38 research outputs found

    Integrated self-consistent macro-micro traffic flow modeling and calibration framework based on trajectory data

    Get PDF
    Calibrating microscopic car-following (CF) models is crucial in traffic flow theory as it allows for accurate reproduction and investigation of traffic behavior and phenomena. Typically, the calibration procedure is a complicated, non-convex optimization issue. When the traffic state is in equilibrium, the macroscopic flow model can be derived analytically from the corresponding CF model. In contrast to the microscopic CF model, calibrated based on trajectory data, the macroscopic representation of the fundamental diagram (FD) primarily adopts loop detector data for calibration. The different calibration approaches at the macro- and microscopic levels may lead to misaligned parameters with identical practical meanings in both macro- and micro-traffic models. This inconsistency arises from the difference between the parameter calibration processes used in macro- and microscopic traffic flow models. Hence, this study proposes an integrated multiresolution traffic flow modeling framework using the same trajectory data for parameter calibration based on the self-consistency concept. This framework incorporates multiple objective functions in the macro- and micro-dimensions. To expeditiously execute the proposed framework, an improved metaheuristic multi-objective optimization algorithm is presented that employs multiple enhancement strategies. Additionally, a deep learning technique based on attention mechanisms was used to extract stationary-state traffic data for the macroscopic calibration process, instead of directly using the entire aggregated data. We conducted experiments using real-world and synthetic trajectory data to validate our self-consistent calibration framework

    Effects of deformation temperature on edge crack characteristics and mechanical properties of as-cast aluminum alloy

    No full text
    In this study, the rolling technique of aluminum alloy was investigated, and the effects of deformation temperature on the edge cracks and mechanical properties of aluminum alloy were studied through a hot compression experiment on high magnesium aluminum alloy. Based on the test, DEFORM-3D software was introduced to optimize the selection of the influence conditions of the experiment. The research results suggested that the crack length of the as-cast aluminum alloy samples decreased with the increase of temperature when the deformation temperature was between 300 °C and 450 °C; the tensile strength and elongation after fracture increased with the increase of temperature when the deformation temperature was between 300 °C and 500 °C. Therefore it is concluded that the cracks of high magnesium aluminum alloy can be reduced through controlling deformation temperature, which provides an idea for the optimization of aluminium alloy

    Input–Output Efficiency of the Beijing–Tianjin Sandstorm Source Control Project and Influencing Factors

    No full text
    From the perspective of economic benefit, this paper uses the DEA method to measure the input–output efficiency of the Beijing–Tianjin sandstorm source control project in Beijing, Hebei, Shanxi, and Inner Mongolia. The results show that from 2003 to 2019, the efficiency of the four regions revealed a U-shaped trend, first decreasing and then increasing, which reflects the lagging characteristics of forestry engineering. The TFP of the sand source control project in these four places was calculated; the average efficiency growth rate was 1.4%, and it was found to be affected greatly by the rate of technological progress. The Tobit model was used to explore the influencing factors, and the results show that educational input and economic development level have a great effect on efficiency, fiscal pressure has a small effect on efficiency, and financial development level has a restraining effect on efficiency

    Complete Genome Sequencing Revealed the Potential Application of a Novel <i>Weizmannia coagulans</i> PL-W Production with Promising Bacteriocins in Food Preservative

    No full text
    Weizmannia coagulans is an important potential probiotic with dual characteristics of Bacillus and Lactobacillus. This study describes a novel Weizmannia coagulans PL-W with excellent antibacterial activity isolated from Mongolian traditional cheese, in which safety and probiotic potential were evaluated by complete genome sequencing. The crude bacteriocins of W. coagulans PL-W showed antibacterial activity against various foodborne pathogens, including Listeria monocytogenes CMCC 54,004, Bacillus cereus ATCC 14,579, and Staphylococcus aureus ATCC 25,923. Moreover, the crude bacteriocins have outstanding stability against pH, temperature, surfactants, and are sensitive to protease. The complete genome sequencing revealed W. coagulans PL-W consists of 3,666,052-base pair (bp) circular chromosomes with a GC content of 46.24% and 3485 protein-coding genes. It contains 84 tRNA, 10 23S rRNA, 10 16S rRNA, and 10 5S rRNA. In addition, no risk-related genes such as acquired antibiotic resistance genes, virulence, and pathogenic factors were identified, demonstrating that W. coagulans PL-W is safe to use. Furthermore, the presence of gene clusters involved in bacteriocin synthesis, adhesion-related genes, and genes contributing to acid and bile tolerance indicate that W. coagulans PL-W is a potential candidate probiotic. Thus, antimicrobial activity and genome characterization of W. coagulans PL-W demonstrate that it has extensive potential applications as a food protective culture

    Mild Preoxidation Treatment of Pt/TiO2 Catalyst and Its Enhanced Low Temperature Formaldehyde Decomposition

