Piezoelectricity of YbAlN films has recently been shown to be almost as high as that of ScAlN films. YbAlN film surface acoustic wave (SAW) resonators are expected to have a high coupling factor. We ...theoretically investigated the propagation characteristics of first-mode Rayleigh SAWs (RSAWs) on Yb0.33Al0.67N film/high-velocity Si, sapphire, AlN, SiC, BN, and diamond substrates. The first-mode RSAWs on the YbAlN layered structures had high coupling factors, higher than those on ScAlN layered structures. An enhancement of the effective coupling factor of the first-mode RSAWs was observed in polarity inverted YbAlN film/BN or diamond substrate structures.
In this study, ultrafast transient signals were detected on a single-shot basis using chirped-pulse up-conversion spectroscopy with dispersion compensation. Unlike in the conventional time-encoding ...technique using chirped pulses, distortion of the ultrafast waveform was reduced by applying dispersion compensation to the chirped probe pulses and using sum-frequency generation with the chirped readout pulses. The method was applied to terahertz time-domain spectroscopy and near-infrared pump–probe spectroscopy, providing ultrafast observations with an improved temporal resolution comparable to the transform-limited pulse durations. Terahertz waveforms, Kerr rotation signals, and phonon-polariton oscillations were measured accurately with no significant waveform distortion, thereby showing the proposed scheme to be promising for single-shot pump–probe spectroscopy in a wide range of spectroscopic applications.
HMG‐CoA reductase (HMGR) is a key enzyme in the mevalonate pathway for sterols and cytosolic isoprenoid production. Although HMGR kinases from spinach, barley, and cauliflower tissues have been ...strongly suggested as members of SNF1‐related protein kinases 1 (SnRK1), the phosphorylation and inactivation of HMGR by plant SnRK1s has not been demonstrated. In this study, we elucidated that AKIN10, an Arabidopsis SnRK1, acts as an HMGR kinase. The recombinant AKIN10 phosphorylates and inactivates AtHMGR1S using recombinant GRIK1 as the AKIN10 activator. In contrast, AKIN10‐GRIK1 fails to inactivate AtHMGR1S‐S577A, suggesting that this is achieved through Ser577 phosphorylation. Moreover, phosphorylation is detected not only in AtHMGR1S but also in AtHMGR1S‐S577A, suggesting the presence of a novel regulatory mechanism of plant HMGR.
Recently, it has been reported that leaky surface acoustic waves (LSAWs) and longitudinal LSAWs on piezoelectric LiNbO3 and LiTaO3 thin plates bonded to high velocity quartz substrates have high ...phase velocity, high coupling, and low attenuation. These lead to high-frequency operation, a wide band-width, and a high Q factor for next generation SAW filters. Moreover, we theoretically demonstrated that longitudinal LSAWs on high piezoelectric ScAlN films/quartz substrates also possesses high phase velocity, high coupling, and low attenuation. In this paper, LSAW characteristics on ScAlN films/quartz substrates were investigated theoretically. When the Euler angles and the film thickness of the ScAlN film and quartz substrate were optimized for LSAW, the LSAW resonators with (0° 90° 72°) Sc0.4Al0.6N film/(0° 128.5° 0°) quartz were found to have a high Q factor of ∼21 610 and a high coupling of ∼5.8%.
Abstract
AlN film bulk acoustic wave (BAW) resonators and filters that operate at frequencies above 5 GHz are required for 5G and beyond 5G communication applications. However, the power-handling ...capability, Q factor, and electromechanical coupling in high-frequency AlN film BAW resonators will be degraded as a result of the significantly reduced thickness and volume of the devices. Higher-order mode BAW resonators with polarity inverted (PI) multilayered films can operate at high frequencies while maintaining the thickness and volume of the devices. In this study, we fabricated an eight-layered PI GeAlN/AlN film BAW resonator by alternately growing Al-polar AlN layers and N-polar GeAlN layers. The PI GeAlN/AlN film BAW resonator resonated in the 8th-order mode. The film thickness of the PI GeAlN/AlN film BAW resonator was approximately thirteen times larger than that of a single-layer AlN film BAW resonator operating in the same frequency range.
Active participation of the older adults in the society is crucial; however, frailty prevents social participation. Meanwhile, many older adults participate daily in social activities, even with ...frailty. This study aims to examine whether older adults with frailty have lower social participation than those without frailty in Japan. We also investigated whether older adults with frailty and higher subjective health participate in society to the same extent as the general older population. This study included 1,082 Japanese individuals aged 65 years and older participating in the online survey. Participants answered questions on social participation, frailty, subjective health, and demographics.
