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Chiral secondary alkyl amines with a vicinal quaternary stereocenter are undoubtedly important and ubiquitous subunits in natural products and pharmaceuticals. However, their asymmetric synthesis remains a formidable challenge. Herein, we merge the ring-opening 1,2-metallate shift with iridium-catalyzed enantioselective C(sp3)–H borylation of aziridines to deliver these frameworks with high enantioselectivities. We also demonstrated the synthetic application by downstream transformations, including the total synthesis of two Amaryllidaceae alkaloids, (−)-crinane and (+)-mesmebrane.

The palladium-catalyzed highly regioselective asymmetric allylic alkylation of 3′-indolyl-3-oxindole derivatives with Morita–Baylis–Hillman (MBH) carbonates was developed to facilely construct chiral 3,3′-bisindole derivatives under mild reaction conditions. The regioselectivity (α/γ) of MBH carbonates was efficiently switched in the presence of chiral oxalamide phosphine or spiroketal-based diphosphine/Pd(0) complexes as a chiral catalyst. A series of multifunctional 3,3′-bisindole derivatives with all-carbon quaternary stereogenic centers were obtained in high yields with good to excellent enantio-, diastereo-, and regioselectivity. The present process is endowed with some salient features such as broad substrate scope, N-protecting group-free, excellent stereoselectivity, as well as adjustable regioselectivity.

Cajaninstilbene acid (CSA), longistylin A (LLA), and longistylin C (LLC) are three characteristic stilbenes isolated from pigeon pea. The objective of this study was to evaluate the antibacterial activity of these stilbenes against Staphylococcus aureusand even methicillin-resistant Staphylococcus aureus(MRSA) and test the possibility of inhibiting biofilm formation. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of these stilbenes were evaluated. And the results showed that LLA was most effective against tested strains with MIC and MBC values of 1.56 μg/mL followed by LLC with MIC and MBC values of 3.12 μg/mL and 6.25 μg/mL as well as CSA with MIC and MBC values of 6.25 μg/mL and 6.25–12.5 μg/mL. Through growth curve and cytotoxicity analysis, the concentrations of these stilbenes were determined to be set at their respective 1/4 MIC in the follow-up research. In an anti-biofilm formation assay, these stilbenes were found to be effectively inhibited bacterial proliferation, biofilm formation, and key gene expressions related to the adhesion and virulence of MRSA. It is the first time that the anti-S. aureusand MRSA activities of the three stilbenes have been systematically reported. Conclusively, these findings provide insight into the anti-MRSA mechanism of stilbenes from pigeon pea, indicating these compounds may be used as antimicrobial agents or additives for food with health functions, and contribute to the development as well as application of pigeon pea in food science.

Unlike center users, edge users are unable to achieve reliable data transmission due to severe path loss, and the resulting frequent retransmissions not only bring additional energy consumption but also lead to unacceptable latency. To achieve the performance requirements of ultra-reliable low latency communication (URLLC), we propose an unmanned aerial vehicle (UAV)-aided URLLC scheme for the edge users, in which the age of information (AoI) is utilized as the indicator of system latency. Inspired by the pylon turn of gunboat aircraft, the same flight pattern is used at the fixed-wing UAV in the proposed scenario. To reduce the AoI of edge users, we optimize the hovering radius of the UAV while considering its aerodynamic model. In addition, to reduce the complexity of solving, we simplify the original AoI minimization problem and derive its closed-form result as a suboptimal solution. Simulation results show that our proposed UAV-aided URLLC scheme is beneficial as its average AoI is lower than those of the fixed radius schemes, and the near-optimal AoI performance is achieved by the proposed low complexity method.

To infer unknown remote sensing scenarios, for remote sensing scene classification (RSSC), most existing deep neural networks (DNNs) are trained on closed datasets. When the acquisition speed and quantity of remote sensing images increase rapidly, these models cannot be used to classify new scenes. Currently, incremental learning as an effective solution for solving the catastrophic forgetting issue, but ignoring the stability-plasticity dilemma. In this article, we propose a new incremental learning network, named efficient channel attention-based multiscale depthwise network (ECA-MSDWNet), in which efficient channel attention (ECA) improves the model’s ability to focus on critical information in complex context, and multiscale depthwise convolution (MSDW Conv) extracts multiscale features in a fine-grained way. In addition, in incremental learning process, we expand new modules based on a dynamic-structure method to fit the residuals between the labels and the outputs of the old model, enhancing the plasticity of the new model for new tasks while maintaining the performance of the old tasks. Finally, we compress the model to reduce redundant parameters and feature dimensions through an effective knowledge distillation strategy. Experiments on four open datasets demonstrate the effectiveness of our method. Our code is available at https://github.com/zhangyu-chd/ECA-MSDWNet.

The human pulmonary valve, a crucial part of the human heart, is located between the right ventricle and the pulmonary artery. Owing to its complex construction, accurate simulations of this valve with a mathematical model are rare. In this paper, according to the structural and physiological characteristics of the pulmonary valve, we use Koiter’s linear shell model to simulate the pulmonary valve under static conditions. Concretely, for discrete space variables, we use the conforming finite element method; that is, we use a linear element to discretize the two tangent components of the displacement, but the normal component of the displacement is discretized by using the Hsieh–Clough–Tocher triangle element. Finally, we conduct numerical experiments for the human pulmonary valve and analyzed the results. The numerical experimental results show that the proposed mathematical model is capable of describing the human pulmonary valve subjected to applied force well.

