支链氨基酸(branched-chain amino acids,BCAA)主要包括亮氨酸、异亮氨酸和缬氨酸,属于家禽营养中的必需氨基酸,具有与支链脂肪酸相似的结构,能够依次被支链氨基酸转氨酶(branched-chain aminotransferase,BCAT)和支链α-酮酸脱氢酶(branched-chain a-keto acid dehydrogenase,BCKD)复合物降解,导致辅酶A复合物发生不可逆的分解代谢.日粮组成不同,其含有的亮氨酸、异亮氨酸和缬氨酸的比例也不同,单个BCAA的浓度过高会引起其他低浓度的BCAA的降解和缺乏,进而影响家禽的生产性能、免疫力和肠道健康.
4-leave tobacco seedlings of K326 and Yun 85 were cultivated in culture solution with different forms of nitrogen: NaNO3,(NH4)2SO4,CO(NH2)2,NH4NO3 in floating-seeding system separately,to study the adaptabilities of the 2 tobacco varieties to the different forms of nitrogen. The results indicated that,Yun 85 grew better than K326 in seedling period and was more sensitive to the any forms of nitrogen. The growth of Yun 85 followed the order CO(NH2)2 NH4NO3 (NH4)2SO4NaNO3. Comparatively,K326 grew less strong in seedling period and was also less sensitive to the different forms of nitrogen,and its growth order was NaNO3,CO(NH2)2,NH4NO3 and (NH4)2SO4. The experiment showed it was necessary to diversify the culture solutions according to the different tobacco varieties in floating-seedling system.
Objective:To analyze comprehensively the effects of human being after took nicotine and to understand objectively the methods to stop smoking and utilize nicotine.Methods:We summarized the previous reports and documents in various aspects.Results:Studies indicated that nicotine could be involved in the pathogenesis of several cognition disorders to protect the nerve such as Alzheimer's disease,Parkinson's disease and epilepsy.It was also applied in inflammation diseases and helped to improve the memory and attention.However,smoking was regard to leading to chronic obstructive diseases,atherosclerosis,cardiovascular disease,emphysema and even lung cancer.Conclusion:Apparently,it was not scientific to take nicotine via smoking.Due to minimize the side effects,it was necessary to be cautious when utilized nicotine in clinical application,especially with the non-smoking patients.
运用中国统计年鉴、中国国民经济和社会发展统计公报、国家烟草专卖局烟草行业经济运行通报等官方数据和计量经济学方法,对2001―2006年中国卷烟价格、税收与消费需求变化进行了实证分析。结果表明:此间中国的卷烟价格年增长率一直保持在10%以上;同期烟草工商税利提高131.42%,年增长率达到18.35%,而此间中国的卷烟消费量也提高了24.03%(年消费增长率达到4.61%),并未出现因卷烟价格、税收提高而消费量降低的变化趋势。由此可见,目前中国出现的烟草消费需求、税收、价格同时增加的影响因素可能来自多个方面。面对中国庞大的消费需求,要实现对烟草消费的有效控制,将是一项长期、复杂而又十分艰巨的工作。对此,国家必须采取积极、严谨的科学态度,对包括税收、价格在内的一系列减少烟草需求措施进行深入细致的研究,才可能提出符合国情,并能有效控制烟草消费需求的战略选择。
