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This paper makes the comparisons on the behaviors of three types of commercial GaN power switching devices, including Schottky gate p-GaN high electron mobility transistor (HEMT), ohmic gate p-GaN HEMT with hybrid drain, and Cascode GaN device, under single-pulse and repetitive unclamp-inductive -switching (UIS) conditions by experiments and simulations. It shows that all the three types of GaN devices withstand the UIS stress by storing energy in parasitic capacitances rather than by avalanche process, which is a different phenomenon compared with traditional Si/SiC devices. However, the failure phenomena under single-pulse UIS condition are different. For the two types of p-GaN gate devices, the inverse-piezoelectric induced punch-through makes the burnout under drain contact region. For the Cascode device, the breakdown of the inner Si device dominates the failure. As for the behaviors under repetitive UIS stresses, p-GaN gate device with hybrid drain performs the best, Schottky gate p-GaN HEMT shows the most serious electrical performance degradations due to the trapping effects and carrier storage phenomena, Cascode GaN device exhibits stable threshold voltage and acceptable degradations of on-state resistance due to the existence of inner Si device.

In this letter, comprehensive static and dynamic electrical parameter degradations of p-GaN gate high electron mobility transistor (HEMT) under repetitive short-circuit (SC) stresses are presented. Meanwhile, the mechanisms behind those degradations are first distinguished. The results indicate that both the gate region and the access region are damaged by the SC stresses, dominating the shifts of electrical parameters. Moreover, a method by modeling the output capacitance is proposed to characterize damages in access region. Finally, the switching characteristics after the stresses are investigated, it is found that the switching speed benefits from the increase in the gate leakage current. Considering the aging of p-GaN HEMT under long-term operation conditions, all the damages brought by repetitive SC stresses should be eliminated to prevent the failure of p-GaN gate and the increase in conduction loss.

Type 2 diabetes mellitus (T2DM) is among the most remarkable public health concerns globally. Accumulating research evidence documents that alteration of gut microbiota has an indispensable role in the onset and progression of obesity and T2DM. A reduced microbial diversity is linked to insulin resistance and energy metabolism, especially for the rise of the Firmicutes/Bacteroidetes ratio. Changes in metabolites followed by the gut dysbacteriosis are linked to the presence of T2DM. Moreover, endotoxin leakage and gut permeability caused by gut dysbacteriosis is more of a trigger for the onset and progression of T2DM. Research documents that natural products are remarkable arsenals of bioactive agents for the discovery of anti-T2DM drugs. Many studies have elucidated that the possible mechanisms of the anti-T2DM effects of natural products are remarkably linked to its regulation on the composition of gut microflora and the successive changes in metabolites directly or indirectly. This review presents a brief overview of the gut microbiota in T2DM and several relevant mechanisms, including short-chain fatty acids, biosynthesis and metabolism of branched-chain fatty acids, trimethylamine N-oxide, bile acid signaling, endotoxin leakage, and gut permeability, and describes how dietary natural products can improve T2DM via the gut microbiota.

Akt/mTOR/p70S6K signaling pathway promotes motor function recovery after spinal cord injury (SCI) in both neurons and astrocytes. But the role and mechanism of this pathway in oligodendrocytes during nerve repair following SCI has not been researched. This study aimed to investigate the effect and mechanism of this signaling pathway in oligodendrocytes on nerve myelin regeneration and motor function recovery in rats with SCI.After inhibiting or activating this signaling pathway, Western blotting and double immunofluorescence labeling were used to determine the levels of the signaling molecules in this pathway and myelin formation-related proteins in the plane of the thoracic segment of the injured spinal cord. The level of motor function recovery was evaluated and the oligodendrocytes involved in nerve myelin regeneration were studied. Primary oligodendrocytes were isolated and culturedAkt/mTOR/p70S6K signaling pathway was activated after SCI compared with the sham-operated rats, prominently elevated levels of the pathway components were observed in the SC79-treated group. The activation of the signaling pathway significantly increased the expression levels of myelin formation-related proteins, including MBP, PLP, and MOG, and improved the Basso, Beattie, and Bresnahan (BBB) scores in the injured spinal cord. Conversely, rapamycin suppressed the expression of these signaling molecules and reduced the levels of myelin formation-related proteins.Akt/mTOR/p70S6K signaling pathway activation can contribute to nerve myelin regeneration and has the potential to improve the regenerative environment and motor function, as well as the potential to promote repair of SCI.

This letter firstly reveals the single pulse unclamped-inductive-switching (UIS) withstanding physics and failure mechanism for p-GaN high electron mobility transistor (HEMT) with Schottky type gate contact. Unlike silicon/silicon carbide (Si/SiC)-based devices, the p-GaN HEMT withstands the surge current from load inductor by storing the energy into the output capacitance of the device, rather than dissipating the energy by avalanche process. To describe the UIS process, physics-based models are proposed. Also, by the simulations and de-cap/de-layer experiments, the failure mechanism is presented as a different manner compared with Si/SiC-based devices. The high voltage during the UIS process introduces high electric field near the drain contact, which leads to the inverse-piezoelectric effect, then bringing the rise-up of the leakage current and high power dissipation. As a result, the region near drain contact is burned by thermal runaway. Moreover, it is demonstrated that higher bus voltage and larger load inductance will increase the UIS-induced failure risk, while the gate resistance, turn- off gate voltage and ambient temperature exhibit little influences upon the UIS withstanding capability of the device.

