MS4000U生物信号定量记录分析系统（MS4000U）简介

我公司1995年推出了MS302生物信号记录分析系统，在国内拥有众多用户。经过近年的努力，MS4000U终于以崭新的面貌问世了!MS4000U的设计站在了一个全新的高度，其基本设计思想是硬件集成度高、图形质量好、分析结果准确、软件功能齐全而且操作简单。为科研提供高性能产品是MS4000U的定位，突出做好信号的定量分析是MS4000U不同其他产品的重要标志!     

MS4000U生物信号定量记录分析系统（MS4000U）简介

我公司1995年推山了MS302生物信号记录分析系统，在国内拥有众多用户，受到用户的好评。经过近年的努力，MS4000U终于以崭新的面貌问世了!MS4000U的设计站在了一个全新的高度，其基本设计思想是硬件集成度高、图形质量好、分析结果准确、软件功能齐全而且操作简单。     

MS4000U生物信号定量记录分析系统（MS4000U）简介

我公司1995年推出了MS302生物信号记录分析系统，在国内拥有众多用户，受到用户的好评。经过近年的努力，MS4000U终于以崭新的面貌问世了!MS4000U的设计站在了一个全新的高度，其基本设计思想是硬件集成度高、图形质量好、分析结果准确、软件功能齐全而且操作简单。为科研提供高性能产品是MS4000U的定位，突出做好信号的定量分析是MS4000U不同其他产品的重要标志!     

MS4000U生物信号定量记录分析系统（MS4000U）简介

我公司1995年推出了MS302生物信号记录分析系统,在国内拥有众多用户,受到用户的好评。经过近年的努力,MS4000U终于以崭新的面貌问世了!MS4000U的设计站在了一个全新的高度,其基本设计思想是硬件集成度高、图形质量好、分析结果准确、软件功能齐全而且操作简单。为科研提供高性能产品是MS4000U的定位,突出做好信号的定量分析是MS4000U不同其他产品的重要标志!     

MS4000U生物信号定量记录分析系统（MS4000U）简介

我公司1995年推出了MS302生物信号记录分析系统,在国内拥有众多用户,受到用户的好评。经过近年的努力,MS4000U终于以崭新的面貌问世了！MS4000U的设计站在了一个全新的高度,其基本设计思想是硬件集成度高、图形质量好、分析结果准确、软件功能齐全而且操作简单。为科研提供高性能产品是MS4000U的定位,突出做好信号的定量分析是MS4000U不同其他产品的重要标志！     

4000万年前青蛙化石完好无缺

不久前,多米尼加共和国的一名矿工发现了一件4000万年前的小青蛙化石。这只青蛙只有2.5厘米长,它是在陷入琥珀里面不能自拔而变成化石的。琥珀是—种坚硬、透明而微带黄色的物体,也就是松柏的树脂。树脂从树干里流出来的时候,时常会粘着一些昆虫和植物,经过数百万年的高温和高压,这种胶状物会变成一种坚硬、透明、像树胶一样的东西。当初被粘在里面的东西现在都可以看得很清楚。由于琥珀的保护,里面的东西不会受到细菌的侵袭,所以,这     

神经介素U(neuromedin U)研究概况

神经介素 (ｎｅｕｒｏｍｅｄｉｎ)是一组平滑肌刺激性多肽 ,通常分成四类 :韩蛙皮素类、肛褶蛙肽类、神经紧张素类、神经介素Ｕ (ｎｅｒｕｏｍｅｄｉｎＵ ,ＮＭＵ) .在这组多肽中 ,神经介素Ｕ最后被发现 ,并因其子宫收缩活性而得名 .神经介素Ｕ是Ｍｉｎａｍｉｎｏ等在 1985年首次从猪脊髓中发现并分离提纯到的多肽 (包括ＮＭＵ 8和ＮＭＵ 2 5 ) ,随后又相继从大鼠、几内亚小猪、狗、家兔、鸡和澳大利亚树蛙等物种中分离得到 .ＮＭＵ产生于一个由 174个氨基酸组成的前体 .该前体包含一个疏水信号肽和几个二元蛋白酶加工位点 ,这些二元加工位…     

