• 한국재료학회지
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• 제21권4호
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• pp.212-215
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• 2011

New organic light-emitting diodes with structure of indium-tin-oxide[ITO]/N,N'-diphenyl-N, N'-bis-[4-(phenyl-m-tolvlamino)-phenyl]-biphenyl-4,4'-diamine[DNTPD]/1,1-bis-(di-4-poly-aminophenyl) cyclohexane[TAPC]/bis(10-hydroxy-benzo(h)quinolinato)beryllium[Bebq2]/Bebq2:iridium(III)bis(2-phenylquinoline-N,C2')acetylacetonate[(pq)2Ir(acac)]/ET-137[electron transport material from SFC Co]/LiF/Al using the selective doping of 5%-(pq)2Ir(acac) in a single Bebq2 host in the two wavelength (green, orange) emitter formation were proposed and characterized. In the experiments, with a 300${\AA}$-thick undoped emitter of Bebq2, two kinds of devices with the doped emitter thicknesses of 20${\AA}$ and 40${\AA}$ in the Bebq2:(pq)2Ir(acac) were fabricated. The device with a 20${\AA}$-thick doped emitter is referred to as "D-1" and the device with a 4${\AA}$-thick doped emitter is referred to as "D-2". Under an applied voltage of 9V, the luminance of D-1 and D-2 were 7780 $cd/m^2$ and 6620 $cd/m^2$, respectively. The electroluminescent spectrum of each fabricated device showed peak emissions at the same two wavelengths: 508 nm and 596 nm. However, the relative intensity of 596 nm to 508 nm at those wavelengths was higher in the D-2 than in the D-1. The D-1 and D-2 devices showed maximum current efficiencies of 5.2 cd/A and 6.0 cd/A, and color coordinates of (0.31, 0.50) and (0.37, 0.48) on the Commission Internationale de I'Eclairage[CIE] chart, respectively.

• 한국광학회지
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• 제18권6호
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• pp.452-460
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• 2007

ZERODUR와 용융 석영으로 저산란 반사경을 제작하고 산란 특성을 연구하였다. Bowl feed 법을 이용하여 초연마면인 표면거칠기 0.326 ${\AA}$인 용융 석영 기판과 표면거칠기 0.292 ${\AA}$의 ZERODUR 기판을 얻었다. 이온빔 스퍼터링 방법으로 초연마된 기판 위에 $SiO_2$와 $Ta_2O_5$를 교번으로 22층을 증착하여 다층박막 고반사 거울을 얻었다. 용융 석영 반사경과 ZERODUR 반사경의 산란이 각각 4.6 ppm과 30.9 ppm으로 측정되었으며, 이로부터 산란이 매우 작은 경우 기판의 표면거칠기가 산란을 결정하는 주요 파라미터가 아니라는 것을 알았다. 나아가 반사경의 표면거칠기를 AFM으로 측정한 결과. ZERODUR 반사경이 용융 석영 반사경 보다 박막의 표면거칠기가 2.3배 더 높게 측정 되었다. 이 결과는 기판-박막 경계면에서 박막 형성 초기에 기판의 화학조성 또는 결정방향과 증착물질의 상호관계로 인하여 박막 형성 초기에 표면거칠기가 급격히 나빠져서 발생하는 것으로 유추되었다. SEO 300A으로 접촉각 측정을 하여 Giriflaco-Good-Fowkees-Young 방법으로 표면에너지를 계산하였다. 표면거칠기 0.46 ${\AA}$을 갖는 용융 석영 기판이 표면거칠기 0.31 ${\AA}$을 갖는 ZERODUR 기판보다 접촉각이 더 작고 표면에너지는 크게 나타났다. 이러한 차이가 기판 종류에 따라 박막형성 초기에 표면거칠기를 다르게 하는 한 요인으로 판단되며, 기판의 표면에너지가 높을수록 미려한 박막표면을 얻는 것으로 확인되었다. ZERODUR의 표면에너지 차이를 설명하기 위해 XPS 분석으로 용융 석영은 Si, O로 구성되었고 ZERODUR는 Si, O, Al, Na 그리고 F로 구성되었다는 것을 알 수 있었다.