Social hierarchy greatly influences behavior and health. Both human and animal studies have signaled the medial prefrontal cortex (mPFC) as specifically related to social hierarchy. Dopamine D1 receptors (D1Rs) and D2 receptors (D2Rs) are abundantly expressed in the mPFC, modulating its functions. However, it is unclear how DR-expressing neurons in the mPFC regulate social hierarchy. Here, using a confrontation tube test, we found that most adult C57BL/6J male mice could establish a linear social rank after 1 week of cohabitation. Lower rank individuals showed social anxiety together with decreased serum testosterone levels. D2R expression was significantly downregulated in the dorsal part of mPFC (dmPFC) in lower rank individuals, whereas D1R expression showed no significant difference among the rank groups in the whole mPFC. Virus knockdown of D2Rs in the dmPFC led to mice being particularly prone to lose the contests in the confrontation tube test. Finally, simultaneous D2R activation in the subordinates and D2R inhibition in the dominants in a pair switched their dominant–subordinate relationship. The above results indicate that D2Rs in the dmPFC play an important role in social dominance. Our findings provide novel insights into the divergent functions of prefrontal D1Rs and D2Rs in social dominance, which may contribute to ameliorating social dysfunctions along with abnormal social hierarchy.

Machine learning (ML) models were developed for understanding the root uptake of per- and polyfluoroalkyl substances (PFASs) under complex PFAS-crop-soil interactions. Three hundred root concentration factor (RCF) data points and 26 features associated with PFAS structures, crop properties, soil properties, and cultivation conditions were used for the model development. The optimal ML model, obtained by stratified sampling, Bayesian optimization, and 5-fold cross-validation, was explained by permutation feature importance, individual conditional expectation plot, and 3D interaction plot. The results showed that soil organic carbon contents, pH, chemical logP, soil PFAS concentration, root protein contents, and exposure time greatly affected the root uptake of PFASs with 0.43, 0.25, 0.10, 0.05, 0.05, and 0.05 of relative importance, respectively. Furthermore, these factors presented the key threshold ranges in favor of the PFAS uptake. Carbon-chain length was identified as the critical molecular structure affecting root uptake of PFASs with 0.12 of relative importance, based on the extended connectivity fingerprints. A user-friendly model was established with symbolic regression for accurately predicting RCF values of the PFASs (including branched PFAS isomerides). The present study provides a novel approach for profound insight into the uptake of PFASs by crops under complex PFAS-crop-soil interactions, aiming to ensure food safety and human health.

Rhizosphere microbiota are an important factor impacting plant uptake of pollutants. However, little is known about how microbial nitrogen (N) transformation in the rhizosphere affects the uptake and accumulation of antibiotics in plants. Here, we determined recruitment of N transformation functional bacteria upon ciprofloxacin (CIP) exposure, by comparing differences in assembly processes of both rhizospheric bacterial communities and N transformation between two choysum (Brassica parachinensis) varieties differing in CIP accumulation. The low accumulation variety (LAV) of CIP recruited more host bacteria (e.g., Nitrospiria and Nitrolancea) carrying nitrification genes (mainly nxrA) but fewer host bacteria carrying denitrification genes, especially narG, relative to the high accumulation variety (HAV) of CIP. The nxrAand narGabundance in the LAV rhizosphere were, respectively, 1.6–7.8 fold higher and 1.4–3.4 fold lower than those in the HAV rhizosphere. Considering that nitrate can decrease CIP uptake into choysum through competing for the proton motive force and energy, such specific bacteria recruitment in LAV favored the production and utilization of nitrate in its rhizosphere, thus limiting its CIP accumulation with 1.6–2.4 fold lower than the HAV. The findings give insight into the mechanism underlying low pollutant accumulation, filling the knowledge gap regarding the profound effects of rhizosphere microflora and N transformation processes on antibiotic accumulation in crops.

A novel 2-D direction finding method is proposed, relying on a 1-bit programmable metasurface and the time modulation method. Both the azimuth and elevation angles of far-field signals are estimated simultaneously by analyzing the harmonic characteristic of received signals in the frequency domain. Low hardware cost and computational complexity can be achieved owing to the intrinsic nature of the single radio frequency (RF) chain in the proposed method. Extensive numerical results confirm that the direction finding attains a near-zero mean square error (MSE), when the signal-to-noise ratio (SNR) attains 10 dB. A Ka-band reflective programmable metasurface with 400 elements is fabricated and tested to verify its effectiveness partly.

Fluorotelomer alcohols (FTOHs), as precursors of perfluoroalkyl carboxylic acids, are difficult to analyze due to their high volatility and matrix interference. A method based on single-factor experiments and response surface methodology design was developed for simultaneous analysis of three common FTOHs in vegetables and soils, using single extraction, dispersive solid phase extraction cleanup, and gas chromatography–mass spectrometry in negative chemical ionization. The method improved the extraction efficiency up to ∼40 folds and showed a commendable linearity range (1–100 ng/mL, R2> 0.991), low limit of detection (0.025−0.897 ng/g, dry weight (dw)), and high accuracy and precision (83 ± 7.2–117 ± 6.0% recoveries at 2–20 ng/g fortification levels). It was successfully applied to determine the FTOHs in real vegetables and soils, demonstrating its feasibility for routine analysis. Concentrations of the FTOHs ranged from 3.5 to 37.9 ng/g (dw) and from 6.5 to 141.0 ng/g (dw), respectively, in the vegetables and soils collected nearby fluorochemical factories, which warrants further investigations on FTOH pollution and food safety concerns for which the developed method will be useful.

A 61-year-old right-handed man presented with decreased cognitive function, short-term memory, fluent speech disorders, and grammatical errors for 1 year. The patient underwent PET imaging with 11C-PIB, 18F-FDG, and 18F-APN-1607. The 11C-PIB PET showed no amyloid accumulation; the 18F-FDG PET showed hypometabolism in the bilateral frontal lobe, temporal lobe, and midbrain; and the 18F-APN-1607 PET showed tau accumulation in the brainstem, basal ganglia, and left inferior frontal gyrus. These findings suggested a diagnosis of nonfluent variant primary progressive aphasia. This case emphasizes the value of combined imaging of glucose metabolism, Aβ, and tau PET in the diagnosis of nonfluent variant primary progressive aphasia.

