• Nuclear Medicine and Molecular Imaging
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• v.42 no.5
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• pp.337-346
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• 2008

Applications of nanotechnology in the medical field have provided the fundamentals of tremendous improvement in precise diagnosis and customized therapy. Recent advances in nanomedicine have led to establish a new concept of theragnosis, which utilizes nanomedicines as a therapeutic and diagnostic tool at the same time. The development of high affinity nanoparticles with large surface area and functional groups multiplies diagnostic and therapeutic capacities. Considering the specific conditions related to the disease of individual patient, customized therapy requires the identification of disease target at the cellular and molecular level for reducing side effects and enhancing therapeutic efficiency. Well-designed nanoparticles can minimize unnecessary exposure of cytotoxic drugs and maximize targeted localization of administrated drugs. This review will focus on major pharmaceutical nanomaterials and nanoparticles as key components of designing and surface engineering for targeted theragnostic drug development.

• Journal of the Optical Society of Korea
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• v.15 no.2
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• pp.196-201
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• 2011

Near-field properties of light emanated from a subwavelength double slit of finite length in a thin metal film, which is essential for understanding fundamental physical mechanisms for near-field optical beam manipulations and various potential nanophotonic device applications, is investigated by using a three-dimensional finite-difference time-domain method. Near-field intensity distribution along the propagation direction of light after passing through the slit has been obtained from the phase relation of transverse electric and magnetic fields and the wave impedance. It is found that the near field of emerged light from the both slits is evanescent, that is consistent with conventional surface plasmon localization near the metal surface. Due to the finite of the slit, the amplitude of this evanescent field does not monotonically approach to than of the infinite slit as the slit length increases, i.e. the near-field of the longer slit along the center line can be weaker than that of the shorter one.

• Geomechanics and Engineering
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• v.19 no.1
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• pp.79-91
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• 2019

Renewed interest in the long-term pile foundations has been driven by the increase in offshore wind turbine installation to generate renewable energy. A monopile subjected to repetitive loads experiences an evolution of displacements, pile rotation, and stress redistribution along the embedded portion of the pile. However, it is not fully understood how the embedded pile interacts with the surrounding soil elements based on different pile geometries. This study investigates the long-term soil response around offshore monopiles using finite element method. The semi-empirical numerical approach is adopted to account for the fundamental features of volumetric strain (terminal void ratio) and shear strain (shakedown and ratcheting), the strain accumulation rate, and stress obliquity. The model is tested with different strain boundary conditions and stress obliquity by relaxing four model parameters. The parametric study includes pile diameter, embedded length, and moment arm distance from the surface. Numerical results indicate that different pile geometries produce a distinct evolution of lateral displacement and stress. In particular, the repetitive lateral load increases the global lateral load resistance. Further analysis provides insight into the propagation of the shear localization from the pile tip to the ground surface.

• Korean Journal of Metals and Materials
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• v.46 no.3
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• pp.144-149
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• 2008

Equal channel angular pressing (ECAP) has been studied intensively over the decade as a typical top-down process to produce ultrafine/nano structured materials. ECAP has successfully been applied for a processing method of severe plastic deformation to achieve grain refinement of magnesium and to enhance its low ductility. However, difficult-to-work materials such as magnesium and titanium alloys were susceptible to shear localization during ECAP, leading to surface cracking. The front pressure, developed by Australian researchers, can impose hydrostatic pressure and increase the strain level in the material, preventing the surface defect on workpiece. In the present study, we investigated the deformation and fracture behavior of pure magnesium using experimental and numerical methods. The finite element method with different ductile fracture models was employed to simulate plastic deformation and fracture behavior of the workpiece.

