Abstract-In this paper, we propose a self-triggered formulation of Model Predictive Control for continuous-time nonlinear input-affine networked control systems. Our control method specifies not only when to execute control tasks but also provides a way to discretize the optimal control trajectory into several control samples, so that the reduction of communication load will be obtained. Stability analysis under the sample-and-hold implementation is also given, which guarantees that the state converges to a terminal region where the system can be stabilized by a local state feedback controller. Some simulation examples validate our proposed framework.

3-Nitrobenzanthrone (3-NBA) has been isolated from diesel exhaust and airborne particles and identified as a potent direct-acting mutagen in vitro and genotoxic agent in vivo. In order to evaluate the in vivo toxicity and carcinogenicity of 3-NBA in a situation corresponding to inhalation, a combined short-term and lifetime study with intratracheal (i.t.) instillation in female F344 rats was performed. DNA adduct formation, as a marker for the primary effect and analyzed by 32P-HPLC after single instillation, showed a few major DNA adducts and a rapid increase with a peak after 2 days, followed by a decline. No DNA adducts above the background level were observed after 16 days. The highest DNA adduct formation was observed in lung [approximately 250 DNA adducts/10(8) normal nucleotides (NN)] closely followed by kidney (approximately 200 DNA adducts/10(8) NN), whereas liver contained only 12% (approximately 30 DNA adducts/10(8) NN) of the levels of DNA adducts found in lung. In the tumor study, squamous cell carcinomas were found after 7-9 months in the high-dose group (total dose of 2.5 mg 3-NBA) and after 10-12 months in the low-dose group (total dose of 1.5 mg 3-NBA). The fraction of squamous cell carcinoma out of the total amount of tumors observed at the end of experiment at 18 months, corresponded to 3/16 and 11/16 in the low- and high-dose group, respectively. A single case of adenocarcinoma was also observed in each group. In the control group, no tumors were observed during the entire study of 18 months. In addition, a few cases of squamous metaplasia were also observed in the lung in both dose groups but not in the controls. In conclusion, 3-NBA forms DNA adducts in the lung immediately after i.t. administration but almost all DNA adducts were eliminated after 16 days. Tumor formation in two dose groups was observed in a dose-dependent manner with squamous cell carcinomas as the predominant tumor type at high exposure.

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Modifications at two points in the sequence of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) analysis have contributed to a more accurate and simplified determination of 8-OH-dG in DNA. The first was an improvement in the detection limit for 8-OH-dG in high-performance liquid chromatography analysis and the second was a pronase digestion and ethanol precipitation method (pronase/ethanol method) for DNA isolation which could minimize artificial formation of 8-OH-dG. Since the changes in background current from electrochemical detection are regularly periodical, it was possible to reduce this background change by connecting a pressure damper, degassing the eluent before use and finally subtracting its theoretical function. After this background correction, the detection limit for 8-OH-dG was improved one order of magnitude, from 20 fmol (5.68 pg) to 1.76 fmol (0.5 pg). Therefore, 0.005 8-OH-dG/10(5) dG can be detected from 50 micrograms DNA. This improvement will allow the analysis of small samples, tissues from needle biopsies, < 5 ml whole blood, etc., and will contribute to the accuracy of 8-OH-dG measurements. The pronase/ethanol method resulted in lower levels of 8-OH-dG than the phenol method in analyses of both rat liver and calf thymus DNA, even after 6 h incubation at 45 degrees C. The level obtained by the pronase/ethanol method with butylated hydroxytoluene was approximately equal to or lower than the 8-OH-dG levels reported in normal rat liver. The pronase/ethanol method for DNA isolation can replace the phenol or other methods in 8-OH-dG analysis. This method also omits the use of highly toxic organic solvents.

Oxidative stress has emerged as a pivotal mechanism that underlies the toxic pulmonary effects of suspended particulate matter (SPM). Experimental evidence shows that redox-active transition metals, redox-cycling quinoids, and polycyclic aromatic hydrocarbons (PAHs) contained in SPM act synergistically, producing reactive oxygen species (ROS). The direct production of superoxide anion and the damaging hydroxyl radical has been studied in aqueous and dimethyl sulfoxide (DMSO) suspensions of SPM both with and without H2O2; however, no study has reported on the release of ROS from ingesting macrophages with SPM. We investigated the time course of the ability to induce lucigenin-dependent chemiluminescence (CL) from human monocyte-derived macrophages exposed to SPM, carbon black particles, and diesel exhaust particles (DEP). We also examined hydroxyl radical generation from the same experimental system using the 2-deoxy-d-robse method. We found an increase of CL for SPM, but not for carbon black particles or for DEP. Hydroxyl radical generation was observed in both SPM and DEP, but the release from DEP was more frequent than that from SPM. These results suggest that certain components of SPM are important in the response of ROS from ingesting macrophages with SPM, and that those components are discharged from SPM into the atmosphere.

In this paper, we propose a new aperiodic formulation of model predictive control for nonlinear continuous-time systems. Unlike earlier approaches, we provide event-triggered conditions without using the optimal cost as a Lyapunov function candidate. Instead, we evaluate the time interval when the optimal state trajectory enters a local set around the origin. The obtained event-triggered strategy is more suitable for practical applications than the earlier approaches in two directions. First, it does not include parameters (e.g., Lipschitz constant parameters of stage and terminal costs) which may be a potential source of conservativeness for the event-triggered conditions. Second, the event-triggered conditions are necessary to be checked only at certain sampling time instants, instead of continuously. This leads to the alleviation of the sensing cost and becomes more suitable for practical implementations under a digital platform. The proposed event-triggered scheme is also validated through numerical simulations.

In this study, the authors propose an aperiodic formulation of model predictive control for distributed agents with additive bounded disturbances. In the proposed method, each agent solves an optimal control problem only when certain control performances cannot be guaranteed according to certain triggering rules. This could lead to the reduction of energy consumption and the alleviation of over usage of communication resources. The triggering rules are derived for both event-triggered and self-triggered formulation. The authors proposed method is also verified through a simulation example.

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