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911.
The molecular epidemiology of the infectious disease caused by feline calcivirus (FCV) in Japan was investigated by analysing the phylogenetic relationship among 21 Japanese field isolates, including the F4 strain, and 30 global isolates. Parts of the capsid gene (B–F) of the isolates were amplified by RT-PCR, and the amino acid sequences were compared with those from the global isolates. Thirty-seven and 14 out of a total of 51 isolates were clustered into two distinct genogroups, I and II respectively, by UPGMA and NJ analysis. Seven of the 21 Japanese isolates (33%) fell into group I together with 30 global isolates, while the other 14 Japanese isolates (67%) belonged to group II. The bootstrap repetition analysis of groups I and II formed by the NJ method gave a value of 99.0%. The 14 latter Japanese isolates were clearly separated from the isolates in group I, and they were different from any previously known FCV, forming a new genogroup, which implies that this lineage has been confined to Japan. Comparing the amino acid sequences shared by groups I and II, the amino acid at position 377 in B region was asparagine (Asn or Asp (NH2)) in group I, while it was lysine (Lys) in all the strains in group II. Similarly, the amino acid at position 539 in the F region was alanine (Ala) or proline (Pro) in group I, while it was valine (Val) in group II; glycine (Gly) at position 557 in group I was serine (Ser) in Group II; and phenylalanine (Phe) or leucine (Leu) at position 566 in genogroup I was tyrosine (Tyr) in group II.  相似文献   
912.
Twenty-four honeybee (Apis mellifera) colonies were used to monitor the efficacy of a solution of 2.9% oxalic acid (OA) and 31.9% sugar against the mite Varroa destructor. Mite mortality was established prior to and after OA treatments, which were conducted in August and September. The treatments resulted in 37% mite mortality as opposed to 1.11% in the controls. OA treatment conducted in September on previously untreated colonies resulted in 25% mite mortality. OA treatments in October and November resulted in approximately 97% mite mortality. These results suggest that OA is effective during the broodless period and less effective when applied to colonies with capped broods. The possible use of OA against the Varroa mite in honeybee colonies as an alternative to routine chemical treatments is discussed.  相似文献   
913.
曹慧  韩振海  许雪峰 《园艺学报》2002,29(6):505-509
 水分胁迫引起苹果属植物中抗旱性较弱的平邑甜茶和抗旱性较强的新疆野苹果幼苗叶片相对含水量(RWC) 、DNA、RNA 含量下降, O2、H2O2 含量增高, DNase、RNase 活性上升; 其中DNA 含量下降的幅度小于RNA , DNase 活性上升的幅度小于RNase。抗旱性较强的新疆野苹果在水分胁迫下幼苗叶片的RWC、DNA、RNA 含量下降的幅度以及O2、H2O2含量增高、DNase、RNase 活性上升的幅度均小于抗旱性较弱的平邑甜茶。水分胁迫下平邑甜茶和新疆野苹果幼苗叶片的DNA、RNA 含量与RWC、O2、H2O2 含量和DNase、RNase 活性间均呈显著相关。  相似文献   
914.
Interactions between Plasmopara helianthi, Glomus mosseae and two plant activators DL--amino-n-butyric acid (BABA) and CGA 245704 (acibenzolar-S-methyl (BTH)) in sunflower plants susceptible to downy mildew were studied in four experiments using different methods of treatment and pathogen inoculation. Both chemicals were applied as soil drenches and foliar sprays, whereas P. helianthi infection was obtained by root and cotyledon inoculations of the seedlings. Soil drenches at the rates of 50 and 100mgkg–1 soil of BABA and BTH given 1 and 3 days before P. helianthi inoculation, respectively to mycorrhizal plants, provided moderate protection against the pathogen (about 50–55%). Morphological changes and decrease in mycorrhizal colonization in roots of BTH-treated plants and in BTH-treated mycorrhizal plants were also observed. Delay in the emergence and reduction of the root systems were more evident at the highest concentration but decreased with time. These effects were absent with the BABA treatment.Foliar spray treatment of BABA and BTH, applied at 4000 and 200µgml–1, respectively (1 day post-inoculation) to mycorrhizal plants provided good protection (about 80%) against P. helianthi foliar infections. No effects on mycorrhizal colonization or on root systems were observed. In vitro tests on the effect of the compounds on the mycorrhizal fungus showed that the germination of G. mosseae sporocarps increased with BABA treatment whereas it was greatly inhibited by BTH treatment.  相似文献   
915.
采用反相高效液相色谱法测定了7头麦洼牦牛后腿肌肉中游离氨基酸的含量。在牦牛肉中检测到16种游离的标准氨基酸,总含量为532.34±86.74 mg/100 g,其中含量最高的游离氨基酸为精氨酸,其次为组氨酸,这两种氨基酸约占游离氨基酸总量的75%。  相似文献   
916.
