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Visual saliency (VS) is an important mechanism for defining which areas of an image will attract more attention of the HVS. Thus, VS can be employed to weight the just noticeable difference (JND) with different attention levels. Some VS-based JND profiles have been proposed in the DCT domain, which used the bottom-up features, such as luminance and texture only. Recently, the research about saliency detection has shown that a better saliency model considering both bottom-up features and top-down features will lead to a significant improvement for the overall saliency detection performance. In this paper, we propose a novel two-layer VS-induced JND profile, which is composed of the bottom-up features and the top-down feature extracted from DCT blocks in the transformed domain. In this model, the luminance and texture features are adapted to calculate the bottom-up features maps, while the top-down feature of focus is used to guide the generation of final salient regions since the camerapersons are used to facilitate the attention regions in focus. The proposed two-layer saliency-induced JND model is further applied to modulate the quantization step in the watermarking framework, which can make full use of its individual merits to achieve a better tradeoff between fidelity and robustness. The experimental results show that the proposed scheme has superior performance than the previous watermarking schemes.

The search for two-dimensional superconductors has attracted increasing interest because of their potential applications in constructing nanoscale superconducting devices. Through swarm-intelligence based CALYPSO method and the first-principles calculations, we have identified a monolayer structure for yttrium sulfide (t-YS), which is energetically and dynamically stable. The application of biaxial strain turns t-YS to a Bardeen–Cooper–Schrieffer superconductor, which mainly originates from the softening of in-plane modes of Y atoms. The superconducting critical temperature increases monotonously with strain, which reaches 6 K at a maximum strain of 10%. Calculations show that doping at 0.3 holes per unit cell based on a strain of 10% could further enhance the superconductivity to 7.3 K. Simulations have helped to propose a candidate substrate with ∼8.3% lattice mismatch to obtain superconductive t-YS experimentally. The findings will enrich two-dimensional superconductors and stimulate immediate experimental interest.

Pressure is a fundamental tool that can induce structural and electronic transformations, which is helpful to search for exotic materials not accessible at ambient conditions. Here, we have performed an extensive structural study on cubic Mg3As2 in a pressure range of 0–100 GPa by using a combination of structure predictions and first-principle calculations. Interestingly, two novel structures with space groups C2/m and P were uncovered that become energetically most stable at pressures of 12 GPa and 30 GPa, respectively. Phonon dispersions demonstrate that the three phases are dynamically stable in their respective low-enthalpy pressure ranges. The electronic calculations show that Mg3As2 keeps semiconductor properties at pressures up to 100 GPa. The interesting thing is that the direct semi-conducting property of Mg3As2 transforms into indirect semi-conducting when the pressure is above 12 GPa. The current results provide new insights for understanding the behavior of Mg3As2 at high pressures.

Materials possessing both superhard and metallic properties are beneficial for the creation of multifunctional devices under extreme conditions. Here, we report the formation of a new metallic superhard boron nitride at high pressure with stoichiometry B2N3 through first-principles calculations and structure searching. At ambient pressure, B2N3 has layered structures (h-B2N3) consisting of hexagonal B4N4 layers intercalated by triply bonded N2 molecules. With the pressure increasing to ∼10 GPa, h-B2N3 transforms to a three-dimensional tetragonal structure (t-B2N3) with the formation of single N–N bonds. Calculations reveal that t-B2N3 can be recovered under ambient conditions in view of the dynamical, thermal and mechanical stability. Interestingly, t-B2N3 is proposed to be a superhard material with an estimated Vicker's hardness of ∼52 GPa by performing stress–strain calculations. More importantly, electronic calculations show unique two-dimensional metallicity in t-B2N3, which originates from the π orbitals of N–N bonds spreading in the ab plane. In addition, the energy density of ∼2.95 kJ g−1 makes t-B2N3 a potential high-energy density material.

2601 Background: Immune checkpoint inhibitors, especially PD-1/PD-L1 inhibitors can promote tumor regression and long-term survival in patients with advanced solid tumors. Despite the characteristic durability of response to ICI, unfortunately some patients may develop acquired resistance after an initial response. The underlying mechanism and effective measure are remarkably limited, perhaps restraining development of immunotherapies. The PRaG trial as a salvage therapy in patients with refractory metastatic solid tumors has obtained satisfactory results(Yuehong Kong et al. ASTRO 2021). With great surprise we found that patients with PD-1/PD-L1 inhibitors acquired resistance are more likely to benefit from the PRaG regimens. This is the PRaG regimen rechallenge that could represent an attractive option in advanced solid tumors. We retrospectively analyzed the clinical efficacy and safety of PRaG regimen (PD-1 inhibitors combined with radiotherapy and GM-CSF with or not IL-2) rechallenge to treat immunotherapy-refractory patients with advanced solid tumors. Methods: This is a retrospective analysis of patients who showed initial resistance to PD-1/PD-L1 inhibitors were retrospectively collected from PRaG serial trails (ChiCTR1900020175 and NCT04892498). Patients received SBRT or HFRT (2-3 doses of 5-8Gy) to a target metastatic site, PD-1 inhibitor was dosing intravenously within one week after completion of SBRT or HFRT, and GM-CSF subcutaneous (SC) injection once daily for 14 days after radiotherapy(the PRaG 2.0 regimen, GM-CSF 200µg SC d1-7, sequentially IL-2 2million IU d8-14.). The specific PRaG regimens had been reported at the meeting of 2020 ASCO. Pooled analysis of response rate (ORR), median progression-free survival (mPFS), and treatment-related adverse events were calculated. Results: A total of 15 multi-metastatic patients were enrolled between October 2020 and February 2022. Thirteen patients showed acquired resistance and underwent at least one assessment, 5 patients were lung cancer, 3 patients were renal cancer, 2 patients were liver cancer, 2 patient was colon cancer, 1 patient was sarcoma. The ORR was 18.2%, and the disease control rate (DCR) was 90.9%. The median PFS was 8.87 months (95%CI, 1.41 to 16.33 months). One lung cancer achieved complete remission, with PFS over 17 months. Treatment-related adverse events of any grade occurred in 11 of 15(73.3%) patients, while there was no grade 3 or higher adverse events. Conclusions: Our preliminary results suggested that PRaG regimens rechallenge maybe an active and feasible strategy in PD-1/PD-L1 inhibitors acquired resistance. The therapy was well tolerated and had acceptable toxicity. A phase III prospective study is being planned to clarify the role of rechallenge after acquired resistance. Clinical trial information: ChiCTR1900020175 and NCT04892498.

