New algorithm and system for measuring size distribution of blood cells

In optical scattering particle sizing, a numerical transform is sought so that a particle size distribution can be determined from angular measurements of near forward scattering, which has been adopted in the measurement of blood cells. In this paper a new method of counting and classification of blood cell, laser light scattering method from stationary suspensions, is presented. The genetic algorithm combined with nonnegative least squared algorithm is employed to inverse the size distribution of blood cells. Numerical tests show that these techniques can be successfully applied to measuring size distribution of blood cell with high stability.     

COMPARATIVE STUDY ON RESIDUAL EFFECTS OF ORGANIC AND INORGANIC FERTILIZER NITROGEN IN WATERLOGGED SOIL AND DRYLAND SOIL

The balance of residual fertilizer nitrogen was studied with the application of crotalariaand ammonium sulfate in two opposite cropping sequences —rice-wheat-rice-wheat and wheatrice-wheat-rice. Air-dried plant of crotalaria tagged with(~(15)NH_4)_2SO_4 and containing 6.5% of ~(15)N in total nitrogen was used as the sources of ~(15)N labelled organic manure. Ammonium sulfate tagged with 10.6% ~(15)N was applied as inorganic fertilizer.The recovery rate of residual fertilizer N was very low, averaging only 2.5% 2% on the basis of applied fertilizer N, in the case of rice as well as wheat in each successive cropping season. After the harvest of the first crop, more fertilizer nitrogen was immobilized as residual form in dryland soil than in waterlogged soil. The percentage of cumulative uptake of fertilizer N in rice-wheat-rice-wheat cropping sequence was much greater than that in the wheat-rice-wheat-rice sequence. It might be more economical to apply this kind of manure as basal dressing first to rice.     

量子信息讲座续讲 第一讲 量子计算中的因子分解

因子分解对所有的现行计算机而言是难解的 .这是现在通用的公共加密系统的基础 .文章介绍了在量子计算机上进行的Shor量子算法 ,即利用量子态的相干叠加和纠缠特性以及量子逻辑门实现量子计算的方法 ;并着重从理论原理和实验实现这两方面说明利用余因子函数和离散傅里叶变换使这种量子算法对因子分解是有效的 .     

α-Synuclein转基因小鼠内源性儿茶酚异喹啉的高效液相色谱-串联质谱检测

建立内源性儿茶酚异喹啉类物质1-甲基-6,7-二羟基-1,2,3,4-四氢异喹啉(Salsolinol,Sal)、6,7-二羟基-1,2-二甲基-1,2,3,4-四氢异喹啉(N-methyl-Sal,NMSal)的高效液相色谱-串联质谱(HPLC-MS/MS)定量检测方法,研究α-Synuclein过表达对Sal、NMSal脑内水平的影响。实验优化了色谱及质谱条件,建立基于多反应监测(MRM)技术的Sal和NMSal的高灵敏度、高选择性、高重复性分析方法,并应用此方法对过表达人源野生型(WT)、突变型(A53T)α-Synuclein蛋白的转基因小鼠脑中Sal、NMSal含量进行测定,发现WT、A53T转基因小鼠脑内Sal、NMSal的含量与对照组相比均显著升高。结果表明:Sal、NMSal分别在6.10pmol/L~6.25nmol/L和97.70pmol/L~100.00nmol/L范围呈线性(相关系数r≥0.9995),日内、日间相对标准偏差(RSD)均小于15.0%,回收率分别为86.5%~90.7%和81.0%~91.4%,Sal、NMSal的检出限分别为1.53pmol/L和24.4pmol/L,定量限分别为6.10pmol/L和97.7pmol/L。α-Synuclein过表达会导致内源性神经毒素Sal、NMSal水平的升高,可能与帕金森病发病机制有关。     

利用多孔阳极氧化铝研究载体孔洞尺寸对负载银粒子团聚的影响

 利用阳极氧化方法制备了具有规整的可控孔洞尺寸的多孔Al2O3 膜,并以此模拟实际的催化剂载体制备了负载银催化剂. 采用扫描电镜、能量分散谱、透射电镜、X射线衍射和X射线光电子能谱等手段,研究了多孔阳极氧化铝的孔洞大小对负载的银粒子团聚的影响. 结果表明,载体孔洞尺寸对银粒子团聚可能起到限制作用,而且这种限制作用随载体孔洞尺寸增大而减小. 当载体的孔洞尺寸约为50 nm时,随温度升高银粒子的团聚和生长都不明显; 当载体的孔洞尺寸约为200 nm时,随温度升高银粒子发生一定程度的团聚和生长,但孔洞尺寸的限制作用仍存在. 这种载体尺寸的限制作用可以有效地阻止催化剂活性组分的团聚.     

