58 research outputs found
Compact hollow waveguide mid-infrared gas sensor for simultaneous measurements of ambient CO2 and water vapor
A compact, sensitive and stable hollow waveguide (HWG) mid-infrared gas sensor, based on gas absorption lines using wavelength modulation spectroscopy with a second harmonic (WMS-2f) detection scheme, was developed for simultaneous measurements of ambient CO 2 and water vapor. Optimization of the laser modulation parameters and pressure parameter in the HWG are performed to improve the strength of the WMS-2f signal and hence the detection limit, where 14.5-time for CO 2 and 8.5-time for water vapor improvement in system detection limit is achieved compared to those working at 1 atm. The stability of the sensor has been improved significantly by optimizing environmental disturbances, incoupling alignment of the HWG and laser scanning frequency. An Allan variance analysis shows detection limit of the developed sensor of ~3 ppmv for CO 2 and 0.018% for water vapor, which correspond to an absorbance of 2.4 Ă— 10 -5 and 2.7 Ă— 10 -5 , with a stability time of 160 s, respectively. Ambient CO 2 and water vapor measurement have been performed in two days in winter and spring separately. The measurement precision is further improved by applying a Kalman adaptive filter. The HWG gas sensor demonstrates the ability in environmental monitoring and the potential to be used in other areas, such as industrial production and biomedical diagnosis
CXCL9 expression in breast cancer and its correlation with the characteristics of tumor immunoinfiltration
Objective·To explore the effect of C-X-C motif chemokine ligand 9 (CXCL9) expression on the prognosis of breast cancer patients and its correlation with tumor-infiltrating immune cells (TIICs).Methods·Transcriptome data of 1 100 breast tumor tissues and 112 adjacent tissues were obtained from The Cancer Genome Atlas (TCGA) database. CIBERSORT deconvolution algorithm was used to analyze the proportion of TIIC subgroups in breast cancer immune microenvironment and its effect on the prognosis of patients. Differentially expressed genes, immune-related genes and breast cancer prognostic-related genes were downloaded from TCGA database, ImmPort database and GEPIA2 data platform, respectively. The intersection relationships of the three gene sets were analyzed by using R language, and the target genes were screened. Based on the downloaded transcriptome data, CXCL9 positive-related genes, the difference of CXCL9 mRNA expression in breast cancer tissues and adjacent tissues and its effect on the prognosis of patients were analyzed. STRING data platform was used to analyze the protein-protein interaction (PPI) network of CXCL9. Gene Ontology (GO) function analysis and Kyoto Encyclopedia of Genes and Genome (KEGG) pathway analysis were performed on CXCL9 positive correlation genes and the genes corresponding to the interacting proteins obtained from the PPI network by using R language. Spearman correlation coefficient was used to analyze the correlation between CXCL9 mRNA expression and TIIC subgroups and immune checkpoint-related genes. Paraffin tissue samples of 60 clinical breast cancer patients were collected and made into tissue chips. The correlation between CXCL9 expression and CD8+ T cells infiltration in the tissue chips was detected by immunohistochemical staining (IHC). The types of CXCL9+ cells in breast cancer interstitium were analyzed by multiplex immunohistochemistry staining (mIHC). Kaplan-Meier (KM) survival curve was used to analyze the effect of CXCL9 mRNA expression and CD8+ T cell infiltration on the prognosis of breast cancer patients.Results·CIBERSORT algorithm analysis showed that the distribution proportion of TIIC subgroups in breast cancer immune microenvironment varied greatly, and their effect on patients′ prognosis was also different. The Venn diagram of three types of gene sets was drawn, and CXCL9 was screened out. The top 150 positive correlation genes with CXCL9 were obtained. CXCL9 mRNA expression levels in four molecular types of breast cancer were higher than those in adjacent tissues (all P=0.000), and their high expressions were significantly associated with good prognosis of patients (P=0.013). A total of 41 interacting proteins were obtained through PPI network analysis. GO and KEGG analysis showed that CXCL9 and its related genes were mainly enriched in biological functions and pathways related to immune regulation. Spearman correlation coefficient analysis showed that the expression level of CXCL9 mRNA was positively correlated with CD8+ T cells infiltration ratio, negatively correlated with M2-type macrophages infiltration ratio, and positively correlated with most immune checkpoint genes expression (all P<0.05). IHC experiments showed that CXCL9 was highly expressed in breast cancer tissues compared with adjacent tissues, accompanied by an increased percentage of CD8+ T cells infiltration (P=0.000). mIHC results showed that CXCL9 was expressed in some CD68+ tumor-associated macrophages (TAMs) and CD11c+ dendritic cells (DCs) in the stroma of breast cancer. KM survival curve showed that when CXCL9 was highly expressed, CD8+ T cells high infiltration could prolong the survival of breast cancer patients.Conclusion·CXCL9 can be used as a biomarker for good prognosis of breast cancer patients. The high expression of CXCL9 in the microenvironment of breast cancer is positively correlated with the infiltration ratio of CD8+ T cells and may activate its anti-tumor effect. The expression of CXCL9 may be closely related to the recruitment of lymphocytes into the tumor microenvironment for anti-tumor immune response
Small extracellular vesicles derived from acute myeloid leukemia cells promote leukemogenesis by transferring miR-221-3p
