• Applied Chemistry for Engineering
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• v.34 no.5
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• pp.479-487
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• 2023

Copper is cost-effective and abundantly available as a biocidal coating agent for a wide range of material surfaces. Natural oxidation does not compromise the efficacy of copper, allowing it to maintain antimicrobial activity under prolonged exposure conditions. Furthermore, copper compounds exhibit a broad spectrum of antimicrobial activity against pathogenic yeast, both enveloped and non-enveloped types of viruses, as well as gram-negative and gram-positive bacteria. Contact killing of copper-coated surfaces causes the denaturation of proteins and damage to the cell membrane, leading to the release of essential components such as nucleotides and cytoplasm. Additionally, redox-active copper generates reactive oxygen species (ROS), which cause permanent cell damage through enzyme deactivation and DNA destruction. Owing to its robust stability, copper has been utilized in diverse forms, such as nanoparticles, ions, composites, and alloys, resulting in the creation of various coating methods. This mini-review describes representative coating processes involving copper ions and copper oxides on various material surfaces, highlighting the antibacterial and antiviral properties associated with different oxidation states of copper.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1127-1132
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• 2006

In our previous study, a novel herb mixture (HIM-I) of Angelica gigas radix, Cnidium officinale rhizoma, and Paeonia japonica radix was developed to protect the intestinal and immune systems and promote its recovery against radiation damage. A new herbal composition (HemoHIM) with the high immune modulating activity was developed from HIM-I. HIM-I was fractionated into ethanol fraction (HIM-I-E) and polysaccharide fraction (HIM-I-P). And HemoHIM was prepared by adding HIM-I-P to HIM-I. HemoHIM showed more effective than HIM-I in immune modulation as well as radioprotection. The present study is designed to investigate the protective effects of HIM-I, HIM-I-P, and HemoHIM on hydrogen peroxide $(H_2O_2)$ induced apoptosis of human promyelocytic leukemia (HL-60) cells. It was shown that $H_2O_2$ treatment reduced the viability of cells, and increased appearance of DNA ladders, hypodiploid (subG1) cells, and phosphatidylserine translocation level. Pretreatment of HemoHIM significantly reduced the cytotoxic effect induced by $H_2O_2$, associated with reducing the translocation of phosphatidylserine, hypodiploid cells and DNA ladders. HemoHIM appeared to be more protective than HIM-I against $H_2O_2$ induced apoptosis whereas, it exhibited similar activity to HIM-I-P. These results indicated that HemoHIM might be an useful agent for protection against oxidative stress $(H_2O_2)-induced$ apoptosis as well as immune modulation, especially since it is a relatively nontoxic natural product.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.2
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• pp.170-178
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• 2011

The purpose of this study was to assess the prevalence of periodontopathic bacteria and resistance determinants from oral biofilm of children. Subgingival dental plaque was isolated from 87 healthy children, and PCR was performed to determine the presence of 5 periodontal pathogens including P. gingivalis, T. forsythia, T. denticola, F. nucleatum, A. actinomycetemcomitans, and nine resistance genes including tet(Q), tet(M), ermF, aacA-aphD, cfxA, $bla_{SHV}$, $bla_{TEM}$, vanA, mecA. 1. The prevalence of F. nucleatum, T. forsythia. and P. gingivalis was 95.4%, 55.2%, and 40.2%, respectively. In addition. the prevalence of A. actinomycetemc omitans was 5.7%, while T. denticola was 3.4%. 2. In analysis of antibiotic resistance determinants. cfxA, $bla_{TEM}$ and tet(M) were detected in all the samples tested. It was also found that the prevalence of tet(Q) showing tetracycline resistance. $bla_{SHV}$ associated with resistance to ${\beta}$-lactams, ermF exhibiting erythromycin resistance, and, vanA resulting vancomycin resistance was 88.5%, 29.9% 87.4%, and 48.5%, respectively. The aacA-aphD gene showing resistance to aminoglycosides and mecA gene harboring methicillin resistance exhibited the lowest prevalence with 9.2%. 3. In a correlation analysis between periodontopathic pathogens and antibiotic resistance determinants, it was found that there was a significant correlation between T. forsythia and $bla_{SHV}$. Also, P. gingivalis and vanA showed a correlation. Finally, tet(Q) and ermF showed a significant correlation (phi: 0.514) while mecA and vanA also showed a correlation(phi: 0.25).

