121 research outputs found
Iron-catalysed cross-coupling of halohydrins with aryl aluminium reagents: a protecting-group-free strategy attaining remarkable rate enhancement and diastereoinduction.
Non-protected halohydrins are cross-coupled with aryl aluminium reagents to produce aryl alkanols in the presence of the iron-bisphosphine catalysts. Remarkable reaction rate enhancement and diastereoinduction are realized by the in situ generated aluminium alkoxides, offering a new method for the reactivity and selectivity control of the iron-catalysed cross-coupling reaction
Okayama University Survey of the current situation of community-based medical facilities supported by part-time work by physicians
We investigated the situation of how physicians at Okayama University support local medical institutions by serving as a part-time worker, and analyzed the difference between the five medical districts of Okayama prefecture and other prefectures. Many physicians (actual number of physicians, full-time equivalent number of physicians) served in the southeastern region of the Okayama prefecture (339, 82.2). On the other hand, fewer physicians (42, 11.4) served in Takahashi・Niimi in the northwestern region of Okayama. Many physicians also served in Hiroshima prefecture (193, 48.8), Hyogo prefecture (109, 26.7), and the four prefectures of Shikoku Island (81, 23.6).
It has been clarified that many physicians at Okayama University are working on a part-time basis to support local and community medical institutions in the wide area of Okayama prefecture, Hiroshima prefecture, Hyogo prefecture and the four prefectures of Shikoku Island
Inhibitory neurons exhibit high controlling ability in the cortical microconnectome
脳が安定して活動を続けられるメカニズムの一端を解明 --新皮質で、抑制性細胞は他細胞を制御しやすいトポロジカルな位置取りをする--. 京都大学プレスリリース. 2021-04-09.The brain is a network system in which excitatory and inhibitory neurons keep activity balanced in the highly non-random connectivity pattern of the microconnectome. It is well known that the relative percentage of inhibitory neurons is much smaller than excitatory neurons in the cortex. So, in general, how inhibitory neurons can keep the balance with the surrounding excitatory neurons is an important question. There is much accumulated knowledge about this fundamental question. This study quantitatively evaluated the relatively higher functional contribution of inhibitory neurons in terms of not only properties of individual neurons, such as firing rate, but also in terms of topological mechanisms and controlling ability on other excitatory neurons. We combined simultaneous electrical recording (~2.5 hours) of ~1000 neurons in vitro, and quantitative evaluation of neuronal interactions including excitatory-inhibitory categorization. This study accurately defined recording brain anatomical targets, such as brain regions and cortical layers, by inter-referring MRI and immunostaining recordings. The interaction networks enabled us to quantify topological influence of individual neurons, in terms of controlling ability to other neurons. Especially, the result indicated that highly influential inhibitory neurons show higher controlling ability of other neurons than excitatory neurons, and are relatively often distributed in deeper layers of the cortex. Furthermore, the neurons having high controlling ability are more effectively limited in number than central nodes of k-cores, and these neurons also participate in more clustered motifs. In summary, this study suggested that the high controlling ability of inhibitory neurons is a key mechanism to keep balance with a large number of other excitatory neurons beyond simple higher firing rate. Application of the selection method of limited important neurons would be also applicable for the ability to effectively and selectively stimulate E/I imbalanced disease states
SN 2018gj: A Short-plateau Type II Supernova with Persistent Blue-shifted H-alpha Emission
We present an extensive, panchromatic photometric (UV, Optical, and NIR) and
low-resolution optical spectroscopic coverage of a Type IIP supernova SN 2018gj
that occurred on the outskirts of the host galaxy NGC 6217. From the V-band
light curve, we estimate the plateau length to be ~ 70 +- 2 d, placing it among
the very few well-sampled short plateau supernovae (SNe). With V-band peak
absolute magnitude Mv < -17.0 +- 0.1 mag, it falls in the middle of the
luminosity distribution of the Type II SNe. The colour evolution is typical to
other Type II SNe except for an early elbow-like feature in the evolution of
V-R colour owing to its early transition from the plateau to the nebular phase.
