• Restorative Dentistry and Endodontics
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• v.29 no.2
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• pp.170-176
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• 2004

Objectives : In the unique metal iris method. the developing interfacial gap at the cavity floor resulting from the cavity wall property during polymerizing composite resin might affect the nominal shear bond strength values. The aim of this study is to evaluate that the iris method reduces the cohesive failure in the substrates and the cavity wall property effects on the shear bond strength tests using iris method. Materials and Methods : The occlusal dentin of 64 extracted human molars were randomly divided into 4 groups to simulate two different levels of cavity wall property (metal and dentin iris) and two different materials ($ONE-STEP^{\circledR}$ and $ALL-BOND^{\circledR}$ 2) for each wall property. After positioning the iris on the dentin surface. composite resin was packed and light-cured. After 24 hours the shear bond strength was measured at a crosshead speed of 0.5 mm/min. Fracture analysis was performed using a microscope and SEM. The data was analyzed statistically by a two-way ANOV A and t-test. Results : The shear bond strength with metal iris was significant higher than those with dentin iris (p＝0.034). Using $ONE-STEP^{\circledR}$, the shear bond strength with metal iris was significant higher than those with dentin iris (p＝0.005), but not in $ALL-BOND^{\circledR}$ 2 (p＝0.774). The incidence of cohesive failure was very lower than other shear bond strength tests that did not use iris method. Conclusions：The iris method may significantly reduce the cohesive failures in the substrates. According to the bonding agent systems. the shear bond strength was affected by the cavity wall property.

• Korean Journal of Weed Science
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• v.17 no.1
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• pp.66-70
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• 1997

LGC-40863(proposed common name ; pyribenzoxim), (benzophenone O-[2,6-bis[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzoyl]oxime) is a new rice herbicide being developed by LG Chemical Ltd. The herbicide is highly selective between rice(Oryza sativa L.) and weeds including barnyardgrass (Echinochloa crus-galli(L.) P. Beauv.), and assumed to inhibit acetolactate synthase(ALS ; EC 4.1.3.18) because other structurally related herbicides inhibit the enzyme. To know inhibitory activity and the mode of inhibition of LGC-40863, $I_{50}$(concentration inhibiting ALS activity by 50%) and inhibition kinetics were investigated using ALS extracted from rice and barnyardgrass. $I_{50}$ values of LGC-40863 were 14 and 16mM in rice and barnyardgrass, respectively. In contrast to imazapyr(2-[4,5-dihydro-4-mythyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-pyridine-carboxylic acid) which showed an uncompetitive inhibition pattern, LGC-40863 was a noncompetitive inhibitor to ALS with respect to pyruvate similar to chlorsulfuron(2-chloro-N-((4-methoxy-6-methyl-l,3,5-triazin-2-yl) aminocarbonyl)benz-enesulfonamide) in both plants.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.4
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• pp.65-70
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• 2008

The mechanical shear strength of BGA(Ball Grid Array) solder joints under high impact loading was investigated. The Sn-37Pb solder balls with a diameter of $500{\mu}m$ were placed on the pads of FR-4 substrates with ENIG(Electroless Nickel Immersion Gold) surface treatment and reflowed. For the High Temperature Storage(HTS) test, the samples were aged a constant testing temperature of $120^{\circ}C$ for up to 250h. After the HTS test, high speed shear tests with various shear speed of 0.01, 0.1, 1, 3 m/s were conducted. $Ni_3Sn_4$ intermetallic compound(IMC) layer was observed at the solder/Ni-P interface and thickness of IMC was increased with aging process. The shear strength increased with increasing shear speed. The fracture surfaces of solder joints showed various fracture modes dependent on shear speed and aging time. Fracture mode was changed from ductile fracture to brittle fracture with increasing shear speed.

• Investigative Magnetic Resonance Imaging
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• v.15 no.2
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• pp.130-138
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• 2011

Purpose : To compare fMRIs of visual and auditory word generation tasks, and to evaluate the difference of its activated areas and lateralization according to the mode of stimuli. Materials and Methods : Eight male normal volunteers were included and all were right handed. Functional maps were obtained during auditory and visual word generation tasks in all. Normalized group analysis were performed in each task and the threshold for significance was set at p<0.05. Activated areas in each task were compared visually and statistically. Results : In both tasks, left dominant activations were demonstrated and were more lateralized in visual task. Both frontal lobes (Broca's area, premotor area, and SMA) and left posterior middle temporal gyrus were activated in both tasks. Extensive bilateral temporal activations were noted in auditory task. Both occipital and parietal activations were demonstrated in visual task. Conclusion : Modality independent areas could be interpreted as a core area of language function. Modality specific areas may be associated with processing of stimuli. Visual task induced more lateralized activation and could be a more useful in language study than auditory task.

