UAV-assisted Semantic Communication with Hybrid Action Reinforcement Learning

In this paper, we aim to explore the use of uplink semantic communications with the assistance of UAV in order to improve data collection effiicency for metaverse users in remote areas. To reduce the time for uplink data collection while balancing the trade-off between reconstruction quality and computational energy cost, we propose a hybrid action reinforcement learning (RL) framework to make decisions on semantic model scale, channel allocation, transmission power, and UAV trajectory. The variables are classified into discrete type and continuous type, which are optimized by two different RL agents to generate the combined action. Simulation results indicate that the proposed hybrid action reinforcement learning framework can effectively improve the efficiency of uplink semantic data collection under different parameter settings and outperforms the benchmark scenarios.Comment: This paper appears in IEEE Global Communications Conference (GLOBECOM) 202

An Architecture for Computer-Aided Detection and Radiologic Measurement of Lung Nodules in Clinical Trials

Computer tomography (CT) imaging plays an important role in cancer detection and quantitative assessment in clinical trials. High-resolution imaging studies on large cohorts of patients generate vast data sets, which are infeasible to analyze through manual interpretation

Ions-induced Epitaxial Growth of Perovskite Nanocomposites for Highly Efficient Light-Emitting Diodes with EQE Exceeding 30%

Cesium lead bromide (CsPbBr3) is a widely used emitter for perovskite light-emitting diodes (PeLEDs), benefiting from its large carrier mobility, high color purity and good thermal stability. However, the three-dimensional CsPbBr3 films encounter challenges due to their massive intrinsic defects and weak exciton binding effect, which limited their electroluminescence efficiency. To address this issue, the prevailing approach is to confine carriers by reducing dimensionality or size. Nonetheless, this method results in an increase in surface trap states due to the larger surface-to-volume ratio and presents difficulties in carrier injection and transport after reducing lattice splitting to smaller sizes. Here, we successfully achieved proper control over film crystallization by introducing sodium ions, which facilitate the epitaxial growth of zero-dimensional Cs4PbBr6 on the surface of CsPbBr3, forming large grain matrixes where CsPbBr3 is encapsulated by Cs4PbBr6. Notably, the ions-induced epitaxial growth enables the CsPbBr3 emitter with significantly reduced trap states, and generates coarsened nanocomposites of CsPbBr3&Cs4PbBr6 with grain size that surpass the average thickness of the thin perovskite film, resulting in a wavy surface conducive to light out-coupling. Additionally, another additive of formamidinium chloride was incorporated to assist the growth of nanocomposites with larger size and lower defects as well as better carrier injection and transportation. As a result, our demonstrated PeLEDs based on the coarsened nanocomposites exhibit low nonradiative recombination, enhanced light extraction and well-balanced carrier transportation, leading to high-performance devices. The champion device achieved an external quantum efficiency of 31.0% at the emission peak of 521 nm with a narrow full width at half-maximum (FWHM) of 18 nm

Effects of uremia and inflammation on growth hormone resistance in patients with chronic kidney diseases

Resistance to the anabolic action of growth hormone may contribute to the loss of strength and muscle mass in adult patients with chronic kidney disease. We tested this hypothesis by infusing growth hormone in patients to levels necessary to saturate hormone receptors. This led to a significant decrease of plasma potassium and amino acid levels in control and hyperkalemic patients with chronic kidney disease. These effects were completely or partially blunted in patients with elevated C-reactive protein levels. In forearm perfusion studies, growth hormone caused a further decrease in the negative potassium and protein balance of hemodialysis patients without inflammation but no effect was seen in patients with inflammation. Only IL-6 levels and age were found to be independent correlates in these growth hormone-induced variations in plasma potassium and blood amino acids. This shows that although a resistance to pharmacologic doses of growth hormone is not a general feature of patients with chronic kidney disease, there is a subgroup characterized by blunted growth hormone action. Our results support the hypothesis that uremia with inflammation, but not uremia per se, inhibits downstream growth hormone signaling contributing to muscle atrophy

