• 제목/요약/키워드: Knowledge flow

검색결과 589건 처리시간 0.032초

타액선 종양에서 혈관내피성장인자와 von Willebrand 인자 유전자 발현에 관한 연구 (EXPRESSION OF THE GENES OF VASCULAR ENDOTHELIAL GROWTH FACTOR AND VON WILLEBRAND FACTOR IN SALIVARY GLAND TUMORS)

  • 정지훈;김지혁;박영욱
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제30권1호
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    • pp.41-51
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    • 2008
  • Mucoepidermoid carcinoma (MEC) is the most common malignant salivary gland tumor which compromises about 6$\sim$8% of all tumors followed by the adenoid cystic carcinoma (ACC) and adenocarcinoma. Most deaths from salivary carcinomas are caused by recurrent or metastatic lesions that are resistant to conventional therapy. Therefore, knowledge of cellular properties and tumor-host interactions that influence the vascular metastasis is important for the design of more effective therapy of salivary carcinomas. Neoangiogenesis is essential for tumor growth, which is postulated to be fundamentally dependent on the induction of stromal neovascularization. However, how neovascularization takes place in live tissue has not been fully established, especially in recruitment and differentiation of endothelial cells in the salivary gland tumors. Vascular endothelial growth factor (VEGF) is a heparin-binding, dimeric polypeptide growth factor known to exert its mitogenic activity specifically on endothelial cells. VEGF has been shown th be directly involved in angiogenesis, which in essential for the pathogenesis of many solid tumors. von Willebrand factor (vWF) is a large multimeric protein synthesized by megakaryocytes and endothelial cells that enable platelets to adhere to exposed subendothelium and, as well, to respond to changes in the blood flow. Recent studies suggest that increased levels of vWF correlate with progression of disease, metastasis, or survival time and thus may have a prognostic significance. vWF is explained as an acute phase proteins which is increased in cancer or as a result of increased endothelial cell synthesis associated with tumor-induced angiogenesis. Due to adhesive properties of vWF, its increased concentrations may also contribute metastasis of tumor. In this study, we determined the mRNA expression of VEGF and vWF in salivary ACC, MEC and pleomorphic adenoma by in situ hybridization. As a result, stronger expression of VEGF and vWF was seen in salivary ACC and MEC which has more invasive nature than the salivary benign tumor.

단고추의 작물 광합성 모델을 위한 $\textrm{CO}_2$ 농도와 엽면적지 수 측정 (Measurement of $\textrm{CO}_2$ Concentration and Leaf Area Index for Crop Photosynthesis Model in Sweet Pepper)

  • Lee, Beom-Seon;Chung, Soon-Ju;Jang, Hong-Gi
    • 생물환경조절학회지
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    • 제8권3호
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    • pp.192-201
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    • 1999
  • 본 연구는 ASKAM모델로 $CO_2$, 광 및 엽면적지수가 단고추의 동적 광합성율에 추정가능성을 평가하기 위하여 수행되었다 $CO_2$ 농도는 2구획으로 구분된 반밀폐된 생장상에서 3수준 (400, 700 or 1000$\mu$mo1 mol$^{-1}$)으로 조절하였다. 온도와 습도는 21$^{\circ}C$ 및 80-95%로 조절하였고, 양액이 순환되는 용기내에서 재배하였다. 일태양복사, 온도 및 $CO_2$농도의 단기 자료를 기초로 하여 일중 단기간격에 대한 작물 순$CO_2$흡수량를 ASKAM모델로 추정하였고, 광합성 측정 중 각 구획과 기부에서의 $CO_2$농도를 매분마다 측정하였다. 순수 $CO_2$의 구획으로의 흐름, 지상방사, 구획내의 광합성유효방사, 은도 및 상대습도를 측정하였다. 본 작물생장모델은 작물의 광합성율을 적절하게 추정할 수 있는 것으로 평가되므로 생장해석, 작물관리 및 온실관리에 광범위하게 적용될 수 있을 것으로 판단되었다.

