25 research outputs found

    Jointly optimized beamforming and power allocation for full-duplex cell-free NOMA in space-ground integrated networks

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    Space-ground integrated networks (SGINs) have attracted substantial research interests due to their wide area coverage capability, where spectrum sharing is employed between the satellite and terrestrial networks for improving the spectral efficiency (SE). We further improve the SE by conceiving a cellfree system in SGINs, where the full-duplex (FD) multi-antenna APs simultaneously provide downlink and uplink services at the same time and within the same frequency band. Furthermore, power domain (PD) non-orthogonal multiple access (NOMA) is employed as the multiple access (MA) technique in the cell-free system. To achieve a performance enhancement, the sum-rate maximization problem is formulated for jointly optimizing the power allocation factors (PAFs) of the NOMA downlink (DL), the uplink transmit power, and both the beamformer of the satellite and of the APs. Successive convex approximation (SCA) and semi-definite programming (SDP) are adopted to transform the resultant non-convex problem into an equivalent convex one. Our simulation results reveal that 1) our proposed system outperforms the well-known approaches (i.e., frequency division duplex (FDD) and small cell systems) in terms of its SE; 2) our proposed optimization algorithm significantly improves the networking performance; 3) the conceived SIC order design outperforms the fixed-order design at the same complexity

    Leaf phenology rather than mycorrhizal type regulates soil nematode abundance, but collectively affects nematode diversity in seven common subtropical tree species

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    The underlying mechanisms of the relationships between tree species and the soil micro-food web in forest ecosystems remain uncertain, primarily ascribed to an insufficient understanding on how tree functional traits drive soil nematode communities, including in subtropical forests. We investigated the impacts of seven subtropical tree species (evergreen: Pinus massoniana, Mytilaria laosensis, Ilex chinensis, Michelia macclurei; and deciduous: Liquidambar formosana, Quercus acutissima, and Betula luminifera) on the soil nematode communities. We found that the abundance of soil nematodes was not affected by mycorrhizal types, but it was around 83% higher under the deciduous trees than the evergreen trees, indicating the importance of leaf phenology to the abundance of soil nematodes. Nonetheless, both the evergreen and the arbuscular mycorrhizal trees increased soil nematode diversity, resulting from changes in root traits and soil properties. Furthermore, root traits (root C, root N, and root C:N ratio), and soil properties (total C, total N, moisture content, and bulk density) were the best predictors of the community composition of soil nematodes, indicating a key role of resource quality and soil microhabitat in regulating soil nematodes. In contrast, the ectomycorrhizal trees had lower plant parasite and Wasilewska indices, and evenness, whereas the evergreen trees slightly improved the evenness of soil nematodes. This study suggests that tree species affect the soil food web through changes in soil conditions and plant functional traits in subtropical forests

    Low-temperature solution-processed MoOx as hole injection layer for efficient quantum dot light-emitting diodes

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    In this work, quantum dot light-emitting diodes (QD-LEDs) based on a low-temperature solution-processed MoOx hole injection layer were fabricated. As a result of the excellent wettability of the MoOx precursor, a smooth sMoO(x) HIL film with a roughness of less than 1 nm was obtained. In comparison with a device based on PEDOT:PSS, the best sMoO(x)-based QD-LED displayed comparable device performance in terms of a maximum luminance of 10 225 cd m(-2), a peak current efficiency of 4.04 cd A(-1), a maximum external quantum efficiency of 1.61% and, more importantly, an approximately threefold increase in operational lifetime. Furthermore, we investigated the relationship between the thermal treatment of the sMoO(x) film and the device performance. UPS measurements revealed that the work function of the sMoOx film underwent an upshift from 5.51 to 4.90 eV when the annealing temperature was increased from 50 to 250 C-circle, which indicated that low-temperature treatment of the sMoO(x) HIL is beneficial for hole injection and EL performance. This demonstration of a bright, efficient and stable sMoO(x)-based QD-LED provides another feasible application of solution-processable transition metal oxide materials as the HIL within QD-LEDs and promotes the development of low-cost, all-solution-processed optoelectronic devices

    Improved performance of quantum dot light emitting diode by modulating electron injection with yttrium-doped ZnO nanoparticles

