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81.
We report the formation of a three-dimensionally ordered array of air bubbles of monodisperse pore size in a polymer film through a templating mechanism based on thermocapillary convection. Dilute solutions of a simple, coil-like polymer in a volatile solvent are cast on a glass slide in the presence of moist air flowing across the surface. Evaporative cooling and the generation of an ordered array of breath figures leads to the formation of multilayers of hexagonally packed water droplets that are preserved in the final, solid polymer film as spherical air bubbles. The dimensions of these bubbles can be controlled simply by changing the velocity of the airflow across the surface. When these three-dimensionally ordered macroporous materials have pore dimensions comparable to the wavelength of visible light, they are of interest as photonic band gaps and optical stop-bands. 相似文献
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Intestinal sections from both experimental and field cases of turkey coronaviral enteritis (TCE) were examined by scanning electron microscopy and light microscopy through 10 days after inoculation and by a direct fluorescent antibody test for TCE through 12 days. Serums were collected for an indirect fluorescent antibody test for TCE through 160 days after inoculation. Lesions observed with the scanning electron microscopy were catarrhal enteritis with hemorrhage per diapedesis, epithelial desquamation, and villous atrophy which developed and regressed within 6 days after inoculation. Light microscopy demonstrated similar lesions, except that villus-to-crypt ratios remained depressed 10 days. The direct fluorescent antibody test demonstrated the presence of coronaviral antigen throughout the sampling period, and serum antibodies to TCE were present until at least 160 days, when the experiment was terminated. 相似文献
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Zulu VC Mwanza A Patel OV Makondo KJ Bhaiyat MI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2000,62(7):757-758
Ultrasonographic examination was carried out in a cow with an ovarian abscess. Real time ultrasound scanning using a 7.5 MHz linear probe per rectum revealed an active left ovary with follicles of up to 11 mm in diameter and an enlarged right ovary measuring 6 x 6 cm, with a mass of 4 x 3 cm. The mass had varied echotexture, a thick hyperechoic boundary and a hypoechoic centre with echoic foci. It was tentatively diagnosed as an ovarian tumour or abscess. After ovariectomy, grossly the right ovary measured 6 x 6 x 5 cm and on cutting cheesy pus oozed out. The abscess was completely localised within the ovary, 4 cm in diameter and encapsulated thickly. On bacteriological examination Staphylococcus spp. was isolated. This is a rare case of ovarian abscess. 相似文献
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Differences in the degree of starch granule swelling and granule morphology are shown as a function of iodine concentration during heating. The observations reveal a restriction and delay in wheat and corn starch swelling in presence of iodine (0.02%) and a lack of swelling at higher iodine concentration (0.2%). The presence of iodine during heating did not influence waxy corn starch granule swelling, even at the higher concentration. A delay in the increase in paste viscosity during heating was observed, and gel formation was precluded after cooling at the higher iodine concentration. Waxy corn starch pastes formed a weak gel even at the higher iodine concentration. Spectrophotometric analyses showed that polymers leach into the solution when heated in the presence of 0.02% iodine, while no leaching was observed at 0.2% iodine concentration. Furthermore, the length and the amount of polymers leaching from normal corn were different from that observed for wheat starch. Thermal analyses reveal a shift in the onset of gelatinization temperature and an increase in the enthalpy in the amylose‐lipid region of the endotherm. While the iodine‐polymer complex did not appear to exhibit an endotherm during heating, the granules exhibited a diffused polarized cross, suggesting the presence of an ordered complex. 相似文献