• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.37 no.3
• /
• pp.219-226
• /
• 2011

The Echinacea, which has been commonly known as a species of composite herb of dicotyledonous plant, has been used in native American traditional medicine for the treatment of diseases like colds or other infections in North America. We artificially cultured the adventitious roots of Echinacea angustifolia using the bioreactor culture system from Echinacea angustifolia and evaluated the efficacy as a cosmetic ingredient for skin care. Several studies previously have reported neogenesis, wound healing and inflammatory inhibition effect of Echinacea angustifolia but other efficacies were not well known. In the present study, we investigated the cosmetic efficacy to know applicable value of adventitious roots cultured from Echinacea angustifolia as a cosmetic ingredient. The adventitious roots extract of Echinacea angustifolia has superior anti-oxidant effect and matrix metalloproteinase-2 inhibitory effect, compared to natural Echinacea angustifolia. These results indicate that the adventitious roots extract cultured from Echinacea angustifolia presents a new possibility of being applicable to skin care and anti-wrinkle products as a cosmetic ingredient.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.33 no.2
• /
• pp.61-67
• /
• 2007

In this study, the antioxidative effects of Equisetum arvense extracts were investigated. The free radical (1,1 diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC_{50}$) of extract/fractions of Equisetum arvense was in the order: 50 % ethanol extract ($182.04{\mu}g/mL$) < ethylacetate fraction ($54.50{\mu}g/mL$) < deglycosylated flavonoid aglycone fraction ($14.13{\mu}g/mL$). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of some Equisetum arvense extracts on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system were investigated using the luminol- dependent chemiluminescence assay. The order of ROS scavenging activity was deglycosylated flavonoid aglycone fraction ($OSC_{50}$, $3.54{\mu}g/mL$) < 50 % ethanol extract ($0.80{\mu}g/mL$) < ethylacetate fraction ($0.006{\mu}g/mL$). Ethylacetate fraction showed the most prominent scavenging activity. The protective effects of extract/fractions of Equisetum arvense on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The ethanol extract (50%) suppressed photohemolysis in a concentration dependent manner, particularly deglycosylated aglycone extract exhibited the most prominent celluar protective effect ($\tau_{50}$, 161.10 min at $10{\mu}g/mL$). These results indicate that extract/fractions of Equisetum arvense can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS.

• Korean journal of applied entomology
• /
• v.39 no.1
• /
• pp.53-58
• /
• 2000

The effect of NeemAzal-T/S was tested by leaf disk method on fecundity, egg mortality, and preference of twospotted spider mite, Tetranychus urticae and its predator mite, Amblyseius womersleyi in the laboratory. Mortalities of T. urticae and A. womersleyi adults were 97.7% and 20.0%, in 100ppm treatment at 72 h after application, respectively. The mean number of eggs laid per T. urticae female adult were 0.0 and 18.5, and those of A. womersleyi were 1.6 and 2.9 at 100 ppm and 0 ppm concentrations, respectively. Hatchability of T. urticae eggs treated with 50 and 100 ppm were 52.8%, and 2.5%, respectively, and those of A. womersleyi eggs were 100% and 91.3%, respectively. Choice and no-choice tests revealed that T. urticae female preferred to alight and oviposit on untreated bean leaf disk with 13.8 to 18.2 eggs per female. In contrast, A. womersleyi female preferred on treated or untreated bean leaf equally. There was no significant differences in the number of consumption of T. urticae eggs by A. womersleyi on treated and untreated bean leaves, except 200 ppm. These results indicate that NeemAzal-TIS is highly toxic to T. urticae, and is less toxic to A. womersleyi. It may be concluded with these results that NeemAzal-T/S could be incorporated into integrated T. urticae management system.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.42 no.6
• /
• pp.23-36
• /
• 2005

PLLs have been widely used for many applications including communication systems. This paper presents a VCO with an improved negative skewed delay scheme and a PLL using this VCO. The proposed VCO and PLL are intended for replacing traditional LC oscillators and PLLs used in communication systems and other applications. The circuit designs of the VCO and PLL are based on 0.18um CMOS technology with 1.8V supply voltage. The proposed VCO employs subfeedback loops using pass-transistors and needs two opposite control voltages for the pass transistors. The subfeedback loops speed up oscillation depending on the control voltages and thus provide a high oscillation frequency. The two voltage controls have opposite frequency gain characteristics and result in low phase-noise. The 7-stage VCO in 0.18um CMOS technology operates from $3.2GHz\~6.3GHz$ with phase noise of about -128.8 dBc/Hz at 1MHz frequency onset. For 1.8V supply voltage, the current consumption is about 3.8mA. The proposed PLL has dual loop-filters for the proposed VCO. The PLL is operated at 5GHz with 1.8V supply voltage. These results indicate that the proposed VCO can be used for radio frequency operations replacing LC oscillators. The circuits have been designed and simulated using 0.18um TSMC library.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.53 no.1
• /
• pp.118-125
• /
• 2016

