• Title/Summary/Keyword: biological applications

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High Frequency Noise Reduction in ECG using a Time-Varying Variable Cutoff Frequency Lowpass Filter (시변 가변차단주파수 저역통과필터를 이용한 심전도 고주파 잡음의 제거)

  • 최안식;우응제;박승훈;윤영로
    • Journal of Biomedical Engineering Research
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    • v.25 no.2
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    • pp.137-144
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    • 2004
  • ECG signals are often contaminated with high-frequency noise such as muscle artifact, power line interference, and others. In the ECG signal processing, especially during a pre-processing stage, numerous noise removal techniques have been used to reduce these high-frequency noise without much distorting the original signal. This paper proposes a new type of digital filter with a continuously variable cutoff frequency to improve the signal quality This filter consists of a cutoff frequency controller (CFC) and variable cutoff frequency lowpass filter (VCF-LPF). From the noisy input ECG signal, CFC produces a cutoff frequency control signal using the signal slew rate. We implemented VCF-LPF based on two new filter design methods called convex combination filter (CCF) and weight interpolation fille. (WIF). These two methods allow us to change the cutoff frequency of a lowpass filter In an arbitrary fine step. VCF-LPF shows an excellent noise reduction capability for the entire time segment of ECG excluding the rising and falling edge of a very sharp QRS complex. We found VCF-LPF very useful and practical for better signal visualization and probably for better ECG interpretation. We expect this new digital filter will find its applications especially in a home health management system where the measured ECG signals are easily contaminated with high-frequency noises .

Controlling Activity of Bacillus subtilis KB-401 against Cucumber Powdery Mildew Caused by Sphaerotheca fusca (오이 흰가루병에 대한 Bacillus subtilis KB-401의 방제 효과)

  • Nam, Myung-Hyeun;Choi, Jae-Pil;Kim, Hyung-Jo;Lee, Jae-Jun;Lim, Keun-Hwan;Kim, Young-Gwon;Kim, Heung-Tae;Jeun, Yong-Chull
    • The Korean Journal of Pesticide Science
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    • v.14 no.1
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    • pp.49-53
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    • 2010
  • Disease control efficacy was evaluated with use of Bacillus subtilis KB-401 against cucumber powdery mildew in a greenhouse and fields. B. subtilis KB-401 showing inhibitory effect on mycelial growth of various phytopathogenic fungi was formulated for the evaluation. The formulated biofungicide of B. subtilis KB-401 was less effective at 1,000 times dilution rate than that at 250 or 500 times dilution rate. The powdery mildew was successfully controlled by the biofungicide at the early stage of disease development. The field performance of the biofungicde was conducted in Asan and Cheonan city. Three or four consecutive applications of the biofungicide at 500 dilution rate with 10-day intervals resulted in considerable efficacy of disease control as high as 83.3%.

Comparative study of 202 herbs on interferon-gamma secretion (202종(種) 한약재(韓藥材)의 $IFN-{\gamma}$ 분비조절에 관한 비교연구)

  • Rhee, See-Hyung;Kang, Mi-Suk;Choi, You-Kyung;Jun, Chan-Yong;Park, Chong-Hyeong;Kim, Dong-Woo
    • The Journal of Internal Korean Medicine
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    • v.27 no.2
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    • pp.336-344
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    • 2006
  • Objects : This study has been carried out to assess the effects of the variable herbs on $IFN-{\gamma}$ secretion in the mouse spleen cell. Methods : 202 kinds of herb extracts were used to evaluate the $IFN-{\gamma}$ secretory distinction by each $1{\mu}g/ml$ and $10{\mu}g/ml$ density of water. All experimental herbs were grouped by oriental herbalogical method. But each herb had its independent variables. Results : The secretions increased in 20% of all herbal water. The density differences also make different effects on the secretion of $IFN-{\gamma}$. The secretion of IFN-${\gamma}$ inclosed in some kinds of herbs of IFN-${\gamma}$. It has representatively increased in Imperaetae Rhizoma(白茅根) of $1{\mu}g/ml$ and Notopterygii Rhizoma(羌活)of $10{\mu}g/ml$. $IFN-{\gamma}$ incresed in 12 kinds of heybs of both densities. The secretion of $IFN-{\gamma}$ decreased in some kinds of herbs of $IFN-{\gamma}$. It has representatively decreased in Moutan Radicis Cortex(蘇丹皮) of $1{\mu}g/ml$ and Angelicae Radix(富歸尾) of $10{\mu}g/ml$. $IFN-{\gamma}$ decreased in 18 kinds of herbs of both densities. In t oriental herb group, The secretion of $IFN-{\gamma}$ increased in Bang-Hyang-Hwa-Sup group(芳香化濕藥), He-Pyo group(解表藥), I-Su-Sam-SuP group(利水渗) The secretion of $IFN-{\gamma}$ decreased in Gu-Chung group(驅蟲藥), An-Sin group(安神藥). Su-Sap group(收澁) On-Li group(溫裏藥), I-Gi group(利氣藥). Conclusions : The result of this study will not only broaden applications of oriental medicine to biological therapy, but also form the basis of oriental medical therapy to find out the meaning of oriental classification.

