247 research outputs found

    Detecting Slow Wave Sleep Using a Single EEG Signal Channel

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    Background: In addition to the cost and complexity of processing multiple signal channels, manual sleep staging is also tedious, time consuming, and error-prone. The aim of this paper is to propose an automatic slow wave sleep (SWS) detection method that uses only one channel of the electroencephalography (EEG) signal. New Method: The proposed approach distinguishes itself from previous automatic sleep staging methods by using three specially designed feature groups. The first feature group characterizes the waveform pattern of the EEG signal. The remaining two feature groups are developed to resolve the difficulties caused by interpersonal EEG signal differences. Results and comparison with existing methods: The proposed approach was tested with 1,003 subjects, and the SWS detection results show kappa coefficient at 0.66, an accuracy level of 0.973, a sensitivity score of 0.644 and a positive predictive value of 0.709. By excluding sleep apnea patients and persons whose age is older than 55, the SWS detection results improved to kappa coefficient, 0.76; accuracy, 0.963; sensitivity, 0.758; and positive predictive value, 0.812. Conclusions: With newly developed signal features, this study proposed and tested a single-channel EEG-based SWS detection method. The effectiveness of the proposed approach was demonstrated by applying it to detect the SWS of 1003 subjects. Our test results show that a low SWS ratio and sleep apnea can degrade the performance of SWS detection. The results also show that a large and accurately staged sleep dataset is of great importance when developing automatic sleep staging methods

    Generation of subcycle isolated attosecond pulses by pumping ionizing gating

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    We present a novel approach named as pumping ionizing gating (PIG) for the generation of isolated attosecond pulses (IAPs). In this regime, a short laser is used to ionize a pre-existing gas grating, creating a fast-extending plasma grating(FEPG) having an ionization front propagating with the velocity of light. A low-intensity long counterpropagating pump pulse is then reflected by a very narrow region of the ionization front, only where the Bragg conditions for resonant reflection is satisfied. Consequently, the pump reflection is confined within a sub-cycle region called PIG, and forms a wide-band coherent IAP in combination with the frequency up-conversion effect due to the plasma gradient. This approach results in a new scheme to generate IAPs fromlong picosecond pump pulses. Three-dimensional (3D) simulations show that a 1.6-ps, 1-{\mu}m pump pulse can be used to generate a 330 as laser pulse with a peak intensity approximately 33 times that of the pump and a conversion efficiency of around 0.1%.These results highlight the potential of the PIG method for generating IAPs with high conversion efficiency and peak intensity.Comment: It provides a new way to generate isolated attosecond pulse(IAP) by a picosecond pump, which has a protential to boost the IAP energy to joule leve

    The Manchurian Walnut Genome: Insights into Juglone and Lipid Biosynthesis

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    Background Manchurian walnut (Juglans mandshurica Maxim.) is a tree with multiple industrial uses and medicinal properties in the Juglandaceae family (walnuts and hickories). J. mandshurica produces juglone, which is a toxic allelopathic agent and has potential utilization value. Furthermore, the seed of J. mandshurica is rich in various unsaturated fatty acids and has high nutritive value. Findings Here, we present a high-quality chromosome-scale reference genome assembly and annotation for J. mandshurica (n = 16) with a contig N50 of 21.4 Mb by combining PacBio high-fidelity reads with high-throughput chromosome conformation capture data. The assembled genome has an estimated sequence size of 548.7 Mb and consists of 657 contigs, 623 scaffolds, and 40,453 protein-coding genes. In total, 60.99% of the assembled genome consists of repetitive sequences. Sixteen super-scaffolds corresponding to the 16 chromosomes were assembled, with a scaffold N50 length of 33.7 Mb and a BUSCO complete gene percentage of 98.3%. J. mandshurica displays a close sequence relationship with Juglans cathayensis, with a divergence time of 13.8 million years ago. Combining the high-quality genome, transcriptome, and metabolomics data, we constructed a gene-to-metabolite network and identified 566 core and conserved differentially expressed genes, which may be involved in juglone biosynthesis. Five CYP450 genes were found that may contribute to juglone accumulation. NAC, bZip, NF-YA, and NF-YC are positively correlated with the juglone content. Some candidate regulators (e.g., FUS3, ABI3, LEC2, and WRI1 transcription factors) involved in the regulation of lipid biosynthesis were also identified. Conclusions Our genomic data provide new insights into the evolution of the walnut genome and create a new platform for accelerating molecular breeding and improving the comprehensive utilization of these economically important tree species

