• Korean Journal of Materials Research
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• v.12 no.4
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• pp.296-303
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• 2002

For potential application to quantum mechanical devices, nano-composite thin films, consisting of GaAs quantum dots dispersed in SiO$_2$ glass matrix, were fabricated and studied in terms of structural, chemical, and optical properties. In order to form crystalline GaAs quantum dots at room temperature, uniformly dispersed in $SiO_2$matrix, the composite films were made to consist of alternating layers of GaAs and $SiO_2$in the manner of a superlattice using RF magnetron sputter deposition. Among different film samples, nominal thickness of an individual GaAs layer was varied with a total GaAs volume fraction fixed. From images of High Resolution Transmission Electron Microscopy (HRTEM), the formation of GaAs quantum dots on SiO$_2$was shown to depend on GaAs nominal thickness. GaAs deposits were crystalline and GaAs compound-like chemically according to HRTEM and XPS analysis, respectively. From measurement of optical absorbance using a spectrophotometer, absorption edges were determined and compared among composite films of varying GaAs nominal thicknesses. A progressively larger shift of absorption edge was noticed toward a blue wavelength with decreasing GaAs nominal thickness, i.e. quantum dots size. Band gaps of the composite films were also determined from Tauc plots as well as from PL measurements, displaying a linear decrease with increasing GaAs nominal thickness.

• Journal of Pharmacopuncture
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• v.18 no.3
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• pp.32-41
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• 2015

Objectives: Condurango (Gonolobus condurango) extract is used by complementary and alternative medicine (CAM) practitioners as a traditional medicine, including homeopathy, mainly for the treatment of syphilis. Condurango bark extract is also known to reduce tumor volume, but the underlying molecular mechanisms still remain unclear. Methods: Using a cervical cancer cell line (HeLa) as our model, the molecular events behind condurango extract's (CE's) anticancer effect were investigated by using flow cytometry, immunoblotting and reverse transcriptase-polymerase chain reaction (RT-PCR). Other included cell types were prostate cancer cells (PC3), transformed liver cells (WRL-68), and peripheral blood mononuclear cells (PBMCs). Results: Condurango extract (CE) was found to be cytotoxic against target cells, and this was significantly deactivated in the presence of N-acetyl cysteine (NAC), a scavenger of reactive oxygen species (ROS), suggesting that its action could be mediated through ROS generation. CE caused an increase in the HeLa cell population containing deoxyribonucleic acid (DNA) damage at the G zero/Growth 1 (G0/G1) stage. Further, CE increased the tumor necrosis factor alpha ($TNF-{\alpha}$) and the fas receptor (FasR) levels both at the ribonucleic acid (RNA) and the protein levels, indicating that CE might have a cytotoxic mechanism of action. CE also triggered a sharp decrease in the expression of nuclear factor kappa-light-chain-enhancer of activated B cells ($NF-{\kappa}B$) both at the RNA and the protein levels, a possible route to attenuation of B-cell lymphoma 2 (Bcl-2), and caused an opening of the mitochondrial membrane's permeability transition (MPT) pores, thus enhancing caspase activities. Conclusion: Overall, our results suggest possible pathways for CE mediated cytotoxicity in model cancer cells.

• Korean journal of food and cookery science
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• v.26 no.4
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• pp.406-412
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• 2010

This study was conducted to investigate the effects of saltwort on the quality characteristics of tofu. In addition, we examined the potential for commercialization of tofu containing saltwort. For this study, saltwort was added to tofu at 0%, 4%, 8%, 12%, 16% and 20% and quality and sensory tests were administered. Analyzing the mineral contents of saltwort juice, K was present in the greatest amount, followed by Mg, P, Ca, and F (in decreasing order). There were significant differences in yield rates and turbidity between the groups. Acidity was highest in the control group, and acidity and volume of tofu tended to decrease with an increase in saltwort powder. L value and a value decreased as the content of slaltwort powder increased, but b value increased with increasing saltwort powder concentration. Hardness, chewiness, and gumminess were rated higher in the control and the 4% supplement groups than the others groups. In the sensory evaluation, cross section and soybean flavor were the highest in the 4% saltwort supplement group, and the presence of an "off-flavor" increased with the content of saltwort powder. The saltiness score was highest in the 20% supplement group. The 4% and 8% supplement groups were favored in the "feel after swallowing" assessment. Softness was the lowest in the 20% supplement group, and the 4% supplement group had the highest overall acceptability. As demonstrated by these results, the addition of saltwort positively affected the overall sensory evaluation of tofu and supplementation with saltwort at 4% and 8% might be considered the most appropriate choices. In conclusion, saltwort tofu expected to increase the functionality of new products, particularly with respect to product variety and health improvement.

