1. |
- Yang, Yang, et al.
(författare)
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Numerical analysis concerning the skid resistance of rubber-contaminated runway grooves
- 2021
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Ingår i: Tribology International. - : Elsevier BV. - 0301-679X .- 1879-2464. ; 163
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Tidskriftsartikel (refereegranskat)abstract
- Runway grooves are essential for water drainage and skid resistance; although the skid resistance of runway grooves has been studied, research on the frictional properties of runway grooves remains limited. This study presents a numerical method for analyzing the skid resistance of runway grooves. A aircraft tire model was developed with rubber and belt layer materials. A grooved runway sample was obtained by simulating the grooves on a runway surface specimen. A numerical algorithm was employed on the runway sample to simulate groove closure caused by rubber deposits; the degree of closure was defined as the percentage of closed grooves resulting from rubber deposits. An interaction model was developed according to the power spectrum density of a grooved runway and the viscoelastic properties of tread rubber. The numerical simulation results were verified using a runway skid resistance field test. The effects of groove closure due to rubber deposit contamination and groove geometry were analyzed. Friction increased as groove depth and width increased, but friction decreased as groove spacing and degree of closure increased.
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2. |
- Yang, Yang, et al.
(författare)
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Numerical analysis of hydroplaning and veer-off risk of dual-tyre on a wet runway
- 2023
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Ingår i: The international journal of pavement engineering. - : Informa UK Limited. - 1029-8436 .- 1477-268X. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- The phenomenon of hydroplaning poses a risk when landing an aircraft on a wet runway. This study developed a finite element (FE) framework comprising a dual-tyre model, water film models, a runway model, and an interaction model to investigate wet runway landings. The dual-tyre model was created with a geometric description and material properties. Water film models for even and uneven water depths were constructed based on a coupled Eulerian-Lagrangian algorithm. The runway model was obtained through surface scanning and 3D reconstruction. The interaction model was calculated using the power spectrum density and viscoelastic property of rubber. Based on the FE approach, the effect of the slip ratio on the hydroplaning phenomenon was discussed. The results indicated that hydroplaning speed generally increases with the slip ratio. Furthermore, single- and dual-tyre wet runway landings with an even water film depth were simulated, and the results revealed similar accuracy between the two landing types. Next, the study of dual-tyre landings indicated that landings in varying depths of water face the risks of hydroplaning and veering off simultaneously. The FE approach was further used to analyse dual-tyre landings on runways with a yaw angle.
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3. |
- Cao, Bin, et al.
(författare)
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Multiobjective Image Compression based on Tensor Decomposition
- 2023
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Ingår i: 2023 8th International Conference on Cloud Computing and Big Data Analytics, ICCCBDA. - : IEEE. - 9781665455336 - 9781665455343 ; , s. 545-550
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Konferensbidrag (refereegranskat)abstract
- Most of the traditional image compression methods vectorize the data contained in the image and then compress it. However, this approach does not take into account the high-dimensional information inside the image. To solve this problem, this paper regards the color image as a third-order tensor, and proposes a method of color image compression based on Tucker decomposition and multiobjective optimization. The tensor size compression ratio and Hu invariant moment similarity are proposed to measure the image compression quality. And to more comprehensively consider the sensitivity of human visual system to different visual signals, the five-objective optimization model of image compression is constructed. The five-objective optimization model includes: the above two indexes, information content weighted structure similarity index, color image feature similarity and information fidelity criterion. In addition, an angle-aware opposition-based learning strategy is proposed to improve the reference vector guided selection strategy of RVEA*. In the experiments, this method could effectively solve the problem of color image compression.
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4. |
- Norbäck, Dan, et al.
(författare)
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Prenatal and perinatal home environment and reported onset of wheeze, rhinitis and eczema symptoms in preschool children in Northern China
- 2021
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 774
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Tidskriftsartikel (refereegranskat)abstract
- Early life environment can affect asthma and allergies but few cohort studies on this issue are available from China. Our aim was to investigate reported onset of childhood wheeze, rhinitis and eczema symptoms in relation to prenatal, perinatal and postnatal home environment. Data on home environment and symptoms (ISAAC based questions) in first two years of life and in the past 12 months were reported by parents of the children (3-6 y) in a cross-sectional questionnaire survey in ten day care centers in Taiyuan, northern China (N = 3606). Changes of symptoms from the first 2 years of life to the past 12 months (recall period) were calculated retrospectively. Multilevel logistic regression analysis was applied. Reported onset of wheeze, rhinitis and eczema were 11.8%, 22.2% and 3.3%, respectively. Redecorating during pregnancy increased reported onset of rhinitis (OR = 2.29) and eczema (OR = 4.91). New furniture during pregnancy increased reported onset of rhinitis (OR = 1.47). Perinatal indoor mould increased reported onset of wheeze (OR = 1.51), rhinitis (OR = 1.65) and eczema (OR = 1.91). Perinatal mould odour increased reported onset of wheeze (OR = 1.85). Perinatal window pane condensation increased reported onset of wheeze (OR = 1.54) and rhinitis (OR = 1.24). Perinatal stuffy air and dry air in the home increased reported onset of all three symptoms (ORs 1.46-2.24). Dog keeping increased reported onset of wheeze (OR = 1.69) and eczema (OR = 2.13). Based on principal component analysis, four exposure scores were calculated (renovation, new furniture, mould and indoor air quality scores). Dose-response relationships were observed between these exposure scores and reported onset of symptoms. In conclusion, prenatal and postnatal exposure to emissions from renovation and new furniture can increase reported onset of childhood wheeze, rhinitis and eczema. Perinatal indoor mould, mould odour, condensation on window panes and impaired indoor air quality at home can be associated with reported development of wheeze, rhinitis and eczema in preschoolers in northern China. (c) 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).
