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利用所测定的猪脂肪组织表达序列标签以及来源于GenBank中非冗余核酸数据库和表达序列标签数据库中的人、牛及小鼠cDNA序列 ,在随机抽样方法建立的基础上 ,分别采集 70个已知功能基因的cDNA序列 ,分析了 4个物种 70× 15 0bp序列连接体的突变规律 ,建立了不同物种之间的综合种系发生分析方法。结果表明 ,在 4个物种 70个已知功能基因所构成的cDNA序列连接体同源性分析中 ,共发现 391个单碱基突变 ,不同物种之间的突变数量大大超过了同一物种基因组水平预测的 1/ 10 0 0。其中以C/T(T/C)转换和A/G(G/A)转换为主要的单碱基突变类型。种系发生分析结果表明 ,作为偶蹄目的猪和牛的遗传关系最近 ,其次是人类 ,小鼠与家猪和牛的遗传关系最远。 4种动物从共同祖先分化的顺序分别为小鼠最早 ,人类次之 ,然后为猪和牛  相似文献   

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The intricate artwork that adorns bamboo artefacts from New Caledonia is made up of a restricted range of basic elements. By combining and recombining these elementary shapes—chevrons, triangles, pentagons—the artists have produced narratives of a potentially high documentary quality. Before these narratives can be incorporated into the history of the country, however, it is necessary that the polysemic richness of the visual motifs and their transfigurative power be understood. This article is a small step in that direction.  相似文献   

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The mathematical tools of Hilbert space theory and Gauß quadrature are used to derive a new method of curve fitting and calculation of statistical moments of the concentration-time curve.  相似文献   

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利用microRNA数据库,获取3种微RNAmir-181a、mir-124和mir-1的成熟序列信息.基于siRNAdu-plex在形成RNA诱导的沉默复合物(RNA-inducedsilencingcomplex,RISC)过程中的不对称性的特点,初步设计了针对上述3种微RNA的microRNAduplex.采用生物学软件Oligo6.0分别评价其热动力学特性,并通过改变反义链3'端个别碱基序列使其满足热动力学的需求,从而确定最终的设计序列.结果显示,利用RISC形成过程的不对称性,结合生物学软件Oligo6.0的热动力学分析来设计miRNAduplex,是一种简便可行、准确有效的方法.  相似文献   

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Autoimmune diseases such as rheumatoid arthritis and gastrointestinal disorders such as stomach ulcers are often treated with drugs. NSAIDs, a common treatment in rheumatoid arthritis, may cause stomach ulcers which call for additional medications, notably antacids in the sense of drugs that suppress acid secretion by the stomach. Infection with Helicobacter pylori also plays a role in the ulcers. The infection is typically treated with antibiotics added to antacids. Considering NSAIDs and antacids, we suspect that overmedication is common to the extent that particular diets are a better option. Current research and current treatments with these drugs are also problematic since circadian rhythms are mostly disregarded. All the processes involved in the disorders treated show marked variations in the course of the day. Hence experiments conforming to the guidelines of evidence-based medicine, and treatments in line with them, have outcomes strongly depending on the time factor. This calls for reforms in medicine with fresh inputs from biology.  相似文献   

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陈旧皮张中DNA提取的新方法   总被引:32,自引:6,他引:26  
对传统的馆藏陈旧皮张标本DNA提取方法进行了改进,所提DNA分子量可达1kb,而且具有样品用量少(约0.01g),消化时间短(约14h)和操作步骤简单等优点,利用所提DNA,对小熊猫等珍稀动物线粒体DNA的细胞色素b和控制区序列的部分片段进行了PCR扩增,序列测定和比较分析,证实所提DNA合格而无污染,完全可以用于珍稀动物保护遗传学研究。  相似文献   

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神经精神类疾病是威胁人类健康的重大疾病,具有高患病率的特点,且患者通常伴随有认知障碍.长期以来,临床针对神经精神疾病的诊断主要是根据患者的临床表现,缺乏统一的客观标准,治疗手段也具有一定的难度且会产生副作用.因此开发高效客观的诊疗方式是神经精神疾病研究和临床实践的重难点.脑电图是反映脑功能变化的一种临床检查方式,其特征性节律的检测可作为大脑损伤的指标. Gamma节律(γ节律)作为与认知相关的一个重要神经节律,在大脑高级功能中扮演重要角色.众多研究发现神经精神类疾病的患者和动物模型伴随有γ节律的紊乱,这预示着基于认知核心脑区γ节律的神经检测与调控可能实现精准诊疗.本文综述了面向神经退行性疾病和精神类疾病开展的γ节律研究进展,通过梳理以往研究中γ节律在调节认知、学习记忆时的特征规律和相关分子基础,提出γ节律可能成为未来临床检测神经精神疾病无创高效的客观靶标,并在此基础上对未来的研究进行了展望.  相似文献   

