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BACKGROUND: Atherosclerosis is one of the main causes of vertebral artery stenosis, which reduces blood supply to the posterior circulation, resulting in cerebral infarction or death. OBJECTIVE: To investigate stenosis rates and locations on the development of vertebral artery plaques. METHODS: Stenosis models with varying degrees and positions of stenosis were established. The stenosis area was comprehensively analyzed using multiphase flow numerical simulation. Wall shear stress (WSS), blood flow velocity, and red blood cell (RBC) volume fraction were calculated. RESULTS: Blood flow velocity in 30–70% stenosis of each segment tended to increase significantly higher than normal. Downstream of 50% stenosis exhibited turbulent flow; downstream of 70% displayed reflux. Severe stenosis increases the WSS and distribution area. The mixed area of high and low WSS appeared downstream of the stenosis. The RBC volume fraction at the stenosis increased (maximum value: 0.487 at 70% stenosis in the V4), which was 1.08 times the normal volume fraction. Turbulent and backflow regions exhibited complex RBC volume fraction distributions. CONCLUSION: Flow velocity, WSS, and RBC volume fraction at the stenosis increase with stenosis severity, increasing plaque shedding. Narrow downstream spoiler and reflux areas possess low WSS and high erythrocyte volume fractions, accelerating plaque growth.

This work proposes an adaptive resource orchestration system for a Wireless Local Area Network (WLAN) that is based on the operating principle of Cognitive Radio (CR) technology. By collecting environmental parameters, including the retransmission rate and the channel occupancy rate, the proposed system has “knowledge” of overall transmission behavior and can regulate transmission resources. An Adaptive Connection Assignment (ACA) mechanism is proposed for end devices; it find out target end devices with poor transmission performance, analyzes their alternative Access Point (AP) availability and causes them to change connections to improve transmission performance. An Adaptive Channel Utilization (ACU) mechanism is designed for APs to identify a target AP that is suffering from interference, to analyze its alternative channel availability and to require it to change its working channel to improve transmission efficiency. Results of simulations of various scenarios indicate that the throughput of end devices is increased by 15 to 24%, the throughput of APs is increased by 6 to 47% and the retransmission rate of APs is reduced by 0.4 to 5.3%. &nbsp

By integrating sensing, memory and processing functionalities, biological nervous systems are energy and area efficient. Emulating such capabilities in artificial systems is, however, challenging and is limited by the device heterogeneity of sensing and processing cores. Here we report an organic electrochemical transistor capable of sensing, memory and processing. The device has a vertical traverse architecture and a crystalline–amorphous channel that can be selectively doped by ions to enable two reconfigurable modes: a volatile receptor and a non-volatile synapse. As a volatile receptor, the device is capable of multi-modal sensing and is responsive to stimuli such as ions and light. As a non-volatile synapse, it is capable of 10-bit analogue states, low switching stochasticity and good state retention. We also show that the homogeneous integration of the devices could provide functions such as conditioned reflexes and could be used for real-time cardiac disease diagnoses via reservoir computing.

Spontaneous low-frequency oscillations (LFO) have been widely studied in cerebrovascular disease, but little is known about their role in Moyamoya disease (MMD). The objective of this study was to assess the value of spontaneous LFO in MMD based on wavelet analysis of near-infrared spectroscopy (NIRS) signals.Sixty-four consecutive idiopathic adult patients were prospectively enrolled. The regional tissue oxygenation index (TOI) obtained from continuous NIRS signals. Five frequency intervals of spontaneous LFO (I, 0.0095-0.02 Hz; II, 0.02-0.06 Hz; III, 0.06-0.15 Hz; IV, 0.15-0.40 Hz; and V, 0.40-2.00 Hz) were extracted based on wavelet analysis. The data were compared between the patients and healthy control groups. Clinical features, cognitive function, and disease progression of MMD were analyzed using TOI and frequency interval data.Compared with the healthy control group, patients with MMD had a higher cerebral TOI in both hemispheres. Based on wavelet analysis, the spontaneous LFO of TOI was found to be significantly lower for patients with MMD in frequency intervals II to IV than that for the controls. The spontaneous LFO of TOI is also related to the Suzuki stages in intervals II to IV, stroke in interval III, and cognitive impairment in intervals III to Ⅳ.There were significant differences in spontaneous LFO between patients with MMD and healthy controls. The change in spontaneous LFO in MMD is related to Suzuki stage, cerebral infarction, and cognitive impairment. This might be an effective method for evaluating the severity and monitoring the progression of MMD.

