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In this paper, a wideband polarization reconfigurable omnidirectional antenna (PROA) based on a single-substrate active metasurface is proposed. By controlling the states of the PIN diodes, the antenna can selectively radiate an omnidirectional linearly polarized wave and an omnidirectional circularly polarized wave. The reflection coefficient, axial ratio (AR), radiation pattern, and gain of the proposed antenna have been analyzed from the perspective of simulation and measurement. The measured results show that the PROA has a wide overlapped bandwidth from 2.87 to 3.67 GHz (relative bandwidth 24.46%). To the authors' best knowledge, this is the first reported wideband PROA based on a single-substrate reconfigurable polarization converter. This study not only offers a novel approach to design PROAs, but also greatly reduces the design complexity of the feed source compared with the traditional design method of PROAs. [ABSTRACT FROM AUTHOR]

Persistent free radicals (PFRs) are emerging substances with diverse impacts in biochar applications, necessitating accurate prediction of their content and types prior to their optimal use and minimal adverse effects. This prediction task is challenging due to the nonlinearity and intricate variable relationships of biochar. Herein, we employed data-driven techniques to compile a dataset from peer-reviewed publications, aiming to systematically predict the PFRs by developing supervised machine learning models. Notably, extreme gradient boosting (XGBoost) model exhibited the best predictive performance for both regression and classification tasks in predicting the PFRs, achieving a test R2 value of 0.95 for PFR content prediction, along with an Area Under the Receiver Operating Curve (AUROC) of 0.92 for PFR type prediction, respectively. Based on XGBoost model, a graphical user interface (GUI) was developed to access PFRs predictions. Analysis of feature importance revealed that the biochar properties, such as metal/non-metal doping, pyrolysis temperature, carbon content, and specific surface area were identified as the four most significant factors influencing PFRs contents. Regarding the types of PFRs in biochar, specific surface area, pyrolysis temperature, carbon content, and feedstock were top-ranked influencing factors. These findings provide valuable guidance for accurately predicting both the contents and types of PFRs in biochar, and also hold significant potential for highly efficient utilization of biochar across various applications. Highlights: • Recognizing dual nature of PFRs, a machine-learning framework predicts them in biochar. • XGBoost excels, achieving an R2 (0.95) for PFR content and an AUROC (0.92) for PFR type. • Important factors of PFR: doping, pyrolysis temp, carbon, and surface area. • GUI enhances accessibility, enabling PFR predictions before biochar preparation. [ABSTRACT FROM AUTHOR]

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While pollution of the environment by polycyclic aromatic hydrocarbons has been rather well studied, the fate of substituted polycyclic aromatic hydrocarbons in ecosystems is less understood, notably in soil–plant systems. Here we hypothesized that substituted polycyclic aromatic hydrocarbons could enter wheat and induce phytotoxicity. We studied the accumulation, root-shoot translocation and phytotoxicity of α-tetralone, 1-nitronaphthalene, 1-nitropyrene, and 7,12-dimethylbenz[a]anthracene in wheat using hydroponic experiments. We deciphered the accumulation and translocation mechanisms by inhibition with sodium vanadate, glycerol and silver nitrate. Results show that pollutant concentrations increased rapidly in roots, reaching maximum of 38.3 μg/g for α-tetralone, 268.7 μg/g for 1-nitronaphthalene, 3566.1 μg/g for 1-nitropyrene, and 3632.7 μg/g for 7,12-dimethylbenz[a]anthracene. In contrast, the root-shoot translocation factors of α-tetralone, 1-nitronaphthalene, 1-nitropyrene and 7,12-dimethylbenz[a]anthracene were 2.4, 1.6, 0.1, and 0.1, respectively, thus decreasing significantly with increasing compound hydrophobicity. This could be explained by preferential adsorption for hydrophobic compounds, whereas less hydrophobic compounds could be partly translocated in a soluble form through plant water channels. The accumulated substituted polycyclic aromatic hydrocarbons in wheat induced the decrease of the total chlorophyll contents by 19.0–30.1%, yet did not cause lipid peroxidation damage. Overall, our findings indicates the bioaccumulation potential and toxicity of substituted polycyclic aromatic hydrocarbons in terrestrial plants. [ABSTRACT FROM AUTHOR]

