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Grulke S Deby-Dupont G Cassart D Gangl M Caudron I Lamy M Serteyn D 《Veterinary pathology》2003,40(1):8-13
In cases of equine acute abdominal disease, where pancreatic damage is suspected, pancreatic damage can be assessed by measuring increased trypsin activity in the plasma of horses suffering intestinal obstruction and severe shock. The pancreas is particularly vulnerable to splanchnic hypoperfusion because it is a highly active tissue. In this study, 10 horses undergoing abdominal surgery for intestinal obstruction were assayed for trypsin activity on admission and, because of extensive intestinal lesions that were not amenable to surgery, euthanasia was selected; the pancreas was removed before euthanasia. Trypsin activity in the plasma of these horses was significantly higher than in healthy horses (196 ng/ml +/- 128.2 versus 28.5 ng/ml +/- 19.2; P = 0.0026). Light and transmission electron microscopy revealed slight to severe lesions of vacuolar degeneration, a few zymogen granules, dilation of the endoplasmic reticulum, and swelling of mitochondria in the exocrine pancreas. The activation of an inflammatory cascade occurring during strangulating intestinal obstruction could increase pancreatic anoxic lesions caused by severe shock and hypoperfusion in the horse. Further studies will show the significance of pancreatic lesions and the ensuing damage in equine acute intestinal obstruction and shock. 相似文献
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Weaver HA Sekanina Z Toth I Delahodde CE Hainaut OR Lamy PL Bauer JM A'Hearn MF Arpigny C Combi MR Davies JK Feldman PD Festou MC Hook R Jorda L Keesey MS Lisse CM Marsden BG Meech KJ Tozzi GP West R 《Science (New York, N.Y.)》2001,292(5520):1329-1333
At least 16 fragments were detected in images of comet C/1999 S4 (LINEAR) taken on 5 August 2000 with the Hubble Space Telescope (HST) and on 6 August with the Very Large Telescope (VLT). Photometric analysis of the fragments indicates that the largest ones have effective spherical diameters of about 100 meters, which implies that the total mass in the observed fragments was about 2 x 10(9) kilograms. The comet's dust tail, which was the most prominent optical feature in August, was produced during a major fragmentation event, whose activity peaked on UT 22.8 +/- 0.2 July 2000. The mass of small particles (diameters less than about 230 micrometers) in the tail was about 4 x 10(8) kilograms, which is comparable to the mass contained in a large fragment and to the total mass lost from water sublimation after 21 July 2000 (about 3 x 10(8) kilograms). HST spectroscopic observations during 5 and 6 July 2000 demonstrate that the nucleus contained little carbon monoxide ice (ratio of carbon monoxide to water is less than or equal to 0.4%), which suggests that this volatile species did not play a role in the fragmentation of C/1999 S4 (LINEAR). 相似文献
6.
During the past 25 years there have been many attempts to detect a possible dust ring around the sun, with contradictory results. Before the 1991 eclipse, infrared eclipse experiments used single-element detectors to scan the corona along the ecliptic for excess surface brightness peaks. The availability of relatively large-format infrared array detectors now provides a considerable observational advantage: two-dimensional mapping of the brightness and polarization of the corona with high photometric precision. The 1991 eclipse path included the high-altitude Mauna Kea Observatory, a further advantage to measure the corona out to large angular distances from the sun. Results are reported from an experiment conducted on Mauna Kea with a HgCdTe-array detector sensitive to wavelengths between 1 and 2.5 micrometers, using broad-band J, H, and K filters. Although the sky conditions were not ideal, the H- and K-band surface brightnesses clearly show the inhomogeneous structure in the K-corona and the elliptical flattening of the F-corona, but no evidence of a circumsolar, local dust component out to 15 solar radii. 相似文献
7.
