Supported by recent human neuroimaging studies, the insula is re-emerging as an important brain area not only in the physiological understanding of the brain, but also in pathological contexts in ...clinical research. In this opinion article, we briefly introduce the anatomical and histological features of the human insula. We then summarize the physiological functions of the insula and underscore its pathological roles in psychiatric and neurological disorders that have long been underestimated. We finally propose possible strategies through which the role of the insula may be further understood for both basic and clinical neuroscience.
Printing technology can be used for manufacturing stretchable electrodes, which represent essential parts of wearable devices requiring relatively high degrees of stretchability and conductivity. In ...this work, a strategy for fabricating printable and highly stretchable conductors are proposed by transferring printed Ag ink onto stretchable substrates comprising Ecoflex elastomer and tough hydrogel layers using a water‐soluble tape. The elastic modulus of the produced hybrid film is close to that of the hydrogel layer, since the thickness of Ecoflex elastomer film coated on hydrogel is very thin (30 µm). Moreover, the fabricated conductor on hybrid film is stretched up to 1780% strain. The described transfer method is simpler than other techniques utilizing elastomer stamps or sacrificial layers and enables application of printable electronics to the substrates with low elastic moduli (such as hydrogels). The integration of printed electronics with skin‐like low‐modulus substrates can be applied to make wearable devices more comfortable for human skin.
Printable and highly stretchable conductors are realized by transferring printed Ag ink onto stretchable substrates comprising Ecoflex and tough hydrogel layers. The elastic modulus of the produced hybrid film is close to that of the hydrogel layer, since the thickness of Ecoflex coated on hydrogel is very small. The fabricated conductor on hybrid film is stretched up to 1780% strain.
Based on the fact that a hybrid electric vehicle (HEV) connects a high number of batteries in series to obtain more than approximately 300 V, this paper proposes a modularized charge equalizer for an ...HEV battery pack. In this paper, the overall battery string is modularized into M*N cells, where M is the number of modules in the string and N is the number of cells in each module. With this modularization, low voltage stress on the electronic devices can be achieved, which means that there is less chance of a failure on the charge equalizer. The power rating selection is one of the most important design issues for a charge equalizer because it is very closely related to equalization time. To solve this problem optimally, this paper presents a power rating design guide. In addition, this paper considers system-level design issues, such as cell voltage acquisition, equalizer control logic, and system-level grounding. The simulation and experimental results are presented to show the usefulness of the optimal power rating selection guide and the low voltage stressed charge equalization process.
Perovskite solar cells are promising candidates for realizing an efficient, flexible, and lightweight energy supply system for wearable electronic devices. For flexible perovskite solar cells, ...achieving high power conversion efficiency (PCE) while using a low-temperature technology for the fabrication of a compact charge collection layer is a critical issue. Herein, we report on a flexible perovskite solar cell exhibiting 12.2% PCE as a result of the employment of an annealing-free, 20 nm thick, amorphous, compact TiO sub(x) layer deposited by atomic layer deposition. The excellent performance of the cell was attributed to fast electron transport, verified by time-resolved photoluminescence and impedance studies. The PCE remained the same down to 0.4 sun illumination, as well as to a 45 degree tilt to incident light. Mechanical bending of the devices worsened device performance by only 7% when a bending radius of 1 mm was used. The devices maintained 95% of the initial PCE after 1000 bending cycles for a bending radius of 10 mm. Degradation of the device performance by the bending was the result of crack formation from the transparent conducting oxide layer, demonstrating the potential of the low-temperature-processed TiO sub(x) layer to achieve more efficient and bendable perovskite solar cells, which becomes closer to a practical wearable power source.
Although three-dimensional (3D) bioprinting technology has gained much attention in the field of tissue engineering, there are still several significant engineering challenges to overcome, including ...lack of bioink with biocompatibility and printability. Here, we show a bioink created from silk fibroin (SF) for digital light processing (DLP) 3D bioprinting in tissue engineering applications. The SF-based bioink (Sil-MA) was produced by a methacrylation process using glycidyl methacrylate (GMA) during the fabrication of SF solution. The mechanical and rheological properties of Sil-MA hydrogel proved to be outstanding in experimental testing and can be modulated by varying the Sil-MA contents. This Sil-MA bioink allowed us to build highly complex organ structures, including the heart, vessel, brain, trachea and ear with excellent structural stability and reliable biocompatibility. Sil-MA bioink is well-suited for use in DLP printing process and could be applied to tissue and organ engineering depending on the specific biological requirements.
Exploiting spin transport increases the functionality of electronic devices and enables such devices to overcome physical limitations related to speed and power. Utilizing the Rashba effect at the ...interface of heterostructures provides promising opportunities toward the development of high‐performance devices because it enables electrical control of the spin information. Herein, the focus is mainly on progress related to the two most compelling devices that exploit the Rashba effect: spin transistors and spin–orbit torque devices. For spin field‐effect transistors, the gate‐voltage manipulation of the Rashba effect and subsequent control of the spin precession are discussed, including for all‐electric spin field‐effect transistors. For spin–orbit torque devices, recent theories and experiments on interface‐generated spin current are discussed. The future directions of manipulating the Rashba effect to realize fully integrated spin logic and memory devices are also discussed.
The Rashba effect provides fascinating functionality for electronic devices because of the electric modulation of spin orientation. Semiconductor spin transistors and spin–orbit torque devices are reviewed. Recent theories and experiments related to generating and controlling spin current are presented. Future directions in the development of spin logic and memory devices are also discussed.
