Effects of dietary leucine supplementation on the hepatic mitochondrial biogenesis and energy metabolism in normal birth weight and intrauterine growth-retarded weanling piglets

Weipeng Su,Wen Xu,Hao Zhang,Zhixiong Ying,Le Zhou,Lili Zhang,Tian Wang 한국영양학회 2017 Nutrition Research and Practice Vol.11 No.2

BACKGROUND/OBJECTIVES: The study was conducted to evaluate the effects of dietary leucine supplementation on mitochondrial biogenesis and energy metabolism in the liver of normal birth weight (NBW) and intrauterine growth-retarded (IUGR) weanling piglets. MATERIALS/METHODS: A total of sixteen pairs of NBW and IUGR piglets from sixteen sows were selected according to their birth weight. At postnatal day 14, all piglets were weaned and fed either a control diet or a leucine-supplemented diet for 21 d. Thereafter, a 2 × 2 factorial experimental design was used. Each treatment consisted of eight replications with one piglet per replication. RESULTS: Compared with NBW piglets, IUGR piglets had a decreased (P < 0.05) hepatic adenosine triphosphate (ATP) content. Also, IUGR piglets exhibited reductions (P < 0.05) in the activities of hepatic mitochondrial pyruvate dehydrogenase (PDH), citrate synthase (CS), α-ketoglutarate dehydrogenase (α-KGDH), malate dehydrogenase (MDH), and complexes I and V, along with decreases (P < 0.05) in the concentration of mitochondrial DNA (mtDNA) and the protein expression of hepatic peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α). Dietary leucine supplementation increased (P < 0.05) the content of ATP, and the activities of CS, α-KGDH, MDH, and complex V in the liver of piglets. Furthermore, compared to those fed a control diet, piglets given a leucine-supplemented diet exhibited increases (P < 0.05) in the mtDNA content and in the mRNA expressions of sirtuin 1, PGC-1α, nuclear respiratory factor 1, mitochondrial transcription factor A, and ATP synthase, H+ transporting, mitochondrial F1 complex, β polypeptide in liver. CONCLUSIONS: Dietary leucine supplementation may exert beneficial effects on mitochondrial biogenesis and energy metabolism in NBW and IUGR weanling piglets.

Energy Evolution and Transfer Characteristics in Spatial Particle–Spring–Beam Model

Weipeng Hu,Yabo He,Fan Zhang,Qiang Zhou 한국항공우주학회 2024 International Journal of Aeronautical and Space Sc Vol.25 No.2

Reproducing the orbit–attitude–vibration coupling dynamic behaviors of the complex flexible spatial structure provides the basis on the orbit design, the attitude adjustment and the vibration control of the structure. In this paper, the tug–tether–debris system is simplified as a spatial particle–spring–beam physical model, in which, the non-smooth stiffness coefficient of the spring is assumed to describe the tension/loose state switching of the tether. Based on the variational principle, the coupling dynamic equations are deduced for the spatial particle–spring–beam model. To investigate the energy evolution and the energy transfer characteristics of the model, the structure-preserving iteration method is developed focusing on the non-smooth stiffness coefficient of the spring. In the structure-preserving iteration method, the symplectic Runge–Kutta method is employed to solve the ordinary differential equations mainly controlling the plane motion of the system and the multi-symplectic method is employed to solve the transverse vibration of the beam in the model. The structure-preserving characteristics of the iteration method result from the symplectic structure contained in the symplectic Runge–Kutta method and the multi-symplectic structure contained in the multi-symplectic method. In the stages when the spring is in a complete loose or a complete tension state, the total energy of system is a conservative quantity that is preserved by the structure- preserving iteration method in the simulation. In addition, the energy transfer laws of the system in the tension process of the spring are revealed numerically, which gives some guidance on the active flexible space debris removal strategy design directly.

Composite passivity-based control of DC/DC boost converters with constant power loads in DC Microgrids

Liu, Weipeng,Cui, Xiaofeng,Zhou, Jiyao,Zhang, Zehua,Hou, Mingxuan,Shan, Shengqi,Wu, Shang The Korean Institute of Power Electronics 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.11

In this paper, a composite passivity-based control method based on a finite-time disturbance observer (FTDO) and a passivity-based control (PBC) is proposed to improve the stability of the Boost converters with constant power loads in DC Microgrids. The FTDO improves the robustness and rapidity of the system by accurately estimating system disturbances. The PBC ensures the stability of the system via its transient energy dissipation. The FTDO operates parallel to the PBC, and compensates the observed value to the PBC through a feedforward channel. When compared with other controls, the proposed composite passivity-based control has the advantages of a fast dynamic response and accurate tracking of system disturbances in a wide working range. Finally, the control method proposed in this paper is verified by MATLAB/Simulink simulations and hardware in the hard-ware-in-loop experiments.

