• Investigative Magnetic Resonance Imaging
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• 제22권1호
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• pp.26-36
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• 2018

Purpose: Children born with single ventricle physiology demonstrate poor growth rate and suffer from malnutrition, which lead to increased morbidity and mortality in this population. We assume that an anabolic steroid, oxandrolone, will promote growth in these infants by improving myocardial energy utilization. The purpose of this paper is to study the efficacy of oxandrolone on myocardial energy consumption in these infants. Materials and Methods: We modeled single ventricle physiology in a lamb by prenatally shunting the aorta to the pulmonary artery and then postnatally, we monitored cardiac energy utilization by quantitatively measuring the first order reaction rate constant, $k_f$ of the creatine-kinase reaction in the heart using magnetization transfer $^{31}P$ magnetic resonance spectroscopy, home built $^1H/^{31}P$ transmit/receive double tuned coil, and transmit/receive switch. We also performed cine MRI to study the structure and dynamic function of the myocardium and the left ventricular chamber. The spectroscopy data were processed using home-developed python software, while cine data were analyzed using Argus software. Results: We quantitatively measured both the first order reaction rate constant and ejection fraction in the control, shunted, and the oxandrolone-treated lambs. Both $k_f$ and ejection fraction were found to be more significantly reduced in the shunted lambs compared to the control lambs, and they are increased in oxandrolone-treated lambs. Conclusion: Some improvement was observed in both the first order reaction rate constant and ejection fraction for the lamb treated with oxandrolone in our preliminary study.

• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.427-427
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• 2016

Organic-inorganic hybrid perovskite have attracted significant attention as a new revolutionary light absorber for photovoltaic device due to its remarkable characteristics such as long charge diffusion lengths (100-1000nm), low recombination rate, and high extinction coefficient. Recently, power conversion efficiency of perovskite solar cell is above 20% that is approached to crystalline silicon solar cells. Planar heterojunction perovskite solar cells have simple device structure and can be fabricated low temperature process due to absence of mesoporous scaffold that should be annealed over 500 oC. However, in the planar structure, controlling perovskite film qualities such as crystallinity and coverage is important for high performances. Those controlling methods in one-step deposition have been reported such as adding additive, solvent-engineering, using anti-solvent, for pin-hole free perovskite layer to reduce shunting paths connecting between electron transport layer and hole transport layer. Here, we studied the effect of alkali metal halide to control the fabrication process of perovskite film. During the morphology determination step, alkali metal halides can affect film morphologies by intercalating with PbI2 layer and reducing $CH3NH3PbI3{\cdot}DMF$ intermediate phase resulting in needle shape morphology. As types of alkali metal ions, the diverse grain sizes of film were observed due to different crystallization rate depending on the size of alkali metal ions. The pin-hole free perovskite film was obtained with this method, and the resulting perovskite solar cells showed higher performance as > 10% of power conversion efficiency in large size perovskite solar cell as $5{\times}5cm$. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma optical emission spectrometry (ICP-OES) are analyzed to prove the mechanism of perovskite film formation with alkali metal halides.

• Journal of Chest Surgery
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• 제10권2호
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• pp.281-294
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• 1977

Superior vena cava to pulmonary arterial shunting operation was made between the superior vena cava and the right pulmonary artery in the fashion of end-to-end anastomosis in 20 mongrel dogs. The experimental animals were divided into three group and blood flow in the superior vena cava was occluded for 20, 30 and 60 minutes respectively, and observations were made for the changes in caval pressure and cerebrospinal fluid pressure. And pathologic examinations were also performed. On occluding the caval blood flow, the superior vena caval pressure was sharply and immediately elevated from $103.5{\pm}19.8mmH_2O$ at thoracotomy to $556.4{\pm}86.lmmH_2O$ within 2 minutes to make its plateau thereafter, and the cerebrospinal fluid pressure followed closely the changes of the superior vena caval pressure in its level and pattern being elevated from $102.0{\pm}19.9mmH_2O$ to $490.5{\pm}79.9mmH_2O$. The drops of both the caval and cerebrospinal fluid pressures were definite and marked on opening the shunt flow through the anastomosis, but these postoperative pressures retained still higher ones above their levels measured at thoracotomy. The pathological examinations of the brain and the spinal cord were also performed in six animals. Characteristic changes uniformly seen in all area and in all animals were the findings of capillary congestion and perivascular edema. On the other hand, ischemic nerve cell changes were rather evident, revealing their degrees and extents being related to the prolongation of the time of caval occlusion which has followed by the sustained high pressures in both the superior vena and the cerebrospinal fluid. The experiment suggests the safety of this surgical procedure with minimal, if any, permanent damage as long as the occlusion of the caval blood flow is not prolonged beyond the expected.