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5. |
- Shu, Xiang, et al.
(författare)
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Evaluation of associations between genetically predicted circulating protein biomarkers and breast cancer risk
- 2020
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 146:8, s. 2130-2138
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Tidskriftsartikel (refereegranskat)abstract
- A small number of circulating proteins have been reported to be associated with breast cancer risk, with inconsistent results. Herein, we attempted to identify novel protein biomarkers for breast cancer via the integration of genomics and proteomics data. In the Breast Cancer Association Consortium (BCAC), with 122,977 cases and 105,974 controls of European descendants, we evaluated the associations of the genetically predicted concentrations of >1,400 circulating proteins with breast cancer risk. We used data from a large-scale protein quantitative trait loci (pQTL) analysis as our study instrument. Summary statistics for these pQTL variants related to breast cancer risk were obtained from the BCAC and used to estimate odds ratios (OR) for each protein using the inverse-variance weighted method. We identified 56 proteins significantly associated with breast cancer risk by instrumental analysis (false discovery rate <0.05). Of these, the concentrations of 32 were influenced by variants close to a breast cancer susceptibility locus (ABO, 9q34.2). Many of these proteins, such as insulin receptor, insulin-like growth factor receptor 1 and other membrane receptors (OR: 0.82–1.18, p values: 6.96 × 10−4–3.28 × 10−8), are linked to insulin resistance and estrogen receptor signaling pathways. Proteins identified at other loci include those involved in biological processes such as alcohol and lipid metabolism, proteolysis, apoptosis, immune regulation and cell motility and proliferation. Consistent associations were observed for 22 proteins in the UK Biobank data (p < 0.05). The study identifies potential novel biomarkers for breast cancer, but further investigation is needed to replicate our findings.
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6. |
- Shu, Xiang, et al.
(författare)
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Large-scale Integrated Analysis of Genetics and Metabolomic Data Reveals Potential Links Between Lipids and Colorectal Cancer Risk
- 2022
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - : American Association for Cancer Research. - 1055-9965 .- 1538-7755. ; 31:6, s. 1216-1226
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Tidskriftsartikel (refereegranskat)abstract
- Background: The etiology of colorectal cancer is not fully understood.Methods: Using genetic variants and metabolomics data including 217 metabolites from the Framingham Heart Study (n = 1,357), we built genetic prediction models for circulating metabolites. Models with prediction R2 > 0.01 (Nmetabolite = 58) were applied to predict levels of metabolites in two large consortia with a combined sample size of approximately 46,300 cases and 59,200 controls of European and approximately 21,700 cases and 47,400 controls of East Asian (EA) descent. Genetically predicted levels of metabolites were evaluated for their associations with colorectal cancer risk in logistic regressions within each racial group, after which the results were combined by meta-analysis.Results: Of the 58 metabolites tested, 24 metabolites were significantly associated with colorectal cancer risk [Benjamini-Hochberg FDR (BH-FDR) < 0.05] in the European population (ORs ranged from 0.91 to 1.06; P values ranged from 0.02 to 6.4 × 10-8). Twenty one of the 24 associations were replicated in the EA population (ORs ranged from 0.26 to 1.69, BH-FDR < 0.05). In addition, the genetically predicted levels of C16:0 cholesteryl ester was significantly associated with colorectal cancer risk in the EA population only (OREA: 1.94, 95% CI, 1.60−2.36, P = 2.6 × 10-11; OREUR: 1.01, 95% CI, 0.99−1.04, P = 0.3). Nineteen of the 25 metabolites were glycerophospholipids and triacylglycerols (TAG). Eighteen associations exhibited significant heterogeneity between the two racial groups (PEUR-EA-Het < 0.005), which were more strongly associated in the EA population. This integrative study suggested a potential role of lipids, especially certain glycerophospholipids and TAGs, in the etiology of colorectal cancer.Conclusions: This study identified potential novel risk biomarkers for colorectal cancer by integrating genetics and circulating metabolomics data.Impact: The identified metabolites could be developed into new tools for risk assessment of colorectal cancer in both European and EA populations.
