• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.296-300
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• 2002

Bacterial cell surface components are the major factors responsible for pathogenesis and bioremediation. In particular, the surface of a Gram-negative bacterium cell has a variety of components compared to that of a Gram-positive cell. In our previous study, we isolated an isogenic mutant of Bradyrhizobium japonicum, which exhibited altered cell surface characteristics, including an increased hydrophobicity. Polyacrylamide gel electrophoretic analysis of the lipopolysaccharide (LPS) in the mutant demonstrated that the O-polysaccharide part was completely absent. Meanwhile, a gel permeation chromatographic analysis of the exopolysaccharide (EPS) in the mutant demonstrated that it was unaltered. Since LPSs are known to have several anion groups that interact with various cation groups and metal ions, the mutant provided an opportunity to examine the direct role of LPS in metal binding by B. japonicum. Using atomic absorption spectrophotometry, it was clearly demonstrated that LPS was involved in metal binding. The binding capacity of the LPS mutant to various metal ions $(Cd^{2+},\;Cu^{2+},\;Pb^{2+},\;and\;Zn^{2+})$ was 50-70% lower than that of the wild-type strain. Also, through an EPS analysis and desorption experiment, it was found that EPS and centrifugal force had no effect on the metal binding. Accordingly, it would appear that LPS molecules on B. japonicum effect the properties, which precipitate more distinctly metal-rich mineral phase.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.08a
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• pp.25-30
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• 2002

The ternary semiconducting compounds of the $A_{4}BX_{6}$(A=Cd, Zn, Hg; B=Si, Sn, Ge; X=S, Se, Te) type exhibit strong fluorescence and high photosensitivity in the visible and near infrared ranges, so these are supposed to be materials applicable to photoelectrical devices. These materials were synthesized and single crystals were first grown by Nitsche, who identified the crystal structure of the single crystals. In this paper. author describe the undoped and $Co^{2+}$-doped $Zn_{4}SnSe_{6}$ single crystals were grown by the chemical transport reaction(CTR) method using iodine of $6mg/cm^{3}$ as a transport agent. For the crystal. growth, the temperature gradient of the CTR furnace was kep at $700^{\circ}C$ for the source aone and at $820^{\circ}C$ for the growth zone for 7-days. It was found from the analysis of x-ray diffraction that undoped and $Co^{2+}$-doped $Zn_{4}SnSe_{6}$ compounds have a monoclinic structure. The optical absorption spectra obtained near the fundamental absorption edge showed that these compounds have a direct energy gaps. These temperature dependence of the optical energy gap were closely investigated over the temperature range 10[K]~300[K]

• Journal of the Korean Society for Precision Engineering
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• v.23 no.8 s.185
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• pp.72-79
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• 2006

We measured grating pitch standards using optical diffractometry and analyzed measurement uncertainty. Grating pitch standards have been used widely as a magnification standard for a scanning electron microscope (SEM) and a scanning probe microscope (SPM). Thus, to establish the meter-traceability in nano-metrology using SPM and SEM, it is important to certify grating pitch standards accurately. The optical diffractometer consists of two laser sources, argon ion laser (488 nm) and He-Cd laser (325 nm), optics to make an incident beam, a precision rotary table and a quadrant photo-diode to detect the position of diffraction beam. The precision rotary table incorporates a calibrated angle encoder, enabling the precise and accurate measurement of diffraction angle. Applying the measured diffraction angle to the grating equation, the mean pitch of grating specimen can be obtained very accurately. The pitch and orthogonality of two-dimensional grating pitch standards were measured, and the measurement uncertainty was analyzed according to the Guide to the Expression of Uncertainty in Measurement. The expanded uncertainties (k = 2) in pitch measurement were less than 0.015 nm and 0.03 nm for the specimen with the nominal pitch of 300 nm and 1000 nm. In the case of orthogonality measurement, the expanded uncertainties were less than $0.006^{\circ}$. In the pitch measurement, the main uncertainty source was the variation of measured pitch values according to the diffraction order. The measurement results show that the optical diffractometry can be used as an effective calibration tool for grating pitch standards.

• The Journal of Internal Korean Medicine
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• v.40 no.4
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• pp.567-581
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• 2019

Objective: This study aimed to evaluate the inhibitory effects of SGX01 on the lung injuries of COPD mice model. Materials and Methods: This study was carried out in two ways: in vitro and in vivo. In vitro, L929 cells were challenged with LPS, and then treated with six concentrations of SGX01 (10, 30, 50, 100, 300, and $500{\mu}g/ml$) and analyzed by ELISA. In vivo, C57BL/6 mice were challenged with LPS and cigarette smoking solution (CSS), and then treated with a vehicle only (control group), dexamethasone 3 mg/kg (dexa group), or a SGX01 200 mg/kg (SGX01 group). After sacrifice, the BALF or lung tissue was analyzed with Cytospin, FACS, ELISA, real-time PCR and H&E, and Masson's trichrome staining. Results: SGX01 significantly decreased NO, $TNF-{\alpha}$, and IL-6 on L929 cells challenged with LPS. In the COPD model, SGX01 significantly inhibited the increase of neutrophils, $TNF-{\alpha}$, IL-17A, CXCL-1, MIP2, CD8+ cells in BALF, and $TNF-{\alpha}$, $IL-1{\beta}$ mRNA expression in lung tissue. It also decreased the severity of the histological lung injury. Conclusion: This study suggests the usability of SGX01 for COPD patients by controlling lung tissue injury.

