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转基因“超级鲤”的构建 总被引:9,自引:0,他引:9
用显微注射的方法共生产出以大麻哈鱼生长激素基因的结构基因,鲤鱼MT基因为启动子的融合基因转基因鲤鱼1.5万尾,同时筛选生长快表型性状好的个体进行Dot Blot和Southern Blot杂交,得到189尾事例外源生长激素基因鲤鱼,并获得1尾经对照组最大个体体重大1.8倍的“超级鲤”。通过年龄鉴定确认春为3龄鱼。“超级鲤”的出现对今后转基因鲤鱼的研究有重要意义。 相似文献
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以F2代转“全鱼”生长激素基因鲤鱼为材料,对其体重、体长和几项血液指标进行了检测。实验显示:转基因鱼体重和体长均极显著地高于对照鱼(P<0.01);转基因鱼每毫升血液中淋巴细胞总数为(25.2±6.7)×106个,对照鱼为(18.2±6.6)×106个,两者差异显著(P=0·015);转基因鱼红细胞压积值和白细胞吞噬百分率都高于对照鱼(P<0·05),但是吞噬指数没有统计学差异;转基因鱼的皮质醇水平为(63·8±16·8)ng/ml,对照鱼为(33·2±9·6)ng/ml,前者明显高于后者(P<0·01)。以上结果表明,转生长激素基因不但加速了鲤鱼的生长,还促进了其血液细胞的增殖和吞噬功能,并直接或间接地引起了血清皮质醇水平的升高。 相似文献
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加强动物生理学实验教学改革,要从培养学生爱护实验动物,观察和记录实验现象,团队精神,抵抗挫折以及实事求是的作风等方面来提高学生的综合素质。同时加强学生基本实验技能的训练,让学生从鲜活、丰富多彩的生命现象中认识理解和探索生命现象的本质,培养学生对真理和知识永无止境的探求精神。 相似文献
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采用显微注射方法,获得了转"全鱼"生长激素(GH)基因鲤鱼(转基因鱼),应用抑制性差减杂交(SSH)技术,构建了4月龄F3转基因鱼胸腺发育差减cDNA文库,筛选并鉴定了与胸腺发育相关的81个与已知基因同源的表达序列标签(EST).这些EST至少代表69个基因.根据基因的作用将其分为5类:18个与免疫和细胞防御有关;23个参与细胞生长、发育和分化等代谢过程;3个参与细胞信号传导和周期调控;8个在转录和表达调节中发挥作用;17个为核糖体蛋白基因,表明转基因鱼胸腺细胞处于活跃的蛋白合成状态.应用RT-PCR和虚拟Northern杂交技术进一步证实其中的若干基因在转基因鱼胸腺组织中的表达量增加.实验结果为阐明转植GH基因促进鲤鱼胸腺发育的相关分子机制提供了依据. 相似文献
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拍摄更好的动物照片!简妮,安·拉里如果你爱好摄影,那你一定和大多数摄影爱好者一样,对动物有着浓厚的兴趣,既把它们当成伙伴,又把它们作为拍摄的对象。也许你曾拥有一只或更多的动物──狗和猫往往是最受欢迎的。它们时而活泼好动,时而倦慵。作为一名“发烧”的摄... 相似文献
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美国转基因大西洋鲑产业化对我国的启示 总被引:1,自引:0,他引:1
2015年11月19日,美国食品药品监督管理局(FDA)批准了转全鱼生长激素基因(gh)大西洋鲑为第一种可供食用的转基因动物产品,从而取得世界转基因动物育种研究与产业化的历史性突破。经过了长达20年的严格审核,转gh大西洋鲑才获准产业化,不仅充分说明了对包括转基因鱼在内的创新产业的管理决策尤其需要尊重科学规律和客观事实;而且表明基础研究只是产业创新的因素之一,转基因知识的科学普及与企业的积极参与是推动高新技术发展和创新产业形成不可或缺的重要条件;高屋建瓴地制定我国基因改良农业品种市场准入的条例和操作细则已经刻不容缓。 相似文献
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目的 以猫为研究对象,获取猫和饲养者对宠物家具的感性需求,探索以用户需求为导向的宠物家具设计,为宠物家具设计提供方向。方法 首先通过实际观察、文献研究及深入访谈,从猫的生理特征、心理特点、行为习性三个方面分析归纳猫对宠物家具的设计需求;其次,搜集饲养者对宠物家具的感性需求,采用模糊Kano模型和Better-Worse系数对饲养者的感性需求进行筛选与分类;最后将总结的宠物需求与筛选后的饲养者需求建立宠物家具设计需求体系,利用层次分析法(AHP)对各项需求进行权重值计算和一致性检验,将权重值较高的需求作为宠物家具设计的依据。结果 宠物家具设计需求较高的有功能区域划分、整体协调、结构稳定、符合猫的尺寸、保持合理的社交距离、擅长跳跃与登高。 相似文献
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Yu MD Peck GE Scott-Moncrieff JC Blevins WE Shaw SM 《Drug development and industrial pharmacy》1999,25(5):565-570
This investigation was designed to compare in vitro dissolution profiles from sodium iodide capsules with radioiodide thyroid uptake in hyperthyroid cats using sodium iodide capsules prepared with a formulation exhibiting a complete release of radioiodide (I-123) in vitro and a formulation with an incomplete release of radioiodide. In vitro dissolution profiles for I-123 sodium iodide capsules with two different formulations were determined using the USP XXIII dissolution test. The two formulations studied in vitro were sodium phosphate dibasic powder with 1% magnesium stearate and calcium phosphate dibasic powder with 3% magnesium stearate. By 20 min after initiation of the dissolution test, over 95% of the I-123 was released from capsules of sodium phosphate dibasic powder. The capsules of calcium phosphate dibasic powder reached 75% at 65 min, with no further release occurring thereafter. There was a statistically significant difference in the dissolution profiles of the two formulations. The thyroid uptake of I-123 from capsules exhibiting complete release and incomplete release of radioiodide was determined in hyperthyroid cats. At 4 hr, the mean percentage thyroid uptake value for sodium phosphate dibasic powder with 1% magnesium stearate (complete release formulation) was 12.0% compared to 9.4% for calcium phosphate dibasic powder with 3% magnesium stearate (incomplete release formulation); at 24 hr, the values were 34.4% compared to 23.7%. The data suggest that the incomplete dissolution profile observed in vitro may correlate with a reduction in the bioavailability of the radioiodide in vivo. However, using the Wilcoxon signed rank test, statistically significant differences did not occur between the complete release formulation and incomplete release formulation at either 4 hr or 24 hr (p > .05). The results of the in vivo study with five hyperthyroid cats were not conclusive due to the variability in response between individual cats. 相似文献
