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We studied a class of exponential potential model $$V(x)=-a\,e^{-b\,x}$$ ( $$a>0, b>0$$ ) and found that its solutions are given by the Bessel functions, but the energy spectra $$E=-b^2(n+1/2)^2/8$$ which are derived from the quantization condition do not correspond to any discrete bound states. The energy levels which are calculated by the boundary condition $$J_{\nu }(2\sqrt{2a}/b)=0$$ at the origin are in good agreement with the numerical results. We illustrate the wave functions through varying the potential parameters a, b and notice that they are pull back to the origin when the potential parameter a or b increases.

Polycyclic polyprenylated acylphloroglucinols (PPAPs) were mainly obtained from the plants of

Carbon nanotubes (CNTs) have been widely used as the motor and rotor in a rotational transmission nanosystem (RTnS), whose function is to transfer the input rotational frequency of the motor into the output frequency of the rotor through motor-rotor interactions. A wide range of techniques has been explored to achieve a CNT-based RTnS with a stable and adjustable transmission. In this work, a CNT-based rotor is partly immersed into a water box and the associated water-rotor interaction leads to effective manipulation of the transmission efficiency of RTnS. Molecular dynamics simulations are performed on this new RTnS to investigate the dynamic response of the rotor and the local flow field near the water-rotor interface. Various parameters, including ambient temperature, tubes’ radii, and volume fractions of water in the box (V f) are examined for their effects on the rotational transmission efficiency. This study offers useful guidelines for the design of stable RTnS with controllable transmission efficiency.

Speckle noise is a main obstacle for change detection tasks of synthetic aperture radar (SAR) images. However, change detection methods often focus on removing noise and ignore the importance of preserving details of SAR images, which results in a loss of classification accuracy. In order to alleviate the contradiction between removing noise and preserving details, a multi-objective change detection method based on a modified Gaussian mixture model (GMM) is proposed in our paper. In the framework of our multi-objective model, one objective is composed of an special GMM of being applied to distinguish changed and unchanged regions and preserve details. The another is a carefully crafted noise reduction operator for removing speckle noise, which is constructed as a penalty to refine the result of classification. The aforementioned conflicting objectives are optimized simultaneously, which is conducted by a common multi-objective evolutionary algorithm based on decomposition (MOEA/D). Then, a series of solutions are obtained, all of which represent a balance of detail preservation and noise reduction. Compared with three classical change detection methods, the proposed method is applied to four real datasets in experimental studies. Experimental results and theoretical analysis reveal its effectiveness.

Background Giant Juncao is often used as feed for livestock because of its huge biomass. However, drought stress reduces forage production by affecting the normal growth and development of plants. Therefore, investigating the molecular mechanisms of drought tolerance will provide important information for the improvement of drought tolerance in this grass. Results A total of 144.96 Gb of clean data was generated and assembled into 144,806 transcripts and 93,907 unigenes. After 7 and 14 days of drought stress, a total of 16,726 and 46,492 differentially expressed genes (DEGs) were observed, respectively. Compared with normal irrigation, 16,247, 23,503, and 11,598 DEGs were observed in 1, 5, and 9 days following rehydration, respectively. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed abiotic stress-responsive genes and pathways related to catalytic activity, methyltransferase activity, transferase activity, and superoxide metabolic process. We also identified transcription factors belonging to several families, including basic helix-loop-helix (bHLH), WRKY, NAM (no apical meristem), ATAF1/2 and CUC2 (cup-shaped cotyledon) (NAC), fatty acyl-CoA reductase (FAR1), B3, myeloblastosis (MYB)-related, and basic leucine zipper (bZIP) families, which are important drought-rehydration-responsive proteins. Weighted gene co-expression network analysis was also used to analyze the RNA-seq data to predict the interrelationship between genes. Twenty modules were obtained, and four of these modules may be involved in photosynthesis and plant hormone signal transduction that respond to drought and rehydration conditions. Conclusions Our research is the first to provide a more comprehensive understanding of DEGs involved in drought stress at the transcriptome level in Giant Juncao with different drought and recovery conditions. These results may reveal insights into the molecular mechanisms of drought tolerance in Giant Juncao and provide diverse genetic resources involved in drought tolerance research.

