• Proceedings of the KOSOMBE Conference
• /
• v.1997 no.05
• /
• pp.334-337
• /
• 1997

Von Mises stress and compliance distribution was evaluated using a finite element analysis on the end-to-side anastomosis of an artery with length of $20\sim24mm$, inner diameter of 4mm, thickness of 0.5mm and a PTFE graft with length of 10mm, inner diameter of 2mm, thickness of 0.2mm when the anastomotic angle was taken from $30^{\circ}\sim90^{\circ}$ in every $10^{\circ}$ and the diameter ratio from $0.1\sim1$ in every 0.1. The inner pressure of $1330dyne/mm^2$ was applied inside the 2 conduits. It was found that the compliance whose magnitude is larger on the acute angle anastomotic side than on the acute angle side became larger as the anastomotic angle became smaller and the diameter ratio larger and that the equivalent stress on the acute angle anastomotic side was larger than that on the abtuse angle side and became larger as the anastomotic angle and the diameter ratio became larger.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• v.15 no.2
• /
• pp.123-135
• /
• 2011

In this paper, we present arc-length estimations for quadratic rational B$\acute{e}$zier curves using the length of polygon and distance between both end points. Our arc-length estimations coincide with the arc-length of the quadratic rational B$\acute{e}$zier curve exactly when the weight ${\omega}$ is 0, 1 and ${\infty}$. We show that for all ${\omega}$ > 0 our estimations are strictly increasing with respect to ${\omega}$. Moreover, we find the parameter ${\mu}^*$ which makes our estimation coincide with the arc-length of the quadratic rational B$\acute{e}$zier curve when it is a circular arc too. We also show that ${\mu}^*$ has a special limit, which is used for optimal estimation. We present some numerical examples, and the numerical results illustrates that the estimation with the limit value of ${\mu}^*$ is an optimal estimation.

• Proceedings of the KSME Conference
• /
• 2001.06a
• /
• pp.90-95
• /
• 2001

Thermo-mechanical and flexural behavior of a wire-bond plastic ball grid array (WB-PBGA) are characterized by high sensitive $moir{\acute{e}}$ interferometry. $Moir{\acute{e}}$ fringe patterns are recorded and analyzed at several various bending loads and temperature steps. At the temperature higher that $100^{\circ}C$, the inelastic deformation in solder balls became more dominant. As a result the bending of the molding compound decreased while temperature increased. The strain results show that the solder ball located at the edge of the chip has largest shear strain by the thermal load while the maximum average shear strain by the bending moment occurs in the end solder. The results also show that $moir{\acute{e}}$ interferometry is a powerful and effective tool in experimental studies of electronic packaging.

• Journal of Chest Surgery
• /
• v.25 no.4
• /
• pp.424-428
• /
• 1992

Post-AMI VSD is an infrequent but often catastrophic complication of acute myocardial infarction In general, the mortality is associated with end organ failure due to low output syndrome. Therefore, a stable hemodynamic is necessary to prevent the end organ failure. If a supportive therapy does not accomplish it, surgical intervention should be considered. Recently, we have experinced a case of post-AMI VSD with cardiogenic shock. Early recognition and surgical repair of post-AMI VSD gave us a good result. Postoperative result was satisfactory and recovery was uneventful. We believe that early surgical repair can be lifesaving in the case of post-AMI VSD with cardiogenic shock.

• Journal of Hospice and Palliative Care
• /
• v.13 no.1
• /
• pp.41-49
• /
• 2010

Purpose: This study was performed to explore the preference for care near the end-of-life of nurses who had been working in an acute hospital. Methods: Data were collected by using PCEOL-K which was originally developed in U.S. and standardized into Korean version. Two hundred nurses from one acute hospital who agreed to participate in the study filled out questionnaires and 177 questionnaires were analyzed for the study results. Results: Relatively positive preference toward spirituality and pain control and negative preference toward decision making by health care professional were uncovered. Conclusion: Nurses consider patient's autonomy, pain control and spirituality as important factors at the end-of-life care. Further studies regarding the preference for the care near the end-of-life of diverse groups such as patients, doctors, and family members are called for.

• Advances in nano research
• /
• v.4 no.3
• /
• pp.167-179
• /
• 2016

The detailed study of acute and sub-acute toxicity of the complex polyvinylpyrrolidon (PVP 20 kDa)-wrapped fullerene $C_{60}$ after intraperitoneal (ip) administration was carried out on adult male Wistar rats. The $LD_{50}$ value of $C_{60}/PVP$ complex was found to be 7, 8 g/kg. In sub-acute study which lasted for 30 days the rats were exposed to daily administration of the complex in the doses of 350 or 700 mg/kg. All animals survived during the study and had no significant changes in clinical signs, organ weight, hematological and biochemical parameters of blood. The electrophysiological properties of myocardium and the excretory function of kidneys remained normal. Histological analysis of liver, kidney and spleen at the end of the study also did not demonstrate toxic alterations. It was thus established that intraperitoneal administration of complex $C_{60}/PVP$ has no toxic effect. These results suggest that $C_{60}/PVP$ has no acute and sub-acute toxicity and is a perspective substance for potential application in biology and medicine.

