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Background: Pathophysiology of intracranial atherosclerotic stenosis (ICAS) development and subsequent stroke occurrence is diverse, including cholesterol deposition, arterial dissection, and intrinsic vasculopathies. To differentiate these specific etiologies, performing high-resolution MRI (HR-MRI) has increased. However, the information on serial change of ICAS on HR-MRI was limited. Methods: Patients hospitalized at a tertiary university hospital for AIS and who took HR-MRI more than twice between 2015 and 2019 were collected. Two specialists manually segmented the contour of the culprit and reference vessel's inner lumen, outer wall, and plaque. The stenotic degree, remodeling index, and enhancement signal were measured for the culprit lesion at each examination. Results: A total of 202 HR-MRI examinations from 93 patients were analyzed. The Median follow-up was 270 days (118-390). The ranges of the serial change in stenotic degree (-86% to 41%), remodeling index (-83% to 266%), and enhancement signal (-85% to 71%) were very diverse. Changes in stenotic degree and enhancement according to the initial stenotic degree were insignificant. On the other hand, the change in enhancement signal was greater in the initially more enhanced lesions (0.1±23.0; mild vs. -23.1±22.6; moderate vs. -35.5±28; severe, p difference difference =.005). Conclusions: ICAS showed very dynamic changes in the follow-up HR-MRIs. To identify the underlying etiology, such as arterial dissection and Moyamoya disease, serial HR-MRI will be helpful.

Introduction: Intracranial arterial disease (ICAD) may have dynamic temporal changes which high-resolution MR (HR-MR) images can visualize. Until now, there is only limited evidence on the risk factor for the evolution of ICAD after ischemic stroke. Method: We have collected acute ischemic stroke patients admitted to a single referral stroke center between 01/2015 and 06/2019 with baseline and follow-up HR-MR images on their ICAD lesions. A total of 246 patients were identified, and for the current pilot study, HR-MR images from 93 patients were used. Degree of stenosis on T1/gadolinium-enhanced (Gd) T1 sequences, remodeling index on proton-density sequence, and enhancement signal on Gd-T1 sequence were measured. Temporal changes were defined as (1-([parameters at the initial]/[parameters at the follow-up])*100. The temporal changes of image parameters were compared by bivariate baseline blood risk factors, such as LDLC ( ≥ 100 vs. ≥ 6.5 vs. Result: A total of 93 patients were analyzed for the pilot study. Temporal changes in the degree of stenosis, remodeling index, and enhancement signal of ICAD lesion were -19.6 ± 50.3%, 2.9 ± 45.6%, and -15.0 ± 31.6%, respectively. ICAD parameters were further mitigated in lower levels of selected markers, such as the degree of stenosis (-24.9±37.6% from lower vs. -16.0±57.5% from higher LDLC, P =0.37; -23.0±54.9% from lower Hb A1c vs. -9.3±32.3% from higher Hb A1c, P =0.16) and the enhancement signal (-18.0±29.1% from lower vs. -12.9±33.2% from higher LDLC, P=0.45; -17.1±32.2% from lower Hb A1c vs. -6.5±28.4% from higher Hb A1c, P=0.17). Linear associations between change in the enhancement signal and LDLC in higher LDLC (B=0.38, P=0.01) and degree of stenosis and Hb A1c in higher Hb A1c (B=0.49, P=0.02) were observed. Conclusion: ICAD lesions in acute ischemic stroke patients may have temporal appearance changes. Baseline LDLC and Hb A1c levels may be used as a marker for the evolution of ICAD.

Introduction: Leptomeningeal collaterals help maintain cerebral perfusion after the large vessel occlusion (LVO), potentially regulated by systemic blood pressure (BP). We hypothesized that the association between BP and endovascular treatment (EVT) outcomes would differ by the baseline perfusions status and before and after recanalization. Method: From a prospective registry, we identified anterior circulation LVO patients who received EVT ≤24 hours after their onset, had baseline perfusion, and achieved post-EVT mTICI ≥2b. BPs were measured from arrival at 5-minute intervals in the ER and during the procedure. Systolic BPs (SBP) up to 24 hours after EVT were summarized as dropmax (the maximal decrement over two consecutive measurements), incmax (the maximal increment), mean, coefficient of variation, and standard deviation. Baseline perfusion images were quantified using Olea Sphere. Infarct proportion was defined as the volume of final infarct on DWI within the volume of Tmax>6 sec. Significant hemorrhage included PH2 or HBC class 3. 3-month mRS was prospectively collected. Result: A total of 388 LVO patients were included. Mean SBP at arrival was 153 ± 42 mm Hg; the average count of BP measurements was 47 ± 17 per patient.In the adequate baseline perfusion group, i.e., hypoperfusion intensity ratio (HIR) Conclusion: Association between BP and patient outcomes differs by baseline perfusion status and before and after recanalization. BP management during the peri-EVT period may therefore need to be individualized.

