• 한국수정란이식학회지
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• 제32권4호
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• pp.331-336
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• 2017

A 2-year-old female Maltese dog was presented with a history of anemia and vaginal hemorrhagic discharge. Physical examination revealed severe vaginal hemorrhagic discharge, abdominal pain, pale mucous membranes, low blood pressure and dehydration. Results of serum biochemistry, hematology, venous blood gas, and electrolyte canine C-reactive protein (CRP) test revealed severe normocytic normochromic anemia, severe neutropenia, a high level of CRP, hypoglycemia, and imbalanced electrolytes. Abdominal ultrasound examination showed focal hypoechoic defect with loss of layering in uterine horn wall. A laparotomy revealed a clear reddish fluid in the abdomen, the fistula of left and right uterine horn, the purulent discharge from fistula, and symptoms of septic peritonitis near by the fistula site. The bitch underwent ovariohysterectomy and recovered without complication. Histopathological diagnosis of the uterine fistula site was adenocarcinoma.

• Macromolecular Research
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• 제14권1호
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• pp.101-106
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• 2006

The transport of reactant gas, electrons and protons at the three phase interfaces in the catalytic layers of membrane electrode assemblies (MEAs) in proton exchange, membrane fuel cells (PEMFCs) must be optimized to provide efficient transport to and from the electrochemical reactions in the solid polymer electrolyte. The aim of reducing proton transport loss in the catalytic layer by increasing the volume of the conducting medium can be achieved by filling the voids in the layer with small-sized electrolytes, such as dendrimers. Generation 1.5 and 3.5 polyamidoamine (PAMAM) dendrimer electrolytes are well-controlled, nanometer-sized materials with many peripheral ionic exchange, -COOH groups and were used for this purpose in this study. The electrochemically active surface area of the deposited catalyst material was also investigated using cyclic voltammetry, and by analyzing the Pt-H oxidation peak. The performances of the fuel cells with added PAMAM dendrimers were found to be comparable to that of a fuel cell using MEA, although the Pt utilization was reduced by the adsorption of the dendrimers to the catalytic layer.

• 한국세라믹학회지
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• 제37권3호
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• pp.263-270
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• 2000

The Pt/copper oxide/n-Si electrodes were fabricated by depositing copper oxide thin film of 500${\AA}$ and very thin Pt layer on the n-type (100) Si substrate. hotoelectrochemical properties and stability profiles of the electrodes were investigated as a function of deposition time of Pt layer. As the deposition time of Pt layer increased up to 10 seconds, the photocurrent and quantum efficiency were increased and then decreased with further depositing time. The better cell stability was observed for the electrode with longer deposition time. The improvements in above photoelectrochemical properties indicate that Pt layer acts as a catalyst layer at electrode/electrolyte interface as well as a protective layer. The decreasing tendency of the photocurrent and efficiency for the electrode with Pt layer deposited above 20 seconds was explained as an increases in probbility of electron-hole pair recombination and also the absorbing photon loss at electrode surface due to the excessive thickness of Pt layer. The results were confirmed by impedance spectroscopy, mutiple cycle voltammograms and microstructural analyses.

• 대한기계학회논문집B
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• 제32권5호
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• pp.359-366
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• 2008

A two-dimensional thermal model of proton exchange membrane fuel cell with large active area is developed to investigate the performance of fuel cell with large active area over various thermal management conditions. The core sub-models of the two-dimensional thermal model are one-dimensional agglomerate structure electrochemical reaction model, one-dimensional water transport model, and a two-dimensional heat transfer model. Prior to carrying out the simulation, this study is contributed to set up the operating temperature of the fuel cell with large active area which is a maximum temperature inside the fuel cell considering durability of membrane electrolyte. The simulation results show that the operating temperature of the fuel cell and temperature distribution inside the fuel cell can affect significantly the total net power at extreme conditions. Results also show that the parasitic losses of balance of plant component should be precisely controlled to produce the maximum system power with minimum parasitic loss of thermal management system.