Background: Neoadjuvant chemotherapy (NACT) becomes the first-line option for advanced tumors, while patients who are not sensitive to it may not benefit. Therefore, it is important to screen patients suitable for NACT. Methods: Single-cell data of lung adenocarcinoma (LUAD) and esophageal squamous carcinoma (ESCC) before and after cisplatin-containing (CDDP) NACT and cisplatin IC50 data of tumor cell lines were analyzed to establish a CDDP neoadjuvant chemotherapy score (NCS). Differential analysis, GO, KEGG, GSVA and logistic regression models were performed by R. Survival analysis were applied to public databases. siRNA knockdown in A549, PC9, TE1 cell lines, qRT-PCR, western-blot, cck8 and EdU experiments were used for further verification in vitro. Results: 485 genes were expressed differentially in tumor cells before and after neoadjuvant treatment for LUAD and ESCC. After combining the CDDP-associated genes, 12 genes, CAV2, PHLDA1, DUSP23, VDAC3, DSG2, SPINT2, SPATS2L, IGFBP3, CD9, ALCAM, PRSS23, PERP, were obtained and formed the NCS score. The higher the score, the more sensitive the patients were to CDDP-NACT. The NCS divided LUAD and ESCC into two groups. Based on differentially expressed genes, a model was constructed to predict the high and low NCS. CAV2, PHLDA1, ALCAM, CD9, IGBP3 and VDAC3 were significantly associated with prognosis. Finally, we demonstrated that the knockdown of CAV2, PHLDA1 and VDAC3 in A549, PC9 and TE1 significantly increased the sensitivity to cisplatin. Conclusions: NCS scores and related predictive models for CDDP-NACT were developed and validated to assist in selecting patients who might benefit from it. [ABSTRACT FROM AUTHOR]

Six organophosphate esters (OPEs) with different octanol-air partition coefficient (KOA) were measured from gas and particle samples collected from an urban area of Central China between June 2018 and May 2019. The highest concentration of total OPEs (∑6OPEs) in total suspended particle (TSP) were found in winter, followed by spring, autumn, and summer. ∑6OPEs showed significant positive correlation with TSP concentration (p < 0.01), significant negative correlation with temperature (p < 0.01), weak negative linear correlations with relative humility (p < 0.05), and no significant correlations with wind speed (p > 0.05). Although OPEs were not detected in polyurethane foams (PUFs), the poly-parameter linear free energy relationship model (pp-LFER) estimated particle fractions of OPEs (fpart pp-LFERg/p) were below 2.73% for Tris (2-chloroisopropyl) phosphate (TCIPP), Tris (chloroethyl) phosphate (TCEP), and Tributyl phosphate (TnBP); 67.8% for Triphenyl phosphate (TPhP); and above 99.6% for TBOEP and TCrP. The concentrations of particle-bound TPhP, TCrP, and TBOEP estimated by pp-LFER (Cpart pp-LFERg/p) were 0.19, 0.09, and 0.05 ng/m3, which were in good agreement with measurements. However, the estimated Cpart pp-LFERg/p of TCEP, TCIPP, and TnBP showed obvious differences with measured data. According to filter-air partitioning estimated by pp-LFER, the strong adsorption of gaseous OPEs to glass fiber filter (GFF) may be responsible to the underestimation. Besides, the weak adsorption of gaseous OPEs to PUF is likely to be another important reason for the discrepancy between measured and modeled results. Therefore, the risk assessment of gaseous OPEs should be of concern in the further research. [ABSTRACT FROM AUTHOR]