2609 Background: It’s been widely recognized that T cells play an essential role in immunotherapy of malignant tumors. Notably, in our previous PRaG trial, we observed that T cell decreasing occurred in some patients with advanced refractory solid tumors during PD-1 inhibitor combined with stereotactic body radiation therapy (SBRT) / hypo-fractionated radiotherapy (HFRT) and granulocyte macrophage-colony stimulating factor (GM-CSF) treatment which might be one of the reasons for their poor efficacy. To further improve the efficacy of immunotherapy combined with radiotherapy, we optimized the PRaG regimen and added interleukin-2 (IL-2), which amplifies and activates T cells. We conducted PRaG 2.0 trial to further explore the effect of T cells on efficacy. Methods: Patients with advanced refractory solid tumors who lacked or were intolerant to the available standard of care were enrolled to receive PRaG 2.0 regimen. A treatment cycle consisted of SBRT or HFRT (5 or 8Gy×2-3f) delivered for one metastatic lesion, PD-1 inhibitor dosing within one week after completion of radiotherapy, GM-CSF 200μg subcutaneous (SC) injection once daily for 7 days (d1-7), and then sequentially followed by IL-2 2million IU SC once daily for 7 days(d8-14). PRaG 2.0 regimen was repeated every 21 days for at least 2 cycles until no appropriate lesions for irradiation or reached the tolerance dose of normal tissues. Patients who could not continue radiotherapy and had not yet developed progression disease (PD) allowed PD-1 inhibitors to be continued as maintenance therapy until PD or unacceptable toxicity but no more than one year. The primary endpoint was Progression-Free Survival (PFS). This trial was registered at www.clinicaltrials.gov with identifier number NCT04892498. Results: With the cutoff date of 31 December 2021, a total of 34 patients were enrolled, in which 28 patients (82%) completed at least 1 tumor assessment with a median follow-up time of 5.5 months (95%CI: 4.4, 6.6). Median PFS and overall survival (OS) were currently not reached. The objective response rate (ORR) was 21.4%, and the disease control rate (DCR) was 71.4% by RECIST1.1. Compared to baseline, no significant decrease of T cells, including CD3+, CD4+, and CD8+ T cells, have been observed in 19 patients who completed ≥ 4 treatment cycles. Treatment-related adverse events (TRAE) occurred in 28 of 34 (82.4%) patients, Grade ≥ 3 TRAEs occurred in three patients (8.8%). TRAEs leading to treatment interruption occurred in three patients (8.8%). Conclusions: These preliminary results of PRaG 2.0 trial demonstrate that PD-1 inhibitors in combination with radiotherapy, GM-CSF, and IL-2 could potentially maintain the T cells and improve clinical outcomes in patients with advanced refractory solid tumors with acceptable toxicity. Clinical trial information: NCT04892498.

e15561 Background: Immunotherapy has improved outcomes for metastatic colorectal cancer(mCRC) patients with MSI-H/dMMR but has not been effective in MSS/pMMR tumors, which comprise 95% of mCRC. In metastatic cancers, radiotherapy can be used as a local therapy and a sensitizer to PD-1/PD-L1 inhibitors. The synergistic effects of radiotherapy and PD-1/PD-L1 inhibitors can be reinforced by adding cytokines like granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-2(IL-2). Our previous PRaG trial demonstrated that PD-1 inhibitors in combination with radiotherapy and GM-CSF could improve clinical response in patients with advanced refractory solid tumors. We found that mCRC patients with MSS/pMMR could also benefit from the PRaG regimen. Methods: Patients of mCRC with MSS/pMMR were collected from the PRaG trial and PRaG 2.0 trial. A treatment cycle consisted of radiotherapy (5 or 8Gy×2-3f) delivered for one metastatic lesion, PD-1 inhibitor dosing within one week after completion of radiotherapy, GM-CSF 200μg subcutaneous (SC) injection once daily for 14 days(d1-14), or GM-CSF 200μg (d1-7), and then sequentially followed by IL-2 200 million IU SC once daily for 7 days(d8-14). PRaG regimen was repeated every 21 days for at least 2 cycles until no appropriate lesions for irradiation or reached the tolerance dose. Pooled analysis of response rate (ORR), median progression-free survival (PFS), and treatment-related adverse eventswere calculated. Results: With the cutoff date of 31 December 2021, a total of 9 mCRC patients with MSS/pMMR were enrolled. All of the patients completed at least 2 cycles of PRaG therapy and one evaluation. The median follow-up was 7.6 months (95%CI, 3.8, 11.4). The ORR was 22.2%, and the disease control rate(DCR) was 66.7%. The median PFS was 5.6 months (95%CI, 1.5 to 9.7). One patient got complete remission, with PFS over 17months. Treatment-related adverse events (TRAE) occurred in 7 of 9 (77.8%) patients. One patient (11.1%) occurred Grade3 TRAE of renal insufficiency. Conclusions: Our preliminary results suggest that the PRaG regimen could improve clinical outcomes in mCRC patients with MSS/pMMR with acceptable toxicity.

e14565 Background: The development of anticancer therapy tends to focusing on pan-cancer analysis, targeted therapy and immunotherapy with the advance of molecular and tumor microenvironment. Radiotherapy produces an immunomodulatory effect that may act synergistically with PD-1/PD-L1 inhibitor in multiple malignancies. Previous phase II trial showed HFRT/SBRT combined with PD-1 inhibitor and GM-CSF (PRaG regimen) has obtained promising results(Yuehong Kong et al. ASTRO 2021). RC48-ADC is a novel HER2-targeting antibody-drug conjugate (ADC). Preclinical studies indicated that ADC elicit immunogenic cell death and selectively radiosensitize to tumours. RC48-ADC combined with HFRT, PD-1/PD-L1 inhibitor sequential GM-CSF and IL-2 (PRaG3.0 regimen) could further improve the synergistic antitumor effects, this precise combination therapy paradigm provides an exploratory path for the treatment of pan-cancer. An exploratory phase II, open-label, multi-centre, single-arm study was conducted to evaluate the initial clinical efficacy and safety of PRaG3.0 regimen for treatment of HER2-expressing advanced solid tumors. Methods: Participants with advanced, confirmed HER2-expressing(IHC3+, 2+ or 1+) solid tumors that had progressed after the standard of care or intolerance were enrolled. In the cycle, those received RC48-ADC(2.0 mg/kg d1, every 3 weeks), then HFRT (2-3 doses of 5-8Gy) was delivered for one metastatic lesion every other day, followed by GM-CSF(200 μg d3-7), sequential IL-2(2million IU d8-12), and PD-1/PD-L1 inhibitor was dosing within one week after completion of HFRT. After RC48-ADC combined with PD-1/PD-L1 inhibitor sequential GM-CSF and IL-2 for at least 6 cycles, then maintenance with PD-1/PD-L1 inhibitor was administered until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR). This trial is registered with ClinicalTrials.gov, number NCT05115500. Results: With the cutoff date of 11 February 2022, a total of 8 patients were enrolled. Among 6 patients who had at least one tumor assessment, involved gastric cancer(3/6), breast cancer(1/6), cervical cancer(1/6), pancreatic cancer(1/6). The ORR was 66.7% (4/6) and disease control rate (DCR) was 83.3%(5/6). One cervical cancer and one pancreatic cancer achieved complete remission. The most common treatment-related adverse events (TRAEs) were alopecia (37.5%), fatigue (25%) and hepatic damage(12.5%). No Grade 3 and higher adverse events occurred. Conclusions: The PRaG3.0 regimen manifested manageable safety profile and encouraging efficacy. So PRaG3.0 regimen is considered as a promising salvage treatment for patients with HER2-expressing advanced solid tumors. And the conclusion should be validated in more patients subsequently. Clinical trial information: NCT05115500.

