• Title/Summary/Keyword: Exhaustion (%)

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Interleukin-2 production and alteration of T cell subsets in mice infected with Naegleria fowleri (Naegleria fowleri 감염 마우스에 있어서 interleukin-2 생성 및 T 림프구 아형변동)

  • Yu, Cheol-Ju;Sin, Ju-Ok;Im, Gyeong-Il
    • Parasites, Hosts and Diseases
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    • v.31 no.3
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    • pp.249-258
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    • 1993
  • Naegleria fowleri is the cause of primary amoebic meningoencephalitis in man, IL-2 levels after stimulation of T lymphocytes by PHA or N.fowleri lysates. the amounts of T lymphocyte subsets and the blastogenic responses of T lymphocytes in mice after Infected with pathogenic N. fowleri were studied comparing between two study groups, one $1{\;}{\times}{\;}10^4$ trophozoites inoculated mice and the other $1{\;}{\times}{\;}10^5$ trophozoites inoculated mice. All experimental samples were obtained on the day 7, 14 and 24 after inoculation. The mice inoculated with $1{\;}{\times}{\;}10^4$ trophozoites showed a 14.3% mortality rate, and 72.2% in the mice inoculated with $1{\;}{\times}{\;}10^5$ trophozoites. The IL-2 levels on day 14 of two experimental groups were significantly decreased as compared with the control group. Thy 1.2+T cells in the total spleen Iymphocytes of $1{\;}{\times}{\;}10^5$ trophozoites inoculated group on day 7 were significantly increased compared with the control group. There was no significant difference between $1{\;}{\times}{\;}10^4$ trophozoites inoculated group and the control group. $L3T4^{+}{\;}T$ cells and $Ly2^{+}$ T cells in the total spleen Iymphocytes of $1{\;}{\times}{\;}10^5$ trophozoites inoculated group on day 7 were sigrlificantly increased compared with the control group. The DNA S fraction of T cells in the spleen of $1{\;}{\times}{\;}10^5$ trophozoites inoculated group was significantly increased on day 7. The amount of S fractions of DNA were sequentially decreased on day 14 and 24 but they were also signiacantly increased compared with the control group. The results obtained in the experiments indicats that cell mediated immunity after N.fowleri infection acts on very important host's protection immunity around the 7th day after infection. IL-2 level was much suppressed on day 14 which resulted from the exhaustion of host immune response. It was observed that the level of IL-2 production ability and the amounts of T lymphocytes subsets and the blastogenic responses of T lymphocytes were not well correlated during the observation period.

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A Study of formative character of Art Nouveau Through the works of $Ren{\acute{e}}$ Lalique, Emile Galle, Louis Comfort Tiffany, Victor Horta (아르누보양식의 조형적 특성연구 - 르네랄리크.에밀갈레.루이스 컴포트 티파니.빅토르오르타의 작품을 중심으로 -)

  • Kim, Bun-Jung
    • Journal of Science of Art and Design
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    • v.11
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    • pp.5-35
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    • 2007
  • When it comes to art, the two conflicting themes of 'scientific progress' and the 'nature' have often motivated the advent of the new mode of arts. By the late 20th century, uniform and simplified mode of arts, inspired by scientific and technological progress of that time, was gradually disillusioned by the contemporaries due to the adverse effect of science on human life. In this context, naturalism pursuing for harmony of human and the nature came up as an alternative to those living in the 21st century. The pendulum has swung from minimalism to naturalism. Though the quantitative improvement of human life cannot be denied, the uprise of such problems as environmental pollution and exhaustion of natural resources degraded the quality of human life, which, eventually, shifted the attention to the theme - 'revival of naturality.' Therefore, this thesis intends to represent the modem interpretation of the 'revival of naturality' by applying the major expressions of Art Nouveau that also emphasized naturalism. Art Nouveau found its motifs from organic figures of natural beings and put them to designs of decorative arts. This carries a historical significance in that Art Nouveau boldly revolutionized historicism, which only repeated adoption and modification of the existing modes of arts, and opened it to the modem design with new attempts to practical applications of the arts. Art Nouveau, which means 'new art', prospered from the late 19th century to the early 20th century, and even after one century, it is highly appreciated, reviving as novel and vivid forms in this contemporary art. Art Nouveau based on naturalism has revisited our contemporary period when naturalism and feminized romanticism came into fashion and its common motifs revive in different jenre of arts such as fashion, furniture, glass works, and jewelry works. This study illustrates and analyzes the works of four major artists who gave a specific attention to botanical motifs of Art Nouveau and applies decorative beauty of highly sophisticated and organic curved lines and the expressional forms of botanical figures to design. Art Nouveau proved this; the nature herself is as beautiful as she can be. Within Art Nouveau, the true humanism can be revitalized with the 'revival of naturality'. This study rediscovered the boundless potential of modern interpretation and application of Art Nouveau in decorative art and design.

