2,967 research outputs found
Neonatal-Onset Chronic Intestinal Pseudo-Obstruction Syndrome with In Utero Urological Manifestation as Megacystis
SummaryObjectiveWe describe a case of neonatal-onset chronic intestinal pseudo-obstruction syndrome (CIPS) with in utero urological manifestation as congenital megacystis. Pitfalls in the interpretation of prenatal sonographic appearance, genetic counseling, and differential diagnosis are discussed.Case ReportA 28-year-old Taiwanese woman, gravida 6, para 3, was referred for further sonographic examination because of a suspected fetal abdominal cyst. Targeted ultrasound at 28 weeks' gestation showed megacystis filling the abdominal cavity. The renal parenchyma appeared normal, and there was no evidence of reflux hydroureteronephrosis. At 38 weeks of gestation, the patient spontaneously delivered a female infant weighing 3,350 g with Apgar scores of 8 and 9 at 1 and 5 minutes, respectively. At the age of 12 days, the infant still required Foley catheterization because of voiding difficulty, so reduction cystoplasty was performed. The infant presented with recurrent episodes of intestinal obstruction thereafter and underwent ileostomy and resections of segmental intestine loops (3 times) in the ensuing years. At the age of 6 years, she is orally fed with partial parenteral infusion support, and the voiding act is satisfactory.ConclusionAttention should be given to the prenatal diagnosis of neonatal-onset CIPS when fetal congenital megacystis with unknown etiology is first detected. Whether there is any relationship between the megacystismicrocolon-intestinal-hypoperistalsis syndrome, CIPS, and pure congenital megacystis requires further study
Partial spin freezing in the quasi-two-dimensional La2(Cu,Li)O4
In conventional spin glasses, the magnetic interaction is not strongly
anisotropic and the entire spin system freezes at low temperature. In
La2(Cu,Li)O4, for which the in-plane exchange interaction dominates the
interplane one, only a fraction of spins with antiferromagnetic correlations
extending to neighboring planes become spin-glass. The remaining spins with
only in-plane antiferromagnetic correlations remain spin-liquid at low
temperature. Such a novel partial spin freezing out of a spin-liquid observed
in this cold neutron scattering study is likely due to a delicate balance
between disorder and quantum fluctuations in the quasi-two dimensional S=1/2
Heisenberg system.Comment: 4 pages, 4 figure
Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. IV. H Time Lags and Implications for Super-Eddington Accretion
We have completed two years of photometric and spectroscopic monitoring of a
large number of active galactic nuclei (AGNs) with very high accretion rates.
In this paper, we report on the result of the second phase of the campaign,
during 2013--2014, and the measurements of five new H time lags out of
eight monitored AGNs. All five objects were identified as super-Eddington
accreting massive black holes (SEAMBHs). The highest measured accretion rates
for the objects in this campaign are , where
,
is the mass accretion rates, is the Eddington luminosity and
is the speed of light. We find that the H time lags in SEAMBHs are
significantly shorter than those measured in sub-Eddington AGNs, and the
deviations increase with increasing accretion rates. Thus, the relationship
between broad-line region size () and optical luminosity at
5100\AA, , requires accretion rate as an additional
parameter. We propose that much of the effect may be due to the strong
anisotropy of the emitted slim-disk radiation. Scaling by
the gravitational radius of the black hole, we define a new radius-mass
parameter () and show that it saturates at a critical accretion rate of
, indicating a transition from thin to slim
accretion disk and a saturated luminosity of the slim disks. The parameter
is a very useful probe for understanding the various types of accretion onto
massive black holes. We briefly comment on implications to the general
population of super-Eddington AGNs in the universe and applications to
cosmology.Comment: 53 pages, 12 figures, 7 tables, accepted for publication in The
Astrophysical Journa
- …