• 대한의용생체공학회:의공학회지
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• 제20권4호
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• pp.471-477
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• 1999

전기자극을 이용한 청각시스템의 진단 및 치료방법에 대하여 많은 연구가 수행되어 왔으나 전기자극이 청각 시스템을 통하여 전달되어지는 과정에 대한 이해가 부족하였기 때문에 표준화된 방법이나 이론적인 배경이 없이 자극조건이 선택되어져 왔다. 따라서 본 연구에서는 실험동물에 이명을 유발시킨 상태에서 전기자극이 어떠한 영향을 미치는 가를 ABRrhk ECochG의 변화를 통해서 관찰하고자 한다. 본 연구에서는 9마리의 guinea pig를 Jastreboff 이명 유발 모델에 다라 salicylate를 이용하여 이명을 유발시킨후 전기자극을 가한 5마리를 실험군(A) 으로하고, 대조군(B)으로는 전기자극을 가하지 않은 4마리의 guinea pig를 대상으로 실험을 실시하였다. 실험조건은 이명유발 이전과 이명유발 1시간, 6시간, 12시간 후로 구분하였고, 각 실험조건에서 ABR과 ECochG를 검출하여 각 파형을 rms 값을 기준으로 정규화한 후 자기상관계수를 계산하여 전기자극을 인가하였을 때의 값들의 변화를 관찰하였다. 그 결과 ABR의 경우에는 이명이 유발된 상태에서 6시간 이후의변수 갑싱 급격히 증가하였다가 12시간이 되면서 최초의 상태로 돌아가고, 전기자극을 인가하였을 때는 이명유발 이전 상태에서의 값을 계속 유지하고 있었다. 그리고, ECochG의 경우에는 전기자극의 효과가 12시간 이후에 나타남을 확인하였다. 즉, 본 실험을 통하여 이명유발 모델에 전기자극을 인가하였을 때의 효과를 ABR과 ECochG 상관분석을 통하여 확인하였다.

• 대한의생명과학회지
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• 제5권1호
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• pp.17-26
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• 1999

Mar (multiple-antibiotic-resistance) 대장균의 marRAB 돌연변이가 그람음성 세균들 사이로 전파 될수 있는지를 알아보기 위해서, 염색체 위의 marRAB 돌연변이를 $\lambda$placMu9 (Km$^{r}$)를 이용하여 대장균의 다른 균주내의 pUC19 (Lac$^{+}$, Ap$^{r}$)의 클로닝 사이트, S. typhimurium 및 P. aeruginosa의 염색체 위로 각각 전달시킨 후, Mar phenotype, Km$^{r}$, Lac$^{-}$, 혹은 Ap$^{r}$ 균주를 선택한 다음, salicylate (SAL)의 유도 (induction) 유무에 따른 항생제 내성검사를 실시하였다. pUC19의 보유 유무에 관계없이 대조군인 야생형 대장균 JM109, NM522에 비해서, pUC19::marRAB 돌연변이를 가진 JM109 혹은 NM522의 대부분 균주들은 항생제 내성 수준들이 훨씬 더 높았으며, Mar표현형의 유도도 SAL에 의해서 훨씬 더 높게 나타났다. 하지만 일부 소수의 항생제에 대해서는 예외적으로 내성 수준이 더 낮게 나타났는데, 야생형 JM109 균주에서는 chloramphenicol (Cm)과 tetracycline (Tc)이 , pUC19::marRAB 돌연변이를 가진 NM522 균주 에서는 Tc와 ciprofloxacin (Cp)에 대한 내성 수준이 각각 더 낮게 나타났다. S. typhimurium 및 P. aeruginosa에 대한 같은 실험의 결과도 야생형 대장균의 경우와 거의 대부분 일치하였다. 형질전환 (transformation)과 형질도입 (transduction)의 방법을 주로 사용한 이 실험의 결과는, marRAB 돌연변이가 그람음성 세균들 사이로 전파될 수 있음을 간접적으로 암시한다.

