Background:
CD8
+
T cells, a critical component of the tumor immune microenvironment, have become a key target of cancer immunotherapy. Considering the deficiency of robust biomarkers for head and ...neck squamous cell carcinoma (HNSCC), this study aimed at establishing a molecular signature associated with CD8+T cells infiltration.
Methods:
Single-cell RNA sequencing data retrieved from the Gene Expression Omnibus (GEO) database was analyzed to obtain the different cell types. Next, the cell proportions were investigated through deconvolution of RNA sequencing in the Cancer Genome Atlas (TCGA) database, and then the immune-related genes (IRGs) were identified by weighted gene co-expression network analysis (WGCNA). LASSO-Cox analysis was employed to establish a gene signature, followed by validation using a GEO dataset. Finally, the molecular and immunological properties, and drug responses between two subgroups were explored by applying “CIBERSORT”, “ESTIMATE”, and single sample gene set enrichment analysis (ssGSEA) methods.
Results:
A total of 215 differentially expressed IRGs were identified, of which 45 were associated with the overall survival of HNSCC. A risk model was then established based on eight genes, including
DEFB1
,
AICDA
,
TYK2
,
CCR7
,
SCARB1
,
ULBP2
,
STC2
, and
LGR5
. The low-risk group presented higher infiltration of memory activated CD4
+
T cells, CD8
+
T cells, and plasma cells, as well as a higher immune score, suggesting that they could benefit more from immunotherapy. On the other hand, the high-risk group showed higher abundance of activated mast cells and M2 macrophages, as well as a lower immune score.
Conclusion:
It was evident that the 8-gene signature could accurately predict HNSCC prognosis and thus it may serve as an index for clinical treatment.
The spindle is the key functional part of the machine tool, and the thermal deformation caused by the heat generation of the bearing seriously affects the machining accuracy. This article studies the ...thermal characteristics of spindle using a variable preload system and an external liquid cooling system, by analyzing the temperature rise mechanism of the machine tool. Firstly, a novel variable preload device for bearings has been designed, which enables adjustable output force direction. Based on the variable preload performance of the device, an integrated thermal analysis model of the spindle variable preload was established to simulate the temperature field and thermal displacement field of the spindle under the variable preload condition. And then, a modular external cooling system was innovatively used on the spindle housing to further reduce thermal deformation of the spindle. By establishing a thermal–flow–structural coupling analysis model of the spindle, the overall thermal characteristics of the spindle under the combined influence of variable preload bearing and modular external cooling system were analyzed in detail. The simulation results indicate that the thermal gradient and deformation of spindle with variable preload and external liquid cooling are lower than those of spindle with a constant preload, while the degree of thermal optimization gradually increases as the spindle speed rises. The accuracy of the simulation was verified by the temperature rise experiment of the spindle, which provides a foundation for engineering application.
In order to obtain the equivalent elastic parameters of its macro-scale structure, the tensile properties of 2D 1×1 braided composite cell model was simulated, and the stress distribution law and ...load displacement relationship of the structure were obtained. Based on elastic theory, the equivalent elastic modulus of unit cell model was used to characterize the elastic properties of 2D braided composites. The effects of different braiding angles on the equivalent elastic modulus of braided composites were further analyzed. The results show that the stress of the fiber bundle and the matrix in the unit cell model decreases with the increase of the braiding angle; and as the main carrier, the stress of the fiber bundle is much higher than that of the matrix; and the equivalent elastic parameters in the braiding direction decrease with the increase of braiding angle.
Dimensional variation has significant effect on the quality of product. Recently, Monte Carlo (MC) simulation is widely used in dimensional variation analysis, with high accuracy and adaptability, ...but there is the problem of low computational efficiency. Aiming to address this problem, an improvement of MC simulation is proposed through a two-phases solution. In the first phase, surrogate model is used to approximate the locating constraint equations for a 3D part, which reduces the nonlinear coupling between dimensional deviations and avoids large-scale solution of nonlinear equations in dimensional variation analysis on the condition of ensuring the accuracy. In the second phase, random samples used in MC simulation are replaced by low discrepancy sequences, which enable the samples to have better homogeneity and representativeness and reduce the number of samples required in the dimensional variation analysis. Finally, two examples are used to demonstrate the effectiveness of the method, and the results show that the two-phases solution has advantages both in the accuracy and efficiency.
In order to rationally lay out the location of automobile maintenance service stations, a method of location selection of maintenance service stations based on vehicle trajectory big data is ...proposed. Taking the vehicle trajectory data as the demand points, the demand points are divided according to the region by using the idea of zoning, and the location of the second-level maintenance station is selected for each region. The second-level maintenance stations selected in the whole country are set as the demand points of the first-level maintenance stations. Considering the objectives of the two dimensions of cost and service level, the location model of the first-level maintenance stations under two-dimensional programming is established, and the improved particle swarm optimization algorithm and immune algorithm, respectively, are used to solve the problem. In this way, the first-level maintenance stations in each region are obtained. The example verification shows that the location selection results for the maintenance stations using the vehicle trajectory big data are reasonable and closer to the actual needs.