The electronic structures of Prussian blue analog $({\mathrm{Rb}}_{x}{\mathrm{Ba}}_{y}){\mathrm{Mn}}_{[3\ensuremath{-}(x+2y)]/2}[\mathrm{Fe}{(\mathrm{CN})}_{6}]$ cyanides have been investigated by employing soft x-ray absorption spectroscopy (XAS) and magnetic circular dichroism (XMCD) at the Fe and Mn $L$ $(2p)$ edges. The measured XAS spectra have been analyzed with the configuration-interaction (CI) cluster model calculations. The valence states of the Fe and Mn ions are found to be ${\mathrm{Fe}}^{2+}\text{\ensuremath{-}}{\mathrm{Fe}}^{3+}$ mixed valent, with an average valency of $v(\mathrm{Fe})\ensuremath{\sim}2.8$ and nearly divalent $({\mathrm{Mn}}^{2+})$, respectively. Our Mn/Fe $2p$ XMCD study supports that ${\mathrm{Mn}}^{2+}$ ions are in the high-spin states while ${\mathrm{Fe}}^{2+}\text{\ensuremath{-}}{\mathrm{Fe}}^{3+}$ ions are in the low-spin states. The Fe and Mn $2p$ XAS spectra are found to be essentially the same for $80\ensuremath{\le}T\ensuremath{\le}300$ K, suggesting that a simple charge transfer upon cooling from ${\mathrm{Fe}}^{3+}\text{\ensuremath{-}}\mathrm{CN}\text{\ensuremath{-}}{\mathrm{Mn}}^{2+}$ to ${\mathrm{Fe}}^{2+}\text{\ensuremath{-}}\mathrm{CN}\text{\ensuremath{-}}{\mathrm{Mn}}^{3+}$ does not occur in $({\mathrm{Rb}}_{x}{\mathrm{Ba}}_{y}){\mathrm{Mn}}_{[3\ensuremath{-}(x+2y)]/2}[\mathrm{Fe}{(\mathrm{CN})}_{6}]$. According to the CI cluster model analysis, it is necessary to take into account both the ligand-to-metal charge transfer and the metal-to-ligand charge transfer in describing Fe $2p$ XAS, while the effect of charge transfer is negligible in describing Mn $2p$ XAS. The CI cluster model analysis also shows that the trivalent ${\mathrm{Fe}}^{3+}$ ions have a strong covalent bonding with the $\mathrm{C}\ensuremath{\equiv}\mathrm{N}$ ligands and are under a large crystal-field energy of $10Dq\ensuremath{\sim}3$ eV, in contrast to the weak covalency effect and a small $10Dq\ensuremath{\sim}0.6$ eV for the divalent ${\mathrm{Mn}}^{2+}$ ions.

In a recent work, the authors presented an extension of robust model reference adaptive control (MRAC) laws for spatially varying partial differential equations (PDEs) proposed by them earlier for the decentralized adaptive control of heterogeneous multiagent networks with agent parameter uncertainty using the partial difference equations (PdEs) on graphs framework. The examples provided demonstrated the capabilities of this approach under the assumption that individual vehicles executing coordinated maneuvers were fully actuated and characterized by linear dynamics. However, detailed models for autonomous vehicles–whether terrestrial, aerial, or aquatic–are often underactuated and strongly nonlinear. Using this approach, but assuming the plant parameters to be known, this work presents the model reference (MR) control laws without adaptation for the coordination of underactuated aquatic vehicles modeled individually in terms of strongly nonlinear dynamic equations arising from ideal planar hydrodynamics. The case of unknown plant parameters for this class of underactuated agents with complex dynamics is an open problem. The paper is based on an invited talk on adaptive control presented at the 2008 World Congress of Nonlinear Analysts.