This study evaluates the performance of image to patient registration algorithm by using stereo vision and CT image for facial region surgical navigation. For the process of image to patient registration, feature extraction and 3D coordinate calculation are conducted, and then 3D CT image to 3D coordinate registration is conducted. Of the five combinations that can be generated by using three facial feature extraction methods and three registration methods on stereo vision image, this study evaluates the one with the highest registration accuracy. In addition, image to patient registration accuracy was compared by changing the facial rotation angle. As a result of the experiment, it turned out that when the facial rotation angle is within 20 degrees, registration using Active Appearance Model and Pseudo Inverse Matching has the highest accuracy, and when the facial rotation angle is over 20 degrees, registration using Speeded Up Robust Features and Iterative Closest Point has the highest accuracy. These results indicate that, Active Appearance Model and Pseudo Inverse Matching methods should be used in order to reduce registration error when the facial rotation angle is within 20 degrees, and Speeded Up Robust Features and Iterative Closest Point methods should be used when the facial rotation angle is over 20 degrees.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.49 no.7
• /
• pp.39-47
• /
• 2012

The combination of the broadband property and the wide area coverage of satellite communications enables high speed transmission. Every user in the region under the satellite beam coverage can tranceiver and one can simultaneously communicate with multiple users. For these reasons, it is one of commendable telecommunication networks for information transfer. Since the satellite communications use open channels, it is likely to cause jamming with unwanted interference signals. In the thesis, APSK (Amplitude Phase Shift Keying) is employed, which is recommended for DVB-S2 due to high-speed transmission and excellent bandwidth efficiency. For obtaining reliable communication under the jamming environments, the communication satellite transponder rests on the polyphase filter bank structure, which enables switching among the subchannels and gain control on each subchannel, resulting in effectively eliminating jamming. Furthermore, the nulling scheme, one of the various anti-jamming approaches, is investigated, in which unwanted jamming signals are eliminated in the frequency domain after passing through the analysis part of the polyphase filter bank. The performance of the nulling scheme is evaluated for tone jamming and partial band jamming in terms of BER and EVM. The simulation results indicate that the nulling scheme improve the BER and EVM performance over the case without any anti-jamming approach.

• Physical Therapy Korea
• /
• v.18 no.1
• /
• pp.57-63
• /
• 2011

The purpose of this study was to identify the effects of manual facilitation and a stick on lumbar and hip joint flexion angles in subject with lumbar flexion syndrome during forward bending from a sitting position. Fifteen subjects with lumbar flexion syndrome were recruited for this study. As a pretest, all subjects performed three repetitions of bending the trunk forward until the tips of their fingers touched the target bar. After this pretest, the subjects practiced the forward bending of the trunk 10 times, using either manual facilitation or a stick. Then, as a posttest, all subjects repeated the pretest procedure. The flexion angles of lumbar spine and hip joint during forward bending in a sitting position were measured using a three-dimensional motion analysis system. A paired t-test was used to determine the statistical differences between pre-test and post-test flexion angles and pre- and post-test flexion angle differences between forward bending with manual facilitation and forward bending with a stick. The level of statistical significance was set at p=.05. The results of the study showed that the angle of the lumbar flexion decreased significantly and the bilateral hip flexion angle increased significantly when performing forward bending with stick and manual facilitation. Furthermore, the angle of lumbar flexion decreased significantly and the angle of bilateral hip flexion increased significantly in forward bending with a stick compared to forward bending with manual facilitation. The findings of this study indicate that both forward bending with manual facilitation and sticks could be used to prevent excessive lumbar flexion and increase hip flexion, and that forward bending with a stick is more effective than forward bending with manual facilitation for inducing lumbar spine and hip joint angle changes.

• Proceedings of the Korea Environmental Mutagen Society Conference
• /
• 2002.05a
• /
• pp.36-42
• /
• 2002

