Oncological therapies usually are applied intermittently, i.e., not continuously over time. In the periods in between, though, the cancer cells are usually left free to grow. This intermittency is a key issue in prostate cancer hormonal therapies based on androgen suppression. Here, we address this treatment modality by analyzing a piecewise smooth vector field approach. In fact, using the PSA (prostate-specific antigen) serum level as a control variable to switch between treatment and no-treatment periods of hormone therapy (androgen withdrawal), by means of typical parameter values, our theoretical analysis supports the idea that intermittent androgen suppression may prevent a prostate cancer relapse for a specific class of patients.
The effect of processing and cooking on phenolic acids profile and antioxidant properties of durum wheat (Triticum turgidum L. var. durum) pasta samples enriched with debranning fractions of an Italian wheat (Triticum aestivum L.) cultivar were studied. 相似文献
The use of wastewater for the biological production of H2 (biohydrogen) by dark fermentation has been studied for a variety of waste substrates and mixed or isolated inocula. However, for brewery wastewater (BW), which is generated in large volumes and has characteristics that are highly suitable for acidogenic fermentation, the available studies describe the use of mixed cultures, especially pretreated methanogenic inocula. The aim of this work was to isolate an enterobacterium from aviary litter that was capable of fermenting BW and generating biogas rich in H2. The biochemical characterization and species confirmation confirmation revealed the isolation of Klebsiella peneumoniae, which provided efficient production of biogas rich in H2 (30–40%) in batch assays performed for up to 72 h, with the inoculum in suspension, at a small scale (in serum bottles) and using a mechanically-stirred anaerobic reactor (AnBBR), employing crude BW without any supplementation. The hydrogen yield and molar hydrogen flow rate were 0.80–1.67 mol H2 mol?1 glucose and 0.2–2.2 mmol H2 h?1, respectively, indicating good performance of the inoculum in metabolizing this substrate and the possibility of optimizing the process by varying the duration of the batch. 相似文献
A robust adaptive parameter estimation method, based on the application of a full-order filter capable of rejecting exogenous disturbances, is proposed in this article. A linear matrix inequality condition is proposed to synthesize the desired robust filter, assuming the presence of a known input control with constraints. The filter uses the output of the system to estimate the desired signal that will be employed in the adaptive estimation procedure and, to assure robustness to exogenous noise and unstructured uncertainties, the guaranteed cost is minimized in the synthesis condition. The filtered signals are then applied to an adaptive procedure to estimate the unknown system's internal parameters, which is also proposed in this article. It is shown that lower values for the guaranteed cost from the disturbance input to the error output of the filter imply more accurate estimations of the parameters. The efficiency of the proposed estimation technique is illustrated through a simulated model and a physical system has been considered to validate real-time estimation. 相似文献
Loss of motivation refers either to the weakening of a motive q or to the loss of energy and persistence with which some subordinate goal p is planned for and pursued in view of q. Although interrelated, such aspects can be kept distinct, and the present work focuses on the loss of strength of the subordinate goal. An analysis is provided of such mental attitudes as subjective frustration, negative expectation, disappointment, and discouragement so as to clarify their respective roles in favoring loss of motivation. The necessary cognitive conditions for the occurrence of loss of motivation are singled out; namely, goal p should be an intention, and a disappointment should occur in regard to the instrumental relationship between p and q , p's attainability, or p's convenience. Both advantages and limits of the model are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
This paper describes the first part of an experimental and theoretical study performed on composite Lanthanum Strontium Manganite
(LSM) and Yttria-stabilized Zirconia (YSZ) electrodes. Cathode electrocatalytic activity was investigated using different
cell configurations and carrying out potentiodynamic polarisation and electrochemical impedance spectroscopy measurements
(EIS). Measurements were carried out at different oxygen partial pressures, overpotentials, temperatures and electrode geometries.
In order to identify the main steps involved in cathodic oxygen reduction, the NLLS-Fit procedure was used. The results for
different cell geometries agree with each other, suggesting a transition in the overall reaction mechanism, from charge transfer
to mass transfer control, at a critical temperature of about 750 °C. The experimental results also show a remarkable effect
of electrode thickness on the overall reaction rate, throughout the temperature range tested. A grey level gradient along
the
thickness of the thicker electrodes were detected by analyzing microscopic images of the cells. These results, together with
electrochemical measurements on cathodes with different thickness, confirm that morphology plays a key role in determining
the performance of Solid Oxide Fuel Cells (SOFC) composite cathodes. 相似文献