共轭亚油酸对脂肪细胞成熟调控机理研究   总被引:1,自引:0,他引:1  
共轭亚油酸(CLA.Conjugated linoleic acid)是一类具有顺、反异构体的十八碳二烯酸的统称,当前,CLA的生物学功能已成为研究热点,尤其在脂肪代谢调控上,具有降低脂肪沉积和血液胆固醇水平的功效。通过对CLA的脂肪细胞成熟(包括对脂肪细胞的增殖、分化,脂肪的沉积、甘油三磷酸的沉积等过程)调控机理的综合论述,以便为CLA更深入的研究提供参考。  相似文献   
917.
传统发酵酸马奶中瑞士乳杆菌耐酸性的筛选   总被引:2,自引:0,他引:2  
从新疆地区牧民家庭32份自然发酵酸马奶样品中分离鉴定出的82株瑞士乳杆菌中,通过耐酸实验选出39株可在pH3.0和pH3.5酸性环境中生长的菌株进行pH为3.0的人工胃液的耐受性实验。结果表明不同菌株对人工胃液的耐受能力有很大差异。  相似文献   
918.
The normal 99mTc-diethylenetriaminepentaacetic acid (DTPA) renal scintigram curve has 3 distinct phases; an arterial phase followed by progressive uptake and subsequent excretion from the kidney. In dogs with X-linked hereditary nephritis, a distinct flattening of the renal scintigram curve has been observed prior to any decline in glomerular filtration rate (GFR). The cause of this shape change is not known, however, it coincided with decreased urine-specific gravity and thus might be related to polyuria. To further evaluate this possibility, we assessed whether diuresis without concurrent renal disease could flatten the 99mTc-DTPA renal scintigram curve. GFR scintigraphy was performed in six healthy dogs once as a baseline, and again after induction of diuresis by each of four different methods. Scintigram curves were evaluated subjectively as well as quantitatively by calculation of GFR estimates, mean renal transit times, time to peak activity and half-time clearance. Complete flattening of the renal scintigram curve did not occur with diuresis alone, and therefore, flattening of the scintigram curve may serve as an early indicator of renal dysfunction. However, during diuresis after intravenous saline administration, alterations in time to peak activity and mean renal transit time may create inaccuracies in GFR estimates based on the conventional regression formula that cause a false lowering of the resultant global GFR value.  相似文献   
919.
Observer variation in kidney depth measurement for correction of soft-tissue attenuation and kidney region of interest (ROI) drawing was evaluated using 60 clinical dogs with a wide range of glomerular filtration rate (GFR) for their effect on the calculated percentage uptake of 99mTc-diethylenetriamine pentaacetic acid (DTPA) and individual kidney GFR by scintigraphy. Kidney depth was measured separately on the lateral image using two color tables: a threshold and a continuous red-green-blue. Within-observer variability of the semi-automatic ROI drawing of the estimated total GFR was up to 10% for the right kidney (RK) and 9% for the left kidney (LK). The variability was lower between observers, 6% for RK and 8% for LK. Manual ROI drawing caused more within observer variation than semi-automatic: up to 14% for RK and 11% for LK. Continuous red-green-blue table caused more variation within and between observers than threshold table. Average within-observer variability from both observers of kidney depth measurement on different color tables could vary up to 5.5% and 6.5% variation of the GFR of RK and LK, respectively. Most variation affecting the DTPA percentage uptake came from the ROI drawing technique. Variations of the method because of the effects of both kidney depth and kidney ROI drawing were up to 8% and 10% for RK and LK, respectively. To minimize these variations a threshold scale should be used for the kidney depth measurement and an automatic or semi-automatic ROI should be used whenever possible. In sequential examinations the same person should make all the measurements.  相似文献   
920.
This study investigated the effect of replacing concentrates with dry wormwood (Artemisia montana) on the performance of sheep. Four Corriedale × Polwarth sheep (41.3 ± 1.3 kg) were fed diets with an 8 : 2 straw to supplement ratio, for four, consecutive 16 d periods (10 d adaptation, 6 d collection) in a 4 × 4 Latin square design. Supplements were made by substituting 0 (Control), 30 (LW), 50 (MW) or 100 (HW) g/kg DM of concentrate (15.6% CP, 72.1% of TDN) with dried, ground wormwood. Ruminal pH, NH3–N and volatile fatty acids (VFA) were measured on d 6 of collection. Ether extract (EE) intake was linearly decreased (P < 0.001) with increasing wormwood inclusion, otherwise intake was unaffected. The Control diet had lower (P < 0.05) DM and CP digestibility than LW and MW diets and lower EE digestibility than the LW diet. Retained N (P < 0.05) and microbial N yield (P < 0.01) linearly increased with dietary wormwood level, but efficiency of microbial N synthesis linearly decreased (P < 0.001). Mean concentrations of rumen NH3–N, total VFA and propionic acid were quadratically increased (P < 0.05) by increasing wormwood inclusion. Replacing concentrates with 30–50 g/kg DM of wormwood increased N retention, microbial N yield and EE digestibility.  相似文献   
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