• Journal of Chest Surgery
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• 제20권1호
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• pp.1-12
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• 1987

Respiratory care with oxygen inhalation is often a necessity to maintain life, and it is one of the important therapeutic adjuncts in respiratory disease and in intensive care after surgery. However, it has been reported that oxygen toxicity occurs after prolonged exposure to 100% 0, [Smith, 1899; Kistler et al. 1967; Schaffner et al. 1967; Rowland and Newman, 1969. Subjective symptoms of oxygen toxicity include tracheal irritation, frequent cough, some burning sensation in the trachea, tachypnea, severe dyspnea, etc. [Welch, 1963; Fisher et al, 1968; Milier et al, 1970; Clark and Lambertsen, 1971; Sackner, 1975]. Pathologic findings are atelectasis, injuries to the pulmonary capillaries and hemorrhage in the alveoli in gross specimens. There can be inflammation, proliferation of fibrin, thickening of alveolar membranes, degeneration of collagen fibers and interstitial edema in the microscopic findings. [Penrod, 1956; Cedergren, 1959; Bean, 1965; Schaffner, 1967]. Dubois and colleagues [1961] found that the amount of pulmonary surfactant was decreased in oxygen toxicity and atelectasis followed by the decreased pulmonary surfactant. Many authors reported that vital capacity, inspiratory force, pulmonary compliance, pulmonary capillary blood flow and pulmonary elasticity were deceased and arteriovenous shunting increased. [Comroe et al, 1945; Fuson et al, 1965; Kistler et al, 1966; Knowles and Blenner-hassett, 1967; Barber et al, 1978]. Many human volunteers were examined after prolonged exposure in a high oxygenated chamber and there were a few reports on animals with oxygen toxicity, subjects including rabbits. Gas partial pressures of alveoli and arteries were measured in rabbits exposed to 100% $O_2$ and the alveolar-arterial gas gradients were analyzed, which is the basis for the study of oxygen toxicity. These rabbits were divided into two groups; rabbits under natural respiration, and second group under artificial respiration with a respirator. The alveolar $PO_2$ [$P]AO_2$] and $PCO_2$ [$PACO_2$], and the arterial $PO_2$ [$PaO_2$] were measured under varying $O_2$ pressures; 15% $O_2$, 21% $O_2$ and 100% $O_2$.

• Journal of Korean Neurosurgical Society
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• 제29권8호
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• pp.1019-1023
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• 2000

Objective : Endoscopic third ventriculostomy is gaining popularity as a minimally invasive surgical option for certain types of hydrocephalus as an alternative to shunting. The authors have tried to fenestrate down to the subdural space passing through the prepontine cistern to lessen or avoid the chance of redoing due to healing. Materials and Method : A 48-year-old male patient with several years of intractable headache was presented. Magnetic Resonance Image(MRI) of the brain revealed marked ventricular dilatation with stenotic cerebral aqueduct. A 2.3mm flexible steerable endoscope($Neuroview^{(R)}$) was introduced via precoronal route and accessed to the third ventricular floor. Using 3-French Fogarty balloon catheter, thin third ventricular floor and the arachnoid membrane of the prepontine cistern were fenestrated, so called "double fenestration". To confirm the fenestration, subdural compa-rtment of the left abducens nerve was identified during the procedure. Forceful pulsating flow through the orifice convinced the patency of the opening. Results : The patient was discharged on the third postoperative day without any postoperative complications. The postoperative follow-up MRI of the brain, at second and sixth months, clearly demonstrated the flow void through the third ventricular floor. Conclusions : Endoscopic third ventriculostomy was successfully performed on an adult hydrocephalus patient with aqueduct stenosis. The third ventricular floor and arachnoid membrane of the prepontine cistern were fenestrated to achieve double fenestration to minimize the chance for failure. The details of this procedure and results are described.