• 마이크로전자및패키징학회지
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• 제16권2호
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• pp.27-31
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• 2009

Sn whiskers can grow from the pure Sn and high Sn-based finish and cause the electrical shorts and failures. Even with the wealth of information on whiskers, we have neither the clear understanding of whisker growth nor methods for its prevention. In this study, the whisker grain roots which connected with intermetallic layer were analyzed by high-resolution transmission electron microscopy (HR-TEM). In the Sn-Cu plated leadframe (LF) that was stored at ambient condition for 540 days, filament-shaped whiskers were grown on the Sn-plated surface and ${\eta}'-Cu_6Sn_5$ precipitates were widely distributed along the grain boundaries at the Sn matrix. The measured of the lattice fringes at the ${\eta}'-Cu_6Sn_5$ was $4.71{\AA}$ at the coarse grain and $2.91{\AA}$ at the fine grain. The $Cu_3Sn$ which generates the tensile stresses was not observed. The formation of $Cu_6Sn_5$ precipitates and intermetallic layer were strongly related to whisker growth, but, the whisker growth tendency does not closely relate with the geometric morphology of irregularly grown intermetallic compound (lMC).

• 한국광물학회지
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• 제13권1호
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• pp.1-14
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• 2000

알루나이트는 포항지역의 제3기 연일층군의 이암 층내의 탄산염 결핵체 주변에서 할로이사이트와 함께 극미립 변질물 (1-2 $\mu\textrm{m}$)로서 산출된다. 알루나이트는 정육면체와 유사한 능면체 결정형을 이루고 침상 내지 단주상의 할로이사이트와 밀접한 공생관계를 이룬다. X-선회절 분석에 의해서 이 알루나이트는 a=6.9897(1) $\AA$, c=17.2327(4)$\AA$, V=728.75(3) $\AA$3의 격자상수값을 갖는 것으로 밝혀졌다. X-선형광된 이 알루나이트의 화학식은 (K0.94N0.06)(Al2.55Fe3+0.45)(SO4)2(OH)6 으로서, 나트로알루나이트 단성분을 6-7 mole%정도 함유하는 것으로 분석되었다. 또한 시차열분석 (TG-DTG-DTA)을 통해서 알루나이트의 승화성 성분들 (H2O와 SO3)의 존재와 함유 정도를 조사하였고, 고온X-선회절분석을 병행하여 이 광물의 OH기의 이탈 반응 (52$0^{\circ}C$)과 고온상으로의 전이 반응 ($600^{\circ}C$ 및 $700^{\circ}C$)을 감정 하였다. K/Ar 법으로 측정된 알루나이트의 생성 연대 ($0.342\pm$0.008 Ma)와 안정동위원소들의 분석 결과 ($\delta$18Oso4=-1.7, $\delta$DSMOW=-31, $\delta$34S=-10.8)는 이 알루미늄 황산염 광물이 연일충군의 융기 이후에 야기된 민물의 유입에 의한 표성기원의 변질작용의 결과로 생성되었음을 지시한다. 알루나이트+할로이사이트 공생군의 침전은 이암 내에서 조성된 강산성 (pH=2-3)의 알루미늄 황산염 용액이 탄산염 결핵체를 만나 반응하여 pH가 국지적으로 증가되어 (pH=4) 과포화되는 과정에 의해서 야기되었다. 컴퓨터를 이용한 Al3+의 포화지수에 관한 화학적 평형 모델링 실험 결과, 알루미늄 황산염 용액으로부터의 알루나이트와 할로이사이트의 침전은 pH=4 및 \ulcornerSO42-=10-4M 조건에서 K+과 Si(OH)4의 농도가 10-4M 이상 유지되어야 가능한 것으로 밝혀졌다.

• Journal of Nutrition and Health
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• 제31권5호
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• pp.897-905
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• 1998

Docosahexaenoic acid(DHA), a $\omega$3 series fatty acid and arachidonic acid(AA). a $\omega$6 series fatty acid were found in relatively high concentrations in the phospholipids(PLs) of cell membranes of nerve tissues, and they can be affected by various factors. The present study examined the effects of dietary $\omega$6 and $\omega$3 fatty acid composition on P/M/S and on $\omega$3/$\omega$6 fatty acid ratios in brain PLs of 2nd generation rats. The expeimental diets consisted of 10% fat(by wt), which were computer- searched mixed oil('M') with P/M/S ratio, 1 : 1.4 : 1 and $\omega$6/$\omega$3 ratio, 6 : 1 and safflower oil('S') poor in $\omega$3 fatty acids. The experimental diets were started 3-4 wks prior to conception. During the lactation period, the feeding mothers were switched 1 wk after birth and provided the pups for 2 wks with milk which had compositions different from that of their natural mother. The same diet as their mothers was provided from weaning to 9 wks of age. The 'M'and 'S' rats were again subdivided into MM, MS, SS, SM rats according to diet which their lactating mothers were fed from the begining of the experiment. The relative percentage of P/M/S fatty acids in brain PLs in all experimental groups converged to a very similar value at 9 wks of age, indicating the existence of a control mechanism for the degree of fatty acids, unsaturation. The $\omega$3/$\omega$6 fatty acid ratios of brain PLs converged to about 1.0 in MM & SM groups and to 0.7 in SS & MS groups, suggesting also the existence of some balance between $\omega$3 and $\omega$6 fatty acids in developing rat brain. The concentrations of $\omega$3 fatty acids, especially DHA, in the SM group were increased and became similar to those in MM group at 9 wks of age. The increase in DHA of brain PLs was counterbalanced b)r a decrease in 22 5$\omega$6. Therefore, the ratios of 22 : 6$\omega$6/22 : 5$\omega$6 were higher in both MM & SM groups than those of SS & MS groups at 9 wak of age. Although dietary $\omega$3 and $\omega$6 fatty acids affected 22 : 6$\omega$S and 22 : 5$\omega$6 contained in rat brain PLs reciprocally, the relative percentage of AA did not appear to be significantly influenced by the diet in all groups at 9 wks of age, suggesting that a mechanism for the maintenance of a certain level of AA in brain PLs exists. In conclusion, the $\omega$3/$\omega$6 fatty acid and 22 : 6$\omega$3/22 : 5$\omega$6 ratios, but not P/M/S ratio, of rat brain PLs were affected by the postnatal dietary changes. Futher studies are required to clarify the mechanism(S) of ensuring a certain level of DHA and of maintaining a similar level of AA in rat brain PLs after. weaning(9 wk) regardless of prenatal and postnatal dietary changes. (Korean J Nutrition 31(5) : 897-905, 1998)