• Journal of the Korean Electrochemical Society
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• v.4 no.2
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• pp.58-64
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• 2001

YSZ ($8mol\%$ yttria-stabilized zirconia)-modified LSM $(La_{0.85}Sr_{0.15}MnO_3)$ composite cathodes were fabricated by formation of YSZ film on triple phase boundary (TPB) of LSM/YSZ/gas. The YSZ coating film greatly enlarged electrochemical reaction sites from the increase of additional TPB. The composite cathode was formed on thin YSZ electrolyte (about 30 Um thickness) supported on an anode and then I-V characterization and AC impedance analyses were performed at temperature between $700^{\circ}C\;and\;800^{\circ}C$. As results of the impedance analysis on the cell at $800^{\circ}C$ with humidified hydrogen as the fuel and air as the oxidant, R1 around the frequency of 1000 Hz represents the anode Polarization. R2 around the frequency of 100Hz indicates the cathode polarization, and R3 below the frequency of 10 Hz is the resistance of gas phase diffusion through the anode. The cell with the composite cathode produced power density of $0.55\;W/cm^2\;and\;1W/cm^2$ at air and oxygen atmosphere, respectively. The I-V curve could be divided into two parts showing distinctive behavior. At low current density region (part I) the performance decreased steeply and at high current density region (part II) the performance decreased gradually. At the part I the performance decrease was especially resulted from the large cathode polarization, while at the part H the performance decrease related to the electrolyte polarization.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.2
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• pp.196-203
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• 2003

The application of sealants is a highly technique-sensitive procedure, requiring an extremely dry field prior to placement. Moisture contamination of the etched enamel surface before sealant placement is cited as the main reason for sealant failure. The purpose of this study was to evaluate the effects of different methods of sealant application on the shear bond strength of sealants to enamel. In groups 1, 2, 3, 4 Teethmate(unfilled sealant) was used, while Ultraseal XTplus(filled sealant) was used in groups 5, 6, 7, 8. Groups 1 and 5(control) were acid etched for 15 seconds using 35% phosphoric acid, washed and then dried. In groups 2, 6 drying agents were applied, and in groups 3, 7 bonding agents were applied and light cured. In groups 4 and 8 both drying agent and bonding agent were applied. Then sealant was cured to the specimen using molds 3mm in diameter and 2mm in height. Thermocycling was performed and shear bond strength was finally measured. The following results were obtained : 1. Groups using filled sealant(groups 5, 6, 7, 8) showed higher shear bond strengths compared to groups using unfilled sealant(groups 1, 2, 3, 4). 2. Among groups using unfilled sealant(groups 1, 2, 3, 4), groups 2, 3, 4 showed significantly higher shear bond strength compared to group 1(p<0.05). There were no significant differences among groups 2, 3 and 4. 3. There were no significant differences(p>0.05) among groups using filled sealant(groups 5, 6, 7, 8). 4. When modes of fracture were examined, cohesive failure was observed in groups 2, 3 and 4.

