• Asian Pacific Journal of Cancer Prevention
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• 제17권7호
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• pp.3167-3171
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• 2016

Prostate cancer (PCa) is one of the most common diseases in men. It is important to assess prognostic factors and whether high cortisol levels and complex hormonal interactions could be responsible for PCa development. We evaluated the relationship between cortisol, leptin and estrogens in 141 men, 71 with PCa and the remaining 70 constituting a low risk group (LRG). They were recruited for this study from a total of 2906 middle-aged men (ages 45-70 years) who completed an evaluation for prostatic diseases at the Urology Division, Hospital de Clínicas "$Jos{\acute{e}}$ de San $Mart{\acute{i}}n$", University of Buenos Aires, in May 2009. In this cross sectional study, cortisol, PSA, total-testosterone, free-testosterone, bioavailable testosterone, LH and estradiol were measured in serum. We observed increased cortisol levels in PCa patients as compared to LRG cases (p=0.004,). Leptin and estradiol levels were also higher in PCa patients (p=0.048; p<0.0001, respectively). Logistic regression analysis indicated that serum cortisol (OR: 1.110 (95% CI 1.016-1.213), p=0.022), estradiol (OR: 1.044 (95% CI 1.008-1.081), p=0.016) and leptin (OR: 1.248 (95% CI 1.048-1.487), p=0.013) explained 27% of the variance of dependent variables, even after adjusting for age, smoking, BMI and waist circumference. We found increased cortisol levels in PCa patients as compared to LRG, as well as an altered circulating hormonal profile.

• 식물병연구
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• 제23권1호
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• pp.1-18
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• 2017

키위 궤양병균인 Pseudomonas syringae pv. actinidiae는 최근 전세계에서 심각하게 경제적 손실을 초래하고 있다. 궤양병균은 우리나라에서 그린키위와 골드키위 품종들을 각각 1988년과 2006년부터 침해해왔다. 최근에는 오염된 수입꽃가루에 의해 유입된 궤양병균 biovar 3 (Psa3)가 주변 키위 재배 농가로 2차감염에 의해 급속하게 확산되어 골드키위와 레드키위 품종들에 대발생하여 피해를 주고 있다. 이 총설에서는 지난 30년간 수행한 연구 업적과 현장 경험 그리고 세계적인 주요 연구 산물들을 기초로 하여 궤양병 발생 회피, 경종적 방제, 궤양병균의 전파 차단, 조기 진단, 전염원 제거, 침입 차단, 약제 방제, 나무 치료 등 다양한 키위 궤양병 관리방법들을 요약하여 장차 키위나무를 건강하게 재배할 수 있도록 농가에서 실용적으로 사용할 수 있는 매뉴얼을 제시하고자 한다.

• 한국수소및신에너지학회논문집
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• 제19권4호
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• pp.305-312
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• 2008

ZnO/Zn redox cycle is the one of the promising thermochemical cycles for hydrogen production via water splitting with high temperature heat source like a concentrated solar energy. This paper reports the particle size effect of Zinc on water splitting behavior. Water splitting reaction experiments were carried out at isothermal conditions of 350 and 400$^{\circ}C$ in TGA (Thermo Gravimetric Analyzer) using four commercial Zinc powders (nano, <10 ${\mu}m$, <150 ${\mu}m$ and $150{\sim}600\;{\mu}m$ particle sizes). Before the experiments, average particle size of Zinc powders was analyzed by PSA (Particle Size Analysis). After the experiments, XRD (X-Ray Diffraction) and SEM (Scanning Electron Microscope) analyses were conducted on the samples. The experimental results showed that particle size had a effect on the conversion of Zinc to ZnO. Zinc conversion was increased, as the particle size decreased. Especially, the nano size particles were aggregated and the particle's morphology changed on the surface during hydrolysis reaction.