Montan resin (MR) is an industrial by-product or solid waste generated during the production of refined montan wax and is not typically reused. In this paper, a bio-modification method using three strains of microorganisms, Acinetobacter venetianus (AV), Pseudomonas aeruginosa (PA), and Phanerochaete chrysosporium (PC), was studied to promote the performance and bio-function of MR so that MR could be recycled. MR can be degraded by these three microorganisms, and their weight loss rates were similar over the treatment period of 15 days. Compared with the original MR, the hydrophilicity of modified MRs was improved, which was related to the increase in apparent oil-water partition coefficients (Kows) and oxygen-containing and hydrophilic groups in modified MRs based on IR and GC-MS analysis. The bio-function of modified MRs by the three strains in terms of promoting maize seed germination and seedling growth was greater compared with untreated MR. Overall, these findings indicate that biomodified MRs might have useful agriculture applications. Implications: An environmentally-friendly method using microorganisms to achieve recycle of solid waste, montan resin (MR) was established in this study. Through this bio-treatment, the performance and bio-function of MR were both improved, that is the appearance and hydrophilicity of modified MRs were better than thoes in before, and the modified MRs treated by three strains showed the better promoting effects on maize seed germination and seedling growth than untreated MR, indicating the modified MRs have the certain potential of agricultural utilization in the future.

To investigate the diagnostic efficacy and predictive value of combined lipoprotein laboratory indexes for atherosclerosis.Clinical data of 250 patients with atherosclerosis admitted to Xianning central hospital, China from January 2015 to December 2018 and 80 healthy subjects on physical examination in the same period were analyzed retrospectively. Serological laboratory indices related to lipid metabolism were measured, and their diagnostic efficacy and predictive value for atherosclerosis were evaluated by univariate and multivariate statistical methods.The levels of lipoprotein-associated phospholipase A2 (Lp-PLA2), small dense low density lipoprotein (sd-LDL), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), triglyceride (TG) and high-sensitivity C-reactive protein (hs-CRP) of the atherosclerosis group were significantly higher than those of the healthy group (P0.05). Logistic regression analysis showed that the levels of LP-PLA2, sd-LDL and hs-CRP were independent factors influencing the occurrence of atherosclerosis (P0.05). Lp-PLA2 combined with sd-LDL had the largest area under ROC curve, and their diagnostic efficiency was higher than that of single serological laboratory indices. There was no significant difference in the levels of Lp-PLA2 and sd-LDL among different types of atherosclerotic diseases (P0.05). The levels of LP-PLA2 and sd-LDL in triple-vessel or left main coronary artery disease were significantly higher than those of single- or double-vessel disease (P0.05). The levels of LP-PLA2 and sd-LDL in double-vessel disease were significantly higher than those of single-vessel disease (P0.05). The level of serum sd-LDL of atherosclerotic patients with alcohol history were significantly higher than those without alcohol history (P0.05).When being used to detect atherosclerosis, Lp-PLA2 combined with sd-LDL has better diagnostic efficacy than separate tests. Meanwhile, there is a correlation between their levels and the severity of disease, which can be used to predict the occurrence of atherosclerosis independently of other risk factors.

Developing novel graphene-based materials with unique mechanical properties is of significance to meet the requirements in new applications. The pristine graphene shows a brittle fracture when the stretching strain on it exceeds the critical value. Further, it fails to bear the external load. Herein, to enhance the ductility of the pristine graphene, we proposed a corrugated sandwich carbon network based on few-layered graphene, in which the two surface layers are bonded with several corrugated core layers via benzene molecules. The effects of factors such as the geometry, temperature, and strain rate on the ductility of the carbon network were evaluated using the uniaxial tension tests by molecular dynamics simulations. Results show that the new carbon material has more than one peak fracture strain in stretching. The second peak fracture strain is proportional to the length difference between the surface layers and core layers. Hence, the carbon network has a tunable ductility, which suggests a flexible design of such novel materials in a nanostructure/nanodevice with large deformation.

