Showing papers by "Chung-Ang University published in 2004"
TL;DR: It is demonstrated that PgSS1 is a key regulatory enzyme not only for phytosterol but also for triterpene biosynthesis and overexpressing of Pg SS1 confers the hyperproduction of triterPene saponins to P. ginseng.
Abstract: ;Roots of Panax ginseng, one of the most famous medicinal plants, contain various phytosterols and bioactive triterpene saponins (ginsenosides). In P. ginseng, phytosterols and triterpenes share the common biosynthetic intermediate, squalene. Here, we investigate the regulatory role of Panax ginseng squalene synthase (PgSS1) on the biosynthesis of phytosterols and triterpene saponins. PgSS1 transcripts are expressed ubiquitously in the various plant tissues, but higher in shoot apex and root. The transcript levels of PgSS1 increased markedly in the adventitious roots during 12- to 96-h period after metyl jasmonate (MeJA) treatment; MeJA treatment induced the activation of the transcripts of squalene epoxidase (SE), β-amyrin synthase (bAS), but not cycloartenol synthase (CAS). Unlike MeJA treatment, overexpression of PgSS1 in adventitious roots of transgenic P. ginseng was followed by the up-regulation of all the downstream genes tested, such as SE, bAS, and CAS. The enhanced activity of PgSS1 enzyme resulted in remarkable increase of phytosterols as well as ginsenoside contents. These results demonstrate that PgSS1 is a key regulatory enzyme not only for phytosterol but also for triterpene biosynthesis and overexpressing of PgSS1 confers the hyperproduction of triterpene saponins to P. ginseng.
334 citations
TL;DR: Findings indicate that the sNPF is expressed in the nervous systems to control food intake and regulate body size in Drosophila melanogaster.
315 citations
TL;DR: A new 8-hydroxyquinoline derivative having an appended boron-dipyrromethene function has been prepared, and its metal ion sensing properties were investigated, and it exhibited pronounced Hg(2+)-selective on-off-type fluoroionophoric properties among the representative transition- and heavy-metal ions in aqueous dioxane solution.
Abstract: A new 8-hydroxyquinoline derivative having an appended boron−dipyrromethene function has been prepared, and its metal ion sensing properties were investigated. The designed compound exhibited pronounced Hg2+-selective on−off-type fluoroionophoric properties among the representative transition- and heavy-metal ions in aqueous dioxane solution. The fluorescence was efficiently quenched more than 98% with 5 equiv of Hg2+ ions, and the detection limit was found to be 5 × 10-6 M in a dioxane−water (1:3, v/v) solvent system. The ionophore also showed a selective chromogenic behavior toward Hg2+ ions by changing the color of the solution from light amber to red, which can be detected with the naked eye.
236 citations
TL;DR: The findings indicate that VIP and PACAP exert their functions through their receptors in specific locations in different combinations, which require further elucidation.
Abstract: To examine the distributions of VIP/PACAP receptors (VPAC1, VPAC2, and PAC1 receptors) in the brain and to identify the cell types that express these receptors, we performed immunohistochemistry and double immunofluorescence in the rat brain with specific antibodies. The immunohistochemistry revealed that the receptors had distinctive, complementary, and overlapping distribution patterns. High levels of the VPAC1 receptor were expressed in the cerebral cortex, hippocampal formation, deep cerebellar nuclei, thalamus, hypothalamus, and brainstem. The VPAC2 receptors were concentrated in the cerebral cortex, hippocampal formation, amygdalar regions, cerebellar cortex, deep cerebellar nuclei, hypothalamus, and brainstem. On the other hand, the PAC1 receptors had a more restricted distribution pattern in the brain, and high levels of the PAC1 receptors were confined to the cerebellar cortex, deep cerebellar nuclei, epithalamus, hypothalamus, brainstem, and white matter of many brain regions. Also, many fibers expressing the PAC1 receptors were observed in various areas, i.e., the thalamus, hypothalamus, and brainstem. The double immunofluorescence showed that the VIP/PACAP receptors were confined to the neuroglia as well as the neurons. All three types of the VIP/PACAP receptors were expressed in the astrocytes, and the PAC1 receptors were also expressed in the oligodendrocytes. These findings indicate that VIP and PACAP exert their functions through their receptors in specific locations in different combinations. We hope that this first demonstration of the distributions of the VIP/PACAP receptors provides data useful in the investigation of the mechanisms of the many functions of VIP and PACAP in the brain, which require further elucidation. J. Comp. Neurol. 476:388–413, 2004. © 2004 Wiley-Liss, Inc.