Ovothiols are thiol-histidines that play important roles in protecting cells against oxidative stresses. Because of challenges faced in their chemical synthesis, biosynthesis provides an alternative option. In ovothiol biosynthesis, a nonheme iron enzyme (OvoA) catalyzes a four-electron oxidative coupling between l-His and l-Cys. There are debates in the literature over whether oxidative C–S bond formation or sulfur oxidation is the first half of OvoA-catalysis. In this report, by incorporating a tyrosine analogue, 2-amino-3-(4-hydroxy-3-(methoxyl) phenyl) propanoic acid (MeOTyr), via an amber-suppressor method, we modulated the rate-limiting steps of OvoA-catalysis and observed an inverse deuterium KIE for [U-2H5]-His. In conjunction with the reported quantum mechanics/molecular mechanics (QM/MM) studies, our results suggest that Y417 plays redox roles in OvoA-catalysis and imply that oxidative C–S bond formation is most likely the first half of the OvoA-catalysis.

Motivated by the idea of 'decomposition and ensemble', this paper proposes a novel method based on the wavelet-denoising algorithm and multiple echo state networks to improve the prediction accuracy of noisy multivariate time series. The noisy time series is first denoised by a wavelet soft thresholding algorithm and decomposed into a set of well-behaved constitutive series. Each constitutive series is then predicted by a separate echo state network with proper parameters that match the specified dynamics. Finally, the overall prediction is achieved by a linear combination of the constitutive series. For each constitutive series, we use the correlation integral method to select the phase-reconstruction parameters and to construct the appropriate input. Two sets of multivariate time series are investigated using the proposed model and some other related work. The simulation results demonstrate the effectiveness of the proposed method.

Rising CO

To explore the feasibility of using Volumetric-Modulated Arc Therapy (VMAT) to protect left anterior descending branch (LAD) after breast-conserving surgery for left breast cancer. 15 left breast cancer patients after breast-conserving surgery were selected. 7F-IMRT and 2A-VMAT treatment plans were designed with Varian Eclipse TPS (13.6version). The prescriptions of PTV and PTV Boost were 43.5Gy and 49.5Gy in 15 fractions. The dosimetric parameters, OARs dose sparing and second cancer risk (SCR) were compared between the two plans using a paired t-test. The VMAT plans obtain better PTV conformity and higher mean dose. VMAT plans show a better dose distribution in high dose areas and better sparing of OARs, including left lung, heart, and LAD. The Dmax and Dmean of LAD decreased significantly in VMAT plans. The SCRs of the contralateral lung and breast significantly increased with a higher mean dose. We recommend that contouring and evaluating the dose of LAD and LAD helping structures in left breast cancer radiotherapy. SCR should be evaluated for younger patients.

Cadmium accumulation in rice is a major source of Cd exposure in humans worldwide. A three-year field experiment was conducted to investigate the ecological safety and long-term stability of biochar combined with lime or silicon fertilizer for Cd immobilization in a polluted rice paddy. The results showed that the application of combined ameliorants could reduce the Cd content in brown rice to meet the Chinese maximum permissible limit for Cd content in food products (0.2 mg/kg). In addition, such amendments stimulated metabolic pathways in soil bacteria, including carbon metabolism, citrate cycle, pyruvate metabolism, biosynthesis of amino acids, and glycolysis/gluconeogenesis, revealing improvements in soil biological activity and soil health. Therefore, the results provide a practical strategy for the safe utilization of farmland with mild levels of heavy metal pollution.

Background. The prevalence of coronary artery anomalies (CAAs) is rare and varies among different countries or areas. More importantly, the symptoms exhibited by some CAAs make the diagnosis of coronary artery disease (CAD) difficult and hamper the physician from making the right intervention for CAD patients. Objective. To investigate the prevalence of CAAs in 11,267 patients from three hospitals in Southwest China. Methods. 11,267 patients who have undergone coronary angiography from three Southwest China hospitals were investigated retrospectively. Dominance patterns, prevalence, and the location of each CAA were recorded and analyzed. Results. The presence of a dominant right coronary artery (RCA) was found in 60.58% of patients. CAAs were found in 11.12% (1258) patients, and 87.66% anomalies were located in the left anterior descending (LAD) artery and its branches. Most of CAAs were found to be myocardial bridges (MBs, 1060 cases, 9.41%). Other CAAs included anomalous coronary origin (43 cases, 0.38%), coronary artery fistulas (CAFs, 36 cases, 0.32%), and coronary artery aneurysm or ectasia (119 cases, 1.06%). It also noted that most anomalies were found with RCA originating from the left coronary sinus (79.07%), most CAFs were located in the LAD and its branches (58.33%), and most coronary artery ectasias were located in the RCA (43.25%). Conclusions. CAAs in patients from Southwest China were unique compared to other studies. Recognition of these CAAs is important for accurate diagnosis and treatment choice of patients with chest pain.

A novel β-cyclodextrin pendant polymer (ε-PL-CD), composed of poly(ε-lysine) (ε-PL) main chain and glycine-β-cyclodextrin (Gly-CD) side chains, was prepared by a simple two-step procedure. The ε-PL-CD was investigated as a drug carrier of hydrophobic drug scutellarin (SCU). The characterization and complexation mode of the SCU:ε-PL-CD were researched in both solution and solid state by means of photoluminescence spectroscopy, 1H and 2D NMR, X-Ray powder diffraction (XRPD), thermal gravimetric analysis, Particle size and Zeta potential. The solubility test indicated that the solubilizing ability of SCU:ε-PL-CD was significantly improved compared with SCU:β-CD and free SCU. Besides, in vitro cell experiment, it was found that SCU:ε-PL-CD has a strong inhibitory effect on the growth and invasion of tumor cells. The present study provides useful information for ε-PL-CD as a drug carrier material.