    Mesenchymal Progenitor Cells and Their Orthopedic Applications: Forging a Path towards Clinical Trials

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    Mesenchymal progenitor cells (MPCs) are nonhematopoietic multipotent cells capable of differentiating into mesenchymal and nonmesenchymal lineages. While they can be isolated from various tissues, MPCs isolated from the bone marrow are best characterized. These cells represent a subset of bone marrow stromal cells (BMSCs) which, in addition to their differentiation potential, are critical in supporting proliferation and differentiation of hematopoietic cells. They are of clinical interest because they can be easily isolated from bone marrow aspirates and expanded in vitro with minimal donor site morbidity. The BMSCs are also capable of altering disease pathophysiology by secreting modulating factors in a paracrine manner. Thus, engineering such cells to maximize therapeutic potential has been the focus of cell/gene therapy to date. Here, we discuss the path towards the development of clinical trials utilizing BMSCs for orthopaedic applications. Specifically, we will review the use of BMSCs in repairing critical-sized defects, fracture nonunions, cartilage and tendon injuries, as well as in metabolic bone diseases and osteonecrosis. A review of www.ClinicalTrials.gov of the United States National Institute of Health was performed, and ongoing clinical trials will be discussed in addition to the sentinel preclinical studies that paved the way for human investigations

    Defective Osteogenic Differentiation in the Development of Osteosarcoma

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    Osteosarcoma (OS) is associated with poor prognosis due to its high incidence of metastasis and chemoresistance. It often arises in areas of rapid bone growth in long bones during the adolescent growth spurt. Although certain genetic conditions and alterations increase the risk of developing OS, the molecular pathogenesis is poorly understood. Recently, defects in differentiation have been linked to cancers, as they are associated with high cell proliferation. Treatments overcoming these defects enable terminal differentiation and subsequent tumor inhibition. OS development may be associated with defects in osteogenic differentiation. While early regulators of osteogenesis are unable to bypass these defects, late osteogenic regulators, including Runx2 and Osterix, are able to overcome some of the defects and inhibit tumor propagation through promoting osteogenic differentiation. Further understanding of the relationship between defects in osteogenic differentiation and tumor development holds tremendous potential in treating OS

    Retinoic Acids Potentiate BMP9-Induced Osteogenic Differentiation of Mesenchymal Progenitor Cells

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    As one of the least studied bone morphogenetic proteins (BMPs), BMP9 is one of the most osteogenic BMPs. Retinoic acid (RA) signaling is known to play an important role in development, differentiation and bone metabolism. In this study, we investigate the effect of RA signaling on BMP9-induced osteogenic differentiation of mesenchymal progenitor cells (MPCs).Both primary MPCs and MPC line are used for BMP9 and RA stimulation. Recombinant adenoviruses are used to deliver BMP9, RARalpha and RXRalpha into MPCs. The in vitro osteogenic differentiation is monitored by determining the early and late osteogenic markers and matrix mineralization. Mouse perinatal limb explants and in vivo MPC implantation experiments are carried out to assess bone formation. We find that both 9CRA and ATRA effectively induce early osteogenic marker, such as alkaline phosphatase (ALP), and late osteogenic markers, such as osteopontin (OPN) and osteocalcin (OC). BMP9-induced osteogenic differentiation and mineralization is synergistically enhanced by 9CRA and ATRA in vitro. 9CRA and ATRA are shown to induce BMP9 expression and activate BMPR Smad-mediated transcription activity. Using mouse perinatal limb explants, we find that BMP9 and RAs act together to promote the expansion of hypertrophic chondrocyte zone at growth plate. Progenitor cell implantation studies reveal that co-expression of BMP9 and RXRalpha or RARalpha significantly increases trabecular bone and osteoid matrix formation.Our results strongly suggest that retinoid signaling may synergize with BMP9 activity in promoting osteogenic differentiation of MPCs. This knowledge should expand our understanding about how BMP9 cross-talks with other signaling pathways. Furthermore, a combination of BMP9 and retinoic acid (or its agonists) may be explored as effective bone regeneration therapeutics to treat large segmental bony defects, non-union fracture, and/or osteoporotic fracture

