[Peak Detection Algorithm of Optical Fiber SPR Signal Based on the Gaussian Fitting].

The spectrum of optical fiber surface plasmon resonance (SPR) shows the characteristics of wider full width at half-maximum (FWHM) and smaller peak value. The traditional peak detection algorithm cannot calculate the resonance wavelength of this kind of spectrum accurately. Therefore, efficient methods to calculate the resonance wavelength are required. This paper presents a method to process the SPR signal based on the Gaussian fitting. Combined with the trust region algorithm to determine the Gaussian fitting function, and then the resonance wavelength be calculated by line search method. Data processing of standard spectrum of glycerin with different concentration proves that this algorithm can adapt to optical fiber SPR spectrum characteristics, and calculate resonance wavelength accurately. The experiment measures the SPR signals of sucrose under different concentrations through the self-building SPR measure system. By using the proposed method, the weighted centroid method and the tracking centroid method to calculate the resonance wavelength, the result shows that the Gaussian fitting method can effectively improve resolution and have a short operation time which is conducive to engineering application.

[Analysis of SPR Signal by Using Optimized Savitzky-Golay Filter].

The spectrum of surface plasmon resonance shows different amplitudes and peak widths with theeffects of resonant intensity and position, so it's necessary to develop the self-adaptive methods to guarantee the accurate positioning of SPR formant. Based on the optimized Savitzky-Golay filter, this paper presents a method for SPR spectrum, which can optimize the parameters (polynomial degree and window size) according to the characteristics of the real time SPR spectrum, and minimizes the Stein's unbiased risk estimate of the mean squared error, and it can be quickly solved by Monte-Carlo methods. It is confirmed that SURE can accurately reflect the trends and the results of the true MSE. The experiment measures the SPR signals of sucrose under different concentrations and integration time through the SPR system. By using the proposed method of optimal parameters on the SPR signal filtering, the results show that the repeatability error of the position of SPR formant is smaller compared with the fixed parameters, and does not increase with the addition of noise levels.

Plasma visfatin, a possible prognostic marker in aneurysmal subarachnoid hemorrhage.

Visfatin is linked to inflammation and associated with clinical outcomes of intracerebral hemorrhage. This study was designed to investigate whether visfatin might serve as a marker of severity and prognosis in aneurysmal subarachnoid hemorrhage. In this study, plasma visfatin levels of 172 consecutive patients and 172 sex and age-matched healthy subjects were determined using enzyme-linked immunosorbent assay. The recorded clinical outcomes included in-hospital mortality and 6-month mortality and unfavorable outcome (Glasgow Outcome Scale score of 1-3). Plasma visfatin level was substantially higher in patients than in healthy controls (92.1 ± 20.5 ng/mL vs. 12.4 ± 3.2 ng/mL; P<0.001), was significantly associated with the World Federation of Neurological Surgeons (WFNS) score (r=0.569, P<0.001) and Fisher score (r=0.657, P<0.001), was an independent predictor of in-hospital mortality [odds ratio (OR), 1.378; 95% confidence interval (CI), 1.036-1.866; P=0.002] and 6-month mortality (OR, 1.261; 95% CI, 1.018-1.745; P=0.004) and unfavorable outcome (OR, 1.207; 95% CI, 1.012-1.682; P=0.008) in multivariate logistic regression analysis and had high predictive value for in-hospital mortality [area under curve (AUC), 0.849; 95% CI, 0.787-0.899; P<0.001] and 6-month mortality (AUC, 0.868; 95% CI, 0.808-0.915; P<0.001) and unfavorable outcome (AUC, 0.859; 95% CI, 0.797-0.907; P<0.001) using receiver operating characteristic curves. AUCs of visfatin were similar to those of WFNS score and Fisher score (all P>0.05), but visfatin did not improve the predictive values of WFNS score and Fisher score (all P>0.05). Thus, visfatin may be associated with clinical severity of aneurysmal subarachnoid hemorrhage and also have prognostic value for clinical outcomes.

[Study on expression of matrix metalloproteinase-2 and matrix metalloproteinase-9 in brain tissue adjacent to hemorrhage after brain hemorrhage in human].

OBJECTIVE: To investigate the expression and significance of matrix metalloproteinase-2 (MMP-2) and MMP-9 in peri-hematoma brain tissues after acute brain hemorrhage in human. METHODS: Forty-two patients with acute brain hemorrhage received surgery, the brain tissues adjacent to hemorrhagic site were obtained during surgery, and positive expressions of MMP-2 and MMP-9 were determined with immunohistochemical staining. Brain tissues from 30 patients with cerebral trauma were obtained to serve as controls. RESULTS: The positive expressions of MMP-2 and MMP-9 in focal brain tissues were significantly elevated in early acute brain hemorrhage. Compared with 28 and 27 cases with MMP-2 and MMP-9 positive expression respectively in control group, there were 39 and 37 cases with MMP-2 and MMP-9 positive expression respectively in acute brain hemorrhage group. There were no significant differences between two groups (both P>0.05). CONCLUSION: MMP-2 and MMP-9 might contribute to brain edema formation in the acute intra-cerebral hemorrhage of human.