• Journal of Korean Biological Nursing Science
• /
• v.17 no.4
• /
• pp.356-362
• /
• 2015

Purpose: The purpose of this study was to explore the experiences of nursing students in Korea who used concept mapping for understanding pathophysiology. Methods: The data were collected using an open-ended questionnaire from 83 sophomore nursing students after studying concept mapping in pathophysiology class. Each group consisted of five nursing students submitting four concept maps regarding cell injury, inflammation, infection, and neoplasm. After familiarity with concept mapping, the participants wrote their experiences anonymously on sheets of paper. The submitted materials were analyzed via qualitative content analysis. Results: The collected materials were classified into 3 themes, 8 categories, and 18 subcategories. Three themes emerged: (1) awareness of capabilities, (2) difficulties of completion, and (3) benefits of application. Conclusion: The study revealed that participants experienced self-capabilities, and the difficulties and benefits of concept mapping. Concept mapping also provided the opportunity for nursing students to realize communication skill improvement by active group discussion within a group.

• Journal of Industrial and Engineering Chemistry
• /
• v.68
• /
• pp.140-145
• /
• 2018

Bulky carbon layer uniformly distributed with nanoscale $Fe_2O_3$ was prepared via a direct carbonation of $Fe^{3+}$-polyacrylonitrile complexes at $700^{\circ}C$ under $N_2$ flow. The iron oxide carbon composites exhibited an excellent cycling performance for lithium storage with a reversible capacity of ${\sim}810mAh\;g^{-1}$ after 250 cycles at a current rate of $100mA\;g^{-1}$. The enhancement was mainly attributed to dual functions of bulky carbon layer which facilitated the lithium-ion diffusion and accommodated the volume changes of active $Fe_2O_3$ during charge/discharge process. Our novel chemical strategy is quite effective for scalable fabrication of high capacity lithium-storage materials.

• Journal of Bio-Environment Control
• /
• v.24 no.2
• /
• pp.79-84
• /
• 2015

This study was carried out in order to develop an economical and convenient way to improve storability of sweet persimmon 'Fuyu'. Natural porous materials (bamboo active carbon, chaff charcoal, and Ge-lite) pouching bags were enveloped in the conventional LDPE (low density polyethylene) package during room temperature and low temperature storage. The changes of soluble solids content, flesh firmness, flavor, decay, and softening of sweet persimmon were investigated in the 1- or 2-week intervals. The LDPE packaging with bamboo active carbon treatment was confirmed to maintain longer storability and higher quality than the LDPE packaging only. This method is expected to be applied to both of conventional and organic farming as an economical and convenient way to improve storability on long term storage and during distribution.

• Journal of Applied Biological Chemistry
• /
• v.42 no.1
• /
• pp.40-44
• /
• 1999

The in vitro antioxidative activities of the 33 plant-derived essential oils and 37 phytochemicals including 3 Mentha arvensis leaf-, 2 Thymus vulgaris leaf- and 2 Syzygium aromaticum flower-derived isolates were determined by the inhibition of linoleic acid autoxidation, the generation of superoxide anion and scavenging of DPPH radical. They were then compared to those of the widely used plant-derived antioxidants (pyrogallol and quercetin) and synthetic antioxidant BHT. At a concentration of 0.01%, potent antioxidative effect was observed in the essential oils from Cinnamomum cassia roots, Mentha arvensis leaves, Ginkgo biloba fruits, and Syzygium aromaticum flowers. Of the phytochemicals used, eugenol and isoeugenol at 0.01% showed potent antioxidative activity, and their activities were comparable to those of pyrogallol, quercetin, and BHT. The Cinnamomum root-, the Mentha leaf-, the Ginkgo fruit-, and the Syzygium flower-derived materials may be a good source for an alternative to the currently used antioxidants.

• Journal of Applied Biological Chemistry
• /
• v.59 no.2
• /
• pp.149-154
• /
• 2016

An endophytic bacterial strain was isolated from kimchi, a Korean traditional fermented Brassica campestris and identified as Bacillus subtilis MJMP2 based on the 16S rRNA sequence. This strain showed strong antagonistic activity against Xanthomonas oryzae pv. oryzae (Xoo) KACC10331, the pathogen of bacterial rice blight disease, as well as activity against some other rice phytopathogenic fungi. The active compound was purified through size-exclusion chromatography and preparative High-performance liquid chromatography. The molecular weight was determined as m/z 1043 by mass spectroscopy, which is identical to that of iturin A. Furthermore, a crude extract from the culture supernatant of Bacillus subtilis MJMP2 showed inhibitory activity against rice blight disease in both a rice leaf explant assay and a pot assay. The crude extract also enhanced the length of roots of Arabidopsis thaliana. These results suggest that the strain Bacillus subtilis MJMP2 could be used as a biological agent to control rice blight disease.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2017.04a
• /
• pp.27-27
• /
• 2017

Biocompatible capsules have recently been highlighted as novel delivery platforms of any "materials" (e.g., drug, food, agriculture pesticide) to address current problems of living systems such as humans, animals, and plats in academia and industry for agriculture, biological, biomedical, environmental, food applications. For example, biocompatible alginate capsules were proposed as a delivery platform of biocontrol agents (e.g., bacterial antagonists) for an alternative to antibiotics, which will be a potential strategy in future agriculture. Here, we proposed a new platform based on biocompatible alginate capsules that can control the movements as an active target delivery strategy for various applications including agriculture and biological engineering. We designed and fabricated large scale biocompatible capsules using alginates and custom-made nozzles as well as gelling solutions. To develop the active target delivery platforms, we incorporated the iron oxide nanoparticles in the large scale alginate capsules. It was found that the sizes of large scale alginate capsules could be controlled via various working conditions such as concentrations of alginate solutions and iron oxide nanoparticles. As a proof of concept work, we showed that the iron oxide particles-incorporated large scale alginate capsules could be moved actively by the magnetic fields, which would be a strategy as active target delivery platforms for agriculture and biological engineering (e.g., controlled delivery of agriculture pesticides and biocontrol agents).

