• Transactions on Electrical and Electronic Materials
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• 제17권4호
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• pp.183-188
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• 2016

This paper presents the design and characterization of wide band ohmic microswitch with an actuation voltage as low as 20~25 V, and a restoring force of 14.1 μN. The design of the proposed switch is primarily composed of an electrostatic actuator, bridge membrane, cantilever (beam) and coplanar waveguide, suspended over the substrate. The analysis shows an insertion loss of −0.002 dB at 1GHz and remains as low as −0.35 dB, even at 100 GHz. The isolation loss of the switch is sustained at −21.09 dB at 100GHz, with a peak value of −99.58 dB at 1 GHz and up-state capacitance of 4 fF. To our knowledge, this is the first demonstration of a series contact switch, which works over a wide bandwidth (DC-100 GHz) and with such a high and sustained isolation, even at high frequencies and with an excellent figure of merit (f_c=1/2.pi.Ron.Cu= 39.7 THz).

• 대한한방내과학회지
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• 제21권1호
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• pp.116-125
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• 2000

Objectives : The aim of this study is to investigate that Sunghyangjeongki-San which has been frequently medicated in the early stage of stroke can protect against ischemic damage in rat brain Methods : Extracellular levels of amino acids(glutamate, aspartate, GABA, glycine, taurine, tyrosine, alanine), organic acids(pyruvate, lactate), and cerebral infarction volume were measured at the striatum of rats subjected to permanant focal cerebral ischemia induced by 2 hours of middle cerebral artery occiusion(MCAO). Rats were orally administered with Sunghyangjeongki-San at 30mins before MCAO and the microdialysate was collected by intracerebral microdialysis three times before MCAO and six times after MCAO at 20mins interval and analyzed by HPLC. After a microdialysis study, the brain was sliced and stained with cresyl violet buffer for the measurement of cerebral infarcted area and volume by image analyzer system Results : The concentrations of glutamate, aspartate, and tyrosine known as excitatory neurotransmitters were significantly decreased in Sunghyangjeongki-San group compared with control group, The concentrations of GABA, glycine, taurine and alanine known as inhibitory neurotransmitters were significantly increased in Sunghyangjeongki-San group compared with control group. The concentrations of pyruvate and lactate showed little significant change in Sunghyangjeongki-San group compared with control group. The measurement of cerebral infarcted area and volume by image analyzer system were significantly decreased in Sunghyangjeongki-San group compared with control group. Conclusions : Sunghyangjeongki-San can affect on protecting against cerebral ischemia by regulating extracellular levels of excitatory and inhibitory amino acid neurotransmitters and improve the conditions of the patients in the early stage of stroke.

• Transactions on Electrical and Electronic Materials
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• 제17권2호
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• pp.86-91
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• 2016

Ever increasing demand for microwave operated applications has cultivated need for high-performance universal systems capable of working on multi-bands. This objective can be realized using Multi-Dielectrics in RF MEMS capacitive switch. In this study, we present a detailed analysis of the effect of various dielectrics on switch performance. The design consists of a capacitive switch and performance is analyzed by changing the dielectric layers beneath the switch. The results are obtained using three different dielectrics including Silicon nitride (7.6), Hafnium dioxide (25) and Titanium oxide (50). Testing of proposed switch yields high isolation (- 87.5 dB) and low insertion loss (- 0.1 dB at 50 GHz) which is substantially better than the conventional switches. The operating bandwidth of the proposed switch (DC to 95 GHz) makes it suitable for wide band microwave applications.