• The Korea Journal of Herbology
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• v.36 no.1
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• pp.41-49
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• 2021

Objective : Citrus unshiu peel (Citri Unshius Pericarpium) has been prescribed to suppress coughing and phlegm in Korean medicine. In this study, the effect of ethanol extract of Citrus unshiu peel (CEE) on apoptosis was investigated using cadmium chloride (CdCl2) treated HepG2 cells. Methods : CEE was prepared by extracting 300 g of Citri Unshius Pericarpium in 3 L of ethanol for 72 h. Apoptosis was determined by the TUNEL assay. The mitochondrial membrane potential (MMP) was monitored using the membrane-permeable fluorescent dye Rh123. The expression level of each protein was monitored by Western blot analysis. Results : CEE protected HepG2 cells from apoptosis as determined by the TUNEL assay. A decrease in MMP was observed in cells exposed to cadmium, indicating that mitochondria are involved in the induction of apoptosis. However, CEE recovered the reduction in MMP caused by cadmium. In addition, decreased expression of B-cell lymphoma 2 (Bcl-2), procaspase, and poly(ADP-ribose) polymerase (PARP) by cadmium was increased by CEE. The anti-apoptotic effect of CEE was found to be associated with inhibition of JNK and p38 phosphorylation when examining the expression of phosphorylated MAPK by Western blot. Conclusion : This study showed that CEE exerted anti-apoptotic effects in cadmium-induced HepG2 cells by inhibiting the reduction of MMP and changes in the expression level of apoptotic proteins. These results suggest the potential for CEE to be used for heavy metal-induced liver damage.

• Current Photovoltaic Research
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• v.10 no.2
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• pp.33-38
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• 2022

Planner configuration thin film solar cells (TFSCs) with SnS/CdS heterojunction performed a lower short-circuit current (J_SC). In this study, we have demonstrated a path to overcome deficiency in J_SC by the incorporation of Se in the SnS absorber. We carried out the incorporation of Se in VTD grown SnS absorber by rapid thermal annealing (RTA). The diffusion of Se is mostly governed by RTA temperature (T_RTA), also it is observed that film structure changes from cube-like to plate-like structure with T_RTA. The maximum J_SC of 23.1 mA cm^-2 was observed for 400℃ with an open-circuit voltage (V_OC) of 0.140 V for the same temperature. The highest performance of 2.21% with J_SC of 18.6 mA cm^-2, V_OC of 0.290 V, and fill factor (FF) of 40.9% is observed for a T_RTA of 300℃. In the end, we compare the device performance of Se- incorporated SnS absorber with pristine SnS absorber material, increment in J_SC is approximately 80% while a loss in V_OC of about 20% has been observed.

• Molecules and Cells
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• v.46 no.9
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• pp.558-572
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• 2023

Chronic obstructive pulmonary disease (COPD) will be the third leading cause of death worldwide by 2030. One of its components, emphysema, has been defined as a lung disease that irreversibly damages the lungs' alveoli. Treatment is currently unavailable for emphysema symptoms and complete cure of the disease. Hyaluronan (HA) and proteoglycan link protein 1 (HAPLN1), an HA-binding protein linking HA in the extracellular matrix to stabilize the proteoglycan structure, forms a bulky hydrogel-like aggregate. Studies on the biological role of the full-length HAPLN1, a simple structure-stabilizing protein, are limited. Here, we demonstrated for the first time that treating human alveolar epithelial type 2 cells with recombinant human HAPLN1 (rhHAPLN1) increased TGF-β receptor 1 (TGF-β RI) protein levels, but not TGF-β RII, in a CD44-dependent manner with concurrent enhancement of the phosphorylated Smad3 (p-Smad3), but not p-Smad2, upon TGF-β1 stimulation. Furthermore, rhHAPLN1 significantly increased sirtuins levels (i.e., SIRT1/2/6) without TGF-β1 and inhibited acetylated p300 levels that were increased by TGF-β1. rhHAPLN1 is crucial in regulating cellular senescence, including p53, p21, and p16, and inflammation markers such as p-NF-κB and Nrf2. Both senile emphysema mouse model induced via intraperitoneal rhHAPLN1 injections and porcine pancreatic elastase (PPE)-induced COPD mouse model generated via rhHAPLN1-containing aerosols inhalations showed a significantly potent efficacy in reducing alveolar spaces enlargement. Preclinical trials are underway to investigate the effects of inhaled rhHAPLN1-containing aerosols on several COPD animal models.

