Recommendation Algorithm for Multi-Task Learning with Directed Graph Convolutional Networks

As an important branch of machine learning, recommendation algorithms have attracted the attention of many experts and scholars. The current recommendation algorithms all more or less have problems such as cold start and single recommended items. In order to overcome these problems and improve the accuracy of personalized recommendation algorithms, this paper proposes a recommendation for multi-task learning based on directed graph convolutional network (referred to as MTL-DGCNR) and applies it to recommended areas for e-commerce. First, the user’s micro-behavior is constructed and converted into directed graph structure data for model embedding. It can fully consider the embedding of first-order proximity nodes and second-order proximity nodes, which can effectively enhance the transformation ability of features. Secondly, this model adopts the multi-task learning method, and uses knowledge graph embedding to effectively deal with the one-to-many or many-to-many relationship between users and commodities. Finally, it is verified by experiments that MTL-DGCNR has a higher interpretability and accuracy in the field of e-commerce recommendation than other recommendation models. The ranking evaluation experiments, various training methods comparison experiments, and controlling parameter experiments are designed from multiple perspectives to verify the rationality of MTL-DGCNR

Recommendation Algorithm for Multi-Task Learning with Directed Graph Convolutional Networks

As an important branch of machine learning, recommendation algorithms have attracted the attention of many experts and scholars. The current recommendation algorithms all more or less have problems such as cold start and single recommended items. In order to overcome these problems and improve the accuracy of personalized recommendation algorithms, this paper proposes a recommendation for multi-task learning based on directed graph convolutional network (referred to as MTL-DGCNR) and applies it to recommended areas for e-commerce. First, the user’s micro-behavior is constructed and converted into directed graph structure data for model embedding. It can fully consider the embedding of first-order proximity nodes and second-order proximity nodes, which can effectively enhance the transformation ability of features. Secondly, this model adopts the multi-task learning method, and uses knowledge graph embedding to effectively deal with the one-to-many or many-to-many relationship between users and commodities. Finally, it is verified by experiments that MTL-DGCNR has a higher interpretability and accuracy in the field of e-commerce recommendation than other recommendation models. The ranking evaluation experiments, various training methods comparison experiments, and controlling parameter experiments are designed from multiple perspectives to verify the rationality of MTL-DGCNR

Experimental study on the self-suspending proppant-laden flow in a single fracture

Abstract The flow of proppant-laden fluid (PLF) in the fracture is a typical problem of solid-liquid two phase flow, and the transportation and deposition of proppants are essential to determine the flow conductivity of hydraulic fracturing. The self-suspending proppant with a water soluble surface coating is a newly presented supporting material and has great potential for hydraulic fracturing. The purpose of this paper is to understand the physical process, and investigate the effect of the self-suspending proppant on particle placement and transportation in the fracture. Two experiments of the PLF flow were conducted in a fracture, using the common ceramic proppant and self-suspending proppant, respectively. The fracture was formed by two parallel plexiglass planes, and was 4000 mm in length, 10 mm in width and 600 mm in height. It was found that four different zones developed when proppants were injected into the fracture continuously, which were the proppant bank zone, tumbling zone, suspending zone, and free zone. Compared with the common proppant, the self-suspending proppant changes the particle distribution in the fracture, and increases the thickness of proppant suspending and bank zone. The motion behavior of self-suspending proppants in the fracture is described. The conclusion is that appropriate reduction in the proppant concentration and density is beneficial to the good distribution and transportation of proppants in the fracture, and the self-suspending proppant favors the effective supporting of fracture

Experimental study on the self-suspending proppant-laden flow in a single fracture

