Search

Key message: Over expression of MsSPL12 improved alfalfa salt tolerance by reducing Na+ accumulation and increasing antioxidant enzyme activity and regulating down-stream gene expression. Improvement of salt tolerance is one of the major goals in alfalfa breeding. Here, we demonstrated that MsSPL12, an alfalfa transcription factor gene highly expressed in the stem cells, plays a positive role in alfalfa salt tolerance. MsSPL12 is localized in the nucleus and shows transcriptional activity in the presence of its C-terminus. To investigate MsSPL12 function in plant response to salt stress, we generated transgenic plants overexpressing either MsSPL12 or a chimeric MsSPL12-SRDX gene that represses the function of MsSPL12 by using the Chimeric REpressor gene-Silencing Technology (CRES-T), and observed that overexpression of MsSPL12 increased the salt tolerance of alfalfa transgenic plants associated with an increase in K+/Na+ ratio and relative water content (RWC) under salt stress treatment, but a reduction in electrolyte leakage (EL), reactive oxygen species (ROS), malondialdehyde (MDA), and proline (Pro) compared to wild type (WT) plants. However, transgenic plants overexpressing MsSPL12-SRDX showed an inhibited plant growth and a reduced salt tolerance. RNA-sequencing and quantitative real-time PCR analyses revealed that MsSPL12 affected the expression of plant abiotic resistance-related genes in multiple physiological pathways. The potential MsSPL12-mediated regulatory pathways based on the differentially expressed genes between the MsSPL12 overexpression transgenics and WT controls were predicted. In summary, our study proves that MsSPL12 is a positive regulator in alfalfa salt tolerance and can be used as a new candidate for manipulation to develop forage crops with enhanced salt tolerance. [ABSTRACT FROM AUTHOR]

Key message: Sequestering microRNA396 by overexpression of MIM396 enhanced alfalfa resistance to Spodoptera litura larvae, which may be due to increased lignin content and enhanced low-molecular weight flavonoids and glucosinolates biosynthesis. Alfalfa (Medicago sativa), the most important leguminous forage crop, suffers from the outbreak of defoliator insects, especially Spodoptera litura, resulting in heavy losses in yield and forage quality. Here, we found that the expression of alfalfa microRNA396 (miR396) precursor genes and mature miR396 was significantly up-regulated in wounding treatment that simulates feeding injury by defoliator insects. To verify the function of miR396 in alfalfa resistance to insect, we generated MIM396 transgenic alfalfa plants with significantly down-regulated miR396 expression by Agrobacterium-mediated genetic transformation. The MIM396 transgenic alfalfa plants exhibited improved resistance to Spodoptera litura larvae with increased lignin content but decreased JA accumulation. Most of the miR396 putative target GRF genes were up-regulated in MIM396 transgenic lines, and responded to the wounding treatment. By RNA sequencing analysis, we found that the differentially expressed genes related to insect resistance between WT and MIM396 transgenic plants mainly clustered in biosynthesis pathways in lignin, flavonoids and glucosinolates. In addition to the phenotype of enhanced insect resistance, MIM396 transgenic plants also displayed reduced biomass yield and forage quality. Our results broaden the function of miR396 in alfalfa and provide genetic resources for studying alfalfa insect resistance. [ABSTRACT FROM AUTHOR]

Background: Based on our previous research conducted on cinnamaldehyde (CA) exhibiting its ability to improve the growth performance of fattening pigs and the adipogenesis induction model of C2C12 cells constructed in our laboratory, we explored the effects of CA on the generation and development of lipid droplets (LDs) in adipogenic differentiated C2C12 cells. Methods and results: C2C12 cells were treated with either 0.4 mM or 0.8 mM CA. BODIPY staining and triglyceride measurements were conducted to observe the morphology of LDs, and Western blotting was used to measure the expression of their metabolism-related proteins. The results showed that the average number of LDs in the CA treatment groups was more than the control group (P < 0.05), whereas the average LD size and triglyceride content decreased (P < 0.05). Compared with the control group, the expression levels of fusion-related genes in the LDs of the CA treatment group significantly decreased, while decomposition-related genes and autophagy-related genes in the LDs in C2C12 cells significantly increased (P < 0.01). Conclusion: Cinnamaldehyde promoted the decomposition and autophagy of lipid droplets in C2C12 cells and inhibited the fusion of lipid droplets. [ABSTRACT FROM AUTHOR]