• Journal of Korea Soil Environment Society
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• v.1 no.1
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• pp.47-54
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• 1996

Soil pollution indices (SPI) were designed for estimating quality of soil polluted with arsenic and heavy metals. Applying the quality reference value of soil based on its multifunctional purpose was a key step. For considereing multifunctions of soil, soil was classified into 4 groups-agricultural land, residential area, recreational area, factorial site. Then, each concentration of arsenic and each of five heavy metals (Cd, Cu, Hg, Pb, Zn) in soils grouped was transformed to a mathematical value based on the soil quality reference value which may stand for ecological impact. Soil pollution score (SPS) was the addition of the 6 values transformed, and the range of the SPS was divided into 4 Soil Pollution Classes (SPC). The SPC 1, 2, 3, and 4 were SPS <100, SPS 100-200, SPS >200-300, and SPS >300, repectively. SPS and SPC were evaluated with the results of the data from employing the Soil Network of 1994. Based on the soil quality reference values, SPS and SPC of the Soil Network's data were transformed and classified, respectively. Then, SPS and SPC were compared with arsenic and the 5 heavy metal contents of their reference values resulted from the Soil Network's. From this method, soil quality of most of the Soil Network area was estimated to be healthy. However, ca. 3.0~4.0% of the Soil Network area was determined in a range of slightly and heavily polluted. As the mean value of SPS of the Soil Network's was 66.2 which indicates most of soil evaluated was healthy. When the SPSs of the data were divided into 4 groups of SPC, Class 1 (Good quality of soil), Class 2 (Need to be checked area 1), Class 3 (Need to be checked area 2) and Class 4 (Polluted area) were 87.0, 9.4, 2.4, 1.2%, respectively. Using SPI were comparable to those of heavy metal contents in soils, and would be comprehenve to determine the status of soil qulity. Methodology of the developing SPI would be applicable to the other soil pollutants such as organic and inorganics than arsenic and 5 heavy metals used here.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.393-398
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• 2012

We investigated the changes in chemical properties of paddy field soils at 300 different sampling sites containing 4 topography in Jeonbuk province, Korea. The soil samples were collected 43.0% from local valley and fans, 39.3% from fluvio-marine deposits, 15.0% from alluvial plains, and 2.7% from diluvium sites. The optimal values of soil properties in the total soil samples were as follows: 65.3% of total samples in soil pH value, 48.3% of total samples in cation exchange capacity (CEC) value, and 22.3% of total samples in available phosphorus content, whereas the deficient values of soil properties were 63.3% of total samples in soil organic matter (SOM) content, 75.7% of total samples in available silicate content, and 61.3%, 51.0%, and 59.3% of total samples in exchangeable $K^+$, $Ca^{2+}$, and $Mg^{2+}$ concentrations, respectively. There were different soil types in the paddy fields: that is, 34.4% immature paddy and 33.6% sandy paddy in the local valley and fans, 57.8% sandy paddy in the alluvial plains, 47.4% normal paddy in the fluvio-marine deposits, and 75.7% immature paddy in the diluvium. Soil textures were also different: 53.5% loam in the local valley and fans, 37.8% sandy loam in the alluvial plains, and 55.1% silty loam in the fluvio-marine deposits. Soil pH and SOM contents were not different among the different topographical sampling sites. However, the mean value of available phosphorus content, 224 mg $kg^{-1}$, was exceeded optimal values in the diluvium. The contents of exchangeable cations were optimal in all the sites, except exchangeable $Ca^{2+}$ contents in the local valley and fans. The contents of available silicate ranged between 112 and 127 mg $kg^{-1}$ in all the sites, which were lower than optimal value. In addition, soil pH values were proportionally correlated to the order of available silicate, exchangeable $Ca^{2+}$, $Mg^{2+}$, $Na^+$, CEC, and exchangeable $K^+$. The contents of SOM were proportionally correlated to the order of CEC, available $P_2O_5$, exchangeable $Ca^{2+}$, and available silicate. The contents of heavy metals, Cd, Cr, Cu, Ni, Pb, and Zn, were only 10% of the threshold levels of the metals, and As content was about 20 to 30% of the threshold level.

• Journal of Food Hygiene and Safety
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• v.20 no.2
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• pp.83-88
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• 2005

This study was conducted to estimate the contents of heavy metals including lead, cadmium, zinc, copper as well as iron status(serum iron, total iron binding capacity, feritin etc)in blood samples of middle school students(n=300). The contents of heavy metals were determined using the GF-AAS (Graphite furnace Atomic Absorption Spectrophotometer). The microwave digestion method and dilution method were compared. The dilution method showed the better recovery and detection limit than microwave digestion method. The values of toxic metals in whloe blood of boys & girls were 3.46 & 3.05 for Pb,0.063 & 0.065 for Cd respectively (ug/dL). Also the values of trace metals in serum of boys & girls were 105.9 & 92.6 for Zn, 98.3 & 99.0 for Cu respectively (ug/dL). The prevalence of iron deficiency was $7.5\%$ in 146 boys and $14.3\%$ in 156 girls. The mean values of lead in girls were higher in iron deficiency, iron deficiency anemia and anemia groups than normal group. The mean values of lead and zinc were higher in boys compared to those in girls(P<0.05), the mean values of cadmium and copper in boys were similar to those in girls. Our results of toxic metals such as Pb & Cd showed lower to CDC's(Centers for Disease Control) blood lead levels of concern for children, 10 ug/dL.