<div><p>Abstract The flow of proppant-laden fluid (PLF) in the fracture is a typical problem of solid-liquid two phase flow, and the transportation and deposition of proppants are essential to determine the flow conductivity of hydraulic fracturing. The self-suspending proppant with a water soluble surface coating is a newly presented supporting material and has great potential for hydraulic fracturing. The purpose of this paper is to understand the physical process, and investigate the effect of the self-suspending proppant on particle placement and transportation in the fracture. Two experiments of the PLF flow were conducted in a fracture, using the common ceramic proppant and self-suspending proppant, respectively. The fracture was formed by two parallel plexiglass planes, and was 4000 mm in length, 10 mm in width and 600 mm in height. It was found that four different zones developed when proppants were injected into the fracture continuously, which were the proppant bank zone, tumbling zone, suspending zone, and free zone. Compared with the common proppant, the self-suspending proppant changes the particle distribution in the fracture, and increases the thickness of proppant suspending and bank zone. The motion behavior of self-suspending proppants in the fracture is described. The conclusion is that appropriate reduction in the proppant concentration and density is beneficial to the good distribution and transportation of proppants in the fracture, and the self-suspending proppant favors the effective supporting of fracture.</p></div

Data_Sheet_2_Association between horizontal violence and turnover intention in nurses: A systematic review and meta-analysis.docx

BackgroundHorizontal violence is common in nurses. Most published studies have focused on horizontal violence and higher turnover rates in nurses; however, it lacks systematic reviews and meta-analyses. The purpose of this review is to quantitatively assess the correlation between horizontal violence and turnover intention in nurses.MethodsSystematic review and meta-analysis were performed in accordance with PRISMA guidelines. The relationship between horizontal violence and turnover intention in nurses was obtained by systematically searching related literature in four English databases (Cochrane, PubMed, Embase, and CINAHL) and three Chinese databases (SinoMed, CNKI, and Wanfang) (up to 6 March 2022). The relationship between horizontal violence and turnover intention was evaluated using Fisher's z-value, which was then converted to r. STATA 16.0 was used to perform statistical analysis. The random-effects model was performed to synthesize data.ResultsA total of 14 studies with 6,472 nurses were included. A low-positive correlation of horizontal violence with turnover intention was found (pooled r=0.32 [0.29–0.34]). Subgroup analysis showed that sample size and quality were not the source of heterogeneity. Measurement tool was the source of heterogeneity. Although geographic region might not be the source of heterogeneity, further subgroup analysis of the country reveals heterogeneity. The funnel plot and Egger's test showed no publication bias.ConclusionHorizontal violence had a low positive correlation with turnover intention in nurses. Nurses who experienced horizontal violence were more likely to leave or change careers than those who did not experience horizontal violence. This finding helps to draw attention to horizontal violence by nursing managers and implement effective interventions for nurses, so as to reduce nurses' turnover.</p

Data_Sheet_1_Association between horizontal violence and turnover intention in nurses: A systematic review and meta-analysis.docx

BackgroundHorizontal violence is common in nurses. Most published studies have focused on horizontal violence and higher turnover rates in nurses; however, it lacks systematic reviews and meta-analyses. The purpose of this review is to quantitatively assess the correlation between horizontal violence and turnover intention in nurses.MethodsSystematic review and meta-analysis were performed in accordance with PRISMA guidelines. The relationship between horizontal violence and turnover intention in nurses was obtained by systematically searching related literature in four English databases (Cochrane, PubMed, Embase, and CINAHL) and three Chinese databases (SinoMed, CNKI, and Wanfang) (up to 6 March 2022). The relationship between horizontal violence and turnover intention was evaluated using Fisher's z-value, which was then converted to r. STATA 16.0 was used to perform statistical analysis. The random-effects model was performed to synthesize data.ResultsA total of 14 studies with 6,472 nurses were included. A low-positive correlation of horizontal violence with turnover intention was found (pooled r=0.32 [0.29–0.34]). Subgroup analysis showed that sample size and quality were not the source of heterogeneity. Measurement tool was the source of heterogeneity. Although geographic region might not be the source of heterogeneity, further subgroup analysis of the country reveals heterogeneity. The funnel plot and Egger's test showed no publication bias.ConclusionHorizontal violence had a low positive correlation with turnover intention in nurses. Nurses who experienced horizontal violence were more likely to leave or change careers than those who did not experience horizontal violence. This finding helps to draw attention to horizontal violence by nursing managers and implement effective interventions for nurses, so as to reduce nurses' turnover.</p

