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        검색결과 52

        4.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Echeveria is a genus belonging to the Crassulaceae family that comprises approximately 170 species. It is a representative plant known as a succulent with economic potential in the floriculture industry. Echeveria plants are widely distributed in dry environments and endemic to Mexico. These plants have a rosette formation and varied leaf colors and shapes, which are characteristics of interest for landscaping, cut flowers, or interior decoration. Given their range of locations in different climates or indoor conditions, it is important to have an understanding and knowledge of their leaf morphology and anatomy and how they function to provide optimum care and management. Owing to high demand in horticultural markets, many breeders have crossed their desired species. However, this method has progressively increased the number of species without proper records of parents or other natural unintended crossings, creating phylogenetic problems and identification issues. The use and understanding of phenotypes, anatomical data, and/or research to aid in taxonomic issues and improve cultural management practices have been reviewed and discussed in this paper. In this review, we have provided a brief background of Echeveria species, focusing on the challenges and studies that have attempted to address these issues.
        4,000원
        6.
        2022.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pregnancy-associated plasma protein-A (PAPP-A) is known as an important biomarker for fetal abnormality during first trimester and has a pivotal role in follicle development and corpus luteum formation. And also, it is being revealed that an expression of PAPP-A in various cells and tissues such as cancer and lesion area. PAPP-A is the major IGF binding protein-4 (IGFBP-4) protease. Cleavage of IGFBP-4 results in loss of binding affinity for IGF, causing increased IGF bioavailability for proliferation, survival, and migration. Additionally, PAPP-A can be used as a promising therapeutic target for healthy longevity. Despite growing interest, almost nothing is known about how PAPP-A expression is regulated in any tissue. This review will focus on what is currently known about the zinc metalloproteinase, PAPP-A, and its role in cells and tissues. PAPP-A is expressed in proliferating cells such as fetus in uterus, granulosa cells in follicle, dermis in wound, cancer cells, and Sertoli cells in testis. They have common characteristics of proliferation faster than normal cells with stimulating IGFs action and inhibiting IGFBPs. The PAPP-A functions and expression studies in livestock have not yet been conducted much. Further studies are needed to use PAPP-A as a marker for healthy longevity in animal science.
        4,000원
        7.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Veronica L., the largest genus in the family Plantaginaceae, is widespread in various habitats. Due to their long-blooming flowers, Veronica species have high horticultural value as indoor potted, garden, and landscape plants. Furthermore, Veronica plants are extremely important owing to their notable diversity in habitat usage, ploidy level, and evolution. Several native taxa, which are of key interest in breeding programs and phylogenetic studies, have been identified in Korea. The genome sizes and chromosomal characteristics are basic cytogenetic features of all taxa, and their knowledge is a prerequisite when commencing genome sequencing projects. It can provide essential information for cytogenetic, taxonomic, phylogenetic, and evolutionary studies. Thus, cytogenetic analysis and genome size estimation of seven Veronica taxa native to Korea were conducted in this study. Fluorescence in situ hybridization (FISH) karyotype analysis and chromosome counting was conducted using metaphase chromosomes probed with 5S and 45S rDNA. Nuclear DNA content and genome size were determined using flow cytometry. FISH karyotype analysis revealed a common number of 5S loci and varying 45S signals that create distinctive rDNA distribution patterns in each taxon. The results indicated that the seven investigated Veronica taxa have calculated genome sizes (1C values) ranging from 517.1 to 862.0 Mbp. This study is the first to report the chromosome number and karyomorphology of seven Veronica taxa native to Korea, as well as the use of rDNA markers for identifying individual chromosomes. These findings contribute to the crucial understanding the genomic characteristics of species within the genus Veronica, serve as a basis for studying Veronica phylogeny and evolution, and provide valuable information for future breeding programs.
        4,300원
        8.
