swelling behaviors were observed in various pH environments. The swelling of SPHs was inhibited at a low pH range, but significantly enhanced above a characteristic pH of Eudragit polymers. This pH dependent swelling behavior of hydrogels could be modulated by the characteristics of the enteric coating polymers.

• FLOWER RESEARCH JOURNAL
• /
• v.18 no.3
• /
• pp.151-156
• /
• 2010

The Objective of this study was to investigate the effect of ethylene exposure and silver thiosulfate (STS) on flower senescence and vase life of cut iris (Iris hollandica). Cut iris flowers were pretreated in 1 mM STS solution for 30 minutes and exposed to 0, $3mL{\cdot}L^{-1}$ethylene for 24 hours. The vase life of iris treated at a bud stage was showed day 4.2 by exposure to $3mL{\cdot}L^{-1}$ ethylene and day 4.6 by exposure to $0mL{\cdot}L^{-1}$ ethylene. The pulsing of STS increased vase life of iris treated at a half-open stage. But, the vase life of iris was not affected by exposure to ethylene. Therefore, iris flowers were not sensitive to ethylene exposure. Iris flowers harvested at a bud stage do not progress to fully open flowers and then show flower senescnce, the optimum harvest stage seems to be a stage when flowers are open to some degree.

• Journal of Applied Biological Chemistry
• /
• v.64 no.1
• /
• pp.33-38
• /
• 2021

Marine sponges contain pharmacologically attractive substances that exhibit strong cytotoxicity and are used as materials to isolate potential drug candidates. However, with a growing interest in marine ecosystem conservation, it is becoming increasingly difficult to gather a sponge for natural product research. To build a database to cope with this issue, we measured the neuroprotective and anti-inflammatory activity of 181 sponge extracts. As a result, we found 17 samples with neuroprotective effects and 14 samples with anti-inflammatory effects. In addition, high-performance liquid chromatography (HPLC) analysis was performed to compare the components contained in each sample, and based on HPLC profiles, a dendrogram according to similarity was created. The results of this study suggested the possibility of discovering the active compounds in the sponge and laid the basis for efficient research on the sponge.

• Journal of The Korean Association For Science Education
• /
• v.24 no.2
• /
• pp.387-398
• /
• 2004

The purpose of this study was to investigate high school students' preference for science(PS) and its causal factors in terms of gender difference, and to suggest the way to improve students' preference for science. A questionnaire to evaluate the PS of high school students and its causal factors was specially designed by researchers. It was administered to 429 boys and 449 girls in eight high schools. The average score of the PS was 3.16 of 5.00 which was not high, but the PS scores of students who had wanted to be engaged in jobs related to science or medical field, were higher than the students who would be in other fields. There was no statistically significant difference between the boys' PS scores and girls', but the average scores of causal factors were higher in boys than in girls. Path analysis using a structural equation model was indicated that the pathways showing how causal factors made effects on each category of the boys' PS were simpler than those of girls. Particularly, while educational factors made indirect effects on three categories of the boys' PS, they did direct effects as well as indirect effect on the girls' PS. This means that the girls' PS is possible to be improved by applying the educational programs specially developed for girls.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.7
• /
• pp.1043-1053
• /
• 2013

We investigated the ability of soybean curd residue (SCR) and its fermented products to inhibit obesity and improve the blood lipid profiles of obese mice fed a high-fat diet. Samples were prepared by fermenting SCR with Aspergillus oryzae var effuses KACC 44990 (ASCR), a microbe used for the fermentation of traditional Korean Meju, and with Monascus pilosus IFO 4480 (MSCR), a microbe used for the production of red rice. In addition, AMSCR, a mixture composed of equal amounts of ASCR and MSCR, was also prepared. Male mice were divided into six groups and fed with either a normal diet, a high-fat diet, or a high-fat diet supplemented with SCR, ASCR, MSCR, or AMSCR. After 8 weeks, body weight gain, serum and hepatic lipid profiles, and the activities of enzymes that generate or scavenge reactive oxygen species (ROS) were evaluated. Compared with the high-fat diet group, all the test groups showed a significant reduction in body, organ, and epididymal fat weight gain. These effects were observed with supplements in the order AMSCR>ASCR>MSCR>SCR. Similarly, supplements of test samples reduced high levels of serum and hepatic triglycerides (TG), total cholesterol, and low-density lipoprotein (LDL) cholesterol caused by hight-fat diet, while high-density lipoprotein (HDL) cholesterol was increased. Interestingly, the ability of ASCR to lower serum TG was stronger than that of MSCR, while MSCR showed a stronger hypocholesterolemic effect than ASCR. Meanwhile, AMSCR returned comprehensively serum lipid levels to normal. In addition, hepatic damage was prevented with effects in the order AMSCR>ASCR>MSCR>SCR. Hepatic ROS generating system including xanthine oxidase (XO) and ROS scavenging system including superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione S-transferase (GST) were recovered to normal level by all test diets. In conclusion, this study suggests that SCR and its fermented products can inhibit obesity and improve lipid profiles.