In order to solve the problem of the speech recognition, this paper proposes a novel framework to process speech signals by using the deep fully convolutional neural network (DFCNN) as the acoustic model and the Transformer as the linguistic model. DFCNN can learn more about speech signals through a deep network structure, while Transformer's self-attention mechanism makes it an efficient linguistic model. In order to better extract the characteristic information of speech signal, we transform the speech signal into a two-dimensional language spectrum by frame division and Fourier transform. In this way, the language spectrum can be processed by using convolutional neural network, which has promising ability to process two-dimensional data. The output of the acoustic model is passed into the linguistic model, and a complete sentence is output. At the same time, considering that there are many hyper parameters in the model, in order to adjust these hyper parameters efficiently, we employ the Bayesian optimization algorithm to optimize the hyper parameters of the acoustic model and the linguistic model, so as to further improve the accuracy of speech recognition. Experimental results on speech recognition library THCHS30 show that compared with other models, the optimized model has higher recognition rate for audio and stronger generalization ability.

Time series prediction is an active area and attracts the attention of researchers from lots of fields. With the expansion of the application of time series forecasting in the real world, many traditional methods that predicted time series with a few data are no longer applicable. Motivated by the demand of accurate prediction, we come up with the piecewise time series prediction model combining stacked long short-term memory network with genetic algorithm. Stacked long short-term memory network (LSTM) is an advanced sequence learning technology. We divide the time series into several segments and then use the stacked LSTM trained on the previous segment to predict the next segment to realize online prediction. The parameters of the stacked LSTM for each segment prediction are optimized by improved genetic algorithm. For purpose of demonstrating the feasibility and effectivity of the proposed model, we carry out simulation experiments on basis of a hybrid benchmark chaotic time series and a real-world dataset of the hourly ozone concentration. Experimental results demonstrate that the proposed model can automatically select the proper structure according to the data, which avoids the structure being too redundant or too simple. Furthermore, it can improve the prediction accuracy of time series and has good practicability.

Background: Collective duct carcinoma (CDC) is a highly malignant kidney tumor which is rare in clinical. We report our 12-year experience of Collecting (Bellini) duct carcinoma (CDC) and retrospectively analyzed patients and tumour characteristics, clinical manifestations, different imaging characteristics including CT, MRI and PET/CT. Methods: From January 2007 to December 2019, we retrospectively examined all renal tumors and identifed 13 cases of CDC from 3 medical centers in the northern China. All 13 patients underwent CT scan, 8 of whom underwent dynamic enhanced CT scan, 2 underwent PET/CT scan and 1 underwent MRCP examination. The lesions were divided into nephritis type and mass type according to the morphology of the tumors.Results: The study group included 10 men and 3 women, with an average age of 64.23±10.74 years old. Of these 13 patients, the main clinical manifestations include gross hematuria, flank pain or waist discomfort. The mean tumour size was 8.48 ± 2.48 cm. In this group of cases, 6 (46.2%) cases are cortical-medullary involved type, 7 (53.8%) cases are cortex-medullary-pelvis involved type. 11 (84.6%) cases were nephritis type and 2 (15.4%) cases were mass type. The lesions appeared solid or complex solid and cystic on CT and MRI. The parenchymal part of 13 CDC tumors showed isodensity or slightly higher density on unenhanced CT scan. the parenchymal part of 13 CDC tumors showed isodensity or slightly higher density on unenhanced CT scan. Two patients with PET/CT showed increased radioactivity intake. Evidence of intra-abdominal metastatic disease was present on CT in 9 ( 69.2% ) cases. The incidence of metastasis reached 69%.Conclusions: The Collecting (Bellini) duct carcinoma has its certain imaging characteristics which were different from the other renal cell carcinoma. A renal tumor should be considered as CDC when it locates in the junction zone of the renal cortex and medulla, with unclear border, slight enhancement and metastases in early stage. PET/CT can greatly enrich the key information of diagnosis, surgery and treatment options, which provide significant help to the clinic.

Rising CO2 levels will change the behavior and toxicity of soil contaminants. However, it remains unclear whether elevated CO2 levels will change the nanoparticle dissolution or their biological effects in soil. In this study, we used a free-air CO2 enrichment system to examine the effects of elevated CO2 on phytotoxicity and bacterial toxicity of zinc oxide nanoparticles (nZnO) in a paddy soil system. The elevated CO2 changed the nZnO diffraction in soil, slightly increasing its dissolution but remarkably improving its bioavailability. Elevated CO2 did not change Zn accumulation in rice, but still alleviated the adverse effects of nZnO on rice growth, although grain protein, K and P decreased. Moreover, nZnO alone significantly decreased the number of observed soil bacterial species and altered the community organization, while elevated CO2 moderated such changes. Overall, these results increase our understanding of plant response and microbial variation in nanoparticle-contaminated soil under elevated-CO2 conditions. It is necessary to pay attention to soil pollution while facing climate change.

Microplastics were reported to adsorb antibiotics and may modify their effects on soil systems. But there has been little research investigating how microplastics may affect the toxicities of antibiotics to microbes under future climate conditions. Here, we used a free-air CO

The design of two-dimensional superconductors has attracted great research interest owing to their wide application in nanoscale devices. Here, we combine first-principles calculations with structure searching technology to identify a unique stable hexagonal $h\text{\ensuremath{-}}{\mathrm{MnB}}_{3}$ monolayer, exhibiting a slightly higher energy with respect to the reported tetragonal $t\text{\ensuremath{-}}{\mathrm{MnB}}_{3}$. Interestingly, $h\text{\ensuremath{-}}{\mathrm{MnB}}_{3}$ contains two boron kagome layers sandwiched with Mn atoms. It exhibits metallic properties and has a superconducting transition temperature of 24.9 K, which is much higher than 2.9 K in $t\text{\ensuremath{-}}{\mathrm{MnB}}_{3}$. Its superconductivity mainly originates from the coupling between in-plane vibrational phonons of boron kagome layers and electrons of Mn atoms. $h\text{\ensuremath{-}}{\mathrm{MnB}}_{3}$ exhibits a tunable superconductivity, and reaches a maximum of 34 K at 2% tensile strain resulting from the softening in-plane modes of boron kagome layers. The Si (111) surface may be an ideal substrate for the growth of superconductive $h\text{\ensuremath{-}}{\mathrm{MnB}}_{3}$. The unique superconducting mechanism observed here could inspire the searching of more boron kagome based two-dimensional superconductors.