• Korean Journal of Materials Research
• /
• v.22 no.6
• /
• pp.316-320
• /
• 2012

$Co_3O_4$, $Al_2O_3$ and $Co_3O_4$/$Al_2O_3$ mesoporous powders were prepared by a sol-gel method with starting matierals of aluminum isopropoxide and cobalt (II) nitrate. A P123 template is employed as an active organic additive for improving the specific surface area of the mixed oxide by forming surfactant micelles. A transition metal cobalt oxide supported on alumina with and without P123 was tested to find the most active and selective conditions as a heterogeneous catalyst in the reaction of styrene epoxidation. A bBlock copolymer-P123 template was added to the staring materials to control physical and chemical properties. The properties of $Co_3O_4$/$Al_2O_3$ powder with and without P123 were characterized using an X-ray diffractometer (XRD), a Field-Emission Scanning Electron Microscope (FE-SEM), a Bruner-Emmertt-Teller (BET) surface analyzer, and $^{27}Al$ MAS NMR spectroscopy. Powders with and without P123 were compared in catalytic tests. The catalytic activity and selectivity were monitored by GC/MS, $^1H$, and $^{13}C$-NMR spectroscopy. The performance for the reaction of epoxidation of styrene was observed to be in the following order: [$Co_3O_4$/$Al_2O_3$ with P123-1173 K > $Co_3O_4$/$Al_2O_3$ with P123-973 K > $Co_3O_4$-973 K>$Co_3O_4$/$Al_2O_3$-973 K > $Co_3O_4$/$Al_2O_3$ with P123-1473 K > $Al_2O_3$-973 K]. The existence of ${\gamma}$-alumina and the nature of the surface morphology are related to catalytic activity.

• Applied Biological Chemistry
• /
• v.36 no.2
• /
• pp.134-137
• /
• 1993

Yongia sonchifolia Max. has been used as raw materials of traditional Kimchi and medicinal herb in Korea. This study was performed to investigate biologically active components in the plant. First, the writer carried out the experiment of antitumor screening test against Sarcoma-180A and the cytotoxic activity against Chinese hamster V-79 cells with methanol extract of the plant. And the aqueous solution of the extract from roots of Youngia sonchifolia Max. was partitioned into n-hexane. The concentrated extract of n-hexane layer was chromatographed on silica gel column and developed with n-hexane and ethylacetate. Two yellow elutes, on concentration, were recrystallized from ethylacetate, and the $R_f$ value of TLC of the crystal was 0.43. After analysis by $^{1}H-NMR$, $^{13}C-NMR$ and MS to confirm the structure, the author could identify the compound as bauerenyl acetate, a naturally occurring pentacyclic triterpene. The crystal was colorless plate and m.p. was $280{\sim}282^{\circ}C$.

• The Plant Pathology Journal
• /
• v.28 no.3
• /
• pp.317-321
• /
• 2012

Plants are the promising reservoirs for natural products with their diverse secondary metabolites. Many invasive plants have been introduced in Korea, which adversely affect on the native ecosystem but holds difficulty removing them due to their proliferation. In this study, we evaluated disease control efficacy of methanol extracts from four invasive plant species against 7 representative crop pathogens. Methanol extract of Phytolacca americana effectively suppressed rice blast, tomato gray mold, and tomato late blight in a dose dependent manner. The methanol extract of Amorpha fruticosa also exhibited potent antifungal activity against pepper anthracnose in a concentration dependent way. These data suggest that the extracts of P. americana and A. fruticosa can be developed as plant disease protection agents against rice blast, tomato gray mold, tomato late blight, and pepper anthracnose. Furthermore, more extensive research will be required to identify and isolate active compounds from problematic invasive plant species to develop valuable agrochemicals.

• Journal of Life Science
• /
• v.33 no.7
• /
• pp.538-548
• /
• 2023

The research has been conducted on the isolation of antimicrobial compounds from plant natural extracts and their potential application in oral health care products. This study aimed to investigate the antimicrobial mechanism by analyzing the changes in gene expression of Streptococcus mutans, a major oral pathogen, in response to complex compounds extracted from Aralia continentalis and Arctii Semen using organic solvents. Transcriptome analysis (RNA-seq) revealed that both natural extracts commonly upregulated or downregulated the expression of various genes associated with different metabolic and physiological activities. Three genes (SMU_1584c, SMU_2133c, SMU_921), particularly SMU_921 (rcrR), known as a transcription activator of two sugar phosphotransferase systems (PTS) involved in sugar transport and biofilm formation, exhibited consistent high expression levels. Additionally, component analysis of the A. continentalis extract was performed to compare its effects on gene expression changes with the A. Semen extract, and two active compounds were identified through gas chromatography-mass spectrometry (GC-MS) analysis of the active fraction. The n-hexane fraction (ACEH) from the A. continentalis extract exhibited antibacterial specificity against S. mutans, leading to a significant reduction in the viable cell counts of Streptococcus sanguinis and Streptococcus gordonii among the tested multi-species bacterial communities. These findings suggest the broad-spectrum antibacterial activity of the A. continentalis extract and provide essential foundational data for the development of customized antimicrobial materials by elucidating the antibacterial mechanism of the identified active compounds.