53 research outputs found

    Combination optimization method of grid sections based on deep reinforcement learning with accelerated convergence speed

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    A modern power system integrates more and more new energy and uses a large number of power electronic equipment, which makes it face more challenges in online optimization and real-time control. Deep reinforcement learning (DRL) has the ability of processing big data and high-dimensional features, as well as the ability of independently learning and optimizing decision-making in complex environments. This paper explores a DRL-based online combination optimization method of grid sections for a large complex power system. In order to improve the convergence speed of the model, it proposes to discretize the output action of the unit and simplify the action space. It also designs a reinforcement learning loss function with strong constraints to further improve the convergence speed of the model and facilitate the algorithm to obtain a stable solution. Moreover, to avoid the local optimal solution problem caused by the discretization of the output action, this paper proposes to use the annealing optimization algorithm to make the granularity of the unit output finer. The proposed method in this paper has been verified on an IEEE 118-bus system. The experimental results show that it has fast convergence speed and better performance and can obtain stable solutions

    Genetic analyses identify GSDMB associated with asthma severity, exacerbations, and antiviral pathways

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    Background The Chr17q12-21.2 region is the strongest and most consistently associated region with asthma susceptibility. The functional genes or single nucleotide polymorphisms (SNPs) are not obvious due to linkage disequilibrium. Objectives We sought to comprehensively investigate whole-genome sequence and RNA sequence from human bronchial epithelial cells to dissect functional genes/SNPs for asthma severity in the Severe Asthma Research Program. Methods Expression quantitative trait loci analysis (n = 114), correlation analysis (n = 156) of gene expression and asthma phenotypes, and pathway analysis were performed in bronchial epithelial cells and replicated. Genetic association for asthma severity (426 severe vs 531 nonsevere asthma) and longitudinal asthma exacerbations (n = 273) was performed. Results Multiple SNPs in gasdermin B (GSDMB) associated with asthma severity (odds ratio, >1.25) and longitudinal asthma exacerbations (P < .05). Expression quantitative trait loci analyses identified multiple SNPs associated with expression levels of post-GPI attachment to proteins 3, GSDMB, or gasdermin A (3.1 × 10−9 < P < 1.8 × 10−4). Higher expression levels of GSDMB correlated with asthma and greater number of exacerbations (P < .05). Expression levels of GSDMB correlated with genes involved in IFN signaling, MHC class I antigen presentation, and immune system pathways (false-discovery rate–adjusted P < .05). rs1031458 and rs3902920 in GSDMB colocalized with IFN regulatory factor binding sites and associated with GSDMB expression, asthma severity, and asthma exacerbations (P < .05). Conclusions By using a unique set of gene expression data from lung cells obtained using bronchoscopy from comprehensively characterized subjects with asthma, we show that SNPs in GSDMB associated with asthma severity, exacerbations, and GSDMB expression levels. Furthermore, its expression levels correlated with asthma exacerbations and antiviral pathways. Thus, GSDMB is a functional gene for both asthma susceptibility and severity

    Career maturity of Korean college students in view of ego-identity status

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    학위논문(석사) --서울대학교 대학원 :교육학과(교육상담전공),2010.2.Maste

    The Chemistry, Biochemistry and Pharmacology of Marine Natural Products from Leptolyngbya, a Chemically Endowed Genus of Cyanobacteria

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    Leptolyngbya, a well-known genus of cyanobacteria, is found in various ecological habitats including marine, fresh water, swamps, and rice fields. Species of this genus are associated with many ecological phenomena such as nitrogen fixation, primary productivity through photosynthesis and algal blooms. As a result, there have been a number of investigations of the ecology, natural product chemistry, and biological characteristics of members of this genus. In general, the secondary metabolites of cyanobacteria are considered to be rich sources for drug discovery and development. In this review, the secondary metabolites reported in marine Leptolyngbya with their associated biological activities or interesting biosynthetic pathways are reviewed, and new insights and perspectives on their metabolic capacities are gained

    Synthesis and Anti-Influenza A Virus Activity of 6′-amino-6′-deoxy-glucoglycerolipids Analogs

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    A series of aminoglucoglycerolipids derivatives had been synthesized, including 6′-acylamido-glucoglycerolipids 1a–1f and corresponding 2′-acylamido-glucoglycerolipids 2a–2c bearing different fatty acids, glucosyl diglycerides 3a–3e bearing different functional groups at C-6′ and ether-linked glucoglycerolipids 4a–4c with double-tailed alkyl alcohol. The anti-influenza A virus (IAV) activity was evaluated by the cytopathic effects (CPE) inhibition assay. The results indicated that the integral structure of the aminoglycoglycerolipid was essential for the inhibition of IAV in MDCK cells. Furthermore, oral administration of compound 1d was able to significantly improve survival and decrease pulmonary viral titers in IAV-infected mice, which suggested that compound 1d merited further investigation as a novel anti-IAV candidate in the future

    Feasibility of laparoscopic gastrectomy for patients with Siewert-type II/III adenocarcinoma of the esophagogastric junction: A propensity score matching analysis.