Integrated Multi-Omics Perspective to Strengthen the Understanding of Salt Tolerance in Rice

Salt stress is one of the major constraints to rice cultivation worldwide. Thus, the development of salt-tolerant rice cultivars becomes a hotspot of current rice breeding. Achieving this goal depends in part on understanding how rice responds to salt stress and uncovering the molecular mechanism underlying this trait. Over the past decade, great efforts have been made to understand the mechanism of salt tolerance in rice through genomics, transcriptomics, proteomics, metabolomics, and epigenetics. However, there are few reviews on this aspect. Therefore, we review the research progress of omics related to salt tolerance in rice and discuss how these advances will promote the innovations of salt-tolerant rice breeding. In the future, we expect that the integration of multi-omics salt tolerance data can accelerate the solution of the response mechanism of rice to salt stress, and lay a molecular foundation for precise breeding of salt tolerance

A Novel Inherently Flame-Retardant Composite Based on Zinc Alginate/Nano-Cu2O

A novel flame-retardant composite material based on zinc alginate (ZnAlg) and nano-cuprous oxide (Cu2O) was prepared through a simple, eco-friendly freeze-drying process and a sol-gel method. The composites were characterized and their combustion and flammability behavior were tested. The composites had high thermal stability and achieved nearly non-flammability with a limiting oxygen index (LOI) of 58. The results show remarkable improvement of flame-retardant properties in the ZnAlg/Cu2O composites, compared to ZnAlg. Furthermore, the pyrolysis behavior was determined by pyrolysis–gas chromatography–mass spectrometry (Py-GC-MS) and the flame-retardant mechanism was proposed based on the combined experimental results. The prepared composites show promising application prospects in building materials and the textile industry

Green synthesis of carbon quantum dots from plant turmeric holds promise as novel photosensitizer for in vitro photodynamic antimicrobial activity

Research has shown that carbon quantum dots (CQDs) are active as novel carbon nanomaterials in photodynamic therapy due to their excellent photophysical properties. However, previously expensive precursors and time-consuming production processes, as well as complex doping/functionalization forms have limited their economic design and use. In this study, we prepared ST-JHCQDs by a simple and green method using natural plant turmeric as the carbon source, and characterized ST-JHCQDs by physical and optical means. In vitro antibacterial results showed that the antibacterial effects of ST-JHCQDs against E. coli and S. aureus under the irradiation of blue light depended on carbonization degrees, concentration and light duration. Biomolecule leakage and confocal laser scanning microscope analysis showed that ST-JHCQDs were effective in producing reactive oxygen species (ROS) under blue light irradiation, which resulted in disturbance of cell membrane integrity and leakage of intracellular macromolecules in both bacteria. Meanwhile, scanning electron microscopy images showed cell membrane wrinkling and fragmentation, which was consistent with ROS damage, demonstrating the effectiveness of ST-JHCQDs as photosensitizers in vitro photodynamic antimicrobial activity. These experiments show that CQDs prepared from turmeric was a new natural photosensitizer material with great antibacterial potential

A Novel Cryptococcal Meningitis Therapy: The Combination of Amphotericin B and Posaconazole Promotes the Distribution of Amphotericin B in the Brain Tissue