Small extracellular vesicles (sEVs) transfer cargos between cells and participate in various physiological and pathological processes through their autocrine and paracrine effects. However, the pathological mechanisms employed by sEV-encapsulated microRNAs (miRNAs) in acute myeloid leukemia (AML) are still obscure. In this study, we aimed to investigate the effects of AML cells-derived sEVs (AML-sEVs) on AML cells and delineate the underlying mechanisms. We initially used high-throughput sequencing to identify miR-221-3p as the miRNA prominently enriched in AML-sEVs. Our findings revealed that miR-221-3p promoted AML cell proliferation and leukemogenesis by accelerating cell cycle entry and inhibiting apoptosis. Furthermore, Gbp2 was confirmed as a target gene of miR-221-3p by dual luciferase reporter assays and rescue experiments. Additionally, AML-sEVs impaired the clonogenicity, particularly the erythroid differentiation ability, of hematopoietic stem and progenitor cells. Taken together, our findings reveal how sEVs-delivered miRNAs contribute to AML pathogenesis, which can be exploited as a potential therapeutic target to attenuate AML progression
Link Prediction in Complex Networks Using Recursive Feature Elimination and Stacking Ensemble Learning
Link prediction is an important task in the field of network analysis and modeling, and predicts missing links in current networks and new links in future networks. In order to improve the performance of link prediction, we integrate global, local, and quasi-local topological information of networks. Here, a novel stacking ensemble framework is proposed for link prediction in this paper. Our approach employs random forest-based recursive feature elimination to select relevant structural features associated with networks and constructs a two-level stacking ensemble model involving various machine learning methods for link prediction. The lower level is composed of three base classifiers, i.e., logistic regression, gradient boosting decision tree, and XGBoost, and their outputs are then integrated with an XGBoost model in the upper level. Extensive experiments were conducted on six networks. Comparison results show that the proposed method can obtain better prediction results and applicability robustness
Research on Profit-Sharing Mechanism of IPD Projects Considering Multidimensional Fairness Preferences and BIM
The integration of building information modeling (BIM) and the integrated project delivery (IPD) mode effectively promotes collaboration among project members and enhances project profitability. However, the issue of profit sharing significantly impacts the successful implementation of IPD projects. To enhance the profit-sharing mechanism of IPD projects and ensure their smooth implementation, a game analysis model of profit sharing in IPD projects was established based on the Stackelberg game theory, taking into account the multidimensional fair preferences of the participants and the application of BIM technology. Through simulation, the impact of various parameters of participants on output utility, total revenue, and sharing coefficient in IPD projects was analyzed. The results show that: (1) participants achieve their highest output utility and total revenue under vertical–horizontal fairness preferences; (2) under vertical fairness preferences, the profit sharing coefficient is the highest, while the output utility and total revenue are the lowest; (3) although the output utility and total revenue of participants under horizontal fairness preferences exceed those under neutral fairness preferences, the profit-sharing coefficient is lower; (4) the output utility, the total revenue, and the profit-sharing coefficient of the participants all increase with the increase in effort utility value and decrease with the increase in the effort cost coefficient and the risk avoidance coefficient. The research findings provide valuable theoretical support for the profit sharing of IPD projects, thereby further promoting the advancement and implementation of the IPD model
Experimental Study and Finite Element Analysis on the Flexural Behavior of Steel Fiber Reinforced Recycled Aggregate Concrete Beams
This paper reports on the flexural behavior of nine steel fiber reinforced-recycled aggregate concrete (SFRAC) beams through combined experimental and finite element analysis. The test parameters in this study include the steel fiber volume fraction, recycled aggregate replacement ratio, and concrete strength. The failure modes, crack development, load-deflection curves, and flexural bearing capacity of SFRAC beams are investigated in detail. The test results indicated that cracks and concrete crushing are formed in the compression zone of all specimens. The flexural bearing capacity of SFRAC beams increases with the increase of steel fiber volume fraction and concrete strength and the decrease of recycled aggregate replacement ratio. In addition, the results are compared with those of the finite element analysis. Based on the uniaxial compressive constitutive model of SFRAC, a new model for calculating the flexural bearing capacity of SFRAC beams is proposed. The prediction and test results are compared to evaluate the accuracy of the developed formula. The studies may provide a considerable reference for designing this type of structure in engineering practice
Experimental study on creep characteristics of glazed hollow beads-cement/sodium silicate grouting materials