    No full text
    The typical platinum nanoparticles loaded on titania (Pt/TiO2) were pretreated with mild oxidation (&lt;300 &deg;C) in pure oxygen to enhance the low-temperature formaldehyde (HCHO) decomposition performance. The structural properties of support and platinum nanoparticles were characterized by X-ray diffraction (XRD), physical adsorption/desorption, high-resolution transmission electron microscopy (HRTEM), in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFITS), and temperature-programmed reduction and oxidation (TPR and TPO). The catalytic results showed that the low temperature HCHO decomposition activity of mild pre-oxidized Pt/TiO2 was around three times that of the pristine one. According to the characterization results, the structure of the Pt/TiO2 support and their Pt particle sizes had negligible change after pre-oxidation treatment. The cationic Pt content of Pt/TiO2 and surface roughness of Pt nanoparticles gradually increased with the increasing temperature of the pre-oxidation treatment. Mild pre-oxidation treatment was beneficial to the oxygen activation and water dissociation of Pt/TiO2. In situ HCHO-DFIRTS results showed that the mild pre-oxidation treatment could enhance the dehydrogenation of formate

    Comparison of the NG-Test Carba 5, Colloidal Gold Immunoassay (CGI) Test, and Xpert Carba-R for the Rapid Detection of Carbapenemases in Carbapenemase-Producing Organisms

    No full text
    Carbapenem-resistant Enterobacterales (CRE) are increasingly recognized as an urgent public health concern. The rapid and accurate identification of carbapenemases could provide insights into antimicrobial therapy and infection control. In this study, we evaluated the efficacy of three different methods, including the NG-test Carba 5, colloidal gold immunoassay (CGI) test, and Xpert Carba-R assay, for the rapid detection of five carbapenemases (KPC, NDM, IMP, OXA-48, and VIM). A total of 207 Gram-negative strains collected from patients and hospital sewages were tested. The presence or absence of carbapenemase genes in the whole-genome sequences was used as the gold standard for evaluating the accuracy of the above-mentioned three methods. Among the 192 strains carrying only one carbapenemase gene, the accuracies of the NG-Test Carba 5, CGI test, and Xpert Carba-R were 96.88% (95% CI, 93.01&ndash;98.72%), 96.88% (95% CI, 93.01&ndash;98.72%), and 97.92% (95% CI, 94.41&ndash;99.33%), respectively. Xpert Carba-R was able to detect all 13 types of KPC variants, including KPC-2, KPC-3, KPC-25, KPC-33, KPC-35, KPC-51, KPC-52, KPC-71, KPC-76, KPC-77, KPC-78, KPC-93, and KPC-123, with a detection sensitivity of 100.00% (95% CI, 96.50&ndash;100.00%), a specificity of 100.00% (95% CI, 92.38&ndash;100.00%), and a &kappa; index of 1.00. For IMP, Carba 5 was superior to the other two methods, with a sensitivity of 100% (95% CI, 71.66&ndash;100.00%), a specificity of 100% (95% CI, 97.38&ndash;100.00%), and a &kappa; index of 1.00. For the remaining 15 strains carrying two or three kinds of carbapenemase genes, Carba 5 performed the best, which accurately identified all the target genes, followed by Xpert Carba-R (12/15, 80.00%) and the CGI test (10/15, 66.67%). Therefore, all three assays demonstrated reliable performances in carbapenemase detection, and Xpert Carba-R should be recommended for the detection of KPC variants, especially for patients at a high risk of infections caused by ceftazidime/avibactam-resistant strains. IMPORTANCE: CRE was listed as one of the top three pathogens that are in critical need of new antibiotics by the WHO. The rapid and accurate identification of carbapenemases is important for antimicrobial therapy and infection control. In recent years, new beta-lactam/beta-lactamase inhibitor combinations such as ceftazidime/avibactam (CZA) have been approved by the Food and Drug Administration (FDA) to cope with CRE challenges. CZA was effective against class A, class C, and some class D enzymes such as OXA-48-like. However, CZA-resistant KPC variants emerged at an alarming speed, which posed a new challenge for the accurate identification of KPC variants. In this study, we evaluated the performance of two lateral flow immunochromatographic assays, namely, NG-test Carba 5 and the CGI test, and the automated real-time quantitative PCR Xpert Carba-R in the rapid detection of carbapenemases. Notably, 13 types of KPC variants were enrolled in this study, which covered most KPC variants discovered in China. Carba-R was superior to NG-teat Carba 5 and the CGI test; it was able to detect all of the included KPC variants, including KPC-2, KPC-3, KPC-25, KPC-33, KPC-35, KPC-51, KPC-52, KPC-71, KPC-76, KPC-77, KPC-78, KPC-93, and KPC-123

    Association of serum uric acid and fasting plasma glucose with cognitive function: a cross-sectional study

