29 research outputs found

    Coarse-to-Fine Contrastive Learning on Graphs

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    Inspired by the impressive success of contrastive learning (CL), a variety of graph augmentation strategies have been employed to learn node representations in a self-supervised manner. Existing methods construct the contrastive samples by adding perturbations to the graph structure or node attributes. Although impressive results are achieved, it is rather blind to the wealth of prior information assumed: with the increase of the perturbation degree applied on the original graph, 1) the similarity between the original graph and the generated augmented graph gradually decreases; 2) the discrimination between all nodes within each augmented view gradually increases. In this paper, we argue that both such prior information can be incorporated (differently) into the contrastive learning paradigm following our general ranking framework. In particular, we first interpret CL as a special case of learning to rank (L2R), which inspires us to leverage the ranking order among positive augmented views. Meanwhile, we introduce a self-ranking paradigm to ensure that the discriminative information among different nodes can be maintained and also be less altered to the perturbations of different degrees. Experiment results on various benchmark datasets verify the effectiveness of our algorithm compared with the supervised and unsupervised models

    The Protective Effects of Trypsin Inhibitor on Hepatic Ischemia-Reperfusion Injury and Liver Graft Survival

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    The aim of this study was to explore the protective effects of ulinastatin (urinary trypsin inhibitor, UTI) on liver ischemia-reperfusion injury (IRI) and graft survival. We employed mouse liver cold IRI and orthotopic liver transplantation (OLTx) models. UTI was added to lactated Ringer’s (LR) solution for liver perfusion and preservation in vitro or combined with UTI injection intraperitoneally to the liver graft recipient. Our results indicated that UTI supplementation protected the liver from cold IRI in a dose-dependent manner and prolonged liver graft survival from extended cold preserved liver donors significantly. The underlying mechanism of UTI on liver IRI may be mediated by inhibition of proinflammatory cytokine release, increasing the expression of the antiapoptotic gene Bcl-2 and decreasing the expression of the proapoptosis genes of Caspase-3 and Bax, and further protects hepatocytes from apoptotic death and improves liver function

    Weight changes from early to middle adulthood and cardiometabolic multimorbidity later in life among middle-aged and older adults: a retrospective cohort study from the NHANES 1999-2018

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    BackgroundWeight gain in adulthood can influence the development of diabetes and cardiovascular diseases. It is speculated that weight gain is related to cardiometabolic multimorbility (CMM). This study was designed to examine the relationships between weight changes from early to middle adulthood and the risk of CMM.MethodsData of the National Health and Nutrition Examination Survey (NHANES) 1999-2018 cycles were analyzed in the present study. Weights at age 25 years and 10 years before recruitment were self-reported and were used to define five weight change patterns including stable normal, maximum overweight, obesity to non-obesity, non-obesity to obesity, and stable obesity patterns. Meanwhile, absolute weight changes were classified into five groups: weight loss≥ 2.5 kg, weight change within 2.5 kg, 2.5 kg≤ weight gain < 10.0 kg, 10.0 kg≤ weight gain < 20.0 kg, and weight gain≥ 20.0 kg. CMM was defined as the coexistence of two or three of diabetes, coronary heart disease (CHD), and stroke.ResultsA total of 25,994 participants were included. Across adulthood, compared to stable normal weight, maximal overweight, obesity to non-obesity, non-obesity to obesity, and stable obesity were consistently associated with increased risks of diabetes, CHD, and CMM. For instance, stable obesity was respectively related to 358.0% (HR: 4.58, 95% CI: 4.57, 4.58), 88.0% (HR: 1.88, 95% CI: 1.88, 1.88), and 292.0% (HR: 3.92, 95% CI: 3.91, 3.92) higher risks of diabetes, CHD, and CMM. Meanwhile, any account of weight loss and gain was linked to higher risks of diabetes, CHD, and CMM than weight change within 2.5 kg. However, participants with maximum overweight had a decreased incidence of stroke (HR: 0.85, 95% CI: 0.85, 0.86), and weight loss ≥ 2.5 kg and weight gain ≥ 2.5 and <20 kg were also related to a lower risk of stroke. J-shaped or U-shaped associations of absolute weight changes with the risks of diabetes, CHD, and CMM were observed.ConclusionsMaintaining a stable normal weight can benefit more from the prevention of diabetes, CHD, and CMM. Both weight gain and loss across adulthood were accompanied by increased risks of diabetes, CHD, and CMM

    Tunable electromagnetically induced transparent window of terahertz metamaterials and Its sensing performance

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    The electromagnetically induced transparency effect of terahertz metamaterials exhibits excellent modulation and sensing properties, and it is critical to investigate the modulation effect of the transparent window by optimizing structural parameters. In this work, a unilateral symmetrical metamaterial structure based on the cut-wire resonator and the U-shaped split ring resonator is demonstrated to achieve electromagnetically induced transparency-like (EIT-like) effect. Based on the symmetrical structure, by changing the structural parameters of the split ring, an asymmetric structure metamaterial is also studied to obtain better tuning and sensing characteristics. The parameters for controlling the transparent window of the metamaterial are investigated in both passive and active modulation modes. In addition, the metamaterial structure based on the cut-wire resonator, unilateral symmetric and asymmetric configurations are investigated for high performance refractive index sensing purposes, and it is found that the first two metamaterial structures can achieve sensitivity responses of 63.6 GHz/RIU and 84.4 GHz/RIU, respectively, while the asymmetric metamaterial is up to 102.3 GHz/RIU. The high sensitivity frequency response of the proposed metamaterial structures makes them good candidates for various chemical and biomedical sensing applications

