The impulsive electroencephalograph (EEG) noises in evoked potential (EP) signals is very strong, usually with a heavy tail and infinite variance characteristics like the acceleration noise impact, hypoxia and etc., as shown in other special tests. The noises can be described by a stable distribution model. In this paper, Wigner-Ville distribution (WVD) and pseudo Wigner-Ville distribution (PWVD) time-frequency distribution based on the fractional lower order moment are presented to be improved. We got fractional lower order WVD (FLO-WVD) and fractional lower order PWVD (FLO-PWVD) time-frequency distribution which could be suitable for a stable distribution process. We also proposed the fractional lower order spatial time-frequency distribution matrix (FLO-STFM) concept. Therefore, combining with time-frequency underdetermined blind source separation (TF-UBSS), we proposed a new fractional lower order spatial time-frequency underdetermined blind source separation (FLO-TF-UBSS) which can work in a stable distribution environment. We used the FLO-TF-UBSS algorithm to extract EPs. Simulations showed that the proposed method could effectively extract EPs in EEG noises, and the separated EPs and EEG signals based on FLO-TF-UBSS were almost the same as the original signal, but blind separation based on TF-UBSS had certain deviation. The correlation coefficient of the FLO-TF-UBSS algorithm was higher than the TF-UBSS algorithm when generalized signal-to-noise ratio (GSNR) changed from 10 dB to 30 dB and a varied from 1. 06 to 1. 94, and was approximately e- qual to 1. Hence, the proposed FLO-TF-UBSS method might be better than the TF-UBSS algorithm based on second order for extracting EP signal under an EEG noise environment.
Algorithms ; Electroencephalography ; Evoked Potentials ; Humans ; Models, Theoretical ; Signal Processing, Computer-Assisted

BACKGROUND:Bioglass has good biocompatibility and biological activity, which can be combined with calcium phosphate bone cement to form an absorbable bioglass that has the advantages of both materials and is expected to have a better use of space. OBJECTIVE:To explore the mechamism of the new type of absorbable bioglass injection for vertebral body supporting and osteogenic induction in osteoporosis rats. METHODS:Twenty-seven female Sprague-Dawley rats were selected to make osteoporosis models by bilateral ovariectomy, and after 1 month, the rats were randomized into three groups. Bone defect models were established in the lumbar L4 segment of al the rats. Rats in the experimental group were subjected to absorbable bioglass injection; rats in the control group 1 underwent polymethylmethacrylate bone cement injection; and rats in the control group 2 were given injectable calcium phosphate. Twelve weeks after implantation, the compressive strength, degradation and osteogenesis of the implant materials were detected, and levels of serum bone morphogenetic protein-2 and transforming growth factor-β were measured. RESULTSAND CONCLUSION: The compressive strength, hydroxyapatite deposition amount, and weight loss ratio in the experimental group were significantly higher than those in the two control groups (P < 0.05); the relative volume, thickness and number of bone trabeculae in the experimental group were significantly higher than those in the control groups (P < 0.05); the bone morphogenetic protein-2 and transforming growth factor-β protein levels in the experimental group were significantly higher than those in the two control groups (P < 0.05). These findings indicate that the new-type absorbable bioglass can greatly strengthen the vertebral body supporting and promote osteogenic effect in osteoporosis by enhancing the bone morphogenetic protein-2 and transforming growth factor-β protein levels.

BACKGROUND:Bony and structural feature often cause pulout strength decrease of pedicle screw, which induces loosening and pulout, and finaly results in fixation failure. Thus, it is very important to elevate the stability of pedicle screw.
OBJECTIVE:To detect the biomechanical stability of bone cement injectable canulated pedicle screw, and to provide reference for bone cement dosage.
METHODS: We selected T11-L4 samples of seven fresh adult corpses, containing 40 vertebral bodies. They were randomly divided into bone cement injectable canulated pedicle screw group and DTPSTM pedicle screw group (n=20). After screw implantation, 1, 2, 3 and 5 mL bone cement was injected. The diffuse distribution of bone cement was observed by imaging. The maximum axial pulout strength was measured.
RESULTS AND CONCLUSION:When the dose of bone cement was 1-3 mL, the average maximum axial pulout strength was significantly greater in the bone cement injectable canulated pedicle screw group than in the DTPSTM pedicle screw group (P < 0.05). When the bone cement dosage was 5 mL, no significant difference in the maximum axial pulout strength was detected between the two groups (P > 0.05). The regression equation was Y=25.269X+133.681 (R2=0.837) in the bone cement injectable canulated pedicle screw, and Y=32.039X+99.251 (R2=0.936) in the DTPSTM pedicle screw group. When the dosage of bone cement was 1-5 mL, the maximum axial pulout strength was highly positively correlated with bone cement dosage (|R| > 0.8). These results suggested that bone cement augmentation pedicle screw could apparently elevate the stability of the screw. The maximum axial pulout strength of the pedicle screw was positively correlated with bone cement dosage. After reaching the satisfactory fixation effects, the bone cement injectable canulated pedicle screw can reduce bone cement dosage, diminish the risk of bone cement leakage, and have more advantages than DTPSTM pedicle screw.

Objective To establish a new rat model of biliary atresia by pure ethanol injection into the common bile duct.Methods A catheter was inserted and fixed in the common bile duct in male SD rats .Saline (8 rats) or pure ethanol (16 rats) was injected through the catheter ,respectively, and the biochemical and pathological changes in the rats were examined .Results SD rats in the experimental group were divided into a persistent injury and a restoration of liver dysfunction groups according to pathological and biochemical detection .In the persistent injury group , biochemical impair-ments were significantly higher at 8 weeks after ethanol injection than those in the control group and restoration group .Dis-tinct pathological changes in the liver were observed using HE , SMA, and Masson staining .Conclusions It is a reliable animal model of biliary atresia induced by injection of pure ethanol into the common bile duct in the rat .It will provide a useful tool in future studies of biliary atresia .

Objective To summarize our experience on the food safety for residents and disaster relief workers in Li county after Wenchuan earthquake in Sichuan province.Methods A comprehensive survey was conducted to assess the current food hygiene status.According to the survey results,we had integrated the local forces and strengthened the food hygiene surveillance and quality detection focusing on the crucial procedures.Besides,effective health educations were applied to advocate the rational dietary after earthquake.Results There was no any food safety incident in the county,and the hygiene awareness of local residents has been improved.Conclusion Powerful organization,focused management and multi-collaboration are the important elements to accomplish the food safety control after earthquake.