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Aspect sentiment triplet extraction (ASTE) is one of the subtasks of aspect-based sentiment analysis, which aims to identify all aspect terms, their corresponding opinion terms and sentiment polarities in sentences. Currently, pipeline or end-to-end models are adopted to accomplish the ASTE task. The former cannot solve the overlapping problem of aspect terms in triplets and ignores the dependency between opinion terms and sentiment polarities. The latter divides the ASTE task into two subtasks of aspect-opinion-extraction and sentiment-polarity-classification, which applies multi-task learning through a shared encoder. However, this setting does not distinguish the differences between the features of the two subtasks, leading to the feature confusion problem. SD-ASTE (span-level dual-encoder model for ASTE), a pipeline model with two modules, is proposed to address the above problems. The first module extracts aspect terms and opinion terms based on spans. The span feature representation incor-porates span head, tail and length information to focus on the boundary information of aspect terms and opinion terms. The second module judges the sentiment polarities expressed by aspect-opinion span pairs. The span-pair feature representation is based on levitated markers to focus on the dependency among triplet elements. The model utilizes two independent encoders to extract different features for each module. Comparative experimental results on multiple datasets show that the model is superior to the state-of-the-art pipeline and end-to-end models. Validity experiments show the effectiveness of the span feature representation, span-pair feature representation and the two independent encoders.

The occurrence of early spring and late frost damage brought severe challenges to the production of walnuts in China, seriously affecting their growth, development, yield and revenue. In order to clarify the harmful characteristics and influencing mechanisms of late frost on walnuts in China, the influencing factors of the degree of damage caused by late frost on walnuts, as well as the changes in physiological and biochemical indicators and molecular mechanisms in response to low temperature stress were reviewed. It was found that research on physiological changes focused on the three aspects including cell membrane system (relative conductivity), antioxidant system (malondialdehyde, superoxide dismutase, peroxidase and catalase) and osmoregulation substances (soluble sugars, soluble protein and proline), in addition, the expression levels of genes such as JrPAL, JrJAZ, JrGRAS, JrICE1, JrCBF/JrDREB1, JrCOR, JrWRKY, JrDHN, JrGST, and JrPUB were induced by low temperature stress. And prospects were put for future research directions, which provided scientific basis for further exploring the response mechanism of walnuts to late frost damage and adopting effective production measures. [ABSTRACT FROM AUTHOR]

Objective To investigate the effect of afatinib on the chemosensitization of multidrug-resistant A2780T cells to adriamycin and related mechanism. Methods MTT assay was used to investigate the effect of afatinib on the IC50 values of adriamycin in A2780 and A2780T cells. The efflux function and ATPase activity of ABCB1 were investigated by rhodamine 123 accumulation assay and ABCB1-GloTM Assay Systems, respectively. The expression of EGFR, HER-2, p-EGFR, p-HER-2 and ABCB1 were investigated by Western blot. RT-PCR assay was applied to test the mRNA expression of MDR1 in A2780T cells. Results Afatinib at nontoxic concentrations significantly decreased the IC50 of adriamycin in A2780T cells (P < 0.05), while no effect in A2780 cells. Afatinib could inhibit the efflux function and increase the ATPase activity of ABCB1 in a concentration-dependent manner(P < 0.05). Afatinib inhibited the phosphorylation of EGFR and HER-2, and decreased the expression of ABCB1 protein and MDR1 mRNA in A2780T cells. Conclusion Afatinib could sensibilize multidrug-resistant A2780T cells to adriamycin by inhibiting the efflux function and downregulating ABCB1 expression.

The study on the effects of sulfur on physiological and biochemical indices and nutrition quality of garlic showed that when soil sulfur content was 8.41 mg kg(-1), the NR and POD activities, photosynthetic pigment content and photosynthetic parameter (Pn, Gs, E) in garlic leaves were higher. The soluble protein content and CAT activity reached maximum when soil sulfur content was 7.92 mg x kg(-1), while the SOD activity was higher when soil sulfur content was 6.45 mg x kg(-1). When soil sulfur content was 8.41 mg x kg(-1), the allicin, soluble sugar and Vc contents in bulb and the allicin, soluble sugar and soluble protein contents in bolt were increased by 33.67%, 23.75%, 68.82%, 40.95%, 3.45% and 7.45%, respectively. Higher content of soil sulfur (9.48 mg x kg(-1)) increased the contents of Vc and free amino acid in bolt and those of free amino acid and soluble protein in bulb by 15.17%, 20.93%, 6.49% and 8.07%, respectively.