In order to investigate the stability of Hydroxyapatite (HA) coated material, the plasma-sprayed coatings of HA were divided into four groups: 1. Keeping in water vapour at 125 degrees C, with a pressure of 0.15 MPa for 6 hr; 2. Heating at 650 degrees C in air for half an hr; 3. Keeping in water vapour at 490 degrees C, with a pressure of 0.01 MPa for 2 hr; and 4. The control. The XRD, FTIR analysis and the dissolution test were carried out. The results showed: 1. The degree of crystalization in XRD analysis was 3. gt; 1. gt; 2. gt; 4.; 2. The ampitude of OH- peak in FTIR analysis was 3. gt; 1. gt; 2. gt; 4. and 3. The dissolution rate in tris-HCl buffer was 3. lt; 1. lt; 2. lt; 4. The conclusions were 1. The treating with water vapour could decrease the transformation temperature which was needed to convert the amorphous phase into cystalline phase; 2. Water vapour treatment could accelerate the transformation of Z-TCP, TCPM into crystalline HA; 3. Water vapour treatment could promote the structural integrity of plasma--sprayed coated of and HA and 4. Water vapour treatment could lower the dissolution rate of HA coated in Tris-HCl buffer.
ObjectiveUnder hypoxic conditions, the survival and apoptosis of human amniotic mesenchymal stem cells (hAMSCs) were observed by transient transfection of hypoxia-inducible factor 1α (HIF-1α) gene, to investigate the effect of HIF-1α on hypoxic tolerance of hAMSCs.MethodsThe hAMSCs were isolated and cultured from amniotic membrane tissue from voluntary donors who were treated with cesarean section. And the morphological observation by inverted phase contrast microscope and immunofluorescence detection of the expressions of stem cell markers OCT-4 and NANOG were performed to identify the cultured cells. The third generation hAMSCs were treated with 200 μmol/L CoCl2, and transient transfection of plasmids were added according to the following grouping: group A was hAMSCs blank group; group B was pcDNA3.1 negative control group; group C was short hairpin RNA (shRNA) negative control group; group D was shRNA-HIF-1α interference group; group E was pcDNA3.1-HIF-1α over expression group. Cell survival rate of each group was measured by cell counting kit 8 (CCK-8) at 12, 24, 48 hours after hypoxia treatment. Flow cytometry was used to detect apoptosis rate of each group at 24 hours after hypoxia treatment. The expression levels of HIF-1α, vascular endothelial growth factor (VEGF), B-cell lymphoma 2 (Bcl-2), Bax, and cleaved Caspase-3 (C-Caspase-3) proteins were detected by Western blot at 24 hours after hypoxia treatment.ResultsCCK-8 assay showed that the cell survival rate of group D was significantly lower than those of groups A and C at all time points after hypoxia treatment; while the cell survival rate in group E was significantly increased than those in groups A and B, and the diffrences at 24 hours were significant (P<0.05). In group E, the cell survival rate at 24 hours was significantly higher than those at 12 and 48 hours (P<0.05). The results of flow cytometry showed that the apoptosis rate in group D was significantly higher than those in groups A and C (P<0.05), and the apoptosis rate in group E was significantly lower than those in groups A and B (P<0.05). Western blot showed that the expressions of HIF-1α, VEGF, and Bcl-2 proteins in group D were significantly decreased when compared with those in groups A and C, and the expressions of Bax and C-Caspase-3 proteins were significantly increased (P<0.05). On the contrary, the expressions of HIF-1α, VEGF, and Bcl-2 proteins in group E were significantly higher than those in groups A and B, and the expressions of Bax and C-Caspase-3 proteins were significantly decreased (P<0.05).ConclusionOverexpression of HIF-1α gene can significantly improve hAMSCs tolerance to hypoxia, the mechanism may be related to up-regulation of VEGF and Bcl-2 expressions, and down-regulation of Bax and C-Caspase-3 expressions.
Objective To explore the effect of spinal neural progenitor transplantation to the cervical spinal on treating brachial plexus injury with the reimplantation of the avulsed spinal roots. Methods Thebrachial plexusavulsed injury model was made on 54 rats and they were evenly divided into 3 groups: fresh group, chronic group, control group. The spinal neural progenitor was cultured and identified. Then 10 μl（1×105/μl）cells were labelled with BrdUand transplanted into the fresh group (15 rats survived, being model for 1 week) and the chronic group (14 rats survived, being model for 2 months). No cell was transplanted into the control group. Two months after the transplantation, therecovery of function of the injured limb was evaluated. Electrophysiologic study and immunohistochemical study of the injured limb were made. Results Spinal neural progenitors were isolated from the spine and became neural sphere. The neural spheres were differentiated into neurons and astrocytes. Fourteen rats out of 15 in the fresh group were recovered, 7 rats out of 14 in the chronic groupwere recovered, and 5 rats out of 12 in the control group were recovered. Immunohistochemical study indicated that the transplanted progenitors in fresh group survived and differentiated into the neural cells, and the transplanted progenitors in chronic group existed and did not differentiate well. Conclusion Transplanted spinal neural progenitors can promote the recovery of the brachial plexus injury with the reimplantation of the avulsed spinal root.
