350 research outputs found

    A planar 3-DOF nanopositioning platform with large magnification

    Get PDF
    AbstractPiezo-actuated flexure-based precision positioning platforms have been widely used in micro/nano manipulation. A conventional major challenge is the trade-off between high rigidity, large magnification, high-precision tracking, and high-accuracy positioning. A compact planar three-degrees-of-freedom (3-DOF) nanopositioning platform is described in which three two-level lever amplifiers are arranged symmetrically to achieve large magnification. The parallel-kinematic configuration with optimised sizes increases the rigidity. Displacement loss models (DLM) are proposed for the external preload port of the actuator, the input port of the platform and the flexible lever mechanism. The kinematic and dynamic modelling accuracies are improved by the compensation afforded by the three DLMs. Experimental results validate the proposed design and modelling methods. The proposed platform possesses high rigidity, large magnification, high-precision circle tracking and high-accuracy positioning

    Simultaneous profiling of transcriptome and DNA methylome from a single cell.

    Get PDF
    BackgroundSingle-cell transcriptome and single-cell methylome technologies have become powerful tools to study RNA and DNA methylation profiles of single cells at a genome-wide scale. A major challenge has been to understand the direct correlation of DNA methylation and gene expression within single-cells. Due to large cell-to-cell variability and the lack of direct measurements of transcriptome and methylome of the same cell, the association is still unclear.ResultsHere, we describe a novel method (scMT-seq) that simultaneously profiles both DNA methylome and transcriptome from the same cell. In sensory neurons, we consistently identify transcriptome and methylome heterogeneity among single cells but the majority of the expression variance is not explained by proximal promoter methylation, with the exception of genes that do not contain CpG islands. By contrast, gene body methylation is positively associated with gene expression for only those genes that contain a CpG island promoter. Furthermore, using single nucleotide polymorphism patterns from our hybrid mouse model, we also find positive correlation of allelic gene body methylation with allelic expression.ConclusionsOur method can be used to detect transcriptome, methylome, and single nucleotide polymorphism information within single cells to dissect the mechanisms of epigenetic gene regulation

    Idiopathic desmoid-type fibromatosis of the pancreatic head: case report and literature review

    Get PDF
    Desmoid-type fibromatosis (DTF) is an uncommon nonmetastatic fibrous neoplasm. Sporadic intraperitoneal DTF is rarely described in current literature. We herein report a case of DTF of unknown cause involving the pancreatic head. A 41-year-old man presented with recurrent epigastric pain and weight loss. An abdominal computed tomography scan showed a well-delineated solid cystic mass inside the pancreatic head. Pylorus-preserving pancreaticoduodenectomy was performed due to the patientā€™s debilitating symptoms and suspected malignancy. The pathological examination revealed massive fibroblastic proliferation arising from the musculoaponeurotic tissues, consistent with a diagnosis of DTF. Immunohistochemical phenotyping determined positive immunoreactivity to vimentin and Ī²-catenin, but negative immunoreactivity to smooth muscle actin, CD117, CD34, or S-100, confirming the diagnosis of DTF. No local recurrence or distant metastasis was found during a 24-month follow-up. Radical resection is recommended as first-line treatment for pancreatic DTF. Long-term follow-up studies are required to establish the prognosis of pancreatic DTF

    An Intelligent Secure Adversarial Examples Detection Scheme in Heterogeneous Complex Environments

    Get PDF
    Funding Information: Funding Statement: This work was supported in part by the Natural Science Foundation of Hunan Province under Grant Nos. 2023JJ30316 and 2022JJ2029, in part by a project supported by Scientific Research Fund of Hunan Provincial Education Department under Grant No. 22A0686, and in part by the National Natural Science Foundation of China under Grant No. 62172058. This work was also funded by the Researchers Supporting Project (No. RSP2023R102) King Saud University, Riyadh, Saudi Arabia.Peer reviewedPublisher PD

    Offset Optimization Based on Queue Length Constraint for Saturated Arterial Intersections

    Get PDF
    Offset optimization is of critical importance to the traffic control system, especially when spillovers appear. In order to avoid vehicle queue spillovers, an arterial offset optimization model was presented in saturated arterial intersections based on minimizing the queue length over the whole duration of the saturated traffic environment. The paper uses the shockwave theory to analyze the queue evolution process of the intersection approach under the saturated traffic environment. Then through establishing and analyzing a function relationship between offset and the maximum queue length per cycle, a mapping model of offset and maximum queue length was established in the saturated condition. The validity and sensitivity of this model were tested by the VISSIM simulation environment. Finally, results showed that when volumes ratios are 0.525ā€“0.6, adjusting offset reasonably under the saturated condition could decrease the queue length and effectively improve the vehicle operating efficiency

    A homoharringtonine-based induction regimen for the treatment of elderly patients with acute myeloid leukemia: a single center experience from China

    Get PDF
    <p>Abstract</p> <p>Background and purpose</p> <p>The response to remission induction in elderly patients with acute myeloid leukemia (AML) remains poor. The purpose of this paper is to evaluate the efficacy and toxicity of a plant alkaloid, homoharringtonine, in combination with cytarabine as an induction therapy for AML in elderly patients (ā‰„60 years).</p> <p>Results</p> <p>Twenty-three patients were treated with the HA regimen consisting of homoharringtonine (2 mg/m<sup>2</sup>/day for 7 days) and cytarabine (Ara-C, 100 mg/m<sup>2</sup>/day for 7 days). The overall response rate was 56.5% with complete remission (CR) rate of 39.1% and partial remission of 17.4%. There was no early death in this cohort of patients. The estimated median overall survival (OS) time of all patients was (12.0 Ā± 3.0) months. The estimated OS time of the CR patients was 15 months. The estimated one-year OS rate of all patients treated with HA protocol was (49.3 Ā± 13.5) %. The estimated one-year OS rate of the CR patients was (62.5 Ā± 17.1) %.</p> <p>Conclusion</p> <p>HA is a suitable induction regimen for elderly patients with AML, with relatively low toxicity and reasonable response rate.</p
    • ā€¦
    corecore