Background: Collective duct carcinoma (CDC) is a highly malignant kidney tumor which is rare in clinical. We report our 12-year experience of Collecting (Bellini) duct carcinoma (CDC) and retrospectively analyzed patients and tumour characteristics, clinical manifestations, different imaging characteristics including CT, MRI and PET/CT. Methods: From January 2007 to December 2019, we retrospectively examined all renal tumors and identifed 13 cases of CDC from 3 medical centers in the northern China. All 13 patients underwent CT scan, 8 of whom underwent dynamic enhanced CT scan, 2 underwent PET/CT scan and 1 underwent MRCP examination. The lesions were divided into nephritis type and mass type according to the morphology of the tumors.Results: The study group included 10 men and 3 women, with an average age of 64.23±10.74 years old. Of these 13 patients, the main clinical manifestations include gross hematuria, flank pain or waist discomfort. The mean tumour size was 8.48 ± 2.48 cm. In this group of cases, 6 (46.2%) cases are cortical-medullary involved type, 7 (53.8%) cases are cortex-medullary-pelvis involved type. 11 (84.6%) cases were nephritis type and 2 (15.4%) cases were mass type. The lesions appeared solid or complex solid and cystic on CT and MRI. The parenchymal part of 13 CDC tumors showed isodensity or slightly higher density on unenhanced CT scan. the parenchymal part of 13 CDC tumors showed isodensity or slightly higher density on unenhanced CT scan. Two patients with PET/CT showed increased radioactivity intake. Evidence of intra-abdominal metastatic disease was present on CT in 9 ( 69.2% ) cases. The incidence of metastasis reached 69%.Conclusions: The Collecting (Bellini) duct carcinoma has its certain imaging characteristics which were different from the other renal cell carcinoma. A renal tumor should be considered as CDC when it locates in the junction zone of the renal cortex and medulla, with unclear border, slight enhancement and metastases in early stage. PET/CT can greatly enrich the key information of diagnosis, surgery and treatment options, which provide significant help to the clinic.

Background: Studies have shown that gut microbiota may be involved in the occurrence and progression of Parkinson's disease (PD). Nevertheless, the alterations in fecal microbiome in PD patients from Central China have not been previously investigated, and the way in which these microbes influence PD remain unclear.Methods: We performed metagenomic shotgun analyses to investigate the gut microbiota composition of 46 Central China PD patients and their healthy spouses. The relationships between microbiota and PD clinical features were analyzed, and functional pathways were compared for further understaning the contributions of gut microbiota in PD. We also explored potential biomarker for PD diagnosis.Results: Microbial communities in the feces of PD patients were notably different from those of healthy spouses at species level. Gut microbiota of patients was characterized by depletion of Subdoligranulum_unclassified and Prevotella_copri, while the Bacteroides_stercoris and Escherichia_coli were markedly elevated. Correlation analysis found that most identified species were negatively correlated with disease clinical features. In particular, Prevotella_copri was negatively correlated with age, H-Y stage, UPDRS total score and UPDRS Ⅲ score. Random forest model indicated that 6 species including Prevotella_copri had good predictive value for disease. Functional analyses of the metagenomes revealed differences in microbiota metabolism. Pathways associated with superpathway of thiamin diphosphate biosynthesis, 4-aminobutanoate degradation, glucose-1-phosphate degradation and methylphosphonate degradation were significant increase in patients, while pathways associated with aromatic amino acid biosynthesis, chorismate biosynthesis, thiamin formation and pyrimidine deoxyribonucleosides salvage were significantly decrease. Functional pathways of Prevotella_copri were mainly concentrated in UMP biosynthesis, S-adenosyl-L-methionine cycle and guanosine ribonucleotides de novo biosynthesis. Conclusion: This study revealed the differences of gut microbiota between PD patients and their healthy spouses. Altered microbiota had correlation with the clinical characteristics of the disease, and maybe used as potential biomarkers for disease status prediction. We also observed differenct functional pathways of gut microbiota in PD patients,which may help to reveal the mechanism of disease occurrence and progression.

Uranus and Neptune are generally assumed to have helium only in their gaseous atmospheres. Here, we report the possibility of helium being fixed in the upper mantles of these planets in the form of NH3–He compounds. Structure predictions reveal two energetically stable NH3–He compounds with stoichiometries (NH3)2He and NH3He at high pressures. At low temperatures, (NH3)2He is ionic with NH3 molecules partially dissociating into (NH2)− and (NH4)+ ions. Simulations show that (NH3)2He transforms into intermediate phase at 100 GPa and 1000 K with H atoms slightly vibrate around N atoms, and then to a superionic phase at ~2000 K with H and He exhibiting liquid behavior within the fixed N sublattice. Finally, (NH3)2He becomes a fluid phase at temperatures of 3000 K. The stability of (NH3)2He at high pressure and temperature could contribute to update models of the interiors of Uranus and Neptune., Helium is generally considered too inert to be present in giant ice planet mantles. The authors, by first-principles calculations and crystal structure searches, find stable ammonia–helium compounds at the conditions of Uranus and Neptune’s upper mantles, with possible implications in the planet composition models.

PEMFC are considered to be the most promising for automotive energy because of their good working effect, low temperature, high efficiency, and zero pollution. Stainless steel as a PEMFC bipolar plate has unparalleled advantages in strength, cost, and processability, but it is easy to corrode in a PEMFC working environment. In order to improve the corrosion resistance, the surface modification of 316L stainless steel is a feasible solution for PEMFC bipolar plates. In the present study, the plasma-nitrided coating and CrNx coating were prepared by the plasma-enhanced balanced magnetron sputtering technology on the 316L stainless steel surface. The microstructures, phase compositions, and corrosion resistance behavior of the coatings were investigated. The corrosion behavior of the prepared plasma-nitrided coating and CrNx coating was investigated by potentiodynamic polarization, potentiostatic polarization, and electrochemical impedance spectroscopy (EIS) in both cathodic and anodic environments. The experimental results show that corrosion resistance of the CrNx coating was better than the plasma-nitrided coating. It was indicated that the technology process of nitriding first and then depositing Cr was better than nitriding only.

Correction for ‘The intrinsic magnetism, quantum anomalous Hall effect and Curie temperature in 2D transition metal trihalides’ by Jiaxiang Sun et al., Phys. Chem. Chem. Phys., 2020, DOI: 10.1039/c9cp05084a.

Searching for experimentally feasible intrinsic quantum anomalous Hall (QAH) insulators is of great significance for dissipationless electronics applications. Here we predict, based on density functional theory (DFT), that four monolayer transition metal tri-bromides (VBr3, FeBr3, NiBr3, and PdBr3) are endowed with intrinsic half-metallicity and possess quantum anomalous Hall insulating phases. DFT+U calculations reveal that the VBr3, NiBr3, and PdBr3 monolayers undergo nontrivial to Mott insulator transitions with increasing on-site Hubbard Coulomb interaction U at 0.5, 2 and 3 eV. The gap opening induced by the spin-orbit coupling drives the systems into the QAH state. The Curie temperatures of the VBr3, NiBr3, and PdBr3 monolayers are ∼190, 100 and 110 K. Additionally, the calculated cleavage energies suggest that the freestanding VBr3, FeBr3, NiBr3, and PdBr3 monolayers can be easily produced by exfoliation using adhesive tape, which may stimulate experimental research interest to achieve QAH phases.