• Bulletin of the Korean Chemical Society
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• 제32권3호
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• pp.1000-1006
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• 2011

The discovery of carbohydrate-based bioactive compounds has recently received considerable interest in the drug development. This paper stresses on the application of 1-methoxy-O-glucoside as the central scaffold, whereas salicylic pharmacophores were introduced with diverse spatial orientations probing into the structural preference of an enzymatic target, i.e. protein tyrosine phosphatase 1B (PTP1B). By employing regioselective protection and deprotection strategy, 2,6-, 3,4-, 4,6- and 2,3-di-O-propynyl 1-methoxy-O-glucosides were previously synthesized and then coupled with azido salicylate via click chemistry in forming the desired bidentate salicylic glucosides with high yields. The inhibitory assay of the obtained triazolyl derivatives leads to the identification of the 2,3-disubstituted salicylic 1-methoxy-O-glucoside as the structurally privileged PTP1B inhibitor among this bidentate compound series with micromole-ranged $IC_{50}$ value and reasonable selectivity over other homologous PTPs tested. In addition, docking simulation was conducted to propose a plausible binding mode of this authorized inhibitor with PTP1B. This research might furnish new insight toward the construction of structurally different bioactive compounds based on the monosaccharide scaffold.

• 한국식품저장유통학회지
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• 제23권7호
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• pp.977-988
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• 2016

제주감귤류(천혜향, 한라봉, 진지향, 황금향 및 레드향)의 휘발성 향기성분을 분석하기 위하여 SDE 방법으로 휘발성 화합물을 추출한 후 GC/MS로 확인하였다. 천혜향의 휘발성 향기성분은 104종(4,939.77 mg/kg), 한라봉 98종(3,286.38 mg/kg), 진지향 105종(3,317.56 mg/kg), 황금향 102종(4,293.39 mg/kg) 및 레드향 108종(4,049.94 mg/kg)으로 확인되었다. Limonene, sabinene, ${\beta}$-myrcene, ${\alpha}$-pinene, ${\beta}$-pinene, linalool, 4-terpineol, ${\alpha}$-terpineol, (E)-${\beta}$-ocimene 및 ${\gamma}$-terpinene 등은 제주감귤류의 공통적인 주요 향기로 확인 되었다. Ethyl-benzene, nonanol, 1-p-menthen-9-al, (E)-isocarveol, methyl salicylate, ${\alpha}$-terpinen-7-al, perilla alcohol 및 ethyl dodecanoate은 천혜향에서만 확인된 휘발성 향기 성분이다. ${\beta}$-Chamigrene 및 ${\alpha}$-selinene은 한라봉에서만 확인되었으며, 3-hydroxybutanal, (E)-2-nonenal, isoborneol, octyl acetate, (E)-2-undecenal, ${\beta}$-ylangene 및 guaia-6,9-diene은 진지향에서만 확인되었다. ${\rho}$-Cymenene, ${\beta}$-thujone, selina-4,11-diene 및 (E,E)-2,6- farnesol은 황금향에서만 확인되었으며, ${\rho}$-cymen-8-ol, bornyl acetate, carvacrol, bicyclo elemene, ${\alpha}$-cubebene 및 7-epi-${\alpha}$-selinene 등은 레드향에서만 확인된 향기성분이다. Limonene은 제주감귤류의 휘발성 향기성분 중 가장 많은 함량으로 확인되었으며, 비율은 42.57%~62.18%이다. 본 연구결과 제주감귤류의 품종에 따른 휘발성 향기성분 함량과 조성의 차이를 확인할 수 있었다.