Diesel exhaust (DE) has been recognized as a noxious mutagen and/or carcinogen, because its components can form DNA adducts. Mechanisms governing the susceptibility to DE and the efficiency of such DNA adduct formation require clarification. The transcription factor Nrf2 is essential for inducible and/or constitutive expression of a group of detoxification and antioxidant enzymes, and we hypothesized that the nrf2 gene knockout mouse might serve as an excellent model system for analyzing DE toxicity. To address this hypothesis, lungs from nrf2(-/-) and nrf2(+/-) mice were examined for the production of xenobiotic-DNA adducts after exposure to DE (3 $mg/m^{3}$ suspended particulate matter) for 4 weeks. Whereas the relative adduct levels (RAL) were significantly increased in the lungs of both nrf2(+/-) and nrf2(-/-) mice upon exposure to DE, the increase of RAL in the lungs from nrf2(-/-) mice exposed to DE were approximately 2.3-fold higher than that of nrf2(+/-) mite exposed to DE. In contrail, cytochrome P4501Al mRNA levels in the nrf2(-/-)mouse lungs were similar to those in the nrf2(+/-) mouse lungs even after exposure to DE, suggesting that suppressed activity of phase II drug-metabolizing enzymes is important in giving ise to the increased level of DNA adducts in the Nrf2-null mutant mouse subjected to DE. Importantly, severe hyperplasia and accumulation of the oxidative DNA adduct 8-hydroxydeoxyguanosine were observed in the bronchial epidermis of nrf(-/-) mite following DE exposure. These results demonstrate the increased susceptibility of the nrf2 germ line mutant mouse to DE exposure and indicate the nrf2 gene knockout mouse nay represent a valuable model for the assessment of respiratory DE toxicity.

• Journal of Korean Elementary Science Education
• /
• v.25 no.4
• /
• pp.430-453
• /
• 2006

The purpose of this study was to explore how an elementary school teacher developed PCK by utilizing her knowledge domains in teaching practice, regarding the specific science topic of 'animals:' A case study approach was adopted with the participation of a 1st grade teacher, in a poor urban neighborhood elementary school in NYC. Data was collected through interview and the participant observation method in order to investigate: a) the teacher's existing knowledge base in terms of subject matter knowledge, pedagogical knowledge and contextual knowledge; b) how she develops PCK during classroom practice, centering on the relationship between knowledge domains. The findings illustrate the ways in which the three knowledge domains are closely related and developed as PCK through the whole teaching process. In particular, the findings indicate that the teacher's contextual knowledge plays a critical role in shaping and developing PCK. Before instruction, her contextual knowledge regarding the administrative policies and the school test system in the district enabled her to make decisions and plans about teaching science. During classroom teaching, her knowledge of students' sociocultural backgrounds and living conditions in the urban setting helped her to identify specific teaching strategies and resources suitable to the students' needs and interests. The study results imply that science instruction can be more feasible in meeting the demands of particular groups of students if teachers make an effort to become knowledgeable about their own teaching context and utilize it in developing their PCK.

• The Journal of Korean Academy of Prosthodontics
• /
• v.45 no.3
• /
• pp.362-374
• /
• 2007

Statement of problem. The intial stability for osseointegration of implant has been an interesting factor. Especially, in the case of poor bone quality or immediately loaded implant, various strategies have been developed focusing on the surface of materials to improve implant fixation to bone. The microscopic properties of implant surfaces play a major role in the osseous healing of dental implants. Purpose. The aims of this study are to perform a histologic and histomorphometric comparison of the healing characteristics of three different surfaces and the comparison of resonance frequency analysis (RFA) values measured by $Osstell^{TM}$ and perio-test values (PTV) measured by Periotest. Material and methods. A total of 24 screw titanium implants (Dentium Co., Seoul, Korea) with 6mm in length and 3.4mm in diameter, were placed in the mandible of 4 beagle dogs. Implants were divided into three groups following the surface treatment methods: Group I is machined(control group). Group II is anodically oxidized. Group III is coated 500nm in thickness with hydroxyapatite(HA) by ion beam assisted deposition(IBAD) on the anodized oxidization. Bone blocks from 2 dogs were caught after 3 weeks of covered healing and another blocks from 2 dogs after 6 weeks. RFA values and PTV were measured right after insertion and at 3 and 6weeks. Histomorphometric analysis was made with Kappa Image Base System to calculate bone-to-implant contact (BIC) and bone area inside the threads. Pearson's correlation analyses were performed to evaluate the correlation between RFA and PTV, BIC and bone area ratio of three different surfaces at 3 and 6 weeks. Results. 1) In all surface treatment methods, the RFA values decreased and the PTV values increased until 6 weeks in comparison to initial values. 2) At 3 weeks, no significant difference was found from bone-to-implant contact ratio and bone area ratio of three different surface treatment methods(P>0.05). However, at 6 weeks, different surface treatment methods showed significantly different bone-toimplant contact ratio and bone area ratio(P<0.05). 3) In the implants with the IBAD on the anodic oxidization, significant difference was found between the 3 weeks and the 6 weeks bone area ratio(P<0.05). 4) Correlation was found between the RFA values and the bone area ratio at 3 and 6 weeks with significant difference(P<0.05). Conclusions. These results indicate that the implants with the IBAD on the anodic oxidization may have a high influence on the initial stability of implant.