139 research outputs found

    COMPATIBILITY EVALUATION OF BZ25-1 CRUDE OILS IN BOHAI BAY, CHINA

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    ABSTRACT BZ25-1 oilfield is located in the southeast of Bohai bay which geographically lies between 119 o 00′to 119 o 15′east longitude and 38 o 10′to 38 o 20′north latitude. It has two oil blocks, including Shahejie (SHJ) waxy oil and Minghuazhen (MHZ) heavy oil, with six wellhead platforms WHPA~WHPF and six submarine pipelines. Therein, the WHPC-WHPB and WHPB-SPM (Single Point Mooring) pipelines transport the mixture of the two produced crude oils. However, the mixing of the two oils will certainly bring out a change in their components and properties, which directly affects the safe operation of the submarine pipelines and offshore production facilities. Therefore, this paper compounds three kinds of MHZ/SHJ mixed oils with blending ratios of 1:1, 3:1 and 9:1, mainly studies how the components, rheological and thermophysical properties of the oil mixtures change with the blending ratio. The major objective of this study is to evaluate the compatibility of the two crude oils and provide a theoretical basis for the production optimization and risk elusion of the oilfield. The results of the study show that the components and properties of SHJ crude oil are quite different from those of MHZ oil, the flow behavior of SHJ oil is more sensitive to temperature. As MHZ oil in the compounds increases, the contents of asphaltene, resin, sulfur and carbon residue will increase except wax contents, their viscosities, densities and flash points will also increase, but their pour points, yield stresses, calorific values and other major thermophysical parameters will decrease. A blending ratio of 2~7:1 for MHZ to SHJ crude oil can be concluded to make the properties of the compounds meet the safe and economic requirements of the subsea pipeline and offshore facility operations and ensure the compatibility of the mixed oils. In actuality, the field operations have confirmed that the recommended blending ratio is reasonable and practicable

    Common promoter variants of the NDUFV2 gene do not confer susceptibility to schizophrenia in Han Chinese

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    <p>Abstract</p> <p>Background</p> <p>The NADH-ubiquinone oxidoreductase flavoprotein gene (<it>NDUFV2</it>), which encodes a 24 kD mitochondrial complex I subunit, has been reported to be positively associated with schizophrenia and bipolar disorder in different populations.</p> <p>Methods</p> <p>We genotyped the promoter variants of this gene (rs6506640 and rs1156044) by direct sequencing in 529 unrelated Han Chinese schizophrenia patients and 505 matched controls. Fisher's Exact test was performed to assess whether these two reported single nucleotide polymorphisms (SNPs) confer susceptibility to schizophrenia in Chinese.</p> <p>Results</p> <p>Allele, genotype and haplotype comparison between the case and control groups showed no statistical significance, suggesting no association between the <it>NDUFV2 </it>gene promoter variants and schizophrenia in Han Chinese.</p> <p>Conclusion</p> <p>The role of NDUFV2 played in schizophrenia needs to be further studied. Different racial background and/or population substructure might account for the inconsistent results between studies.</p

    New Region-Scalable Discriminant and Fitting Energy Functional for Driving Geometric Active Contours in Medical Image Segmentation

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    We propose a novel region-based geometric active contour model that uses region-scalable discriminant and fitting energy functional for handling the intensity inhomogeneity and weak boundary problems in medical image segmentation. The region-scalable discriminant and fitting energy functional is defined to capture the image intensity characteristics in local and global regions for driving the evolution of active contour. The discriminant term in the model aims at separating background and foreground in scalable regions while the fitting term tends to fit the intensity in these regions. This model is then transformed into a variational level set formulation with a level set regularization term for accurate computation. The new model utilizes intensity information in the local and global regions as much as possible; so it not only handles better intensity inhomogeneity, but also allows more robustness to noise and more flexible initialization in comparison to the original global region and regional-scalable based models. Experimental results for synthetic and real medical image segmentation show the advantages of the proposed method in terms of accuracy and robustness

    Three-Dimensional Reconstruction of Thoracic Structures: Based on Chinese Visible Human

