• 제목/요약/키워드: stimulation cause

검색결과 190건 처리시간 0.022초

수리자극에 의한 지열저류층에서의 유도지진과 단층대의 변형에 관한 입자기반 개별요소법 모델링 연구 (Particle Based Discrete Element Modeling of Hydraulic Stimulation of Geothermal Reservoirs, Induced Seismicity and Fault Zone Deformation)

  • 윤정석;아미르 하킴하쉐미;아노 짱;귄터 찜머만
    • 터널과지하공간
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    • 제23권6호
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    • pp.493-505
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    • 2013
  • 본 수치해석논문에서는 절리와 단층대를 포함한 지열저류층에 수리자극을 가할 시 수반되는 유도지진과 단층대의 변형을 개별요소법을 사용하여 모델링하였다. 수채해석기법은 2차원 입자유동코드를 기반으로 하며 수리역학적 상호작용기법과 미소파괴음의 모멘트텐서 역산알고리즘이 결합되었다. 수치해석의 주요결과로는 시공간적으로 변하는 유도지진의 분포와 규모 그리고 단층대의 변형(파괴 및 전단변위)과 주입유체압력의 시공간적 분포와의 상관관계이다. 첫 번째 수치해석으로부터 절리가 분포하는 지열저류층에서의 수리자극에 의한 유도지진의 분포는 주입유체의 점성에 상당한 영향을 받는 것으로 나타났다. 주입유체의 점성이 낮은 경우 (1 cP), 유도지진의 발생범위가 큰 것으로 나타났으며, 주입 후 발생하는 유도지진의 개수와 규모 또한 높게 나타났다. 단층대가 존재하는 지열저류층의 수리자극 모델링의 결과, 주입정의 위치가 단층대와 가까운 경우 작은 주입수 압력분포(<0.1 MPa)로도 단층대의 파괴와 전단변형을 일으킬 수 있는 것으로 나타났다. 본 논문에서 소개한 수치해석기법은 수리자극을 통한 지열저류층 개발 시 유도지진의 분포와 규모를 실제 유체주입작업전에 예측할 수 있게 함으로써 지열에너지개발 분야에서 유용하게 사용될 수 있을 것으로 기대한다.

경두개 자기자극과 확산텐서 신경섬유로 검사를 통한 대뇌 병변의 국소화: 증례보고 (Localization of Bilateral Hemisphere Lesion Using Combined Transcranial Magnetic Stimulation and Diffusion Tensor Imaging: Report of Two Cases)

  • 이형남;오영빈;김기욱;원유희;고명환;서정환;박성희
    • 대한근전도전기진단의학회지
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    • 제20권2호
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    • pp.106-111
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    • 2018
  • Transcranial magnetic stimulation (TMS) has been a gold standard for investigating central motor pathways in humans. Diffusion tensor imaging with fiber tractography (DTI FT) is known for its usefulness in detecting white matter lesion in vivo. We investigated the clinical usefulness of elucidating the integrity and continuity of corticospinal tract (CST) by combined use of TMS and DTI FT in this study. We report two cases who have presented with left hemiparesis and evaluated by both TMS and DTI FT; 10-year-old boy with Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke-like episode syndrome and 20-year-old woman with traumatic brain injury. Combined use of TMS and DTI FT successfully led to localize the brain lesion that might cause motor impairment in patients with abnormal signal intensities in MRI. The results of this study suggest that TMS and DTI FT might provide the detailed information between function and anatomy of the CST, complementarily.

심인적(心因的) Stressor로서의 칠정(七情)과 비만(肥滿)과의 상관관계(相關關係) (Study for Correlation between Seven Emotion(七情) as an emotional stressor and Obesity)

  • 송미연;신현대;한애리
    • 한방비만학회지
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    • 제3권1호
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    • pp.75-84
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    • 2003
  • Objective : In Western medicine, the cause of obesity include overeating, lack of exercise, genetic factor, endocrinal impediment and psychological factor. Since the society becomes more complexed and the tensions among social members gets intensified, psychological factor getting more important. In Oriental medicine, Seven Emotion(七情, in oriental medical term) as an emotional stressor was thought to be a factor of obesity. Therefore the purpose of this study is to examine the relationship between Seven Emotion and obesity in detail. Methods : overview the stress with the view of Oriental medicine and research the relationship between Seven Emotion as an emotional stressor and obesity. Results : 1. Seven Emotion can be understood as an emotional stress in Western medicine. If Seven Emotion is excessive, its extreme mental stimulation causes physical illness. 2. Having influence upon the function of internal organs, excessive Seven Emotion causes obesity. Since it hinders normal flow of Gangi(肝氣), Seven Emotion disturbs healthy function of Bi-Wi(脾胃) and normal fluctuation of Qi. Consequently, obesity is resulted from the accumulation of fat since normal metabolism of body is disrupted. 3. In Seven Emotion-Anger(怒), Joy(喜), Anxiety(憂), Thought(思), Sorrow(悲), Fear(恐), Surprise(驚)-give rise to Gan-bi-bul-wha(肝脾不和), Sim-hi-yang-huh(心脾兩虛), Bi-qi-huh(碑氣虛), Dam-sup-jeo-po(痰濕沮胞) and Wi-wha-sang-youm(胃火上炎) in type of symptom in obesity and therefore, cause obesity.

