• 제목/요약/키워드: coma

검색결과 466건 처리시간 0.032초

Evolution of cometary dust particles to the inner solar system: Initial conditions, mutual collision and final sinks

  • Yang, Hongu;Ishiguro, Masateru
    • 천문학회보
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    • 제42권2호
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    • pp.48.3-49
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    • 2017
  • Interplanetary space of the solar system contains a large number of dust particles, referred to as Interplanetary Dust Particles (IDPs) cloud complex. They are observable through meteors and zodiacal lights. The relative contribution of possible sources to the IDPs cloud complex was an controversial topic, however, recent research (Yang & Ishiguro, 2015 and references therein) suggested a dominance of cometary origin. In this study, we numerically investigated the orbital evolution of cometary dust particles, with special concerns on different evolutionary tracks and its consequences according to initial orbits, size and particle shape. The effect of dust particle density and initial size-frequency distribution (SFD) were not decisive in total cloud complex mass and mass supply rate, when these physical quantities are confined by observed zodiacal light brightness and dust particle SFD at 1 au. We noticed that, if we assume the existence of fluffy aggregates discovered in the Earth's stratosphere and the coma of 67P/Churyumov-Gerasimenko, the required mass supply rate decreases significantly. We also found out that close encounters with planets (mostly Jupiter) are the dominating factor of the orbital evolution of dust particles, as the result, the lifetime of cometary dust particles are shorter than Poynting-Robertson lifetime (around 250 thousand years). As another consequence of severe close encounters, only a small fraction of cometary dust particles can be transferred into the orbit < 1 au. This effect is significant for large size particles of ${\beta}$ < 0.01. The exceptional cases are dust particles ejected from 2P/Encke and active asteroids. Because they rarely encounter with Jupiter, most dust particles ejected from those objects are governed by Poynting-Robertson effect and well transferred into the orbits of small semimajor axis. In consideration of the above effects, we directly estimated probability of mutual collisions between dust particles and concluded that mutual collisions in the IDPs cloud complex is mostly ignorable, except for the case of large sized particles from active asteroids.

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mTOR Signal Transduction Pathways Contribute to TN-C FNIII A1 Overexpression by Mechanical Stress in Osteosarcoma Cells

  • Zheng, Lianhe;Zhang, Dianzhong;Zhang, Yunfei;Wen, Yanhua;Wang, Yucai
    • Molecules and Cells
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    • 제37권2호
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    • pp.118-125
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    • 2014
  • Osteosarcoma is the most common primary malignant bone tumor with a very poor prognosis. Treating osteosarcoma remains a challenge due to its high transitivity. Tenascin-C, with large molecular weight variants including different combinations of its alternative spliced FNIII repeats, is specifically over expressed in tumor tissues. This study examined the expression of Tenascin-C FNIIIA1 in osteosarcoma tissues, and estimated the effect of mechanical stimulation on A1 expression in MG-63 cells. Through immunohistochemical analysis, we found that the A1 protein was expressed at a higher level in osteosarcoma tissues than in adjacent normal tissues. By cell migration assay, we observed that there was a significant correlation between A1 expression and MG-63 cell migration. The relation is that Tenascin-C FNIIIA1 can promote MG-63 cell migration. According to our further study into the effect of mechanical stimulation on A1 expression in MG-63 cells, the mRNA and protein levels of A1 were significantly up-regulated under mechanical stress with the mTOR molecule proving indispensable. Meanwhile, 4E-BP1 and S6K1 (downstream molecule of mTOR) are necessary for A1 normal expression in MG-63 cells whether or not mechanical stress has been encountered. We found that Tenascin-C FNIIIA1 is over-expressed in osteosar-coma tissues and can promote MG-63 cell migration. Furthermore, mechanical stress can facilitate MG-63 cell migration though facilitating A1 overexpression with the necessary molecules (mTOR, 4E-BP1 and S6K1). In con-clusion, high expression of A1 may promote the meta-stasis of osteosarcoma by facilitating MG-63 cell migration. Tenascin-C FNIIIA1 could be used as an indicator in metastatic osteosarcoma patients.

가미계혈등탕이 Glutamate receptor와 Free radical 및 뇌손상 보호에 미치는 영향 (Study on the Effect of Gamigehyuldeung-tang on Gultamate Receptor, free Radical and Brain Damage in Rats)

  • 안종석;김동희;김윤식;이용구;박종오;남궁욱;설인찬
    • 동의생리병리학회지
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    • 제17권3호
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    • pp.728-737
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    • 2003
  • This study was investigated to prove the effect of GMGHT on the gultamate receptor, free radical and brain damage in rats sujected to Brain Ischemia The results were as follows; 1, GMGHT showed significant inhibitory effect of GMGHT on LDH release induced by NMDA, AMPA, and kinate. 2. GMGHT showed significant inhibitory effect of GMGHT on LDH release induced by BSO and Fe/sup 2+/. 3. GMGHT decreased coma duration time in a infatal dose of KCN and showed 30% of survival rate in a fatal dose. 4. GMGHT decreased ischemic area and edema incited by the MCA blood flow block. 5. GMGHT showed improvement of forelimb and hindlimb test after MCA occulusion in neurological exemination. 6. GMGHT showed no significant change after MCA occulusion in pathological observation as normal group. These results indicate that GMGHT can be used in the brain damage sujected to Brain Ischemia. Further study will be needed about the functional mechanism and etc.