• Corrosion Science and Technology
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• 제16권2호
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• pp.59-63
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• 2017

Chelating solutions can be damaged by strong acids during oil production. To design effective corrosion inhibitors and other alternatives for corrosion control, it is important to understand not only the behavior of the system under operating condition but also the kinetics of electrochemical reactions during the corrosion process. In this study, the electrochemical behaviors of P-110 steel in aqueous fluids based on ethylenediaminetetraacetic acid (EDTA) compounds under various temperatures and hydrodynamic regime conditions were assessed. Electrochemical measurements were conducted using rotating disc electrodes manufactured. Electrolytes were prepared using aqueous compounds of EDTA like diammonium salt, disodium salt, and tetrasodium salt. Potentiodynamic polarization, electrochemical impedance, and mass loss tests were performed in order to assess the corrosion kinetic in electrolytes. Hydrodynamic effects were observed only in the cathodic polarization curve. This proves that hydrodynamic regime plays an important role in the corrosion of steel mainly in disodium and diammonium EDTA solutions. Two cathodic reactions controlled the corrosion process. However, oxygen level and pH of the electrolyte played the most important role in metal corrosion. Corrosion rates in those fluids were decreased drastically when oxygen concentration was reduced.

• International journal of thyroidology
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• 제11권2호
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• pp.88-91
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• 2018

After introducing tyrosine kinase inhibitors (TKIs) as promising treatments for radioactive iodine refractory advanced thyroid cancer patients, we more often meet patients with TKI-related hormone and electrolyte imbalances in clinics. Hypocalcemia associated with TKI is associated with an imbalance in calcium-vitamin D metabolism. TKI-related hypothyroidism is related to the metabolic rate of thyroid hormones. The two side effects usually occur in the early stages of TKI treatment, and if the imbalance is corrected appropriately, the effects are minor, but in severe cases, the TKI should be discontinued. The authors reported a case of severe hypocalcemia and thyroid dysfunction after TKI treatment. A 56-year-old man suffered from symptomatic hypocalcemia during TKI treatment, which was resolved after he stopped taking the TKI medication. Although calcium and vitamin D replacement have increased, hypocalcemia was recurred and TKI treatments have been permanently stopped due to serious weight loss in grade 3. After the interruption, his calcium levels normalized.

• Journal of Electrochemical Science and Technology
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• 제10권3호
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• pp.271-275
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• 2019

Anodic $TiO_2$ nanotubes were simultaneously grown and doped with $RuO_2$ by single-step anodization in a negatively-charged $RuO_4{^-}$ precursor. Subsequently, a high positive voltage was imposed on the nanotubes in an $F^-$-based electrolyte (a process referred to as potential shock), which led to the formation of a through-hole $RuO_2$-doped $TiO_2$ nanotube membrane without significant loss of the $RuO_2$ catalyst. XPS results confirmed that the doped Ru metal was converted into $RuO_2$ as the potential shock voltage increased. Further increases in the potential shock voltage led to the formation of $RuO_x/Ru$ in the $TiO_2$ nanotubes. All of our results clearly showed that a through-hole catalyst-doped $TiO_2$ nanotube membrane can be produced by a sequence consisting of single-step anodization and the potential shock process.

• 정신신체의학
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• 제19권2호
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• pp.109-114
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• 2011

연구목적: 시상하부-뇌하수체-부신 축의 이상은 다양한 정신과적 증상과 연관이 있으며, 우울 증상도 나타날 수 있다. 저자들은 뇌하수체 기능저하 및 이차성 부신기능저하와 연관된 두통, 무의욕, 무기력, 정신운동 저하, 식욕 저하, 불면 및 걱정 등의 우울 증상을 주소로 정신과에 입원한 71세 남자 환자에 대해 증례 보고하고자 한다. 환자는 정신과 입원 후 두통, 불면, 불안 및 소화기 증상은 호전되었으나, 무기력감은 지속되었다. 퇴원 후 고열 및 의식 혼탁으로 감염내과에 재입원을 하였으며, 부신기능 저하소견을 동반한 범뇌하수체기능저하증이 진단되었고, 코티졸 투여로 전반적인 증상이 호전되었다. 뇌하수체 기능저하에 따른 갑상선 기능저하, 부신기능저하, 성장호르몬 저하 등은 무기력, 피곤, 불면, 체중 감소, 식욕 저하 등의 여러 가지 비특이적 증상들을 나타내고, 임상에서 이러한 비특이적 우울 증상을 가진 환자의 경우, 내분비 질환에 대한 감별이 필요하다.