Tribological performances of copper perrhenate/graphene nanocomposite as lubricating additive under various temperatures

Junhai Wang,Weipeng Zhuang,Tingting Yan,Wenfeng Liang,Ting Li,Lixiu Zhang,Xiaoyi Wei 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.100 No.-

Herein, copper perrhenate (Cu(ReO4)2) was synthesized using a micro-emulsion method and adhered tographene (Gr) using an ultrasonic process. Then, the as-prepared Cu(ReO4)2/Gr composite was added intothe synthetic oil as a lubricant additive with the help of ionic liquid to achieve enhanced dispersionstability within the base oil. The tribological performances of the Cu(ReO4)2/Gr additive wereinvestigated using four-ball tests and the ball-on-disk reciprocating configuration under varioustemperatures. The potential lubrication mechanisms of the Cu(ReO4)2/Gr additive were performed usinga series of characterization methods including XRD, Raman, SEM-EDS, TEM, DSC/TG, and XPS. The resultsof four-ball tests at room temperature indicated that the Cu(ReO4)2/Gr additive could substantiallyimprove the tribological performances of the base oil. The smallest coefficient of friction (COF) and wearscar diameter (WSD) values were 0.068 and 495 mm, respectively, when 0.05 wt% of Cu(ReO4)2/Gr wasadded. Additionally, the graphene accelerated friction-induced heat transfer, which led to decreasedfriction and wear. The results of reciprocating friction experiments at elevated temperatures revealedthat the Cu(ReO4)2/Gr additive had excellent friction-reduction properties when the temperature washigh. This could be attributed to the generation of a protective layer containing tribo-oxides from thealloy, some residual carbides and copper perrhenate induced by friction heat and stress. This protectivelayer was uniformly and stably covered on the worn surface, which could effectively alleviate directcontact between the rubbing pair.

Energy-Efficiency of Distributed Antenna Systems Relying on Resource Allocation

( Xiaoge Huang ),( Dongyu Zhang ),( Weipeng Dai ),( She Tang ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.3

Recently, to satisfy mobile users’ increasing data transmission requirement, energy efficiency (EE) resource allocation in distributed antenna systems (DASs) has become a hot topic. In this paper, we aim to maximize EE in DASs subject to constraints of the minimum data rate requirement and the maximum transmission power of distributed antenna units (DAUs) with different density distributions. Virtual cell is defined as DAUs selected by the same user equipment (UE) and the size of virtual cells is dependent on the number of subcarriers and the transmission power. Specifically, the selection rule of DAUs is depended on different scenarios. We develop two scenarios based on the density of DAUs, namely, the sparse scenario and the dense scenario. In the sparse scenario, each DAU can only be selected by one UE to avoid co-channel interference. In order to make the original non-convex optimization problem tractable, we transform it into an equivalent fractional programming and solve by the following two sub-problems: optimal subcarrier allocation to find suitable DAUs; optimal power allocation for each subcarrier. Moreover, in the dense scenario, we consider UEs could access the same channel and generate co-channel interference. The optimization problem could be transformed into a convex form based on interference upper bound and fractional programming. In addition, an energy-efficient DAU selection scheme based on the large scale fading is developed to maximize EE. Finally, simulation results demonstrate the effectiveness of the proposed algorithm for both sparse and dense scenarios.

Concomitance of P-gp/LRP Expression with EGFR Mutations in Exons 19 and 21 in Non-Small Cell Lung Cancers

Shen Lu,Hong Wei,Weipeng Lu,Mei Li,Qiuping Zhang 연세대학교의과대학 2016 Yonsei medical journal Vol.57 No.1

Purpose: Traditional chemotherapy is the main adjuvant therapy for the treatment of non-small cell lung cancer (NSCLC). However,the emergence of multi-drug resistance (MDR) has greatly restricted the curative effect of chemotherapy. Therefore, it isnecessary to find a method to treat MDR NSCLC clinically. It is worth investigating whether NSCLCs that are resistant to traditionalchemotherapy can be effectively treated with tyrosine kinase inhibitors targeting epidermal growth factor receptor (EGFR). Materials and Methods: The expression of P-glycoprotein (P-gp) and lung resistance-related protein (LRP) was detected by immunohistochemistry,and mutations in EGFR (exons 19 and 21) and Kirsten rat sarcoma viral oncogene homolog (KRAS) (exon 2)were detected by high-resolution melting analysis (HRMA) of surgical NSCLC specimens from 127 patients who did not undergotraditional chemotherapy or radiotherapy. A Pearson chi-square test was performed to analyze the correlations between the expressionof P-gp and LRP and mutations in EGFR and KRAS. Results: The expression frequencies of P-gp and LRP were significantly higher in adenocarcinomas from non-smoking patients;the expression frequency of LRP was significantly higher in cancer tissue from female patients. The frequency of EGFR mutationswas significantly higher in well to moderately differentiated adenocarcinomas from non-smoking female patients. The frequencyof EGFR mutations in the cancers that expressed P-gp, LRP, or both P-gp and LRP was significantly higher than that in cancersthat did not express P-gp or LRP. Conclusion: NSCLCs expressing P-gp/LRP bear the EGFR mutation in exon 19 or 21 easily.

