• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.1
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• pp.51-58
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• 2002

PSI-H is an intrinsic membrane protein known to be essential for efficient electron flow in PSI complex. We isolated a cDNA clone encoding a PSI-H subunit homolog from Chinese cabbage (Brassica campestris L.). The cDNA, designated bpsaH, had an insert of 435 bp and a full open reading frame that would encode a protein of 145 amino acids. The amino acid sequence deduced from the cDNA sequence is 79.3% identical to that of spinach, suggesting the cDNA most likely encodes Chinese cabbage PSI-H subunit. The bpasH was expressed at high level in leaf tissue and low level in flower bud, whereas it was undetectable in root tissue.

• Korean Journal of Food Science and Technology
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• v.43 no.3
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• pp.381-386
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• 2011

This study investigated the effect of herbal extracts fermented by Lactobacillus plantarum (MBN) on hair growth in C57BL/6 mice and HaCaT cells. Five week old mice were applied with MBN topically (0.2 mL) once per for 21 days. Hair regrowth was evaluated by gross examination and verified by hematoxylin-eosin staining. Gene expression of vascular endothelial growth factor (VEGF), keratinocyte growth factor (KGF), and transforming growth factor-beta1 ($TGF{\beta}1$), relevant to hair growth, were examined. The data revealed that MBN successfully promoted hair growth in both male and female mice at a dose between 200-500 mg/kg and improved hair thickness. The VEGF and KGF genes were expressed in a dose-dependant manner, whereas $TGF{\beta}1$ was not expressed. Moreover, nitric oxide was significantly increased, suggesting an improvement in blood flow. These results indicate that MBN effectively promoted hair growth and gene expression relevant to hair growth in an animal model.

• Journal of Sensor Science and Technology
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• v.23 no.2
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• pp.114-121
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• 2014

We report a polysilicon active area membrane field effect transistor (PSAFET) pressure sensor for low stress deflection of membrane. The PSAFET was produced in conventional FET semiconductor fabrication and backside wet etching. The PSAFET located at the front side measured pressure change using 300 nm thin-nitride membrane when a membrane was slightly strained by the small deflection of membrane shape from backside with any physical force. The PSAFET showed high sensitivity around threshold voltage, because threshold voltage variation was composed of fractional function form in sensitivity equation of current variation. When gate voltage was biased close to threshold voltage, a fractional function form had infinite value at $V_{tn}$, which increased the current variation of sensitivity. Threshold voltage effect was dominant right after the PSAFET was turned on. Narrow transistor channel established by small current flow was choked because electron could barely cross drain-source electrodes. When gate voltage was far from threshold voltage, threshold voltage effect converged to zero in fractional form of threshold voltage variations and drain current change was mostly determined by mobility changes. As the PSAFET fabrication was compatible with a polysilicon FET in CMOS fabrication, it could be adapted in low pressure sensor and bio molecular sensor.

• Journal of Life Science
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• v.16 no.6
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• pp.898-903
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• 2006

The genetic diversity and population structure of fifteen Potentilla discolor Bunge populations in Korea were determined using genetic variations at 19 allozyme loci. Fourteen of the 19 loci (73.7%) showed detectable polymorphism. Genetic diversity at the species level and at the population level was high ($H_{ES}\;=\;0.215$, $H_{EP}\;=\;0.196$, respectively), whereas the extent of the population divergence was relatively low $(G_{ST}\;=\;0.069)$. Total genetic diversity values $(H_T)$ varied between 0.0 and 0.656, giving an average overall polymorphic loci of 0.292. The interlocus variation of genetic diversity within populations $(H_S)$ was high (0.274). On a per locus basis, the proportion of total genetic variation due to differences among populations $(G_{ST})$ ranged from 0.010 for Pgm-2 to 0.261 for Pgd-2 with a mean of 0.069, indicating that about 6.9% of the total allozyme variation was among populations. Wide geographic ranges, perennial herbaceous nature and the persistence of multiple generations are associated with the high level of genetic variation in P. discolor. The estimate of gene flow based on $G_{ST}$ was high among Korean populations of P. discolor (Nm = 3.36).