Silicon (Si)-based Schottky junction photoelectrodes have attracted considerable attention for photoelectrochemical (PEC) water splitting in recent years. To realize highly efficient Si-based Schottky junction photoelectrodes, the critical challenge is to enable the photoelectrodes to not only have a high Schottky barrier height (SBH), by which a high photovoltage can be obtained, but also ensure an efficient charge transport. Here, we propose and demonstrate a strategy to fabricate a high-performance NiSi/n-Si Schottky junction photoanode by metal silicidation in conjunction with dopant segregation (DS). The metal silicidation produces photoanodes with a high-quality NiSi/Si interface without a disordered SiO

This brief first reports the behaviors of three different kinds of 650-V commercial normally- OFF GaN devices under repetitive reverse freewheeling stress, and the mechanisms are illustrated by experiments and mix-mode technology computer-aided design simulations. After the stress, unlike the stable behaviors of the device with ohmic-type metal/p-GaN gate stack and the device with cascode structure, there are degradations on the threshold voltage, the ON-state resistance, and the source-to-drain reverse voltage for the device with Schottky-type metal/p-GaN gate stack. During the freewheeling stress, there is a dynamic positive gate to drain voltage on the devices. Especially, the Schottky-type contact leads to a barrier height at metal/p-GaN junction and makes the p-GaN layer to become floating, which can lock the injected carriers. Worse more, there is a high electric field at the gate contact, which leads to the trapping of injected electrons. Once the stress is removed, more positive gate voltage is needed during the turn-on process to suppress the influences of unreleased electrons; as the results, the electrical parameters shift. Finally, the mix-mode simulation results prove the carrier injection, and the measured segmental shifts of gate leakage current prove the trapping process in p-GaN layer successfully.

This brief proposes novel integrated GaN high-electron-mobility transistor (HEMT) with multichannel Schottky barrier diode (SBD) structures to achieve ultrahigh reverse conduction capability and maintain the blocking characteristic at the same time. The simulative results indicate that the reverse voltage drop and reverse ON-state resistance can be reduced by 38.6% and 38% compared with the traditional metal–insulator–semiconductor HEMT, respectively. Meanwhile, the forward conduction capability, the blocking performances, and the capacitance characteristics are little influenced. Moreover, it is proved that the proposed devices also exhibit superior dynamic performances, indicating the application potential of reducing the power loss of power electronic systems. Finally, the key fabrication flows for the novel devices are presented and discussed.

Multiferroic BiFeO3 thin films have been widely studied for their intriguing fundamental physics and exotic functional properties. Integration of the BiFeO3 thin films with semiconductor Si is crucial for the practical development of novel electronic and photosensitive devices. Here, we report the fabrication and physical properties of BiFeO3 thin films grown directly on bare Si substrate by laser-molecular beam epitaxy. It was found that a predeposition process performed at room temperature and high vacuum conditions is effective and necessary for obtaining the pure-phase BiFeO3 thin films. X-ray diffraction measurements indicate that the obtained BiFeO3 thin films are in a single-phase polycrystalline state and show improved crystallinity with increasing thickness, and a transmission electronic microscopy image illustrates an interface layer around 3 nm in thickness existing between the BiFeO3 thin films and Si substrate. Electrical measurements show that the BiFeO3 thin films have good ferroelectricity and low leakage current. Moreover, optical properties investigated by spectroscopic ellipsometry demonstrate that the direct band gap of the thin films increases with decreasing thickness.

The spatio-temporal residual network (ST-ResNet) leverages the power of deep learning (DL) for predicting the volume of citywide spatio-temporal flows. However, this model, neglects the dynamic dependency of the input flows in the temporal dimension, which affects what spatio-temporal features may be captured in the result. This study introduces a long short-term memory (LSTM) neural network into the ST-ResNet to form a hybrid integrated-DL model to predict the volumes of citywide spatio-temporal flows (called HIDLST). The new model can dynamically learn the temporal dependency among flows via the feedback connection in the LSTM to improve accurate captures of spatio-temporal features in the flows. We test the HIDLST model by predicting the volumes of citywide taxi flows in Beijing, China. We tune the hyperparameters of the HIDLST model to optimize the prediction accuracy. A comparative study shows that the proposed model consistently outperforms ST-ResNet and several other typical DL-based models on prediction accuracy. Furthermore, we discuss the distribution of prediction errors and the contributions of the different spatio-temporal patterns.

Magnetoelectric (ME) coupling has gradually developed into one of the core means of advancing ultralow-power memory, logic and sensor technologies. Among various strategies, magneto-ionic control of magnetism based on mechanism such as redox, intercalation/deintercalation, and charge accumulation can be achieved in ion battery or capacitor systems. In this work, we demonstrate a ME effect originating from the spin capacitance, combining the advantages of intercalation batteries and supercapacitors. A giant, fast and reversible modulation on the saturation magnetization of ferromagnetic Fe is achieved by lithium ions motion across the Fe/Li2O interface at no more than 1 V. Furthermore, the magnetic evolution driven by the conversion reaction between FeO and Fe over a larger voltage range demonstrates ferromagnetic ordering of the FeO surface. These findings not only open new perspectives for developing high-performance magneto-ionic devices, but also are crucial to designing spintronic devices composed of iron and oxide multilayer structures.

