• Journal of Pharmaceutical Investigation
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• 제36권3호
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• pp.169-174
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• 2006

The aim of this work was to prepare tenoxicam-ethanolamine salt with improved physicochemical properties for transdermal application. Tenoxicam-ethanolamine salt was prepared in methylene chloride and its physicochemical properties were investigated by DSC and FT-lR. The broad peak of tenoxicam around 3600-3200 $cm^-1$ was shifted to lower wavenumber and more broadened. The characteristic endothermic melting peak of tenoxicam appeared at $223^{\circ}C$. The melting peak of tenoxicam-ethanolamine salt was shifted to $159^{\circ}C$. In contrast to relatively small difference in the partition coefficients of tenoxicam and the tenoxicam-ethanolamine salt, large difference in aqueous solubility was observed. $Crovol^{\circledR}$ PK4O (PEG-12 palm kernel glycerides) provided the highest skin flux for both compounds. The order of the enhancing effect of the various vehicles tested was similar for tenoxicam and tenoxicam-ethanolamine salt, which indicated that their enhancing mechanism for tenoxicam and tenoxicam-ethanolamine salt is similar. Tenoxicam-ethanolamine salt had a higher skin flux than tenoxicam by 1.2- to 31.7-fold, depending on the vehicles used. It is suggested that the vehicles with medium HLB value, 1 double bond, and lower ethylene oxide chain length have a better ability to modify the permeability of the stratum corneum and to promote the effective penetration of tenoxicam and tenoxicam-ethanolamine salt.

• Earthquakes and Structures
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• 제6권1호
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• pp.89-110
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• 2014

Nonlinear dynamic analyses are carried out to investigate the influence of the pinching hysteretic response of the exterior RC beam-column joints on the seismic behavior of multistory RC frame structures. The effect of the pinching on the local and global mechanisms of an 8-storey bare frame and an 8-storey pilotis type frame structure is evaluated. Further, an experimental data bank extracted from literature is used to acquire experimental experience of the range of the real levels that have to be considered for the pinching effect on the hysteretic response of the joints. Thus, three different cases for the hysteretic response of the joints are considered: (a) joints with strength and stiffness degradation characteristics but without pinching effect, (b) joints with strength degradation, stiffness degradation and low pinching effect and (c) joints with strength degradation, stiffness degradation and high pinching effect. For the simulation of the beam-column joints a special-purpose rotational spring element that incorporates the examined hysteretic options developed by the authors and implemented in a well-known nonlinear dynamic analysis program is employed for the analysis of the structural systems. The results of this study indicate that the effect of pinching on the local and global responses of the examined cases is not really significant at early stages of the seismic loading and especially in the cases when strength degradation in the core of exterior joint has occurred. Nevertheless in the cases when strength degradation does not occur in the joints the pinching may increase the demands for ductility and become critical for the columns at the base floor of the frame structures. Finally, as it was expected the ability for energy absorption was reduced due to pinching effect.

• Applied Biological Chemistry
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• 제25권4호
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• pp.224-231
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• 1982

liposome에 결합되어 있는 ${\alpha}-Tocopherol$의 형광을 이용하여 liposome의 상전이온도를 측정할 수 있었다. 이는 ${\alpha}-Tocopherol$의 vitamin E로서의 중요성 이외에 형광성 프로브로서의 새로운 가치의 발견이다. 형광성 프로브로서 그 응용의 확대를 위한 필수적인 기초자료의 수집을 위해, 분자분광학적성질을 조사하였다. 용액중의 ${\alpha}-Tocopherol$은 monomer와 dimer의 두가지 형태로 존재하며, 단파장흡수대$(291{\sim}294nm)$의 monomer는 형광성인데 반하여 dimer는 298nm 부근을 흡수하는 비형광성이고 분자간수소결합에 의하여 형성되었음이 밝혀졌다. liposome에 결합된 ${\alpha}-Tocopherol$은 각종 유기용매 중에서의 ${\alpha}-Tocopherol$과는 판이한 형광성질을 갖고 있었고 chromanolate이온형태의 화학종으로부터 생긴 것으로 해석되었다.

