• Title/Summary/Keyword: biological methods

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Cyclic Peptides as Therapeutic Agents and Biochemical Tools

  • Joo, Sang-Hoon
    • Biomolecules & Therapeutics
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    • v.20 no.1
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    • pp.19-26
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    • 2012
  • There are many cyclic peptides with diverse biological activities, such as antibacterial activity, immunosuppressive activity, and anti-tumor activity, and so on. Encouraged by natural cyclic peptides with biological activity, efforts have been made to develop cyclic peptides with both genetic and synthetic methods. The genetic methods include phage display, intein-based cyclic peptides, and mRNA display. The synthetic methods involve individual synthesis, parallel synthesis, as well as split-and-pool synthesis. Recent development of cyclic peptide library based on split-and-pool synthesis allows on-bead screening, in-solution screening, and microarray screening of cyclic peptides for biological activity. Cyclic peptides will be useful as receptor agonist/antagonist, RNA binding molecule, enzyme inhibitor and so on, and more cyclic peptides will emerge as therapeutic agents and biochemical tools.

Effective grafting method for Korean jujube nursery tree

  • Park, Hee-Seung;Kim, Yong-Koo;Chung, Kyu-Hwan;Ahn, Young-Hee
    • Journal of Environmental Science International
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    • v.12 no.2
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    • pp.119-124
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    • 2003
  • An effective grafting method for jujube nursery trees was developed to shorten the operation time, improve the percentage of "takes" and shoot emergence, and form the better graft union. Out of 7 grafting methods the splice, modified scion Ono graft and the bark graft showed relatively short operation time during the grafting operation comparing to the modified rootstock Ono graft or the chip budding. Among these methods, the bark graft demonstrated 100% "takes", but the modified scion Ono graft or the standard Ono graft showed 58.3% of "takes". The percentages of the vegetative shoot emergence were 100% fir the bark graft, 70% f3r the modified scion Ono graft and lower emergence percent for the rest grafting methods. The union tissue formation for the modified scion Ono graft, the bark graft, or the whip-and-tongue graft was significantly larger than the standard Ono graft or the splice graft. In a close examination of the cross sectional areas of the graft union formation through the microscope, the bark graft was superior, the standard Ono graft was inferior and rest of the grafting methods were intermediate.ing methods were intermediate.

Comparison of covariance thresholding methods in gene set analysis

  • Park, Sora;Kim, Kipoong;Sun, Hokeun
    • Communications for Statistical Applications and Methods
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    • v.29 no.5
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    • pp.591-601
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    • 2022
  • In gene set analysis with microarray expression data, a group of genes such as a gene regulatory pathway and a signaling pathway is often tested if there exists either differentially expressed (DE) or differentially co-expressed (DC) genes between two biological conditions. Recently, a statistical test based on covariance estimation have been proposed in order to identify DC genes. In particular, covariance regularization by hard thresholding indeed improved the power of the test when the proportion of DC genes within a biological pathway is relatively small. In this article, we compare covariance thresholding methods using four different regularization penalties such as lasso, hard, smoothly clipped absolute deviation (SCAD), and minimax concave plus (MCP) penalties. In our extensive simulation studies, we found that both SCAD and MCP thresholding methods can outperform the hard thresholding method when the proportion of DC genes is extremely small and the number of genes in a biological pathway is much greater than a sample size. We also applied four thresholding methods to 3 different microarray gene expression data sets related with mutant p53 transcriptional activity, and epithelium and stroma breast cancer to compare genetic pathways identified by each method.

Trend and Perspective of Weed Control Techniques in Organic Farming (유기농 재배에서 잡초방제기술의 동향 및 전망)

  • Ock, Hwan-Suck;Pyon, Jong-Yeong
    • Korean Journal of Weed Science
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    • v.31 no.1
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    • pp.8-23
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    • 2011
  • Weeds are one of the major constraints to crop production in organic farming systems. This paper reviews major results and techniques achieved with physical, cultural, and biological weed control and their perspectives in organic agriculture. Physical methods includes mechanical, thermal, lighting, electrocution, pneumatic, autonomous robot weeding control techniques. Cultural weed control methods includes mulching, tillage, crop rotation, cover crops and crop competition. Physical and cultural weed control techniques are especially important in organic farming crops where other weed control options are limited or not available without use of herbicides. Biological weed control includes mycoherbicides, innundative biological control, broad-spectrum biological control and allelopathy. Successful weed management in organic farming requires well managed integrated systems of mechanical control using newly developed machines, cultural control and biological control methods. Weed management decision-aid models may also needed to develop to provide greater assurance of achieving profitability and appropriate long-term weed management in organic farming in the future.

Quantification of the galactose-operon mRNAs 5 bases different in their 5'-ends

  • Ji, Sang-Chun;Wang, Xun;Jeon, Heung-Jin;Yun, Sang-Hoon;Lee, Hee-Jung;Lim, Heon-M.
    • BMB Reports
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    • v.43 no.7
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    • pp.474-479
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    • 2010
  • Three assay methods for quantification of the two galactose-operon mRNAs that only differ by 5 bases in their 5'-end are presented. The 5' ends of each mRNA were extended by ligating the 3'-end of the abundant 5S rRNA. This ligation extends the 5' ends of the two gal mRNAs long enough to be distinguished by the specific PCR primers in the following quantification reactions. Quantification of the corresponding cDNAs was performed either by primer extension assay or real-time qPCR. To circumvent the problem of the RNA ligation reaction (i.e. very low ligation efficiency), we devised a new method that employs real-time qPCR directly for the quantification of the gal transcripts which differ by 5 bases in their 5'-ends.

