The neuroblast and angioblast chemotaxic factor SDF-1 (CXCL12) expression is briefly up regulated by reactive astrocytes in brain following neonatal hypoxic-ischemic injury

Background  

Stromal cell-derived factor 1 (SDF-1 or CXCL12) is chemotaxic for CXCR4 expressing bone marrow-derived cells. It functions in brain embryonic development and in response to ischemic injury in helping guide neuroblast migration and vasculogenesis. In experimental adult stroke models SDF-1 is expressed perivascularly in the injured region up to 30 days after the injury, suggesting it could be a therapeutic target for tissue repair strategies. We hypothesized that SDF-1 would be expressed in similar temporal and spatial patterns following hypoxic-ischemic (HI) injury in neonatal brain.     

Dehalogenation of α -haloketones and vic-dibromides with nickel boride

α-Haloketones and $\text{vic}$-dibromides are converted to the corresponding ketones and alkenes respectively with nickel boride generated $\text{in situ}$ from sodium borohydride and nickel chloride.     

电感耦合等离子体原子发射光谱法(ICP-AES)测定铁镍软磁合金中的镍

研究了电感耦合等离子体原子发射光谱法(ICP-AES)快速测定铁镍软磁合金中的镍含量,确定了最佳测定条件,以波长221.647nm作为镍的分析线,对溶解酸和酸浓度的影响进行探讨,选择钇作为内标元素。分析试样得到结果的相对标准偏差RSD小于0.91%(n=6),方法回收率为99.8%~100.1%(n=6),分析结果与丁二酮肟分光光度法相一致。电感耦合等离子体原子发射光谱法比传统的化学法准确、快速,已成功用于生产中。     

New mass spectrometric approaches to structural analysis in mixtures

Structural analysis of minor components in mixtures is a vital requirement in the development of any pharmaceutical compound. Mass spectrometry is uniquely able to give this kind of information on the trace amounts of material present as minor impurities in a drug substance. In this study we show that a combination of mass spectrometric analysers with different characteristics is an even more powerful approach with a higher chance of establishing a potential structure. In particular the advent of analysers capable of accurate mass measurement on small amounts of material has enabled structures to be proposed in situations where previously no real conclusions could be made. Copyright 1999 John Wiley & Sons, Ltd.     

Rational matrix approximation with a priori error bounds for non-symmetric matrix Riccati equations with analytic coefficients

In this paper the exact solution of the non-symmetric matrixRiccati equation with analytic coefficients is approximatedby a rational matrix function with a prefixed accuracy. Thisrational matrix function is locally defined as the exact solutionof a Riccati problem with matrix polynomial coefficients obtainedby truncation of the Taylor expansions of the matrix coefficientsof the original problem.