Background After spinal cord injury (SCI), destructive immune cell subsets are dominant in the local microenvironment, which are the important mechanism of injury. Studies have shown that inflammasomes play an important role in the inflammation following SCI, and apoptosis-associated speck-like protein containing a card (ASC) is the adaptor protein shared by inflammasomes. Therefore, we speculated that inhibiting ASC may improve the local microenvironment of injured spinal cord. Here, CRID3, a blocker of ASC oligomerization, was used to study its effect on the local microenvironment and the possible role in neuroprotection following SCI. Methods Murine SCI model was created using an Infinite Horizon impactor at T9 vertebral level with a force of 50 kdynes and CRID3 (50 mg/kg) was intraperitoneally injected following injury. ASC and its downstream molecules in inflammasome signaling pathway were measured by western blot. The immune cell subsets were detected by immunohistofluorescence (IHF) and flow cytometry (FCM). The spinal cord fibrosis area, neuron survival, myelin preservation, and functional recovery were assessed. Results Following SCI, CRID3 administration inhibited inflammasome-related ASC and caspase-1, IL-1β, and IL-18 activation, which consequently suppressed M1 microglia, Th1 and Th1Th17 differentiation, and increased M2 microglia and Th2 differentiation. Accordingly, the improved histology and behavior have also been found. Conclusions CRID3 may ameliorate murine SCI by inhibiting inflammasome activation, reducing proinflammatory factor production, restoring immune cell subset balance, and improving local immune microenvironment, and early administration may be a promising therapeutic strategy for SCI.

The progression of the cell cycle is continuous in most cells, but gametes (sperm and egg cells) exhibit an arrest of the cell cycle to await fertilization to form a zygote, which then continues through the subsequent phases to complete cell division. The phase in which gametes of flowering plants arrest has been a matter of debate, since different phases have been reported for the gametes of different species. In this study, we reassessed the phase of cell-cycle arrest in the gametes of two species, Arabidopsis (Arabidopsis thaliana) and Torenia fournieri. We first showed that 4’, 6-diamidino-2-phenylindole staining was not feasible to detect changes in gametic nuclear DNA in T. fournieri. Next, using 5-ethynyl-2’-deoxyuridine (EdU) staining that detects DNA replication by labeling the EdU absorbed by deoxyribonucleic acid, we found that the replication of nuclear DNA did not occur during gamete development but during zygote development, revealing that the gametes of these species have a haploid nuclear DNA content before fertilization. We thus propose that gametes in the G1 phase participate in the fertilization event in Arabidopsis and T. fournieri.

Domain adaptation aims at learning from the la-beled source domain to build an accurate classifier for a related but different target domain. Existing methods attempt to reduce domain discrepancy explicitly by means of statistical properties yet ignore the inherent differences among samples. In this paper, we present a novel solution for domain adaptation based on collaborative representation, named Discrepancy-Aware Collaborative Representation (DACR). Inspired by the success of nearest regularization, DACR develops a novel indicator to measure the discrepancy among every source sample and target domain. Then the indicator is employed in sparse regularization thus ensure that samples with small discrepancy have larger weights in the learned representation. Extensive experiments verify that DACR is able to achieve comparable performance with existing methods while significantly reducing computing complexity.

