123 research outputs found
A New Instrumentation Amplifier Architecture Based on Differential Difference Amplifier for Biological Signal Processing
In this paper, a new Instrumentation Amplifier (IA) architecture for biological signal pro-cessing is proposed. First stage of the proposed IA architecture consists of fully balance differential difference amplifier and three resistors. Its second stage was designed by using differential difference amplifier and two resistors. The second stage has smaller number of resistors than that of conventional one. The IA architectures are simulated and compared by using 1P 2M 0:6-m CMOS process. From HSPICE simulation result, lower common-mode voltage can be achieved by the proposed IA architecture. Average common-mode gain (Ac) of the proposed IA architecture is 31:26 dB lower than that of conventional one under 3% resistor mismatches condition. Therefore, the Ac of the proposed IA architecture is more insensitive to resistor mismatches and suitable for biological signal processing
Low Common-Mode Gain Instrumentation Amplifier Architecture Insensitive to Resistor Mismatches
In this paper, an instrumentation amplifier architecture for biological signal is proposed. First stage of conventional IA architecture was modified by using fully balanced differential difference amplifier and evaluated by using 1P 2M 0.6μm CMOS process. From HSPICE simulation result, lower common-mode voltage can be achieved by proposed IA architecture. Actual fabrication was done and six chips were evaluated. From the evaluation result, average common-mode gain of proposed IA architecture is 10.84 dB lower than that of conventional one without requiring well-matched resistors. Therefore, the proposed IA architecture is suitable for biological signal processing
Mass-dependent evolution of the relation between supermassive black hole mass and host spheroid mass since z ~ 1
We investigate the evolution of supermassive black hole mass (M_BH) and the
host spheroid mass (M_sph) in order to track the history of the M_BH-M_sph
relationship. The typical mass increase of M_BH is calculated by a continuity
equation and accretion history, which is estimated from the active galactic
nucleus (AGN) luminosity function. The increase in M_sph is also calculated by
using a continuity equation and a star formation model, which uses
observational data for the formation rate and stellar mass function. We find
that the black hole to spheroid mass ratio is expected to be substantially
unchanged since z~1.2 for high mass objects (M_BH>10^8.5M_SUN and
M_sph>10^11.3M_SUN). In the same redshift range, the spheroid mass is found to
increase more rapidly than the black hole mass if M_sph>10^11M_SUN. The
proposed mass-dependent model is consistent with the current available
observational data in the M_BH-M_sph diagram.Comment: 15 pages, 8 figures, accepted to MNRA
Astrometric VLBI observations of HO masers in an extreme OH/IR star candidate NSV17351
Results of astrometric very long baseline interferometry (VLBI) observations
towards an extreme OH/IR star candidate NSV17351 are presented. We used the
VERA (VLBI Exploration of Radio Astrometry) VLBI array to observe 22\,GHz
HO masers of NSV17351. We derived an annual parallax of 0.2470.035 mas
which corresponds to a distance of 4.050.59 kpc. By averaging the proper
motions of 15 maser spots, we obtained the systemic proper motion of NSV17351
to be () (1.19
0.11, 1.30 0.19) mas\,yr. The maser spots spread out over a
region of 20 mas 30 mas, which can be converted to a spatial
distribution of 80 au 120 au at the source distance.
