• 공업화학
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• 제25권6호
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• pp.581-585
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• 2014

Reduced graphene oxide (RGO)를 수용성 고분자인 poly(styrene sulfonate) (PSS)로 wrapping한 수분산성 그래핀 치환체인 G-PSS와 전도성 고분자인 poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT/PSS)의 복합화에 관하여 연구하였다. G-PSS의 존재 하에서 PEDOT/PSS의 제자리 화학 중합 반응을 수행하여 복합체(GP)를 얻었다. 생성물의 XPS, IR 및 Raman 분석을 통하여 모노머인 EDOT의 중합이 원활하게 진행되어 PEDOT/PSS가 생성됨과 동시에 그래핀과 복합화되었다는 것을 확인할 수 있었다. 또한 GP는 $4.46{\times}10^2S/m$의 전도도를 나타냈으며, 0.5%의 농도까지 물에 분산이 되어 G-PSS보다 전기적 특성 및 수분산성 모두 우수하였다.

• Archives of Pharmacal Research
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• 제29권8호
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• pp.627-632
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• 2006

Chromatographic separation of the MeOH extract from the stems and rhizomes of Sinomemium acutum led to the isolation of nine alkaloids and a lignan. Their structures were determined to be dauriporphine (1), bianfugecine (2), dauriporphinoline (3), menisporphine (4), (-)-syringaresinol (5), N-feruloyltyramine (6), acutumine (7), dauricumine (8), sinomenine (9), and magnoflorine (10) by spectroscopic means. These compounds were examined for their P-gp mediated MDR reversal activity in human cancer cells. Compound 1 showed the most potent P-gp MDR inhibition activity with an $ED_{50}$ value $0.03\;{\mu}g/mL$ and $0.00010\;{\mu}g/mL$ in the MESSA/DX5 and HCT15 cells, respectively.

• 한국산학기술학회논문지
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• 제19권4호
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• pp.492-504
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• 2018

본 연구는 에스테틱과 메디컬에서 여드름 치료제로 잘 알려진 글리콜릭산필링과 해초필링, 일반스크럽제를 사용하여 모공각화증 피부에 미치는 영향을 살펴보고 모공각화증 피부 개선 프로그램의 기초 자료로 제시하고자 수행하였다. 실험방법은 실험군인 글리콜릭산필링(GP)군과 해초필링(SP)군, 대조군인 일반스크럽제(GS)군으로 분류하였으며, 모공각화증이 다소 많은 팔과 다리 부위를 각 군별 5부위씩 선정하여 6주간 시행하였다. 피부측정은 실험 전 0주차, 실험 2주차, 실험 4주차, 실험 6주차에 각질량, 유분량, 수분량, 색소침착을 측정하여 실험 전 후를 비교 분석하였다. 분석결과 실험군인 GP군은 실험 후 수분량 증가(t=-4.064, p<0.01)와 색소침착 감소(t=3.536, p<0.01), SP군은 실험 후 각질량의 감소(t=2.370, p<0.05)와 색소침착의 감소(t=4.017, p<0.01) 대조군인 GS군은 각질량의 감소(t=2.834, p<0.05)와 수분량의 증가(t=-7.589, p<0.001)로 유의미한 차이가 있는 것으로 나타났다. 또한 피부 자극 반응 차이에서는 GS군이 가장 자극일 적은 것으로 나타났다. 모공각화증 관리의 개선 만족도는 실험군의 SP군이 만족도가 가장 높은 것으로 나타났다. 동일한 제품으로 관리를 받은 의향에서는 실험군의 SP군과 GP군이 동일하게 높게 나타났으며, 실험군과 대조군 모두 모공각화증의 관리가 필요한 것으로 나타났다. 결론적으로 여드름의 치료제로도 많이 사용되는 해초필링, 글리콜릭산필링, 일반스크럽제는 모공 주변에 쌓인 각질을 제거하여 각질주기를 정상화시키고, 피부의 수분을 증가시켜 모공각화증 피부를 개선시키는 효과가 있음을 알 수 있었다. 따라서 모공각화증 피부 개선을 위해서는 적절한 각질제거와 피부장벽을 보호하는 보습제 사용이 꾸준히 함께 적용되어야 할 것이며, 향후 본 연구가 모공각화증 피부 개선 프로그램의 기초 자료로 사용이 가능할 것으로 사료된다.