Natural hazard named entity recognition is a technique used to recognize natural hazard entities from a large number of texts. The method of natural hazard named entity recognition can facilitate acquisition of natural hazards information and provide reference for natural hazard mitigation. The method of named entity recognition has many challenges, such as fast change, multiple types and various forms of named entities. This can introduce difficulties in research of natural hazard named entity recognition. To address the above problem, this paper constructed a natural disaster annotated corpus for training and evaluation model, and selected and compared several deep learning methods based on word vector features. A deep learning method for natural hazard named entity recognition can automatically mine text features and reduce the dependence on manual rules. This paper compares and analyzes the deep learning models from three aspects: pretraining, feature extraction and decoding. A natural hazard named entity recognition method based on deep learning is proposed, namely XLNet-BiLSTM-CRF model. Finally, the research hotspots of natural hazards papers in the past 10 years were obtained through this model. After training, the precision of the XLNet-BilSTM-CRF model is 92.80%, the recall rate is 91.74%, and the F1-score is 92.27%. The results show that this method, which is superior to other methods, can effectively recognize natural hazard named entities. [ABSTRACT FROM AUTHOR]

In this paper, we evaluated the effect of seven stabilizers with different shapes (including cylinder, cubic and ball shape) on zircon U–Pb dating analysis by laser ablation inductively coupled plasma quadrupole mass spectrometry (LA-ICP-QMS) in detail. In the case of stabilizer volume examined, the analytical efficiency of cylinder stabilizers (21.2, 25.1, 35.3 and 125 mL) were investigated in terms of signal stabilization, signal rising/washout time and U–Pb dating accuracy. By using zircon 91500 as reference material for external calibration, the 206Pb/238U age of zircon Plešovice was determined by a nanosecond LA-ICP-QMS, where the stabilizer was placed directly after the ablation cell and sample aerosols carried by helium passed through the stabilizer and subsequently mixed with make-up gas (argon) before ICP. It was found that transient signal oscillations were invisible and signal intensities were comparable using all the stabilizers, while signal rising time was 2.0-fold and washout time was 27.6-fold for stabilizer with volume of 125 mL to that of 21.2 mL. The obtained average 206Pb/238U age of zircon Plešovice was 335.53 ± 1.02, 361.73 ± 5.04, 340.10 ± 1.98 and 341.21 ± 5.17 Ma (2σ, n ≥ 5), respectively, giving average relative deviations of a single point of age (1σ) less than 2.0%. Among the corresponding 206Pb/238U ratios, it was also found that the value (0.05343 ± 0.87‰, 1σ, n = 5) obtained using 21.2 mL of cylinder stabilizer highly agreed with that of 0.05384 ± 0.74‰ (1σ, n = 5) using the commercially available "squid" stabilizer. The analytical efficiency of the 21.2 mL of cylinder stabilizer was then compared to that of cubic shape stabilizer (18.5 mL) and ball shape stabilizer (14.1 mL). Results showed that there were no significant differences of the obtained 206Pb/238U ages using stabilizers with volume in the range of 14.1–21.2 mL. But both cubic and ball shape stabilizers exhibited washout time over 270 s. We also studied the particle filter effect of the stabilizers by packing the 21.2 mL of cylinder stabilizer with 1.0 g of stainless wire. Despite the average 206Pb/238U age deviation was only − 0.81%, spiky signals occasionally occurred which might be ascribed to the use of a nanosecond laser and relatively low density of stainless wire in the stabilizer. This study confirmed that an empty stabilizer with volume of 21.2 mL and cylinder shape was preferred to produce smoothing signals. The improved analytical accuracy of zircon U–Pb dating using such a stabilizer ensured the future application to trace element analysis by LA-ICP-QMS. [ABSTRACT FROM AUTHOR]

The red arrow points to the PAS-positive and CD31-negative vessels lined with tumor cells. 6 Silencing of METTL3 suppresses VM formation and cancer progression in orthotopic transplantation tumor models of HCC. a The expression of METTL3 in stable METTL3 knockdown cell lines by G418 screening. b In vivo Imaging in the BALB/C nude mice. [Extracted from the article]