Eurya chinensis has been recorded as a folk medicine traditionally used for treatment of a variety of symptoms. However, the phytochemical and pharmacological investigations of this plant are still scarce. A novel phenolic glycoside named Euryachincoside (ECS) was isolated by chromatographic separation from E. chinensis, and its chemical structure was identified by analysis of HRMS and NMR data. Its anti-hepatic fibrosis effects were evaluated in both HSC-T6 (rat hepatic stellate cells) and carbon tetrachloride (CCl4)-induced mice with Silybin (SLB) as the positive control. In an in vitro study, ECS showed little cytotoxicity and inhibited transforming growth factor-beta (TGF- β)-induced Collagen I (Col1) along with alpha-smooth muscle actin (α -SMA) expressions in HSC-T6. An in vivo study suggested ECS significantly ameliorated hepatic injury, secretions of inflammatory cytokines, and collagen depositions. Moreover, ECS markedly mediated Smad2/3, nuclear factor kappa B (NF- κ B) and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathways both in vitro and vivo. These present findings confirmed that ECS is a novel phenolic glycoside from E. chinensis with promising curative effects on hepatic fibrosis, and its mechanisms may include decreasing extracellular matrix accumulation, reducing inflammation and attenuating free radicals via Smad2/3, NF- κ B and Nrf2 signaling pathways, which may shed light on the exploration of more effective phenolic glycoside-based anti-fibrotic agents. [ABSTRACT FROM AUTHOR]

Surface modification is a fascinating way to improve the compounding effect between inorganic fillers and polymers. In this study, zirconium tungsten phosphate (ZWP) with negative thermal expansion was surface modified by silane coupling agent 3-(Trimethoxysilyl)propyl methacrylate. The effects of surface modification and the modification mechanism were analyzed in detail by X-ray diffractometer, scanning electron microscopy, Fourier transform infrared spectroscopy and thermal mechanical analysis. The surface modification could effectively reduce the thermal expansion properties of the composite. When the added amount of 3-methacryloxypropyl trimethoxysilaneSilane (trade name: KH570) is 0.50 wt%, the thermal expansion coefficient of ZWP/Aromatic polyimide composite decreased by 9.76%. The surface modification also can effectively improve the dielectric performance of aromatic polyimides. The present work provides one new way to improve the thermal expansion behavior of composites.

Hepatic ischemia-reperfusion injury (HIRI) is a common complication of liver surgeries, such as hepatectomy and liver transplantation. In recent years, several non-coding RNAs (ncRNAs) including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been identified as factors involved in the pathological progression of HIRI. In this review, we summarized the latest research on lncRNAs, miRNAs and the lncRNA-miRNA regulatory networks in HIRI.

Since its publication by Adanson in 1763, the name Pacoserocahas been treated as a synonym of several genera of Zingiberaceae by different authors. It is currently treated as a homotypic synonym of ZingiberMill. (≡ AmomumL., nom. rej.) in Index Nominum Genericorum. No binomial combination has ever been proposed in Pacoseroca, and the typification of this long‐forgotten generic name has never been undertaken. We show here that Pacoserocais not homotypic with AmomumL.Instead, its protologue included elements that belong to at least three rather distantly related genera of Zingiberaceae (Aframomum, Elettaria, Renealmia), over all of which Pacoserocahas priority. Based on a study of the protologue and of Adanson's working methods, we typify Pacoserocawith Renealmia alpinia(Rottb.) Maas (≡ Amomum alpiniaRottb.), a species which is the best fit to a plant recorded by Marcgrave under the vernacular name “Paco seroca” and upon which Adanson based his generic name. A formal proposal to reject Pacoserocawill be submitted to uphold the well‐known Renealmiaand to prevent new combinations for 82 species names currently accepted in this genus, which is widespread in Africa and South America.

The integrated sensing and communication (ISAC) has been proposed as an enabling technology for improving the network efficiency, where the wireless infrastructures and spectrum resources can be reused by co-designing the sensing and communication (S&C) functionalities. Different networks adopt the technique of ISAC to achieve the enhanced capabilities in precise localization, tracking, and imaging. To further improve the performance of cooperative detection, data dissemination can be carried out for ISAC-enabled networks. However, as sensing information sharing among S&C devices generally proceeds in a multi-hop manner, there exist various design challenges in ISAC-enabled networks, e.g., data dissemination modeling and deployment of S&C devices. Since epidemic theory has been developed as an innovative tool for modeling data dissemination, it can also be applied to design and analyze the ISAC-enabled network. In this article, we first introduce the ISAC-enabled network as well as several design challenges. Then, we present some key design issues of the ISAC-enabled network, including the sensing information dissemination, where some scenarios or use cases for practical applications of the ISAC-enabled network are given to validate the effectiveness of the epidemic theory-based modeling. Finally, the potential directions of epidemic theory on ISAC-enabled networks are discussed to motivate future works.

Covert communication, also known as communication with low probability of detection, aims to provide reliable communication for legal users and prevent any other user from detecting the occurrence of legal communication. Motivated by the strong need of security links of the next generation communication systems, we study covert communication with millimeter-wave (mmWave) massive multiple-input multiple-output (MIMO) hybrid beamforming. Consistent with existing studies on covert communication, we use the Kullback-Leibler (KL) divergence and the total variation (TV) distance as the covertness measure. Under both covertness measures, for block fading channels, we derive the covert transmission rate with and without artificial noise. These results are obtained by optimizing the transmit power and the jamming power to satisfy the covertness constraints and to maximize the transmission rate. Specifically, when artificial noise is allowed, we show that there exists an optimal jamming power to achieve the covert transmission rate given the transmit signal power. Furthermore, we propose a metric to measure the inherent sparsity of the mmWave massive MIMO channel in the spatial domain, and study its effect on the covertness measures and the corresponding covert transmission rates. Our results provide insights and benchmarks for the design of practical covert communication systems with mmWave massive MIMO.

