350 research outputs found
SWOT ANALYSIS - CHINESE PETROLEUM
This article was written in early December 2013,combined with the historical development andthe latest data on the Chinese Petroleum carried SWOT- analysis. This paper discusses corporate resources, cost, management and external factorssuch as the political environment and the marketsupply and demand, conducted a comprehensiveand profound analysis
Radiofrequency ablation can reverse the structural remodeling caused by frequent premature ventricular contractions originating from the right ventricular outflow tract even in a normal heart
OBJECTIVE: The aim of this study was to evaluate whether frequent premature ventricular contractions originating from the right ventricular outflow tract remodel the cardiac structure and function in patients with a “seemingly normal heart” and whether radiofrequency ablation can reverse this remodeling. METHODS: Sixty-eight patients with idiopathic frequent premature ventricular contractions originating from the right ventricular outflow tract and normal heart structure and function were enrolled in this study. The patients were divided into three groups according to the therapeutic method: radiofrequency ablation group (24 cases), anti-arrhythmia drug group (26 cases), and control group (18 cases without any treatment). Clinical Registration number: ChiCTR-ONRC-12002834 RESULTS: The basic patient characteristics were comparable between the three groups, except for the premature ventricular contraction rate, which was significantly lower in the control group. After six months of follow up, the premature ventricular contraction rate was significantly reduced in the radiofrequency ablation group, which was accompanied by a significant decrease in the following cardiac cavity inner diameters, as determined by echocardiography: right atrium (33.33±3.78 vs. 30.05±2.60 mm, p = 0.001), right ventricle (23.24±2.40 vs. 21.05±2.16 mm, p = 0.020), and left ventricle (44.76±4.33 vs. 41.71±3.44 mm, p = 0.025). These results were similar in the anti-arrhythmia drug group, although this group exhibited a smaller extent of change (right atrium: 33.94±3.25 vs. 31.27±3.11 mm, p = 0.024; right ventricle: 22.97±3.09 vs. 21.64±2.33 mm, p = 0.049; left ventricle: 45.92±6.38 vs. 43.84±5.67 mm, p = 0.039), but not in the control group (p>;0.05). There was a tendency toward improvement in the cardiac functions in both the radiofrequency ablation and anti-arrhythmia drug groups. However, these differences were not statistically significant (p>;0.05). CONCLUSIONS: These results indicate that radiofrequency ablation can potentially reverse the cardiac remodeling caused by frequent premature ventricular contractions even in structurally normal hearts and that frequent premature ventricular contractions should be abated even in structurally normal hearts
SWOT-АНАЛИЗ КИТАЙСКОЙ НЕФТЯНОЙ КОМПАНИИ
This article was written in early December 2013,combined with the historical development andthe latest data on the Chinese Petroleum carried SWOT- analysis. This paper discusses corporate resources, cost, management and external factorssuch as the political environment and the marketsupply and demand, conducted a comprehensiveand profound analysis.Эта статья была написана в начале декабря 2013 года, осуществляющаяся SWOT-анализ в сочетании с историческим развитием и последним данным на китайский нефтяной. В данной статье обсуждается корпоративные ресурсы, стоимость, управление и внешние факторы, такие как политической среды и рыночного спроса и предложения, провели всесторонний и глубокий анализ
Identification of Hydrolyzable Tannins (Punicalagin, Punicalin and Geraniin) as Novel inhibitors of Hepatitis B Virus Covalently Closed Circular DNA
The development of new agents to target HBV cccDNA is urgently needed because of the limitations of current available drugs for treatment of hepatitis B. By using a cell-based assay in which the production of HBeAg is in a cccDNA-dependent manner, we screened a compound library derived from Chinese herbal remedies for inhibitors against HBV cccDNA. Three hydrolyzable tannins, specifically punicalagin, punicalin and geraniin, emerged as novel anti-HBV agents. These compounds significantly reduced the production of secreted HBeAg and cccDNA in a dose-dependent manner in our assay, without dramatic alteration of viral DNA replication. Furthermore, punicalagin did not affect precore/core promoter activity, pgRNA transcription, core protein expression, or HBsAg secretion. By employing the cell-based cccDNA accumulation and stability assay, we found that these tannins significantly inhibited the establishment of cccDNA and modestly facilitated the degradation of preexisting cccDNA. Collectively, our results suggest that hydrolyzable tannins inhibit HBV cccDNA production via a dual mechanism through preventing the formation of cccDNA and promoting cccDNA decay, although the latter effect is rather minor. These hydrolyzable tannins may serve as lead compounds for the development of new agents to cure HBV infection
The effects of co-colonising ectomycorrhizal fungi on mycorrhizal colonisation and sporocarp formation in Laccaria japonica colonising seedlings of Pinus densiflora
