We have fabricated Si-based micromachined DNA polymerase chain reaction (PCR) chips with different groove depths. The platinum thin-film micro heater and the temperature sensor have been integrated on the chip. The volume of the PCR chamber in the chip is about 3.6 µl and the chip size is 17 × 40 mm2. The effects of groove geometry, including width, depth and position, on the thermal characteristics of the PCR chip have been investigated by numerical analysis and experimental measurement. From the results, the power consumption required for the PCR chip is reduced with the increase of groove depth. Compared with results for the case of no groove, the power consumption of the chip with a groove of 280 µm is reduced by 24.0%, 23.3% and 25.6% with annealing, extension and denaturation, respectively. The heating rate is increased rapidly with the increase of the groove depth. In particular, it is revealed that this effect is predominant for depths in the region above 280 µm. For a more precise control of chip temperature, the nonlinear feedback proportional-integral control scheme is used. The obtained heating and cooling rates are about 36 °C s−1 and 22 °C s−1, respectively. The overshoot and the steady state error are less than 0.7 °C and ±0.1 °C, respectively. In the experiment, the effects of the PCR buffer and the bubbles in the chamber on the temperature uniformity have also been studied. From the temperature measurement, it is revealed that the temperature difference between the thin-film sensor (on the lower plate) and the PCR buffer can be neglected if there is no air bubble in the PCR buffer. With such a high performance control scheme, we could implement a remarkable thermal cycling of conducting 30 cycles for 3 min. Finally, the chip PCR of plasmid DNA was successfully performed with no additives using the temperature control system.

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Many researches have been trying to find the potential biomarkers for Alzheimer’s disease (AD). We hereby used the proteomics method to search for protein expression differences in the serum between AD patients and controls. We enrolled 59 AD patients and 74 age- and sex-matched controls in this study. Ten AD patients and 10 controls were selected for proteomic analysis. Apolipoprotein A-I (ApoA-I) was found to have a lower expression in the AD group by a proteomics two-dimensional gel electrophoresis study. We further measured the serum ApoA-I level which was significantly lower in the AD patients (112.29 ± 21.33 mg/dl) in comparison to the controls (144.53 ± 19.91 mg/dl; p < 0.0002). Lower serum ApoA-I levels might be a potential biomarker for AD.

In this paper, we propose a modified Smith predictor with a new structure for unstable processes. The proposed new structure makes it possible to use the unstable model itself as a process model, while the previous modified Smith predictors provided no option to use a mismatched stable process model to guarantee stability. Accordingly, the proposed Smith predictor can predict the dynamics of the actual process much better than previous approaches. It also guarantees good robustness to modeling errors by separating servo and regulatory problems. Moreover, it demonstrates good disturbance rejection performances because the adjustable parameters of the PID controller for the regulatory problem are tuned systematically with an internal feedback loop.