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Prospects of Fertilizer Demand based on Recent Consumption (최근(最近)의 비료소비면(肥料消費面)에서 본 비료수요전망(肥料需要展望))

  • Park, Young-Dae
    • Korean Journal of Soil Science and Fertilizer
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    • v.9 no.3
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    • pp.149-163
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    • 1976
  • In Korea, the ever-increasing population has become a serious problem and the decreasing of cultivated lard area per person has become a major concern. Therefore, today we are implementing a green revolution using miracle varieties which require more fertilizer. The increased use of fertilizer along with development and adoption of high yielding varieties is the key to carrying out this green revolution. Fertilizer consumption in Korea is mainly influenced by agricultural techniques, fertilizer prices and government policies for increasing food production. If there are no special change, such as a cataclysm or an exhaustion of resources, it is quite clear that the fertilizer demand will increase to the near maximum ceiling point of optimum levels for crops in the year 2000. Fertilizer demand is not the amount of fertilizer that will be used by the farmer, but the actual optimum amount of plant nutrients required for maximum production. In this report, two alternative strategies are consideded in forecasting the future feitilizer demands. Alternative I is projected by reviewing consumption amounts over the last 10 years (1966~75) in Korea. The annual rate of increase in fertilizer consumption for the last 10 years was approximately 8.7% (table 1). Plant nutrient consumption rates in later years have been more balanced, and also fertilizer consumption per total acreage is considerably higher in Korea than in other countries (table 11), consequently the rate of increase in the future is expected to decline. Looking at the long term projections, the average annual rate of increase is expected to be 7% for 1976~80, 2.5% for 1981~90, 1.5% for 1991~2000. Thus, total projected fertilizer demands are estimated at 1,208,000M/T by 1980, 1,547,000M/T by 1990, 1,795,000M/T by 2000 (table 16). Alternative II is based on projected optimum fertilizer levels for crops and on increased crop acreage. The government recommended fertilizer rate has increased by a factor of 0.99 to 5.49 over the past twelve years depending on the specific crops (table 4). Levels of fertilizer demand recommended by government (table 7) in 1976 are still low compared with actual optimum fertilizer demands for crops (table 5). Therefore, future incaeases in fertilizer usage are anticipated. Thus, total projected fertilizer demands are estimated at 1,229,000M/T by 1980, 1,493,000M/T by 1990 and 1,898,000M/T by 2000(table 16).

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Effects of Herbal Sports Drinks Containing Prunus mume Fruit Extract on the Plasma Lipid Profile and Endurance of Rats (매실을 첨가한 한방스포츠음료가 흰쥐의 혈중지질 및 운동수행력 증강에 미치는 영향)