Land application is suggested to be the most economical sludge disposal method but is also a potential source of bisphenol analogs (BPs) to the environment. In this study, BP concentrations in sewage sludge from Henan province ranged from 15.1 to 2237 ng g−1 dw. BPA was dominant with mean concentration of 140 ng g−1 dw, followed by BPS (mean 43.4 ng g−1 dw), BPF (mean 7.98 ng g−1 dw), BPAF (mean 1.04 ng g−1 dw), BPAP (mean 0.88 ng g−1 dw), BPB (mean 0.38 ng g−1 dw), and BPZ (mean 0.33 ng g−1 dw). Apart from BPB, no significant correlations were found between BPs and wastewater treatment plants characteristics, probably because adsorption does not play a major role in the removal of BPs. The estimated total emission flux of BPs from sludge-amended soils are approximately 62.7 kg year−1. BPA is the largest contributor with emission flux of 45.3 kg year−1. Hazard quotient values for BPs in sludge-amended soils are 3–6 orders of magnitude lower than 1 with total 17β-estradiol equivalents ranging from 0.33 to 26.8 pg g−1 E2EQ dw. Overall, although being partially replaced by other analogs, BPA is still widely used in Henan province. [ABSTRACT FROM AUTHOR]

In this study, nine OPEs were measured in 60 street dust samples collected from the central province of Henan, China. The total concentrations of OPEs (∑9OPEs) in street dust range from 2.77 to 505 μg/kg (median 59.3 μg/kg). Chlorinated OPEs are dominant in street dust with median concentration of 33.5 μg/kg, followed by aryl OPEs (median 9.05 μg/kg), and alkyl OPEs (median 6.19 μg/kg). No significant correlations are found between ∑9OPEs and parameters, such as population (p = 0.931), population density (p = 0.602), car ownership (p = 0.618), and gross domestic product (p = 0.863). Principal component analysis (PCA) result reveals that road traffic could be a major source of OPEs in street dust because of their extensive use in various vehicles. The total average (median) and high-level exposure (95th percentile) of OPEs are 1.01 × 10−2, 7.17 × 10−2 ng/kg bw/d for adults and 6.03 × 10−2, 0.43 ng/kg bw/d for children, respectively. Hazard quotient (HQ) values are 5–6 orders of magnitude lower than the acceptable risk level (HQ < 0.1), indicating there is still a low risk to local residents at current levels. [ABSTRACT FROM AUTHOR]

To develop a potential dengue vaccine candidate, a full-length cDNA clone of a novel chimeric virus was constructed using recombinant DNA technology, with Japanese encephalitis virus (JEV) vaccine strain SA14-14-2 as the backbone, with its premembrane (prM) and envelope (E) genes substituted by their counterparts from dengue virus type 1 (DENV1). The chimeric virus (JEV/DENV1) was successfully recovered from primary hamster kidney (PHK) cells by transfection with the in vitro transcription products of JEV/DENV1 cDNA and was identified by complete genome sequencing and immunofluorescent staining. No neuroinvasiveness of this chimeric virus was observed in mice inoculated by the subcutaneous route (s.c.) or by the intraperitoneal route (i.p.), while some neurovirulence was displayed in mice that were inoculated directly by the intracerebral route (i.c.). The chimeric virus was able to stimulate high-titer production of antibodies against DENV1 and provided protection against lethal challenge with neuroadapted dengue virus in mice. These results suggest that the chimeric virus is a promising dengue vaccine candidate. [ABSTRACT FROM AUTHOR]

Reference 1 Yan X., Yang H., Mo H., Xie Y., Jin Z., Zhou Y. Numerical Simulation on the Smoke Prevention Performance of Air Curtains in an Island-Type Subway Station. Footnotes 1 B Disclaimer/Publisher's Note: b The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). Numerical Simulation on the Smoke Prevention Performance of Air Curtains in an Island-Type Subway Station. [Extracted from the article]