Accurate prediction of solar irradiance is beneficial in reducing energy waste associated with photovoltaic power plants, preventing system damage caused by the severe fluctuation of solar irradiance, and stationarizing the power output integration between different power grids. Considering the randomness and multiple dimension of weather data, a hybrid deep learning model that combines a gated recurrent unit (GRU) neural network and an attention mechanism is proposed forecasting the solar irradiance changes in four different seasons. In the first step, the Inception neural network and ResNet are designed to extract features from the original dataset. Secondly, the extracted features are inputted into the recurrent neural network (RNN) network for model training. Experimental results show that the proposed hybrid deep learning model accurately predicts solar irradiance changes in a short-term manner. In addition, the forecasting performance of the model is better than traditional deep learning models (such as long short term memory and GRU).

Just noticeable distortion (JND) is widely employed to describe the perception redundancy in the quantization-based watermarking framework. However, the existing JND models are generally constructed to treat every region of the photograph with an equal focus level, whereas the defocus effect has never been considered. In this paper, the defocus feature, which can portray the aesthetic emphasis in the photograph, is provided to improve the perceptual JND model. Firstly, two indicators which consider the block energy in the defocus measurement (DM) are proposed. Then, the defocus feature map (DFM) is obtained by integrating the influence of the circumambient blocks, and it is applied to the proposed JND contrast masking (CM) processing. In this way, a new blind photograph watermarking method, with emphasis on defocus-JND estimation combined with the proposed CM, is presented. Simulations show that the proposed JND is more suitable for watermarking framework than some exiting JND models, and the proposed watermarking scheme with the improved defocus-based JND model has superior robustness compared with some watermarking schemes.

Crystalline silicon is dominating the current solar cell market due to the significant efficiency improvement and cost reduction in last decades. However, its indirect band gap nature leads to inefficient visible-light absorption, which seriously impedes further performance enhancement in silicon-based photovoltaic devices. Thus, it is highly desirable to develop direct band gap silicon materials. Herein, by means of ab initio swarm-intelligence structure-searching method, we predicted a quasi-direct gap semiconducting tri-layer silicene structure consisting of alternating arrays of six-membered Si rings, which can be converted into a direct gap semiconductor of 0.86 eV by applying a low tensile strain (~ 2.5%). Our calculations revealed that the photovoltaic efficiency of the tri-layer silicene reaches 29% at 1.0 µm, which is comparable to that of bulk GaAs with the highest conversion efficiency among thin-film solar cell absorbers.

Two-dimensional (2D) materials have recently attracted significant interest in condensed-matter physics and materials science due to rich intriguing physics and potential applications. Here, by first-principles calculations, we discover a phase of transition-metal dichalcogenides (MoS2 and its family) named the 1H′ phase. We demonstrate that 1H′MoS2 monolayer has multiple topological phase transitions from a topologically trivial insulator state to a 2D type-II Dirac semimetal state, and then to a 2D ideal type-I semimetal state under a moderate tensile strain. The Dirac points are protected by the coexistence of space-inversion (P) and time-reversal (T) symmetry. Our results highlight a family of nonhoneycomb 2D Dirac semimetals with potential application in nanoelectronics.

Ground surface settlement forecasting in the process of tunnel construction is one of the most important techniques towards sustainable city development and preventing serious damages, such as landscape collapse. It is evident that modern artificial intelligence (AI) models, such as artificial neural network, extreme learning machine, and support vector regression, are capable of providing reliable forecasting results for tunnel surface settlement. However, two limitations exist for the current forecasting techniques. First, the data provided by the construction company are usually univariate (i.e., containing only the settlement data). Second, the demand of tunnel surface settlement is immediate after the construction process begins. The number of training data samples is limited. Targeting at the above two limitations, in this study, a novel ensemble machine learning model is proposed to forecast tunnel surface settlement using univariate short period of real-world tunnel settlement data. The proposed Adaboost.RT framework fully utilizes existing data points with three base machine learning models and iteratively updates hyperparameters using current surface point locations. Experimental results show that compared with existing machine learning techniques and algorithms, the proposed ensemble learning method provides a higher prediction accuracy with acceptable computational efficiency.

Background Allopolyploids require rapid genetic and epigenetic modifications to reconcile two or more sets of divergent genomes. To better understand the fate of duplicate genes following genomic mergers and doubling during allopolyploid formation, in this study, we explored the global gene expression patterns in resynthesized allotetraploid Brassica napus (AACC) and its diploid parents B. rapa (AA) and B. oleracea (CC) using RNA sequencing of leaf transcriptomes. Results We found that allopolyploid B. napus formation was accompanied by extensive changes (approximately one-third of the expressed genes) in the parental gene expression patterns (‘transcriptome shock’). Interestingly, the majority (85%) of differentially expressed genes (DEGs) were downregulated in the allotetraploid. Moreover, the homoeolog expression bias (relative contribution of homoeologs to the transcriptome) and expression level dominance (total expression level of both homoeologs) were thoroughly investigated by monitoring the expression of 23,766 B. oleracea-B. rapa orthologous gene pairs. Approximately 36.5% of the expressed gene pairs displayed expression bias with a slight preference toward the A-genome. In addition, 39.6, 4.9 and 9.0% of the expressed gene pairs exhibited expression level dominance (ELD), additivity expression and transgressive expression, respectively. The genome-wide ELD was also biased toward the A-genome in the resynthesized B. napus. To explain the ELD phenomenon, we compared the individual homoeolog expression levels relative to those of the diploid parents and found that ELD in the direction of the higher-expression parent can be explained by the downregulation of homoeologs from the dominant parent or upregulation of homoeologs from the nondominant parent; however, ELD in the direction of the lower-expression parent can be explained only by the downregulation of the nondominant parent or both homoeologs. Furthermore, Gene Ontology (GO) enrichment analysis suggested that the alteration in the gene expression patterns could be a prominent cause of the phenotypic variation between the newly formed B. napus and its parental species. Conclusions Collectively, our data provide insight into the rapid repatterning of gene expression at the beginning of Brassica allopolyploidization and enhance our knowledge of allopolyploidization processes. Electronic supplementary material The online version of this article (10.1186/s12864-018-4966-5) contains supplementary material, which is available to authorized users.