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    In a typical light emitting diode (QD-LED), with ZnO nanoparticles (NPs) serving as the electron transport layer (ETL) material, excessive electron injection driven by the matching conduction band maximum (CBM) between the QD and this oxide layer usually causes charge imbalance and degrades the device performance. To address this issue, the electronic structure of ZnO NPs is modified by the yttrium (Y) doping method. We demonstrate that the CBM of ZnO NPs has a strong dependence on the Y-doping concentration, which can be tuned from 3.55 to 2.77 eV as the Y doping content increases from 0% to 9.6%. This CBM variation generates an enlarged barrier between the cathode and this ZnO ETL benefits from the modulation of electron injection. By optimizing electron injection with the use of a low Y-doped (2%) ZnO to achieve charge balance in the QD-LED, device performance is significantly improved with maximum luminance, peak current efficiency, and maximal external quantum efficiency increase from 4918 cd/m(2), 11.3 cd/A, and 4.5% to 11,171 cd/m(2), 18.3 cd/A, and 7.3%, respectively. This facile strategy based on the ETL modification enriches the methodology of promoting QD-LED performance. Published by AIP Publishing

    Serum prolactin and gonadal hormones in hemodialysis women: a meta-analysis

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    Abstract Background A meta-analysis followed by PRISMA 2020 statement was performed aiming to present a whole prolactin and sex hormone profile in hemodialysis women. Methods Literatures were searched in PubMed, Cochrane library, Embase, and Web of science before March 11, 2023. Trial sequential analysis (TSA) was performed to test the conclusiveness of this meta-analysis. Egger’s test and trim-and-fill analysis was used to test publication bias. We took standardized mean difference (SMD) as pool effect of hormones values including prolactin (PRL), follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2) and progesterone (P). This study was registered in PROSPERO and the number was CRD42023394503. Results Twenty-two articles from 13 countries were analyzed. Combining the results of TSA and meta-analysis, we found that compared with healthy control, hemodialysis women had higher PRL, follicular FSH and LH values and lower P levels (PRL: I 2  = 87%, SMD 1.24, 95% CI: 0.79–1.69, p < 0.00001; FSH: I 2  = 0%, SMD 0.34, 95% CI: 0.13–0.55, p = 0.002; LH: I 2  = 39%, SMD 0.64, 95% CI: 0.34–0.93, p < 0.00001; P: I 2  = 30%, SMD − 1.62, 95% CI: -2.04 to -1.20, p < 0.00001). What’s more, compared with women after renal transplantation, hemodialysis women had higher PRL levels (I 2  = 0%, SMD 0.51, 95% CI: 0.25–0.78, p = 0.0001). There was not enough evidence to draw a conclusion on the comparison of hormones between regular and irregular menses hemodialysis women. Egger’s test and trim-and-fill analysis didn’t show significant publication bias. Conclusions Hemodialysis women had higher serum PRL, follicular phase FSH, LH and lower serum P values compared with healthy control. PRL values of hemodialysis women were also higher than that of women after renal transplantation

    Time Course Analysis of Genome-Wide Identification of Mutations Induced by and Genes Expressed in Response to Carbon Ion Beam Irradiation in Rice (Oryza sativa L.)

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    Heavy-ion irradiation is a powerful mutagen and is widely used for mutation breeding. In this study, using whole-genome sequencing (WGS) and RNA sequencing (RNA-seq) techniques, we comprehensively characterized these dynamic changes caused by mutations at three time points (48, 96, and 144 h after irradiation) and the expression profiles of rice seeds irradiated with C ions at two doses. Subsequent WGS analysis revealed that more mutations were detected in response to 40 Gy carbon ion beam (CIB) irradiation than 80 Gy of CIB irradiation at the initial stage (48 h post-irradiation). In the mutants generated from both irradiation doses, single-base substitutions (SBSs) were the most frequent type of mutation induced by CIB irradiation. Among the mutations, the predominant ones were C:T and A:G transitions. CIB irradiation also induced many short InDel mutations. RNA-seq analysis at the three time points showed that the number of differentially expressed genes (DEGs) was highest at 48 h post-irradiation. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of the DEGs showed that the “replication and repair” pathway was enriched specifically 48 h post-irradiation. These results indicate that the DNA damage response (DDR) and the mechanism of DNA repair tend to quickly start within the initial stage (48 h) after irradiation

    Adverse trends of cardiovascular risk factors among low risk populations (1983-1994) - a cohort study of workers and farmers in Guangzhou, China