The amalgamation of sparse code multiple access (SCMA) and simultaneous wireless information and power transfer (SWIPT) is envisioned to be a promising solution to massive connectivity while providing both information and power to myriads of wireless machines and sensors in Internet-of-Things (IoT) application. However, the benefit of the SCMA-based SWIPT system has not been fully exploited yet, especially when the communications link is hostile. Fortunately, the propagation-induced impairment can be mitigated by the emerging technique of reconfigurable intelligent surface (RIS). In this paper, we investigate the beneficial role of RIS in SCMA-based SWIPT systems, where $K$ single-antenna information receivers and one signal-antenna energy receiver are served by a multiple-antenna base station over $J$ orthogonal subcarriers with the aid of RIS. We propose transmit power minimization algorithms for both i) the perfect and ii) the imperfect channel state information (CSI) scenarios, by jointly optimizing the codebook assignment, the BS active beamforming, as well as RIS reflection coefficients, relying on advanced techniques both of alternating optimization and of successive convex approximations, and on the robust design framework. Furthermore, we compare and evaluate the detection performance of the system considered. The numerical results demonstrate that our proposed RIS-aided SCMA-based SWIPT system significantly outperforms the conventional SCMA-based SWIPT system without RIS and is capable of adapting to the imperfect full channel estimation results.

Unmanned aerial vehicles (UAVs) have attracted growing research interests in recent years, which can be used as cost-effective aerial platforms to transmit collected data packets to ground access points (APs). Thus, it is crucial to investigate robust air-tos-ground (A2G) wireless links for high-speed UAVs. However, the A2G wireless link is unstable as it suffers from large path-loss and severe Doppler effect due to the high mobility of UAVs. In order to meet these challenges, we propose an orthogonal time frequency space (OTFS)-based UAV communication system to relief the Doppler effect. Besides, considering that the energy of UAV is limited, we optimize the trajectory planning of UAV to minimize the energy consumption under the constraints of bit error rate (BER) and transmission rate, where the Doppler compensation is taken into account. Simulation results show that the performance of OTFS-based UAV system is superior to orthogonal frequency division multiplexing (OFDM)-based UAV systems, which can accomplish transmission tasks over shorter distances with lower energy consumption.

Due to increasing demands of seamless connection and massive information exchange across the world, the integrated satellite-terrestrial communication systems develop rapidly. To shed lights on the design of this system, we consider an uplink communication model consisting of a single satellite, a single terrestrial station and multiple ground users. The terrestrial station uses decode-and-forward (DF) to facilitate the communication between ground users and the satellite. The channel between the satellite and the terrestrial station is assumed to be a quasi-static shadowed Rician fading channel, while the channels between the terrestrial station and ground users are assumed to experience independent quasi-static Rayleigh fading. We consider two cases of channel state information (CSI) availability. When perfect CSI is available, we derive the instantaneous achievable sum rate of all ground users and formulate an optimization problem to maximize the sum rate. When only channel distribution information (CDI) is available, we derive a closed-form expression for the outage probability and formulate another optimization problem to minimize the outage probability. Both optimization problems correspond to scheduling algorithms for ground users. For both cases, we propose low-complexity user scheduling algorithms and demonstrate the efficiency of our scheduling algorithms via numerical simulations.

The inability of semantic segmentation methods to detect anomaly road obstacles not pre-defined in the datasets significantly hinders the safety-critical application in autonomous driving. The excessively complex anomaly detection approaches cannot accommodate the constraints on the inference time of intelligent vehicles. Inspired by the fact that humans have a natural instinct to be curious about unknown objects in a new environment, we propose a novel curiosity-driven attention mechanism (CuDAM) for anomaly road obstacles segmentation. CuDAM adopts the attention map as a new uncertainty judging criterion and utilizes it to improve the efficiency of the model. Specifically, CuDAM is composed of three parts: 1) an attention module for generating an attention map; 2) a reward mechanism for encouraging the network to focus its attention on uncertain regions; 3) an attention loss function for widening the distance between the attention values of deterministic and uncertain pixels. Different from previous approaches, CuDAM can improve both anomaly detection and semantic segmentation performance without complex operations and training, which makes it widely applicable to existing semantic segmentation models. The result of qualitative and quantitative experiments shows that such a straightforward approach achieves consistent significant improvements in anomaly detection performances with the various uncertainty estimation methods, demonstrating the broad applicability of CuDAM.

We study the mismatched successive refinement problem where one uses Gaussian codebooks to compress an arbitrary memoryless source with successive minimum Euclidean distance encoding under the quadratic distortion measure. Specifically, we derive achievable refined asymptotics under both the joint excess-distortion probability (JEP) and the separate excess-distortion probabilities (SEP) criteria. For both second-order and moderate deviations asymptotics, we consider two types of codebooks: the spherical codebook where each codeword is drawn independently and uniformly from the surface of a sphere and the i.i.d. Gaussian codebook where each component of each codeword is drawn independently from a Gaussian distribution. We establish the achievable second-order rate-region under JEP and we show that under SEP any memoryless source satisfying mild moment conditions is strongly successively refinable. When specialized to a Gaussian memoryless source (GMS), our results provide an alternative achievability proof with specific code design. We show that under JEP and SEP, the same moderate deviations constant is achievable. For large deviations asymptotics, we only consider the i.i.d. Gaussian codebook since the i.i.d. Gaussian codebook has better performance than the spherical codebook in this regime for the one layer mismatched rate-distortion problem (Zhou et al., 2019). We derive achievable exponents of both JEP and SEP and specialize our results to a GMS, which appears to be a novel result of independent interest.