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고용량 방사선 조사 후 골육종 세포주(Saos-2)의 아포프토시스 발생 (Induction of Apoptosis in Human Osteosarcoma Cell Lines(Saos-2) by Single Fraction High Dose Irradiation)

  • 김재도;정소학;홍영기;최장석
    • 대한골관절종양학회지
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    • 제5권1호
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    • pp.1-8
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    • 1999
  • A single fraction of 50 Gy extracorporeal irradiation, as a modality of limb-sparing operation, has been used to achieve tumor necrosis in osteosarcoma. Although this modality of radiation therapy preserving the mobility of a joint is commonly practiced, the precise knowledge on the radiobiological response of osteosarcoma cell has remained to be elucidated. We therefore observed whether a single high dose irradiation caused apoptosis in osteosarcoma cells and whether the commitment to apoptosis was associated with cell kinetics. We also investigated radiation dose response along the time course for development of apoptosis following single high dose irradiation. The morphologic change in apoptosis was observed by fluorescence with Hoechst 33258 and the degree and the fraction of cells by flow cytometry. Irradiation of osteosarcoma cells with 10, 30 and 50 Gy resulted in chromatin condensation and apoptotic body formation. The degree of apoptosis in osteosarcoma cells was $29.5{\pm}3.56%$, $39.9{\pm}4.83%$ at 24 and 48 hours after 10 Gy irradiation ; $41.1{\pm}3.93%$, $66.9{\pm}5.21%$ at 24 and 48 hours after 30 Gy irradiation ; and $48.0{\pm}3.69%$, $75.6{\pm}4.65%$ at 24 and 48 hours after 50 Gy irradiation. The fraction of cells in cell-cycle kinetic was $39.2{\pm}4.3%$ in G2/M, $22.1{\pm}4.65%$ in G1 at 24 hours after 10 Gy irradiation ; $51.0{\pm}4.3%$ in G2/M, $20.4{\pm}4.7%$ in G1 at 48 hours after 10 Gy irradiation ; $40.3{\pm}3.9%$ in G2/M, $26.1{\pm}4.7%$ in G1 at 24 hours after 30 Gy irradiation ; $59.2{\pm}3.9%$ in G2/M, $5.9{\pm}5.1%$ in G1 at 48 hours after 30 Gy irradiation ; and $44.3{\pm}4.2%$ in G2/M, $21.1{\pm}3.5%$ in G1 at 24 hours after 50 Gy irradiation. The fraction of cells at 48 hours after 50 Gy irradiation could not be observed because of irradiation induced cell death of most of cells. All values for irradiated cells showed accumulation in G2/M phase and reduction in G1 phase, irrespective of irradiation dose. The results suggest that a single fraction of high dose irradiation with 50 Gy results in accumulation of cells at G2/M phase, leading to apoptosis.

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월경곤란시 여자중학생이 지각하는 스트레스 및 그 대응에 관한 소고 (A Review on Stress and Coping Level at Dysmenorrhea Perceived by Middle School Girls in Seoul)

  • 정문희
    • 한국보건간호학회지
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    • 제5권2호
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    • pp.45-51
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    • 1991
  • The purpose of this study is to investigate the stress and coping level as a result of dysmenorrhea which was experienced by girls. For the collection of data, the girls from the 1st to the 3rd grade in middle school in Seoul were selected through a random sampling technique. The survey was conducted from the 1st. to the 14th of June, 1991 by the use of questionnaires made after a pilot study. The final subjects for analysis were restricted to only those who had experienced me~arche, the number of which totaled 1,131. The stress, coping level, and other variables, were tested and analysed by descriptive statistics (eg, frequency, percentage, mean and standard deviation), t-test, ANOVA and Pearson's correlation coefficients. The obtained results are summarized as follows. 1. The chronological start for menarche was at a mean age of 13.1 The respondents who had experienced menarche numbered $70.9\%$ of the 1st grades and $96.2\%$ of the 2nd grades in middle school, otherwise the starting age for menarche was in the 4th grade in primary school. 2. Their menstrual cycle and period were longer than adult's one. The number of students studied who had experienced dysmenorrhea during their menstrual cycle were 860, and 650 of those revealed that their mothers or sisters had experienced similar problems. 3. The subjects who were late or head left early rather than being absent from school every menstruation cycle were more stressful. The results are thought to show that the girl's perception of dysmenorrhea seems to be more sensitive than adult's one. 4, A significant negative correlation was found between the perception of menstrual flow and strees level. It means that an increase in the stress of dysmenorrhea was associated with decreased menstrual bleeding. The degree of hypochondrical concern assessed by the girls was significantly correlated to stress and coping level. When the girls perceived high stress as a result of dysmenorrhea, they worried about their physical health more. The above results lead us to the suggestion that the starting point of early education with a school program is appropriate for the 4th grade in primary school. Especially if the girls in middle school should be required to give the information about correct knowledge and sufficient self -care management of menstruation monthly, if this could be implemented the loss in school days among the students due to dysmenorrhea would be minimized with more ease.