This study focuses on the effect of a weak jet of a porous plate on the aerodynamic heating of high-speed vehicles. By using a variable nozzle to form different weak air jets through a uniformly distributed porous plate in a shock tunnel, the heat flux distribution on the surface of the porous plate near the ejection area under different Mach numbers, attack angles, and jet velocities is studied. The main results show that the uniformly distributed pore structure increases the wall roughness and promotes transition during heating, the jet velocity has a remarkable impact on the heat transfer characteristics of the plate, and the heat flux on the plate as well as the cooling effect increase with the attack angle.

The concept of metamaterials offers a flexible pathway to manipulate the macroscopic behavior of light by delicately designed microscopic subwavelength structures, which has been recently introduced to integrated photonics to create devices with ultra-compact footprint, excellent performance or versatile functionalities. However, the conventional design approach of metamaterials, including two separated steps of subwavelength structure design and the assembly of unit cells, often encounters challenges when facing extreme design targets. In this work, we propose a hierarchical inverse design approach by cascading a conventional unit-cell-based design with a holistic topology optimization. As a proof-of-concept, we demonstrate ultra-short-range light focusing and mode-size conversion enabled by on-chip meta-lenses. The shortening of tapering region pushes higher numerical aperture of on-chip lenses, leading to the violation of locally periodic approximation used in meta-lens design and thus poor device performance, which fortunately, can be well compensated by the follow-up holistic optimization step. We experimentally realize mode-size squeezing by almost 20 times in a tapering region as short as 8 μm and 5 μm with low insertion loss and broadband performance. The proposed design scheme provides practical guidelines to design metamaterials as flexible on-chip wavefront control and light routing devices for various applications in fiber communication, sensing and optical computing.

Understanding the basic physicochemical properties of gas molecules confined within nanobubbles is of fundamental importance for chemical and biological process. Here we successfully monitored the nanobubble-confined electrochemical behaviors of single platinum nanoparticles (PtNPs) at a carbon fiber ultramicroelectrode in HClO4 and H2O2 solution. Owing to the catalytic decomposition of H2O2, a single oxygen nanobubble formed on individual PtNPs to block the active surface of particle for proton reduction and suppress their stochastic motion, resulting in significantly distinguished current traces. Furthermore, the combination of theoretical calculation and high-resolution electrochemical measurement allowed the size of nanobubble and the oxygen gas density inside a single nanobubble to be quantified. And the ultrahigh oxygen density inside (9286 kg/m3) was revealed, indicating gas molecules in a nanosized space existed with a high state of aggregation. Our approach sheds light on gas aggregation behaviors of nanoscale bubbles using single-entity electrochemical measurement.

Early death is a major factor of treatment failure in acute promyelocytic leukemia (APL), however, the recent trends in the incidence of early death based on the population-level are not clear. Hence, this study is aimed at describing the incidence, recent trends, causes and characteristics of early death in APL based on the real world.APL patients diagnosed from 1986 to 2015 in the Surveillance, Epidemiology, and End Results (SEER) dataset were enrolled, and categorized based on gender, age, year of diagnosis, race, marital status, resident county and socioeconomic status (SES). The risk factors for all-cause and acute myelocytic leukemia (AML) specific early death were determined by univariate and multivariate logistic regression analyses, and stratified analysis was conducted by age.Overall, 3212 APL patients were included in analysis between 1986 and 2015, of which a total of 683 (21.3%) patients were noted for early death. Significant differences were recognized for patient distribution by age, year of diagnosis, marital status, and SES. The early death rate of APL patients diagnosed during 2006-2015 was significantly lower than that of the early stage, but this trend was not evident in juvenile patients. At the same time, older age, and lower SES score were independent risk factors for early death in the multivariate analysis.We established that the early death trend in APL has decreased over the past few years, but the early death rate remains high, especially in older patients and those with lower SES.

