45 research outputs found

    Uncertainty-Guided Lung Nodule Segmentation with Feature-Aware Attention

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    Since radiologists have different training and clinical experiences, they may provide various segmentation annotations for a lung nodule. Conventional studies choose a single annotation as the learning target by default, but they waste valuable information of consensus or disagreements ingrained in the multiple annotations. This paper proposes an Uncertainty-Guided Segmentation Network (UGS-Net), which learns the rich visual features from the regions that may cause segmentation uncertainty and contributes to a better segmentation result. With an Uncertainty-Aware Module, this network can provide a Multi-Confidence Mask (MCM), pointing out regions with different segmentation uncertainty levels. Moreover, this paper introduces a Feature-Aware Attention Module to enhance the learning of the nodule boundary and density differences. Experimental results show that our method can predict the nodule regions with different uncertainty levels and achieve superior performance in LIDC-IDRI dataset.Comment: 10 pages, 4 figures, 30 reference

    The minimum degree of minimal kk-factor-critical claw-free graphs*

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    A graph GG of order nn is said to be kk-factor-critical for integers 1k<n1\leq k< n, if the removal of any kk vertices results in a graph with a perfect matching. A kk-factor-critical graph is minimal if for every edge, the deletion of it results in a graph that is not kk-factor-critical. In 1998, O. Favaron and M. Shi conjectured that every minimal kk-factor-critical graph has minimum degree k+1k+1. In this paper, we confirm the conjecture for minimal kk-factor-critical claw-free graphs. Moreover, we show that every minimal kk-factor-critical claw-free graph GG has at least k12kV(G)\frac{k-1}{2k}|V(G)| vertices of degree k+1k+1 in the case of (k+1)(k+1)-connected, yielding further evidence for S. Norine and R. Thomas' conjecture on the minimum degree of minimal bricks when k=2k=2.Comment: 17 pages, 12 figure

    Cinnamaldehyde Exerts Its Antifungal Activity by Disrupting the Cell Wall Integrity of Geotrichum citri-aurantii

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    Our previous study showed that cinnamaldehyde (CA) significantly inhibited the mycelial growth of Geotrichum citri-aurantii, one of the main postharvest pathogens in citrus fruits. This study investigated the antifungal mechanism of CA against G. citri-aurantii. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed that CA treatment led to clear morphological changes in the cell walls and membranes of G. citri-aurantii. However, the membrane integrity, total lipids and ergosterol contents were not apparently affected by CA treatment. Notably, the extracellular alkaline phosphatase (AKP) activity was increased after CA treatment, suggesting impairment in cell wall permeability. A weakened fluorescence in the cell wall, a decrease in the chitin contents, and changes of ten genes involved in cell wall integrity were also observed. These results suggested that CA may exhibit its antifungal activity against G. citri-aurantii by interfering the build of cell wall and therefore lead to the damage of cell wall permeability and integrity

    Lysosomal enzyme cathepsin D protects against alpha-synuclein aggregation and toxicity

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    α-synuclein (α-syn) is a main component of Lewy bodies (LB) that occur in many neurodegenerative diseases, including Parkinson's disease (PD), dementia with LB (DLB) and multi-system atrophy. α-syn mutations or amplifications are responsible for a subset of autosomal dominant familial PD cases, and overexpression causes neurodegeneration and motor disturbances in animals. To investigate mechanisms for α-syn accumulation and toxicity, we studied a mouse model of lysosomal enzyme cathepsin D (CD) deficiency, and found extensive accumulation of endogenous α-syn in neurons without overabundance of α-syn mRNA. In addition to impaired macroautophagy, CD deficiency reduced proteasome activity, suggesting an essential role for lysosomal CD function in regulating multiple proteolytic pathways that are important for α-syn metabolism. Conversely, CD overexpression reduces α-syn aggregation and is neuroprotective against α-syn overexpression-induced cell death in vitro. In a C. elegans model, CD deficiency exacerbates α-syn accumulation while its overexpression is protective against α-syn-induced dopaminergic neurodegeneration. Mutated CD with diminished enzymatic activity or overexpression of cathepsins B (CB) or L (CL) is not protective in the worm model, indicating a unique requirement for enzymatically active CD. Our data identify a conserved CD function in α-syn degradation and identify CD as a novel target for LB disease therapeutics

