Identification of interpolymorph transformations of progesterone by terahertz time-domain spectroscopy

Yeon Joo Son,이동규,Joo-Hiuk Son 한국물리학회 2016 Current Applied Physics Vol.16 No.1

We utilized the terahertz time-domain spectroscopy system to differentiate the two polymorphs of progesterone and to identify the occurrence of interpolymorph transitions. The stable polymorph of progesterone was prepared by ethanol-mediated evaporating/cooling methods, and the metastable state was obtained by using pregnenolone as an additive. These two polymorphs show distinct different absorption spectrum in the terahertz region. As the metastable state of progesterone naturally converted to the stable state over time, the absorption mode of the metastable state disappeared and those of the stable state re-emerged. Interpolymorph transformations of progesterone can be rapidly identified using an apparent absorption mode as an indicator, which represents the existence of the metastable state of progesterone.

Principle and applications of terahertz molecular imaging

IOP Pub 2013 Nanotechnology Vol.24 No.21

<P>The principle, characteristics and applications of molecular imaging with terahertz electromagnetic waves are reviewed herein. The terahertz molecular imaging (TMI) technique uses nanoparticle probes to achieve dramatically enhanced sensitivity compared with that of conventional terahertz imaging. Surface plasmons, induced around the nanoparticles, raise the temperature of water in biological cells, and the temperature-dependent changes in the optical properties of water, which are large in the terahertz range, are measured differentially by terahertz waves. TMI has been applied to cancer diagnosis and nanoparticle drug delivery imaging. The technique is also compared with magnetic resonance imaging by using a dual-modality nanoparticle probe.</P>

Terahertz electromagnetic interactions with biological matter and their applications

American Institute of Physics 2009 JOURNAL OF APPLIED PHYSICS - Vol.105 No.10

4-Acetoxyscirpendiol of Paecilomyces tenuipes Inhibits Na+/D-Glucose Cotransporter Expressed in Xenopus Laevis Oocytes

( Ocki Yoo ),( Joo Hiuk Son ),( Dong Hee Lee ) 생화학분자생물학회 2005 BMB Reports Vol.38 No.2

Cordyceps, an entomopathogenic fungus, contains many health-promoting ingredients. Recent reports indicate that the consumption of cordyceps helps reduce blood-sugar content in diabetics. However, the mechanism underlying this reduction in circulatory sugar content is not fully understood. Methanolic extracts were prepared from the fruiting bodies of Paecilonlyces tenuipes, and 4-beta acetoxyscirpendiol (4-ASD) was eventually isolated and purified. Na+/Glucose transporter-1 (SGLT 1) was expressed in Xenopus oocytes, and the effect of 4-ASD on SGLT 1 was analyzed utilizing a voltage clamp and by performing 2-deoxy-D-glucose (2-DOG) uptake studies. 4-ASD was shown to significantly inhibit SGLT 1 activity compared to the non-treated control in a dose-dependent manner. In the presence of the derivatives of 4-ASD (diacetoxyscirpenol or 15-acetoxyscirpendiol), SGLT-1 activity was greatly inhibited in an 4-ASD-like manner. Of these derivatives, 15-acetoxyscirepenol inhibited SGLT-1 as well as 4-ASD, whereas diacetoxyscirpenol was slightly less effective. Taken together, these results strongly indicate that 4-ASD in P tenuipes may lower blood sugar levels in the circulatory system. We conclude that 4-ASD and its derivatives are effective SGLT 1 inhibitors.

Enhancement of terahertz reflection tomographic imaging by interference cancellation between layers

Park, Hochong,Son, Joo-Hiuk,Ahn, Chang-Beom The Optical Society 2016 Optics express Vol.24 No.7

4-Acetoxyscirpendiol of Paecilomyces tenuipes Inhibits Na⁺/D-Glucose Cotransporter Expressed in Xenopus laevis Oocytes

Yoo, Oc-Ki,Son, Joo-Hiuk,Lee, Dong-Hee Korean Society for Biochemistry and Molecular Biol 2005 Journal of biochemistry and molecular biology Vol.38 No.2

Cordyceps, an entomopathogenic fungus, contains many health-promoting ingredients. Recent reports indicate that the consumption of cordyceps helps reduce blood-sugar content in diabetics. However, the mechanism underlying this reduction in circulatory sugar content is not fully understood. Methanolic extracts were prepared from the fruiting bodies of Paecilomyces tenuipes, and 4-beta acetoxyscirpendiol (4-ASD) was eventually isolated and purified. $Na^+$/Glucose transporter-1 (SGLT-1) was expressed in Xenopus oocytes, and the effect of 4-ASD on SGLT-1 was analyzed utilizing a voltage clamp and by performing 2-deoxy-D-glucose (2-DOG) uptake studies. 4-ASD was shown to significantly inhibit SGLT-1 activity compared to the non-treated control in a dose-dependent manner. In the presence of the derivatives of 4-ASD (diacetoxyscirpenol or 15-acetoxyscirpendiol), SGLT-1 activity was greatly inhibited in an 4-ASD-like manner. Of these derivatives, 15-acetoxyscirepenol inhibited SGLT-1 as well as 4-ASD, whereas diacetoxyscirpenol was slightly less effective. Taken together, these results strongly indicate that 4-ASD in P. tenuipes may lower blood sugar levels in the circulatory system. We conclude that 4-ASD and its derivatives are effective SGLT-1 inhibitors.

