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21.
Masoud Shahram Robin A.J. Nicholas Roger J. Miles Ann P. Wood Donovan P. Kelly 《Research in veterinary science》2009,87(3):364-366
Mycoplasma mycoides subsp. mycoides Large Colony (LC) type is a pathogen of goats causing contagious agalactia and respiratory disease, found on all continents where small ruminants are kept. It shares close genetic characteristics with M. mycoides subsp. capri. Substrate oxidation by 22 strains of M. mycoides subsp. mycoides LC from nine countries was compared with that of eight strains of M. mycoides subsp. capri from five countries. There was considerable similarity in the substrates used, but substrate saturation coefficients (Ks) varied for different substrates. Substrate utilization patterns and Ks values did not (1) significantly differentiate the LC strains from each other, (2) show any correlation with geographical origin, or (3) distinguish the LC strains from the capri strains. These results support previous studies justifying the reclassification of these subspecies as a single species. 相似文献
22.
OBJECTIVES: To measure the acute analgesic properties of extracorporeal shock wave therapy (ESWT) in horses with navicular disease using objective ground reaction forces (GRF). STUDY DESIGN: Prospective study. ANIMALS: Nine client-owned horses with unilateral forelimb lameness caused by navicular disease. METHODS: Horses were trotted at 3 m/s over a force plate to record pre-treatment GRF of the lame and contra-lateral forelimbs. After ESWT of the lame limb, applied with a radial unit to each of the frog and heel bulb areas with 1500 pulses at 4 bar and 10 Hz, GRF measurements were repeated at 15 minutes and 24-hour intervals for 7 days. From the 5 trials recorded at each time, peak vertical force (PVF) was calculated and averaged. Data were compared between limbs and over time using a 2-way repeated-measures ANOVA. RESULTS: Mean (+/-SD) PVF was significantly different between lame (day 1; 4339+/-626 N) and contra-lateral (day 1; 5236+/-515 N) limbs pre-treatment (P<.05). After ESWT treatment, this difference remained unchanged at 15 minutes and from days 1 to 7. To confirm navicular disease, palmar digital analgesia significantly reduced the lameness (lame 5144+/-430 N; contralateral 5082+/-586 N; P>.05). CONCLUSIONS: Single ESWT treatment applied in this manner does not influence lameness in horses with navicular disease. CLINICAL RELEVANCE: Although many equine regulatory commissions currently ban the use of ESWT before competition, our results suggest that such regulations may be unfounded. Further research is required to determine the long-term analgesic properties of this frequently used treatment modality in equine athletes. 相似文献
23.
利用经济学中的产权理论和委托-代理理论研究基因资源的产权配置与利益分享问题。首先利用产权理论从静态和动态两个方面比较了基因资源初始产权不同配置的经济效率,得出基因资源初始产权配置不同,经济效率也不同。基因资源的国家所有权形式的经济效率大于人类共同产权形式的经济效率。然后利用委托-代理理论分析了植物培育权利益分享问题,得出发达国家将利用基因资源培育出的新品种收益的一部分分配给发展中国家,能够实现双赢。 相似文献
24.
Vilar P Couto CG Westendorf N Iazbik C Charske J Marín L 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2008,22(2):374-379
BACKGROUND: Bleeding disorders in patients with normal coagulation test results are frequently reported in Greyhounds. The purpose of this study was to compare Greyhounds to non-Greyhounds by thromboelastography (TEG). HYPOTHESIS: TEG parameters in Greyhounds are different from those in non-Greyhounds. ANIMALS: Forty-three healthy dogs (28 Greyhounds and 15 non-Greyhounds) based on the results of physical examination, CBC, activated partial thromboplastin time, prothrombin time, fibrinogen, and platelet count. MATERIALS AND METHODS: Recalcified citrated native TEGs were performed in both groups; data were compared using Student's, Mann-Whitney, and Pearson's statistical tests. RESULTS: In Greyhounds, mean +/- SD were as follows: R-time 4.3 +/- 1.7 minutes, K-time 3.8 +/- 1.4 minutes, angle (alpha) 50.0 +/- 8.0 degrees , maximum amplitude (MA) 47.6 +/- 5.6 mm, clot strength (G) 4,647 +/- 1,097 dyn/cm2, and percent lysis at 60 minutes (LY60) 2.8 +/- 5.0%. In the non-Greyhounds they were R-time 3.7 +/- 1.6 minutes, K-time 2.5 +/- 0.9 minutes, angle 59.8 +/- 7.0 degrees , MA 53.1 +/- 5.6 mm, G 5,811 +/- 1,256 dyn/cm2, and LY60 3.1 +/- 2.5%. All parameters were significantly different between the groups, except for R-time and LY60. CONCLUSION: In Greyhounds, clotting kinetics are slower and clot strength are weaker than in non-Greyhounds, supporting the increased tendency to bleed observed after minor trauma or surgical procedures in the breed. The findings may also be attributed to blood viscosity or to the concentration of citrate in the sample (ie, Greyhounds have higher hematocrit and less plasma per unit volume). 相似文献
25.
