113 research outputs found
Rapunzel syndrome: A South African variety
Trichobezoars are intraluminal accretions of ingested hair. Rapunzel syndrome is a rare and extreme presentation, with the trichobezoar extending into the small intestine. It is most frequently reported in children and psychiatric patients. We report a South African series of 5 patients who presented with trichobezoars. Each patient was retrospectively reviewed and analysed with regard to background, demographics, clinical presentation, diagnosis, surgical management and complications. Five female patients with a median age of 19 (range 12 - 27) years presented with clinical symptoms, including early satiety, intermittent vomiting with gastric outlet obstruction, abdominal pain and weight loss. The diagnosis was made by endoscopy, abdominal computed tomography (CT) imaging, barium meal examination or plain abdominal radiography. Two patients presented with sealed/contained gastric perforations, and 1 patient with a smallbowel perforation. All 5 bezoars, 2 of which consisted entirely of artificial hair extensions, extended into the jejunum, the longest measuring 1.4 m. All were removed by laparotomy. While trichobezoars are a rare entity, they may present with significant complications, such as obstructions and perforations. In view of the infection risk and considerable size of many of these bezoars, an open removal is probably safer than any minimally invasive attempt.S Afr Med J 2018;108(7):559-562
Radial Velocities of Six OB Stars
We present new results from a radial velocity study of six bright OB stars
with little or no prior measurements. One of these, HD 45314, may be a
long-period binary, but the velocity variations of this Be star may be related
to changes in its circumstellar disk. Significant velocity variations were also
found for HD 60848 (possibly related to nonradial pulsations) and HD 61827
(related to wind variations). The other three targets, HD 46150, HD 54879, and
HD 206183, are constant velocity objects, but we note that HD 54879 has
H emission that may originate from a binary companion. We illustrate
the average red spectrum of each target.Comment: Accepted for publication in PASP July 2007 issu
Spectroscopic analysis of the B/Be visual binary HR 1847
We studied both components of a slightly overlooked visual binary HR 1847
spectroscopically to determine its basic physical and orbital parameters. Basic
stellar parameters were determined by comparing synthetic spectra to the
observed echelle spectra, which cover both the optical and near-IR regions. New
observations of this system used the Ond\v{r}ejov and Rozhen 2-m telescopes and
their coud\'e spectrographs. Radial velocities from individual spectra were
measured and then analysed with the code {\FOTEL} to determine orbital
parameters. The spectroscopic orbit of HR 1847A is presented for the first
time. It is a single-lined spectroscopic binary with a B-type primary, a period
of 719.79 days, and a highly eccentric orbit with e=0.7. We confirmed that HR
1847B is a Be star. Its H\alpha emission significantly decreased from 2003 to
2008. Both components have a spectral type B7-8 and luminosity class IV-V.Comment: Astronomy and Astrophysics, accepte
The Long Period, Massive Binaries HD 37366 and HD 54662: Potential Targets for Long Baseline Optical Interferometry
We present the results from an optical spectroscopic analysis of the massive
stars HD 37366 and HD 54662. We find that HD 37366 is a double-lined
spectroscopic binary with a period of 31.8187 +/- 0.0004 days, and HD 54662 is
also a double lined binary with a much longer period of 557.8 +/- 0.3 days. The
primary of HD 37366 is classified as O9.5 V, and it contributes approximately
two-thirds of the optical flux. The less luminous secondary is a broad-lined,
early B-type main-sequence star. Tomographic reconstruction of the individual
spectra of HD 37366 reveals absorption lines present in each component,
enabling us to constrain the nature of the secondary and physical
characteristics of both stars. Tomographic reconstruction was not possible for
HD 54662; however, we do present mean spectra from our observations that show
that the secondary component is approximately half as bright as the primary.