Controlling magnetism of two-dimensional multiferroics by an external electric field provides special opportunities for both fundamental research and future development of low-cost electronic nanodevices. Here, we report a general scheme for realizing a magnetic phase transition in 2D type-I multiferroic systems through the reversal of ferroelectric polarization. Based on first-principles calculations, we demonstrate that a single-phase 2D multiferroic, namely, ReWCl_{6} monolayer, exhibits two different low-symmetric (C_{2}) phases with opposite in-plane electric polarization and different magnetic order. As a result, an antiferromagnetic-to-ferromagnetic phase transition can be realized by reversing the in-plane electric polarization through the application of an external electric field. These findings not only enrich the 2D multiferroic family, but also uncover a unique and general mechanism to control magnetism by electric field, thus stimulating experimental interest.

Pectate lyase catalyses the eliminative cleavage of de-esterified pectin, which is a major component of primary cell walls in many higher plants. Pectate lyase-like (PLL) genes have been identified in various plant species and are involved in a broad range of physiological processes associated with pectin degradation. Previous studies have functionally identified two PLL genes in rice (Oryza sativa. L). However, the knowledge concerning genome-wide analysis of this family remains limited, and functions of the other PLL genes have not been thoroughly elucidated to date. In this study, we identified 12 PLL genes based on a genome-wide investigation in rice. A complete overview of this gene family is presented, including chromosomal locations, exon-intron structure, cis-acting elements and conserved motifs. PLL protein sequences from multiple plant species were compared and divided into five groups based on phylogenetic analysis. Quantitative RT-PCR analysis revealed that only a portion of OsPLL genes (4 of 12) exhibits detectable expression levels. Notably, OsPLL1, OsPLL3, OsPLL4 and OsPLL12 exhibit strong and preferential expression in panicles suggesting that the potential roles of these genes are crucial during rice panicle development. Moreover, knockdown of OsPLL3 and OsPLL4 by artificial microRNA (amiRNA) disrupted normal pollen development and resulted in partial male sterility. These results could provide valuable information for characterising the functions and dissecting the molecular mechanisms of the OsPLL genes.

With the applications of Internet of Things (IoT) for smart cities, the real-time performance for a large number of network packets is facing serious challenge. Thus, how to improve the emergency response has become a critical issue. However, traditional packet scheduling algorithms cannot meet the requirements of the large-scale IoT system for smart cities. To address this shortcoming, this paper proposes EARS, an efficient data-emergency-aware packet scheduling scheme for smart cities. EARS describes the packet emergency information with the packet priority and deadline. Each source node informs the destination node of the packet emergency information before sending the packets. The destination node determines the packet scheduling sequence and processing sequence according to emergency information. Moreover, this paper compares EARS with a first-come, first-served, multilevel queue algorithm and a dynamic multilevel priority packet scheduling algorithm. Simulation results show that EARS outperforms these previous scheduling algorithms in terms of packet loss rate, average packet waiting time, and average packet end-to-end delay.

Background Meningeal carcinomatosis (MC) is characterized by diffuse infiltration of tumor cells in meninges. There is no tumor mass in the brain and parenchyma of the spinal cord. MC is divided into primary and metastatic types. MC cases were previously diagnosed postoperatively or at autopsy. Recent advances in spinal abbreviation cytology and imaging have led to increase in number of reported cases. In this study, we discuss the manifestations of MC patients based on magnetic resonance imaging (MRI) findings, as well as the correlation between the manifestations and pathology. Case presentation MC was confirmed in all three cases by lumbar puncture and gadopentetate dimeglumine-enhanced magnetic resonance imaging. Due to different primary diseases, the patients had specific imaging manifestations. Conclusion Enhanced MRI examination is extremely sensitive for detecting abnormalities in meninges, which plays a very important role in the diagnosis of MC. Since meninges of some MC patients cannot be enhanced, the enhanced MRI examination cannot be replaced by conventional cerebrospinal abbreviation examination. Attribute to the diversity of MR contrast agents, which could provide higher lesion conspicuity and enhances lesion detection, there may be some more choices to improve the detection rate of MC patients and prolong their survival lifetime.

Monolayer MoS2 has long been considered as the most promising candidate for wearable photovoltaic devices. However, its photovoltaic efficiency is restricted by its large band gap (2.0 eV). Though the band gap can be reduced by increasing the number of layers, the indirect band gap nature of the resulting multilayer MoS2 is unfavorable. Herein, we report a theoretical discovery of the hitherto unknown symmetry-broken phase (denoted as 1Td) of monolayer MoS2 through a swarm structure search. The 1Td phase has a distorted octahedral coordinated pattern of Mo, and its direct band gap of 1.27 eV approaches the optimal value of 1.34 eV that gives the Shockley–Queisser limit for photovoltaic efficiency. Importantly, the direct band gap nature persists in thin films with multilayers owing to extremely weak vdW forces between adjacent 1Td layers. The theoretical photovoltaic efficiency at 30 nm thickness reaches ∼33.3%, which is the highest conversion efficiency among all the thin-film solar cell absorbers known thus far. Furthermore, several feasible strategies including appropriate electron injection and annealing methods were proposed to synthesize the 1Td phase. Once synthesized, the superior photovoltaic properties of the 1Td phase may lead to the development of an entirely new line of research for transition metal dichalcogenide solar cells.

The corrosion behavior of a high manganese steel in simulated marine splash zone environment was studied by dry-wet cyclic corrosion experiment and electrochemical experiment. Corrosion kinetics, composition, surface morphology, cross-section morphology, element distribution, valence state, polarization curve and electrochemical impedance spectroscopy were analyzed with the aim of characterizing the characteristics of corrosion product films. The results show that in chloride-containing environment, in the initial corrosion products, Mn oxides with porous structure lead to higher corrosion rate. As corrosion extends, the formation of alloy element oxides in corrosion products changes the corrosion properties of rust layers at different stages. Mo oxides form a stable passivation film, which reduces the influence of chloride ion on corrosion. Ni oxides in the inner rust layer facilitate the transformation of goethite, and Cr oxides in the outer rust layer increase the densification of the rust layer. The stability and compactness of Fe3O4, α-FeOOH and FeCr2O4 in the later corrosion products inhibit the corrosion action of manganese iron oxides and slow down the corrosion rate. With the corrosion durations, the corrosion current density of the sample with the corrosion product film first increases and then decreases, and the corrosion potential first moves negative and then shifts in a positive direction subsequently, indicating that the protective effect of the corrosion product film is gradually significant.