This study introduces a new thermal insulation grouting material designed for high-temperature mine environment. The thermal insulation effect of cement/sodium silicate grouting materials can be enhanced by adding glazed hollow beads with outstanding thermal insulation properties. The ratio with the best comprehensive performance was selected through orthogonal tests, and the long-term creep mechanical characteristics of glazed hollow beads-cement/sodium silicate grouting materials were analyzed. Graded equal incremental loading with different loading durations was used to test the specimens' instantaneous strain, creep strain, creep rate, critical stress, and microscopic structures. For each loading stage, the Burgers model was used to fit the creep curve. The results show that graded loading intensity surpasses uniaxial loading across different loading durations. The different loading durations significantly affect the creep parameters, and stress concentration damage initially manifests on the surface of glazed hollow beads. Finally, the theoretical curve obtained by the Burgers model fits well with the creep test curve. This study has good practical significance for high-temperature roadway thermal grouting insulation technology
A Priority-Based Synchronous Phasor Transmission Protocol Extension Method for the Active Distribution Network
With the advancement of active distribution network construction, to solve the shortcomings of the existing distribution network technology in distribution network perception and control, the relevant technologies of the Wide Area Measurement System (WAMS) in the transmission network have attracted more attention in terms of their usage in the distribution network. Micro Multifunction Phasor Measurement Unit (μMPMU), as an example, is being gradually utilized in the distribution network. However, the existing synchronous phasor transmission protocol is mainly designed for the transmission network, which requires an extension to meet the communication requirements to be directly used in the distribution network. In this work, the requirements of active distribution network communication are analyzed, and trade-offs between National Standard of the People’s Republic of China/Recommended (GB/T) 26865.2-2011 and International Electro technical Commission (IEC) 60870-5-101/104 protocol are compared. An extension method of the communication protocol is proposed, with the benefits of the prioritized transmission of important data, expanded remote control function of μMPMU, increased types of offline files, and reduced amount of network communication and data storage. The method is built upon the existing GB/T 26865.2-2011 protocol, and refers to the Application Service Data Unit (ASDU) of IEC 60870-5-101/104 to add an application extension frame. Application extension frames are used to transmit telemetry data, telesignalization, partial commands, and partial offline files. Finally, an experimental environment is set up, which includes a phasor measurement unit (PMU) Emulator, distribution network phasor data concentrator (PDC), and main station emulator to implement the standard GB/T 26865.2-2011 protocol and extension protocol. The feasibility and effectiveness of the method are confirmed by the superior performance of the extended protocol compared with the standard protocol
Table2Analysis: Modeling and Recommendation of Common Analysis Patterns for Multi-Dimensional Data
Given a table of multi-dimensional data, what analyses would human create to extract information from it? From scientific exploration to business intelligence (BI), this is a key problem to solve towards automation of knowledge discovery and decision making. In this paper, we propose Table2Analysis to learn commonly conducted analysis patterns from large amount of (table, analysis) pairs, and recommend analyses for any given table even not seen before. Multi-dimensional data as input challenges existing model architectures and training techniques to fulfill the task. Based on deep Q-learning with heuristic search, Table2Analysis does table to sequence generation, with each sequence encoding an analysis. Table2Analysis has 0.78 recall at top-5 and 0.65 recall at top-1 in our evaluation against a large scale spreadsheet corpus on the PivotTable recommendation task
Volatiles from Cotton Plants Infested by Agrotis segetum (Lep.: Noctuidae) Attract the Larval Parasitoid Microplitis mediator (Hym.: Braconidae)
Herbivore-induced plant volatiles (HIPVs), chemicals produced by plants infested by herbivorous insects, can act as kairomones that recruit natural enemies of the pest herbivore. Agrotis segetum (Denis and Schiffermüller) is a common, important pest of seedling cotton in Xinjiang Province, China, and the braconid Microplitis mediator (Haliday) is an important mortality factor of this pest’s larvae. In olfactometer tests, which included healthy foliage, infested foliage, or infested roots, M. mediator preferred A. segetum-infested cotton plants to healthy cotton plants. In GC-MS analyses of plant-emitted volatiles, we found that compounds emitted increased 14.9- and 13.3- fold after leaf infestation and root infestation, respectively, compared to healthy control plants. The volatiles were mainly p-xylene, nonanal, tetradecane, decanal, benzaldehyde, β-caryophyllene, and humulene, while linalool was only present in the leaf-infestation treatment. In addition, principal component analysis indicated that all 18 compounds were associated with the infested plants, especially β-caryophyllene, p-xylene, and decanal. Based on the above studies and previous functional evaluations of the volatile compounds, it can be demonstrated that these compounds play a crucial role in modulating the interactions between A. segetum and M. mediator and regulating parasitoid behavior. It may be possible to enhance the biological control of A. segetum by M. mediator through the application of HIPVs
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