• 생명과학회지
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• 제25권9호
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• pp.1027-1035
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• 2015

미생물유래 다당류 생산균주를 분리하기 위해 전국 각지의 토양시료로부터 가장 높은 점성과 다당류 생산성을 나타내는 균주 GP32를 분리하였으며, 분리균주 GP32의 동정을 분리균주의 형태학적, 생리학적 특성을 조사한 결과, Pseudomonas 속 세균으로 확인되었으며 최종적으로 Pseudomonas sp. GP32로 명명하였다. 플라스크 수준에서 Pseudomonas sp. GP32의 다당류 생산을 위한 가장 적합한 탄소원과 질소원은galactose와 (NH₄)₂SO₄를 이용하였을 때 가장 많은 다당류를 생산하는 것으로 확인되었으며, 다당류 생산을 위한 최적의 C/N ratio는 50이었다. 다당류 생산을 위한 최적 pH와 온도는 각각 7.5와 32℃였다. 최적화된 배지를 이용한 fermentor 배양에서 다당류 생산은 배양 70시간에 최고치를 나타내었으며, 이때 다당류 생산량은 15.7 g/l이었다. Pseudomonas sp. GP32로부터 생산된 다당류는 ethanol 침전, cetylpyridimium 침전과 gel permeation chromatography를 통하여 정제하였으며, 정제된 다당류는 Biopol32로 명명하였다. Biopol 32의 분자량은 3×10⁷ datons이었으며, Biopol32가 함유하고 있는 구성당은 galactose : glucose : gulcouronic acid : galactouronic acid 등이 1.85 : 3.24 : 1.00 : 1.42의 몰비로 함유되어있다. Biopol32 용액은 의가소성 성질을 갖는 고분자 화합물로서 Zoogloea ramigera가 생산하는 생물고분자인 zooglan보다 모든 농도에서 높은 점성을 나타내었다. Biopol32의 실제 폐수처리현장에서 응집제로의 사용 가능성을 검토하기 위하여 식품폐수, 섬유폐수와 제지폐수를 대상으로 응집효율을 조사한 결과, 높은 COD 감소율 (58.4~67.3%)과 SS제거율(82.6~91.3%)를 나타내어 실제 산업폐수에서 뛰어난 응집효율을 나타내었다.

• 한국수산과학회지
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• 제42권6호
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• pp.703-710
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• 2009

The spectral irradiance and underwater transmission characteristics of a combined high-luminance light-emitting diode (LED) lights have been studied to evaluate suitable light sources for fishing lamps of the next generation. The wavelengths at which the irradiance was maximum were changed from 473, 501, 525, and 465 nm for blue, peacock blue, green, and white LED light to 475, 504 and 528 nm for [$F_{WB}$], [$F_{PB}$] and [$F_{GB}$] combined LED lights, respectively. If the irradiance characteristics at 400-700 nm wavelengths are set as 100%, the irradiance rates at 450-499 nm and 500-549 nm were decreased from 82.4% and 56% for blue, peacock blue LED light to 60.0%, 38.5% for [$F_{WB}$], [$F_{WP}$] combined LED lights. The underwater transmission characteristics of the combined LED lights were superior in the order [$F_{WB}$], [$F_{BP}$], [$F_{GB}$] in optical water type I; [$F_{WB}$], [$F_{PB}$], [$F_{GP}$] in optical water type II-III; and [$F_{GP}$], [$F_{WP}$], [$F_{PB}$] in optical water type 1. Setting the 10m depth underwater transmission characteristics of the combined LED lights in optical water type I at 100%, the transmission of water types II, III and 1 drops to 29.5%, 8.0% and 2.2%. Based on the distribution of spectral irradiance and underwater transmission characteristics calculated in optical water types II-III, where was the jigging ground for fishing lamps, the [$F_{WB}]$ and [$F_{GP}$] combined LED lights can be used as a suitable light sources for fishing lamps of the next generation.

• Journal of Microbiology and Biotechnology
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• 제22권12호
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• pp.1659-1664
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• 2012

TSAHC [4'-(p-toluenesulfonylamido)-4-hydroxychalcone] is a promising antitumorigenic chalcone compound, especially against TM4SF5 (four-transmembrane L6 family member 5)-mediated hepatocarcinoma. We evaluated the potential of TSAHC to inhibit the catalytic activities of nine cytochrome P450 isoforms and of P-glycoprotein (P-gp). The abilities of TSAHC to inhibit phenacetin O-deethylation (CYP1A2), coumarin 6-hydroxylation (CYP2A6), bupropion hydroxylation (CYP2B6), amodiaquine N-deethylation (CYP2C8), diclofenac 4-hydroxylation (CYP2C9), omeprazole 5-hydroxylation (CYP2C19), dextromethorphan O-demethylation (CYP2D6), chlorzoxazone 6-hydroxylation (CYP2E1), and midazolam 1'-hydroxylation (CYP3A) were tested using human liver microsomes. The P-gp inhibitory effect of TSAHC was assessed by [$^3H$]digoxin accumulation in the LLCPK1-MDR1 cell system. TSAHC strongly inhibited CYP2C8, CYP2C9, and CYP2C19 isoform activities with $K_i$ values of 0.81, 0.076, and $3.45{\mu}M$, respectively. It also enhanced digoxin accumulation in a dose-dependent manner in the LLCPK1-MDR1 cells. These findings indicate that TSAHC has the potential to inhibit CYP2C isoforms and P-gp activities in vitro. TSAHC might be used as a nonspecific inhibitor of CYP2C isoforms based on its negligible inhibitory effect on other P450 isoforms such as CYP1A2, CYP2A6, CYP2B6, CYP2D6, CYP2E1, and CYP3A.