• The Korean Journal of Nuclear Medicine
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• 제4권1호
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• pp.37-42
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• 1970

In an endeavor to help understand some typical scan findings and portal hemodynamics in liver cirrhosis, several commonly occurring scan changes and esophageal varices as demonstrated by esophagram were correlated one another from quantitative and qualitative stand points. Clinical materials consisted of 34 patients with proven diagnosis of liver cirrhosis and esophageal varices. Liver scan was performed with colloidal 198-Au and the changes in the size and internal architecture of the liver, splenic uptake and splenomegaly were graded and scored by repeated double-blind readings. The variceal changes on esophagrams were also graded according to the classification of Shanks and Kerley following modification. Of 34 patients, 91% showed definite reduction in liver volume (shrinkage) constituting the most frequent scan change. The splenic uptake and splenomegaly were noted in 73.5 and 79.4%, respectively. The present study revealed no positive correlation between the graded scan findings including shrinkage of the liver, splenic uptake or splenomegaly and severity of variceal changes of the esophagus. Exceptionally, however, apparently paradoxical correlation was noted between the severity of mottlings and varices. Thus, in the majority (73.5%) of patients mottlings were either absent or mild. This interesting observation is in favor of the view held by Christie et al. who consider the mottlings to be not faithful expression of actual scarring of the cirrhotic liver. This also would indicate that variceal changes are to be the results of intrahepatic arteriovenous shunting of blood with hypervolemic load to the portal system rather than simple hypertension secondary to fibrosis and shrinkage.

• Journal of Korean Neurosurgical Society
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• 제43권4호
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• pp.177-181
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• 2008

Objective : Hydrocephalus is a common sequelae of aneurysmal subarachnoid hemorrhage (SAH) and patients who develop hydrocephalus after SAH typically have a worse prognosis than those who do not. This study was designed to identify factors predictive of shunt-dependent chronic hydrocephalus among patients with aneurysmal SAH, and patients who require permanent cerebrospinal fluid diversion. Methods : Seven-hundred-and-thirty-four patients with aneurysmal SAH who were treated surgically between 1990 and 2006 were retrospectively studied. Three stages of hydrocephalus have been categorized in this paper, i.e., acute (0-3 days after SAH), subacute (4-13 days after SAH), chronic (${\geqq}14$ days after SAH). Criteria indicating the occurrence of hydrocephalus were the presence of significantly enlarged temporal horns or ratio of frontal horn to maximal biparietal diameter more than 30% in computerized tomography. Results : Overall, 66 of the 734 patients (8.9%) underwent shunting procedures for the treatment of chronic hydrocephalus. Statistically significant associations among the following factors and shunt-dependent chronic hydrocephalus were observed. (1) Increased age (p < 0.05), (2) poor Hunt and Hess grade at admission (p < 0.05), (3) intraventricular hemorrhage (p < 0.05), (4) Fisher grade III, IV at admission (p < 0.05), (5) radiological hydrocephalus at admission (p < 0.05), and (6) post surgery meningitis (p < 0.05) did affect development of chronic hydrocephalus. However the presence of intracerebral hemorrhage, multiple aneurysms, vasospasm, and gender did not influence the development of shunt-dependent chronic hydrocephalus. In addition, the location of the ruptured aneurysms in posterior cerebral circulation did not show significant correlation of development of shunt-dependent chronic hydrocephalus. Conclusion : Hydrocephalus after aneurysmal subarachnoid hemorrhage seems to have a multifactorial etiology. Understanding predisposing factors related to the shunt-dependent chronic hydrocephalus may help to guide neurosurgeons for better treatment outcomes.