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세포 노화에 있어서 복제 세네센스 현상과 산화적 스트레스의 영향 (Replicative Senescence in Cellular Aging and Oxidative Stress)

  • 박영철
    • Toxicological Research
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    • 제19권3호
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    • pp.161-172
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    • 2003
  • Explanted mammalian cells perform a limited number of cell division in vitro and than are arrested in a state known as replicative senescence. Such cells are irreversibly blocked, mostly in the G1 phase of cell cycle, and are no longer sensitive to growth factor stimulation. Thus replicative senescence is defined as a permanent and irreversible loss of replicative potential of cells. For this characteristic, replicative senescence seems to evolve to protect mammalian organism from cancer. However, senescence also contributes to aging. It seems to decrease with age of the cell donor and, as a form of cell senescence, is thought to underlie the aging process. Extensive evidence supports the idea that progressive telomere loss contributes to the phenomenon of cell senescence. Telomeres are repetitive structures of the sequence (TTAGGG)n at the ends of linear chromosomes. It has been shown that the average length of telomere repeats in human somatic cells decreases by 30∼200 bp with each cell division. It is generally believed that when telomeres reach a critical length, a signal is activated to initiate the senescent program. This has given rise to the hypothesis that telomeres act as mitotic clocks to regulate lifespan. One proposes that cumulative oxidative stress, mainly reactive oxygen species generated from mitochondria, may mainly cause telomere shortening, accelerating aging. Here, the biological importance and mechanism of replicative senescence were briefly reviewed. Also it was summarized that how oxidative stress affects replicative senescence and telomere shortening.

Insulin activates EGFR by stimulating its interaction with IGF-1R in low-EGFR-expressing TNBC cells

  • Shin, Miyoung;Yang, Eun Gyeong;Song, Hyun Kyu;Jeon, Hyesung
    • BMB Reports
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    • 제48권6호
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    • pp.342-347
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    • 2015
  • The expression of epidermal growth factor receptor (EGFR) is an important diagnostic marker for triple-negative breast cancer (TNBC) cells, which lack three hormonal receptors: estrogen and progesterone receptors as well as epidermal growth factor receptor 2. EGFR transactivation can cause drug resistance in many cancers including TNBC, but the mechanism underlying this phenomenon is poorly defined. Here, we demonstrate that insulin treatment induces EGFR activation by stimulating the interaction of EGFR with insulin-like growth factor receptor 1 (IGF-1R) in the MDA-MB-436 TNBC cell line. These cells express low levels of EGFR, while exhibiting high levels of IGF-1R expression and phosphorylation. Low-EGFRexpressing MDA-MB-436 cells show high sensitivity to insulinstimulated cell growth. Therefore, unexpectedly, insulin stimulation induced EGFR transactivation by regulating its interaction with IGF-1R in low-EGFR-expressing TNBC cells. [BMB Reports 2015; 48(6): 342-347]

하악과두골절 수술 후 발생한 Frey Syndrome (Frey Syndrome after Retromandibular Approach for Condyle Fracture Reduction)

  • 이재민;기은정;천해명;최문기
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제35권6호
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    • pp.376-380
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    • 2013
  • Frey syndrome is a disease characterized by abnormal sweating, facial redness, and rare pain by stimulation of taste sense on the limited area dominated by the auriculotemporal nerve and great auricular nerve. Although the developmental mechanism and histopathologic cause of Frey syndrome are still being debated, the most reliable theory is based on injury of the parathympathetic nerve connected to the auriculotemporal nerve continuing to abnormal regeneration. The other theory is that the sweat glands develop an increased sensitivity after degeneration of sympathetic fibers. Therapy of Frey syndrome includes drugs, radiographic treatment, and surgical treatment; however, in most cases, treatment is not satisfactory. This is a case report on a 24-year-old male patient with Frey syndrome caused by the fracture reduction with retromandibular approach after multiple facial traumas and spontaneous healing without any special treatment.

