79 research outputs found

    Fast Iterative Graph Computation: A Path Centric Approach

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    Abstract—Large scale graph processing represents an inter-esting challenge due to the lack of locality. This paper presents PathGraph for improving iterative graph computation on graphs with billions of edges. Our system design has three unique features: First, we model a large graph using a collection of tree-based partitions and use an path-centric computation rather than vertex-centric or edge-centric computation. Our parallel computation model significantly improves the memory and disk locality for performing iterative computation algorithms. Second, we design a compact storage that further maximize sequential access and minimize random access on storage media. Third, we implement the path-centric computation model by using a scatter/gather programming model, which parallels the iterative computation at partition tree level and performs sequential updates for vertices in each partition tree. The experimental results show that the path-centric approach outperforms vertex-centric and edge-centric systems on a number of graph algorithms for both in-memory and out-of-core graphs

    Brominated B1-polycyclic aromatic hydrocarbons for the synthesis of deep-red to near-infrared delayed fluorescence emitters

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    This project has received funding from the Leverhulme Trust (Grant RPG-2022-032) and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (Grant Agreement 769599). C.S. thanks the China Scholarship Council (201806890001), and M.I. and E.Z.-C. thank the EPSRC Programme Grant “Boron: Beyond the Reagent” (EP/W007517) for support.Bromo-functionalized B1-polycyclic aromatic hydrocarbons (PAHs) with LUMOs of less than −3.0 eV were synthesized and used in cross-couplings to form donor–acceptor materials. These materials spanned a range of S1 energies, with a number showing thermally activated delayed fluorescence and significant emission in the near-infrared region of the spectrum. These B1-PAHs represent a useful family of acceptors that can be readily synthesized and functionalized.Publisher PDFPeer reviewe

    PO-105 Exercise regulates HMGB1 / TLR4 / NF- κ B pathway by H2S to improve OJ intestinal injury

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    Objective To study the effect of aerobic exercise on the damage of intestinal mucosal barrier function caused by obstructive jaundice(OJ)and to explore its mechanism of action. Methods  50 male KM mice were randomly divided into 5 groups: sham operation group (S), model group (M), exercise group (TM), DL-Propargylglycine + exercise (PT) group and sodium hydrosulfide + exercise (NT) group.In addition to the S group which are in the common bile duct to the abdominal wall hanging 48 hours to build mouse obstructive jaundice model. In the PT group, PAG (40 mg/kg) was intraperitoneally injected 7 days after surgery; NaHS (50 μmol/kg) was intraperitoneally injected in the NT group 7 days after surgery; TM group, NT group and PT group were graded at 0%, and the speed was 10m/min no weight training (30min/day).After 6 weeks, HE staining was used to observe the morphological changes of the intestinal mucosa.Biochemical analysis was used to detect the concentration of hydrogen sulfide (H2S) in blood and ileum, and total bilirubin (TBIL), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) Liver function, diamine oxidase (DAO), D-lactic acid intestinal barrier function biochemical index; qRT-PCR and immunohistochemical staining were used to observe the expression changes of H2S-mediated related channel mRNA and protein(HMGB1, TLR4 and NF-Kbp6)in intestinal tissues. Results HE staining showed that the intestinal mucosa of group M was atrophied and the villus was broken.Compared with M group, the intestinal mucosa arrangement in TM group was relatively regular. Compared with TM group, intestinal mucosa atrophy in PT group, fluff hair loss, sparseness and disorder, partial mucosa The layer was separated from the lamina propria and the gland was severely damaged. The intestinal mucosa of the NT group was relatively regular, and the changes of intestinal mucosa atrophy were restored. Serum test results showed that H2S levels were higher in the TM group than in the M group; compared with the TM group, the PT group decreased and the NT group increased. DAO level: The TM group was lower than the M group; compared with the TM group, the PT group was elevated and the NT group was decreased.  Changes in serum D-lactic acid levels were similar to DAO. The results of qRT-PCR and immunohistochemical staining showed that the expressions of HMGB1, TLR4 and NF-Kbp6 mRNA and protein in the intestinal tissues of mice in TM group were significantly lower than those in M group and PT group, and the mRNA and protein expression levels in NT group were the lowest. Conclusions Aerobic exercise inhibits the HMGB1 / TLR4 / NF-κB signaling pathway through the H2S / CSE system, thereby exerting a protective effect on the intestinal mucosal barrier

