140 research outputs found
Visual servo control with artificial neural network
In this paper a robotic manipulator system is presented, which uses visual feedback to control both the position and orientation of the manipulator. In this system, visual data from the camera are directly used in the servo control process of the manipulator, without calculations of the inverse kinematics. This approach is achieved by the use of an artificial neural network (ANN) to learn the relationship between the position and the orientation of the manipulator and the joint angles. As there are no pre-stored parameters of the manipulator, the system is adaptable to slight changes in the kinematics of the manipulator or the working environment. Hence, this technique should able to extend the application of robotic technology in some special industrial areas. The results of computer simulations of this system are also presented in the paper.published_or_final_versio
A novel induction machine design suitable for inverter-driven variable speed systems
Induction machines designed for inverter-driven variable speed systems are different from those fed directly from a utility power line. In this paper, a novel design approach for inverter driven induction machines is presented and implemented. This is followed by an investigation on sizing equations and rotor slot shape specifically for this purpose. The proposed approach permits the integration of the design of machines with inverters, comprehensive performance analysis, and system optimization, resulting in 20-30% higher power density for the induction machine than those designed for direct utility power supplies by conventional methods. Simulation analysis and experimental results are presented to substantiate the conclusions.published_or_final_versio
Adaptive neuro-fuzzy modeling of battery residual capacity for electric vehicles
This paper proposes and implements a new method for the estimation of the battery residual capacity (BRC) for electric vehicles (EVs). The key of the proposed method is to model the EV battery by using the adaptive neuro-fuzzy inference system. Different operating profiles of the EV battery are investigated, including the constant current discharge and the random current discharge as well as the standard EV driving cycles in Europe, the U.S., and Japan. The estimated BRCs are directly compared with the actual BRCs, verifying the accuracy and effectiveness of the proposed modeling method. Moreover, this method can be easily implemented by a low-cost microcontroller and can readily be extended to the estimation of the BRC for other types of EV batteries.published_or_final_versio
2009. Antioxidant properties of Hibiscus: species variation, altitudinal change, coastal influence and floral colour change
Bagi daun Hibiscus rosa-sinensis dan Hibiscus tiliaceus, kesan perubahan altitud dan pengaruh pesisiran pantai masing-masing dinilai. Pertukaran warna bunga Hibiscus mutabilis dianalisis. AOP yang dikaji ialah jumlah kandungan fenol (TPC), jumlah kandungan antosianin (TAC), aktiviti menyerang radikal yang dinyatakan sebagai kebolehan antioksida asid askorbik (AEAC), kuasa menurun ferik (FRP) dan pengkelatan ion ferum (FIC). Nilai-nilai TPC, AEAC dan FRP paling tinggi bagi daun dan bunga H. tiliaceus. Bunga merah H. rosa-sinensis dan Hibiscus schizopetalus menunjukkan nilai TAC dan FIC tertinggi. AOP daun H. rosa-sinensis bagi populasi gunung lebih tinggi daripada populasi tanah pamah. Tidak ada perbezaan dalam AOP daun populasi H. tiliaceus yang jauh dari pantai dengan populasi pesisiran pantai. AOP bunga merah H. mutabilis lebih tinggi daripada bunga merah muda dan/atau putih. Secara amnya, nilai AOP bunga ketika pertukaran warna ialah merah > merah muda > putih
Azacytidine sensitizes acute myeloid leukemia cells to arsenic trioxide by up-regulating the arsenic transporter aquaglyceroporin 9
Abstract BACKGROUND: The therapeutic efficacy of arsenic trioxide (As2O3) in acute myeloid leukemia (AML) is modest, which is partly related to its limited intracellular uptake into the leukemic cells. As2O3 enters cells via the transmembrane protein aquaglyceroporin 9 (AQP9). Azacytidine, a demethylating agent that is approved for the treatment of AML, has been shown to have synergistic effect with As2O3. We tested the hypothesis that azacytidine might up-regulate AQP9 and enhances As2O3-mediated cytotoxicity in AML. METHODS: Arsenic-induced cytotoxicity, the expression of AQP9, and the intracellular uptake of As2O3 were determined in AML cell lines and primary AML cells with or without azacytidine pre-treatment. The mechanism of AQP9 up-regulation was then investigated by examining the expression of transcription factors for AQP9 gene and the methylation status of their gene promoters. RESULTS: As2O3-induced cytotoxicity in AML cell lines was significantly enhanced after azacytidine pre-treatment as a result of AQP9 up-regulation, leading to increased arsenic uptake and hence intracellular concentration. Blocking AQP9-mediated As2O3 uptake with mercury chloride abrogated the sensitization effect of azacytidine. AQP9 promoter does not contain CpG islands. Instead, azacytidine pre-treatment led to increased expression of HNF1A, a transcription activator of AQP9, through demethylation of HNF1A promoter. HNF1 knockdown abrogated azacytidine-induced AQP9 up-regulation and almost completely blocked intracellular As2O3 entry, confirming that azacytidine enhanced As2O3-mediated cell death via up-regulation of HNF1A and hence increased AQP9 and As2O3 intracellular concentration. Azacytidine sensitization to As2O3 treatment was re-capitulated also in primary AML samples. Finally, azacytidine did not enhance arsenic toxicity in a liver cell line, where HNF1A was largely unmethylated. CONCLUSIONS: Azacytidine sensitizes AML cells to As2O3 treatment, and our results provide proof-of-principle evidence that pharmacological up-regulation of AQP9 potentially expands the therapeutic spectrum of As2O3. Further clinical trial should evaluate the efficacy of azacytidine in combination with As2O3 in the treatment of AML.published_or_final_versio
Treatment outcome and prognostic factor analysis in transplant-eligible Chinese myeloma patients receiving bortezomib-based induction regimens including the staged approach, PAD or VTD
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Influence of drying treatments on antioxidant capacity of forage legume leaves
This study was aimed to investigate the antioxidant capacities of four common forage legume leaves namely, Arachis pintoi (Pintoi), Calapogonium mucunoides (Calapo), Centrosema pubescens (Centro), and Stylosanthes guanensis (Stylo). Two different drying methods (oven-drying and freeze-drying) were employed and antioxidant activities were determined by DPPH, Ferric Reducing Antioxidant Power (FRAP) and β-carotene bleaching assays. Total phenolic content (TPC) was determined using Folin-Ciocalteu assay. Freeze-dried extract showed the highest antioxidant activities by DPPH (EC50 values 1.17–2.13 mg/ml), FRAP (147.08–246.42 μM of Fe2+/g), and β-carotene bleaching (57.11–78.60%) compared to oven drying. Hence, freeze drying treatment could be considered useful in retention of antioxidant activity and phenolic content
In vitro anti-inflammatory, cytotoxic and antioxidant activities of boesenbergin A, a chalcone isolated from Boesenbergia rotunda (L.) (fingerroot)
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