• Title/Summary/Keyword: Shunting

Search Result 148, Processing Time 0.023 seconds

Toluene Monooxygenase의 Peroxide shuntting에 의한 TCE와 PCE 분해 특성

  • 류두현;김형수;최용욱;김용미;이경애;유재수;조현
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
    • /
    • 2004.09a
    • /
    • pp.277-280
    • /
    • 2004
  • TCE and PCE, suspected carcinogens, are the most common groundwater pollutant from extensive use as a solvent and degreaser. Escherichia coli TGI pBSKAN TOM Green and E. coli TGI pBSKAN ToMO, which were used DNA shuffling technique, produce Toluene-o-monooxygenase(TOM) and toluene-o-xylene- monooxygenase(ToMO). These cells and enzymes are degrading TCE and PCE, TOM and ToMO are needed to cofactor, such as NADH, NADPH and other cofactors. Used TCE and PCE degrading microorganisms experiment the contaminated material removal efficiency. A shunting test used NAD and Hydrogen peroxide.

  • PDF

Learning-possibility for neuron model in Medical Superior Temporal area

  • Sekiya, Yasuhiro;Zhu, Hanxi;Aoyama, Tomoo;Tang, Zheng
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2000.10a
    • /
    • pp.516-516
    • /
    • 2000
  • We propose a neuron model that is possible to learn three-dimensional movement. The neuron model by imitating structure of a neuron, has the system resemble a neuron. We considered a neuron system based on the arguments, and wished to examine whether the system had reasonable function. Koch, Poggio and Torre believed that inhibition signal would shunt excitation signal on the dendrites. They believed that excitation signal operated input-signals and inhibition did as delayed ones. Thus, they were sure that function for directional selectivity was arisen by the shunting. Koch's concept is so important; therefore, we construct the neuron system with their concept. The neuron system makes the shunting function; thus, the model may have a function for directional selectivity. We initialized the connections and the dendrites by random data, and trained them by the back-propagation algorithm for three-dimensional movement. We made sure the defection of three-dimensional movement in the system.

  • PDF

Complete Coverage Path Planning of Cleaning Robot

  • Liu, Jiang;Kim, Kab-Il;Son, Young-I.
    • Proceedings of the KIEE Conference
    • /
    • 2003.11c
    • /
    • pp.429-432
    • /
    • 2003
  • In this paper, a novel neural network approach is proposed for cleaning robot to complete coverage path planning with obstacle avoidance in stationary and dynamic environments. The dynamics of each neuron in the topologically organized neural network is characterized by a shunting equation derived from Hodgkin and Huxley's membrane equation. There are only local lateral connections among neurons. The robot path is autonomously generated from the dynamic activity landscape of the neural network and the previous robot location without any prior knowledge of the dynamic environment.

  • PDF

Endoscopic Aqueductoplasty and Stenting for Isolated Fourth Ventricle

  • Cho, Won-Ho;Lee, Sang-Weon;Cha, Seung-Heon
    • Journal of Korean Neurosurgical Society
    • /
    • v.39 no.4
    • /
    • pp.292-295
    • /
    • 2006
  • Isolated fourth ventricle[IFV] is a rare entity producing symptoms of a progressive posterior fossa mass lesion. It is mainly reported in a patient who undergo shunt placement as its late complication. However, its surgical management has been difficult and its optional treatment remains controversial. We had an occasion to admit 19-year-old female to our hospital due to hydrocephalus : she had a history of meningitis when she was 2 years old. Ten years later she was diagnosed as hydrocephalus and managed by lateral ventriculo-peritoneal shunting procedure. Seven years after the procedure, the patient presented with headache, nausea, truncal ataxia and nystagmus. Computed tomography and magnetic resonance image scan demonstrated markedly enlarged fourth ventricle : and thus, neuroendoscopic aqueductoplasty and aqueductal stent insertion was performed. The authors present a case of an IFV after lateral ventriculo-peritoneal shunting for hydrocephalus, which was treated successfully with a neuroendoscopic surgery. The technique of this procedure is described below.

Congenital portal vein aplasia with portocaval shunting in two dogs

  • Hwang, Taesung;Moon, Jonghyun;Lee, Hee Chun
    • Korean Journal of Veterinary Research
    • /
    • v.59 no.3
    • /
    • pp.171-173
    • /
    • 2019
  • Two dogs presented with vomiting and head pressing. In both dogs, a large vessel was revealed in computed tomography (CT) angiography, which was found to leave the portal vein (PV) cranial to the splenomesenteric confluence and enter the pre-hepatic caudal vena cava cranial to the right renal vein. The flow of portal blood to the liver was not identified. Based on CT angiography, the dogs were suspected to have congenital PV aplasia with portocaval shunting. Diagnostic imaging of potential malformations for PV continuation should be conducted before attempting shunt closure.

A Comparative Result of Ventriculoperitoneal Shunt, Focusing Mainly on Gravity-Assisted Valve and Programmable Valve