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7. |
- Sun, Yu, et al.
(författare)
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Indoor microbiome, air pollutants and asthma, rhinitis and eczema in preschool children - A repeated cross-sectional study
- 2022
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Ingår i: Environment International. - : Elsevier. - 0160-4120 .- 1873-6750. ; 161
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Tidskriftsartikel (refereegranskat)abstract
- Background: Indoor microbiome exposure is associated with asthma, rhinitis and eczema. However, no studies report the interactions between environmental characteristics, indoor microbiome and health effects in a repeated cross-sectional framework. Methods: 1,279 and 1,121 preschool children in an industrial city (Taiyuan) of China were assessed for asthma, rhinitis and eczema symptoms in 2012 and 2019 by self-administered questionnaires, respectively. Bacteria and fungi in classroom vacuum dust were characterized by culture-independent amplicon sequencing. Multi-level logistic/linear regression was performed in two cross-sectional and two combined models to assess the associations. Results: The number of observed species in bacterial and fungal communities in classrooms increased significantly from 2012 to 2019, and the compositions of the microbial communities were drastically changed (p < 0.001). The temporal microbiome variation was significantly larger than the spatial variation within the city (p < 0.001). Annual average outdoor SO2 concentration decreased by 60.7%, whereas NO2 and PM10 concentra-tions increased by 63.3% and 40.0% from 2012 to 2019, which were both associated with indoor microbiome variation (PERMANOVA p < 0.001). The prevalence of asthma (2.0% to 3.3%, p = 0.06) and rhinitis (28.0% to 25.3%, p = 0.13) were not significantly changed, but the prevalence of eczema was increased (3.6% to 7.0%; p < 0.001). Aspergillus subversicolor, Collinsella and Cutibacterium were positively associated with asthma, rhinitis and eczema, respectively (p < 0.01). Prevotella, Lactobacillus iners and Dolosigranulum were protectively (negatively) associated with rhinitis (p < 0.01), consistent with previous studies in the human respiratory tract. NO2 and PM10 concentrations were negatively associated with rhinitis in a bivariate model, but a multivariate mediation analysis revealed that Prevotella fully mediated the health effects. Conclusions: This is the first study to report the interactions between environmental characteristics, indoor microbiome and health in a repeated cross-sectional framework. The mediating effects of indoor microorganisms suggest incorporating biological with chemical exposure for a comprehensive exposure assessment.
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8. |
- Wen, Wanqing, et al.
(författare)
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Genome-wide association studies in East Asians identify new loci for waist-hip ratio and waist circumference
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Sixty genetic loci associated with abdominal obesity, measured by waist circumference (WC) and waist-hip ratio (WHR), have been previously identified, primarily from studies conducted in Europeanancestry populations. We conducted a meta-analysis of associations of abdominal obesity with approximately 2.5 million single nucleotide polymorphisms (SNPs) among 53,052 (for WC) and 48,312 (for WHR) individuals of Asian descent, and replicated 33 selected SNPs among 3,762 to 17,110 additional individuals. We identified four novel loci near the EFEMP1, ADAMTSL3, CNPY2, and GNAS genes that were associated with WC after adjustment for body mass index (BMI); two loci near the NID2 and HLA-DRB5 genes associated with WHR after adjustment for BMI, and three loci near the CEP120, TSC22D2, and SLC22A2 genes associated with WC without adjustment for BMI. Functional enrichment analyses revealed enrichment of corticotropin-releasing hormone signaling, GNRH signaling, and/or CDK5 signaling pathways for those newly-identified loci. Our study provides additional insight on genetic contribution to abdominal obesity.
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10. |
- Wu, Lang, et al.
(författare)
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An integrative multi-omics analysis to identify candidate DNA methylation biomarkers related to prostate cancer risk.
- 2020
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- It remains elusive whether some of the associations identified in genome-wide association studies of prostate cancer (PrCa) may be due to regulatory effects of genetic variants on CpG sites, which may further influence expression of PrCa target genes. To search for CpG sites associated with PrCa risk, here we establish genetic models to predict methylation (N = 1,595) and conduct association analyses with PrCa risk (79,194 cases and 61,112 controls). We identify 759 CpG sites showing an association, including 15 located at novel loci. Among those 759 CpG sites, methylation of 42 is associated with expression of 28 adjacent genes. Among 22 genes, 18 show an association with PrCa risk. Overall, 25 CpG sites show consistent association directions for the methylation-gene expression-PrCa pathway. We identify DNA methylation biomarkers associated with PrCa, and our findings suggest that specific CpG sites may influence PrCa via regulating expression of candidate PrCa target genes.
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