• Korean Journal of Veterinary Research
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• v.45 no.1
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• pp.39-43
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• 2005

The present study was carried out to investigate the skin irritation potential of oregano oil in rabbits. A volume of 0.5 ml of test article was applied to intact and abraded skins, respectively, for 24 h in 6 healthy male New Zealand White rabbits. Parameters measured during 72 h observation period were mortality, clinical signs, body weight changes, and local irritation. Treatment-related toxic symptoms, as evidenced by anorexia and decreased locomotor activity, were observed in all rabbits tested. Two rabbits out of the 6 total died on day 2 after the application of test article due to treatment-related toxicity. The mean body weight of test animals decreased progressively during the 72 h observation period. All animals showed very slight edema at 24 h and then recovered at 72 h. These animals also showed very slight to severe erythema and/or slight eschar formation at both 24 h and 72 h. The eschar formation induced by oregano oil was not recovered at the end of additional 11-day recovery period. Based on these results, it was concluded that a single dermal application of the undiluted oregano oil caused an increased incidence of clinical signs and death and a decrease in the body weight and showed a primary irritation index score of 2.79 indicating moderate irritation.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.5
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• pp.445-452
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• 2015

A tubular packed bed reactor for the steam-$CO_2$ combined reforming of natural gas to produce the synthesis gas of a target $H_2/CO$ ratio 2.0 was simulated. The effects of the reactor dimension, the feed gas composition, and the gas feeding temperature upon the possibility of coke formation across the catalyst bed were investigated. For this purpose, 2-dimensional heterogeneous reactor model was used to determine the local gas concentrations and temperatures over the catalyst bed. The thermodynamic potential distribution of coke formation was determined by comparing the extent of reaction with the equilibrium constant given by the reaction, $CH_4+2CO{\Leftrightarrow}3C+2H_2O$. The simulation showed that catalysts packed in the central region nearer the entrance of the reactor were more prone to coking because of the regional characteristics of lower temperature, lower concentration of $H_2O$, and higher concentration of CO. With the higher feeding temperature, the feed gas composition of the increased $H_2O$ and correspondingly decreased $CO_2$, or the decrease in the reactor diameter, the volume fraction of the catalyst bed subsequent to coking could be diminished. Throughout the simulation, reactor dimension and reaction condition for coking-free operation were suggested.

• Archives of Plastic Surgery
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• v.48 no.4
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• pp.440-447
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• 2021

Background Brown adipose tissue (BAT) is a potential target for anti-obesity treatments. Previous studies have shown that BAT activation causes an acute metabolic boost and reduces adiposity. Furthermore, BAT and BAT-derived cell transplantation reportedly help treat obesity by regulating glucose and fatty acid metabolism. However, since BAT transplantation leads to whole-body weight loss, we speculated that earlier approaches cause a generalized and unnecessary fat tissue loss, including in breast and hip tissues. Methods We transplanted white adipose tissue-derived or BAT-derived preadipocytes prepared from C57BL/6 mice into one side of the inguinal fat pads of an obese mouse model (db/db mice) to examine whether it would cause fat loss at the peri-transplant site (n=5 each). The same volume of phosphate-buffered saline was injected as a control on the other side. Six weeks after transplantation, the inguinal fat pad was excised and weighed. We also measured the concentrations of glucose, triglycerides, fatty acids, and total cholesterol in the peripheral blood. Results BAT-derived preadipocytes showed abundant mitochondria and high levels of mitochondrial membrane uncoupling protein 1 expression, both in vivo and in vitro, with a remarkable reduction in weight of the inguinal fat pad after transplantation (0.17±0.12 g, P=0.043). Only free fatty acid levels tended to decrease in the BAT-transplanted group, but the difference was not significant (P=0.11). Conclusions Our results suggest that brown adipocytes drive fat degradation around the transplantation site. Thus, local transplantation of BAT-derived preadipocytes may be useful for treating obesity, as well as in cosmetic treatments.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.578-589
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• 2003

