• Archives of Plastic Surgery
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• 제38권4호
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• pp.415-420
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• 2011

Purpose: The reconstruction of a soft tissue defect of the heel pad can be challenging. One vital issue is the restoration of the ability of the heel to bear the load of the body weight. Many surgeons prefer to use local flaps or free tissue transfer rather than a skin graft. In this study, we evaluated the criteria for choosing a proper flap for heel pad reconstruction. Methods: In this study, 23 cases of heel pad reconstruction were performed by using the flap technique. The etiologies of the heel defects included pressure sores, trauma, or wide excision of a malignant tumor. During the operation, the location, size and depth of the heel pad defect determined which flap was chosen. When the defect size was relatively small and the defect depth was limited to the subcutaneous layer, a local flap was used. A free flap was selected when the defect was so large and deep that almost entire heel pad had to be replaced. Results: There was only one complication of poor graft acceptance, involving partial flap necrosis. This patient experienced complete recovery after debridement of the necrotic tissue and a split thickness skin graft. None of the other transferred tissues had complications. During the follow-up period, the patients were reported satisfactory with both aesthetic and functional results. Conclusion: The heel pad reconstructive method is determined by the size and soft-tissue requirements of the defect. The proper choice of the donor flap allows to achieve satisfactory surgical outcomes in aesthetic and functional viewpoints with fewer complications.

• 한국진공학회지
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• 제7권2호
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• pp.82-87
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• 1998

$O_2$기체에 $NH_3/O_2$기체를 첨가하여 실리콘 표면에 산화막을 형성하는 $NH_3/O_2$산화법 에 의한 산화공정시 반응석영관 외부에 방출하는 기체는 $N_2,O_2$및 $H_2O$이며 극소량의 $CO_2$, NO 및 $NO_2$가 검출되었다. 두 종류의 산화제($O_2$ 및 $H_2O$)가 산화에 기여하며 성장률은 $NH_3$및 $O_2$ 의 부분압과 온도에 의해 결정되며, 그 기울기는 건식 및 습식 산화법의 중간에 평행 하게 위치함을 확인하였다. Auger Electron Spectroscopy(AES) 측정결과 $NH_3/O_2$ 산화막은 정확한 $SiO_2$의 화학량론을 가지며 $SiO_2/Si$계면에 발생하는 결합을 억제하며 고정전하의 발 생을 최소화함을 알 수 있었다. $NH_3/O_2$ 산화막(470$\AA$)의 항복전압을 57.5Volt이며, C-V특성 곡선을 축정한 결과 플랫밴드 전압은 0.29Volt이며 곡선의 형태는 이상곡선과 일치하였다.

• 한국재료학회지
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• 제25권3호
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• pp.138-143
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• 2015

Aluminum nitride, a compound semiconductor, has a Wurtzite structure; good material properties such as high thermal conductivity, great electric conductivity, high dielectric breakdown strength, a wide energy band gap (6.2eV), a fast elastic wave speed; and excellent in thermal and chemical stability. Furthermore, the thermal expansion coefficient of the aluminum nitride is similar to those of Si and GaAs. Due to these characteristics, aluminum nitride can be applied to electric packaging components, dielectric materials, SAW (surface acoustic wave) devices, and photoelectric devices. In this study, we surveyed the crystallization and preferred orientation of AlN thin films with an X-ray diffractometer. To fabricate the AlN thin film, we used the magnetron sputtering method with $N_2$, NH3 and Ar. According to an increase in the partial pressures of $N_2$ and $NH_3$, Al was nitrified and deposited onto a substrate in a molecular form. When AlN was fabricated with $N_2$, it showed a c-axis orientation and tended toward a high orientation with an increase in the temperature. On the other hand, when AlN was fabricated with $NH_3$, it showed a-axis orientation. This result is coincident with the proposed mechanism. We fabricated AlN thin films with an a-axis orientation by controlling the sputtering electric power, $NH_3$ pressure, deposition speed, and substrate temperature. According to the proposed mechanism, we also fabricated AlN thin films which demonstrated high a-axis and c-axis orientations.

