29 research outputs found
Construction of retrovirus vector taking MDR1/ACBC1 and its transfection into human placenta derived mesenchymal stem cells
In the study, we used both the methods of perfusion and density gradient centrifugation to isolate and purify mesenchymal stem cells (MSCS) from placenta tissue, and constructed a retroviral vector with multiple drug resistant genes, and the green fluorescent protein (GFP) has been used as an indicative mark. The 293T cell was transfected by the retroviral vector PMX-flag-MDR1-GFP together with its peripheral membrane protein gene. After the infective and replication–defective retrovirus were acquired, we transfected them into human placenta-derived mesenchymal stem cells (HPMSCs). We successfully observed the expression of the reporter gene-GFP by using the green light fluorescence microscope and the p-glycoprotein (P-gp) expressed by exogenous gene MDR1 by Western Blotting. All these facts indicated that the retroviral vector PMX-flag-MDR1-GFP had successfully been transfected into HPMSCs and the exogenous gene multidrug resistance (MDR)1 was detected as normally expressed. The daunorubicin (DNR) pump experiment proved that P-gp of HPMSCs transfected with PMX-flag-MDR1-GFP was of biological activity. The result indicates that MDR1 retroviral vector can transfect the HPMSCs. Not only can the exogenous gene be expressed, but also the expression protein had the biological activity. The conclusion lays a solid foundation of the clinical application of MDR1 genetic therapy.Keywords: Transfect, human placenta-derived mesenchymal stem cells, multidrug resistance (MDR)1 gene
VR-GNN: Variational Relation Vector Graph Neural Network for Modeling both Homophily and Heterophily
Graph Neural Networks (GNNs) have achieved remarkable success in diverse
real-world applications. Traditional GNNs are designed based on homophily,
which leads to poor performance under heterophily scenarios. Current solutions
deal with heterophily mainly by mixing high-order neighbors or passing signed
messages. However, mixing high-order neighbors destroys the original graph
structure and passing signed messages utilizes an inflexible message-passing
mechanism, which is prone to producing unsatisfactory effects. To overcome the
above problems, we propose a novel GNN model based on relation vector
translation named Variational Relation Vector Graph Neural Network (VR-GNN).
VR-GNN models relation generation and graph aggregation into an end-to-end
model based on Variational Auto-Encoder. The encoder utilizes the structure,
feature and label to generate a proper relation vector. The decoder achieves
superior node representation by incorporating the relation translation into the
message-passing framework. VR-GNN can fully capture the homophily and
heterophily between nodes due to the great flexibility of relation translation
in modeling neighbor relationships. We conduct extensive experiments on eight
real-world datasets with different homophily-heterophily properties to verify
the effectiveness of our model. The experimental results show that VR-GNN gains
consistent and significant improvements against state-of-the-art GNN methods
under heterophily, and competitive performance under homophily
Theoretical Research on Ellipsoidal Structure Methane Gas Detection Based on Near Infrared Light Sources of PbSe Quantum Dots
To improve the precision and sensitivity of the detection in near infrared gas detection system, the selection of light source and design of gas chamber structure are two key links. In this paper, the near infrared (NIR) light sources fabricated with PbSe quantum dots (QDs) and a new gas cell structure using an ellipsoid reflector were designed to test the concentration of methane (CH4). The double wavelengths differential detection method was used in the paper. The signal wavelength is 1.665 μm from the NIR QD-based light source with 5.1 nm PbSe QDs. The reference wavelength is 1.943 μm from the NIR QD-based light source with 6.1 nm PbSe QDs. The experimental results show that the differential gain signal could be enhanced 80 times when the major axis, the focus, and the open length of the ellipsoid reflector are 4.18 cm, 3.98 cm, and 0.36 cm, respectively. The structure will be convenient for the signal amplifying, AD converting, and other process in the latter circuits, and therefore both the detection sensitivity and precision can be improved
Type-Aware Anchor Link Prediction across Heterogeneous Networks Based on Graph Attention Network
Anchor Link Prediction (ALP) across heterogeneous networks plays a pivotal role in inter-network applications. The difficulty of anchor link prediction in heterogeneous networks lies in how to consider the factors affecting nodes alignment comprehensively. In recent years, predicting anchor links based on network embedding has become the main trend. For heterogeneous networks, previous anchor link prediction methods first integrate various types of nodes associated with a user node to obtain a fusion embedding vector from global perspective, and then predict anchor links based on the similarity between fusion vectors corresponding with different user nodes. However, the fusion vector ignores effects of the local type information on user nodes alignment. To address the challenge, we propose a novel type-aware anchor link prediction across heterogeneous networks (TALP), which models the effect of type information and fusion information on user nodes alignment from local and global perspective simultaneously. TALP can solve the network embedding and type-aware alignment under a unified optimization framework based on a two-layer graph attention architecture. Through extensive experiments on real heterogeneous network datasets, we demonstrate that TALP significantly outperforms the state-of-the-art methods
Touch Locating and Stretch Sensing Studies of Conductive Hydrogels with Applications to Soft Robots