Endometriosis is a common chronic gynecological disease greatly affecting women health. Prior studies have implicated that dysferlin (DYSF) aberration might be involved in the pathogenesis of ovarian endometriosis. In the present study, we explore the potential presence of DYSF mutations in a total of 152 Han Chinese samples with ovarian endometriosis. We analyze the potential presence of DYSF mutations by direct DNA sequencing. A total of seven rare variants/mutations in the DYSF gene in 10 out of 152 samples (6.6%) were identified, including 5 rare variants and 2 novel mutations. For the 5 rare variants, p.R334W and p.G941S existed in 2 samples, p.R865W, p.R1173H and p.G1531S existed in single sample, respectively; for the two novel mutations, p.W352* and p.I1642F, they were identified in three patients. These rare variants/mutations were absent or existed at extremely low frequency either in our 1006 local control women without endometriosis, or in the China Metabolic Analytics Project (ChinaMAP) and Genome Aggregation Database (gnomAD) databases. Evolutionary conservation analysis results suggested that all of these rare variants/mutations were evolutionarily conserved among 11 vertebrate species from Human to Fox. Furthermore, in silico analysis results suggested these rare variants/mutations were disease-causing. Nevertheless, we find no significant association between DYSF rare variants/mutations and the clinical features in our patients. To our knowledge, this is the first report revealing frequent DYSF mutations in ovarian endometriosis. We identified a high frequency of DYSF rare variants/mutations in ovarian endometriosis for the first time. This study suggests a new correlation between DYSF rare variants/mutations and ovarian endometriosis, implicating DYSF rare variants/mutations might be positively involved in the pathogenesis of ovarian endometriosis.

Accumulating evidence has indicated that microRNAs (miRNAs/miRs) regulate the occurrence and development of various diseases, including diabetes, osteoporosis and cardiovascular conditions. However, the role of miRNAs in acute myocardial infarction (AMI) is not completely understood. The present study aimed to evaluate the therapeutic efficacy and mechanisms underlying the effects of miR-126-5p on H9c2 cell proliferation and apoptosis by targeting interleukin (IL)-17A. A total of 40 patients with AMI and 40 healthy volunteers were recruited in the present study and the expression levels of serum miR-126-5p and IL-17A were determined. Following confirmation that IL-17A was a target of miR-126-5p via a dual-luciferase reporter assay, H9c2 cells were exposed to hypoxic conditions. H9c2 cell viability and apoptosis were subsequently assessed. Additionally, the protein expression levels of apoptosis-associated proteins were detected following transfection. Compared with healthy individuals, miR-126-5p expression was significantly decreased in the serum samples of patients with AMI, whereas IL-17A, the target of miR-126-5p, was significantly increased. Following hypoxic treatment, miR-126-5p overexpression enhanced H9c2 cell viability compared with the NC group, which was subsequently reversed following co-transfection with pcDNA3.1-IL-17A. Additionally, the results indicated that hypoxia-induced H9c2 cell apoptosis was significantly reduced following transfection with miR-126-5p mimics via the PI3K/AKT signaling pathway compared with the NC group. The present study indicated that miR-126-5p may serve as a novel miRNA that regulates H9c2 cell viability and apoptosis by targeting IL-17A under hypoxic conditions. Therefore, miR-126-5p may serve as a crucial biomarker for the diagnosis of AMI.

Knowledge modeling, representation, and automatic knowledge inference are fundamental problems for developing automatic situation awareness (ASA) systems in the field of complex power system rescheduling. In this paper, we present a knowledge representation model named dynamic rescheduling graph (DRG), i.e., a new kind of relational knowledge graph, to represent the knowledge of the power dispatchers. DRG has many advantages, such as using different knowledge representation methods like function and logic expression and setting attributes to nodes and edges, which make it easier to develop an ASA system for complex situation diagnose, event solving, and rescheduling. To make inference timely in the DRG, we develop a unique algorithm called hybrid mapping inference (HMI), which supports forward, backward, and mapping inference. We also build an initial ASA system based on the proposed knowledge model and the inference algorithm. We validate the effectiveness of the ASA system in the Guangzhou regional power grid.

Exploring and manipulating domain configurations in ferroelectric thin films are of critical importance for the design and fabrication of ferroelectric heterostructures with a novel functional performance. In this study, BiFeO3 (BFO) ultrathin films with various Bi/Fe ratios from excess Bi to deficient Bi have been grown on (La0.7Sr0.3)MnO3 (LSMO)-covered SrTiO3 substrates by a laser molecular beam epitaxy system. Atomic force microscopy and piezoresponse force microscopy measurements show that both the surface morphology and ferroelectric polarization of the films are relevant to Bi nonstoichiometry. More significantly, a Bi-excess thin film shows an upward (from substrate to film surface) uniform ferroelectric polarization, whereas a Bi-deficient thin film exhibits a downward uniform polarization, which means the as-grown polarization of BFO thin films can be controlled by changing the Bi contents. Atomic-scale structural and chemical characterizations and second-harmonic generation measurements reveal that two different kinds of structural distortions and interface atomic configurations in the BFO/LSMO heterostructures can be induced by the change of Bi nonstoichiometry, leading to the two opposite as-grown ferroelectric polarizations. It has also been revealed that the band gap of BFO thin films can be modulated via Bi nonstoichiometry. These results demonstrate that Bi nonstoichiometry plays a key role on the ferroelectric domain states and physical properties of BFO thin films and also open a new avenue to manipulate the structure and ferroelectric domain states in BFO thin films.

In this letter, we utilize the beam-propagation method to design and simulate a high-birefringence square-lattice polarization microstructure to realize 45-degree rotation when light passes through, and confirm its arrangement and parameters. Optical parameters in allusion to polarization controller of photonic crystal fiber such as birefringence characteristics have been studied, and optical simulation of the polarization microstructure of the depolarized Lyot photonic crystal has been performed.

