193 research outputs found
Tau phosphorylation at Alzheimer\u27s disease-related Ser356 contributes to tau stabilization when PAR-1/MARK activity is elevated.
Abnormal phosphorylation of the microtubule-associated protein tau is observed in many neurodegenerative diseases, including Alzheimer\u27s disease (AD). AD-related phosphorylation of two tau residues, Ser262 and Ser356, by PAR-1/MARK stabilizes tau in the initial phase of mismetabolism, leading to subsequent phosphorylation events, accumulation, and toxicity. However, the relative contribution of phosphorylation at each of these sites to tau stabilization has not yet been elucidated. In a Drosophila model of human tau toxicity, we found that tau was phosphorylated at Ser262, but not at Ser356, and that blocking Ser262 phosphorylation decreased total tau levels. By contrast, when PAR-1 was co-overexpressed with tau, tau was hyperphosphorylated at both Ser262 and Ser356. Under these conditions, the protein levels of tau were significantly elevated, and prevention of tau phosphorylation at both residues was necessary to completely suppress this elevation. These results suggest that tau phosphorylation at Ser262 plays the predominant role in tau stabilization when PAR-1/MARK activity is normal, whereas Ser356 phosphorylation begins to contribute to this process when PAR-1/MARK activity is abnormally elevated, as in diseased brains
Identification and Radiofrequency Catheter Ablation of a Nonsustained Atrial Tachycardia at the Septal Mitral Annulus with the Use of a Noncontact Mapping System: A Case Report
AbstractHere we report a case of a 16-year old female with symptomatic nonsustained atrial tachycardia (NSAT) originating from the septal mitral annulus. NSAT was induced by atrial burst pacing after an intravenous isoproterenol (ISP) injection. The array mode of the noncontact mapping system (NCM) allowed us to quickly identify the tachycardia focus at the septal mitral annulus, where the contact bipolar voltage map revealed no low voltage area (<0.5 mV). The NSAT was eliminated by a radiofrequency energy application to the identified tachycardia focus during sinus rhythm, and the patient has been free from any symptoms during 10 months of follow-up
Low energy proton-proton scattering in effective field theory
Low energy proton-proton scattering is studied in pionless effective field
theory. Employing the dimensional regularization and MS-bar and power
divergence subtraction schemes for loop calculation, we calculate the
scattering amplitude in 1S0 channel up to next-to-next-to leading order and fix
low-energy constants that appear in the amplitude by effective range
parameters. We study regularization scheme and scale dependence in separation
of Coulomb interaction from the scattering length and effective range for the
S-wave proton-proton scattering.Comment: 23 pages, 6 eps figures, revised considerably, accepted for
publication in Phys. Rev.
An Alternative Approach for Radiofrequency Catheter Ablation for Intra-atrial Reentrant Tachycardia Associated with Open-Heart Surgery
We present case reports of 2 patients with scar-related intra-atrial reentrant tachycardia (IART) associated with previous open-heart surgeries, in which standard ablation strategies failed to eliminate atrial tachycardia (AT). The strategies targeted a narrow conducting channel between the right atrial scars or between the scar and inferior vena cava. In these patients, an alternative approach to transect another narrow conducting pathway between the scar and crista terminalis (CT), which was revealed by a noncontact mapping system, successfully terminated and eliminated the IART. Both the cases were free of recurrent AT at the 24-and 25-month follow up visits, respectively. Transection of the corridor between the CT and the incision scar appears to be an effective technique for eliminating scar-related IART and can be considered as a second-line procedure for radiofrequency catheter ablation to eliminate IART
X-ray magnetic circular dichroism and photoemission study of the diluted ferromagnetic semiconductor ZnCrTe
We have performed x-ray magnetic circular dichroism (XMCD) and valence-band
photoemission studies of the diluted ferromagnetic semiconductor
ZnCrTe. XMCD signals due to ferromagnetism were observed at the Cr
2p absorption edge. Comparison with atomic multiplet calculations suggests that
the magnetically active component of the Cr ion was divalent under the
tetrahedral crystal field with tetragonal distortion along the crystalline a-,
b-, and c-axes. In the valence-band spectra, spectral weight near the Fermi
level was strongly suppressed, suggesting the importance of Jahn-Teller effect
