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This paper proposes a point of common coupling (PCC) voltage compensation method for islanding microgrids using an improved power sharing control scheme among distributed generators (DGs) without communication. The PCC voltage compensation algorithm is implemented in the droop control scheme to reduce the PCC voltage deviation produced by the droop controller itself and the voltage drop on the line impedance. The control scheme of each individual DG unit is designed to use only locally measured feedback variables and an obtained line impedance to calculate the PCC voltage. Therefore, traditional voltage measurement devices installed at the PCC as well as communication between the PCC and the DGs are not required. The proposed control scheme can maintain the PCC voltage amplitude within an allowed range even to some extent assuming inaccurate line impedance parameters. In addition, it can achieve proper power sharing in islanding microgrids. Experimental results obtained under accurate and inaccurate line impedances are presented to show the performance of the proposed control scheme in islanding microgrids. [ABSTRACT FROM AUTHOR]

With fewer power electronic devices, the two-/three-level voltage source converter (VSC) is more suitable for medium-voltage direct current (MVDC) distribution system than the modular multi-level converter (MMC). However, two important system dynamic performances, including voltage fluctuation during a normal power change and voltage collapse during a fault, are contradictory in two existing capacitor arrangement schemes. To balance both dynamic performances, a novel capacitor arrangement scheme is proposed, with the capacitors dispersed at the source side. First, the structure and basic working principle of the proposed scheme are presented. Then, dynamic performances of two-/three-level VSC-MVDC system with the proposed scheme are discussed, and detailed comparisons among two existing capacitor arrangement schemes and the proposed scheme are made. In the end, simulation models of 20 kV two-/three-level VSC-MVDC system with the three different capacitor arrangement schemes are established in the MATLAB/Simulink platform. Simulation results have proved that in the proposed scheme, voltage fluctuation during normal power change is minimum, and voltage collapse during a short-circuit fault is suppressed dramatically. [ABSTRACT FROM AUTHOR]

Voxel-based morphometry is used to detect structural brain changes in patients with migraine. However, the relevance of migraine and structural changes is not clear. This study investigated structural brain abnormalities based on voxel-based morphometry using a rat model of recurrent headache. The rat model was established by infusing an inflammatory soup through supradural catheters in conscious male rats. Rats were subgrouped according to the frequency and duration of the inflammatory soup infusion. Tactile sensory testing was conducted prior to infusion of the inflammatory soup or saline. The periorbital tactile thresholds in the high-frequency inflammatory soup stimulation group declined persistently from day 5. Increased white matter volume was observed in the rats three weeks after inflammatory soup stimulation, brainstem in the in the low-frequency inflammatory soup-infusion group and cortex in the high-frequency inflammatory soup-infusion group. After six weeks’ stimulation, rats showed gray matter volume changes. The brain structural abnormalities recovered after the stimulation was stopped in the low-frequency inflammatory soup-infused rats and persisted even after the highfrequency inflammatory soup stimulus stopped. The changes of voxel-based morphometry in migraineurs may be the result of recurrent headache. Cognition, memory, and learning may play an important role in the chronification of migraines. Reducing migraine attacks has the promise of preventing chronicity of migraine. [ABSTRACT FROM AUTHOR]

The ERK/HIF-1α signaling pathway is believed to play an important role in the genesis of progressive fibrosis. An increasing expression of HIF-1α and ERK accompanies CCl4-induced liver fibrosis in rats. Curcumin is verified to have antifibrotic effects in several kinds of liver fibrosis models. There is no specific evidence illustrating a connection between curcumin and the HIF-1α/ERK pathway in rat liver fibrosis induced by CCl4. In this study, liver fibrosis was induced by CCl4 in treated rats. The data demonstrated that curcumin was able to attenuate liver fibrosis and inhibit the proliferation of HSC. Moreover, curcumin could remarkably elevate the hepatic function by decreasing serum levels of ALT, AST and ALP, and increasing levels of ALB, TP and α-SMA, Col III mRNA expression. Meanwhile, ECM status could also be reflected by curcumin treatment. The alleviation with curcumin treatment was associated with inhibition of HIF-1α and phosphor-ERK. This study indicates that curcumin alleviates fibrosis by reducing the expression of HIF-1α partly through the ERK pathway. [ABSTRACT FROM AUTHOR]