The distinctive nature of the endophyte

Alcohol use disorder (AUD) is an enormous public health problem that poses significant social, medical, and economic burdens. Under AUD, the liver is one of the most adversely affected organs. As current therapies and protective drugs for AUD-mediated liver injury are very limited, the prevention and therapy of alcoholic liver disease are urgently needed. The present study aims to investigate the beneficial effects of tartary buckwheat extract (TBE), the important component of Maopu tartary buckwheat liquor, on both alcoholic-induced acute and chronic liver injuries. We show that the TBE administration, similar to curcumin, significantly reduces the elevated serum aspartate aminotransferase and alanine aminotransferase levels, improves liver index, alleviates the elevated contents of hepatic malondialdehye, and restores the decreased contents of hepatic glutathione both in acute and chronic liver injuries in alcohol-exposed rats. Furthermore, histopathological analyses show that a medium dose of TBE (16.70 ml/kg body weight) alleviates hepatocyte morphology changes in both acute and chronic alcohol exposure models. We also show the protective effects of TBE on the cell death rates of alcohol-exposed primary cultured hepatocytes, HepG2 hepatoma, and Huh 7 hepatoma cells. Furthermore, we demonstrate that TBE exerts hepatoprotection partly through inhibiting the mitochondrial cell death pathway by reducing cytochrome c release, caspase-9 and -3 activities, and the number of TUNEL-positive cells. These effects of TBE were accompanied by enhanced levels of Bcl-2 and Bcl-xL and autophagic cell death pathway by reducing Beclin-1 expression, as well as through promoting its anti-oxidant capacity by suppressing reactive oxygen species production. This study demonstrates, for the first time, the protective effect of TBE against alcohol-induced acute and chronic liver injury in vivo and in vitro. Given the dietary nature of tartary buckwheat, pueraria, lycium barbarum, and hawthorn, the oral intake of TBE or liquor contained TBE, e.g., Maopu Tartary buckwheat liquor, compared with pure liquor consumption alone, may have the potential to alleviate alcoholic-induced liver injuries.

Three new homoadamantane-type polyprenylated acylphloroglucinols, hyperacmosins E-G (1-3), with seven known compounds were isolated from the air-dried aerial parts of Hypericum asmosepalum. Their structures were determined by NMR, HRESIMS and experimental electronic circular dichroism (ECD) spectra. The hepatoprotective activity of these compounds were evaluated. Compounds 4 and 8 exhibited hepatoprotective activity against paracetamol-induced HepG2 cell damage.

In this study, papain-generated casein hydrolysates (CH) with a degree of hydrolysis of 13.7% were subjected to a papain-mediated plastein reaction in the absence or presence of one of the exogenous amino acids—Gly, Pro, and Hyp—to prepare four plastein modifiers, or mixed with one of three amino acids to prepare three mixtures. The assay results confirmed that the reaction reduced free NH2 for the modifiers and caused amino acid incorporation and peptide condensation. When RAW264.7 macrophages were exposed to the CH, modifiers, and mixtures, these samples promoted macrophage growth and phagocytosis in a dose-dependent manner. In addition, the CH shared similar activity in the cells as the mixtures, while the modifiers (especially the PCH-Hyp prepared with Hyp addition) exerted higher potential than CH, the mixtures, and PCH (the modifier prepared without amino acid addition). The plastein reaction thus enhanced CH bioactivity in the cells. When RAW264.7 macrophages were stimulated with lipopolysaccharide (LPS), the inflammatory cells produced more lactate dehydrogenase (LDH) release and reactive oxygen species (ROS) formation, and caused more four inflammatory mediators (NO, PGE2, TNF-α, and IL-6) and two anti-inflammatory mediators (TGF-β1 and IL-10). However, the PCH-Hyp, PCH, and CH at dose levels of 100 μg/mL could combat against the LPS-induced inflammation. Overall, the PCH-Hyp was more active than the CH and PCH in reducing LDH release, ROS formation, and the secretion of these inflammatory mediators, or in increasing the secretion of the anti-inflammatory mediators. The qPCR and Western blot analysis results further confirmed that these samples had anti-inflammatory effects on the stimulated cells by suppressing the LPS-induced activation of the NF-κB signaling pathway, via regulating the mRNA/miRNA expression of iNOS, IL-6, TNF-α, IL-1β, COX-2, TLR4, IL-10, TGF-β1, miR-181a, miR-30d, miR-155, and miR-148, as well as the protein expression of MyD88, p-IKKα, p-IκBα, p-NF-κB p65, and iNOS, involved in this signaling pathway. In addition, the immunofluorescence assay results revealed that these samples could block the LPS-mediated nuclear translocation of the p65 protein and displayed the same function as the NF-κB inhibitor BAY 11-7082. It was concluded that CH could be endowed with higher anti-inflammatory activity to the macrophages by performing a plastein reaction, particularly that in the presence of exogenous Hyp.

