13 research outputs found
Conflicting actions of 4-vinylcatechol in rat lymphocytes under oxidative stress induced by hydrogen peroxide
4-Vinylcatechol (4VC) has been identified as an aroma compound in roasted foods, especially coffee. It is also a component in traditional herbal medicines. This compound may be subconsciously ingested through foods and herbs. Recent experimental evidence has shown that 4VC possesses an antioxidative action. However, the antioxidative action of 4VC at cellular levels is not well characterized. The effects of 4VC (0.1–100 μM) were examined on rat thymic lymphocytes without and with oxidative stress induced by 300 μM hydrogen peroxide (H2O2). Cell treatment with 100 μM 4VC alone for 4 hr significantly increased the population of dead cells. Thus, 4VC at 100 μM or above elicits cytotoxicity. However, 4VC at sublethal concentrations (1–10 μM) significantly attenuated the H2O2-induced increase in cell lethality in a concentration-dependent manner. While application of 10 μM 4VC slowed the process of cell death induced by H2O2, 4VC did not antagonize the H2O2-induced reduction of cellular nonprotein thiols. Although 4VC at 10 μM did not affect intracellular Ca2+ and Zn2+ levels, the agent potentiated the H2O2-induced increases in these levels. These actions of 10 μM 4VC are adverse to the cells under the oxidative stress. However, 10 μM 4VC partly attenuated the cell death induced by 100 nM A23187, a calcium ionophore. There are conflicting actions of 4VC at 1–100 μM on the cells under oxidative stress although the agent is used for an antioxidant. Thus, caution is required when using 4VC as a therapeutic agent
CO Multi-line Imaging of Nearby Galaxies (COMING) IV. Overview of the Project
Observations of the molecular gas in galaxies are vital to understanding the
evolution and star-forming histories of galaxies. However, galaxies with
molecular gas maps of their whole discs having sufficient resolution to
distinguish galactic structures are severely lacking. Millimeter wavelength
studies at a high angular resolution across multiple lines and transitions are
particularly needed, severely limiting our ability to infer the universal
properties of molecular gas in galaxies. Hence, we conducted a legacy project
with the 45 m telescope of the Nobeyama Radio Observatory, called the CO
Multi-line Imaging of Nearby Galaxies (COMING), which simultaneously observed
147 galaxies with high far-infrared flux in CO, CO, and CO
lines. The total molecular gas mass was derived using the standard
CO-to-H conversion factor and found to be positively correlated with the
total stellar mass derived from the WISE m band data. The fraction of
the total molecular gas mass to the total stellar mass in galaxies does not
depend on their Hubble types nor the existence of a galactic bar, although when
galaxies in individual morphological types are investigated separately, the
fraction seems to decrease with the total stellar mass in early-type galaxies
and vice versa in late-type galaxies. No differences in the distribution of the
total molecular gas mass, stellar mass, and the total molecular gas to stellar
mass ratio was observed between barred and non-barred galaxies, which is likely
the result of our sample selection criteria, in that we prioritized observing
FIR bright (and thus molecular gas-rich) galaxies.Comment: Accepted for publication in PASJ; 47 pages, 5 tables, 29 figures.
On-line supplementary images are available at this URL
(https://astro3.sci.hokudai.ac.jp/~radio/coming/publications/). CO data is
available at the Japanese Virtual Observatory (JVO) website
(https://jvo.nao.ac.jp/portal/nobeyama/coming.do) and the project website
(https://astro3.sci.hokudai.ac.jp/~radio/coming/data/
Protein-losing Gastroenteropathy Related to Mixed Connective Tissue Disease: A Case Report of a Successful Outcome and Literature Review
Different Molecular Arrangement of Perylene in Metallic and Semiconducting Carbon Nanotubes: Impact of van der Waals Interaction
The arrangement of molecules on material
surfaces has been a central
focus in the fields of chemistry and physics. The molecular arrangement
on two-dimensional surfaces has been extensively studied, and the
electronic properties of substrates are one of the crucial factors
for the arrangement. Recently, the arrangement of molecules in tubular
materials can be investigated by using carbon nanotubes. In this study,
the preferential molecular arrangement of perylene in single-walled
carbon nanotubes (SWNTs), which is determined by their electronic
properties, is reported. A combination of transmission electron microscopy
observations, optical measurements, and first-principles calculations
revealed differences in the molecular arrangement of perylene in metallic
and semiconducting SWNTs. Perylene molecules in metallic SWNTs formed
H-type molecular dimers, while those in semiconducting SWNTs were
one-dimensionally stacked with their stacking axis directed along
the nanotube axis. The difference in the molecular arrangement was
discussed in terms of London dispersion force (van der Waals interaction)
between the encapsulated molecules and the SWNTs. Our findings provide
an insight into the application of SWNTs for encapsulating molecules
as nanohybrid materials and nanoscale reaction chambers that possess
effective functionalities