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21.
Fevicordin-A (FevA) isolated from Phaleria macrocarpa (Scheff) Boerl. seeds was evaluated for its potential anticancer activity by in vitro and in silico approaches. Cytotoxicity studies indicated that FevA was selective against cell lines of human breast adenocarcinoma (MCF-7) with an IC50 value of 6.4 μM. At 11.2 μM, FevA resulted in 76.8% cell death of T-47D human breast cancer cell lines. Critical pharmacophore features amongst human Estrogen Receptor-α (hERα) antagonists were conserved in FevA with regard to a hypothesis that they could make notable contributions to its pharmacological activity. The binding stability as well as the dynamic behavior of FevA towards the hERα receptor in agonist and antagonist binding sites were probed using molecular dynamics (MD) simulation approach. Analysis of MD simulation suggested that the tail of FevA was accountable for the repulsion of the C-terminal of Helix-11 (H11) in both agonist and antagonist receptor forms. The flexibility of loop-534 indicated the ability to disrupt the hydrogen bond zipper network between H3 and H11 in hERα. In addition, MM/GBSA calculation from the molecular dynamic simulations also revealed a stronger binding affinity of FevA in antagonistic action as compared to that of agonistic action. Collectively, both the experimental and computational results indicated that FevA has potential as a candidate for an anticancer agent, which is worth promoting for further preclinical evaluation.  相似文献   
22.
In an effort to focus on tractable problems, computational natural language understanding systems have typically addressed language phenomena that are amenable to combinatorial approaches using static and stereotypical semantic representations. Although such approaches are adequate for much of language, they're not easily extended to capture humans' more creative language interpretation capacities. This paper proposes a model of humor comprehension based on frame-shifting within a simulation-based natural-language-understanding system.  相似文献   
23.
Since the early 1990s, there have been a number of small-scale computer programs that automatically constructed simple verbal jokes (puns), but none of these were fully developed systems that could be used for a practical application. We describe the building and testing of the STANDUP program – a large-scale, robust, interactive, user-friendly pun-generator (inspired by Binsted's JAPE program), which is aimed at allowing children, particularly those with communication disabilities, to develop their linguistic skills. The STANDUP system was designed in consultation with potential users and suitable experts, was rigorously engineered using public-domain linguistic data, and has a special purpose, child-friendly, graphical user interface. The software was tested successfully with real users (children with complex communication needs).  相似文献   
24.
In this research, the effect of parameters in Resistance Spot Welding (RSW) on the weld zone development was first investigated using Taguchi Method. Further, the RSW parameters were to be optimized based on multiple quality features, focusing on weld nugget and Heat Affected Zone using multi-objective Taguchi Method (MTM). The optimum welding parameter for MTM was obtained using Multi Signal to Noise Ratio and the significant level was further analyzed using Analysis of Variance. Lastly, Response Surface Methodology was employed to develop the mathematical model for predicting the weld zone development. The experimental study was conducted under varied welding current, weld time and hold time. To validate the predicted model, experimental confirmation test was conducted for plate thickness of 1 and 1.5 mm. Based on the results, the developed model can be effectively used to predict the size of weld zone which can improve the welding quality and performance in RSW.  相似文献   
25.
提出了适用于子波变换系数的矢量量化方法--子波/分类矢量量化(W/CVQ)。以子波变换系数中对应于图像边缘信息的零交叉片段的具体情况为依据,将子波变换图像矢量分为不同的类别,然后为各类矢量建立码本。初步实验结果表明,该方法能克服传统矢量量化编码子波交换系数不能准确恢复有关边缘信息的缺点,此结果在光学实时指纹识别系统中的应用表明,它能够充分保留原因图像的信息,保证识别系统的准确识别。  相似文献   
26.