Blending is a promising method to modify the ash-fusion characteristics of coal to meet gasification requirements. To investigate the variation in ash-fusion behavior for high ash-fusion-temperature (AFT) coal through coal blending and its regulating mechanism, the ash-chemistry characteristics of four coals (Nantun, Pengzhuang, Biaodian, and Xiangyuan) were analyzed. Mineral-transformation behaviors in the mixed ashes were investigated by X-ray powder diffractometry using normalized reference intensity ratio software, scanning electron microscopy analyzer equipped with energy-dispersive X-ray spectrometry, and FactSage software. Pengzhuang and Biaodian coals, AFTs meet entrained-flow gasifier requirements when the Xiangyuan mass ratio reaches 20%. The Nantun requires a Xiangyuan mass ratio of XY > 30% because of its high aluminum oxide content. The required Xiangyuan optimal blending mass ratio is 40%–70% for the three high AFT coals to meet gasification requirements in the entrained-flow gasifier. An increased Xiangyuan mass ratio leads to decreasing contents of high melting-point mullite and silica and increasing contents of low melting-point anorthite, hercynite, gehlenite, and hedenbergite. Amorphous matter in three mixed ash types resulted in a decrease in their AFTs. The variation in liquid phase under certain conditions reflects the change in AFT.

Manure application can benefit soil quality and sustainable food productivity, but overapplication can spread high levels of antibiotics and antibiotic resistance genes. A two-year field experiment was conducted to evaluate the comprehensive impacts of organic fertilizer substitution in North China under a wheat–maize rotation. Four treatments were conducted: control (ZF), mineral fertilizer (MF), 50% nitrogen (N) mineral fertilizer substituted with organic fertilizer (MOF), and organic fertilizer (OF). Sulfonamide content, abundance of sulfonamide resistance (sul) genes, soil bacterial community, crop yield, and grain mineral elements were analyzed. Results showed that the MOF and OF treatments increased grain nutrients (phosphorus, potassium), and enriched sulfonamide residue and sul genes in soil. Additionally, the relative abundances of sul1 and sul2 in MOF and OF soils planted with maize were higher than in those planted with wheat. Compared to MF, the OF treatment decreased soil pH and crop yields but increased soil total nitrogen, phosphorus contents, and the abundance of Firmicutes. However, the MOF treatment significantly increased soil bacterial diversity and maintained yields of both wheat and maize. Increases in potential sul genes source bacteria (Planifilum), antibiotics, and soil nutrients accelerated the spread of sul genes in soil. Partial least squares path modeling analysis indicated that the soil bacterial diversity had a strong positive effect on maize yield. These results indicate that substitution of 50% N mineral fertilizer with organic fertilizer has the potential to benefit the stability and sustainability of the soil ecosystem, helping to meet the food demand in North China. However, the risk of antibiotics should be reduced through technical advances.

Whether quality can be improved and style characteristics of different types of tobaccos can be changed after being cured using different methods has not been clear yet. It is necessary to explore the influences of different curing methods on chemical compositions of different types of tobaccos. For this purpose, by taking flue-cured tobacco K326, burley tobacco Yunbai 3 and oriental tobacco Basma 14 as materials, the effects of air-curing, sun-curing and flue-curing methods on chemical compositions of these three types of tobaccos were investigated by taking the freeze-dried tobacco as the control group based on the equilibrium method of matter loss. The results show that compared with freeze-dried tobacco, (1) The air-cured, flue-cured and sun-cured were displayed in a descending order in terms of the dry matter loss and dry matter loss rate of K326, burley and oriental tobaccos thereby. (2) After performing air-cured, sun-cured and flue-cured, the starch contents in the oriental and flue-cured tobaccos greatly reduce while their contents of the total sugar and reducing sugar rose; the contents of starch and reducing sugar in the burley tobacco both decreased. (3) The contents of protein, total nitrogen and nicotine in the three types of air-cured, sun-cured and flue-cured tobaccos all significantly decreased. (4) The reduction amounts of the pigment content in the sun-dried burley and flue-cured tobaccos were the largest while that in the flue-cured oriental tobacco reaches the largest. (5) The total polyphenol contents in the three types of tobaccos all significantly reduced after being air-cured, sun-cured and flue-cured. The total polyphenol contents in the flue-cured and burley tobaccos were significantly larger than those in air-cured and sun-cured ones; the total polyphenol content in the sun-cured oriental tobacco was significantly larger than those in the groups treated with other curing methods. (6) The potassium (K) and chlorine (Cl) contents in the three types of tobaccos processed by the other curing methods were relatively stable. (7) The sensory evaluation scores of flue-cured tobaccos, burley tobacco and oriental tobacco were higher after flue-cured based on Yunnan sensory evaluation method. The study clarifies the transformation law of chemical compositions in different types of tobaccos under different curing methods. A type of tobaccos is not only limited to single curing method. It is feasible to combine multiple curing methods to enrich the style characteristics of tobaccos.

Microplastics were reported to adsorb antibiotics and may modify their effects on soil systems. But there has been little research investigating how microplastics may affect the toxicities of antibiotics to microbes under future climate conditions. Here, we used a free-air CO2 enrichment system to investigate the responses of soil microbes to sulfamethazine (SMZ, 1 mg kg−1) in the presence of polystyrene microplastics (PS, 5 mg kg−1) at different CO2 concentrations (ambient at 380 ppm and elevated at 580 ppm). SMZ alone decreased bacterial diversity, negatively affected the bacterial structure and inter-relationships, and enriched the sulfonamide-resistance genes (sul1 and sul2) and class 1 integron (intl1). PS, at both CO2 conditions, showed little effect on soil bacteria but markedly alleviated SMZ’s adverse effects on bacterial diversity, composition and structure, and inhibited sul1 transmission by decreasing the intl1 abundance. Elevated CO2 had limited modification in SMZ’s disadvantages to microbial communities but markedly decreased the sul1 and sul2 abundance. Results indicated that increasing CO2 concentration or the presence of PS affected the responses of soil microbes to SMZ, providing new insights into the risk prediction of antibiotics under future climate conditions.

In this paper, a novel method (Hybrid–ELM–PLSR) is proposed based on hybrid variable selection algorithm and improved extreme learning machine (ELM) for multivariate chaotic time series prediction. The hybrid variable selection algorithm combines the advantages of filter and wrapper, effectively balancing the calculation speed and prediction accuracy. Moreover, for ELM, multicollinearity, which can result in ill-condition, is always existent among the hidden layer output matrix. And the optimal number of hidden nodes is also difficult to be determined. Therefore,in order to overcome these problems, an improved ELM (ELM–PLSR) is proposed based on partial least square regression (PLSR). It can effectively enhance the stability performance and prediction performance of ELM. Hybrid–ELM–PLSR can be divided into three stages. At first, filter is used to rearrange the input variables through the correlations with desired variables. Then wrapper is used to select the optimal variable subset through evaluating the prediction performance of different subsets. Finally, ELM–PLSR is used to build the prediction model. The simulation experiment results based on San Francisco river runoff dataset demonstrate that the proposed method is effective for multivariate chaotic time series. And the prediction accuracy and reliability are higher than other methods.