To solve the heavy metal water contamination problem of mercury ions, salix psammophila (SPP) powder was functionalized by thiol to prepare a novel adsorbent (TSPP). The materials were characterized by scanning electron microscope (SEM), Fourier-transform infrared (FTIR), energy-dispersive spectroscopy (EDS), thermogravimetry (TG), and X-ray photoelectron spectroscopy (XPS). The maximum adsorption capacity of TSPP was 1615.1 mgg−1 in 60 min (pH = 2, temperature 45 ℃, Hg2+ concentration = 700 mgL−1). The adsorption of Hg2+ by TSPP conforms to the pseudo-secondary kinetic model and Langmuir isotherm model. The adsorption process of Hg2+ mainly includes ion exchange of -COOH, electrostatic attraction of -NH−, electron transfer of -NH2, and chelation of sulfhydryl group and other functional groups. In addition, TSPP still has a high adsorption capacity of 1547.5 mgg−1 after four recycling times, indicating that it can be used as a low-cost, high-economy, and environmentally friendly adsorbent. [ABSTRACT FROM AUTHOR]

Quantification of viable lactic acid bacteria is an important quality index of fermented dairy products, but the current detection method, which is plate counting, is time-consuming. This study describes a modified PMA-qPCR assay that allows the detection and enumeration of total viable Lactobacillus spp. in commercial fermented milk products. Here, a new pair of genus-specific primers and minor groove binder probes was designed based on the 16S rRNA gene sequences of 24 reference strains, 13 of which were from different Lactobacillus species commonly used in commercial fermented dairy products. Subsequently, compared with the heat killing method, the 20-cycle homogenization method was chosen for initial PMA-qPCR optimization. Standard curves were prepared, and the efficiency obtained was 97% (R2 = 0.992), demonstrating that this PMA-qPCR method was feasible and effective. Additionally, the viable Lactobacillus spp. detection range was 103–109 CFU/mL, which meets the detection requirements in fermented dairy products. Furthermore, total number of viable Lactobacillus spp. in six different commercial fermented dairy products was estimated by three individual methods (plate count in MRS agar, qPCR, and PMA-qPCR). Comparison of results obtained by PMA-qPCR and plate counts was similar, and both decreased accordingly, showing a good correlation with the decline of strain vitality, 30 days after the expiration date. The PMA-qPCR procedure established in this paper allows the quantification of viable Lactobacillus spp. in approximately 3 h, greatly improving detection efficiency, and has broad application prospects in the testing of fermented dairy products. [ABSTRACT FROM AUTHOR]

Vasculogenic mimicry (VM) formed by aggressive tumor cells to mimic vasculogenic networks plays an important role in the tumor malignancy of HCC. However, the pathogenesis underlying VM is complex and has not been fully defined. m6A is a common mRNA modification and has many biological effects. However, the relationship between m6A and VM remains unclear. In this research, we found that m6A methyltransferase METTL3 in HCC tissues was positively correlated with VM. The m6A level of mRNA significantly increased in 3D cultured cells treated with VEGFa and was related to VM formation. Transcriptome sequencing analysis of 3D cultured cells with knockdown Mettl3 showed that the Hippo pathway was involved in m6A-mediated VM formation. Further mechanism research indicated that the m6A modification of YAP1 mRNA affected the translation of YAP1 mRNA. In conclusion, m6A methylation plays a key role in VM formation in HCC. METTL3 and YAP1 could be potential therapeutic targets via impairing VM formation in anti-metastatic strategies. [ABSTRACT FROM AUTHOR]

Key message: Overexpression of OsDST-SRDX chimeric gene in switchgrass promotes plant growth and improves the salt tolerance of transgenic switchgrass by improving its antioxidative ability. Switchgrass (Panicum virgatum L.) is a forage and model feedstock plant. To avoid competing with crops in arable land utilization, improving salt tolerance of switchgrass is required to use marginal saline land for switchgrass production. To improve salt tolerance of switchgrass, a chimeric DROUGHT AND SALT TOLERANCE (DST) gene OsDST-SRDX was constructed using the Chimeric REpressor gene-Silencing Technology (CRES-T), and introduced into switchgrass genome by Agrobacterium-mediated transformation. Compared to wild-type (WT) plants, OsDST-SRDX transgenic (TG) switchgrass plants showed wider leaves and thicker stems. They performed better under salt stress, had higher relative leaf water content, lower electrolyte leakage and lower malondialdehyde (MDA) content, and accumulated less Na+ and more K+ than WT controls. The transgenic plants had also higher activities of antioxidant enzymes associated with suppressed expressing of genes in H2O2 homeostasis, including glutathione S-transferase (GST2, GST6), cytochrome P450, peroxidase 24 precursor, and induced expressing of CAT and SOD under salt stress to eliminate excess H2O2. Our results indicate that overexpression of the chimeric gene OsDST-SRDX improves salt tolerance of switchgrass, a C4 biofuel crop. [ABSTRACT FROM AUTHOR]