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Current Status of Registered Korean Patents Related to the Health Functional Food for Skin Care (피부미용 관련 건강기능식품 국내 특허 등록현황)

  • Chung, Kap-Taeck;Lee, Sang-Hyun
    • The Korean Journal of Food And Nutrition
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    • v.25 no.2
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    • pp.308-316
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    • 2012
  • Proper skin care promotes good metabolism and the biological activity of skin, helps maintain the skin in a healthy and beautiful state when combined with nutritional nourishment. Health functional foods are being used for the purpose of enhancing efficient skin care. Health functional foods related to skin care maintain the epidermis, dermal fibroblast layer and subcutaneous tissue that form the skin. Efficient functional foods alleviate the signs of endogenous aging that come with getting older and exogenous aging caused by sunlight. Even though the field of skin care related to health functional foods has received less attention and been the subject of less research compared to functional cosmetics which are developing widely, this area of skin care that maintains and improves the layer of dermal fibroblast through the intake of food, is expected to progress with the commercialization of products in many fields when the related technical research development is galvanized and the related patents are applied for. Research into health functional foods related to skin care in Korea started rather late in comparison to other advanced countries where patents for relevant techniques have been applied for since 1990's together with research conducted on how they might be used for practical purposes. This study used the key words 'skin care, health functional food' to search for Korean patents that have been applied for at the Korean Intellectual Property Office from 1983 to 2011 using the KIPRIS database, in order to help researchers in the related fields by organizing the patented formulas for health functional foods for skin care which have gained attention recently. According to the number of registrations in each industry field, the total number of patents was 1,120 we screened the major patents among them, the field with the largest number was food foodstuff non-alcoholic beverage and preparation or treatment(A23L) with 135, then natural plant medicine & medical supplies and cosmetics(A61K) with 112, microorganisms or enzymes(C12N) with 63, heterocyclic compounds(C07D) with 44, horticulture or cultivation of sea weeds, forestry(A01G) 16 times, listed from the highest to the lowest number of applications. It has been revealed that food, foodstuff, non-alcoholic beverage and preparation or treatment(A23L) was the industry field where the most patents for health functional foods related to skin care were registered.

Improved Vapor Recognition in Electronic Nose (E-Nose) System by Using the Time-Profile of Sensor Array Response (센서 응답의 Time-Profile 을 이용한 전자 후각 (E-Nose) 시스템의 Vapor 인식 성능 향상)

  • Yoon Seok, Yang
    • Journal of Biomedical Engineering Research
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    • v.25 no.5
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    • pp.329-334
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    • 2004
  • The electronic nose (E-nose) recently finds its applications in medical diagnosis, specifically on detection of diabetes, pulmonary or gastrointestinal problem, or infections by examining odors in the breath or tissues with its odor characterizing ability. The odor recognition performance of E-nose can be improved by manipulating the sensor array responses of vapors in time-profile forms. The different chemical interactions between the sensor materials and the volatile organic compounds (VOC's) leave unique marks in the signal profiles giving more information than collection of the conventional piecemal features, i.e., maximum sensitivity, signal slopes, rising time. In this study, to use them in vapor recognition task conveniently, a novel time-profile method was proposed, which is adopted from digital image pattern matching. The degrees of matching between 8 different vapors were evaluated by using the proposed method. The test vapors are measured by the silicon-based gas sensor array with 16 CB-polymer composites installed in membrane structure. The results by the proposed method showed clear discrimination of vapor species than by the conventional method.