• 한국안광학회지
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• 제13권3호
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• pp.35-43
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• 2008

목적: 콘택트렌즈의 피팅에 따른 눈물 층의 두께, 렌즈의 Dk 값 및 두께 변화가 각막에 유입되는 산소확산에 미치는 영향을 고찰하였다. 방법: 확산에 관한 Fick 법칙 및 연속법칙을 사용하여 액체(눈물)-CL-눈물 층을 통하여 각막으로 유입되는 산소 flux 및 각막 표면의 산소 분압을 계산할 수 있는 일련의 방정식을 세우고 이들 식에 의거하여 피팅에 따른 눈물 층의 두께, 렌즈의 Dk 및 두께 변화가 각막에 유입되는 산소 flux에 어떠한 영향을 미치는가를 예측하였다. 결과: 본 모델을 사용하여 적절한 피팅 조건에 부합하고 또한 각막 표면의 산소 분압이 보장되는 렌즈의 Dk 및 두께를 결정할 수 있었다. 결론: 대단히 높은 Dk 값을 지닌 렌즈라도 너무 flat 또는 tight하게 피팅된 경우 렌즈의 주변부와 각막 사이 눈물 층의 간격이 커짐으로 인하여 각막에 도달하는 산소 flux 및 각막표면의 산소 분압이 급격히 감소될 수 있다.

• Biomolecules & Therapeutics
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• 제2권4호
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• pp.336-342
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• 1994

The general pharmacological properties of EPO were investigated in various animals administering intravenously and in vitro system. The results were as follows. 1. Central nervous system: EPO at doses of 70, 700, 7000 U/kg showed no effect In mice on general behavior, on strychnine- and pentetrazol-induced convulsion and on acetic acid-induced writhing syndrome. The hexobarbital-induced sleeping time in mice was slightly reduced by EPO at a dose of 7000 U/kg but did not change at doses of 70, 700 U/kg. The body temperature in rats was slightly decreased by EPO at doses of 700, 7,000 U/kg but the change was in normal physiological range. 2. Respiratory and cardiovascular system: EPO showed no effect on respiratory rate, blood pressure, heart rate, femoral blood flow, and electrocardiogram in anesthetized dogs at doses of 70, 700, 7000 U/kg. 3. Smooth muscle: EPO at concentrations of 70, 700 U/ml had no effect on the contractile response of isolated guinea pig ileum to histamine and acetylcholine. 4. Water and electrolytes excretion: EPO at dose above 700 U/kg increased urine volume in rats but did not affect the concentrations of $Na^{+},\;K^{+},\;Cl^{-}$ in urine. 5. Gastrointestinal system: EPO(70, 700, 7000 U/kg) had no effect on the intestinal charcoal meal propulsion 6. Blood coagulation system: The administration of EPO(70, 700, 7000 U/kg) had no effect on the plasma prothrombin time(PT) and activated partial thromboplastin time(APTT) in mice. Platelet aggregation induced by ADP and collagen was not influenced by EPO(70 U/ml, 700 U/ml). The overall results obtained indicated that EPO exerts almost no serious pharmacological effect even at a 100-fold clinical dose(7000 U/kg).

• Biomolecules & Therapeutics
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• 제7권3호
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• pp.271-277
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• 1999

Safety evaluation of LB71350, a new HIV-1 protease inhibitor, was performed in mice, rats and dogs. For the general behavior of mice, LB71350 at an oral dose of 200 mg/kg did not show any significant effects on muscle tone and locomotor activity. In terms of central nervous system, at oral doses of 200 mg/kg and 1000 mg/kg, LB71350 inhibited acetic acid-induced pain response approximately 41% and 83% of control. respectively. At oral doses of 200 mg/kg and 500 mg/kg, it reduced the rectal body temperature in rats. Pentylenetetrazole-induced seizure in mice was slightly potentiated by oral administration of LB71350 at doses ranging from 200 mg/kg to 1000 mg/Ag. Single or five day treatment of LB71350 doubled the hexobarbital- induced sleeping time in mice at oral doses ranging from 50 mg/kg to 500 mg/kg. It did not cause any effects on gastric secretion and acidity in rat at oral doses of 200 mg/kg and 1000 mg/kg and also it did not change intestinal motility in mice up to 1000 mg/kg. Blood coagulation indices such as prothrombin time (PT), activated partial thromboplastin time (aPTT), and thrombin time (TT) in rats were not affected by the treatment of LB71350 up to 500 mg/kg. LB71350 caused no significant effects on the cardiac output, stroke volume, heart rate, and mean blood pressure when infused intravenously to the anesthetized rats and dogs. Taken together, LB71350 at high oral doses caused significant pharmacological effects on the central nervous system and the hexobarbital-induced sleeping time.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.465-469
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• 2006