    PO-106 Anisochronous aerobic exercise improves glucose and lipid metabolism of obstructive jaundice by activating Akt signaling pathway

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    Objective To observe the effect of moderate intensity and different interval aerobic exercise on hepatic injury and AKT signaling pathway induced by severe obstructive jaundice in mice. Methods 40 male KM mice were randomly divided into 4 groups: sham operation (OJ) group, model (OM) group, 3-week exercise (ST) group and 6-week exercise (SU) group. Mice in OM group, ST group and SU group all adopted the orthotopic hanging choledochotomy method modified by this study group to construct the animal model of obstructive jaundice. The slope of group ST and group SU were 0% and the speed was 10m/min. After the above 6 weeks of intervention, HE staining was used to observe the morphological changes of hepatocytes. Methods of automatic biochemical analyzer test serum total bilirubin (TBIL), alanine aminotransferase (ALT), aspertate aminotransferase (AST), liver function and fasting plasma glucose (GLU), glycosylated hemoglobin (HbA1c), glycosylated serum protein (GSP), total cholesterol (TC), triglyceride (TG) and high-density lipoprotein cholesterol (HDL - C) of sugar, lipid metabolism and biochemical indexes such as detection; Immunohistochemical staining and qrt-pcr technology were used to observe the expression changes of AKT related molecules such as SREBP-1c, LDL-C, gsk-3β, GCK and G6Pase in liver tissues. Results HE staining showed that the liver cell cords of the normal group were orderly. In the model group, the hepatocytes of the rats were fibrosed in large amounts, which showed degeneration, necrosis and even disordered structure of hepatocytes. In the 3-week exercise group, a small number of hepatic cells were found with patchy necrosis, hepatic lobule structure was changed, and hepatic cords were not well arranged. There was no obvious tissue necrosis in the 6-week exercise group, the hepatic lobule structure was basically normal, and the liver cord was arranged in order. Serological results showed that the levels of TG, TC, LDL-C, HDL - C and GLU in the 6-week exercise group were significantly lower than those in the model group (P < 0.01), and the levels of TG and TC in the 3-week group were also significantly decreased (P < 0.05). In liver tissues, the mRNA and protein expression of related molecules of AKT pathway such as SREBP-1c, LDL-C, gsk-3β, GCK and G6Pase were significantly decreased.  Conclusions Moderate intensity aerobic exercise can regulate glucose and lipid metabolism in mice with severe liver injury caused by obstructive jaundice. The underlying mechanism may be related to regulating the AKT pathway

    The synthesis of brominated-boron-doped PAHs by alkyne 1,1-bromoboration: mechanistic and functionalisation studies

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    The research leading to these results has received funding from the European Research Council under the Horizon 2020 Research and Innovation Program (Grant no. 769599), the Leverhulme Trust (RPG-2014-340) and the EPSRC (EP/P010482/1). C. Si thanks the China Scholarship Council (201806890001).The synthesis of a range of brominated-Bn-containing (n = 1, 2) polycyclic aromatic hydrocarbons (PAHs) is achieved simply by reacting BBr3 with appropriately substituted alkynes via a bromoboration/electrophilic C-H borylation sequence. The brominated-Bn-PAHs were isolated as either the borinic acid or B-mesityl-protected derivatives, with the latter having extremely deep LUMOs for the B2-doped PAHs (with one example having a reduction potential of E1/2 = -0.96 V versus Fc+/Fc, Fc = ferrocene). Mechanistic studies revealed the reaction sequence proceeds by initial alkyne 1,1-bromoboration. 1,1-bromoboration also was applied to access a number of unprecedented 1-bromo-2,2-diaryl substituted vinylboronate esters direct from internal alkynes. Bromoboration/C-H borylation installs useful C-Br units onto the Bn-PAHs, which were utilised in Negishi coupling reactions, including for the installation of two triarylamine donor (D) groups onto a B2-PAH. The resultant D-A-D molecule has a low optical gap with an absorption onset at 750 nm and emission centered at 810 nm in the solid state.Publisher PDFPeer reviewe