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전립선 비대증에 대한 뜸치료의 효과 : 체계적 문헌고찰과 메타분석 (Moxibustion for Benign Prostatic Hyperplasia: A Systematic Review and Meta-analysis)

  • 배고은;이승환;홍진우;이인;김소연;최준용;한창우;윤영주;박성하;권정남
    • 대한한방내과학회지
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    • 제39권3호
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    • pp.372-388
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    • 2018
  • Objective: This study evaluates the effectiveness and safety of moxibustion for benign prostatic hyperplasia (BPH). Methods: Using the keywords "benign prostatic hyperplasia", "benign prostatic hypertrophy", "benign prostatic enlargement", "prostatic hyperplasia", and "moxibustion", we searched papers in numerous databases, including National Discovery for Science Leaders (NDSL), Korean Traditional Knowledge Portal (KTKP), Oriental Medicine Advanced Searching Integrated System (OASIS), Research Information Sharing Service (RISS), PubMed, Embase, and CENTRAL. The search range included randomized controlled trials (RCTs). Papers not matched with inclusion criteria were excluded. The methodological quality of each RCT was assessed using the Cochrane risk-of-bias tool. Where appropriate, meta-analyses were performed. Results: Initially, 77 studies were found. Of these, 11 duplicate studies were removed and 27 were excluded following title and abstract screening. After the remaining 39 papers were scanned, 13 RCTs were selected and analyzed. Among these 13 RCTs, five compared moxibustion therapy and oral medication, seven compared moxibustion plus acupuncture therapy and oral medication, and one compared moxibustion plus acupuncture therapy and sham-moxibustion. The meta-analysis showed positive results for the use of moxibustion therapy in terms of International Prostate Symptom Score (IPSS), Quality Of Life (QOL), Maximum Flow Rate (Qmax), Prostate Volume (PV), and the efficacy rate. The meta-analysis showed positive results for the use of moxibustion plus acupuncture therapy in terms of IPSS, QOL, and the efficacy rate. Conclusions: This meta-analysis of clinical trials suggests that moxibustion is effective intreating BPH patients. The results of this study could be applied to clinical treatment of BPH. However, additional large-scale clinical researches should be conducted.

플라보노이드 대사 조절을 통한 화색 변경 (Flower Color Modification by Manipulating Flavonoid Biosynthetic Pathway)

  • 임선형;김재광;김동헌;손성한;이종렬;김영미;하선화
    • 원예과학기술지
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    • 제29권6호
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    • pp.511-522
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    • 2011
  • 화색은 화훼 육종의 주요한 목표형질이다. 최근 유전공학 기술의 발달로 기존의 전통육종에서는 볼 수 없었던 파란장미와 파란카네이션과 같은 새로운 화색 개발이 성공적으로 보고되었다. 플라보노이드 생합성에 관해 축적된 지식기반 연구 결과를 바탕으로 새롭고 독특한 형질의 화색을 도입하는 것이 가능하게 된 것이다. 이러한 화색변경은 플라보노이드 대사경로의 조절, 즉 내재유전자의 발현조절 및 새로운 플라보노이드 합성 또는 특정 플라보노이드 합성을 위한 외래유전자의 추가도입과 플라보노이드 대사 전체를 조절하는 전사인자의 도입을 통해서 이루어져 왔다. 그러나 보다 실증적으로 이러한 플라보노이드 대사를 조절하기 위해서는 작물별 내재 플라보노이드의 조절 기작에 대한 이해를 바탕으로 목표로 하는 플라보노이드 합성을 위해 보다 정교한 대사흐름의 조절이 요구된다. 본 총설에서는 화훼작물의 화색변경 성공 예들을 자세히 소개하고 그 요인 분석을 통해 향후 더 성공적인 화색변경의 전략을 수립하는데 도움이 되고자 한다.