• Journal of Pharmaceutical Investigation
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• 제29권3호
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• pp.227-234
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• 1999

Solid dispersions were prepared to increase the dissolution rate of biphenyl dimethyl dicarboxylate (DDB) using water-soluble carriers such as povidone, copolyvidone, $2-hydroxypropyl-{\beta}-cyclodextrin (HPCD)$, sodium salicylate or sodium benzoate by solvent evaporation method. Solid dispersions were characterized by infrared spectrometry, differential scanning calorimetry (DSC) and powder X-ray diffractometry, dissolution and permeation studies. DDB tablets (7.5 mg) were prepared by compressing the powder mixtures composed of solid dispersions, lactose, com starch, crospovidone and magnesium stearate using a single-punch press. DDB capsules (7.5 mg) were also prepared by filling the mixtures in empty hard gelatin capsules (size No.1). From the DSC and powder x-ray diffractometric studies, it was found that DDB was amorphous in the HPCD or copolyvidone solid dispersions. Dissolution rates after 10 min of DDB alone and solid dispersions (1 : 10) in sodium benzoate, sodium salicylate and copolyvidone were 11.8, 23.5, 22.8 and 82.5%, respectively. Dissolution rates of DDB after 30 min from 1 : 10 and 1 : 20 copolyvidone solid dispersions were 80.5 and 95.0%, respectively. For the DDB tablets prepared using solid dispersions (1 : 20), the initial dissolution rate was dependent on carrier material, and was ranked in order, $Kollidon\;30\;{\ll}$ copolyvidone < HPCD. For the HPCD solid dispersion tablets, dissolution rate reached 97.4% after 15 min, but thereafter slowly decreased to 80.7% after 2 hr due to the precipitation of DDB. However, in the case of copolyvidone solid dispersion tablets, dissolution increased linearly and reached 93.4% after 2 hr. Reducing the volume of test medium from 900 to 300 ml markedly decreased the dissolution rate of the tablets containing 1 : 20 HPCD solid dispersions and 1 : 10 copolyvidone solid dispersion. For 1 : 20 copolyvidone solid dispersion tablets, there was no significant change in dissolution rate up to 1 hr with different volumes of test medium. Preparation of the copolyvidone solid dispersion (1 : 20) in capsules markedly delayed the dissolution (31.2 % after 2hr) due to the limited diffusion within capsules. The permeation rate $(13.4\;g/cm^2\;after\;8\;hr)$ of DDB through rabbit duodenal mucosa from copolyvidone solid dispersion (1 : 10) was markedly enhanced, when compared with drug alone or physical mixtures. From overall findings, DDB formulations containing copolyvidone solid dispersions (1 : 20) could be used to remarkably improve the dissolution rate in dosage form of powders and tablets.

• 한국응용과학기술학회지
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• 제31권3호
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• pp.422-439
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• 2014

본 연구에서는 자외선 차단제품에서 오일의 극성도, 에멀젼의 종류, 제품의 점도, 증점제의 종류 그리고 광안정제 등이 자외선 차단 효율에 미치는 영향을 조사해 보았다. 그 결과 오일의 극성도가 높으면 자외선 차단 효과는 높게 측정되었으며(Butyloctyl salicylate: SPF 44.10, PA 7.93), 반대로 오일의 극성도가 낮으면 자외선 차단 효과는 낮게 측정되었다(Dimethicone: SPF 16.40, PA 5.57). 에멀젼의 종류는 O/W 에멀젼보다 유기 자외선 차단제가 외상에 존재하는 W/O 에멀젼에서 자외선 차단 효율이 더 높게 측정되었다. 제품의 점도는 높아질수록 자외선 차단 효율이 비례적으로 상승하는 경향을 나타내었으며, 증점제의 종류 및 유화입자 크기는 자외선 차단 효과에 미치는 영향이 크지 않았다. 또한 광안정제의 함유 여부도 자외선 차단 효율에 영향을 미치는 중요한 인자 중의 하나로 나타났다. 이러한 결과들은 자외선 차단제의 추가적인 증량이 없어도 자외선 차단 효율을 더 높일 수 있음을 의미하는 것으로, 앞으로 자외선 차단제품 개발 시 경제적 효율성을 높이는데 큰 도움이 될 것으로 사료된다.