The aim of this study was to investigate the effect of lidocaine for patient controlled intravenous analgesia (PCIA) in patients who underwent open hepatectomy.A retrospective analysis.A total of 281 patients who underwent open hepatectomy from July 2018 to December 2018 were included. All patients were assigned into two groups: the lidocaine group (PCIA consisted of lidocaine, sufentanil, tramadol and granisetron) and the control group (PCIA consisted of sufentanil, tramadol and granisetron). The postoperative visual analogue scale (VAS) and complications (including respiratory depression, hypotension, nausea and vomiting, pruritus, numbness of the corners of the mouth, dizziness) between the groups were compared.There were no significant differences between the characteristics, duration of surgery and anesthesia, and recovery of postoperative activity between the two groups. In the first 3 days after the operation, the postoperative VAS score of the lidocaine group was lower than that of the control group at resting state, while after activity, the postoperative VAS contrast results were completely opposite. In particularly, the resting state at 48 hours (h) (1.05 ± 1.25 vs 1.57 ± 1.54) after surgery and the activity state at 72 h (3.02 ± 1.51 vs 2.2 ± 1.66) after surgery (P0.05). The incidence of mouth numbness and dizziness were significantly increased in the lidocaine group (P0.05).The addition of lidocaine in PCIA was not beneficial to improve the pain during activities and increased the incidence of perioral numbness and dizziness.

Since the tax of carbon emission is popular and consumers are exhibiting low-carbon preference, a manufacturer may invest to adopt carbon emission reduction (CER) technologies to produce green products. In face of high cost of CER investment and random yield in low carbon production processes for the manufacturer, this paper explores the incentive role of the contracts of revenue-sharing (RS) and cost-sharing with subsidy (CSS) offered by a retailer in a low-carbon supply chain. Theoretical analysis and numerical experiments show that both RS and CSS can promote the manufacturer’s Carbon Emission Reduction (CER) efforts and improve the efficiency of the supply chain, and RS boosts these more than CSS. RS and CSS can also decrease firms’ profit losses due to yield uncertainty, and RS also decreases firms’ profit losses more than CSS. Moreover, to motivate manufacturer’s CER efforts, the government should levy the highest-possible carbon tax under RS, the medium-level carbon tax under CSS, and the lowest-possible carbon tax for the decentralized case, and levy the same carbon tax on the centralized case with that under RS.

In this work, the self-assembly behavior of a pair of low-symmetry carboxylic acid molecules (H4OBDB and H4ADDI) and their co-assembly behavior with trimesic acid (TMA) as a bridging molecule were studied using a scanning tunneling microscope (STM).

N-dopants optimize the utilization of spontaneously formed photocharges by reducing the exciton binding energy and segregating the counter charges in non-fullerene acceptors.

More J-type polymer aggregations and the prioritized polymer reduction from its pure domain help to achieve high LUE in ST-OSCs during the polymer donor diluting process.

The all-fused-ring molecules with near-infrared absorption and high stability are developed. The organic solar cells by using these molecules as electron acceptors exhibit a PCE of 11.4% and high device stability.

High-performance eco-friendly all-polymer solar cells were realized by balancing the crystallinity and domain size via hot halogen-free solvent slot-die coating.

Typical preparation techniques and performance enhancement strategies for WO3-based electrochromic films are described in detail in this review.

When UAVs apply a pesticide at different speeds, droplet deposition area and canopy vortex area are not at the same location, which prevents droplets from depositing on the backside of leaves and lower part of plants in canopy vortex, and affects spray quality and pests and diseases control effect. To shorten the distance between the two areas and improve droplet penetration, a method for adjusting nozzle inclination angle based on droplet force analysis and tests was proposed in this paper. According to the obtained model, an automatic nozzle angle adjustment system was developed from hardware and software. The experimental results showed that the number of droplets deposited on the entire leaf increased by 21.58% when UAV spraying with the system mounted. The average number of droplets on the front side of the leaf increased by 14.44% while 66.05% was on the backside of the leaf with the system mounted. This indicates that the method and system proposed have a significant impact on improving the UAV spray penetration.