칠정학설천석(七情學說淺釋) (Reference study for concept difinition of 'Seven emotions theory')

  • 안상우
    • 제3의학
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    • 제1권2호
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    • pp.39-55
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    • 1996
  • The theory of seven emotions is a unique theory in oriental medicine which describes the mutual relationship between body and mind of human. Although, the term 'Seven emotions' was not clearly indicated in ${\ulcorner}$The Yellow Emperor's Internal Classic(黃帝內經)${\lrcorner}$, it is appeared in ${\ulcorner}$A Treatise on the Three Catagories of Cause of Diseases(三因方)${\lrcorner}$ written by Chen Yan(陳言) in South-Song Dynasty. It seemed that Chen Yan explained seven emotions as the internal etiologic factor according to the classification of seven emotions of ${\ulcorner}$Ye-Gi(禮記)${\lrcorner}$ under the academic influence during Song Dynasy which emphasized more on the standard of right and wrong rather than individual emotion. Meditation or consideration modulates the function of spleen and stomach and the metabolism of blood and body fluid and it also controls the various emotions and maintains the equilibrium of human body. Human emotions are influenced by the changes of nature and deeply related to time and space including social-environmental factors. The function and strength of seven emotions: joy, anger, anxiety, worry, grief, apprehension and fright are determined by the external stimulation as the causes of illness.

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진행성 전신성 경화증환자에게서 보인 동통성 삼차신경병증 1예 (A Case of Painful Trigeminal Neuropathy as a Complication of Progressive Systemic Sclerosis)

  • 신경진;전동철;김주한;김승현
    • Annals of Clinical Neurophysiology
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    • 제4권2호
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    • pp.146-148
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    • 2002
  • Progressive systemic sclerosis (PSS) is a multi-systemic disorder characterized by abundant fibrosis of the skin, blood vessels, and visceral organs. But it rarely affects the peripheral nervous system. We report a 36-year-old man of painful trigeminal neuropathy as a complication of PSS. He was referred from Rheumatology for the evaluation of abruptly developed bilateral facial pain. He had facial hypesthesia and paresthesia on neurologic examinations. In the blink reflex, ipsilateral and contralateral R1 and R2 responses were not detected during bilateral supraorbital stimulation. But normal latency and CMAP amplitude of facial NCV were found. Under the impression of trigeminal neuropathy caused by PSS, steroid therapy was tried, and his clinical symptoms and electrophysiologic findings were improved. PSS could be the cause of the painful trigeminal neuropathy.

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야뇨증의 병태생리: 뇌, 수면장애 그리고 정신적 효과 (Pathogenesis of Enuresis: Brain, Sleep Dysfunction and Psychological Effects)

  • 박관진
    • Childhood Kidney Diseases
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    • 제16권1호
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    • pp.9-14
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    • 2012
  • The relationship between central nervous system (CNS) and enuresis has not been sufficiently elucidated despite the presence of several circumstantial evidences. Contrary to common belief, polysomnographic sleep analysis revealed that the disturbance of arousal rather than deep sleep was responsible for enuresis. Subsequent studies confirmed depressed sympathetic tone and retarded brainstem reflex indicating abnormal arousal threshold in enuretics. In accordance with the bladder-brain dialogue, chronic stimulation of bladder may modify the brainstem function elevating arousal threshold. Epidemiological studies have suggested the association between enuresis and various psychosomatic disorders like attention deficit hyperactivity disorder (ADHD), which has shown the abnormal brainstem reflex similar to enuresis. Taken together, CNS is assumed to play a crucial role in the pathogenesis of enuresis. Psychological assessment is vital to understand the psychodynamic effect of enuresis. Studies have shown that the prevalence of psychological problems was higher in enuretic children and externalization of the symptoms was usually found. Several explanations have been brought up regarding the development of enuresis and psychological problems. Enuresis may cause psychological problems and vice versa. Otherwise, both may be associated with other variables, such as socioeconomic status (SES).

무봉합심근전극을 사용한 인공심박조정기 설치40례 보고 (Ventricular pacing with screw-in sutureless myocardial electrode)

  • 심영목;노준량
    • Journal of Chest Surgery
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    • 제16권1호
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    • pp.115-120
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    • 1983
  • We implanted pacemakers using screw-in sutureless myocardial electrode in 40 patients between February, 1980 and November, 1982 at Seoul Nation University Hospital. Mean age of total patient who received the pacemaker implantation was 39.9 years, but excluding the patient who received the open heart surgery, mean age was 49.3 years. Cause of pacemaker implantation was complete A-V block in 13 patients, symptomatic sick sinus syndrome in 12 patients, complete A-V block after open heart surgery in 12 patients, second degree A-V block with dizziness in one patient, and atrial fibrillation with slow ventricular response in two patients. In thirty nine cases, electrodes were implanted by subxiphoid approach, on the diaphragmatic surface of right ventricle. I n one case, electrode was implanted through the left anterior thoracotomy. Acute stimulation threshold, measured in 35 patients, varied from 0.1 to 2.5 mA [mean 0.85 mA.], and R-wave amplitude [sensitivity], measured in 19 patients, varied from 2.9 mV to 11.5 mV [mean 7.6 mV]. There was no hospital death. The postoperative complications included wound seroma in two patients [5%], wound hematoma in three patients [7.5%], and pacing failure in one patient [2.5%]. The subxiphoid implantation of the pacemaker using sutureless myocardial lead was valuable in obtaining safe, reliable and long-term impulse generation.

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