• The Korean Journal of Pesticide Science
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• v.7 no.1
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• pp.58-65
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• 2003

Various physicochemical parameters for the active ingredients of 245 herbicides were calculated to develope a diagnosis and estimation system for utility as herbicide. The range of physico-chemical parameters for each inhibitors of photo system II (H1), acetolactate synthase (ALS) (H2) and herbicides were confirmed. The distribution ranges of 85% dependence for each physicochemical parameters were Obs.logP :$-0.90\sim4.50$, dipol moment: $1.80\sim12.22$ (debye), molecular refractivity: $53.0\sim104.0(cm^3/mol)$, polarizability: $19.0\sim37.0(\AA^3)$, HOMO energy: $-9.98\sim-7.34$ (eV), LUMO energy:$-2.76\sim0.40$ (eV), Van der Waals molecular volumes: $558.0\sim995.0(cm^3)$, molecular weight: $202.0\sim430.0$ (amu) and surface areas (Grids): $194.0\sim356.0(\AA^2)$, hydration energy: $-10.16\sim114.7$ Kcal/mol, respectively. It is suggested that MR and polarizability constants will be able to distinguish between herbicides and medicinal drugs. Results revealed that various compounds based on the range of physicochemical parameters of herbicides could be diagnosed and estimated.

• Journal of Embryo Transfer
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• v.28 no.3
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• pp.243-250
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• 2013

Pyracantha is a genus of thorny evergreen large shrubs in the family of Rosaceae, with common names Firethorn or Pyracantha. It's extract has also been used in cosmetics as a skin-whitening agent and functioning through tyrosinase inhibition. Recent studies have shown that pyracantha extract possesses antioxidant activities and may significantly improve lipoprotein metabolism in rats. Although the mode of action of Pyracantha extract is not fully understood, a strong relationship was observed between antioxidant and apoptosis in some types of cells. Thus, the aim of this study was to evaluated the effect of pyracantha extract on blastocysts formation and their quality of the porcine parthenogenetic embryos. After parthenogenetic activation by chemicals, presumptive porcine parthenogenetic embryos were cultured in PZM-3 medium supplemented with extracts of pyracantha leaf, stalk and root for 6 day (1, 5 and $10{\mu}g/ml$, respectively). In our results, the frequency of blastocyst formation in pyracantha root extract ($5{\mu}g/ml$) treated group had increased that of other groups. Furthermore, blastocysts derived from pyracantha root extract ($5{\mu}g/ml$) treated group had increased the total cell numbers and reduced apoptotic index. Blastocyst development was significantly improved in the pyracantha root extract ($5{\mu}g/ml$) treated group when compared with the $H_2O_2$ treated group (p<0.05). Subsequent evaluation of the intracellular levels of ROS in pyracantha root extract ($5{\mu}g/ml$) treated groups under $H_2O_2$ induced oxidative stress were decreased (p<0.05). In conclusion, our results indicate that treatment of pyracantha root extract may improve in vitro development of porcine parthenogenetic embryos through its antioxidative and antiapoptotic effects.

• The Journal of Advanced Prosthodontics
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• v.9 no.4
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• pp.244-251
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• 2017

PURPOSE. The purpose of this study was to determine fracture resistance and failure modes of three-unit fixed dental prostheses (FDPs) made of lithium disilicate pressed on zirconia (LZ), monolithic lithium disilicate (ML), and monolithic zirconia (MZ). MATERIALS AND METHODS. Co-Cr alloy three-unit metal FDPs model with maxillary first premolar and first molar abutments was fabricated. Three different FDPs groups, LZ, ML, and MZ, were prepared (n = 5 per group). The three-unit FDPs designs were identical for all specimens and cemented with resin cement on the prepared metal model. The region of pontic in FDPs was given 50,000 times of cyclic preloading at 2 Hz via dental chewing simulator and received a static load until fracture with universal testing machine fixed at $10^{\circ}$. The fracture resistance and mode of failure were recorded. Statistical analyses were performed using the Kruskal-Wallis test and Mann-Whitney U test with Bonferroni's correction (${\alpha}=0.05/3=0.017$). RESULTS. A significant difference in fracture resistance was found between LZ ($4943.87{\pm}1243.70N$) and ML ($2872.61{\pm}658.78N$) groups, as well as between ML and MZ ($4948.02{\pm}974.51N$) groups (P<.05), but no significant difference was found between LZ and MZ groups (P>.05). With regard to fracture pattern, there were three cases of veneer chipping and two interfacial fractures in LZ group, and complete fracture was observed in all the specimens of ML and MZ groups. CONCLUSION. Compared to monolithic lithium disilicate FDPs, monolithic zirconia FDPs and lithium disilicate glass ceramics pressed on zirconia-based FDPs showed superior fracture resistance while they manifested comparable fracture resistances.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3267-3272
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• 2015