Rationale: Amniotic fluid embolism (AFE) is a rare obstetrical complication and is a leading cause of maternal death in developed countries. Despite the development of supportive therapeutic measures, the mortality rate remains high. Patient concerns: A 38-year-old nulliparous pregnant woman, who underwent in vitro fertilization-embryo transfer, was admitted for labor at 37 weeks’ gestation. Approximately 30 minutes after delivery of the placenta, the puerpera developed postpartum hemorrhage with uterine atony. Soon after, the patient experienced hypotension, repeated cardiac arrest, refectory hypoxia, and disseminated intravascular coagulopathy. Diagnosis: AFE is diagnosed clinically. The pregnant woman in this case fulfilled the diagnostic criteria for AFE: acute hypotension, cardiac arrest, acute hypoxia, and coagulation disorders within approximately 30 minutes after delivery of the placenta. Interventions: The patient was intubated, connected to a ventilator, and was administered a high dose of vasoactive drugs to maintain blood pressure and underwent an emergency hysterectomy. Considering the risk for recurrent cardiac arrest and severe refractory hypoxia, venoarterial extracorporeal membrane oxygenation was initiated and discontinued as soon as cardiac function was restored based on serial bedside ultrasound assessment. Outcomes: The patient stabilized on day 7 in the intensive care unit and was transferred to the obstetrics ward and, 1 week later, was discharged with no complications. Two months later, follow-up revealed that the patient was in good condition. Lesson: Serial bedside ultrasound was crucial for assessing cardiac function and optimal weaning. Timely application of venoarterial extracorporeal membrane oxygenation and weaning was significant to avoid the occurrence of complications and improve long-term outcomes.

The rapid development of the artificial intelligence field has increased the demand for retina-inspired neuromorphic vision sensors with integrated sensing, memory, and processing functions. Here, we present a neuromorphic vision sensor with an optoelectronic transistor structure consisting of monolayer molybdenum disulfide and barium titanate ferroelectric film. Beyond conventional electrical tuning of ferroelectric polarization, the optoelectronic transistor can exhibit a light-dosage tunable synaptic behavior with a high switching ratio and good non-volatility, enabled by photo-induced ferroelectric polarization reversal. The wavelength-dependent optical sensing and multi-level optical memory properties are utilized to achieve the in-sensor neuromorphic visual pre-processing. A simulated artificial neural network built from the proposed vision sensors with neuromorphic pre-processing function demonstrated that the image recognition rate for the Modified National Institute of Standards and Technology (MNIST) handwritten dataset could be significantly improved by reducing redundant data. The obtained results suggest that 2D semiconductor/ferroelectric optoelectronic transistors can provide a promising hardware implementation towards constructing high-performance neuromorphic visual systems

The defect chemistry of perovskite oxides involves the cause to most of their abundant functional properties, including interface magnetism, charge transport, ionic exchange, and catalytic activity. The possibility to achieve dynamic control over oxygen anion vacancies offers a unique opportunity for the development of appealing switchable devices, which at present are commonly based on ferroelectric materials. Herein, we report the discovery of a switchable photovoltaic effect, that the sign of the open voltage and the short circuit current can be reversed by inverting the polarity of the applied field, upon electrically tailoring the distribution of oxygen vacancies in perovskite oxide films. This phenomenon is demonstrated in lateral photovoltaic devices based on both ferroelectric BiFeO3 and paraelectric SrTiO3 films, under a reversed applied field whose magnitude is much smaller than the coercivity value of BiFeO3. The migration of oxygen vacancies was directly observed by employing an advanced annul...

The development of artificial synapses has enabled the establishment of brain-inspired computing systems, which provides a promising approach for overcoming the inherent limitations of current computer systems. The two-terminal memristors that faithfully mimic the function of biological synapses have intensive prospects in the neural network field. Here, we propose a high-performance artificial synapse based on oxide tunnel junctions with oxygen vacancy migration. Both short-term and long-term plasticities are mimicked in one device. The oxygen vacancy migration through oxide ultrathin films is utilized to manipulate long-term plasticity. Essential synaptic functions, such as paired pulse facilitation, post-tetanic potentiation, as well as spike-timing-dependent plasticity, are successfully implemented in one device by finely modifying the shape of the pre- and postsynaptic spikes. Ultralow femtojoule energy consumption comparable to that of the human brain indicates its potential application in efficient neuromorphic computing. Oxide tunnel junctions proposed in this work provide an alternative approach for realizing energy-efficient brain-like chips.

Nano-electromagnetic communication networks, namely, wireless nano networks (WNNs), are wireless communication networks composed of interacting nanonodes (sizes ranging from a few hundred cubic nanometers to micrometers). The extremely limited capabilities and resources of nanonodes, as well as the severe path loss of terahertz band communication in WNNs, represent a challenge to the communication distance among nanonodes and the overall network performance. Therefore, appropriate routing protocols are necessary for guaranteeing multihop communication in WNNs. In this chapter, the existing routing protocols for WNNs are comprehensively analyzed and classified into three categories: limit-flood-areabased routing protocols, dynamic-infrastructure-based (DIF-based) routing protocols, and single-path-based routing protocols. Based on the peculiarities of WNNs, especially the constrained resources and limited energy supply, the features of each protocol are presented through a detailed comparison. Finally, by integrating the features of WNNs and the problems of existing routing technologies, we present our views on the future research directions of routing techniques in WNNs.

Coronary extraction is a crucial step in the assessment of cardiovascular diseases during clinical diagnosis and surgical planning. Coronary artery structures in CTA (Computed Tomography Angiography) images are affected by other nearby tissues due to scattered distribution. Therefore, in this paper, we present a deep learning method for the Coronary ascending aorta segmentation on CTA images. This core trainable segmentation engine consists of an encoder network, a corresponding decoder network followed by a pixel-wise classification layer. In the process of convolution operation, in order to reduce the computation, a new decomposition convolution method of reducing number of parameters is introduced. The adoption of this approach is not only greatly reduces the compute largely, but also has little effect on the performance loss during convolution calculation. This approach greatly improves the degree of automated segmentation with less manual intervention.