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    We managed to establish three-dimensional digitized visible model of human thoracic structures and to provide morphological data for imaging diagnosis and thoracic and cardiovascular surgery. With Photoshop software, the contour line of lungs and mediastinal structures including heart, aorta and its ramus, azygos vein, superior vena cava, inferior vena cava, thymus, esophagus, diaphragm, phrenic nerve, vagus nerve, sympathetic trunk, thoracic vertebrae, sternum, thoracic duct, and so forth were segmented from the Chinese Visible Human (CVH)-1 data set. The contour data set of segmented thoracic structures was imported to Amira software and 3D thorax models were reconstructed via surface rendering and volume rendering. With Amira software, surface rendering reconstructed model of thoracic organs and its volume rendering reconstructed model were 3D reconstructed and can be displayed together clearly and accurately. It provides a learning tool of interpreting human thoracic anatomy and virtual thoracic and cardiovascular surgery for medical students and junior surgeons

    Identification of Dominant Spoilage Bacteria in Chicken Feet with Pickled Peppers and Analysis of Their Spoilage Capacity

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    The dominant spoilage bacteria in chicken feet with pickled peppers were analyzed by high-throughput sequencing technology and isolated by the traditional culture method to evaluate their spoilage capacity by back inoculation. The results showed that the dominant genus identified was Bacillus, and four dominant strains were identified including B. methylotrophicus, B. velezensis, B. subtilis and B. safensis. All these strains were able to produce protease and lipase activity. Among them, B. safensis showed the strongest protease activity (51.19 U/mL), while B. methylotrophicus showed the strongest lipase activity (3.75 U/mL). The pH, total volatile basic nitrogen (TVB-N) content and thiobarbituric acid reactive substances (TBARS) value of the samples inoculated with each of the four Bacillus strains were higher than those of the uninoculated control group, indicating that all four Bacillus strains had spoilage capacity. This study will provided a theoretical basis for preventing and controlling the spoilage of chicken feet with pickled peppers and extending its shelf life

    Interferon Tau Affects Mouse Intestinal Microbiota and Expression of IL-17

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    This study was conducted to explore the effects of interferon tau (IFNT) on the intestinal microbiota and expression of interleukin 17 (IL-17) in the intestine of mice. IFNT supplementation increased microbial diversity in the jejunum and ileum but decreased microbial diversity in the feces. IFNT supplementation influenced the composition of the intestinal microbiota as follows: (1) decreasing the percentage of Firmicutes and increasing Bacteroidetes in the jejunum and ileum; (2) enhancing the percentage of Firmicutes but decreasing Bacteroidetes in the colon and feces; (3) decreasing Lactobacillus in the jejunum and ileum; (4) increasing the percentage of Blautia, Bacteroides, Alloprevotella, and Lactobacillus in the colon; and (5) increasing the percentage of Lactobacillus, Bacteroides, and Allobaculum, while decreasing Blautia in the feces. Also, IFNT supplementation decreased the expression of IL-17 in the intestines of normal mice and of an intestinal pathogen infected mice. In conclusion, IFNT supplementation modulates the intestinal microbiota and intestinal IL-17 expression, indicating the applicability of IFNT to treat the intestinal diseases involving IL-17 expression and microbiota

    PANDORA-seq expands the repertoire of regulatory small RNAs by overcoming RNA modifications

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    Although high-throughput RNA sequencing (RNA-seq) has greatly advanced small non-coding RNA (sncRNA) discovery, the currently widely used complementary DNA library construction protocol generates biased sequencing results. This is partially due to RNA modifications that interfere with adapter ligation and reverse transcription processes, which prevent the detection of sncRNAs bearing these modifications. Here, we present PANDORA-seq (panoramic RNA display by overcoming RNA modification aborted sequencing), employing a combinatorial enzymatic treatment to remove key RNA modifications that block adapter ligation and reverse transcription. PANDORA-seq identified abundant modified sncRNAs—mostly transfer RNA-derived small RNAs (tsRNAs) and ribosomal RNA-derived small RNAs (rsRNAs)—that were previously undetected, exhibiting tissue-specific expression across mouse brain, liver, spleen and sperm, as well as cell-specific expression across embryonic stem cells (ESCs) and HeLa cells. Using PANDORA-seq, we revealed unprecedented landscapes of microRNA, tsRNA and rsRNA dynamics during the generation of induced pluripotent stem cells. Importantly, tsRNAs and rsRNAs that are downregulated during somatic cell reprogramming impact cellular translation in ESCs, suggesting a role in lineage differentiation

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field
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