• Tuberculosis and Respiratory Diseases
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• v.41 no.3
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• pp.248-261
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• 1994

Background: Lectins are proteins or glycoproteins of non-immune origin that recognize a specific sequence of sugar residues. The availability of a large number of lectins has provided the capacity to identify selectively glycoconjugates possessing distinctive chemical structure in diverse sites of highly specialized biological activity. The purpose of the present study was to investigate the lectin binding patterns of various components in human pulmonary tubercles. Method: Biopsy specimens of tuberculous lung were obtained from male adult patients who underwent a surgical resection for severe pulmonary tuberculosis. The specimens were processed and stained with 13 kinds of biotinylated lectins according to some modification of Hsu and Raine's methods. Results: 1) In the caseous necrotic lesions, BS $I-B_4$ showed negative reaction and BS I were also negative except some irregularly-shaped cells located in the marginal zone. All other lectins, however, showed a positive reaction with various binding patterns. 2) The epithelioid cells were broadly divided into three groups according to the reaction patterns in the cytoplasms and cell membranes. 3) WGA, ECL, PHA-L, PHA-E and LCA showed strong staining in the lymphocytes. 4) SBA showed a different binding patterns between the endothelial layers located in the region beyond the fibrous layers and those located within the fibrous layers. 5) PNA showed a positive reaction in the outer 1/3 to 1/2 of the fibrous layer, but showed no staining in the inner 1/2 to 2/3 of the fibrous layers. Conclusion: The present lectin histochemical study provided a useful information to assess the characterization and distribution of various glycoconjugates in each constituent of human pulmonary tubercles. The results demonstrate structural differences in the glycoconjugate composition of various components of the tubercles and reveal changes in glycosylation in the components during soft tubercle formation. This study provides a new data useful for the studies on the pathogenesis and pathology of human pulmonary tubercles.

• Journal of Korean Society of Forest Science
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• v.45 no.1
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• pp.62-67
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• 1979

Ultraviolet microscopy of ultrathin sections of wood has proved to be one of the useful means for determining the lignin distribution in the various regions of the cell wall. Also, spectral approach and quantitative analysis of isolated compound middle lamella fraction from birch xylem have revealed that the lignin associated with the vessel secondary wall and middle lamella is composed predominantly of gualacylpropane units. Lignin deposited in the fiber and ray parenchyma secondary walls is composed mostly of syringylpropane units. The middle lamella lignin around fibers and ray cells contains both guaiacyl and syringyl propane quits. On the basis of the results above, this research was carried out to clarify the origin of milled wood lignin (MWL) by analysing the chemical characteristics of ML MWLs extracted at various milling stages. The amount of phenolic hydroxyl-, ${\alpha}$-carbonyl-, and methoxyl-group in the MWL's increases the milling time. And progressive mining contributes to the merease of ratio of syringylaldehyde to vanillin(S/V ratio) after nitrobenzene oxidation of MWL. Accordingly, It could be concluded that milled wood lignin extracted at the initial milling stage derives from compound middle lamella region of cell wall, whereas, with progressive milling, lignin of secondary wall of fiber is introduced gradually to milled wood lignin. These results are suggesting that heterogeneous chemical structure of lignins in hardwood exists. Although milled wood lignin at the initial stage seems to have lower molecular weight in comparison with milled wood lignin extracted at final milling stage from the result of Gel-filtration curves, further study would be required on molecular weight distribution of milled wood lignin in future.

• The Korean Journal of Nuclear Medicine
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• v.38 no.2
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• pp.180-189
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• 2004

Although the outcome of cancer patients after cytotoxic chemotherapy is related diverse mechanisms, multidrug resistance (MDR) for chemotherapeutic drugs due to cellular P-glycoprotein (Pgp) or multidrug-resistance associated protein (MRP) is most important factor in the chemotherapy failure to cancer. A large number of pharmacologic compounds, including verapamil, quinidine, tamoxifen, cyclosporin A and quinolone derivatives have been reported to overcome MDR. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) are available for the detection of Pgp and MRP-mediated transporter. $^{99m}Tc$-MIBI and other $^{99m}Tc$-radiopharmaceuticals are substrates for Pgp and MRP, and have been used in clinical studies for tumor imaging, and to visualize blockade of PgP-mediated transport after modulation of Pgp pump. Colchicine, verapamil and daunorubicin labeled with $^{11}C$ have been evaluated for the quantification of Pgp-mediated transport with PET in vivo and reported to be feasible substrates with which to image Pgp function in tumors. Leukotrienes are specific substrates for MRP and $N-[^{11}C]acetyl-leukotriene$ E4 provides an opportunity to study MRP function non-invasively in vivo. SPECT and PET pharmaceuticals have successfully used to evaluate pharmacologic effects of MDR modulators. Imaging of MDR and reversal of MDR with bioluminescence in a living animal is also evaluated for future clinical trial. We have described recent advances in molecular imaging of MDR and reviewed recent publications regarding feasibility of SPECT and PET imaging to study the functionality of MDR transporters in vivo.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.517-528
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• 2010