• Journal of the Korean Society of School Health
• /
• v.3 no.1
• /
• pp.101-118
• /
• 1990

This study was intended to investigate actual conditions and problems relating to a variety of substance which have been used by students. A Questionnaire survey was carried out with the subject of 2411 students in an academic boys' high school, academic girls' high school, technical boys' high school and technical girls' high school in Pusan, from the 15th day to 29th day of March, 1989. The summarized results were as follows. There was not a remarkable difference in distribution of these subjects in boys' & girls' high school. The common and good health condition of subjects accounted for 90 percent or higher. 24.4 percent of them also had smoking experience, 11.6 percent of which continues to smoking. The understanding rate of these substances name other than sedative, psychostimulants and antihypnotic accounted for 90 percent or higher. The experience rate taking these substances for one year showed that anodyne, digestive and nutritive tonic accounted for 70 percent, antihypnotic for 15.6 percent, sedative for 1.4 percent, respectively, and psychostimulants for 0.5 percent. Moreover. it was shown that drugs accounted for 1.5 percent, bond for 1.4 percent, and thinner for 0.5 percent. The rate of the daily experiencers who took anodyne, digestive, nutritive tonic, sedatives, and psychostimulants and so on was 7.7 percent, 6.2 percent, 5.2 percent, 5.9 percent, and 5.0 percent respectively. This fact implied that there was a serious problem in high school students' non - narcotic abuse. The usage rate of these substances for treatment purpose showed that anodyme accounted for 90 percent or higher, and digestive for 70-80 percent, respectively, where girl students showed higher rate than one of boy students. Additionally, there was higher the usage rate for other purposes. The usage rate of drugs was highest when these students felt melancholy and curiousity. Their obtaining place appeared that these students mainly obtained these drugs, bonds and thinners from a small shop or peddler and their friend while they usually obtained other substance from the pharmacy and medical institute. The first usage time of these substances appeared during the middle school (the age of 14-15) which was the highest rate. The smoker of all subjects used remarkly large substances as compared with one of no-smoker. Particularly, it appeared that the usage of drugs was very closely related to smoking. The large number of students did not use these substances for oesrable purposes even though they understood the name of these substances. For this reason, from primasy schools it is required to teach the students dependence and harmful effects caused by these substances abuse. Moreover, it was shown that these students firstly used these substances during the middle school (the age of 14-15)due to curiosity. As a result, it is very urgent to give the students health education suitabale for prevention of these substance abuse, when considering harmful effects of these substances. And so health education for no-smoking. Finally, considering that it is very easy to obtain these substances from a small shop and pharmacy, the regulation of these substances control should be considered and completed in the future.

