1,792 research outputs found
Hereditary Systemic Angiopathy (HSA) with cerebral calcifications, retinopathy, progressive nephropathy, and hepatopathy
Several hereditary conditions affecting cerebral, retinal and systemic microvessels have recently been described. They include CADASIL, CRV, and HERNS. We here report on a variant form of a hereditary systemic angiopathy (HSA) affecting two generations of a Caucasian family. Clinical symptoms of HSA appear in the mid-forties and are characterized by visual impairment, migrainelike headache, skin rash, epileptic seizures, progressive motor paresis and cognitive decline. Late symptoms include hepatic and renal failure. Retinal capillary microaneurysms and arteriolar tortuosity are associated with marked optic disc atrophy. Radiological hallmarks consist of multiple cerebral calcifications and tumor-like subcortical white matter lesions. Brain, peripheral nerve, muscle, kidney and colon biopsies have revealed a multi organ small vessel involvement with partly altered endothelium, perivascular inflammation and thrombotic microangiopathy. No curative therapeutic options are known for hereditary cerebral vasculopathies. The use of cyclophosphamide, azathioprine and methotrexate was of no benefit in our cases of HSA. Early diagnosis of hereditary systemic angiopathies is important in order to prevent patients from repetitive invasive diagnostic measures and to avoid the use of inappropriate and potentially harmful drug
Mitochondrial precursor proteins are imported through a hydrophilic membrane environment
We have analyzed how translocation intermediates of imported mitochondrial precursor proteins, which span contact sites, interact with the mitochondrial membranes. F1-ATPase subunit β(F1β) was trapped at contact sites by importing it into Neurospora mitochondria in the presence of low levels of nucleoside triphosphates. This F1β translocation intermediate could be extracted from the membranes by treatment with protein denaturants such as alkaline pH or urea. By performing import at low temperatures, the ADP/ATP carrier was accumulated in contact sites of Neurospora mitochondria and cytochrome b2 in contact sites of yeast mitochondria. These translocation intermediates were also extractable from the membranes at alkaline pH. Thus, translocation of precursor proteins across mitochondrial membranes seems to occur through an environment which is accessible to aqueous perturbants. We propose that proteinaceous structures are essential components of a translocation apparatus present in contact sites
Sub-Poissonian statistics in order-to-chaos transition
We study the phenomena at the overlap of quantum chaos and nonclassical
statistics for the time-dependent model of nonlinear oscillator. It is shown in
the framework of Mandel Q-parameter and Wigner function that the statistics of
oscillatory excitation number is drastically changed in order-to chaos
transition. The essential improvement of sub-Poissonian statistics in
comparison with an analogous one for the standard model of driven anharmonic
oscillator is observed for the regular operational regime. It is shown that in
the chaotic regime the system exhibits the range of sub- and super-Poissonian
statistics which alternate one to other depending on time intervals. Unusual
dependence of the variance of oscillatory number on the external noise level
for the chaotic dynamics is observed.Comment: 9 pages, RevTeX, 14 figure
Isospin Dependence in the Odd-Even Staggering of Nuclear Binding Energies
The FRS-ESR facility at GSI provides unique conditions for precision
measurements of large areas on the nuclear mass surface in a single experiment.
Values for masses of 604 neutron-deficient nuclides (30<=Z<=92) were obtained
with a typical uncertainty of 30 microunits. The masses of 114 nuclides were
determined for the first time. The odd-even staggering (OES) of nuclear masses
was systematically investigated for isotopic chains between the proton shell
closures at Z=50 and Z=82. The results were compared with predictions of modern
nuclear models. The comparison revealed that the measured trend of OES is not
reproduced by the theories fitted to masses only. The spectral pairing gaps
extracted from models adjusted to both masses, and density related observables
of nuclei agree better with the experimental data.Comment: Physics Review Letters 95 (2005) 042501
http://link.aps.org/abstract/PRL/v95/e04250
High-resolution measurement of the time-modulated orbital electron capture and of the decay of hydrogen-like Pm ions
The periodic time modulations, found recently in the two-body orbital
electron-capture (EC) decay of both, hydrogen-like Pr and
Pm ions, with periods near to 7s and amplitudes of about 20%,
were re-investigated for the case of Pm by using a 245 MHz
resonator cavity with a much improved sensitivity and time resolution. We
observed that the exponential EC decay is modulated with a period s, in accordance with a modulation period s as obtained
from simultaneous observations with a capacitive pick-up, employed also in the
previous experiments. The modulation amplitudes amount to and
for the 245 MHz resonator and the capacitive pick-up,
respectively. These new results corroborate for both detectors {\it exactly}
our previous findings of modulation periods near to 7s, though with {\it
distinctly smaller} amplitudes. Also the three-body decays have been
analyzed. For a supposed modulation period near to 7s we found an amplitude , compatible with and in agreement with the preliminary
result of our previous experiment. These observations could
point at weak interaction as origin of the observed 7s-modulation of the EC
decay. Furthermore, the data suggest that interference terms occur in the
two-body EC decay, although the neutrinos are not directly observed.Comment: In memoriam of Prof. Paul Kienle, 9 pages, 1 table, 5 figures Phys.
Lett. B (2013) onlin
Schottky mass measurements of heavy neutron-rich nuclides in the element range 70\leZ \le79 at the ESR
Storage-ring mass spectrometry was applied to neutron-rich Au
projectile fragments. Masses of Lu, Hf, Ta,
W, and Re nuclei were measured for the first time. The
uncertainty of previously known masses of W and Os nuclei
was improved. Observed irregularities on the smooth two-neutron separation
energies for Hf and W isotopes are linked to the collectivity phenomena in the
corresponding nuclei.Comment: 10 pages, 9 figures, 2 table
The validity of the Landau-Zener model for output coupling of Bose condensates
We investigate the validity of the Landau-Zener model in describing the
output coupling of Bose condensates from magnetic traps by a chirped
radiofrequency field. The predictions of the model are compared with the
numerical solutions of the Gross-Pitaevskii equation. We find a dependence on
the chirp direction, and also quantify the role of gravitation.Comment: 4 pages, Late
Present and Future Experiments with Stored Exotic Nuclei at Relativistic Energies
Recent progress is presented from experiments on masses and lifetimes of bare
and few-electron exotic nuclei at GSI.Comment: Proceedings of International Conference on "Frontiers in Nuclear
Structure, Astrophysics and Reactions", Kos, Greece, September 12-17, 200
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