In the classic transistor, the number of electric charge carriers--and thus the electrical conductivity--is precisely controlled by external voltage, providing electrical switching capability. This ...simple but powerful feature is essential for information processing technology, and also provides a platform for fundamental physics research. As the number of charges essentially determines the electronic phase of a condensed-matter system, transistor operation enables reversible and isothermal changes in the system's state, as successfully demonstrated in electric-field-induced ferromagnetism and superconductivity. However, this effect of the electric field is limited to a channel thickness of nanometres or less, owing to the presence of Thomas-Fermi screening. Here we show that this conventional picture does not apply to a class of materials characterized by inherent collective interactions between electrons and the crystal lattice. We prepared metal-insulator-semiconductor field-effect transistors based on vanadium dioxide--a strongly correlated material with a thermally driven, first-order metal-insulator transition well above room temperature--and found that electrostatic charging at a surface drives all the previously localized charge carriers in the bulk material into motion, leading to the emergence of a three-dimensional metallic ground state. This non-local switching of the electronic state is achieved by applying a voltage of only about one volt. In a voltage-sweep measurement, the first-order nature of the metal-insulator transition provides a non-volatile memory effect, which is operable at room temperature. Our results demonstrate a conceptually new field-effect device, extending the concept of electric-field control to macroscopic phase control.
The tropical intraseasonal (30–90 days) oscillation (ISO) displays distinctive behaviors in boreal summer and winter. How well each mode is simulated in climate models has been investigated; however, ...very few studies have examined whether these modes are simulated in appropriate season. Here we developed diagnostics to assess this aspect and applied these diagnostics to numerous atmosphere‐only and atmosphere–ocean‐coupled models. We found out that all models share serious biases and that they sometimes incorrectly simulate the boreal summer ISO mode even in boreal winter and underestimate the appearance frequency of the boreal summer ISO in boreal summer. Nearly all atmosphere‐ocean‐coupled models show some improvements in the ISO seasonality representation compared to their atmosphere‐only counterparts. It is suggested that good models for simulating the ISO seasonality have good life cycles for each ISO mode and that an accurate reproduction of the seasonal mean low‐level zonal wind is crucial.
Plain Language Summary
The leading intraseasonal (30–90 days) oscillation (ISO) in the tropical atmosphere has different characteristics in the boreal summer and winter. Accordingly, it has different impacts on extreme weather such as heavy precipitation and tropical cyclone activity. Many studies have examined how well the boreal summer and winter modes are simulated in climate models; however, very few studies have examined whether climate models can simulate the boreal summer and winter ISOs appropriately in the boreal summer and winter, respectively. In this study, we developed a new method to examine this aspect and applied it to numerous present‐day climate simulations using both atmosphere‐only and atmosphere–ocean‐coupled models. We found out that all models share serious biases and that they inadequately simulate the boreal summer mode even in boreal winter and underestimate the appearance frequency of the boreal summer mode in boreal summer. Nearly all atmosphere–ocean‐coupled models show some improvements in the ISO seasonality representation compared to their atmosphere‐only counterparts. It is suggested that good models for simulating the seasonality of the ISO show good life cycles for each ISO mode and a seasonal mean zonal wind in the lower troposphere. These results are helpful for further improving climate models.
Key Points
The seasonality of two major modes of ISO (MJO/BSISO) in global climate models was examined
Global climate models have larger deficits in their performances when representing the BSISO than the MJO
The presented method helps in examining the model performance in detail and suggesting further improvements
The tropical intraseasonal oscillation (ISO) strongly influences tropical cyclone (TC) genesis. However, little is known concerning its impact on TC tracks. Here, we examine how TC tracks in the ...western North Pacific are modulated by the boreal summer ISO (BSISO) during each month of the TC season (June–October) using the best track data and how well the modulation are reproduced in the European Centre for Medium‐Range Weather Forecasts (ECMWF) model forecasts. The results reveal that the impact of the BSISO on the typhoon tracks varies month to month. The ECMWF model successfully reproduces this impact up to a month in advance. A simple advection model shows that the reproduction of the modulations in the TC genesis location leads to accurate TC track forecasts. These results suggest that the BSISO is one of the major sources of TC track predictability at the subseasonal time scale (2 weeks to 2 months).