    Availability, cost, and prescription patterns of antihypertensive medications in primary health care in China: a nationwide cross-sectional survey

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    Background: Around 200 million adults in China have hypertension, but few are treated or achieve adequate control of their blood pressure. Available and affordable medications are important for successfully controlling hypertension, but little is known about current patterns of access to, and use of, antihypertensive medications in Chinese primary health care. Methods: We used data from a nationwide cross-sectional survey (the China Patient-Centered Evaluative Assessment of Cardiac Events Million Persons Project primary health care survey), which was undertaken between November, 2016 and May, 2017, to assess the availability, cost, and prescription patterns of 62 antihypertensive medications at primary health-care sites across 31 Chinese provinces. We surveyed 203 community health centres, 401 community health stations, 284 township health centres, and 2474 village clinics to assess variation in availability, cost, and prescription by economic region and type of site. We also assessed the use of high-value medications, defined as guideline-recommended and low-cost. We also examined the association of medication cost with availability and prescription patterns. Findings: Our study sample included 3362 primary health-care sites and around 1 million people (613 638 people at 2758 rural sites and 478 393 people at 604 urban sites). Of the 3362 sites, 8·1% (95% CI 7·2–9·1) stocked no antihypertensive medications and 33·8% (32·2–35·4) stocked all four classes that were routinely used. Village clinics and sites in the western region of China had the lowest availability. Only 32·7% (32·2–33·3) of all sites stocked high-value medications, and few high-value medications were prescribed (11·2% [10·9–11·6] of all prescription records). High-cost medications were more likely to be prescribed than low-cost alternatives. Interpretation: China has marked deficiencies in the availability, cost, and prescription of antihypertensive medications. High-value medications are not preferentially used. Future efforts to reduce the burden of hypertension, particularly through the work of primary health-care providers, will need to improve access to, and use of, antihypertensive medications, paying particular attention to those with high value

    Validation of the Target Protein of Insecticidal Dihydroagarofuran Sesquiterpene Polyesters

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    A series of insecticidal dihydroagarofuran sesquiterpene polyesters were isolated from the root bark of Chinese bittersweet (Celastrus angulatus Max). A previous study indicated that these compounds affect the digestive system of insects, and aminopeptidase N3 and V-ATPase have been identified as the most putative target proteins by affinity chromatography. In this study, the correlation between the affinity of the compounds to subunit H and the insecticidal activity or inhibitory effect on the activity of V-ATPase was analyzed to validate the target protein. Results indicated that the subunit H of V-ATPase was the target protein of the insecticidal compounds. In addition, the possible mechanism of action of the compounds was discussed. The results provide new ideas for developing pesticides acting on V-ATPase of insects

    Subacute‐onset cataract in a 29‐year‐old man with mitochondrial encephalomyopathy: A case report

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    Key Clinical Message This case report aims to emphasize that subacute occurrence of nuclear cataract might be one of the underestimated manifestations of mitochondrial encephalomyopathy, thus periodical ophthalmologic examinations are recommended

    Identification and Characterization of the HD-Zip Gene Family and Dimerization Analysis of HB7 and HB12 in Brassica napus L.

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    Homeodomain-leucine zipper (HD-Zip) genes encode plant-specific transcription factors, which play important roles in plant growth, development, and response to environmental stress. These genes have not been fully studied in allopolyploid Brassica napus, an important kind of oil crop. In this study, 165 HD-Zip genes were identified in B. napus and classified into four subfamilies. If proteins belong to the same subfamily, they exhibit similarities in gene structure, motifs, and domain distribution patterns. BnHD-Zip genes were unevenly distributed in the An and Cn subgenomes. Whole genome triplication (WGT) events may be major mechanisms accounting for this gene family expansion. Orthologous gene analysis showed that the process of this gene family expansion was accompanied by domain loss. We further found three genes homologous to HB7 and three genes homologous to HB12, all induced by PEG, ABA, and NaCl treatment. HB7 could not form homodimers but could form heterodimers with HB12 based on yeast two-hybrid assays. The results of this study provide valuable information for further exploration of the HD-Zip gene family in B. napus
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