In the present study, a hemp straw activated carbon (HSAC) was simply prepared by hydrothermal process followed by a pre-oxidization and carbonization by KOH solid-state activation. The as-synthesized HSAC shows abundant porosity, which is designed to be beneficial to the fast transportation of electrolyte. The preparation conditions for HSACs under different mass ratios of KOH:precursors were optimized, and the sample obtained by a mass ratio of 4:1 showed an outstanding capacitive property (specific capacitance of 279 F g−1 at 0.5 A g−1 current density). Besides, the capacitance of 91.6% was retained after 5000 charge-discharge cycles under 2 A g−1 current density. The resulting symmetrical supercapacitor obtained by using the HSAC electrodes exhibited an excellent electrochemical performance, which successfully illuminated a LED light. The HSAC has great potentials as electrode material for high-performance supercapacitor, which opens a new way for value increment of natural products. [ABSTRACT FROM AUTHOR]

Biomass-based nanofibers were prepared by electrospinning a mixture of polyacrylonitrile and acid-treated biomass from industrial hemp straw. The as-prepared biomass-based nanofibers were then carbonized and activated by high-temperature carbonization and KOH to obtain the activated biomass-based carbon nanofibers. The scanning electron microscopy images show that the precursors and carbon nanofibers are composed of fibers 179 nm in diameter, and the nitrogen adsorption/desorption measurements indicate that the carbon nanofibers possess a high-specific surface area of 2348.73 m2·g−1. The carbon nanofibers exhibit excellent electrical performance. The specific capacitance is as high as 244.8 F·g−1 at a current density of 1 A·g−1. The specific capacitance remains at 96% after 3000 cycles of charge and discharge at a current density of 2 A·g−1, showing excellent cycle stability. This work provides new ideas for the future development of supercapacitors electrode materials and enhances the development of biomass energy. [ABSTRACT FROM AUTHOR]

In this study, using multiparameter flow cytometry (FCM), we investigate the impact of minimal residual disease prior to transplantation (pre-MRD) on the transplant outcomes of AML patients with fms-related tyrosine kinase 3 (FLT3)-internal tandem duplication (ITD) mutation. A total of 20 patients who received HLA-matched sibling donor transplantation (MSDT) and 63 patients who received unmanipulated haploidentical hematopoietic stem cell transplantation (haplo-HSCT) were enrolled. Patients were classified into four groups based on the status of pre-FCM: group 1 with positive pre-FCM before MSDT, group 2 with negative pre-FCM before MSDT, group 3 with positive pre-FCM before haplo-HSCT, and group 4 with positive pre-FCM before haplo-HSCT. The results showed that patients in group 1 had the highest cumulative incidence of relapse (2-year CIR, 75.0%), the lowest leukemia-free survival (2-year LFS, 33.3%), and the overall survival (2-year OS, 25.0%) among all four groups. The other three groups of patients had comparable CIR (2-year CIR: group 2 vs. 3 vs. 4, 12.5% vs. 31.3% vs. 22.2%, P > 0.05) and LFS (2-year LFS: group 2 vs. 3 vs. 4, 87.5% vs. 62.5% vs. 66.5%, P > 0.05). Multivariate analysis indicated that disease status (> CR) and pre-MRD were associated with a higher CIR and a lower LFS when patients were classified by pre-MRD and transplant type. Our results suggested that AML patients with FLT3-ITD were able to be separated into high-risk and low-risk relapse groups based on pre-MRD, as determined by multiparameter FCM. Haplo-HSCT might overcome the negative impact of pre-MRD on patient outcomes compared to MSDT. These results require further investigation in prospective study with large numbers of cases. [ABSTRACT FROM AUTHOR]

