• The Journal of Korean Academy of Prosthodontics
• /
• 제56권3호
• /
• pp.199-205
• /
• 2018

Purpose: This study evaluated the effect of nonthermal plasma treatment on the bond strength of autopolymerizing relining resin to the injection molded thermoplastic denture base resins (TDBRs) with different surface treatments. Materials and methods: Acrylic Resin (Acrytone), Polyester (Estheshot-Bright), Polyamide (Valplast) and Polypropylene (Weldenz) were subjected to various surface treatments: No treatment, Nonthermal plasma, Sandblasting, Sandblasting and nonthermal plasma. Specimens were bonded using an autopolymerizing relining resin. Shear bond strength was tested using universal testing machine with crosshead speed of 1 mm/min. Statistical analysis by two-way analysis of variance with Tukey's test post hoc was used. Results: Acrytone showed significantly higher shear bond strength value among other TDBR group while Weldenz had the lowest. The sandblasting and nonthermal plasma condition had significantly higher shear bond strength value in all of the resin groups (P < .05). Conclusion: The use of nonthermal plasma treatment showed limited effect on the shear bond strength between TDBRs and relining resin, and combination of nonthermal plasma and sandblasting improved the shear bond strength between TDBR and reline material.

• Journal of Gastric Cancer
• /
• 제20권1호
• /
• pp.60-71
• /
• 2020

Purpose: The utility of 18-fluordesoxyglucose positron emission tomography ([¹⁸F]-FDG-PET) combined with computer tomography or magnetic resonance imaging (MRI) in gastric cancer remains controversial and a rationale for patient selection is desired. This study aims to establish a preclinical patient-derived xenograft (PDX) based [¹⁸F]-FDG-PET/MRI protocol for gastric cancer and compare different PDX models regarding tumor growth and FDG uptake. Materials and Methods: Female BALB/c nu/nu mice were implanted orthotopically and subcutaneously with gastric cancer PDX. [¹⁸F]-FDG-PET/MRI scanning protocol evaluation included different tumor sizes, FDG doses, scanning intervals, and organ-specific uptake. FDG avidity of similar PDX cases were compared between ortho- and heterotopic tumor implantation methods. Microscopic and immunohistochemical investigations were performed to confirm tumor growth and correlate the glycolysis markers glucose transporter 1 (GLUT1) and hexokinase 2 (HK2) with FDG uptake. Results: Organ-specific uptake analysis showed specific FDG avidity of the tumor tissue. Standard scanning protocol was determined to include 150 μCi FDG injection dose and scanning after one hour. Comparison of heterotopic and orthotopic implanted mice revealed a long growth interval for orthotopic models with a high uptake in similar PDX tissues. The H-score of GLUT1 and HK2 expression in tumor cells correlated with the measured maximal standardized uptake value values (GLUT1: Pearson r=0.743, P=0.009; HK2: Pearson r=0.605, P=0.049). Conclusions: This preclinical gastric cancer PDX based [¹⁸F]-FDG-PET/MRI protocol reveals tumor specific FDG uptake and shows correlation to glucose metabolic proteins. Our findings provide a PET/MRI PDX model that can be applicable for translational gastric cancer research.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권14호
• /
• pp.5681-5686
• /
• 2015

Background: Pancreatic cancer ranks fourth in deaths caused by cancers throughout the world. Gemcitabine chemotherapy is the primary method of treatment of advanced pancreatic cancer, and in asco2014, it is still firstline chemotherapy. Howeve,r gemcitabine+fluorouracil regimens are also licensed and widely used worldwide. Clinical trials are the best way to evaluate drug efficacy. In this study, we performed a systematic review and a meta-analysis of randomized controlled trials (RCTs) to assess whether gemcitabine+fluoropyrimidine combination therapy improves the prognosis of unresectable pancreatic cancer compared with gemcitabine treatment alone. Materials and Methods: A quantitative up-to-date meta-analysis was undertaken to investigate the efficacy of gemcitabine-based combination treatment compared with gemcitabine monotherapy for locally advanced or metastatic pancreatic cancer. Inclusion was limited to high-quality randomized clinical trials. Results: A total of 12 studies were included in the present analysis, with a total of 3,038 patients recruited. The studies were divided into three subgroups including 5-FU / CAP / S-1 combined with gemcitabine. For the primary endpoint of overall survival (OS), gemcitabine-based combination therapy demonstrated significantly better outcome (HR, 0.88; 95% CI, 0.81-0.95) than gemcitabine monotherapy. The analysis of progression free survival (PFS) also provided a significant result for the combined therapy in a total of 8 trials (2,130 patients) (HR, 0.74; 95% CI, 0.63-0.86). With subgroup analysis according to the method of dosing delivery, we found that in the injection group with 3 trials (889 patients), a negative result was found (HR, 0.93; 95% CI, 0.77-1.12); while a positive result was observed in the oral group with 9 trials (2,149 patients) (HR, 0.87; 95% CI, 0.80-0.95). Conclusions: Gemcitabine combination therapy provides a modest improvement of survival, but is associated with more toxicity compared with gemcitabine monotherapy.

