26 research outputs found

    A Hierarchical Control Strategy Based on Dual-Vector Model Predictive Current Control for Railway Energy Router

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    The multiport and multidirectional energy flow of railway energy routers (RERs) poses a significant challenge when integrating photovoltaic (PV) systems and energy storage systems (ESSs). To address this issue, this paper proposes an improved hierarchical control strategy for RERs with a reference signal generation layer and an inverter control layer. In the reference signal generation layer, a time-segmentation energy allocation strategy based on a state machine is proposed to manage the multidirectional energy flow in RERs resulting from PV systems and ESSs while minimizing peak power demand. In the inverter control layer, a dual-vector model predictive current control (MPCC) strategy is designed for back-to-back inverters. The dual-vector MPCC strategy eliminates the need for individual PWM blocks, thereby enhancing RER current-tracking accuracy and efficiency. The prominent advantage of the dual-vector MPCC strategy is its ability to achieve high current-tracking accuracy while minimizing active power losses. Simulations and hardware-in-the-loop experiments are conducted to validate the feasibility and effectiveness of the proposed method

    Detailed Mapping of Urban Land Use Based on Multi-Source Data: A Case Study of Lanzhou

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    Detailed urban land use information is the prerequisite and foundation for implementing urban land policies and urban land development, and is of great importance for solving urban problems, assisting scientific and rational urban planning. The existing results of urban land use mapping have shortcomings in terms of accuracy or recognition scale, and it is difficult to meet the needs of fine urban management and smart city construction. This study aims to explore approaches that mapping urban land use based on multi-source data, to meet the needs of obtaining detailed land use information and, taking Lanzhou as an example, based on the previous study, we proposed a process of urban land use classification based on multi-source data. A combination road network dataset of Gaode and OpenStreetMap (OSM) was synthetically applied to divide urban parcels, while multi-source features using Sentinel-2A images, Sentinel-1A polarization data, night light data, point of interest (POI) data and other data. Simultaneously, a set of comparative experiments were designed to evaluate the contribution and impact of different features. The results showed that: (1) the combination utilization of Gaode and OSM road network could improve the classification results effectively. Specifically, the overall accuracy and kappa coefficient are 83.75% and 0.77 separately for level I and the accuracy of each type reaches more than 70% for level II; (2) the synthetic application of multi-source features is conducive to the improvement of urban land use classification; (3) Internet data, such as point of interest (POI) information and multi-time population information, contribute the most to urban land use mapping. Compared with single-moment population information, the multi-time population distribution makes more contributions to urban land use. The framework developed herein and the results derived therefrom may assist other cities in the detailed mapping and refined management of urban land use

    A risk prediction model for renal damage in a hypertensive Chinese Han population

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    Backgroud: While numerous risk factors for renal damage in the hypertensive population have been reported, there is no single prediction model. The purpose of this study was to develop a model to comprehensively evaluate renal damage risk among hypertensive patients. Methods: We analyzed the data of 582 Chinese hypertensive patients from 1 January 2013 to 30 June 2016. Basic patient information was collected along with laboratory test results. According to the albumin-to-creatinine ratio, the subjects were divided into a hypertension with renal damage group and a hypertension without renal damage group. The prediction model was established by logistic regression based on principal component analysis, and the area under the receiver operating characteristic curve was used to evaluate the predictive performance of the model.Results: There are 11 indicators have statistically significant difference between the two groups (P < 0.05); The equation expressed including all 11 risk factors was as follows: Y = (–0.236) – 0.1705 (sex) – 0.0098 (age) – 0.1067 (smoking history) + 0.0303 (drinking history) – 0.3031 (CHD) + 0.1276 (diabetes history) – 0.0596 (CRP level) – 0.0732 (CysC level) + 0.0949 (β2-MG level) + 0.5407 (blood pressure type) + 0.6470 (RRI). The calculated AUC was 74.4%; The risk in males was much higher than that in females of the same age. However, with increasing age, the male:female risk ratio gradually decreased. Conclusion: Eleven  indicators (including sex, age, smoking history, drinking history, coronary heart disease, diabetes history, C-reactive protein, CystatinC,  β2-microglobulin protein, blood pressure type, renal artery resistance index)  may be the risk factors of renal damage in hypertension. Our regression equation provides a feasible means of predicting renal damage in Chinese hypertensive populations, and the model showed good predictive power. In addition, estrogen may confer a protective effect on the kidney. Abbreviations: PCA: principal component analysis; SLPs: synthetic latent predictors; CKD: chronic kidney disease; RRI: renal artery resistance index; MLR: multivariate logistic regression; CHD: coronary heart disease; UACR: urine trace albumin/uric creatinine ratio; CysC: CystatinC; TG: Triglyceride; CHO: cholesterol; HDL: high-density lipoprotein cholesterol; LDL: low-density lipoprotein cholesterol; CRP: C-reactive protein; HCY: homocysteine; UA: uric acid; AUC: area under the ROC curve; CVE: cardiovascular events; RFF: renal function related factor; PHF: personal history related factor; CVF: cardiovascular factor; GMF: glucose metabolism factor; IF: inflammatory factor; BPF: blood pressure facto

