57 research outputs found

    Web-based Multi-dimensional Medical Image Collaborative Annotation System

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    Medical image annotation is playing an increasingly important role in clinical diagnosis and medical research. Existing medical image annotation is faced with many demands and challenges. 1) The emergence and sharp increasing speed of multi-dimensional medical images. 2) Image annotation includes not only text annotation, but also graphical annotation, clinical diagnostic information and image content features information. 3) Uneven distribution of medical resources, which makes difficult to aggregate group intelligence from a much larger scale of distributed experts. Most of the present study is texted based within hospitals on single images annotation. It is difficult to organize and manage unstructured medi-cal image annotation and collaborative sharing information. This paper dedicated to the research on collaborative web-based multi-dimensional medical image an-notation and retrieval in order to address these problems, overcome the shortcom-ing of traditional thin client and facilitate medical experts in different locations to exchange views and comments,. It proposed 1) a system architecture that provides authoring, storing, querying, and exchanging of annotations, and supports web-based collaboration. 2) 2D multi-frame and 3D medical image collaborative anno-tation data model. 3) Collaborative annotation mechanisms

    Synthesis and Properties of La1βˆ’x_{1-x}Srx_xNiO3_3 and La1βˆ’x_{1-x}Srx_xNiO2_2

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    Superconductivity has been realized in films of La1βˆ’x_{1-x}Srx_xNiO2_2. Here we report synthesis and characterization of polycrystalline samples of La1βˆ’x_{1-x}Srx_xNiO3_3 and La1βˆ’x_{1-x}Srx_xNiO2_2 (0≀x≀0.20\le x\le 0.2). Magnetization and resistivity measurements reveal that La1βˆ’x_{1-x}Srx_xNiO3_3 are paramagnetic metals and La1βˆ’x_{1-x}Srx_xNiO2_2 exhibit insulating behavior. Superconductivity is not detected in bulk samples of La1βˆ’x_{1-x}Srx_xNiO2_2. The absence of superconductivity in bulk La1βˆ’x_{1-x}Srx_xNiO2_2 may be due to the generation of hydroxide during reduction or a small amount of nickel impurities. The effect of interface in films of La1βˆ’x_{1-x}Srx_xNiO2_2 may also play a role for superconductivity.Comment: 9 pages, 4 figure

    Spin-Labeling Magnetic Resonance Imaging Detects Increased Myocardial Blood Flow After Endothelial Cell Transplantation in the Infarcted Heart

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    Background We quantified absolute myocardial blood flow (MBF) using a spin-labeling MRI (SL-MRI) method after transplantation of endothelial cells (ECs) into the infarcted heart. Our aims were to study the temporal changes in MBF in response to EC transplantation and to compare regional MBF with contractile function (wall motion) and microvascular density. Methods and Result We first validated the SL-MRI method with the standard microsphere technique in normal rats. We then induced myocardial infarction in athymic rats and injected 5 million ECs (human umbilical vein endothelial cells) suspended in Matrigel or Matrigel alone (vehicle) along the border of the blanched infarcted area. At 2 weeks after myocardial infarction, MBF averaged over the entire slice (P=0.038) and in the infarcted region (P=0.0086) was significantly higher in EC versus vehicle group; the greater MBF was accompanied by an increase of microvasculature density in the infarcted region (P=0.0105 versus vehicle). At 4 weeks after myocardial infarction, MBF in the remote region was significantly elevated in EC-treated hearts (P=0.0277); this was accompanied by increased wall motion in this region assessed by circumferential strains (P=0.0075). Intraclass correlation coefficients and Bland-Altman plot revealed a good reproducibility of the SL-MRI method. Conclusion MBF in free-breathing rats measured by SL-MRI is validated by the standard color microsphere technique. SL-MRI allows quantification of temporal changes of regional MBF in response to EC treatment. The proof-of-principle study indicates that MBF is a unique and sensitive index to evaluate EC-mediated therapy for the infarcted heart

    Rapid and Visual Detection of Monkey B Virus Based on Recombinase Polymerase Amplification