• Bulletin of the Korean Chemical Society
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• 제27권4호
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• pp.508-514
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• 2006

In this study, we have performed ab initio computer simulations to investigate the conformational and complexation characteristics of the trimethyl ether of p-tert-butylmonodeoxycalix[4]arene (6) with a potassium ion. The structures of different conformers of 6 and their potassium complexes were optimized by using ab initio RHF/6-31G and B3LYP/6-31G(d,p) methods. The relative stability of the various conformers of the uncomplexed 6 is in following order: cone (most stable) > 1-partial-cone ~ 2i-partial-cone > 2-partial-cone ~ 1,3-alternate > 3i-partial-cone. However, the relative stability of the conformational complexes of 6 with $K^+$ is in the following order: 2-partial cone ~ 1,3-alternate > cone > 3-partial cone > 1-partial cone (least stable). The highest binding strengths of 2-partial-cone and 1,3-alternate complexes originate from two strong cation-$\pi$ interactions and two strong cation-oxygen interactions in the complex of 6+$K^+$. Due to the cation-$\pi$ interactions, the calculated C-C bond distances in the arenes of the $K^+$-complexes are about 0.0048 $\AA$ longer than the values of their isolated hosts.

• Asian Pacific Journal of Cancer Prevention
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• 제13권12호
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• pp.6385-6390
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• 2012

A number of studies have been conducted to explore the association of XRCC1 polymorphisms with thyroid cancer risk, but the results have been inconsistent. Thus we performed the present meta-analysis to clarify this issue based on all of the evidence available to date. Relevant studies were retrieved by searching PubMed and statistical analysis conducted using Stata software. Nine studies were included in this meta-analysis (1,620 cases and 3,557 controls). There were 6 studies (932 cases and 2,270 controls) of the Arg194Trp polymorphism, 7 studies (1432 cases and 3356 controls) of the Arg280His polymorphism and 9 studies (1,620 cases and 3,557 controls) for the Arg399Gln polymorphism. No association of XRCC1 Arg194Trp, Arg280His and Arg399Gln polymorphism with thyroid cancer risk was observed in the overall analysis. However, subgroup analysis revealed: 1) an elevated risk in aa vs AA analysis (OR=2.03, 95%CI= 1.24-3.31) and recessive genetic model analysis (OR=1.93, 95%CI= 1.20-3.08) in the larger sample size trials for XRCC1 Arg194Trp polymorphism; 2) a decreased thyroid cancer risk on subgroup analysis based on ethnicity in Aa vs AA analysis (OR=0.84, 95%CI= 0.72-0.98) and in a dominant genetic model (OR=0.84, 95%CI= 0.72-0.97) in Caucasian populations for the XRCC1 Arg399Gln polymorphism; 3) a decreased thyroid cancer risk on subgroup analysis based on design type in Aa vs AA analysis (OR=0.72, 95% CI= 0.54-0.97) among the PCC trials for the Arg399Gln polymorphism. Our results suggest that the XRCC1 Arg399Gln polymorphism may be associated with decreased thyroid cancer risk among Caucasians and XRCC1 Arg194Trp may be associated with a tendency for increased thyroid cancer risk in the two larger sample size trials.