• Korean Journal of Bronchoesophagology
• /
• v.10 no.1 s.19
• /
• pp.41-45
• /
• 2004

Tracheostomy and endotracheal intubation are often performed in patients with acute and chronic respiratory failure. Recently, the incidence of iatrogenic tracheal stenosis has increased. Tracheal resection and end-to-end anastomosis would be one of the most physiologic treatment options for severe tracheal stenosis. Also, this treatment can be applied to the management of trachea invaded by thyroid cancer and tracheal neoplasm. The authors aimed to analyze the outcomes of end-to-end anastomosis of trachea following segmental resection in tracheal stenosis and tracheal invasion of cancer that we have recently experienced. Materials and methods Authors retrospectively studied 19 cases treated by tracheal resection with end-to-end anastomosis between Feburuary 1996 and January 2003. 12 patients had tracheal stenosis, 6 patients had tracheal invasion by thryroid cancer and 1 patient had tracheal cancer. We analyzed the direct causes of tracheal stenosis, preoperative vocal cord function, operation technique, early and delayed postoperative complications, and the outcome of end-to-end anastomois. Result Decannulation without significant aspiration was achieved in 16 cases($89.5\%$). A 27 year-old man could not be decannulated because of restenosis. A 62 year-old woman could not be decannulated because of bilateral vocal cord palsy. Conclusion End-to-end anastomosis is a safe and effective surgical method for tracheal stenosis. Case selection for end-to-end anastomosis and preservation of recurrent laryngeal nerve during operation is very important.

• Journal of Yeungnam Medical Science
• /
• v.29 no.2
• /
• pp.145-149
• /
• 2012

Systemic capillary leak syndrome (SCLS) is an unusual entity characterized by hypovolemic shock, hemoconcentration, and hypo-albuminemia associated with paraproteinemia as a result of marked capillary hyper-permeability. Complications of this syndrome can include compartment syndromes, pulmonary edema, thrombosis, and acute kidney injury. This paper reports a case of severe SCLS accompanied by acute tubular necrosis caused by hypoperfusion and myoglobinuria secondary to rhabdomyolysis, which resulted in chronic kidney disease that necessitated hemodialysis. However, there have been rare data of residual end-organ damage after acute attacks in Korea. Therefore, this paper reports a case of complicated SCLS enough to hemodialysis and that developed into chronic kidney disease.

• The Korean Journal of Physiology and Pharmacology
• /
• v.21 no.4
• /
• pp.423-428
• /
• 2017

Vestibular compensation is a recovery process from vestibular symptoms over time after unilateral loss of peripheral vestibular end organs. The aim of the present study was to observe time-dependent changes in long-term potentiation (LTP) at Schaffer collateral-CA1 synapses in the CA1 area of the hippocampus during vestibular compensation. The input-output (I/O) relationships of fEPSP amplitudes and LTP induced by theta burst stimulation to Schaffer's collateral commissural fibers were evaluated from the CA1 area of hippocampal slices at 1 day, 1 week, and 1 month after unilateral labyrinthectomy (UL). The I/O relationships of fEPSPs in the CA1 area was significantly reduced within 1 week post-op and then showed a non-significant reduction at 1 month after UL. Compared with sham-operated animals, there was a significant reduction of LTP induction in the hippocampus at 1 day and 1 week after UL. However, LTP induction levels in the CA1 area of the hippocampus also returned to those of sham-operated animals 1 month following UL. These data suggest that unilateral injury of the peripheral vestibular end organs results in a transient deficit in synaptic plasticity in the CA1 hippocampal area at acute stages of vestibular compensation.

• Journal of Trauma and Injury
• /
• v.29 no.2
• /
• pp.37-42
• /
• 2016

Purpose: Arterial injury in children is a challenging problem for its special characteristics. It is rare even during warfare. This review described a personal experience in the management and outcome of acute pediatric arterial injuries of extremities. Methods: Thirty-six children below age of 13 years were studied during period from 2004 through 2014 in Iraq. Results: Male patients were 27 (75%) and female were 9 (25%). Seven to twelve years old was the most affected age group. The incidence of iatrogenic injuries was greater in infants and toddlers while penetrating injuries were the most common in older children. Upper limbs arteries were affected in 17 (47.2%) and lower limb in 19 (52.8%) patients. Hard signs were the commonest mode of presentation (83.3%). Lateral wall tear and complete transection were the most frequent types of arterial injury (36.1% and 27.8% respectively). The most frequent procedures performed were end-to-end anastomosis and lateral arteriorrhaphy. Surgical outcome was good. In 27 cases distal pulsations were regained. Seven cases had impalpable distal pulses but still viable limbs. Limb length discrepancy was detected in one case. One case was complicated with limb loss. No death was recorded. Conclusion: Arterial injuries in children are age related. The proper treatment of arterial injuries in children requires high index of suspicion, early operative intervention and continuous postoperative follow-up throughout years of active growth. Angiogram has a limited role as a diagnostic tool in acute arterial injuries.