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    Monkey B virus (BV) infection in humans and other macaque species has a mortality rate of approximately 80%. Because BV infects humans through bites, scratches, and other injuries inflicted by macaques, the simple and rapid diagnosis of BV in field laboratories is of great importance to protect veterinarians, laboratory researchers, and support personnels from the threat of infection. Two recombinase polymerase amplification (RPA) assays with a closed vertical flow (VF) visualization strip (RPA-VF-UL27 and RPA-VF-US6) were developed that target two conserved genes combined with a one-off, closed visualization strip device. We compared the sensitivities and specificities of the two assays after optimization of the reaction conditions. The performance of RPA-VF-US6 at room temperature was determined to evaluate its potential in point-of-care (POC) testing. RPA-VF-US6 specifically detected the positive plasmid control (rather than nucleic acids of herpesviruses) with a detection limit of 28 copies, while RPA-VF-UL27 had cross-reactivity with HSV-1, but even 3.4 copies of plasmid standards were readout by this assay. Moreover, RPA-VF-US6 had excellent performance at room temperature (the detection limit was 2,800 plasmid copies), indicating the potential of RPA-VF-US6 in POC testing. We developed two RPA assays for BV visualization diagnosis. RPA-VF-US6 is a simple, rapid, and specific detection method for BV. The entire reaction can be performed at a constant temperature within 30 min, suggesting the potential of RPA-VF-US6 for POC testing in field laboratories without sophisticated instruments

    Tulp1 deficiency causes early-onset retinal degeneration through affecting ciliogenesis and activating ferroptosis in zebrafish

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    Mutations in TUB-like protein 1 (TULP1) are associated with severe early-onset retinal degeneration in humans. However, the pathogenesis remains largely unknown. There are two homologous genes of TULP1 in zebrafish, namely tulp1a and tulp1b. Here, we generated the single knockout (tulp1a(βˆ’/βˆ’) and tulp1b(βˆ’/βˆ’)) and double knockout (tulp1-dKO) models in zebrafish. Knockout of tulp1a resulted in the mislocalization of UV cone opsins and the degeneration of UV cones specifically, while knockout of tulp1b resulted in mislocalization of rod opsins and rod-cone degeneration. In the tulp1-dKO zebrafish, mislocalization of opsins was present in all types of photoreceptors, and severe degeneration was observed at a very early age, mimicking the clinical manifestations of TULP1 patients. Photoreceptor cilium length was significantly reduced in the tulp1-dKO retinas. RNA-seq analysis showed that the expression of tektin2 (tekt2), a ciliary and flagellar microtubule structural component, was downregulated in the tulp1-dKO zebrafish. Dual-luciferase reporter assay suggested that Tulp1a and Tulp1b transcriptionally activate the promoter of tekt2. In addition, ferroptosis might be activated in the tulp1-dKO zebrafish, as suggested by the up-regulation of genes related to the ferroptosis pathway, the shrinkage of mitochondria, reduction or disappearance of mitochondria cristae, and the iron and lipid droplet deposition in the retina of tulp1-dKO zebrafish. In conclusion, our study establishes an appropriate zebrafish model for TULP1-associated retinal degeneration and proposes that loss of TULP1 causes defects in cilia structure and opsin trafficking through the downregulation of tekt2, which further increases the death of photoreceptors via ferroptosis. These findings offer insight into the pathogenesis and clinical treatment of early-onset retinal degeneration

    The splicing factor DHX38 enables retinal development through safeguarding genome integrity

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    DEAH-Box Helicase 38 (DHX38) is a pre-mRNA splicing factor and also a disease-causing gene of autosomal recessive retinitis pigmentosa (arRP). The role of DHX38 in the development and maintenance of the retina remains largely unknown. In this study, by using the dhx38 knockout zebrafish model, wedemonstrated that Dhx38 deficiency causes severe differentiation defects and apoptosis of retinal progenitor cells (RPCs) through disrupted mitosis and increased DNA damage. Furthermore, we found a significant accumulation of R-loops in the dhx38-deficient RPCs and human cell lines. Finally, we found that DNA replication stress is the prerequisite for R-loop-induced DNA damage in the DHX38 knockdown cells. Taken together, our study demonstrates a necessary role of DHX38 in the development of retina and reveals a DHX38/R-loop/replication stress/DNA damage regulatory axis that is relatively independent of the known functions of DHX38 in mitosis control

    Orbital-Dependent Electron Correlation in Double-Layer Nickelate La3Ni2O7

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    The latest discovery of high temperature superconductivity near 80K in La3Ni2O7 under high pressure has attracted much attention. Many proposals are put forth to understand the origin of superconductivity. The determination of electronic structures is a prerequisite to establish theories to understand superconductivity in nickelates but is still lacking. Here we report our direct measurement of the electronic structures of La3Ni2O7 by high-resolution angle-resolved photoemmission spectroscopy. The Fermi surface and band structures of La3Ni2O7 are observed and compared with the band structure calculations. A flat band is formed from the Ni-3dz2 orbitals around the zone corner which is 50meV below the Fermi level. Strong electron correlations are revealed which are orbital- and momentum-dependent. Our observations will provide key information to understand the origin of high temperature superconductivity in La3Ni2O7.Comment: 18 pages, 4 figure

    Noisy smoothing image source identification

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