The deficient brain tissue distribution of amphotericin B (AMPB) seriously restricts its treatment for the clinical efficacy of cryptococcus neoformans meningitis (CNM). We strive to develop a tactic to increase its concentration in brain tissue. We aimed to investigate whether the combination of AMPB and posaconazole (POS) could be more effective in the treatment of CNM and to elucidate its potential mechanisms. HPLC analysis was used to analyze the concentration of AMPB in mouse serum, brain tissue, and BCECs cells. Schrodinger molecular docking, in vitro plasma balance dialysis, and ultrafiltration analysis were performed to evaluate the combinative effect of AMPB and POS with serum albumin and POS on AMPB plasma protein binding. H&E staining and colonization culture experiment of CN were employed to assess the effect of POS on the efficacy of AMPB. POS + AMPB significantly reduced the concentration of plasma total AMPB and increased its concentration in the brain tissue. However, the P-gp inhibitor zosuquidar, BCRP inhibitor Ko143, and a common inhibitor of both, elacridar, had no significant effect on its concentration. Molecular docking, balance dialysis, and ultrafiltration analysis showed that AMPB and POS had potential binding properties to serum albumin. Meanwhile, 4 and 8 μg/mL POS could significantly increase the concentration of free AMPB in plasma. POS and three inhibitors all had no significant effect on the uptake of AMPB by BCECs, but serum albumin had. The therapeutic effect of CNM in mice was confirmed that AMPB and AMPB+POS could restrain the infiltration of neutrophils and lymphocytes in cortical neurons and improve the bleeding and markedly inhibit the proliferation of CN. Collectively, we propose that POS competitively binds to the plasma protein sites of AMPB, thereby increasing its level in the brain tissue. Meanwhile, POS could enhance the efficacy of AMPB in the treatment of CNM, which may be independent of P-gp and BCRP proteins

Efficient enzymatic synthesis of (S)-1-(3′-bromo-2′-methoxyphenyl)ethanol, the key building block of lusutrombopag

(S)-1-(3′-Bromo-2′-methoxyphenyl)ethanol ((S)-1b) is the key precursor for the synthesis of Lusutrombopag. The bioreduction of 1-(3′-bromo-2′-methoxyphenyl)ethanone (1a) offers an attractive method to access this important compound. Through screening the available carbonyl reductases, we obtained a carbonyl reductase from Novosphingobium aromaticivorans (CBR), which could completely convert 100 ​g/L of 1a to (S)-1b. Furthermore, a carbonyl reductase from Novosphingobium sp. Leaf2 (NoCR) was identified to completely convert 200 ​g/L of 1a to (S)-1b with excellent enantioselectivity (>99% ee) and 77% isolated yield using FDH/formate system for NADH regeneration. The Km and kcat of recombinant NoCR towards 1a were 0.66 ​mmol/L and 7.5 s-1, and the catalytic efficiency kcat/Km was 11.3 ​mmol/s.L. Meanwhile, NoCR showed high catalytic activity and stereoselectivity towards acetophenone derivatives with halogen or methoxy substitution on the benzene ring, indicating that NoCR is a valuable biocatalyst with potential practical applications

Bioactivity-Guided Fractionation of Physical Fatigue-Attenuating Components from Rubus parvifolius L.

Alleviation of fatigue has been emerging as a serious issue that requires urgent attention. Health professionals and sports physiologists have been looking for active natural products and synthetic compounds to overcome fatigue in humans. This study was designed to define the anti-fatigue property of Rubus parvifolius L. (RPL) by characterization of active constituents using a mouse forced swimming test model. Four RPL fractions with different polarities containing anti-fatigue activity were sequentially isolated from the n-butanol RPL extract, followed by elution of 50% ethanol-water fraction from D101 macroporous resin chromatography to obtain nigaichigoside F1, suavissimoside R1 and coreanoside F1. Active constituents of the 50% ethanol-water eluate of RPL were total saponins. The fractions were examined based on the effect on weight-loaded swimming capacity of mice. Serum levels of urea nitrogen (SUN), triglyceride fatty acids (TG), lactate dehydrogenase (LDH), lactic acid (LA), ammonia and hepatic glycogen (HG) were also examined for potential mechanisms underlying the anti-fatigue effect of RPL extracts. During the experiment, two inflammatory markers, interleukin-6 (IL-6) and tumor necrosis factor (TNF-α) in serum, were measured. We found that total saponins from RPL possess potent capabilities to alleviate mouse fatigue induced by forced swimming and that nigaichigoside F1 was responsible for the pharmacological effect. The underlying mechanisms include delays of SUN and LA accumulation, a decrease in TG level by increasing fat consumption, increases in HG and LDH so that lactic acid accumulation and ammonia in the muscle were reduced, and suppression of increased immune activation and inflammatory cytokine production. Our findings will be helpful for functional identification of novel anti-fatigue components from natural medicinal herbs