Using the expanding photospheric method, we present an independent estimate of
the distance to SN 2018gj. We report the spectral evolution to be typical of a
Type II SNe. However, we see a persistent blue shift in emission lines until
the late nebular phase, not ordinarily observed in Type II SNe. The amount of
radioactive nickel (56Ni) yield in the explosion was estimated to be 0.026 +-
0.007 Msol. We infer from semi-analytical modelling, nebular spectrum, and 1-D
hydrodynamical modelling that the probable progenitor was a red supergiant with
a zero-age-main-sequence mass < 13 Msol. In the simulated hydrodynamical model
light curves, reproducing the early optical bolometric light curve required an
additional radiation source, which could be the interaction with the proximal
circumstellar matter (CSM).Comment: Accepted for publication in ApJ (31 pages, 23 figures and 7 tables
Willingness-to-Pay-Associated Right Prefrontal Activation During a Single, Real Use of Cosmetics as Revealed by Functional Near-Infrared Spectroscopy
Use of applied neuroscience to complement traditional methods of consumer research is increasing. Previously, fMRI has shown that prefrontal activity contains information relating to willingness-to-pay (WTP). The aim of the present study was to determine if functional near infrared spectroscopy (fNIRS) can record WTP-related brain activation in the dorsolateral prefrontal cortex (DLPFC) during a single, real use of cosmetic products. Thirty female participants, were divided into two groups (one low frequency users of foundation and one high frequency users of foundation), asked to apply different foundations to their face and then record how much money they were willing to pay. The oxyhemoglobin time series was analyzed with the GLM and the correlation between the beta scores for the foundations and their respective WTP values conducted for each participant. These subject level correlations were then converted to z scores and averaged for each group. The results revealed a significant mean correlation for the high but not low frequency group. In other words, the brain activity in right hemisphere dorsolateral PFC (RH-DLPFC) during single, real use of foundations correlated with their respective WTP values for the high frequency but not low frequency group. The difference between groups may reflect the importance of learning and automation on activity in RH-DLPFC. Our research provides further evidence supporting the use of fNIRS to complement traditional consumer research in a commercial setting and to extend neuroscience research into more naturalistic environments
Early Spectroscopy of the 2010 Outburst of U Scorpii
We present early spectroscopy of the recurrent nova U~Sco during the outburst
in 2010. We successfully obtained time-series spectra at 0.37--0.44~d, where denotes the time from the discovery of the
present outburst. This is the first time-resolved spectroscopy on the first
night of U Sco outbursts. At ~d the H line consists
of a blue-shifted ( km s) narrow absorption component and a wide
emission component having triple peaks, a blue ( km s), a
central ( km s) and a red ( km s) ones. The
blue and red peaks developed more rapidly than the central one during the first
night. This rapid variation would be caused by the growth of aspherical wind
produced during the earliest stage of the outburst. At ~d the
H line has a nearly flat-topped profile with weak blue and red peaks at
km s. This profile can be attributed to a nearly
spherical shell, while the asphericity growing on the first night still
remains. The wind asphericity is less significant after d.Comment: 5 pages, 3 figures, Accepted for publication of PASJ Letter
Gamma rays from a reverse shock with turbulent magnetic fields in GRB 180720B
Gamma-ray bursts (GRBs) are the most electromagnetically luminous cosmic
explosions. They are powered by collimated streams of plasma (jets) ejected by
a newborn stellar-mass black hole or neutron star at relativistic velocities
(near the speed of light). Their short-lived (typically tens of seconds) prompt
-ray emission from within the ejecta is followed by long-lived
multi-wavelength afterglow emission from the ultra-relativistic forward shock.
This shock is driven into the circumburst medium by the GRB ejecta that are in
turn decelerated by a mildly-relativistic reverse shock. Forward shock emission
was recently detected up to teraelectronvolt-energy -rays, and such
very-high-energy emission was also predicted from the reverse shock. Here we
report the detection of optical and gigaelectronvolt-energy -ray
emission from GRB 180720B during the first few hundred seconds, which is
explained by synchrotron and inverse-Compton emission from the reverse shock
propagating into the ejecta, implying a low-magnetization ejecta. Our optical
measurements show a clear transition from the reverse shock to the forward
shock driven into the circumburst medium, accompanied by a 90-degree change in
the mean polarization angle and fluctuations in the polarization degree and
angle. This indicates turbulence with large-scale toroidal and
radially-stretched magnetic field structures in the reverse and forward shocks,
respectively, which tightly couple to the physics of relativistic shocks and
GRB jets -- launching, composition, dissipation and particle acceleration.Comment: 5 pages, 4 figures (main) plus Methods and Supplementary Methods,
accepted for publicatio
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