• Journal of Electrochemical Science and Technology
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• v.15 no.2
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• pp.220-241
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• 2024

Due to its unique advantages, electrochemical machining (ECM) is playing an increasingly significant role in the manufacture of difficult-to-machine materials. Most of the current ECM research is conducted at room temperature, with studies on ECM in a cryogenic environment not having been reported to date. This study is focused on the electrochemical dissolution characteristics of typical iron and nickel base alloys in NaNO₃ solution at low temperature (-10℃). The polarization behaviors and passive film properties were studied by various electrochemical test methods. The results indicated that a higher voltage is required for decomposition and more pronounced pitting of their structures occurs in the passive zone in a cryogenic environment. A more in-depth study of the composition and structure of the passive films by X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy showed that the passive films of the alloys are modified at low temperature, and their capacitance characteristics are more prominent, which makes corrosion of the alloys more likely to occur uniformly. These modified passive films have a huge impact on the surface morphologies of the alloys, with non-uniform corrosion suppressed and an improvement in their surface finish, indicating that lowering the temperature improves the localization of ECM. Together with the cryogenic impact of electron energy state compression, the accuracy of ECM can be further improved.

• Journal of Biomedical Engineering Research
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• v.16 no.4
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• pp.481-491
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• 1995

Endovaginal and endorectal receiver only surface coils were designed for MR imaging (MRI) and $^1H$ MR spectroscopy (MRS) for the uterine cervix and the prostate. The shape of endovaginal coil wire was rectangular with round corner. Size of the coil wire was empirically determined for 7cm and 4cm along the long and short axis, respectively. The coil wire loop was supported by acryl handle and bent about $150^{\circ}$ at one side of the loop considering the average angle of the cervix to the vagina. We called this as a "spoon-type endovaginal coil". The wire of the endorectal coil was made of the flexible materials so that the wire loop became long elliptic shape by pushing the acryl handle into the plastic tube for the comfort of patients when the coil was inserted into the cervix. Then, the shape was maintained to be circle by popping out handle. Conventional spin echo (SE) and fast spin echo (FSE) sequences were used as 71 and 72 weighted imaging sequences, respectively. Matrix size was 128~$256{\times}256$. FOVs for surface coil and body coil were 14cm and 24cm, respectively. 3D volume localized in vivo $^1H$ MR spectroscopy of the human cervix and prostate was performed using PRESS or STEAM localization method with the following parameters . TR=3 sec, TE=135 msec for PRESS or 30 msec for STEAM, NEX=2, NS=48, Sl=2048, and SW=2500 Hz. Using home-built endovaginal and endorectal coils, excellent T1- and T2-images were obtained to visualize early cervical and prostate tumors. 3D volume localized in vivo IH MRS was useful to differentiate the cancerous tissue from the normal tissue.

• Korean Journal of Optics and Photonics
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• v.24 no.2
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• pp.86-91
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• 2013

In this study, we have investigated the correlation of far-field detection sensitivity of surface plasmon resonance (SPR) biosensors with optical signatures associated with the near-field overlap of biomolecules. The results confirm a direct relation between the far-field and near-field parameters, particularly for optical signatures defined in terms of lateral electric field components that are tangential to the interface and thus continuous across the interface. The overall correlation between near-field optical signatures and far-field resonance shift exceeded 97%. The results can be highly useful to evaluate detection sensitivity of SPR biosensors that take advantage of complex structures for localization of surface waves.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.7
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• pp.1030-1038
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• 2007

Results on localization of growth hormone receptor (GHR), interaction of growth hormone (GH) with receptor in buffalo adipose tissue and identification of activated signaling molecules in the action of GH are presented. Bovine GH (bGH) was labeled with fluorescein or biotin. Fluorescein-labelled bGH was used for localization of GHRs in buffalo adipocytes. The receptors were present on the cell surface. The affinity of binding of GH to its receptor was determined by designing an experiment in which buffalo adipose tissue explants, biotinylated GH and streptavidin-peroxidase conjugate were employed. The affinity constant was calculated to be $2{\times}10^8M^{-1}$. The receptor density on adipose tissue was found to be 1 femto mole per mg of tissue. Signalling molecules generated in the action of GH were tentatively identified by employing Western blot and enhanced chemiluminescence techniques using anti-phosphotyrosine antibody. Based on molecular weights of proteins reactive to anti-phosphotyrosine antibody, three signaling molecules viz. insulin receptor substrate, Janus activated kinase (Jak) and mitogen activated protein were tentatively identified. These signaling molecules appeared in a time (incubation time of explants with growth hormone) dependent way. The activation of Jak2 was confirmed by employing anti-Jak2 antibody in a Western blot. The activation of Jak2 occurred during 5 min incubation of buffalo adipose tissue explants with GH and incubation for an additional period, viz. 30 min. or 60 min., resulted in a drastic reduction in activation. The results suggest that Jak2 activation is an early event in the action of GH in buffalo adipose tissue.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.3
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• pp.334-342
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• 2013