Involvement of Lysosome Membrane Permeabilization and Reactive Oxygen Species Production in the Necrosis Induced by Chlamydia muridarum Infection in L929 Cells

  • Chen, Lixiang;Wang, Cong;Li, Shun;Yu, Xin;Liu, Xue;Ren, Rongrong;Liu, Wenwen;Zhou, Xiaojing;Zhang, Xiaonan;Zhou, Xiaohui
    • Journal of Microbiology and Biotechnology
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    • 제26권4호
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    • pp.790-798
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    • 2016
  • Chlamydiae, obligate intracellular bacteria, are associated with a variety of human diseases. The chlamydial life cycle undergoes a biphasic development: replicative reticulate bodies (RBs) phase and infectious elementary bodies (EBs) phase. At the end of the chlamydial intracellular life cycle, EBs have to be released to the surrounded cells. Therefore, the interactions between Chlamydiae and cell death pathways could greatly influence the outcomes of Chlamydia infection. However, the underlying molecular mechanisms remain elusive. Here, we investigated host cell death after Chlamydia infection in vitro, in L929 cells, and showed that Chlamydia infection induces cell necrosis, as detected by the propidium iodide (PI)-Annexin V double-staining flow-cytometric assay and Lactate dehydrogenase (LDH) release assay. The production of reactive oxygen species (ROS), an important factor in induction of necrosis, was increased after Chlamydia infection, and inhibition of ROS with specific pharmacological inhibitors, diphenylene iodonium (DPI) or butylated hydroxyanisole (BHA), led to significant suppression of necrosis. Interestingly, live-cell imaging revealed that Chlamydia infection induced lysosome membrane permeabilization (LMP). When an inhibitor upstream of LMP, CA-074-Me, was added to cells, the production of ROS was reduced with concomitant inhibition of necrosis. Taken together, our results indicate that Chlamydia infection elicits the production of ROS, which is dependent on LMP at least partially, followed by induction of host-cell necrosis. To our best knowledge, this is the first live-cell-imaging observation of LMP post Chlamydia infection and report on the link of LMP to ROS to necrosis during Chlamydia infection.

대화행위의 연쇄관계와 대화흐름에 대하여 -[일정협의 대화] 중심으로 (On the Sequences of Dialogue Acts and the Dialogue Flows-w.r.t. the appointment scheduling dialogues)

  • 박혜은;이민행
    • 인지과학
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    • 제10권2호
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    • pp.27-34
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    • 1999
  • 이 연구의 목적은 대화행위 개념을 이용하여 독일어 일정협의 대화에서 나타나는 대화의 일반적인 흐름을 밝히는 데에 있다. 이 연구의 기본가정은 대화행위 개념의 도입이 자동번역시스템의 성능향상에 기여한다는 것이다. 그 이유는 통사적인 분석이나 의미적인 분석이 해결하지 못하는 문제들을, 문맥지식을 활용하여 해결하는 데에 있어 대화행위개념이 매우 유용하기 때문이다. 이 대화행위 개념의 하위분류작업은 독일에서 수행되고 있는 VERBMOBIL 프로젝트에서 이루어진 것이다. 본 연구에서는 전문가들에 의해 전사된 실제 대화 자료들을 대화행위의 개념을 활용하여 분석하고, 하나의 대화차례 안에서 발생하는 대화행위들의 연쇄와 각각의 대화차례 사이에서 발생하는 대화행위 연쇄를 조사했다. 여기서 분석대상으로 삼은 전사자료가 다른 연구에서 제시된 전사 자료와는 다소 차이를 보였기 때문에, 본 연구에서는 연쇄 개념을 대화차례사이에 뿐만 아니라 하나의 대화차례 내부까지 적용시켰다. 그리고 대화행위들간의 연쇄관계를 조사함으로써‘일정협의 대화’의 대화 흐름 도를 도출하였다. 이 대화 흐름 도는 통계분석 절차를 통해 가장 빈도수가 높게나온 대화행위 연쇄들을 토대로 만들어진 모형이기 때문에, 일상적인‘일정협의 대화’에 대한 대표성을 갖는다고 볼 수 있다.