• Journal of Ginseng Culture
• /
• v.3
• /
• pp.54-73
• /
• 2021

The Natural Products Research Institute (NPRI, 生藥硏究所), an institution affiliated with Keijo Imperial University (京城帝國大學), was the predecessor of the NPRI at Seoul National University and a comprehensive research institute that focused on ginseng research during the Japanese colonial era. It was established under the leadership of Noriyuki Sugihara (杉原德行), a professor of the second lecture in pharmacology at the College of Medicine in Keijo Imperial University. Prof. Sugihara concentrated on studying Korean ginseng and herbal medicine beginning in 1926 when the second lecture of pharmacology was established. In addition to Prof. Sugihara, who majored in medicine and pharmacology, Kaku Tenmin (加來天民), an assistant professor who majored in pharmacy; Tsutomu Ishidoya (石戶谷勉), a lecturer who majored in agriculture and forestry; and about 36 researchers actively worked in the laboratory before the establishment of the NPRI in 1939. Among these personnel, approximately 14 Korean researchers had basic medical knowledge, derived mostly from specialized schools, such as medical, dental, and pharmaceutical institutions. As part of the initiative to explore the medicinal herbs of Joseon, the number of Korean researchers increased beginning in 1930. This increase started with Min Byung-Ki (閔丙祺) and Kim Ha-sik (金夏植). The second lecture of pharmacology presented various research results in areas covering medicinal plants in Joseon as well as pharmacological actions and component analyses of herbal medicines. It also conducted joint research with variousinstitutions. Meanwhile, in Gaesong (開城), the largest ginseng-producing area in Korea, the plan for the Pharmaceutical Industry Complex was established in 1935. This was a large-scale project aimed at generating profits through research on and the mass production of drugs and the reformation of the ginseng industry under collaboration among the Gaesong Ministry, Kwandong (關東) military forces, Keijo Imperial University, and private organizations. In 1936 and 1938, the Gyeonggi Provincial Medicinal Plant Research Institute (京畿道立 藥用植物硏究所) and the Herb Garden of Keijo Imperial University (京城帝國大學 藥草園) and Pharmaceutical Factory were established, respectively. These institutions merged to become Keijo Imperial University's NPRI, which wasthen overseen by Prof. Sugihara as director. Aside from conducting pharmacological research on ginseng, the NPRI devoted efforts to the development and sale of ginseng-based drugs, such as Sunryosam (鮮麗蔘), and the cultivation of ginseng. In 1941, the Jeju Urban Test Center (濟州島試驗場) was established, and an insecticide called Pancy (パンシ) was produced using Jeju-do medicinal herbs. However, even before research results were published in earnest, Japanese researchers, including Prof. Sugihara, hurriedly returned to Japan in 1945 because of the surrender of Japanese forces and the liberation of Korea. The NPRI was handed over to Seoul National University and led by Prof. Oh Jin-Sup (吳鎭燮), a former medical student at Keijo Imperial University. Scholars such as Woo Lin-Keun (禹麟根) and Seok Joo-Myung (石宙明) worked diligently to deal with the Korean pharmaceutical industry.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.258-258
• /
• 2013

최근 건조 제품의 양질화, 고급화 및 편의화가 요구되어 이를 충족시키기 위한 새로운 건조방법이 계속 개발 되어 왔다. 이러한 방법들 중에서 저온과 진공하에서 건조가 이루어지는 진공 동결 건조는 가장 완벽한 건조 방법으로 최근 실용화 되고 있다. 진공동결건조란 건조의 한 종류로 수분을 함유한 시료를 동결시킨 후 진공펌프를 이용하여 수증기압을 3중점 이하로 낮추어 얼음을 직접 증기로 만드는 승화의 원리에 의해서 얻어진다. 분무진공동결건조의 특징은 (1) 물리적구조의 보존성, (2) 화학적인 안정성, (3) 생물학적인 활동의 보존성, (4) 제품의 높은 복원성 및 재생성이다. 따라서 분무진공동결건조 기술은 크게 진공, 분무, 동결, 건조, 멸균 등과 같은 요소기술의 복합기술이라 할 수 있다. 분말을 제조하기 위해서 진공동결건조 후 분쇄하는 방법을 사용하나 본 방법에서는 정밀화학품 제조를 위해서 분무진공동결건조 방식을 사용한다. 이를 통하여 적당한 크기인 5~10 um의 입경 제조가 가능하고, 공기동력학적인 입경이 기존 방식에 비해 작아서 허파까지의 운반효율이 1.5~2배 우수하다. 화학, 의학 분야에서의 분무동결 건조는 주로 민감한 제품, 즉 생물학적 고유성의 손상 없이 물을 제거하는데 사용되어 영구적으로 저장 가능한 상태로 보관할 수 있으며 물의 첨가로 원상태로 복구할 수 있어서 매우 각광을 받고 있다. 의약용 냉동건조 제품은 항생물질, 박테리아, 혈청, 백신, 검사 약물, 단백질을 포함하는 생물공학 제품들, 세포, 섬유, 화학제품 등이 있으며 주로 vial 또는 ampule 상태로 건조가 이루어진다.본 연구에서는 원료를 $-194^{\circ}C$의 액체질소에 분무시켜 동결된 미립자를 형성한 후 진공 및 저온상태에서얼음의 승화(sublimation)에 기반한 1차 건조와 수증기 탈착(desorption)에 기초한 2차 건조 과정으로 구성된 분무진공동결건조기를 개발하였다. 분무동결 과정의 해석을 통해 2유체식 노즐을 통해 분무된 미세 입경의 액적이 액체 질소 표면까지 도달하는 회수률, 분무 노즐의 위치, 운전 조건 및 용기의 설계의 최적화를 수행하였다. 초기 액적속도, 분무노즐의 높이, 흡입구 추가에 따른 액적 유동 및 회수의 특성을 제시하였으며 이를 통한 분사시스템 고도화 가능성을 제시하였다. 구형의 미세 입자가 적층된 제품의 동결건조 공정의 해석은 흡착승화 모델(sorption sublimation model)을 기반으로 다음과 같은 열전달, 물질전달, 상변화 모델을 고려하여 유도되었다. 분무노즐 및 냉동/진공 배기계 시작품을 개발하여, 표면의 고다공도를 갖춘 입경 3~20 m 정도의 시료를 얻을 수 있으며, 동역학적 입경 5 m 충족함을 확인하였다.

