• Advances in materials Research
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• v.11 no.3
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• pp.225-235
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• 2022

It includes the synthesis of pristine ZnO nanoparticles and a series of Ag-doped zinc oxide nanoparticles was carried out by reflux method by varying the amount of silver (1, 3, 5, 7 and 9% by mol.). The morphology of these nanoparticles was investigated by SEM, XRD and FT-IR techniques. These techniques show that synthesized particles are homogenous spherical nanoparticles having an average particle size of about 50-100 nm along with some agglomeration. The photocatalytic activity of the ZnO nanoparticles and Ag doped ZnO nanoparticles were investigated via photodegradation of methylene blue (MB) as a standard dye. The data from the photocatalytic activity of these nanoparticles show that 7% Ag-doped ZnO nanoparticles exhibit much enhanced photocatalytic activity as compared to pristine ZnO nanoparticles and other percentages of Ag-doped ZnO nanoparticles. Furthermore, 7% Ag-doped ZnO was made composites with sulfur-doped graphitic carbon nitride by physical mixing method and a series of nanocomposites were made (3.5, 7.5, 25, 50, 75% by weight). It was observed that the 25% composites exhibited better photocatalytic performance than pristine S-g-C 3 N 4 and pure 7% Ag-doped ZnO. Tauc's plot also supports the photodegradation results.

• Current Photovoltaic Research
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• v.11 no.3
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• pp.67-74
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• 2023

The earth-abundant element-based Cu₂ZnSn(S,Se)₄ (CZTSSe) thin film solar cells (TFSCs) have attracted greater attention in the photovoltaic (PV) community due to their rapid development in device power conversion efficiency (PCE) >13%. In the present work, we demonstrated the fine-tuning of the bandgap in the CZTSSe TFSCs by altering the sulfur (S) to the selenium (Se) chalcogenide ratio. To achieve this, the CZTSSe absorber layers are fabricated with different S/(S+Se) ratios from 0.02 to 0.08 of their weight percentage. Further compositional, morphological, and optoelectronic properties are studied using various characterization techniques. It is observed that the change in the S/(S+Se) ratios has minimal impact on the overall Cu/(Zn+Sn) composition ratio. In contrast, the S and Se content within the CZTSSe absorber layer gets altered with a change in the S/(S+Se) ratio. It also influences the overall absorber quality and gets worse at higher S/(S+Se). Furthermore, the device performance evaluated for similar CZTSSe TFSCs showed a linear increase and decrease in the open circuit voltage (V_oc) and short circuit current density (J_sc) of the device with an increasing S/(S+Se) ratio. The external quantum efficiency (EQE) measured also exhibited a linear blue shift in absorption edge, increasing the bandgap from 1.056 eV to 1.228 eV, respectively.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.6
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• pp.1500-1508
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• 2008

The author investigated whether Chwiyeon-tang(PC), Haengso-tang(PH), Jawanchihyo-san(PJ) and Gamisocheongryong-tang(PS) significantly affect both PMA-induced mucin production and MUC5AC gene expression in airway epithelial cells and sulfur-dioxide-induced airway goblet cell hyperplasia and mucus hypersecretion animal model using rat. Possible cytotoxicity of each herbal medicine was assessed by measuring the survival and proliferation rate of NCI-H292 cells. Confluent NCI-H292 cells were pretreated for 30 min in the presence of PC, PH, PJ and PS, respectively, and treated with PMA(10 $ng/m{\ell}$), to assess the effect of each herbal medicine on PMA-induced mucin production by enzyme-linked immunosorbent assay(ELISA). Effects of each herbal medicine on PMA-induced MUC5AC gene expression from the same cells were investigated. Also, hypersecretion of airway mucus and goblet cell hyperplasia were induced by exposure of rats to $SO_2$ during 3 weeks. Effects of orally-administered PC, PH, PJ and PS during 1 week on intraepithelial mucosubstances and hyperplasia of goblet cells were examined using histological analysis after staining the epithelial tissue with PAS-alcian blue. (1) PC, PJ, PS and PH did not show significant effects on the survival and proliferation of NCI-H292 cells ; (2) PC, PJ and PS significantly decreased PMA-induced mucin production from NCI-H292 cells ; (3) PC, PJ and PS significantly inhibit the expression levels of PMA-induced MUC5AC gene in NCI-H292 cells ; (4) Among PC, PJ, PS and PH, only PS decreased $SO_2$-induced hyperplasia of airway goblet cells and intraepithelial mucosubstances. This result suggests that PC, PJ and PS can not only affect the production of mucin but also affect the expression of mucin gene and this can explain, at least in part, the traditional use of PC, PJ and PS for controlling airway diseases showing hypersecretion of mucus in oriental medicine.

• The Journal of Internal Korean Medicine
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• v.31 no.3
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• pp.650-666
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• 2010