Summary Oxide-based resistive switching devices, including ferroelectric tunnel junctions and resistance random access memory, are promising candidates for the next-generation non-volatile memory technology. In this work, we propose a ferroionic tunnel junction to realize a giant electroresistance. It functions as a ferroelectric tunnel junction at low resistance state and as a Schottky junction at high resistance state, due to interface engineering through the field-induced migration of oxygen vacancies. An extremely large electroresistance with ON/OFF ratios of 5.1×107 at room temperature and 2.1×109 at 10 K is achieved, using an ultrathin BaTiO3-δ layer as the ferroelectric barrier and a semiconducting Nb-doped SrTiO3 substrate as the bottom electrode. The results point toward an appealing way for the design of high-performance resistive switching devices based on ultrathin oxide heterostructures by ionic controlled interface engineering., Graphical Abstract, Highlights • Ferroionic tunnel junctions with ON/OFF ratio of 5.1×107 at 300 K were demonstrated • Both ferroelectric and ionic degrees of freedom were exploited in the device • Field-induced oxygen vacancy migration switches it between FTJ and Schottky junction, Interface Science; Transport Property of Condensed Matter; Devices

SnSe2 field-effect transistor was fabricated based on exfoliated few-layered SnSe2 flake, and its electrical and photoelectric properties have been investigated in detail. With the help of a drop of de-ionized (DI) water, the SnSe2 FET can achieve an on/off ratio as high as ~ 104 within 1 V bias, which is ever extremely difficult for SnSe2 due to its ultrahigh carrier density (1018/cm3). Moreover, the subthreshold swing and mobility are both improved to ∼ 62 mV/decade and ~ 127 cm2 V−1 s−1 at 300 K, which results from the efficient screening by the liquid dielectric gate. Interestingly, the SnSe2 FET exhibits a gate bias-dependent photoconductivity, in which a competition between the carrier concentration and the mobility under illumination plays a key role in determining the polarity of photoconductivity.

Strontium titanate (SrTiO3), which is a crucial perovskite oxide with a direct energy band gap of 3.2 eV, holds great promise for ultraviolet (UV) photodetection. However, the response performance of the conventional SrTiO3-based photodetectors is limited by the large relative dielectric constant of the material, which reduces the internal electric field for electron-hole pair separation to form a current collected by electrodes. Recently, graphene/semiconductor hybrid photodetectors by van-der-Waals heteroepitaxy method demonstrate ultrahigh sensitivity, which is benefit from the interface junction architecture and then prolonged lifetime of photoexcited carriers. Here, a graphene/SrTiO3 interface-based photodetector is demonstrated with an ultrahigh responsivity of 1.2 × 106 A/W at the wavelength of 325 nm and ∼ 2.4 × 104 A/W at 261 nm. The corresponding response time is in the order of ∼ ms. Compared with graphene/GaN interface junction-based hybrid photodetectors, ∼ 2 orders of magnitude improvement of the ultrahigh responsivity originates from a gain mechanism which correlates with the large work function difference induced long photo-carrier lifetime as well as the low background carrier density. The performance of high responsivity and fast response speed facilitates SrTiO3 material for further efforts seeking practical applications.

Polycystic ovary syndrome (PCOS) affects 8-13% of reproductive-age females worldwide and mutations or aberrant expression of androgen receptor (AR) may cause the onset of this disease. In the present study, 258 samples from Han Chinese patients with PCOS were analyzed for the presence of AR mutations via sequencing of all coding exons of the AR gene. A total of five heterozygous missense mutations, namely p.V3M, p.Q72R, p.S158L, p.S176R and p.G396R, were identified in five of the patients. Among these, p.S158L was a novel mutation that, to the best of our knowledge, has not been reported previously. Although the remaining four mutations have been reported previously, they existed at low frequencies or were absent in the control subjects and in the Exome Aggregation Consortium database. The results of evolutionary conservation and in silico analysis revealed that the p.V3M, p.S158L and p.S176R mutations were pathogenic, whereas the p.Q72R and p.G396R mutations were benign. Compared with the patients with PCOS without AR mutations or with benign AR mutations, markedly lower estrogen levels on the day of human chorionic gonadotropin injection were observed in the three patients with PCOS with potentially pathogenic mutations. In addition, patients with PCOS with pathogenic mutations had lower numbers of oocytes; however, the difference was not statistically significant. Of note, these observations should be interpreted with caution due to the relatively small sample size in the present study. Therefore, a larger number of samples should be collected to validate the results of the present study in future studies. In summary, the present study identified three potential pathogenic mutations in 258 Han Chinese patients with PCOS and these mutations may have an implication in the pathogenesis of PCOS.

We have grown VO2 films and combined with terahertz metamaterials to manipulate the memory effect during the insulator-to-metal transition. The temperature-dependent resonant frequency of hybrid structure shows a thermal hysteresis accompanied with frequency shift and bandwidth variation due to the presence of a VO2 dielectric layer. This frequency memory effect significantly depends on the metallic micro-structure. Further theoretical calculation demonstrates this phenomenon mainly originates from the different coupling strength between VO2 and metallic structures. Our findings could facilitate the application of VO2 films in the smart window and dynamical terahertz modulators.