• 한국산학기술학회논문지
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• 제17권7호
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• pp.54-62
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• 2016

열을 전기로 바꾸는 장치로 가장 효율이 우수한 장치인 AMTEC은 알칼리금속을 작동유체로 하여 열을 직접적으로 전기로 변환시키는 장치이다. AMTEC은 저압용기, 고압용기, 베타 알루미나 고체 전해질, 그리고 순환윅으로 이루어져있다. AMTEC에서의 열손실은 주요하게 저압용기에서의 BASE와 응축부 사이에서 발생하는 열복사손실이며, 암텍의 발전량은 BASE의 온도유지력에 영향을 받기에 BASE의 표면온도를 고온으로 유지시켜주어야 고효율 발전량은 일정하게 유지할 수 있다. 이를 위하여 저압챔버에서의 복사 열손실을 줄이고 BASE온도는 상승시키고, AMTEC 시스템의 발전량 향상을 위하여 저압용기 내부의 6가지 형태의 열복사차단막에 따른 출력을 전산유체해석을 통하여 분석하였다. 분석에서 최적의 열복사차단막 형상은 수직부에 곡률을 가질 때이며, 그 때의 온도에 대한 무차원수(응축부온도/BASE온도 비)는 0.665 정도이고 출력은 약 17.69 W 정도로 다른 형상에 대비하여 높은 발전량을 갖는 것으로 계산되었다. 높이에 따른 발전량의 차이에서는 수평차단막이 BASE 상부로부터 멀리 떨어진 경우 발전량이 가장 우수하며, 17.58W 정도로 나타났다. 여러 개의 작은 홀과 다중 수평차단막을 설계한 경우는 기준이 되는 형상보다 오히려 발전량이 감소하였으며, 각각 0.91W, 2.06W 정도 감소하였다.

• Clinical and Experimental Pediatrics
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• 제52권3호
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• pp.376-379
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• 2009

가성 저알도스테론혈증은 신장 세뇨관의 알도스테론 수용체의 이상으로 알도스테론의 분비는 증가되지만 반응성은 감소되어 저알도스테론혈증의 증상을 보이는 질병이다. 가성 저알도스테론혈증은 다뇨증, 과도한 소변 내 염분소실, 저나트륨혈증, 고칼륨혈증, 대사성 산증을 특징으로 하며, 산전부터 다뇨 증상이 시작되면 양수과다증을 초래할 수 있다. 미숙아에서는 생후 초기 불감 수분 손실량이 많으며, 폐 기능과 신장 기능이 미숙하여 전해질 이상을 흔히 동반하는데, 몸무게의 소실에도 불구하고 지속적인 다뇨와 저나트륨혈증, 고칼륨혈증의 증상이 있다면 전해질 불균형을 초래하는 기저질환을 확인하여야 한다. 저자들은 양수 과다증의 산전력이 있는 산모에게서 출생한 재태주령 32주 미숙아에서 지속적인 몸무게 감소에도 불구하고 계속되는 다뇨와 저나트륨혈증, 고칼륨혈증이 있어 17수산화프로게스테론을 조기에 선별 검사하여 선천성 부신 과형성증의 가능성을 배제함으로써 불필요한 스테로이드 치료를 피하고, 지속적인 전해질 보충으로 점차 전해질 이상의 호전을 보인 가성 저알도스테론혈증 1예를 경험하였기에 문헌 고찰과 함께 보고하는 바이다.