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《Drug development and industrial pharmacy》2013,39(5):565-570
This investigation was designed to compare in vitro dissolution profiles from sodium iodide capsules with radioiodide thyroid uptake in hyperthyroid cats using sodium iodide capsules prepared with a formulation exhibiting a complete release of radioiodide (I-123) in vitro and a formulation with an incomplete release of radioiodide. In vitro dissolution profiles for I-123 sodium iodide capsules with two different formulations were determined using the USP XXIII dissolution test. The two formulations studied in vitro were sodium phosphate dibasic powder with 1% magnesium stearate and calcium phosphate dibasic powder with 3% magnesium stearate. By 20 min after initiation of the dissolution test, over 95% of the I-123 was released from capsules of sodium phosphate dibasic powder. The capsules of calcium phosphate dibasic powder reached 75% at 65 min, with no further release occurring thereafter. There was a statistically significant difference in the dissolution profiles of the two formulations. The thyroid uptake of I-123 from capsules exhibiting complete release and incomplete release of radioiodide was determined in hyperthyroid cats. At 4 hr, the mean percentage thyroid uptake value for sodium phosphate dibasic powder with 1% magnesium stearate (complete release formulation) was 12.0% compared to 9.4% for calcium phosphate dibasic powder with 3% magnesium stearate (incomplete release formulation); at 24 hr, the values were 34.4% compared to 23.7%. The data suggest that the incomplete dissolution profile observed in vitro may correlate with a reduction in the bioavailability of the radioiodide in vivo. However, using the Wilcoxon signed rank test, statistically significant differences did not occur between the complete release formulation and incomplete release formulation at either 4 hr or 24 hr (p >. 05). The results of the in vivo study with five hyperthyroid cats were not conclusive due to the variability in response between individual cats. 相似文献
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Spatiotemporal receptive fields of cells in V1 are optimally shaped for stimulus velocity estimation
Cocci G Barbieri D Sarti A 《Journal of the Optical Society of America. A, Optics, image science, and vision》2012,29(1):130-138
In recent literature, particularly interesting stimulus velocity-selective behaviors were found in the response properties of neurons belonging to the primary visual cortex (V1). In this work, 93 simple and complex cell receptive fields were obtained from the recordings of different experiments made on cats (DeAngelis, Blanche, Touryan) with reverse correlation and the spike-triggered covariance methods and then fitted with a three-dimensional Gabor model, so that cells are seen as minimizers of the Heisenberg uncertainty principle over both space and time. Analysis of the model parameters' cortical distribution suggests that V1 is spatiotemporally organized to maximize the resolution on the stimulus velocity measure. 相似文献
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Abstract A filtering algorithm which takes the measured Radon transform of the Wigner function of a quantum signal with thermal noise and produces the Wigner function of the corresponding ‘clean’ (noiseless) signal, is proposed. The general method is exemplified for number eigenstates with thermal noise and also for Schrödinger cats with thermal noise. 相似文献
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Abstract In this paper we study the decoherence process occurring when a field prepared in quantum superpositions of coherent states (Schrödinger cats) interacts with a two-level atom in the framework of the Jaynes-Cummings model. We emphasize the influence of the relative phase in the initial superposition state on the purity of the field during the evolution 相似文献