Recently, neuromorphic devices for artificial intelligence applications have attracted much attention. In this work, a three-terminal electrolyte-gated synaptic transistor based on NdNiO3 epitaxial films, a typical correlated electron material, is presented. The voltage-controlled metal–insulator transition was achieved by inserting and extracting H+ ions in the NdNiO3 channel through electrolyte gating. The non-volatile conductance change reached 104 under a 2 V gate voltage. By manipulating the amount of inserted protons, the three-terminal NdNiO3 artificial synapse imitated important synaptic functions, such as synaptic plasticity and spike-timing-dependent plasticity. These results show that the correlated material NdNiO3 has great potential for applications in neuromorphic devices.

We report the synthesis of single-crystal La0.67Sr0.33MnO3 (LSMO) freestanding films with different crystal orientations. By using pulsed laser deposition, water soluble perovskite-like sacrificial layers Sr3Al2O6 (SAO) followed by LSMO films are grown on differently oriented SrTiO3 substrates. Freestanding LSMO films with different orientations are obtained by etching the SAO in pure water. All the freestanding films show room-temperature ferromagnetism and metallicity, independent of the crystal orientation. Intriguingly, the Curie temperature (TC) of the freestanding films is increased due to strain relaxation after releasing from the substrates. Our results provide an additional degree of freedom to tailor the properties of freestanding perovskite oxide heterostructures by crystal orientation and an opportunity to further integrate different oriented films together.

Switchable ferroelectric diode and photovoltaic effects in epitaxial BiFeO3 (BFO) thin films have drawn intense attention for its potential applications in resistive memory and solar cell. However, both of these two effects were observed almost entirely in epitaxial BFO thin films or bulk crystal. In this paper, we demonstrate these effects in a polycrystalline BFO thin film grown on a transparent Indium Tin Oxide (ITO) covered quartz plate by the pulsed laser deposition technique. The BFO thin film shows good ferroelectricity with remanent polarization of around 60 μC/cm2 and has a direct band gap of 2.64 eV. The current-voltage curves measured at an Au/BFO/ITO configuration show diode-like rectifying characteristics, and the diode polarity can be reversed with polarization switching. The polycrystalline BFO thin film also exhibits a switchable photovoltaic effect with an open-circuit voltage of approximately 0.2 V and a short-circuit current of nearly 60 μA/cm2 under illumination. This study demonstrates that the polycrystalline BFO thin film on a transparent substrate also has the ferroelectric switchable diode and photovoltaic effects. Therefore, these results will be useful to expand the application of BFO thin films in optoelectronic devices.

A class of linear polarization conversion coding metasurfaces (MSs) based on a metal cut-wire structure is proposed, which can be applied to the reduction properties of radar cross section (RCS). We firstly present a hypothesis based on the principle of planar array theory, and then verify the RCS reduction characteristics using linear polarization conversion coding MSs by simulations and experiments. The simulated results show that in the frequency range of 6–14 GHz, the linear polarization conversion ratio reaches a maximum value of 90%, which is in good agreement with the theoretical predictions. For normal incident x- and y-polarized waves, RCS reduction of designed coding MSs 01/01 and 01/10 is essentially more than 10 dB in the above-mentioned frequency range. We prepare and measure the 01/10 coding MS sample, and find that the experimental results in terms of reflectance and RCS reduction are in good agreement with the simulated ones under normal incidence. In addition, under oblique incidence, RCS reduction is suppressed as the angle of incidence increases, but still exhibits RCS reduction effects in a certain frequency range. The designed MS is expected to have valuable potential in applications for stealth field technology.

At present, the converter and AOD furnace temperature often use platinum and rhodium thermocouple, the method can only be a single point temperature and high cost. In order to solve this problem, an on-line infrared dual-light colorimetric non-contact temperature measurement system was developed.The temperature measuring system was used to reconstruct the original sub-gun, and the temperature of the nozzle was realized without affecting the original function. According to the theory of tuyere gray body, the function conversion of the body cavity in the nozzle is analyzed, and the mathematical model of temperature compensation is established, which realizes the compensation of the temperature at the nozzle. The temperature measurement system has been applied to the production practice, with online continuous temperature measurement, high precision, long life and other advantages, improve the end hit rate.

Sepsis can cause myocardial injury, which is one of the leading causes of death in critically ill patients. The underlying mechanisms associated with sepsis-induced myocardial injury (SIMI) include impaired cardiac contractility, excessive cardiac inflammation, oxidative stress, cardiomyocyte apoptosis, and so on. SIMI is usually accompanied with dynamic changes of microRNAs (miRNAs) expression. And previous studies have shown that miR-214 plays a vital role in the protection of cardiomyocyte subjected to oxidative stress. In this study, we aimed to test whether miRNA-214 plays any roles in sepsis-induced myocardial injury. We performed quantitative real-time polymerase chain reaction in the septic mouse model induced by cecal ligation and puncture (CLP) and found the expression of miR-214 was upregulated. Then we transfected with the miRNA-214 precursor (pre-miR-214) to upregulate miR-214 expression and with the miR-214 inhibitor (anti-miR-214) to downregulate miR-214 expression respectively. Pre-miR-214 mouse model, anti-miR-214 mouse model, and wild-type mice were subjected to CLP or sham surgery. We observed that compared with control wild types, cardiac function, inflammatory response, the degree of myocardial injury, and myocyte apoptosis were remarkably alleviated in CLP-treated pre-miR-214 mice and aggravated in CLP-treated anti-miR-214 mice. Taken together, our study reveals that miR-214 has a protective effect in SIMI and thereby may provide a potential novel approach to treat SIMI.

