• Journal of the Microelectronics and Packaging Society
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• v.27 no.4
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• pp.119-125
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• 2020

Transition metal dichalcogenides (TMDCs), two-dimensional atomic layered materials with direct bandgap in the range of 1.1-2.1 eV, have attracted a lot of research interest due to their high response to light and capability to build new types of artificial heterostructures. However, the large-area synthesis of high-quality and uniform TMDC films with vertical-stacked heterostructure still remains challenge. In this study, we have developed a metal-organic chemical vapor deposition (MOCVD) system for TMDCs and conducted a systematic study on the growth of single-layer TMDCs and their heterostructures. In particular, using a bubbler-type organometallic compound sources, the concentration and flow rate of each source can be precisely controlled to obtain uniformly single-layered MoS2 and WS2 films over the centimeter scale. In addition, the MoS2/WS2 vertical heterostructure was achieved by growing WS2 film directly on the MoS2 film, as confirmed by electron microscopy, UV-visible spectrophotometer, Raman spectroscopy, and photoluminescence spectroscopy.

• The Journal of the Korean bone and joint tumor society
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• v.11 no.1
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• pp.46-53
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• 2005

Purpose: Bisphosphonates (BPs) are the analogues of endogenous pyrophosphates: they have been used in the treatment of skeletal diseases such as Paget's disease, osteoporosis, and tumorinducing ostelysis, and are used in treatment of osteolytic metastasis of breast cancer recently. They are also used as one of the therapeutic agents for metastasis of prostatic cancer of which metastasis makes the mixed nature of osteolysis and ostegenesis. Although the action mechanism of BPs are well known for diseases with excessive osteoclastic bone resorption, the direct effect of BPs has not been known yet. This study was intended to see the tumor suppression capability of Zoledronic acid(ZOL) using nude mouse with osteosarcoma. Materials and Methods: MG-63 and HOS osteosarcoma cell lines were used and the transforemed MG-63-GFP and HOS-GFP cells, which were made for detection under fluorescent light, were subcutaneously injected to make osteosarcoma. The five 6-week male mice were used for the experiment at each group. After the injection, mice were cultivated until tumor pieces grow up to $3{\times}3{\times}3$ $mm^3$ and ZOL of 120 ug/kg was subcutaneously injected twice a week. Sizes of tumor were measured twice a week and photographed under fluorescent light. Results: In in vivo test with HOS osteosarcoma cell lines, mean size of tumors was 2,520 $mm^3$ in control group and was 131 $mm^3$ in ZOL group, which showed 94% of reduction comparing with the control ; with MG-63 osteosarcoma cell lines, mean size of tumors was 2,866 $mm^3$ in control group and was 209 $mm^3$ in test group with 72% of reduction (p<0.05). Conclusion: In in vivo tests with nude mice, we suggest that ZOL has direct effect on osteosarcoma cells and it would be used as one of the therapeutic agents for osteosarcoma, especially to ZOL-sensitive osteosarcoma cells.

• Applied Microscopy
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• v.33 no.2
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• pp.145-154
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• 2003

The present study was designed to demonstrate ionic zinc in the rat nasal mucosa by means of zinc selenium autometallography ($ZnSe^{AMG}$). Rats were given sodium selenide either intraperitoneally (i.p) or intranasally (i.n). Prior to the i.n. administration the rats were anesthetized with pentobarbital sodium (30 mg/kg, i.p.). A thin plastic tube coupled to a Hamilton syringe was then inserted into the right nostril and $10{\mu}l$ of the solution was instilled. For the i.p. administration non-anesthetized rats were given $100{\mu}l$ of the sodium selenide solution (10 mg/kg). Control rats were instilled with saline. After 2 hrs survival, the rats were anaesthetized and transcardially perfused with 3% glutaraldehyde. The olfactory area was removed and put into same fixative. The nose was then sectioned ($30{\mu}m$) horizontally, autometallography (AMG) was performed according to Danscher et al. (1997). After silver enhancement, fine AMG grains were scattered in the whole length of the olfactory epithelium containing olfactory receptor neurons, sustentacular and basal cells. However, much higher concentration of the AMG grains occupied near the surface and in the basal region of the olfactory epithelium. Both groups of i.p. and i.n. administration showed almost same level in the concentration of the AMG grains. In i.n. group, few AMG grains were also found in olfactory nerves of the lamina propria, suggesting zinc transport into the olfactory bulb via olfactory axons. At the electron microscopic level, the AMG grains were most entirely found in the supporting cells of the olfactory epithelium, and they were mostly localized in lysosome-like organelles. The i.n. group showed various signs of tissue damage of the olfactory mucosa, where dense concentration of AMG grains were localized at crystalloid structures. The present study demonstrated dense population of ionic zinc in the rat olfactory epithelium. zinc may play a role in the olfactory functioin and in the pathogenesis of the neurodegerative disorders affecting nose.