다발성 손상에 의한 중증외상환자의 경피적 동맥색전술의 유용성 (The Usefullness of Percutaneous Transarterial Embolization in Patients with Severe Multiple Traumas)

  • 유인규;임청환
    • 한국방사선학회논문지
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    • 제6권2호
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    • pp.107-114
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    • 2012
  • 사고로 인해 응급실을 내원한 중증외상환자로 등록된 환자 중 혈관조영술을 시행 받고, 동맥 출혈이 진단되어 동맥색전술을 시행 받은 환자를 대상으로 생존군과 사망군을 비교하여 생존의 영향을 미치는 인자와 치료방법으로 혈관조영술 및 색전술의 유용성과 적절한 시행 시점을 연구하였다. 2006년 7월부터 2010년 12월에 경기도에 위치한 H병원 응급실에 중증외상환자로 분류된 환자 중 혈관조영술과 동맥색전술을 시행한 환자 45명을 대상으로 하여 후향적 분석을 실시하였다. 주요 지표로 ISS(Injury Severity Score)와 RTS(Revised Trauma Score), 적혈구 용적률 (Hematocrit)를 삼았다. 다발성 손상의 의한 중증외상환자의 경피적 동맥색전술은 모두 성공적으로 시술되었고, 환자의 사망률과 합병증을 줄이는데 도움을 줄 수 있으며, RTS, ISS, Hematocrit, 쇼크 등이 사망률 조기 인자로써 예측이 가능하였으며 생체활력증후가 안 좋은 환자는 색전술 시행 시점을 가능한 빠르게 진행시켜야 한다.

당뇨 환자에서 발생한 안면부 털곰팡이증에 대한 증례 (Fatal Facial Mucormycosis on a Diabetic Patient: A Case Report)

  • 최정훈;김영준;권지은;김훈;남상현;최영웅
    • Archives of Plastic Surgery
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    • 제38권1호
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    • pp.93-95
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    • 2011
  • Purpose: Mucormycosis generally occurs in patients with uncontrolled diabetes mellitus and immunocompromised conditions. It is rare, but once a patient is infected with it, it can occur as a rapidly extending, aggressive, and life-threatening rhinocerebral infection with a high mortality rate. Methods: A 70-year-old female patient had a 40 years of history of adult onset diabetes mellitus. She presented herself with severe right hemifacial pain, swelling, and weakness for 3 days and was admitted to ENT. On a facial computed tomography (CT) scan, it was found that her infection extended from her inferior temporal scalp to her submental area and involved her submandibular, masseter, prevertebral, parapharyngeal, retropharyngeal, and pharyngeal mucosal space and pansinusitis. Through endoscopic sinus surgery, mucormycosis was confirmed via histologic examination. Results: Despite empiric antibiotics and amphotericin B administration, the patient was in a septic condition and in a coma. The patient's family wanted to withdraw her life support, and the patient expired. Conclusion: Mucormycosis is very rare, but is one of the disastrous complications of uncontrolled diabetes mellitus. Suspicion of its occurrence, based on identified risk factors, and its rapid diagnosis can enhance the chance of its cure.

산전 초음파로 발견되고 출생 후 4회의 코일 색전술과 심 교정술로 치료된 심실 중격 결손을 동반한 선천성 간내 문맥전신성 단락 1례 (A Case of Congenital Intrahepatic Portosystemic Shunt Associated with VSD Detected by Antenatal Sonography and Treated with Four Coil Embolizations and Open Heart Surgery after Birth)

  • 나지윤;김은선;김상덕;김이경;김한석;최중환;천정은;정진욱
    • Neonatal Medicine
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    • 제15권2호
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    • pp.176-182
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    • 2008
  • 드문 선천성 문맥전신성 단락에 대한 표준화된 치료는 없으나 저자들은 출생 직후부터 심부전 증상을 보인 환아에서 심실 중격 결손증을 동반한 선천성 문맥전신성단락을 4회의 코일 색전술 및 심 교정술로 치료한 증례를 경험하였기에 문헌고찰과 함께 보고하는 바이다.