Background Breastfeeding confers substantial benefits to child health and has also been associated with lower risk of maternal cardiovascular diseases ( CVDs ) in later life. However, the evidence on the effects of CVD is still inconsistent, especially in East Asians, in whom the frequency and duration of breastfeeding significantly differ from those in the West. Methods and Results In 2004–2008, the nationwide China Kadoorie Biobank recruited 0.5 million individuals aged 30 to 79 years from 10 diverse regions across China. During 8 years of follow‐up, 16 671 incident cases of coronary heart disease and 23 983 cases of stroke were recorded among 289 573 women without prior CVD at baseline. Cox regression yielded adjusted hazard ratios ( HR s) and 95% CIs for incident CVD by breastfeeding. Overall, ≈99% of women had given birth, among whom 97% reported a history of breastfeeding, with a median duration of 12 months per child. Compared with parous women who had never breastfed, ever breastfeeding was associated with a significantly lower risk of CVD , with adjusted HR s of 0.91 (95% CI, 0.84–0.99) for coronary heart disease and 0.92 (95% CI, 0.85–0.99) for stroke. Women who had breastfed for ≥24 months had an 18% ( HR, 0.82; 0.77–0.87) lower risk of coronary heart disease and a 17% ( HR, 0.83; 0.79–0.87) lower risk of stroke compared with women who had never breastfed. Among women who ever breastfed, each additional 6 months of breastfeeding per child was associated with an adjusted HR of 0.96 (95% CI, 0.94–0.98) for coronary heart disease and 0.97 (95% CI, 0.96–0.98) for stroke. Conclusions Among Chinese women, a history of breastfeeding was associated with an ≈10% lower risk of CVD in later life and the magnitude of the inverse association was stronger among those with a longer duration of breastfeeding.

BiFeO 3 (BFO) thin films with BaTiO 3 (BTO) or SrTiO 3 (STO) as buffer layer were epitaxially grown on SrRuO 3 -covered SrTiO 3 substrates. X-ray diffraction measurements show that the BTO buffer causes tensile strain in the BFO films, whereas the STO buffer causes compressive strain. Different ferroelectric domain structures caused by these two strain statuses are revealed by piezoelectric force microscopy. Electrical and magnetical measurements show that the tensile-strained BFO/BTO samples have reduced leakage current and large ferroelectric polarization and magnetization, compared with compressively strained BFO/STO. These results demonstrate that the electrical and magnetical properties of BFO thin films can be artificially modified by using a buffer layer.

As a main way of electric power equipment procurement, scientific and operational comprehensive assessing index system are essential for successful tendering and bidding. The background and significance of tendering procurement for electric power equipment are introduced in this paper. Aiming at the practice of tendering and bidding procurement, the model of selection of bidding scheme is set up based on value engineering. Empirical analysis of tendering procurement for coal mining machine and atomizing pump proved the feasibility of value engineering analysis in tendering and bidding.

Based on the research progress of off-line programming system, propose a virtual manufacturing platform to simulate and monitor industrial robot welding task, by combining motion simulation of three-dimensional models, welding characteristics information-driven and monitoring communications. The platform designed as a three-dimensional solid modeling foreground, with kinematics algorithms and task characteristics as the core, to achieve a common solution that provide jobs simulation ,tatistical information and on-line monitoring. And there is a feasibility analysis of technical means.

Resection of the cavernous sinus (CS) lesions has been a surgical challenge because the anatomy of the CS presents a high grade of complexity. This report describes the feasibility of the purely endoscopic endonasal approach to the CS. Twenty-five patients with intracavernous sinus tumors were treated with a purely endoscopic endonasal approach. The indications, efficacy, surgical techniques, and complications of this approach were discussed. Gross total resection occurred in 19 cases (76%), subtotal resection occurred in 2 cases (8%), and partial resection occurred in 4 cases (16%) including pituitary adenoma in 10 cases (total 70%; subtotal 10%; partial 20%), meningioma in 6 cases (total 66.6%; subtotal 16.7%, partial 16.7%), schwannoma in 5 cases (100%, total 5), malignant tumor in 4 cases (total 75%; subtotal 25%). All patients experienced resolution or improvement of symptoms. No patient experienced intraoperative complication and new neurological deficit. Only 1 case of postoperative cerebrospinal fluid leakage repaired via endoscopic endonasal approach on the 14th day after the surgery. The purely endoscopic endonasal approach to the CS in appropriately evaluated patients can be used to address a wide variety of benign and malignant tumor pathology with favorable outcomes and a low incidence of complications.

Wireless NanoNetworks (WNNs) are wireless communication networks composed of interacting nanonodes. The extremely limited capabilities and resources of nanonodes, as well as the severe path loss of terahertz band communication in WNNs, represent a challenge to the communication distance among nanonodes and the overall network performance. Therefore, appropriate routing protocols are necessary for guaranteeing multihop communication in WNNs. In this survey, the existing routing protocols for WNNs are comprehensively analyzed and classified based on three principles: network architecture, node mobility and routing path. Following that, we will describe each type of routing protocol in detail. On the basis of the peculiarities of WNNs, especially the constrained resources and limited energy supply, the features of each protocol are presented through a detailed comparison. Finally, by integrating the features of WNNs and the problems of existing routing technologies, we present our views on the future research directions of routing techniques in WNNs.

Hardware implementation of artificial synaptic devices that emulate the functions of biological synapses is inspired by the biological neuromorphic system and has drawn considerable interest. Here, a three-terminal ferrite synaptic device based on a topotactic phase transition between crystalline phases is presented. The electrolyte-gating-controlled topotactic phase transformation between brownmillerite SrFeO2.5 and perovskite SrFeO3- δ is confirmed from the examination of the crystal and electronic structure. A synaptic transistor with electrolyte-gated ferrite films by harnessing gate-controllable multilevel conduction states, which originate from many distinct oxygen-deficient perovskite structures of SrFeOx induced by topotactic phase transformation, is successfully constructed. This three-terminal artificial synapse can mimic important synaptic functions, such as synaptic plasticity and spike-timing-dependent plasticity. Simulations of a neural network consisting of ferrite synaptic transistors indicate that the system offers high classification accuracy. These results provide insight into the potential application of advanced topotactic phase transformation materials for designing artificial synapses with high performance.