怎样把化学结构学说贯穿在有机化学教学中

由俄罗斯天才学者 A.M.布特列洛夫(Бутлеров)所奠定的化学结构学说,一直光辉的指导有机化学和有机合成工业的发展;它是有机化学的主要理论基础。显而易见,帮助学生巩固的掌握这一武器,是学好有机化学的关键;也只有在整个有机化学教学中贯穿这根红线,学生才能深刻的认识有机化合物和有机化学反应的本质,在真正理解的基础上,才会学好有关的有机化学的基本知识。全面的贯彻化学结构学说,不可能是通过一、两堂课而一举告成的,应该根据教材的实际情况,本着突出重点分散难点的原则,分阶段进行;每一阶段着重解决     

近红外荧光探针天青A检测DNA

近红外荧光探针天青A(AZ)可与DNA结合,结合常数为K=5.90×105L/mol,结合位点数n=0.94碱基对。利用在pH=8.0的tris-HCl缓冲体系中,DNA浓度与天青A的荧光强度呈线性关系,在近红外区建立测定核酸的方法。其检测下限为0.064mg/L;线性范围为0.064~26mg/L(r=0.9942)。本方法具有测试简单、背景干扰小、灵敏度高等优点。     

Laser-based transfection with conjugated gold nanoparticles

The irradiation of ceils combined with the immunoconjugate of gold nanoparticles by the short pulse laser can make the plasma membrane be transiently permeabilized, which can be used to transfer exogenous molecules into the cells. We explore this technique as a novel gene transfection method for floating cells. Three different floating cells exposed to the laser are selectively transfected with fluorescein isothiocyanatedextran, antibody, and green fluorescent protein （GFP） coding plasmids, and the viability of cells are determined by propidium iodide. For fluorescein isothiocyanate-dextran, the best transfection efficiency of 65% is obtained; for the antibody, it is 74%; whereas for the green fluorescent protein coding plasmids, a very small transfection efficiency is gained. If the transfection efficiency is improved, gold nanoparticles will be very useful as mediator for gene transfection in living cells.     

心肌膜电位的光学标测技术及实验研究

基于电压敏感染料膜电位光学标测的原理,建立了一套光标测系统,主要包括LED激发光源、以及由滤光片、CCD、A/D采集卡及计算机构成的荧光信号采集、处理部分.目前,整套系统已可自动完成图像采集、实时显示,以及部分后处理等工作,已获得兔心室组织细胞膜动作电位.另外,在建立系统的同时,研究了光学标测实验方法,对离体兔心脏急性缺血的主要电生理特征进行了标测实验,并结合仿真研究的结论说明了缺血后有效不应期时空异质性的存在以及组织中电兴奋传导速度的减慢是缺血导致折返性心律失常的主要机制.     

心脏组织的自体荧光研究

测量并研究了家兔心脏组织自体荧光的三维光谱和发射光谱。果表明：冰冻前后心室和心房组织的三维荧光光谱差异较主动脉明显,说明冰冻后其NADH和黄素的含量改变。心房、心室和主动脉组织在340 nm激发光下的自体荧光光谱具有特定的差异,其主要荧光峰位于460 nm 的NADH,以及290～400 nm之间的胶原蛋白和弹性蛋白。根据心房和心室组织的高斯拟和光谱发现,光谱的峰位、相对荧光强度和半宽等参数各不相同。由此,可以根据荧光光谱的谱形和峰强比可以显著区分出不同的心脏组织类型。此外,研究首次发现心室组织NADH的荧光强度会随心肌死亡时间增加而衰减,可作为死亡时间确定的新方法。