SUMMARYIn this paper, an optimization method of low-order multivariable controllers for H ∞ control is proposed. Starting from a low-order stabilizing controller, our method gives a sequence of controllers for which the H ∞ norm performance index is monotonically non-increasing by tuning the numerator coefficient matrices of the low-order controller. This controller class includes multivariable PID controllers. The proposed method is a descent method where the feasible direction is calculated by solving a linear matrix inequality that represents a sufficient condition for the H ∞ criterion for each frequency. Usefulness is shown by two numerical examples.

The purpose of the current study was to clarify the blood flow pattern in the left atrium (LA), potentially causing the formation of thrombosis after left upper lobectomy (LUL). The blood flow in the LA was evaluated and compared between LUL patients with and without thrombosis. For the evaluation, we applied highly accelerated 4D flow MRI with dual-velocity encoding (VENC) scheme, which was expected to be able to capture slow flow components in the LA accurately.Methods: Eight volunteers and 18 patients subjected to LUL underwent dual-VENC 4D Flow MRI. Eight patients had a history of thrombosis. We measured the blood flow velocity and stasis ratio (proportion in the volume that did not exceed 10 cm/s in any cardiac phase) in the LA and left superior pulmonary vein (LSPV) stump. For visual assessment, the presence of each collision of the blood flow from pulmonary veins and vortex flow in the LA were evaluated. Each acquired value was compared between healthy participants and LUL patients, and in LUL patients with and without thrombosis.Results: In LUL patients, blood flow velocity near the inflow part of the left superior pulmonary vein (Lt Upp) and mean velocity in the LA were lower, and stasis ratio in the LA was higher compared with healthy volunteers (Lt Upp 9.10 ± 3.09 vs.13.23 ± 14.19 cm/s, mean velocity in the LA 9.81 ± 2.49 vs. 11.40 ± 1.15 cm/s, and stasis ratio 25.28 ± 18.64 vs. 4.71 ± 3.03%, P = 0.008, 0.037, and < 0.001). There was no significant difference in any quantification values between LUL patients with and without thrombosis. For visual assessment, the thrombus formation was associated with no collision pattern (62.5% vs. 10%, P = 0.019) and not with vortex flow pattern (50% vs. 30%, P = 0.751). Conclusion:The net blood flow velocity was not associated with the thrombus formation. In contrast, a specific blood flow pattern, the absence of blood flow collision from pulmonary veins, correlates to the thrombus formation in the LA.

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Wettability tuning for organic solvents is demonstrated with the "combination method", a reversal of the conventional "cleavage method". Several advantages are inherent to this method: for example, the syntheses are simple, various surface-active groups can be used, and the reaction proceeds with a low-energy light source. The image shows the result after UV irradiation through a patterning mask.

We investigated, through the measurement of nonlinear magnetic responses, the effects of pressure on twodimensional (2D) networked single-molecule magnets (SMMs), in which the Ising nature of SMMs and their aggregates (SMM-aggregates) competed with the magnetic correlation between SMMs or between SMM-aggregates, respectively. At ambient pressure, as the frequency of the AC field increases, the initial magnetic behavior of SMMaggregate consisting of several SMMs transforms to that shown by individual SMMs. We investigated the effects of pressure on the above AC-field-switchable magnetic properties by varying temperature, AC field frequency, and pressure. Pressurization destroyed the regular intermolecular network, and above approximately 3 kbar, the magnetic network was enlarged randomly. Hence, the regularity in SMM-aggregate is weakened with increasing pressure, resulting in the suppression of the Ising nature of SMM-aggregate. Furthermore, above approximately 3 kbar, a glassy behavior becomes prominent owing to the randomness in the Ising nature of SMM.

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