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以DL-丝氨酸为原料制备D-丝氨酸的新方法   总被引:2,自引:0,他引:2  
以DL-丝氨酸为原料经过酯化、拆分和水解制备D-丝氨酸。使L-2,3-二苯甲酰酒石酸(L-DBTA)与DL-丝氨酸甲酯在无水乙醇中于60℃反应形成非对映体盐,冷却到0℃,D-丝氨酸甲酯.L-DBTA二盐析出,过滤后再经水解,得到D-丝氨酸,总收率为74.8%,旋光纯度达到98%以上。  相似文献   

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昆虫谷胱甘肽S-转移酶分离纯化的新方法   总被引:4,自引:0,他引:4  
谷胱甘肽S-转移酶(glutathioneS-transferases,GST)是一类具有多种生理功能的同功酶.从蜡螟幼虫(Galeriamelonela)的提取液中分离纯化谷胱甘肽S-转移酶的基本方法如下:首先将冷冻的蜡螟幼虫在磷酸缓冲液中匀桨,经10000g和100000g分级离心;取上清液通过QAE-SephadexA-25离子交换柱层析除去部分色素和杂蛋白;然后采用谷胱甘肽-琼脂糖凝胶亲和层析(GSH-QT4),四溴酚酞二磺酸盐-琼脂糖凝胶亲和层析(BSP-QT4),铜离子-琼脂糖凝胶螯合层析(Cu2+-QT4)及PBE94-Sepharose(PBE94)聚焦层析等层析技术进一步分离纯化.将上述方法获得的色谱峰以CDNB和DCNB为底物检测生物活性.具有生物活性部分的蛋白质,通过SDS-PAGE测定其分子量.实验结果表明,采用GSH-QT4亲和层析法获得的活性峰,在SDS-PAGE图谱上呈现出两条带,分子量为24kD,24.5kD左右;Cu2+-QT6螯合层析法分离的活性峰,呈现出一条带,分子量为24kD左右;PBE94-聚焦层析法分离获得三个活性峰:第一色谱峰,呈现出一条带,分子量为23kD左右  相似文献   

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Objective: To validate transthoracic echocardiography as an easy and reliable imaging method for visceral adipose tissue (VAT) prediction. VAT is recognized as an important indicator of high cardiovascular and metabolic risk. Several methods are applied to estimate VAT, with different results. Research Methods and Procedures: We selected 60 healthy subjects (29 women, 31 men, 49.5 ± 16.2 years) with a wide range of body mass indexes. Each subject underwent transthoracic echocardiogram and magnetic resonance imaging (MRI) to measure epicardial fat thickness on the right ventricle. Measurements of epicardial adipose tissue thickness were obtained from the same echocardiographic and MRI views and points. MRI was also used to measure VAT cross‐sectional areas at the level of L4 to L5. Anthropometric indexes were also measured. Results: Subjects with predominant visceral fat accumulation showed higher epicardial adipose tissue thickness than subjects with predominant peripheral fat distribution: 9.97 ± 2.88 vs. 4.34 ± 1.98 (p = 0.005) and 7.19 ± 2.74 vs. 3.43 ± 1.64 (p = 0.004) in men and women, respectively. Simple linear regression analysis showed an excellent correlation between epicardial adipose tissue and waist circumference (r = 0.895, p = 0.01) and MRI abdominal VAT (r = 0.864, p = 0.01). Multiple regression analysis showed that epicardial adipose tissue thickness (r2 = 0.442, p = 0.02) was the strongest independent variable correlated to MRI VAT. Bland test confirmed the good agreement between the two methods. Discussion: Epicardial adipose tissue showed a strong correlation with anthropometric and imaging measurements of VAT. Hence, transthoracic echocardiography could be an easy and reliable imaging method for VAT prediction.  相似文献   

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目的:建立一种从小鼠表皮组织提取高质量RNA的方法。方法:用热击法分离小鼠表皮,用TRIzol法提取RNA,用紫外分光光度计测定RNA的产率和纯度,用琼脂糖电泳和RT-PCR检测RNA的质量和完整性。结果:采用新方法提取的小鼠表皮总RNA,其D260nm/D280nm值为1.8~2.0,大于1.5,且RNA产率高于100μg/g;琼脂糖电泳出现5S、18S和28S等3条清晰的rRNA条带,而且28SrRNA条带的亮度约为18S的2倍;用新方法制备的总RNA可成功地用于RT-PCR实验。结论:采用热击法分离表皮并结合TRIzol法可提取到高质量、完整性好的小鼠表皮总RNA,并能用于相关的分子生物学实验。  相似文献   

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