Plain Language Summary
A 30–90‐day oscillation of convective activity in the tropical atmosphere affects the formation of tropical cyclones (TCs) in the western North Pacific (WNP) in summer. However, how this oscillation modulates the TC tracks is not yet well documented. In this study, we analyze the observational data and how well the modulation is simulated by a state‐of‐the‐art operational numerical weather prediction model to discuss further improvements in TC predictions beyond 2 weeks that are necessary to mitigate the risk of TCs. The results show that the modulation of the TC track by the oscillation varies month to month. For example, TCs formed in the enhanced convection phases in the WNP have a lower chance of hitting Japan than those formed in the suppressed phases in September. In October, however, TCs formed in the enhanced phases have a higher chance of hitting Japan. The model can simulate the TC track modulation well in June, July, and September but not in August and October. Further detailed analyses suggest that model error in the modulation of the TC formation distribution caused by the oscillation causes errors in the TC tracks. These findings will help further improvement of the TC predictions beyond 2 weeks.
Key Points
The impact of the boreal summer intraseasonal oscillation on the typhoon tracks varies month to month
The European Centre for Medium‐Range Weather Forecasts model successfully reproduces the impact up to a month in advance
Reproduction of modulations in the typhoon genesis location leads to accurate tropical cyclone track forecasts
•A semi-active suspension which can produce a stroke-dependent actuating force is proposed.•This suspension performs both high controllability and effective stiffness nonlinearity.•The controllable ...damping force compensates the actuating force to further improve the control effect.•A hybrid algorithm based on TS fuzzy and robust control considering the stiffness variation is implemented.
The group of active suspensions with controllable actuating force is noted with their excellent performance in reducing vibrations, however, their demanding requirements for high power consumption and high cost as well as the highly potential instability issue have hindered their practical usage. Semi-active suspensions with controllable stiffness or damping are simple, stable and cost-efficient, but they cannot provide equivalent performance with active suspensions. By incorporating the negative stiffness mechanism into the semi-active suspension using a magnetorheological (MR) damper, this paper provides a solution to improving the vibration-reduction performance of the semi-active suspensions to the level achievable by active suspensions while avoiding the disadvantages of active control. The experimental results demonstrated that the new suspension has brought better vibration-reduction performance than the passive suspension and the conventional MR suspension, and that the vibration reduction performance is comparable with that of some of the active systems reported. Therefore, this new semi-active suspension using MR damper with negative stiffness component can be considered as a new generation of vibration control method given that it has led to a great advancement in semi-active vibration control technology.
The transport and accumulation of moisture played an essential role in the extremely heavy rainfall of July 2020 in Japan. To better understand this event in terms of moisture sources and transport ...routes, backward particle trajectory analysis was conducted. We found two major moisture sources: transport from the tropics and uptake from the subtropics. A narrow moisture channel was found along the edge of the western Pacific Subtropical High (WPSH), transporting the moisture to the Baiu front. However, most moisture from the tropics was lost due to precipitation, and their contributions were reduced to about 15%. In contrast, the subtropical regions contributed over 80% moisture via evaporation and lower tropospheric convection. Among those regions, the western Pacific contributed the most (>33%). This study highlights the role of WPSH in moisture transport and demonstrated the importance of moisture uptake during transport.
Plain Language Summary
Heavy rainfalls hit Japan in July 2020, and the related atmospheric river was found to be accumulated by the moisture from tropics and subtropics. The moisture was transported by a narrow moisture channel along the edge of western Pacific Subtropical High. But, due to the precipitation during the transport, the moisture from the tropics decreased. On the other hand, when the air flows passed over the subtropical regions, they were moistened by evaporation and lower troposphere convection. Thus, our results suggest that the moisture from subtropical regions contributed the most to the moisture accumulation during the heavy rain event.