• 한국분말재료학회지
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• 제27권3호
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• pp.233-240
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• 2020

Nano-sized ZnSe particles are successfully synthesized in an aqueous solution at room temperature using sodium borohydride (NaBH₄) and thioglycolic acid (TGA) as the reducing agent and stabilizer, respectively. The effects of the mass ratio of the reducing agent to Se, stabilizer concentration, and stirring time on the synthesis of the ZnSe nanoparticles are evaluated. The light absorption/emission properties of the synthesized nanoparticles are characterized using ultraviolet-visible (UV-vis) spectroscopy, photoluminescence (PL) spectroscopy, and particle size analyzer (PSA) techniques. At least one mass ratio (NaBH4/Se) of the reducing agent should be added to produce ZnSe nanoparticles finer than 10 nm and to absorb UV-vis light shorter than the ZnSe bulk absorption wavelength of 460 nm. As the ratio of the reducing agent increases, the absorption wavelengths in the UV-vis curves are blue-shifted. Stirring in the atmosphere acts as a deterrent to the reduction reaction and formation of nanoparticles, but if not stirred in the atmosphere, the result is on par with synthesis in a nitrogen atmosphere. The stabilizer, TGA, has an impact on the Zn precursor synthesis. The fabricated nanoparticles exhibit excellent photo-absorption/discharge characteristics, suggesting that ZnSe nanoparticles can be alloyed without the need for organic solutions or high-temperature environments.

• 산업기술연구
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• 제25권A호
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• pp.151-156
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• 2005

Auto exhausts and air pollution can become trapped in the cabin of vehicle, reducing the amount of oxygen available for breathing. Driver may feel sleepy, headaches, nausea, confusion, dizziness and lower levels of oxygen can damage the driver's general health. Consequently, oxygen generator purified oxygen into the car to help driver get the oxygen driver's body needs. In this study, in order to evaluate the oxygen generator performance, the samples that the various conditions(humidity(50%, 100%), flow and oxygen concentration) were examined. There were three types of oxygen generator; sample 1($2.5{\ell}/min$, $36%O_2$), sample 2($4.5{\ell}/min$, $41%O_2$) and sample 3($5{\ell}/min$, $39%O_2$). As the humidity increased from 50% to 100%, the oxygen concentration of the sample 1(36%), 2(41%) and 3(39%) was reduced $31%O_2$, $38%O_2$ and $38%O_2$, respectively. Also, the each sample measured that effect of human in car on oxygen concentration, if the oxygen concentration is one person in car, each sample of oxygen concentration was $20.8%O_2$, $23.7%O_2$ and $21.2%O_2$. From the above results, it was shown that oxygen generator for car, if the oxygen concentration is increased, effect of humidity is reduced, and that in the sample of supplying a high-rate of oxygen, the oxygen concentration is increased. It was suggested that effect of humidity on oxygen generator for car can be reduced according to the supply of oxygen.

• Nuclear Engineering and Technology
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• 제36권1호
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• pp.112-120
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• 2004

The purpose of this paper is to analyze the piping failure frequency for the main feedwater system in domestic nuclear power plants(NPPs) for the application to an in-service inspection(ISI), leak before break(LBB) concept, aging management program(AMP), and probabilistic safety analysis(PSA). First, a database was developed for piping failure events in domestic NPPs, and 23 domestic piping failure events were collected. Among the 23 events, 12 locations of wall thinning due to flow accelerated corrosion(FAC) were identified in the main feedwater system in 4 domestic WH 3-loop NPPs. Two types of the piping failure frequency such as the damage frequency and rupture frequency were considered in this study. The damage frequency was calculated from both the plant population data and damage(s) including crack, wall thinning, leak, and/or rupture, while the rupture frequency was estimated by using both the well-known Jeffreys method and a new method considering the degradation due to FAC. The results showed that the damage frequencies based on the number of the base metal piping susceptible to FAC ranged from $1.26{\times}10^{-3}/cr.yr\;to\;3.91{\times}10^{-3}/cr.yr$ for the main feedwater system of domestic WH 3-loop NPPs. The rupture frequencies obtained from the Jeffreys method for the main feedwater system were $1.01{\times}10^{-2}/cr.yr\;and\;4.54{\times}10^{-3}/cr.yr$ for the domestic WH 3-loop NPPs and all the other domestic PWR NPPs respectively, while those from the new method considering the degradation were higher than those from the Jeffreys method by about an order of one.

• 한국결정성장학회지
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• 제31권5호
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• pp.212-217
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• 2021

Silica sol에 YAG 형광체를 첨가량별로 spin 코팅 후, 코팅막의 blue LED에서 백색광이 발현되는 정도와 표면 및 곡면 코팅용 binder로써, 적용가능성을 확인하였다. SEM, PSA를 통해YAG의 입자 크기는 D₅₀: 9~10 ㎛ 내외이며, XRD를 통해 YAG의 결정구조가 garnet(Y₃Al₅O₁₂), cubic인 것을 확인하였다. 코팅막은 crack이 없고 동시에 silica sol이YAG 형광체를 균질하게 도포된 형상을 보였으며, 첨가량 증가와 비례하게 코팅막 내에서 YAG 첨가량과 두께는 최대 40 ㎛까지 증가하는 추세를 보였다. 그리고 YAG 첨가량이 증가할수록 PL emission intensity 증가와 chromatic locus 곡선 끝 방향으로 색좌표 이동을 확인하였다. Soda-lime 유리기판 표면에 코팅 후, crack이 없으며 YAG 형광체가 균질하게 도포된 코팅성과 코팅막의 백색광 발현특성을 확인할 수 있었고 이는 직접적으로 LED에 다양한 형태의 형광 형상의 구현이 가능하다는 것을 의미한다.