Self-assembly of the anionic surfactant AOT with the protein alpha-lactalbumin in isooctane/brine mixtures results in phase structures whose type, size, and shape differ considerably from those formed by the surfactant alone. Small-angle X-ray scattering was used to determine the size and shape of these structures for 5.4 < pH < 11.2 and 0.25, 0.33, and 0.4 wt % NaCl. All pH values were above the reported isoelectric point for the protein. The composition of the system (except for salt) was fixed, with 2.5 wt % surfactant in equivolume mixtures of oil and water and either 0 or 0.4 wt % protein. Under these conditions, AOT in the absence of protein always formed spherical, water-in-oil (w/o) microemulsion droplets in the organic phase with no self-assembly in the aqueous phase. In the presence of alpha-lactalbumin, self-assembled structures were formed in both aqueous and organic phases, and the size and shape of these was tuned by both pH and [NaCl]. Protein-surfactant interaction was weakest at the most alkaline pH, with protein-free, spherical droplets forming in the organic phase and surfactant-decorated soluble protein clusters forming in the aqueous phase. As pH was decreased, protein increasingly partitioned to the organic phase and droplets became ellipsoidal and much larger in volume, with these effects enhanced at lower salt concentration. Aqueous structures were also strongly affected by pH, shifting from prolate protein/surfactant aggregates at alkaline pH to oil-in-water, oblate microemulsion droplets at neutral pH. At acidic pH and higher salt concentration, self-assembly shifted toward a third, anisotropic aqueous phase, which contained discoid bilayer structures. It is proposed that hydrophobic attraction causes association of the protein with the surfactant monolayer, and pH and [salt] tune the system via the protein by modifying electrostatic repulsion and monolayer curvature.

A recently introduced class of the well-posed error systems and the corresponding robust model reference adaptive control laws for the systems represented by the parabolic or the hyperbolic partial differential equations (PDEs) with the spatially varying parameters and a distributed sensing and actuation is extended to encompass the disturbance rejection capability. The disturbance is modeled as a space–time-varying signal generated by a parabolic PDE with the known parameters, a spatially varying time-invariant signal, and a space–time-varying signal with the known time variation. The case of the time-invariant disturbance model is shown to lead to a distributed adaptive PI control law, thereby making a well-posed connection to the classical finite-dimensional control structures. The numerical simulations indicate that the control laws proposed are robust with respect to the plant/reference model as well as the disturbance/disturbance observer mismatch in the boundary conditions. Copyright © 2008 John Wiley & Sons, Ltd.

A long-standing problem of the start-up instability in the model-reference adaptive control of distributed parameter systems caused by setting the initial controller parameter values sufficiently far from the ideal ones, unknown a priori, is solved for a class of systems. The latter include systems modeled by parabolic and hyperbolic partial differential equations (PDEs) with spatially varying parameters. The stabilizing direct model reference adaptive control (MRAC) laws are synthesized using Lyapunov redesign. The controller uses plant state and for hyperbolic case, additionally, its time derivative. The key feature of the approach proposed is the elimination from the control laws of the plant state spatial derivatives that could give rise to the closed loop system ill-posedness. The approach also prevents closed-loop system instability by keeping the gains for plant state and, in the hyperbolic case - state and its time derivative, negative under arbitrary initial controller parameter setting.

A recently introduced class of the well-posed error systems and the corresponding robust model reference adaptive control (MRAC) laws for systems represented by parabolic or hyperbolic partial differential equations (PDEs) with spatially varying parameters is extended to encompass the disturbance rejection capability. The disturbance is modeled as a space-time-varying signal generated by a parabolic PDE with known parameters or as a spatially-varying time-invariant signal.

The GaInP/AlGaInP heterostructure was grown on (100) GaAs substrate using low pressure metal-organic vapor phase epitaxy (LP MOVPE) . The growth temperature and pressure were held constant at 740 °C and 40 torr, respectively. The GalnP multiquantum well layers from 10 A to 85 A were lattice matched to the substrate. High resolution transmission electron microscopy and low temperature photoluminescence measurements indicated that the GaInP/AlGaInP well layers were uniform in thickness and that the interface was abrupt and free of defects. For high performance of visible laser diodes, highly doped p-AlGaInP layer(8X1017/cm3) was obtained. It was also found that the Zn acceptor concentration increased with growth rate. In this study, the GaInP/AlGaInP laser diode, 645nm and 20mW, was fabricated by employing multiquantum well and highly doped p-cladding layer.