180 citations
TL;DR: Methanolic extracts of seven herbs used in traditional Korean medicine for improvement of memory and cognition in old age were tested for cholinesterase inhibitory properties using the Ellman colorimetric method.
178 citations
TL;DR: In this paper, the effects of Portland's urban growth boundary (UGB) on urban development patterns and mobility were investigated, and three different methods were adopted for evaluating Portland's UGB.
Abstract: This research investigates the effects of Portland's urban growth boundary (UGB) on urban development patterns and mobility. Three different methods are adopted for evaluating Portland's UGB: inter...
169 citations
TL;DR: In this article, a push-out test on large stud shear connectors is performed to evaluate the shear stiffness and strength of the connectors in an elastic range and tri-linear load-slip curves.
163 citations
TL;DR: Examination of H2O2 effects on changes of paracellular permeability, actin, and TJ proteins using primary culture of bovine brain microvessel endothelial cells suggests that H2 O2 induces increased parace cellular permeability of BBB that is accompanied with redistribution of occludin and ZO-1 and increased protein expression of occLudinand actin.
149 citations
TL;DR: In a two-stage bioreactor culture, total ginsenosides, after elicitation with 100 μm MJ peaked after 10days at 48mgg−1 dry wt and then dropped sharply and of the two groups of ginsenoides, higher amounts of Rb accumulated in the adventitious roots.
Abstract: Adventitious roots of ginseng were treated with methyl jasmonate (MJ) up to 150 microM and cultured for 40 days. Up to 100 microM MJ inhibited the root growth but increase ginsenoside accumulation. In a two-stage bioreactor culture, total ginsenosides, after elicitation with 100 microM MJ peaked after 10 days at 48 mg g(-1) dry wt and then dropped sharply. Of the two groups of ginsenosides (Rb and Rg), higher amounts of Rb accumulated in the adventitious roots.
149 citations
TL;DR: The correlation between duodenal DMT1 and MTP1 expression and Cd body burden in rats suggests an important role of DMT/MTP1 in Cd absorption.
131 citations
TL;DR: The results suggest that the COMT L/L genotype is associated with PD and the genetic variant of theCOMT enzyme may be related to the clinical severity and treatment response to paroxetine in PD.
TL;DR: In this paper, the relations between regular production and contract workers in a major KG in the US were investigated. But the focus was on the relationship between contract workers and regular production workers.
Abstract: Against the background of a rise in contingent labour and an emphasis by employers on flexibility, this article focuses on the relations between regular production and contract workers in a major K...
TL;DR: Wild ginseng ethanol extract has potential as a preventive agent for type 2 diabetes mellitus (and possibly obesity) and deserves clinical trial in the near future.
Abstract: Ginseng is a shade-loving perennial herb that is cultivated mainly in Korea, Japan, and China. The ginseng root has been used as a tonic remedy, and its antidiabetic activity has been demonstrated as early as 1920s. Although wild ginseng was anecdotally thought to be superior to cultivated ginseng as far as pharmacological properties were concerned, there have been no prior reports on the antidiabetic effect of wild ginseng. In this study, we investigated the preventative anti-diabetic and anti-obese effects of wild ginseng ethanol extract (WGEE). In the preventive experiment, WGEE co-administered with a high fat diet significantly inhibited body weight gain, fasting blood glucose, triglyceride, and free fatty acid levels in a dose dependent manner. WGEE-treated mice at doses of 250 and 500 mg/kg improved the insulin resistance index by 55% and 61% compared to the high fat diet (HFD) control, respectively. Diameters of white and brown adipocytes were also decreased by 62% and 46% in the WG500-treated group compared to those in HFD fed control mice. Taken together, WGEE has potential as a preventive agent for type 2 diabetes mellitus (and possibly obesity) and deserves clinical trial in the near future.
TL;DR: An adaptive mode decision algorithm is presented, with rate-distortion optimisation that reduces complexity of the H.264 encoder without loss of image quality and compression ratio.
Abstract: An adaptive mode decision algorithm is presented, with rate-distortion optimisation that reduces complexity of the H.264 encoder without loss of image quality and compression ratio. The proposed algorithm uses the property of an all-zero coefficients block that is produced by quantisation and coefficient thresholding to effectively skip unnecessary modes. Experimental results show that the speed of the adaptive mode decision algorithm is two times faster than the full-mode decision algorithm of the JM72 reference encoder, without any coding loss.
TL;DR: It is suggested that the evolutionary history of the PlcR regulon differs from those of the other chromosomal genes and that recombination of the plcR gene may be frequent and shown to be of recent origin or to be due to the narrow taxonomic definition of species.