        2022.05 구독 인증기관·개인회원 무료
        It is essential to provide a safe working environment for radiation workers. At a research reactor decommissioning site in Seoul (KRR1 & KRR2), radioactive waste drum disposal work is in progress. Before performing radiation work, it is necessary to determine the radioactivity of the waste drum to ensure safety. In this reason, we conducted a study to determine the detection efficiency of waste drums using the EXVol code. Determination of the full energy absorption peak efficiency (detection efficiency) is one of the important processes of the gamma-ray activation analysis. For the large voluminous gamma-ray sources like waste drum, the geometrical and attenuation effect should be considered. EXVol (Efficiency calculator for eXtended Voluminous source) code is a detection efficiency calculation code using the effective solid angle method. EXVol can calculate both coaxial and asymmetric structure. In addition, the introduction of a collimator made it possible to reduce the radiation intensity of a high radiation source. And it is possible to determine the precise detection efficiency according to the energy of a gamma ray at a specific position of the volume source. To verify the performance of the EXVol, a high resolution gamma spectroscopy system was constructed and measurement and analysis were performed. Measurements were performed on coaxial, asymmetric and collimated structures with standard point source, standard 1 L liquid volume source and HPGe detector. The measured results were compared with the calculation results of EXVol. The relative deviation of the measurement and calculation in the coaxial and asymmetric structures was 10%, and that of the collimation structure was 20%. Results can be available in analysis of waste drums’ radioactivity determination at a specific position.
        19.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was aimed to evaluate the dose-response the effects of nano-encapsulated conjugated linoleic acids(CLAs) on in vitro ruminal fermentation profiles. A fistulated Holstein cow was used as a donor of rumen fluid. Nano-encapsulated CLAs(LF, 5% of nano-encapsulated CLA-FFA; HF, 10% of nano-encapsulated CLA-FFA; LT, 5% of nano-encapsulated CLA-TG; HT, 10% of nano-encapsulated CLA-TG) were added to the in vitro ruminal fermentation experiment. In the in vitro ruminal incubation test, the total gas production on incubation with nano-encapsulated CLAs was increased significantly according to the incubation time, compared with the control(p<0.05). The tVFA concentrations on addition of LF and HT were significantly higher than that of the control(p<0.05). Thus, nano-encapsulated CLAs might improve the ruminal fermentation characteristics without adverse effects on the incubation process. In addition, the population of Butyrivibrio fibrisolvens which is closely related to ruminal biohydrogenation was increased by adding HT, while decreased by adding LF at 12 h incubation. These results showed that nano-encapsulated CLA-FFA could be applied to enhance CLA levels in ruminants by maintaining the stability of CLA without causing adverse effects on ruminal fermentation profiles considering the optimal dosage.
        4,000원
        20.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We introduce a depth scaling strategy to improve the accuracy of frequency-domain elastic full waveform inversion (FWI) using the new pseudo-Hessian matrix for seismic data without low-frequency components. The depth scaling strategy is based on the fact that the damping factor in the Levenberg-Marquardt method controls the energy concentration in the gradient. In other words, a large damping factor makes the Levenberg-Marquardt method similar to the steepest-descent method, by which shallow structures are mainly recovered. With a small damping factor, the Levenberg-Marquardt method becomes similar to the Gauss-Newton methods by which we can resolve deep structures as well as shallow structures. In our depth scaling strategy, a large damping factor is used in the early stage and then decreases automatically with the trend of error as the iteration goes on. With the depth scaling strategy, we can gradually move the parameter-searching region from shallow to deep parts. This flexible damping factor plays a role in retarding the model parameter update for shallow parts and mainly inverting deeper parts in the later stage of inversion. By doing so, we can improve deep parts in inversion results. The depth scaling strategy is applied to synthetic data without lowfrequency components for a modified version of the SEG/EAGE overthrust model. Numerical examples show that the flexible damping factor yields better results than the constant damping factor when reliable low-frequency components are missing.
        4,000원
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