Forest trees are colonised by different species of ectomycorrhizal (ECM) fungi that interact competitively or mutualistically with one another. Most ECM fungi can produce sporocarps. To date, the effects of co-colonising fungal species on sporocarp formation in ECM fungi remain unknown. In this study, we examined host plant growth, mycorrhizal colonisation, and sporocarp formation when roots of Pinus densiflora are colonised by Laccaria japonica and three other ECM fungal species (Cenococcum geophilum, Pisolithus sp., and Suillus luteus). Sporocarp numbers were recorded throughout the experimental period. The biomass, photosynthetic rate, and mycorrhizal colonisation rate of the seedlings were also measured at 45days, 62days, and 1year after seedlings were transplanted. Results indicated that C. geophilum and S. luteus may negatively impact mycorrhizal colonisation and sporocarp formation in L. japonica. Sporocarp formation in L. japonica was positively correlated with conspecific mycorrhizal colonisation but negatively correlated with the biomass of seedlings of P. densiflora. The co-occurring ECM fungi largely competed with L. japonica, resulting in various effects on mycorrhizal colonisation and sporocarp formation in L. japonica. A variety of mechanisms may be involved in the competitive interactions among the different ECM fungal species, including abilities to more rapidly colonise root tips, acquire soil nutrients, or produce antibiotics. These mechanisms need to be confirmed in further studies.Peer reviewe
Acute and subacute toxicity study of Aucklandia lappa Decne seed oil
Purpose: To investigate the acute and subacute toxicity of Aucklandia lappa Decne. seed oil (ALDO) in mice and rats.Methods: A single dose of 10 g ALDO/kg was administered to Kunming mice in an acute oral toxicity experiment. Their weight and feed consumption were recorded for 14 days to observe whether they had symptoms of poisoning and mortality. Sprague-Dawley (SD) rats were administered 0.89, 1.77 and 3.54 g/kg for 28 days, and symptoms of poisoning and mortality were monitored daily. Body weight, feedconsumption, hematology, serum biochemical parameters, relative organ weight, and histopathology of the experimental and control groups were compared.Results: The acute oral toxicity study revealed that there was no significant difference in the macroscopic results, including mortality, feed consumption and weight growth between the group dosed with 10 g ALDO/kg (p > 0.05) and the control group. In the subacute toxicity test, SD rats had a higher weight growth rate and feed utilization after doses of 0.89 g ALDO/kg (p < 0.01). However, compared with the control group (p > 0.05), there was also no significant difference in biochemical and hematological parameters, relative organ weight, or in macroscopic and histological features of both animal types. The electrolyte concentrations of Na and Cl increased at the doses of 1.77 and 3.54 g/kg (p < 0.01).Conclusion: These results suggest that ALDO is relatively safe when administered orally to rats and provide a theoretical basis for the development of new food resources
Past hybridization between two East Asian long-tailed tits (Aegithalos bonvaloti and A. fuliginosus)
Introduction: Incomplete lineage sorting and hybridization are two major nonexclusive causes of haplotype sharing between species. Distinguishing between these two processes is notoriously difficult as they can generate similar genetic signatures. Previous studies revealed that the mitochondrial DNA (mtDNA) differentiation between two East Asian long-tailed tits (Aegithalos bonvaloti and A. fuliginosus) was extremely low, even lower than intraspecific differentiation in some other long-tailed tits. Using a combination of multilocus and coalescent analyses, we explored the causes of the anomalous lack of mtDNA differentiation between the two species.Results: The mtDNA divergence between the two species was shallow, while the nuclear DNA (nuDNA) divergence was considerably deeper. The IMa analyses based on the mtDNA dataset suggested relatively high gene flow from A. fuliginosus to A. bonvaloti, while negligible gene flow in the opposite direction. In contrast to mtDNA, the migration rates at autosomal and Z-linked nuDNA loci were negligible or much lower. The NEWHYBRIDS analysis assigned all individuals except one to pure parental species with high posterior probability. The Bayesian skyline plot showed that both species underwent population expansions during the Last Glacial Maximum (LGM), and the ecological niche modelling suggested that their ranges overlapped more during the LGM than at present.Conclusions: We suggest that historical hybridization, in combination with selective sweep and/or genetic drift might be the main causes of the extremely low mtDNA differentiation between the two species. The hybridization probably occurred mainly between A. fuliginosus females and A. bonvaloti males. The LGM distribution expansion might have facilitated hybridization, while the post-LGM distribution contraction could have facilitated some mtDNA sorting. Ongoing hybridization between the two species might be very limited, but further studies with more samples from the contact zone are needed to test this conclusion
Identification and Function Prediction of Novel MicroRNAs in Laoshan Dairy Goats
MicroRNAs are a class of endogenous small RNAs that play important roles in post-transcriptional gene regulation by directing degradation of mRNAs or facilitating repression of target gene translation. In this study, three small RNA cDNA libraries from the mammary gland tissues of Laoshan dairy goats (Capra hircus) were constructed and sequenced, individually. Through Solexa high-throughput sequencing and bioinformatics analysis, we obtained 50 presumptive novel miRNAs candidates, and 55,448 putative target genes were predicted. GO annotations and KEGG pathway analyses showed the majority of target genes were involved in various biological processes and metabolic pathways. Our results discovered more information about the regulation network between miRNAs and mRNAs and paved a foundation for the molecular genetics of mammary gland development in goats
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