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고령군 뇌동맥류 환자의 치료 (Management of Elderly Patients with Intracranial Aneurysm)

  • 박현선;이재환;김진영;신용삼;주진양;허승곤;이규창
    • Journal of Korean Neurosurgical Society
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    • 제29권6호
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    • pp.786-793
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    • 2000
  • Objectives : A clinical analysis was performed to provide management strategy and to improve management outcome of elderly patients with intracranial aneurysm. Patients and Methods : We reviewed medical records of 746 consecutive patients with intracranial aneurysm who were admitted from July 1991 to December 1996. They were divided into two age groups : elderly(120 patients aged 65 years or older) and non-elderly(626 patients aged 64 years or younger). We investigated the differences between the two groups in clinical characteristics, management outcome and surgical results. Results : Female(80.0%), internal carotid artery aneurysm(48.9%), poor clinical grade(Hunt and Hess Grade IV, V : 39.8%), postoperative subdural fluid collection(38.2%), and postoperative hydrocephalus(39.7%) were more frequent in the elderly patients. There were no significant differences in the incidence of hypertension, multiple aneurysm, unruptured aneurysm, rebleeding, delayed ischemic neurological deficits, postoperative hemorrhage, and low density on the postoperative brain CT scan. In some cases, surgical clipping of ruptured aneurysm could not be performed due to moribund state or refusal of surgery by the elderly patient's family. Both management outcome and surgical results in elderly aneurysm patients at 3 months after rupture were worse than those of the non-elderly group. The most common reason of unfavorable outcome was poor clinical grade in both groups, while serious medical illness causing unfavorable outcome was more common in the elderly group. Conclusion : Surgical treatment of a ruptured aneurysm should not be avoided in elderly patient solely on the basis of advanced age. If the patients are in good clinical grade, early aneurysm surgery followed by early ambulation should be recommended. Further improvements in outcome may be achieved by thorough knowledge of poor resilience of brain, CSF flow dynamics, and diminished cardiopulmonary reserve in elderly patients with intracranial aneurysm.

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A study on legal service of AI

  • Park, Jong-Ryeol;Noe, Sang-Ouk
    • 한국컴퓨터정보학회논문지
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    • 제23권7호
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    • pp.105-111
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    • 2018
  • Last March, the world Go competition between AlphaGo, AI Go program developed by Google Deep Mind and professional Go player Lee Sedol has shown us that the 4th industrial revolution using AI has come close. Especially, there ar many system combined with AI hae been developing including program for researching legal information, system for expecting jurisdiction, and processing big data, there is saying that even AI legal person is ready for its appearance. As legal field is mostly based on text-based document, such characteristic makes it easier to adopt artificial intelligence technology. When a legal person receives a case, the first thing to do is searching for legal information and judical precedent, which is the one of the strength of AI. It is very difficult for a human being to utilize a flow of legal knowledge and figures by analyzing them but for AI, this is nothing but a simple job. The ability of AI searching for regulation, precedent, and literature related to legal issue is way over our expectation. AI is evaluated to be able to review 1 billion pages of legal document per second and many people agree that lot of legal job will be replaced by AI. Along with development of AI service, legal service is becoming more advanced and if it devotes to ethical solving of legal issues, which is the final goal, not only the legal field but also it will help to gain nation's trust. If nations start to trust the legal service, it would never be completely replaced by AI. What is more, if it keeps offering advanced, ethical, and quick legal service, value of law devoting to the society will increase and finally, will make contribution to the nation. In this time where we have to compete with AI, we should try hard to increase value of traditional legal service provided by human. In the future, priority of good legal person will be his/her ability to use AI. The only field left to human will be understanding and recovering emotion of human caused by legal problem, which cannot be done by AI's controlling function. Then, what would be the attitude of legal people in this period? It would be to learn the new technology and applying in the field rather than going against it, this will be the way to survive in this new AI period.