Importance of taxonomic research for biodiversity of Korea

  • Hur, Wee-Haeng;Park, Chan-Ho;Min, Gi-Sik;Hyun, Chang-Woo;Bae, Eun Hee;Lee, Jeong Hyun;Jung, Eun-Hee;Yoo, Jung-Sun;Suh, Min Hwan
    • Journal of Species Research
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    • v.5 no.3
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    • pp.261-263
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    • 2016
  • In 2012, the NIBR started publishing the Journal of Species Research (JSR) as an international specialized journal of biological taxonomy focusing on taxonomic research. JSR Volume 5 Number 3, to be published in October 2016, has been planned as a 'Special Edition on New and Unrecorded Species of Invertebrates in Korea', and so it consists of the reports of 149 new and unrecorded invertebrate species (including protozoa) discovered in Korea. In future, the JSR should further accelerate the use of such methods to generate valid data for new species and effectively support the compilation of 'National List of Species of Korea'. In this way, it will contribute significantly to enrich for biodiversity in Korea.

Growth, reproduction and recruitment of Silvetia siliquosa (Fucales, Phaeophyceae) transplants using polyethylene rope and natural rock methods

  • Gao, Xu;Choi, Han Gil;Park, Seo Kyoung;Lee, Jung Rok;Kim, Jeong Ha;Hu, Zi-Min;Nam, Ki Wan
    • ALGAE
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    • v.32 no.4
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    • pp.337-347
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    • 2017
  • Silvetia siliquosa is an ecologically and commercially important brown alga that is harvested from its natural habitats, but its population has recently been diminishing along the Korean coast. To develop new techniques for algal population restoration, we tested two newly developed transplantation methods (using polyethylene ropes and natural rock pieces) at two study sites, Gwanmaedo and Yeongsando, on the southwest coast of Korea, from May to November 2014. The transplants on polyethylene ropes showed significantly greater survival, maturity, and growth than those on natural rocks at both study sites. Newly recruited juveniles (<3 cm) of S. siliquosa increased remarkably from May to December near the transplants on polyethylene ropes and natural rocks.Therefore, we suggest that transplantation using polyethylene ropes is more effective than using natural rocks to restore the population of S. siliquosa in Korea.

Polarography of Phenyl Mercuric Acetate (초산(醋酸)훼닐수은(水銀)의 Polarography)

  • Gang, Yeong-Gyu
    • Applied Biological Chemistry
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    • v.1
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    • pp.26-33
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    • 1960
  • Organic mercurial fungicides, for seed treatments and dust formulations, has been increasingly used by farmers. Evaluation of the purity of organic mercurial fungicides has been performed by precipitation method at this laboratory. There are several methods for the an alyses of organic mercuric formulation, among which are (1) Precipitation met hod, (2) Volatilization method, (3) Volumetric method, and (4) Dithizon method. These methods, however, show some deffects in specificity (differentiation of organic form) and quantitativity. Polarography applied for the estimation of phenyl mercuric acetate was found to be simple, rapid and accurate. Tile fundamental method of polarography arid accuracy of analysis are discussed statistically and a satisfactory results was obtained.

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Degree of Gelatinization of Cooked Sweet Potatoes by Different Cooking Methods (가열방법에 따른 고구마의 호화도 측정)

  • Shin, Mal-Shick;Ahn, Seung-Yo
    • Applied Biological Chemistry
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    • v.29 no.4
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    • pp.372-374
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    • 1986
  • Changes in moisture content and degrees of gelatinization during cooking of sweet potatoes by different cooking methods were studied. The samples were cooked by boiling, steaming, gas oven or microwave oven baking. Changes in the moisture content of sweet potato during cooking were +30.0% by boiling, +4.4% by steaming, -5.8% by gas oven baking, and -46.6% by microwave oven baking. The degrees of gelatinization of sweet potatoes were 83.8%, 75.7%, 73.0% and 67.7%, respectively.

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The Development of Exposure Assessment Tools for Risk Assessment of Volatile Organic Compounds (VOCs의 위해성 평가를 위한 노출분석 방법 연구)

  • Jo, Seong-Joon;Shin, Dong-Chun;Chung, Yong;Lee, Duck-Hee;Breysse, Patrick N.
    • Environmental Analysis Health and Toxicology
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    • v.17 no.2
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    • pp.147-160
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    • 2002
  • Volatile organic compounds (VOCs) are an important public health issue in Korea and many important questions remain to be addressed with respect to assessing exposure to these compounds. Because they are ubiquitous and highly volatile, special techniques must be applied in their analytic determination Valid Personal exposure assessment methods are needed to evaluate exposure frequency, duration and intensity, as well as their relationship to personal exposure characteristics. Biological monitoring is also important since it may contribute significantly in risk assessment by allowing the estimation of effective absorbed doses. This study was on ducted to establish the environmental measurement, personal dosimetry and biological monitoring methods for VOCs. These methods are needed to compare blood, urinary and exhalation breath VOC levels and to provide tools for risk assessment of VOC exposure. Passive monitors (badge type) and a active samplers (trap) for the VOCs collection were used for air sampling. Methods development included determining the minimum detectable amounts of VOCs in each media, as well as evaluating collection methods and developing analytical procedures. Method reliability was assessed by determining breakthrough volumes and comparing results between laboratories and with other methods. A total capacity of trap used in this study was 60ι. Although variable by compound, the average breakthrough was 20%. Also, there was no loss of compounds in trap even if keep for 45 day in -7$0^{\circ}C$. The recovery of active and passive methods was 69% ~ 126% and method detection limit was 0.24 $\mu\textrm{g}$/trap and 0.07 $\mu\textrm{g}$/badge. There was no statistical difference (P > 0.05) between active and passive methods.