    Evaluation of A Better Approach for Open Reduction Of Severe Gartland Type III Supracondylar Humeral Fracture

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    Background An optimal surgical approach is required to treat Gartland type III supracondylar humerus fractures (SHFs) in children when open reduction is inevitable, especially in patients with neurovascular injuries. The purposes of this study were to find a better approach for open reduction of Gartland type III SHFs and to achieve anatomic reduction, stable fixation, and good functional and cosmetic outcomes with this approach. Methods: This retrospective study was performed in our hospital between January 2008 and June 2014. After the exclusion criteria were applied, 91 children were treated with the mini-anterior approach for severe Gartland type III SHFs. A 2–3-cm long anterior incision was made radially along the anterior transverse groove of the elbow, through which the nerve and vessel were probed, if necessary, and fracture reduction and Kirschner (K)-wire insertion were performed. Radiological evaluation included the Baumann angle and carrying angle. The functional and cosmetic evaluation was based on range-of-motion measurements and the criteria defined by Flynn. Chi-square and independent t tests were used for the statistical analyses. Results: Thirty-two patients were impossible to reduce, 1 patient had brachial artery injury, 37 patients had a sign with compartmental syndrome, 6 patients had open fractures, and 15 patients had multiple trauma. The interval between injury and hospitalization was 1 hour to 12 days. Overall, 91 patients were followed for 12 months to 4 years (average, 26.5 months). All incisions were healed by primary intervention. The fracture healing time was 3–5 weeks (average, 3.8 weeks). Elbow function recovered after 3 months, without obvious cubitus varus. Postoperative radial nerve paralysis occurred in 2 patients and healed within 2 months. Postoperative ulnar nerve paralysis occurred in 2 patients, and one of the K-wires was removed after 1 day. Nerve injuries were relieved within 3 months for both patients. The outcomes, according to the Flynn criteria, were excellent in 73 patients, good in 12 patients, and fair in 6 patients. The rate of excellent and good outcomes was 93.41%. Conclusions: The advantages of the mini-anterior approach include minimal trauma, simple and rapid exposure, easy tissue repair, and possibility of probing and repairing nerves, vessels, and muscles. It is an optimal surgical approach for the treatment of Gartland type III SHFs when open reduction is inevitable, especially in patients with neurovascular injuries

    Risk factors of deep vein thrombosis in children with osteomyelitis

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    AbstractObjective To investigate the risk factors for deep vein thrombosis (DVT) in children with osteomyelitis and provide diagnostic and treatment strategies for the prevention, early detection and treatment of DVT.Study design The clinical data of nine children diagnosed with osteomyelitis and DVT between July 2012 and March 2021 were collected at our hospital, including age, sex, clinical manifestations, body temperature, coagulation function and other data, as well as the clinical data of 27 children diagnosed with osteomyelitis without DVT during the same period. Thirty-six children were divided into thrombus and thrombus-free groups. The clinical characteristics and risk factors for DVT in children with osteomyelitis were analysed.Results Among the 36 children in this study, nine cases of thrombus formation mainly occurred in the femoral vein, popliteal vein and iliac vein, all near the infection site. The main clinical manifestations were lower extremity pain, swelling and pulmonary embolism in three cases. Among them, intensive care unit (ICU) admission, sepsis, higher D-dimer, higher body temperature during hospitalization, and pathogen culture showed that methicillin-resistant Staphylococcus aureus (MRSA) was associated with DVT. MRSA was the independent risk factor for DVT.Conclusions Admission to ICU, sepsis, higher D-dimer, higher body temperature during hospitalization, and MRSA are risk factors for thrombosis. MRSA is the independent risk factor for DVT. For patients with related risk factors, timely ultrasound examination of the infected site should be considered to achieve early detection and treatment
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