Classification and fatty acid composition analysis of Cronobacter spp. isolated from powdered infant formula in China

Yang, Xiaojuan,Wu, Qingping,Zhang, Jumei,Guo, Weipeng,Mo, Shuping,Liu, Shengrong 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.4

This study aimed to classify a collection of Enterobacter sakazakii (E. sakazakii) strains previously identified from powdered infant formula (PIF) to species level by recN gene sequencing and biochemical testing to determine the distribution of Cronobacter species in China and investigate the strain diversity by cellular fatty acid (CFA) analysis. Of 24 E. sakazakii isolates, 23 were identified as C. sakazakii and one was C. malonaticus. The 23 C. sakazakii isolates showed the same CFA profiles. The C. malonaticus isolate was discriminated from the C. sakazakii isolates by the significant difference in the amounts of $C_{12:0}$, $C_{14:0}$, and $C_{17:0\;cyclo}$ acids. These results showed that C. sakazakii and C. malonaticus were the common Cronobacter species distributed in PIF in China and that the isolates of the two species exhibited different CFA profiles. These findings are of value for epidemiological investigations and provide an alternative method for confirming various Cronobacter spp.

Three-coil Magnetically Coupled Resonant Wireless Power Transfer System with Adjustable-position Intermediate Coil for Stable Transmission Characteristics

Xuling Chen,Lu Chen,Weiwei Ye,Weipeng Zhang 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

In magnetically coupled resonant (MCR) wireless power transfer (WPT) systems, the introduction of additional intermediatecoils is an effective means of improving transmission characteristics, including output power and transmission efficiency, whenthe transmission distance is increased. However, the position of intermediate coils in practice influences system performancesignificantly. In this research, a three-coil MCR WPT system is adopted as an exemplification for determining how the spatialposition of coils affects transmission characteristics. With use of the fundamental harmonic analysis method, an equivalentcircuit model of the system is built to reveal the relationship between the output power, the transmission efficiency, and thespatial scales, including the axial, lateral, and angular misalignments of the intermediate and receiving coils. Three cases oftransmission characteristics versus different spatial scales are evaluated. Results indicate that the system can achieve relativelystable transmission characteristics with deliberate adjustments in the position of the intermediate and receiving coils. A prototypeof the three-coil MCR WPT system is built and analyzed, and the experimental results are consistent with those of the theoreticalanalysis.

Three-coil Magnetically Coupled Resonant Wireless Power Transfer System with Adjustable-position Intermediate Coil for Stable Transmission Characteristics

Chen, Xuling,Chen, Lu,Ye, Weiwei,Zhang, Weipeng The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

In magnetically coupled resonant (MCR) wireless power transfer (WPT) systems, the introduction of additional intermediate coils is an effective means of improving transmission characteristics, including output power and transmission efficiency, when the transmission distance is increased. However, the position of intermediate coils in practice influences system performance significantly. In this research, a three-coil MCR WPT system is adopted as an exemplification for determining how the spatial position of coils affects transmission characteristics. With use of the fundamental harmonic analysis method, an equivalent circuit model of the system is built to reveal the relationship between the output power, the transmission efficiency, and the spatial scales, including the axial, lateral, and angular misalignments of the intermediate and receiving coils. Three cases of transmission characteristics versus different spatial scales are evaluated. Results indicate that the system can achieve relatively stable transmission characteristics with deliberate adjustments in the position of the intermediate and receiving coils. A prototype of the three-coil MCR WPT system is built and analyzed, and the experimental results are consistent with those of the theoretical analysis.

Classification and fatty acid composition analysis of Cronobacter spp. isolated from powdered infant formula in China

Xiaojuan Yang,Qing-Ping Wu,Ju-Mei Zhang,Weipeng Guo,Shuping Mo,Sheng-Rong Liu 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.4

This study aimed to classify a collection of Enterobacter sakazakii (E. sakazakii) strainspreviously identified from powdered infant formula (PIF) to species level by recN gene sequencing andbiochemical testing to determine the distribution of Cronobacter species in China and investigate thestrain diversity by cellular fatty acid (CFA) analysis. Of 24 E. sakazakii isolates, 23 were identified as C. sakazakii and one was C. malonaticus. The 23 C. sakazakii isolates showed the same CFA profiles. TheC. malonaticus isolate was discriminated from the C. sakazakii isolates by the significant difference inthe amounts of C12:0, C14:0, and C17:0 cyclo acids. These results showed that C. sakazakii and C. malonaticuswere the common Cronobacter species distributed in PIF in China and that the isolates of the twospecies exhibited different CFA profiles. These findings are of value for epidemiological investigationsand provide an alternative method for confirming various Cronobacter spp.