• Journal of Chest Surgery
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• 제48권6호
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• pp.381-386
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• 2015

Background: Postinfarction ventricular septal defects (pVSDs) are a serious complication of acute myocardial infarctions. The aim of this study was to analyze the clinical outcomes of the surgical treatment of pVSDs. Methods: The medical records of 23 patients who underwent operations (infarct exclusion in 21 patients and patch closure in two patients) to treat acute pVSDs from 2001 to 2011 were analyzed. Intra-aortic balloon counterpulsation was performed in 19 patients (82.6%), one of whom required extracorporeal membrane support due to cardiogenic shock. The mean follow-up duration was $26.2{\pm}18.6months$. Results: The in-hospital mortality rate was 4.3% (1/23). Residual shunts were found in seven patients and three patients required reoperation. One patient needed reoperation due to the transformation of an intracardiac hematoma into an abscess. No patients required reoperation due to recurrence of a ventricular septal defect during the follow-up period. The cumulative survival rate was 95.5% at one year, 82.0% at five years, and 65.6% at seven years. Conclusion: The use of a multiple-patch technique with sealants appears to be a reliable method of reducing early mortality and the risk of significant residual shunting in patients with pVSDs.

• Journal of Trauma and Injury
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• 제28권4호
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• pp.262-265
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• 2015

An arteriovenous fistula (AVF) from the renal artery following a penetrating abdominal trauma is not common. We report the case of a 19-year-old male who presented with a knife stab wound in the right upper quadrant. Due to unstable vital signs and to the protrusion of the mesentery through the stab wound, providing definite evidence of peritoneal violation, an emergent exploratory laparotomy was carried out. There were injuries at the proximal transverse mesocolon and the second portion of the duodenum, with bile leakage. There was also a mild amount of retroperitoneal hematoma near the right kidney, without signs of expansion or pulsation. The mesocolon and the duodenum were repaired. After the operation, abdominal computerized tomography (CT) was performed, which revealed contrast from the right renal artery shunting directly into the vena cava. Transcatheter arterial embolization with a coil and vascular plug was performed, and the fistula was repaired. The patient recovered completely and was discharged without complication. For further and thorough evaluation of an abdominal trauma, especially one involving the retroperitoneum, a CT scan is recommended, when possible, either prior to surgery or after surgery when the patient is stabile. Furthermore, a lateral retroperitoneal hematoma and an AVF after a penetrating trauma may not always require exploration. Sometimes, it may be safely treated non-operatively or with embolization.

• The Korean Journal of Nuclear Medicine
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• 제19권2호
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• pp.43-50
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• 1985

With the improvement of hemodialysis, the course of the disease in patient with endstage renal disease has been clearly improved. Nevertheless, among several shortcomings to our present mode of renal replacement therapy, cardiovascular complications have been the leading cause of morbidity and mortality. Several factors such as anemia, arteriovenous shunting of blood, intermittent extracorporeal circulation and hypertension may be contributing. But little is known about the quantitative cardiac hemodynamic characteristics occurred during hemodialysis. The purpose of this study is to observe the sequential hemodynamic changes before, during and after the hemodialysis and to investigate reliable parameters in the detection of ventricular dysfunction. In the present study, equilibrium radionuclide cardiac angiography was performed and left and right ventricular volume indices, ejection phase indices of both ventricular, performance were measured in the 16 stable patients with chronic renal failure treated with maintenance hemodialysis sequentially i.e. before, during (early and late phase) and after the hemodialysis. The results obtained were as follows; 1) The indices of the left ventricular function were not changed during the hemodialysis but increased after the hemodialysis. 2) The indices of the right ventricular function(EF, SVI) were significantly decreased in the early phase (15, 30 minutes after starting extracorporeal circulation) but recovered after the hemodialysis. 3) The ratio of right ventricular to left ventricular ejection fraction was significantly decreased in the early phase and the lung volume indices were significantly increased at the same phase. As a conclusion, hemodialysis improves left ventricular function maybe due to increased contractility, and effects on the right ventricular function maybe due to the increased lung volume in the early phase of hemodialysis.