The observed spectral energy distributions (SEDs) were fit with model SEDs and
galactic reddening curves to determine the angular sizes of the stars. By
assuming radii appropriate for their classifications, we determine distance
ranges of 1.4 - 1.9 and 1.2 - 1.5 kpc for HD 37366 and HD 54662, respectively.Comment: 27 pages, 8 figures, Accepted for publication in Ap
Rapunzel syndrome: A South African variety
Trichobezoars are intraluminal accretions of ingested hair. Rapunzel syndrome is a rare and extreme presentation, with the trichobezoar extending into the small intestine. It is most frequently reported in children and psychiatric patients. We report a South African series of 5 patients who presented with trichobezoars. Each patient was retrospectively reviewed and analysed with regard to background, demographics, clinical presentation, diagnosis, surgical management and complications. Five female patients with a median age of 19 (range 12 - 27) years presented with clinical symptoms, including early satiety, intermittent vomiting with gastric outlet obstruction, abdominal pain and weight loss. The diagnosis was made by endoscopy, abdominal computed tomography (CT) imaging, barium meal examination or plain abdominal radiography. Two patients presented with sealed/contained gastric perforations, and 1 patient with a small-bowel perforation. All 5 bezoars, 2 of which consisted entirely of artificial hair extensions, extended into the jejunum, the longest measuring 1.4 m. All were removed by laparotomy. While trichobezoars are a rare entity, they may present with significant complications, such as obstructions and perforations. In view of the infection risk and considerable size of many of these bezoars, an open removal is probably safer than any minimally invasive attempt
A Spectroscopic Study of Field and Runaway OB Stars
Identifying binaries among runaway O- and B-type stars offers valuable
insight into the evolution of open clusters and close binary stars. Here we
present a spectroscopic investigation of 12 known or suspected binaries among
field and runaway OB stars. We find new orbital solutions for five single-lined
spectroscopic binaries (HD 1976, HD 14633, HD 15137, HD 37737, and HD 52533),
and we classify two stars thought to be binaries (HD 30614 and HD 188001) as
single stars. In addition, we reinvestigate their runaway status using our new
radial velocity data with the UCAC2 proper motion catalogs. Seven stars in our
study appear to have been ejected from their birthplaces, and at least three of
these runaways are spectroscopic binaries and are of great interest for future
study.Comment: 21 pages, 1 figure, 7 tables; Accepted to Ap
Rapunzel syndrome: A South African variety
Trichobezoars are intraluminal accretions of ingested hair. Rapunzel syndrome is a rare and extreme presentation, with the trichobezoar extending into the small intestine. It is most frequently reported in children and psychiatric patients. We report a South African series of 5 patients who presented with trichobezoars. Each patient was retrospectively reviewed and analysed with regard to background, demographics, clinical presentation, diagnosis, surgical management and complications. Five female patients with a median age of 19 (range 12 - 27) years presented with clinical symptoms, including early satiety, intermittent vomiting with gastric outlet obstruction, abdominal pain and weight loss. The diagnosis was made by endoscopy, abdominal computed tomography (CT) imaging, barium meal examination or plain abdominal radiography. Two patients presented with sealed/contained gastric perforations, and 1 patient with a small-bowel perforation. All 5 bezoars, 2 of which consisted entirely of artificial hair extensions, extended into the jejunum, the longest measuring 1.4 m. All were removed by laparotomy. While trichobezoars are a rare entity, they may present with significant complications, such as obstructions and perforations. In view of the infection risk and considerable size of many of these bezoars, an open removal is probably safer than any minimally invasive attempt
An optically stimulated superconducting-like phase in K3C60 far above equilibrium Tc
The control of non-equilibrium phenomena in complex solids is an important
research frontier, encompassing new effects like light induced
superconductivity. Here, we show that coherent optical excitation of molecular
vibrations in the organic conductor K3C60 can induce a non-equilibrium state
with the optical properties of a superconductor. A transient gap in the real
part of the optical conductivity and a low-frequency divergence of the
imaginary part are measured for base temperatures far above equilibrium Tc=20
K. These findings underscore the role of coherent light fields in inducing
emergent order.Comment: 40 pages, 23 figure
The Spectroscopic Orbit of the Evolved Binary HD 197770
We have used spectra taken between 1992 and 1997 to derive the spectroscopic
orbit of the eclipsing double-lined spectroscopic binary HD 197770. This binary
has a period of 99.69 +/- 0.02 days and K amplitudes of 31.2 +/- 0.8 and 47.1
+/- 0.4 km s^{-1} for components A & B, respectively. The msin^{3}i values for
A & B are 2.9 and 1.9, respectively, and are close to the actual masses due to
the eclipsing nature of this binary. Both components of HD 197770 have spectral
types near B2 III. This means both components are undermassive by about a
factor of five and, thus, evolved stars. Additional evidence of the evolved
nature of HD 197770 is found in 25, 60, and 100 micron IRAS images of HD
197770. These images show 2 apparent shells centered on HD 197770; a bright 60
micron shell with a 14' diameter and a larger (1.2 degeree diameter)
bubble-like feature. At least one of the components of HD 197770 is likely to
be a post-AGB star.Comment: will be published in the AJ (1998 June), also availible at
http://snake.phys.lsu.edu/~gordon/papers/hd197770.htm
25 Orionis: A Kinematically Distinct 10 Myr Old Group in Orion OB1a
We report here on the photometric and kinematic properties of a well defined
group of nearly 200 low-mass pre-main sequence stars, concentrated within ~ 1
deg of the early-B star 25 Ori, in the Orion OB1a sub-association. We refer to
this stellar aggregate as the 25 Orionis group. The group also harbors the
Herbig Ae/Be star V346 Ori and a dozen other early type stars with photometry,
parallaxes, and some with IR excess emission, consistent with group membership.
The number of high and low-mass stars is in agreement with expectations from a
standard Initial Mass Function. The velocity distribution for the young stars
in 25 Ori shows a narrow peak centered at 19.7 km/s, very close to the velocity
of the star 25 Ori. Our results provide new and compelling evidence that the 25
Ori group is a distinct kinematic entity, and that considerable space and
velocity structure is present in the Ori OB1a sub-association. The low-mass
members follow a well defined band in the color-magnitude diagram, consistent
with an isochronal age of ~ 7-10 Myr, depending on the assumed evolutionary
model. The highest density of members is located near the star 25 Ori, but the
actual extent of the cluster cannot be well constrained with our present data.
In a simple-minded kinematic evolution scenario, the 25 Ori group may represent
the evolved counterpart of a younger aggregate like the sigma Ori cluster. The
25 Ori stellar aggregate is the most populous ~ 10 Myr sample yet known within
500 pc, setting it as an excellent laboratory to study the evolution of
solar-like stars and protoplanetary disks.Comment: 28 pages, 5 figures. Astrophysical Journal, in press. Abridged
abstrac
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