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31.
苹果试管苗不定根起源及其发育状况的研究 总被引:4,自引:0,他引:4
利用光学和扫描电子显微镜观察结果表明,经琼脂生根培养基诱导产生的长富—2苹果 (Malus pumila Mill.) 试管苗的不定根起源于维管形成层。这种不定根发育不良,根表面缺乏根毛,内部解剖构造为典型的初生结构。为避免因不定根吸收、运输能力差而影响试管苗移栽成活,宜采用通透性良好的基质进行瓶内或瓶外生根,可诱导出优质不定根。 相似文献
32.
T M Byrem T F Robinson Y R Boisclair A W Bell W S Schwark D H Beermann 《Journal of animal science》1992,70(12):3812-3819
Pharmacokinetic parameters for the beta 2-adrenergic agonist, cimaterol (CIM), were determined in growing Holstein steers. Compartmental analysis was used after measurement of CIM in body fluids by affinity chromatography and HPLC using UV detection. Recoveries from spiked plasma and urine standards were 70 +/- 1.2% and 68 +/- 1.1%, respectively. The minimum detection level in plasma was 1 ng/mL and the average CV was 5.1% for concentrations that ranged from 1 to 30 ng/mL. Four steers (276 +/- 24 kg) received 15 mg of CIM by bolus intravenous injection. Plasma CIM levels declined in a biphasic manner with half-lives of 2.5 min for the distribution phase and 54 min for the elimination phase. A two-compartment open model was used to describe the disappearance of CIM and the following pharmacokinetic parameters were obtained: central compartment volume (Vc) = .76 L/kg, apparent volume of distribution (Vd) = 4.1 L/kg, and transfer rate constants from the central to peripheral compartment (k12) = .177/min, from the peripheral to central compartment (k21) = .054/min and elimination from the central compartment (kel) = .074/min. After 8 h, total urinary CIM accounted for only 18.3% of the administered dose. Results suggest that circulating concentrations of CIM in growing steers are influenced by its accumulation in an unidentified peripheral pool and its conversion into unknown metabolite(s) before elimination. 相似文献
33.
T N Tully S M Shane R P Poston J J England C C Vice D Y Cho B Panigrahy 《Avian diseases》1992,36(3):808-812
Eastern equine encephalitis (EEE) was diagnosed in a flock of emus in southeastern Louisiana. The outbreak involved juvenile and adult breeders ranging in age from 20 to 36 months, with an attack rate of 76% and a case fatality rate of 87%. The diagnosis was confirmed by isolation and characterization of the viral agent, and by detection of EEE antibody in two recovered emus. High mortality was preceded by marked depression, hemorrhagic diarrhea, and emesis of blood-stained ingesta. On postmortem examination, hemorrhagic enteritis and multiple petechia of viscera were observed. Microscopic changes included severe necrosis of hepatocytes, intestinal mucosa, and necrotizing vasculitis of the spleen and lamina propria of the intestine. No nervous system lesions were observed. This outbreak occurred concurrently with EEE in horses and was attributed to unseasonably heavy rainfall with an abundance of arthropod vectors and proximity to free-living reservoir host species. 相似文献
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D E Gunson P S Sahota W O Iverson R Y Chau G M McCormick V M Traina 《Veterinary pathology》1992,29(2):145-151
Male and female Sprague-Dawley rats were given CGS 21595, a pro-drug that is almost immediately metabolized to CGS 19213, a naphthoquinone that acts as a 5-lipoxygenase inhibitor. The compound was administered by gavage to five groups of Sprague-Dawley rats (group Nos. 1, 5, n = 30; group Nos. 2-4, n = 20) at daily doses of 0, 50, 150, 500, or 1,000 mg/kg for 13 weeks. Rats in the higher dose groups had a reduced weight gain, but significant neurologic signs were not observed. A peripheral neuropathy consisting predominantly of myelin destruction in the spinal nerve roots and sciatic nerves in male rats treated with greater than or equal to 150 mg/kg CGS 21595 and in female rats treated with greater than or equal to 50 mg/kg CGS 21595 for 13 weeks. This lesion was not fully reversible after a recovery period of 4 weeks. Lesions consisted of ballooning of myelin sheaths, infiltration by macrophages, demyelination, and occasional areas of remyelination. Axons were generally preserved, and the brain and spinal cord were not affected. Male and female rats in all treatment groups had cytoplasmic hyaline droplets in the proximal renal tubules. This change was reversible after 4 weeks and was not associated with any other adverse effects on the kidney. 相似文献
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37.
魔盒(如左图)只有拳头般大小,但它的功能却多样,在挤奶的同时,能在线检测原料奶的各种成分,包含乳脂、乳蛋白、乳糖、总固体、尿素,血、体细胞,其中体细胞又可分成四个类别,(a)体细胞<20万/mL,(b)体细胞在20 ̄40万/mL,(c)体细胞在40 ̄80万/mL,(d)体细胞>80万/mL。检测的时间就是牛只完成挤奶的同时,即在挤奶的瞬间,魔盒对牛奶中的上述指标进行检测。测出的数据将自动显示并保存在电脑中,并由阿菲牧(由以色列阿菲金公司研发)牛场管理软件永久保存,方便随时随地查阅。这些数据对牛场和乳品企业具有如下意义:1对牧场生产具有直接的指导意义牛… 相似文献
38.
Mouse pronuclear stage embryos with intact slit zona pellucida (manipulated) were cultured in vitro until the hatched blastocyst stage in simplex optimized medium with higher K+ concentration (KSOM) prepared with three different water types: tap, deionized reverse osmosis (D‐O) water and Milli‐Q system (M‐Q) water. The culture media were supplemented with or without protein and ethylenediaminetetraacetic acid (EDTA, disodium salt). The rates of hatched blastocysts were significantly affected (p < 0.01) by micromanipulation, protein supplement and water source. The water source has no influence (p > 0.05) on development in EDTA‐supplemented protein‐free culture media, whereas in EDTA‐ and protein‐free culture media, the water quality significantly (p < 0.001) affected the rates of development, with higher rates in media prepared with M‐Q water. The micromanipulated embryos showed higher sensitivity to the water quality (p < 0.01). It worth mentioning that the rates of hatched blastocysts in protein‐free culture media were very low (0–7.5%). Furthermore, the three different water types were analysed by measuring the electrical conductivity, inorganic ions, total organic carbon and endotoxins to evaluate the purity. M‐Q water showed the lowest levels of inorganic ion, total organic carbon and endotoxin concentrations. We concluded that manipulated mouse embryos are good system to evaluate the quality of water used in biological system. 相似文献
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