and the strong Coulomb interaction between the Cr 3d electrons
SDSSp J104433.04012502.2 at is Gravitationally Magnified by an Intervening Galaxy
During the course of our optical deep survey program on L emitters at
in the sky area surrounding the quasar SDSSp
J104433.04012502.2 at , we found that a faint galaxy with (AB)
is located at \timeform{1".9} southwest of the quasar. Its
broad-band color properties from to suggest that the galaxy is
located at a redshift of -- 2.5. This is consistent with no strong
emission line in our optical spectroscopy. Since the counter image of the
quasar cannot be seen in our deep optical images, the magnification factor
seems not to be very high. Our modest estimate is that this quasar is
gravitationally magnified by a factor of 2.Comment: 11 pages, 5 figures, PASJ, in pres
The Discovery of a Very Narrow-Line Star Forming Obat a Redshift of 5.66ject
We report on the discovery of a very narrow-line star forming object beyond
redshift of 5. Using the prime-focus camera, Suprime-Cam, on the 8.2 m Subaru
telescope together with a narrow-passband filter centered at
= 8150 \AA with passband of = 120 \AA, we have obtained a very
deep image of the field surrounding the quasar SDSSp J104433.04012502.2 at a
redshift of 5.74. Comparing this image with optical broad-band images, we have
found an object with a very strong emission line. Our follow-up optical
spectroscopy has revealed that this source is at a redshift of
, forming stars at a rate
yr. Remarkably, the velocity dispersion of Ly-emitting gas is
only 22 km s. Since a blue half of the Ly emission could be
absorbed by neutral hydrogen gas, perhaps in the system, a modest estimate of
the velocity dispersion may be 44 km s. Together with a linear
size of 7.7 kpc, we estimate a lower limit of the dynamical mass
of this object to be . It is thus suggested that
LAE J10440123 is a star-forming dwarf galaxy (i.e., a subgalactic object or
a building block) beyond redshift 5 although we cannot exclude a possibility
that most Ly emission is absorbed by the red damping wing of neutral
intergalactic matter.Comment: 6 pages, 2 figures. ApJ Letters, in pres
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Objective: Outcomes of tracheoesophageal diversion and laryngotracheal separation were evaluated in 15 neurologically impaired children treated for intractable aspiration.
Methods: A retrospective analysis of the hospital records was carried out in 15 consecutive pediatric patients who underwent either tracheoesophageal diversion or laryngotracheal separation with trumpet-shaped tracheotomy from 1999 to 2006 in Kagawa Childrenâs Hospital.
Results: The number of hospital admissions for aspiration pneumonia after surgery was signiïŹcantly decreased in 6 patients who were cared for at home. The parent-reported number of secretion suctioning was decreased after surgery especially in patients with pre-operative tracheotomy or intubation. Four patients fed through naso-gastric tube progressed with oral diet post-operatively, whereas 3 patients who had pre-operative tracheotomy developed temporary post-operative tracheocutaneous ïŹstula that was managed by local wound care.
Conclusion: It is suggested that tracheoesophageal diversion and laryngotracheal separation decrease the morbidity of pediatric patients and improve their quality of life and that of their parents. It is suggested that the risk of developing post-operative ïŹstula is higher in pediatric patients with than without pre-operative tracheotomy
A Young Brown Dwarf Companion to DH Tauri
We present the detection of a young brown dwarf companion DH Tau B associated
with the classical T Tauri star DH Tau. Near-infrared coronagraphic
observations with CIAO on the Subaru Telescope have revealed DH Tau B with H =
\~15 mag located at 2.3" (330 AU) away from the primary DH Tau A. Comparing its
position with a Hubble Space Telescope archive image, we confirmed that DH Tau
A and B share the common proper motion, suggesting that they are physically
associated with each other. The near-infrared color of DH Tau B is consistent
with those of young stellar objects. The near-infrared spectra of DH Tau B show
deep water absorption bands, a strong K I absorption line, and a moderate Na I
absorption line. We derived its effective temperature and surface gravity of
Teff = 2700 -- 2800 K and log g = 4.0--4.5, respectively, by comparing the
observed spectra with synthesized spectra of low-mass objects. The location of
DH Tau B on the HR diagram gives its mass of 30 -- 50 M_Jupiter.Comment: 10 pages, 14 figures, 1 table, accepted for publication in Ap
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