Abstract: The population structure of the Bacillus cereus group (52 strains of B. anthracis, B. cereus, and B. thuringiensis) was investigated by sequencing seven gene fragments (rpoB, gyrB, pycA, mdh, mbl, mutS, and plcR). Most of the strains were classifiable into two large subgroups in six housekeeping gene trees but not in the plcR tree. In addition, several consistent clusters were identified, which were unrelated to species distinction. Moreover, interrelationships among these clusters were incongruent in each gene tree. The incongruence length difference test and split decomposition analyses also showed incongruences between genes, suggesting horizontal gene transfer. The plcR gene was observed to have characteristics that differed from those of the other genes in terms of phylogenetic topology and pattern of sequence diversity. Thus, we suggest that the evolutionary history of the PlcR regulon differs from those of the other chromosomal genes and that recombination of the plcR gene may be frequent. The homogeneity of B. anthracis, which is depicted as an independent lineage in phylogenetic trees, is suggested to be of recent origin or to be due to the narrow taxonomic definition of species.
TL;DR: A simple algorithm is presented to solve the constrained longest common subsequence problem in O(n . m . r) time and it is shown that this problem is equivalent to a special case of the constrained multiple sequence alignment problem which can also be solved with the same time complexity.
TL;DR: The results suggest that 60 Hz, MF could deteriorate antioxidant defensive system by reactive oxygen species (ROS), other than superoxide radicals, other thansuperoxide radicals.
Abstract: Among the putative mechanisms, by which extremely low frequency (ELF) magnetic field (MF) may affect biological systems is that of increasing free radical life span in organisms. To test this hypothesis, we investigated whether ELF (60 Hz) MF can modulate antioxidant system in mouse brain by detecting chemiluminescence and measuring superoxide dismutase (SOD) activity in homogenates of the organ. Compared to sham exposed control group, lucigenin-initiated chemiluminescence in exposed group was not significantly increased. However, lucigenin-amplified t-butyl hydroperoxide (TBHP)-initiated brain homogenates chemiluminescence, was significantly increased in mouse exposed to 60 Hz, MF, 12 G for 3 h compared to sham exposed group. We also measured SOD activity, that plays a critical role of the antioxidant defensive system in brain. In the group exposed to 60 Hz, MF, 12 G for 3 h, brain SOD activity was significantly increased. These results suggest that 60 Hz, MF could deteriorate antioxidant defensive system by reactive oxygen species (ROS), other than superoxide radicals. Further studies are needed to identify the kind of ROS generated by the exposure to 60 Hz, MF and elucidate how MF can affect biological system in connection with oxidative stress.
TL;DR: In this paper, an ammonia gas sensor was prepared by polymerizing aniline on the surface of nylon 6 fabrics and doped with various acids, such as formic acid, acrylic acid and trichloroacetic acid.
Abstract: Conducting polymers constitute a new class of sensing materials, which can be prepared by a simple oxidative polymerization method. An ammonia gas sensor was prepared by polymerizing aniline on the surface of nylon 6 fabrics and doped with various acids in this study. The fabricated polyaniline (PANI)-nylon 6 composite fab- rics showed high sensitivity and fast response for NH3 gas. In particular, the PANI-nylon 6 composite fabrics doped by monocarboxylic acids (such as formic acid, acrylic acid, and trichloroacetic acid) displayed excellent sensitivity and fast response. Moreover, no significant changes in the Tm and crystallinity were found in these composite fabrics. Hence the PANI-nylon 6 composite fabrics are attractive alterna- tives for use in sensing applications because of their excel- lent sensing ability, low cost, and ease of preparation. © 2004
TL;DR: In this paper, the authors investigated the relationship between Cl/sub 2/Ar mixing ratio, plasma parameters, plasma chemistry and etching kinetics using a combination of experimental investigations and modeling.
Abstract: In this paper, we investigated the relationships between Cl/sub 2/--Ar mixing ratio, plasma parameters, plasma chemistry and etching kinetics using a combination of experimental investigations and modeling. Modeling of plasma chemistry was represented by zero-dimensional quasi-stationary model assuming electron energy distribution to be close to Maxwellian. For the surface kinetics, we used the simplified model based on the theory of active surface sites. The model confirmed the possibility of nonmonotonic behavior of etch rate behavior in the system with monotonic changes of fluxes of active species.
TL;DR: In this paper, the structure and thermal behavior of boron nitride (BN) nanotubes were investigated using molecular-dynamics simulations based on the Tersoff-like potential.