• Analytical Science and Technology
• /
• v.18 no.1
• /
• pp.5-12
• /
• 2005

It has been established that soft error of high precision electronic circuits can be induced by alpha particles emitted from the naturally occurring radioactive impurities such as U, and Th. As the electronic circuits have recently become lower dimension and higher density, these alpha-particle emitting radioactive impurities have to be strictly controlled. The aim of this study is to develop of NAA (Neutron Activation Analysis) and gamma-spectrometry to improve the analytical sensitivity and precision of U and Th. A new NAA method has been established using the HTS (Hydrulic transfer system) irradiation facility which has been used to produce radioisotopes for industries and medicines instead of the PTS (pneumatic transfer system) irradiation facility which has been used in general NAA. When the ultratrace impurities have to be analyzed by NAA, background gamma-ray spectra induced from $^{222}Rn$ and its progenies in air is serious problem. This unstable background has been eliminated or stabilized by the use of a nitrogen purging system. Ultra trace amounts of U (0.1 ng/g) and Th (0.01 ng/g) in high purity silica used for EMC could be analyzed by the use of HTS-NAA and low background gamma-spectrometry.

• Journal of Life Science
• /
• v.30 no.10
• /
• pp.835-843
• /
• 2020

Obesity, the world's leading metabolic disease, is a serious health problem in both industrialized and developing countries. Natural substances are of great interest in preventative medicine, especially in the field of metabolic syndromes-from insulin resistance to obesity and diabetes. In the present study, we investigated the effect of A. pullulans SM-2001 Extract (Polycan^®) on the adipocyte differentiation of 3T3-L1 preadipocytes and the anti-obesity effect of 3T3-L1 adipocytes. Although β-glucan has been found to have health benefits in the regulation of the immune system and blood cholesterol levels, its role in obesity has not been fully investigated. Polycan^® suppressed lipid accumulation and glycerol-3-phosphate dehydrogenase (GPDH) activity without affecting cell viability in 3T3-L1 preadipocytes and adipocytes. Polycan^® also inhibited cellular lipid accumulation through down-regulation of transcription factors, such as PPARγ and C/EBPα, and induced dose-dependent phosphorylation of AMP-activated protein kinase (AMPK)-a cellular energy sensor-while the total AMPK protein content remained unchanged. Taken together, this shows that the activation of AMPK by Polycan^® in adipocytes plays a critical role in Polycan^®-induced inhibition of adipocyte differentiation. Our results show that Polycan^® has an anti-obesity action in vitro, suggesting a potential novel preventative agent for obesity and other metabolic diseases.