118 research outputs found

    Identification of multi-fault in rotor-bearing system using spectral kurtosis and EEMD

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    Condition monitoring and fault diagnosis via vibration signal processing play an important role to avoid serious accidents. Aiming at the complexity of multiple faults in a rotor-bearing system and drawback, the characteristic frequency of relevant fault could not be determined effectively with traditional method. The Spectral Kurtosis (SK) is useful for the bearing fault detection. Nevertheless, the simulation of experiment in this paper shows that the SK is unable to identify multi-fault of rotor-bearing system fully when different faults excite different resonance frequencies. A new multi-fault detection method based on EEMD and spectral kurtosis (SK) is proposed in order to overcoming the shortcoming. The proposed method is applied to multi-faults of rotor imbalance and faulty bearings. The superiority of the proposed method based on spectral kurtosis (SK) and EEMD is demonstrated in extracting fault characteristic information of rotating machinery

    Radiotracer technique optimization for breast cancer internal mammary sentinel lymph node biopsy

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    Background and purpose: The modified injection technique developed in Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences has significantly improved the visualization rate of internal mammary sentinel lymph nodes (IMSLN), however there is still a gap between the visualization rate of IMSLN obtained by this technique and that of axillary sentinel lymph nodes (ASLN). The study aimed to further improve the IMSLN visualization rate and promote the widespread use of internal mammary sentinel lymph node biopsy (IM-SLNB) by optimizing the modified injection technique. Methods: A total of 159 patients with primary breast cancer were enrolled in a prospective group and divided into the optimized radiotracer technique group (group A, n=81) and the modified injection technique group (group B, n=78). In group A, 99mTc-sulfur colloid was injected averagely into parenchyma in the gland's three most abundant regions under ultrasound guidance (total radioactive intensity 1.0-1.3 mCi; 0.8-1.0 mL/point). In group B, 99mTc-sulfur colloid was injected averagely into the parenchyma of the breast at 6 and 12 points under ultrasound guidance (total radioactive intensity 1.0-1.3 mCi; 0.8-1.0 mL/point). Single photon emission computed tomography (SPECT)/computed tomography (CT) lymphoscintigraphy was performed preoperatively, and the sentinel lymph nodes were detected intraoperatively by γ probe. In this study, we evaluated the differences in IMSLN and ASLN visualization rates between the groups, and also analyzed the factors that may affect the IMSLN visualization rate. Results: There was no statistically significant difference in visualization rate of IM-SLN measured by preoperative SPECT/CT between the two groups (P=0.806). The intraoperative visualization rate of IM-SLN was significantly higher in group A than in group B (87.65% vs 70.51%, P=0.008). Analysis of subgroups showed that the intraoperative visualization rate of IMSLN was 92.31% and 83.33% (P=0.315) in group A patients aged ≤50 years and >50 years, respectively, and the intraoperative visualization rate of IMSLN was significantly higher in group B patients aged ≤50 years than in patients aged >50 years (81.58% vs 60.00%, P=0.037). The median in vitro radioactivity count of IMSLN was significantly higher in group A than in group B (160.50 vs 59.00, P=0.005). Conclusion: The optimized radiotracer technique can effectively increase the lymphatic drainage and uptake in the internal mammary region of the radiotracer, which can significantly improve the visualization rate of IM-SLN without affecting the visualization rate of ASLN, and is conducive to the promotion and application of IM-SLNB

    How much genetic variation is stored in the endangered and fragmented shrub Tetraena mongolica Maxim?

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    Tetraena mongolica Maxim (Zygophyllaceae) is an endangered species endemic to western Inner Mongolia and China, and is currently threatened by habitat loss and human over-exploitation. We explored the genetic background, its genetic diversity, population structure, and demographic history, based on 12 polymorphic nuclear microsatellite loci. Our results indicated high genetic diversity in extant populations, but no distinguishable gene cluster corresponding with a specific biogeography. Population demography analysis using a MSVAR indicated a strong, recent population decline approximately 5,455 years ago. These results suggest that the Yellow River and Zhuozi Mountain range may not prevent pollination between populations. Finally, we surmised that the population demography of T. mongolica was likely to have been affected by early mankind activities

    Internal mammary sentinel lymph node biopsy for breast cancer: a long-term follow-up research for assessment of prognosis and guiding individualized internal mammary lymph node irradiation

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    Background and purpose: Internal mammary lymph node irradiation (IMNI) improves survival in patients with internal mammary lymph node (IMLN) high-risk metastatic breast cancer. The purpose of this study was to study the advantages of internal mammary sentinel lymph node (IMLN) biopsy (IM-SLNB) for assessing prognosis and directing individualized IMNI. Methods: This study evaluated patients recruited in three prospective clinical trials (NCT01642511, NCT03541278, and NCT03024463) from November 2011 to December 2021, assessed for prognostic risk variables based on IMSLN metastatic status and prognosis between subgroups. In patients who received regional lymph node irradiation, the implementation status, survival benefit, and influence of IMNI on radiation-induced lung injury (RILI) were studied. The primary endpoint was disease-free survival (DFS), with overall survival (OS) and RILI as secondary endpoints. Results: The study enrolled 537 patients and had a 60-month median follow-up. Patients with IMSLN metastasis had a significantly worse 5-year DFS and OS (DFS: 95.1% vs 71.4%, OS: 99.1% vs 90.1%, both P<0.05), and IMSLN metastatic status was an independent risk factor for DFS and OS (both P<0.05). Adding IMNI did not improve DFS (P = 0.099) or OS (P = 0.486) in patients with negative IMSLN, while it did increase the risk of RILI (OR = 3.678, P<0.05). However, adding IMNI improved 5-year DFS (87.3% vs 52.5%, P = 0.040) for patients with positive IMSLN but had no effect on OS (P = 0.603). Conclusion: This study discovered that IMSLN metastatic status has significant prognostic importance. Patients with IMSLN metastasis who receive IMNI have significantly improved prognosis, and patients without IMSLN metastasis have a much lower risk of RILI by being exempt from IMNI without worse prognosis