ZnO压敏陶瓷具有优异的非线性特性,广泛应用于电子仪器和电力装置领域.为了满足电子元器件低压化、小型化和集成化的要求,必须开发出烧结温度低且能与Cu、Zn、Al等贱金属实现共烧兼容的ZnO压敏陶瓷体系.总结了当前ZnO压敏陶瓷低温烧结的研究现状,讨论了ZnO压敏陶瓷低温烧结方法的优缺点,同时分析了ZnO压敏陶瓷低温烧结...  相似文献   
27.
In this study, the feasibility of using an industrial fluidized bed furnace to perform low-temperature thermochemical treatments of austenitic stainless steels has been studied, with the aim to produce expanded austenite layers with combined wear and corrosion resistance, similar to those achievable by plasma and gaseous processes. Several low-temperature thermochemical treatments were studied, including nitriding, carburizing, combined nitriding-carburizing (hybrid treatment), and sequential carburizing and nitriding. The results demonstrate that it is feasible to produce expanded austenite layers on the investigated austenitic stainless steel by the fluidized bed heat treatment technique, thus widening the application window for the novel low-temperature processes. The results also demonstrate that the fluidized bed furnace is the most effective for performing the hybrid treatment, which involves the simultaneous incorporation of nitrogen and carbon together into the surface region of the component in nitrogen- and carbon-containing atmospheres. Such hybrid treatment produces a thicker and harder layer than the other three processes investigated.  相似文献   
28.
This paper investigates the capability of linear thermal elastic numerical analysis to predict the welding distortion that occurs due to GMAW process. Distortion is considered as the major stumbling block that can adversely affect the dimensional accuracy and thus lead to expensive corrective work. Hence, forecast of distortion is crucially needed and ought to be determined in advance in order to minimize the negative effects, improve the quality of welded parts and finally to reduce the production costs. In this study, the welding deformation was simulated by using relatively new FEM software WELD PLANNER developed by ESI Group. This novel Welding Simulation Solution was employed to predict welding distortion induced in butt and T-joints with thickness of 4 mm. Low carbon steel material was used for the simulation and experimental study. A series of experiments using fully automated welding process were conducted for verification purpose to measure the distortion. By comparing between the simulation and experimental results, it was found out that this program code offered fast solution analysis time in estimating weld induced distortion within acceptable accuracy.  相似文献   
29.
Identifying optimal fertilizer management to ensure high nutrient use efficiency is important to reduce negative environmental impacts in oil palm (Elaeis guineensis) cultivation. A 4-year fertilizer trial was established in an oil palm plantation, located at a sandy area with occasional monthly water deficit in Central Kalimantan. We examined the responses of oil palm yield and nutrient use efficiency to fertilizer application frequency (standard frequency of 1–2 times yr?1 versus 4 times yr?1) and rate (standard rate of 136, 12, and 200 kg ha?1 yr?1 of N, P and K, respectively versus 80% of standard rate). There were no treatment effects on annual yield in fresh fruit bunch, bunch number, or individual bunch weight. Increasing fertilizer frequency did not increase nutrient use efficiency at the last 2 years of the trial. In contrast, reducing fertilizer rate resulted in higher nutrient use efficiency in K, compared to the standard treatment and increasing fertilizer frequency. Average concentrations of N, P, K, Mg, Ca, and Cl in leaflet under all treatments were above critical levels both in the beginning and at the end of the trial. Monthly yield in fresh fruit bunch correlated positively with soil water balance with correlation coefficients of 0.24–0.29, during the developmental period of inflorescence sex differentiation at 28–30 months before fruit maturity. Our study provides useful information for fertilizer management optimization in sandy areas with occasional water deficit, corresponding to most of the new expansion areas of oil palm in Southeast Asia.  相似文献   
30.
提出一种应用人工神经网络根据多路光学相关器相关面输出图像识别目标的方法.运用统计规律确定相关峰的位置,不但把自相关峰作为目标特征,还将互相关峰也引入了识别,并通过神经网络实现相关峰复杂特征的抽取.该方法能有效地排除目标背景干扰和器件性能波动的影响,实现了对目标的实时识别  相似文献   
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