HPLC-DAD和LC/MS/MS测定豆奶中三聚氰胺

目的：建立二极管阵列高效液相色谱仪和三重四级杆液质联用仪对豆奶中三聚氰胺的测定方法。方法：采用三氯乙酸和乙腈为提取剂、蛋白质为沉淀剂,提取液过净化柱纯化。结果：三重四级杆液质联用法对三聚氰胺的检出限为0-001 5 mg/kg,标准曲线在0-01~0-5 μg/mL范围内,R2为0-999 8,线性良好,再回收率为85 %~89 %,适用于检测低浓度的样品;二极管阵列高效液相色谱法检出限为0-024 mg/kg,标准曲线在0-5~100 μg/mL范围内,R2为0-999 9,线性良好,回收率为83 %~91 %,可以快速地对高浓度样品进行筛查。结论以上两种检测方法结合使用,可检测0-01~100 mg/kg的三聚氰胺含量,极大地拓宽了检测范围。     

美国用4000美元解读个人基因组

第三代人类基因组测序公司——美国Complete Genomics公司，制造出自我装配DNA纳米球列阵（self-assembled DNA nano—bolearray），并将cPAL（C0mbinatorial probe anchor ligation）技术应用到该列阵上，用读取每个独立的碱基（unchained base）的方法，解读了个人的基因组。据说采用这种方法解读人的基因组时，消费品平均成本为4000美元，详细情况在2009年11月5日的Science杂志上有所报道。     

GC–MS and GC–MS/MS measurement of the cardiovascular risk factor homoarginine in biological samples

l-Homoarginine (hArg) has recently emerged as a novel cardiovascular risk factor and to herald a poor prognosis in heart failure patients. Here, we report on the development and thorough validation of gas chromatography–mass spectrometry (GC–MS) and gas chromatography–tandem mass spectrometry (GC–MS/MS) methods for the quantitative determination of hArg in biological samples, including human plasma, urine and sputum. For plasma and serum samples, ultrafiltrate (10 µL; cutoff, 10 kDa) was used. For urine samples, native urine (10 µL) was used. For sputum, protein precipitation by acetone was performed. hArg is derivatized to its methyl ester tri(N-pentafluoropropionyl) derivative; de novo synthesized trideutero-methyl ester hArg is used as the internal standard (IS). Alternatively, [guanidino-¹⁵N₂]-arginine can be used as an IS. Quantitative analyses were performed after electron-capture negative-ion chemical ionization by selected-ion monitoring in GC–MS and selected-reaction monitoring in GC–MS/MS. We obtained very similar hArg concentrations by GC–MS and GC–MS/MS, suggesting that GC–MS suffices for accurate and precise quantification of hArg in biological samples. In plasma and serum samples of the same subjects very close hArg concentrations were measured. The plasma-to-serum hArg concentration ratio was determined to be 1.12 ± 0.21 (RSD, 19 %), suggesting that blood anticoagulation is not a major preanalytical concern in hArg analysis. In healthy subjects, the creatinine-corrected urinary excretion of hArg varies considerably (0.18 ± 0.22 µmol/mmol, mean ± SD, n = 19) unlike asymmetric dimethylarginine (ADMA, 2.89 ± 0.89 µmol/mmol). In urine, hArg correlated with ADMA (r = 0.475, P = 0.040); in average, subjects excreted in the urine about 17.5 times more ADMA than hArg. In plasma of healthy humans, the concentration of hArg is of the order of 2 µM. hArg may be a low-abundance constituent of human plasma proteins. The GC–MS and GC-MS/MS methods we report in this article are useful to study the physiology and pathology of hArg in experimental and clinical settings.     

