ZBTB20 Is a Sequence-Specific Transcriptional Repressor of Alpha-Fetoprotein Gene

Alpha-fetoprotein (AFP) represents a classical model system to study developmental gene regulation in mammalian cells. We previously reported that liver ZBTB20 is developmentally regulated and plays a central role in AFP postnatal repression. Here we show that ZBTB20 is a sequence-specific transcriptional repressor of AFP. By ELISA-based DNA-protein binding assay and conventional gel shift assay, we successfully identified a ZBTB20-binding site at -104/-86 of mouse AFP gene, flanked by two HNF1 sites and two C/EBP sites in the proximal promoter. Importantly, mutation of the core sequence in this site fully abolished its binding to ZBTB20 in vitro, as well as the repression of AFP promoter activity by ZBTB20. The unique ZBTB20 site was highly conserved in rat and human AFP genes, but absent in albumin genes. These help to explain the autonomous regulation of albumin and AFP genes in the liver after birth. Furthermore, we demonstrated that transcriptional repression of AFP gene by ZBTB20 was liver-specific. ZBTB20 was dispensable for AFP silencing in other tissues outside liver. Our data define a cognate ZBTB20 site in AFP promoter which mediates the postnatal repression of AFP gene in the liver

Non-Markovian Transmission through Two Quantum Dots Connected by a Continuum

We consider a transport setup containing a double-dot connected by a continuum. Via an exact solution of the time-dependent Schr\"odinger equation, we demonstrate a highly non-Markovian quantum-coherence-mediated transport through this dot-continuum-dot (DCD) system, which is in contrast with the common premise since in typical case a quantum particle does not reenter the system of interest once it irreversibly decayed into a continuum (such as the spontaneous emission of a photon). We also find that this DCD system supports an unusual steady state with unequal source and drain currents, owing to electrons irreversibly entering the continuum and floating there

Grid-tied single-phase bi-directional PEV charging/discharging control

This paper studies the bi-directional power flow control between Plug-in Electric Vehicles (PEVs) and an electrical grid. A grid-tied charging system that enables both Grid-to-Vehicle (G2V) and Vehicle-to-Grid (V2G) charging/discharging is modeled using SimPowerSystems in Matlab/Simulink environment. A bi-directional AC-DC converter and a bi-directional DC-DC buck-boost converter are integrated to charge and discharge PEV batteries. For AC-DC converter control, Predictive Current Control (PCC) strategy is employed to enable grid current to reach a reference current after one modulation period. In addition, Phase Lock Loop (PLL) and a band-stop filter are designed to lock the grid voltage phase and reduce harmonics. Bi-directional power flow is realized by controlling the mode of the DC-DC converter. Simulation tests are conducted to evaluate the performance of this bi-directional charging system. The simulation results show that the integrated PCC, PLL, and band-stop filter can achieve fast dynamic response, low Total Harmonics Distortion (THD) of grid voltage and current, and unity power factor

Model-based micro-grid modeling and optimal PEV charging control

© 2016 IEEE. Micro-grid systems can support distribution network to avoid insufficient electricity supply by effectively integrating renewable energy sources and energy storage systems. This paper studies the modeling of a micro-grid system using SimPowerSystems in Matlab/Simulink environment. The Micro-grid consists of ten Electric Vehicle Service Equipment (EVSE), a Photovoltaics (PV) farm, an Energy Storage System (ESS), and a commercial building. To minimize charging cost as well as limit the micro-grid peak load, the Non-Integer Generic Algorithm (NIGA) optimization method is used to obtain optimized Plug-in Electric Vehicle (PEV) charging/discharging schedule with time-varying charging rate. The time-of-use (TOU) price and discharge incentive are applied to implement the cost minimization. The simulation results show that the total load is flattened corresponding to TOU price structures. The optimization that considers both discharge incentive and micro-grid load limit can generate a cost-power win-win result

Mitigation of the Impact of High Plug-in Electric Vehicle Penetration on Residential Distribution Grid Using Smart Charging Strategies

Vehicle electrification presents a great opportunity to reduce transportation greenhouse gas emissions. The greater use of plug-in electric vehicles (PEVs), however, puts stress on local distribution networks. This paper presents an optimal PEV charging control method integrated with utility demand response (DR) signals to mitigate the impact of PEV charging to several aspects of a grid, including load surge, distribution accumulative voltage deviation, and transformer aging. To build a realistic PEV charging load model, the results of National Household Travel Survey (NHTS) have been analyzed and a stochastic PEV charging model has been defined based on survey results. The residential distribution grid contains 120 houses and is modeled in GridLAB-D. Co-simulation is performed using Matlab and GridLAB-D to enable the optimal control algorithm in Matlab to control PEV charging loads in the residential grid modeled in GridLAB-D. Simulation results demonstrate the effectiveness of the proposed optimal charging control method in mitigating the negative impacts of PEV charging on the residential grid

Mitigation of the Impact of High Plug-in Electric Vehicle Penetration on Residential Distribution Grid Using Smart Charging Strategies