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    The chloroplast genome of aromatic plants Cinnamomum burmanni (Lauraceae)

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    Cinnamomum burmanni (Nees et T. Nees) Blume is a valuable aromatic timber tree of the genus Cinnamomum Tree in the family Lauraceae. To better determine its phylogenetic location with respect to the other Cinnamomum species, the complete chloroplast genome of C. burmanni was sequenced. The total chloroplast genome size is 152,775 bp, consisting of a pair of inverted repeats (IRa/b) with a length of 20,092 bp separated by a large single-copy region (LSC) and a small single-copy region (SSC) which are 93,687 and 18,903 bp, respectively. The overall GC content of the cp genome is 39.1%. Further, maximum-likelihood phylogenetic analysis with K3Pu + F+I model was performed using eleven complete plastomes of the Lauraceae, which revealed that C. burmanni is closely related to C. verum

    Insight into the role of α-arabinofuranosidase in biomass hydrolysis: cellulose digestibility and inhibition by xylooligomers

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    Abstract Background α-l-Arabinofuranosidase (ARA), a debranching enzyme that can remove arabinose substituents from arabinoxylan and arabinoxylooligomers (AXOS), promotes the hydrolysis of the arabinoxylan fraction of biomass; however, the impact of ARA on the overall digestibility of cellulose is controversial. In this study, we investigated the effects of the addition of ARA on cellulase hydrolytic action. Results We found that approximately 15% of the xylan was converted into AXOS during the hydrolysis of aqueous ammonia-pretreated corn stover and that this AXOS fraction was approximately 12% substituted with arabinose. The addition of ARA removes a portion of the arabinose decoration, but the resulting less-substituted AXOS inhibited cellulase action much more effectively; showing an increase of 45.7%. Kinetic experiments revealed that AXOS with a lower degree of arabinose substitution showed stronger affinity for the active site of cellobiohydrolase, which could be the mechanism of increased inhibition. Conclusions Our findings strongly suggest that the ratio of ARA and other xylanases should be carefully selected to avoid the strong inhibition caused by the less-substituted AXOS during the hydrolysis of arabinoxylan-containing biomass. This study advances our understanding of the inhibitory mechanism of xylooligomers and provides critical new insights into the relationship of ARA addition and cellulose digestibility

    The complete chloroplast genome sequence of Eriobotrya fragrans

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    Eriobotrya fragrans Champion ex Bentham is a potential medicinal plant of the genus Eriobotrya Lindl in the family Rosaceae. To better determine its phylogenetic location with respect to the other Rosaceae species, the complete chloroplast genome of E. fragrans was sequenced. The whole E. fragrans chloroplast genome is 159,286 bp in length, consisting of a pair of inverted repeat (IR) regions of 26,343 bp, one large single-copy (LSC) region of 87,301 bp, and one small single-copy (SSC) region of 19,299 bp. The overall GC content of the whole chloroplast genome is 36.7%. Further, phylogenetic analysis using maximum likelihood with TVM + F+R2 model strongly supports the relationship: sisterhood of E. fragrans and E. japonica, followed by three species of Pyrus L

    The complete plastome sequence of Illigera grandiflora

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    Illigera grandiflora, a kind of traditional medicinal liana, belongs to the Illigera Blume of the Hernandiaceae. In this study, we reported the characteristics of complete plastome for I. grandiflora. Its total plastome was 156,138 bp in length, comprising a large single-copy region(LSC) of 84,931 bp, a small single-copy region (SSC) of 18,544 bp, and a pair of inverted repeat (IR) regions of 26,549 bp. The overall GC content was 39.16% (LSC, 37.77%; SSC, 33.89%; IR, 43.21%). The plastome encoded 134 genes, including 83 protein-coding genes, 42 transfer RNA genes, and 10 ribosomal RNA genes. The relationships in our phylogeny showed that the two Illigera species are located in the same clade, with Hernandia nymphaeifolia being the next sister group, followed by Wilkiea huegeliana

    The complete plastome sequence of a subtropical tree Pyrus betulaefolia (Rosaceae)

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    The genus Pyrus, comprising several popular fruit crops worldwide, includes over 30 tree species. Here we determined the complete plastid genome sequence of Pyrus betulaefolia. The plastome consists of 160,184 bp, including a pair of inverted repeats (IRs) with a length of 26,384 bp separated by a large single-copy region (LSC) and a small single-copy region (SSC) of 88,121 bp and 19,295 bp, respectively. Further phylogenetic analyze was conducted using 11 complete plastid genomes of Rosaceae with KVM + F + I model, which supports Pyrus betulaefolia as a sister to all other eight Pyrus taxa with published plastomes
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