• 대한방사성의약품학회지
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• 제6권1호
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• pp.20-26
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• 2020

Accelerator mass spectrometry (AMS) is a powerful detection technique with the exquisite sensitivity and high precision compared with other traditional analytical techniques. Accelerator mass spectrometry can be widely applied in the technique of radiocarbon dating in the fields of archeology, geology and oceanography. The ability of accelerator mass spectrometry to measure rare ¹⁴C concentrations in microgram and even sub-microgram amounts suggests that extension of ¹⁴C-accelerator mass spectrometry to biomedical field is a natural and attractive application of the technology. Drug development processes are costly, risky, and time consuming. However, the use of ¹⁴C-accelerator mass spectrometry allows absorption, distribution, metabolism and excretion (ADME) studies easier to understand pharmacokinetics of drug candidates. Over the last few decades, accelerator mass spectrometry and its applications to preclinical/clinical trials have significantly increased. For accelerator mass spectrometry analysis of biological samples, graphitization processes of samples are important. In this paper, we present a detailed sample preparation procedure to apply to graphitization of biological samples for accelerator mass spectrometry.

• 한국전자파학회논문지
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• 제19권9호
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• pp.1051-1057
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• 2008

본 논문에서는 연자성 금속 분말인 sendust를 flake화 과정을 통하여 형상과 입도를 변화시켜 전파 흡수체를 제작하고, 그 특성을 분석하였다. 먼저 attrition milling에 의해 입도를 달리한 세 종류의 flake sendust 분말과 지지 재인 CPE(Chlorinated Polyethylene)를 이용하여 전파 흡수체를 제작하고, 이 전파 흡수체로부터 재료 정수를 계산하여 입도에 따른 변화를 조사한 후 전파 흡수능을 측정하여 비교 분석하였다. 그 결과 평균 입도가 $140{\mu}m$인 flake sendust 분말로 제작된 전파 흡수체가 와전류 손실의 감소(복소비 투자율 증가)와 입자간의 정전 용량의 증가(복소비 유전율 증가)에 기인하여 고주파 대역에서 우수한 전파 흡수능을 보임을 확인하였다.

• 한국어류학회지
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• 제17권2호
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• pp.105-111
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• 2005

A. signifer의 숙주 조개인 U. douglasiae sinuolatus 각 장이 30~45 mm에서 대부분의 알과 자어가 발견되었으며, 각장이 30 mm 이상에서는 크기에 따른 선택성의 차이는 없었다. 조개 내에서 발견된 난 및 전기자어의 수는 1~7개(마리)이었으며, 난 또는 자어의 보유율은 1개(마리)가 50.0%로 가장 높았고, 조개 1개체 당 평균 보유수는 2.5개 (마리)였다. A. signifer의 전기자어는 조개내에서 유영능력을 갖추면 상새방으로 이동하였으며, 상새방에서 성장기간은 4~6주 정도로 추정되었다. 전기자어의 표피상 돌기는 부화 직후부터 관찰되었다. 부화 7일째부터 표피상돌기의 흡수가 진행되기 시작하였으며, 부화 13일째부터 대부분의 표피상돌기는 흡수되었고, 난황이 완전히 흡수된 직후인 부화 20일 후에는 표피상돌기가 완전히 흡수되었다.

• Computers and Concrete
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• 제19권3호
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• pp.233-241
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• 2017

During the last two decades, CFRP have been extensively used for repair and rehabilitation of existing structures as well as in new construction applications. For rehabilitation purposes CFRP are currently used to increase the load and the energy absorption capacities and also the shear strength of concrete columns. Thus, the effect of CFRP confinement on the strength and deformation capacity of concrete columns has been extensively studied. However, the majority of such studies consider empirical relationships based on correlation analysis due to the fact that until today there is no general law describing such a hugely complex phenomenon. Moreover, these studies have been focused on the performance of circular cross section columns and the data available for square or rectangular cross sections are still scarce. Therefore, the existing relationships may not be sufficiently accurate to provide satisfactory results. That is why intelligent models with the ability to learn from examples can and must be tested, trying to evaluate their accuracy for composite compressive strength prediction. In this study the forecasting of wrapped CFRP confined concrete strength was carried out using different Data Mining techniques to predict CFRP confined concrete compressive strength taking into account the specimens' cross section: circular or rectangular. Based on the results obtained, CFRP confined concrete compressive strength can be accurately predicted for circular cross sections using SVM with five and six input parameters without spending too much time. The results for rectangular sections were not as good as those obtained for circular sections. It seems that the prediction can only be obtained with reasonable accuracy for certain values of the lateral confinement coefficient due to less efficiency of lateral confinement for rectangular cross sections.

