• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.10
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• pp.1-11
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• 1998

This paper presents a new implementation method of the pulsed NMR(nuclear magnetic resonance) apparatus, which contains a single coil in a magnet console, to detect a NMR signal. Applying an RF magnetic field of 5MHz to the magnet console which is designed to have Larmor frequency of 5MHz for hydrogen atom, the hydrogen NMR signal was obtained from the glycerin which was put in the magnet console as a sample. The DC magnetic field in the magnet console was implemented with a permanent magnet of 1168 gauss and the RF magnetic field was generated appling an RF signal with the frequency of 5MHz and the current magnitude of 8A to a coil of 5.73${\mu}$H. The magnitude of the NMR signal was maximum when the RF magnetic field was generated for 2.8 ${\mu}$sec, and the period of generating the RF magnetic field was designed to 100msec for detecting the NMR signal repeatedly. The NMR signal, radiated from the sample in the magnetic console, was appeared as an amplitude-modulated signal with a frequency equal to the Larmor frequency. The signal, induced in the coil, was amplified in the tx/rx separation circuit, preamplifier and intermediate amplifier by a factor of 20.7dB, 36dB and 40dB, respectively, and the signal was detected by a synchronous detection circuits, then the NMR signal was obtained.

• Journal of Life Science
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• v.26 no.6
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• pp.737-748
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• 2016

By this time, insect antimicrobial peptides (AMPs) have been characterized more than 150 peptides since purification of cecropin in the hemolymph of pupae from Hyalophora cecropia in 1980. Therefore, it is considered that insects are good sources of AMP selection. Insect AMPs are small (low molecular weight) and cationic, and amphipathic with variable length, sequence, and structure. They perform a pivotal role on humoral immunity in the insect innate immune system against invading pathogens such as bacteria, fungi, parasites, and viruses. Most of the insect AMPs are induced rapidly in the fat bodies and other specific tissues of insects after septic injury or immune challenge. Then the AMPs subsequently released into the hemolymph to act against microorganisms. These peptides have a broad antimicrobial spectrum against various microbes including anticancer activities. Insect AMPs could be divided into four families based on their structures and sequences. That is the α-helical peptides, cysteine-rich peptides, proline-rich peptides, and glycine-rich peptides/proteins. For instance, cecropins, insect defensins, proline-rich peptides, and attacins are common insect AMPs, but gloverins and moricins have been identified only in lepidopteran species. This review focuses on AMPs from insects and discusses current knowledge and recent progress with potential applications of insect AMPs.

• The Korean Journal of Physiology
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• v.29 no.1
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• pp.13-27
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• 1995

single $K^{+}$ channels of skeletal muscle from the rat and frog were into planar lipid bilayers and their properties were studied. Fusion was induced by an osmotic gradient. Of the four types of $K^{+}$ channels recorded, the two most frequently observed were a voltage and $Ca^{2+}-activated$ $K^{+}$ channel and a $K^{+}$ channel with a prominent conductance substate. The first $K^{+}$ channel was identified as the large $Ca^{2+}-activated$ $K^{+}$ (BK) channel because the open-state probability was increased with depolarization (e-fold change per $10.6{\pm}3.5$ mV, n=8) and internal $Ca^{2+}$ (half-activation at $16.7{\pm}3.8$ mV, n=8, pCa 4) and its conductance was large ($247{\pm}4.9$ pS, n=24 in 0.1 M KCI). Lifetime distributions of open- and closed-states could be fitted with single exponentials of several milliseconds. The mean open- and closed-lifetimes were linearly dependent on the intracellular $[Ca^{2+}]$ and $1/[Ca^{2+}]$, respectively. The second $K^{+}$ channel showed a conductance substate at $30{\sim}60%$ of the open state. Its current-voltage relation was linear in the range of $-80\;{\sim}\;+80\;mV$. The slope conductance of the substate and open-state were 40 and 144 pS in 0.2 M KCl, respectively. The channel was highly selective for $K^{+}$ over Cl. The open-state probability was weakly voltage-dependent (e-fold change per 35 mV. The lifetime distributions of open- and closed-states were fitted with two exponentials and the major gating occurred slowly at several hundred milliseconds. Based on the above results, we think the second type of $K^{+}$ channel is the sarcoplasmic reticulum $K^{+}$ (SRK) channel. In addition, both types of channel were also incorporated into the lipids extracted from the skeletal muscle. The channel properties recorded in the bilayers termed from synthetic and extracted lipids were qualitatively similar. Our data indicate that BK and SRK channels are rich in the skeletal muscle and their properties and regulation could be effectively studied in planar lipid bilayer.