Objective: To obtain the cortex and cancellous parameter of the vertebral bone of healthy subjects using QCT. To explore which is earlier or faster for bone loss with age. Materials and methods: 733 physical examiners underwent chest low-dose CT examination were recruited, from April 1, 2021 to October 1, 2021. QCT sequence was used to obtain the bone mineral density of T12-L2 vertebral body without additional radiation. The mass and area of vertebral cortex and cancellous at the central level of L2 vertebral body were measured. The age -related characteristics of vertebral cortex and cancellous between male and female was analyzed and compared. Results: The vBMD of T12-L2 vertebral body decreased with age. Significant differences were found in volumetric bone mineral density (vBMD) of T12-L2 vertebral body. For female, significant differences were found in bone content involving cortical mass, cancellous mass, cortical area, cancellous area, cortical mass/cancellous mass and cortical area/cancellous area in different age groups, respectively. The cortical mass decreased with age in female. The cancellous mass of female increased and then decreased with peak at 31–40 y. The cortical area of female decreased gradually before 71 y. The cancellous area of female increased and then decreased with peak at 51–60 y. The values of mass ratio and area ratio in female showed a slowly downward trend with age. Significant differences of bone content between non-menopausal and menopausal women were found except the cancellous mass. For male, no significant differences were found in all parameters of bone content. Conclusion: The changes of vertebral BMD, bone content of cortex and cancellous have different characteristics in different age. The change of cortex in female maybe earlier and faster than that of cancellous, especially in menopausal women.

Background: Ultrasound-guided central venous catheter placement has significantly improved the success rate of punctures and reduced the risk of complications. However, catheterizing the internal jugular vein under ultrasound guidance in neonates remains challenging.Methods: Ninety-six patients were screened for eligibility in this randomized controlled trial between November 2018 and October 2019. After meeting the inclusion criteria, 90 term neonates undergoing cardiothoracic, general, or neurosurgery procedures were randomly assigned to the modified dynamic needle tip positioning short-axis (n= 45) or long-axis groups (n= 45) using a computer-generated random numbers table. The primary outcome was the first-attempt success rate. The secondary outcomes included the total success rate, cannulation time, and incidence of cannulation-related complications, including hematoma, accidental arterial puncture, or pneumothorax. Data were compared between the two groups.Results: The success rate for the first attempt was higher (88.9% vs 64.4%; p= 0.001; relative risk, 1.4; 95% confidence interval, 1.1–1.8), while the cannulation time was shorter (171.0 ± 47.8 s vs 304.4 ± 113.5 s; p= 0.001; estimated difference, −133.4; 95% confidence interval, −170.1 to −96.7), in the modified dynamic needle tip positioning short-axis group compared with the long-axis group. Six hematomas and two common carotid artery punctures were identified in the long-axis group, while none were identified in the modified dynamic needle tip positioning short-axis group.Conclusions: The modified dynamic needle tip positioning short-axis out-of-plane technique enhanced the procedural efficacy and safety of internal jugular vein catheterization in neonates.

Imbalanced data classification is a challenging problem in the field of machine learning. Class imbalance, class overlap, and large data volume significantly affect classification performance. Focusing on the impact of class overlap on classification effectiveness, we propose a two-step ensemble under-sampling algorithm based on boundary information mining (TSSE-BIM) with the goal of reducing the information loss from under-sampling methods on large-scale imbalanced data. In the first stage, the proposed method applies an improved equalization under-sampling strategy to mine sample contribution information and quickly obtains the distribution information of data relative to the decision boundary. In the second stage, based on the boundary information, a weighted boundary sampling is performed to remove noisy and highly overlapping samples. It is easy to retain samples with high contribution and effectively suppress the information loss caused by under-sampling. Then, the overall framework is designed based on a serial ensemble similar to boosting, where the weights of each base classifier are assigned to achieve a more powerful performance based on the false positive rate and false negative rate on the original data. Finally, extensive experiments indicate that TSSE-BIM outperforms state-of-the-art methods and ranks first on average under four metrics, especially F1 and MCC. [ABSTRACT FROM AUTHOR]

Sparse code multiple access (SCMA) is an emerging paradigm for efficient enabling of massive connectivity in future machine-type communications (MTC). In this letter, we conceive the uplink transmissions of the low-density parity check (LDPC) coded SCMA system. Traditional receiver design of LDPC-SCMA system, which is based on message passing algorithm (MPA) for multiuser detection followed by individual LDPC decoding, may suffer from the drawback of the high complexity and large decoding latency, especially when the system has large codebook size and/or high overloading factor. To address this problem, we introduce a novel receiver design by applying the expectation propagation algorithm (EPA) to the joint detection and decoding (JDD) involving an aggregated factor graph of LDPC code and sparse codebooks. Our numerical results demonstrate the superiority of the proposed EPA based JDD receiver over the conventional Turbo receiver in terms of both significantly lower complexity and faster convergence rate without noticeable error rate performance degradation.

Vertebrates use the mannose 6-phosphate (M6P)-recognition system to deliver lysosomal hydrolases to lysosomes. Key to this pathway is N-acetylglucosamine (GlcNAc)-1-phosphotransferase (PTase) that selectively adds GlcNAc-phosphate (P) to mannose residues of hydrolases. Human PTase is an α2β2γ2heterohexamer with a catalytic core and several peripheral domains that recognize and bind substrates. Here we report a cryo-EM structure of the catalytic core of human PTase and the identification of a hockey stick-like motif that controls activation of the enzyme. Movement of this motif out of the catalytic pocket is associated with a rearrangement of part of the peripheral domains that unblocks hydrolase glycan access to the catalytic site, thereby activating PTase. We propose that PTase fluctuates between inactive and active states in solution, and selective substrate binding of a lysosomal hydrolase through its protein-binding determinant to PTase locks the enzyme in the active state to permit glycan phosphorylation. This mechanism would help ensure that only N-linked glycans of lysosomal enzymes are phosphorylated.