• Korea-Australia Rheology Journal
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• 제15권3호
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• pp.151-156
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• 2003

In this research, experimental studies were performed to examine the rheological behavior of equimolar solutions of cetylpyridinium chloride (CPyCl) and sodium salicylate (NaSal) solutions with concentration. The surfactant solutions were prepared by dissolving 2 mM/2 mM - 80 mM/80 mM of surfactant/counterion in double-distilled water. It has been observed that the zero shear viscosity shows abrupt changes at two critical values of C^*$ and C^{**}$. These changes are caused by the switching of relaxation mechanism with concentration of CPyCl/NaSal solutions at those concentrations. The wall slip velocities of dilute and semidilute CPyCl/NaSal solutions show a dramatic increase with shear rate where the shear viscosity exhibits shear thickening behavior for dilute solutions and shear thinning behavior for semi-dilute solutions, respectively. Considering that the dramatic increase in wall slip velocity should be related to the formation of shear-induced structure (SIS) in the surfactant solution, the shear thickening behavior of semi-dilute solutions is caused by elastic instability unlike the case of dilute solutions.

• Restorative Dentistry and Endodontics
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• 제13권1호
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• pp.113-120
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• 1988

The purpose of this study was to evaluate and compare the sealing ability of ZOE, FR and AH-26. Seventy two upper and lower anterior and premolor teeth were randomly selected and instrumented in a conventional method with K-file. After instrumentation and dry the canal, the teeth were divided into 3 groups and twenty four teeth in each group were filled with ZOE, FR, and AH-26 respectively. All the specimens were immersed into Indian Ink and decalcified in nitric acid and cleared in methyl salicylate. The apical leakage was evaluated by measuring the degree of ink penetration with caliper at the intervals of 1 day, 7 days and 14 days. The results were as follows; 1. In AH-26 and FR groups, there was increase in penetration related to increased time of immersion in the ink. 2. FR group showed the least penetration in 3 groups. 3. Statistics showed that there was no significant difference among the each sealer groups.

• Journal of Microbiology and Biotechnology
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• 제7권4호
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• pp.250-257
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• 1997

A new sensing system based on the immobilization of luminescent bacteria, photobacterium phosphoreum, was proposed for continuous real-time monitoring of pollutants. The response curves demonstrate that Photobacterium phosphoreum immobilized on the strontium alginate were very sensitive to seven reference chemicals used. The significant inhibitory concentrations for bioluminescence emission were 5 ppm for Pb$(NO_3)_2$), $NiCl_2$, $CdCl_2$, 50 ppm for $NaASO_2$, 0.1 ppm for $HgCl_2$, 0.5 ppm for pentachlorophenol and less than 5 ppm for SDS, respectively. The alginate mixed-cells (AMC) retained their luminescence during experimental period (29 days) under storage condition of $-80^{\circ}C$. The variables affecting performance of continuous flow through monitoring (CFTM) was optimized in order to ensure stability and efficiency. The flow through cell with strontium-alginate immobilized luminescent bacteria was tested with salicylate and 4-nitrophenol. A rapid response of luminescence was recorded by time drive mode in bioluminescence spectrometer after exposure to both toxicants.

• Journal of Pharmaceutical Investigation
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• 제39권1호
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• pp.43-49
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• 2009

Aspirin or acetylsalicylic acid, a member of the salicylate family, is frequently used as an analgesic, antipyretic, anti-inflammatory and antiplatelet drug. Because aspirin is chemically unstable in water and heat for tablet formulation, additives including lubricants are used in preparing aspirin tablets, using a dry-granulation process. Aspirin tablets are produced by a number of manufacturers which usually use their own unique combination of additives during the manufacturing process. In this study, we employed an NMR based metabolomics technique to identify the manufacturers of various aspirin tablets. Aspirin tablets from six different companies were analyzed by 1H 400 MHz NMR. The acquired data was then integrated and processed by principal component analysis (PCA). Based on the NMR data, we were able to identify peaks corresponding to acetylsalicylic acid in all of the six samples, whereas different NMR patterns were found in the aromatic and aliphatic regions depending on the unique additive used. These observations led to the conclusion that the differences in the NMR patterns among the different aspirin tablets were due to the presence of additives.