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目的 研究符合当前城市家庭用户饲养需求及宠物生活习性的宠物家具设计方法,促进宠物家具设计方法理论及实践的完善。方法 首先,通过网络数据分析、用户访谈、文献研究、实地观察等方法,从饲养者和宠物猫双重视角获取宠物猫家具的设计需求并利用KJ法对其进行归类;然后,编制Kano问卷进行用户调研,运用Kano模型对宠物猫家具的各需求类别进行属性分类;最后,结合Better-Worse系数明确各需求的优先级,以此作为现有宠物猫家具的设计方向和依据。结果 得出3项必备型需求、3项期望型需求、6项魅力型需求及各项需求的优先等级,指出了宠物猫家具设计的方向及思路。结论 从需求角度出发,运用Kano模型分析宠物猫家具各项设计需求类别及优先级,为宠物猫家具设计提供了依据和方向,有利于丰富和完善现有宠物家具的设计理论。 相似文献
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We investigate the dynamics of a two-level atom in a cavity filled with a nonlinear medium. We show that the atom-field detuning δ and the nonlinear parameter χ(3) may be combined to yield a periodic dynamics, allowing the generation of almost exact superpositions of coherent states (Schrödinger cats). By analysing the atomic inversion and the field purity, we verify that any initial atom-field state is recovered at each revival time, and that a coherent field interacting with an excited atom evolves to a superposition of coherent states at each collapse time. We show that a mixed field state (statistical mixture of two coherent states) evolves towards an almost pure field state as well (Schrödinger cat). We discuss the validity of these results by using the field fidelity and the Wigner function. 相似文献
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Narges Bahi-Jaber David Fouchet Dominique Pontier 《Journal of the Royal Society Interface》2008,5(26):1031-1039
Stochastic fluctuations in the transmission process of microparasites generate a risk of parasite extinction that cannot be assessed by deterministic models, especially in host populations of small size. While this risk of extinction represents a strong selection pressure for microparasites, it is usually not clearly separated from the deterministic ones. We suggest here that this stochastic selection pressure can affect the selection of the transmission mode of microparasites. To avoid extinction, parasites should maximize their inter-population transmission to ensure frequent reintroductions. Since the types of contacts may differ if congeners belong to the same or distinct populations, strains that are mainly transmitted through inter-population contacts might be selected. To examine this assumption, we analyse the issue of the competition between two strains differing in their transmission mode using a stochastic metapopulation model in which hosts may display different behaviours inside and outside their populations. We show that stochastic selection pressures may drive parasite evolution towards a transmission mode that maximizes the persistence of the parasite. We study the conditions under which stochastic selection pressures may surpass the deterministic ones. Our results are illustrated by the cases of feline immunodeficiency virus in cats and of sexually transmitted diseases in mammals. 相似文献
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Abstract We present various schemes for measuring the quantum state of a single mode of the electromagnetic field. These involve measuring the photon statistics for the mode before and after an interaction with either one or two two-level atoms. The photon statistics conditioned on the final state of the atoms, for two choices of the initial set of atomic states, along with the initial photon statistics, may be used to calculate the complete quantum state in a simple manner. Alternatively, when one atom is used, two unconditioned sets of photon statistics, each after interaction with a single atom in different initial states, along with the initial photon statistics may be used to calculate the initial state in a simple manner. When the cavity is allowed to interact with just one atom, only pure cavity states which do not contain zeros in the photon distribution may be reconstructed. When two atoms are used we may reconstruct pure states which do not contain adjacent zeros in the photon distribution. Coherent states and number states are among those that may be measured with one-atom interaction, and squeezed states and ?Schrödinger cats‘ are among those that may be measured with a two-atom interaction. 相似文献