Biomedical subjects

Zhi-Yong Liu

Publications and source records attributed to Zhi-Yong Liu.

5 recordsLinked to original sources

PubMed2006

[Genetic polymorphisms of three loci and implication to forensic medicine].

OBJECTIVE: To obtain population genetic data of short tandem repeat (STR) locus D2S1327, D1S1390, and D11S2008 and to investigate the disparity of allelic frequency distributions among populations from different regions. METHODS: Blood samples of 300 unrelated individuals from Chengdu (Han), Bangkok (Thai) and Maint (Germany) were taken and analyzed with single PCR, polyacrylamide gel electrophoresis and silver staining. RESULTS: In the three loci, 9, 6, and 8 alleles and 32,14, and 22 genotypes were found respectively. The observed heterozygosity of 79%-82%, 63.0%-74.3%, and 72.0%-74.3% and discrimination power of 87.8%-92.6%, 79.6%-82.5%, and 87.6%-89.0% were identified for the three loci respectively. The genotype distributions of the three loci in the three populations fitted well with Hardy-Weinberg equilibrium. There was no significant difference in allelic frequency distributions among the three populations. CONCLUSION: The methods described in this paper are easy to perform and have high sensitivities. The discrimination power and exclusion chances of these three loci are desirable for forensic analysis and application.

China↗

PubMed2004

Off-pump coronary artery bypass grafting versus on-pump coronary artery bypass grafting: which is better in patients with chronic obstructive pulmonary disease?

To evaluate the clinic outcome of off-pump coronary bypass grafting (OPCABG) of patients with coronary heart disease and chronic obstructive pulmonary disease, we collected and analyzed 1998-2002 data on 28 patients with these two diseases who had received off-pump coronary bypass operation in our hospital, and compared with data on those who also had the same two diseases but received on-pump coronary artery bypass at same time. There were no operation-related death; one died of respiratory failure 14 days after operation while staying in hospital; there were more respiratory complications in the conventional coronary artery bypass grafting group (CCABG) than in the OPCABG group; and the PaO2/FiO2 in the CCABG group was higher than that in the OPCABG group during operation because of CPB, but lower than that in the OPCABG group 6-12 hours after operation. OPCABG seemed more suitable than CCABG for coronary artery disease patients with chronic obstructive pulmonary disease due to less damage to their oxygen-exchange capability and the fewer respiratory complications.

Aged↗

PubMed2004

One-bit-matching conjecture for independent component analysis.

The one-bit-matching conjecture for independent component analysis (ICA) could be understood from different perspectives but is basically stated as "all the sources can be separated as long as there is a one-to-one same-sign-correspondence between the kurtosis signs of all source probability density functions (pdf's) and the kurtosis signs of all model pdf's" (Xu, Cheung, & Amari, 1998a). This conjecture has been widely believed in the ICA community and implicitly supported by many ICA studies, such as the Extended Infomax (Lee, Girolami, & Sejnowski, 1999) and the soft switching algorithm (Welling & Weber, 2001). However, there is no mathematical proof to confirm the conjecture theoretically. In this article, only skewness and kurtosis are considered, and such a mathematical proof is given under the assumption that the skewness of the model densities vanishes. Moreover, empirical experiments are demonstrated on the robustness of the conjecture as the vanishing skewness assumption breaks. As a by-product, we also show that the kurtosis maximization criterion (Moreau & Macchi, 1996) is actually a special case of the minimum mutual information criterion for ICA.

Algorithms↗

PubMed2004

[Infection of recombinant adenovirus expressing acidic fibroblasts growth factor enhances rabbit corneal endothelium proliferation].

OBJECTIVE: To transfer the gene encoding mammalian aFGF to rabbit corneal endothelial cell and determine transfection efficiency and the effect of Ad-aFGF on proliferation of RCEC. METHODS: Replication-defective adenovirus was used to deliver the LacZ reporter gene to RCEC to determine transfection efficiency by X-gal staining. A cDNA encoding mammalian aFGF was cloned into an adenoviral vector that was used to transfect RCEC. The expression of aFGF gene mRNA and protein were demonstrated by Reverse transcription PCR and Western blot respectively. The effect of Ad-aFGF on proliferation of RCEC was determined by MTT assay. RESULTS: RT-PCR and Western blot from RCEC infected with Ad-aFGF for 48 h detected a specific cDNA amplification and protein expression of aFGF gene, and no positive result in control cells. Consistently, RCEC infected by MOI 20 of Ad-aFGF demonstrated an enhanced RCEC proliferation compared to controls (F = 217.107, P < 0.05). CONCLUSION: Adenoviral-mediated expression of aFGF can stimulate the proliferation of RCEC.

Adenoviridae↗

PubMedDate not supplied

Improved system for object detection and star/galaxy classification via local subspace analysis.

The two traditional tasks of object detection and star/galaxy classification in astronomy can be automated by neural networks because the nature of the problems is that of pattern recognition. A typical existing system can be further improved by using one of the local Principal Component Analysis (PCA) models. Our analysis in the context of object detection and star/galaxy classification reveals that local PCA is not only superior to global PCA in feature extraction, but is also superior to gaussian mixture in clustering analysis. Unlike global PCA which performs PCA for the whole data set, local PCA applies PCA individually to each cluster of data. As a result, local PCA often outperforms global PCA for data of multi-modes. Moreover, since local PCA can effectively avoid the trouble of having to specify a large number of free elements of each covariance matrix of gaussian mixture, it can give a better description of local subspace structures of each cluster when applied on high dimensional data with small sample size. In this paper, the local PCA model proposed by Xu [IEEE Trans. Neural Networks 12 (2001) 822] under the general framework of Bayesian Ying Yang (BYY) normalization learning will be adopted. Endowed with the automatic model selection ability of BYY learning, the BYY normalization learning-based local PCA model can cope with those object detection and star/galaxy classification tasks with unknown model complexity. A detailed algorithm for implementation of the local PCA model will be proposed, and experimental results using both synthetic and real astronomical data will be demonstrated.

Astronomy↗