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Seroepidemiological evidence of avian H4, H5, and H9 influenza A virus transmission to pigs in southeastern China 总被引:1,自引:0,他引:1
Pig serum samples collected in southeastern China were examined for antibodies to influenza A viruses. Since the hemagglutination inhibition (HI) test does not accurately detect antibodies to the hemagglutinins (HAs) of "avian" influenza viruses, we utilized the neutralization (NT) test to detect subtype-specific antibodies to the HA of avian viruses in pig sera. Neutralizing antibodies to H1, H3, H4, and H5 influenza viruses were detected in the serum samples collected in 1977-1982 and 1998, suggesting that pigs in China have been sporadically infected with avian H4 and H5 viruses in addition to swine and human H1 and H3 viruses. Antibodies to H9 virus, on the other hand, were found only in the sera collected in 1998, not in those collected in 1977-1982, correlating with the recent spread in poultry and subsequent isolation of H9N2 viruses from pigs and humans in 1998. The present results indicate that avian influenza viruses have been transmitted to pig populations in southeastern China. 相似文献
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Structural reinvestigation of corticatic acid A from a marine sponge, Petrosia sp., resulted in the revision of its structure, which conformed to the structural features of the biosynthetically related linear acetylenes isolated from Petrosia sp. In the process of isolating an authentic corticatic acid A, we isolated three new congeners and determined their structures. We also suggested that the structures of other corticatic acids need revision. 相似文献
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Shogo Higaki Takaaki Todo Reiko Teshima Ikuo Tooyama Yasuhiro Fujioka Noriyoshi Sakai Tatsuyuki Takada 《Fish physiology and biochemistry》2018,44(2):503-513
We investigated the feasibility of cryopreservation of spermatogonia and oogonia in the critically endangered cyprinid honmoroko Gnathopogon caerulescens using slow-cooling (freezing) and rapid-cooling (vitrification) methods. Initially, we examined the testicular cell toxicities and glass-forming properties of the five cryoprotectants: ethylene glycol (EG), glycerol (GC), dimethyl sulfoxide (DMSO), propylene glycol (PG), and 1,3-butylene glycol (BG), and we determined cryoprotectant concentrations that are suitable for freezing and vitrification solutions, respectively. Subsequently, we prepared the freezing solutions of EG, GC, DMSO, PG, and BG at 3, 2, 3, 2, and 2 M and vitrification solutions at 7, 6, 5, 5, and 4 M, respectively. Following the cryopreservation of the testicular cells mainly containing early-stage spermatogenic cells (e.g., spermatogonia and primary spermatocytes), cells were cultured for 7 days and immunochemically stained against germ cell marker protein Vasa. Areas occupied by Vasa-positive cells indicated that vitrification led to better survival of germ cells than the freezing method, and the best result was obtained with 5 M PG, about 50% recovery of germ cells following vitrification. In the case of ovarian cells containing oogonia and stage I, II, and IIIa oocytes, vitrification with 5 M DMSO resulted the best survival of oogonia, with equivalent cell numbers to those cultured without vitrification. The present data suggest that male and female gonial cells of the endangered species G. caerulescens can be efficiently cryopreserved using suitable cryoprotectants for spermatogonia and oogonia, respectively. 相似文献
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Erika Sato Yuko Suga Chihiro Kisaki Koki Toyota Kazuto Miyake Atsushi Takada 《Soil Science and Plant Nutrition》2013,59(2):213-222
Abstract The humus composition was analyzed and the humic acid characterized by UV and visible absorption spectroscopy in order to investigate the rotting and maturing process of city refuse compost according to the method of Kumada et al. During the composting process, the following findings were obtained: (1) the HT value was almost constant, but the HE/HT ratio varied somewhat, (2) HA increased with decrease in FA, and the PQ value so increased clearly, (3) the shoulder-like absorption at a wavelength near 270 nm weakened, and (4) the RF value of humic acid increased, whereas the Δ log K value seldom varied. The IR spectrum of humic acid gradually changed as follows: (1) the absorption band in the 1700-1600 cm-1 region and in the 1550-1500 cm-1 region increased slightly, (2) the band in the 1100-1000 cm-1 region decreased, and (3) the bands at 835 and 710 cm-1 com pletely disappeared. On the whole, the shape of the IR spectrum of the city refuse compost became featureless. These changes were probably due to the oxidation which occurred in the composting process. 相似文献