57 research outputs found

    Validation of Worst-Case and Statistical Models for an Automotive EMC Expert System

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    Previous papers have presented algorithms for an EMC expert system used to predict potential electromagnetic compatibility problems in a vehicle early in the design process. Here, the accuracy of inductive and capacitive coupling algorithms are verified through representative measurements of crosstalk within an automobile. Worst-case estimates used by the algorithms are compared to measured values and are compared to values estimated using statistical methods. The worst-case algorithms performed well up to 10-20 MHz, but overestimated measured results by several dB in some cases and up to 10-15 dB in others. An approximate statistical variation of the current expert system algorithms also worked well and can help avoid overestimation of problems; however, worst-case estimates better ensure that problems will not be missed, especially in the absence of complete system information

    Beam energy distribution influences on density modulation efficiency in seeded free-electron lasers

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    The beam energy spread at the entrance of undulator system is of paramount importance for efficient density modulation in high-gain seeded free-electron lasers (FELs). In this paper, the dependences of high harmonic micro-bunching in the high-gain harmonic generation (HGHG), echo-enabled harmonic generation (EEHG) and phase-merging enhanced harmonic generation (PEHG) schemes on the electron energy spread distribution are studied. Theoretical investigations and multi-dimensional numerical simulations are applied to the cases of uniform and saddle beam energy distributions and compared to a traditional Gaussian distribution. It shows that the uniform and saddle electron energy distributions significantly enhance the performance of HGHG-FELs, while they almost have no influence on EEHG and PEHG schemes. A numerical example demonstrates that, with about 84keV RMS uniform and/or saddle slice energy spread, the 30th harmonic radiation can be directly generated by a single-stage seeding scheme for a soft x-ray FEL facility

    Imidazole-dione conjugate induces apoptosis and inhibits proliferation of osteosarcoma cells via activation of p65NFκB

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    Purpose: To investigate the effect of imidazole-dione conjugate (IMC) on proliferation of MG63 osteosarcoma cells. Methods: The effect of IMC on proliferation of MG63 osteosarcoma cells was determined using 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, while mRNA expressions of PTEN, FasL and FasR were assayed with real-time reverse transcription polymerase chain reaction (RT-PCR). Cell apoptosis was studied by flow cytometry. The protein expression level of IκBα was determined using western blotting. Results: There were reductions in the proliferation of IMC-treated MG63 cells and Saos-2 cells at IMC dose of ≥ 4 μM (p < 0.05). Degree of proliferation of MG63 cells on exposure to 1, 2, 4, 6, 8 and 10 μM IMC was 99, 98, 76, 59, 34 and 21 %, respectively, relative to 100 % in untreated cultures. In MG63 cell cultures, treatment with 4, 6, 8 and 10 μM IMC led to 22, 39, 62 and 69 % apoptosis, respectively, when compared with 0.9 % apoptosis in control cell cultures (p < 0.05). Concentration-dependent increases were observed in PTEN, FasL and FasR mRNA in IMC-treated MG63 cells. Western blot assay showed a marked increase in the level of IκBα in MG63 cells following treatment with IMC. IMC treatment also caused a concentration-dependent increase in the expression of phospho-Ser536 p65NF-κB (p < 0.05). Conclusion: IMC exerts inhibitory effect on the proliferation of MG63 cells via up-regulation of NF-κB phosphorylation. Thus, IMC may be useful as a therapeutic agent for osteosarcoma

    Polarization control proposal for Shanghai deep ultraviolet free electron laser

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    In this paper, a fully coherent radiation option with controllable polarization is proposed for Shanghai deep ultraviolet free electron laser (FEL) test facility. Intensive start-to-end simulation suggests that, the two crossed planar undulators which generate the horizontal and vertical linear polarized FEL respectively, should be placed as close as possible for avoiding the polarization performance degradation of the final combined FEL radiation. With the existence of the phase-shifter between the two crossed radiators, Fourier-Transform-Limited output radiation with 100 nJ order pulse energy, 5 ps full pulse length and circular polarization degree above 90% could be achieved.Comment: 9 pages, 5 figures, 1 tabl

    Identification of common signature genes and pathways underlying the pathogenesis association between nonalcoholic fatty liver disease and atherosclerosis