  • Kim, Young Je;Jung, Un Ju;Lee, Gee Dong;Choi, Myung-Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.10
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    • pp.1409-1416
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    • 2012
  • This study examined the effects of four herbal sports drinks containing Prunus mume, Liriope platyphylla, and Acanthopanax senticosus fruit extracts on body fat and endurance of rats trained by a progressive loaded exercise program. Forty male Sprague-Dawley rats (6 weeks old) were divided into five groups and fed experimental diets for 6 weeks according to the following protocol: C, exercise-trained control group (n=8); A, exercise group with Acanthopanax senticosus extract (n=8); L, exercise group with Liriope platyphylla extract (n=8); PA, exercise group with Prunus mune fruit extract plus Acanthopanax senticosus extract (n=8); PL, exercise group with Prunus mune fruit extract plus Liriope platyphylla extract (n=8). Endurance was measured by a progressive loaded exercise test using a treadmill. PA and PL supplementation significantly extended time to exhaustion compared to the control group (p<0.05). Further, the four herbal sports drinks all significantly reduced epididymal and interscapular white adipose tissue weights compared to the control group (p<0.05). Plasma triglyceride concentration was significantly lower in the A group compared to the control group. Plasma free fatty acid concentration was higher in the A group compared to the control group. On the other hand, Acanthopanax senticosus fruit extract supplementation tended to reduce the plasma glucose concentration compared to the control group. PA and PL supplementation significantly increased gastrocnemius muscle LDH activities compared to the control group (p<0.05). These results show that sports drink containing Acanthopanax senticosus improved endurance capacity, plasma lipids, and glucose concentrations. Sports drink with Prunus mume and Liriope platyphylla or Acanthopanax senticosus was synergistically improved endurance.

Interpretation of the Umbrella Clause in Investment Treaties (국제투자조약상 포괄적 보호조항(Umbrella Clauses)의 해석에 관한 연구)

  • Jo, Hee-Moon
    • Journal of Arbitration Studies
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    • v.19 no.2
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    • pp.95-126
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    • 2009
  • One of the controversial issues in investor-state investment arbitration is the interpretation of "umbrella clause" that is found in most BIT and FTAs. This treaty clause requires on Contracting State of treaty to observe all investment obligations entered into with foreign investors from the other Contracting State. This clause did not receive in-depth attention until SGS v. Pakistan and SGS v. Philippines cases produced starkly different conclusions on the relations about treaty-based jurisdiction and contract-based jurisdiction. More recent decisions by other arbitral tribunals continue to show different approaches in their interpretation of umbrella clauses. Following the SGS v. Philippines decision, some recent decisions understand that all contracts are covered by umbrella clause, for example, in Siemens A.G. v. Argentina, LG&E Energy Corp. v. Argentina, Sempra Energy Int'l v. Argentina and Enron Corp. V. Argentina. However, other recent decisions have found a different approach that only certain kinds of public contracts are covered by umbrella clauses, for example, in El Paso Energy Int'l Co. v. Argentina, Pan American Energy LLC v. Argentina and CMS Gas Transmission Co. v. Argentina. With relation to the exhaustion of domestic remedies, most of tribunals have the position that the contractual remedy should not affect the jurisdiction of BIT tribunal. Even some tribunals considered that there is no need to exhaust contract remedies before bringing BIT arbitration, provoking suspicion of the validity of sanctity of contract in front of treaty obligation. The decision of the Annulment Committee In CMS case in 2007 was an extraordinarily surprising one and poured oil on the debate. The Committee composed of the three respected international lawyers, Gilbert Guillaume and Nabil Elaraby, both from the ICJ, and professor James Crawford, the Rapportuer of the International Law Commission on the Draft Articles on the Responsibility of States for Internationally Wrongful Acts, observed that the arbitral tribunal made critical errors of law, however, noting that it has limited power to review and overturn the award. The position of the Committee was a direct attack on ICSID system showing as an internal recognition of ICSID itself that the current system of investor-state arbitration is problematic. States are coming to limit the scope of umbrella clauses. For example, the 2004 U.S. Model BIT detailed definition of the type of contracts for which breach of contract claims may be submitted to arbitration, to increase certainty and predictability. Latin American countries, in particular, Argentina, are feeling collectively victims of these pro-investor interpretations of the ICSID tribunals. In fact, BIT between developed and developing countries are negotiated to protect foreign investment from developing countries. This general characteristic of BIT reflects naturally on the provisions making them extremely protective for foreign investors. Naturally, developing countries seek to interpret restrictively BIT provisions, whereas developed countries try to interpret more expansively. As most of cases arising out of alleged violation of BIT are administered in the ICSID, a forum under the auspices of the World Bank, these Latin American countries have been raising the legitimacy deficit of the ICSID. The Argentine cases have been provoking many legal issues of international law, predicting crisis almost coming in actual investor-state arbitration system. Some Latin American countries, such as Bolivia, Venezuela, Ecuador, Argentina, already showed their dissatisfaction with the ICSID system considering withdrawing from it to minimize the eventual investor-state dispute. Thus the disagreement over umbrella clauses in their interpretation is becoming interpreted as an historical reflection on the continued tension between developing and developed countries on foreign investment. There is an academic and political discussion on the possible return of the Calvo Doctrine in Latin America. The paper will comment on these problems related to the interpretation of umbrella clause. The paper analyses ICSID cases involving principally Latin American countries to identify the critical legal issues arising between developing and developed countries. And the paper discusses alternatives in improving actual investor-State investment arbitration; inter alia, the introduction of an appellate system and treaty interpretation rules.