Two mesophilic trickling bed bioreactors filled with two different types of media, hydrophilic- and hydrophobic-cubes, were designed and tested for hydrogen production via anaerobic fermentation of sucrose. Each reactor consisted of a column packed with polymeric cubes and inoculated with heat-treated sludge obtained from anaerobic digestion tank. A defined medium containing sucrose was fed with changing flow rate into the capped reactor, hydraulic retention time and recycle rate. Hydrogen concentrations in gas-phase were constant, averaging 40% for all conditions tested. Hydrogen production rates increased up to $10.5 L{\cdot};h^{-1}{\cdot}L^{-1}$ of reactor when influent sucrose concentrations and recycle rates were varied. Hydrophobic media provided higher value of hydrogen production rate than hydrophilic media at the same operation conditions. No methane was detected when the reactor was under a normal operation. The major fermentation by-products in the liquid effluent of the both trickling biofilters were acetate and butyrate. The reactor filled with hydrophilic media became clogged with biomass and bio gas, requiring manual cleaning of the system, while no clogging occurred in the reactor with hydrophobic media. In order to make long-term operation of the reactor filled with hydrophilic media feasible, biofilm accumulation inside the media in the reactor with hydrophilic media and biogas produced from the reactor will need to be controlled through some process such as periodical backwashing or gas-purging. These tests using trickling bed biofilter with hydrophobic media demonstrate the feasibility of the process to produce hydrogen gas in a trickle-bed type of reactor. A likely application of this reactor technology could be hydrogen gas recovery from pre-treatment of high carbohydrate-containing wastewaters.

• 공업화학
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• 제9권5호
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• pp.624-628
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• 1998

초임계 이산화탄소내에서 방향족 유기용매(BTX)를 0.5% $Pt/{\gamma}-Al_2O_3$ 촉매가 충전된 고정층 반응기를 이용하여 완전분해를 시도하였다. BTX의 전환율은 반응기 입구에서 유기용매의 농도와 초임계 이산화타소의 몰밀도에 의존하는데, 입구농도가 감소함에 따라 전환율은 크게 증가되었고, 일정한 입구농도에서 온도 증가에 따라 반응은 잘 진행되어 전환율이 증가됨을 알 수 있었다. 동일 온도에서 압력이 증가함에 따라 큰 전환율을 보임을 알 수 있었다. 또한 실험조건 $300^{\circ}C$, 204.1 atm에서 benzene은 98.5% 이상의 전환율로 거의 완전산화 되었고, toluene과 xylene의 전환율은 $350^{\circ}C$, 204.1 atm의 조건에서 각각 82.0, 76.5%로 나타났다. 부분산화에 의한 중간생성물의 크로마토그램을 확인한 결과 중간생성물은 benzaldehyde, phenol, benzenemethanol 등으로 확인되었다. 충분한 산화반응 조건하에서 BTX가 중간생성물 없이 환경에 크게 영향을 미치지 않는 $CO_2$와 $H_2O$의 분해생성물로 분해가 가능한 것으로 판단되었다.

• 공업화학
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• 제23권2호
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• pp.204-209
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• 2012

상업용 루테늄 촉매 상에서 에탄의 수증기 개질 반응에 대한 kinetics 데이터를 얻기 위하여 반응온도, 에탄의 분압, 수증기/에탄의 비 등을 변화시키면서 반응 실험을 수행하였다. Kinetics 데이터를 사용하여 Power rate law kinetic model 과 Langmuir-Hinshelwood model의 parameter를 구하였다. 또한 kinetic model식을 적용하여 PRO/II를 이용한 공정 모사를 통해서 에탄의 수증기 개질 반응기 sizing을 수행하였다. 동일한 전환율을 얻기 위해서는 Power rate law model을 적용하였을 경우가 Langmuir-Hinshelwood model을 적용하였을 경우보다 개질 반응기의 부피가 더 큼을 알 수 있었다. Langmuir-Hinshelwood model에 의해 계산된 반응 속도가 반응 실험 결과에 의해 구해진 반응 속도와 더 잘 일치했기 때문에 Langmuir-Hinshelwood model을 적용하여 계산된 반응기의 크기가 실제 반응기 설계에 더 적절하다고 판단된다.

• Journal of Korean Neurosurgical Society
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• 제30권sup2호
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• pp.364-367
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• 2001

A 4-month-old female patient admitted because of hydrocephalus. She was premature infant with germinal matrix hemorrhage at gestational period 27 wks. A ventriculoperitoneal shunt with a low-pressure type valve was placed. Follow-up CT scan obtained 3 months after VP shunt placement, revealed a new Lt. middle cranial fossa cyst. The girl was readmitted to hospital at 7 months after VP shunt placement, complaining of lethargy and vomiting. A CT scan was demonstrated a increase in size of a cyst, She subsequently underwent a left-sided pterional craniotomy with partial excision of membrane and cyst fenestration into the basal cisterns. Follow-up CT scan after 18 months revealed reaccumulation of cyst, the girl was reoperated on. After 2 months, the size of cyst was not decreased. Finally, She underwent a cystoperitoneal shunt. Follow-up CT scan after 5 months was demonstrated disappeared cyst and reexpansion of brain parenchyma. We report the development of a symptomatic sylvian fissure arachnoid cyst developed after ventriculoperitoneal shunt.