3D Aligned Nanofiber Scaffold Fabrication with Trench-Guided Electrospinning for Cardiac Tissue Engineering

Constructing three-dimensional (3D) aligned nanofiber scaffolds is significant for the development of cardiac tissue engineering, which is promising in the field of drug discovery and disease mechanism study. However, the current nanofiber scaffold preparation strategy, which mainly includes manual assembly and hybrid 3D printing, faces the challenge of integrated fabrication of morphology-controllable nanofibers due to its cross-scale structural feature. In this research, a trench-guided electrospinning (ES) strategy was proposed to directly fabricate 3D aligned nanofiber scaffolds with alternative ES and a direct ink writing (DIW) process. The electric field effect of DIW poly(dimethylsiloxane) (PDMS) side walls on guiding whipping ES nanofibers was investigated to construct trench design rules. It was found that the width/height ratio of trenches greatly affected the nanofiber alignment, and the trench width/height ratio of 1.5 provided the nanofiber alignment degree over 60%. As a proof of principle, 3D nanofiber scaffolds with controllable porosity (60–80%) and alignment (30–60%) were fabricated. The effect of the scaffolds was verified by culturing human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), which resulted in the uniform 3D distribution of aligned hiPSC-CMs with ∼1000 μm thickness. Therefore, this printing strategy shows great potential for the efficient engineered tissue construction

3D Aligned Nanofiber Scaffold Fabrication with Trench-Guided Electrospinning for Cardiac Tissue Engineering

Constructing three-dimensional (3D) aligned nanofiber scaffolds is significant for the development of cardiac tissue engineering, which is promising in the field of drug discovery and disease mechanism study. However, the current nanofiber scaffold preparation strategy, which mainly includes manual assembly and hybrid 3D printing, faces the challenge of integrated fabrication of morphology-controllable nanofibers due to its cross-scale structural feature. In this research, a trench-guided electrospinning (ES) strategy was proposed to directly fabricate 3D aligned nanofiber scaffolds with alternative ES and a direct ink writing (DIW) process. The electric field effect of DIW poly(dimethylsiloxane) (PDMS) side walls on guiding whipping ES nanofibers was investigated to construct trench design rules. It was found that the width/height ratio of trenches greatly affected the nanofiber alignment, and the trench width/height ratio of 1.5 provided the nanofiber alignment degree over 60%. As a proof of principle, 3D nanofiber scaffolds with controllable porosity (60–80%) and alignment (30–60%) were fabricated. The effect of the scaffolds was verified by culturing human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), which resulted in the uniform 3D distribution of aligned hiPSC-CMs with ∼1000 μm thickness. Therefore, this printing strategy shows great potential for the efficient engineered tissue construction

3D Aligned Nanofiber Scaffold Fabrication with Trench-Guided Electrospinning for Cardiac Tissue Engineering

Constructing three-dimensional (3D) aligned nanofiber scaffolds is significant for the development of cardiac tissue engineering, which is promising in the field of drug discovery and disease mechanism study. However, the current nanofiber scaffold preparation strategy, which mainly includes manual assembly and hybrid 3D printing, faces the challenge of integrated fabrication of morphology-controllable nanofibers due to its cross-scale structural feature. In this research, a trench-guided electrospinning (ES) strategy was proposed to directly fabricate 3D aligned nanofiber scaffolds with alternative ES and a direct ink writing (DIW) process. The electric field effect of DIW poly(dimethylsiloxane) (PDMS) side walls on guiding whipping ES nanofibers was investigated to construct trench design rules. It was found that the width/height ratio of trenches greatly affected the nanofiber alignment, and the trench width/height ratio of 1.5 provided the nanofiber alignment degree over 60%. As a proof of principle, 3D nanofiber scaffolds with controllable porosity (60–80%) and alignment (30–60%) were fabricated. The effect of the scaffolds was verified by culturing human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), which resulted in the uniform 3D distribution of aligned hiPSC-CMs with ∼1000 μm thickness. Therefore, this printing strategy shows great potential for the efficient engineered tissue construction