One of the most common problems encountered by patients using artificial joints is the high wear rate. In this study, a polyvinyl alcohol/polyethylene glycol (PVA/PEG) gel was prepared through the ...cross-linking reaction between polyvinyl alcohol (PVA) and polyethylene glycol (PEG) solutions. This gel can lubricate artificial joints, thereby lowering their coefficient of friction (COF) and increasing their service life. Various techniques, such as Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectra, X-ray photon spectroscopy, and thermogravimetric analyses, were used to analyze the structure of this synthetic gel. The tribological results indicated that the synthetic gel’s lubrication effect was the most optimum when it contained PVA (10 wt%) and PEG (15 wt%). An average COF of 0.05 was obtained under a load of 10 N and at a speed of 1.0 cm/s. In addition, the wear rate was reduced in comparison to distilled water. Furthermore, the biological tests proved that the PVA/PEG gel was highly biocompatible. Thus, this study introduces a novel technique to prepare PVA/PEG gels that improve the tribological performance of artificial joints.
The precision spool valve is the core component of the electro-hydraulic servo control system, and its performance has an important influence on the flight control of aviation and aerospace products. ...The non-uniform surface topography error causes a non-uniform mating gap field inside the spool valve, which causes oil leakage and leads to deterioration of the spool valve performance. However, the current oil leakage calculation method only considers the influence of size errors, which is not comprehensive. Thus, how to characterize the mating behavior of the spool valve and its effect on oil leakage with consideration of surface topography errors is the key to evaluating the performance of the spool valve. This paper proposes a new way of analyzing the mating performance of precision spool valves, which considers the surface topography errors based on digital twin technology. Firstly, a general framework for the analysis of mating performance of precision spool valve based on a digital twin is proposed. Then, key technologies of assembly interface geometry modeling, matching behavior modeling and performance analysis are studied. Finally, a quantitative correlation between the mating parameters and the oil leakage of the precision spool valve is revealed. The method is tested on a practical case. This proposed method can provide theoretical support for the accurate prediction and evaluation of the mating performance of the precision spool valve.
Aiming at solving the problem of dual resource constrained flexible job shop scheduling problem (DRCFJSP) with differences in operating time between operators, an artificial intelligence (AI)-based ...DRCFJSP optimization model is developed in this paper. This model introduces the differences between the loading and unloading operation time of workers before and after the process. Subsequently, the quantum genetic algorithm (QGA) is used as the carrier; the process is coded through quantum coding; and the niche technology is used to initialize the population, adaptive rotation angle, and quantum mutation strategy to improve the efficiency of the QGA and avoid premature convergence. Lastly, through the Kacem standard calculation example and the reliability analysis of the factory workshop processing process example, performance evaluation is conducted to show that the improved QGA has good convergence and does not fall into premature ability, the improved QGA can solve the problem of reasonable deployment of machines and personnel in the workshop, and the proposed method is more effective for the DRCFJSP than some existing methods. The findings can provide a good theoretical basis for actual production and application.
•The immune cell infiltration (ICI) landscape of HNSCC was evaluated by CIBERSORT.•The ICI score was computed by the PCA algorithm.•The immune-related gene risk signature was constructed using 57 ...DEGs.•Both the ICI score and the risk score were promising reliable biomarkers for HNSCC prognosis.•A nomogram was built by integrating ICI score, risk score and clinical features.
Immunotherapy directed at the tumor microenvironment is effective in the treatment of head and neck squamous cell carcinoma (HNSCC). In contrast, there has been a paucity of research on the relationship between the HNSCC microenvironment and prognostic outcome. Meanwhile, tumor immune cell infiltration (ICI) has emerged as a critical step in immunotherapy.
Two algorithms, CIBERSORT and ESTIMATE, were performed to evaluate the ICI view of 885 HNSCC patients using three databases: the Cancer Genome Atlas (TCGA), Arrayexpress, and Gene Expression Omnibus (GEO).
Different ICI subtypes were identified. Following that, 57 different expression genes (DEGs) were discovered. The ICI scores of all patients were calculated using the Principal Component Analysis (PCA) algorithm. Additionally, an immune-related prognostic signature was developed and validated using 17 of 57 DEGs. Patients with a low-ICI or low-risk score had a higher infiltration immune-activated related cells and higher expression of most immune checkpoint-related molecules, indicating a better prognosis. Furthermore, using the pRRophetic algorithm, the sensitivities of many chemotherapeutic drugs were significantly different between two ICI subtypes or two risk groups. Moreover, a nomogram incorporating the ICI score, risk score, and clinical characteristics was developed and was capable of accurately predicting outcomes. Conclusion: The ICI score and 17-gene signature could improve HNSCC survival prediction, promote individual treatment strategies, and provide promising novel immunotherapy biomarkers.
Polyvinyl alcohol (PVA) hydrogel is considered the most promising candidate for artificial cartilage because of its good lubricity and low permeability. However, the efficacy of single‐network PVA ...hydrogels under variable loads has not yet been determined. In this study, a one‐step physical‐cross‐linking method was used to compose PVA/PEG double‐network composite hydrogels. We changed the polyethylene glycol (PEG) content of the composite gel and tested the frictional‐wear performance under different loads and speeds. With the mass fraction of PEG at 30 wt.%, the hardness of the PVA/PEG composite gel increased to 167.7% that of pure PVA. Under dry‐friction conditions, the average coefficient of friction was approximately 0.14 and the wear rate on the surface of the hydrogel was insignificant. The cross‐linking between PVA and PEG greatly enhanced the stability of the composite hydrogel polymer network. The structure of the composite gel was analyzed by a variety of standard methods. The hydrogel has excellent biocompatibility and self‐healing ability and is a self‐lubricating, self‐healing candidate material for articular‐cartilage repair.
PDF