• Preventive Nutrition and Food Science
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• v.8 no.1
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• pp.46-53
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• 2003

The current study investigated the effect of Korean safflower (Carthamus tinctorius L.) seed powder and its water and ethanol extracts on bone metabolism during recovery from rib-fracture induced by surgical operation in rats. 10-week-old male Sprague-Dawley rats weighing about 320 g were divided into 9 groups after arrival: 10d control (AIN 76 semi-purified diet), 10d safflower seed powder (10d SS-powder), 10d safflower seed ethanol extract (10d SS-EtOH), 10d safflower seed water extract (10d SS-$H_2O$), 20d control (AIN-76 semi-purified diet), 20d safflower heed powder (20d SS-powder), 20d safflower seed ethanol extract (20d SS-EtOH), 20d safflower seed water extract (20d SS-$H_2O$), and 20d sham-operation (20d sham), The dietary level for all the supplements was 5% based on the raw material weight. The rats were fed the experimental diets for 10 days before the rib fracture operation and for a further 10 or 20 days after the operation. A number 9 rib was fractured surgically and a sham-operation also performed. The rats were then sacrificed on the l0th or 20th day after the operation. The body weight initially decreased after the operation in all the rib-fractured groups, then gradually recovered. The concentrations of plasma osteocalcin were higher in the control group than in all the safflower-supplemented groups 10 and 20 days after the rib-fracture (p < 0.05). The bone-specific ALP (alkaline phosphatase) activity was significantly higher in the SS-EtOH group than in the other groups 20 days after the rib-fracture (p < 0.05). The level of urinary DPD (deoxypridinoline) was significantly higher in the SS-EtOH and SS-$H_2O$ groups than in the other groups 10 days after the rib-fracture. When comparing the PTH (parathyroid hormone) and calcitonin levels, the SS-$H_2O$ group exhibited the highest PTH level among the groups 10 and 20 days after the rib-fracture. Thus, it was concluded that the bone turnover during the fracture-healing period was more rapid in the rats supplemented with safflower seed powder or its fractions than in the control rats. Furthermore, the SS-$H_2O$ fraction was identified as the most effective in stimulating bone remodeling, as bone resorption and bone formation were both significantly increased during fracture healing when compared to the control group.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.12
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• pp.1327-1336
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• 2012

In this paper, the dual-faced monopole antenna, which is arranged by numerous rectangular ring patches in sequence for the multi-bands is proposed. The ring type structure of the patch can be increased the bandwidth. Therefore the bandwidth and beam width are improved by using multiple arrayed patches. When the ring type patches are inserted serially, the resonance frequencies are occurred by the current flow from the first ring patch. It is possible because the gap between the patches is very narrow. In addition, if the patches are composed on the same plane as the feed-line, fabrication could be very difficult because the gap between the patches is extremely narrow. The thickness and permittivity of the antenna, moreover, are very important parameters because both sides of the substrate are used. We finally found the optimal thickness and permittivity to generate the coupling effect by simulation. All patches are consisted of 4-steps which the patch size was decreased 85 % by each step. In conclusion, the resonant frequency bands are 1.75~2.6 GHz(850 MHz), 3.24~3.46 GHz(220 MHz), 3.8~4.0 GHz(200 MHz), and 4.4~4.9 GHz(500 MHz).

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.10
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• pp.1439-1445
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• 2010

In this study, we investigated the inhibition of phyto-extract mixture (PEM) in several digestive enzymes ($\alpha$-amylase, $\alpha$-glucosidase and lipase) for anti-obesity. The current study also examined the effects of PEM on adiposity and serum lipid levels in obese mice fed with high fat diet. ICR male mice weighing $33{\pm}1.1\;g$ were randomly divided into three groups, one normal diet group (control, ND group) and two high fat diet groups with or without PEM supplement (HFD group and PEM group). The mice were fed the PEM experimental for 6 weeks and then they were sacrificed. The results showed that the final weight, weight gain, food efficiency ratio and body fat were decreased by the addition of PEM compared to those of HFD group. White adipose tissue weights of epididymal, mesenteric and retroperitoneal areas in the PEM group were reduced to 31.2%, 8.8%, and 37.8%, respectively, compared to the HFD group. The levels of serum triglyceride, total cholesterol, LDL-cholesterol in the PEM group were significantly lower than those of HFD group. The body weight gain and food efficiency ratio of PEM group were significantly lower compared with those of HFD group. From the above results, the PEM may be effective material for anti-obesity through reducing serum triglyceride and body fats as well as decreasing body weight.