• 대한한방종양학회지
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• 제9권1호
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• pp.99-108
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• 2003

Recently, the proportion of the population older has increased rapidly. As the aged population is increasing, the prevalence of malignancy rises with age, too. We believe that the potential benefits of approach to cancer care in the elderly are self-evident. In order to investigate the characteristics of cancer in the elderly, we reviewed literature related with the biology of the aged with cancer. The elderly undergo age-related changes in their physiology which may result in altered tolerance to disease and to the requirements of the management of illness. The possible reasons for the increased prevalence of cancer in the elderly are a longer potential duration of exposure to carcinogens, a reduced ability of repair DNA and reduced host defences against malignancy. In general, cancer patients in the elderly have a shorter survival. Because it is impossible to offer the active treatment of cancer in the elderly. Also, they have the problems that the psychosocial change and reduce of physiological function such as absorption, metabolism and excretion. We hope that other groups will further research cancer in the elderly in future.

• 폴리머
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• 제28권2호
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• pp.194-200
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• 2004

돼지의 소장 점막하 조직은 면역반응이 없는 재료로 널리 사용되고 있다. 본 연구에서는 소장 점막하 조직을 1-ethyl-(3,3-dimethyl aminopropyl) carboimide hydrochloride(EDC)를 이용하여 경화시켰으며 동시에 스폰지 형태로 제조하여 조직공학적 담체와 상처 드레싱재료로서의 응용 가능성을 검토하였다. 다세포 구성분을 제거한 소장 점막하 조직 분말을 3% 아세트산에 용해하여 일정한 형태의 몰드 내에 붓고 동결 건조하였다 이 소장 점막하 조직 스폰지를 여러 농도의 EDC용액에 침지하여 가교반응을 실시하였다 이를 전자주사 현미경, 시차 주사열량계, 적외선 분광분석기, 다공도 테스트 및 흡수성 실험을 수행하여 특성을 결정하였다. 소장 점막하 조직 스폰지는 경화제의 농도가 50mM 이상에서 물리적 특성이 우수한 것으로 판단되었다. 일련의 실험을 통하여 경화된 소장 점막하 조직 스폰지가 조직공학적 담체와 상처치료 드레싱재료로 유용하게 사용될 수 있음을 확인하였다.

• 한국미생물·생명공학회지
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• 제41권1호
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• pp.60-69
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• 2013

Purified melanin pigment from Klebsiella sp. GSK was characterized by thermogravimetric, differential thermal, X-ray diffraction and elemental analysis. This melanin pigment is structurally amorphous in nature. It is thermally stable up to $300^{\circ}C$ and emits a strong exothermic peak at $700^{\circ}C$. Its carbon, hydrogen and nitrogen composition is 47.9%, 6.9% and 12.0%, respectively. It was used to scavenge metal ions and free radicals. After immobilizing the pigment and using it to adsorb copper and lead ions, the metal ion adsorption capacity was evaluated by atomic absorption spectroscopy (AAS) and the identity of melanin functional groups involved in the binding of metal ions was determined by Fourier transform infrared (FT-IR) spectroscopy. Batch adsorption studies showed that 169 mg/g of copper and 280 mg/g of lead were adsorbed onto melanin-alginate beads. The metal ion adsorption capacity of the melanin-alginate beads was relatively significant compared to alginate beads. The metal ion desorption capacity of HCl was greater (81.5% and 99% for copper and lead, respectively) than that of EDTA (80% and 71% for copper and lead, respectively). The ability of the melanin pigment to scavenge free radicals was evaluated by inhibition of the oxidation of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and was shown to be about 74% and 98%, respectively, compared with standard antioxidants.