Abstract: We investigate the structure and thermal behaviour of boron nitride (BN) nanotubes using molecular-dynamics simulations based on the Tersoff-like potential. The strain energy decreases with increasing diameter, which is proportional to the inverse square of the tube diameter on the basis of continuum elastic theory. The disintegration temperature of zigzag nanotubes is smaller than that of armchair nanotubes of nearly the same diameter and increases with increasing diameter due to the decrease in strain energy. Despite homoelemental bonds, the Stone–Wales (SW) defect is found in BN nanotubes during thermal treatment. The formation energy of the SW defect increases with increasing tube diameter. These results agree well with the trend for carbon nanotubes.
TL;DR: In this article, an equation which describes the dependence of critical micelle concentration (XCMC) with temperature was derived on the basis of Δ G 0 =−RT ln K, linear behavior of the enthalpy of micellization with temperature, and compensation phenomena in which the entropy and the change linearly with each other.
TL;DR: In this paper, the authors investigated the diffusion of copper nanoclusters in carbon nanotubes using a classical molecular dynamics simulation and three empirical potential functions, and the results indicated a growth mechanism of the copper-filled ultra-thin carbon Nanotubes.
23 Jun 2004
TL;DR: A method of synonymous paraphrasing of a text based on WordNet synonymy data and Internet statistics of stable word combinations (collocations) and steganography: hiding of additional information in the text by special selection of synonyms is proposed.
Abstract: We propose a method of synonymous paraphrasing of a text based on WordNet synonymy data and Internet statistics of stable word combinations (collocations). Given a text, we look for words or expressions in it for which WordNet provides synonyms, and substitute them with such synonyms only if the latter form valid collocations with the surrounding words according to the statistics gathered from Internet. We present two important applications of such synonymous paraphrasing: (1) style-checking and correction: automatic evaluation and computer-aided improvement of writing style with regard to various aspects (increasing vs. decreasing synonymous variation, conformistic vs. individualistic selection of synonyms, etc.) and (2) steganography: hiding of additional information in the text by special selection of synonyms. A basic interactive algorithm of style improvement is outlined and an example of its application to editing of newswire text fragment in English is traced. Algorithms of style evaluation and information hiding are also proposed.
Journal Article•
TL;DR: The main aim of this review was to evaluate the current literature regarding the pathovirology, diagnostics, vaccines, therapy, risk groups, and further therapeutic directions for HPV infections in South Korean women, as evidenced by data.
Abstract: Papillomaviruses infect a wide variety of animals, including humans. The human papillomavirus (HPV), in particular, is one of the most common causes of sexually transmitted disease. More than 200 types of HPV have been identified by DNA sequence data, and 85 HPV genotypes have been well characterized to date. HPV can infect the basal epithelial cells of the skin or inner tissue linings, and are, accordingly, categorized as either cutaneous or mucosal type. HPV is associated with a panoply of clinical conditions, ranging from innocuous lesions to cervical cancer. In the early 1980s, studies first reported a link between cervical cancer and genital HPV infection. Genital HPV infections are now recognized to be a major risk factor in at least 95% of cervical cancers. 30 different HPV genotypes have been identified as causative of sexually transmitted diseases, most of which induce lesions in the cervix, vagina, vulva, penis, and anus, as the result of sexual contact. There is also direct evidence demonstrating that at least four of these genotypes are prerequisite factors in cervical cancer. The main aim of this review was to evaluate the current literature regarding the pathovirology, diagnostics, vaccines, therapy, risk groups, and further therapeutic directions for HPV infections. In addition, we reviewed the current status of HPV infections in South Korean women, as evidenced by our data.
TL;DR: In this paper, an inverse radiation analysis is presented for estimating the wall emissivities for an absorbing, emitting, scattering media in a two-dimensional irregular geometry with diffusely emitting and reflecting opaque boundaries from the measured temperatures.
Abstract: An inverse radiation analysis is presented for estimating the wall emissivities for an absorbing, emitting, scattering media in a two-dimensional irregular geometry with diffusely emitting and reflecting opaque boundaries from the measured temperatures. The finite-volume method was employed to solve the radiative transfer equation for 2D irregular geometry. The hybrid genetic algorithm which contains local optimization algorithm was adopted to estimate wall emissivities by minimizing an objective function, while reducing computation time. It was found that an increase in the standard deviation in measurements significantly deteriorated the estimation of wall emissivities. Thus, a very accurate measurement was required in inverse radiation for better estimation of wall emissivities, especially, in a high temperature environment.
TL;DR: Transformed hairy roots were efficiently induced from seedlings of Taraxacum platycarpum by infection with Agrobacterium rhizogenes 15834 and transgenic plantlets showed considerable differences in their morphology when compared to the corresponding wild-type (non-transgenic) plants.