Purpose: To retrospective assess the potential predictors for relapse and create an effective clinical mode for surveillance after orchidectomy in clinical stage I non-seminomatous germ cell testicular tumors (CSI-NSGCTs). Materials and Methods: We analyzed data for CSI-NSGCTs patients with non-lymphatic vascular invasion, %ECa < 50% (percentage of embryonal carcinoma < 50%), and negative or declining tumor markers to their half-life following orchidectomy (defined as low-risk patients); these patients were recruited from four Chinese centers between January 1999 and October 2013. Patients were divided into active surveillance group and retroperitoneal lymph node dissection (RPLND) group according to different therapeutic methods after radical orchidectomy was performed. The disease-free survival rates (DFSR) and overall survival rates (OSR) of the two groups were compared by Kaplan-Meier analysis. Results: A total of 121 patients with CSI-NSGCT were collected from four centers, and 81 low-risk patients, including 54 with active surveillance and 27 with RPLND, were enrolled at last. The median follow-up duration was 66.2 (range 6-164) months in the RPLND group and 65.9 (range 8-179) months in the surveillance group. OSR was 100% in active surveillance and RPLND groups, and DFSR was 89.8% and 87.0%, respectively. No significant difference was observed between these two groups ($X_2=0.108$, P=0.743). No significant difference was observed between the patients with a low percentage of embryonal carcinoma (<50%) and those without embryonal carcinoma (87.0% and 91.9%, $X_2=0.154$, P=0.645). No treatment-related complications were observed in the active surveillance group whereas minor and major complications were observed in 13.0% and 26.1% of the RPLND group, respectively. Conclusions: Active surveillance resulted in similar DFSR and OSR compared with RPLND in our trial. Patients with low-risk CSI-NSGCTs could benefit from risk-adapted surveillance after these patients were subjected to radical orchidectomy.

• Journal of the Korean Wood Science and Technology
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• v.27 no.2
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• pp.15-22
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• 1999

Polymeric meterials that are used for noise and vibration damper in wood/polymer/wood sandwich composites, must have a high loss factor(tan ${\delta}$), and at the same time the storage modulus(E) of $5{\times}10^7$ to $10^9$ dyne/$cm^2$ must withstand over a wide temperature and frequency ranges. In this study, the series of epoxy resinlpolyacrylate interpenetrating polymer networks(IPNs) were synthesized by simultaneous polymerization. Their dynamic tensile properties were measured at 110Hz using Rheovibron instrument. Composite damping factor(tan ${\delta}_c$) and dynamic bending modulus($E_c,\;E_^{\prime\prime}c$) of wood/polymer/wood sandwich composites were measured at 110Hz using a Rheovibron in bending mode of vibration. These dynamic tensile studies indicated that cured epoxy resin/polyacrylates IPNs were semicompatible in the sense that both the shifting of T($E^{\prime\prime}_{max}$) or T(tan ${\delta}_{max}$) and the broadening of glass transition temperature range were observed. Especially, the cured Epikote871/P(n-BMA) IPNs of composition 70/30 to 50/50 showed a relatively high tan a and appropriate E' value over a wide temperature range; consequently the tan a e curves of wood/IPNs/wood sandwich composites was broadened over a wide temperature range.

• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.523-532
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• 2010

The proposed method is simple, sensitive and specific Liquid chromatography-tandem mass spectrometry (LCESI-MS/MS) method for the quantification of Entacapone (EA) in human plasma using Entacapone-d10 (EAD10) as an internal standard (IS). Chromatographic separation was performed on Zorbax SB-C18, $2.1{\times}50\;mm$, $5\;{\mu}m$ column, mobile phase composed of 10 mM Ammonium formate (pH 3.0): Acetonitrile (60:40 v/v), with a flow-rate of 0.7 mL/min, followed by Liquid-liquid extraction. EA and EAD10 were detected with proton adducts at m/z $306.1{\rightarrow}233.1$ and $316.3{\rightarrow}233.0$ in multiple reaction monitoring (MRM) positive mode respectively. The method was validated over a linear concentration range of 1.00 - 2000.00 ng/mL with correlation coefficient ($r^2$) $\geq$ 0.9993. Intra and inter-day Precision within 3.60 to 7.30 and 4.20 to 5.50% and Accuracy within 97.30 to 104.20 and 98.30 to 105.80% proved for EA. This method is successfully applied in the bioequivalence study of healthy Indian human volunteers.