• 한국작물학회지
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• 제42권1호
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• pp.95-103
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• 1997

우리나라에서 식용목적으로 생산되고 있는 단옥수수, 초당옥수수 및 찰옥수수의 수확후 품질관리와 고품질 선도유지 및 안전유통 방안 확립의 기초자료를 얻고자, 단옥 002, 초당옥 Cocktail 86 및 찰옥 001 옥수수를 수확직후 얼음처리후 0~2$^{\circ}C$의 저온저장고에 저장하면서 일반상온 및 저온저장과 비교한 결과는 다음과 같다. 1. 풋옥수수를 수확후 상온 및 저온에 저장하면 15일후 낱알의 수분함량이 옥수수의 종류에 따라서 각각 22~24 및 7.4~8.2% 감소되어 품질이 크게 떨어졌으나 얼음처리 후 저온저장 한 것은 수분의 변화가 적었다. 2. 풋옥수수의 종류별 과피함량은 수확시 찰옥수수가 1.71%로 초당옥수수와 단옥수수의 0.81% 및 1.09%보다 높았으며, 15일 저장후에는 단옥수수의 경우 무예냉 상온 및 저온저장 구에서 13.25% 및 3.5%로 수확시보다 3~12배 증가되었으나, 얼음처리 저온저장구에서는 1.31%로 증가율이 아주 적었으며, 초당옥수수 및 찰옥수수도 단옥수수와 유사하였다. 3. 알코올 불용성 고형물 함량도 과피함량의 경우와 유사하여 얼음처리 저온저장 효과가 인정되었는데, 특히 찰옥수수에서 그 효과가 크게 나타났다. 4. 종류별 유리당함량은 단옥수수의 경우 sucrose, glucose, fructose 및 maltose 등 4종이 분리되었으나, 초당옥수수와 찰옥수수는 maltose가 검출되지 않았고, 유리당류의 구성 비율은 sucrose가 60~74%를 차지하여 주종을 이루고 있었으며, 저장중 당 종류별 손실율도 sucrose가 높았으나 얼음예냉 저온저장으로 저장 중 유리 당 손실을 최소화 할 수 있었다. 5. 종류별 유리 아미노산의 경우 단옥수수는 alanine 외 20종, 초당옥수수는 glutamic acid외 18종, 찰옥수수는 glutamic acid외 20종이 확인되었으며, 특히 성인병 예방에 효과가 있어 기능성 아미노산으로 알려진 ${\gamma}$-aminobutylic acid (GABA)가 3종류 모두에서 검출되었고, 15일 저장후 총 유리 아미노산함량으로 볼 때 얼음예냉 저온저장구가 품질 유지 효과가 큰 것으로 나타났다.

• 한국작물학회지
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• 제51권spc1호
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• pp.133-138
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• 2006

본 연구는 삼투포텐셜이 동일한 NaCl과 PEG6000 용액을 사용하여 염해와 한발에 대한 보리의 생화학적 반응을 검토하였으며 시험결과를 요약하면 다음과 같다. 1. 보리의 지상부 생육 및 보리 잎의 상대수분함량은 염해보다 한발에 의해서 더욱 감소하였다. 2. 과산화수소의 발생은 염해처리 후 6일에 한발보다 27.5% 많았으며, 영해처리 후 4일에 나타난 APX, CAT 및 GR의 활성은 한발처 리보다 각각 12.6%, 27.9%, 23.3% 높았다. 한편, 보리의 경우 CAT의 활성은 한발보다 염해조건에서 더욱 신속하게 유도되는 것으로 나타났다. 3. 아미노산 함량의 변화는 염해 및 한발처리에 의해서 서로 다른 양상을 보였다. 특히 glycine, arginine 및 GABA의 함량은 한발처리에서 더욱 증가하였으나, proline의 함량은 염해처리에서 크게 증가하였다. 4. 본 연구를 통해서 보리의 항산화효소 활성 및 아미노산 함량이 염해와 한발에 의해서 상이하게 조절되는 것이 확인되었다. 이러한 결과들은 염해에 대한 보리의 특이적인 반응지표가 될 수 있을 것으로 생각되었다.