• Korean Journal of Agricultural Science
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• v.3 no.1
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• pp.61-65
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• 1976

This study was conducted to induce superovulation by P.M.S. injection and P.M.S. associate with Estrogen comparatively in the rabbit. The results obtained in this study are as follows. At 23-48 hours following mating, there were 21.3-24.1 ova (Ovulation rate was increased 50.5-63.6%) in average in the group of 40 I.U P.M.S. injected per day per herd for 5 days (total 200 I.U. of P.M.S.) and 32.5-37.8 ova (Ovulation rate was increased 87.5-100%) in the group of P.M.S. associats with 0.1mg at 5th day. She number of unovulated-follicle were fewer in P.M.S.-Estrogen group than PMS group. As the result that dia meter of ova were classified in 3 group as 1-1. 4mm, 1.5-2.4mm and 2.5mm and observed, the ova in P.M.S. Estrogen group were slightly larger in size than P.M.S. group. It was conclued that P.M.S. associate with Estrogen injection was not so much effect on growth of ova but effect on ovulation of ova. so the number of ovulated ova were increased than P.M.S. group.

• Restorative Dentistry and Endodontics
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• v.36 no.6
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• pp.490-497
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• 2011

Objectives: This study examined the effect of the uncured dentin adhesives on the bond interface between the resin inlay and dentin. Materials and Methods: Dentin surface was exposed in 24 extracted human molars and the teeth were assigned to indirect and direct resin restoration group. For indirect resin groups, exposed dentin surfaces were temporized with provisional resin. The provisional restoration was removed after 1 wk and the teeth were divided further into 4 groups which used dentin adhesives (OptiBond FL, Kerr; One-Step, Bisco) with or without light-curing, respectively (Group OB-C, OB-NC, OS-C and OS-NC). Pre-fabricated resin blocks were cemented on the entire surfaces with resin cement. For the direct resin restoration groups, the dentin surfaces were treated with dentin adhesives (Group OB-D and OS-D), followed by restoring composite resin. After 24 hr, the teeth were assigned to microtensile bond strength (${\mu}TBS$) and confocal laser scanning microscopy (CLSM), respectively. Results: The indirect resin restoration groups showed a lower ${\mu}TBS$ than the direct resin restoration groups. The ${\mu}TBS$ values of the light cured dentin adhesive groups were higher than those of the uncured dentin adhesive groups (p < 0.05). CLSM analysis of the light cured dentin adhesive groups revealed definite and homogenous hybrid layers. However, the uncured dentin adhesive groups showed uncertain or even no hybrid layer. Conclusions: Light-curing of the dentin adhesive prior to the application of the cementing material in luting a resin inlay to dentin resulted in definite, homogenous hybrid layer formation, which may improve the bond strength.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.141-146
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• 2004