• Investigative Magnetic Resonance Imaging
• /
• 제16권2호
• /
• pp.152-158
• /
• 2012

Purpose : To compare the arterial and venous detection sites of triggering methods in contrast-enhanced-MR-venography (CE-MRV) for the evaluation of intracranial venous system. Materials and Methods: 41 healthy patients underwent CE-MRV with autotriggering at either the cavernous segment of internal carotid artery with an inserted time-delay of 6 seconds (n = 20) or the superior sagittal sinus without any timedelay (n = 21). 0.1 mmol/kg gadolinium-based contrast material ($Magnevist^{(R)}$, Schering, Germany) was intravenously injected by hand injection. A sagittal fast-spoiled-gradient-echo-sequence ranging from one ear to the other was performed (TR/TE5.2/1.5, Matrix $310{\times}310$, 124 sections in the 15-cm-thick volume). 17 predefined venous structures were evaluated on all venograms by two neuroradiologists and defined as completely visible, partially visible, or none visible. Results: The rate of completely visible structures were 272 out of 323 (84%) in the arterial triggering CE-MRV and 310 out of 340 (91%) in the venous triggering CE-MRV. The venous triggering CE-MRV demonstrated an overall superior visualization of the cerebral veins than the arterial triggering CE-MRV (Fisher exact test, p < 0.006). Conclusion: CE-MRV using venous autotriggering method provides higher-quality images of the intracranial venous structures compared to that of arterial.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 한국공작기계학회 2004년도 추계학술대회 논문집
• /
• pp.145-149
• /
• 2004

It is necessary for managing a perfect process for degasing aluminum molten metal according to the increase of a grade of aluminum and its alloy products. There are some methods that have been used to manage a degasing process in recent years, such as an injection method that uses aluminum molten metal powder and chemicals supplier and input method that supplies argon and nitrogen, or chlorine gas by using a gas blow-tube. However, these methods show some problems, and it shows that it is a difficult process to handle. pollution due to the producing a lot of toxic gases like chlorine and fluoride gas. irregular effects, and lowering work efficiency due to the excessive processing time. The problems that are the most fatal are the producing a lot of sludge due to the reaction of aluminum molten metal with chemicals. loss of metals, and decreasing the life of refractory materials. In order to solve these problems. this paper develops a technology that is related to aluminum continuous casting molten metal and monolithic degasing apparatus. A degasing apparatus developed in this study improved the exist ing methods and prevented environmental pollution wi th smokeless. odor less, and harmlessness by using a new method that applies argon and nitrogen gas in which the methods used in the West and Japan are eliminated. The developed method can significantly reduce product faults that are caused by the production of gas and oxidation because it uses a preprocessed molten metal with chemicals. In addition. the amount of the produced sludge can also be reduced by 60-80% maximum compared with the existing methods. Then. it makes it possible to minimize the loss of metals. Moreover. the molten metal processing and settling time is also shortened by comparing it with the existing methods that are applied by using chemicals. In addition, it does much to improve the workers' health, safety and environment because there is no pollution. The improvement of productivity and prevent ion effects of disaster from the results of the development can be summarized as follows. It will contribute to the process rationalization because it does not have any unnecessary processes that the molten metal will be moved to an agitator by using a ladle and returned to process for degasing like the existing process due to the monolithic configuration. There are no floating impurities due to the oxidation caused by the contact with the air as same as the existing process. In addition. it can protect the blending of precipitation impurities. Because it has a monolithic configuration. it can avoid the use of additional energy to compensate the temperature decreasing about 60t that is caused by the moving of molten metal. It is not necessary to invest an extra facilities in order to discharge the gas generated from a degasing process by using an agitator. The working environment can be improved by the hospitable air in the factory because the molten metal is almost not exposed in the interior of the area.