• Journal of Life Science
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• v.20 no.6
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• pp.819-824
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• 2010

Genus Phyllostachys is a long-lived woody species primarily distributed throughout South East Asia. Many species of this genus has been regarded as medically and ecologically important in the world. We evaluated representative samples of the four taxa with RAPD to estimate genetic relationships within the genus Phyllostachys. The percentages of polymorphic loci were 8.9-33.3% at the species level. P. bambusoides was found to show lower genetic diversity (H=0.018) than other species. Total genetic diversity ($H_T$) was 0.315, genetic diversity within populations ($H_S$) was 0.043, the proportion of total genetic diversity partitioned among populations ($G_{ST}$) was 0.659 and the gene flow (Nm) was 0.0263. As some Korean populations were isolated and patchily distributed, they exhibited low levels of genetic diversity. The four taxa of the genus Phyllostachys analyzed were distinctly related to a monophyletic. P. nigra var. henonis. Stapf was found to be more closely related to P. pubescens than to P. nigra. P. bambusoides was quite distinct from the remaining species.

• Journal of Radiation Protection and Research
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• v.37 no.2
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• pp.56-62
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• 2012

To determine the biological effects of low-dose-rate radiation ($^{137}Cs$, 2.95 mGy/h) on EL4 lymphoma cells during 24 h, we investigated the expression of genes related to apoptosis, cell cycle arrest, DNA repair, iron transport, and ribonucleotide reductase. EL4 cells were continuously exposed to low-dose-rate radiation (total dose: 70.8 mGy) for 24 h. We analyzed cell proliferation and apoptosis by trypan blue exclusion and flow cytometry, gene expression by real-time PCR, and protein levels with the apoptosis ELISA kit. Apoptosis increased in the Low-dose-rate irradiated cells, but cell number did not differ between non- (Non-IR) and Low-dose-rate irradiated (LDR-IR) cells. In concordance with apoptotic rate, the transcriptional activity of ATM, p53, p21, and Parp was upregulated in the LDR-IR cells. Similarly, Phospho-p53 (Ser15), cleaved caspase 3 (Asp175), and cleaved Parp (Asp214) expression was upregulated in the LDR-IR cells. No difference was observed in the mRNA expression of DNA repair-related genes (Msh2, Msh3, Wrn, Lig4, Neil3, ERCC8, and ERCC6) between Non-IR and LDR-IR cells. Interestingly, the mRNA of Trfc was upregulated in the LDR-IR cells. Therefore, we suggest that short-term Low-dose-rate radiation activates apoptosis in EL4 lymphoma cells.

• Journal of Power System Engineering
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• v.17 no.5
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• pp.58-63
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• 2013

In this study, the effect of deep ocean condenser inlet temperature ($T_{DOI}$), condenser inlet pressure ($P_{cond,in}$), and thermal diffusivity on system efficiency of some selected refrigerants was analyzed using HYSYS. The proposed DOTEC cycle is similar to the reheat Rankine cycle but eliminates irreversibilities by bleeding a fraction of the steam between certain stages of the turbine. The evaporator inlet mass flow rate, inlet temperature of turbine 1, turbine efficiency and inlet and outlet temperature of heat source were imposed. The working fluids considered are sorted in ascending order of their molecular weights as R717, R600a and R152a. Results indicated that a fluid with a lower boiling point temperature like R717 needs a corresponding high heat source and/or evaporator inlet pressure. Also, the response of thermal diffusivity closely follows the change in TDOI as an increase in $T_{DOI}$ increases $P_{cond,in}$ which reduces thermal diffusivity and system efficiency. Furthermore, the fluid with the nominal boiling point temperature has the highest efficiency with efficiency decreasing with an increase in TDOI.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2000.10a
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• pp.116-122
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• 2000