Sirtuin 1 (SIRT1), the NAD-dependent histone deacetylase, has been extensively investigated due to its cognitive protective effect. Studies suggest microRNAs (miRNAs) and histone modifications are key epigenetic regulators of gene expression and play important role in brain development. We previously showed that cognitive impairment by lead (Pb) was associated with downregulation of SIRT1, but the epigenetic role of this is unclear. Thus, we exposed 4-week-old male mice to 0.2% lead acetate solution for three months, and subsequently extracted brain homogenate from mice cortex and hippocampus at the age of 1, 4, and 16 months, respectively. In this study, we found that the protein level of SIRT1 was inhibited in the hippocampus and cortex of 16-month-old aged mice exposed to Pb. Moreover, changes in the levels of miR-138-5p and miR-141-3p, which were considered to the mechanistic target of SIRT1 by bioinformatic analysis, were negative correlations SIRT1 protein expression. We also found miR-34c-3p expression was increased in the cortex of mice at the age of 16 months. Collectively, our results showed the expression of neural SIRT1 and three selected microRNAs at different age nodes of mice for the first time of following Pb exposure. Our results suggest that additional efforts should focus on the consequences of early Pb exposure from an epigenetic perspective.

Neuronal activation is required for the formation of drug-associated memory, which is critical for the development, persistence, and relapse of drug addiction. Nevertheless, the metabolic mechanisms underlying energy production for neuronal activation remain poorly understood. In the study, a large-scale proteomics analysis of lysine crotonylation (Kcr), a type of protein posttranslational modification (PTM), reveals that cocaine promoted protein Kcr in the hippocampal dorsal dentate gyrus (dDG). We find that Kcr is predominantly discovered in a few enzymes critical for mitochondrial energy metabolism; in particular, pyruvate dehydrogenase (PDH) complex E1 subunit α (PDHA1) is crotonylated at the lysine 39 (K39) residue through P300 catalysis. Crotonylated PDHA1 promotes pyruvate metabolism by activating PDH to increase ATP production, thus providing energy for hippocampal neuronal activation and promoting cocaine-associated memory recall. Our findings identify Kcr of PDHA1 as a PTM that promotes pyruvate metabolism to enhance neuronal activity for cocaine-associated memory.

The rapid development of additive manufacturing technology has offered a new avenue for designing and fabricating high wave-absorbing meta structures. In this study, the mechanical properties and broadband absorption performance of Poly-Ether-Ether-Ketone (PEEK)–based electromagnetic wave–absorbing composite materials was investigated. The high-performance polymer PEEK was used as the matrix, and the materials with electromagnetic wave loss, such as reduced graphene oxide, Carbonyl Iron (CI), and Flake CI (FCI), were used as absorbers. Based on the theory of impedance matching, a wave-absorbing structure with a gradual impedance gradient was designed and printed. The test results showed that at the 2.0–18.0 GHz frequency band, the coverage rate of the effective absorption bandwidth was up to 72.0%, the average optimal reflectivity was –18.09 dB, and the wide-angle absorption range was 0°–30°. The advantages of additive manufacturing technology in designing and fabricating wave-absorbing structures are presented, demonstrating that the technology is an effective method for creating broadband absorbing structures.

Dynamic characteristics of UV enhanced gas–solid PVC chlorination process were revealed by a UV–Vis spectral online analysis method. Experimental results showed an instantaneous increase of the chlorination rate as soon as UV light was affiliated, which demonstrated the intensified effect of UV radiation on PVC chlorination directly. Different affiliation methods of UV light were then studied, proving that continuous UV radiation could enhance the chlorination process significantly while intermittent UV radiation was able to initiate the chlorination reaction once it was conducted. Besides, experiments were carried out to study the influences of parameters on the chlorination process such as UV wavelength, chlorination temperature, partial pressure of chlorine gas and PVC raw materials. Among all the parameters, chlorination temperature and partial pressure of chlorine gas were testified as two key factors to determine the chlorination performance. Thermal analysis of CPVC products showed that their corresponding properties such as the glass transition temperature (Tg) and the homogeneity of chlorine distribution in polymer phase were improved with the increase of chlorine content.

Actinidia arguta, the most widely distributed Actinidia speciesand the second cultivated species in the genus, can be distinguished from the currently cultivated Actinidia chinensison the basis of its small and smooth fruit, rapid softening, and excellent cold tolerance. Adaptive evolution of tetraploid Actinidiaspecies and the genetic basis of their important agronomic traits are still unclear. Here, we generated a chromosome-scale genome assembly of an autotetraploid male A. argutaaccession. The genome assembly was 2.77 Gb in length with a contig N50 of 9.97 Mb and was anchored onto 116 pseudo-chromosomes. Resequencing and clustering of 101 geographically representative accessions showed that they could be divided into two geographic groups, Southern and Northern, which first diverged 12.9 million years ago. A. argutaunderwent two prominent expansions and one demographic bottleneck from the mid-Pleistocene climate transition to the late Pleistocene. Population genomics studies using paleoclimate data enabled us to discern the evolution of the species’ adaptation to different historical environments. Three genes (AaCEL1, AaPME1, and AaDOF1) related to flesh softening were identified by multi-omics analysis, and their ability to accelerate flesh softening was verified through transient expression assays. A set of genes that characteristically regulate sexual dimorphism located on the sex chromosome (Chr3) or autosomal chromosomes showed biased expression during stamen or carpel development. This chromosome-level assembly of the autotetraploid A. argutagenome and the genes related to important agronomic traits will facilitate future functional genomics research and improvement of A. arguta.

