• Bulletin of the Korean Chemical Society
• /
• 제19권6호
• /
• pp.650-654
• /
• 1998

Aggregations of 1,1'-diethyl-2,2'-carbocyanine iodide (DCI) and 1,1'-diethyl-2,2'-dicarbocyanine iodide (DDT) in aqueous solution have been investigated by the steady-state absorption spectroscopy. The equilibrium constants for dimerization of DCI and DDT are found to be $(9.8{\pm}0.5){\times}10^4 \;and\; (1.6{\pm}0.5){\times}10^5\; M^{-1}$, respectively, at 293 K. The enthalpy changes for the dimerization of DCI and DDT are -6.7±0.7 and -7.7±0.8 kcal/mol, respectively. The results show that the dispersion force plays an important role in the aggregation of DCI and DDT in aqueous solution. The absorption bandwidth of DCI/ethanol system has been measured as a function of temperature, providing the evidence for no strong interaction between DCI and solvent molecules. The participation of hydrophobic force in driving the aggregation is suggested. For the first time, DCI in aqueous solution is found to form a new aggregate which has both J- and H- bands.

• Archives of Pharmacal Research
• /
• 제26권9호
• /
• pp.723-726
• /
• 2003

Five coumarins, isoimperatorin (1), pabulenol (2), isooxypeucedanin (3), oxypeucedanin hydrate (4) and osthol (5) were isolated from the MeOH extract of Angelica genuflexa in the course of searching for anti-platelet and anti-coagulant components from plants. Pabulenol (2) was isolated from A. genuflexa for the first time. The five compounds isolated from A. genuflexa, together with decursinol angelate (6), decursin (7) and nodakenin (8) from A. gigas were evaluated for their effects on platelet aggregation and blood coagulation. Compounds 2, 5, 6 and 7 were observed to be either equally effective or 2∼4 times more inhibitory than ASA in both arachidonic acid and U46619 ($TXA_2$ mimetic) induced platelet aggregations.

• 수산해양기술연구
• /
• 제27권1호
• /
• pp.1-12
• /
• 1991

적분방식에 의한 어군량추정법을 실험적으로 검증하기 위하여, 실험수조에서 50 kHz와 200 kHz의 주파수를 대상으로 모의어군의 분포밀도와 초음파산란강도의 관계를 검토하고, 또 계량어군탐지기의 정도를 개선하기 위한 문제들에 대하여 고찰을 행한 결과를 요약하면 다음과 같다. 1. 어체의 모의표적으로 이용한 steel ball (직영 35mm)의 실측 echo 파형은 이론 echo 파형과 잘 일치하였다. 2. 5 종류의 주파수에 대하여 고등어 (체장 36cm)의 반사주파수특성을 조사한 결과, 측정주파수가 변화함에 따라 어체에 의한 echo 신호의 진폭과 파형이 크게 변동하고 있음을 알 수 있었다. 3. 송수파기의 음속 내에서 5개/m 상(3)와 30개/m 상(3)의 표적 군이 서로 상하로 존재할 때, 상부 표적군의 존재에 의해 하부 표적군의 echo level이 -0.43 dB 감쇠하는, 소위 그늘효과(shadowing effect)가 발생하였다. 4. 동지나해에서 정박 중에 탐지한 고밀도 어군의 echo신호와 그 어군직하의 해저에서 산란된 echo 신호를 상호 연관시켜 분석한 결과, 어군층내에서 발생한 어군감쇠와 다중산란효과가 해저 echo 신호의 변동에 큰 영향을 미치고 있음을 알 수 있었다. 5. 정치망의 원통에 인망한 정어리의 단위체적당에 대한 분포밀도가 36마리/m 상(3)였을 때, 해저기녹이 소실되는 어군감쇠현상과, 어군 echo 신호가 해저까지 신장되는 다중산란현상이 동시에 발생하였다. 6. 50kHz와 200kHz의 주파수에서 표적군의 평균체적산란강도(:dB)와 표적의 분포밀도($\rho$:개/m 상(3))의 간에 다음의 회귀직선식을 얻었다. 50kHz : =-46.2+13.7 Log($\rho$). 200kHz : =-43.9+13.4 Log($\rho$). 7. 표적의 분포밀도가 5, 10, 15, 20, 25, 30 개/m 상(3)였을 때, 적분방식에 의한 추정치는 50kHz에서 2.0, 8.1, 9.9, 14.1, 19.2, 26.7 개/m 상(3)이었고, 200kHz에서는 2.0, 8.0, 9.1, 15.0, 20.1, 24.1 개/m 상(3)이었으며, 단위체적당에 분포하는 표적의 수가 많을수록, 그 추정치의 정도가 높아지는 경향을 나타내었다. 또한, 양주파수에서 분포밀도의 추정치는 실제보다 약 30%정도 과소추정되었다.