The molecular modification of antiepileptic drugs and direct synthesis of new drugs with the predetermined antiepileptic properties are perspective. New neurochemical attacking to solve the problem including prevention and inhibition of seizures seems to be related to ginsenosides and ginseng polypeptides. The main study based on the severity of febrile convulsions of rat pups has been done from the earlier investigations of antiepileptical action of ginsenosides between KGTRI and MSU (Chepurnov, Park et al., 1995) with different kinds of experimental models of epilepsy. From the cultured cell line DAN25 of ginseng root, the extracts of ginsenosides made in "BIOKHIMMASH" were studied by the project of preclinical anticonvulsant screening (Stables, Kupferberg, 1997). The inhibition of severity of convulsions, decrease of seizures threshold, decrease of audiogenic seizures in rats of different strains and normalization of cerebral blood flow (measured by hydrogen test) were demonstrated in rats after i.c.v., intraperitoneally and orally administration, respectively. The antiepileptical effects by the combination of compounds from ginseng; were compared with the iuluence of Rg1, Rb1, Rc and with the well known antiepileptical drugs such as carbamazepine, valproic acid. The base for the research is obtained by using the WAG/Rij strain (Luijtelaar, Coenen, Kuznetcova), an excellent genetic model for human generalized absence epilepsy. The improving action of gensinosides was effectively demonstrated on the model of electrical kindling of amygdala of WAG/Rij rats with genetically determined absences, and the influences of ginsenosides on the slow wave discharges have also been being investigated. The different characteristics of a kindling process exerted in the sex-different region of the amygdala and demonstrated that the level of sex steroids and content of neurosteroids in amygdaloid tissue can modify the development of seizures. The chemical structures of ginsenosides not only have some principal differences from well-known antiepileptical drugs but the Plant Pharmacology gives us unique possibility to develop new class of antiepileptic drugs and to improve its biological activity.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.877-881
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• 2007

The genetic diversity and population structure of Potentilla freyniana in Korea were determined using genetic variations at 19 allozyme loci. Thirteen of the 19 loci (68.4%) showed detectable polymorphism. Genetic diversity at the population level was high ($H_{EP}$ = 0.270). Total genetic diversity values ($H_T$) varied between 0.190 and 0.584, giving an average overall polymorphic loci of 0.371. The interlocus variation of genetic diversity within populations ($H_S$) was high (0.354). On a per locus basis, the proportion of total genetic variation due to differences among populations ($G_{ST}$) ranged from 0.008 for Fe-2 to 0.310 for Gpi with a mean of 0.065, indicating that about 6.5% of the total allozyme variation was among populations. Wide geographic ranges, perennial herbaceous nature and the persistence of multiple generations are associated with the high level of genetic variation in P. freyniana. The estimate of gene flow based on $G_{ST}$, was high among Korean populations of P. freyniana (Nm =3.57). Although P. freyniana usually propagated by asexually-produced ramets, I could not rule out the possibility that sexual reproduction occurred at a low rate because each ramet may produce terminal flowers.

• Journal of Life Science
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• v.24 no.8
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• pp.903-909
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• 2014

Plants are an invaluable source of potential new anti-cancer drugs. Sasa quelpaertensis Nakai (Korean name, Jeju-Joritdae) is one of these plants with medical value, which is a bamboo grass widely distributed in Mt. Halla on Jeju Island, Korea. Here, we investigated the apoptotic effects of S. quelpaertensis leaf extracts in six human cancer cell lines (A549, MCF-7, HepG-2, Hela, HCT116 and A375). MTT assay signified the antiproliferative nature of S. quelpaertensis extracts against all tested cancer cells: S. quelpaertensis displayed slight cytotoxicity against A549, MCF-7 and HepG-2 cells, whereas it was exclusively cytotoxic to Hela, HCT116 and A375 cells. Apoptotic cells were evaluated using PI staining of DNA fragmentation by flow cytometry (sub-G1 peak). PI staining indicated increasing accumulation of Hela, HCT116 and A375 cells at sub-G1 phase. Further events like generation of nitric oxide ($NO^{\bullet}$) were accompanied in the S. quelpaertensis Nakai-induced apoptosis. Augmented $NO^{\bullet}$ generation resulted in the DNA fragmentation of Hela, HCT116 and A375 cells by treatment with S. quelpaertensis leaf extracts. These results suggest that S. quelpaertensis may be a potential natural resource for treating cancer cell. To identify the exact mechanisms of molecular mechanism of S. quelpaertensis induced apoptosis awaits further investigation.