  • Lee, Won-Chul;Seo, Dae-Hee;Choe, II-Seung;Park, Sung-Choon;Ha, Young-Soo;Lee, Kyu-Chang
    • Journal of Korean Neurosurgical Society
    • /
    • v.48 no.3
    • /
    • pp.251-258
    • /
    • 2010
  • Objective : Despite rapid evolution of shunt devices, the complication rates remain high. The most common causes are turning from obstruction, infection, and overdrainage into mainly underdrainage. We investigated the incidence of complications in a consecutive series of hydrocephalic patients. Methods : From January 2002 to December 2009, 111 patients underwent ventriculoperitoneal (VP) shunting at our hospital. We documented shunt failures and complications according to valve type, primary disease, and number of revisions. Results : Overall shunt survival time was 268 weeks. Mean survival time of gravity-assisted valve (GAV) was 222 weeks versus 286 weeks for other shunts. Survival time of programmable valves (264 weeks) was longer than that of pressure-controlled valves (186 weeks). The most common cause for shunt revision was underdrainage (13 valves). The revision rate due to underdrainage in patients with GAV (7 of 10 patients) was higher than that for other valve types. Of 7 patients requiring revision for GAV underdrainage, 6 patients were bedridden. The overall infection rate was 3.6%, which was lower than reported series. Seven patients demonstrating overdrainage had cranial defects when operations were performed (41%), and overdrainage was improved in 5 patients after cranioplasty. Conclusion : Although none of the differences was statistically significant, some of the observations were especially notable. If a candidate for VP shunting is bedridden, GAV may not be indicated because it could lead to underdrainage. Careful procedure and perioperative management can reduce infection rate. Cranioplasty performed prior to VP shunting may be beneficial.

Clinical Outcome of Endoscopic Procedure in Patients with Shunt Malfunction

  • Kyung Hyun Kim;Youngbo Shim;Ji Yeoun Lee;Ji Hoon Phi;Eun Jung Koh;Seung-Ki Kim
    • Journal of Korean Neurosurgical Society
    • /
    • v.66 no.2
    • /
    • pp.162-171
    • /
    • 2023
  • Objective : The goal of this study was to analyze the clinical outcomes of endoscopic third ventriculostomy (ETV) and endoscopic septostomy when shunt malfunction occurs in a patient who has previously undergone placement of a ventriculoperitoneal shunt. Methods : From 2001 to 2020 at Seoul National University Children's Hospital, patients who underwent ETV or endoscopic septostomy for shunt malfunction were retrospectively analyzed. Initial diagnosis (etiology of hydrocephalus), age at first shunt insertion, age at endoscopic procedure, magnetic resonance or computed tomography image, subsequent shunting data, and follow-up period were included. Results : Thirty-six patients were included in this retrospective study. Twenty-nine patients, 18 males and 11 females, with shunt malfunction underwent ETV. At the time of shunting, the age ranged from 1 day to 15.4 years (mean, 2.4 years). The mean age at the time of ETV was 13.1 years (range, 0.7 to 29.6 years). Nineteen patients remained shunt revision free. The 5-year shunt revision-free survival rate was 69% (95% confidence interval [CI], 0.54-0.88). Seven patients, three males and four females, with shunt malfunction underwent endoscopic septostomy. At the time of shunting, the age ranged from 0.2 to 12 years (mean, 3.9 years). The mean age at the time of endoscopic septostomy was 11.9 years (range, 0.5 to 29.5 years). Four patients remained free of shunt revision or addition. The 5-year shunt revision-free survival rate was 57% (95% CI, 0.3-1.0). There were no complications associated with the endoscopic procedures. Conclusion : The results of our study demonstrate that ETV or endoscopic septostomy can be effective and safe in patients with shunt malfunction.

Physiological Shunt Following Open Heart Surgery (개심술후의 Physiological shunt 의 추이)

  • 김규태
    • Journal of Chest Surgery
    • /
    • v.10 no.2
    • /
    • pp.274-280
    • /
    • 1977
  • As a major cause for postoperative hypoxia, the importance of increased physiological shunting is increasingly emphasized. This study is a review and analysis of postoperative physiological shunting following open heart surgery with the aid of extracorporeal circulation. Sixteen patients were selected from among 21 patients who underwent elective open heart surgery at the Department of Thoracic and Cardiovascular Surgery, Kyungpook National University, School of Medicine, from December, 1975 to September, 1977. The results were as follows: 1. The degree of postoperative physiological shunt was progressively increased from 18.8% mean value one hour after surgery to 22.7% mean value, reaching a peak on the second postoperative days. 2. For up to one week, large physiological shunt[15%] was persisted in one patient. 3. Comparing long[more than 90 minutes] with short[less than 90 minutes] perfusion time group using pump oxygenator, it was found that the physiological shunt increased about 3% in the long as compared with the short perfusion time group. 4. The mean blood pressure was 70-80 mmHg without a remarkable causal relationship between physiological shunt and mean blood pressure. 5. On elevated $PaO_2$[>200 torr], the physiological shunt was decreased less than 20% of cardiac output, but on diminished $PaO_2$[102 torr] after two days, it was 22.7% of cardiac output. From above results, a contrary causal relationship between $PaO_2$ and physiological shunt was obtained. Co Reviewing chest X-rays postperfusion, it was demonstrated that no remarkable causal relationship between roentgen-ray evidence and physiological shunt could be obtained.

  • PDF

Late Results of Successful Replantation of Severed Limb by Avulsion Injury (결출성 절단사지에 대한 재접합 후 추시결과)

  • Lim, H.C.;Suh, S.W.;Hong, J.S.;Jang, W.S.
    • Archives of Reconstructive Microsurgery
    • /
    • v.2 no.1
    • /
    • pp.53-61
    • /
    • 1993
  • High level, major limb amputation above the wrist and ankle joint has some characteristic problems because of the large muscle mass and poor potential for nerve regeneration. As an adjunct method to reduce warm ischemic time prior to bony stabilization, temporary vascular shunting by simple catheterization has been performed, which has not been associated with any significant complication and has improved on success rate in replantation surgery. The authors have experienced 198 cases replantation of amputated limbs and digits from September, 1983 at the Korea medical center, Guro hospital, of which, 13 cases of successful replantation of amputated limbs by avulsion injury above the wrist and ankle joint level, which is generally considered as contraindication, were followed up for average 4.5 years(minimum 1.5 to maximum 8.4 years) on terms of survival rate, function and appearance. The clinical analysis upon these cases is to be presented with review of references.

  • PDF