Surface Reaction Products of CP- Ti and Ti-25wt%Pd Castings Used for Dental Application (치과용 티타늄 및 Ti-25wt%Pd 주조체의 표면반응생성물)

  • 정준영;문수;이진형
    • Journal of Biomedical Engineering Research
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    • v.25 no.5
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    • pp.383-389
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    • 2004
  • A commercially pure Ti(CP-Ti) and Ti-25wt%Pd alloy for dental applications were cast into a phosphate-bonded Al$_2$ $O_3$/ $SiO_2$ investment mold and the surface of the casting specimens were investigated by means of SEM/EDS, XRD and XPS. The addition of 25wt%Pd in CP-Ti showed a moderate mold reaction owing to the considerable lowering of melting point. XRD analysis of the investment after burn-out treatment revealed that it consisted essentially of $SiO_2$, Al$_2$ $O_3$, P$_2$O$\_$5/, Mg$_3$(P $O_4$)$_2$, AlP $O_4$, Mg$_2$ $SiO_4$, MgAl$_2$ $O_4$ The mold reaction products were Ti$\_$5/Si$_3$ and Ti $O_2$ in case of CP-Ti casting and Ti $O_2$ and SiO$\_$x/ in case of Ti-25wt% Pd casting.

Studies on the Effects of Systematic Applications of Several Insecticides on the Population of the Brown Planthopper, Nilaparvata lugens Stal. II. Some Properties of Buprofezin (Applaud) and Isoprothiolane (Fuji-one) in their Effects upon the BPH Population (살충제의 체계적 처리에 의한 벼멸구개체군밀도 억제효과에 관한 연구 II. Buprofezin(Applaud)과 Isoprothiolane(Fuji-one)의 벼멸구개체군 밀도억제에 미치는 몇가지 생물학적특성)

  • 배윤환;현재선
    • Korean journal of applied entomology
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    • v.28 no.2
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    • pp.61-68
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    • 1989
  • To investigate the possibility of the BPH control by systematic application of insecticides, biological effects of buprofezin and isoprothiolane upon the BPH population was evaluated in the laboratory and pot. Both chemicals did not affect the developmental period of the nymphal stage with the applied dosages. When the buprofezin treated instar nymph was developed to the adult, adult's longevity was fairly reduced and such an effect of buprofezin was greater upon the younger instar nymphs. Residual effect of buprofezin was about 30 days in the pot. And it could suppress the BPH population when the younger instar nymphs were dominant age group in the population at the time of treatment. Isoprothiolane was also more effective for the suppression of the BPH population when the younger instar nymphs were dominant at the time of treatment. And it was expected that by buprofezin treatment in July the control effect of isoprothiolane against the BPH population could be maximized when it was treated to control the rice neck blast in late July or early August, because buprofezin could induce the biased population age distribution in which younger instar nymphs were main group at the time of isoprothiolane treatment.

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Usability of DNA Sequence Data: from Taxonomy over Barcoding to Field Detection. A Case Study of Oomycete Pathogens

  • Choi, Young-Joon;Thines, Marco
    • 한국균학회소식:학술대회논문집
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    • 2015.11a
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    • pp.41-41
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    • 2015
  • Oomycetes belong to the kingdom Straminipila, a remarkably diverse group which includes brown algae and planktonic diatoms, although they have previously been classified under the kingdom Fungi. These organisms have evolved both saprophytic and pathogenic lifestyles, and more than 60% of the known species are pathogens on plants, the majority of which are classified into the order Peronosporales (includes downy mildews, Phytophthora, and Pythium). Recent phylogenetic investigations based on DNA sequences have revealed that the diversity of oomycetes has been largely underestimated. Although morphology is the most valuable criterion for their identification and diversity, morphological species identification is time-consuming and in some groups very difficult, especially for non-taxonomists. DNA barcoding is a fast and reliable tool for identification of species, enabling us to unravel the diversity and distribution of oomycetes. Accurate species determination of plant pathogens is a prerequisite for their control and quarantine, and further for assessing their potential threat to crops. The mitochondrial cox2 gene has been widely used for identification, taxonomy and phylogeny of various oomycete groups. However, recently the cox1 gene was proposed as a DNA barcode marker instead, together with ITS rDNA. To determine which out of cox1 or cox2 is best suited as universal oomycete barcode, we compared these two genes in terms of (1) PCR efficiency for 31 representative genera, as well as for historic herbarium specimens, and (2) in terms of sequence polymorphism, intra- and interspecific divergence. The primer sets for cox2 successfully amplified all oomycete genera tested, while cox1 failed to amplify three genera. In addition, cox2 exhibited higher PCR efficiency for historic herbarium specimens, providing easier access to barcoding type material. In addition, cox2 yielded higher species identification success, with higher interspecific and lower intraspecific divergences than cox1. Therefore, cox2 is suggested as a partner DNA barcode along with ITS rDNA instead of cox1. Including the two barcoding markers, ITS rDNA and cox2 mtDNA, the multi-locus phylogenetic analyses were performed to resolve two complex clades, Bremia lactucae (lettuce downy mildew) and Peronospora effuse (spinach downy mildew) at the species level and to infer evolutionary relationships within them. The approaches discriminated all currently accepted species and revealed several previously unrecognized lineages, which are specific to a host genus or species. The sequence polymorphisms were useful to develop a real-time quantitative PCR (qPCR) assay for detection of airborne inoculum of B. lactucae and P. effusa. Specificity tests revealed that the qPCR assay is specific for detection of each species. This assay is sensitive, enabling detection of very low levels of inoculum that may be present in the field. Early detection of the pathogen, coupled with knowledge of other factors that favor downy mildew outbreaks, may enable disease forecasting for judicious timing of fungicide applications.

