Highly crystalline 2D/3D‐mixed p‐transition metal dichalcogenide (TMD)/n‐Ga2O3 heterojunction devices are fabricated by mechanical exfoliation of each p‐ and n‐type material. N‐type β‐Ga2O3 and ...p‐type TMD separately play as a channel for junction field effect transistors (JFETs) with each type of carriers as well as materials for a heterojunction PN diode. The work thus mainly focuses on such ambipolar channel transistors with two different types of channel in a single device architecture. For more extended applications, the transparency of high energy band gap β‐Ga2O3 (Eg ≈ 4.8 eV) is taken advantage of, firstly to measure the electrical energy gap of p‐TMDs receiving visible or near infrared (NIR) photons through the β‐Ga2O3. Next, the p‐TMD/n‐Ga2O3 JFETs are put to high speed photo‐sensing which is achieved from the p‐TMD channel under reverse bias voltages on n‐Ga2O3. The photo‐switching cutoff frequency appears to be ≈16 and 29 kHz for visible red and NIR illuminations, respectively, on the basis of −3 dB photoelectric power loss. Such a high switching speed of the JFET is attributed to the fast transport of photo‐carriers in TMD channels. The 2D/3D‐mixed ambipolar channel JFETs and their photo‐sensing applications are regarded novel, promising, and practically easy to achieve.
Highly crystalline 2D/3D‐mixed p‐TMD/n‐Ga2O3 heterojunction devices are fabricated by mechanical exfoliation of each p‐ and n‐type material, to finally realize ambipolar channel junction field‐effect transistors (JFETs) as well as PN diodes. For more extended applications, p‐TMD channel JFETs are used to sense visible or NIR photons through the β‐Ga2O3 at high speed.
Gallium trioxide, β‐Ga2O3, has been recently studied due to its promising semiconducting properties as active material in transistors or Schottky diodes. Transistors with β‐Ga2O3 channels are mostly ...metal oxide field effect transistors (MOSFET), and they show very negative threshold voltages (Vth) in general. Metal semiconductor field effect transistors (MESFETs) with top gate are also reported with less negative Vth. Still, β‐Ga2O3 MESFETs are only a few. Here, bottom gate architecture β‐Ga2O3 MESFETs using transition metal dichalcogenide (TMD) NbS2 and TaS2 are reported. Due to the large work functions of those metallic TMDs, the MESFETs display minimum subthreshold swing of 61 mV dec−1, small Vth of −1.2 V, minimum OFF ID of ≈100 fA, and maximum ON/OFF current ratio of ≈108. Both β‐Ga2O3 Schottky diodes with TaS2 and NbS2 display good junction stability even after 300 °C measurements in 10 mTorr vacuum. When the β‐Ga2O3 MESFET with TaS2 gate is integrated as a switching FET into an organic light emitting diode (OLED) circuit, it demonstrates long‐term leakage endurance performance, maintaining an OLED brightness higher than 58% of the initial intensity after 100 s passes since the ON‐switching point, which is even superior to the performance of conventional a‐IGZO MOSFET switch.
β‐Ga2O3 channel metal semiconductor field effect transistor (MESFETs) with metallic transition metal dichalcogenide (TMD) gates using NbS2 and TaS2 are successfully fabricated. The MESFETs demonstrate stable junction properties and superior transistor performance in respects of Vth, SS and IOFF, since a large Schottky barrier forms at the TMD gate/β‐Ga2O3 channel junction. They also demonstrate excellent long‐term leakage endurance performances when integrated with OLED pixel circuits as switching FETs.
Applications of 2D semiconductors have been extensively studied, much oriented to various electron devices. Recently, multivalue field‐effect transistors (FETs) are also included among 2D‐based ...electron device studies in consideration that multivalue FETs may resolve power consumption issues in future integrated circuits. Several n‐channel devices are thus reported along with a few p‐channel devices, while studies to achieve both n‐ and p‐channel multivalue FETs are hardly found. Here, both n‐ and p‐channel multivalue FETs are fabricated using p‐MoTe2/n‐MoS2 heterostack channel architecture, where either p‐ or n‐channel ternary value FET is reproducible by switching the stacking order of p‐ and n‐channel layer. The main ternary value mechanism originates from resonant tunneling type injection and channel inversion, which take place during device operation. For a state‐of‐the‐art device application in 2D electronics, a quaternary NAND logic circuit is for the first time demonstrated by integrating two ternary n‐channel FETs, and a complementary ternary inverter is also fabricated by integrating multivalue p‐channel and plain n‐channel FET.