Internal motions of the maser spots suggest an outward moving maser region with
respect to the estimated position of the central star. From single dish
monitoring of the HO maser emission, we estimate the pulsation period of
NSV17351 to be 112224 days. This is the first report of the periodic
activity of NSV17351, indicating that NSV17351 could have a mass of
4\,M. We confirmed that the time variation of HO masers can
be used as a period estimator of variable OH/IR stars. Furthermore, by
inspecting dozens of double-peaked HO maser spectra from the last 40 years,
we detected a long-term acceleration in the radial velocity of the
circumstellar matter to be km\,s\,yr Finally, we
determined the position and kinematics of NSV17351 in the Milky Way Galaxy and
found that NSV17351 is located in an interarm region between the Outer and
Perseus arms. We note that astrometric VLBI observations towards extreme OH/IR
stars are useful samples for studies of the Galactic dynamics.Comment: Published in the Publications of the Astronomical Society of Japa
Role of cyclooxygenase-2-mediated prostaglandin E2-prostaglandin E receptor 4 signaling in cardiac reprogramming
Direct cardiac reprogramming from fibroblasts can be a promising approach for disease modeling, drug screening, and cardiac regeneration in pediatric and adult patients. However, postnatal and adult fibroblasts are less efficient for reprogramming compared with embryonic fibroblasts, and barriers to cardiac reprogramming associated with aging remain undetermined. In this study, we screened 8400 chemical compounds and found that diclofenac sodium (diclofenac), a non-steroidal anti-inflammatory drug, greatly enhanced cardiac reprogramming in combination with Gata4, Mef2c, and Tbx5 (GMT) or GMT plus Hand2. Intriguingly, diclofenac promoted cardiac reprogramming in mouse postnatal and adult tail-tip fibroblasts (TTFs), but not in mouse embryonic fibroblasts (MEFs). Mechanistically, diclofenac enhanced cardiac reprogramming by inhibiting cyclooxygenase-2, prostaglandin E2/prostaglandin E receptor 4, cyclic AMP/protein kinase A, and interleukin 1β signaling and by silencing inflammatory and fibroblast programs, which were activated in postnatal and adult TTFs. Thus, anti-inflammation represents a new target for cardiac reprogramming associated with aging
Indirect energy transfer channel between fast ions via nuclear elastic scattering observed on the large helical device
An energy transfer phenomenon between energetic ions, which cannot be explained only considering the Coulomb scattering process, was observed on a large helical device (LHD). This phenomenon often occurs in fusion reactivity enhancement and fast-ion slowing-down process that can be observed as a delay in the decay time of the D(d,n)3He neutron generation rate. The transferred energy required to induce such a reactivity enhancement or delay in the fast-ion slowing-down time (neutron decay time) was examined based on the Boltzmann−Fokker−Planck analysis in which a discrete energy transfer process, called nuclear elastic scattering (NES), is included. It was shown that even though the cross section of the NES is smaller than that of the Coulomb scattering, enough knock-on population appears in the energetic region in ion distribution function to induce the observable NES effects; thus, enough energy is transferred from beam ions to fast component of bulk ion distribution function indirectly and the transferred energy per unit time via NES is comparable to the Coulomb scattering rate. This study analytically demonstrates that the observed phenomena on LHD can be explained smoothly by considering the alternative indirect energy transfer channel between energetic ions, which can be comparable with the one via Coulomb scattering
Hitomi X-Ray Studies of Giant Radio Pulses from the Crab Pulsar
To search for giant X-ray pulses correlated with the giant radio pulses (GRPs) from the Crab pulsar, we performed a simultaneous observation of the Crab pulsar with the X-ray satellite Hitomi in the 2300 keV band and the Kashima NICT radio telescope in the 1.41.7 GHz band with a net exposure of about 2 ks on 2016 March 25, just before the loss of the Hitomi mission. The timing performance of the Hitomi instruments was confirmed to meet the timing requirement and about 1000 and 100 GRPs were simultaneously observed at the main pulse and inter-pulse phases, respectively, and we found no apparent correlation between the giant radio pulses and the X-ray emission in either the main pulse or inter-pulse phase. All variations are within the 2 fluctuations of the X-ray fluxes at the pulse peaks, and the 3 upper limits of variations of main pulse or inter-pulse GRPs are 22% or 80% of the peak flux in a 0.20 phase width, respectively, in the 2300 keV band. The values for main pulse or inter-pulse GRPs become 25% or 110%, respectively, when the phase width is restricted to the 0.03 phase. Among the upper limits from the Hitomi satellite, those in the 4.510 keV and 70300 keV bands are obtained for the first time, and those in other bands are consistent with previous reports. Numerically, the upper limits of the main pulse and inter-pulse GRPs in the 0.20 phase width are about (2.4 and 9.3) 10(exp 11) erg cm(exp 2), respectively. No significant variability in pulse profiles implies that the GRPs originated from a local place within the magnetosphere. Although the number of photon-emitting particles should temporarily increase to account for the brightening of the radio emission, the results do not statistically rule out variations correlated with the GRPs, because the possible X-ray enhancement may appear due to a >0.02% brightening of the pulse-peak flux under such conditions
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