Glucocorticoids induce cellular senescence, including of stem/progenitor cells in the bone marrow of growing long bone, which leads to bone loss in glucocorticoid–induced osteoporosis. There is no specific drug available to treat this disease. Clearance of senescent cells has been reported to be an effective therapy for osteoporosis. LepR+cells in the bone marrow are the key kind of stem/progenitor cells conducive to bone remodeling in adulthood. Here, we show that glucocorticoids induce cellular senescence, demonstrated by increased activity of senescence-associated β-galactosidase (SA-βGal+) cells and simultaneous upregulation of coimmunofluorescence staining of p16INK4awith LepR in longitudinal femoral sections. We applied pulsed electromagnetic fields (PEMFs), which alleviated bone loss in glucocorticoid-induced osteoporosis mice. We found the increased accumulation of senescent LepR+cells in the bone marrow of adult mice after glucocorticoid treatment, and this could be counteracted by PEMFs. Moreover, PEMFs maintained type H vessel formation and osteogenesis. This process was modulated by the polycomb histone methyltransferase enhancer of zeste homolog 2 (EZH2) and its trimethylation of histone H3 on lysine 27 (H3K27me3). These results provide evidence that PEMFs alleviate bone loss induced by glucocorticoids by eliminating senescent cells, maintaining angiogenesis-osteogenesis coupling, and shedding light on the mechanisms, providing a potential method to treat glucocorticoid-induced osteoporosis.

Much palaeontology research on biomineralization has been directed to studying the Cambrian radiation of biomineralizing animals. The evolutionary radiation of biomineralization in the Cambrian Period was preceded by weakly biomineralized animals in the late Ediacaran period around 550–539 Ma. Here we report many new tubular fossils from the upper part of the Ediacaran Dengying Formation in the Lijiagou section, Ningqiang area, southern Shaanxi Province, China, consisting of two new genera and species, namely Shufangtubulus inornatusn. gen. n. sp., and Palaeorhopalon spiniferumn. gen. n. sp. The newly discovered materials expand the list of the Ediacaran tubular fossils. The borings first found on the outer surface of Sinotubulites baimatuoensisare similar to those of Cloudina, which may reveal the earliest predator-prey dynamics. The small and delicate drill holes detected on the inner walls of Sinotubulites baimatuoensisare inferred to be infested traces by parasitism.

In recent years, convolutional neural network (CNN) has gained popularity in many engineering applications especially for computer vision. In order to achieve better performance, more complex structures and advanced operations are incorporated into neural networks, which results in very long inference time. For time-critical tasks such as autonomous driving and virtual reality, real-time processing is fundamental. In order to reach real-time processing speed, a lightweight, high-throughput CNN architecture namely RoadNet-RT is proposed for road segmentation in this article. It achieves 92.55% MaxF score on KITTI road segmentation dataset. The inference time is about 9 ms per frame when running on GTX 1080 GPU. Comparing to the state-of-the-art network, RoadNet-RT speeds up the inference time by a factor of 17.8 at the cost of only 3.75% loss in accuracy. What is more, on CamVid dataset its accuracy is 92.98%. Several techniques such as depthwise separable convolution and non-uniformed kernel size convolution are optimized in the hardware accelerator design. The proposed CNN architecture has been successfully implemented on a ZCU102 MPSoC FPGA that achieves the computation capability of 331 GOPS using INT8 quantization. The system throughput reaches 196.7 frames per second with input image size of $280\times 960$. The source code is published at https://github.com/linbaiwpi/RoadNet-RT. [ABSTRACT FROM AUTHOR]

Accurate rice area extraction and yield simulations are important for understanding how national agricultural policies and environmental issues affect regional spatial changes in rice farming. In this study, an improved regional parametric syntheses approach, that is, the rice zoning adaptability criteria and dynamic harvest index (RZAC-DHI), was established, which can effectively simulate the rice cultivation area and yield at the municipal level. The RZAC was used to extract the rice area using Moderate Resolution Imaging Spectroradiometer time-series data and phenological information. The DHI was calculated independently, and then yield was obtained based on the DHI and net primary productivity (NPP). Based on the above results, we analyzed the spatial–temporal patterns of the rice cultivation area and yield in Northeast China (NEC) during 2000–2015. The results revealed that the methods established in this study can effectively support the yearly mapping of the rice area and yield in NEC, the average precisions of which exceed 90 and 80%, respectively. The rice planting areas are mainly located on the Sanjiang, Songnen and Liaohe plains, China, which are distributed along the Songhua and Liaohe rivers. The rice cultivation area and yield in this region increased significantly from 2000 to 2015, with increases of nearly 58 and 90%, respectively. The rice crop area and yield increased the fastest in Heilongjiang Province, China, whereas small changes occurred in Jilin and Liaoning provinces, China. Their gravity centers exhibited evident northward and eastward shifts, with offset distances of 107 and 358 km, respectively. Moreover, Heilongjiang Province has gradually become the new main rice production region. The methodologies used in this study provide a valuable reference for other related studies, and the spatial-temporal variation characteristics of the rice activities have raised new attention as to how these shifts affect national food security and resource allocation.

Behavioral sensitization is a progressive increase in locomotor or stereotypic behaviours in response to drugs. It is believed to contribute to the reinforcing properties of drugs and to play an important role in relapse after cessation of drug abuse. However, the mechanism underlying this behaviour remains poorly understood. In this study, we showed that mTOR signaling was activated during the expression of behavioral sensitization to cocaine and that intraperitoneal or intra-nucleus accumbens (NAc) treatment with rapamycin, a specific mTOR inhibitor, attenuated cocaine-induced behavioural sensitization. Cocaine significantly modified brain lipid profiles in the NAc of cocaine-sensitized mice and markedly elevated the levels of phosphatidylinositol-4-monophosphates (PIPs), including PIP, PIP2,and PIP3. The behavioural effect of cocaine was attenuated by intra-NAc administration of LY294002, an AKT-specific inhibitor, suggesting that PIPs may contribute to mTOR activation in response to cocaine. An RNA-sequencing analysis of the downstream effectors of mTOR signalling revealed that cocaine significantly decreased the expression of SynDIG1, a known substrate of mTOR signalling, and decreased the surface expression of GluA2. In contrast, AAV-mediated SynDIG1 overexpression in NAc attenuated intracellular GluA2 internalization by promoting the SynDIG1–GluA2 interaction, thus maintaining GluA2 surface expression and repressing cocaine-induced behaviours. In conclusion, NAc SynDIG1 may play a negative regulatory role in cocaine-induced behavioural sensitization by regulating synaptic surface expression of GluA2.