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Studies on the storage of fresh fruits and vegetables by plastic coating (1) on Rall's Janet Apple- (Plastic Coating에 의(依)한 청과물저장연구(靑果物貯藏硏究) (제1보(第1報)) -사과(국광(國光))에 대(對)하여-)

  • Park, Nou-Pung
    • Applied Biological Chemistry
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    • v.12
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    • pp.89-97
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    • 1969
  • These studies were made on coating of fresh fruits and vegetables with PVC under view on preservation of fresh fruits and vegetables due to restrain water evaporation of them and control gas metabolisms. The results obtained, as selection of PVC materials availble for preservation of them, procedure of the coating, useful organic solvents, concentration of PVC solution and the time of dipping, and effects of the preservation of them, were summarized as follows: 1) PVC powder 222 and PVC powder 443 were surveyed as suitable materials for coating apple, and later was excellent in lustrous aspect. 2) The coating procedure which dipt into PVC solution was suitable to treat much within a short space of time, and using of ventillator accelerate rather evaporation of the organic solvent. 3) Aceton and methyethylketon as solvent of the PVC were, in purpose of storage only, avaible, while aceton was, in view ef taste, better. 4) 10% of the PVC solutions were better to preserve the freshness of apple and 5, 4, 1 and 0.5% of them in order were gradually decreased in preservability, and 15% of them as high concentration were looked like fermentation in one week after the coating. 5) The dipping time was also better n minute than 10 seconds in a preservation but 1-2 minutes could be applied owing to be not affected of the taste due to coating. 6) The freshness of treatment groups were extend about 48 days after coating in room temperature but control lost market value with 12 days. 7) Weight of control was decreased to 10-13% but treatment which was dipped into 10% of coating solution for one minute was decreased to 3.5-4.6% and treatment for four minutes was did to 2.9-3.0%. 8) Change in respiration was less is treatment groups than control in exhaustion of $CO_2$, and water soluble sugar, reduced sugar and pH were not changed almost due to coating. 9) Pannel discussion of the taste was indicated that control was better than treatments soon after coating, but treatments were rather than control last period of storage and treatment with aceton solvent specially was better than others.

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A Study Exhaustion Experiences in Adolescents - Samples of 12th Grade Examinees- (청소년의 소진 경험에 관한 연구 -고3 수험생을 중심으로-)

