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11.
锥—46抑制[^3H]次黄嘌呤掺入伊氏锥虫核酸的研究   总被引:1,自引:1,他引:1  
用液体闪烁计数法对锥—46的抗锥虫作用的机理做了初步研究。发现T-46与Berenil很相似,均可显著抑制[~3H]次黄嘌呤掺入伊氏锥虫,抑制作用与浓度及时间呈正相关。T-46和Berenil对DNA合成的IC_(60)分别为1.33和1.73μg·ml~(-1)。本实验还提示T-46抗锥虫作用可能与损伤DNA模板有关。  相似文献   
12.
刈割对羊茅黑麦草叶片生长的影响   总被引:6,自引:0,他引:6  
利用植物组织转化分析方法,研究在不同刈割开始时期和留茬高度对羊茅黑麦草叶片发生、伸长、枯萎和死亡的影响.结果表明,在营养期以低茬刈割有利于羊茅黑麦草叶片的发生和生长,适合频繁强度利用.  相似文献   
13.
These studies examined responses of serum prolactin (PRL) and growth hormone (GH) to opioid agonist and antagonist administration in heifers. To minimize nonspecific and behavioral effects and to facilitate future studies with specific opioid receptor agonists, a cannula was placed within the third cerebral ventricle of the brain of 4- to 10-mo-old heifers to directly access hypothalamic regions involved in the regulation of PRL and GH secretion. Increasing doses of morphine (M) from 2 to 1,500 micrograms injected into the third cerebral ventricle increased (P less than .001) serum PRL concentrations in a dose-related manner. Growth hormone responses were variable, resulting in elevated (P less than .05) serum concentrations following morphine, but no dose-related effects were apparent. Both PRL and GH responses to 700 micrograms M were absent when an intracerebral ventricle injection of an equimolar dose of naloxone, an opioid receptor antagonist, was administered prior to M. In a replicated 4 x 4 latin square, the effects of intravenous naloxone on PRL and GH responses was tested in young (86 +/- 11 d) and older (234 +/- 6 d) heifers. Naloxone at doses of 1, 2 and 4 mg/kg reduced (P less than .05) serum concentrations of PRL for 45 to 60 min. Mean concentrations of GH tended to be higher (P less than .07) in older heifers All doses of naloxone decreased (P less than .05) serum GH concentrations in older heifers but proved ineffective in younger heifers. There were no differences between doses of naloxone on either PRL or GH. These data suggest that endogenous opioids are involved in the regulation of PRL and GH secretion in heifers.  相似文献   
14.
通过对兔毛纤维类型、物理特性和结构特征的分析,并与相关动物纤维作比较,探讨了兔毛在纺织上的应用价值。  相似文献   
15.
近年来,河南省以保障猪肉质量安全和群众身体健康为目标,通过采取充实屠宰监管力量,开展暗访巡查/飞行检查,强化技术手段、黑名单管理,启用畜禽屠宰监管平台等系列措施,严打屠宰领域违法行为,取得了明显成效。同时,也指出了当前存在企业主体责任落实不到位、监管存漏洞、法律法规不健全、行刑衔接不畅等问题。由此提出了推动主体责任落实、提升监督执法实效、健全完善法律法规、强化两法衔接、完善技术手段等对策思考。  相似文献   
16.