To avoid broadband noise from a slat cove, the deployed slat contour is usually modified by filling cove, but the design is sensitive to aerodynamic performance. In the paper, a bionic slat without a cove is built on the basis of a bionic airfoil (i.e. stowed bionic multi-element airfoil), which is extracted from a long-eared owl wing. The quasi-two-dimensional models with a deployed bionic slat and a stowed bionic slat are manufactured by rapid manufacturing and prototyping system, respectively, and measured in a low-turbulence wind tunnel. The results are used to characterize high-lift effect: the lift coefficients of the model with a stowed slat are larger at less than 4°angle of attack, but the model with a deployed slat has the larger lift coefficients at greater than 4°angle of attack. Furthermore, the deployed bionic slat can increase stall angle and maximum lift coefficient, but also delay the decline of the lift coefficient curve slope meaning that the leading-edge separation is postponed within a certain range of angle of attack. At the same time, the flow field around the models is visualized by smoke wire method. The leading-edge separation of the model with a stowed slat is shown at low Reynolds number and angle of attack. However, the finding does not occur in the flow field of the model with a deployed slat at the same conditions, probably because the gap between the bionic slat and the main wing results in favorable pressure gradient, the deployed bionic slat decreases the peak of adverse pressure gradient by increasing the chord of the bionic multi-element model, and the bionic slat wake excites transition to the boundary layer on upper surface of the main wing. This superiority may be used as reference in the design of the leading-edge slat without a cove.

A portable mind wave monitor which is a special made headband for intellectual disabled children is proposed. The headband could make the children easier to be understood by the teachers and researchers. The EEG (electroencephalogram-graph) sensor, live camera, microphone and a series of sensors is consisted in the headband. With the Wi-Fi or 3G network, the headband could connect to server though the internet at any time. The teachers and researchers can access on the website or apps on smartphone to manage the children daily testing data. Intellectual disable children always have low self-control ability, limited language ability and self-associated complications, and this system meets the special needs for the teachers and researchers. This headband enable teachers and parents have the same perspective as the intellectual disabled children.

Study design Clinical study. Objective To investigate the feasibility of the transoral endoscopic odontoidectomy without occipitocervical fusion. Summary of background data Endoscopic transnasal resection of the odontoid process is less invasive than the conventional transoral odontoidectomy. However, the endonasal approach has a much longer working distance compared with the transoral approach to the craniovertebral junction and usually the endonasal approach needs a previous occipitocervical posterior fusion. Methods From July 2007 to June 2010, 5 patients (3 males and 2 females, age range, 25-41 yr) with irreducible cervicomedullary junction compression were subjected to endoscopic transoral odontoidectomy without occipitocervical posterior fixation and bone fusion. Results A purely endoscopic transoral odontoidectomy for decompression of the cervicomedullary junction without the occipitocervical fusion was achieved successfully in 5 patients. None of the patients underwent tracheotomy and postoperative gastrostomy tube placement. The patients were started on liquids on the third postoperative day and advanced to a regular diet on the fourth postoperative day. There was no postoperative velopharyngeal insufficiency, cerebrospinal fluid leakage, regional infection, or meningitis. The patients were discharged in 10 to 12 days after the surgery. There were no evidence of instability at the craniovertebral junction at 12 to 47 months of follow-up and remarkable improvement in neurological function was observed in each patient. Conclusion The endoscopic transoral approach may be a more direct route to C1 and the odontoid than the endoscopic endonasal approach. This approach allows complete resection odontoid to decompress the cervicomedullary junction without increasing the risk of complications such as wound infection, meningitis, and velopharyngeal insufficiency. Usually, the occipitocervical posterior fusion and tracheotomy is less necessary in this approach.

A body wave based in-seam seismic technique was developed for measuring the width of barrier pillars in trona mines for the purpose of assessing the dissolution rate of barrier pillars when in contact with water, a critical problem faced by the trona industry. The main difference between this technique and the conventional in-seam seismic technique is that this technique makes use of high frequency P- and S-wave signals. The technique was tested at two trona mines in Wyoming. Three mine sites were utilized for the study, where the pillar widths varied from 82 to 107 m. The velocity survey showed that the trona seam under study was very stable for the wave propagation with a mean standard deviation of only 1.5% for both P- and S-wave velocities. High frequency signals, in the range of 2500–5000 Hz, were utilized for high resolution surveys. Three types of reflected signals were observed, which are P-waves, S-waves and S-waves due to the mode conversion at the seam-void interface. The elliptical mapping method was used to accommodate highly irregular survey lines encountered in underground mines. The method also allowed all reflected signals to be used simultaneously and, as a result, significantly increased the physical data available for the pillar width calculation. The average mapping error was estimated within ±4.6 m, or about 5% of the pillar width. This body wave based in-seam seismic technique may also be utilized for other mines, such as limestone mines, where the seam impedance is similar to or higher than the impedance of surrounding rocks.

Luminous efficiency of high power white light LED (light emitting diode) at different temperature and driver current is measured with the photometric, chromatic and electric characteristics analyzer. It is shown that the luminous efficiency decreases as the temperature and (or) the driver current increases. The highter the driver current is, the more strongly temperature worsens the efficiency. However, the changing rate of efficiency with current is similar at different temperature. At last, a luminous efficiency model with temperature and current is constructed. This research is very important for the design of energy-saving LED lamps.