Aspect-Category-Opinion-Sentiment Quadruple Extraction (ACOS) is a critical subtask of Aspect-Based Sentiment Analysis (ABSA), aiming to extract all quadruples <aspect, category, opinion, sentiment> ...in a review sentence. Existing ACOS methods are categorized into pipeline methods and unified methods. Pipeline methods face error propagation and ignore the interdependency among four sentiment elements. Unified methods generate a long target sequence when the number of quadruples increases, which degrades the model performance. In this paper, we pay attention to the implicit aspects and opinions to obtain comprehensive aspect-level sentiment information. To this end, we propose a novel sequence generation model for ACOS named SG-ACOS. We design a linearization method to express ACOS quadruples as a sequence. The proposed linearization method incorporates natural language tokens and two special tokens into the target sequence. Natural language tokens are employed to represent the four sentiment elements, thus facilitating the model to learn the semantics of sentiment elements. Special tokens reduce the length of the target sequence, thereby improving the model efficiency and performance. Our proposed model obtains an absolute F_{1} improvement of 3.52% and 2.74% against previous state-of-the-art methods on two ACOS datasets, respectively. Further experimental results show the model effectiveness in implicit sentiment detection and the robustness of our model.
Aspect sentiment triplet extraction (ASTE) is a crucial sub-task of aspect-based sentiment analysis, which aims to extract each aspect term along with its opinion term and sentiment polarity. Prior ...works accomplish ASTE by jointly modeling its two sub-tasks, i.e., term extraction and sentiment classification. However, they ignore that different features have different importance to the two sub-tasks, resulting in feature confusion and insufficient feature fusion. To address this, we propose a dual-encoder attention fusion model (DuaIAF) for ASTE, consisting of a term extraction module and a sentiment classification module. First, we adopt a grid tagging scheme to model word-to-word interactions within word pairs. Second, we employ a dual-encoder framework to obtain BERT-style grid multi-features for term extraction and contextualized features for sentiment classification, thus alleviating feature confusion. Third, deep fusion networks are applied to refine word-level and span-level features. A convolution neural network (CNN)-based self-attention network deeply fuses word-level grid multi-features to explore the 2D structure information and long-distance dependency information. Moreover, attention pooling aggregates contextualized features into span-level features, which helps capture span-to-span interactions between aspect term spans and opinion term spans. The experimental results show that our model outperforms previous state-of-the-art methods over 4 English and 2 Chinese datasets in various domains.
Multiple lines of evidence have shown that the functional defect of pancreatic β cells is the root cause of type 2 diabetes. FoxO1, a key transcription factor of fundamental cellular physiology and ...functions, has been implicated in this process. However, the underlying molecular mechanism is still largely unknown. Here, we show that the overexpression of FoxO1 promotes the proliferation of cultured pancreatic β cells exposed to low nutrition, while no change in apoptosis was observed compared with the control group. Moreover, by using two specific inhibitors for PI3K and MAPK signaling, we found that FoxO1 might be the downstream transcription factor of these two pathways. Furthermore, a luciferase assay demonstrated that FoxO1 could regulate the expression of Ccnd1 at the transcription level. Collectively, our findings indicated that FoxO1 modulated by both MAPK and PI3K signaling pathways was prone to cause the proliferation, but not the apoptosis, of pancreatic β cells exposed to low nutrition, at least partially, by regulating the expression of Ccnd1 at the transcription level.
We transfected ovarian cancer cells and administered recombinant plasmid encoding hPNAS-4 to nude mice bearing ovarian cancer, aiming to evaluate the effect of hPNAS-4 against ovarian cancer in vitro ...and in vivo.
Ovarian cancer SKOV3 cells were transfected with hPNAS-4-plasmid, and cell proliferation was evaluated by MTT assay; apoptosis was examined by DNA ladder, Hoechst33258 staining and flow-cytometric assays. Nude mice bearing ovarian cancers were treated with hPNAS-4-p/liposome. Tumor growth was determined and survival was recorded. TUNEL assay and microvessel density was assessed to evaluate apoptosis and angiogenesis.
Both inhibition of proliferation (p < 0.05) and induction of apoptosis (p < 0.05) were observed in SKOV3 cells transfected with hPNAS-4-p in vitro. In hPNAS-4-p-treated tumor cells in vivo, tumor growth significantly decreased, while the survival time of tumor-bearing mice was prolonged compared with control groups (p < 0.05). Increased apoptosis of tumor cells and decreased angiogenesis in tumor tissue were also observed.