    Progress in the biological function of alpha-enolase

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    Alpha-enolase (ENO1), also known as 2-phospho-D-glycerate hydrolase, is a metalloenzyme that catalyzes the conversion of 2-phosphoglyceric acid to phosphoenolpyruvic acid in the glycolytic pathway. It is a multifunctional glycolytic enzyme involved in cellular stress, bacterial and fungal infections, autoantigen activities, the occurrence and metastasis of cancer, parasitic infections, and the growth, development and reproduction of organisms. This article mainly reviews the basic characteristics and biological functions of ENO1

    High-sensitivity and throughput optical fiber SERS probes based on laser-induced fractional reaction method

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    Surface-enhanced Raman scattering (SERS) is widely used in many fields, such as biosensors, medical diagnostics, materials science, and food security. Here, we report a low-cost, high-throughput laser-induced fractional reaction method for optical fiber SERS probes. Under laser irradiation, the local thermal effect and the electromagnetic interaction between nanoparticles effectively contribute to the formation and growth of silver nanoparticles on the optical fiber facet. Sodium dodecyl sulfate (SDS) solution with a concentration of 2 mM is employed as a surfactant to control the shape and size of the silver nanoparticles. A detection limit of 1.0 × 10−11 M for R6G is achieved, which is, as far as we know, the highest sensitivity that laser-induced fabricated optical fiber SERS probes have achieved. The SERS enhancement factors (EFs) are calculated to be 6.795 × 1011. The SERS intensity of R6G at peaks of 621 cm−1, 1281 cm−1, and 1359 cm−1 are measured with probes fabricated under the same condition, and showed perfect repeatability with an RSD of less than 4.5%. This new method shows effectively in fabricating optical fiber SERS probes with high sensitivity and good repeatability

    The Favored Mechanism for Coping with Acute Cold Stress: Upregulation of miR-210 in Rats

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    Background/Aims: The main aim of this study was to determine the mechanisms by which rno-miR-210-3p affects changes in gene expression, metabolism, apoptosis and proliferation of cells under acute cold stress (ACS) conditions. Methods: The treatment group (n=6, weight 340±20 g) was exposed to ACS (temperature 4±0.5°C, relative humidity 45±0.5%) and the control group (n=6, weight 340±20 g) to normal temperature (NT) (temperature 24±0.5°C, relative humidity 45±0.5%). Rat liver samples were collected for qRT-PCR and western blot analyses to detect relative expression of rno-miR-210-3p, ISCU, Rap1b, ATP1b1, GPD1, E2F3, RAD52, PSMB6 and GPD2. For cell experiments, 100 pmol/dish rno-miR-210-3p mimic and 150 pmol/dish rno-miR-210-3p inhibitor were used. Mitochondrial glucose flux and glycolysis were measured using the XFe24 Extracellular Flux Analyzer. Cells were collected for apoptosis analysis 24 h after transfection and proliferation was quantified using the WST-1 Cell Proliferation and Cytotoxicity Assay Kit (Beyotime, Shanghai, China), according to the manufacturerʹs instructions. Results: In the rat experiment, expression of rno-miR-210-3p under ACS was increased sharply while ISCU, E2F3, RAD52, and PSMB6 levels declined, along with protein expression of ISCU and PSMB6. In cell experiments, ISCU, Rap1b, ATP1b1, GPD1, E2F3, RAD52, PSMB6 and GPD2 genes were downregulated while ISCU and PSMB6 protein expression decreased with upregulation of rno-miR-210-3p. Conversely, in response to decreased rno-miR-210-3p expression, ISCU, E2F3, RAD52, PSMB6 and GPD2 genes were upregulated, in addition to ISCU and PSMB6 proteins. Upregulation of miR-210 inhibited cell proliferation and induced cell death whereas its downregulation promoted cell proliferation. Upregulation or downregulation of miR-210 promoted glycolysis and mitochondrial respiration of BRL cells. However, downregulation of miR-210 caused acid production in cells. Conclusion: Expression of rno-miR-210-3p is significantly increased under ACS. Upregulation of rno-miR-210-3p inhibits the expression of ISCU, Rap1b, ATP1b1, GPD1, E2F3, RAD52, PSMB6 and GPD2 genes, promotes glycolysis of liver and enhances the mitochondrial respiratory capacity of cells, but may also cause cell death. Our findings collectively indicate that regulation of rno-miR-210-3p is a preferential mechanism of choice used by the body to cope with ACS
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