一种基于稀疏分解去除EEG信号中MRI伪迹的新方法

在脑电图(Electroencephalography,EEG)和功能磁共振成像(Functional magnetic resonance imaging, FMRI)同时记录时,如何有效的去除混入EEG信号中的强磁共振(Magnetic resonance imaging,MRI)伪迹干扰信号是当前在EEG和FMRI的联合研究中面临的一个信号前期处理难点。主要从MRI干扰信号和EEG信号在时空上的差别出发,提出了一种基于混合过完备库的稀疏成分分析的分解方法,实现了强MRI干扰下的EEG信号的估计。在方法实现中,首先利用小波和离散余弦构造能体现MRI干扰和EEG时空特性差别的混合过完备库,然后通过匹配追踪(Matching pursuit,MP)方法在混合过完备库中的学习,实现MRI伪迹的消除。对模拟数据以及真实记录的混入了MRI干扰的EEG信号的估计实验结果,证实了该方法的有效性。     

一种基于独立成分分析的功能磁共振数据处理方法

独立成分分析（ICA）是统计信号处理中的一项新技术，用来从混合信号的多维观测中提取具有统计独立性的成分。我们针对功能磁共振数据处理，采用先对相邻的两体元信号作ICA分离，然后与参考信号进行相关，把相关系数大于一定阈值的体元作为刺激引起兴奋的体元，从而实现刺激的功能定位。经实际脑功能磁共振数据试验，初步证明了方法的有效性。     

Purification of the NADH reductase component of the steroid 9α-hydroxylase fromMycobacterium fortuitum

The NADH reductase component of the steroid 9α-hydroxylase fromMycobacterium fortuitum was purified to homogeneity. Recovery of the enzyme from the 50≈60% ammonium sulfate saturated fraction was 49%, with a purification factor of 100-fold. The NADH reductase has a relative molecular mass of 60 KDa as determined by SDS-PAGE. The absorption maxima at 410 and 450 nm indicate the presence of iron-sulfur group and flavin. These prosthetic groups seemed to function as redox groups that transfer electrons from NADH to the following protein. The K_M value for NADH as substrate was 68 μM. The NH₂-terminal amino acid sequence of the reductase was determined as Met-Asp-Ala-Ile-Thr-Asn-Val-Pro-Leu-Pro-Ala-Asn-Glu-Pro-Val-His-Asp-Tyr-Ala-Thr. This sequence does not show a homology with the NH₂-terminal sequences reported for the reductase component of other monooxygenases, suggesting that the NADH reductase component of the steroid 9α-hydroxylase system is novel.     

Amyloid-P-component-like immunoreactivity in β/A4-immunoreactive deposits in Alzheimer-type dementia brains

An immunohistochemical study using the mirror-image technique was performed in order to establish whether amyloid P component is involved in the mechanism of deposition of amyloid fibrils in senile plaques (SPs) in Alzheimer-type dementia (ATD). Ninety percent of /A4 protein-immunoreactive SPs were also stained by the anti-amyloid P component immunchistochemistry, and this applied to all of the diffuse, primitive and classical types of /A4 deposits. These findings may suggest an involvement of amyloid P component in the formation of amyloid fibrils in senile plaques in ATD brains.     

A new long shelf life formulation of modified Ham's F-10 medium: Biochemical and clinical evaluation

Purpose To evaluate biochemically and clinically a new formulation of modified Ham's F-10 medium made without the inclusion of hypoxanthine. The medium was formulated for long-term storage and use by separately preparing a stable liquid (basal) portion and a freeze-dried supplement containing the labile medium components.Results Following 18 months of storage the basal medium was biochemically analyzed for its amino acid (aa's) and vitamin content. Cysteine and tryptophan were decreased to less than 30% of their starting theoretical concentrations (STCs). Asparagine, serine, tyrosine, histidine and lysine were present at 50% to 70% of their STC. The remaining aa's were all within 90% of their STCs except arginine which was at 77%. All of the vitamins were present at 90% or more of their STCs except inositol, riboflavin and'thiamine which were present at 70% of their STCs. IVF with the new formulation resulted in 13 deliveries from 51 aspirations (25%) as compared with 10/39 (26%) in 1991, when standard medium preparation was used. Oocyte donation resulted in 30 deliveries from 84 cycles (36%) with the new formulation as compared with 21/65 (32%) in 1991.Conclusions (1) The new basal with lyophilized supplement formulation produces similar clinical results in the IVF laboratory as medium prepared in the standard fashion, (2) certain amino acids and vitamins are not stable in the liquid basal medium, and (3) the separate formulation of a liquid basal medium with lyophilized supplement is convenient, viable alternative to modified Ham's F-10 medium prepared in the standard manner (i.e., from powder) and may decrease the need for frequent medium preparation.Modified Ham's F-10 Medium, Irvine Scientific, Santa Ana, California.Presented at the 42nd Annual Meeting of the Pacific Coast Fertility Society, Indian Wells, California, April 20–24, 1994.     

成分输血在自体外周血干细胞移植中的应用

目的　探讨成分输血对恶性血液病患者自体外周血干细胞移植后的支持效果。方法　恶性血液病患者经预处理化疗及干细胞回输后,在骨髓“空虚”期当Ｈｂ＜ ８０ｇ／Ｌ 时,输注照射的浓缩红细胞;血小板＜ ２０ ×１０９／Ｌ时,输注照射的富血小板血浆,血小板输注量３ ．０ ×１０１１ 。结果　输注血小板悬液的患者,血小板计数可提高（６ ～２６）×１０９／Ｌ,维持时间为１ ～４ 天,无１ 例因血小板过低致颅内出血。结论　成份输血是自体干细胞移植后的强有力支持,其中血小板输注的数量最为关键     

Efficiency of Superfine Glass Fiber Membrane\= Filters for Depleting Leukocytes

ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｔｈｅｄｏｎｏｒｂｌｏｏｄｃｏｌｅｃｔｅｄｂｙｂｌｏｏｄｃｅｎ－ｔｅｒｓ,ｌｅｕｋｏｃｙｔｅｓｈａｖｅｎｏｔｈｅｒａｐｅｕｔｉｃｆｕｎｃｔｉｏｎｔｏｐａｔｉｅｎｔｓｂｕｔｍａｙｉｎｄｕｃｅｍａｎｙｓｉｄｅｅｆｅｃｔｓ．Ｃｏ...     

Spatio-temporal progression of the AEP P300 component using the cortical imaging technique

Summary The cortical imaging technique (CIT), a mathematical method for simulating the potential fields on the surface of the brain, was used to analyze the spatio-temporal progression of the AEP P300 component (as well as the preceding and subsequent N2a and N3 components) from thirty normal adult subjects recorded in a standard oddball paradigm. Comparisons were made between the progressions of the endogenous event-related cognitive potentials and the exogenous stimulus-dependent potentials (Nl component). Cortical imaging results suggest that different and multiple generator sites are involved in the production of exogenous and endogenous evoked responses. We particularly note the asymmetric development of the P300 component and the apparent anterior generator sites for the N2a component. This last result is interesting because the N2a precedes the P300 component and supports an earlier frontal contribution.