Both n‐ and p‐channel multivalue field‐effect transistors (FETs) are fabricated using p‐MoTe2/n‐MoS2 heterostack channel architecture, where either p‐ or n‐channel ternary value FET is reproducible by switching the stacking order. For a state‐of‐the‐art device application, a quaternary NAND logic circuit is for the first time demonstrated by integrating two ternary n‐channel FETs, and a complementary ternary inverter is also fabricated.
Energy efficiency has been a hot research topic for many years and many routing algorithms have been proposed to improve energy efficiency and to prolong lifetime for wireless sensor networks (WSNs). ...Since nodes close to the sink usually need to consume more energy to forward data of its neighbours to sink, they will exhaust energy more quickly. These nodes are called hot spot nodes and we call this phenomenon hot spot problem. In this paper, an Enhanced Power Efficient Gathering in Sensor Information Systems (EPEGASIS) algorithm is proposed to alleviate the hot spots problem from four aspects. Firstly, optimal communication distance is determined to reduce the energy consumption during transmission. Then threshold value is set to protect the dying nodes and mobile sink technology is used to balance the energy consumption among nodes. Next, the node can adjust its communication range according to its distance to the sink node. Finally, extensive experiments have been performed to show that our proposed EPEGASIS performs better in terms of lifetime, energy consumption, and network latency.
Many studies have examined the negative impact on smartphone addiction in adolescents. Recent concerns have focused on predictors of smartphone addiction. This study aimed to investigate the ...association of adolescents' smartphone addiction with family environment (specifically, domestic violence and parental addiction). We further investigated whether self-control and friendship quality, as predictors of smartphone addiction, may reduce the observed risk.
We used the 2013 national survey on internet usage and utilization data from the National Information Agency of Korea. Information on exposure and covariates included self-reported experience of domestic violence and parental addiction, sociodemographic variables, and other variables potentially related to smartphone addiction. Smartphone addiction was estimated using a smartphone addiction proneness scale, a standardized measure developed by national institutions in Korea.
Adolescents who had experienced domestic violence (OR = 1.74; 95% CI: 1.23-2.45) and parental addiction (OR = 2.01; 95% CI: 1.24-3.27) were found to be at an increased risk for smartphone addiction after controlling for all potential variables. Furthermore, on classifying adolescents according to their level of self-control and friendship quality the association between domestic violence and parental addiction, and smartphone addiction was found to be significant in the group with adolescents with lower levels of self-control (OR = 2.87; 95% CI: 1.68-4.90 and OR = 1.95; 95% CI: 1.34-2.83) and friendship quality (OR = 2.33; 95% CI: 1.41-3.85 and OR = 1.83; 95% CI: 1.26-2.64).
Our findings suggest that family dysfunction was significantly associated with smartphone addiction. We also observed that self-control and friendship quality act as protective factors against adolescents' smartphone addiction.
Wireless body area networks (WBANs) are expected to play a vital role in the field of patient-health monitoring shortly. They provide a convenient way to collect patient data, but they also bring ...serious problems which are mainly reflected in the safe storage of the collected data. The privacy and security of data storage in WBAN devices cannot meet the needs of WBAN users. Therefore, this paper adopts blockchain technology to store data, which improves the security of the collected data. Moreover, a storage model based on blockchain in WBAN is proposed in our solution. However, blockchain storage brings new problems, for example, that the storage space of blockchain is small, and the stored content is open to unauthorized attackers. To solve the problems above, this paper proposed a sequential aggregate signature scheme with a designated verifier (DVSSA) to ensure that the user's data can only be viewed by the designated person and to protect the privacy of the users of WBAN. In addition, the new signature scheme can also compress the size of the blockchain storage space.
Coupling between non‐toxic lead‐free high‐k materials and 2D semiconductors is achieved to develop low voltage field effect transistors (FETs) and ferroelectric non‐volatile memory transistors as ...well. In fact, low voltage switching ferroelectric memory devices are extremely rare in 2D electronics. Now, both low voltage operation and ferroelectric memory function have been successfully demonstrated in 2D‐like thin MoS2 channel FET with lead‐free high‐k dielectric BaxSr1‐xTiO3 (BST) oxides. When the BST surface is coated with a 5.5‐nm‐ultrathin poly(methyl methacrylate) (PMMA)‐brush for improved roughness, the MoS2 FET with BST (x = 0.5) dielectric results in an extremely low voltage operation at 0.5 V. Moreover, the BST with an increased Ba composition (x = 0.8) induces quite good ferroelectric memory properties despite the existence of the ultrathin PMMA layer, well switching the MoS2 FET channel states in a non‐volatile manner with a ±3 V low voltage pulse. Since the employed high‐k dielectric and ferroelectric oxides are lead‐free in particular, the approaches for applying high‐k BST gate oxide for 2D MoS2 FET are not only novel but also practical towards future low voltage nanoelectronics and green technology.