For a vehicle, its speed can be adjusted via a transmission system. In this study, we propose a model of two-class rotation transmission nanosystem to adjust the input rotation via a gigahertz rotary nanomotor. To obtain an efficient rotation transmission system, carbon nanotubes, which have super-high in-shell strength but extremely low inter-shell friction, are adopted to build the coaxially rotary components. Besides 200 GHz motor, the other two components are the rotor1 in the class-1 nanobearing, and the rotor2 in the class-2 bearing, respectively. Considering both the chirality and radii differences of the rotary components, 27 types of transmission models are built and tested via molecular dynamic simulations. When the transmission ratio of the rotational frequency of the rotor2 and the input frequency is between 0.1 and 0.9, a successful transmission system is obtained. According to the rotation transmission ratios (RTRs) of both rotors in each model, some conclusions are drawn for potential design of such nanodevice. Besides, temperature can also influence the output rotation of the rotor2. It implies another way to adjust the output rotation from the same transmission system.

Using argon to protect the rotary nanoring made from curved carbon nanotube, we discover that the gas can act as an on–off and/or a speed controller of the rotary nanoring. The mechanism is that the argon cluster formed at lower temperature provides friction on the nanoring, which may stop rotating due to the friction. Molecular dynamics simulation results demonstrate that the nanoring cannot rotate at 100 K, but rotates at 300 K, or it rotates faster at higher temperature. Periodic fluctuation of the rotational frequency of the ring happens when the argon cluster is formed periodically. Using the nanoring as an engine of a nanomachine, the speed of the machine can be adjusted by changing the ambient temperature. Hence, the argon on–off provides potential application in nanodevices.

Low rank and sparse matrix decomposition is increasingly concerned in many research fields for its particular properties in exploring local and global components. The objective of this problem consists of two conflicting terms, the low rank term and the sparse term, most of the previous methods combine these two terms into a scalar objective with weight parameter. However, the preset of weight parameter is a difficult task because any priori knowledge about two terms is unavailable before optimization. In this paper, we establish a singular value encoding based multi-objective low rank and sparse matrix decomposition model. Two conflicting objectives are constructed to find the low rank and sparse components of the given data matrix. A novel multi-objective memetic algorithm , which encodes the singular value of the low rank matrix, is proposed to minimize two objectives simultaneously. The proposed method can obtain a series of different trade-off solutions between low rank and sparse components, and decision makers can choose satisfying solution from them directly. The experimental results demonstrate that the proposed method is effective and has better performance than some existing approaches in terms of the decomposition accuracy and the diversity of solutions.

Hyperascyrins A-H (1-11) and four known compounds (12-15) were acquired from the air-dried aerial parts of Hypericum ascyron and were all identified as methylated polycyclic polyprenylated acylphloroglucinol derivatives. Their structures were established by NMR spectroscopy, experimental and calculated electronic circular dichroism (ECD) data, and comparison with established compounds. Compounds 8 and 9 showed protection against paracetamol-induced HepG2 cell damage at 10 μM. The neuroprotective activities of all compounds (10 μM) were evaluated, and compounds 1 and 8 exhibited mild neuroprotection against glutamate-induced toxicity in SK-N-SH cells.

Diamondene can be formed by compressing two or more layers of graphene. As a sp2/sp3 orbital hybridized two-dimensional material, its physical properties are different from either graphene or diamond. This new material is ultrahard on a SiC substrate. Here, we focus on the thermal stability and the basic mechanical properties of diamondene without passivation. We used molecular dynamics calculations to show that diamondene has isotropic thermal expansion at temperature below 280 K. At room temperature, it is unstable. When stretched along the armchair direction, diamondene has a maximum elastic strain that is higher than 0.17. It then experiences further plastic deformation before collapse. However, when stretched along the zigzag direction, the maximum elastic strain is higher than 0.3, e.g., 0.318 at 250 K. The ribbon collapses soon after the strain exceeds the critical value. Hence, diamondene has an elastic-brittle property along the zigzag direction. This excellent elasticity is significant for applications of diamondene in a flexible device. Keywords: Carbon, Diamondene, Graphene, Mechanical property, Molecular dynamics