Background Nucleolin, as a multifunctional protein, has been demonstrated to play an oncogenic role in human hepatocellular carcinoma (HCC). The aim of this study was to investigate the expression pattern of nucleolin in HCC and determine its correlation with tumor progression and prognosis. Methods Nucleolin expression at both mRNA and protein levels in HCC and adjacent nonneoplastic tissues were respectively detected by quantitative real time polymerase chain reaction (QPCR), immunohistochemistry and western blotting. Results Nucleolin expression, at both mRNA and protein levels, was significantly higher in HCC tissues than in the adjacent nonneoplastic tissues (both P < 0.001). In addition, the elevated nucleolin expression was markedly correlated with advanced tumor stage (P = 0.001), high tumor grade (P = 0.02) and serum AFP level (P = 0.008). Moreover, HCC patients with high nucleolin expression had shorter 5-year disease-free survival and shorter 5-year overall survival than those with low expression (both P < 0.001). Furthermore, the Cox proportional hazards model showed that nucleolin expression was an independent poor prognostic factor for both 5-year disease-free survival (hazards ratio [HR] = 3.696, 95% confidence interval[CI] = 1.662-8.138, P = 0.01) and 5-year overall survival (HR = 3.872, CI = 1.681- 8.392, P = 0.01) in HCC. Conclusion These results showed that the markedly and consistently increasing expression of nucleolin may be associated with aggressive characteristics of HCC, and implied that nucleolin expression may serve as a promising biochemical marker for predicting the clinical outcome of patients with this malignancy. [ABSTRACT FROM AUTHOR]

Several complex molecular events are involved in tumorigenesis of hepatocellular carcinoma (HCC). The interactions of these molecules may constitute the HCC imbalanced network. Gansui Banxia Tang (GSBXT), as a classic Chinese herbal formula, is a popular complementary and alternative medicine modality for treating HCC. In order to investigate the therapeutic effects and the pharmacological mechanisms of GSBXT on reversing HCC imbalanced network, we in the current study developed a comprehensive systems approach of integrating disease-specific and drug-specific networks, and successfully revealed the relationships of the ingredients in GSBXT with their putative targets, and with HCC significant molecules and HCC related pathway systems for the first time. Meanwhile, further experimental validation also demonstrated the preventive effects of GSBXT on tumor growth in mice and its regulatory effects on potential targets. [ABSTRACT FROM AUTHOR]

Background The purpose of this study is to investigate the effects of a high-fat diet from perilla oil on serum lipids, hepatic lipid metabolism and insulin sensitivity. Methods Male Sprague-Dawley (SD) rats were fed either a control (CT) diet or a diet high in perilla oil (HP). After 16 weeks of feeding, the serum lipids were measured, and the gene expressions involved in hepatic fatty acid oxidation and synthesis were determined. In addition, hepatic fat deposition was detected, and insulin sensitivity was evaluated by means of euglycemic-hyperinsulinemic clamp. Results Compared with the rats in the CT group, the HP-feeding significantly decreased the levels of triglyceride (TG), total cholesterol (TCH) and HDL-cholesterol (HDL-c). HP-feeding did not change the levels of LDL-cholesterol (LDL-c), free fatty acid (FFA), intrahepatic lipids or body weight. Moreover, the HP-feeding dramatically increased the mRNA expressions of fatty acid oxidation markers (PPAR-alpha, CPT1A) and fatty acid synthesis markers (SREBP-1, FASN and ACC) in the liver. The HP-feeding induced increased protein levels of CPT1A, while reducing the protein levels of FASN and ACC in the liver. However, the glucose infusion rate significantly increased in the HP group compared with the CT group. Conclusions Our data show that, in rats, excessive perilla oil intake may significantly lower serum lipids, strengthen hepatic fatty acid oxidation, and inhibit hepatic fatty acid synthesis, but at the same time may also lead to insulin resistance. [ABSTRACT FROM AUTHOR]

