879 research outputs found
A COMPARATIVE STUDY OF THE ULTRASTRUCTURE OF MICROVILLI IN THE EPITHELIUM OF SMALL AND LARGE INTESTINE OF MICE
A comparative analysis of the fine structure of the microvilli on jejunal and colonic epithelial cells of the mouse intestine has been made. The microvilli in these two locations demonstrate a remarkably similar fine structure with respect to the thickness of the plasma membrane, the extent of the filament-free zone, and the characteristics of the microfilaments situated within the microvillous core. Some of the core microfilaments appear to continue across the plasma membrane limiting the tip of the microvillus. The main difference between the microvilli of small intestine and colon is in the extent and organization of the surface coat. In the small intestine, in addition to the commonly observed thin surface "fuzz," occasional areas of the jejunal villus show a more conspicuous surface coat covering the tips of the microvilli. Evidence has been put forward which indicates that the surface coat is an integral part of the epithelial cells. In contrast to the jejunal epithelium, the colonic epithelium is endowed with a thicker surface coat. Variations in the organization of the surface coat at different levels of the colonic crypts have also been noted. The functional significance of these variations in the surface coat is discussed
Vaginal surgery for pelvic organ prolapse using mesh and a vaginal support device
OBJECTIVES: To describe a new surgical procedure for pelvic organ prolapse using mesh and a vaginal support device (VSD) and to report the results of surgery. DESIGN: A prospective observational study. SETTING: Two tertiary referral Urogynaecology practices. POPULATION: Ninety-five women with International Continence Society pelvic organ prolapse quantification stage 2 or more pelvic organ prolapse who underwent vaginal surgery using mesh augmentation and a VSD. METHODS: Surgery involved a vaginal approach with mesh reinforcement and placement of a VSD for 4 weeks. At 6 and 12 months, women were examined for prolapse recurrence, and visual analogue scales for satisfaction were completed. Women completed quality-of-life (QOL) questionnaires preoperatively and at 6 and 12 months. MAIN OUTCOME MEASURES: Objective success of surgery at 6 and 12 months following surgery. Secondary outcomes were subjective success, complications, QOL outcomes and patients' satisfaction. RESULTS: Objective success rate was 92 and 85% at 6 and 12 months, respectively. Subjective success rate was 91 and 87% at 6 and 12 months, respectively. New prolapse in nonrepaired compartments accounted for 7 of 12 (58%) failures at 12 months. Two of 4 mesh exposures required surgery. Sexual dysfunction was reported by 58% of sexually active women preoperatively and 23% at 12 months. QOL scores significantly improved at 12 months compared with baseline (P < 0.0001). CONCLUSION: Vaginal surgery using mesh and a VSD is an effective procedure for pelvic organ prolapse. However, further studies are required to establish the role of the surgery described in this study
Structure and Composition of Molecular Clouds with CN Zeeman Detections I: W3OH
We have carried out a multi-species study of a region which has had previous
measurements of strong magnetic fields through the CN Zeeman effect in order to
to explore the relationship between CN and NH, both of which have
evidence that they remain in the gas phase at densities of 10 - 10
cm. To achieve this we map the 1 arcmin region around the UCHII
region of W3(OH) using the Combined Array for Millimeter-wave Astronomy
(CARMA). Approximately 105 hours of data were collected in multiple array
configurations to produce maps with an effective resolution of
2.5\arcsec at high signal-to-noise in CN, CO, HCN, HCO, NH,
and two continuum bands (91.2 GHz and 112 GHz). These data allow us to compare
tracer molecules associated with both low and high density regions to infer gas
properties. We determine that CARMA resolves out approximately 35% of the CN
emission around W3(OH) when compared with spectra obtained from the IRAM-30
meter telescope. The presence of strong absorption lines towards the continuum
source in three of the molecular transitions infers the presence of a cold,
dark, optically thick region in front of the continuum source. In addition, the
presence of high-velocity emission lines near the continuum source shows the
presence of hot clumpy emission behind the continuum source. These data
determine that future high-resolution interferometric CN Zeeman measurements
which cannot currently be performed (due to technical limitations of current
telescopes) are feasible. We confirm that CN is indeed a good tracer for high
density regions; with certain objects such as W3(OH) it appears to be a more
accurate tracer than NH.Comment: 33 pages, 16 figures. Accepted by Ap
Infrared and radio observations of W51: Another Orion-KL at a distance of 7kpc
