13 research outputs found

    A kinematic study of the irregular dwarf galaxy NGC 2366 using HI and Halpha observations

    Full text link
    Abridged. Context. The metal content of dwarf galaxies and the metal enrichment of the intergalactic medium both suggest that mass loss from galaxies is a significant factor for the chemical evolution history of galaxies, in particular of dwarf galaxies. However, no clear evidence of a blow-away in local dwarf galaxies has been found so far. Aims. We therefore performed a detailed kinematic analysis of the neutral and ionised gas in the nearby star-forming irregular dwarf galaxy NGC 2366 in order to make predictions about the fate of the gas and to get a more complete picture of this galaxy. Methods. A deep Halpha image and Fabry-Perot interferometric data of NGC 2366 were obtained. They were complemented by HI synthesis data from the THINGS survey. We searched for line-splitting both in Halpha and HI by performing a Gaussian decomposition. To get an idea whether the expansion velocities are high enough for a gas blow-away, we used the pseudo-isothermal halo model, which gives us realistic values for the escape velocities of NGC 2366. The good data quality also allowed us to discuss some peculiarities of the morphology and the dynamics in NGC 2366. Results. A large red-shifted outflow north west of the giant extragalactic HII region with an expansion velocity of up to 50 km/s is found in Halpha, but not in HI. Additionally, a blue-shifted component north of the giant extragalactic HII region was detected both in Halpha and HI with an expansion velocity of up to 30 km/s. A comparison with the escape velocities of NGC 2366 reveals that the gas does not have enough kinetic energy to leave the gravitational potential.Comment: 15 pages, 14 figures, accepted for publication by A&

    Gemini GMOS--IFU spectroscopy of the compact HII galaxies Tol 0104-388 and Tol 2146-391: The dependence on the properties of the interstellar medium

    Full text link
    Using GMOS--IFU spectroscopic observations of the compact HII/BCD galaxies Tol 0104-388 and Tol 2146-391, we study the spatial distribution of emission lines, equivalent width EW(Hb), extinction c(Hb), ionization ratios ([OIII]5007/Hb, [SII]6717,6731/Ha and [NII]6584/Ha), kinematics, and the chemical pattern (O/H, N/H and N/O) of the warm interstellar medium in these galaxies. We also investigate a possible dependence of these properties on the I(HeII4686)/I(Hb) ratio and find no significant correlation between these variables. In fact, the oxygen abundances appear to be uniform in the regions where the HeII4686 emission line was measured. It can be interpreted in the sense that these correlations are related to global properties of the galaxies and not with small patches of the interstellar medium. Although a possible weak N/H gradient is observed in Tol 2146-391, the available data suggest that the metals from previous star-formation events are well mixed and homogeneously distributed through the optical extent of these galaxies. The spatial constancy of the N/O ratio might be attributed to efficient transport and mixing of metals by starburst-driven super-shells, powered by a plethora of unresolved star cluster in the inner part of the galaxies. This scenario agrees with the idea that most of the observed HeII4686 emission line, in our sample of galaxies, is produced by radiative shocks.Comment: 16 pages, 18 figures, 5 tables, accepted for publication in MNRA

    In vitro bioactivities of Codonopsis javanica root extract from Kon Tum province, Vietnam

    Get PDF
    Dangshen Codonopsis javanica exhibits invaluable medicinal properties in herbal remedies; however, there has currently not been much specific analysis of the phytochemicals and bioactivities of this plant. The root ethanol extract of C. javanica contains substances such as saponins, phenolic acids, terpenoids, and alkaloids. It displays an antibacterial effect against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus cereus with the IC50 values of 150, 100, 150, and 90 μg/mL, respectively. The antioxidant capacity of the root extract was also observed with an IC50 value of 46.8 ± 6.8 μg/mL. Furthermore, the extract exhibits activity on human cancer cell lines HepG2 (IC50 = 83.6 ± 2.7 μg/mL) and MCF-7 (IC50 = 95.3 ± 2.3 μg/mL). Hence, this study provides the basic data for further research on the bioactivities of natural compounds of Dangshen C. javanica for the first time

    A Novel BRCA1 Gene Mutation Detected With Breast Cancer in a Vietnamese Family by Targeted Next-Generation Sequencing: A Case Report

    No full text
    International audienceHereditary breast cancer is an inherited genetic condition, mainly caused by BRCA1 and BRCA2 gene mutations. These genetic changes can increase the risks of breast and ovarian cancers in women, while prostate and breast cancers in men. Especially, mutations in either BRCA1 or BRCA2 genes take important roles in early-onset breast cancer. The present study focused on a 47-year-old Vietnamese woman with breast cancer by applying targeted next-generation sequencing technique. A novel BRCA1 gene mutation, namely NM_007294.3 (BRCA1): c.4998insA (p. Tyr1666Terfs), was identified both in this patient and in some of the members in her family proved the fact that the mutated genes passed down through generations. This change may exponentially initiate breast cancer risks and become a valuable marker for exact clinical prognosis and treatment

    Novel Removal of Diazinon Pesticide by Adsorption and Photocatalytic Degradation of Visible Light-Driven Fe-TiO2/Bent-Fe Photocatalyst

    No full text
    In the study, Fe was used as a dopant to enhance photocatalytic activity of TiO2. Then, the Fe-doped TiO2 was deposited on bentonite, which was pillared by Fe. The synthesized materials were characterized by SEM, XRD, UV-Vis, BET, and point of zero charge (pHPZC). Then, the synthesized materials were used for diazinon removal under both dark and visible light conditions to investigate adsorption and photocatalytic degradation abilities of the synthesized materials. The maximum diazinon adsorption capacity of the synthesized Fe-TiO2/Bent-Fe was 27.03 mg/g. The obtained results indicated that the Fe-TiO2/Bent-Fe exhibited high photocatalytic degradation activity for removal of diazinon even under visible light. The diazinon removal experiments were also conducted using different photocatalyst dosages, under different pH and light sources to figure the optimal conditions for removal processes. The obtained results indicated that optimal photocatalyst dosage and pH were 0.5 g/L and 4.5, respectively. Finally, the natural light generated from solar could be suitable used for diazinon removal by the synthesized Fe-TiO2/Bent-Fe

    COVID-19 in Southeast Asia: current status and perspectives

    Get PDF
    Coronavirus Disease-2019 (COVID-19) has spread globally with catastrophic damages to the public health, social and economy since the beginning of the outbreak. In 2020, Southeast Asia proved that it could prevent the worst effects of a pandemic through the closure of activities and borders and movement restriction, as well as social distancing. Nevertheless, with the occurrence of the common variants of concern (VOCs), especially Alpha (B.1.1.7), Beta (B.1.351), Delta (B.1.617.2), Southeast Asia is facing a significant increase in the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infections. Now, the area also has the threats of the spreading out of the dangerous variant - Omicron (B.1.1.529) from other close countries or regions. COVID-19 countermeasures such as closures and social distancing seem to be insufficient. Moreover, Southeast Asia is being held back by a shortage of vaccines and other medical resources. This work focuses on describing the COVID-19 situation, the virus variants, and the coverage of COVID-19 vaccination in the area. We also provide perspectives on the COVID-19 vaccine distribution, protecting the economic capitals, developing the green zone, and the importance of finding more vaccine supplies in Southeast Asia
    corecore