Subway fires are a major threat to the safe and smooth operation of subway stations. In this paper, an island-type subway station was taken as an example to conduct a series of numerical simulations using Fire Dynamics Simulator (FDS). The temperature, visibility, and CO concentration in the subway station were analysed under different thicknesses and jet velocities of the air curtains. The smoke-prevention performance of the air curtains in the subway station was investigated. As the thickness and jet velocity increase, the flame tilts significantly, which greatly hinders the spread of smoke toward the stairs. The smoke temperature and CO concentration on the left side of the air curtains gradually decrease, while the visibility increases significantly. For a 3 MW fire scenario, to satisfy the evaluation criteria, the results show that the thickness of the air curtains needs to be at least 0.3 m, and the jet velocity needs to be at least 2 m/s. The sealing effectiveness (Esealing) tends to increase and then remains constant with increasing momentum, and the maximum is obtained when the momentum of the air curtains (Ia) is 12.5 kg·m/s2. Meanwhile, it is found that an energy-saving efficiency of 85.2% can be achieved by replacing positive pressure ventilation with air curtains. The results of this work can provide a significant reference for the design of smoke protection in subway stations. [ABSTRACT FROM AUTHOR]

For cobalt-rich crusts in a contract area, the regular-shaped cells for relinquishment are obviously different from the natural ore distribution, and this brings challenges in evaluating the resources within them. Based on survey data in the China Ocean Mineral Resources Research and Development Association (COMRA) contract area, this study analyzed factors that could influence the relinquishment of cobalt-rich crusts. According to the guidelines of the International Seabed Authority, each original block of the COMRA contract area was subdivided into 16 cells. The contract areas were then divided into orebodies, unclear areas, and non-resource areas based on the distribution of the orebodies. Then, these attributions were assigned to the cells and the resources inside each cell were evaluated and identified, according to resource quantity, as resource cells, unclear cells, and non-resource cells. Finally, relinquishment was assessed by a step-by-step method in the following priority order: non-resource cells, unclear cells, and resource cells. This method was applied to the Caiqi Guyot (a guyot in the COMRA contract area) as a case study. The results show that the proposed method is suitable for the relinquishment of cobalt-rich crusts in the COMRA contract area and can also be applied to other contract areas worldwide. [ABSTRACT FROM AUTHOR]

Hepatitis B is a leading cause of death worldwide. Here, we performed a large, population-based, cross-sectional study in Chongqing, China from 2011 to 2016 to assess the prevalence of HBsAg among couples of reproductive age, to predict subsequent trends, and to provide evidence for the WHO goal of "the elimination of viral hepatitis as a public health threat by 2030". A total of 386,286 couples aged 20 to 49 years were enrolled in the study. Approximately 14.35% of couples were HBsAg positive, including 95.00% with discordant HBsAg positivity. HBsAg prevalence was higher in men than in women. Among different occupations, the two categories of "houseworker" (female 6.73%, male 9.99%) and "unemployed" (female 6.64%, male 9.94%) showed the highest HBsAg positivity. In different regions, the lowest prevalence appeared in southeastern Chongqing (female 4.87%, male 7.71%). In 2030, the HBsAg positivity rate is expected to be 2.79%, 7.27% and 5.13% in females, males, and the whole population, respectively. According to the trends, this rate would drop to less than 2% in 2034, 2078 and 2051. In conclusion, the HBsAg prevalence in Chongqing is still relatively high compared with that in other parts of western China, especially among reproductive-age men. HBsAg-positive couples should be taken as an important unit of care. Vaccination is necessary before pregnancy if no antibody is found. More attention should be given to people without stable jobs. HBsAg-positive rate will decrease perceptibly by 2030 and will reach the level of low in epidemic areas by 2050. [ABSTRACT FROM AUTHOR]

Purpose For the climbing rod object with large diameter variation and the need of obstacle crossing, this paper aims to propose a new embracing-type climbing robot named as EVOC-I robot.Design/methodology/approach The design philosophy and structural scheme are introduced. The kinematic analysis of embracing and telescoping mechanisms is carried out to provide the theoretical foundation for the effective climbing of the robot. Based on the prototype robot, three preliminary experiments are carried out to verify the effectiveness of the designed robot.Findings The theoretical and experimental analyses have verified the reasonability and effectiveness of the proposed robot design.Research limitations/implications As the preliminary study, the prototype still need a lot of improvement. The experimental verification is also limited. Future work will focus on improving the design and increasing the theoretical analysis, especially increasing experimental study and designing the next generation of the rod climbing robot.Practical implications The designed climbing robot can be used for climbing the rod with variation diameter and flange obstacle, especially the lightening rod in the transformer substation.Originality/value The paper designs a new climbing robot that integrates the ability of large variation diameter adaptation and obstacle crossing. [ABSTRACT FROM AUTHOR]