Participants in the robust group had higher social participation rates than those in the frailty and pre-frailty groups. Meanwhile, frail older participants with higher subjective health had similar social participation as the robust participants. Many older adults acquire frailty despite their individual effort. Meanwhile, improving subjective health may be effective, even with frailty. The relationship between subjective health, frailty, and social participation is primitive and further studies are needed.
The efficacy of magnetic resonance-guided focused ultrasound (MRgFUS) ablation for essential tremor (ET) is well known; however, no prognostic factors have been established. The authors aimed to ...retrospectively investigate MRgFUS ablation outcomes and associated factors and to define the cutoff values for each prognostic factor.
Sixty-four Japanese patients who underwent unilateral ventral intermediate nucleus thalamotomy with MRgFUS for ET were included. Follow-up evaluations were performed at 1 week and 1, 3, 6, 12, and 24 months postoperatively. Tremor suppression was evaluated using the Clinical Rating Scale for Tremor (CRST), and adverse effects were recorded postoperatively. Outcome-associated factors were examined preoperatively, intraoperatively, and postoperatively using multivariate analyses. The cutoff values for the prognostic factors were calculated using receiver operating characteristics.
Percentage improvements in the CRST scores of the affected upper limb were 82.4%, 72.2%, 68.6%, and 65.9% at 1, 3, 6, and 12 months, respectively. Preoperatively, a high skull density ratio (SDR) (p ≤ 0.047), low CRST part B score (used to assess tremors during several tasks) (cutoff value 25, p ≤ 0.041), and nonoccurrence of resting tremors (p = 0.027) were significantly associated with improved tremor control. An intraoperatively high maximum mean temperature (cutoff value 52.5°C, p ≤ 0.047), postoperatively large lesion (cutoff value 3.9 mm in the anterior-posterior direction, p ≤ 0.002; cutoff value 5.0-5.55 mm in the superior-inferior direction, p ≤ 0.026), and small transducer focus correction (p ≤ 0.015) were also associated with improved tremor control. No valid cutoff value was found for SDR. Adverse effects (limb weakness, sensory disturbance, ataxia/walking disturbance, dysgeusia, dysarthria, and facial swelling) occurred transiently and were associated with high SDR, high temperature, high number of sonication sessions, large lesion, and occurrence of resting tremor. Patients who developed leg weakness experienced greater percentage improvement in tremors at 3 months postoperatively than those who did not.
MRgFUS ablation could be used to achieve good tremor control with acceptable adverse effects in Japanese patients with ET. The relatively low SDR in Asian ethnic groups as compared with that of Western populations makes treatment difficult; however, the cutoff values obtained in this study may be useful for achieving good treatment outcomes even in such patients. Clinical trial registration no.: UMIN000026952 (University Hospital Medical Information Network).
ACPC = anterior commissure-posterior commissure; AP = anterior to posterior; CRST = Clinical Rating Scale for Tremor; ET = essential tremor; MRgFUS = magnetic resonance-guided focused ultrasound; PC = posterior commissure; PSA = posterior subthalamic area; RL = right to left; ROC = receiver operating characteristic; SDR = skull density ratio; SI = superior to inferior; T2WI = T2-weighted imaging; VIM = ventral intermediate nucleus.
Abstract
The rapid development of mobile communications requires high performance surface acoustic wave (SAW) filters. ScAlN film SAW resonators have a high coupling factor (
K
2
) and high phase ...velocity, enabling them to function as effective SAW filters. We theoretically investigated high-order mode Rayleigh SAWs (RSAWs) on single-layered or polarity inverted two-layered ScAlN film/AlN or BN substrate structures to find the optimal structure to achieve a higher
K
2
and higher frequency. The
K
2
and phase velocity for the single-layered ScAlN film/BN substrate structure were higher than those for the corresponding AlN substrate structure. The
K
2
was enhanced in the polarity inverted ScAlN film/AlN or BN substrate structure. Finite element method analysis revealed that the effective coupling factor
K
eff
2
for the 2nd to 4th mode RSAWs on polarity inverted multilayered ScAlN films was enhanced by setting the boundary of the polarity inverted structure at the all positions where the particle displacements were concentrated.
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