• 한국정보통신설비학회:학술대회논문집
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• 2005.08a
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• pp.259-262
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• 2005

Ground resistance measurement is an elementary technique for the evaluation of grounding system. There are main environmental factors to consider for correct measurement but the problem is that it is practically most cases to measure ground resistance unable to know the factors. This paper presents a methodology toward true value of resistance in the unknown circumstances, utilizing the defined term 'variation rate' of potential difference curve appearing in the distance to a current probe as in the three point fall-of-potential method which comprises the characteristics of environmental factors. This methodology is a induced result from the previous demostrated studies.

• Clinics in Shoulder and Elbow
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• v.10 no.2
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• pp.183-189
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• 2007

Introduction: While uncommon, humeral head osteonecrosis is an indication for arthroplasty when the humeral head collapse is advanced. The current authors report the short-term clinical results of 7 hemiarthroplasties to treat humeral head osteonecrosis. Materials and Methods: This study focused on 7 reconstructed shoulders of 5 patients whose humeral head osteonecrosis was treated with hemiarthroplasty. The postulated causes were alcohol-induced (4 cases) and steroidinduced (3 cases). The minimum follow-up was 12 months. This study compared the preoperative and postoperative shoulder pain, range of motion, and ASES scores. The postoperative patient satisfaction was assessed. Results: The level of pain during exercise was reduced from a preoperative average of 7.6 to a postoperative average of 1.9. The range of motion, in terms of forward flexion, abduction, and external rotation, improved from preoperative averages of $105.7^{\circ}$, $80^{\circ}$, and $22.1^{\circ}$ to postoperative averages of $146.6^{\circ}$, $139.3^{\circ}$, and $44.3^{\circ}$, respectively. The ASES scores increased from a preoperative mean of 39.0 to a postoperative mean of 84.1. The patients' ratings of the outcomes were excellent (5 cases) and good (2 cases). Conclusions: These short-term results indicate that hemiarthroplasty is a reliable treatment method for humeral head osteonecrosis improving shoulder pain, range of motion, and patient satisfaction.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.1
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• pp.81-96
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• 2007

Nonlinear shoaling characteristics over surf zone are numerically investigated based on spatially averaged NavierStokes equation. We also test the validity of gradient model for turbulent stresses due to wave breaking using the data acquainted during SUPERTANK LABORATORY DATA COLLECTION PROJECT(Krauss et al., 1992). It turns out that the characteristics length scale of breaking induced current is not negligible, which firmly stands against ever popular gradient model, ${\kappa}-{\varepsilon}$ model, but favors Large Eddy Simulation with finer grid. Based on these observations, we model the residual stress of spatially averaged NavierStokes equation after Lagrangian Dynamic Smagorinsky(Meneveau et al., 1996). We numerically integrate newly proposed wave equations using SPH with Gaussian kernel function. Severely deformed water surface profile, free falling water particle, queuing splash after landing of water particle on the free surface and wave finger due to structured vortex on rear side of wave crest(Narayanaswamy and Dalrymple, 2002) are successfully duplicated in the numerical simulation of wave propagation over uniform slope beach, which so far have been regarded very difficult features to mimic in the computational fluid mechanics.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.2
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• pp.124-130
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• 2013

Of all the brominated flame retardants (BFRs), TBBPA has the largest production volume (50% of the BFRs in current use). It is interest to investigate how they may degrade, because of it can pose an environmental hazard. By using UV-A (${\lambda}=352nm$ ), we have found that the UV-A irradiation increased the photodecomposition reaction rate of TBBPA in an intensity-dependent manner. We also observed 2,6-dibromo-p-benzosemiquinone radical ($a_{2H}=2.36G$, g = 2.0056) generated from TBBPA by reaction with singlet oxygen ($^1O_2$). On the other hand, when an aqueous preparation of HA was irradiated in the presence of TBBPA, the typical spectrum of semiquinone radical was detected by electron spin resonance (ESR). And then, we have found that the photodecomposition rate of TBBPA is decreased in depend on HA concentration. Radical formation and the reactive rate of TBBPA were inhibited by sodium azide used as a singlet oxygen quencher. Therefore we report that a similar $^1O_2$-induced oxidation can be initiate in aqueous solutions of TBBPA dissolved in humic acid (HA) by the UV-A irradiation (${\lambda}=352nm$). From these results, we suggest that the reaction rate of HA with $^1O_2$ is faster than that of TBBPA with $^1O_2$.