• Journal of Pharmaceutical Investigation
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• 제41권5호
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• pp.295-300
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• 2011

Paclitaxel is a well known anticancer agent and has been a pharmaceutical challenge because of its extremely poor water-solubility and susceptibility to the p-glycoprotein (p-gp)-mediated efflux in multi-drug resistant (MDR) cancer cells. Tributyrin (TB), a triglyceride with relatively short fatty acid chains, was chosen as solubilizing vehicle for paclitaxel based on the solubility study (26.6 mg/mL). Tributyrin (10%) o/w emulsion containing paclitaxel (5%), egg phosphatidylcholine (5%) and pegylated phospholipid (0.5%) was prepared by high pressure homogenization to obtain submicron-sized emulsion. The mean particle size of the resultant TB emulsion was 395.5 nm. Paclitaxel in TB emulsion showed higher anticancer activity against human breast cancer cell line, MCF-7, than free form delivered in DMSO solution. On the other hand, its anticancer activity was significantly reduced in MCF-7/ADR, a MDR variant cancer cell line of MCF-7, and recovered by the presence of verapamil, suggesting of the susceptibility to the p-gp mediated efflux even though paclitaxel was encapsulated into emulsion. The TB emulsion showed great potential as a promising vehicle for water-insoluble anticancer agent, paclitaxel.

• Journal of Pharmaceutical Investigation
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• 제38권5호
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• pp.313-317
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• 2008

This study investigated the effect of naringin, a flavonoid, on the bioavailability of etoposide administered orally to rats. Etoposide (6 mg/kg) was administered orally to rats alone or with naringin (1, 4 or 12 mg/kg). Compared with the control group, the co-administration of etoposide with 4 and 12 mg/kg of naringin significantly (p<0.05) increased the area under the plasma concentration-time curve (AUC) and the peak plasma concentration ($C_{max}$) of the oral etoposide. Consequently, the absolute bioavailability (AB) of etoposide in the presence (4 and 12 mg/kg) of naringin was significantly (p<0.05) increased by $9.4{\sim}10.6%$ compared with the control group (7.4%). The relative bioavailability (RB) of etoposide was increased 1.13- to 1.44-fold compared to the control group. Enhanced bioavailability of etoposide might be due to inhibition of both cytochrome P450 (CYP) 3A4 in the intestine or liver and P-glycoprotein (P-gp) transport efflux of etoposide in the intestinal membrane. This data indicate that careful consideration of the dosage for therapy with etoposide is required in a case of clinical application of the co-administration of etoposide and naringin.

• 한국콘텐츠학회논문지
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• 제6권5호
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• pp.14-19
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• 2006

텔레매틱스는 자동차 등 최첨단 기계산업과 이동통신 등 IT산업의 집합체로서 향후 자동차 문화에 엄청난 변화를 몰고 올 전망이다. 본 논문에서는 GPS와 CDMA 이동통신망 및 인터넷을 이용하여 구현한 순환차량 도착시각 안내 시스템에 대하여 기술하였다. 본 시스템은 GPS수신기와 이동단말기(PDA)로 구성된 탑재장치를 실은 순환 차량의 위치정보를 CDMA망 및 인터넷을 이용하여 위치서버로 전송하고, 사용자는 웹, PDA 또는 휴대전화를 이용하여 순환 차량의 현재위치와 도착예정 시각을 확인할 수 있다.

• Imaging Science in Dentistry
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• 제47권4호
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• pp.233-239
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• 2017

Purpose: This study was performed to quantify the repeat rate of imaging acquisitions based on different clinical examinations, and to assess the prevalence of error types in intraoral bitewing and periapical imaging using a digital complementary metal-oxide-semiconductor(CMOS) intraoral sensor. Materials and Methods: A total of 8,030 intraoral images were retrospectively collected from 3 groups of undergraduate clinical dental students. The type of examination, stage of the procedure, and reasons for repetition were analysed and recorded. The repeat rate was calculated as the total number of repeated images divided by the total number of examinations. The weighted Cohen's kappa for inter- and intra-observer agreement was used after calibration and prior to image analysis. Results: The overall repeat rate on intraoral periapical images was 34.4%. A total of 1,978 repeated periapical images were from endodontic assessment, which included working length estimation (WLE), trial gutta-percha (tGP), obturation, and removal of gutta-percha (rGP). In the endodontic imaging, the highest repeat rate was from WLE (51.9%) followed by tGP (48.5%), obturation (42.2%), and rGP (35.6%). In bitewing images, the repeat rate was 15.1% and poor angulation was identified as the most common cause of error. A substantial level of intra- and inter-observer agreement was achieved. Conclusion: The repeat rates in this study were relatively high, especially for certain clinical procedures, warranting training in optimization techniques and radiation protection. Repeat analysis should be performed from time to time to enhance quality assurance and hence deliver high-quality health services to patients