• Natural Product Sciences
• /
• 제11권2호
• /
• pp.67-74
• /
• 2005

The ethanolic extracts of the leaves and bulbs of Allium victorialis var. platyphyllum (Liliaceae) collected from Daegwallyoung (D) and Ullung Island (U) in Korea were obtained using three different extracting methods. The first extracts, DL-1 DB-1, UL-1 and UB-1, were obtained from leaves (L) and bulbs (B) dried at $90^{\circ}C$, respectively, and the second extracts, DL-2, DB-2, UL-2 and UB-2, were obtained by extracting the leaves and bulbs of fresh plant parts. The third extracts DL-3, DB-3, UL-3 and UB-3 were obtained by incubating leaves and bulbs at $36^{\circ}C$. The six extracts obtained from A. victorialis var. platyphyllum at Daegwanllyoung (cultivated site) were orally administered to examine for a possible antihepatotoxic effect in $CCl_4-induced$ rats. DL-1 exhibited the most pronounced effect. The extracts inhibited serum ALT, AST, SDH, ${\gamma}-GT$, ALP and LDH activities elevated by $CCl_4$ injection and attenuated decreased glutathione S-transferase, glutatione reductase and ${\gamma}-glutamylcysteine$ synthetase activities and a decreased hepatic glutathione. However, the extracts obtained from Ullung Is. (native site) were less active than the extracts from Daegwallyoung, suggesting that A. victorialis var. platyphyllum from the cultivated site is more useful for functional food than of native site. These results also suggest that the antihepatotoxic effect is due to a higher content of hepatic glutathione. Gas chromatography of the twelve extracts showed significantly different sulfides, disulfides or trisulfides contents belonging to volatile sulfur substances (VSS). Nine components were identified on the basis of their mass spectra, namely, dimethyl disulfide, dimethyl trisulfide, diallyl disulfide, dipropyl disulfide, allyl methyl sulfide, allyl methyl trisulfide, 2-vinyl-4H-1,3-dithiin, 3,4-dihydro-3-vinyl-1,2-dithiin, and allithiamine. Extract DL-1 had the highest VSS content. Dried plant materials contained larger amounts of the VSSs than other extracts, and the leaves contained larger amount than the bulbs. These results suggest that heat treatment increases the antiheaptotoxic ability of A. victorialis var. platyphyllum by increasing the proportion of VSSs.

• The Korean Journal of Nuclear Medicine
• /
• 제35권4호
• /
• pp.231-240
• /
• 2001

Purpose: Normal aging results in detectable changes in the brain structure and function. We evaluated the changes of regional cerebral glucose metabolism in the normal aging process with FDG PET. Materials and Methods: Brain PET images were obtained in 44 healthy volunteers (age range 20-69 'y'; M:F = 29:15) who had no history of neuropsychiatric disorders. On 6 representative transaxial images, ROIs were drawn in the cortical and subcortical areas. Regional FDG uptake was normalized using whole brain uptake to adjust for the injection dose and correct for nonspecific declines of glucose metabolism affecting all brain areas equally. Results: In the prefrontal, temporoparietal and primary sensorimotor cortex, the normalized FDG uptake (NFU) reached a peak in subjects in their 30s. The NFU in the prefrontal and primary sensorimotor cortex declined with age after 30s at a rate of 3.15%/decade and 1.93%/decade, respectively. However, the NFU in the temporoparietal cortex did not change significantly with age after 30s. The anterior (prefrontal) posterior (temporoparietal) gradient peaked in subjects in their 30s and declined with age thereafter at a rate of 2.35%/decade. The NFU in the caudate nucleus was decreased with age after 20s at a rate of 2.39%/decade. On the primary visual cortex, putamen, and thalamus, the NFU values did not change significantly throughout the ages covered. These patterns were not significantly different between right and left cerebral hemispheres. Of interest was that the NFU in the left cerebellar cortex was increased with age after 20s at a rate of 2.86%/decade. Conclusion: These data demonstrate regional variation of the age-related changes in the cerebral glucose metabolism, with the most prominent age-related decline of metabolism in the prefrontal cortex. The increase in the cerebellar metabolism with age might reflect a process of neuronal plasticity associated with aging.