In the genome of strains of very virulent Marek's disease virus serotype 1(vvMDV1), such as Md5 and RB1B, the meq open reading frame (ORF) encoding a 339-amino-acid bZIP protein, is present, while a slightly longer meq ORF, termed as L-meq, in which a 180-bp sequence is inserted into the meq ORF is found in other strains of MDV1, such as CV1988/R6 and attenuated JM. When chickens were infected with vvMDV1 strains and the meq gene was amplified by nested polymerase chain reaction (PCR), the meq gene was detected throughout the experimental period for 7 weeks post inoculation (pi). However, the L-meq gene was also detected at 3 to 5 weeks and 3 to 4 weeks pi. in Md5-infected and RB1B-infected chickens, respectively. In the case of chickens infected with an attenuated MDV1, the JM strain, the L-meq gene was detected at 2 to 7 weeks pi., and the meq gene was also detected at 2 to 6 weeks pi. Both L-meq and meq genes were detected in chickens infected with an attenuated nononcogenic vaccine strain of MDV1 (CVI988/R6), throughout the experimental period. Though quantitative PCR was not performed, a larger amount of the PCR products corresponding to the L-meq than the meq gene was amplified from chickens infected with JM or CVI988/R6. These results suggest that a dynamic population shift between the MDV subpopulations displaying meq and L-meq genes occurs in chickens during the course of MDV infection. Since the MDV subpopulation that displays the L-meq gene only displays it during the latent phase, the L-meq and its gene product, if any, might contribute to the maintenance of the MDV latency.  相似文献   
17.
ELISA对动物舍气载魏氏梭菌型别的研究   总被引:3,自引:1,他引:3  
采用ELISA方法对从一个犊牛舍空气中分离到的魏氏梭菌进行型别的鉴定。结果显示:88%的菌种属于A型,3.4%为C型,8.6%是D型,B型未能确认。  相似文献   
18.
The efficacy of a piglet-specific inactivated Porcine circovirus type 2 (PCV2) vaccine was evaluated with clinical field trials, as recommended by the Republic of Korea’s Animal, Plant & Fisheries Quarantine & Inspection Agency. Three farms were selected on the basis of their history of postweaning multisystemic wasting syndrome. On each farm 60, 1-week-old pigs were randomly allocated to 1 of 2 treatment groups: vaccination at 1 and 3 wk of age or no vaccination. The 2-dose schedule of vaccination with inactivated PCV2 vaccine improved the average daily weight gain from birth to 16 wk of age, the PCV2 load in the blood, and the frequency and severity of lymph node lesions. Inactivated PCV2 vaccine seems to be very effective in controlling PCV2 infection under field conditions.  相似文献   
19.
One-day-old Taiwan native male chicks were fed with maize-soybean rearing diets without supplemental vitamin E to 23 weeks of age. From 23 to 52 weeks of age, the cockerels (n = 90) were assigned at random to 5 dietary treatments and fed with maize-soybean diets supplemented with 0, 20, 40, 80 and 160 mg/kg of vitamin E (dl-alpha-tocopherol acetate). Pullets (225) of the same age were fed with standard diets throughout. They were artificially inseminated with one dose of 0.04 ml/bird intact and 5-fold diluted pooled semen at 31 to 43 weeks of age and at 49 weeks of age, respectively. The criteria evaluated included: semen quality, fertility and maximum and effective duration of fertility, blood characteristics, body and testes weight. Supplemental vitamin E did not affect cockerels' effective duration of fertility and percentage of fertility. However, when pullets were inseminated with diluted semen, supplementing 160 mg/kg vitamin E increased the maximum duration of fertility at 49 weeks of age. Cockerels receiving 40 to 160mg/kg supplements had higher sperm viability and motility after 39 weeks of age and those fed 80 mg/kg had higher sperm concentration at 39 weeks of age. Cockerels receiving supplements of more than 40 mg/kg vitamin E had higher body weight gain. Plasma cholesterol and testosterone were not affected by supplemental vitamin E. However, plasma luteinising hormone (LH) concentration was lower in cockerels fed 160 mg/kg. Lack of supplemental vitamin E over 39 weeks was associated with lower semen quality but did not reduce the proportion of fertile eggs laid by inseminated hens, perhaps because the insemination dose compensated for low sperm quality. We found that the maximum duration of fertility might be improved by supplementing 160 mg/kg vitamin E at 49 weeks of age.  相似文献   
20.
A 7-year-old female Maltese presented for evaluation of severe vomiting. A diagnosis of pylorogastric intussusception was made during ultrasonographic examination. The intussusception spontaneously underwent reduction by the following morning.  相似文献   
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