270 research outputs found

    Oxidation Analyses of Massive Air Ingress Accident of HTR-PM

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    The double-ended guillotine break (DEGB) of the horizontal coaxial gas duct accident is a serious air ingress accident of the high temperature gas-cooled reactor pebble-bed module (HTR-PM). Because the graphite is widely used as the structure material and the fuel element matrix of HTR-PM, the oxidation analyses of this severe air ingress accident have got enough attention in the safety analyses of the HTR-PM. The DEGB of the horizontal coaxial gas duct accident is calculated by using the TINTE code in this paper. The results show that the maximum local oxidation of the matrix graphite of spherical fuel elements in the core will firstly reach 3.75⁎104 mol/m3 at about 120 h, which means that only the outer 5 mm fuel-free zone of matrix graphite will be oxidized out. Even at 150 h, the maximum local weight loss ratio of the nuclear grade graphite in the bottom reflectors is only 0.26. Besides, there is enough time to carry out some countermeasures to stop the air ingress during several days. Therefore, the nuclear grade graphite of the bottom reflectors will not be fractured in the DEGB of the horizontal coaxial gas duct accident and the integrity of the HTR-PM can be guaranteed

    LncRNA HCP5 : A Potential Biomarker for Diagnosing Gastric Cancer

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    BackgroundIt has been reported that long non-coding RNAs (lncRNAs) can be regarded as a biomarker and had particular clinical significance for early screening and gastric cancer (GC) diagnosis. Therefore, this study aimed to investigate whether serum HCP5 could be a new diagnostic biomarker.MethodsFiltered out the HCP5 from the GEO database. The specificity of HCP5 was verified by real-time fluorescence quantitative PCR (qRT-PCR), and then the stability of HCP5 was verified by room temperature storage and repeated freeze-thaw experiments. Meanwhile, the accuracy of HCP5 was verified by agarose gel electrophoresis (AGE) and Sanger sequencing. Simultaneously, the expression level of serum HCP5 was detected by qRT-PCR in 98 patients with primary gastric cancer, 21 gastritis patients, 82 healthy donors, and multiple cancer types. Then, the methodology analysis was carried on. Moreover, receiver operating characteristic (ROC) was used to evaluate its diagnostic efficiency.ResultsqRT-PCR method had good repeatability and stability in detecting HCP5. The expression level of HCP5 in the serum of gastric cancer patients was remarkably higher than that of healthy controls, and it could distinguish gastritis patients from healthy donors. Besides, the expression of HCP5 was increased dramatically in MKN-45 and MGC-803. The FISH assay showed that HCP5 was mainly distributed in the cytoplasm of MKN-45 and BGC-823 cells. When HCP5 was combined with existing tumor markers, the diagnostic efficiency of HCP5 was the best, and the combined diagnosis of carcinoembryonic antigen (CEA), carbohydrate antigen199 (CA199), and HCP5 can significantly improve the diagnostic sensitivity. Besides, compared with the expression levels of thyroid cancer (THCA), colorectal cancer (CRC), and breast cancer (BRCA), serum HCP5 in gastric cancer was the most specific. Moreover, the high expression of serum HCP5 was related to differentiation, lymph node metastasis, and nerve invasion. The term of serum HCP5 after the operation was significantly lower than that of patients with primary gastric cancer.ConclusionSerum HCP5 can be used as a potential biomarker of non-invasive fluid biopsy, which had a unique value in the early diagnosis, development, and prognosis of gastric cancer

    The role of evolutionary time, diversification rates and dispersal in determining the global diversity of a large radiation of passerine birds

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    Aim: Variation in species diversity among different geographic areas may result from differences in speciation and extinction rates, immigration and time for diversification. An area with high species diversity may be the result of a high net diversification rate, multiple immigration events from adjacent regions,anda long time available for the accumulation of species (know as the "time-for-speciation effect"). Here, we examine the relative importance of the three aforementionedprocesses in shaping the geographic diversity patterns of a large radiation of passerine birds. Location: Global Time period: Early Miocene to present Major taxa studied: Babblers (Aves: Passeriformes) Methods: Using a comprehensive phylogeny of extant species (~90% sampled) and distributions of the world's babblers, we reconstructed their biogeographic history and analysed the diversification dynamics. We examined how species richness correlates with the timing of regional colonization, the number of immigration events and the rate of speciation within all 13 geographic distribution regions. Results: We found thatbabblers likely originated in the Sino-Himalayan Mountains (SHM) in the early Miocene, suggesting a long time for diversification and species accumulation within the SHM. Regression analyses showed the regional diversity of babblers can be well explained by the timing of the first colonization within of these areas, while differences in rates of speciation or immigration have far weaker effects. Nonetheless, the rapid speciation of Zosteropsduring the Pleistocene has accounted for the increased diversification and accumulation of species in the oceanic islands. Main conclusions: Our results suggest that the global diversity patterns of babblers have predominantly been shaped by the time-for-speciation effect. Our findings also support an origin centred in tropical and subtropical parts of the SHM, with a cradle of recent diversification in the oceanic islands of the Indo-Pacific region, which provides new insights into the generation of global biodiversity hotspots.A near-complete phylogeny of babblers has been reconstructed in BEAST 1.8.4 based on 12 gene loci

    Metformin targets multiple signaling pathways in cancer

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    Abstract Metformin, an inexpensive and well-tolerated oral agent commonly used in the first-line treatment of type 2 diabetes, has become the focus of intense research as a candidate anticancer agent. Here, we discuss the potential of metformin in cancer therapeutics, particularly its functions in multiple signaling pathways, including AMP-activated protein kinase, mammalian target of rapamycin, insulin-like growth factor, c-Jun N-terminal kinase/mitogen-activated protein kinase (p38 MAPK), human epidermal growth factor receptor-2, and nuclear factor kappaB pathways. In addition, cutting-edge targeting of cancer stem cells by metformin is summarized.http://deepblue.lib.umich.edu/bitstream/2027.42/135949/1/40880_2017_Article_184.pd

    CORRELATION BETWEEN LEUKOCYTE TELOMERE LENGTH AND DRUG ELUTING STENT STRUT COVERAGE BY OPTICAL COHERENCE TOMOGRAPHY

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    El cementiri de Sant Andreu fou inaugurat el 1839 i pertanyia a Sant Andreu del Palomar que formava part del Pla de Barcelona. Sembla que fou la primera població del Pla que va disposar de cementiri desprès de la construcció del de Poblenou

    Past hybridization between two East Asian long-tailed tits (Aegithalos bonvaloti and A. fuliginosus)

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    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

    Evolutionary genomics of the pandemic 2009 H1N1 influenza viruses (pH1N 1v)

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    There are ongoing health risks posed by the pandemic 2009 H1N1 influenza viruses. This research provides a detailed phylogenetic analysis in 394 sequences of H1N1 viruses, taken from swine, human and avian sources from 1918 to 2009, to estimate a temporal reconstruction of reassortment history of 2009 H1N1 viruses. H1N1 influenza viruses were first isolated from swine in 1930; in Europe, avian H1N1 viruses were first detected in pigs in 1979. Pigs have been considered a possible “mixing vessel” in which genetic material can be exchanged. There is a potential for novel progeny viruses to arise, to which humans would be susceptible
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