Distributed Power Balancing for the FREEDM System

The FREEDM microgrid is a test bed for a smart grid integrated with Distributed Grid Intelligence (DGI) to efficiently manage the distribution and storage of renewable energy. Within the FREEDM system, DGI applies distributed algorithms in a unique way to achieve economically feasible utilization and storage of alternative energy sources in a distributed fashion. The FREEDM microgrid consists of residential or industrial nodes with each node running a portion of the DGI process called Intelligent Energy Management (IEM). Such IEM nodes within FREEDM coordinate among themselves to efficiently and economically manage their power generation, utility and storage. Among a variety of services offered by the DGI, the Power Balancing scheme optimizes the distribution of power generation and storage among the IEMs. This paper presents the key aspects in implementing such a scheme and outlines the preliminary results obtained by integrating the proposed methodology with a functional SST model of FREEDM. The results demonstrate the potential benefits of adopting advanced \u27smart\u27 technology on a local grid

Neuroprotective Potential of Biphalin, Multireceptor Opioid Peptide, Against Excitotoxic Injury in Hippocampal Organotypic Culture

Biphalin is a dimeric opioid peptide that exhibits affinity for three types of opioid receptors (MOP, DOP and KOP). Biphalin is undergoing intensive preclinical study. It was recognized that activation of δ-opioid receptor elicits neuroprotection against brain hypoxia and ischemia. We compare the effect of biphalin and morphine and the inhibition of opioid receptors by naltrexone on survival of neurons in rat organotypic hippocampal cultures challenged with NMDA. Findings: (1) 0.025–0.1 μM biphalin reduces NMDA-induced neuronal damage; (2) biphalin neuroprotection is abolished by naltrexone; (3) reduced number of dead cells is shown even if biphalin is applied with delay after NMDA challenge

Two-dimensional zymography differentiates gelatinase isoforms in stimulated microglial cells and in brain tissues of acute brain injuries.

Excessive activation of gelatinases (MMP-2/-9) is a key cause of detrimental outcomes in neurodegenerative diseases. A single-dimension zymography has been widely used to determine gelatinase expression and activity, but this method is inadequate in resolving complex enzyme isoforms, because gelatinase expression and activity could be modified at transcriptional and posttranslational levels. In this study, we investigated gelatinase isoforms under in vitro and in vivo conditions using two-dimensional (2D) gelatin zymography electrophoresis, a protocol allowing separation of proteins based on isoelectric points (pI) and molecular weights. We observed organomercuric chemical 4-aminophenylmercuric acetate-induced activation of MMP-2 isoforms with variant pI values in the conditioned medium of human fibrosarcoma HT1080 cells. Studies with murine BV-2 microglial cells indicated a series of proform MMP-9 spots separated by variant pI values due to stimulation with lipopolysaccharide (LPS). The MMP-9 pI values were shifted after treatment with alkaline phosphatase, suggesting presence of phosphorylated isoforms due to the proinflammatory stimulation. Similar MMP-9 isoforms with variant pI values in the same molecular weight were also found in mouse brains after ischemic and traumatic brain injuries. In contrast, there was no detectable pI differentiation of MMP-9 in the brains of chronic Zucker obese rats. These results demonstrated effective use of 2D zymography to separate modified MMP isoforms with variant pI values and to detect posttranslational modifications under different pathological conditions

2D zymography reveals gelatinase isoforms from LPS-stimulated microglial BV-2 cells conditioned medium.

<p>(<b>A</b>) BV-2 cells were treated with 100 or 500 ng/ml endotoxin lipopolysaccharide (LPS) for 16 hr. Proteolytic activity of gelatinases was visualized as a single band of proform of gelatinases (proMMP-2 and proMMP-9) by 1D zymography. (<b>B</b>) In 2D zymograms, proMMP-9 isoforms were visualized as a serious 105-kDa transparent spots with pI values ranging from 3.5 to 7 and proMMP-2 as a 65-kDa single spot with pI value between 4 and 5. These zymograms are representative results from 3 independent experiments.</p

2D zymography reveals enzymatic isoforms of gelatinases of brain tissues from ZO rats.

<p>(<b>A</b>) Gelatinase activity from the brain tissues of the Zucker lean and obese rats was visualized using 1D gelatin zymography. ProMMP-9, act.MMP-9 and proMMP-2 were identified as bright bands. For the act.MMP-9, ZO vehicle-treated rats showed stronger bands than Zucker lean rats; Linagliptin ameliorates MMP-9 upregulation. (<b>B</b>) Gelatinase isoforms from ZO rats were visualized with 2D gelatin zymography. ProMMP-9 was identified as a 105-kDa single spot, act. MMP-9 as a 95-kDa single spot both with pI values between 3 and 4, as well as proMMP-2 as a 65-kDa single spot with pI value between 4 and 5. Purified gelatinases were applied on 1D zymography on the left side of the same gel for comparison. These zymograms are representative results from 4 independent experiments.</p

2D zymography reveals enzymatic isoforms of gelatinases in TBI mouse brains.

<p>Mice were sacrificed 6 h after CCI-induced TBI. In contralateral hemispheres, proMMP-9 was identified as a 105-kDa single spot with pI value between 3 and 4 and a 105-kDa streak of pI values ranging from 5.5 to 8. In lesioned hemispheres, proMMP-9 was identified as a streak with higher intensity of pI values ranging from 5.5 to 8. Traumatic brain lysate was applied on the left side of the gel for comparison. These zymograms are representative results from 4 independent experiments.</p

Identification of gelatinase isoforms from HT1080 cell conditional medium by 1D and 2D zymography.

<p>After incubating with gelatin Sepharose 4B (gelatin 4B) overnight in conditioned medium of HT1080 cells 1D and 2D zymography was performed. Transparent spots (2D) and bands (1D, right side of the gel) revealed proteolytic activity of gelatinases. (<b>A</b>) 2D zymogram showed a 92-kDa proMMP-9 spot with pI value between 3 and 4, and a 65-kDa proMMP-2 spot with pI value between 4 and 5, corresponding to the respective molecular weights of the bands resolved by 1D zymography on the right of the same gel. (<b>B</b>) Conditioned medium of HT1080 cells treated with or without a broad-spectrum MMP inhibitor 1,10 PA were loaded to two IEF dry strips. After IEF separation, these two strips were cut in the pI values ranging from 3 to 6 based on the 2D zymography mapping in Fig 1A, then loaded on the same SDS-PAGE gel for comparison. MMP inhibitor 1,10 PA attenuated gelatinase activity compared to the untreated control.</p