The fuzzy rat that expresses hypersecretion of sebum and hyperplastic sebaceous glands is a genetic mutant for the study of many pharmacological aspects especially human acne. Through this model, we examined the effects of several phospholipids on the secretion of sebum after topical application. The phospholipid derivatives were phosphatidylcholine (PC), hydrogenated phosphatidylcholine (HPC), phosphati dylserine (PS) and hydrogenated phosphatidylserine(HPS). All agents were dissolved into the vehicle (1, 3-Butanediol, ethanol and water) at 0.5％ weight volume and applied on the dorsal area of the fuzzy rat. To observe histological changes, the skin biopsies were stained with Oil Red O and the size and morphology of sebaceous gland was observed under microscope. Topical treatment with PC and/or HPC showed a marked decrease in sebum excretion. Especially hydrogenated PC (HPC) appeared to have more predominant sebosuppressive function than any other treatment. The other agents such as PS and HPS showed a marginal effect on sebum secretion. With the sebosuppressive activity, HPC and PC seem to have a good potential application on acne treatment. In order to obtain more insights into possible mechanisms behind the above observations, effects of each phospholipid on the expression of peroxisome proliferator-activated receptor (PPAR) genes were investigated. Recently, it has been demonstrated that expression and activation of PPAR subtypes appear to modulate the accumulation of cytoplasmic fat droplets that characterizes the sebocyte differentiation(1). It was also previously suggested that PPAR${\gamma}$ antagonist would seem possible to interfere sebum production without side effects (2). In this study we examined the diverse effects of the tested phospholipids on the expression of several PPAR genes based on reverse transcription-polymerase chain reaction (RT-PCR) from the topically treated skin of fuzzy rats. The results and possible implications are discussed.

• Food Science of Animal Resources
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• v.43 no.4
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• pp.712-720
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• 2023

Osteoporosis is a growing global health concern primarily associated with decreased estrogen in postmenopausal women. Recently, some strains of probiotics were examined for potential anti-osteoporotic effects. This study intended to evaluate the impacts of Lactiplantibacillus plantarum MGE 3038 strain (MGE 3038) in ovariectomized rats. For this purpose, twelve weeks old female Wistar rats (n=21; 250-300 g) were divided into 3 groups; ovariectomy (OVX) group, OVX/MGE 3038 group and Sham group (control). In these groups; two went through respective OVX and one had daily MGE 3038 administration through oral gavage. Prior to 16 weeks after OVX, we collected blood samples and extracted the tibiae. We scanned the extracted tibiae by in-vivo micro-computed tomography (micro-CT) and evaluated pathology by hematoxylin and eosin (H&E) and Masson's trichrome staining. The serum levels of C-telopeptide of type I collagen (CTX), osteocalcin (OC), and the receptor activator of nuclear factor-κB ligand (RANKL) were examined. The OVX/MGE 3038 group showed increases in bone mineral density, trabecular bone volume, trabecular number, and trabecular thickness (Tb.Th), and a decrease in trabecular spacing than the OVX group. However, OVX/MGE 3038 group and control group were measurably comparable in Tb.Th. Micro-CT, H&E, and Masson's trichrome findings exhibited increased preservation and maintenance of trabecular bone structure in the OVX/MGE 3038 group in comparison to the OVX group. In serum, the levels of CTX, OC and RANKL were significantly different between the OVX and OVX/MGE 3038 groups. Taken together, L. plantarum MGE 3038 could be helpful for the treatment of osteoporosis.

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.756-761
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• 2006

The physical and sensory properties of puffed mulberry-rice snack (PMRS) by pellet with mulberry leaf and brown rice flour were evaluated at different temper moisture contents and at varying puffing temperatures. The mulberry pellets were prepared using a food extruder to extrude the dough made from mulberry leaf powder and brown rice flour. The mulberry pellets were tempered to 14, 16, and 18% moisture content and were puffed at 220, 230, and 240$^{\circ}C$ for 4, 5, and 6 sec. The specific volume and breaking strength of PMRS increased with heating temperature and time; however, the breaking strength decreased as the moisture content increased. The Hunter L value decreased as the heating temperature and time increased, showing an especially large decrease with increased heating time. The a and b values increased with increasing heating temperature and time. These results indicated that PMRS, which has a distinctive flavor and color, could be effectively used as a functional food with the use of a puffing machine and that PMRS shows potential for use as new snack product.

• Journal of the Korea Concrete Institute
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• v.21 no.5
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• pp.589-597
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• 2009

High Performance Fiber-reinforced Cement Composite (HPFRCC) shows the multiple crack and damage tolerance capacity due to the interfacial bonding of the fibers to the cement matrix. For practical application, it is needed to investigate the fractural behavior of HPFRCC and understand the micro-mechanism of cement matrix with reinforcing fiber. This study is devoted to the investigation of the AE signals in HPFRCC under monotonic and cyclic uniaxial compressive loading, and total four series were tested. The major experimental parameters include the type and volume fraction of fiber (PE, PVA, SC), the hybrid type and loading pattern. The test results showed that the damage progress by compressive behavior of the HPFRCC is a characteristic for the hybrid fiber type and volume fraction. It is found from acoustic emission (AE) parameter value, that the second and third compressive load cycles resulted in successive decrease of the amplitude as compared with the first compressive load cycle. Also, the AE Kaiser effect existed in HPFRCC specimens up to 80% of its ultimate strength. These observations suggested that the AE Kaiser effect has good potential to be used as a new tool to monitor the loading history of HPFRCC.