뇌 혈관계를 침범한 전신성 홍반성 루푸스 2례 (Two Cases of Systemic Lupus Erythematosus with Cerebrovascular Involvement)

  • 김봉준;이은영;홍영훈;박기도;송영두;이충기;심영란
    • Journal of Yeungnam Medical Science
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    • 제15권2호
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    • pp.371-380
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    • 1998
  • 저자들은 최근 루푸스가 뇌 혈관계를 침범하여 신경 정신과적 이상 증상을 보였으며 면역 검사, 뇌파 검사 및 뇌 자기공명사진에서 중추 신경 루푸스의 소견에 부합되는 양상을 보였고 고용량의 부신피질 호르몬 충격 요법에 반응이 좋았던 2례를 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

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분선충의 Hyperinfection 1례 (Hyperinfection of Strongyloides stercoralis)

  • 신경철;전준하;박찬원;이충기;이현우
    • Journal of Yeungnam Medical Science
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    • 제10권2호
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    • pp.518-524
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    • 1993
  • 저자 등은 만성질환으로 인해 영양결핍 및 면역저하상태로 생각되는 75세 폐결핵환자에서 분선충의 대량의 자가감염을 객담, 분변에서 확인하여 치료하였으나 사망한 1례를 경험하였기에 문헌고찰과 함께 보고하는 바이다.

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Valaciclovir 복용 후 중추신경계 부작용을 보였던 복막투석 환자 1예 (A Case of Neurotoxicity Induced by Valaciclovir in a Continuous Ambulatory Peritoneal Dialysis Patient)

  • 김준석;양지은;이보영;이서현;박희정;이선표;이상구
    • Journal of Yeungnam Medical Science
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    • 제29권2호
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    • pp.121-124
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    • 2012
  • Valaciclovir is metabolized to acyclovir after ingestion and thereafter exerts its antiviral activity. Because of its superior pharmacokinetic profile, it has quickly replaced acyclovir in the treatment of herpesvirus infection. Neurotoxicity caused by valaciclovir has been reported, however, among patients with pre-existing impaired renal function. This paper reports a case of neurotoxicity of valaciclovir in a patient with end-stage renal disease who was undergoing continuous ambulatory peritoneal dialysis (CAPD). A 67-year-old female on CAPD took 500 mg of valaciclovir twice for herpes zoster. After she took her second dose orally, she developed confusion and disorientation, along with involuntary movements. Her mental confusion progressed to a coma. Discontinuation of valaciclovir showed no rapid improvement. There- fore, hemodialysis was started. After two sessions of hemodialysis, the patient became alert; and after four sessions of hemodialysis, her neurological abnormalities were completely reversed. In conclusion, valaciclovir can induce life-threatening neurotoxicity, especially in CAPD patients, even with appropriate dose reduction, which can be effectively managed by hemodialysis.

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벤조디아제핀 급성 중독에서 발생하는 흡인성 폐렴 위험 인자 (Risk Factors for Aspiration Pneumonia in Acute Benzodiazepine Overdose)

  • 정원식;차경만;김형민;정원중;소병학
    • 대한임상독성학회지
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    • 제14권1호
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    • pp.26-32
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    • 2016
  • Purpose: Aspiration pneumonia is an important complication of drug intoxication with decreased mental status. The purpose of the study is to investigate the risk factors of aspiration pneumonia in the patients of benzodiazepine overdose with or without co-ingestion of other drugs. Methods: A retrospective chart review of patients who visited the emergency department between January 2012 and December 2014 was conducted. Demographic data, time from ingestion to visit, initial vital signs, symptoms, mental status, medical history, laboratory results, chest radiological findings and co-ingested medications were recorded. Multiple logistic analyses were performed to verify the association between variables and the development of aspiration pneumonia. Results: A total of 249 patients presented to the emergency department with benzodiazepine overdose. Aspiration pneumonia had developed in 24 patients (9.6%). Univariate analysis revealed time from ingestion to visit was longer, Glasgow coma scale score was lower, hypoxia was presented, leukocytosis was shown, types of ingested drugs was high, less activated charcoal was applied and tricyclic antidepressants was taken in patients that developed aspiration pneumonia. Time from ingestion to visit (odds ratio (OR) 1.121, 95% confidence interval (CI), 1.057-1.189, p=0.000), GCS score (OR 0.724. 95% CI, 0.624-0.839, p=0.000), oxygen saturation (OR 0.895, 95% CI, 0.835-0.959, p=0.002), and co-ingestion of TCA (OR 4.595, 95% CI, 1.169-18.063, p=0.029) were identified as risk factors of morbidity of aspiration pneumonia upon multiple logistic regression analysis. Conclusion: Time from ingestion to visit, low GCS score, low oxygen saturation and co-ingestion of TCA were risk factors of the development of aspiration pneumonia in benzodiazepine overdose patients.

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