• 수산해양기술연구
• /
• 제27권1호
• /
• pp.13-20
• /
• 1991

어군의 분포밀도와 초음파산란강도의 관계를 검토하기 위하여, 50kHz의 주파수에서 net cage (농망)에 분포밀도가 기지인 어군을 수용하고, 어군밀도의 변화에 기인하는 echo energy의 변동을 고찰하고, 또 cage 실험에 의해 추정한 어체의 평균적인 반사강도와 개개의 어체를 대상으로 구한 평균반사강도를 상호 비교, 검토한 결과를 요약하면 다음과 같다. 1. cage 실험에 의한 붕어의 평균반사강도는 -41.9dB로서, 이 값은 현장에서 개개의 붕어(마취어, 평균체장 19.1cm)를 대상으로 측정한 평균반사강도 -42.6dB보다 0.7dB 더 컸다. 2. cage내에 수용한 어군의 분포밀도가 증가함에 따라, 어군에 의한 평균체적산란강도는 직선적으로 증가하는 경향을 나타내었다. 즉, 어군밀도가 7, 13, 20, 26, 39, 52, 66 마리/m 상(3)였을 때, 각각의 어군에 의한 평균체적산란강도는 -33.0, -28.9, -27.6, -24.3, -25.1, -23.6, -22.1dB이었다. 3. 어군밀도 $\rho(마리/m$ 상(3))와 평균체적산란강도 (dB)와의 사이에는 다음의 관계식이 성립하였다. =-41.9+11.0 $Log(\rho),$ r=0.97 이 식에 회귀직선의 기울기 11은 이론적인 값 10에 거의 근사하였다.

• Journal of Ginseng Research
• /
• 제31권2호
• /
• pp.109-116
• /
• 2007

Korean red ginseng has broad efficacious effects against hypertension, diabetes, nociception, and cancer, and it counteracts weakness. It has been reported that Korean red ginseng is able to normalize blood pressure, improve cholesterol and lower blood glucose levels. We have recently reported that Korean red ginseng extract (KRGE) significantly prevented rat carotid arterial thrombosis in vivo, and inhibited platelet aggregation ex vivo and in vitro in a dose-dependent manner. The purpose of this study was to examine the effects of KRGE on blood circulation in human by measuring ex vivo platelet aggregation, plasma coagulation and serum lipid profiles in healthy volunteers. Subjects were randomly divided into three groups (placebo-group, KRGE-low dose group, KRGE-high dose group). Administration of KRGE to subjects significantly inhibited ADP-induced platelet aggregations both in KRGE-low dose group from $72.79{\pm}20.53$ to $62.00{\pm}23.06%$ (p=0.0009), and in KRGE-high dose group from $75.14{\pm}21.86$ to $64.52{\pm}24.72%$ (p=0.0039), respectively. Administration of KRGE to subjects also significantly inhibited collagen-induced platelet aggregations both in KRGE-low dose group from $85.52{\pm}12.57$ to $79.62{\pm}20.47%$ (p=0.0916), and in KRGE-high dose group from $80.24{\pm}18.11$ to $70.31{\pm}25.93%$ (p=0.0565), respectively. Whereas, KRGE has no significant effects on coagulation system, such as prothrombin time (PT) and activated partial thromboplastin time (APTT), and serum lipid profiles, such as total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol and triglyceride. KRGE also has no significant effects on hematological and serum biochemical profiles. These results suggest that KRGE has a potential to improve blood circulation through antiplatelet activity in human, and KRGE intake may be beneficial for the individuals with high risks of thrombotic and cardiovascular diseases.

• 한국응용과학기술학회지
• /
• 제26권1호
• /
• pp.102-108
• /
• 2009

Behaviors of saturated fatty acid halides (CI4, C16, C18) were measured by LB method when the molecules were stimulated by pressure. The saturated fatty acid halides were deposited on the indium tin oxide(lTO) glass by the LB method. The average organic ultra thin film size and the surface roughness of the fatty acid halides thin films were investigated using AFM. It was found that AFM images show small surface roughness ($2.5{\sim}5.0\;nm$) and the organic ultra thin film size of $2.5{\sim}12\;nm$. Both aggregations and pin-holes were also seen on the AFM images. However we found that the surface roughness. These effects seem to be reasonable to be related to the increase of the organic ultra thin film size of fatty acid halides.

