7 research outputs found

    Mass-accretion, spectral, and photometric properties of T Tauri stars in Taurus based on TESS and LAMOST

    Full text link
    We present the analysis of 16 classical T Taur stars using LAMOST and TESS data, investigating spectral properties, photometric variations, and mass-accretion rates. All 16 stars exhibit emissions in Hα\alpha lines, from which the average mass-accretion rate of 1.76×10−9 M⊙yr−11.76\times10^{-9}~M_{\odot}yr^{-1} is derived. Two of the stars, DL Tau and Haro 6-13, show mass-accretion bursts simultaneously in TESS, ASAS-SN, and/or ZTF survey. Based on these observations, we find that the mass-accretion rates of DL Tau and Haro 6-13 reach their maximums of 2.5×10−8 M⊙yr−12.5 \times 10^{-8}~M_{\odot}yr^{-1} and 2×10−10 M⊙yr−12 \times 10^{-10}~M_{\odot}yr^{-1} during the TESS observation, respectively. We detect thirteen flares among these stars. The flare frequency distribution shows that the CTTSs' flare activity is not only dominated by strong flares with high energy but much more active than those of solar-type and young low-mass stars. By comparing the variability classes reported in the literature, we find that the transition timescale between different classes of variability in CTTSs, such as from Stochastic (S) to Bursting (B) or from quasi-periodic symmetric (QPS) to quasi-periodic dipping (QPD), may range from 1.6 to 4 years. We observe no significant correlation between inclination and mass-accretion rates derived from the emission indicators. This suggests that inner disk properties may be more important than that of outer disk. Finally, we find a relatively significant positive correlation between the asymmetric metric "M" and the cold disk inclination compared to the literature. A weak negative correlation between the periodicity metric "Q" value and inclination has been also found.Comment: 39 pages, 22 figures, 8 table

    A Rare Adverse Effect of the COVID-19 Vaccine on Autoimmune Encephalitis

    No full text
    Since countries commenced COVID-19 vaccination around the world, many vaccine-related adverse effects have been reported. Among them, short-term memory loss with autoimmune encephalitis (AE) was reported as a rare adverse effect. Since case numbers are limited, this brief report may draw the attention of the medical community to this uncommon adverse effect and serve as a reference for future vaccine improvement. However, given the high risk of adverse outcomes when infected with SARS-CoV-2 and the clearly favorable safety/tolerability profile of existing vaccines, vaccination is still recommended

    The Effects of Prior Mammography Screening on the Performance of Breast Cancer Detection in Taiwan

    No full text
    The aim of this study was to investigate the influence of previous mammography screening on the performance of breast cancer detection. The screened women were divided into first-visit and follow-up groups for breast cancer screening. The positive predictive value (PPV), cancer detection rate (CDR), and recall rate were used to evaluate and analyze the overall screening performance among the two groups. Among them, 10,040 screenings (67.2%) were first visits and 4895 screenings (32.8%) were follow-up visits. The proportion of positive screening results for first-visit participants was higher than that for their follow-up counterparts (9.3% vs. 4.0%). A total of 98 participants (74 first-visit and 24 follow-up visit) were confirmed to have breast cancer. The PPV for positive mammography for women who underwent biopsy confirmation was 28.7% overall, reaching 35.8% for the follow-up visit group and 27.0% for the first-visit group. The CDR was 6.6 per 1000 overall, reaching 7.4 per 1000 for first-visit group and 4.9 per 1000 for the follow-up group. The overall recall rate was 7.9%, reaching 9.7% for the first-visit group and 4.2% for the follow-up group. The PPV is improved and the recall rate is decreased if prior mammography images are available for comparison when conducting mammography screening for breast cancer. By this study, we concluded that prior mammography plays an important role for breast cancer screening, while follow-up mammography may increase the diagnostic rate when compared to the prior mammography. We suggest that the public health authority can encourage subjects to undergo screenings in the same health institute where they regularly visit

    Utilizing Proteomic Approach to Analyze Potential Antioxidant Proteins in Plant against Irradiation

    No full text
    Gamma-ray irradiation is an effective and clean method of sterilization by inactivating microorganisms. It can also be applied to induce anti-oxidants for future application. In this study, the mung bean (Vigna radiata) was exposed to gamma-ray irradiation under the dose of 0, 5 or 10 kGy. With increasing irradiation doses, the concentrations of malondiadehyde decreased while the levels of total flavonoids and DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity increased. It has been shown that consuming flavonoids can provide protective effects. In addition, proteomic analysis identified several proteins having anti-oxidant activities in the 5 kGy irradiated group. These proteins are Apocytochrome f, Systemin receptor SR 160, DELLA protein DWARF8, DEAD-box ATP-dependent RNA helicase 9, ζ-carotene desaturase (ZDS), and Floral homeotic protein AGAMOUS. Our findings indicate that plants contain a variety of phytochemicals and antioxidant proteins which may effectively prevent oxidative stress caused by irradiated peroxidation

    Cell division cycle-associated 7-like gene: A novel biomarker for adverse survival in human high-grade gliomas

    No full text
    Background: High-grade primary gliomas are aggressively growing and have an unfavorable prognosis. The utility of prognostic biomarkers of outcome in glioma patients is important for medical practice. Cell division cycle-associated 7-like (CDCA7L) protein modifies cancer progression and metastasis. Nevertheless, its character in defining the clinical prognosis of human gliomas has not been illuminated. Subjects and Methods: The hypothesis of this study was that CDCA7L is upregulated in human gliomas. We studied two de-linked data from Gene Expression Omnibus (GEO) profile. The first dataset (GDS1816/225081_s_at/CDCA7L) in primary high-grade glioma included age, gender, and survival time. Another dataset (GDS1962/225081_s_at/CDCA7L) was also encompassed to estimate CDCA7L gene expression in each pathological grading. Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) was used to survey the protein-protein interaction (PPI) network of CDCA7L-regulated oncogenesis. Results: Statistical analysis of the GEO profile revealed that the World Health Organization (WHO) Grade IV (n = 81) gliomas had higher CDCA7L mRNA expression level than in Grade II (n = 7, P = 2.15 × 10 −14) gliomas and nontumor controls (n = 23, P = 2.87 × 10 − 18). Kaplan-Meier analysis reported that patients with high CDCA7L mRNA levels (n = 49) had adverse survival than those with low CDCA7L expression (n = 28). The PPI analysis of CDCA7L-regulated oncogenesis showed CDCA7L as a potential hub protein. Conclusions: The expression of CDCA7L has a positive correlation with the WHO pathological grading and shorter survival. This finding suggests that CDCA7L may be a potential biomarker of prognosis in human gliomas
    corecore