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In order to implement a high-efficiency bridgeless power factor correction converter, a new topology and operation principles of continuous conduction mode (CCM) and DC steady-state character of the converter are analyzed, which show that the converter not only has bipolar-gain characteristic but also has the same characteristic as the traditional Boost converter, while the voltage transfer ratio is not related with the resonant branch parameters and switching frequency. Based on the above topology, a novel bridgeless Bipolar-Gain Pseudo-Boost PFC converter is proposed. With this converter, the diode rectifier bridge of traditional AC-DC converter is eliminated, and zero-current switching of fast recovery diode is achieved. Thus, the efficiency is improved. Next, we also propose the one-cycle control policy of this converter. Finally, experiments are provided to verify the accuracy and feasibility of the proposed converter.

This study aims to explore factors that affect carsharing demand characteristics in different time periods based on EVCARD transaction data, which is the largest station-based one-way carsharing program in Shanghai, China. Monthly usage intensity and degree of usage imbalance are used as proxies of demand. This study uses three groups of independent variables: carsharing station attributes, built environment (density, diversity, design, and destination accessibility), and transportation facilities. The adaptive elastic net regression is developed to identify factors that influence carsharing usage intensity and degree of usage imbalance after factor selection using extra-randomized-tree algorithm. Finally, a station layout is proposed according to both usage intensity and degree of imbalance. The main results of this study are presented as follows: (1) different effects of built environment and transportation factors cause dynamic demand across different time periods; (2) factors with positive and negative effect on carsharing demand are divided clearly for guidance of the carsharing station layout; (3) public parking space leads to more personal vehicle trip compared to a carsharing trip; and (4) as public transportation, the relationship of the metro and carsharing is complementary. However, the bus stop and carsharing have a competitive relationship. This study provides a carsharing layout method based on both usage intensity and degree of imbalance. Furthermore, several policies concerning carsharing are proposed., 1. Introduction Carsharing service allows users to avoid the money and time cost of car ownership, such as maintenance, insurance, and finding parking space. It offers more flexible car travel [...]

Summary: Composite expended graphite (EG)/Ba(OH)2·8H2O form‐stable phase change material (PCM) is prepared with porous adsorption method in this study to solve the problem of the leakage risk in the application process based on barium hydroxide octahydrate. In addition, the thermal properties and stability have been measured and verified. Thermal conductivity of each group composite material was enhanced by about two to four times, while the addition has little negative effect on the other properties. With microscopic features being characterized by scanning electron microscope (SEM), the experimental result demonstrates that the composite material with 7 wt% of EG is optimal to be a saturated state between two phases. After the thermal cyclings of 100, 300, and 500 times, thermal properties did not change dramatically, which can be used as an ideal material for solar thermal storage system within finite thermal cyclings. In order to simulate the operating condition of solar energy or waste heat storage, the composite material was encapsulated in the heat storage unit with pipe bundle, and heat storage/release experiences were performed to test the performance of the material and hot water supply. The results indicate that the composite material is qualified to storage and release sufficient heat. The experimental data can provide necessary technical reference for engineering design and effect prediction in practical application. [ABSTRACT FROM AUTHOR]

The pathogenesis of inflammatory bowel disease (IBD) is due in part to a loss of equilibrium among the gut microbiota, epithelial cells, and resident immune cells. The gut microbiota contains a large proportion of probiotic commensal Lactobacillus species; some natural microbiota and probiotics confer protection against IBD. In this study, mice with colitis triggered by dextran sodium sulphate (DSS) were given Lactobacillus plantarum orally. We assessed the damage caused by DSS and the therapeutic activity of L. plantarum. The colitis triggered by DSS was less severe in the mice that received the L. plantarum treatment, which also diversified the microbe species in the colon, enhanced the ratio of Firmicutes to Bacteroidetes, and diminished the relative abundance of Lactobacillus. The taxonomic units of greatest diversity in the DSS and L. plantarum groups were identified using a linear discriminant and effect size (LEfSe) analysis. Aliihoeflea was established to be the genus of bacteria that was affected in the L. plantarum group most extensively. In conclusion, gut health was promoted by L. plantarum, as it diversified the microbes in the colon and restricted the activity of pathogenic bacteria in the intestine. Moreover, according to the LEfSe analysis, the DSS group was impacted more significantly by gut microorganisms than the L. plantarum group, suggesting that L. plantarum improved the stability of the intestinal tract. [ABSTRACT FROM AUTHOR]

Erythropoietin-producing hepatocyte B4 (EphB4) has been reported to be a key molecular switch in the regulation of bone homeostasis, but the underlying mechanism remains poorly understood. In this study, we investigated the role of EphB4 in regulating the expression of periostin (POSTN) within bone marrow-derived mesenchymal stem cells (MSCs) and assessed its effect and molecular mechanism of osteogenic induction in vitro. Treatment with ephrinB2-FC significantly increased the expression of POSTN in MSCs, and the inhibition of EphB4 could abrogate this effect. In addition, osteogenic markers were upregulated especially in MSCs overexpressing EphB4. To elucidate the underlying mechanism of cross talk between EphB4 and the Wnt pathway, we detected the change in protein expression of phosphorylated-glycogen synthase kinase 3β-serine 9 (p-GSK-3β-Ser9) and β-catenin, as well as the osteogenic markers Runx2 and COL1. The results showed that GSK-3β activation and osteogenic marker expression levels were downregulated by ephrinB2-FC treatment, but these effects were inhibited by blocking integrin αvβ3 in MSCs. Our findings demonstrate that EphB4 can promote osteogenic differentiation of MSCs via upregulation of POSTN expression. It not only helps to reveal the interaction mechanism between EphB4 and Wnt pathway but also brings a better understanding of EphB4/ephrinB2 signaling in bone homeostasis. [ABSTRACT FROM AUTHOR]