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    Abstract Background The levels and trends of cardiovascular risk factors vary greatly throughout China. We examine 10-year trends of cardiovascular risk factors (1983-1994) and the factors related to these trends among low-risk cohorts of workers and farmers in Guangzhou, China. Methods This is a cohort study of 3,131 workers and 3,493 farmers aged 25-64 years at baseline with 10 years of follow-up. We performed a longitudinal analysis to account for the aging of the cohorts and the repeated measures of the same individual. Results At baseline the prevalence of overweight (including obese) ranged from 1.0% to 11.8%, hypertension ranged from 3.8% to 10.5%, and mean serum total cholesterol (TC) ranged from 155.4 mg/dl to 187.2 mg/dl. Although prevalence of smoking declined, blood pressure levels and body mass index (BMI) increased significantly, and lipid profiles changed unfavorably during the 10-year follow-ups. The prevalence of hypertension increased from 5.0 percentage points (female farmers) to 12.3 percentage points (male farmers). Mean TC increased significantly (e.g., +22.8 mg/dl and +17.0 mg/dl in male and female farmers, respectively). In the longitudinal data analyses, increase in BMI was associated with increase in blood pressure levels and TC. Significant adverse trends of risk factors persisted after adjustment for aging, education, BMI, smoking, and alcohol intake. Conclusion Urgent action is needed to prevent and reverse the unhealthy trends occurring among these low risk Chinese workers and farmers.</p

    Over-Expressing TaSPA-B Reduces Prolamin and Starch Accumulation in Wheat (Triticum aestivum L.) Grains

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    Starch and prolamin composition and content are important indexes for determining the processing and nutritional quality of wheat (Triticum aestivum L.) grains. Several transcription factors (TFs) regulate gene expression during starch and protein biosynthesis in wheat. Storage protein activator (TaSPA), a member of the basic leucine zipper (bZIP) family, has been reported to activate glutenin genes and is correlated to starch synthesis related genes. In this study, we generated TaSPA-B overexpressing (OE) transgenic wheat lines. Compared with wild-type (WT) plants, the starch content was slightly reduced and starch granules exhibited a more polarized distribution in the TaSPA-B OE lines. Moreover, glutenin and &omega;- gliadin contents were significantly reduced, with lower expression levels of related genes (e.g., By15, Dx2, and &omega;-1,2 gliadin gene). RNA-seq analysis identified 2023 differentially expressed genes (DEGs). The low expression of some DEGs (e.g., SUSase, ADPase, Pho1, Waxy, SBE, SSI, and SS II a) might explain the reduction of starch contents. Some TFs involved in glutenin and starch synthesis might be regulated by TaSPA-B, for example, TaPBF was reduced in TaSPA-B OE-3 lines. In addition, dual-luciferase reporter assay indicated that both TaSPA-B and TaPBF could transactivate the promoter of &omega;-1,2 gliadin gene. These results suggest that TaSPA-B regulates a complex gene network and plays an important role in starch and protein biosynthesis in wheat

    Micro‐histology combined with cytology improves the diagnostic accuracy of endometrial lesions

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    Abstract Background In the study, we aimed to evaluate the ability of micro‐histology combined with cytology to improve the quality of slides and diagnose endometrial lesions. Methods Endometrial specimens were collected from Li Brushes. Every specimen was prepared for micro‐histological and cytological slides, using cell block (CB) and liquid‐based cytology (LBC) technologies. Semi‐quantitative scoring system was used to evaluate the qualities of slides. CB slides were assessed by 5‐category scoring system. Diagnostic accuracy was calculated in LBC, CB, and LBC + CB groups based on the histological gold standard. Endometrial atypical hyperplasia, and endometrial cancer were considered positive, whereas others were considered negative. Results A total of 167 patients were enrolled. CB slides were inferior to LBC slides only in cellularity (p < 0.001), but superior in the other six parameters (all p < 0.001). The satisfaction rate of micro‐histology accounted for 92.3%. The accuracy index in the CB group was higher than in the LBC group in terms of sensitivity (85.5% vs. 82.7%) and specificity (98.9% vs. 95.7%). The sensitivity and specificity in the LBC + CB group were increased to 94.2% and 99.0%, respectively. Conclusions The quality of micro‐histological slides was higher than that of cytological slides. By combining micro‐histology with cytology, higher accuracy was achieved for endometrial lesions diagnosis
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