Key Points
Moisture came from both the tropical regions and subtropical regions
The western Pacific Subtropical High is major forcing of moisture transport and also helped the moistening of low‐level flows
Subtropical regions (especially the western Pacific) contributed the most to the moisture accumulation
Seismic wave extractions have been performed using ambient noise records observed by distributed acoustic sensing (DAS) technology. Extractions of microseisms can be investigated at a local scale ...using such DAS records observed in the ocean. Here, we show P and Scholte wave extractions from ambient seafloor noise observed by DAS along a submarine cable deployed off Cape Muroto in the Nankai subduction zone, Japan. The P waves can be observed at a frequency band of 0.1–0.3 Hz and up to a distance of 8 km. The distance at which the P waves can be observed is controlled by the P incident angle and the DAS sensitivity to the observable apparent velocity. Effective extractions of P and Scholte waves, corresponding to large intensity of wave‐wave interaction at the sea surface, are performed, indicating that the waves are originated from pressure field at the sea surface.
Plain Language Summary
The density of seismic observations on land is typically higher than that in the ocean. However, higher‐density observations in both land and ocean regions can be made using the recently developed distributed acoustic sensing (DAS). In this study, we focus on the waves persistently propagating through the Earth, which are excited by ocean swell and are called microseisms. Ocean swell at the sea surface primarily excites surface waves: however, P and S waves excited by ocean swell, especially during tropical storms, were observed on a global scale. Because this indicates that body waves may be locally excited by sea surface disturbances, we investigate the problem using DAS records. Our results show that large amplitudes of P waves occur when an atmospheric low pressure passes through Japan, and those amplitudes become weak when the wave‐wave interaction intensity at the ocean surface is weak. Although many previous studies at global or regional scales have indicated that microseisms are originated from fluid disturbances at the sea surface, the current study observed the excitation of P and surface waves right beneath the sea surface disturbances.
Key Points
P waves were extracted from ambient seafloor noise records observed by distributed acoustic sensing (DAS) at a frequency band of 0.1–0.3 Hz and up to a distance of 8 km
Extraction of P waves depends on weather conditions, particularly for wave‐wave interaction intensity at the sea surface
The distance at which the P waves emerge is controlled by the P incident angle and the DAS sensitivity to apparent velocities
•A new MRE base isolation system with an omnidirectional energy harvester is reported.•The self-powering unit can collect vibration energy from all horizontal directions.•The conflicting requirements ...during daily operation and earthquake events can be met.•Vibration isolation evaluations verify the improved performance of the new isolator.
Base isolator is one of the most adopted and effective means of mitigating unwanted and harmful vibrations to protect buildings and other key civil infrastructure from seismic events. For this reason, the base isolation technology has advanced greatly in recent years, especially the magnetorheological elastomer (MRE) isolator. However, the operation of such an MRE isolator needs external power supply to be activated, which may fail due to the power outage caused by the seismic movement. To this end, this work developed an MRE base isolation system with self-powering capability. This characteristic enables the isolation system self-sufficient without relying on external power. The self-powering component is an innovative omnidirectional element and can collect vibration energy from all horizontal directions. In addition, the self-powered isolation system performs rate-dependent softening behaviour which overcomes the conflicting requirements that the stiffness is required to be hard during daily operation but soft when the earthquake happens. For this reason, this new isolation system has been built and tested, including its MRE isolator and self-powering components. Its vibration reduction capability for building is also investigated on a scaled building. The theoretical analysis and verification is also performed and the conclusions coincide with the experimental results. The experimental and simulation results demonstrate that this new isolation system is capable of generating electricity which is sufficient to power itself when it is subjected to ground motions, and that it shows a high effectiveness in reducing the floor accelerations and the relative displacement.
Abstract
Background
For decades, ICD is a well-established therapy for improving prognosis of structural heart disease with severe cardiac dysfunction, and ICD for primary prophylaxis against sudden ...cardiac death were routinely provided. However, long-term prognosis and clinical course are different in each individual patient with an ICD, and it is moreover unclear what kind of factors might have influences on their clinical outcomes.
Purpose
The aim of this study is to clarify long-term prognosis and predictors of future major adverse cardiac events (MACEs) in HFrEF patients with an ICD as primary prophylaxis in Japanese population.
Methods
We retrospectively analyzed our ICD database. Patients underwent primary prophylactic ICD implantation from 2006 to 2020 at our institute and met the criteria of ICD recommendation of the latest Japanese guideline. Its requirements are receiving optimal medication therapy, symptomatic heart failure (New York Heart Association classification II or greater), and severe cardiac dysfunction (left ventricular ejection fraction (LVEF) is 35% or less). Additionally, prior NSVT is considered Class I ICD recommendation. In the case of ischemic cardiomyopathy (ICM), ICD implantation was done at least 40 days after myocardial infarction and at least 90 days after revascularization. MACEs were defined as composite outcome of cardiovascular death, heart failure hospitalization, and appropriate ICD therapies.
