Underwater image restoration based on adaptive parameter optimization of the physical model.

Underwater images have the advantage of carrying high information density and are widely used for marine information acquisition. Due to the complex underwater environment, the captured images are often unsatisfactory and often suffer from color distortion, low contrast, and blurred details. Physical model-based methods are often used in relevant studies to obtain clear underwater images; however, water selectively absorbs light, making the use of a priori knowledge-based methods no longer applicable and thus rendering the restoration of underwater images ineffective. Therefore, this paper proposes an underwater image restoration method based on adaptive parameter optimization of the physical model. Firstly, an adaptive color constancy algorithm is designed to estimate the background light value of underwater image, which effectively guarantees the color and brightness of underwater image. Secondly, aiming at the problem of halo and edge blur in underwater images, a smoothness and uniformity transmittance estimation algorithm is proposed to make the estimated transmittance smooth and uniform, and eliminate the halo and blur of the image. Then, in order to further smooth the edge and texture details of the underwater image, a transmittance optimization algorithm for smoothing edge and texture details is proposed to make the obtained scene transmittance more natural. Finally, combined with the underwater image imaging model and histogram equalization algorithm, the image blurring is eliminated and more image details are retained. The qualitative and quantitative evaluation on the underwater image dataset (UIEBD) shows that the proposed method has obvious advantages in color restoration, contrast and comprehensive effect, and has achieved remarkable results in application testing. It shows that the proposed method can effectively restore underwater degraded images and provide a theoretical basis for the construction of underwater imaging models.

The Biochemical Markers Associated with the Occurrence of Coronary Spasm.

Coronary artery spasm (CAS) is one of the mechanisms of angina pectoris. Unlike the diagnosis of acute myocardial infarction which is based on the elevation of cardiac markers, the diagnosis of CAS is difficult and sometimes requires sophisticated and risky provocative test which is not widely accepted in China. There is no well-established biomarker for the diagnosis or prediction of CAS. However, there are some biomarkers proven to be associated with the occurrence of CAS. For example, inflammatory factors including C-reactive protein and cytokines, lipoprotein (a), and cystatin-C might be precipitating factor for CAS. Rho-kinase as a mediator involved in multiple mechanisms of CAS, serotonin, and endothelin-1 as powerful vasoconstrictors leading to vasospasm were all observed being elevated in patients with CAS. Thioredoxin and nitrotyrosine reflected the oxidative status and could be observed to be elevated after the occurrence of CAS. In some cases doubted to be CAS without the evidence of provocative test, the blood test for the biomarkers mentioned above could be useful for the diagnosis of CAS.

Association of liver enzymes levels with fasting plasma glucose levels in Southern China: a cross-sectional study.

OBJECTIVE: According to several studies, liver enzymes levels are associated with fasting plasma glucose (FPG) levels. However, the association stratified by body mass index (BMI) remains to be elucidated, especially in Southern China. Therefore, the aim of this study was to investigate the correlation between liver enzymes levels and FPG levels stratified by BMI in Southern China. DESIGN: Cross-sectional study. PARTICIPANTS AND SETTING: 3056 individuals participated in real-time interviews and blood tests in Southern China. Participants were divided into three groups (underweight, normal weight and overweight or obesity) based on BMI cut-offs. MAIN OUTCOME MEASURED: Partial correlation analysis was performed to investigate the relationship between FPG levels and liver tests. Multivariate logistic regression analyses were applied to calculate the adjusted ORs for FPG levels based on liver enzymes levels. RESULTS: There was no association between liver enzymes and FPG either in the underweight group or in the normal weight group; however, a significant correlation was observed in the overweight or obesity group (alanine transaminase (ALT), p<0.01; aspartate aminotransferase (AST), p<0.05). After adjusting for confounding factors, the highest tertiles of ALT still remained significantly positively related to FPG levels in the overweight or obesity group, with an OR of 2.205 (95% CI 1.442 to 3.371) for the 5.56≤FPG<7.00 mmol/L vs the FPG<5.56 mmol/L group and with an OR of 2.297 (95% CI 1.017 to 5.187) for the FPG≥7.00 mmol/L vs the FPG<5.56 mmol/L group, but this correlation was not found for AST. CONCLUSIONS: The association of liver enzymes levels with FPG levels differed based on different BMI cut-offs. ALT levels were significantly positively associated with FPG levels in the overweight or obesity group, but not in the other two groups; AST levels were not associated with FPG levels in any group.

Early neurological deterioration during the acute phase as a predictor of long-term outcome after first-ever ischemic stroke.