• 대한비뇨기종양학회지
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• 제16권3호
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• pp.126-134
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• 2018

Purpose: The purpose of this study is to compare the radiation therapy (RT) and radical prostatectomy (RP) of high-risk or locally advanced prostate cancer (PC) patients after neoadjuvant hormonal therapy (NHT). Materials and Methods: This retrospective study evaluated patients underwent RT (42 patients) or RP (152 patients) after NHT at a single center during 2003-2014. Times to biochemical recurrence (BCR), pelvic local recurrence (PLR), metastasis, clinical painful symptom progression (CPSP), castration-resistant PC (CRPC), and overall survival were compared between the RT and RP groups, after adjustment for TN stage, using the Kaplan-Meier method and log-rank test. Results: Significant inter-group differences were observed for age, Gleason score, initial PSA, and clinical and pathological T stages (all p<0.05). During a median follow-up of 71.7 months, the overall incidences of BCR, PLR, metastasis, CPSP, CRPC, and death were 49.5%, 16.5%, 8.3%, 7.7%, 7.7%, and 17.5%, respectively. The median times to BCR were 100 months for RT and 36.2 months for RP (p=0.004), although the median times were not reached for the other outcomes (all p>0.05). The independent predictor of CPSP was RP (hazard ratio, 0.291; p=0.013). Conclusions: Despite significantly different baseline parameters, RP provided better CPSP-free survival than RT among patients with localized high-risk or locally advanced PC.

• 한국결정성장학회지
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• 제30권6호
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• pp.220-225
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• 2020

반응부, 이송부, 포집부로 이루어진 기상합성장치를 구축하여 Oxide TFT의 대표적인 물질인 IGZO 반도체용 타겟의 기초 소재인 산화갈륨 나노분말을 기상합성법으로 제조하였다. 반응부에서 갈륨 금속을 증발시켜 1150℃ 이상의 온도에서 산화갈륨 나노분말이 만들어지는 것을 확인하였다. 갈륨 금속은 증발 즉시 반응부에서 산화갈륨 나노분말로 합성되었으며, 반응부의 온도가 증가함에 따라 높은 결정도와 큰 입자 크기를 보였다. 또한, 합성된 산화갈륨 나노분말은 구형의 모양을 가지면서 매우 낮은 응집성을 가졌다. 기상합성법으로 얻은 산화갈륨 나노분말을 상용 산화인듐, 산화아연 분말(몰비 = 1 : 1 : 1)과 혼합하여 소결을 시행한 결과, 소결온도 1450℃에서 5.83 g/㎤의 최대밀도를 얻어 같은 조건하에서 상용 산화갈륨 분말을 이용해 만든 IGZO 소결체(5.61 g/㎤)보다 높은 밀도를 얻음을 볼 수 있었다.

• 접착 및 계면
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• 제23권3호
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• pp.80-86
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• 2022

본 연구에서는 수계형 아크릴 점착제의 성능 및 점착 물성을 향상시키기 위해 분자량 조절제인 1-dodecanethiol(n-DM)의 함량이 다른 수계 아크릴 점착부여제를 합성하였으며 수계 아크릴 점착부여제의 투입량에 따른 물성 변화 확인을 위해 수분산성 아크릴 에멀젼에 수계 아크릴 점착부여제를 10/20/30 phr로 투입하여 물성을 측정하였다. 합성된 수계 아크릴 점착부여제의 분자량 및 유리전이온도(T_g)는 n-DM의 함량이 증가함에 따라 감소하는 경향을 나타내었다. 수분산성 아크릴 에멀젼에 수계 아크릴 점착부여제를 첨가하였을 때의 점착력 및 내열 유지력은 증가하였으며 수계 아크릴 점착부여제를 10 phr 또는 20 phr로 투입하였을 때에 가장 우수한 값을 나타내었다.