The bright infrared sources W51-IRS2 has at least three components with different physical and evolutionary properties. The spatial distribution and the near infrared spectra of the components in IRS2 are remarkably similar to, but more luminous than those found in Orion, where an H2 region of comparable linear size is also located close to a cluster of compact infrared sources. The characteristics of the nearby W51-NORTH H2O maser source, and the detection of 2 micro m H2 quadrupole emission in IRS2 indicate that the mass loss phenomena found in Orion-KL also exist in W51
A COMPARATIVE STUDY OF THE ULTRASTRUCTURE OF MICROVILLI IN THE EPITHELIUM OF SMALL AND LARGE INTESTINE OF MICE
Infrared studies of H II regions and dust clouds near K3 - 50
New ground-based infrared observations of the K3–50 region are reported at wavelengths between 2 and 34 μm, and at 1 mm. The main results are (a) that the visible nebula K3–50 is displaced from its infrared and radio counterparts, (b) that component C1 (the OH source ON-3) appears very faint at λ ⩽ 20μm, and is therefore probably obscured by several hundred magnitudes of visual extinction, (c) that both K3–50 and component Care associated with separate condensations of molecular hydrogen, each of about 3000 M⊙, and (d) there are no strong sources in this region at 20 μm other than those associated with H II condensations
Infrared studies of H II regions and dust clouds near K3 - 50
New ground-based infrared observations of the K3–50 region are reported at wavelengths between 2 and 34 μm, and at 1 mm. The main results are (a) that the visible nebula K3–50 is displaced from its infrared and radio counterparts, (b) that component C1 (the OH source ON-3) appears very faint at λ ⩽ 20μm, and is therefore probably obscured by several hundred magnitudes of visual extinction, (c) that both K3–50 and component Care associated with separate condensations of molecular hydrogen, each of about 3000 M⊙, and (d) there are no strong sources in this region at 20 μm other than those associated with H II condensations
A LOFAR mini-survey for low-frequency radio emission from the nearest brown dwarfs
We have conducted a mini-survey for low-frequency radio emission from some of the closest brown dwarfs to the Sun with rapid rotation rates: SIMP J013656.5 +093347, WISEPC 150649.97+702736.0, and WISEPA J174124.26+255319.5.We have placed robust 3s upper limits on the flux density in the 111 – 169 MHz frequency range for these targets: WISE 1506: < 0:72 mJy; WISE 1741: < 0:87 mJy; SIMP 0136: < 0:66 mJy. At 8 hours of integration per target to achieve these limits, we find that systematic and detailed study of this class of object at LOFAR frequencies will require a substantial dedication of resources
An infrared study of the NGC 7538 region
Infrared observations of the NGC 7538 region at wavelengths from 1 μm to 1 mm are presented and analysed with the aim of understanding both the large-scale structure of this region of current star formation and the properties of the individual compact objects within it. At far-infrared wavelengths (25–130 μm), emission is seen from the visible H II region, from the vicinity of the previously known maser sources and dust-embedded compact H II regions, and from a new region called NGC 7538(E). Coincident with NGC 7538(E) are a point-like 1–25 μm infrared source, NGC 7538-IRS9, which probably provides the power for the far-infrared emission, and an extended source of 2.2 μm emission which appears to be an infrared reflection nebula. NGC 7538-IRS9 strongly resembles the compact H II region NGC 7538-IRS1 in its infrared properties but shows no radio continuum emission. The compact H II regions, the maser sources and IRS9 are located within a dense molecular cloud at the edge of the optical H II region. This cloud, which has M∼9×10³M⊙, is detected in emission at 1 mm. The NGC 7538 region appears to contain examples of different stages in the formation of massive stars; it is suggested that the centre of star formation is moving systematically to the south-east in this region
An infrared study of the NGC 7538 region
Infrared observations of the NGC 7538 region at wavelengths from 1 μm to 1 mm are presented and analysed with the aim of understanding both the large-scale structure of this region of current star formation and the properties of the individual compact objects within it. At far-infrared wavelengths (25–130 μm), emission is seen from the visible H II region, from the vicinity of the previously known maser sources and dust-embedded compact H II regions, and from a new region called NGC 7538(E). Coincident with NGC 7538(E) are a point-like 1–25 μm infrared source, NGC 7538-IRS9, which probably provides the power for the far-infrared emission, and an extended source of 2.2 μm emission which appears to be an infrared reflection nebula. NGC 7538-IRS9 strongly resembles the compact H II region NGC 7538-IRS1 in its infrared properties but shows no radio continuum emission. The compact H II regions, the maser sources and IRS9 are located within a dense molecular cloud at the edge of the optical H II region. This cloud, which has M∼9×10³M⊙, is detected in emission at 1 mm. The NGC 7538 region appears to contain examples of different stages in the formation of massive stars; it is suggested that the centre of star formation is moving systematically to the south-east in this region
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