Soft robots possess great potential in environmental adaptations, while their environmental sensing abilities are critical. Conductive hydrogels have been suggested to possess sensing abilities. However, their application in soft robots is lacking. In this work, we fabricated a soft and stretchable gel material, introduced its sensing mechanisms, and developed a measurement setup. Both experimental and simulation studies indicate strong nonlinearity of touch locating on a square touch panel with Cartesian coordinates. To simplify the touch locating, we proposed a touch locating system based on round touch panels with polar coordinates. Mathematical calculations and finite element method (FEM) simulations showed that in this system the locating of a touch point was only determined by its polar radius. This was verified by experimental studies. As a resistor, a gel strip’s resistance increases with stretching. To demonstrate their applications on soft robots, a 3D printed three-fingered soft gripper was employed with gel strips attached. During finger bending for rod grasping, the resistances of the gel strips increased, indicating stretching of the soft material. Furthermore, the strain and stress of a gel strip increased with a decrease of the rod diameter. These studies advance the application of conductive hydrogels on soft robots
Theoretical Research on Ellipsoidal Structure Methane Gas Detection Based on Near Infrared Light Sources of PbSe Quantum Dots
To improve the precision and sensitivity of the detection in near infrared gas detection system, the selection of light source and design of gas chamber structure are two key links. In this paper, the near infrared (NIR) light sources fabricated with PbSe quantum dots (QDs) and a new gas cell structure using an ellipsoid reflector were designed to test the concentration of methane (CH 4 ). The double wavelengths differential detection method was used in the paper. The signal wavelength is 1.665 m from the NIR QD-based light source with 5.1 nm PbSe QDs. The reference wavelength is 1.943 m from the NIR QD-based light source with 6.1 nm PbSe QDs. The experimental results show that the differential gain signal could be enhanced 80 times when the major axis, the focus, and the open length of the ellipsoid reflector are 4.18 cm, 3.98 cm, and 0.36 cm, respectively. The structure will be convenient for the signal amplifying, AD converting, and other process in the latter circuits, and therefore both the detection sensitivity and precision can be improved
Comparison of the sensitivity of three cell cultures to ORFV
Abstract Background Contagious ecthyma (CE) appears in the countries and regions containing goat and sheep farms, and it is considered a global epidemic. CE not only severely endangers the healthy development of the sheep and goat industries but also threatens human health. For viral infectious diseases, fast and effective isolation and culture of the pathogen is critical for CE diagnosis, and for disease prevention and control. Therefore, the sensitivity of bovine Sertoli cells to ORFV was estimate in this study. Results The sensitivities of bovine Sertoli cells, primary neonatal bovine testicular cells, and Madin-Darby bovine kidney (MDBK) cell line to ORFV were compared. Our results showed that the isolated bovine Sertoli cells were sensitive to inoculated ORFV, and viral titers were approximately 1 log higher than those in primary neonatal bovine testicular cells and in MDBK cell lines. Conclusion Appropriately sensitive cells for the highly efficient isolation and culture of the ORFV were obtained. Culture of ORFV using the Sertoli cells showed good consistency and stability and also avoided the risk of other pathogens presenting during viral culture using a primary cell line. In addition, using these passaged bovine Sertoli cells to proliferate ORFV may simplify the CE diagnosis process, thereby reducing detection time and cost. Hence, this test has important practical significance for the diagnosis of CE and the research on the pathogenic mechanism of ORFV
Systematic Identification of the Light-quality Responding Anthocyanin Synthesis-related Transcripts in Petunia Petals
Previous studies have shown that high light intensity can induce anthocyanin synthesis (AS) in petunia plants. To identify which kind of light quality plays a role in inducing such metabolic process, and what transcripts participate in controlling it, we carried out whole-transcriptome sequencing and analysis of petunia petals treated with different light-quality conditions. Among the red and white light treatments, a total of 2 205 differentially expressed genes and 15, 22, and 20 differentially expressed circRNAs, miRNAs, and lncRNAs, were identified respectively. The AS-related genes, including the structural genes CHSj, F3'H, F3'5'H, DFR, and ANS , and the regulatory genes AN4, DPL, PHZ and MYBx were found to be downregulated under red light condition compared with their levels under white light condition. Furthermore, the light photoreceptor Cryptochrome 3 (CRY3) and a series of light-dependent genes, such as PIF, HY5, and BBXs, were also determined to respond to the light treatments. The anthocyanin contents in early petunia petals under red light were significantly lower than that under white and blue light. The results of qRT-PCR further confirmed the expression pattern of some AS-related and light-response genes in response to different light quality. Yeast two-hybrid results showed that the key elements in the light signal pathway, HY5 can interact with BBX19, BBX24 and BBX25. And PHZ, the important AS regulator can induce anthocyanin synthesis in response to blue light quality from transient expression analysis in petunia petals. These findings presented here not only deepen our understanding of how light quality controls anthocyanin synthesis, but also allow us to explore potential target genes for improving pigment production in petunia flower petals