64 research outputs found
Rhus verniciflua Stokes against Advanced Cancer: A Perspective from the Korean Integrative Cancer Center
Active anticancer molecules have been searched from natural products; many drugs were developed from either natural products or their derivatives following the conventional pharmaceutical paradigm of drug discovery. However, the advances in the knowledge of cancer biology have led to personalized medicine using molecular-targeted agents which create new paradigm. Clinical benefit is dependent on individual biomarker and overall survival is prolonged through cytostatic rather than cytotoxic effects to cancer cell. Therefore, a different approach is needed from the single lead compound screening model based on cytotoxicity. In our experience, the Rhus verniciflua stoke (RVS) extract traditionally used for cancer treatment is beneficial to some advanced cancer patients though it is herbal extract not single compound, and low cytotoxic in vitro. The standardized RVS extract's action mechanisms as well as clinical outcomes are reviewed here. We hope that these preliminary results would stimulate different investigation in natural products from conventional chemicals
Capillary force lithography with impermeable molds
Capillary force lithography (CFL) with impermeable mold is presented. For the CFL to be operative over large area, either the mold or the substrate has to be flexible. With a silicon wafer mold and a flexible substrate, a repeated line and space pattern with a spacing of 30 nm is shown to be well patterned. With a flexible mold and a hard substrate, a similar pattern with a spacing of 60 nm is demonstrated by CFL. The flexibility is needed for the intimate contact that is required between the mold and the substrate for the capillarity to take hold over large area. The forte of CFL with impermeable mold lies in the fact that the driving force for the patterning, which is capillary force, increases with decreasing pattern size.This work was supported by the Korea Foundation Grant funded by MOEHRD (KRF-2005-041-D00250)
Transfer Tiling of Nanostructures for Large-Area Fabrication
The fabrication of nanoscale patterns over a large area has been considered important but difficult, because there are few ways to satisfy both conditions. Previously, visually tolerable tiling (VTT) for fabricating nanopatterns for optical applications has been reported as a candidate for large area fabrication. The essence of VTT is the inevitable stitching of the nanoscale optical component, which is not seen by the naked eye if the boundary is very narrow while the tiles are overlapped. However, it had been difficult to control the shape of the spread of liquid prepolymers in the previous work, and there was room for the development of tiling. Here, we propose a method for transferring various shapes of tiles, which can be defined with a shadow mask. The method of using a transparent shadow mask can provide a wide process window, because it allows the spreading of a liquid prepolymer to be more easily controlled. We optimize the coating condition of a liquid prepolymer and the ultraviolet (UV) exposure time. Using this method, we can attach tiles of various shapes without a significant visible trace in the overlapped region
Analysis of the APR1400 Benchmark Using High-Fidelity Pin-Wise Core Calculation Codes
The KEPCO Nuclear Fuel Company (KNF) has undertaken considerable efforts to improve the KARMA/ASTRA nuclear design code system to meet the increasing demand for high-fidelity core analyses. Through years of effort, the KARMA lattice transport code based on the method of characteristics (MOC) has evolved into KARMA2, a direct whole core calculation code using a 3D calculation method based on planar (2D) MOC principles. Simultaneously, ASTRA2, designed as the successor to the ASTRA nodal diffusion code, has been developed. ASTRA2 exhibits enhanced capabilities in multigroup pin-by-pin core calculations, achieved by decoupling the 3D whole core problem into a series of planar and axial problems. The domain size of each axial problem can be adjusted, ranging from pin-cell to assembly scale, thereby optimizing efficiency. The verification and validation process of the KARMA2/ASTRA2 code system involves various benchmark problems and measured data from operational PWRs. In this study, the APR1400 benchmark analysis was performed to verify the neutronics calculation capabilities of both codes. The results underscore the reliability and accuracy of the KARMA2 solutions across various core conditions, exhibiting close agreement with the McCARD reference solutions. Similarly, the ASTRA2 results agree with the corresponding KARMA2 results. These successful results demonstrate the high-fidelity core calculation capabilities of KNF’s next-generation code system
Estimating System State through Similarity Analysis of Signal Patterns
State prediction is not straightforward, particularly for complex systems that cannot provide sufficient amounts of training data. In particular, it is usually difficult to analyze some signal patterns for state prediction if they were observed in both normal and fault-states with a similar frequency or if they were rarely observed in any system state. In order to estimate the system status with imbalanced state data characterized insufficient fault occurrences, this paper proposes a state prediction method that employs discrete state vectors (DSVs) for pattern extraction and then applies a naive Bayes classifier and Brier scores to interpolate untrained pattern information by using the trained ones probabilistically. Each Brier score is transformed into a more intuitive one, termed state prediction power (SPP). The SPP values represent the reliability of the system state prediction. A state prediction power map, which visualizes the DSVs and corresponding SPP values, is provided a more intuitive way of state prediction analysis. A case study using a car engine fault simulator was conducted to generate artificial engine knocking. The proposed method was evaluated using holdout cross-validation, defining specificity and sensitivity as indicators to represent state prediction success rates for no-fault and fault states, respectively. The results show that specificity and sensitivity are very high (equal to 1) for high limit values of SPP, but drop off dramatically for lower limit values
Simple Fabrication of Asymmetric High-Aspect-Ratio Polymer Nanopillars by Reusable AAO Templates
We present a simple method of utilizing anodized aluminum oxide (AAO) as a reproducible template for fabricating high-aspect-ratio uniformly bent polymeric nanopillars that can be used as a physical adhesive. It is shown how to achieve straight high-aspect-ratio nanopillars with concepts of the work of adhesion and lateral collapse between polymer pillars without serious damage to the master template. With the support of manufacturing polymeric nanopillars from the reusable AAO, a simple route to asymmetric dry adhesive nanopillars bent by residual stresses was demonstrated
Fabrication of a hierarchical structure by oxygen plasma etching of a photocured microstructure containing a silicon moiety
We present a simple and straightforward method for creating a hierarchical structure in which the nanoscale roughness is derived from a microstructure. This hierarchical structure is at the backbone of almost all biomimetic functions. A liquid blend of a photocurable prepolymer and a functionalized polysiloxane is moulded by photocuring, and then the moulded film is simply exposed to a blanket oxygen plasma to produce the hierarchical structure. The nanoscale roughness is controlled by varying the weight ratio of acrylate-functionalized polysiloxane to acrylated prepolymer. To demonstrate the efficacy of the fabrication method, a superhydrophobic surface was produced by coating the hierarchical structure with a self-assembled monolayer (SAM)
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