26.
柞蚕丝素/丙二醇共混膜的制备及性能测试 总被引:1,自引:1,他引:1
为了开发适用于人工皮肤、创面覆盖等的生物材料,用硫氰酸锂溶液溶解柞蚕丝素纤维,制备不同配比的柞蚕丝素(TSF)/丙二醇共混膜。用X-射线衍射法、红外光谱法对不同配比共混膜的结构进行表征,并测定其溶失率和分析其力学性能变化。当TSF/丙二醇共混膜中丙二醇的质量分数<30%时,共混膜的聚集态结构主要以α-螺旋结构为主,此时共混膜的溶失率较高,仍有30%左右;随着共混膜中丙二醇的质量分数增加,共混膜的聚集态结构逐渐向β-折叠结构转变,溶失率也随之降低;当共混膜中丙二醇的质量分数达到45%以上时,共混膜基本不溶于水,溶失率<2%。同时,当共混膜中丙二醇的质量分数达到30%时,共混膜的断裂伸长率显著增大,虽然断裂强度有所减小,但即使丙二醇的质量分数达到45%时,断裂强度仍然有20 MPa左右。研究结果显示,丙二醇的加入能显著降低柞蚕丝素膜的溶失率,并改善其力学性能。 相似文献
27.
丝胶凝胶物理性状的研究 总被引:5,自引:3,他引:5
丝胶在凝胶化时,强力增加,而表面张力减小。丝胶凝胶,在30~40℃热水处理时,溶解量很小;50一70℃热水处理时,溶解量增多,溶解速度呈恒定状态;80℃以上,呈快速溶解。根据丝胶凝胶的DTA分析,其吸热分解峰向高温侧移动,这表明丝胶分子的有序性、结晶度提高了。丝胶凝胶在热水处理时,转化为液胶,同时丝胶分子也由β构象转化为无视卷曲结构。并且,丝胶液胶又可重新凝胶化。 相似文献
28.
放牧强度对羊草草原的影响 总被引:14,自引:4,他引:14
研究放牧强度对羊草草原植物群落组成、数量特征、生物量及土壤特性等的影响.结果表明,随着放牧强度的增加,羊草草原的植被盖度和生物量随之降低,优势羊草群落将逐渐被盐生植物所替代,群落结构趋于简化,物种向旱生化和盐生化演替.同时土壤容重、含水量、有机质和氮、磷、钾、钙、镁等营养元素含量亦随着放牧强度的增加而逐渐降低.春季过度放牧对土壤表层的水分、有机质和钙、镁等元素造成的损失最为严重.因此,制定科学的草原管理措施,特别是春季限制放牧等措施对于维持草原的可持续发展具有重要意义. 相似文献
29.
伪狂犬病病毒Bartha株TK-/LacZ+突变株的构建及其生物学特性研究 总被引:2,自引:1,他引:2
本研究将伪狂犬病病毒Bartha株基因组与含有LacZ标志基因的TK基因转移质料pUEKPZ共转染猪肾传代细胞PK-5,细胞出现病变后,反复冻融3次收毒,按1:5稀释接种于IBRS-2细胞。在X-gal存在下挑取蓝斑,蓝斑筛选3次,再进行空斑试验,同时用PCR扩增LacZ基因,经3次空斑纯化,随机挑取的空斑均能扩增出LacZ基因,证实所获得的重组病毒为伪狂犬病病毒Bartha株TK^-/LacZ^ 突变株。TCID50试验表明,TK失活对Bartha株在细胞上增殖无影响;Balb/C小鼠试验表明,该突变对Balb/C小鼠的安全性明显高于Bartha亲本毒株。 相似文献
30.
本文以外周血淋巴细胞姐妹染色单体互换(SCE)频率和细胞周期动力学为指标,以较长期(4~13年)生活在砷污染区的黄牛和水牛为对象,对砷在动物体内慢性蓄积所诱发细胞遗传学效应进行了研究。其结果表明,砷污染区黄牛和水牛SCE频率均显著高于对照组,参照有关评价标准,可判为弱阳性,提示在当地污染水平下,黄牛和水牛都诱发了一定程度的细胞遗传学效应。对细胞周期动力学的观察结果表明,砷对黄牛和水牛没有明显的细胞毒性。本试验还报告了正常黄牛和水牛外周血液淋巴细胞SCE的自发频率以及培养72小时各期细胞的正常比率。 相似文献