Our promising results on the potential antitumor effects of hPNAS-4 on ovarian cancer in vitro and in vivo may be explained, in part, by the induction of apoptosis and inhibition of angiogenesis. Consequently, hPNAS-4 has potential as a new gene therapy for human ovarian cancer.
This paper developed a new hydrophobic honokiol transdermal delivery system. First, Honokiol was loaded into Pluronic F127 micelles by direct dissolution method assisted by ultrasound. Then the ...obtained honokiol-loaded F127 micelles were incorporated into thermosensitive F127 hydrogel, which made the composite system bioadhesive. The particle size, drug loading, and encapsulation efficiency were determined. The sol-gel transitions of the copolymer, honokiol release profile in vitro, and the permeation studies in vitro were studied in detail. The lower critical solution temperature (LCST) of the composite system decreases with increase in the mass of honokiol in the system. Honokiol could be sustained released from the system in vitro. In in vitro permeation studies, honokiol could be absorbed per cutem. The described drug delivery system might have great potential application for transdermal delivery of hydrophobic drugs such as honokiol.
PNAS-4 has been demonstrated to induce apoptosis in U2OS cells. To evaluate its feasibility as a new strategy for cancer therapy, we analyzed its anti-tumor effect with or without gemcitabine in A549 ...lung cancer cells. MTT assay, Hoechst 33258 staining and flow cytometric analysis were used to determine the cytotoxicity of PNAS-4 alone or plus gemcitabine. The anti-tumor efficacy was further investigated in vivo with nude mice. PNAS-4 plasmid/liposome complexes were injected by tail vein every 4 days. Gemcitabine was given ip on a weekly schedule for 4 weeks. PNAS-4 alone and plus gemcitabine induced apoptosis in A549 cells in vitro. The xenograft lung cancer treated with PNAS-4 retarded growth compared with the empty vector. The combination of PNAS-4 with gemcitabine induced anti-tumor activity accompanied by an increase in apoptotic cells compared with PNAS-4 or gemcitabine alone. No other obvious toxicity was found. PNAS-4 therefore suppresses tumor growth in vivo and enhances sensitivity to gemcitabine. This suggests that the PNAS-4 gene could be a potential candidate for lung cancer therapy alone or in combination with gemcitabine.
In this paper, the poly(vinyl alcohol)/poly(epsilon-caprolactone)-PEG-poly(epsilon-caprolactone)/nano-hydroxyapatite (PVA/PCEC/n-HA) composite membranes were prepared by solution casting and ...evaporation methods. The effect of n-HA content on the properties of the composite membranes was studied. The PVA/PCEC/n-HA composite membranes were analyzed by FTIR spectroscopy, X-ray diffraction, water content measurement, contact angle, mechanical test, scanning electron microscopy. The results showed that the surface roughness of the composite membranes increased with the increase of n-HA contents. The n-HA content had obvious influence on the swelling ratio, tensile strength and elongation rate of the composite membranes. With the increase of n-HA contents, the swelling ratio increased at first, and then decreased; tensile strength and elongation rate decreased gradually. The PVA/PCEC/n-HA composite membranes may be applied in the field of tissue engineering.
A novel phase change microcapsule with compound crust is briefly introduced in this paper, and the heat transfer enhancement due to a microencapsulated phase change material is investigated ...parametrically for laminar convective heat transfer in a circular tube with constant wall temperature. The size of the phase change mushy region and the phase change interface locations are given for the various governing parameters. Two enhancement ratios, the traditional enhancement ratio and a modified enhancement ratio, were used to quantify the enhanced heat transfer characteristics of the microencapsulated phase change suspension for six major parameters. The six parameters are the bulk Stephan number, the volumetric concentration of the solid-phase, the particle-to-tube radius ratio, the dimensionless initial subcooling, the dimensionless phase change temperature range, and the bulk Reynolds number. The simulations show that the bulk Stephan number and the volumetric concentration are the most important parameters influencing the heat transfer enhancement of the microencapsulated suspension. The influence of the microcapsule diameters on the heat transfer enhancement comes from the microconvection, instead of the latent heat release due to the phase change. In addition, the combined effect of changes in all of these parameters on the heat transfer enhancement was examined.
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