Results
A total of 148 consecutive patients were enrolled (male, 120 (81%); age, 62.1±11.8 years; LVEF, 23.0±5.86%; left ventricular end-diastolic diameter (LVDd), 67.6±9.26mm; paroxysmal or persistent atrial fibrillation (AF), 38 (26%); NSVT, 113 (76%); use of class III antiarrhythmic drugs, 48 (32%); ICM, 49 (33%); cardiac resynchronization therapy (CRT), 63 (43%)). One hundred twenty patients (81%) were programmed with a shock-only zone over 200 beats per minute. The median follow-up duration was 58.5 months. Among those 148 patients, MACEs were occurred to 60 patients (41%). As a result of dividing all patients into two groups by the occurrence of MACE, LVEF and LVDd were worse in MACE(+) group, whereas, MACE(−) had greater number of co morbidities. The results of cox-regression analysis showed LVDd (HR: 1.07, 95% CI: 1.03–1.12, p<0.001), AF (HR: 2.88, 95% CI: 1.56–5.31, p<0.001) and ICM (HR: 1.78, 95% CI: 1.00–3.16, p=0.049) were the independent predictors of MACEs (Table). However, initial ICD programming was not related to the occurrence of MACE.
Conclusions
The incidence of MACEs in patients with an ICD and severe HFrEF was substantially high in this Japanese population. Etiology of ICM, left ventricle size, and AF were the potential risk factors for future MACEs.
Funding Acknowledgement
Type of funding sources: None.
Summary
We report a unique case of a Japanese woman with herpetiform pemphigus (HP) who had IgG autoantibodies reactive with nondesmosomal sites of keratinocytes and presented characteristic ...transmission electron microscopic (TEM) findings of various‐sized vacuoles in keratinocytes without acantholysis. The patient presented with pruritic annular oedematous erythemas with small blisters lining the margins on the trunk and extremities. Histopathological examinations showed intraepidermal blisters with prominent infiltrations of eosinophils. Direct and indirect immunofluorescence tests revealed the presence of in vivo bound and circulating IgG autoantibodies to the keratinocyte cell surfaces. However, enzyme‐linked immunosorbent assays for desmoglein (Dsg) 1, Dsg3 and desmocollins 1–3 showed negative results. Immunoblotting using the full‐length human Dsg1 recombinant protein showed a positive band. TEM examination showed various‐sized vacuoles squashing the nuclei in many keratinocytes, resulting in rupture of the cells. Immunoelectron microscopic examination revealed IgG deposition over the entire keratinocyte cell surfaces, which spared the desmosomes. IgG antibodies were also present on the inside walls of the vacuoles around the nuclei of keratinocytes and on the cell surfaces of infiltrating eosinophils. This patient also had marked eosinophilia and high levels of thymus and activation‐regulated chemokine and interleukin‐5 in the serum. These results indicated a novel autoantigen on the nondesmosomal keratinocyte cell surfaces and the pathogenesis of bullous spongiotic change with inflammation in HP.
What's already known about this topic?
Herpetiform pemphigus (HP) is a rare variant of pemphigus characterized clinically by pruritic annular erythemas with vesicles resembling dermatitis herpetiformis and histopathologically by eosinophilic spongiosis without apparent acantholysis.
The targets of IgG autoantibodies in patients with HP are usually desmoglein 1 and 3, which are both components of desmosomes.
What does this study add?
This study reports the unique case of a patient with HP with IgG autoantibodies reactive to nondesmosomal sites of keratinocytes and characteristic transmission electron microscopic findings of various‐sized vacuoles in keratinocytes, while desmosomal adhesion remained.
Regarding pathogenesis, we speculate that the ballooning vacuoles might result in the bullous spongiotic changes without acantholysis seen in this patient.
This study also focuses on the relationships between blood eosinophil counts, serum thymus and activation‐regulated chemokine levels and HP disease activity.
Linked Comment: Yuan and Pan. Br J Dermatol 2019; 180:22.