• Asian-Australasian Journal of Animal Sciences
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• 제28권1호
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• pp.86-94
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• 2015

This experiment was conducted to evaluate the chemical composition and amino acid (AA) digestibility of sunflower seed meal (SFSM) and to use this data to develop prediction equations for estimating AA digestibility for growing pigs. Ten SFSM were collected from five provinces in China. Twelve barrows ($38.8{\pm}4.6kg$), fitted with ileal T-cannula were allotted into two $6{\times}6$ Latin square designs. Each of six experimental periods comprised a 5-d adaption period followed by a 2-d collection of ileal digesta. The ten test diets contained 50% SFSM as the sole source of AA. Another nitrogen-free diet was used to measure the basal endogenous losses of crude protein (CP) and AA. Chromic oxide (0.3%) was used as an inert marker in each diet. There was considerable variation (CV>10%) among the ten SFSM in chemical composition (dry matter [DM]). The concentration of CP and ether extract (EE) ranged from 29.33% to 39.09% and 0.88% to 11.33%, respectively. Crude fibre (CF), neutral detergent fibre and acid detergent fibre ranged from 21.46% to 36.42%, 38.15% to 55.40%, and 24.59% to 37.34%, respectively. There was variation among the ten SFSM in apparent ileal digestibility (AID) and standardized ileal digestibility (SID) for lysine and threonine, which ranged from 63.16 to 79.21 and 55.19% to 72.04% for AID and 67.03% to 82.07% and 61.97% to 77.01% for SID, respectively. The variation in CP and methionine ranged from 60.13% to 74.72% and 74.79% to 88.60% for AID and 66.70% to 79.31% and 77.16% to 90.27% for SID, respectively. Methionine was a good indicator to predict AA digestibility. These results indicate that conventional chemical composition of SFSM was variable (CV>10%) among the ten SFSM (DM). The results of AID, SID and prediction equations could be used to evaluate the digestibility of SFSM in growing pigs.

• Journal of Microbiology and Biotechnology
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• 제18권1호
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• pp.43-47
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• 2008

The nickel and cobalt resistance of Cupriavidus metallidurans CH34 is mediated by the CnrCBA efflux pump encoded by the cnrYHXCBAT metal resistance determinant. The products of the three genes cnrYXH transcriptionally regulate expression of cnr. CnrY and CnrX are membrane-bound proteins, probably functioning as anti-sigma factors, whereas CnrH is a cnr-specific extracytoplasmic functions (ECF) sigma factor. The periplasmic domain of CnrX (residues 29-148) was cloned as a N-terminal His-tagged protein, expressed in Escherichia coli, and purified using affinity chromatography and gel filtration. The molecular mass was estimated to be about 13.6kDa by size exclusion chromatography, corresponding to a monomer. The tetragonal bipyramid crystals were obtained by mixing an equal volume of protein in 50mM Tris-HCl, pH 7.5, 1% glycerol, 100mM NaCl, 1mM DTT, and the reservoir solution of 15% w/v PEG 2000, 100mM lithium chloride at 277K in 2-4 days using hanging drop vapor diffusion. The protein concentration was 24mg/ml. The crystal that diffracted to $2.42{\AA}$ resolution belongs to space group $P4_1\;or\;P4_3$ with unit cell parameters of $a=b=32.14{\AA},\;c=195.31{\AA},\;{\alpha}={\beta}={\gamma}=90^{\circ}$, with one molecule of CnrX in the asymmetric unit.

• Journal of Korean Neurosurgical Society
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• 제51권4호
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• pp.199-202
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• 2012

Objective: This retrospective study was performed to evaluate the role of chemotherapy in the management of patients with anaplastic astrocytoma (AA). Methods: We compared the survival outcome among the 3 different treatment protocol groups in a single institution. A total of 86 patients (39 men and 47 women) with newly diagnosed AA after surgery were analyzed. Among them, 31 patients (36.0%) were treated with radiotherapy only (RT Group), 30 patients (34.9%) were treated with nimustine-cisplatin chemotherapy before RT (ACNU-COOP group), and 25 patients (29.1 %) were treated with procarbazine, lomustine and vincristine (PCV) chemotherapy after radiotherapy (PCV group). Results: The median survival was 14.0, 30.0 and 72.0 months in RT, ACNU-COOP, and PCV group, respectively and showed significant differences (RT vs. ACNU-COOP; p=0.039, RT vs. PCV; 0.002, ACNU-COOP vs. PCV; 0.045). PCV group showed less toxicity rate (5 patients; 20%) than ACNU-COOP group (12 patients; 40%), while only 3 patients (9.6%) in RT group experienced grade 3 or 4 toxicities. Conclusion: An application of chemotherapy before or after radiotherapy is beneficial in prolonging the survival of patients with AA. Adjuvant PCV chemotherapy after radiotherapy is recommendable.