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排序方式: 共有136条查询结果,搜索用时 46 毫秒
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Morphological and immunological findings of three dogs with primary lymphangiectasia are described and compared with three normal dogs. Scanning electron microscopy showed distended and fused intestinal villi in dogs with intestinal lymphangiectasia, and morphometric evaluation revealed deeper crypts in the small intestine of dogs with intestinal lymphangiectasia. Although plasma cells of all classes were diminished in the cranial parts of the small intestine, there was an absolute and relative increase of immunoglobulin G-containing plasma cells in the caudal small intestine in dogs with intestinal lymphangiectasia. 相似文献
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JI Yun HJ Park MH Park MS Kim JH Choi E Lee SP Gong JM Lim ST Lee 《Reproduction in domestic animals》2014,49(5):705-710
Recently, isolation and in vitro culture of putative spermatogonial stem cells (SSCs) in the domestic cat have been conducted. However, the cellular niche conditions that facilitate the establishment and long‐term maintenance of feline SSCs (FSSCs) have not been described. Therefore, we investigated the type of feeder cells used to stimulate colony formation and growth of FSSCs among the various factors in the FSSC niche. Spermatogonial stem cells isolated from feline testes were cultured on mitotically inactivated testicular stromal cells (TSCs) derived from cats, dogs and mice, and mouse embryonic fibroblasts (MEFs). The formation and growth of colonies derived from SSCs cultured on each type of feeder cell were identified at passage 0, and the morphology, alkaline phosphatase (AP) activity and expression of SSC‐specific genes in surviving colonies were investigated at passage 4. Among these diverse feeder cells, TSCs from cat showed the greatest colony formation, growth and maintenance of FSSCs, and SSC colonies cultured by passage 4 showed a typical dome‐shaped morphology, AP activity and expression of SSC‐specific genes (NANOG, OCT4, SOX2 and CD9). Accordingly, these results demonstrate that feline TSCs could be used as feeder cells to support the establishment and maintenance of SSCs from domestic cats. 相似文献
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Cyanide adsorption on sesquioxides, clay-minerals and humic substances The adsorption of cyanide (KCN) on sesquioxides, clay minerals, and humic substances at different pH-values was studied. Moreover we looked for the CN-adsorption on L-layers of the humus forms mull, moder and mor. Cyanide was only adsorbed by humic acid. The amount of CN adsorbed increased with increasing pH of the reaction solution. IR-spectroscopic investigations of CN treated humic acids revealed that the cyanide was adsorbed at low pH (<7) as HCN-molecules by formation of hydrogen bonds with COOH-, COH-, OH- and NH2-groups of the humic acid. At pH > 7 the cyanide was mainly adsorbed as CN? by charge transfer with acceptor-molecules such as chinones. The cyanide adsorption of L-layers of humus forms decreased in the order mor > mull > moder. It is surmised that the HCN-molecules were not only adsorbed by humic acids in these layers but also by oxidation products of lignin, pectin, protein, cellulose, and carbon-hydrates of fulvic acids. Solutions of K2HPO4 did not desorb cyanides from humic acids to any great extent. 相似文献
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Grundy WM Buratti BJ Cheng AF Emery JP Lunsford A McKinnon WB Moore JM Newman SF Olkin CB Reuter DC Schenk PM Spencer JR Stern SA Throop HB Weaver HA;New Horizons Team 《Science (New York, N.Y.)》2007,318(5848):234-237
The New Horizons spacecraft observed Jupiter's icy satellites Europa and Ganymede during its flyby in February and March 2007 at visible and infrared wavelengths. Infrared spectral images map H2O ice absorption and hydrated contaminants, bolstering the case for an exogenous source of Europa's "non-ice" surface material and filling large gaps in compositional maps of Ganymede's Jupiter-facing hemisphere. Visual wavelength images of Europa extend knowledge of its global pattern of arcuate troughs and show that its surface scatters light more isotropically than other icy satellites. 相似文献
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Spencer JR Stern SA Cheng AF Weaver HA Reuter DC Retherford K Lunsford A Moore JM Abramov O Lopes RM Perry JE Kamp L Showalter M Jessup KL Marchis F Schenk PM Dumas C 《Science (New York, N.Y.)》2007,318(5848):240-243
Jupiter's moon Io is known to host active volcanoes. In February and March 2007, the New Horizons spacecraft obtained a global snapshot of Io's volcanism. A 350-kilometer-high volcanic plume was seen to emanate from the Tvashtar volcano (62 degrees N, 122 degrees W), and its motion was observed. The plume's morphology and dynamics support nonballistic models of large Io plumes and also suggest that most visible plume particles condensed within the plume rather than being ejected from the source. In images taken in Jupiter eclipse, nonthermal visible-wavelength emission was seen from individual volcanoes near Io's sub-Jupiter and anti-Jupiter points. Near-infrared emission from the brightest volcanoes indicates minimum magma temperatures in the 1150- to 1335-kelvin range, consistent with basaltic composition. 相似文献
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Dimitrios Moshou Stijn Wahlen Reto Strasser Ann Schenk Herman Ramon 《Computers and Electronics in Agriculture》2003,40(1-3):103
The chlorophyll fluorescence kinetics of ‘Jonagold’ and ‘Cox’ apples, stored under different conditions to induce mealiness, were measured. Three different storage conditions were considered causing three mealiness levels: not mealy, moderately and strongly mealy. Also destructive measurements of the texture (firmness, hardness, juice content and soluble solids content) were done. Classification into different mealiness levels based on the fluorescence measurements was more performant than a classification based on the destructive measurements. To estimate the mealiness level in a non-destructive way from the fluorescence features, a number of different classifiers were constructed. Quadratic discriminants and supervised and unsupervised neural networks were tested and compared. The self-organising map gives promising results when compared with the multi-layer perceptrons and quadratic discriminant analysis. The different advantages of the constructed classifiers suggest that fluorescence can be used in an automatic sorting line to assess certain types of mealiness. 相似文献
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Distributions of the vector Culicoides brevitarsis Kieffer (Diptera: Ceratopogonidae) (determined from light trap data) and 2 arboviruses (determined from seroconversions in sentinel cattle) were studied in eastern New South Wales in 1993–94. C brevitarsis was recorded progressively from endemic areas on the north coast, to Nowra on the south coast, and westward to Scone, in the Hunter Valley. C brevitarsis also survived through winter at Paterson, in the Hunter Valley. Its apparently focal reappearance in this marginal area had no obvious effect on the broad pattern of its progression or the dispersal of Akabane and bluetongue viruses. These viruses were first recorded from foci near Coffs Harbour, on the mid-north coast. Their first occurrences at different locations were associated with those of C brevitarsis, but not with each other. The viruses were found only within the recorded limits of the vector's distribution. Delays between the initial occurrence of C brevitarsis and first evidence of virus transmissions at locations ranged from 2 to 7 months. The delays decreased away from the points of focus and were negatively associated with the time of initial occurrence of the vector. Seroconversions to the viruses were related to the presence of C brevitarsis. However, the densities of C brevitarsis had no apparent effect on the initial numbers of cattle seroconverting to either virus. The results support the conclusion that the progressions of C brevitarsis and Akabane and bluetongue viruses were the result of gradual movements by the vector. 相似文献
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