Electrocardiogram (ECG) signals are susceptible to be disturbed by 50 Hz power frequency in the process of acquisition and conversion. This paper puts forward the improved Levkov algorithm combined with the antisymmetry of sine wave and the characteristic of not-easily mutation of the sine wave amplitude. The improved and the original algorithms were compared with signal to noise ratio (SNR), root mean square error (RMSE) and coincidence of the signals. Based on the experimental comparison, it was concluded that the improved algorithm had better filtering functions, because it not only highly coincided with ECG, but also retained certain details of ECG.
Real-time updates of metrical data can not generally be realized in the commonly used methods for calculating the pulse wave of blood oxygen saturation. Based on the hardware platform of pulse wave signal from NJL5501R, and high linear correlation of the red laser and infrared light collected in pulse wave signal measurement, an approach to determine the value of the blood oxygen saturation is proposed in the present paper by establishing the linear regression model of the red laser and infrared light. The effect of the sampling number of pulse wave signal in calculation on the characteristic parameters of pulse wave is also analyzed. The experimental results showed that the approach could guarantee the measuring accuracy and realize the fast updates of blood oxygen saturation data. This paper provides an effective method for real-time and accurate monitoring of pulse blood oxygen saturation in human body.
ObjectiveTo systematically review the efficacy of irbesartan combined with metoprolol plus conventional treatment compared with single drug (irbesartan, metoprolol) plus conventional treatment or conventional treatment for elderly patients with severe heart failure.MethodsPubMed, The Cochrane Library, Web of Science, CNKI, WanFang Data and VIP databases were electronically searched to collect randomized controlled trials (RCTs) on irbesartan combined with metoprolol in the treatment of elderly patients with severe heart failure from January 2009 to September 2019. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Network meta-analysis was then performed using gemtc package of R software.ResultsA total of 58 RCTs involving 5 064 patients were included. The results of meta-analysis showed that the efficiency, left ventricular ejection fraction (LVEF) and brain natriuretic peptide (BNP) of combination group were significantly superior to single drug group.ConclusionsThe current evidence shows that under the premise of conventional treatment, the combination of irbesartan and metoprolol is more effective than irbesartan or metoprolol alone in the treatment of elderly patients with severe heart failure. Due to limited quality and quantity of the included studies, more high quality studies are required to verify above conclusions.
In this paper, a heart rate variability analysis system is presented for short-term (5 min) applications, which is composed of an electrocardiogram signal acquisition unit and a heart rate variability analysis unit. The electrocardiogram signal acquisition unit adopts various digital technologies, including the low-gain amplifier, the high-resolution analog-digital converter, the real-time digital filter and wireless transmission etc. Meanwhile, it has the advantages of strong anti-interference capacity, small size, light weight, and good portability. The heart rate variability analysis unit is used to complete the R-wave detection and the analyses of time domain, frequency domain and non-linear indexes, based on the Matlab Toolbox. The preliminary experiments demonstrated that the system was reliable, and could be applied to the heart rate variability analysis at resting, motion states. etc.
To compare and evaluate the whole effect of anterior decompression approach to treat cervical spondylotic myelopathy by using cervical retractor systems and the traditional surgical approach. Methods From April 2001 to August 2004, group A included 30 males and 23 females aging from 31 to 69 years, and the involved time was from 7 months to 15 years. Involved segments included 22 one-segments, 24 two-segments and 7 three-segments. In all 53 cases, anterior windowing decompression and fusion with autograft and titanium plate internal fixation by using traditionalcircular saw were performed. Group B included 48 males and 20 females aging from 33 to 74 years, and the involved time was from 5 months to 18 years. Involved segments included 23 one-segments, 34 two-segments and 11 three-segments. In all 68 cases, anterior undermined far-reaching decompression and fusion with autograft and titanium plate internal fixation by using removing disc merely in the single-level or separately in the multilevels employing self-retractor and Caspar cervical retractor systems via interspinal approach were performed. X-rays and MRI showed cervical disc degeneration, herniation and spinal cord compression. The surgery time, loss of blood, vertebral body fusion time, difference in height of involved segments preor postoperatively and compl ications were counted up and compared between the two groups. Improvement rate of spinal function pre- or postoperatively were valued by using JOA score. Results A total of 92 cases including 42 of group A and 50 of group B were followed up for 3 to 5 years, mean 3.5 years. In group A, surgery time, loss of blood, time of vertebral body fusion, difference in height of involved segments pre- or postoperatively, and improvement ratio of spinal function were(76.80 ± 28.41) min,(564.00 ± 181.96) mL,(12.10 ± 3.58) weeks, (1.30 ± 0.67) mm and 0.49% ± 0.14%, respectively. In group B, they were(57.90 ± 15.01) min,(317.50 ± 136.92) mL,(9.75 ± 1.36) weeks, (3.00 ± 0.56) mm and 0.71% ± 0.17% , respectively. The differences between the two groups were significant in all measured values(P lt; 0.05). Compl ications occurred in 7 cases ofgroup A including 1 spinal cord injury, 1 plate displacement, 1 bonegraft displacement and 4 disfunctions of il iac region. No compl ication happened in group B. Conclusion Anterior decompression approach using cervical retractor systems is significantly superior to the traditional approach as to the whole effect to treat cervical spondylotic myelopathy, and furtherperfects the traditional anterior decompression approach. The modified approach is scientific, safe and easily spread.