Hyperspectral data are useful for the nondestructive and timely monitoring of the physiological status and photosynthetic performance of crops. The objectives of the present study were (i) to analyze the effect of N application rate on the post-silking N uptake and vegetative N remobilization status and (ii) to indicate the optimum vegetation index (VI) for the assessment of the N remobilization status in maize. Two field experiments were conducted with five N treatments with varying rates and three maize (Zea mays L.) cultivars in 2016 and 2017, and time-course hyperspectral measurements were taken of collected plant samples. The present study considered the following three approaches: commonly used vegetation indices, novel indices of all possible two-band combinations as either simple ratios (SR) or normalized differences (ND) and spectral differences between the periods 63 and 75 (or 90) day after sowing (DAS). The commonly used VIs, such as the Green normalized difference vegetation index (GNDVI) at 75 DAS and Green model (G-M) at 90 DAS, were successfully used to assess the leaf N remobilization. The VIs computed with all possible two-band combinations ranging from 350 to 1350 nm were related to vegetative N remobilization. The results show that novel indices, such as SR (764 nm/716 nm), SR (762 nm/700 nm), ND (756 nm/550 nm) and ND (900 nm/750 nm), were successfully used to assess leaf N remobilization during the filling stage but were not suitable for monitoring culm N remobilization. Moreover, the spectral differences (i.e., between reflectance at 940 and 799 nm) between the corresponding 63 and 75 (90) DAS could stably estimate leaf N remobilization (R2 > 0.47, RMSE

Exact spare parts demand forecast is an important task of equipment maintenance support. In spare parts demand forecast of aircraft, there exists problems such as the lack of comparable existing equipments, less historical data of fault or spare parts demand and lack of understanding of the aircraft’s own guarantee characteristics. In this paper, a spare parts demand forecast method based on fractional-order discrete gray model is proposed. In this method, a fractional-order cumulative gray model is established from historical data containing “small sample” and “poor information Then, the genetic algorithm is applied to determine the optimal order of the model and the generation coefficient. Finally, the spare parts demand is predicted. Experimental results based on specific examples show that the proposed method can effectively predict the spare parts demand, and have good performance compared with the traditional integer-order model.

TiO2 is a famous electron-transport-material (ETM) that used widely in perovskite solar cells. Photo-catalysis effect is a highly concerned issue for such TiO2 based devices because of its impact on device stability. To deal with the problem, a strategy was proposed to passivate the surface of TiO2 by a thin layer of in-situ formed SnO2, and then perovskite solar cells (PSCs) were prepared using such modified TiO2. It was observed that, after the surface passivation, photo-to-electric power conversion efficiency, hysteresis as well as stability of the TiO2 based PSCs were all improved. For example, efficiency increased from 14.92 (±1.86)% (AM 1.5G, 100 mW/cm2) to 16.33 (±0.26)%; hysteresis index decreased from 20.49 (±11.85)% to 1.40 (±0.01)%. As for stability, after being stored for 25 days (relative humidity of about 45%, no encapsulation), efficiency could preserve 73.99% of the original value, comparing to 47.55% for device based on bare TiO2. Moreover, the passivation was found to accelerate electron extraction, while retard charge recombination between perovskite and TiO2. The improvement was ascribed to the enhanced contact between perovskite and bottom electron-transport-material, passivated surface defects of TiO2 by SnO2, as well as the high mobility of SnO2. Finally, designated ultraviolet (UV) illumination experiment showed that SnO2 passivation could obviously retard the photo-catalysis activity of TiO2, thus improve the UV stability of the devices.

In view of the fact that traditional air target threat assessment methods are difficult to reflect the combat characteristics of uncertain, dynamic and hybrid formation, an algorithm is proposed to solve the multi-target threat assessment problems. The target attribute weight is calculated by the intuitionistic fuzzy entropy (IFE) algorithm and the time series weight is gained by the Poisson distribution method based on multi-times data. Finally, assessment and sequencing of the air multi-target threat model based on IFE and dynamic VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) is established with an example which indicates that the method is reasonable and effective.