  • Kim, Kyung Hee;Kwon, Hye Jin;Yeoum, Soon Gyo
    • Journal of the Korean Society of School Health
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    • v.10 no.2
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    • pp.241-257
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    • 1997
  • This study identifies a basic framework to analyze specific experiences of examinees so that which nurses are better able to understand reactions of examinees and, further, to provide better nursing treatments to them. This study follows Strauss & Corbin's analysis tool (1990). This basic framework identifies the specific mental reactions in a process away from the "being tightened" state. The main factors explaining this process include the 28 following variables : anxiety, being burdened, being suppressed, lack of agency, being suffocated, term pressure, expectation pressure, grade pressure, firmness, feebleness, helping others, being disturbed, watching others, off ficiousness, staightening on, depending on, getting along with, getting out of, shooting out, giving up, being alone, devoting, bracing up, being industrious, being harassed, being distressed, troubles, and quiting. Twelve variables are factored from the above factors which include pressure, being tighened, terms, expectations, grades, will, friends, family, open-minded confrontation, close-minded confrontation, pursuing, and wandering around. The Examinees' state of being tightened is first developed, watched by others, and finally resolved causing students either to pursue (positive reactions) or to wander around (negative reactions). Based on the theoretical framework, the following sixteen hypotheses are developed : 1. Students are less tightened in the first term. 2. Students are more tightened in the second term. 3. Students with higher grades feel less tightened. 4. Students with lower grades feel more tightened. 5. Students with higher expectations feel more tightened. 6. Students with lower expectations feel less tightened. 7. Students who are less tightened confront open-mindedly. 8. Students who are higher tightened confront close-mindedly. 9. Students with a strong will confront open-mindedly. 10. Students with a weak will confront close-mindedly. 11. Students who have more sincere friends confront open-mindedly. 12. Students who have less sincere frieds confront close-mindedly. 13. Students with family support confront open-mindedly. 14. Students with little family support confront close-mindedly. 15. Students confronting open-mindedly pursue. 16. Students confronting close-mindedly wander. We identify the following four relations from the data analysis : 1. Students with average grades in their first term are more tightened from high expectations and have a tendency to wander if they have less supporting families even if they also have a strong will and sincere friends. 2. Students with low grades in their second term are less tighened because of low expectations and have a tendency to wander if they have a weak will and few sincere friends even if they have strong family support. 3. Students with high grades in their second term are more tightened with high expectations and have a tendency to pursue confrontations open-mindedly if they have supporting families and a strong will even if they have few sincere friends. 4. Students with average grades in their first term are less tightened from fewer expectations and have a tendency to pursue confrontations open-mindedly when they have more supporting families and sincere friends even if they have a weak will. A Student's degree of being tightened are affected by grades, terms, and expectations. Being tightened is resolved positively or negatively based on will, friends, and family. We conclude that will, family support, and sincere friends cause students to confront "being tightened" open-mindedly. We also conclude that practical nursing for students who are tightened have to focus on creating environments in which students are able to confront open-mindedly.

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A Bibliographical Research of the Correlation Among Sasang Constitutional Disease(사상체질병증) and the Pulse Diagnosis(맥진) (사상체질병증(四象體質病症)과 맥진(脈診)의 상관성(相關性)에 대(對)한 문헌적(文獻的) 고찰(考察))

