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排序方式: 共有371条查询结果,搜索用时 46 毫秒
91.
92.
Chin-I Chang Chia-Che Wu Ta Chih Cheng Jyh-Ming Tsai & King-Jung Lin 《Aquaculture Research》2009,40(10):1182-1190
A multiplex nested-polymerase chain reaction (PCR)-based (m-nested PCR) method was developed for simultaneous detection of four important freshwater/marine fish pathogens in subtropical Asia, including Aeromonas hydrophila, Edwardsiella tarda, Photobacterium damselae and Streptococcus iniae . The specificity of the oligonucleotide primers used for PCR detection was confirmed to generate specific amplicons for the corresponding pathogens. Moreover, non-specific amplicons were observed when the primers were tested using pure DNA extracted from 31 related bacterial strains belonging to 23 species or tissue homogenates of infected tilapia. This m-nested PCR approach could detect 19 colony forming unit (CFU) for A. hydrophila , 62 CFU for E. tarda , 280 CFU for P. damselae subsp. piscicida and 179 CFU for S. iniae in infected tilapia kidney homogenates, consistent with the results derived from bacteriological methods. The assay described in this paper is a sensitive and effective method for simultaneous detection of multiple fish pathogens. 相似文献
93.
Laufer H Borst D Baker FC Reuter CC Tsai LW Schooley DA Carrasco C Sinkus M 《Science (New York, N.Y.)》1987,235(4785):202-205
Juvenile hormone (JH) has central roles in the regulation of insect development and reproduction but has not previously been identified in other arthropod classes. The hemolymph of a crustacean, Libinia emarginata (Leach), has now been analyzed for JH-like compounds. Samples contained 0.003 to 0.030 nanogram of JH III per milliliter and 10 to 50 nanograms of methyl farnesoate per milliliter; methyl farnesoate is a compound structurally related to JH III that has JH bioactivity. Several tissues were examined for synthesis and secretion of JH-like compounds. Of these tissues, only the mandibular organs produced and secreted JH III and methyl farnesoate. However, microchemical analysis revealed that this JH III was racemic, and thus likely an artifactual oxidation product of methyl farnesoate. Secretion of methyl farnesoate was related to reproduction in females, with the highest rates observed in Libinia near the end of the ovarian cycle when oocyte growth and vitellogenesis are greatest. These results indicate that JH-like compounds such as methyl farnesoate have regulatory roles in crustaceans. 相似文献
94.
Shih Yi Chen Tsung Yu Li Chih Heng Tsai Dan Yuan Lo Kuo Lung Chen 《Animal Science Journal》2014,85(3):305-312
This study investigated gender, caponization and exogenous estrogen effects on lipids, bone and blood characteristics in Taiwan country chickens. Thirty male chickens were caponized at 8 weeks (capons); 15 capons were injected with estrogen (5 mg/bird estradiol 3‐benzoate) every 2 weeks from 8 to 28 weeks, and 15 sham‐operated male (shams) chickens and 15 females were selected for this trial. The results showed that the shams had lower relative abdominal and chest subcutaneous fat than females (P < 0.05). The estrogen‐treated capons had greater relative abdominal and chest subcutaneous fat than shams and capons (P < 0.05), which might result from higher blood very low‐density lipoproteins and triacylglycerol concentrations (P < 0.05). Caponization could dramatically increase relative abdominal fat (506%; P < 0.05). The shams had higher tibia weight and biomechanical properties, such as maximum bone strength and bending moment values than the capons (P < 0.05). Tibia biomechanical properties were reduced by estrogen treatment (P < 0.05). The females obtained the lowest biomechanical value in all treatments (P < 0.05). Histological examination revealed cavity formation in the cortical bone of estrogen‐treated capons and female chickens, which suggested that estrogen reduced bone biomechanical properties by destroying its structural integrity. 相似文献
95.
96.
Antigenic and genetic properties of viruses linked to hemorrhagic fever with renal syndrome 总被引:38,自引:0,他引:38
C S Schmaljohn S E Hasty J M Dalrymple J W LeDuc H W Lee C H von Bonsdorff M Brummer-Korvenkontio A Vaheri T F Tsai H L Regnery 《Science (New York, N.Y.)》1985,227(4690):1041-1044
Hemorrhagic fever with renal syndrome (HFRS) comprises a variety of clinically similar diseases of viral etiology that are endemic to and sporadically epidemic throughout the Eurasian continent and Japan. Although HFRS has not been reported in North America, viruses that are antigenically similar to HFRS agents were recently isolated from rodents in the United States. Examination and comparison of eight representative isolates from endemic disease areas and from regions with no known associated HFRS indicate that these viruses represent a new and unique group that constitutes a separate genus in the Bunyaviridae family of animal viruses. 相似文献
97.
Tsai TY Choi YS Ma W Pomerening JR Tang C Ferrell JE 《Science (New York, N.Y.)》2008,321(5885):126-129
A simple negative feedback loop of interacting genes or proteins has the potential to generate sustained oscillations. However, many biological oscillators also have a positive feedback loop, raising the question of what advantages the extra loop imparts. Through computational studies, we show that it is generally difficult to adjust a negative feedback oscillator's frequency without compromising its amplitude, whereas with positive-plus-negative feedback, one can achieve a widely tunable frequency and near-constant amplitude. This tunability makes the latter design suitable for biological rhythms like heartbeats and cell cycles that need to provide a constant output over a range of frequencies. Positive-plus-negative oscillators also appear to be more robust and easier to evolve, rationalizing why they are found in contexts where an adjustable frequency is unimportant. 相似文献
98.
Thyroid hormone action: a cell-culture system responsive to physiological concentrations of thyroid hormones 总被引:19,自引:0,他引:19
Cells from a rat pituitary tumor cell line will respond in vitro to physiological concentrations of L-thyroxine and L-triiodothyronine. The cells are grown in a cultutre medium that contains serum from a hypothyroid calf. Dose-response relationships of a vacriety of thyronine derivatives indicate that this system has a specificity of response which is similar to that observed in vitro. 相似文献
99.
100.
Tsai TH 《Journal of agricultural and food chemistry》2002,50(23):6669-6674
To determine naringin levels in various biological fluids, we developed an in vivo microdialysis technique coupled with a microbore HPLC system to investigate the pharmacokinetics of naringin and its interaction with cyclosporin A in rat blood, brain, liver, and bile. After naringin administration, naringin was undetectable in the brain; the distribution ratios of area under the curve (AUC) of liver over that in blood (AUC(liver)/AUC(blood)) and of AUC of bile over that in blood (AUC(bile)/AUC(blood)) of naringin were 5.39 +/- 0.94 and 29.17 +/- 3.58, respectively. When cyclosporin A (20 mg/kg) was concomitantly administered with naringin (30 mg/kg), the naringin was detected in brain dialysate, but the distribution ratios of liver and bile showed no statistical difference. These results suggest that naringin was concentrated in the liver and bile by the processes of active transport. The blood-brain barrier penetration of naringin may be enhanced by P-glycoprotein inhibitor; however, the pathway of hepatobiliary excretion of naringin may not be related to the P-glycoprotein. 相似文献