Fungal products indirectly mediate anti-tumor effects in vitro and in vivo. To investigate whether Lentinus edodes might possess direct anti-tumor substance, L. edodes was extracted and tested on human papillomavirus (HPV) 16 oncogenes-associated animal tumor cells (TC-1) and in an animal tumor model. Only water extract displayed direct anti-proliferative effects in TC-1 tumor cells in vitro. This inhibition was dose-dependent, and inhibitory concentration ($IC_{50}$) was $800\;{\mu}g/mL$. Fungal extracts also showed growth inhibition to human cervical cancer cells (CaSki and HeLa) similarly to TC-1 tumor cells. When fungal extracts were added at a high dose (1.5 mg/mL), cell growth was inhibited within 6 hr following extract treatment. Cell growth inhibition was blocked by heat treatment, but not by low pH, which is indicative of heat sensitivity of this anti-proliferative substance. Cell growth suppression was mediated by apoptosis, as determined by Annexin V and propidium iodide staining. When challenged with TC-1 cells, direct intratumoral injection of fungal extracts resulted in some positive effect on tumor growth inhibition, as compared to oral delivery. Results suggest that heat labile substance of L. edodes suppresses growth of HPV oncogenes-associated tumor cells through apoptosis.

• The Korean Journal of Nuclear Medicine
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• v.33 no.1
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• pp.84-93
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• 1999

Purpose: We investigated the direct labeling method of antibody with $^{99m}Tc$ and $^{188}Re$ and examined the stability and function of these labeled compounds in in vitro and in vivo. Materials and Methods: Disulfide bond of nonspecific human IgG was reduced to -SH group by 2-mercaptoethanol. Stannous ion was used to reduce $^{99m}Tc$ and $^{188}Re$. The stability of $^{99m}Tc$-IgG and $^{188}Re$-IgG was estimated upto 24 hrs. Biodistribution was evaluated in abscess bearing rats at 4 and 24 hr post-injection of $^{99m}Tc$ or $^{188}Re$ labeled IgG. Results: The number of -SH group per reduced IgG molecule was 2.34. The labeling yield of $^{99m}Tc$-IgG and $^{188}Re$-IgG were 90% and 95%, respectively The stability of $^{99m}Tc$-IgG at 1, 4, 6 and 24 hr was 91%, 83%, 78%, 7% and that of $^{188}Re$-IgG at 1, 4, 16 and 24 hr was 94%, 80%, 47%, 42%, respectively. At 4 hr post-injection of $^{99m}Tc$-IgG, high uptake was found on kidney, blood, stomach and abscess ($9.42{\pm}0.68,\;1.43{\pm}0.24,\;0.86{\pm}0.18,\;0.72{\pm}0.10$ %ID/g, respectively). The uptakes at 24 hr were kidney, abscess,.itomach, and blood in descending order. In case of $^{188}Re$-lgG, high uptake at 4 hr post injection appeared on kidney, blood, abscess and stomach ($3.92{\pm}0.62,\;1.32{\pm}0.08,\;0.88{\pm}0.01,\;0.26{\pm}0.06$, respectively). The uptakes at 24 hr were kidney, abscess, blood and stomach in descending order. The abscess to blood uptake ratio of $^{99m}Tc$-IgG was 0.5 at 4 hr and 2.02 at 24 hr and that of $^{188}Re$-IgG was 0.67 and 1.29. Conclusion: $^{99m}Tc$-IgG and $^{188}Re$-IgG canbe labeled efficiently with direct labeling method. However, $^{99m}Tc$-IgG and $^{188}Re$-IgG, labeled with direct method, was unstable. Further study is needed to enhance the stability of the antibody labeling.

• Journal of Life Science
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• v.22 no.9
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• pp.1224-1230
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• 2012

Cancer chemotherapy drugs command a large share of the market, and the development of new therapeutics with high efficacy and specificity is an active area of study. Recently, the development of cancer therapeutics from natural products targeting angiogenesis has drawn attention due to conventional chemotherapeutics showing serious side effects and resistance in cancer cells. In this study, we investigated the pharmacological efficacy of Gomisin A, an active ingredient of Schizandra chinensis baillon, on tumor growth and metastasis. Administration of Gomisin A at 10 and 100 ${\mu}g/ml$ reduced tumor growth in vivo by $80.5{\pm}8.1%$ and $96.2{\pm}2%$, respectively, compared with positive tumor controls. Treatment of Gomisin A in normal and various tumor cell lines did not exert significant toxicity. Mice treated with Gomisin A at a concentration of 10 and 100 ${\mu}g$/head showed a significant reduction in tumor-induced angiogenesis of $151{\pm}16.9%$ and $98.5{\pm}29.5%$, respectively. Furthermore, tumor metastasis analysis revealed that the administration of Gomisin A at a concentration of 10 and 100 ${\mu}g$/head inhibited tumor metastasis by $13.5{\pm}8.56%$ and $58.3{\pm}9.12%$, respectively. In addition, Gomisin A significantly decreased cell adhesion of the B16BL6 cells to the extracellular matrix. These results demonstrate that Gomisin A inhibits tumor growth via suppression of angiogenesis and tumor metastasis inhibition, without cellular toxicity. The pharmacological efficacy of Gomisin A suggests that it may be a potential candidate for the development of cancer drugs.

