Biomedical subjects

Guohua Lu

Publications and source records attributed to Guohua Lu.

5 recordsLinked to original sources

PubMed2006

[Study on second filtering algorithm based on tracing the interfering spectral peaks of radar non-contact life-parameter detection system].

To develop a filtering algorithm which could trace the spectral peaks of the interference and which was used to extract the breath signal with the same band interference in radar non-contact life-detecting system, second filtering algorithm was studied. Through first filtering,the probable interfering spectral peaks (ISP) could be detected by Yule-Walker spectrum estimating and could be located by calculating the coefficients of normalized cross-correlation function according to standard breath signal. Thus the breath signal could be extracted through a second filtering. By using the second filtering algorithm (SFA), the same band interfering spectral peaks with breath signal could be recognized and inhibited. So we conclude that the same band mono-ISP could be inhibited by using SFA and breath signals could be effectively extracted.

Adult↗

PubMed2005

[A study on technology to identify human beings or animals in life-detector based on radar].

To determine whether a living object is human being or animal by detecting the respiration signal using the life-detector based on radar to penetrate the building or debris. To fully utilize the nonstationary character of the respiration signal, short time Fourier transform (STFT) is employed to get the signal's time-frequency representation. Singular value decomposition (SVD) is then used in the spectrogram to extract feature vector for pattern identification. Human beings and animals can be identified from the respiration sensed by the life-detector based on radar. Experimental results show that the method based on STFT and SVD is stable and efficient to differ from the human being and animal.

Animals↗

PubMed2004

[Study on eliminating self-dithering interference of the system for non-contact detecting life parameters based on an adaptive algorithm].

The non-contact life parameters detecting systems can detect many important life parameters such as heartbeat and breathing at certain distance. In practice, the self-dithering interference of the system is produced by some factors; it makes the signal-to-noise ratio (SNR) of the recorded signal lower. This paper is discussed an adaptive technology based on a variable step-size LMS algorithm, which is used to eliminate the self-dithering interference of the system and hence to raise the SNR of the detecting signal. A method to obtain the reference signal by vibration sensor is brought forward and the optimum parameters settings are discussed. The results show that the reference signal is an integral part of output signal of the vibration sensor and has a relationship with the setting direction of the sensor. The conclusion is that the method is effective and feasible; also the algorithm is well convergent.

Algorithms↗

PubMed2003

FBN1 mutation in Chinese patients with Marfan syndrome and its gene diagnosis using haplotype linkage analysis.

OBJECTIVES: To analyze the FBN1 mutations in Chinese patients with Marfan syndrome (MFS) and to make a genetic diagnosis based on haplotype linkage analysis for MFS. METHODS: Nine MFS families (17 patients) were analyzed with single strand conformation polymorphism (SSCP) and sequencing. Four primers were designed for the flanking sequences of FBN1 gene and used for haplotype-segregation analysis of MFS(B). RESULTS: SSCP band alteration was detected in the PCR products for exon 25 in MFS(A) II:1. Direct sequencing revealed a small 13 bp deletion; the deleted sequence is gccTc Tgcaccca at bases 3243-3456 of the cDNA in exon 25. This mutation was novel. MFS(B) families were analyzed using the haplotype linkage technique. The data suggested that MFS(B) families were linked to the FBN1 gene. The proband's daughter was an asymptomatic patient. CONCLUSION: The combination of mutation detection and chromosome haplotype analysis can provide better evidence for a genetic diagnosis of MFS.

Fibrillin-1↗

PubMed2002

TGF-beta(1) gene modified immature dendritic cells exhibit enhanced tolerogenicity but induce allograft fibrosis in vivo.

Administration of donor-derived immature dendritic cells (DC) can prolong the survival of MHC-mismatched cardiac allografts. Genetic modification of DC by immunosuppressive molecules can enhance their potential tolerogenicity. In this study bone marrow derived immature DC were genetically modified by transforming growth factor (TGF) beta1 by recombinant Ad. TGF-beta(1) gene modified immature DC (TGF-beta-DC) displayed a characteristic phenotype of immature DC, decreased ability to secrete interleukin 12, and reduced allostimulatory ability. TGF-beta-DC induced alloantigen-specific T cell hyporesponsiveness in vitro and in vivo, and Th2 cytokine polarization. mRNA expression of donor MHC class II (Ia(b)) and human TGF-beta(1) was detected in spleen and lymph nodes of the allogeneic recipients for 3 weeks after TGF-beta-DC infusion, indicating that microchimerism of TGF-beta-DC is exhibited in allogeneic recipients. In this murine cervical heterotopic heart transplantation model, the survival of the allograft in recipients intravenously infused with TGF-beta-DC 7 days before transplantation was greatly prolonged, and about 67% of cardiac grafts survived more than 40 days. Histological analysis of the allografts showed that the normal myocardial architecture was well preserved, accompanied by very little necrotic cells, but interstitial fibrosis replaced myocytes, and moderate collagen suffused the whole cardiac allograft in the recipients infused with TGF-beta-DC. mRNA expression of type III procollagen was markedly increased in the allografts of the recipients infused with TGF-beta-DC. Our results suggest that infusion of TGF-beta(1) gene modified immature DC prolongs the survival of the allograft through the effective induction of donor-specific T cell hyporesponsiveness. However, TGF-beta(1) expressed by gene modified immature DC can cause the fibrosis of the allografts, which may limit the application of this approach in the allograft transplantation.

Animals↗