    Clinical relevance of molecular testing methods in the diagnosis and guidance of therapy in patients with staphylococcal empyema: a systematic review and meta-analysis

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    BackgroundEfficient detection tools for determining staphylococcal pleural infection are critical for its eradication. The objective of this meta-analysis was to assess the diagnostic utility of nucleic acid amplification tests (NAAT) in suspected empyema cases to identify staphylococcal strains and avoid unnecessary empiric methicillin-resistant Staphylococcus aureus (MRSA) therapy.MethodsFrom inception to July 24, 2021, relevant records were retrieved from PubMed, Embase, Scopus, Web of Science, and the Cochrane Library. The quality of studies was determined using the QUADAS-2 tool. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and hierarchical summary receiver operating characteristic (HSROC) curve for NAAT’s diagnostic performance were evaluated using an HSROC model.ResultsEight studies comprising 424 samples evaluated NAAT accuracy for Staphylococcus aureus (SA) identification, while four studies comprising 317 samples evaluated methicillin-resistant Staphylococcus aureus (MRSA) identification. The pooled NAAT summary estimates for detection of both SA (sensitivity: 0.35 (95% CI 0.19–0.55), specificity: 0.95 (95% CI 0.92–0.97), PLR: 7.92 (95% CI 4.98–12.59), NLR: 0.44 (95% CI 0.14–1.46), and DOR: 24.0 (95% CI 6.59–87.61) ) and MRSA (sensitivity: 0.45 (95% CI 0.15–0.78), specificity: 0.93 (95% CI 0.89–0.95), PLR: 10.06 (95% CI 1.49–67.69), NLR: 0.69 (95% CI 0.41–1.15), and DOR: 27.18 (95% CI 2.97–248.6) ) were comparable. The I2 statistical scores for MRSA and SA identification sensitivity were 13.7% and 74.9%, respectively, indicating mild to substantial heterogeneity. PCR was frequently used among NAA tests, and its diagnostic accuracy coincided well with the overall summary estimates. A meta-regression and subgroup analysis of country, setting, study design, patient selection, and sample condition could not explain the heterogeneity (meta-regression P = 0.66, P = 0.46, P = 0.98, P = 0.68, and P = 0.79, respectively) in diagnostic effectiveness.ConclusionsOur study suggested that the diagnostic accuracy of NAA tests is currently inadequate to substitute culture as a principal screening test. NAAT could be used in conjunction with microbiological culture due to the advantage of faster results and in situations where culture tests are not doable

    Anthropogenic Aerosols Cause Recent Pronounced Weakening of Asian Summer Monsoon Relative to Last Four Centuries