Objectives : In this study, the author tried to investigate whether wood vinegar produced from Morus alba (MA) significantly affects the increase in airway epithelial mucosubstances and hyperplasia of tracheal goblet cells of rats, and in vitro airway mucin secretion and PMA- or EGF- or TNF-alpha-induced MUC5AC mucin production / gene expression from human airway epithelial cells. Materials and Methods : For the in vivo experiment, the author induced hypersecretion of airway mucus and goblet cell hyperplasia by exposure of rats to SO2 over 3 weeks. Effect of orally-administered MA over 2 weeks on increase in airway epithelial mucosubstances from tracheal goblet cells of rats and hyperplasia of goblet cells were assessed using histopathological analysis after staining the epithelial tissue with alcian blue. For the in vitro experiment, confluent RTSE cells were chased for 30 min in the presence of MA to assess the effect of MA on mucin secretion by enzyme-linked immunosorbent assay (ELISA). Also, effects of MA on PMA- or EGF- or TNF-alpha-induced MUC5AC mucin production and gene expression from human airway epithelial cells (NCI-H292) were investigated. Confluent NCI-H292 cells were pretreated for 30 min in the presence of MA and treated with PMA (10 ng/ml), EGF (25 ng/ml) or TNF-alpha (0.2 nm) for 24 hrs, to assess both effects of MA on PMA- or EGF- or TNF-alpha-induced MUC5AC mucin production by enzyme-linked immunosorbent assay (ELISA) and gene expression by reverse transcription-polymerase chain reaction (RT-PCR). Possible cytotoxicities of MA in vitro were assessed by examining LDH release from RTSE cells and the rate of survival and proliferation of NCI-H292 cells. In vivo liver and kidney toxicities of MA were evaluated by measuring serum GOT/GPT activities and serum BUN/creatinine concentrations of rats after administering MA orally. Results : 1. MA decreased the amount of intraepithelial mucosubstances of rats exposed to sulfur dioxide inhalationally. 2. MA decreased in vitro mucin secretion from cultured RTSE cells. 3. MA significantly inhibited PMA-, EGF-, and TNF-alpha-induced MUC5AC mucin productions and the expression levels of MUC5AC mRNA from NCI-H292 cells. 4. MA did not show either in vitro or in vivo hepatic or renal toxicities. Conclusion : The results from this study suggests that MA can regulate the secretion, production and gene expression of airway mucin observed in diverse respiratory diseases accompanied by mucus hypersecretion and does not show in vivo toxicity to liver and kidney functions after oral administration. Effects of MA should be further studied using animal experimental models that simulate the diverse pathophysiology of respiratory diseases via future research.

• Journal of Life Science
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• v.11 no.6
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• pp.582-594
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• 2001

This experiment was performed to investigate the effects of sulfur dioxide on the histological changes, properties of mucosubstances and glycoconjugates of the nasal respiratory mucosa in the rat. Sprague-Dawley male rats weighing about 200~250g were divided into a control group and SO$_2$ exposed groups. Again SO$_2$ exposed groups were divided into 10 ppm, 25 ppm, 50 ppm, 100 ppm, and 200 ppm subgroups, according to concentrations of SO$_2$ and each SO$_2$exposed groups were divided into 1, 3 and 6 hours groups. For the histological changes, hematoxylin-eosin(H-E) and periodic acid Schiff's(PAS) stainings were used, and for the properties of mucosubstances, PAS, alcian blue (AB) pH 2.5, pH 2.5-PAS, AB pH 1.0 and aldehyde fuchsin (AF) pH1.7-AB pH 2.5 were used. In all the SO$_2$ exposed groups, loss of cilia and detachment of epithelial cells, vacuolation of goblet cells were observed in the respiratory epithelium while epithelial squamous metaplasia and intraepthelial mucous cells were observed in the higher concentration of SO$_2$ and the degree of the loss cilia was higher according as concentration was higher and exposed time was longer. The intraepitheial mucous cells appeared most remarkable in the 50 ppm SO$_2$ exposed group. The numbers of goblet cells and acini of nasal septal gland were varied according to concentration of SO$_2$ and exposed time, but the numbers in the 25 ppm and 50 ppm, SO$_2$ exposed increased remarkably. However, the numbers in the 100 ppm and 200 ppm SO$_2$ exposed group had a tendency to decrease noticeably, or disappeared.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.3
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• pp.219-226
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• 1986

To confirm the application of a newer in vitro assays to determining the nutritional value of marine crustaceans (mainly shrimps and crabs), which have been considered to be highly nutritive depending on their levels of the essential amino acids and digestibility, their C-PERs and DC-PERs were determined and studied the factors influencing their in vitro results. Four species of seawater shrimps and 2 species of seawater crabs were used in this experiment. The in vitro digestibilities showed $83{\sim}86\%$ for raw shrimps and the trypsin indigestibile substrate content (TIS) was ranged from 1.32 to 3.33 mg/g solid expressed quantitatively as mg of purified soybean trypsin inhibitor. The smaller size of shrimps revealed a greater in vitro digestibility and a lower contents of TIS. It was noted that the in vitro digestibility of raw blue crab meat was around $85\%$ while boiled tenner crab meat showed $86\%$ or above, and the leg meat had the greatest in vitro digestibility in the various parts of crab meats. The poor in vitro digestibilities for shrimp's and crab's meat, compared with that of the other seafoods as noted in previous reports, suggest that the drop in pH, due to the change in their freshness during harvesting and frozen storage, resulted in underestimating their digestibilities using four-enzyme digestion technique. The lysine contents in all samples were higher than that of ANRC casein but they contained a slightly lower sulfur-containing amino acids than those in ANRC casein. But the other EAA, such as valine, tyrosine and phenylalanine, were found to be a half as little as that in casein and played a key-factor in calculation of C-PER or DC-PER. It was observed that the value of C-PER and DC-PER for all samples ranged from 2.1 to 2.4, and the predicted digestibilities showed $90\%$ or above in all samples. It was a different results from the fact that the animal proteins bear a higher values and predicted digestibilities than those of C-PER values. The lack of correlation between C-PER and DC-PER values is attributable to the fact that the lower content of valine, tyrosine and phenylalanine, and drop in pH owing to the changes of freshness in marine crustacea proteins. Therefore, if a newer in vitro digestion technique-which are taken into account the pH drop before digestion, TIS content and released free amino acids and/or peptides-developed, C-PER assays can provide more advantages in assessing the protein nutritional value of marine crustacea than any other in vitro assays.