Proteases and protease inhibitors play key roles in most physiological processes, including cell migration, cell signaling, and cell surface and tissue remodeling. Among these, the matrix metalloproteinase (MMPs) pathway is one of the most efficient biosynthetic pathways for controlling the activation of enzymes responsible for protein degradation. This also indicates the association of MMPs with the maturation of spermatozoa. In an attempt to investigate the effect of MMP activation and inhibitors in cultures with various hormones during sperm capacitation, we examined and monitored the localization and expression of MMPs (MMP-2 and MMP-9), tissue inhibitors of metalloproteinases (TIMP-2 and TIMP-3), as well as their expression profiles. Matured spermatozoa were collected from cultures with follicle-stimulating hormone (FSH), luteinizing hormone (LH), and Lutalyse at 1 h, 6 h, 18 h, and 24 h. ELISA detected the expression of MMP-2, MMP-9, TIMP-2, and TIMP-3 in all culture media, regardless of medium type (FSH-supplemented fertilization Brackett-Oliphant medium (FFBO), LH-supplemented FBO (LFBO), or Lutalyse-supplemented FBO (LuFBO)). TIMP-2 and TIMP-3 expression patterns decreased in LFBO and LuFBO. MMP-2 and MMP-9 activity in FBO and FFBO progressively increased from 1 h to 24 h but was not detected in LFBO and LuFBO. The localization and expression of TIMP-2 and TIMP-3 in sperm heads was also measured by immunofluorescence analysis. However, MMPs were not detected in the sperm heads. MMP and TIMP expression patterns differed according to the effect of various hormones. These findings suggest that MMPs have a role in sperm viability during capacitation. In conjunction with hormones, MMPs play a role in maintaining capacitation and fertilization by controlling extracellular matrix inhibitors of sperm.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.193-193
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• 2022

Cowpea(Vigna unguiculata L. Walp) has a low fat and protein content and a relatively high starch content, so it is mainly used in various ways for song-pyeon sediment, rice-cake paste, and porridge. In Yeonggwang-gun, Jeollanam-do, cowpea for seed production is being cultivated for the localization of raw material for Rice cake with ramie leave. A cowpea variety 'Jang-Alchan' was improved from the cross between IT145373 and IT145391 at the JARES in 2019. 'Jang-alchan' has an erect plant with an intermediate plant habit, light purple-colored corolla, and heart-shaped leaflets. 'Jang-alchan' has an orange-yellow seed seed-surface of faint luster, and brown and straight pods when matured. The stem length of 'Jang-alchan' was 48cm, 9cm longer than that of the control cultivar 'Okdang' and the 100-seed weight was 14.1g. The weight ratio of the seed coat for the entire seed was 11.2%, which was 0.2%p lower than that of the control cultivar. Field resistance of 'Jang-alchan' to leaf and systemic diseases was similar to that of the control cultivar. Is field resistance of 'Jang-alchan' to lodging was slightly lower than that of the control cultivar. The average yield of 'Jang-alchan' was 1.85ton per hectare, which was 14% higher than that of the control cultivar 'Okdang', 'Jang-Alchan' does not require the installation of an espalier-net and is taller than the existing supplied 'Okdang', so it can be harvested by combine harvesting. In addition, it is expected to contribute to the localization of raw material grains for regional specialties as it can be cultivated over a large area.