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Maximising the lateral resolution of near-surface seismic refraction methods (천부 탄성파 굴절법 자료의 수평 분해능 최대화 연구)

  • Palmer, Derecke
    • Geophysics and Geophysical Exploration
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    • v.12 no.1
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    • pp.85-98
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    • 2009
  • The tau-p inversion algorithm is widely employed to generate starting models with most computer programs, which implement refraction tomography. This algorithm emphasises the vertical resolution of many layers, and as a result, it frequently fails to detect even large lateral variations in seismic velocities, such as the decreases which are indicative of shear zones. This study demonstrates the failure of the tau-p inversion algorithm to detect or define a major shear zone which is 50m or 10 stations wide. Furthermore, the majority of refraction tomography programs parameterise the seismic velocities within each layer with vertical velocity gradients. By contrast, the Generalized Reciprocal Method (GRM) inversion algorithms emphasise the lateral resolution of individual layers. This study demonstrates the successful detection and definition of the 50m wide shear zone with the GRM inversion algorithms. The existence of the shear zone is confirmed by a 2D analysis of the head wave amplitudes and by numerous closely spaced orthogonal seismic profiles carried out as part of a later 3D refraction investigation. Furthermore, an analysis of the shot record amplitudes indicates that a reversal in the seismic velocities, rather than vertical velocity gradients, occurs in the weathered layers. The major conclusion reached in this study is that while all seismic refraction operations should aim to provide as accurate depth estimates as is practical, those which emphasise the lateral resolution of individual layers generate more useful results for geotechnical and environmental applications. The advantages of the improved lateral resolution are obtained with 2D traverses in which the structural features can be recognised from the magnitudes of the variations in the seismic velocities. Furthermore, the spatial patterns obtained with 3D investigations facilitate the recognition of structural features such as faults which do not display any intrinsic variation or 'signature' in seismic velocities.

Antioxidant and photoprotective activities of various extracts from the roots of Rumex crispus L. (소리쟁이(Rumex crispus L.) 뿌리 추출물의 항산화 및 광피해 억제 효과)

  • Kim, Yeon-Soon;Suh, Hwa-Jin;Park, Shin
    • Food Science and Preservation
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    • v.20 no.5
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    • pp.684-690
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    • 2013
  • The antioxidant and photoprotective effects of various extracts from the roots of Rumex crispus L. were evaluated. The concentrations ($IC_{50}$) of various extracts required to exert a 50% reducing effect on a DPPH radical were found to be 0.005~0.093 mg/mL. The ethyl acetate extract showed a more remarkable effect than the positive control ascorbic acid. The concentrations ($QC_{50}$) of the butanol and ethyl acetate extracts required to exert a 50% reducing effect on the singlet oxygen $^1O_2$ were found to be 0.464 and 0.365 mg/mL, respectively. Both extracts were also found to protect the in vitro biological system from the detrimental effect of a singlet oxygen $^1O_2$ on type II photosensitization in E. coli and genomic DNA. Among all the tested extracts, the ethyl acetate and butanol extracts contained higher amounts of total phenolic contents. The results suggest that our study may contribute to the development of new bioactive products with potential applications to the reduction of photo-produced oxidative stress involving reactive oxygen species in living organisms.