Rice seed maturation and germination involve drastic changes in water and nutrient transport, in which tonoplast aquaporins may play an important role. In the present study, gene expression profiles of 10 tonoplast intrinsic proteins (TIP) from rice were investigated by RT-PCR during seed development and germination. OsTIP3;1 and OsTIP3;2 were specifically expressed in mature seeds. Their transcript level rapidly decreased after onset of seed germination and gene expression was induced by ABA treatment. In contrast, expression of OsTIP2;1 and OsTIP4;3 was not seed specific as transcripts were found in vegetative tissues as well. Their respective transcript levels decreased at an early stage of seed development, whereas they increased at a later stage of seed germination and elongation of embryonic roots and shoots. When seed germination was inhibited by various stress conditions and ABA, expression of OsTIP2;1 and OsTIP4;3 was completely suppressed. In contrast, the expression level of OsTIP2;2 rapidly increased after seed imbibition and the transcript level was maintained under conditions inhibiting seed germination. These results implicate that tissue specific and developmental transcriptional regulation of OsTIPs in rice seeds depends on their specific function. In addition, OsTIPs can be discriminated by different potential phosphorylation and methylation sites in their protein structures. OsTIP3;1 and OsTIP3;2 possess unique phosphorylation signatures at their N-terminal domain, loop B and loop E, respectively. OsTIP2;1 and OsTIP4;3 have a potential methylation site at their Nterminal domain. This suggests that activity of specific tonoplast aquaporins may be regulated by post-translational modification as well as by transcriptional control.

• Journal of Nutrition and Health
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• v.55 no.2
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• pp.211-226
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• 2022

Choline, an essential nutrient for humans, is required for the structural integrity of the cell membranes, methyl-group metabolism, synthesis of the neurotransmitter acetylcholine, synthesis of the membrane phospholipid components of the cell membranes, and the transport of lipids and cholesterol. Choline can be synthesized in the body, but it is insufficient to meet the daily requirements and hence it must be obtained through the diet. In the United States/Canada, Australia/New Zealand, Europe, China, and Taiwan, the adequate intake (AI) and tolerable upper intake level (UL) of choline have been established, while the establishment of the 2020 Dietary Reference Intakes for Koreans (KDRI) for choline was postponed due to the lack of a choline database for Korean foods and studies on the choline intake of Koreans. However, as part of the preparation work for the 2020 DRI revision and finalization, choline intake and the possibility of disease occurrence were verified through analysis of published data. The groundwork for the subsequent establishment of a choline DRI was laid through a literature search, evaluation, and review of the literature reported from 1949 up to 2019. This can be regarded as the culmination of this project. According to the results of randomized controlled trials (RCTs), cohort studies, case-control studies, and cross-sectional observational studies in humans, approximately 400-500 mg/day of choline intake was effective in preventing liver function damage (fatty liver), neural tube damage, cardiovascular disease, breast cancer, and cognitive function improvement. The same amount of choline intake, however, also correlated with the risk of prostate and colorectal cancer. At present, there is limited information available on choline intake and health outcomes, particularly for the Korean population. More human studies, including clinical trials on the requirements and the physiological benefits associated with dietary intake, are needed to establish the KDRI for choline.