Early neurological deterioration (END) is associated with increased risk of functional disability and mortality. However, data are limited regarding the long-term risk of poor functional outcomes. Thus we explored the association between END and long-term outcomes in patients with acute ischemic stroke.A total of 1064 patients were enrolled with acute ischemic stroke who were consecutively admitted to the 3 stroke units of Huai-He Hospital, Kaifeng, China. END was defined as an increment change of at least one point in motor power or total National Institute of Health Stroke Scale (NIHSS) score deterioration ≥2 points within the first week after admission. We retrospectively assessed the risk factors of END and prospectively explored the relationship between END and the long-term outcomes by multivariable regression models after adjusting the potential confounding factors. Outcomes were evaluated at 18 months based on modified Rankin scale (MRS) scores.Approximately 32% of first-ever ischemic stroke patients experienced END during the acute phase. END was associated with diabetes (odds ratio [OR], 2.218; 95% confidence interval [CI] 1.619-3.037), NIHSS score at admission (OR, 1.052; 95% CI 1.023-1.082), C-reactive protein (CRP) levels (OR, 1.224; 95% CI 1.066-1.406]), and homocysteine (HCY) levels (OR, 1.203; 95% CI 1.061-1.365) after adjusting related factors, such as hypertension, diabetes, NIHSS at admission, and some blood laboratory values, including direct bilirubin, total cholesterol, low-density lipoprotein, glucose, CRP, HCY, and D-dimer levels. During the follow-up period, 52 (4.9%) patients died, 160 (15.0%) recrudesced, and 317 (29.8%) suffered poor outcomes. Multivariate logistic regression analyses revealed that poor outcome was associated with END (OR, 3.366; 95% CI 2.495-4.542), age (OR, 1.028; 95% CI 1.015-1.041), body mass index (OR, 1.096; 95% CI 1.051-1.144), coronary heart disease (OR, 1.637; 95% CI 1.108-2.416), and CRP (OR, 2.474; 95% CI 1.840-3.326).The risk factors of END are multifaceted. Diabetes, NIHSS score at admission, CRP, and HCY are independent predictors of END. In addition, the results of this study indicate that END is an important predictor of poor functional outcome.

Serum albumin level is associated with the recurrence of acute ischemic stroke.

BACKGROUND: Previous studies have confirmed that low serum albumin levels in acute ischemic stroke patients increased the risk for poor outcome and death, demonstrating the neuroprotective role of albumin. However, there are few studies investigating the relationship between albumin levels and recurrence of stroke. The aim of this study was to evaluate the effect of serum albumin level on the risk of recurrence in patients with acute ischemic stroke. METHODS: Seven hundred fifty-three consecutive patients with acute first-ever ischemic stroke were recruited in this study. Recurrent outcome was measured 1 year after stroke through home interviews (n = 692). RESULTS: Patients with recurrence had significantly lower serum albumin level than those without recurrence (37.07 ± 4.21 vs 38.91 ± 3.25). The multiple logistic regression adjustment for confounding factors showed that the association remained significant for patients in the second albumin quartile, the third quartile, and the fourth quartile compared with patients in the first quartile (adjusted odds ratio [aOR] = 0.543, 95% confidence interval [CI]: 0.307-0.959, P= .036; aOR = 0.449, 95% CI: 0.249-0.812, P= .008; and aOR = 0.290, 95% CI: 0.148-0.570, P < .001). CONCLUSION: Lower serum albumin level increases the risk of recurrence in patients with acute ischemic stroke, suggesting that serum albumin level might be used as an indicator for stroke recurrence.

[Determination of ascorbic acid by suppressed chemiluminescence].

This paper describes a method for determining ascorbic acid by the suppression of DTMC-H2O2 chemiluminescence. Various factors affecting the chemiluminescence determination of ascorbic acid were examined. Under the optimal conditions (1.2 x 10(-4) mol.L-1 of DTMC, 5.0 x 10(-5) mol.L-1 of H2O2, and pH 11.4 Na2HPO4-NaOH), the quenching of the chemiluminescent intensity was proportional to the concentration of ascorbic acid in the range of 1.0 x 10(-7)-8.0 x 10(-6) mol.L-1, and the detection limit was 8.0 x 10(-8) mol.L-1 (S/N = 3). The RSD was 4.6% for 1.0 x 10(-6) mol.L-1 of ascorbic acid (n = 10). The selectivity of this method was high and no making agent required. The proposed method has been applied to the determination of ascorbic acid in real samples. The obtained results were in agreement with those by CuSO4-KI titration.