Abstract: Transformed hairy roots were efficiently induced from seedlings of Taraxacum platycarpum by infection with Agrobacterium rhizogenes 15834. Root explants produced transformed roots at a higher frequency (76.5±3.5%) as compared to stem (32.7±4.8%) or cotyledon (16.2±5.7%). Hairy roots exhibited active elongation with high branching of roots on growth regulator-free medium. The competence of plant regeneration from non-transformed adventitious roots and transformed hairy roots was compared. The frequency of adventitious shoot formation from transformed roots was much higher (88.5±9.8%) than that of non-transformed roots (31.7 ±9.5%) on hormone-free medium. Rooting of hairy root-derived adventitious shoots occurred easily on growth regulator-free medium but no rooting was observed on non-transformed shoots. The stable introduction of rol genes into Taraxacum plants was confirmed by PCR and Southern hybridization. Transgenic plantlets showed considerable differences in their morphology when compared to the corresponding wild-type (non-transgenic) plants. Plantlets formed from transformed roots had numerous fibrous roots with abundant lateral branches instead of the thickened taproots in non-transformed plants. The differences observed may reflect the modification of morphological root characters by introduction of rol genes.
TL;DR: In this article, a direct method for the synthesis of α-halocarbonyl compounds using sequential treatment of carbonyls compounds with [hydroxy(tosyloxy)iodo]benzene followed by magnesium halides under solvent-free microwave irradiation conditions is described.
TL;DR: It is evident from the data that the two Tsukamurella strains isolated from activated sludge foam should be classified as a novel Tsuk amurella pseudospumae sp.
Abstract: The taxonomic position of two Tsukamurella strains isolated from activated sludge foam was clarified. The organisms, isolates JC85 and N1176T, were found to have chemical and morphological properties typical of members of the genus Tsukamurella. DNA–DNA relatedness studies showed that the strains formed a distinct genomic species that was most closely related to Tsukamurella spumae. The two isolates also share a range of phenotypic properties that distinguishes them from representatives of all species of Tsukamurella with validly published names. It is evident from the data that the two organisms should be classified as a novel Tsukamurella species, Tsukamurella pseudospumae sp. nov. The type strain is N1176T (=DSM 44118T=NCIMB 13963T).
TL;DR: In this article, cross-cultural differences in the amount and meaning of context-sensitive self were investigated in three Western cultures (Australia, Germany, and UK) and two East Asian cultures (Japan and Korea).
Abstract: Self-concepts change from context to context. The experience that one's self is context-sensitive may be universal, however the amount and meaning of context-sensitive self vary across cultures. Cross-cultural differences in the amount and meaning of context-sensitive self were investigated in three Western cultures (Australia, Germany, and UK) and two East Asian cultures (Japan and Korea). The amount of context-sensitivity of self was greater in Japan than in Western cultures and Korea. The meaning of context-sensitive self also varied across cultures. In the Western cultures, a context-invariant self was seen to be clear and true; however, these patterns were not observed in the East Asian cultures. In Korea, a context-invariant self was interpreted to be exhibiting a relational self, which adheres to the ethics of care. In Japan, it was a context-sensitive self that was seen to be true, implying that the true self in Japan may mean to be true to the self-in-context, rather than the transcendental, decontextualized self. The results suggest the importance of differentiating East Asian cultures such as Japan and Korea. The utility of quantitative methods in explicating cultural meaning was highlighted.
TL;DR: Elevated MGO levels observed in diabetes may cause apoptosis in bovine retinal pericytes through an oxidative stress mechanism and suggests that the nuclear activation of NF-κB are involved in the apoptotic process.
Abstract: One of the histopathologic hallmarks of early diabetic retinopathy is the loss of pericytes. Evidences suggest that the pericyte loss in vivo is mediated by apoptosis. However, the underlying cause of pericyte apoptosis is not fully understood. This study investigated the influence of methylglyoxal (MGO), a reactive alpha-dicarbonyl compound of glucose metabolism, on apoptotic cell death in bovine retinal pericytes. Analysis of internucleosomal DNA fragmentation by ELISA showed that MGO (200 to 800 microM) induced apoptosis in a concentration-dependent manner. Intracellular reactive oxygen species were generated earlier and the antioxidant, N-acetyl cysteine, inhibited the MGO-induced apoptosis. NF-kappaB activation and increased caspase-3 activity were detected. Apoptosis was also inhibited by the caspase-3 inhibitor, Z-DEVD-fmk, or the NF-kappaB inhibitor, pyrrolidine dithiocarbamate. These data suggest that elevated MGO levels observed in diabetes may cause apoptosis in bovine retinal pericytes through an oxidative stress mechanism and suggests that the nuclear activation of NF-kappaB are involved in the apoptotic process.