Cellulose/multi-walled carbon nanotubes (MWCNTs)- composite membranes applied in electrochemical and biomedical fields were prepared using 1-ethyl-3-methylimidazolium diethyl phosphate (EmimDEP) as solvent in this study. With the increasing of MWCNTs amount, the membrane conductivity increased, and the conductivity reached 9.1 S/cm as the mass ratio of MWCNTs to cellulose being 2:1. The additions of sodium dodecyl sulfate (SDS), 1-hexadecyl-3-methylimidazolium bromide (CmimBr) and 1-butyl-3-methylimidazolium tetrafluoroborate (BmimBF) efficiently improved the conductivity, mechanical property, and thermal stability by promoting the dispersion of MWCNTs. When the mass ratio of CmimBr to MWCNTs changed from 0 to 0.3:1, the conductivity increased from 0.08 S/cm to 0.14 S/cm, and the tensile strength increased from 13.3 MPa to 17.0 MPa. These results indicate that the binary ionic liquids (ILs) system can regulate the properties of the composite membranes, and is a feasible approach for preparing cellulose/MWCNTs composite membranes with enhanced properties. [ABSTRACT FROM AUTHOR]

To explore the long-term efficacy of imatinib to chronic myeloid leukemia, a total of 46 late chronic phase (CP) patients were assessed after achieving complete cytogenetic response (CCyR). The median duration of imatinib treatment was 68 (61–74) months. Two hundred fifty-three bone marrow samples were detected BCR–ABL messenger RNA (mRNA) levels by TaqMan-based real-time quantitative reverse transcription–polymerase chain reaction. The median time when CCyR was first achieved was eight (3–72) months. Thirty-four patients achieved major molecular response (MMoR), and their median time when MMoR was first achieved was 35 (3–65) months. More patients achieving CCyR within 18 months obtained MMoR than those after 18 months (85% vs 42%, p = 0.006). One patient progressed into blastic crisis, and four patients suffered cytogenetic relapse later. The estimated 6-year event-free survival (EFS) rate of all patients was 81%. The BCR–ABL mRNA levels at the time of first CCyR of relapsed patients were significantly higher than those in continuous CCyR ( p = 0.011). The 6-year estimated EFS rate of MMoR patients was significantly higher than that of non-MMoR patients (100% vs 44%, p = 0.0001). Achieving CCyR within 18 months had a higher probability of achieving MMoR within 6 years. The 6-year estimated EFS rate was significantly higher for patients achieving CCyR within 12 months than those after 12 months (97% vs 55%, p = 0.05). The time when MMoR was first achieved did not affect 6-year estimated EFS. Therefore, imatinib could induce most late CP patients to achieve long-term durable responses after achieving CCyR. Both the time when CCyR was first achieved and the depth of BCR–ABL reduction after CCyR are relevant to long-term EFS. [ABSTRACT FROM AUTHOR]

Peroxisome proliferator-activated receptor γ (PPARγ) is recognized as a key regulator of insulin resistance. In this study, we searched for novel PPARγ agonists in a library of structurally diverse organic compounds and determined that podophyllotoxin exhibits partial agonist activity toward PPARγ. Eight novel podophyllotoxin-like derivatives were synthesized and assayed for toxicity and functional activity toward PPARγ to reduce the possible systemic toxic effects of podophyllotoxin and to maintain partial agonist activity toward PPARγ. Cell-based transactivation assays showed that compounds (E)-3-(hydroxy(3,4,5-trimethoxyphenyl)methyl)-4-(4(trifluoromethyl)styryl)dihydrofuran-2(3H)-one (3a) and (E)-4-(3-acetylstyryl)-3-(hydroxyl (3,4,5-trimethoxyphenyl)methyl)dihydrofuran-2(3H)-one (3f) exhibited partial agonist activity. An experiment using human hepatocarcinoma cells (HepG2) that were induced to become an insulin-resistant model showed that compounds 3a and 3f improved insulin sensitivity and glucose consumption. In addition, compounds 3a and 3f significantly improved hyperglycemia and insulin resistance in high-fat diet-fed streptozotocin (HFD-STZ)-induced type 2 diabetic rats at a dose of 15 mg/kg/day administered orally for 45 days, without significant weight gain. Cell toxicity testing also showed that compounds 3a and 3f exhibited weaker toxicity than pioglitazone. These findings suggested that compounds 3a and 3f improved insulin resistance in vivo and in vitro and that the compounds exhibited potential for the treatment of type 2 diabetes mellitus. [ABSTRACT FROM AUTHOR]