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    BACKGROUND/AIM:The feasibility of using laparoscopic gastrectomy for the treatment of Siewert-type II/III adenocarcinoma of the esophagogastric junction (AEG) has not been addressed. This study aimed to comparatively evaluate the short- and long-term effects on laparoscopic versus open surgery using (propensity score matching) PSM for Siewert-type II/III AEG. METHODS:We retrospectively collected data from the patients with Siewert-type II/III AEG who were treated in our cancer center between January 2013 and December 2015. Patients undergoing laparoscopic gastrectomy and open gastrectomy were matched via PSM. The cumulative 2-year Overall survival (OS) rate of patients in the two cohorts was estimated by Kaplan-Meier plots. Multi-variable analysis using a Cox regression model was conducted to identify independent risk factors. RESULTS:A total of 963 patients with Siewert-type II/III AEG were included, of which 132 cases were in the laparoscopic gastrectomy group, and 831 cases were in the open gastrectomy group. After regrouping with PSM, 132 patients in the laparoscopic gastrectomy group were balanced with 264 similar patients in the open gastrectomy group. As expected, the laparoscopic gastrectomy group had significantly longer operation times, but less blood loss. Furthermore, the two groups showed similar results for post-operative complications, duration of hospital stay and 2-year OS rate. Combined organ resection was an independent risk factor for 2-year OS rate. CONCLUSION:This study suggests that laparoscopic gastrectomy may serve as a safe and feasible treatment for Siewert-type II/III AEG and achieve similar oncologic outcomes as open gastrectomy

    Acetylated Chitosan Oligosaccharides Act as Antagonists against Glutamate-Induced PC12 Cell Death via Bcl-2/Bax Signal Pathway

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    Chitosan oligosaccharides (COSs), depolymerized products of chitosan composed of β-(1→4) d-glucosamine units, have broad range of biological activities such as antitumour, antifungal, and antioxidant activities. In this study, peracetylated chitosan oligosaccharides (PACOs) and N-acetylated chitosan oligosaccharides (NACOs) were prepared from the COSs by chemcal modification. The structures of these monomers were identified using NMR and ESI-MS spectra. Their antagonist effects against glutamate-induced PC12 cell death were investigated. The results showed that pretreatment of PC12 cells with the PACOs markedly inhibited glutamate-induced cell death in a concentration-dependent manner. The PACOs were better glutamate antagonists compared to the COSs and the NACOs, suggesting the peracetylation is essential for the neuroprotective effects of chitosan oligosaccharides. In addition, the PACOs pretreatment significantly reduced lactate dehydrogenase release and reactive oxygen species production. It also attenuated the loss of mitochondrial membrane potential. Further studies indicated that the PACOs inhibited glutamate-induced cell death by preventing apoptosis through depressing the elevation of Bax/Bcl-2 ratio and caspase-3 activation. These results suggest that PACOs might be promising antagonists against glutamate-induced neural cell death

    The Inhibitory Effect of Propylene Glycol Alginate Sodium Sulfate on Fibroblast Growth Factor 2-Mediated Angiogenesis and Invasion in Murine Melanoma B16-F10 Cells In Vitro

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    Melanoma is one of the most malignant and aggressive types of cancer worldwide. Fibroblast growth factor 2 (FGF2) is one of the critical regulators of melanoma angiogenesis and metastasis; thus, it might be an effective anti-cancer strategy to explore FGF2-targeting drug candidates from existing drugs. In this study, we evaluate the effect of the marine drug propylene glycol alginate sodium sulfate (PSS) on FGF2-mediated angiogenesis and invasion. The data shows that FGF2 selectively bound to PSS with high affinity. PSS inhibited FGF2-mediated angiogenesis in a rat aortic ring model and suppressed FGF2-mediated invasion, but not the migration of murine melanoma B16-F10 cells. The further mechanism study indicates that PSS decreased the expression of activated matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9), and also suppressed their activity. In addition, PSS was found to decrease the level of Vimentin in B16-F10 cells, which is known to participate in the epithelial&#8722;mesenchymal transition. Notably, PSS did not elicit any changes in cancer cell viability. Based on the results above, we conclude that PSS might be a potential drug to regulate the tumor microenvironment in order to facilitate the recovery of melanoma patients
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