Keller HU Jorda L Küppers M Gutierrez PJ Hviid SF Knollenberg J Lara LM Sierks H Barbieri C Lamy P Rickman H Rodrigo R 《Science (New York, N.Y.)》2005,310(5746):281-283
The OSIRIS cameras (optical, spectroscopic, and infrared remote imaging system) onboard the European Space Agency's Rosetta spacecraft observed comet 9P/Tempel 1 for 17 days continuously around the time of NASA's Deep Impact mission. The cyanide-to-water production ratio was slightly enhanced in the impact cloud, compared with that of normal comet activity. Dust particles were flowing outward in the coma at >160 meters per second, accelerated by the gas. The slope of the brightness increase showed a dip about 200 seconds after the impact. Dust Afrho values before and long after the impact confirm the slight decrease of cometary activity. The dust-to-water mass ratio was much larger than 1. 相似文献
8.
Pätzold M Andert TP Asmar SW Anderson JD Barriot JP Bird MK Häusler B Hahn M Tellmann S Sierks H Lamy P Weiss BP 《Science (New York, N.Y.)》2011,334(6055):491-492
Asteroid 21 Lutetia was approached by the Rosetta spacecraft on 10 July 2010. The additional Doppler shift of the spacecraft radio signals imposed by 21 Lutetia's gravitational perturbation on the flyby trajectory were used to determine the mass of the asteroid. Calibrating and correcting for all Doppler contributions not associated with Lutetia, a least-squares fit to the residual frequency observations from 4 hours before to 6 hours after closest approach yields a mass of (1.700 ± 0.017) × 10(18) kilograms. Using the volume model of Lutetia determined by the Rosetta Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) camera, the bulk density, an important parameter for clues to its composition and interior, is (3.4 ± 0.3) × 10(3) kilograms per cubic meter. 相似文献
9.
Andosols developed on basaltic material are naturally rich in metals. Organic matter and allophane, the key colloids of these soils, have a strong affinity for trace metals, but are intimately mixed so that speciation of trace metal is difficult to determine. We used three complementary approaches, namely physical fractionation, chemical extraction and potentiometric measurement, to distinguish them. Physical particle-size separations and chemical selective dissolution of allophanes and organic matter were combined to demonstrate relations between the occurrence of colloids and contents of Cu and Zn in an andic B horizon. About 22% of total soil Cu and 7% of total soil Zn were present in the < 5-μm fraction, associated with organic or amorphous mineral constituents. To support this association further, the affinity of soil colloids for Cu and Zn in a mimicked system was demonstrated. An Al-rich allophane was synthesized, and a portion of the organic matter was extracted from the clay fraction, and their reactivities towards Cu2+ or Zn2+ were studied by potentiometry. The two metallic cations displayed specific affinity towards allophane or soluble organic matter. Furthermore, the behaviour of copper and zinc in the ternary system, allophane + soluble organic matter + trace element, revealed a synergy in the surface complexation. The use of these three speciation approaches highlighted the linkage between metals and constituents, and showed how important the colloidal constituents are in the behaviour of Cu and Zn in Andosols. 相似文献
10.
N. Grati-Kamoun F. Lamy Mahmoud A. Rebaï A. Gargouri O. Panaud A. Saar 《Genetic Resources and Crop Evolution》2006,53(2):265-275
About 29 olive (Olea europaea L.) cultivars including oil and table olive cultivars originating from Tunisia and other Mediterranean countries, were genotyped
using amplified fragment length polymorphism (AFLP) DNA markers. This technique is a rapid and efficient method for producing
DNA fingerprints. Using nine AFLP primer combinations, we produced a total of 410 AFLP markers, among which 172 revealed polymorphism.
The results demonstrated a high degree of polymorphism in the olive germplasm we examined with an average of 39%. These AFLP
markers were analyzed to estimate genetic distances between pairs of cultivars using Jaccard’s similarity coefficient. Furthermore,
cluster and principal component analyses were performed in order to identify the genetic variation patterns. Two main groups
were obtained: one comprising primarily small-fruited cultivars grown mainly for oil production and the other comprising large
fruited cultivars (regardless of their end-use). Our results show no evidence of clustering of olive cultivars according to
their geographic origin. 相似文献