The Internet of Things (IoT) has been extensively investigated as an enabling technology for situation awareness and data collection. Since power-limited or battery-free IoT devices may have limited transmission coverage, unmanned aerial vehicles (UAVs) can be employed as mobile edge computing (MEC) servers to collect and process data packets from multiple IoT devices due to their high mobility and low operating cost. However, data transmission becomes vulnerable when eavesdroppers exist, as those IoT devices may have limited computing power for encryption. Moreover, it is noteworthy that the identity and location information of IoT devices themselves are also crucial to particular implementations (e.g., regional situation awareness), especially when massive IoT devices are involved using random access schemes. In this article, a secure structure is proposed as a promising strategy to support UAV-aided IoT networks, where the identity and location information of multiple IoT devices are utilized as the key to encrypt data packets collected from IoT networks. In the new structure, the trajectory planning of UAVs is developed to minimize the energy consumption among multiple clusters of a UAV, while the deployment optimization is used to maximize the secrecy capacity in each cluster, and the beam hopping is carried out to encrypt multi-access IoT devices within a coverage of a UAV. After introducing the structure, some key technologies are presented, and then future works for the secure UAV-aided IoT network are discussed.

The endoplasmic reticulum (ER) membrane complex (EMC) cooperates with the Sec61 translocon to co-translationally insert a transmembrane helix (TMH) of many multi-pass integral membrane proteins into the ER membrane, and it is also responsible for inserting the TMH of some tail-anchored proteins1–3. How EMC accomplishes this feat has been unclear. Here we report the first, to our knowledge, cryo-electron microscopy structure of the eukaryotic EMC. We found that the Saccharomyces cerevisiaeEMC contains eight subunits (Emc1–6, Emc7 and Emc10), has a large lumenal region and a smaller cytosolic region, and has a transmembrane region formed by Emc4, Emc5 and Emc6 plus the transmembrane domains of Emc1 and Emc3. We identified a five-TMH fold centred around Emc3 that resembles the prokaryotic YidC insertase and that delineates a largely hydrophilic client protein pocket. The transmembrane domain of Emc4 tilts away from the main transmembrane region of EMC and is partially mobile. Mutational studies demonstrated that the flexibility of Emc4 and the hydrophilicity of the client pocket are required for EMC function. The EMC structure reveals notable evolutionary conservation with the prokaryotic insertases4,5, suggests that eukaryotic TMH insertion involves a similar mechanism, and provides a framework for detailed understanding of membrane insertion for numerous eukaryotic integral membrane proteins and tail-anchored proteins.

The ability to organize nanoscale objects into well-defined three-dimensional (3D) arrays can translate advances in nanoscale synthesis into targeted material fabrication. Despite successes in nanoparticle assembly, most extant methods are system specific and not fully compatible with biomolecules. Here, we report a platform for creating distinct 3D ordered arrays from different nanomaterials using DNA-prescribed and valence-controlled material voxels. These material voxels consist of 3D DNA frames that integrate nano-objects within their scaffold, thus enabling the object’s valence and coordination to be determined by the frame’s vertices, which can bind to each other through hybridization. Such DNA material voxels define the lattice symmetry through the spatially prescribed valence decoupling the 3D assembly process from the nature of the nanocomponents, such as their intrinsic properties and shapes. We show this by assembling metallic and semiconductor nanoparticles and also protein superlattices. We support the technological potential of such an assembly approach by fabricating light-emitting 3D arrays with diffraction-limited spectral purity and 3D enzymatic arrays with increased activity.

Radiotherapy remains a major treatment modality for cancer types such as non-small cell lung carcinoma (or NSCLC). To enhance treatment efficacy at a given radiation dose, radiosensitizers are often used during radiotherapy. Herein, we report a nanoparticle agent that can selectively sensitize cancer cells to radiotherapy. Specifically, we nitrosylated maytansinoid DM1 and then loaded the resulting prodrug, DM1-NO, onto poly(lactide-co-glycolic)-block-poly(ethylene glycol) (PLGA-b-PEG) nanoparticles. The toxicity of DM1 is suppressed by nanoparticle encapsulation and nitrosylation, allowing the drug to be delivered to tumors through the enhanced permeability and retention effect. Under irradiation to tumors, the oxidative stress is elevated, leading to the cleavage of the S–N bond and the release of DM1 and nitric oxide (NO). DM1 inhibits microtubule polymerization and enriches cells at the G2/M phase, which is more radiosensitive. NO under irradiation forms highly toxic radicals such as peroxynitrites, which also contribute to tumor suppression. The two components work synergistically to enhance radiotherapy outcomes, which was confirmed in vitroby clonogenic assays and in vivowith H1299 tumor-bearing mice. Our studies suggest the great promise of DM1-NO PLGA nanoparticles in enhancing radiotherapy against NSCLC and potentially other tumor types.

Aiming at the high-temperature strain gauge on the turbine blade of aero-engine, which needs to bear the high-temperature effect and reliably carry out the strain test, the turbine blades and adhesive strength of rubber layer of adhesive strain gauge were studied by the theoretical analysis, software simulation and experimental verification method. Three-dimensional model of turbine blade was built firstly. And then, the CFD of the blade fluid domain was analyzed. The bonding position of the strain gauge was determined under the actual working condition by the coupling analysis of hydrodynamics, centrifugal force, thermal stress and aerodynamic force. The reliability of strain position simulation of turbine blade was verified by dynamic strain contact measurement experiment. The effect of high temperature and CFD analysis of turbine blades with rubber layer was carried out. The effects of different rotational speeds on the adhesive strength of the adhesive were studied. It was shown that the strain and stress distribution of the blade’s pressure surface was more uniform than the suction surface.