This paper presents an experimental investigation of the fatigue properties of limestone subjected to triaxial compression with axial cyclic loading. Tests were conducted on intact limestone samples with a loading frequency of 0.5 Hz and a confining pressure of 10 MPa. The test results show the following five points. (1) Under triaxial conditions, the axial and circumferential deformations at the failure point induced by cyclic loading are slightly larger than the corresponding deformations at the peak stress achieved by conventional compression tests. (2) The first level cyclic loading process has a strong influence on rock deformation in the primary phase during subsequent level cyclic loading. A smaller difference in stress amplitude between the two loading stress levels leads to less deformation during the latter. (3) Circumferential and volumetric changes are more sensitive to fatigue failure in terms of deformation and strain rate than axial changes. (4) The three phases of dissipated energy evolution are consistent with a sample’s deformation such that the energy dissipation characteristics reflect the fatigue damage evolution process. (5) A new damage formula is proposed that can concisely describe a rock’s zero-cycle damage and damage evolution. [ABSTRACT FROM AUTHOR]

TREE submodel affiliated with TREEDYN was used to simulate biomass dynamics of Masson pine ( Pinus massoniana) forest under different managements (including thinning, clear cutting, combining thinning with clear cutting). The purpose was to represent biomass dynamics involved in its development, which can provide scientific arguments for management of Masson pine forest. The results showed the scenario that 10% or 20% of biomass of the previous year was thinned every five years from 15 to 40 years made total biomass of pine forest increase slowly and it took more time to reach a mature community; If clear cutting and thinning were combined, the case C (clear cutting at 20 years of forest age, thinning 50% of remaining biomass at 30 years of forest age, and thinning 50% of remaining biomass again at 40 years of forest age) was the best scenario which can accelerate speed of development of Masson pine forest and gained better economic values. [ABSTRACT FROM AUTHOR]

Background: Spinibarbus hollandi is an economically important fish species in southern China. This fish is known to have nutritional and medicinal properties; however, its farming is limited by its slow growth rate. In the present study, we observed that a compensatory growth phenomenon could be induced by adequate refeeding following 7 days of fasting in S. hollandi. To understand the starvation response and compensatory growth mechanisms in this fish, the muscle transcriptomes of S. hollandi under control, fasting, and refeeding conditions were profiled using next-generation sequencing (NGS) techniques. Results: More than 4.45 × 108 quality-filtered 150-base-pair Illumina reads were obtained from all nine muscle samples. De novo assemblies yielded a total of 156,735 unigenes, among which 142,918 (91.18%) could be annotated in at least one available database. After 7 days of fasting, 2422 differentially expressed genes were detected, including 1510 up-regulated genes and 912 down-regulated genes. Genes involved in fat, protein, and carbohydrate metabolism were significantly up-regulated, and genes associated with the cell cycle, DNA replication, and immune and cellular structures were inhibited during fasting. After refeeding, 84 up-regulated genes and 16 down-regulated genes were identified. Many genes encoding the components of myofibers were significantly up-regulated. Histological analysis of muscle verified the important role of muscle hypertrophy in compensatory growth. Conclusion: In the present work, we reported the transcriptome profiles of S. hollandi muscle under different conditions. During fasting, the genes involved in the mobilization of stored energy were up-regulated, while the genes associated with growth were down-regulated. After refeeding, muscle hypertrophy contributed to the recovery of growth. The results of this study may help to elucidate the mechanisms underlying the starvation response and compensatory growth. [ABSTRACT FROM AUTHOR]