• Tuberculosis and Respiratory Diseases
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• v.41 no.5
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• pp.504-512
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• 1994

Background: It is well known that severe hypoxemia is often associated with liver cirrhosis without preexisting cardiac or pulmonary diseases. Pulmonary vascular impairments, more specifically, intrapulmonary shunting have been considered as a major mechanism. Intrapulmonary shunting arises from pulmonary vascular dilatation at the precapillary level or direct arteriovenous communication and has relationship with the characteristic skin findings of spider angioma. However, these results are mainly from Western countries where alcoholic and primary biliary cirrhosis are dominant cuases of cirrhosis. It is uncertain that the same is true in viral hepatitiss associated liver cirrhosis, which is dominant causes of liver cirrhosis in Korea. We investigated the incidences of hypoxemia and orthodeoxia in Korean cirrhotic patients dominantly composed of postnecrotic cirrhosis and the significance of intrapulmonary shunting as the suggested mechanism of hypoxemia, Method: We performed the arterial blood gas analysis separately both at the supine and errect position in 48 stable cirrhotic patients without the evidences of severe complications such as ascites, variceal bleeding, and hepatic coma. According to the results of arterial blood gas analysis, all patients were divided into hypoxemic and normoxemic group. In each group, pulmonary function test and Tc-99m-MAA whole body scan were performed. The shunting fraction was calculated based on the fact that the sum of cerebral and bilateral renal blood flow is 32% of the systemic blood flow. Results: The hypoxemia of $PaO_2$ less than 80 mmHg was observed in 9 patients(18.8%) and Orthodeoxia more than 10 mmHg was observed in 8 patients(16.7%). But there was no patient with significant hypoxemia of $PaO_2$ less than 60 mmHg. $PaO_2$ was significantly decreased in the patients with spider angioma than the pathients without spider angioma and showed no correlation with the serologic type and severities of liver function test findings. Any parameters of pulmonary function test did not demonstrate the difference between normoxemic and hypoxemic group. But hypoxemic group showed significantly increased shunt fraction of $11.4{\pm}4.1%$ than normoxemic group of $4.1{\pm}2.0%$ (p<0.05). Conclusions: Hypoxemia is not infrequently observed complication in liver cirrhosis and intrapulmonary shunting is suggested to p1ay a major ro1e in the development of hypxemia. But there was no great likelihood of clinically significant hypoxemia in our domestic cirrhotic patients predominantly composed of postnecrotic type.

• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.616-623
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• 1996

Eum Yang Kwak, the aerial part of Epimedium koreanum, is widely used as a folk medicine for stimulant in man, tonic, and hypotensive purpose. The plant contains icariin (a specific flavonoid), magnoflorine (an alkaloid) and tannin, but their contents are not known until now. In this paper, a quantitative analysis method for them was developed. Determination of icariin and magnoflorine was successfully achived by high performance liquid chromatography equipped with a UV detector in the ranges of $0.1{\sim}0.4\;mg$ and $0.002{\sim}0.1\;mg\;per\;ml$ sample, respectively. Extraction of the plant was carried out with water or 50% ethanol using different decocting temperatures and times. Icariin was well extracted either by water ($100^{\circ}C$, 3hr) or 50% ethanol ($85^{\circ}C$, 1hr), and its content in the plant was measured to be 0.94%. On the other hand, magnoflorine was fully extracted by 50% ethanol ($85^{\circ}C$, 1hr), and its content was determined to be 0.16%. Therefore, decoction of the medicinal plant with water at $100^{\circ}C$ for 3hr turned out to be recommendable for the best extraction.