Soft neuroprosthetics that monitor signals from sensory neurons and deliver motor information can potentially replace damaged nerves. However, achieving long‐term stability of devices interfacing ...peripheral nerves is challenging, since dynamic mechanical deformations in peripheral nerves cause material degradation in devices. Here, a durable and fatigue‐resistant soft neuroprosthetic device is reported for bidirectional signaling on peripheral nerves. The neuroprosthetic device is made of a nanocomposite of gold nanoshell (AuNS)‐coated silver (Ag) flakes dispersed in a tough, stretchable, and self‐healing polymer (SHP). The dynamic self‐healing property of the nanocomposite allows the percolation network of AuNS‐coated flakes to rebuild after degradation. Therefore, its degraded electrical and mechanical performance by repetitive, irregular, and intense deformations at the device–nerve interface can be spontaneously self‐recovered. When the device is implanted on a rat sciatic nerve, stable bidirectional signaling is obtained for over 5 weeks. Neural signals collected from a live walking rat using these neuroprosthetics are analyzed by a deep neural network to predict the joint position precisely. This result demonstrates that durable soft neuroprosthetics can facilitate collection and analysis of large‐sized in vivo data for solving challenges in neurological disorders.
A soft but durable fatigue‐resistant neuroprosthetic device is proposed for peripheral nerve interfacing based on a self‐recoverable nanocomposite. The nanocomposite can spontaneously recover its electrical conductivity even after repetitive degradations by severe mechanical deformation. The neuroprosthetics implanted on a rat sciatic nerve achieve stable bidirectional signaling for 5 weeks. Deep neural network analysis predicts the joint position of the rat precisely.
Increasing consumption of food with high caloric density and a sedentary lifestyle have influenced the increasing obesity prevalence worldwide. The recent pandemic has contributed to this problem. ...Obesity refers to a state in which lipid accumulates excessively in adipocytes and adipose tissues. Dried heat-killed
(EF-2001) prevents allergic mechanisms, inflammation, and tumor progression. In the present study, we investigated the effects of EF-2001 on high fat diet (HFD)-induced obese rats. The degree of obesity in experimental rats was reduced after 6 weeks of oral administration of 3 mg/kg or 30 mg/kg dosages of EF-2001, indicating regulating effects in rats with HFD-induced obesity. We found that EF-2001 decreased the amounts of total cholesterol, triglyceride, and non-high density lipoprotein (HDL) in HFD-induced obese rats. The effects of EF-2001 on 3T3-L1 adipocytes stained with Oil red O stain are shown in reductions of lipid accumulation, respectively. In addition, we examined the relationships between EF-2001 treatment and mechanisms for the insulin signaling of adipogenesis in 3T3-L1 cells. EF-2001 induced down-regulation in phosphorylation of Erk, JNK, and Akt through the inhibition of insulin receptor phosphorylation. EF-2001 inhibits the expressions of C/EBP-α and PPAR-
, a lipid metabolism-related transcription factor through confocal microscope observation and Western blot on 3T3-L1 adipocytes and HFD-induced obese rats. Based on our results, intake of EF-2001 significantly prevented HFD-induced obesity in rats through inhibition of C/EBP-α and PPAR-γ in the insulin signaling pathway on lipid accumulation.
The cost-effectiveness to screen hepatic fibrosis in at-risk population as recommended by several professional societies has been limited. This study aimed to investigate the cost-effectiveness of ...this screening strategy in the expanded at-risk population recently proposed by several societies.
A combined model of the decision tree and Markov models was developed to compare expected costs, quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratio (ICER) between screening and no screening groups. The model included liver disease-related health states and cardiovascular disease (CVD) states as a base-case analysis. Screening strategy consisted of fibrosis-4 index (FIB-4) followed by vibration-controlled transient elastography (VCTE) and intensive lifestyle intervention (ILI) as a treatment for diagnosed patients.
Cost-effectiveness analysis showed that screening the at-risk population entailed $298 incremental costs and an additional 0.0199 QALY per patient compared to no screening (ICER $14 949/QALY). Screening was cost-effective based on the implicit ICER threshold of $25 000/QALY in Korea. When the effects of ILI on CVD and extrahepatic malignancy were incorporated into the cost-effectiveness model, the ICER decreased by 0.85 times from the base-case analysis (ICER $12 749/QALY). In contrast, when only the effects of liver disease were considered in the model, excluding cardiovascular disease effects, ICER increased from the baseline case analysis to $16 305. Even when replacing with medical costs in Japan and U.S., it remained cost-effective with the estimate below the countries' ICER threshold.
Our study provides compelling evidence supporting the cost-effectiveness of FIB-4-based screening the at-risk population for advanced hepatic fibrosis.
The charge equalizer design for a series-connected battery string is very challenging because it needs to satisfy many requirements, such as implementation possibility, equalization speed, ...equalization efficiency, controller simplicity, size and cost issues, voltage and current stress, and so on. Numerous algorithms and circuits were developed to meet the foregoing demands, and some interesting results have been obtained. However, for a large number of cells, for example, 80 or more batteries, the previous approaches might not easily satisfy the foregoing requirement. To overcome these difficulties, we propose a charge equalizer design method based on a battery modularization technique. In this method, a very long battery string is divided into several modules, and then, an intramodule equalizer and an outer-module equalizer are designed. This battery modularization scheme effectively reduces the number of cells that we consider in an equalizer design procedure; thus, the design of a charge equalizer becomes easier. Furthermore, by applying the previously verified charge equalizers to the intramodule and the outer module, we can make the equalizer design more flexible. Several examples and experimental results are presented to demonstrate the usefulness of the charge equalizer design method.
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