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    The Asian Summer Monsoon (ASM) affects ecosystems, biodiversity, and food security of billions of people. In recent decades, ASM strength (as represented by precipitation) has been decreasing, but instrumental measurements span only a short period of time. The initiation and the dynamics of the recent trend are unclear. Here for the first time, we use an ensemble of 10 tree ring-width chronologies from the west-central margin of ASM to reconstruct detail of ASM variability back to 1566 CE. The reconstruction captures weak/strong ASM events and also reflects major locust plagues. Notably, we found an unprecedented 80-year trend of decreasing ASM strength within the context of the 448-year reconstruction, which is contrary to what is expected from greenhouse warming. Our coupled climate model shows that increasing anthropogenic sulfate aerosol emissions over the Northern Hemisphere could be the dominant factor contributing to the ASM decrease. Plan Language Summary Monsoonal rainfall has a certain influence on agriculture and industry in the regions of Asian Summer Monsoon (ASM). An understanding of the spatial-temporal variability of the ASM and the associated dynamics is vital for terrestrial ecosystems, water resources, forests, and landscapes. We have developed a 448-year ASM reconstruction back to 1566 CE using 10 tree ring chronologies from the margin region of ASM. We find that historical severe droughts and locust plague disasters during weak ASM events. The recent decreasing ASM trend persisting for over 80 years is unprecedented over the past 448 years. Coupled climate models show that increasing anthropogenic aerosol emissions are the dominant underlying factor. Our aim is that the time series will find a wide range of utility for understanding past climate variability and for predicting future climate change.National Natural Science Foundation of China [41630531]; National Research Program for Key Issues in Air Pollution Control [DQGG0104]; Chinese Academy of Sciences [QYZDJ-SSW-DQC021, XDPB05, GJHZ1777]; Institute of Earth Environment, Chinese Academy of Sciences; State Key Laboratory of Loess and Quaternary Geology6 month embargo; first published: 09 April 2019This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

    DICCCOL: Dense Individualized and Common Connectivity-Based Cortical Landmarks

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    Is there a common structural and functional cortical architecture that can be quantitatively encoded and precisely reproduced across individuals and populations? This question is still largely unanswered due to the vast complexity, variability, and nonlinearity of the cerebral cortex. Here, we hypothesize that the common cortical architecture can be effectively represented by group-wise consistent structural fiber connections and take a novel data-driven approach to explore the cortical architecture. We report a dense and consistent map of 358 cortical landmarks, named Dense Individualized and Common Connectivity–based Cortical Landmarks (DICCCOLs). Each DICCCOL is defined by group-wise consistent white-matter fiber connection patterns derived from diffusion tensor imaging (DTI) data. Our results have shown that these 358 landmarks are remarkably reproducible over more than one hundred human brains and possess accurate intrinsically established structural and functional cross-subject correspondences validated by large-scale functional magnetic resonance imaging data. In particular, these 358 cortical landmarks can be accurately and efficiently predicted in a new single brain with DTI data. Thus, this set of 358 DICCCOL landmarks comprehensively encodes the common structural and functional cortical architectures, providing opportunities for many applications in brain science including mapping human brain connectomes, as demonstrated in this work

    The Genomes of Oryza sativa: A History of Duplications

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    We report improved whole-genome shotgun sequences for the genomes of indica and japonica rice, both with multimegabase contiguity, or almost 1,000-fold improvement over the drafts of 2002. Tested against a nonredundant collection of 19,079 full-length cDNAs, 97.7% of the genes are aligned, without fragmentation, to the mapped super-scaffolds of one or the other genome. We introduce a gene identification procedure for plants that does not rely on similarity to known genes to remove erroneous predictions resulting from transposable elements. Using the available EST data to adjust for residual errors in the predictions, the estimated gene count is at least 38,000–40,000. Only 2%–3% of the genes are unique to any one subspecies, comparable to the amount of sequence that might still be missing. Despite this lack of variation in gene content, there is enormous variation in the intergenic regions. At least a quarter of the two sequences could not be aligned, and where they could be aligned, single nucleotide polymorphism (SNP) rates varied from as little as 3.0 SNP/kb in the coding regions to 27.6 SNP/kb in the transposable elements. A more inclusive new approach for analyzing duplication history is introduced here. It reveals an ancient whole-genome duplication, a recent segmental duplication on Chromosomes 11 and 12, and massive ongoing individual gene duplications. We find 18 distinct pairs of duplicated segments that cover 65.7% of the genome; 17 of these pairs date back to a common time before the divergence of the grasses. More important, ongoing individual gene duplications provide a never-ending source of raw material for gene genesis and are major contributors to the differences between members of the grass family
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