The research of sleep staging based on single-lead electrocardiogram and deep neural network

The polysomnogram (PSG) analysis is considered the golden standard for sleep staging under the clinical environment. The electroencephalogram (EEG) signal is the most important signal for classification of sleep stages. However, in-vivo signal recording and analysis of EEG signal presents us with a few technical challenges. Electrocardiogram signals on the other hand, are easier to record, and can provide an attractive alternative for home sleep monitoring. In this paper we describe a method based on deep neural network (DNN), which can be used for the classification of the sleep stages into Wake (W), rapid-eye-movement (REM) and non-rapid-eye-movement (NREM) sleep stage. We apply the sleep stage stacked autoencoder to constitute a 4-layer DNN model. In order to test the accuracy of our method, eighteen PSGs from the MIT-BIH Polysomnographic Database were used. A total of 11 features were extracted from each electrocardiogram recording The experimental design employs cross-validation across subjects, ensuring the independence of the training and the test data. We obtained an accuracy of 77% and a Cohen's kappa coefficient of about 0.56 for the classification of Wake, REM and NREM.

Polymorphism of killer cell immunoglobulin-like receptor gene and its correlation with leukemia / 中国实验血液学杂志

The study was purposed to investigate the polymorphism of killer cell immunoglobulin-like receptor (KIR) gene of the patients with leukemia and to explore the correlation between the KIR gene and susceptibility of leukemia. The KIR genotype of 50 patients with leukemia and 60 healthy controls in northern. Hans were analyzed by PCR-SSP. The results indicated that the present known 18 KIR genes were detected and identified. The frequencies of KIR 3DL3, 3DL2 and 2DL4 were 100% in all subjects, with the most frequent genotype KIR 3DP1 (0.86) followed by 2DP1, 2DL3, 3DL1, 2DL1, 3DS1, 2DL5, 2DS4, 2DS2, 1D, 2DS5, 2DL2, 2DS1, 2DS3 and 3DP1v in leukemia successively. Compared with the control, the KIR 3DL1 (0.60) and 2DL1 (0.57) were significantly lower in the leukemia patient group than that in the control group (1.00) (P < 0.01). It is concluded that the polymorphism of KIR gene is associated with susceptibility of leukemia in Hans. There may be a negative correlation between pathogenesis of leukemia and KIR 3DL1, KIR 3DS1, KIR 2DL1, KIR 2DL5 genes.

Distribution features of HLA-DRB1 allele frequencies in normal cord blood donors of 3 438 Shandong Hans / 中国实验血液学杂志

The objective of the study was to research the distribution features of HLA-DRB1 alleles in Shandong Hans' population and explore the possibility of finding the cord blood donor of HLA-DR matched to perform the stem cell transplantation for more patients from larger region of China and even other areas in the world. The subjects of the study were drawn from 3 438 Shandong Hans donors in Shandong Umbilical Cord Blood Bank and were tested by PCR-SSP technique for HLA-DR low resolution typing. The result indicated that the most prevalent five alleles of HLA-DRB1 locus were DRB1 * 15 (0.1817), * 07 (0.1369), * 09 (0.1221), * 04 (0.1084) and * 12 (0.1038). The DR18 has the lowest gene frequency 0.0003, while DRB1 * 10, * 16 and * 01 showed lower gene frequencies (GF), which GF were 0.0151, 0.0262, and 0.0322 respectively. As compared the HLA-DRB1 GF of Shandong Hans with those of other Han Chinese and other ethnic populations, there were unique distributed features of DRB1 alleles among various races populations, and those among the studied population groups from various regions with the same race origin. The difference from various regions in the same race was less than that among different races. In conclusion, a patient of Han Chinese is easier to search a DR-matched cord blood donor in Shandong Umbilical Cord Blood Bank, especially from northern Hans. No DRB1 allele is unique to single racial group and majority of DRB1 low-resolution phenotypes are common to all studied groups. It is reasonable for some patients from other races including Caucasian and Japanese to receive a transplant of cord blood stem cell matched with HLA-DR in Shandong Umbilical Cord Blood Bank.

The Influence of Fibrin on the Reaction of Plasminogen Activation by Mut ant of Pro-Urokinase / 生物化学与生物物理进展

Because the influence of fibrin on the reaction of plasm inogen activation by various plasminogen activators is different, the kinetic co nstant of the reaction of plasminogen activation catalyzed by InB with and witho ut fibrin were detected. The result is: Kfibrinm＝4.2 μmol*L -1，greater than the normal Km=0.379 μmol*L-1; kfib rincat＝0.107 s-1，greater than the normal kcat=0.0165 s-1. The results suggest that existence of fibrin in the reaction system of plasminogen activation depress the affinity between InB and plasminog en, but accelerates the hydrolysis of plasminogen by InB. The count up effect is inhibition.

Characterization of Bifunctional Chimeric Molecule of PRGDWR Containing Pro-Urokinase / 生物化学与生物物理进展

In order to obtain the bifunctional chimeric molecule of single-chain urokinase-type plasminogen activator (scu-PA) which can inhibit platelet aggregation, PRGDWR peptide was inserted into the site between Gly 118 and Leu119 (called insertion mutant B, InB). The recombinant gene of InB was expressed by Pichia pastoris. The secreted protein was purified by metal chelate affinity and strong cation exchange chromatography. The amidolytic ability of mutant InB is 5 900 IU/mg, the kinetic constants is: KInB m,plg=56.8 μmol*L-1，kInBcat,plg=0.33 s- 1. The kinetic constants of plasminogen activation reaction is: KInB m,plg=0.397 μmol*L-1，kInBcat,plg=0.0164 s-1. Fibrin inhibit the catalytiv ability of InB during plasminogen activatio n, the influence factor is 0.463(means InB remain 46.3% of the catalytic abili ty when fibrin was involved in the reaction system). The mutant not only has alm ost the same catalytic ability as wild type scu-PA, but also has strong ability of anti-platelet aggregation(compared with scu-PA), IC50 of InB is 12.7 μmol*L-1.