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    BackgroundAtherosclerosis (AS) is one of the leading causes of the cardio-cerebral vascular incident. The constantly emerging evidence indicates a close association between nonalcoholic fatty liver disease (NAFLD) and AS. However, the exact molecular mechanisms underlying the correlation between these two diseases remain unclear. This study proposed exploring the common signature genes, pathways, and immune cells among AS and NAFLD.MethodsThe common differentially expressed genes (co-DEGs) with a consistent trend were identified via bioinformatic analyses of the Gene Expression Omnibus (GEO) datasets GSE28829 and GSE49541, respectively. Further, the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed. We utilized machine learning algorithms of lasso and random forest (RF) to identify the common signature genes. Then the diagnostic nomogram models and receiver operator characteristic curve (ROC) analyses were constructed and validated with external verification datasets. The gene interaction network was established via the GeneMANIA database. Additionally, gene set enrichment analysis (GSEA), gene set variation analysis (GSVA), and immune infiltration analysis were performed to explore the co-regulated pathways and immune cells.ResultsA total of 11 co-DEGs were identified. GO and KEGG analyses revealed that co-DEGs were mainly enriched in lipid catabolic process, calcium ion transport, and regulation of cytokine. Moreover, three common signature genes (PLCXD3, CCL19, and PKD2) were defined. Based on these genes, we constructed the efficiently predictable diagnostic models for advanced AS and NAFLD with the nomograms, evaluated with the ROC curves (AUC = 0.995 for advanced AS, 95% CI 0.971–1.0; AUC = 0.973 for advanced NAFLD, 95% CI 0.938–0.998). In addition, the AUC of the verification datasets had a similar trend. The NOD-like receptors (NLRs) signaling pathway might be the most crucial co-regulated pathway, and activated CD4 T cells and central memory CD4 T cells were significantly excessive infiltration in advanced NAFLD and AS.ConclusionWe identified three common signature genes (PLCXD3, CCL19, and PKD2), co-regulated pathways, and shared immune features of NAFLD and AS, which might provide novel insights into the molecular mechanism of NAFLD complicated with AS

    E183K Mutation in Chalcone Synthase C2 Causes Protein Aggregation and Maize Colorless

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    Flavonoids give plants their rich colors and play roles in a number of physiological processes. In this study, we identified a novel colorless maize mutant showing reduced pigmentation throughout the whole life cycle by EMS mutagenesis. E183K mutation in maize chalcone synthase C2 (ZmC2) was mapped using MutMap strategy as the causal for colorless, which was further validated by transformation in Arabidopsis. We evaluated transcriptomic and metabolic changes in maize first sheaths caused by the mutation. The downstream biosynthesis was blocked while very few genes changed their expression pattern. ZmC2-E183 site is highly conserved in chalcone synthase among Plantae kingdom and within species’ different varieties. Through prokaryotic expression, transient expression in maize leaf protoplasts and stable expression in Arabidopsis, we observed that E183K and other mutations on E183 could cause almost complete protein aggregation of chalcone synthase. Our findings will benefit the characterization of flavonoid biosynthesis and contribute to the body of knowledge on protein aggregation in plants