  • Kim, Dong-Jun;Kim, Jung-Ryul;Kim, Dal-Rae
    • Journal of Pharmacopuncture
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    • v.6 no.3
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    • pp.23-37
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    • 2003
  • The purpose of this research was to investigate the correlation Among Sasang Constitutional Disease and Examination of the pulse. I have gone over literatures of mainly ${\ulcorner}$Dongyi Soose Bowon${\lrcorner}$ and the others Oriental Medical book was studied about the Pulse Diagnosis. And then I came to get some conclusion as follows. 1. Soeumin(소음인) the initial-stage symptoms of wulkwang disease(울광증) ; when the Superficial Pulse and the Superficial+ Moderate Pulse is made a diagnosis, Ceongunggyegitang(천궁계지탕) and Gunggyuhyangsosan(궁귀향소산) can be used. 2. Soeumin(소음인) the initial-stage blood disease symptoms of wulkwang disease(울광증) ; when the Minute+deep Pulse is made a diagnosis, Palmulgnnjatang(팔물군자탕) and Guakhyanggeonggisan(곽향정기산) can be used. 3. Soeumin(소음인) the initial-stage symptoms of mangyang disease(망양증) ; when the Yang region Superficial Pulse and the Yin region Weak Pulse is made a diagnosis, Hwanggigyegitang(황기계지탕), Bojungikgitang(보증익기탕) and Sengyangikgitang(승양익기탕) can be used. 4. Soeumin(소음인) the symptoms of taeum disease(태음증) ; when the Minute Pulse and Deep+Thin Pulse is made a diagnosis, Sasang Prescription can be used. 5. Soeumin(소음인) the symptoms of soeum disease(소음증) ; when the Minute+Thin Pulse, Deep Pulse and Thin+Deep+Rapid Pulse is made a diagnosis, Sasang Prescription can be used. 6. Soyangin(소양인) Wind of soyang disease(소양상풍증) ; when the Superficial+Tight Pulse is made a diagnosis, Hungbangpaedogsan(형방패독산) can be used. And when the Deep+Full with strong power Pulse is made a diagnosis, Hyungbangdojeoksan(형방도적산) can be used. 7. Soyangin(소양인) the symptoms of mangyeum disease(망음증) ; when the Superficial+Large+Rapid Pulse and Flood+Large Pulse is made a diagnosis, Hungbangsabaeksan(형방사백산) can be used. And when the Wiry+Thin Pulse is made a diagnosis, Hungbanggiwhangtang(형방지황탕) can be used. 8. Soyangin(소양인) the chest-phrenic fever syndrome(흉격열증) ; when the Superficial Pulse, Flood+Full+Rapid Pulse and Flood+Large Pulse is made a diagnosis, Sasang Prescription can be used. 9. Soyangin(소양인) the after fever syndrome(음허오열증) ; when the Empty+Soft+Rapid Pulse is made a diagnosis, Sasang Prescription can be used. 10. Taeumin(태음인) the upper neck exterior disease caused by Cold(배추표병) ; when the Superficial and Superficial+Tight Pulse is made a diagnosis, Mawhangbalpoytang(마황발표탕) can be used, And when the Superficial and Superficial+Tight with strong power on left hand Pulse is made a diagnosis, Ungdamsan(웅담산) and Handayulsotang(한다열소탕) can be used. 11. Taeumin(태음인) the Coldness syndrome in esophagus(위완한증) ; when the Superficial+Tight Pulse with weak power on left hand Pulse is made a diagnosis, Taeumjowetang(태음조위탕) can be used. 12. Taeumin(태음인) the Dryness-Heat syndrome(조열증) ; when the Flood+Large Pulse, Long Pulse and Long+Large Pulse is made a diagnosis, Galgeunhaegitang(갈근해기탕) can be used. And when the Tight+Full+Rapid Pulse with deep region is made a diagnosis, Yuldahansotang(열다한소탕) can be used. And when the Superficial+Slippery Pulse is made a diagnosis, Chungsimyunjatang(청심연자탕) can be used. 13. Taeumin(태음인) the symptoms of Yin-blood Exhaustion(음혈모갈증) ; when the Superficial with weak power Pulse is made a diagnosis, Nokyongdaebotang(녹용대보탕) can be used. And when the Deep with weak power Pulse is made a diagnosis, Gongjinheukwondan(공진흑원단) can be used. 14. Taeyangin(태양인) a slight Lumbar vertebrae disease(외감경증) ; when the Superficial+Hollow Pulse is made a diagnosis, Gunshitang(건시탕) can be used. 15. Taeyangin(태양인) the Generalized and Fatigue syndrome(해역증) ; when the Moderate+Choppy Pulse with left hand chi region(척맥) is made a diagnosis, Ogapijangchuktang(오가피장척탕) can be used. 16. Taeyangin(태양인) a slight Small Intestine disease(내촉경증)

Optimization of Heteropolysaccharide-7 Production by Beijerinckia Indica (Beijerinckia Indica 배양을 통한 Heteropolysaccharide-7 생산 최적화)