• 한국식품과학회지
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• 제52권5호
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• pp.427-434
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• 2020

본 연구에서는 녹차 국내종(보향, 참녹), 외래종(후슌, 야부기다)의 채취시기를 달리하여 테아닌, GABA 등 유용 성분 함량을 분석하였고, 항산화능, α-glucosidase 활성 억제, HMG-CoA 저해도, 세포독성 측정, 뇌 신경세포 보호 효과, 항 스트레스 효과를 조사하여 유용 성분과의 상관성을 파악하고자 하였다. 테아닌과 GABA 함량은 모든 품종에서 채취시기가 늦어질수록 함량이 감소하는 경향을 나타내었다. 총 아미노산 함량에서는 채엽시기가 늦어질수록 보향 품종에서 증가하는 경향을 나타내었고 후슌, 야부기다 그리고 참녹은 여름차에서 감소 후 다시 가을차에서 증가하는 경향을 보였다. 총페놀과 플라보노이드의 함량과 항산화능을 조사했을 때 ABTS는 후슌, 보향, 참녹에서 플라보노이드 농도와 비례하는 경향을 보였으며, 재래 녹차와 야부기다는 총페놀의 농도와 비례하는 경향을 나타내었다. DPPH radical 소거능은 참녹을 제외한 모든 시료에서 여름차의 활성이 가장 높고 가을차에서 활성이 다시 감소하는 것을 확인하였다. 카테킨류 측정에서 EGCg 함량은 카테킨류에서 50% 이상을 차지했고, 총 카테킨 함량과 Ecg, EGCg는 종과 관계없이 채취 시기가 늦어질수록 증가하는 경향을 보였으며 EGC는 감소하는 경향을 보였다. 품종별 봄, 여름, 가을차를 시료로 하여 측정한 α-glucosidase 저해 활성과 HMG-CoA reductase 저해능은 채취 시기가 늦어질수록 증가함을 보였고 그 중 가을에 채취한 참녹에서의 저해 활성이 각각 72.93%, 69.78%로 두 저해능 측정에서 가장 높은 저해활성을 보였다. 또한 뇌신경세포(SH-SY5Y)를 이용한 세포 독성 측정에서 참녹 품종이 96.34%로 가장 높은 세포생존율을 보였고 항스트레스 측정에서 269.2 ng/mL로 가장 낮은 cortisol 함량이 확인되었다.

• Journal of Pharmaceutical Investigation
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• 제35권3호
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• pp.193-199
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• 2005

Gabapentin is an antiepileptic drug that is structurally similar to ${\gamma}-aminobutyric$ acid (GABA), but does not interact with the GABA receptor. It does not bind significantly to plasma proteins, and is excreted to unchanged form in the urine. The purpose of the present study was to evaluate the bioequivalence of two gabapentin capsules, $Neurontin^{TM}$ capsule 300 mg (Pfizer Pharm. Co., Ltd.) and Kuhnil $Gabapentin^{TM}$ capsule 300 mg (Kuhnil Pharm. Co., Ltd), according to the guidelines of the Korea Food and Drug Administration (KFDA). The release of gabapentin from the two gabapentin formulations in vitro was tested using KP VIII Apparatus II method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty six healthy male subjects, $22.46{\pm}1.86$ years in age and $67.64{\pm}7.24$ kg in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After a single capsule containing 300 mg as gabapentin was orally administered, blood samples were taken at predetermined time intervals and the concentrations of gabapentin in serum were determined using HPLC with fluorescence detector. The dissolution profiles of two formulations were similar at all dissolution media. In addition, the pharmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$, $C_{max}$ and untransformed $T_{max}$. The results showed that the differences between two formulations based on the reference drug, $Neurontin^{TM}$ capsule 300 mg, were -2.03, -0.43 and 4.29% for $AUC_t$, $C_{max}$ and $T_{max}$, respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log 0.8 to log 1.25 $(e.g.,\;log\;0.89{\sim}log\;1.09\;and\;log\;0.91{\sim}log\;1.09$ for $AUC_t$ and $C_{max}$, respectively). Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Kuhnil $Gabapentin^{TM}$ capsule 300 mg was bioequivalent to $Neurontin^{TM}$ capsule 300 mg.