Molybdenum dioxide (MoO2) has attracted many interests due to its unique properties and potential applications. Here, we report the synthesis of high quality MoO2@MoS2 nanorods on c-sapphire substrates through an atmospheric pressure chemical vapor deposition (APCVD) approach. Optical microscopy (OM), cross-sectional scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and (grazing incidence) X-ray diffraction ((GI)XRD) measurements reveal that these MoO2 nanorods exhibit epitaxial growth behaviors on c-sapphire substrates with the orientation relationship of MoO2(100)∥sapphire(0001) and MoO2 ⟨001⟩ aligned well with sapphire ⟨1010⟩. Raman spectroscopy/imaging, energy dispersive spectroscopy (EDS), and GIXRD results disclose that such MoO2 nanorods are wrapped by MoS2 (MoO2@MoS2). Devices based on transferred individual MoO2@MoS2 nanorods show a resistivity of ∼1.65 × 10–4 Ω·cm, comfirming that such nanorods possess higher...

Eleven new polyketones named diaporthsins A–K (1–11) were isolated from the fermentation of Diaporthe sp. JC-J7. The chemical structures of compounds (1–11) were elucidated by spectroscopic methods including HRESIMS, 2DNMR, NMR and chemical methods. Compound 11 features an unusual acyclic polyketone–phenolic polyketone hybrid structure that integrates the characteristics of different fungal metabolites (cytosporone and multiplolide). Compound 3 was the only C12-polyketone obtained in this research. These new polyketones showed inhibitory activity on triglycerides (TG) in steatosis hepatocyte L-02 cells. Among them, compound 5 and (4E)-6,7,9-trihydroxydec-4-enoic acid displayed inhibitory activities on TG in steatotic L-02 cells with inhibition ratios of 26% and 21% at concentration of 5 μg mL−1; also, inhibition ratios of 8-O-acetylmultiplolide A and phomopsisporone A at concentration of 5 μg mL−1 were calculated to be about 24% and 16%, respectively, which were equivalent to the antihyperlipidemic activity of lovastatin. The preliminary structure–activity relationship indicated that acetyl at C-8 can increase the antihyperlipidemic activity of multiplolide A and the glycol ester and hydroxyl at C-6 can also increase the corresponding activity of diaporthsin B.

Recommender systems recommend contents or services via collecting and analyzing numerous user data, which may raise serious privacy concerns when the recommender is untrusted. Inspired by federated learning, a user-level distributed matrix factorization framework has been proposed where the model can be learned via collecting gradient information from users (instead of the raw data). This approach focuses on protecting model-privacy and value-privacy from untrusted recommender but has limited consideration on existence-privacy. To address this issue, we enhance the aforementioned framework with Homomorphic Encryption and randomized response. Extensive experiments demonstrate that our method can provide more secure protection for users’ privacy with less performance degradation and smaller computational burden.

As a new type of nano-catalytic material, copper nanoclusters (Cu NCs) have received more and more attention in various fields such as biosensors and catalysis. In this work, an electrochemical stripping chemiluminescent (ESCL) aptamer sensor based on Cu NCs was constructed for the detection of carcinoembryonic antigen (CEA). The Cu NCs were generated using DNA duplex (the CEA aptamer and its complementary strand) as template. During the ESCL detection process, Cu NCs catalyzed the reduction of H2O2 and were gradually electrochemically oxidized to Cu2+, which both promoted the decomposition of H2O2 and thus greatly improved the ECL of luminol. CEA could specifically bind with its aptamer, so the DNA duplex was damaged, causing a decrease of Cu NCs and lower ECL signals. Under the optimized conditions, the sensor achieved a high sensitivity detection of CEA with a linear range of 0.2 fg mL−1 to 1 ng mL−1 and a detection limit of 66.67 ag mL−1 (S/N = 3). In addition, the sensor exhibited good specificity, stability and reproducibility, and the detection of actual samples obtained satisfactory results, indicating that the provided strategy has potential application prospects in clinical detection.