BIA–MS–MS: biomolecular interaction analysis for functional proteomics

One of the experimental processes of functional proteomics is the analysis of protein interaction. Here, we review a new analytical platform, BIA–MS, for protein interaction analysis. BIA–MS is an integration of a surface plasmon resonance biosensor for real-time interaction analysis and mass spectrometry for the subsequent identification of interacting molecules.     

In vivo kinetics of U4/U6·U5 tri-snRNP formation in Cajal bodies

The U4/U6·U5 tri-small nuclear ribonucleoprotein particle (tri-snRNP) is an essential pre-mRNA splicing factor, which is assembled in a stepwise manner before each round of splicing. It was previously shown that the tri-snRNP is formed in Cajal bodies (CBs), but little is known about the dynamics of this process. Here we created a mathematical model of tri-snRNP assembly in CBs and used it to fit kinetics of individual snRNPs monitored by fluorescence recovery after photobleaching. A global fitting of all kinetic data determined key reaction constants of tri-snRNP assembly. Our model predicts that the rates of di-snRNP and tri-snRNP assemblies are similar and that ∼230 tri-snRNPs are assembled in one CB per minute. Our analysis further indicates that tri-snRNP assembly is approximately 10-fold faster in CBs than in the surrounding nucleoplasm, which is fully consistent with the importance of CBs for snRNP formation in rapidly developing biological systems. Finally, the model predicted binding between SART3 and a CB component. We tested this prediction by Förster resonance energy transfer and revealed an interaction between SART3 and coilin in CBs.     

BIA–MS–MS: biomolecular interaction analysis for functional proteomics

One of the experimental processes of functional proteomics is the analysis of protein interaction. Here, we review a new analytical platform, BIA–MS, for protein interaction analysis. BIA–MS is an integration of a surface plasmon resonance biosensor for real-time interaction analysis and mass spectrometry for the subsequent identification of interacting molecules.     

MS基因缺失的发现

衣阿华大学(Iowa City,IA)和法国的科研人员发现,第17条染色体上缺失adhalin基因可引起严重型儿童常染色体退行性肌营养不良(SCARMD)。该病能引起严重的随意肌功能丧失。 基因的缺失能导致肌蛋白adhalin的缺乏,该蛋白能在肌肉受损害收缩过程中保护肌肉细胞。受此病折磨的患者第17条染色体上缺失2个adhalin基因,它们分别来自患者的双亲。在不久的将来,将通过基     

Endogenous U2·U5·U6 snRNA complexes in S. pombe are intron lariat spliceosomes

Excision of introns from pre-mRNAs is mediated by the spliceosome, a multi-megadalton complex consisting of U1, U2, U4/U6, and U5 snRNPs plus scores of associated proteins. Spliceosome assembly and disassembly are highly dynamic processes involving multiple stable intermediates. In this study, we utilized a split TAP-tag approach for large-scale purification of an abundant endogenous U2·U5·U6 complex from Schizosaccharomyces pombe. RNAseq revealed this complex to largely contain excised introns, indicating that it is primarily ILS (intron lariat spliceosome) complexes. These endogenous ILS complexes are remarkably resistant to both high-salt and nuclease digestion. Mass spectrometry analysis identified 68, 45, and 43 proteins in low-salt-, high-salt-, and micrococcal nuclease-treated preps, respectively. The protein content of a S. pombe ILS complex strongly resembles that previously reported for human spliced product (P) and Saccharomyces cerevisiae ILS complexes assembled on single pre-mRNAs in vitro. However, the ATP-dependent RNA helicase Brr2 was either substoichiometric in low-salt preps or completely absent from high-salt and MNase preps. Because Brr2 facilitates spliceosome disassembly, its relative absence may explain why the ILS complex accumulates logarithmically growing cultures and the inability of S. pombe extracts to support in vitro splicing.