    Association between malnutrition and leucopenia in patients with osteosarcoma

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    Background and aimLeucopenia (LP) greatly limits the efficacy of chemotherapy in osteosarcoma patients. This study aimed to evaluate the nutritional status of osteosarcoma patients before chemotherapy, assess the risk of LP during the perichemotherapy period, and explore the association between malnutrition and LP.Materials and methodsThis study retrospectively analyzed osteosarcoma patients treated in the Tianjin Medical University Cancer Institute and Hospital, China, between January 2009 and December 2020 according to the inclusion and exclusion criteria. Malnutrition in adolescents (5 to 19 years old) and adults (≥20 years old) was diagnosed using WHO AnthroPlus software (version 1.0.4) and Global Leadership initiative on Malnutrition (GLIM), respectively. According to the diagnostic criteria of LP in CTCAE 5.0, patients were divided into the LP group and the non-LP group.ResultsA total of 245 osteosarcoma patients were included. The incidence of malnutrition was 49.0%, and the incidence of LP was 51.8%. The incidence of malnutrition in adolescent patients was 53.1%, and their incidence of LP was 55.2%; the incidence of malnutrition in adult patients was 43.1%, and their incidence of LP was 47.1%. Logistic regression analysis showed that malnutrition before chemotherapy was an independent risk factor for the occurrence of LP after chemotherapy (OR = 6.85, 95% CI = 2.16-25.43; and OR = 35.03, 95% CI = 6.98-238.46 in mildly and severely malnourished young patients; OR = 6.06; 95% CI = 1.43-30.16; and OR = 38.09, 95% CI = 7.23-285.78 in mildly and severely malnourished adult patients, respectively). The results showed that age and nutritional status had a joint effect on the occurrence of LP.ConclusionThe nutrition status of osteosarcoma patients before chemotherapy is significantly correlated with the occurrence and severity of LP during peri-chemotherapy period. During osteosarcoma chemotherapy, necessary nutritional support should be given to patients of different ages to correct their malnutrition status in a timely manner, ultimately improving the efficacy of chemotherapy and the prognosis of patients

    Applications of Regional Economics to Income Distribution, Migration, and Effects of Internet Commerce on Retailing

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    This dissertation consists of three essays on regional economics that deal with earnings inequality in cities, interstate migration and spatial competition in the retail market. Chapter 1 provides a theoretical framework to analyze the observation of rising earnings inequality with city size. Many papers have found a positive relation between income inequality and city size in the US and other countries. This literature has assumed that the relation is linear. Tests performed here find that it is concave, resembling the classic Kuznets curve. A theoretical model based on the Income Elasticity Hypothesis (IEH), explains that inequality is a concave function of housing prices that tend to increase with city size. Further tests confirm the concavity of the relation between Gini and housing costs that is predicted by the IEH. Although for most cities, inequality still rises with housing costs, if housing costs continue to grow in large cities, inequality should eventually fall, resembling the Kuznets Curve at the country level. Chapter 2 is an empirical study of the declining internal migration in the United States. Persistent declines in the rates of interstate and intercity migration have been noted in many recent studies. Research has indicated that this trend does not appear due to changes in population composition. This paper retests the population composition hypothesis along with two other theoretical possibilities, falling returns to migration and improved search and matching technology. Empirical tests establish results that are partially consistent with the hypothesis of falling returns to migration. The fact that return migration rates have risen while gross, initial and subsequent rates have fallen, reported for the first time in this study, is particularly difficult to reconcile with existing theories. And results in this paper suggest more studies focusing on inter-regional equilibrium. Chapter 3 develops a theoretical model of the effect of on-line shopping on spatial competition of bricks-and-mortar retail stores. In this paper, a spatial competition model is built with a large multi-product shopping center and numerous local single-product stores in the market. The retailers therefore constitute a spatially inter-dependent retail system. The model suggests that more on-line alternatives to the durable good in the system has complex and counter-intuitive effects on the market size and pricing strategy in the long run

    Spatiotemporal of ecosystem service values response to land use/cover change based on geo-informatic Tupu – A case study in Tianjin, China

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    Revealing the spatiotemporal evolution of ecosystem service value (ESV) is a prerequisite for regional ecosystem management. This paper integrates the Geo-informatic Tupu method, the Markov transfer model, and the Barycenter model to propose an analytical method for the spatiotemporal response of ESV to land use/cover change(LUCC). Taking Tianjin as the empirical study area, we estimated its ESV and spatiotemporal transfer, rise and fall changes, and migration of the barycenter. The results showed that: (1) The land use composite index of Tianjin increased, and land use changes tended to level off throughout the study period. (2) From 2000 to 2020, ESV rose and then fell, with a total decrease of 8.03 billion RMB. (3) The change of Tupu is most dramatic in Xiqing, Binhai New Area, and Dongli, where economic and social growth is rapid. The barycenter of transfer Tupu shifts from centralized distribution to decentralized distribution around Dongli, and the ESV tends to increase to the south. (4) LUCC, NDVI, and DEM mainly drive the spatial heterogeneity of ESV in Tianjin. This research offers new insights into the spatiotemporal evolution analysis of ESV and could provide scientific references for regional ecological management and policy formulation
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