Deep neural networks have achieved significant development and wide applications for their amazing performance. However, their complex structure, high computation and storage resource limit their applications in mobile or embedding devices such as sensor platforms. Neural network pruning is an efficient way to design a lightweight model from a well-trained complex deep neural network. In this paper, we propose an evolutionary multi-objective one-shot filter pruning method for designing a lightweight convolutional neural network. Firstly, unlike some famous iterative pruning methods, a one-shot pruning framework only needs to perform filter pruning and model fine-tuning once. Moreover, we built a constraint multi-objective filter pruning problem in which two objectives represent the filter pruning ratio and the accuracy of the pruned convolutional neural network, respectively. A non-dominated sorting-based evolutionary multi-objective algorithm was used to solve the filter pruning problem, and it provides a set of Pareto solutions which consists of a series of different trade-off pruned models. Finally, some models are uniformly selected from the set of Pareto solutions to be fine-tuned as the output of our method. The effectiveness of our method was demonstrated in experimental studies on four designed models, LeNet and AlexNet. Our method can prune over 85%, 82%, 75%, 65%, 91% and 68% filters with little accuracy loss on four designed models, LeNet and AlexNet, respectively.

A TiO2/SiOx/Si composite derived from cellulosic cotton as the structural template was biomimetically synthesized. Modified sol–gel deposition processes were performed to coat each cellulose nanofiber with a SiO2 thin gel layer, followed by layer-by-layer self-assembly processes to form an external TiO2 coating with controllable thickness. The resulted matter was calcined in air to obtain the TiO2/SiO2 composite, which was successively put in N2 atmosphere and treated with magnesiothermic reduction reaction, resulting in the final TiO2/SiOx/Si composite. The composite possessed a typical hierarchical three-dimensional (3D) nanotubular network microstructure precisely inherited from the cellulosic cotton template, and each nanotube had a core-shell nanostructure with Si-based matters as the core and TiO2 coating as the shell. Compared with the bare nanotubular SiOx/Si material, the TiO2/SiOx/Si composite showed a highly enhanced electrochemical performance as an anode material for lithium-ion batteries (LIBs), delivering an initial discharge capacity of 2370 mAh g−1 at a current density of 0.2 A g−1 (an initial Coulombic efficiency of 56.4%), a reversible capacity of 682 mAh g−1 after 100 discharge/charge cycles, and a discharge capacity of 241 mAh g−1 at a high current density of 2.0 A g−1. The excellent specific capacity, cycling stability and rate capability are ascribed to the synergistic effect of the unique 3D porous nanotubular network structure and the uniform TiO2 coating layer, which accommodates the volume variation of Si-based components during cycling, offers sufficient ion transport pathways and improves the electron transfer efficiency. This work provides a facile biomass-based strategy for fabrication of metal oxide/Si composites with well-defined microstructures that exhibit significant potential as anode materials for LIBs.

The recommendations for soil fertilization based on soil testing are time-critical and labor-intensive for farmers in the winter wheat–summer maize double cropping system. Understanding the relationships between the crop yield, nitrogen requirement, and nitrate residue level under the combined N and P fertilizer application is necessary to optimize the fertilizer recommendation method in order to reduce the nitrate residue levels. In 2009, we established a long-term field fertilization experiment with five N application rates and four P application rates in the winter wheat-summer maize double cropping system. The grain yield, N requirement, and soil nitrate residue were determined during 2016–2019 to optimize the N inputs for nitrate residue control. The crop yield was increased by N application and it increased further when combined with P fertilizer. The N requirement of crops increased by N application but decreased when combined with P. The calculated maximum winter wheat yield was 7235 kg ha−1 and the theoretical N requirement for 1000 kg grain formation (NR) was 28.68 kg Mg−1. The maximum summer maize yield was 7866 kg ha−1, and the theoretical NR was determined as 23.43 kg Mg−1. The residual nitrate-N was increased by N application but decreased by combined P fertilizer. The correlation between the nitrate-N content in 0–20 cm top soil (SNC) and nitrate-N residue in 0–100 cm soil (SNR) was linear at the winter wheat harvest but exponential at the summer maize harvest. Thus, the SNR can be predicted by the SNC according to their correlation at the harvest. The predicted SNR at the harvest of the previous crop, the target yield and NR for the subsequent crop obtained from long-term in-situ observations can be used to guide the fertilizer amounts applied to the following crop. Therefore, we developed a convenient method to optimize the fertilizer recommendation method for the winter wheat–summer maize cropping system.