Ricin toxin binding subunit B (RTB) is one of the subunits of the ricin protein. RTB has been used as adjuvant, but little is known about its mechanism. In this study, we found that RTB increased not only nitric oxide (NO) release, but also tumor necrosis factor (TNF)-a and interleukin (IL)-6 production in mouse macrophage cell line RAW264.7 cells. They subsequently exhibited enhanced ConA-induced T-cell and LPS-induced B-cell proliferative responses. We also examined the cytokines that were produced from splenocytes following in vitro RTB administration. Increased levels of IL-2, interferon (IFN)-? and TNF-a were observed, while IL-4 and IL-5 were unaffected. These results demonstrate that recombinant RTB can act on the immune system and activate T-cells by introducing a Th1 immune response. Th1 cells might be the primary cellular target affected by RTB. Our results suggest that the recombinant RTB can promote the activation of macrophages and has a beneficial effect on immunomodulatory activity. [ABSTRACT FROM AUTHOR]

A reverse phase ultra performance liquid chromatography and photodiode array (UPLC-PDA) detection method was established for the determination of six alkaloids in Zoagumhwan (ZGW), and further for investigating the influence of nonpolar substances on the extraction efficiency of these alkaloids. The method was based on a BEH C18 (50 mm × 2.1 mm, 1.7 μm) column and mobile phase of aqueous phosphoric acid and acetonitrile including 0.05% buffer solution under gradient elution. ZGW samples of ZGW I, II, III and IV were obtained and prepared by pre-processing the crude materials of Coptidis rhizoma and Evodiae fructus using four technologies, namely direct water decoction, removal of nonpolar substances in Evodiae fructus by supercritical fluid extraction (SFE), removal of nonpolar substances in ZGW by SFE and removal of nonpolar substances in ZGW by steam distillation. The developed and validated UPLCPDA method was precise, accurate and sensitive enough based on the facts that the six alkaloids showed good regression (r > 0.9998), the limit of detections and quantifications for six alkaloids were less than 28.8 and 94.5 ng/mL, respectively, and the recovery was in the range of 98.56%--103.24%. The sequence of the total contents of six alkaloids in these samples was ZGW II > ZGW IV > ZGW III > ZGW I. ZGW II, in which nonpolar substances, including essential oils, were firstly removed from Evodiae fructus by SFE, had the highest content of the total alkaloids, indicating that extraction efficiency of the total alkaloids could be remarkably increased after Evodiae fructus being extracted by SFE. [ABSTRACT FROM AUTHOR]

Coxiella burnetii strains carry one of four large, conserved, autonomously replicating plasmids (QpH1, QpRS, QpDV, or QpDG) or a QpRS-like chromosomally integrated sequence of unknown function. Here, we report the characterization of the QpH1 plasmid of C. burnetii Nine Mile phase II by making QpH1-deficient strains. A shuttle vector pQGK containing the CBUA0036 to CBUA0039a region (predicted as being required for QpH1 maintenance) was constructed. The pQGK vector can be stably transformed into Nine Mile II and maintained at a similar low copy number like QpH1. Importantly, transformation with pQGK cured the endogenous QpH1 due to plasmid incompatibility. Compared to a Nine Mile II transformant of an RSF1010-ori-based vector, the pQGK transformant shows a similar growth curve in both axenic media and Buffalo green monkey kidney cells, a variable growth defect in macrophage-like THP-1 cells depending on the origin of inoculum, and dramatically reduced ability to colonize wild-type bone marrow-derived murine macrophages. Furthermore, we found that CBUA0037 to CBUA0039 open reading frames (ORFs) are essential for plasmid maintenance, and CBUA0037 and CBUA0038 ORFs account for plasmid compatibility. In addition, plasmid-deficient C. burnetii can be isolated by using CBUA0037 or CBUA0038 deletion vectors. Furthermore, QpH1-deficient C. burnetii strains caused a lesser extent of splenomegaly in SCID mice, but, intriguingly, they had significant growth in SCID mouse-sourced macrophages. Taken together, our data suggest that QpH1 encodes a factor(s) essential for colonizing murine, not human, macrophages. This study suggests a critical role of QpH1 for C. burnetii persistence in rodents and expands the toolkit for genetic studies in C. burnetii. [ABSTRACT FROM AUTHOR]