• 생명과학회지
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• 제23권4호
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• pp.560-568
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• 2013

GABA 함량이 높은 청국장을 발효하는 Bacillus subtilis MC 31의 청국장 품질특성을 조사하였다. B. subtilis MC 31에 의해 발효된 청국장으로부터 24개의 아미노산이 검출되었고 그 중에서도 leucine이 가장 높은 함량을 나타냈다. B. subtilis MC31에 의해 발효가 된 청국장의 미생물의 생육 변화를 조사한 결과 총 균수가 정지기에 들어서면서 log $9.52{\pm}0.5$~log $9.049{\pm}0.5$ CFU/g까지 증가하였다. 청국장의 일반성분은 수분 $61.7{\pm}0.01%$, 회분 $1.52{\pm}0.01%$, 조단백 $17.66{\pm}0.04%$, 조지방 $8.96{\pm}0.03%$, 조섬유가 2.61%를 함유하였다. 암모니아태, 아미노태, 환원당은 모두 삶은 콩보다 청국장의 함량이 높게 조사되었지만 산도와 총 당은 청국장이 삶은 콩보다 함량이 낮았다. 청국장의 pH는 시간이 지날수록 알칼리화되고 점질물은 $4.7{\pm}0.05%$, protease activity는 $0.519{\pm}7.36$ g/l로 나타났으며 Fibrin plate와 Robbin실험을 통하여 fibrinolytic activity도 높음을 확인하였다. 이상의 결과로 미루어 보아 B. subtilis MC 31은 우수한 청국장 품질을 띄어 제조용 균주로 사용이 가능한 것으로 사료된다.

• 약학회지
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• 제52권3호
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• pp.195-200
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• 2008

Gabapentin, [1-(aminomethyl) cyclohexaneacetic acid], a structural analog of $\gamma$-aminobutyric acid (GABA), is being developed for the treatment of epilepsy. Unlike GABA, gabapentin crosses the blood-brain barrier after systemic administration. Gabapentin is an effective antiepileptic drug in patients with partial and secondarily generalized seizures who are uncontrolled with use of existing anticonvulsant drug therapy. The purpose of the present study was to evaluate the bioequivalence of two gabapentin 400 mg capsules, $Neurontin^{(R)}$ capsule 400 mg (Pfizer Inc.) and Gabatin capsule 400 mg (Korean Drug Co. Ltd), according to the guidelines of the Korea Food and Drug Administration (KFDA). The release of gabapentin from the two gabapentin formulations in vitro was tested using KP VIII Apparatus II method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty six healthy male subjects, 23.58$\pm$1.50 years in age and 66.74$\pm$8.31 kg in body weight, were divided into two groups and a randomized 2$\times$2 cross-over study was employed. After one capsule containing 400 mg as gabapentin were orally administered, blood was taken at predetermined time intervals and the concentrations of gabapentin in serum were determined using HPLC with fluorescence detector. The dissolution profiles of two formulations were similar at all dissolution media. In addition, the pharmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$, $C_{max}$ and untransformed $T_{max}$. The results showed that the differences between two formulations based on the reference drug, $Neurontin^{(R)}$ capsule 400 mg, were 2.04, -3.68 and 16.79% for $AUC_t$, $C_{max}$ and $T_{max}$, respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log 0.8 to log 1.25 (e.g., log 0.91$\sim$log 1.16 and log 0.87$\sim$log 1.11 for $AUC_t$ and $C_{max}$, respectively). Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Gabatin capsule 400 mg was bioequivalent to $Neurontin^{(R)}$ capsule 400 mg.

• 한국식품과학회지
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• 제49권1호
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• pp.56-62
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• 2017

The purpose of this study was to determine how seeding time changes the properties of soybean products meju and doenjang. Soybeans were seeded on the last day of May (5L), on the mid day of June (6M), and on the last day of June (6L), respectively. The 5L soybeans experienced a distinguishing hot and humid climate at the ripening stage, and these climate conditions resulted in smaller seed sizes. Fermentation briskly progressed in all doenjang until 120 days, and the 5L doenjang exhibited the lowest fermentation efficiency. The 5L soybeans showed the highest GABA, polyphenol contents, and ACE inhibitory activity, and the 6M soybeans showed the highest radical scavenging activity among the groups tested. In doenjang, the functional properties generally increased as the aging time approached the $120^{th}$ day, and the 6M doenjang showed the highest functional properties at the $120^{th}$ day. Therefore, 6M soybeans had the most appropriate characteristics when producing doenjang.