  • Wu Jian-Rong;Son Jeong Hwa;Kim Ki Myong;Nam Soo-Wan;Lee Jin-Woo;Kim Sung-Koo
    • Microbiology and Biotechnology Letters
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    • v.33 no.2
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    • pp.117-122
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    • 2005
  • Beijerinckia indica was cultured in mineral salts medium (MSM) medium with various carbon and nitrogen sources to improve the production yield of heteropolysaccharide-7 (PS-7). At high C/N ratio, the high concentration of PS-7 was produced until 40 h of the culture, whereas most of the glucose as a carbon source was used for the cell growth at low C/N ratio. However, at the high C/N ratio, PS-7 accumulation stopped at 48 h of the culture due to the increasing viscosity of the culture broth would inhibit the cell growth. Therefore, the optimized value of C/N ratio was 33.3 (20 g/L glucose, 7.5 mM $NH_{4}NO_3$) for the high production of PS-7. In the culture with various carbon sources, B. indica effectively used the hexoses or glucose-generating sugars for PS-7 formation. Especially, sucrose was the best carbon source for the high production of PS-7 (6.96 g/L) with a high viscosity (40772 cp). In the culture of B. indica with MSM medium containing 20 g/L glucose and 7.5 mM $NH_{4}NO_3$ in a 51 fermentor, the highest cell concentration was 2.5 g/L and the highest concentration of PS-7 was 7.5 g/L (35174 cp). The additional nitrogen sources of 7.5 mM $NH_{4}NO_3$, glutamine and glutamate at 12 h of the culture after exhaustion of a nitrogen source regulated the metabolism of carbon sources, therefore the nitrogen sources could control PS-7 synthesis.

The Optimal Activation State of Dendritic Cells for the Induction of Antitumor Immunity (항종양 면역반응 유도를 위한 수지상세포의 최적 활성화 조건)

  • Nam, Byung-Hyouk;Jo, Wool-Soon;Lee, Ki-Won;Oh, Su-Jung;Kang, Eun-Young;Choi, Yu-Jin;Do, Eun-Ju;Hong, Sook-Hee;Lim, Young-Jin;Kim, Ki-Uk;Jeong, Min-Ho
    • Journal of Life Science
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    • v.16 no.6
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    • pp.904-910
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    • 2006
  • Dendritic cells (DCs) are the only antigen presenting cells (APCs) capable of initiating immune responses, which is crucial for priming the specific cytotoxic T lymphocyte (CTL) response and tumor immunity. Upon activation by DCs, CD4+ helper T cells can cross-prime CD8+ CTLs via IL-12. However, recently activated DCs were described to prime in vitro strong T helper cell type 1 $(Th_1)$ responses, whereas at later time points, they preferentially prime $Th_2$ cells. Therfore, we examined in this study the optimum kinetic state of DCs activation impacted on in vivo priming of tumor-specific CTLs by using ovalbumin (OVA) tumor antigen model. Bone-marrow-derived DCs showed an appropriate expression of surface MHC and costimulatory molecules after 6 or 7-day differentiation. The 6-day differentiated DCs pulsed with OVA antigen for 8 h (8-h DC) and followed by restimulation with LPS for 24 h maintained high interleukin (IL)-12 production potential, accompanying the decreased level in their secretion by delayed re-exposure time to LPS. Furthermore, immunization with 8-h DC induced higher intracellular $interferon(IFN)-{\gamma}+/CD8+T$ cells and elicited more powerful cytotoxicity of splenocytes to EG7 cells, a clone of EL4 cells transfected with an OVA cDNA, than immunization with 24-h DC. In the animal study for the evaluation of therapeutic or protective antitumor immunity, immunization with 8-h DC induced an effective antitumor immunity against tumor of EG7 cells and completely protected mice from tumor formation and prolonged survival, respectively. The most commonly used and clinically applied DC-based vaccine is based on in vitro antigen loading for 24 h. However, our data indicated that antigen stimulation over 8 h decreased antitumor immunity with functional exhaustion of DCs, and that the 8-h DC would be an optimum activation state impacted on in vivo priming of tumor-specific CTLs and subsequently lead to induction of strong antitumor immunity.