Lead‐free inorganic high‐k dielectric BaxSr1–xTiO3 oxides are successfully introduced to support MoS2 channels in field effect transistors, targeting both extremely low voltage operation and ferroelectric nonvolatile memory function by simply adjusting the composition ratio of Ba and Sr.
Various source-derived mesenchymal stem cells (MSCs) have been considered for cell therapeutics in incurable diseases. To characterize MSCs from different sources, we compared human bone marrow (BM), ...adipose tissue (AT), and umbilical cord blood-derived MSCs (UCB-MSCs) for surface antigen expression, differentiation ability, proliferation capacity, clonality, tolerance for aging, and paracrine activity. Although MSCs from different tissues have similar levels of surface antigen expression, immunosuppressive activity, and differentiation ability, UCB-MSCs had the highest rate of cell proliferation and clonality, and significantly lower expression of p53, p21, and p16, well known markers of senescence. Since paracrine action is the main action of MSCs, we examined the anti-inflammatory activity of each MSC under lipopolysaccharide (LPS)-induced inflammation. Co-culture of UCB-MSCs with LPS-treated rat alveolar macrophage, reduced expression of inflammatory cytokines including interleukin-1α (IL-1α), IL-6, and IL-8 via angiopoietin-1 (Ang-1). Using recombinant Ang-1 as potential soluble paracrine factor or its small interference RNA (siRNA), we found that Ang-1 secretion was responsible for this beneficial effect in part by preventing inflammation. Our results demonstrate that primitive UCB-MSCs have biological advantages in comparison to adult sources, making UCB-MSCs a useful model for clinical applications of cell therapy.
Recently, wireless sensor network (WSN) has drawn wide attention. It can be viewed as a network with lots of sensors that are autonomously organized and cooperate with each other to collect, process, ...and transmit data around targets to some remote administrative center. As such, sensors may be deployed in harsh environments where it is impossible for battery replacement. Therefore, energy efficient routing is crucial for applications that introduce WSNs. In this paper, we present an energy efficient routing schema combined with clustering and sink mobility technology. We first divide the whole sensor field into sectors and each sector elects a Cluster Head (CH) by calculating its members' weight. Member nodes calculate energy consumption of different routing paths to choose the optimal scenario. Then CHs are connected into a chain using the greedy algorithm for intercluster communication. Simulation results prove the presented schema outperforms some similar work such as Cluster-Chain Mobile Agent Routing (CCMAR) and Energy-efficient Cluster-based Dynamic Routing Algorithm (ECDRA). Additionally, we explore the influence of different network parameters on the performance of the network and further enhance its performance.
Objective
There is no scale for rating the severity of autoimmune encephalitis (AE). In this study, we aimed to develop a novel scale for rating severity in patients with diverse AE syndromes and to ...verify the reliability and validity of the developed scale.
Methods
The key items were generated by a panel of experts and selected according to content validity ratios. The developed scale was initially applied to 50 patients with AE (development cohort) to evaluate its acceptability, reproducibility, internal consistency, and construct validity. Then, the scale was applied to another independent cohort (validation cohort, n = 38).
Results
A new scale consisting of 9 items (seizure, memory dysfunction, psychiatric symptoms, consciousness, language problems, dyskinesia/dystonia, gait instability and ataxia, brainstem dysfunction, and weakness) was developed. Each item was assigned a value of up to 3 points. The total score could therefore range from 0 to 27. We named the scale the Clinical Assessment Scale in Autoimmune Encephalitis (CASE). The new scale showed excellent interobserver (intraclass correlation coefficient ICC = 0.97) and intraobserver (ICC = 0.96) reliability for total scores, was highly correlated with modified Rankin scale (r = 0.86, p < 0.001), and had acceptable internal consistency (Cronbach α = 0.88). Additionally, in the validation cohort, the scale showed high interobserver reliability (ICC = 0.99) and internal consistency (Cronbach α = 0.92).
Interpretation
CASE is a novel clinical scale for AE with a high level of clinimetric properties. It would be suitable for application in clinical practice and might help overcome the limitations of current outcome scales for AE. ANN NEUROL 2019;85:352–358.
PDF