• 한국세라믹학회지
• /
• 제31권8호
• /
• pp.911-919
• /
• 1994

As the study for preparation of single-layer anti-reflective coating on glass, the conditions of synthesis of sol for coating and of reproducible coating procedure were investigated. In case of water-based sol, coating was impossible because of poor wettability of sol. The Substitution of solvent with ethanol improved the wettability of sol on the glass surface, and optimum amount of ethanol for substitution was 70 vol%. Maximum specific surface area and total pore volume of water-based sol were 268.7$m^2$/g and 0.315 cc/g, but after substitution, those values increased to 404.1 $m^2$/g and 0.376 cc/g, respectively. The upper limit withdrawl speed of coating in order to get clean coated films without aggregations or stains was 7 cm/min. In case of addition of 0.1 mol HNO3 and substitution with 70 vol% ethanol and heat-treatment at 40$0^{\circ}C$ for 1 hour, thin film with thickness of 94 nm was obtained at withdrawl speed of 4 cm/min. The thickness of thin film was independent of drying time.

• Biomolecules & Therapeutics
• /
• 제23권2호
• /
• pp.149-155
• /
• 2015

Our previous study demonstrated that yuzu has an anti-platelet effect in rat blood. In the present study, we examined whether the anti-platelet effect of yuzu can be extended to human blood by investigating its ability to inhibit aggregations induced by various agonists in human platelet rich plasma (PRP). This study also investigated the underlying mechanism of yuzu focusing on ADP granule secretion, $TXB_2$ formations, and $PLC{\gamma}$/Akt signaling. The results from this study showed that ethanolic yuzu extract (YE), and its components, hesperidin and naringin, inhibited human platelet aggregation in a concentration-dependent manner. YE, hesperidin and naringin also inhibited $TXB_2$ formation and ADP release. The phosphorylation of $PLC{\gamma}$ and Akt was significantly inhibited by YE, heperidin and naringin. Furthermore, we demonstrated that YE, heperidin and naringin has anti-platelet effects in rat ex vivo studies, and lower side effects in mice tail bleeding time studies. The results from this study suggest that YE, hesperidin and naringin can inhibit human platelet aggregation, at least partly through the inhibition of $PLC{\gamma}$ and Akt, leading to a decrease in $TXB_2$ formation and granule secretion.

• 환경생물
• /
• 제21권3호
• /
• pp.240-244
• /
• 2003

Conidia of molds within the Asian dust were captured in the ambient air of mid-west Korea, in springtime of 2000~2002. An eight-stage Cascade impactor and 0.22 $\mu\textrm{m}$ pore size membrane filters were used for the dust samples. Several kinds of molds grown from the samples were identified to the genus level. Those are Aspergillus, Basipetospora, Epicoccum, Fusarium, Monotospora and Penicillium. Relatively diversified mycelia of hyphomycetes were grown on the fine dust sample (1.1~2.1 $\mu\textrm{m}$) in the first year Asian dust episode (23~24 March, 2000). On the other hand, some fluffy molds and dark molds aggregations were grown on even the backup particle sample less than 0.43 $\mu\textrm{m}$ during the second year episode (24~26 April, 2001). The result of the last year episode (21~22 March, 2002) showed various mycelia grown on the sample contained from 1.1 to 2.1 $\mu\textrm{m}$ sized particles, just like the result of the first year episode (23~24 March, 2000). These variations between the episodes might be caused by the difference of the dust origins.

• 정보과학회 논문지
• /
• 제42권6호
• /
• pp.781-790
• /
• 2015

인터넷과 모바일 환경의 발전에 따라 최근에는 마이크로블로그가 성행하고 있다. 마이크로블로그에는 부가적인 데이터가 담겨있다. 그 중 위치 정보에 대한 데이터를 포함하는 마이크로블로그 데이터를 공간 소셜 웹 객체라고 지칭한다. 이러한 마이크로블로그 데이터에 대한 일반 집계는 사용자별 데이터 집계 등이 있으나, 단일 정보에 대한 집계만 가능하다. 본 연구는 공간 소셜 웹 객체의 특성을 갖는 마이크로블로그 데이터의 공간 소셜 분석을 위해, 일반 집계와 공간 데이터를 결합하고 지오해시와 맵리듀스를 이용한 공간 집계에 대한 알고리즘을 제시한다. 이를 통해 의미있는 공간 소셜에 대한 분석의 기반을 마련하였다.