• Applied Biological Chemistry
• /
• 제12권
• /
• pp.43-51
• /
• 1969

The purpose of this study was to determine protein amino acid contents of some Korean foods by gas-liquid chromatography, and to evaluate this technique as a procedure for the quantitative determination of amino acids in foods. The crude protein content of foods was also estimated from the nitrogen content. 1. Nitrogen content of each food sample was determined previously to adjust the amount of sample for GLC analysis 2. In the analysis of 17 known amino acids, a linear relationship was found between the weight of 13 amino acids of 17 amino acids, the internal standard as well as the injection volume of a mixture and the detector responses for the derivatives of the amino acids. No response for arginine, cystein, histidine, and tyrosine was observed. 3. The relative molar response (RMR) values for the 13 amino acids of standard solution relative to glutamic acid as '1.00' were obtained under normal operating conditions with a hydrogen flame ionization detector. 4. The recovery of amino acids from their mixtures with natural food materials was carried out. The recoveries were essentially quantitative except threonine and serine. An overall mean recovery of 11 amino acids was $101.4{\pm}8.4$ per cent before hydrolysis and $98.1{\pm}8.7$ per cent after hydrolysis of samples. 5. The comparative analysis of the acid hydrolysates of two food samples by gas-liquid and ion-exchange chromatographic analysis were carried out. In white-bait pemmican, only threonine and asparagine amounts by GLC analysis had similar values to those obtained by ion-exchange chromatography. The other seven amino acids gave higher values as measured by GLC than by ion-exchange. With the food sample, soybean, alanine, valine, asparagine, and glutamic acid were in good agreement in two analysis, while leucine, proline, threonine, phenylalanine, and lysine were found in slightly higher concentrations in the GLC analysis. 6. Grant variations of amino acid content were found among samples analyzed. The amino acid contents of each sample were compared with the values found in the literature.

• Journal of the Korean Vacuum Society
• /
• 제19권5호
• /
• pp.377-384
• /
• 2010

Many routes have been developed for the synthesis of signle-walled carbon nanotubes (SWCNTs). We spun fibers of SWCNTs directly from vertical furnace using a liquid source of carbon and an iron-contained molecule. The solution was prepared by ethanol as a carbon source, in which ferrocene as a catalyst, thiophene were dissolved. It was then injected from the top of the furnace into hot zone with hydrogen as a carrier gas. We successfully synthesized high-quality SWCNTs by adjusting the various experimental conditions, such as concentration of ferrocene, solution injection rate, concentration of thiophene, and hydrogen flow rate. Measurement of Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy were carried out to find the optimized conditions. The synthesized SWCNTs (1.16~1.64 nm) appeared a bundle structure and well-aligned parallel to the direction of furnace. These results also provide an simple way for high-quality SWCNTs mass production and fabricating direct spining SWCNTs fiber. It will allow one-step production of SWCNTs fiber with potentially excellent properties and wide-range applications.

• Applied Microscopy
• /
• 제27권1호
• /
• pp.13-30
• /
• 1997

The experiment was performed to study the morphological responses of the thymus of the mice, to antitumour agents (5-Fluorouracil or mitomycin C). Healthy adult mice weighing 25 gm each were divided into normal and experimental groups. 5-Fluorouracil (60 mg/kg) or Mitomycin-C $(400{\mu}g/kg)$ were injected subcutaneously to the animals every other day. Animals were sacrificed at 4 days and 7 days following the first injection. Pieces of the tissue taken from the thymus were prefixed with 2.5% paraformaldehyde-l.5% glutaraldehyde, followed by post-fixation with 1% osmium tetroxide. Ultrathin sections stained with uranyl acetate and lead citrate were observed with a JEM 100 CX-II electron microscope. The observed results were as follow: 1. Apoptoses of T-lymphocytes were observed more frequently in the thymus of the experimental groups than in those of a normal group. 2. In the experimental group, the plasma cells with distended cisternae of the granular endoplasmic reticulum and the eosinophile leukocytes were observed frequently. 3. In the experimental group, newly forming Hassall's corpurscles were observed frequently. 4. In the mitomycin-treated group, the epithelial reticular cells containing distended perinuclear cisternae, distended the granular endoplasmic reticula and pyknotic nuclei were observed in the cortico-medullary junctional area. 5. In the mitomycin-treated group, nuclear bodies with medium electron dense materials were often observed in the T lymphocyte. 6. In the 5-fluorouracil-treated groups, fused and dissolved tonofilament bundles and apoptotic bodies were observed in the some epithelial reticular cells in the medullary area. 7. In the 5-fluorouracil-treated groups, some elongated and bar-shaped lysosomes with electron lucent gap were often observed in the macrophages. 8. In the 5-fluorouracil-treated group, membrane complex of the smooth endoplasmic reticulum were ofen observed in the macrophage. From the above results, it was suggested that 5-fluorouracil or mitomycin could induce rapid involution of the thymus, and disturb maturation and differentiation of T lymphocytes, and, in turn, supress immunity.