    UTR introns, antisense RNA and differentially spliced transcripts between Plasmodium yoelii subspecies

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    Additional file 1. Evaluation of RNA quality from the two NSM parasite samples in agarose gel (a), and a flow chart of data processing and analysis (b)

    Chromosome-level genome assembly of a high-altitude-adapted frog (Rana kukunoris) from the Tibetan plateau provides insight into amphibian genome evolution and adaptation

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    Background The high-altitude-adapted frog Rana kukunoris, occurring on the Tibetan plateau, is an excellent model to study life history evolution and adaptation to harsh high-altitude environments. However, genomic resources for this species are still underdeveloped constraining attempts to investigate the underpinnings of adaptation. Results The R. kukunoris genome was assembled to a size of 4.83 Gb and the contig N50 was 1.80 Mb. The 6555 contigs were clustered and ordered into 12 pseudo-chromosomes covering similar to 93.07% of the assembled genome. In total, 32,304 genes were functionally annotated. Synteny analysis between the genomes of R. kukunoris and a low latitude species Rana temporaria showed a high degree of chromosome level synteny with one fusion event between chr11 and chr13 forming pseudo-chromosome 11 in R. kukunoris. Characterization of features of the R. kukunoris genome identified that 61.5% consisted of transposable elements and expansions of gene families related to cell nucleus structure and taste sense were identified. Ninety-five single-copy orthologous genes were identified as being under positive selection and had functions associated with the positive regulation of proteins in the catabolic process and negative regulation of developmental growth. These gene family expansions and positively selected genes indicate regions for further interrogation to understand adaptation to high altitude. Conclusions Here, we reported a high-quality chromosome-level genome assembly of a high-altitude amphibian species using a combination of Illumina, PacBio and Hi-C sequencing technologies. This genome assembly provides a valuable resource for subsequent research on R. kukunoris genomics and amphibian genome evolution in general.Peer reviewe

    Toxin-Encoding Genes and Drug Susceptibility of Staphylococcus aureus from Vegetables Consumed Raw

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    Objective: To investigate the toxin-encoding genes and antibiotic susceptibility of Staphylococcus aureus isolates from retail vegetables consumed raw. Methods: The 27 S. aureus isolates from tomato, lettuce, spinach and cabbage collected from supermarkets, farmers’ markets and vendors in Xi’an, Baoji, Hanzhong and Yan’an of Shaanxi province were identified by PCR amplification of the nuc gene, the prevalence of 19 toxin-encoding genes and 12 antibiotic resistance encoding genes in these isolates was evaluated, and the antibiotic susceptibility to 14 antibiotics was determined by the agar dilution method. Results: Seventeen of these isolates were identified as methicillin-susceptible S. aureus (MSSA) and the remaining 10 isolates were identified as oxacillin-susceptible methicillin-resistant S. aureus (OS-MRSA). A total of eight toxin-encoding genes were detected in the 27 isolates, and the detection rate (29.6%, 8/27) of sec was highest. In addition, 51.9% (14/27) of these isolates carried at least one toxin-encoding gene, and nine toxin-encoding gene profiles were totally identified. Seven antibiotic resistance genes including blaZ, mecA, ermC, tetK, dfrG, dfrK, and aac(6’)/aph(2”) were detected. The isolates were all susceptible to oxacillin, rifampicin and vancomycin. Resistance to amoxicillin/clavulanate was most commonly detected, followed by trimethoprim/sulfamethoxazole, ampicillin, erythromycin, cefoxitin, ciprofloxacin, ceftriaxone, gentamicin, amikacin, tetracycline and chloramphenicol. Twenty-four (88.9%) isolates were resistant to three or more antibiotics. Conclusion: OS-MRSA is prevalent in vegetables consumed raw in Shaanxi province, and it has multiple antibiotic resistances and carries multiple toxin-encoding gens, posing a potential food safety hazard

    Expression of Hemolysin Is Regulated Under the Collective Actions of HapR, Fur, and HlyU in Vibrio cholerae El Tor Serogroup O1

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    The biotype El Tor of serogroup O1 and most of the non-O1/non-O139 strains of Vibrio cholerae can produce an extracellular pore-forming toxin known as cholera hemolysin (HlyA). Expression of HlyA has been previously reported to be regulated by the quorum sensing (QS) and the regulatory proteins HlyU and Fur, but lacks the direct evidence for their binding to the promoter of hlyA. In the present work, we showed that the QS regulator HapR, along with Fur and HlyU, regulates the transcription of hlyA in V. cholerae El Tor biotype. At the late mid-logarithmic growth phase, HapR binds to the three promoters of fur, hlyU, and hlyA to repress their transcription. At the early mid-logarithmic growth phase, Fur binds to the promoters of hlyU and hlyA to repress their transcription; meanwhile, HlyU binds to the promoter of hlyA to activate its transcription, but it manifests direct inhibition of its own gene. The highest transcriptional level of hlyA occurs at an OD600 value of around 0.6–0.7, which may be due to the subtle regulation of HapR, Fur, and HlyU. The complex regulation of HapR, Fur, and HlyU on hlyA would be beneficial to the invasion and pathogenesis of V. cholerae during the different infection stages
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