    No full text
    Abstract Background The combined effect of serum uric acid (SUA) and blood glucose on cognition has not been explored. This study aimed to examine the separate and combined association of SUA and fasting plasma glucose (FPG) or diabetes mellitus (DM) with cognition in a sample of Chinese middle-aged and elderly population. Methods A total of 6,509 participants aged 45 years or older who participated in the China Health and Retirement Longitudinal Study (CHARLS, 2011) were included. The three cognitive domains assessed were episodic memory, mental status, and global cognition (the sum of the first two terms). Higher scores indicated better cognition. SUA and FPG were measured. The participants were grouped based on SUA and FPG quartiles to evaluate their combined associations of cognition with SUA Q1–Q3 only (Low SUA), with FPG Q4 only (High FPG), without low SUA and high FPG levels (Non), and with low SUA and high FPG levels (Both), multivariate linear regression models were used to analyze their association. Results Lower SUA quartiles were associated with poorer performance in global cognition and episodic memory compared with the highest quartile. Although no association was found between FPG or DM and cognition, high FPG or DM combined with low SUA levels in women (βFPG = -0.983, 95% CI: -1.563–-0.402; βDM = -0.800, 95% CI: -1.369–-0.232) had poorer cognition than those with low SUA level only (βFPG = -0.469, 95% CI: -0.926–-0.013; βDM = -0.667, 95% CI: -1.060–-0.275). Conclusion Maintaining an appropriate level of SUA may be important to prevent cognitive impairment in women with high FPG

    Comparison of the NG-Test Carba 5, Colloidal Gold Immunoassay (CGI) Test, and Xpert Carba-R for the Rapid Detection of Carbapenemases in Carbapenemase-Producing Organisms

    No full text
    Carbapenem-resistant Enterobacterales (CRE) are increasingly recognized as an urgent public health concern. The rapid and accurate identification of carbapenemases could provide insights into antimicrobial therapy and infection control. In this study, we evaluated the efficacy of three different methods, including the NG-test Carba 5, colloidal gold immunoassay (CGI) test, and Xpert Carba-R assay, for the rapid detection of five carbapenemases (KPC, NDM, IMP, OXA-48, and VIM). A total of 207 Gram-negative strains collected from patients and hospital sewages were tested. The presence or absence of carbapenemase genes in the whole-genome sequences was used as the gold standard for evaluating the accuracy of the above-mentioned three methods. Among the 192 strains carrying only one carbapenemase gene, the accuracies of the NG-Test Carba 5, CGI test, and Xpert Carba-R were 96.88% (95% CI, 93.01–98.72%), 96.88% (95% CI, 93.01–98.72%), and 97.92% (95% CI, 94.41–99.33%), respectively. Xpert Carba-R was able to detect all 13 types of KPC variants, including KPC-2, KPC-3, KPC-25, KPC-33, KPC-35, KPC-51, KPC-52, KPC-71, KPC-76, KPC-77, KPC-78, KPC-93, and KPC-123, with a detection sensitivity of 100.00% (95% CI, 96.50–100.00%), a specificity of 100.00% (95% CI, 92.38–100.00%), and a κ index of 1.00. For IMP, Carba 5 was superior to the other two methods, with a sensitivity of 100% (95% CI, 71.66–100.00%), a specificity of 100% (95% CI, 97.38–100.00%), and a κ index of 1.00. For the remaining 15 strains carrying two or three kinds of carbapenemase genes, Carba 5 performed the best, which accurately identified all the target genes, followed by Xpert Carba-R (12/15, 80.00%) and the CGI test (10/15, 66.67%). Therefore, all three assays demonstrated reliable performances in carbapenemase detection, and Xpert Carba-R should be recommended for the detection of KPC variants, especially for patients at a high risk of infections caused by ceftazidime/avibactam-resistant strains. IMPORTANCE: CRE was listed as one of the top three pathogens that are in critical need of new antibiotics by the WHO. The rapid and accurate identification of carbapenemases is important for antimicrobial therapy and infection control. In recent years, new beta-lactam/beta-lactamase inhibitor combinations such as ceftazidime/avibactam (CZA) have been approved by the Food and Drug Administration (FDA) to cope with CRE challenges. CZA was effective against class A, class C, and some class D enzymes such as OXA-48-like. However, CZA-resistant KPC variants emerged at an alarming speed, which posed a new challenge for the accurate identification of KPC variants. In this study, we evaluated the performance of two lateral flow immunochromatographic assays, namely, NG-test Carba 5 and the CGI test, and the automated real-time quantitative PCR Xpert Carba-R in the rapid detection of carbapenemases. Notably, 13 types of KPC variants were enrolled in this study, which covered most KPC variants discovered in China. Carba-R was superior to NG-teat Carba 5 and the CGI test; it was able to detect all of the included KPC variants, including KPC-2, KPC-3, KPC-25, KPC-33, KPC-35, KPC-51, KPC-52, KPC-71, KPC-76, KPC-77, KPC-78, KPC-93, and KPC-123
    corecore