Numerical Model for Cerebrovascular Hemodynamics with Indocyanine Green Fluorescence Videoangiography

Hwayeong Cheon,Young Je Son,Sung Bae Park,Pyoung-Seop Shim,Joo-Hiuk Son,Hee-Jin Yang 대한신경외과학회 2023 Journal of Korean neurosurgical society Vol.66 No.4

Objective : The use of indocyanine green videoangiography (ICG-VA) to assess blood flow in the brain during cerebrovascular surgery has been increasing. Clinical studies on ICG-VA have predominantly focused on qualitative analysis. However, quantitative analysis numerical modelling for time profiling enables a more accurate evaluation of blood flow kinetics. In this study, we established a multiple exponential modified Gaussian (multi-EMG) model for quantitative ICG-VA to understand accurately the status of cerebral hemodynamics. Methods : We obtained clinical data of cerebral blood flow acquired the quantitative analysis ICG-VA during cerebrovascular surgery. Varied asymmetric peak functions were compared to find the most matching function form with clinical data by using a nonlinear regression algorithm. To verify the result of the nonlinear regression, the mode function was applied to various types of data. Results : The proposed multi-EMG model is well fitted to the clinical data. Because the primary parameters—growth and decay rates, and peak center and heights—of the model are characteristics of model function, they provide accurate reference values for assessing cerebral hemodynamics in various conditions. In addition, the primary parameters can be estimated on the curves with partially missed data. The accuracy of the model estimation was verified by a repeated curve fitting method using manipulation of missing data. Conclusion : The multi-EMG model can possibly serve as a universal model for cerebral hemodynamics in a comparison with other asymmetric peak functions. According to the results, the model can be helpful for clinical research assessment of cerebrovascular hemodynamics in a clinical setting.

Frequency-dependent characteristics of terahertz radiation on the enamel and dentin of human tooth

Sim, Yookyeong Carolyn,Maeng, Inhee,Son, Joo-Hiuk Elsevier 2009 Current Applied Physics Vol.9 No.5

<P><B>Abstract</B></P><P>The accurate terahertz (THz) electrical and optical properties of biomaterials are required as the biological applications of THz electromagnetic waves were recently increased. The frequency-dependent characteristics of enamel and dentin of human tooth were measured in this study through THz time-domain spectroscopy. The power absorptions of enamel and dentin were found to be similar while the index of refraction of enamel was found to be bigger than that of dentin. The power absorption results of enamel and dentin were also compared with those of the wet samples.</P>

Pre- and post-processing for tomographic reconstruction of terahertz time-domain spectroscopy

Hong, Hye-Jin,Park, Jinho,Park, Hochong,Son, Joo-Hiuk,Ahn, Chang-Beom The Optical Society 2013 Optics express Vol.21 No.17

테라헤르츠 분광학을 이용한 중수(D₂O)와 경수(H₂O) 혼합물의 특성연구

정중건,손주혁,Chong, Joong-Gun,Son, Joo-Hiuk 한국광학회 2008 한국광학회지 Vol.19 No.6

중수($D_2O$, 산화중수소)는 수소원자(H)보다 중성자 한 개가 더 많은 수소원자 동위원소(D)로 이루어진 물이다. 중수는 자연 상태의 물 가운데 5만분의 1정도 존재하며 경수($H_2O$)와 매우 비슷한 성질을 가지고 있으나 경수보다 11%정도 무겁고, 특이점은 235 K로 228 K인 경수와 약간의 차이를 가진다. 중수는 중성자를 흡수하여 원자로의 중성자 감속재로 쓰이고 최근 중수 농도에 따라 세포에 미치는 독성효과가 다르게 나타나는 현상이 발견 되어 암 치료에 사용하려는 연구가 진행되고 있다. 우리는 테라헤르츠 시간축 분광학을 이용하여 경수와 중수 혼합물의 농도별 굴절률과 흡수율 변화를 거대 분자간 결합에너지 영역을 포함하는 테라헤르츠 영역 ($0{\sim}2.5\;THz$)에서 측정하여 중수의 비율이 높을수록 굴절률은 감소하고 흡수율 또한 감소하는 결과를 얻었다. D2O, which is used in nuclear power generation, is slightly different from $H_2O$. $D_2O$ consists of deuterium (D), which is an isotope of hydrogen (H) and has one more neutron than H. $D_2O$ is heavier by about 11% than $H_2O$, and $D_2O$ is present in water in natureat about 0.002%. Its melting point and boiling point are $3.81^{\circ}C$ and $101.42^{\circ}C$, respectively. $D_2O$ is harmful to the human body if it replaces water in the human body by more than $25%{\sim}50%$. We have measured the index of refractive and power absorption of 0%, 25%, 50%, 75%, and 100% of $D_2O$ in $H_2O$ using terahertz time-domain spectroscopy, and we have found that the refractive index decreases and power absorption also decreases as the concentration of $D_2O$ increases.