Vehicle electrification presents a great opportunity to reduce transportation greenhouse gas emissions. The greater use of plug-in electric vehicles (PEVs), however, puts stress on local distribution networks. This paper presents an optimal PEV charging control method integrated with utility demand response (DR) signals to mitigate the impact of PEV charging to several aspects of a grid, including load surge, distribution accumulative voltage deviation, and transformer aging. To build a realistic PEV charging load model, the results of National Household Travel Survey (NHTS) have been analyzed and a stochastic PEV charging model has been defined based on survey results. The residential distribution grid contains 120 houses and is modeled in GridLAB-D. Co-simulation is performed using Matlab and GridLAB-D to enable the optimal control algorithm in Matlab to control PEV charging loads in the residential grid modeled in GridLAB-D. Simulation results demonstrate the effectiveness of the proposed optimal charging control method in mitigating the negative impacts of PEV charging on the residential grid

Original Article Expression of Wnt-5a and β-catenin in primary hepatocellular carcinoma

Abstract: It has been reported that changes in Wnt5a expression are closely related to hepatocellular carcinoma (HCC) development, while decreased or abnormal β-catenin expression may promote the invasion and metastasis of tumor cells. In this study, the roles and clinical significance of Wnt-5a and β-catenin expression were analyzed in primary HCC. Real-time PCR (RT-PCR) analysis of Wnt-5a mRNA expression was performed in 26 fresh HCC samples and the corresponding para-carcinoma tissues. Wnt-5a and β-catenin protein expression was detected by immunohistochemical staining of paraffin-embedded tissues of 85 cases of HCC and corresponding para-carcinoma tissues and 15 cases of hepatic cirrhosis. Results showed that Wnt-5a mRNA levels were significantly higher in HCC tissue than in the para-carcinoma tissue (0.102 ± 0.159 and 0.020 ± 0.022, respectively; P < 0.05), while Wnt-5a protein was absent or low in HCC. Wnt-5a expression was detected in significantly fewer HCC tissue samples than in the para-carcinoma and hepatic cirrhosis tissue samples (21.2% (18/85), 81.26% (69/85) and 86.7% (13/15), respectively; P < 0.01). Abnormal localization of β-catenin protein shown by intracytoplasmic or intranuclear staining was observed in 72.94% (62/85) of HCC samples. These observations indicate that the role of Wnt-5a in HCC is mediated at the protein level rather than the transcriptional level. Furthermore, the abnormal localization of β-catenin observed in HCC tissues may be associated with gene mutation leading to the generation of truncated β-catenin proteins, which in turn, may represent an initiating or contributing factor in the development of HCC

Real-time modeling to enable hardware-in-the-loop simulation of plug-in electric vehicle-grid interaction

Real-Time simulation and Hardware-in-the-Loop (HIL) testing are increasingly adopted by industry for the development and validation of complex systems. This paper presents the real-time modeling and power management of a Vehicle-Grid Integration (VGI) system. The VGI system consists of six AC level 2 Plug-in Electric Vehicle (PEV) charging stations, a Photovoltaics (PV) farm, a commercial building load, and a switch connecting to 240V single phase power grid. PEV charging activities follow the SAE J1772 standard. An energy management algorithm is designed for the VGI system to coordinate the PEV charging with the building load and PV renewable generation. The coordination maintains the power consumption of the VGI system below utility’s demand charge pricing threshold. A real-time power system simulator, Opal-RT, is used in this study. The OPAL-RT system allows users to build detailed power system models using Matlab Simulink/SimPowerSystems and RT-LAB library, and run the models in real-time. The model-based approach enables the integration of power system models seamlessly with the power management algorithm and power electronics-level controllers. The simulation results show that the VGI model emulates the real system well and the coordinated PEV charging helps to balance the power generation and consumption of the VGI system to meet power management requirement

A comparative analysis for the volatile compounds of various Chinese dark teas using combinatory metabolomics and fungal solid-state fermentation

A total of 98 compounds including 20 aldehydes, eight arenes, six acids, 17 alcohols, 13 ketones, nine esters, nine methoxyphenolics, three alkenes, seven alkanes, and six other components were tentatively identified in six Chinese dark teas (CDTs) using gas chromatography–mass spectrometry. Multivariate statistical analysis revealed that dark teas from Yunnan and Guangxi provinces could be classified into one group, and other CDTs belonged to the other cluster. The diagnostic volatile compounds being responsible for CDTs' discrimination were observed as (E,E)-2,4-decadienal, methoxyphenolics, geraniol, α-terpineol, 2,4-heptadienal, cis-jasmone, linalool oxides, and 2-nonenal. Furthermore, mature tea leaves were separately fermented using Eurotium cristatum and Aspergillus niger. The results showed that E. cristatum increased the contents of cis-jasmone, α-terpineol, ß-ionone, nonanal, and 2-pentylfuran, whereas A. niger advanced the levels of geraniol, linalool oxides, 9,12-octadecadienoic acid, and ß-ionone after short-term fermentation. Fungus species may contribute to forming the flavor of Chinese dark teas by affecting the volatile compounds during postfermentation